The degree of bacterial translocation is a determinant factor for mortality after burn injury and is improved by prostaglandin analogs.

Bacterial translocation and related mortality rates were examined in previously transfused BALB/c mice that were gavaged with 14C radioisotope-labeled Escherichia coli before inflicting a 20% full-thickness flame burn. Radionuclide counts were measured in blood obtained by retro-orbital puncture 4 hours postburn, and survival was recorded for 10 days. Radionuclide counts in the blood correlated well with both radionuclide counts and numbers of viable bacterial in the tissues. Survivors had significantly less bacterial translocation as evidenced by blood radionuclide counts compared with nonsurvivors, and there was a significant inverse correlation between the degree of translocation and the length of survival. In the next experiment, the prostaglandin E (PGE) analogs misoprostol, enisoprost, or 16,16-dimethyl PGE2 were administered to transfused animals for 3 days before burn. Prostaglandin E analogs significantly reduced bacterial translocation as measured by blood radionuclide counts 4 hours postburn and improved survival. The data demonstrate that the intensity of bacterial translocation after burn injury is significantly associated with subsequent death. Improvement of survival by PGE analogs is associated with decreased bacterial translocation.


High-level expression of recombinant human tPA in cultivated canine endothelial cells under varying conditions of retroviral gene transfer.

Successful genetic transduction of endothelial cells (EC) provides a theoretic means of increasing luminal secretion of tissue-type plasminogen activator (tPA) and lessening arterial and venous thrombotic processes. To identify the duration and number of retroviral exposures for an optimal tPA expression, enzymatically derived adult canine jugular venous EC were subjected to different exposure regimens using an amphotropic murine retroviral vector, MFG, containing the human tPA gene. Human tPA antigen secretion and its functional activity were determined at 2 days (subconfluent cells) and 14 days (confluent cells) after retroviral exposure. High-level secretion of human tPA was detected among transduced EC in all experimental groups. No secretion of human tPA occurred in control EC exposed to media alone. At 2 days after transduction, no significant differences in tPA secretion rates occurred among the different exposure regimens. At 14 days, the 12-hour X two-exposure group exhibited higher tPA secretion rates than all other exposure regimens (analysis of variance, p < 0.05). All exposure groups at 14 days exhibited significantly higher tPA secretion compared with those at 2 days (analysis of variance, p < 0.05). The presence of retroviral sequences in the genome of transduced EC was confirmed by Southern blot analysis. At 14 days, increased EC numbers were observed in vector-exposed wells compared with controls. Human tPA functional activity paralleled tPA antigen secretion. Genetically modified canine EC are capable of high levels of constitutive expression of human tPA after relatively short exposures to a retroviral vector containing the reporter gene. Increased cell number of tPA-transduced EC in culture suggests that tPA also may have other biologically important effects. These results support the efficacy of MFG-tPA gene transfer as a means of genetically modifying EC fibrinolytic activity and establishes the potential of this technology in vivo.


Delayed surgical repair and ECMO improves survival in congenital diaphragmatic hernia.

One hundred ten infants with congenital diaphragmatic hernia (CDH) developed life-threatening respiratory distress in the first 6 hours of life. Associated anomalies were present in 33%. Twenty-eight of 65 infants (43%) treated before 1987 (pre-extracorporeal membrane oxygenation [ECMO] era) survived after immediate CDH repair, and mechanical ventilation with or without pharmacologic support. Only two of 16 (12.5%) infants requiring a prosthetic diaphragmatic patch survived. Since 1987, 31 of 46 (67.4%) infants with birth weight, gestational age, and severity of illness similar to the pre-1987 group survived. All patients were immediately intubated and ventilated. Seven (four with lethal chromosomal anomalies) infants died before treatment, and 30 stabilized (partial pressure of carbon dioxide [PCO2] < 50; partial pressure of oxygen [PO2] > 100; pH > 7.3) and underwent delayed CDH repair at 5 to 72 hours. Fifteen did well on conventional support and survived. Fifteen infants deteriorated after operation: 11 were placed on ECMO with eight survivors, and four infants were not considered ECMO candidates. Nine babies failed to stabilize initially and were placed on ECMO before CDH repair (alveolar-arterial gradient > 600 and oxygenation index > 40), and seven survived. The overall survival rate was 80% at 3 months in this ECMO-treated group. Early mortality was due to inability to wean from ECMO (one), intracranial hemorrhage (one), liver injury (one), and pulmonary hypoplasia (one). Nine of 11 babies requiring a prosthetic patch in the post-1987 ECMO group survived (81.8%). There were three late post-ECMO deaths (3 to 18 months) of right heart failure (two) and sepsis (one). Symptomatic gastroesophageal reflux occurred in nine cases, six requiring a fundoplication in the bypass babies. Recurrent diaphragmatic hernia occurred in nine cases (five ECMO). The overall survival rate was significantly improved in the delayed repair/ECMO group (67% versus 43%; p < 0.05) and was most noticeable in infants requiring a prosthetic diaphragm (81.2% versus 12.5%; p < 0.005). These data indicate that early stabilization, delayed repair, and ECMO improve survival in high-risk CDH. Early deaths are related to pulmonary hypertension and can be reversed by ECMO.


Prolongation of survival in metastatic melanoma after active specific immunotherapy with a new polyvalent melanoma vaccine.

A new polyvalent melanoma cell vaccine (MCV) was administered to 136 stage IIIA and IV (American Joint Committee on Cancer) melanoma patients. Induction of cell-mediated and humoral immune responses to common melanoma-associated antigens present on autologous melanoma cells was observed in patients receiving the new MCV. This was accompanied by increased activation of tumor-infiltrating lymphocytes. Survival correlated significantly with delayed cutaneous hypersensitivity (p = 0.0066) and antibody responses to MCV (p = 0.0117). Of 40 patients with evaluable disease, nine (23%) had regressions (three complete). From our historical database of 126 stage IIIA and 1275 stage IV melanoma patients, there were no significant changes in the natural history of metastatic melanoma during the past 20 years. Univariate and multivariate analyses demonstrated prognostic significance for site of metastases (p = 0.0001) and immunotherapy with the new MCV (p = 0.0001). Overall our new MCV increased the median and 5-year survival of stage IIIA melanoma patients with regional soft tissue metastases twofold (p = 0.00024), and stage IV patients threefold (p = 0.0001) compared with previous immunotherapy and other treatments.


Long-term intraperitoneal insulin delivery.

Over the past 5 years, 21 patients with insulin-dependent diabetes mellitus have been managed at the Johns Hopkins Medical Institutions with variable rate, remotely controlled implanted insulin pumps. To date, nearly 70 patient-years of experience has been gained with intraperitoneal delivery of a new U-400 insulin with a surfactant. All 21 patients are alive after a mean of 39.3 months (range, 10 to 65 months) after insulin pump implantation. Nineteen of the 21 patients remain on intraperitoneal insulin, for a 5-year actuarial system survival of 90%. Glucose control was improved, especially during the first 16 months after pump implantation, without an increased incidence of severe hypoglycemia. Catheter blockage has been a significant problem, occurring in nine of the 21 patients (43%). Catheter occlusion has been successfully managed, however, with laparoscopic repair in seven of 10 attempts or with catheter change in four of five patients. Nevertheless, quality of life and patient acceptance remain excellent. Moreover, pre-existing nephropathy, neuropathy, and retinopathy have been surprisingly stable. With an aggressive policy of catheter change or laparoscopic clearance of catheter blockage, long-term intraperitoneal insulin delivery is now a safe and effective treatment for type I diabetics.


Perioperative blood transfusion and determinants of survival after liver resection for metastatic colorectal carcinoma.

The authors reviewed their institutional experience with liver resection for metastatic colorectal carcinoma to (1) determine whether perioperative blood transfusion affects survival; (2) identify prognostic determinants; and (3) estimate the patient requirement for a prospective randomized trial designed to demonstrate efficacy of liver resection. Two hundred eighty consecutive patients treated by potentially curative liver resection between 1960 and 1987 were included. Data were obtained for all but 10 patients for at least 5 years after operation or through 1990. Actuarial survival curves related to potential prognostic determinants were analyzed with the log-rank test. Overall, survival was 47 +/- 3% at 3 years and 25 +/- 3% at 5 years, including 4% 60-day operative mortality rate. Eighty-one patients who did not receive blood 7 days before to 14 days after operation had 60 +/- 6% 3-year and 32 +/- 6% 5-year survival compared with 40 +/- 4% and 21 +/- 3% survival rates for 183 patients who received at least one unit (p = 0.03, operative deaths excluded). Extrahepatic disease (p = 0.015), extrahepatic lymph node involvement (p = 0.002), satellite configuration of multiple metastases (p = 0.0052), and initial detection by abnormal liver enzymes (p = 0.0005) were associated with poor survival rates. Synchronous presentation of metastatic and stage B primary disease was associated with a favorable prognosis (p = 0.003). The requirement for a prospective randomized trial estimated by an exponential survival model would be 36, 74, 168, or 428 patients if 5-year survival without resection were 1, 5, 10, or 15%. We conclude that (1) perioperative blood transfusion may be adversely associated with survival; (2) extrahepatic disease, extrahepatic lymph node involvement, satellite configuration, and initial detection by clinical examination or a liver enzyme abnormality portend a poor prognosis; and (3) a prospective randomized trial of liver resection is impractical because of the large patient requirement, at least by a single institution.


RS-61443 (mycophenolate mofetil). A multicenter study for refractory kidney transplant rejection.

RS-61443 (mycophenolate mofetil) inhibits a key enzyme of the de novo synthesis of purine nucleotides in T and B lymphocytes. The purpose of this study was to evaluate the efficacy of RS-61443 in patients with refractory renal allograft rejection. Patients eligible for the study had previously undergone anti-rejection therapy with high-dose steroids or OKT3 monoclonal antibody. All rejection episodes were proven by renal biopsy. Successful rescue was achieved in 52 (69%) patients. Rescue was more successful when patients were entered with a creatinine of 4 mg/dL or lower (79%), versus a 52% rescue rate in patients entered with a creatinine of 4 mg/dL or above. Major side effects were predominantly gastrointestinal, but there was no overt nephrotoxicity, hepatotoxicity, or bone marrow suppression. The overall infection rate was 40%, with the spectrum of infections characteristic for the highly immunocompromised patient. The conclude that this pilot study suggests that RS-61443 is effective in refractory kidney allograft rejection. Based on this study, prospectively randomized multi-center trails have been planned and are in progress.


Plasmodium falciparum: effect of chloroquine, halofantrine and pyrimethamine on the infectivity of gametocytes for Anopheles stephensi mosquitoes.

