transurethral resection of the prostate ( turp ) is considered the best option for treating benign prostatic enlargement ( bpe ) ; however , it is associated with significant bleeding . in recent years
, we have seen a gradual increase in life expectancy and , particularly in more developed countries , an increased incidence of cardiovascular diseases , metabolic syndrome , and cerebrovascular stroke , all of which are conditions that require oral antiplatelet or anticoagulation ( oap / oac ) therapy . owing to the severe bleeding risk in these patients ,
turp is contraindicated . furthermore , suspending oap / oac therapy is also not recommended .
for example , the use of laser technology has advantages in patients receiving oap / oac therapy who have severe comorbidities and bleeding disorders .
thulium vaporesection of the prostate ( thuvarp ) with a 2-m continuous - wave ( cw ) thulium - doped yttrium - aluminum - garnet ( tm : yag ) laser has been established as a new approach for bpe treatment .
this laser has a peak absorption spectrum closer to that of water than the holmium laser , which causes increased tissue vaporization and results in reduced penetration depth .
however , because the thulium laser operates in cw mode , it permits smaller and more precise cutting and consequently decreased risk of bleeding .
the aim of this study was to demonstrate the efficacy and safety of vaporesection with the 120-w tm : yag laser ( revolix duo ) in patients with bpe receiving systemic oap / oac therapy and to evaluate medium - term functional outcomes .
between october 2011 and december 2013 , a total of 103 patients with lower urinary tract symptoms due to bpe were enrolled in the study , and data were retrospectively analyzed .
a , oap / oac therapy was interrupted for 10 days before the operation and patients were switched to low molecular weight heparin ( lmwh ) until 2 weeks after the procedure . in group
group b patients were also divided into subgroups according to the oap / oac therapy that they were using : warfarin , acetyl salicylic acid ( asa ) , clopidogrel , ticlopidine , or asa+clopidogrel . according to the standard protocol of the university hospital in which the study was carried out ,
each patient was informed of the procedure upon admission and signed an informed consent allowing data collection for research purposes .
the study design was in accordance with the helsinki declaration , conformed to the committee on publication ethics guidelines , and was approved by the institutional review board of the department of human pathology , section of urology , university of messina , messina , italy in which it was performed .
all the design , analysis , data interpretation , drafting , and revisions followed the strobe ( strengthening the reporting of observational studies in epidemiology ) statement as well as the guidelines for reporting observational studies , available through the equator ( enhancing the quality and transparency of health research ) network .
all operations were performed by a single surgeon ( cm ) with extensive experience in laser prostatectomy and prostate resection .
the thuvarp technique used in this study was the same described in our previous publication .
the procedure was performed by using the 120-w 2-m cw tm : yag laser ( revolix duo ) .
the revolix duo has 2 laser generators : ( 1 ) a 120-w cw mode for soft tissue use and ( 2 ) a 20-w pulsed head to holmium for lithotripsy .
a 550-m core nude - ended fiber ( rigifib ; ohg , lisa laser , katlenburg - lindau , germany ) was used in combination with a 26-f continuous - flow laser resectoscope ( karl storz gmbh & co. kg , tuttlingen , germany ) .
incisions were made on the bladder neck at the 5 and 7 o'clock positions and vaporesection was performed on the median lobe .
finally , vaporesection of the lateral lobe was performed until the prostatic capsule was reached . by performing this technique ,
small tissue chips are obtained , which were evacuated through the resectoscope sheath . at the end of every procedure ,
a 20-f foley catheter was placed and bladder irrigation was performed in the case of hematuria .
the catheter was routinely removed 48 to 72 hours after the procedure regardless of preoperative prostate size when the urine was clear .
cefazolin ( 2 g ) was administered as a short protocol 1 hour before the procedure .
data collected included operative time , hospital stay , catheterization time , and hemoglobin values pre- and postoperatively .
