however , their use for large upper and middle ureteral stones remains controversial . particularly with impacted stones , the success rate of swl and urs diminishes , and when the stone size exceeds 1 cm , swl efficacy decreases to from 84 to 42% . although 7% of the ureteral stones treated with endourological methods require repeated treatment , 1% 10% of such patients may need open surgery . open surgery has the advantage of a high success rate in one session for such complicated patients . because open surgery increases the length of hospital stay and requires additional analgesic treatment for the patient , laparoscopic ureterolithotomy ( lu ) it has been proposed that the success rate of lu is similar to that of open surgery and that it is superior to open surgery in reduced analgesic requirement , hospital stay , recovery , and cosmetic outcome . in this study , we analyzed the outcomes of lus performed in our clinic in patients with upper or middle ureteral stones . this study was performed with the approval of the ethics committee of bakirkoy research and training hospital . we retrospectively analyzed the data of 213 patients who underwent conventional lu for upper or middle ureteral stones from april 2006 through january 2015 in our clinic . the indications for lu were a stone > 15 mm in diameter or a history of failed swl or urs . the preoperative evaluation included a detailed history , urinalysis , urine culture , complete blood count , and biochemical analysis of serum , coagulation tests , and intravenous pyelography , computed tomography , or both . stone size was measured by using the longest axis of stone viewed on preoperative imaging ( figure 1 ) . urinary drainage was performed through either a double - j ( d - j ) catheter or a nephrostomy tube in patients who had symptoms of sepsis , acute renal failure , severe hydronephrosis , and severe pain in the preoperative period . even though we preferred the retroperitoneal approach in our clinic for lu , we used the transperitoneal approach in patients with a nephrostomy tube or a history of open retroperitoneal surgery . we have previously described the retroperitoneal lu technique in detail with its modifications . to avoid stone migration , we used a babcock clamp to grab the ureter proximal to the stone and performed all dissection cranially to caudally . ureterotomy was performed with a cold knife or a fine electrocautery hook , set at the lowest power setting . when stones migrated into the kidney during manipulation or were present in the same - side kidney , they were taken into a basket catheter by entering through the working port with a flexible cystoscope ( karl storz , tuttlingen , germany ) . stones that were not small enough to pass through the lumen of the ureter were removed after being fragmented via laser lithotripsy ( figure 2 ) . a d - j stent was not routinely applied , but was used only in cases of ureteral mucosa inflammation as a result of long - term irritation of impacted stones . all patients were mobilized and returned to oral feeding on the evening of the day of surgery . on the postoperative first day , an abdominal radiograph was performed to check for the presence of a residual stone and the condition of the d - j catheter . the drain was withdrawn on the second postoperative day if the drainage level fell below 50 ml . postoperative analgesia was not a routine procedure ; however , diclofenac sodium ( 75 mg intramuscularly ) and/or paracetamol ( 500 mg orally ) were administered if analgesia was necessary . postoperative analgesic use and visual analog scale ( vas ) for pain were evaluated on the day of surgery and on the first postoperative day . the d - j catheter was removed under local anesthesia between the second and fourth postoperative weeks . serum creatinine and urine tests were carried out in the first postoperative month , and intravenous urography was performed in the third postoperative month . the number cruncher statistical system 2007 ( kaysville , ut , usa ) was used for statistical analysis . descriptive statistics ( mean , standard deviation , median , frequency , and ratio ) were used for evaluation of the study data . the independent samples t test was used for intergroup comparison of normally distributed random variables , and the mann - whitney u test was applied for nonnormally distributed variables . the qualitative data were compared by the pearson  test and the fisher 's exact test . this study was performed with the approval of the ethics committee of bakirkoy research and training hospital . we retrospectively analyzed the data of 213 patients who underwent conventional lu for upper or middle ureteral stones from april 2006 through january 2015 in our clinic . the indications for lu were a stone > 15 mm in diameter or a history of failed swl or urs . the preoperative evaluation included a detailed history , urinalysis , urine