The activity of chloroquine, halofantrine and pyrimethamine against the gametocytes and sporogonic stages of Plasmodium falciparum (strain NF54) was tested. Five-day-old gametocytes (stages I and II) from in vitro cultures were exposed to the drugs for 48 hours. The effect of the drugs on gametocyte development was assessed by counting gametocytes on days nine and 15 of culture and determining the infectivity of the drug-treated gametocytes to mosquitoes. Gametocytogenesis was partially inhibited by all three drugs; there were 71% of the number of gametocytes in drug-free control cultures in cultures with 3 x 10(-8) M chloroquine, 51% with 5 x 10(-8) M chloroquine, 78% with 5-7 x 10(-9) M halofantrine, and 48% with 10(-7) M pyrimethamine. Halofantrine- and pyrimethamine-treated gametocytes were found to be more infective to Anopheles stephensi than untreated controls. The three drugs were also administered to the mosquitoes, either in the first bloodmeal, which contained gametocytes from in vitro cultures, or in the second, parasite-free bloodmeal, given four days after infection. The sporontocidal activity of the drugs was evaluated by counting the number of oocysts on the midgut seven or eight days after infection, or the number of sporozoites in the salivary glands 15 days after infection. A sporontocidal effect was observed only when pyrimethamine was administered with the infective bloodmeal. Neither chloroquine nor halofantrine had any marked effect on sporogony at the concentrations tested.


Infectivity to the vector Triatoma infestans of dogs infected with Trypanosoma cruzi in north-west Argentina.

The influence of reinfections on the infectivity to Triatoma infestans of dogs seropositive to Trypanosoma cruzi was investigated in Amamá, north-west Argentina, before (1984) and after (1986-1987) elimination of domestic bugs with residual insecticides in 1985. Infectivity was quantified by the percentage of infected bugs in each xenodiagnosis of a seropositive dog, i.e. the infective force (IF). Exposure to reinfection was represented by the domiciliary density of infected bugs and by an index of the potentially-infective contacts (IPIC) experienced by each dog (calculated as the product of the relative density of bugs per dog, the proportion of infected bugs, and the proportion of bugs taking blood meals from the dog). IF was unrelated to the dog's age or sex, or the level of specific antibodies to T. cruzi. Before vector elimination, the IF of seropositive dogs was significantly associated with both the density of infected bugs and the IPIC. After vector elimination, seropositive dogs resident at houses which had 10-70 infected bugs before spraying showed a higher median IF (67-75%) than those living in houses with zero to eight infected bugs before spraying (47-55%). The age-specific IF of seropositive dogs aged one year or older, recorded before (45-64%) and after (52-56%) the elimination of domestic bugs, did not differ significantly. Our data suggest that the infectivity of seropositive dogs to bugs is modified by previous or current exposure to bug-mediated reinfections, and that this relationship might be irreversible in the short term.


Western blot of Entamoeba histolytica antigenic fractions: reactivity analysis with sera from intestinal amoebiasis patients.

The reactivity of sera from acute-phase intestinal amoebiasis patients (two weeks evolution) was studied to determine which of the Entamoeba histolytica antigens are most frequently immunogenic. Sera were examined by means of immunoelectrotransferase assay using crude extract of HM1:IMSS E. histolytica trophozoites. Three populations of clinically healthy adults from Mexico, Canada and Germany, with no evidence of parasites in faeces, were used as controls. The frequency of antigen recognition was analysed. In ailing individuals, the bands of 23, 24, 26 and 51 kDa were recognized most frequently (65 and 60%) followed by the 62 kDa band (56%). The combination of some of these bands, namely 3.4, 4.1 and 6.7, with molecular weights of 62, 51 and 24 kDa, increased the recognition frequency of patients to 91.4%. These results constitute a first but important step towards the design of more accurate methods for the successful immunodiagnosis and epidemiology of acute intestinal amoebiasis.


Epidemiology of Blastocystis hominis infection in Papua New Guinea: age-prevalence and associations with other parasites.

A community-based study of Blastocystis and other intestinal parasites in the Asaro Valley, Papua New Guinea showed an extraordinary high prevalence and variety of protozoan infections. Apart from infants, nearly everybody had at least one infection, and the mean number of infections per person was around 2.7. The graph of age-specific prevalence for Blastocystis is similar in shape to those for Entamoeba coli and Endolimax nana, indicating probable similarity in transmission patterns and host response. There was no evidence for pathogenicity of Blastocystis at the community level. Three methods are compared for the measurement of association between infections. Two show strong associations, but these are considered to be the result of parallel age-prevalence curves and environmental factors at the village level. When age- and village-matched pairs were considered, only a weak positive association with E. nana was detectable.


A survey of taeniid cestodes in farm dogs in mid-Wales.

In 1983-1988, dogs on 315 farms in Powys, mid-Wales, were purged once with arecoline acetarsol and the faecal purges were examined for cestodes. A few dogs were examined by autopsy. Ninety-seven farms had at least one infected dog, and cestodes were found in 161 of the 882 dogs examined. The ovine strain of Echinococcus granulosus was found in 41 dogs on 25 farms. Taenia hydatigena, T. pisiformis, T. multiceps, T. serialis, T. ovis and Dipylidium caninum were recovered from 85, 35, 15, 3, 19 and 29 dogs respectively. The results are compared with those of previous surveys in Powys and in other regions of Wales.


The cestodes of foxhounds and foxes in Powys, mid-Wales.

Cestodes were found in 129 of 875 foxhounds from 20 packs in Powys, mid-Wales, examined by purging in 1983-1988, in the following order of prevalence: Taenia hydatigena in 57 hounds (6.51%), Echinococcus granulosus in 27 (3.09%), Dipylidium caninum in 25 (2.86%), T. ovis in 14 (1.60%), T. pisiformis in 10 (1.14%), T. serialis in five (0.57%) and T. multiceps in four (0.46%). Of 197 foxes examined by autopsy, 22 harboured cestodes: two (1.02%) had E. granulosus, nine (4.57%) T. polyacantha, eight (4.06%) T. pisiformis, two (1.02%) T. serialis, one (0.51%) D. caninum and one (0.51%) Mesocestoides sp. This is the first definite report of T. polyacantha in British foxes. The results are compared with those of previous surveys in Powys and in other parts of Wales, and the reasons for changes in prevalence are discussed.


Polycystic hydatid disease (Echinococcus vogeli). Treatment with albendazole.

Six patients with polycystic hydatid disease (PHD) were treated with 10 mg kg-1 day-1 albendazole. One patient was treated continuously for eight months and another for three months. In three other patients treatment was discontinuous, consisting of a series of at least three 30-day cycles separated by 15 days without treatment. The last patient was treated continuously with 12 mg kg-1 day-1 albendazole for 51 days and then with three 30-day cycles of treatment with 10 mg kg-1 day-1 separated by 15-day drug-free intervals. Follow-up ranged from 10-30 months. Considerable clinical improvement and cyst reduction or disappearance occurred in four patients. Clinical improvement, but no changes in the hepatic alterations detected by computerized tomography, occurred in the other two patients, although a pulmonary cyst disappeared in one of them. Adverse effects were proteinuria, alopecia, leucopenia, itching and discrete elevation in aspartate transaminase, all of them reversed after the end of treatment. These results indicate that albendazole is effective for the treatment of PHD.


Cultivation of the third-stage larvae of Necator americanus in vitro.

When filariform larvae of Necator americanus, enclosed within the second sheath, were cultured in various semi-defined media, the best larval development was achieved in Waymouth's MB 752/1 with 20% foetal calf serum (FCS). In this medium, most of the filariform larvae cast off the second sheath and developed into third-stage larvae with provisional buccal capsules and some larvae developed further; 26% were fourth stage after 49 days of culture. Of several supplements tested, only FCS supported such development and no further development occurred if the medium was further supplemented with human red blood cells, liver extract, intestinal extract or tryptose phosphate broth. Larval development stopped at or before early third stage in Eagle's Basal Medium, F-12, NCTC 135 and L-15, even when these media were supplemented with FCS.


Studies on environmentally-induced colour variation in Simulium sirbanum (Diptera: Simuliidae) using a portable rearing system.

Previous studies on the morphological identification of adult female Simulium damnosum s.l. have involved use of colour characters. To determine the degree to which these qualitative characters are influenced by the physical environment, a portable rearing system was constructed. Wild-caught female flies and flies emerging from pupae maintained at ambient temperatures or above showed entirely pale antennae, fore-coxae, wing-tufts and hairs on the scutellum and ninth abdominal tergite, as is normal for S. sirbanum. Adults reared from larvae at below ambient temperatures were also pale, except for the antennae which were dark in all specimens. Adult females emerging from pupae maintained at below ambient temperatures were entirely pale up to the fourth day of emergence and mostly with dark antennae. The biological significance and the implications to the morphological identification of the savannah species of the S. damnosum complex in West Africa are discussed.


Phlebotomine sandfly species in Paraguay and their infection with Leishmania.

Nine species of sandflies, Lutzomyia (Nyssomyia) whitmani (Antunes and Countinho), Lutzomyia (Nyssomyia) intermedia (Lutz and Neiva), Lutzomyia (Psathyromyia) shannoni (Dyar), Lutzomyia migonei (Franca), Lutzomyia (Pintomyia) fischeri (Pinto), Lutzomyia (Pintomyia) pessoai (Countinho and Barretto), Lutzomyia cortelezzii (Brethes), Lutzomyia walkeri (Newstead) and Lutzomyia (Trichopygomyia) longispinus (Mangabeira), were caught, by human bait and Shannon trap, in four areas of Paraguay hyper-endemic for human leishmaniasis. Lutzomyia whitmani and L. intermedia were the predominant species. All the species collected were found to be anthropophilic. Hindgut infections with leishmanial promastigotes were observed in only one (0.38%) of the 266 L. whitmani dissected. No L. intermedia were found infected, giving an overall infection rate of one (0.16%) of 615 flies dissected. The results indicate a very low rate of natural infection in endemic areas of Paraguay.


A study of the sugar chemoreception niches of two bulinid snail hosts of schistosomiasis.

Components of the sugar chemoreception niches of two host snails of urinary schistosomiasis, namely Bulinus globosus (Morelet) and Bulinus rohlfsi (Clessin), were measured by using a buccal mass olfactometer. Among the polysaccharides tested, amylose was found to be the strongest phagostimulant for adults and juveniles of both snail species. Other phagostimulants identified were maltose and xylose for B. rohlfsi and maltotriose for B. globosus. The a(1-4)-glucosidic linkage and the presence of glucose residues were found to be key factors in the stimulus recognition system of the snails. The possible use of these findings in the design of controlled-release formulations for the selective removal of schistosome host snails is considered. The ecological implications of these studies are also examined.


Placental Plasmodium falciparum parasitaemia in East Sepik (Papua New Guinea) women of different parity: the apparent absence of acute effects on mother and foetus.