in addition , maximal flow rate ( qmax ) , postmicturition residual urine ( pmr ) , international prostate symptom score ( ipss ) , and quality of life ( qol ) scores were assessed immediately before surgery ( baseline ) and at 3 , 6 , 12 , 18 , and 24 months after treatment .
prostate - specific antigen ( psa ) values were assessed preoperatively and at 12 and 24 months .
baseline variables were described by using mean and standard deviation or percentages , as appropriate .
mann - whitney u - tests were used to evaluate the difference between quantitative measurements that had nonparametric distributions .
a total of 103 patients who underwent laser prostatectomy were included in the study . in group
a , anticoagulant therapy was interrupted and switched for lmwh in 47 patients , whereas in group b , 56 patients underwent surgery while still on their anticoagulant therapy regimen . the mean ages of groups a and b were 68.56 and 69.66.8 years , respectively .
the mean operation , hospitalization , and catheterization durations are given in table 1 for each group .
the mean preoperative prostate volumes were 66.814.1 and 65.39.5 ml for groups a and b , respectively .
the mean amounts of resected prostate tissue were 43.810.9 and 43.16.7 ml for groups a and b , respectively .
in group b , 7 patients were on warfarin , 23 patients were on asa , 14 were on ticlopidine , 8 were on clopidogrel , and 4 patients were on asa + clopidogrel combination treatment .
the mean preoperative hemoglobin level of patients in group a was 13.71 and that of patients in group b was 13.51.5 .
the mean postoperative hemoglobin level of patients in group a was 131 and that of patients in group b was 13.21.5 . neither pre- nor postoperative hemoglobin values were statistically significantly different between groups a and b. however , the drop in hemoglobin values in the pre- and postoperative periods was significantly higher in group a : 0.70.5 and 0.30.5 in groups a and b , respectively ( p<0.005 ) .
when subgroup analyses were performed within group b , the mean drop in hemoglobin was significantly lower in patients who were on warfarin and ticlopidine compared with patients in group a ( p<0.005 , p<0.005 , respectively ) .
the mean pre- and postoperative hemoglobin values along with the mean drop in hemoglobin are given for each group in fig .
when the ipss values were compared between groups a and b , group a had significantly lower ipss values at 3 , 12 , 18 , and 24 months after surgery ( p<0.005 , p<0.05 , p<0.005 , p<0.001 , respectively ) .
however , in the preoperative period , the ipss was 15.9 in group a and 18.6 in group b and the difference was not statistically significant .
no statistically significant differences were found between groups a and b or subgroups of group b in qol scores , qmax values , or pmr volumes ( ml ) . during the whole follow - up period ,
the mean ipss , qmax , and pmr values along with qol scores for groups a and b and the subgroups of group b are given in table 2 and fig .
the mean psa values in the preoperative period were 3.11.5 and 3.11.9 in groups a and b , respectively . at 12 months after the operation , the values were 2.30.9 and 2.41.2 , and at 24 months , the values were 2.20.8 and 2.30.9 for groups
a , 38 patients had no complications , whereas 4 had transient urge incontinence , 4 had urinary tract infection ( uti ) , and 1 patient needed recatheterization for slight hematuria for 5 days which resolved without further intervention .
no complications occurred in 41 patients in group b ; however , in 6 patients , transient urge incontinence occurred ; 7 patients had a uti ; 1 patient needed recatheterization for 4 days due to hematuria ; and 1 patient needed transfusion due to intraoperative bleeding .
according to the latest guidelines of the european association of urology , turp is the best treatment option for patients with nonneurogenic lower urinary tract symptoms affected by bpe .
however , morbidity with turp remains fairly high , with associated bleeding risk and electrolytic disorders .
in particular , patients receiving oap / oac treatment carry a major risk for hemorrhage , and discontinuation of these treatments carries the risk of thromboembolic events .
this may be considered a double - edged sword : the management of bpe is problematic for the urologist owing to the increased use of oap / oac for primary or secondary prevention of cardiovascular complications . in their study , capodanno et al
.   expressed that this commonly used bridging practice is potentially harmful in patients undergoing noncardiac surgeries and can result in worse ischemic outcomes , especially in the first 30 days , along with significant risk of bleeding .
