U J - Spring 2012.pdf 457Vol. 9 | No. 2 | Spring 2012 |U R O LO G Y J O U R N A L 2nd Department of Urol- ogy, Sisli Etfal Training and Research Hospital, Istanbul, Turkey Orhan Tanriverdi, Mesrur Selcuk Silay, Mustafa Kadihasanoglu, Mustafa Aydin, Muammer Kendirci, Cengiz Miroglu Revisiting the Predictive Factors for Intra-Op- erative Complications of Rigid Ureteroscopy A 15-Year Experience Corresponding Author: Mesrur Selcuk Silay, MD Sisli Etfal Egitim ve Ara- stirma Hastanesi, 2. Uroloji Klinigi, 34360, Istanbul, Turkey Tel: +90 212 231 2209 Fax: +90 212 233 9876 E-mail: selcuksilay@gmail. com Received August 2011 Accepted October 2011 Endourology and Stone Disease Purpose: To revise the predictive factors for intra-operative complications of rigid ureteroscopy in the treatment of ureteral calculi. Materials and Methods: consecutive patients who had undergone 1660 ureteroscopy procedures were retro- spectively reviewed. After exclusion of the cases for diagnostic purposes, diseases other than ureteral calculi, and repeated ureteroscopy procedures, 1189 patients were left as the study population. Those patients were then divided into two groups based regarding patients’ age and gender, stone surface area, lateralization and localization of the stone, impaction of the stone, type of the ureteroscope, necessity of ureteral effect of leaving the fragmented stones in situ small enough to pass spontaneously Results: - surface area, lateralization, and type of lithotripter used were comparable between the groups, but impacted stones and the stones located at the upper ureters were as- less complication has been observed in cases where we performed break’n’leave. Furthermore, multivariate analysis revealed that stone impaction and failure to ad- here to the “break’n’leave” principle were the independent predictors of occurring of the complications. Conclusion: Ureteroscopy is safe and effective in the treatment of ureteral calculi. Careful attention for the patients having a potential for occurrence of the complica- tions and selection of the techniques are of importance for reducing untoward events. Keywords: ureteroscopy, complications, retrospective studies, ureteral calculi, lith- otripsy 458 | Endourology and Stone Disease INTRODUCTION Technical advances in the design of uretero-scopes have encouraged urologists for the for the treatment of ureteral calculi or for some diagnostic approaches. Continuously, evolving - ious baskets and stents, and improvements in the ability of stone fragmentation have broadened the indications of URS and upgraded this procedure location of the collecting system of the urinary tract. The competitions among URS, extracorpore- - renal surgery, and percutaneous nephrolithotomy subject of numerous publications in the last dec- ade, maintaining the debate among urologists. Unfortunately, surgical misadventures may still occur, some of which have lasting consequences. The nature of the ureteroscopic complications is well-known, but the predictive factors are still a question that has yet to be clearly elucidated. Care- ful attention to the selection of the instruments and techniques are of importance for reducing unto- ward events related to ureteroscopic procedures. Furthermore, the ultimate technologies are still not available in the majority of the urological centers in developing countries that make rigid or semi- rigid URS the best cost-effective option for the urologists. Frankly, patients having a potential for occurrence of the complications should be well- discriminated and addressed to different treatment modalities, such as SWL, PNL, laparoscopy, or multimodal approaches. Our aim is to report the predictive factors related to the occurrence of intra- operative complications during URS procedures in the treatment of ureteral calculi. MATERIALS AND METHODS 1660 URS procedures were retrospectively ana- lyzed. After exclusion of the cases for diagnostic purposes, diseases other than ureteral calculi, and repeated URS procedures, 1189 patients were left as the study population. Analysis was focused on intra-operative compli- cations and possible predictive factors. The study population was divided into two groups based on the presence of the complications: Complication– - complications were mucosal injury, mucosal ever- sion, ureteral perforation, ureteral avulsion, he- maturia, and rupture of the basket catheter inside such as push-back of the stone towards the kidney were included in the analysis of the risk factors for the complications, they were primarily de- a complication of the procedure. Mucosal injury without the perforation of the ureter. The presence of visible periureteral fatty tissue and/or contrast extravasation was considered as evidence of com- plete ureteral perforation. Hematuria was usually minor and occurred in most of the patients, but was only considered as a complication when caused a - mination of the procedure. Comparative parameters were as follows: pa- tients’ age and gender, stone surface area, later- alization and localization of the stone, impaction of the stone, type of the ureteroscope, necessity of - ing and after the procedure. Furthermore, push- back of the stone and adhering to the break’n’leave policy were also evaluated for whether they have an impact on occurring of the complications. Stones located below the pelvic brim were called as distal or lower and above the pelvic brim were called as proximal or upper. Break’n’leave policy 459Vol. 9 | No. 2 | Spring 2012 |U R O LO G Y J O U R N A L Intra-Operative Complications of Ureteroscopy | Tanriverdi et al was named by our department previously. Stone - plete ureteral obstruction on excretory urography, causing