The effects of malaria were studied in a group of parturient women of East Sepik Province, Papua New Guinea. Further information was gathered from a search of hospital records and interviews with village aid post orderlies. Examination of placental blood revealed a Plasmodium falciparum parasitaemia rate of 41% of the primiparae, 23% in parous 2, 25% in parous 3, and 3% in multiparae greater than 3. Approximately one-half of those with placental parasitaemia had a concomitant detectable peripheral parasitaemia. Placental parasitaemias were of relatively low density, averaging 1.6%. There were no instances in the observed series of births, hospital records, or village studies of the occurrence of severe malaria in the mother or its acute effects on the foetus. Neither birthweight nor maternal or cord blood haematocrit was related to the presence or absence of placental parasitaemia. Neonatal birthweight and risk of delivering a low birthweight (less than 2.5 kg) baby was statistically associated only with maternal parity. The possible reasons for the relatively benign effect of malaria in the pregnant women of this population are discussed.


Cerebral blood flow and metabolism in hypothermic circulatory arrest.

Although hypothermic circulatory arrest has been accepted for use in cardiovascular operations, the potential for cerebral injury exists. The mechanism of the cerebral injury remains unclear. To address these questions we studied cerebral blood flow and metabolism. Sixteen puppies were randomly assigned to undergo either 45 or 90 minutes of hypothermic circulatory arrest after perfusion/surface cooling to 13 degrees C. Cerebral blood flow, cerebral oxygen and glucose metabolism, and cerebral vascular resistance measurements were obtained at 37 degrees C, 13 degrees C, 10 minutes after reperfusion, 30 degrees C and 2 and 4 hours after hypothermic circulatory arrest. No neurologic or behavioral changes were observed in any of the long-term survivors (11/16). Metabolic and cerebral blood flow data did not differ between groups. Cerebral blood flow was significantly lower in the late postarrest measurements, whereas oxygen and glucose consumption had returned to baseline values. In the presence of low cerebral blood flow and high cerebral vascular resistance it is notable that control levels of oxygen consumption were attained by abnormally high oxygen extraction. These data strongly suggest a vulnerable interval after hypothermic circulatory arrest in which cerebral metabolism is limited by cerebral blood flow.


Does a posterior aneurysm increase the risk of endocardial resection?

The bias has been that the ideal anatomic circumstance for endocardial resection is the anterior left ventricular location. Posterior left ventricular aneurysms have been thought to be problematic to map and more difficult to close, and possibly to have a different substrate for ventricular tachycardia. To address this problem, we retrospectively reviewed the cases of 110 consecutive patients who underwent sequential endocardial resection for ventricular tachycardia between 1983 and 1991. Ninety-six patients had an anterior aneurysm, and 14 patients had a posterior aneurysm or infarct. Operative survival and 5-year survival were very similar between the two groups (p = not significant). A positive postoperative electrophysiological study was present in 11% of the anterior group versus 14% of the posterior group (p = not significant). There was a significantly greater incidence of mitral valve replacement in the posterior group, and we believe this was most likely due to frequent localization of the arrhythmia to the papillary muscle. Otherwise, patients with a posterior aneurysm or infarct had surgical results equivalent to those in patients with an anterior location. As long as there is a discrete aneurysm or infarct, endocardial resection is a safe and effective therapeutic procedure for ventricular tachycardia.


Anomalous left coronary artery from the pulmonary artery: results of isolated aortic reimplantation.

Thirty-one consecutive children with anomalous left coronary artery underwent direct aortic reimplantation of the anomalous artery without an associated procedure. There were five deaths (16%; 70% confidence limits, 9% to 26%), three in the hospital and two early (within 3 months). The severity of preoperative left ventricular dysfunction was the only incremental risk factor for mortality: 31% mortality rate among patients with left ventricular shortening fraction of less than 0.20 versus 0% among patients with a left ventricular shortening fraction of 0.20 or more (p = 0.03). There were no late deaths up to 6 years, a survival rate of 84% +/- 7%. Late results were studied in 23 survivors having a follow-up of longer than 12 months. Ninety-six percent were free of symptoms; left ventricular function recovered to normal in all patients; moderate to severe mitral regurgitation decreased to minimal or no regurgitation in most patients (5/7); and the reimplanted anomalous left coronary artery was patent in each patient. Based on this study, we reached five conclusions. (1) Direct aortic reimplantation is technically feasible in most patients with anomalous left coronary artery and yields a high rate of late patency. (2) Left ventricular resection is unnecessary. (3) The mitral valve should not be interfered with at the initial operation, but mitral regurgitation may persist in a few patients and necessitate later operation. (4) In patients with moderate left ventricular dysfunction, the operative risk is low and early operation indicated. (5) In patients with severe left ventricular dysfunction, the operative risk is high; heart transplantation may be suggested, but our current approach favors an immediate corrective procedure.


Anterior mediastinal tracheostomy with and without cervical exenteration.

Anterior mediastinal tracheostomy (AMT) facilitates resection of stomal recurrences after laryngectomy for carcinoma and tumors involving the cervicothoracic trachea and esophagus. Erosion of the innominate artery has been reported as a frequent major complication of AMT, and routine prophylactic division of the innominate artery with AMT has even been advised. Forty-four patients underwent AMT, 10 as an isolated procedure (for stomal recurrence [5], laryngeal carcinoma [1], or benign stenosis after laryngectomy [4]) and 34 with concomitant cervical exenteration (laryngopharyngoesophagectomy) for laryngeal, thyroid, or cervicothoracic esophageal malignancies. Transposition of the remaining tracheal stump beneath and to the right of the innominate artery to eliminate tension on the vessel was carried out in 14 patients (32%). Postoperatively, anastomotic leaks complicated nine of 31 pharyngogastric anastomoses. Iatrogenic hypoparathyroidism occurred in 10 patients. All six hospital deaths (14%) occurred in patients undergoing AMT with cervical exenteration, not isolated AMT. There was only one instance of innominate artery erosion. Survival was related to the pathology for which AMT was performed. Anterior mediastinal tracheostomy is a valuable adjunct in the treatment of select patients with malignancies of the cervicothoracic trachea and esophagus, and with attention to operative detail, innominate artery erosion should rarely, if ever, complicate the operation. Prophylactic division of the innominate artery with AMT is unnecessary.


Postpneumonectomy syndrome: diagnosis, management, and results.

Airway obstruction may be caused by extreme mediastinal shift and rotation after right pneumonectomy or after left pneumonectomy in the presence of a right aortic arch. Eleven adults (aged 18 to 58 years) with severe symptoms were treated surgically between 5 months to 17 years after pneumonectomy (7 right, 4 left). An initial patient with only one functional lobe was treated unsuccessfully by aortic division and bypass graft. Ten underwent mediastinal repositioning. After two recurrences prostheses were used to maintain mediastinal position. Five patients who underwent such repositioning are doing well from 5 months to more than 5 years later. One died 1 month after operation probably of pulmonary embolism. One who showed residual airway collapse after operation has some recurrent obstruction. Three other patients who showed severe malacic obstruction of the airway after mediastinal repositioning variously underwent aortic division with bypass graft and tracheal and bronchial resection. One is well almost 6 years later. Two died postoperatively. Occurrence of the syndrome is unpredictable. Where malacic changes have not occurred, mediastinal repositioning may reasonably be expected to correct obstruction. Optimal treatment for concurrent severely malacic airways is unclear.


Clinical and hemodynamic assessment of the Hancock II bioprosthesis.

The Hancock II bioprosthesis was used for heart valve replacement in 614 patients from 1982 to 1990. Aortic valve replacement (AVR) was performed in 376 patients, mitral valve replacement (MVR) in 195, and aortic and mitral valve replacement (DVR) in 43. The mean age was 62.7 years, and 78% of all patients were in New York Heart Association functional class III or IV before operation. Coronary artery bypass graft was necessary in 232 patients and replacement of ascending aorta in 55. There were 31 operative deaths (AVR, 4%; MVR, 6%; DVR, 9%). Follow-up was complete in 98.5% of the patients and extended from 12 to 103 months, with a mean of 49 months. At the last follow-up, 85% of the patients were in New York Heart Association class I or II. The actuarial survival at 8 years was 79% +/- 3% for AVR, 68% +/- 4% for MVR, and 65% +/- 10% for DVR. The freedom from stroke at 8 years was 93% +/- 2% for AVR, 83% +/- 5% for MVR, and 90% +/- 5% for DVR. At the end of 8 years 96% +/- 1% of all patients were free from endocarditis, 92% +/- 1% were free from primary tissue failure, and 89% +/- 3% were free from reoperation. The actuarial freedom from valve-related death at 8 years was 98% +/- 1% for AVR, 86% +/- 5% for MVR, and 91% +/- 6% for DVR. Hemodynamic assessment was obtained by Doppler echocardiography in all operative survivors and demonstrated satisfactorily effective valve orifices and transvalvular gradients. The clinical results obtained with the Hancock II bioprosthesis have been gratifying, particularly in the aortic position. This bioprosthesis is our biological valve of choice.


Use of epicardial electrocardiograms for detecting cardiac allograft rejection.

Since the advent of cyclosporin A surface electrocardiograms have been unreliable for diagnosing cardiac allograft rejection. Although several noninvasive methods have been proposed, none have been sufficiently accurate to be considered for clinical use. We have studied the use of the QRS complex amplitude, the unipolar peak-to-peak amplitude, recorded from intramyocardial electrodes for detecting rejection. Ten adult mongrel dogs underwent placement of intramyocardial electrodes on each ventricle. After stabilization of signals the hearts were transplanted heterotopically into unmatched recipients receiving cyclosporin A, azathioprine and methylprednisolone. Endomyocardial biopsies were performed after stabilization of unipolar peak-to-peak amplitude, twice weekly thereafter, and when unipolar peak-to-peak amplitude fell significantly. This detected 13 of 14 episodes of rejection. There was one false-positive and one false-negative result. The false-negative study became positive the following day. Thus, analysis of unipolar peak-to-peak amplitude detected all episodes of rejection in a clinically relevant time frame and was able to detect mild forms of rejection and multiple episodes of rejection in the same heart even in the presence of therapeutic levels of cyclosporin A.


Predictive criteria for the need of extracorporeal circulation in single-lung transplantation.

