it is frequently asymptomatic but when being symptomatic the most presenting problems are flank pain and urinary tract infection with an atrophic upper pole which may also cause hypertension .
the standard treatment for a duplex kidney with a poorly functioning upper pole moiety is an upper pole heminephrectomy .
this procedure is usually performed by open surgery but with recent developments in endo - urology techniques and uro - laparoscopy , many attempts started to do this procedure laparoscopically , , .  
there are few reports in laparoscopic heminephrectomy in children that are mainly done with retroperitoneal approach , , , and there is just one large series in adults with acceptable results . in this article
we describe our results and patients outcomes with laparoscopic transperitoneal heminephrectomy in our consecutive cases .
from february 2001 to may 2007 , 14 patients ( 10 females , 4 males ) with complete duplex kidneys were presented with flank pain or uti leading to final diagnosis of non functioning upper moiety which became candidate for transperitoneal laparoscopic heminephrectomy .
prior to the procedure , complete radiologic evaluation including abdominopelvic sonography , intravenous urography ( ivu ) and abdomino - pelvic ct scan were contemplated in all patients to delineate renal anatomy and hydronephrosis . by dmsa
isotope scan , hypofunctioning of this moiety was confirmed . in patients suspected of vesico - ureteral reflux , voiding cystourethrography ( vcug )
all patients were admitted the day before operation ; received adequate bowel preparation and other needed medications .
renal function tests as well as complete blood count , urine analysis and culture were all performed during that period .
with the patients under general anesthesia , a foley catheter as well as a nasogastric tube was inserted and they were placed in a 60 degrees lateral decubitus position with minimal flexion of the operating table supported by adequate padding .
the abdominal cavity was explored using 4 port transperitoneal approach for left side operation ( a camera port at the level of umbilicus lateral to the rectus muscle , two 5 mm and one 10 mm trocars as working ports ) .
for right side operation , the same trocar arrangement was employed but another 5 mm subxiphoid port was added for liver retraction .
after incising the white line of toldt , superior retraction of spleen / liver and medial mobilization of colon ( and duodenum : on right side ) , exposure to the renal pedicle was made possible .
after complete dissection of both renal artery and vein , gerota 's fascia was incised and the kidney fully mobilized within the gerota 's fascia .
afterwards , the dilated ureter of the corresponding nonfunctioning moiety was localized and carefully dissected to the renal hilum .
care was taken not to induce ureteral devascularization of the other healthy ureter . the diseased ureter was clipped and divided at the level of lower pole and used as a handle and guide to facilitate the dissection of segmental branches of renal artery and vein which supplied the nonfunctioning moiety .
such dissection was embarked as meticulous as possible trying not to induce any ischemia and/or injury to the healthy moiety .
then , the corresponding segmental renal artery and vein were doubly clipped and divided ; the nonfunctioning renal moiety was incised and separated from the whole renal unit on the demarcated ischemic line , using a ureteric stamp as a handle which facilitated this part of the procedure .
the retroperitoneum irrigated and suctioned , hemostasis of the renal cut surface was ensured and an external drainage was placed with a tubular drain .  
all patients received prophylactic peri - operative intravenous antibiotics as of our routine program . upon ambulation ,
complete blood count and renal function tests were rechecked and assigned 6 hours after the operation as post - procedural analysis .
surgical demographics such as operative time , blood loss , early and late complications were registered .
three - month follow - up ivp was performed in all patients to assess about the functional status of the remained ipsilateral renal moiety .
ten cases ( 71.5% ) were adults and 4 cases ( 28.5% ) were children ( ages 3 , 3 , 5 , and 5 years ) . overall mean age of the patients was 24.216.8 years old ( adult age range : 18 to 52 years ; pediatric age range ( table 1 ( tab .
1 ) ) : 3 to 5 years ) . the main presenting symptoms were flank pain in 10 patients ( 71.4% ) followed by urinary tract infection in three ( 21.4% ) .
in one pediatric patient follow up of prenatal hydronephrosis confirmed the diagnosis of nonfunctioning upper pole moiety .
the atrophic part was located in the left side and in six patients ( 42.86% ) in the right side .
, sd 80 ( range 95 to 360 min ) . estimated blood loss was negligible .
differences in pre - operative and post - operative hemoglobin and creatinine were not significant .
mean hospital stay was 4.1 days ( range 2 to 7 ) .   in one patient
mild bleeding occurred due to injured abdominal wall vessels in the trocar site . on the second postoperative day the patient 's hemoglobin level dropped from 11.1 g / dl to 9.2
the patient 's abdominal wall hematoma , observed by daily ultrasonography , resolved spontaneously within one week .   on patients ' mean
follow up of 32 months there was not any pain or episodes of recurrent urinary tract infection in any case . in all patients post - operative ivps were done after 3 months .
follow - up ivps showed ipsilateral functioning moieties with an intact collecting system in all cases ( figure 1 ( fig .
