ROBOTIC & LAPAROSCOPIC UROLOGY Robot-assisted Laparoscopic Pyeloplasty in Adults: A Comparison Analysis of Primary versus Redo Pyeloplasty in a Single Center Najib Isse Dirie1,4, Mahad A Ahmed3, Mohamed Abdulkadir Mohamed2, Zongbiao Zhang*1, Shaogang Wang*1 Purpose: Approximately 10% of all primary pyeloplasties will require at least one secondary intervention. Our aim was to analyze whether secondary repair will pose additional challenges during robotic pyeloplasty compared with the primary pyeloplasty. Material and Methods: 114 patients who underwent robot-assisted laparoscopic pyeloplasty (RALP) between February 2015 and August 2018 were retrospectively reviewed. Patients were divided into; primary and second- ary repair. The demographics, intraoperative parameters, postoperative parameters, and success rate of these two groups were collected and compared. Primary RALP data were further stratified into those who previously under- went ipsilateral endourological surgeries (IES) at the obstruction site and those who did not, to evaluate the effect of IES has on the outcome of RALP. Success was defined as symptomatic and radiological relief. Results: Of the 114 patients, five complicated cases (three horseshoe kidneys, one duplicated system, and one retrocaval ureter) were excluded from the comparison. The remaining 96 primary and 13 secondary repairs were compared. Intraoperative and postoperative parameters showed no significant difference between the two groups. The results of 99 patients (87 vs. 12 in primary vs. secondary, respectively) were available after 27.5 months mean follow-up. The overall success was 92%, 8 patients failed (5 vs. 3 in primary vs. secondary, respectively) and required further surgical interventions. Conclusion: Though surgically challenging with increased recurrence rates according to the literature we re- viewed. However, our data failed to show any significant difference between the primary and redo RALP perhaps due to the smaller size in the redo RALP group. Keywords: primary pyeloplasty; secondary pyeloplasty; robot-assisted laparoscopy; comparison; outcomes INTRODUCTION Open pyeloplasty has been the gold standard treat-ment for the management of ureteropelvic junc- tion obstruction (UPJO) for more than a century with an excellent success rate of up to 100%(1). Nevertheless, reports indicate that approximately 11.4% of post-py- eloplasty patients will require at least one redo pro- cedure, and within one year in up to 87% (2). Unlike primary pyeloplasty, the redo approach is particularly challenging due to the disrupted anatomical planes, de- creased vascularity to the ureteropelvic junction (UPJ) area, and scar tissue around the previously repaired site. Several minimally invasive techniques such as balloon dilatations, retrograde or antegrade endopyelotomy, conventional laparoscopy, and lately robotic approach have been reported in the literature to replace open repair in redo pyeloplasty for their lower morbidity. 1Department of Urology, Tongji Hospital, Tongji Medical College of HUST, Wuhan 430030, P.R. China. 2Department of Cardiac surgery, Tongji hospital, Tongji Medical College of HUST, Wuhan 430030, P.R. China. 3Internal Medicine Department, Beaumont Health Dearborn, Dearborn, Michigan, USA 4Urology department, Dr.Sumait hospital, Faculty of Medicine and Health Science, SIMAD University, Mogadishu ,Somalia. *Corespondence: Department of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Liberalization Ave, No. 1095, Wuhan 430030, P.R. China. Tel: 86-27- 83663460; Tel & Fax: +86-27-83663460, E-mail: sgwangtjm@163.com and zzb070@126.com Received April 2019 & Accepted December 2019 Nevertheless, techniques such as endopyelotomy have shown significantly lower success rates than open redo pyeloplasty(3). In the last 2 decades, robot-assisted laparoscopic ap- proach has gained significant attention. Compared with traditional laparoscopy, da Vinci® robotic system (In- tuitive Surgical, Inc., Sunnyvale, CA) provides a better hand instrument and vision which has tremendously improved the speed of intracorporeal