Use of extracorporeal circulation is mandatory in heart-lung and en bloc double-lung transplantation. However, no criteria exist to predict the necessity of its application during single-lung transplantation for parenchymal lung diseases. We therefore reviewed our experience in 23 patients undergoing single-lung transplantation for idiopathic pulmonary fibrosis. All patients were evaluated by preoperative right heart catheterization. For intraoperative monitoring, a pulmonary artery thermodilution catheter was placed in the contralateral lung to repeatedly assess pulmonary artery pressure, cardiac output, and pulmonary vascular resistance. Extracorporeal circulation was necessary during graft implantation in 4 patients, whereas 19 patients underwent operation without it. Preoperative demographic patient data, time of ischemia, and hemodynamic values obtained preoperatively and before the clamping of the pulmonary artery showed no significant differences between groups. In contrast, after the clamping of the pulmonary artery, a significant drop in cardiac index of about 1.5 L.min-1.m-2 (p less than 0.01) and a concomitant rise in pulmonary vascular resistance (p less than 0.01) was observed in the group requiring extracorporeal circulation, whereas these variables showed no significant changes in the other 19 patients. Pulmonary artery pressure rose significantly in both groups (p less than 0.05), without significant differences between them. It is concluded that intraoperative assessment of cardiac index and pulmonary vascular resistance is essential for estimation of cardiac performance during single-lung transplantation. A decrease in cardiac index of more than 1.5 L.min-1.m-2 after the clamping of the pulmonary artery rather than the degree of pulmonary hypertension is indicative of the need of extracorporeal circulation.


Stentless porcine and pericardial valve in aortic position.

Fifty-seven patients underwent aortic valve replacement with a stentless glutaraldehyde-fixed bioprosthesis; 27 received a porcine aortic valve and 30 had a bovine pericardial valve. Two groups of 30 patients each who had aortic valve replacement with a tilting-disc mechanical valve or a stented porcine bioprosthesis served as controls. There were no differences in sex, body surface area, valve lesion, and valve size among the four groups. Results were assessed on a Doppler-based determination of maximum velocity across the valve, aortic valve area, and degree of valve regurgitation. Velocity across the valve was significantly less with stentless pericardial valves than with stentless porcine valves, stented bioprostheses, and mechanical valves. Stentless valves had a significantly larger aortic valve area when compared with stented valves. Mild central aortic insufficiency was detected more often with stentless pericardial than with stentless porcine bioprostheses (p = 0.04). Stentless valves showed a higher incidence of complete atrioventricular block when compared with stented valves (p = 0.04). Long-term studies are now warranted to assess the durability of both types of stentless valves.


Transhiatal esophagectomy: a safe alternative for selected patients.

One hundred one consecutive patients underwent an esophagectomy with gastric interposition for benign and malignant processes from January 1982 through July 1990. Seventy-seven underwent transhiatal esophagectomy and 24, transthoracic esophagectomy. Multivariate analysis was performed comparing the hospitalization experience of the two groups. There was no significant difference found between the mean intraoperative blood loss for transhiatal esophagectomy (770 +/- 105 mL) and that of transthoracic esophagectomy (700 +/- 175 mL). There was a significant difference between operative time, with transhiatal esophagectomy averaging 5.4 hours and transthoracic esophagectomy averaging 7.3 hours. Postoperative stay was not significantly different although there was a wide range of values for the transthoracic esophagectomy group. An 8% operative mortality was experienced by both groups. There were a significant number of minor anastomotic leaks at the cervical anastomotic level for the transhiatal esophagectomy group, but all responded to nonoperative management. The highest morbidity and mortality were seen in the subgroup of transhiatal esophagectomies done for laryngocervical malignancies. The lowest morbidity and mortality were seen in the subgroup of 12 patients who underwent transhiatal esophagectomy for nonmalignant esophageal conditions. Transhiatal esophagectomy appears to be a safe alternative for early intrathoracic esophageal malignancies at any level, for bulky distal esophageal lesions, and for benign conditions requiring total esophagectomy.


The learning curve for intraoperative echocardiography during congenital heart surgery.

Our group has previously reported a large prospective experience with the use of intraoperative echocardiography with Doppler color-flow imaging (IE-DCFI) during the repair of congenital heart defects. We have now performed IE-DCFI in 621 patients and have observed a major change in the impact of this technology, which has stabilized during our most recent experience (the last 207 patients). To evaluate the surgical learning curve with IE-DCFI, we divided patients into three groups: group 1, patients 1 through 207; group 2, patients 208 through 414; and group 3, patients 415 through 621. There were no major differences between groups with respect to age or disease entities. The average time needed to perform an IE-DCFI examination decreased from 3.75 +/- 1.77 minutes in group 1 to 3.35 +/- 1.52 minutes in group 2 and has remained stable. The number of patients requiring revisions in the operating room (based on IE-DCFI findings) decreased from 17 (8%) in group 1 to 7 (3%) in group 2 to 5 (2%) in group 3. Furthermore, revisions were 100% successful in correcting the problem in groups 2 and 3, whereas 18% of group 1 patients left the operating room with persistent residual defects by IE-DCFI. Surgeons can acquire the ability to interpret the results of IE-DCFI themselves and use it to enhance their operative repair of congenital heart defects, but this requires an experience of at least 200 cases.(ABSTRACT TRUNCATED AT 250 WORDS)


Emergent applications of cardiopulmonary support: a multiinstitutional experience.

The use of emergent portable bypass systems is increasing. Because of limited patient use in any one institution, a combined experience can better determine the applicability of these systems. A total of 187 patients from 17 centers were analyzed. Causes leading to bypass initiation were cardiac arrest (125 patients), cardiogenic shock (44), profound hypothermia (7), pulmonary insufficiency (9), and miscellaneous (2). Weaning from bypass was successful in 30.5% (57 patients). Sixty-four patients (34.2%) were transferred to standard bypass or other modes of circulatory assist. Of the total population, 40 patients (21.4%) were alive greater than 30 days. There were no survivors of unwitnessed arrests. Major diagnostic or therapeutic interventions were carried out on bypass in 74.9% of all patients. In survivors, 77.1% (37/48) had major therapeutic interventions as compared with 50.0% (67/135) of nonsurvivors. Emergency portable bypass systems can successfully resuscitate and support cardiac hemodynamics, although the underlying causes necessitating bypass remain difficult to correct. When corrective intervention can be performed, there is an increased chance of survival. Unwitnessed arrest, prolonged cardiopulmonary resuscitation, and lack of treatment options are relative contraindications. Appropriate patient selection and early application of these systems should lead to improved survival.


Effect of light dose on the photodynamic destruction of endobronchial tumors.

The effects of various light power densities (milliwatts per centimeter of diffusing fiber [mW/cf]) and light doses (joules per centimeter of diffusing fiber [J/cf]) on the effectiveness of photodynamic therapy to endobronchial and tracheal tumors were evaluated at 46 different sites. All patients had squamous cell carcinoma or adenocarcinoma. They received 2 mg/kg body weight dihematoporphyrin ether intravenously 2 days before treatment bronchoscopy. Only one light treatment was delivered to the site. Patients were treated with diffusing cylinder light tips and underwent toilet bronchoscopy 2 days after photodynamic therapy. The percentage of obstruction was estimated before and after treatment and before and after toilet bronchoscopy. There was no difference between the effects resulting from power densities of 400 and 500 mW/cf, nor were there differences in the reactions between squamous cell carcinoma and adenocarcinoma. The amount of tumor that could be removed at the end of the treatment bronchoscopy, the amount of reobstruction by secretions and exudate seen at toilet bronchoscopy, and the final percent decrease in obstruction at the end of toilet bronchoscopy were proportional to the light dose. Because the final percentage decrease in obstruction plateaued at light doses of 400 to 500 J/cf and there was no statistically significant difference between 400 and 500 J/cf, we recommend using a power density of 500 mW/cf and a light dose of 400 J/cf during photodynamic therapy.


Nicardipine: myocardial protection in isolated working hearts.

The effectiveness of the calcium antagonist nicardipine in protecting the ischemic myocardium was evaluated using the hemodynamic recovery of isolated working rat hearts subjected to hyperkalemic cardiac arrest followed by ischemia at 37.5 degrees C and 10 degrees C. Rat hearts (n = 51) received 20 mL of cardioplegia and were subjected to 27 minutes of ischemia at 37.5 degrees C. Group A (control) did not receive nicardipine. Groups B through F received nicardipine in the cardioplegia with total doses ranging from 2 micrograms to 6 micrograms. Group A had 46% survival of ischemia, whereas groups C (3 micrograms) and D (4 micrograms) had survival rates of 88% and 100%, respectively (p less than 0.05). The recovery of aortic flow after ischemia was 35% in group A, compared with 76% in group B (2 micrograms) and 81% in group D (p less than 0.05). Group A had 49% postischemic recovery of cardiac output, whereas groups B and D had 82% and 85% recovery (p less than 0.05). The postischemic recovery of stroke volume was 48% in group A compared with 84% in group B, 87% in group D, and 73% in group E (5 micrograms) (p less than 0.05). Additional rats were exposed to 210 minutes of ischemia (n = 41) or 240 minutes of ischemia (n = 56) at 10 degrees C. Control groups did not receive nicardipine, whereas treatment groups received nicardipine in the cardioplegia with total doses ranging from 1.4 micrograms to 6.4 micrograms. There were no significant differences in the survival of ischemia or the recovery of function after ischemia at 10 degrees C.(ABSTRACT TRUNCATED AT 250 WORDS)


Electrophysiologic study of dysrhythmias after atrial operations in dogs.

Experiments were conducted with 159 dogs to investigate the mechanism of persistent dysrhythmias clinically encountered after atrial-level operations. Those found after incisions to the internodal pathways (INPs) of the right atrium were analyzed using cardiac mapping in an anesthetized or extracorporeally perfused state. Longitudinal incisions of the posterior INP often allowed inducible sustained atrial flutter, with circus movement of excitation around the right atrium near the tricuspid orfice. Sustained atrial flutter thus produced was modified in cycle length by coexisting division of the middle INP but inhibited by that of the anterior INP. Its incidence increased at chronic stage, with marked cicatricial changes. The disrupted anterior INP markedly prolonged conduction time to the atrioventricular node and A-H interval compared with the other disruptions. Persistent atrioventricular junctional rhythm developed in about 50% of the animals after disruption of all three INPs or anterior and posterior INPs; division of the anterior INP was the common potent factor, although no single blocked INP produced persistent junctional rhythm. Our results support the "summation theory." The incidence of junctional rhythm and hypoxia of the sinoatrial node (flow rate of less than 10 mL.100 g-1.min-1) were markedly enhanced by coexisting blockade of atrial feeding arteries in addition to division of the anterior INP. In conclusion, massive posterior INP disruption is a potent anatomic substrate in producing sustained atrial flutter, middle INP division a modifier, and anterior INP division an inhibitor. Division of the anterior INP is a potent anatomic substrate in producing junctional rhythm, and hypoxia involving the sinoatrial node reacts as its synergic factor.


Time for new concepts about measurement of complement activation by cardiopulmonary bypass?

