- Email: [email protected]
V5-02 COMPLEX ROBOTIC PARTIAL NEPHRECTOMY FOR HILAR MASSES
THE JOURNAL OF UROLOGYâ
e616
Vol. 191, No. 4S, Supplement, Monday, May 19, 2014
PD20-12
Renal Oncology/Robotics
EVALUATION OF SUBJECTIVE ASSESSMENT OF NERVESPARING QUALITY ON POSTOPERATIVE ERECTILE FUNCTION IN PATIENTS UNDERGOING ROBOT-ASSISTED LAPAROSCOPIC RADICAL PROSTATECTOMY Pengbo Jiang*, Chris Wright, Newark, NJ; Ihor Sawczuk, Ravi Munver, Hackensack, NJ INTRODUCTION AND OBJECTIVES: The quality of the nerve preservation during nerve-sparing radical prostatectomy is believed to contribute to postoperative erectile function. We report our outcomes of subjective nerve preservation with objective erectile function in patients undergoing bilateral nerve-sparing robot-assisted laparoscopic radical prostatectomy (RALP). METHODS: A review of bilateral nerve-sparing RALP performed at a single institution from 2004 to June 2011 was performed. Eligibility criteria included complete intraoperative data and a minimum 2 year postoperative follow-up. The quality of each nerve-sparing (NS) procedure was subjectively classified on each side and prospectively recorded as good/total athermal NS (3), fair/partial or thermal NS (2), or poor/limited or excessive thermal NS (1). Patients were stratified by their combined score of each side (range 2-6). All patients were followed for a minimum of 24 months for assessment of erectile function. The primary outcome measure of potency was maintenance of an erection sufficient for penetration during vaginal intercourse. 95% confidence intervals were calculated, comparison of proportions was performed, and one-way ANOVA and Tukey HSD test were used to analyze other key characteristics. RESULTS: During the study period, a total of 240 RALPs met the inclusion critera and were subsequently stratified based on their graded nerve-sparing score. Table 1 summarizes key patient characteristics of each group as well as 24-month potency outcomes. Patients with a nerve-sparing score of 6 had a significantly higher potency rate at 24 months as compared to patients with a score of 2 (p<0.0002), 3 (p<0.05), and 4 (p<0.01). Better nerve-sparing grades were associated with decreased estimated blood loss (EBL) (p<0.01) and shorter operative times (p< 0.01) when compared with poor nerve-sparing grades. There was no significant difference in patient age, PSA prior to operation, or prostate volume between the groups. CONCLUSIONS: Subjective assessment of quality of nervesparing during RALP correlates with postoperative erectile function. The quality of the NS procedure, operative time, and EBL, can be important prognostic indicators of postoperative potency. Nerve-
Monday, May 19, 2014
10:30 AM-12:30 PM
V5-01 ROBOT ASSISTED LAPAROSCOPIC RETROPERITONEAL PARTIAL NEPHRECTOMY FOR A POSTERIOR HILAR TUMOR AND A POSTERIOR HORSESHOE KIDNEY TUMOR David Y. Yang, B.S.*, Clinton D. Bahler, M.D., Chandru P. Sundaram, M.D., Indianapolis, IN INTRODUCTION AND OBJECTIVES: Recent reports have demonstrated that in posterior tumors, retroperitoneal (RP) robotic partial nephrectomy (RPN) compared to transperitoneal (TP) RPN resulted in shorter operating time and length of stay without sacrificing margin status or complication rates. We present two cases utilizing RPRPN. The first is a posterior tumor in a horseshoe kidney, which does not allow traditional mobilization and flipping of the kidney, and the second is a posterior hilar tumor in close proximity to the collecting system and renal vasculature. METHODS: The first case is a 1.8 cm mass in the posteromedial aspect of the left renal moiety of a horseshoe kidney with a preoperative R.E.N.A.L. nephrometry score of 5P. The second case is a 2.2 cm hilar right kidney mass with a preoperative R.E.N.A.L. nephrometry score of 8PH. RESULTS: Total case time for the first procedure was 129 minutes. Warm ischemia time (WIT) was 16 min, and estimated blood loss (EBL) was 100mL. At discharge (Post-operative day #2) the patient’s serum creatinine was 0.87 (baseline 0.82) and at one month follow-up the creatinine was 0.95. Total case time for the second procedure was 274 minutes with WIT being 21 min and EBL being 50 mL. At discharge (post- operative day #2) the serum creatinine was 1.08 (baseline 1.26). The one month follow-up creatinine was 1.36. There were no complications in either case. CONCLUSIONS: RP-RPN is a safe and feasible option for posterior hilar masses. For horseshoe kidneys with a posterior mass, the RP approach may be essential. Source of Funding: none
Mean
sparing
Median
Median
Prostate
Mean OR
Mean
Total
(%)
95% CI
Age
PSA
Volume (gm)
Time (min)
EBL (ml)
2
21
4 (19%)
0.08-0.40
60
6.9
65
203
338
3
17
7 (41%)
0.22-0.64
59
5.8
49
182
214
4
55
25 (45%)
0.33-0.58
61
5.8
54
173
201
5
40
21 (53%)
0.38-0.67
58
4.4
45
165
174
6
107
71 (66%)
0.57-0.75
58
5.9
48
159
163
Score
Video
Potency
Source of Funding: None.