suturing in all laparoscopic reconstructive surgeries. For the above advantages, many centers, including ours, have utilized da Vinci® robotic system when dealing with failed py- eloplasty for its excellent image quality and better fine dissections which is very vital for this technically de- manding procedure. In the literature, we found numerous studies addressing the novelty, operational safety, efficacy, and success of the robotic pyeloplasty, some studies compared with Urology Journal/Vol 18 No. 1/ January-February 2021/ pp. 45-50. [DOI: 10.22037/uj.v16i7.5257] traditional laparoscopy, and open technique. However, only a few reports have compared primary with redo pyeloplasty in the robotic setting. Therefore, we aimed to evaluate the surgical and clinical outcomes of robotic redo pyeloplasty compared to primary pyeloplasty. MATERIALS AND METHODS From February 2015 to August 2018, 114 consecu- tive patients underwent robot-assisted laparoscopic pyeloplasty (RALP) at Tongji Hospital, Urology de- partment using da Vinci Si robotic system for UPJO management. During preoperative imaging work-up, a multislice computed tomography (CT) scan, intrave- nous urography, magnetic resonance urography (MRU) or retrograde urography were utilized to localize and evaluate the extent and the degree of the obstruction. Diuretic 99mTc-mercaptoacetyltriglycine (MAG3) re- nography examination was performed if an ipsilateral renal parenchymal loss is suspected. Once the diagnosis was established, a complete preoperative work-up con- taining; detailed history, physical examination, renal function test, blood chemistry, urinalysis, coagulation Primary vs. redo robotic pyeloplasty in adults-Isse Dirie et al. Endourology and Stones diseases 130 study, and blood screening study was conducted. An informed consent document was obtained from each patient before any surgery was carried out. Our institution’s ethical committee approval was ob- tained to conduct this retrospective review. After that, we collected the data and divided patients into two groups; primary RALP and secondary RALP (after open or laparoscopic primary pyeloplasty has failed). The surgical and clinical outcomes of these two groups were compared and analyzed. Preoperative parameters such as; age, sex, body mass index (BMI), symptoms, obstruction side, history of prior surgery, type of pre- vious intervention, and associated conditions were re- corded. Intraoperative, and postoperative parameters such as; American Society of Anesthesiologists (ASA) score, estimated blood loss (EBL), operative time, com- plication rates, length of hospital stays (LOS), double J (D-J) removal time, follow-up period, and recurrence rates between the groups were also collected and ana- lyzed. In the primary RALP group, some patients had a history of ipsilateral endourological surgery (IES) such as percutaneous nephrolithotomy (PCNL), ureter- Table 1. Patient demographics (primary vs. secondary RALP) Demographicsa Overall n (%) Primary pyeloplasty Secondary pyeloplasty p-value No. of Patients 109 96 13 - Sex, n (%) Male 74 (67.9) 65 (67.7) 9 (69.2) .999 Female 35 (32.1) 31 (32.3) 4 (30.8) Age, years; median (range) 29 (10 -70) 33 (10 - 70) 25 (18 - 51) .156 BMI, kg/m2; mean ± SD 22.6 ± 3.4 22.8 ± 3.3 21.7 ± 4.0 .273 ASA score, n (%) I 32 (29.3) 28 (29.2) 4 (30.8) II 73 (67) 64 (66.7) 9 (69.2) .999 III 4 (3.7) 4 (4.1) 0 - Presented symptom, n (%) Flank pain 31 (28.4) 30 (31.3) 1 (7.7) .104 Asymptomatic hydronephrosis 32 (29.4) 29 (30.2) 3 (23.1) .752 Abdominal pain 20 (18.4) 17 (17.7) 3 (23.1) .703 Others 26 (23.8) 20 (20.8) 6 (46.1) .076 Obstruction side, n (%) Left 58 (53.2) 49 (51.0) 9 (69.2) .217 Right 51 (46.8) 47 (49.0) 4 (30.8) History of ipsilateral urolithiasis, n (%) Yes 33 (30.3) 30 (31.2) 3 (23.1) .751 No 76 (69.7) 66 (68.8) 10 (76.9) Crossing vessel, n (%) 8 (7.3) 7 (7.3) 1 (7.7) .999 Abbreviations: RALP, Robot-Assisted Laparoscopic Pyeloplasty; BMI, Body Mass Index; ASA, American Association of Anesthesiol- ogists; SD, Standard Deviation. a Categorical and continuous (except BMI parameter) data were