Fifty-one patients admitted for routine coronary bypass operations were randomized to cardiopulmonary bypass with a membrane oxygenator (Capiox) or a bubbler (Polystan or William Harvey). Complement activation was measured using enzyme immunoassays for concentrations of C3 activation products and the terminal complement complex. From 5.8 to 8.1 arbitrary units (AU)/mL (medians), the plasma concentrations of C3 activation products increased by 119.9 AU/mL (Capiox), 124.6 AU/mL (Polystan), and 79.5 AU/mL (William Harvey) to a peak at closure of the sternum (not significant when related to baseline concentrations). The increase in C3 activation products and baseline C3 activation were linearly correlated (R2 = 0.30; p less than 0.0001). From 5.5 to 6.1 AU/mL, the plasma terminal complement complex concentrations increased by 45.2 AU/mL (Capiox), 15.4 AU/mL (Polystan), and 17.4 AU/mL (William Harvey) to a peak before termination of cardiopulmonary bypass. Maximal terminal (C5-C9) activation was significantly higher in the membrane oxygenator group (p less than 0.0001) and showed no relationship to C3 activation. Measurement of C3 activation only gives no information about C5-C9 activation. At present, terminal complement complex quantitation is probably the best index of C5-C9 activation during cardiopulmonary bypass.


Congenital malformations of the coronary arteries: the Texas Heart Institute experience.

Coronary artery anomalies, some of which are considered clinically insignificant, can be associated with other congenital heart defects, myocardial ischemia, and reduced life expectancy. We conducted a retrospective study to determine the efficacy of surgical treatment in 191 patients who had a total of 202 coronary artery anomalies, which were classified as anomalies of origin (88 patients), termination (93), or distribution (10). Of the 88 patients with anomalies of origin, 60 had a coronary artery arising from the pulmonary artery, 18 had a right coronary artery arising from the left anterior descending artery, and 10 had a coronary artery arising from the contralateral sinus of Valsalva. All patients with an anomaly of termination had a coronary arteriovenous fistula, and all patients with an anomaly of origin had a single coronary artery. The diagnostic and operative techniques for each of the defects are evaluated. Based on our experience, early diagnosis and surgical intervention can yield satisfactory results in patients with coronary artery anomalies, with most experiencing relief of symptoms. The operative procedures were associated with a low early and late mortality; in addition, few patients experienced complications.


Endotoxin release and tumor necrosis factor formation during cardiopulmonary bypass.

Endotoxin, when released into the systemic circulation during cardiopulmonary bypass (CPB), might induce activation of plasmatic systems and blood cells during CPB, in addition to a material-dependent blood activation during CPB. However, the role of endotoxin in the development of this so-called whole-body inflammatory reaction in CPB is still unclear. We investigated the release of endotoxin into the systemic circulation in relation with the activation of the complement system and in particular the formation of tumor necrosis factor in 10 patients undergoing CPB. Immediately after the start of CPB the endotoxin concentrations increased significantly (p less than 0.01), accompanied by increases in C3a concentration (p less than 0.05). After release of the aortic cross-clamp, there was a second increase in endotoxin followed by a continuous increase in tumor necrosis factor, reaching a peak concentration 1 hour after the end of CPB (p less than 0.01). These observations demonstrate a release of endotoxin into the systemic circulation associated with tumor necrosis factor formation, which contributes to the whole-body inflammatory reaction associated with CPB.


Temperature monitoring during CPB in infants: does it predict efficient brain cooling?

We examined jugular venous oxygen saturation data in 17 pediatric patients less than 1 year of age undergoing hypothermic cardiopulmonary bypass (CPB). Jugular venous oxygen saturations (JvO2SATS) were measured before bypass and during the active core cooling portion of CPB. The study intervals during CPB included 1 minute after initiation of CPB, at a tympanic membrane temperature of 15 degrees C, and at a rectal temperature of 15 degrees C. During these measurement intervals, there were no significant changes in mean arterial pressure, pump flow rate, arterial oxygen saturation, mixed venous oxygen saturation, carbon dioxide tension, or hematocrit. Six of the 17 patients (29%) demonstrated a significantly lower JvO2SAT (87.1% +/- 6.3% versus 98.1% +/- 0.9%) at a tympanic membrane temperature of 15 degrees C. Patients demonstrating jugular venous desaturation could not be predicted from continuous monitoring of tympanic membrane and rectal temperatures or through on-line measurements of mixed venous oxygen saturation. Low JvO2SAT suggests higher levels of cerebral metabolism and cerebral uptake of oxygen. In the presence of deep hypothermic CPB and stable anesthetic levels, the most likely cause of a low JvO2SAT is inadequate cerebral cooling. We believe JvO2SAT monitoring may be an important adjunct to conventional temperature monitoring in the patient undergoing deep hypothermic CPB or total circulatory arrest.


Surgical management of infective endocarditis in children.

Infective endocarditis occurs infrequently in the general pediatric population, occurring mostly in patients with congenital heart disease. This study reviews our surgical experience with infective endocarditis based on a policy of aggressive intervention, conservative operative debridement, and creative reconstruction options using pericardium and prosthetic heart valves. From 1982 to 1989, 16 patients, 3 weeks to 16 years of age, underwent 19 intracardiac operations for infective endocarditis therapy at Kosair Children's Hospital. Eight (42%) were for resection of vegetations alone; an additional 11 operations (58%) involved more extensive debridements requiring either valve replacement or valvuloplasty using pericardium for exclusion of an abscess cavity, closure of a fistula, or for valve repair. Operative mortality was 25% (4 patients) and related to preoperative disease severity. There was one late death. Offending organisms included Staphylococcus species (31%), Haemophilus influenzae (13%), pneumococcus (5%), gram-negative organisms (13%), and Candida (13%); no organism grew on culture in 25%. We conclude that aggressive surgical exploration in patients with infective endocarditis is indicated and often requires resection of vegetations alone. More extensive procedures should preserve as much valvular tissue as possible. Pericardium is useful for reconstruction after debridement.


Left ventricular diverticulum with hypertrophy of the left ventricular apex.

A surgical case of diverticulum in the left ventricular apex is presented. A two-dimensional echocardiogram and magnetic resonance image showed a calcified tumor buried in the marked hypertrophied apex of the left ventricle. Enucleation of the oval and hard tumor (4 x 2.5 x 2.5 cm) was performed through the apex, and the defect was anastomosed by buttress sutures. Histologic examination demonstrated that the tumor cavity was filled with a thrombus encapsulated by thickened and calcified endocardium that extended to the left ventricular cavity. In this report, the etiology of the diverticulum with a hypertrophied myocardium is discussed.


Chronic fibrosing mediastinitis and superior vena caval obstruction from blastomycosis.

Chronic fibrosing mediastinitis is most commonly a complication of granulomatous disease caused by histoplasmosis. We report a case of Blastomyces dermatitidis causing superior vena caval obstruction from fibrosing mediastinitis.


Saphenous vein graft pseudoaneurysm formation after postoperative mediastinitis.

Pseudoaneurysm formation involving the body of an aortocoronary saphenous vein graft is a rare event. True aneurysmal dilatation of the graft and anastomotic pseudoaneurysm formation occur more commonly. We present the case of a 73-year-old woman in whom a pseudoaneurysm communicating with the body of a posterior descending coronary artery saphenous vein graft developed, presumably after a postoperative sternal wound infection. The aneurysm was excised and the defect within the saphenous vein graft repaired using hypothermia and circulatory arrest.


Unusual complication of temporary pacing wires in children.

There have been numerous complications described concerning temporary epicardial pacing wires including infection, bleeding, and coronary artery graft disruption. We report a case in which the heart was ensnared by the pacing wire, resulting in cardiac decompensation during attempted removal. This complication may be avoided by assuring that a smaller loop of pacing wire remains in the pericardium.


Aneurysm of coronary arteriovenous fistula presenting as a calcified mediastinal mass.

A 61-year-old woman with a giant aneurysm of the coronary arterial fistula between the left anterior descending coronary artery and the main pulmonary artery underwent aneurysmal resection and closure of the fistula. This was a very unusual case with rare congenital malformation with secondary atherosclerotic change.


Bilateral elastofibroma dorsi.

Elastofibroma dorsi was diagnosed in a 76-year-old woman with bilateral subscapular tumor masses and a 3-year history of recurrent, right-sided scapular pain. A bilateral tumor extirpation was performed and the patient left the hospital free of symptoms 10 days later. We suggest that both constant trauma with resulting excessive elastin production and collagen degeneration might play a major role in the pathogenesis of this rare proliferative lesion.


Double-lung transplantation using donor lungs with a right tracheal bronchus.

A 58-year-old man underwent sequential bilateral lung transplantation. On the donor heart-lung block, it was discovered that the right apical segment was supplied by a tracheal bronchus. After the separate implantation of both lungs, a right apical segmentectomy was performed and the postoperative course was uneventful. The management of this problem is discussed.


Surgical management of left coronary artery ostial atresia and supravalvar aortic stenosis.

Congenital atresia of the left main coronary artery ostium is a rare lesion, particularly when found in association with supravalvar aortic stenosis. This report describes the preoperative evaluation and surgical management of this lesion found in conjunction with a quadricuspid aortic valve in a 5-year-old child. Patch aortoplasty and left internal thoracic artery to left anterior descending coronary artery bypass were performed to correct this lesion.


Hyperbaric oxygen: value in management of nonhealing saphenectomy wounds.

The greater saphenous vein is commonly used as a conduit for arterial bypass in both cardiac and peripheral vascular operations. Although saphenectomy wound complications occur infrequently, such problems may be quite serious. We report a case in which hyperbaric oxygen therapy was extremely valuable in the management of a very difficult saphenectomy wound.


Pericardial repair of a tracheal laceration during transhiatal esophagectomy.

Transhiatal esophagectomy has recently been popularized for both benign and malignant esophageal disease. While we were performing a transhiatal esophagectomy for a squamous cell cancer of the upper third of the esophagus, a tear in the membranous trachea near the carina occurred. This was repaired through the cervical incision with a free pericardial patch. This solution to a potentially catastrophic complication of transhiatal esophagectomy gave a satisfactory result without early or late postoperative respiratory complications.


Limited vertical skin incision for median sternotomy.

The cosmetic deformity of the vertical skin incision for median sternotomy was decreased by using a mechanical traction system to increase exposure at the superior margin of a shorter wound. The limited vertical skin incision did not impede technical surgical maneuvers and produced a scar that was more acceptable than submammary incision or right anterior thoracotomy. The limited skin incision is especially useful in young women with congenital heart disease.


Directed atraumatic coronary sinus cannulation for retrograde cardioplegia administration.

A simple method of coronary sinus cannulation for retrograde cardioplegia administration is described that reduces cardiac manipulation. Intraoperative transesophageal echocardiography is used to direct atraumatic coronary sinus cannulation, confirm the depth of insertion of the cannula tip in relation to the ostium, and reduce overall cannulation time.


Bilateral anterior thoracotomy for automatic implantable cardioverter defibrillator placement in patients with previous sternotomy.