culture , complete blood count , and biochemical analysis of serum , coagulation tests , and intravenous pyelography , computed tomography , or both . stone size was measured by using the longest axis of stone viewed on preoperative imaging ( figure 1 ) . urinary drainage was performed through either a double - j ( d - j ) catheter or a nephrostomy tube in patients who had symptoms of sepsis , acute renal failure , severe hydronephrosis , and severe pain in the preoperative period . even though we preferred the retroperitoneal approach in our clinic for lu , we used the transperitoneal approach in patients with a nephrostomy tube or a history of open retroperitoneal surgery . we have previously described the retroperitoneal lu technique in detail with its modifications . to avoid stone migration , we used a babcock clamp to grab the ureter proximal to the stone and performed all dissection cranially to caudally . ureterotomy was performed with a cold knife or a fine electrocautery hook , set at the lowest power setting . when stones migrated into the kidney during manipulation or were present in the same - side kidney , they were taken into a basket catheter by entering through the working port with a flexible cystoscope ( karl storz , tuttlingen , germany ) . stones that were not small enough to pass through the lumen of the ureter were removed after being fragmented via laser lithotripsy ( figure 2 ) . preoperative and peroperative images of the patient who had ipsilateral ureteral and renal stones . ( a ) preoperative ct imaging . a d - j stent was not routinely applied , but was used only in cases of ureteral mucosa inflammation as a result of long - term irritation of impacted stones . all patients were mobilized and returned to oral feeding on the evening of the day of surgery . on the postoperative first day , an abdominal radiograph was performed to check for the presence of a residual stone and the condition of the d - j catheter . the drain was withdrawn on the second postoperative day if the drainage level fell below 50 ml . postoperative analgesia was not a routine procedure ; however , diclofenac sodium ( 75 mg intramuscularly ) and/or paracetamol ( 500 mg orally ) were administered if analgesia was necessary . postoperative analgesic use and visual analog scale ( vas ) for pain were evaluated on the day of surgery and on the first postoperative day . the d - j catheter was removed under local anesthesia between the second and fourth postoperative weeks . serum creatinine and urine tests were carried out in the first postoperative month , and intravenous urography was performed in the third postoperative month . the number cruncher statistical system 2007 ( kaysville , ut , usa ) was used for statistical analysis . descriptive statistics ( mean , standard deviation , median , frequency , and ratio ) were used for evaluation of the study data . the independent samples t test was used for intergroup comparison of normally distributed random variables , and the mann - whitney u test was applied for nonnormally distributed variables . the qualitative data were compared by the pearson  test and the fisher 's exact test . the mean patient age was 39.3  12.0 years , with a range between 16 and 67 years . there were 135 ( 63.3% ) male and 78 ( 26.7% ) female patients in the study . stones were located in the right side in 134 ( 62.9% ) patients , and were located in the left side in 79 ( 37.1% ) patients . of the 213 patients , 178 ( 83.5% ) had upper ureteral stones , and 35 ( 16.% ) had middle stones . lu was performed on 174 patients with the primary indication of stone size > 15 mm . the size of the stones varied from 12 to 25 mm among the patients ; the mean stone size was 19.7  2.5 mm . the retroperitoneal approach was used in 170 ( 79.8% ) patients , the transperitoneal approach was used in the remaining 43 ( 20.2% ) . in the transperitoneal group , 32 of the 43 patients had a nephrostomy catheter . urinary drainage rate was significantly higher in the transperitoneal group ( p < .01 ) . moreover , 13 patients who had a history of open abdominal surgery were treated with the retroperitoneal approach . there were significant differences among groups regarding the mean age ( p < .01 ) : the transperitoneal group was significantly older . no statistically significant difference was found between groups regarding gender distribution ( p > .05 ) . the body mass index measurements , stone size , stone location , failed swl rate , and failed urs rate did not reveal any significant difference between groups ( p > .05 ) . the mean operative time was 80.9  10.9 minutes , whereas the mean blood loss was 63.3  12.7 ml . the procedure was converted to open surgery in one ( 1% ) patient because of an aberrant vessel . in another patient , the ureteral stone migrated to the kidney and a d - j stent was placed , and the stone was removed in 3 swl sessions . after