compared using Fisher’s Exact test and Man-Whitney U test, respectively. Table 2. Intra and postoperative outcomes (primary vs. secondary RALP) Parametersa Overall Primary pyeloplasty Secondary pyeloplasty p-value No. of Patients 109 96 13 - Operative timeb (min); median (range) 0 (0 – 300) 0 (0 – 300) 100 (0 – 300) .104 EBL (ml); median (range) 141 (47 – 375) 137 (47 – 375) 148 (79 – 308) .340 Complications, n (%) Clavien II 16 (14.68) 14 (14.58) 2 (15.38) .995 Clavien III 8 (7.34) 7 (7.29) 1 (7.69) LOS (days); median (range) 6 (3 – 14) 6 (3 – 14) 6 (3 – 14) .872 Stent removal time (weeks); median (range) 8 (4 – 10) 8 (4 – 10) 8 (4 – 10) .636 Follow-up periodc (months); median (range) 25 (6 – 57) 25.5 (6 – 57) 25 (15 – 56) .807 Recurrence rateb, n (%) 8 (8.1) 5 (5.7) 3 (25) .054 Abbreviations: RALP, Robot-Assisted Laparoscopic Pyeloplasty; EBL, Estimated Blood Loss; LOS, Length Of hospital Stays; GA, General Anesthesia. b One subject’s data was unavailable; c Contains 99 cases (87 vs. 12) since 10 cases were lost in the follow-up. a Categorical and continuous data were compared using Fisher’s Exact test and Man-Whitney U test, respectively. Robotic and Laparoscopic Urology 46 Vol 18 No 1 January-February 2021 20 oscopic laser lithotripsy (URL), and endopyelotomy at the obstruction site for stone or UPJO treatment. We compared patients with IES history to those who did not undergo any prior ipsilateral surgery at obstruction site to evaluate the effect of IES on the outcome of RALP. During the follow-up, CTU or MRU was used as the first choice in the postoperative imaging review. How- ever, some patients chose ultrasound imaging for its convenience, lower price, and absence of radiation. The first examination was conducted one month after the double J stent removal, and then every six months. Success was defined as symptomatic and radiological relief; symptomatic relief is accounted according to pa- tients subjectively reporting that their pain has subsided and they are no longer using any pain medication. Radi- ological success is achieved if the hydronephrotic state is not severed compared to before the surgery, and no apparent radiological evidence of any obstruction seen at the operated site. Statistical Analysis We have used version 16 of the Software of Statistical Package for the Social Sciences (SPSS) to compare our data. Fisher’s exact test was performed in all categorical data for the group comparison (except obstruction side in Table 1 for which we performed a Pearson’s Chi- squared test). For the continuous data, since data was not normally distributed, we performed a Man-Whitney U test to compare the groups, and the results are pre- sented as median and range (except the BMI for which we performed a student t test and the results are shown as mean and ± SD). P < 0.05 was considered to be sta- tistically significant. RESULTS Of 114 patients, seventy-percent were symptomatic while the rest presented with asymptomatic hydrone- phrosis. Transperitoneal approach with dismembered pyeloplasty was performed in all operations using da Vinci® Si robotic system under two experienced sur- geons (each surgeon performed >1500 robotic proce- dures). The primary pyeloplasty group comprised of 101 subjects while the secondary pyeloplasty group contained 13 patients. Of the 101 primary pyeloplas- ty patients, five anatomically complicated cases (three horseshoe kidneys, one duplicated system, and one retrocaval ureter) were excluded from the comparison analysis since these conditions could have extra surgi- cal challenges and have a tendency to alter the results. The remaining 96 vs. 13 patients of primary vs. sec- ondary RALP, respectively, were compared. Table 1 shows the overall demographic data of the two groups. Intraoperative and postoperative parameters are shown in Table 2. The previous failed interventions of the secondary RALP group were five open pyeloplasties and eight conventional laparoscopic pyeloplasties, and the meantime from their primary surgery was 5.6 years (range, five months to 20 years). The surgical details of our approach have been previ- ously well described by other investigators(4). A double J ureter stent was placed before the completion of each anastomosis (Figure 1). No patient required conversion to an open approach. In the comparison analysis, none of the intraoperative and postoperative parameters we compared showed significant between the two groups. The primary RALP group contained two sets of patients; 32 patients who had prior ipsilateral UPJ surgeries (the list of their previous surgeries is shown in Table 3), and 64 patients who did not have any previous ipsilateral surgery. 