Bilateral anterior thoracotomy, extrapericardial patches, and endocardial sensing lead placement have been used in 40 patients with previous sternotomy. The mean defibrillation threshold was 15 J, and in all patients the defibrillation threshold was less than 20 J. The surgical procedure is simplified with less risk by avoiding dissection of previously operated regions. Serious pulmonary complications have been avoided by adequate pain control with epidural analgesia and early mobilization. This technique has successfully been used in patients with underlying chronic obstructive pulmonary disease and amiodarone-induced pulmonary fibrosis. All patients have been extubated by the first postoperative day.


New side-holed sheath for intraaortic balloon pumping to maintain limb perfusion.

We developed a new side-holed shunt sheath for inserting intraaortic balloon pumps to maintain lower limb perfusion in patients with stenotic and tortuous aortoiliac arteries. This sheath has a large internal diameter and several side holes, which act as an internal shunt. It was useful and effective in 11 patients with severe aortoiliac occlusive lesions who required assistance by intraaortic balloon pumping.


New surgical technique for type B aortic interruption.

Restoring continuity of the aortic arch in aortic interruption continues to be a problem in terms of both surgical technique and long-term results. We report here a surgical technique using the left subclavian artery along with an aberrant right subclavian artery to form a conduit in a patient with type B interruption, to reestablish aortic continuity.


Video-assisted thoracic surgery: basic technical concepts and intercostal approach strategies.

Video-assisted thoracic surgery is emerging as a viable approach to a number of intrathoracic disorders. Technical difficulties related to improper instrument selection and suboptimal intercostal operative access can reduce the utility of, and the enthusiasm for, the video-assisted thoracic surgical approach. This report describes the intercostal access strategy and the instrument positioning that we now prescribe for many video-assisted thoracic surgical procedures. These approaches have become refined during the course of our experience with 467 patients undergoing video-assisted thoracic operations over the last 18 months.


Intrathecal perfusion of an oxygenated perfluorocarbon prevents paraplegia after aortic occlusion.

A canine model was used to evaluate the effects of continuous intrathecal perfusion of an oxygenated perfluorocarbon emulsion on systemic and cerebral hemodynamics and neurologic outcome after 70 minutes of normothermic aortic occlusion. Twelve mongrel dogs were instrumented to monitor proximal and distal arterial blood pressure, cerebrospinal fluid pressure, spinal cord perfusion pressure, and somatosensory evoked potentials. The intrathecal perfusion apparatus consisted of two perfusing catheters, placed in the intrathecal space through a laminectomy, and a draining catheter percutaneously inserted in the cisterna cerebellomedullaris. The aorta was cross-clamped just distal to the left subclavian artery for 70 minutes. Animals were randomized into two groups: group 1 (n = 6) animals were treated with intrathecal perfusion of saline solution, whereas group 2 (n = 6) animals received oxygenated Fluosol-DA 20%. Data were acquired at baseline, during the cross-clamp period, and after reperfusion. Normothermic Fluosol or saline solution was infused at a rate of 15 mL/min beginning 15 minutes before cross-clamping and continued throughout the ischemic interval. There was no difference in proximal arterial blood pressure (97.2 versus 95.4 mm Hg; p > 0.05) or distal arterial blood pressure (14.6 versus 15.0; p > 0.05) between the two groups throughout the cross-clamp interval. Cerebrospinal fluid pressure rose significantly in both groups with the onset of intrathecal perfusion of either saline solution or Fluosol (7 +/- 1 versus 24 +/- 5 and 8 +/- 1 versus 40 +/- 4 mm Hg, respectively; p < 0.05). The rise in cerebrospinal fluid pressure was sustained throughout the perfusion interval in both groups.(ABSTRACT TRUNCATED AT 250 WORDS)


Cryopreserved allograft veins as alternative coronary artery bypass conduits: early phase results.

Traditional autologous conduits are sometimes unavailable or unsuitable to permit total revascularization during coronary artery bypass grafting. In these patients the results of using nonautologous alternative conduits has been disappointing. Encouraged by the excellent long-term results seen with cryopreserved allograft valves, a clinical protocol was developed to evaluate the use of a commercially cryopreserved allograft saphenous vein (CPV). Our protocol consisted of using CPV when left internal mammary arteries and autologous saphenous vein grafts were unavailable or unsuitable for complete revascularization. Blood group (ABO) typed CPVs were thawed and implanted as required using standard surgical techniques. From December 1989 through June 1991, 19 of 1,602 patients who underwent coronary revascularization had CPVs implanted (1.2%). There were no operative deaths. An attempt was made to evaluate the patency of all grafts with coronary arteriography or ultrafast computed tomographic scans. Fourteen patients were available for patency evaluation. Patency rate in the 14 patients studied at a mean of 7 +/- 2 months (range, 2 to 16 months) were: internal mammary artery, 93% (14/15); saphenous vein graft, 80% (4/5); and CPV, 41% (7/17). The patency of the CPV was significantly less than the patency rate for the saphenous vein and internal mammary artery (p = 0.004). We conclude that the short-term patency rate of CPVs is inferior to that of autologous vessels. Due to its poor patency, we recommend that CPV should only be used when no other autologous conduit is available.


Late results of operation for ventricular tachycardia.

We have analyzed results in 54 consecutive patients with recurrent ventricular tachycardia and coronary artery disease in whom we used an aggressive surgical approach involving map-directed ventricular tachycardia ablation, scar excision and left ventricular remodeling, and coronary artery bypass grafting, as well as staged mitral valve replacement when necessary. We have previously shown age greater than 65 years to be an independent predictor of mortality and have excluded such patients from this series. Average age was 56 +/- 7 years. All patients had a previous myocardial infarction; 24% of the infarctions (13/54) were posterior in location. Symptoms included syncope or presyncope in 83% of the patients (45/54), angina in 54% (29/54), and congestive heart failure in 52% (28/54). Extensive coronary artery disease was found in 78% (42/54), and 89% (48/54) had serious compromise of left ventricular function (ejection fraction < 0.40; average ejection fraction, 0.28 +/- 0.12). Only 63% (34/54) appeared to have a resectable left ventricular aneurysm on the preoperative angiogram. Ablation techniques included endocardial excision in 82% (44/54), with the addition of cryoablation in 60% (32/54), and balloon electric shock ablation in 22% (12/54); coronary artery bypass grafting was performed in 85% (46/54). There were four hospital deaths (7%). The surgical cure rate (no inducible VT at postoperative electrophysiologic study was 72% (39/54). During follow-up (mean, 50 +/- 31 months) there have been six late deaths (1 sudden death, 1 stroke, 4 congestive heart failures with or without mitral regurgitation). Four patients with progressive congestive heart failure and serious mitral regurgitation have undergone repeat operation for mitral valve replacement.(ABSTRACT TRUNCATED AT 250 WORDS)


Cardiac retransplantation: a viable option? The Registry of the International Society for Heart and Lung Transplantation.

To evaluate cardiac retransplantation as an appropriate utilization of scarce donor organs we analyzed data from the registry of the International Society for Heart and Lung Transplantation (ISHLT) (n = 449) and the Utah Cardiac Transplant Program (n = 20). Actuarial survival among retransplants was lower than in patients who received only one transplant in both the ISHLT registry patients (1 year survival, 48% versus 78%; p = 0.001) and the Utah series (1 year survival, 74% versus 88%; p = 0.06). Uncontrolled rejection, short interval (< 6 months) between transplantations, and the need for mechanical circulatory support were identified as risk factors for retransplantation. The incidence of rejection and infection was similar in first and second transplant recipients. Second transplant recipients had a higher level of sensitization, a greater incidence of donor-specific positive crossmatches, and an increased early mortality. Repetition in the second donor of mismatched HLA antigens present in the first donor did not adversely affect survival. If patients who underwent retransplantation within 6 months of their initial transplantation, those receiving transplants for uncontrolled rejection, and those requiring mechanical assistance were eliminated from the study, the short-term and long-term survival after cardiac retransplantation does not differ from that in patients having a single transplant.


Acute rejection of lung allografts with various immunosuppressive protocols.

Between February 1990 and December 1991, 69 patients who survived for a minimum of 5 days after single-lung (27), double-lung (32), or heart-lung transplantation (10) were studied to learn the incidence and severity of acute rejection and the possible effects of various immunosuppressive protocols on this rejection. Acute rejection was less common (2.1 versus 3.1 episodes/patient) after transplantation in those 30 candidates who received rabbit antithymocyte globulin for the first 5 postoperative days versus the 28 who were maintained on cyclosporine, azathioprine, and prednisone alone (p < 0.05), but no patient escaped at least one episode. Patients given cyclosporine received more 3-day courses of methylprednisolone (p < 0.02) than those given rabbit antithymocyte globulin (2.5 versus 1.7 courses). Although no disadvantage in terms of infectious morbidity was noted in the rabbit antithymocyte globulin group, no obvious intermediate advantage was noted in survival (85% at 12 months) or grade of rejection or airway flows. The most common histopathologic grades were mild (A2) and moderate (A3); the average grade was A2.3. FK 506 was tested in 11 patients, and early results are promising relative to low early and likely fewer late episodes of rejection. No differences were noted in the likelihood of rejection for any procedures.


Improved myocardial ischemic tolerance by contractile inhibition with 2,3-butanedione monoxime.

Contracture of the arrested myocardium during prolonged storage of the heart results in both systolic and diastolic dysfunction, and is a major limitation to extended preservation. We studied the effects of a reversible contractile inhibitor, 2,3-butanedione monoxime (BDM), on myocardial ischemic tolerance. Isolated rabbit hearts were flushed with University of Wisconsin (UW) solution with and without 30 mmol/L BDM and 1 mmol/L CaCl, stored at 4 degrees C for 24 hours, and subsequently reperfused for 60 minutes. Left ventricular pressure-volume relationships and adenine nucleotide content were determined before reperfusion. Left ventricular systolic pressure, diastolic volume, and adenine nucleotide content were measured after reperfusion. Hearts stored in UW solution underwent contracture and adenosine triphosphate (ATP) depletion during storage, and exhibited systolic dysfunction, impaired diastolic relaxation, and poor ATP regeneration upon reperfusion. The addition of calcium worsened contracture and ATP depletion (p < 0.005) and slightly improved function and ATP regeneration (p = not significant). Hearts stored in the presence of BDM experience no contracture during storage; ATP was preserved (10.7 versus 15.7 nmol/mg; p < 0.05), and left ventricular systolic pressure and ATP content recovered to 74% and 93% of control on reperfusion, respectively (p < 0.005). Left ventricular diastolic volume remained depressed, however, although less than with UW solution (0.87 versus 0.45 mL; p < 0.001). When both BDM and calcium were included in the UW solution, calcium-stimulated ATP hydrolysis and contracture were prevented, left ventricular systolic pressure returned to 87% of control, and left ventricular diastolic volume and ATP content returned to control levels.(ABSTRACT TRUNCATED AT 250 WORDS)


Extracorporeal membrane oxygenation for cardiac failure after congenital heart operation.