that surgery , we used flexible cystoscopy through a working port and removed the stones with a basket catheter in the other 23 patients : 4 had stone migration into the kidney and 19 had kidney stones in addition to ureteral stones . the stones were removed after fragmentation via laser lithotripsy in 4 patients owing to large stone size . the stone - free rate did not differ among groups ( p > .05 ) . operative time was found to be significantly longer in the transperitoneal group ( p < .01 ) . moreover , the number of patients requiring d - j stenting was significantly higher in the transperitoneal group ( p < .01 ) . in addition , length of hospital stay and time to return to daily activities were significantly longer in the cases of transperitoneal surgery ( p < .01 ) . vas scores were higher in the transperitoneal group compared with those in the retroperitoneal group on the day of surgery and first postoperative days ( p < .01 ) . table 2 presents detailed information regarding the intraoperative and postoperative data . operative and postoperative data data are the mean [ plus / minus ] sd , unless otherwise stated independent - samples test . gonadal vein injury was controlled with an endoclip in 4 patients . in 4 retroperitoneal cases , inadvertent peritoneotomy was observed and treated through enlargement of the peritoneal tear to equalize the pressure in 2 compartments . although the drainage stopped on the fifth postoperative day in 7 patients , 3 patients required d - j stenting . antibiotic therapy was administered to 4 patients with postoperative fever and 1 patient with port - site infection . no ureteral stricture was encountered during follow - up . although no significant difference was observed between groups regarding complications ( p > .05 ) , only the ileus rate was significantly higher in the transperitoneal group ( p < .01 ) . the first retroperitoneal ureterolithotomy was performed in 1979 by wickham , and the first transperitoneal ureterolithotomy was performed in 1992 by raboy et al . in several studies lu showed a > 95% success rate in the treatment of large ureter stones . according to the european association of urology guidelines on urolithiasis , large impacted ureteral stones , failure of minimally invasive procedures , different operative requirements for a concurrent indication , and technological deficiency are considered to be indications for performing lu . ko et al compared lu with rigid ureteroscopy as the primary treatment modality for large upper ureteral stones and found the stone - free rate after a single session to be significantly higher in the lu group ( 93% vs 68% ) . neto et al compared laparoscopy , swl , and rigid urs and found success rates of 93 , 35 , and 62% , respectively . ozturk et al reported that laparoscopy , swl , and flexible urs had 81 , and 79% success rates , respectively regarding treatment of large ureteral stones . these results may prove that lu is associated with higher success rates and lower requirement for auxiliary procedures . lu has been proposed as the primary treatment method for larger ureteral stones , especially in developing countries , where endourological technologies are expensive . our previous study , in which a single surgeon 's 6-year experience was reported , compared flexible urs and urs for upper ureteral stones > 15 mm . although laparoscopy cases did not require additional intervention , 11 patients who underwent ureteroscopy required an additional procedure . in this series of 213 cases , we could not reach the stone , so a d - j catheter was inserted and the stone was removed subsequently during multiple swl sessions . after that patient , we had 23 patients4 with stone migration into the kidney and 19 with kidney stones besides ureteral stones  who underwent flexible cystoscopy through a working port stone removal . in this series , only 1 patient needed conversion to open surgery because of an aberrant vessel . however , compared with several series that reported open conversion rates , our series resulted in lower conversion rates . the transperitoneal approach is advantageous because it provides a wider working space , better visibility , and better identifiable anatomical landmarks . conversely , there is no need for colon mobilization and , the risk for visceral organ injury is lower in the retroperitoneal approach . in addition , the risk for contamination of the peritoneal cavity caused by postoperative urinary leakage and the rate of postoperative ileus are lower in this approach . . nevertheless , it may be difficult to perform retroperitoneal lu in the patients with a nephrostomy tube or those with a history of open retroperitoneal surgery . in these patients , , we observed that both approaches provided high stone - free rates , but the retroperitoneal approach seems superior because of shorter operative time and faster postoperative recovery . however , morbidity does not increase as long as the urine is drained and remains noninfected . kijvikai and patcharatrakul emphasized suturing of the ureter to be an essential stage of the procedure . bellman and smith , conversely , reported no need for incision suturing as long as the incision is small and the preoperative urine is sterile . karami et al compared the patients with a d - j stent with those without a d - j stent , and reported that the presence of the d - j stent significantly decreased complication rates without increasing operative time . alternatively , hammady et al compared the outcomes of patients with stents versus no stents and reported lower analgesic requirement , shorter operative time , and lower cost  in favor of stenting . kijvikai and patcharatrakul recommended stenting only for prolonged impacted ureteral stones and for patients who could not receive ureteral sutures because of chronic inflammation of the ureteral mucosa . we placed d - j stents only in the presence of impacted stones or intensive inflammation of the ureter wall . et al , the rate of ureteral stricture was found to be 2.5% . in the present series , ureteral stricture was not detected in any of the patients through intravenous pyelography follow - ups after 3 months . the correlation of the development of ureteral stricture with dilation  closure of the ureter is questionable . nouira et al argued that a cold knife should be used to make an incision in the ureter to prevent ureteral stricture . gaur et al indicated in their large series that ureter incision with an electric hook in cutting mode would be easier and safer to perform . harewood et al claimed that the use of diathermy hook electrode is a reliable method for opening the ureter . we used a cold knife for our first cases , but then began using a monopolar hook for incision in light of the data provided by the aforementioned series . nouira et al stated that too - tight sutures may create ischemia on the wall , resulting in ureteral strictures , and argued that the main goal of the suturing method should be to ensure water resistance and approximation of the ureter ends to facilitate healing . nevertheless , kijvikai and patcharatrakul did not encounter ureteral stricture during their 6-month follow - up in their cases with watertight suturing . mitchinson and bird suggested that prolonged urinary leakage may result in retroperitoneal fibrosis and ureteral strictures . because of the increased visibility provided by laparoscopy , we can approximate the mucosal edges during ureteral suturing in a more accomplished fashion . we believe that , in this way , we may decrease both the urinary leakage and stricture rates . owing to these findings , including the high prevalence of urolithiasis in turkey , with our clinic 's position as the reference center , social factors , and patient preference , we frequently perform lu . to our knowledge , this is one of the largest series in literature of a single - surgeon experience on laparoscopic ureterolithotomy . the retrospective nature of the study and short - term follow - up are the limitations of the study . even though swl and urs are considered to be the first - line treatment options for ureteral stones , retroperitoneal or transperitoneal lu can be established as an effective and reliable method , particularly in cases with large impacted stones and failure of the first - line treatments .
background and objective : the present study retrospectively analyzed the data of 213 patients who underwent laparoscopic ureterolithotomy.methods:we retrospectively analyzed the data of 213 patients , in whom we performed conventional laparoscopic ureterolithotomy from april 2006 and january 2015 based on the diagnosis of an upper or middle ureteral stone . 
 patients with large ureteral stones ( > 15 mm ) or a history of failed shock - wave lithotripsy or ureteroscopy were included in the study . 
 although the retroperitoneal approach was preferred for 170 patients , the transperitoneal approach was used in the remaining 43 patients.results:the mean patient age was 39.3  12.0 years ( range , 1873 ) . 
 the study population was composed of 78 ( 26.7% ) female and 135 ( 63.3% ) male patients . 
 the mean stone size was 19.7  2.5 mm . 
 the mean operative time was 80.9  10.9 minutes , and the mean blood loss was 63.3  12.7 ml . 
 intraoperative insertion of a double - j catheter was performed in 76 patients . 
 the overall stone - free rate was 99% . 
 no major complication was observed in any patient . 
 however , conversion to open surgery was necessary in 1 patient.conclusion:with high success and low complication rates , laparoscopic ureterolithotomy is an effective and reliable method that ensures quick recovery and may be the first treatment option for patients with large , impacted ureteral stones , as well as for those with a history of failed primary treatment .