30 patients (two patients with a history of open lithotomy were excluded from this subgroup compar- ison) who previously underwent IES were compared with the 64 patients who did not receive prior ipsilateral surgery to evaluate the effect of IES on RALP outcome. The analysis results showed no significant difference between the two subgroups (Table 4). We encountered one case of antegrade double J inser- tion failure in the primary RALP group, which required intraoperative use of a retrograde ureteroscope for stent placement. Six patients required postoperative cys- toscopic stent pulling into the bladder to prevent further stent migration. The ureter stent was challenging to be removed under cystoscope in one case, which required the use of ureteroscopy under general anesthesia. Ten patients were lost to follow-up; for this reason, the results of the remaining 87 vs. 12 cases in primary vs. secondary RALP, respectively, were used when com- paring the follow-up period and success rates. Finally, Table 3. List of previous ipsilateral surgeries Procedure No. of Patients Mean time from previous intervention, year (range) Ureteroscopic laser lithotripsy (URL) 19 2.7 (6 month – 13 years) Percutaneous nephrolithotomy (PCNL) 6 1.2 (1 month - 3 year) Both PCNL and URL 3 6 (2 - 10 years) Endopyelotomy 2 0.3 (3 month - 4 month) Open lithotomy 2 8 (7 – 9 years) Parametera No Previous Endourological surgery Previous Endourological surgery P-value No. of patients 64 30 - BMI, kg/m2; mean ± SD 22.2 ± 3.1 24 ± 3.6 .014 Operative time (min); median (range) 140 (47 – 375) 137 (80 – 295) .984 EBL (ml); median (range) 10 (0 – 300) 0 (0 – 300) .136 LOS (days); median (range) 6 (3 – 14) 6 (4 – 14) .726 Stent removal time (weeks); median (range) 8 (4 – 10) 8 (4 – 10) .544 Follow-up (months); median (range) 26 (7 – 57) 25 (6 – 53) .917 Recurrence rate, n (%) 4 (6.9) 1 (3.7) .999 Abbreviations: RALP, Robot-Assisted Laparoscopic Pyeloplasty; EBL, Estimated Blood Loss; LOS, Length Of hospital Stays. a Categorical and continuous (except BMI parameter) data were compared using Fisher’s Exact test and Man-Whitney U test, respectively. Table 4. Effect of previous ipsilateral endourological surgeries on outcome of RALP Primary vs. redo robotic pyeloplasty in adults-Isse Dirie et al. Vol 18 No 1 January-February 2021 47 in Table 5, we have summarized previously published articles comparing primary vs. secondary RALP. DISCUSION Minimally invasive techniques and open approach for primary pyeloplasty are abundant in the literature, un- like redo pyeloplasty studies, which are very limited. One explanation could be the rarity of persistent and re- current UPJO due to the high success rates of the prima- ry pyeloplasty, particularly when an open technique is utilized in the primary setting. Several causes that may lead to the failure of the primary pyeloplasty have been suggested including; formation of periureteric fibrosis due to urine extravasation after pelviureteral anasto- motic failure, thermal damage to the ureteral blood sup- ply, and missed lower pole crossing vessel during the initial surgery(5). Furthermore, the dissection and repair of failed pyeloplasty’s are technically very challenging, due to abdominal adhesions and periureteric fibrosis. Techniques such as; placement of ureter stents, balloon dilations, and endopyelotomy are among the least inva- sive procedures for the management of UPJO. Some of the techniques were associated with superior surgical and clinical outcomes compared with others