although endourological management can be a first - line treatment for ureteropelvic junction obstruction ( upjo ) , its indications are limited and its success rate does not exceed 80% .
open pyeloplasty has a high success rate of 90% in long - term follow - up results .
laparoscopic pyeloplasty , which was first introduced in 1993 , is minimally invasive , like endourological management , and has a high success rate , like open pyeloplasty .
however , the long - term follow - up results of laparoscopic pyeloplasty are unclear , as are its indications and limitations .
we present our experience with long - term follow - up of laparoscopic pyeloplasty and identify the risk factors for failure of the technique .
a single surgeon performed 107 laparoscopic pyeloplasties between december 2001 and december 2013 . of these patients , 65 who underwent standard laparoscopic pyeloplasties with transperitoneal approaches and who were followed up for more than 12 months were enrolled in this study .
exclusion criteria were retroperitoneal approaches , concomitant stone surgery , insufficient follow - up study , and short follow - up time .
the 65 patients comprised 35 males and 30 females with a mean age of 45.0219.47 years ( range , 11 - 76 years ) .
the patients ' mean body mass index was 23.343.14 kg / m ( range , 17.69 - 30.59 kg / m ) .
twenty - one patients ( 32.3% ) had undergone previous abdominal surgeries , including 10 patients who had undergone open pyeloplasty and endopyelotomy .
mean stricture length was 1.060.82 cm ( range , 0.2 - 3.7 cm ) on intravenous pyelography ( ivp ) or retrograde pyelography .
the degree of hydronephrosis on ultrasonography was grade 1/4 ( n=5 ) , grade 2/4 ( n=10 ) , grade 3/4 ( n=36 ) , and grade 4/4 ( n=14 ) .
all patients had more than 15% of split renal function on a 99mtc mercaptoacetyltriglycine ( mag-3 ) renal scan , and an obstructive pattern ( t1/2 of more than 20 minutes ) was present in 53 patients ( 81.5% ) .
the type of laparoscopic pyeloplasty was chosen at the surgeon 's discretion on the basis of radiologic findings .
palpation of the indwelling guidewire helped to identify the course of the ureter to the upj .
the upjo area was transected by using scissors and a redundant pelvis could be excised if necessary .
the proximal end of the guidewire was pulled from the pelvis , and then a double - j ureteral stent was inserted over the guidewire .
a 4 - 0 or 5 - 0 vicryl suture was placed between the spatulated ureter and the renal pelvis from the posterior side to the anterior side .
if an anterior lower pole vessel was encountered , it was transposed behind the renal pelvis .
radiologic success was defined as imaging of a patent upj on ivp and resolution of obstruction on a mag-3 renal scan .
patient baseline characteristics ( age , body mass index , abdominal operation history ) , anatomical parameters ( stricture length , ipsilateral renal function using radioisotope uptake , degree of hydronephrosis , presence of crossing vessel ) , and operative parameters ( operation time , blood loss , drained amount ) were evaluated to assess the relationship to failure of laparoscopic pyeloplasty .
19.0 ( ibm co. , armonk , ny , usa ) . for the mann - whitney test and fisher exact test , p<0.05 was considered to indicate statistical significance .
fifty - seven patients were treated by dismembered anderson - hynes pyeloplasty and eight patients by fenger pyeloplasty . during the operation ,
mean estimated blood loss was 973.13335.87 ml ( range , 489 - 2152 ml ) , and six patients ( 9.2% ) required transfusion .
although there were no cases of open conversion , one patient had an ascending colon injury that was detected postoperatively and repaired .
the mean starting time of postoperative ambulation and diet was 1.540.64 days ( range , 1 - 3 days ) and 1.861.41 days ( range , 1 - 3 days ) , respectively .
the mean follow - up period was 36.5 months ( range , 12 - 111 months ) .
the follow - up ivp and 99mtc - mag3 renal scans showed improvements in 59 patients ; the radiologic success rate was 90.8% .
eight patients showed failure on radiologic or symptomatic evaluation , and the overall success rate was 87.7% . among the six patients with radiologic failure ,
one patient was treated with endopyelotomy at 7 months postoperatively and one patient was treated by use of robotic pyeloplasty at 24 months postoperatively .
we studied differences in variables between the success group ( group i ) and the failure group ( group ii ) to try to identify risk factors for failure .
drained amount was only the risk factor related to overall failure of laparoscopic pyeloplasty ( table 1 ) .
upjo is defined as an anatomic or functional impedance of urine flow from the renal pelvis into the ureter .
upjo is caused by a congenital intrinsic narrowing of the lumen or by external compression .
several reconstructive procedures have been described for the management of upjo since trendelenburg 's first description . after anderson and hynes described a modified dismembered technique in 1949 , open pyeloplasty was reported in large series and became a standard treatment option for upjo because of its high success rate . however , the morbidity associated with flank incision was a serious problem and led to the development of minimally invasive surgery .
endopyelotomy was initially described in the early 1900s , and the concept of davis intubated ureterotomy was applied .
the procedure has evolved dramatically during the past three decades with the advent of minimally invasive treatments for upjo , compared with standard open pyeloplasty .
cold - knife , electrocautery , and holmium laser incision are used to incise the obstruction , and a ureteral cutting balloon ( acucise , applied medical resources , laguna hills , ca , usa ) is also used . however , antegrade or retrograde outcomes vary from 65% to 94% , which is mainly determined by surgeon 's experience and causes of upjo .