2 ) ) except our first patient in whom atrophic kidney was detected . in this patient and during the renal pedicle dissection the lower pole artery was injured because of vascular anomalies .
no hypertension was detected in this case after long - term follow - up in spite of atrophic kidney .
duplication of the ureter and renal pelvis is the most common anomaly of the upper urinary tract with an incidence of 1 in 125 or 0.8% , , .
the upper moiety is frequently obstructed , poor functioning , and can become symptomatic due to urinary tract infection or flank pain .
recent advances in laparoscopic techniques have led to the selection of laparoscopic surgery for many if not most urological procedures .
the first case of a laparoscopic partial nephrectomy was reported by winfield et al . in 1992 . with further development of the technique ,
since then several reports on laparoscopic heminephrectomy have been published describing advantages , disadvantages and complications of the procedure .
based on the literature review , and regardless of applied techniques , the main complications of laparoscopic heminephrectomy are urinoma , urine leakage , recurrent urinary tract infections , postoperative hypertension , and functional loss of the remaining moiety , . in our series
just one case of functional loss of the remaining moiety was seen due to inadvertent injury of lower pole renal artery .
this complication was detected as ipsilateral renal atrophy at follow - up ivp , 3 months after operation .  
almost all of the published series reported the efficacy of the procedure in pediatric patients .
series which have exclusively studied the efficacy of the procedure in adult cases have recently been published by abouassaly et al .   and gao et al . .
in his series of 18 cases of transperitoneal laparoscopic heminephrectomy no major complication or open conversion occurred .
the mean operative time was 142 min and the mean estimated blood loss was 196 ml .
only one case of postoperative urine leakage was reported in his series that was treated with prolonged urethral catheterization .
castellan et al . published their experience in a series of 48 pediatric patients ( mean age 4.08 years ) who underwent transperitoneal and retroperitoneal laparoscopic heminephrectomy .
mean hospitals stay was 2.6 days in the transperitoneal and 2.3 days in the retroperitoneal group .
one retroperitoneal procedure required conversion to open surgery . in this largest series of laparoscopic heminephrectomy , complications were seen in 5 patients ( 10% ) , including urinary leak , urinoma , pneumothorax , recurrent urinary tract infection , and postoperative hypertension .
the authors found that laparoscopic heminephrectomy can be performed with minimal morbidity , improved cosmesis and short hospital stay .  
laparoscopic approach to heminephrectomy offers the patient the typical benefits of laparoscopy including shorter hospital stay , minimal morbidity , improved cosmesis , and lower need for analgesic use , , , , , .
improved preservation of the functioning pole of kidney could be an advantage of laparoscopy specifically mentioned in this procedure .
it is of worth noting that the objective of heminephrectomy is the safe maximal removal of the nonfunctioning moiety and simultaneous maximal preservation of the functioning pole .
laparoscopic approach enables an excellent differentiation of each hemirenal tissue , separating the ill kidney and preserving the maximal possible function for the other half - kidney .
there was not any major or minor operative complication in our series except one in which blood transfusion was needed because of trocar site hemorrhage due to injured abdominal wall vessels .
mean hospital stay was only 4 days which is much less than open series . in mean
follow up period of 32 months , the remaining kidney functioned properly ( figure 1 ( fig .
excellent visualization during laparoscopy helps better preservation of renal pedicle especially in pediatric age groups and offers a preferred approach for management of atrophic renal moieties in duplex systems .
 purpose : the standard treatment for a duplex kidney with poorly functioning upper pole moiety is ipsilateral upper pole heminephrectomy . 
 this procedure is usually performed by open surgery , but with recent developments in techniques of uro - laparoscopy , it can be done with it , safely . in this study 
 we evaluated the results and safety of laparoscopic heminephrectomy in our consecutive cases.materials and methods : from february 2001 to may 2007 fourteen unilateral laparoscopic heminephrectomy were performed in our center . 
 patients ' characteristics , presenting symptoms , operative time , and blood loss , early and late complications were all collected retrospectively . using pre - operative ultrasonography , intravenous pyelography ( ivp ) and ct scanning , 
 unilateral upper pole hydronephrosis was detected in all cases . by dmsa isotope scan hypofunctioning of ipsilateral moieties 
 was detected in all cases.results : mean operative time was 20380 minutes . 
 no major intra - operative or early complications were identified . mean hospital stay was 4.1 days . on mean follow - up of 32 months no disturbing symptoms or episodes of urinary tract infections ( utis ) were detected . 
 atrophic kidney was detected in one case in post - operative ivp.conclusion : laparoscopic heminephrectomy is a valuable minimal invasive procedure that can be performed safely in experienced hands without any important complication . 
 perfect renal pedicles vascular system manipulation is important for the preservation of renal function post - operatively . 
Introduction
Materials and methods
Surgical technique
Results
Discussion
Conclusion
Notes
Competing interests