obstructive anuria, or present at the same site for more than 3 months, or documented to be impacted in the operative details. Hospital charts, operative notes, and available videos of URS procedures were reviewed in or- der to determine the stone-free status with the detailed evaluation of radiographic images. Di- mension of stones were calculated from the radi- ographic images pre-operatively. Treatment suc- as stone-free status after multimodal intervention in 3 months. Stone-free status was determined ei- ther by direct visualization of the involved ureter or by radiographic follow-up imaging. If possible, extracted calculi were sent for analy- sis and additional medical therapy was provided for recurrent urolithiasis. Patients with positive urine cultures were treated according to the cul- ture results at least for 3 days prior to the pro- cedure. Antibiotic prophylaxis (third-generation on the day of surgery. After obtaining signed informed consent, URS was performed under regional or general anes- thesia. The patients were placed in the lithotomy position on an endoscopy table allowing the use - of the procedure, patient’s characteristics, avail- ability, and individual surgeon preference. To minimize heat loss during the operation, 0.9% NaCl warmed to 37°C was used as an irrigant. Routine cystoscopy and ureteral dilation were not used and the safety guidewire was inserted under direct vision. The ureteroscope was passed along - der video monitoring. A 0.035/0.038-inch stand- controlled hydrodilation was used to traverse the intramural ureter. An electrohydraulic lithotripter was used in the lithotripter for the remaining cases. A tempo- in some patients to avoid ureteral damage or in whom were considered for SWL treatment. The decision of stenting was made according to the duration of the procedure and the degree of vis- ible ureteral trauma at the end of the procedure. Complications were treated with stents, percu- taneous nephrostomy, or open surgical repair according to the severity or patient’s condition. complications or comorbidity demanded pro- longed hospitalization. In patients in whom URS was not possible due to inability to advance the ureteroscope into the ureter, a ureteric stent was placed and URS was performed a few days later Univariate analyses, including Chi-Square and Student’s t test, were performed to detect any - - tic regression analysis was used to determine the predictive factors affecting intra-operative com- plications. The values were provided as mean P value of less than RESULTS 13.89 years, respectively, P - cal difference was found regarding the male-to- 460 | P The groups were comparable regarding the P 87.05 mm², respectively, P - tion of the ureteral stones was found to be a signif- icant predictor in occurring of the complications in the univariate analysis (P The type of the ureteroscope used did not exhibit any impact on the complication rates (P Of the intra-operative complications, 51 out of 57 of a DJ catheter, whereas remaining 6 procedures required open surgery. The reasons for open sur- gical approach in these cases were ureteral perfo- The stone-free rate after a single ureteroscopic 86.30%. The push-back of the ureteral stone to- procedures and was mostly encountered in the - rected to SWL for further treatment. Furthermore, the inability in advancing the ureteroscope in the - ary procedures, including re-URS, SWL, PNL, and open surgery, the overall stone-free rate was Pneumatic lithotripsy was the most commonly Of the patients who had stones, the break’n’leave (P - - tions in univariate analysis. Another predictor in the univariate analysis was the impaction of the - 5.60%, respectively, P - formed in only 16 out of 1189 URSs when the ureteroscope could not be advanced. There was P - - dures to facilitate the advance of the ureteroscope, hand-held irrigation pump was enough for ure- teral access in the rest of the cases. There was groups with regards to the rate of using an access catheter (P In multivariate stepwise logistic regression analy- sis, the independent predictive factors associated The impaction of the stone was found to be the in- dependent factor for increased complication rates. Furthermore, deeming the stones small enough to be the other predictor decreasing the complica- tion rates. DISCUSSION Table 1. Classification of complications. Intra-operative Complications n (%) 30 (52.6) Hematuria 9 (15.7) Ureteral perforation Ureteral avulsion 2 (3.5) Mucosal eversion 1 (1.7) Rupture of the basket catheter 2 (3.5) Total number 57 (100) Endourology and Stone Disease 461Vol. 9 | No. 2 | Spring 2012 |U R O LO G Y J O U R N A L studies. with the auxiliary procedures. In univariate analy- sis, upper location of the stones, stone impaction, and disrespect to the break’n’leave policy were complication rates. Presence of stone impaction and the break’n’leave policy remained independ- ent predictors at multivariate analyses. th century, with the development of small diameter endoscopes and a widely accepted modality in the treatment of ureteral calculi. Therefore, URS has been a saf- worldwide experience. However, complications may still occur and the predictive factors should be clearly elucidated to understand the nature of the complications. In this study, mucosal injury was the most fre- which was treated with stent placement and re- solved with no further consequences. Parallel to our results, mucosal injury was the most common intra-operative complication over other compli- - ries. Ureteral perforation was second most common complication in our group. Of 13 ure- teral perforations, while 11 were treated with DJ surgery due to guidewire slippage and failed DJ placement. Stone