.   pointed out the importance of these risks and proposed an immediate change in daily practice to abandon bridging therapy in most of these patients .
to clarify this issue for urological procedures , several studies were conducted on turp in patients receiving oap / oac therapy regimens .
analyzed 163 cases and found a higher rate of perioperative bleeding in patients who continued oap / oac therapy than in those who were not on an oap / oac therapy . also , cerebrovascular and cardiovascular events occurred in patients who had discontinued their oap / oac treatments .
this study demonstrates the importance of studies in which patients are evaluated while they are still receiving oap / oac treatments . to question the safety of bridging therapy with lmwh and the discontinuation of prophylactic anticoagulants , dotan et al .  
compared the bleeding rates of patients who were on chronic oap / oac treatment and switched to lmwh perioperatively with those of non  warfarin - treated patients .
they found a bleeding rate of 20% in patients who switched to perioperative lmwh , and this situation is presumed to result in longer hospitalization duration .
high rates of bleeding were also reported by parr et al .   in a cohort of 12 patients with more than 30% of them having transfusions .
however , they reported that several such patients who switched from warfarin to heparin before surgery presented to the emergency department with major thromboembolic events and some even required open - heart surgery .
thus , they concluded that there is no need for bridging therapy and that bleeding problems can be easier to manage than thromboembolic events .
ong et al .   reported that in a population of 293 patients on chronic oap / oac therapies who underwent turp , bleeding complications occurred in 10% of patients , of whom 8% required prolonged bladder irrigation , 2% required re - catheterization , 2% required reoperation , and 2% needed blood transfusion .
although turp has been the gold standard for the surgical management of bpe for the past several decades , in recent years , a new series of lasers and techniques have become well established as an alternative treatment for bpe . in particular , holmium and thulium lasers have shown safety and efficacy in numerous studies throughout the past decade .
studies reporting the safety of laser prostatectomy in patients on oap / oac therapies are also becoming more common . in their study in 2007 , ruszat et al .   reported that in 116 patients on oap / oac therapy who were compared with a group of 92 control cases , none of the patients required transfusions . owing to slight hematuria , 17% of these patients required prolonged bladder irrigation ; however , this frequency was 5% among the control cases . in our patient groups ,
one patient in each group was catheterized as a result of bleeding after the retrieval of the urinary catheter and required prolonged irrigation .
reported no statistically significant differences among the 2 groups in terms of ipss , qol scores , or qmax .
these findings agree with our study . in our patient cohort , although these variables all improved after surgery , there were no statistically significant differences between the groups showing that bridging oap / oac with lmwh or continuing oap / oac affected functional outcomes . in various studies ,
for example , fu et al .   compared thuvarp and monopolar turp and stated that the efficacy of the two modalities was similar , although thuvarp resulted in less blood loss and a shorter hospital stay .
bach et al .   compared the 120-w and 70-w tm : yag lasers in terms of hemostatic properties .
the device that we used , the 120-w tm : yag laser , provided better ablation rates and fewer bleeding problems compared with the 70-w device .
the 120-w thulium laser has a wavelength of 2013 nm , which is close to the absorption peak of water .
thus , the effects are independent of tissue vascularization , which provides good hemostasis , comparable to that of the holmium : yag laser . additionally , the cw laser beam in tm : yag lasers provides precise incisions and sufficient vaporization . in the study by bach et al .   in 2010 and the study by fu et al .   in 2010 about thuvarp , the authors did not indicate the vaporized prostate volume . in our study written by netsch et al .  
in 2015 comparing thuvarp and thuvep , the amount of vaporized tissue was 42.5 ml .
the amount of vaporized tissue in our current study was 43.1 and 43.8 ml in the different groups .
psa is a tool that can be used to predict prostate volume and prostate growth . additionally , according to the pless ( proscar long - term efficacy and safety ) study , psa is valuable in predicting changes in symptoms , qol , and qmax . in our study ,
psa values were lower in the postoperative period compared with preoperative values in both groups a and b. this drop was due to tissue vaporization and the decrease in prostate volume , which also supports the amelioration of symptoms and improved qol after surgery . as expressed earlier , the bleeding complications during turp in patients receiving oap / oac therapies are high . with technological advancements and new laser devices ,
the bleeding rate is expected to decrease as a result of the high ablative and coagulative power of these modalities . in our study , apart from showing low bleeding rates similar to those reported in fu et al .
