ureteropelvic anastomosis is the most important step in pyeloplasty and has a large bearing on its success rate .
although continuous sutures are more watertight compared with interrupted sutures , the possibility of seeing the purse - string effect and tissue damage may be a concern .
we present the results of our retrospective analysis of the effects and outcome of continuous and interrupted sutures during laparoscopic pyeloplasty .
we retrospectively reviewed all patients who underwent laparoscopic pyeloplasty at our center from june 1998 to march 2012 .
all procedures were performed by a single surgeon with > 3 years of prior laparoscopic suturing experience .
twenty - two patients were excluded from the study : 8 patients who underwent transperitoneal but nondismembered pyeloplasty ( which included 3 redo nondismembered pyeloplasties ) , 9 patients who underwent retroperitoneoscopy , 2 patients who underwent redo dismembered pyeloplasty , and 3 infants who underwent laparoscopy - assisted pyeloplasty ( pelvis and ureter brought out through a 10-mm flank port for extracorporeal anastomosis ) .
the initial 65 patients ( until december 2007 ) underwent anastomosis using interrupted sutures , and the latter 42 patients had continuous sutures .
all patients had a preoperative ultrasonogram , intravenous urogram or computed tomography urogram , and diuretic renogram ; a sterile urine culture before surgery ; and an indwelling ureteric stent placed during surgery .
patients were followed up with a urine culture and diuretic renogram at 6 months and then annually for 5 years .
data on the operation time , suturing time , drain quantity , hospital stay , success rate ( based on renogram done at 6 months ) , complications , and the overall cost of the procedures were analyzed .
the cost analysis was done using the methodology of converting historic cost into present values and applying average rates of inflation in india obtained from the consumer price index .
the cost included the combined costs of hospital stay , operation charges , and drug charges .
fvschedule ,  which is designed to calculate future values as they relate to current values . the statistical analysis using student t test to assess the level of significance was done with spss 20.0 software ( spss , inc./ibm , armonk , new york ) . while under general anesthesia
, the patient was placed in the lithotomy position and a retrograde pyelogram was done to assess the length of the adynamic segment of the ureteropelvic junction ( upj ) and ureter .
a stent was not placed at the same time because it would have been a hindrance for spatulation .
four ports were used ( 10-mm port 3 cm above and lateral to the umbilicus for the camera ; two 5-mm ports in the midclavicular line in the subcostal region and iliac fossa , and the fourth port in the anterior axillary line for suction or irrigation ) ( figure 1 ) . for the transperitoneal approach ,
the proximal ureter was mobilized , with care taken to preserve the vascularity and crossing vessels if present . in patients with left upj obstruction ,
if the vascular pattern of the mesocolon was conducive and if the fat in the mesentery was minimal , the upj was dissected using the transmesocolic approach .
the size of the suture used depended on the age of the patient : 4 - 0/5 - 0 polyglactin and 4 - 0/5 - 0 polydioxanone sutures were used for interrupted and continuous sutures , respectively .
the posterior layer suturing was done initially ( figure 2 ) , followed by antegrade stent insertion ( figure 3 ) .
sutures were equidistant in both the continuous and interrupted sutures . in both the continuous suture group and the interrupted suture group ,
postoperatively , the urethral catheter was removed on the second or third day once the urine cleared .
the tube drain was removed if the drainage was < 20 ml per day and if there was no perirenal or intraperitoneal collection on ultrasonography .
the procedure was defined as successful if there was an improvement or stabilization of the renal function and improved drainage ( based on the measurement of glomerular filtration rate [ gfr ] and t on isotope renogram postoperatively ) , along with relief of symptoms .
while under general anesthesia , the patient was placed in the lithotomy position and a retrograde pyelogram was done to assess the length of the adynamic segment of the ureteropelvic junction ( upj ) and ureter .
a stent was not placed at the same time because it would have been a hindrance for spatulation .
four ports were used ( 10-mm port 3 cm above and lateral to the umbilicus for the camera ; two 5-mm ports in the midclavicular line in the subcostal region and iliac fossa , and the fourth port in the anterior axillary line for suction or irrigation ) ( figure 1 ) . for the transperitoneal approach ,
the proximal ureter was mobilized , with care taken to preserve the vascularity and crossing vessels if present . in patients with left upj obstruction ,
if the vascular pattern of the mesocolon was conducive and if the fat in the mesentery was minimal , the upj was dissected using the transmesocolic approach . the upj was dismembered and the ureter spatulated laterally using scissors without using diathermy .
the size of the suture used depended on the age of the patient : 4 - 0/5 - 0 polyglactin and 4 - 0/5 - 0 polydioxanone sutures were used for interrupted and continuous sutures , respectively .
the posterior layer suturing was done initially ( figure 2 ) , followed by antegrade stent insertion ( figure 3 ) .