Despite continuing improvement in myocardial protection and surgical technique, the repair of complex congenital heart lesions can result in cardiopulmonary compromise refractory to conventional therapy. In a 29-month period, 24 patients (aged 14 hours to 6 years) were treated with extracorporeal membrane oxygenation (ECMO) 28 times for profound cardiopulmonary failure. Four patients required ECMO after each of two cardiopulmonary bypass procedures. Seventeen patients required ECMO to be initiated in the operating room: 12 (71%) were weaned successfully from ECMO, and 8 (47%) survived. Seven patients had ECMO initiated in the intensive care unit: 6 (86%) were weaned, and 5 (71%) survived. Serial echocardiograms demonstrated substantial recovery of cardiac function in 18 of 21 instances (86%) of ventricular failure from myocardial dysfunction. Overall, 18 of 24 patients (75%) were successfully weaned from ECMO including all 4 who underwent 2 ECMO treatments. We conclude that ECMO can successfully salvage children who have serious cardiopulmonary failure immediately after a congenital heart operation and that long-term survival is possible after two ECMO treatments.


Coarctation of the aorta in infants: does the aortic arch grow after repair?

Infants with coarctation of the aorta frequently require a corrective operation during the first year of life. These patients frequently have a smaller than normal transverse aortic arch. Despite good repairs with different techniques, the proximal transverse aortic arch often remains smaller than normal. The hemodynamic molding theory predicts that growth of the aortic arch should occur when normal flow is established through the aortic arch. Preoperative and postoperative aortograms were reviewed in patients who underwent subclavian flap aortoplasty for the repair of coarctation. Patients were divided into two groups. Subclavian flap aortoplasty was performed at 1 month of age or earlier in group I, and at more than 1 month but less than 1 year of age in group II. Aortograms performed in patients without coarctation were used as age-matched controls (group III). The transverse aortic arch in groups I and II did grow and were compared with the control group. Group I patients achieved more growth than those in group II. No aortic arch gradients were present at postoperative follow-up.


Postinfarct ventricular septal defect repair: effect of coronary artery bypass grafting.

Between June 1968 and April 1991, 75 patients who had undergone coronary angiography underwent repair of a postinfarction ventricular septal defect. Group 1 (n = 33) includes patients who had two- or three-vessel serious (> 75% narrowing) proximal coronary artery disease and underwent complete revascularization in addition to repair of the ventricular septal defect. Group 2 (n = 19) patients also had two- or three-vessel coronary artery disease but bypass grafting was not performed; only the ventricular defect was repaired. Group 3 (n = 23) patients had only single-vessel coronary artery disease that corresponded to the region of the infarct; they underwent ventricular septal defect repair only. Follow-up of hospital survivors was 96% complete at a mean of 86.2 months (range, 1 to 288 months). Hospital mortality after ventricular septal defect repair was 21.2% in the cohort with bypassed coronary artery disease (group 1), 26.3% in those with unbypassed disease (group 2), and 26.1% in those with only single-vessel coronary artery disease (group 3) (p = 0.88). With follow-up after 5 and 10 years, the actuarial survival was 72.2% +/- 8% and 47.8% +/- 10%, respectively, in the bypassed group, 29.2% +/- 11% and 0%, respectively, in the unbypassed group, and 52.2% +/- 10% and 36.5% +/- 11%, respectively, in the cohort with single-vessel disease. Bypassing associated coronary artery disease significantly increased long-term survival when compared with patients with unbypassed coronary artery disease (p = 0.0015).


Risk analysis of operative intervention for failed coronary angioplasty.

To assess the outcome of emergency coronary artery bypass grafting (CABG) after failed percutaneous transluminal coronary angioplasty (PTCA), 91 patients undergoing emergency CABG after failed PTCA over a 30-month period ending July 31, 1991, were studied. For reference, a cohort of patients (91) concurrently undergoing elective CABG equally matched for age, sex, number of grafts, ventricular function, and reoperative status was compared. Specific outcomes including death, hospital length of stay, use of blood products, and development of myocardial infarction were analyzed. More than half the patients undergoing emergency CABG for failed PTCA required three or more grafts. Operative mortality was 12.1% (11/99) for emergency CABG compared with 1% (1/91) for elective case-matched CABG patients (p = 0.007). Emergency CABG patients required frequent use of postoperative inotropes (p = 0.02) and intraaortic balloon counterpulsation (p = 0.001). Length of hospital stay (p = 0.005), administration of blood products (p = 0.009), postoperative myocardial infarction (p = 0.0005), and ventricular arrhythmias (p = 0.0004) were increased after emergency compared with elective CABG. The presence of multivessel disease or use of a reperfusion catheter had no influence on clinical outcome. Despite accumulated experience and improved operative management, patients requiring emergency CABG for failed PTCA remain at increased risk for postoperative complications and death.


Partial median sternotomy for repair of heart defects: a cosmetic approach.

A modified median sternotomy incision that results in a cosmetically appealing scar is described. It includes the use of a low-lying short skin incision and partial transection of the sternum. The outcome in 182 infants and children indicates that this approach is safe, provides adequate exposure, and has excellent cosmetic results.


Surgical considerations in bypassing coronary arteries with 100% proximal occlusion.

Objective data on the ability of cineangiography to predict the size of reconstituted totally occluded coronary arteries, as well as the clinical outcome of such revascularization, are sparse. Accordingly, we reviewed 200 consecutive cases of coronary revascularization to determine the answers to these questions. Group I patients (n = 57, with 86 totally occluded coronary arteries) had at least one coronary artery with a 100% proximal occlusion that reconstituted distally. Group II patients (n = 143, with 205 subtotally occluded coronary arteries) had 50% to 99% proximal stenosis of at least one coronary artery. Cineangiograms were blindly reviewed to measure the size of the coronary arteries, which were compared with the actual vessel size at operation. In group I, the totally occluded coronary arteries had a cineangiographic size of 1.9 +/- 0.7 mm and an actual size of 1.6 +/- 0.4 mm (p = 0.00004). In group II, the subtotally occluded coronary arteries had a cineangiographic size of 1.8 +/- 0.4 mm compared with an actual size of 1.8 +/- 0.3 mm (p = not significant). The site of bypass grafting was significantly smaller in group I (1.6 +/- 0.4 mm versus 1.8 +/- 0.3 mm; p = 0.00008). The two groups were similar with respect to preoperative and intraoperative parameters. Operative mortalities were similar (group I, 1.8%; group II, 3.5%; p = 0.68). Creatine kinase isoenzyme profiles and electrocardiographic changes were similar, except for a significant late rise of creatine kinase-MB in group I (56.1 +/- 14.7 versus 30.7 +/- 33.7 MIU/mL; p < 0.001). In conclusion, cineangiography significantly overestimates the size of totally occluded coronary arteries.(ABSTRACT TRUNCATED AT 250 WORDS)


Role of open lung biopsy in diagnosing pulmonary complications of AIDS.

Over a 4-year period, 25 patients with pulmonary complications of acquired immunodeficiency syndrome underwent open lung biopsy for diagnosis. Results of the biopsy led to a change in therapy in 15, and of this group, 8 patients improved clinically and were discharged. We believe that a select group of acquired immunodeficiency syndrome patients with pulmonary disease will benefit from open lung biopsy. Our indications for open lung biopsy are (1) a nondiagnostic bronchoscopy, (2) failed medical therapy after a diagnostic bronchoscopy, (3) failed empiric medical therapy after a nondiagnostic bronchoscopy or after a second nondiagnostic bronchoscopy, and (4) when any of the forementioned are accompanied with a worsening chest roentgenogram. Patients with acquired immunodeficiency syndrome who have a deteriorating respiratory status or require mechanical ventilation should not undergo open lung biopsy.


Tetralogy of Fallot: favorable outcome of nonneonatal transatrial, transpulmonary repair.

This report describes our experience with 366 patients who had a transatrial, transpulmonary repair of tetralogy of Fallot between December 1980 and December 1991. Included in this group are patients with tetralogy of Fallot plus atrioventricular septal defect as well as patients displaying all degrees of aortic override (in the presence of subaortic ventricular septal defect and right ventricular outflow tract obstruction). Median age was 15.3 months and median weight, 12.3 kg. Of the 366 patients, 72% required a pericardial patch to reconstruct the main pulmonary artery or right ventricular outflow tract. Serious coronary anomalies were seen in 11 patients, without influencing surgical approach. There were two hospital deaths (0.5%; 70% confidence limits, 0.2% to 1.2%). Actuarial survival was 97.5% at 42 months (95% confidence limits, 95% to 99%) reflecting four late deaths over 1,129 patient-years of follow-up. Postoperative cardiac catheterization studies were performed in 61 patients at a mean follow-up interval of 23 months. Mean right ventricular/left ventricular systolic pressure ratio after repair was 0.46 (standard deviation, 0.28), and mean gradient across the right ventricular outflow tract was 15 mm Hg (standard deviation, 24 mm Hg). Actuarial freedom from reoperation for any reason has been 95% (95% confidence limits, 92% to 97%) at 5-year and 10-year follow-up. These early and medium-term results encourage us to continue with transatrial, transpulmonary repair of tetralogy of Fallot. We believe that this approach has an operative risk similar to or lower than transventricular repair, and that it will result in better preservation of right ventricular function in the long term.


Benefits of combined balloon pumping and percutaneous cardiopulmonary bypass.

Sixteen patients (2 women, 14 men) aged 29 to 72 years with continued cardiogenic shock during intraaortic balloon pumping (IABP) had additional treatment with percutaneous cardiopulmonary bypass (PBY). Cause of cardiogenic shock was myocardial infarction in 7 (3 survived), failed percutaneous transluminal coronary angioplasty requiring emergency coronary artery bypass grafting in 5, postoperative aortic valve replacement in 1, postoperative emergency coronary artery bypass grafting in 1, after cardiac transplantation in 1, and bridging to transplantation in 1. Mean blood pressure with PBY and IABP combined was 75 mm Hg versus 60 mm Hg with IABP off. Percutaneous cardiopulmonary bypass flows ranged from 0.8 to 2.1 L/min with a mean flow of 1.3 L/min. Time on IABP ranged from 24 hours to 1 week. Time on IABP to PBY ranged from 1 to 20 hours, and time on PBY ranged from 65 minutes to 20 hours. Ten of 16 (63%) were successfully weaned, and 3 died after weaning. Seven of 16 (44%) survive. Combined IABP with PBY appears to be a better therapy than either one individually. Staging the therapy as the balloon first in and last out appears to be a good methodology.


Coronary artery bypass using internal mammary artery branches.