extraction and repair of the damaged segment of the ureter were successfully surgery was required due to the rupture of the tip of the basket catheter inside the ureter, which were both successfully managed with open sur- gery. The most tragic complication, however, was the complete ureteral avulsion in two cases. One of them had multiple ureteral stones in the proximal ureter and the other one had proximally located stone with acute kinkings in the mid-ureter. The proximally located stones were fragmented suc- cessfully, but with the unbalanced downward Table 2. Univariate analysis of risk factors for occurring of the complications. Categorical factor Group 1 (n = 57) Group 2 (n = 1132) P Age (mean ± SD)*, y .363 Gender (male), % 63.20 64.50 Stone surface area (mean ± SD), mm² .757 Lateralization, % Right 43.90 46.10 .744 Upper 47.40 31.70 .047 Type of ureteroscope (Wolf ), % 66.70 73.20 .537 Ureteral access catheter, % 63.20 47.00 .109 Postoperative ureteral catheter, % 56.10 45.30 .263 Stone impaction, % 17.50 5.60 .0001 Balloon dilation of the ureteral orifice, % 1.75 1.32 Push-back, % 7.01 .650 Break’n’leave, % 19.30 .0001 *SD indicates standard deviation. Intra-Operative Complications of Ureteroscopy | Tanriverdi et al 462 | traction of the ureteroscope, the whole ureter came out in both cases. Primary anastomosis was tried initially, but after a period of follow-up with the ancillary procedures, including ileal neoureter placement, unfortunately both cases had under- gone nephrectomy. In a comprehensive review of endoscopic ureteral injuries, complete ureter- al avulsion has been reported in 17 out of 5117 Furthermore, nephrectomy has also been reported as one of the most worrisome complications of URS in other published series. Another technical factor to consider is the success rate of the procedures. The reported overall stone- free rate of URS for ureteral stones is remarkably high ranging between 85% and 100%. Our data demonstrated comparable results with the literature, ranging from 86.3% with initial URS Taking the main goal of ureteroscopic lithotripsy as rendering the patient stone-free without any complication either during or after URS into ac- groups according to the presence of complica- tions. Both groups were statistically evaluated for outcome. the complications was stone location. The stones located in the upper portion of the ureters were tended to be complicated. Although some re- stone location and complication, in those studies, the number of the procedures was either low, or statistical evaluation was not possible for the in- dependent prediction. However, some other reports showed that proximal location of the stone was the predictor for complications using multi- variate analyses. which are also supported by the published series, as for the initial treatment, it would be wiser to refer the patients with proximally located stones to SWL treatment. After multivariate analysis of all factors, two in- dependent predictors of complications have been impaction. The edema at the impaction site may easily result in false route and mucosal injury. As outlined by some researchers, the risk for perfora- tion might be increased in impacted stones. We - teral perforations had impacted stones in the ureter. El-Nahas and coworkers also found that stone im- paction was the independent predictor for the unfa- vorable results similar to our series. Finally, adhering to the break’n’leave policy was found to be the other predictor for decreasing the complication rates. The idea for break’n’leave is that if the left fragments of the stone are small procedure should be terminated without any other maneuvers. The effort of continuing the fragmen- - cant fragments down may cause damage to the ureter and prolong the procedure. We found that in the procedures in which break’n’leave were Table 3. Multivariate analysis of risk factors for occurring of the complications. Independent factor B* Exp (B)° 95% Confidence Interval P Stone impaction -2.164 0.115 0.036 to 0.365 .0001 Disrespect to break’n’leave 1.959 .01 Localization (upper) 0.055 0.003 to 0.925 .692 ° Relative risk Endourology and Stone Disease 463Vol. 9 | No. 2 | Spring 2012 |U R O LO G Y J O U R N A L not performed, the patient has almost seven times higher risk of having a complication. To the best this factor statistically as a possible predictor of complications. Some limitations of our study must be taken into long-term follow-up period. This is because our center is a referral for many hospitals in our re- gion and thus many patients were followed up elsewhere after the procedure. Therefore, the main focus of our study was the prediction of intra-operative complications. Another drawback of our study might be the lack of the use of a la- ser energy source, which may decrease the rate of push-back ratios, particularly for the proximally located stones. Although laser lithotripsy with limited complications, because of its high cost it may not be available in many urology depart- ments like ours. Recently, we were equipped with laser system and due to limited number of cases, these patients have not been included into the present study. CONCLUSION Ureteroscopy is a safe and highly effective pro- cedure for the treatment of ureteral calculi. Com- plications are rare and generally can be managed with the placement of a ureteral catheter or with minimally-invasive treatments. Stones located - cantly increased complication rates. Furthermore, multivariate analysis revealed that stone impac- tion and failure to adhere to the “break’n’leave” principle were the independent predictors of oc- curring of the complications. 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