sutures were equidistant in both the continuous and interrupted sutures . in both the continuous suture group and the interrupted suture group ,
postoperatively , the urethral catheter was removed on the second or third day once the urine cleared .
the tube drain was removed if the drainage was < 20 ml per day and if there was no perirenal or intraperitoneal collection on ultrasonography .
the procedure was defined as successful if there was an improvement or stabilization of the renal function and improved drainage ( based on the measurement of glomerular filtration rate [ gfr ] and t on isotope renogram postoperatively ) , along with relief of symptoms .
sixty - five patients had interrupted suturing and 42 patients had continuous suturing for pelviureteric anastomosis .
twelve patients had crossing vessel ( 7 in the interrupted suturing group and 5 in the continuous suturing group ) .
six patients had secondary renal pelvic calculi ( 4 in the interrupted suturing group and 2 in the continuous suturing group ) .
patient demographic characters and preoperative gfr the mean operative time was 219 minutes ( range , 180240 ) for the interrupted suturing group patients and 186 minutes ( range , 135225 ) for the continuous suturing group patients . in the interrupted suturing group , anastomosis was done using 4 - 0 or 5 - 0 vicryl interrupted sutures for the pelviureteric anastomosis . in the continuous suturing group , continuous 4 - 0 or 5 - 0 polydioxanone sutures were used for the anastomosis .
operative and postoperative details the mean drain output ( 108 ml vs 175 ml ) , drain tube retention ( 2.8 days vs 4.2 days ) , and duration of hospitalization ( 2.7 days vs 4.6 days ) were significantly less in the continuous suturing group compared with the interrupted suture group ( table 2 ) .
the overall cost of the procedure was reduced among the continuous suturing group ( mean 59 530 indian rupees [ 1101 usd ] vs 55 760 indian rupees [ 1031 usd ] ; p < .001 ) .
the complication rate was 15.38% in the interrupted suturing group and 7.14% in the continuous suturing group ( tables 3 and 4 ) .
the end of the stent extruded through the suture line , and in the other patient the stent came out during removal of the urethral catheter . in the first patient ,
the stent was replaced , but the patient developed a stricture and underwent an open re - pyeloplasty . in the other patient , stent replacement was also done , and there was also an unfavorable outcome .
fungal pyelonephritis developed in one patient in the continuous suturing group ; he was both obese and diabetic .
he had extravasation and prolonged ileus , which resulted in partial anastomotic disruption and he required an open re - pyeloplasty .
one child in the continuous suturing group had omental protrusion through the drain site after drain removal , which required reduction under anesthesia .
complications grading ( clavien  dindo classification ) the mean duration of follow - up was 78 months ( range , 156 months to 6 months ) .
overall , 5 patients had failure of pyeloplasty . among them , 3 patients were in the interrupted suturing group and 2 were in the continuous suturing group . among the 3 failed pyeloplasties in the interrupted suturing group , one patient preferred repeated long - term ureteric stenting and 1 patient underwent open re - pyeloplasty .
one 3-year - old child who had gross hydronephrosis with a gfr of 15 ml / min had deterioration of gfr ( 3 ml / min ) over 2 years after pyeloplasty .
the 2 failed pyeloplasty in continuous suturing group , 1 had laparoscopic redo pyeloplasty and 1 patient had open redo pyeloplasty .
pyeloplasty comprises most of the laparoscopic procedures done at our center ( 22% of all the laparoscopic urological procedures performed at our center ) .
we use freehand suturing for laparoscopic pyeloplasty . for the initial 65 patients ( 60% ) , interrupted sutures with intracorporeal knotting
were used ( interrupted suturing group ) , and for the subsequent 42 patients ( 40% ) , continuous sutures using polydioxanone ( nonbraided suture ) were used ( continuous suturing group ) .
the effect of continuous and interrupted sutures with regards to tissue vascularity and collagen damage is controversial .
most of the experimental studies were done in laboratory animals and mainly involved bowel anastomoses .
sarin et al concluded that there was no significant increase in the incidence of leak or tissue damage with continuous sutures , although previous reports suggest that there can be vascular compromise with continuous suturing .
margo et al compared continuous and interrupted suturing techniques for ureteroneocystostomy in cats and inferred that continuous suturing causes more tissue ischemia and necrosis .
kass et al have suggested using interrupted sutures , especially for pyeloplasty in infants , to prevent the purse - string effect .
another difficulty with using continuous sutures in laparoscopy is maintaining appropriate tension during the procedure .
when braided polyglactin sutures are used for continuous suturing , tightening of the suture after 3 or 4 continuous sutures may become difficult .
the memory of nonbraided sutures can sometimes be a hindrance , but the advantage is that the sutures could be appropriately tightened at any stage .