when deal- ing with recurrent UPJO. For instance, Abdel-Karim et al. reported higher EBL and pain score, and prolonged operative time and LOS in open redo pyeloplasty (ORP) compared with laparoscopic redo pyeloplasty (LRP)(5). Similarly, a meta-analysis study comprising 88 LRP vs. 153 ORP has shown significantly reduced LOS in the Table 5. Summary of published articles comparing primary vs. redo RALP Author (year) No. of participants Age (year) Sex (M/F) Crossing Vessel (n) Operative time (min) EBL (mL) Primary/Redo Primary/Redo Primary/Redo Primary/Redo Primary/Redo Primary/Redo Atug (10) (2006) 37/7 32.8/37.8 (20/24)/ (2/5) 16/2 219.4/279.8 49.5/52.5 Mufarrij (26) (2008) 117/23 38.2/40 (52/65)/ (14/5) 62/15 217.2/215.9 57.5/68.3 Sivaraman (27) (2012) 147/21 37.8/36.0 (82/65)/ (12/9) 63/12 125.9/190.4 42.9/86.2 Niver (28)(2012) 97/20 39.4/41.8 (41/56)/ (9/11) 64/16 218.7/217.9 62.8/98.8 Thom (11) (2012) 46/9 41a 23/32a NA 192/205 90/125 Baek (9) (2018) 55/10 5.1/8.2 (40/15)/ (9/1) NA/NA 143.2/187.7 NA/NA Current study 96/13 35.4/27.5 (65/31)/ (9/4) 7/1 150.2/170.5 40.5/85.4 Author (year) Complication rate Conversion rate LOS (days) Follow-up (months) Successb rate (%) Primary/Redo Primary/Redo Primary/Redo Primary/Redo Primary/Redo Atug (10)(2006) 0/0 0/0 1.1/1.2 13.5/10.7 100/100 Mufarrij (26)(2008) 0/0 0/0 2.1/2.1 30.1/24.1 96.6/91.3 Sivaraman (27) (2012)8/3 0/0 1.4/1.7 39a 97.6% a Niver (28) (2012) 15/3 0/0 2.5/2.8 21.9/26 96.6/95 Thom (11) (2012) 1a 1a NA 16a 98/78 Baek (9) (2018) 0/1 0/0 1.4/1.2 10.5/13.6 98.2/100 Current study 21/3 0/0 6.3/6.6 27.4/28.1 94.3/75 Abbreviations: Bold data: Indicates significance difference between the groups”; NA; Not available; a: Only overall results were report- ed; b: Success means “not requiring further intervention”; Note: The results in the table are expressed as “Mean values”. Figure 1. Robot-assisted laparoscopic dismembered pyeloplasty (RALP) A)Urography image (contrast media is injected percutaneously and retrogradely). B)MRU scan showing severe left kidney hydronephrosis due to UPJO C)CT scan taken 1 year after left side RALP D)Robotic dissection at the UPJ area E)Performing robotic dismembered pyeloplasty F)D-J stent placement before pelviureteral anastomosis completion Primary vs. redo robotic pyeloplasty in adults-Isse Dirie et al. Robotic and Laparoscopic Urology 48 LRP with no significant difference in the success rate, although the operative time was shorter in the ORP(6). Furthermore, endopyelotomy technique as a second- ary intervention has also shown to decrease the LOS compared with ORP(7). However, the success rates were significantly higher in LRP compared with endopyelot- omy, 87.5% vs. 74%, respectively(8). Recognizing the increased challenge when doing sub- sequent reconstructive surgeries, we expected a signif- icant rise in surgical time, complication rates, and EBL in redo pyeloplasty. Nevertheless, our analysis failed to show any significant difference in terms of operative time, EBL, complication rates, and recurrence. Unlike ours, Baek et al.(9) and Atug et al.(10) found significantly longer operative time, console time, and dissecting time in the secondary RALP group when compared with pri- mary RALP. Thom et al.(11) have also significantly in- creased EBL in the redo robotic pyeloplasty compared with primary RALP. Similarly, a newly published me- ta-analysis study by Dirie et al.(12) (containing; 613 vs. 107 patients in primary vs. redo RALP, respectively) found significantly increased operative time, EBL, and recurrence in redo robotic pyeloplasty compared with primary RALP. On the other hand, the literature concerning previous abdominal surgeries (PAS) and their impact on the subsequent abdominal surgeries are conflicting; some reported that PAS has no adverse effect on secondary operations(13) while others reported the opposite. Two recent studies; one laparoscopic radical cystectomy and one robot-assisted laparoscopic partial nephrectomy have found a higher EBL in those patients who had pre- vious major abdominal surgery compared to those who did not(14,15). Conventional