The excellent long-term patency rates achieved with use of the internal mammary artery (IMA) to bypass the left anterior descending coronary artery have stimulated a variety of approaches to expand the use of this conduit in coronary bypass surgery. In this report we document our results using the two terminal branches of the IMA to bypass two arteries in a Y configuration. Sixty-seven patients received IMA Y grafts during a 6-month period in 1987. A total of 150 IMA branch anastomoses were performed (8 patients received bilateral IMA Y grafts). Fourteen of 67 patients were revascularized using IMA grafts only. Operative mortality was 2 of 67 (3%), and follow-up mortality was 5 of 67 (7.5%). Fifty-eight patients could be evaluated 37 +/- 2.7 months later. Clinically 36% of patients reported some recurrence of angina and 12 of 47 (25%) had a positive electrocardiographic stress test. Four patients were reoperated on (2 redo coronary artery bypass grafting, 2 transplants). Sixty (40%) of the 150 branch anastomoses could be evaluated objectively and 30 (50%) were patent. Five (8.5%) were stenotic and 25 (41.5%) were occluded (overall patency rate, 58.5%). We conclude that although the use of IMA Y grafts is a technically feasible means to increase IMA usage, extended application of this technique cannot be recommended unless improved patency rates can be demonstrated.


Isolated biventricular working rat heart preparation.

The isolated perfused heart from small animals has been used extensively for hemodynamic and metabolic studies. The left working heart preparation proved superior to the Langendorff model for functional evaluations but has not allowed study of right heart function. A simple and inexpensive biventricular working heart preparation has been developed by modifying the left working rat heart model. Under general anesthesia the heart was removed surgically leaving sufficient vessels attached to it. Cannulation of the aorta, left atrium, right atrium, and pulmonary artery was completed in 10 minutes. A pressurized compliance chamber allowed rapid and reliable regulation of aortic impedance. For the 7 hearts that were subjected to 3-hour biventricular perfusion (their end points expressed as percent of their initial values), the aortic output (95% +/- 3%), pulmonary flow (88% +/- 9%), mean aortic pressure (109% +/- 5%), mean pulmonary pressure (100% +/- 2%), heart rate (106% +/- 8%), myocardial adenosine triphosphate level (85% +/- 8%), and creatine phosphate level (89% +/- 4%) were all maintained at physiologic levels. For the 11 hearts that were converted from left working heart preparation to biventricular working mode, significant improvement in stroke volume, aortic and cardiac output, and pressure development were observed. Experimental results indicate that the biventricular working model for isolated perfused rat hearts is superior to the left working preparation for studying the function of the total heart. Further study of the biventricular perfused working rat heart appears warranted.


Effect of prostaglandin I2 and superoxide dismutase on reperfusion injury of warm ischemic lung.

A prostaglandin I2 (PGI2) analogue and superoxide dismutase (SOD) were administered to dogs with pulmonary denervation, and their effects on warm ischemic damage to the lung were studied. Twenty-seven adult mongrel dogs were divided into a control group (6 dogs), a PGI2 group (7 dogs), an SOD group (6 dogs), and a heparin group (8 dogs). The left pulmonary hilum was dissected, with PGI2 (1 microgram/kg) being administered to the PGI2 group and heparin (100 U/kg) to the heparin group. Then the left lung was placed in a warm ischemic state for 1 hour. The SOD group also received 20 mg/kg of SOD intravenously 1 minute before reperfusion. Before warm ischemia, immediately after reperfusion, and 1 hour and 2 hours afterward, the blood gases, left pulmonary vascular resistance, and other data were measured under right pulmonary artery clamping. Arterial oxygen tension showed significantly better values in the SOD and PGI2 groups than in the control and heparin groups. The left pulmonary vascular resistance increased with time in the control group but did not increase in the PGI2 group. Pulmonary microangiography showed that dilatation of the pulmonary arterioles was prominent in the PGI2 group. The quantity of pulmonary extravascular fluid was significantly less in the PGI2 and SOD groups than in the control and heparin groups. Histological examination showed marked collapse of capillaries, intraalveolar hemorrhage, and edema in the control and heparin groups, whereas these changes were only slight in the PGI2 and SOD groups.(ABSTRACT TRUNCATED AT 250 WORDS)


Comparison of 180-degree and 360-degree skeletal muscle nerve cuff electrodes.

Use of skeletal muscle for cardiac augmentation is a promising technique for treatment of end-stage cardiac failure. An electrode woven through the latissimus dorsi that recruits nearby nerve fibers is commonly used to pace skeletal muscles both in clinical practice and in the laboratory. A proximally placed nerve cuff electrode offers potential advantages in improved recruitment of muscle fibers and low threshold for stimulation. We tested the effectiveness of a nerve cuff electrode passed directly about the proximal thoracodorsal nerve. Our report looks at the efficacy of nerve cuff electrode stimulation and compares electrical and histologic characteristics of a 180-degree wrap of the thoracodorsal nerve to a 360-degree wrap in dogs over 3 months. Threshold voltage at the commonly used pulse width of 200 microseconds was typically in the range of 400 to 600 mV for each electrode after 3 months. Statistical analysis revealed no significant difference (p < 0.05) in threshold voltage or current between the 180-degree and 360-degree nerve cuff electrode either at acute evaluation or after 3 months. Even contraction of latissimus dorsi was achieved with all implants. Adenosine triphosphatase staining revealed 100% conversion of type II to type I fibers in all stimulated muscles. Histologic examination of the thoracodorsal nerve and latissimus dorsi muscle revealed no abnormalities grossly or by light microscopy. Thus, a carefully applied nerve cuff electrode is an atraumatic, effective method for skeletal muscle stimulation. The 180-degree and 360-degree nerve cuff configurations are equally effective.


Technique of open distal anastomosis for repair of descending thoracic aortic aneurysms.

Ischemic injury to the spinal cord and kidneys continues to be the major complication after resection of aneurysms involving the descending and proximal abdominal aorta. Our recent surgical experience with use of only a proximal clamp on the aorta to perform an "open" distal anastomosis has proved this technique to be safe and expeditious. We therefore compared our results using the technique of open distal anastomosis for aneurysm repair with those of the conventional two-clamp technique. Since January 1989, we have used the conventional two-clamp technique in 31 patients (group 1) and the technique of open distal anastomosis in 24 patients (group 2). No significant differences were noted between the two groups in terms of age, sex, cause of aneurysm, extent of aneurysm, or site of proximal cross-clamp. The average distal ischemic time was 31 minutes in group 1 patients and 26 minutes in group 2 patients. Renal insufficiency occurred in 8 of 31 patients in group 1 and in 0 of 24 patients in group 2 (p = 0.01). Neurologic complications occurred in 4 patients in group 1 and in 1 patient in group 2. Early mortality rates were similar for both groups (4 of 31 [13%], group 1; 4 of 24 [17%], group 2). Deaths were attributed to multiorgan failure and sepsis in 6 patients and coexisting coronary artery disease in 2 patients. Based on these results, we believe the technique of open distal anastomosis is safe and may improve the outcome in patients undergoing operation for descending thoracic aneurysms.(ABSTRACT TRUNCATED AT 250 WORDS)


Extrapleural pneumonectomy in the treatment of malignant pleural mesothelioma.

A technique for extrapleural pneumonectomy in diffuse, malignant, pleural mesothelioma is described. The technique used in a protocol at Brigham and Women's Hospital has resulted in improved operative mortality figures and length of hospital stay. The right-sided procedure is presented followed by differences in technique required by the left-sided approach.


Considerations in the skeletonization technique of internal thoracic artery dissection.

Skeletonization of the internal thoracic artery during myocardial revascularization procedures may provide some degree of protection from sternal wound infection in diabetic, obese, or pulmonary compromised patients when both internal thoracic arteries are used as conduits. Prior descriptions of the technique fail to provide specific details and possible pitfalls of the dissection. A method of skeletonization that has been used at the California Center for Cardiothoracic Surgery in more than 1,000 patients is presented in detail. Potential advantages and disadvantages are discussed.


The Meadox-Gabbay pericardial xenograft: failure of the unicusp principle.

Durability of a new bioprosthesis, the Meadox-Gabbay unileaflet pericardial xenograft, was evaluated by reviewing a series of 12 patients who received this device in the mitral position from 1983 to 1985. Bioprosthetic failure necessitated reoperation in 5 patients 21, 22, 53, 66, and 81 months after placement. Three patients died of cardiac failure after 31, 52, and 70 months; no postmortem examinations were done. In 2 of the 3 patients, an echocardiographic study had shown signs of valvular dysfunction. Pathological examination of five available explants revealed the presence of redundancy and stretching of the single pericardial leaflet in all of them; in one, this lesion alone caused severe prosthetic incompetence. Other pathological findings included cusp and commissural calcification and commissural tears with or without calcification. Histologic examination and electron microscopy showed intrinsic calcification involving both collagen bundles and cellular debris and various degrees of collagen disruption. In this limited series of patients, the Meadox-Gabbay pericardial xenograft demonstrated various modes of failure that markedly impair its durability and render it unsuitable as a cardiac valve substitute.


Comparison of cardiac output measured by intrapulmonary artery Doppler, thermodilution, and electromagnetometry.

A Doppler pulmonary artery catheter system (Doppler cardiac output monitor or DOPCOM) that continuously measures instantaneous and mean cardiac output was recently introduced. Because thermodilution (TD) flow measurements may not represent an adequate standard, the present study was designed to compare TD and DOPCOM cardiac output measurements with aortic electromagnetic (EM) flow in cardiac surgical patients. Twenty-one patients scheduled for elective coronary artery bypass grafting were enrolled in the study. Simultaneous measurement of cardiac output by all three methods was performed before cardiopulmonary bypass, after cardiopulmonary bypass with the aorta cannulated and volume intermittently infused, and after decannulation. Analysis of all data demonstrated fair TD and EM correlation (r = 0.80), with minimal bias (0.03 +/- 1.21 L/min) and a median absolute error of 0.53 L/min; DOPCOM and EM data showed moderate correlation (r = 0.64), a bias of -0.61 +/- 1.50 L/min, and a median absolute error the same as TD (0.51 L/min). However, distribution of DOPCOM values was heavily skewed by 3 patients in whom flow measurements immediately after cardiopulmonary bypass were markedly different between the DOPCOM and electromagnetometry, probably because of malposition of the Doppler transducers secondary to partial catheter withdrawal during bypass. Consistent with this theory was the finding that before CPB, the DOPCOM was significantly better than TD in predicting EM flow (median absolute error: DOPCOM, 0.12 L/min, and TD, 0.48 L/min; p = 0.04). Our data suggest that, in general, the DOPCOM shows similar precision to TD for predicting EM flow measurements, although the DOPCOM may underestimate actual flow.(ABSTRACT TRUNCATED AT 250 WORDS)