's study , we also compared patients on continuous oap / oac therapy and patients who underwent lmwh bridging .
although the subgroup comparisons showed statistically significant differences , the drop in hemoglobin levels was similar and the differences were not clinically relevant .
these results show that bridging therapy with lmwh has a small impact on bleeding complications that have clinical relevance .
although no cardiopulmonary adverse events occurred in our patient cohort , the high level of evidence in the literature about the seriousness of these events draws great attention to patients undergoing bridging therapy with lmwh .
when the low risk due to bleeding complications in our patient group is combined with the high risk of potential cardiopulmonary adverse events in the case of lmwh bridging , continuing oap / oac therapy during thuvarp seems to be the better way of patient management .
apart from bleeding complications , we did not encounter any bladder neck contracture or urethral stricture in the long - term follow - up .
fu et al .   reported one case of urethral stricture and no cases of bladder neck contracture in their study .
in a recent study by yu et al . , the authors reported a uti rate of 10% . in our study , 4 of 47 patients in group a ( 8.5% ) and 7 of 56 patients in group b ( 12.5% ) had uti .
in fu et al . 's study , the rate of uti in thuvarp group was 6.9% .
another minor limitation was the lack of comparison with a group of patients undergoing turp , which is considered the gold standard operation for bpe .
however , in the absence of good prospective trials , the results obtained from well - analyzed retrospective studies can play significant roles in clinical practice and can set up new ideas for future randomized prospective studies .
continuing oap / oac therapy regimens for certain endoscopic procedures has been strongly encouraged in recent years owing to the high risk of cardiopulmonary thromboembolic events in these patients .
our study showed the safety profile of continuing different oap / oac regimens in terms of bleeding problems in patients undergoing thuvarp .
we strongly recommend abandoning lmwh bridging and maintaining the patient 's current oap / oac therapy regimen
. a larger cohort of patients and a longer follow - up period are needed to add more valuable contributions to our results .
 purposethulium vaporesection of the prostate ( thuvarp ) is a new and safe approach for patients receiving anticoagulant therapy in whom transurethral resection of the prostate ( turp ) may possess a high bleeding risk . 
 we aimed to demonstrate the efficacy and safety of thuvarp in patients receiving oral antiplatelet / anticoagulant ( oap / oac ) therapy.materials and methodsa total of 103 patients who underwent thuvarp between 2011 and 2013 were enrolled in the study . 
 patients were divided into 2 groups . 
 group a consisted of 47 patients who underwent low molecular weight heparin ( lmwh ) bridging and group b consisted of 56 patients who were operated on while receiving oap / oac therapy.resultsthe drop in hemoglobin levels in the pre- and postoperative periods was significantly higher in group a than in group b. when subgroups were analyzed , the mean drop in hemoglobin was significantly lower in the warfarin and ticlopidine subgroups of group b than in group a. international prostate symptom scores were significantly lower 3 , 12 , 18 , and 24 months after surgery in group a than in group b. quality of life scores , maximal flow rate values , and postmicturition residual urine volumes ( ml ) were similar between the 2 groups . 
 a total of 38 and 41 patients in groups a and b , respectively , had no complications.conclusionsour study showed the safety profile of continuing different oap / oac therapies in terms of bleeding problems in patients undergoing thuvarp . 
 we strongly recommend abandoning lmwh bridging and maintaining the oap / oac regimen patients are already receiving . 
INTRODUCTION
MATERIALS AND METHODS
RESULTS
DISCUSSION
CONCLUSIONS