laparoscopic pyeloplasty was introduced for the treatment of upjo to decrease operative morbidity and maintain the high success rate of open pyeloplasty .
it was first performed in 1993 , and its rate of use has increased dramatically to overtake open pyeloplasty . it is now considered a standard treatment for upjo and has a success rate of about 90% with less invasiveness .
however , it remains hampered by technical difficulties , a steep learning curve , and the absence of long - term operative results .
although open , endoscopic , and laparoscopic treatment options with acceptable success rates can be applied to most cases of upjo , long - term follow - up results are needed to confirm the approach as the gold standard of treatment .
reported a success rate of 67% in a 55-month follow - up of antegrade endopyelotomies .
reported a recurrence - free survival rate of 41% in antegrade endopyelotomies over 10 years .
yanke et al .   also reported a 60% success rate in retrograde endopyelotomies at 20 months .
recommended that patients who undergo endopyelotomy be observed for at least 36 months , because some failures do not become apparent until that point .
madi et al .   reported an 81% success rate for the long - term success of laparoscopic pyeloplasty for primary upjo . in that study
varkarakis et al .   also emphasized longer follow - up after laparoscopic pyeloplasty . in their failures
they did repeat pyeloplasty , balloon dilatation , and endopyelotomy as a secondary treatment , and these were performed a mean of 18.5 months after the first laparoscopic pyeloplasty .
presented long - term outcomes of laparoscopic pyeloplasty in 132 patients with a follow - up of 18 to 108 months .
the average operative time was 127 minutes and the overall success rate was 96% . however , that was a multicenter study with five surgeons and four different techniques . in the present study
, we present the long - term , follow - up results of laparoscopic pyeloplasty in a single surgeon 's experience .
the mean follow - up period was 36.5 months and radiologic , symptomatic , and overall success rates were 92.3% , 94.7% , and 87.7% , respectively . among the eight patients with failed laparoscopic pyeloplasty ,
three patients underwent operative management including open and robotic pyeloplasties , which were performed at a mean of 25.7 months after the primary laparoscopic pyeloplasty .
our long - term , follow - up results confirm the efficacy of laparoscopic pyeloplasty as a standard treatment for upjo and also confirm the possibility of late failure .
although laparoscopic pyeloplasty can be applied to most situations in contrast with endoscopic management , it may have risk factors that affect the operative result .
suggested that the success rate of laparoscopic pyeloplasty was not associated with age , body mass index , american society of anesthesiologists ( asa ) score , side , gender , horseshoe kidney , coexisting stone , presence of ureteral stent preoperatively , presence of preoperative symptoms , preoperative differential renal function , presence of crossing vessel , type of crossing vessel , attending surgeon , primary operating surgeon , case order , or operative time .
.   revealed that 18 patients with failed laparoscopic pyeloplasty were more likely to have diabetes mellitus , longer length of stay , higher asa score , a stent placed at the time of pyeloplasty , or ureteral stent malfunction .
we tried to find factors that affected the failure rate of laparoscopic pyeloplasty , such as patient factors , anatomical factors , and operative factors . in our study ,
second , because the data were from a single institution , the number of patients was not large .
we present an excellent success rate in these long - term follow - up results of laparoscopic pyeloplasty , which suggests this as a standard treatment for upjo .
we found that drained amount was the only risk factor related to failure of laparoscopic pyeloplasty .
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 purposeto assess the long - term follow - up results of laparoscopic pyeloplasty for ureteropelvic junction obstruction.materials and methodssixty - five patients ( mean age , 43.8 years ) who underwent standard laparoscopic pyeloplasty by transperitoneal approaches were enrolled in this study . 
 the chief complaint was flank pain ( n=57 patients ) ; the remaining cases were detected incidentally . 
 twenty - three patients had undergone previous abdominal surgeries , including open pyeloplasty and endopyelotomy . 
 mean stricture length was 1.06 cm . 
 grade 3/4 and 4/4 hydronephrosis was detected in 36 and 14 patients , respectively . 
 an obstructive pattern was present on the renal scan in 53 patients ( 81.5%).resultsfifty - seven patients were treated with dismembered anderson - hynes pyeloplasty and eight patients with fenger pyeloplasty . during the operation , crossing vessels were found in 27 patients ( 41.5% ) . 
 mean operating time was 159.42 minutes . 
 although there were no cases of open conversion , two patients with colon and spleen injuries were detected postoperatively . 
 the mean starting time of postoperative ambulation and diet was 1.54 days and 1.86 days , respectively . 
 mean hospital stay was 8.09 days . 
 mean follow - up period was 36.5 months . follow - up intravenous pyelography and renal scan showed improvements in 59 patients , and the radiologic success rate was 90.8% . 
 eight patients showed failure on radiologic or symptomatic evaluation , and the overall success rate was 87.7% . 
 in the comparative analysis between the success and failure groups , drained amount was the only risk factor related to failure ( 554.41 ml . vs. 947.70 ml , 
 p=0.024).conclusionslong - term follow - up results support laparoscopic pyeloplasty as the standard treatment for ureteropelvic junction obstruction . 
 drained amount is a risk factor for failure of the operation . 
INTRODUCTION
MATERIALS AND METHODS
RESULTS
DISCUSSION
CONCLUSIONS
SUPPLEMENTARY MATERIALS