haudart et al studied continuous and interrupted sutures in bowel anastomosis and concluded that there is no difference in the leak rate between the 2 types of anastomosis .
bruch et al reported that single - layer continuous suturing could be accomplished in bowels in less time and at a lower cost . in a study on porcine models ,
leiber et al concluded that interrupted sutures were more often associated with extensive muscular fibrosis compared with continuous suturing .
the improvement in gfr among patients in the interrupted suturing group was 4.6 ml / min and in the continuous suturing group was 4.7 ml / min .
however , reports of large studies of laparoscopic pyeloplasty by rassweiler et al and teber et al , wherein continuous sutures have been used , show comparable outcomes and complication rates .
indicate that the suturing time is not significantly different between standard suturing and self - retaining barbed sutures .
self - retaining barbed sutures are more frequently used for vesicourethral anastomosis during laparoscopic radical prostatectomy .
the mean suturing time was considerably reduced using continuous sutures , from 64 minutes ( range , 5580 ) to 55 minutes ( range , 5065 ) ( p < .001 ) .
papalia et al and shao et al have also mentioned similar findings in a study comparing interrupted and continuous sutures .
however , papalia et al mentioned that the reduction in operative time was related to the combined use of continuous suture and retrograde stenting .
drain volume and its relation to the continuous or interrupted suture were not studied . in our study , all patients had antegrade stenting .
if a large redundant pelvis needs to be sutured , the time taken would be longer .
the presence of secondary calculi may also prolong the procedure . the time taken for stenting may also vary from patient to patient .
recently , a few reports of robot - assisted pyeloplasty have been published and show no difference in all the parameters , even though suturing may be easier .
the volume of drainage was significantly less in the continuous suturing group , and hence the drain tube was retained for a shorter period ( mean , 2.8 days for the continuous suturing group vs 4.2 days for the interrupted suturing group , p < .001 ) .
this may be caused by less leakage from the suture line with the use of continuous sutures .
reduced drain output also had an impact on the duration of hospitalization ( 2.7 days vs 4.6 days in favor of continuous sutures ; p < .001 ) , because many of the patients preferred to be discharged after the drain was removed .
the overall cost of the procedure was less among the continuous suturing group patients ( mean , 59 530 indian rupees or 1101 usd vs 55 760 indian rupees or 1031 usd ; p < .001 ) .
the reduced overall cost of the surgery for the continuous suturing group patients may be attributed to the reduced duration of surgery and hospitalization and fewer complications .
shao et al mention that the incidence of urine leak was negligible in the continuous suturing group .
however , the mean hospital stay was 6 days in their study vs a mean stay of 2.7 days in the continuous suturing group in our study .
similarly , papalia et al mention that one patient had a significant leak in the continuous suturing group .
however , no comparison was made between the volume of drainage output and its impact on the hospital stay , as in our study .
the urinary leak and drain output are more relevant to the transperitoneal approach than the retroperitoneal approach . in the study by shao et al ,
however , all of the procedures were done by a single surgeon with 3 years of laparoscopic suturing experience .
ureteropelvic anastomosis using the continuous suturing technique has a comparable success rate with that using interrupted suturing .
the time taken for suturing , postoperative drain output , and duration of drainage were lower , hence the duration of hospitalization was significantly less with continuous suturing .
continuous suturing may be preferred to interrupted suturing for ureteropelvic anastomosis in patients undergoing laparoscopic pyeloplasty .
 background : laparoscopic pyeloplasty is one of the most common reconstructive procedures performed by urologists . 
 both continuous and interrupted sutures are being practiced for ureteropelvic anastomosis . the success rate and the complications associated with the suturing technique needs evaluation . 
 we analyzed the results from of our patients who underwent laparoscopic pyeloplasty using both techniques.objective:to review the outcome differences among patients undergoing laparoscopic pyeloplasty regarding suturing technique.materials and methods : all patients who underwent laparoscopic , transperitoneal dismembered pyeloplasty of the primary pelviureteric obstruction were analyzed . 
 the primary outcome was successful pyeloplasty , as assessed by the resolution of symptoms and t < 10 minutes . 
 the secondary outcomes were the complication rate and the operative parameters . 
 the difference in the parameters was assessed by student t test analysis.results:of the 107 patients we studied , 65 had interrupted suturing and 42 had continuous suturing . 
 the success rate was not significantly different among the 2 groups . 
 the mean suturing time , postoperative drainage volume , postoperative hospital stay , and total cost of the procedure were significantly less in the continuous suturing group.conclusion:the continuous suturing technique is preferred over the interrupted suturing technique for laparoscopic pyeloplasty because the success rates are equal and the postoperative stay , suturing time , drain output , and cost of the procedure are better . 
INTRODUCTION
MATERIALS AND METHODS
Operative Technique
RESULTS
DISCUSSION
CONCLUSION