laparoscopy in redo pyeloplasty has shown poor outcomes when compared with laparo- scopic primary pyeloplasty. Nishi et al. found an in- creased operative time, EBL, and complication rates in LRP when compared with secondary laparoscopic pyeloplasty(16). Additionally, the longer learning curve and the technical challenges related to mastering intra- corporeal suturing skills made conventional laparosco- py less popular approach than robotics in reconstructive urology. However, we should acknowledge the newly emerged technologies in traditional laparoscopy such as 3D laparoscopic cameras and robotized laparoscopic needle drivers; these technologies have demonstrated improved surgical outcomes in reconstructive surgeries (17,18). Improvements in conventional laparoscopy could be appreciated considering the higher cost required to purchase and maintain robotic machines, especially for those medical centers with smaller budgets. Robot-assisted laparoscopy has been the cornerstone surgical modality for reconstructive urology includ- ing RALP surgery since its birth in the early 2000s. Robot-assisted laparoscopy has an excellent surgical and clinical record in both adults and children in the primary pyeloplasty. Autorino and colleagues(19) pre- sented the largest review study to date in which they have critically analyzed a large data concerning robotic and laparoscopic pyeloplasty. Of the 841 RALP adult cases reviewed in the study, the operative time ranged between 105-335minutes with only three conversions while reintervention and success rates were 1.8-13.1% and 81-100%, respectively. Compared with the conventional laparoscopy, signifi- cantly shorter operative time, suturing time, and LOS were found in RALP(20). Similarly, another study linked RALP with significantly improved obstruction, pain, and fewer secondary intervention needed(21). Further- more, Hemal et al. reported 10 cases of redo RALP with a 100% success rate after 7.4 months of mean follow-up (22). Despite the growing popularity and the outstand- ing results with robotic surgeries, the high direct and indirect costs to purchase and maintain it makes robotic surgeries economically less competitive than open ap- proach(23). Besides the technique utilized, one should keep in mind that there are other factors such as the surgeon’s ex- perience, the preoperative severity of hydronephrosis, and renal function which can influence the surgical and clinical outcomes after pyeloplasty repair. For instance, some studies associated poor preoperative renal func- tion and severe hydronephrosis with increased failure rates after the surgery(24,25). There are some limitations in our study that must be addressed such as; the retrospective nature, lack of long-term follow-up since failure can be seen even af- ter many years later, lack of urographic imaging in all cases in the follow-up, and the small sample size of our cohort. CONCLUSIONS According to the existing literature and our current study, robot-assisted laparoscopic pyeloplasty is an ex- cellent surgical approach in primary pyeloplasty. Fur- thermore, our data failed to show any significant differ- ence in terms of surgical and clinical outcomes between primary and redo pyeloplasty, perhaps the smaller data in our redo pyeloplasty. However, one must be aware the increased surgical challenges and the higher recur- rence after surgery in the redo pyeloplasty according to the other similar literature we reviewed including re- cently published meta-analysis study. ACKNOWLEDGEMENT Authors are grateful to Dr. Magdalena F. Dennis and Jama Yasin Farah for correcting the language. Special thanks to Mr. Wilhellmuss Mauka and Mr. Olotu Frank for providing advices about statistics. CONFLICT ON INTEREST Authors declare that there is no conflict of interest to disclose. REFERENCES 1. Bansal P, Gupta A, Mongha R, Narayan S, Das RK, Bera M, et al. Laparoscopic versus open pyeloplasty: comparison of two surgical approaches- a single centre experience of three years. Indian J Surg. 2011;73:264-7. 2. 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