V5-02 COMPLEX ROBOTIC PARTIAL NEPHRECTOMY FOR HILAR MASSES Michael Maddox*, Philip Dorsey, Christopher Keel, Julie Wang, Benjamin Lee, New Orleans, LA INTRODUCTION AND OBJECTIVES: Robotic partial nephrectomy is performed increasingly for complex renal masses. We present technique of addressing a right posterior hilar renal mass abutting the collecting system, as well as the renal hilum. Our objective was to demonstrate our technique for dissection and extirpation of a hilar mass using the robotic-assisted laparoscopic approach. METHODS: The patient was diagnosed with a three centimeter posterior hilar mass found incidentally on a computerized tomography scan. The RENAL nephrometry score for the mass was 9h, demonstrating the significantly complex nature of the lesion. The video demonstrates our technique used to dissect the mass from the hilum and safely reconstruct the kidney without inadvertent injury to the adjacent structures. RESULTS: Following dissection of the renal artery and vein, the kidney is mobilized in its entirety to align the posterior hilar mass to optimize reconstruction. Dissection into the renal sinus is performed off
THE JOURNAL OF UROLOGYâ
Vol. 191, No. 4S, Supplement, Monday, May 19, 2014
clamp. In our experience with hilar lesions, only the renal artery is clamped while the renal vein remains open throughout the procedure. Reconstruction of the kidney is performed with care not to obstruct the renal pelvis post operatively. CONCLUSIONS: Robotic-assisted laparoscopic partial nephrectomy is a safe and feasible option for the treatment of complex renal masses including hilar tumors. Source of Funding: none
V5-03 MINIMIZING WARM ISCHEMIA DURING ROBOTIC ASSISTED PARTIAL NEPHRECTOMY ALAA HAMADA*, Janice C. Santos, Alan M. Nieder, Akshay Bhandari, Miami Beach, FL INTRODUCTION AND OBJECTIVES: To evaluate the efficacy of our approach in minimizing warm ischemia during robotic assisted partial nephrectomy (RAPN). METHODS: We retrospectively evaluated data of patients who underwent RAPN at a single institution by a single surgeon. After IRB approval patient charts were queried for all pertinent patient data which included demographic and perioperative data. Nephrometry score was calculated for all patients. Pathologic data and postoperative complications were also recorded. Patients who underwent an off clamp partial nephrectomy were excluded from analysis. With the intent to minimize warm ischemia Vloc suture was used to over sew the resection bed as well as a single running Vloc suture was used to reapproximate the kidney parenchyma (renorrhaphy) in a horizontal mattress fashion using the sliding hemolok technique. RESULTS: From September 2011 to August, 2013 a total of 48 patients underwent RAPN. The mean age was 67.2 years. Male to female ratio was: 2:1. The average ASA score was 2.6z3: The mean nephrometry score was 6. The median warm ischemia time was 14 minutes and mean estimated blood loss was 129cc. There were no conversions to open however, the procedure was converted to a radical nephrectomy in 3 cases due to concern for incomplete tumor resection. Clear renal cell carcinoma (RCC) was the predominant pathology (68.8%). Positive margin was recorded in 1 (2%) patient. Overall there were two complications (4%) e delayed hemorrhage with negative angiogram and a delayed urinary fistula requiring percutaneous drain placement. By using linear regression analysis, no significant predictive effect of nephrometry score on duration of WIT in our patients (odds ratio: 0.8, 95% CI (0.145 to 1.7), p¼0.094. CONCLUSIONS: Single suture renorrhaphy using Vloc suture performed during robotic partial nephrectomy is helpful in shortening the warm ischemia time with no increased risk of bleeding or urine leak. Source of Funding: None
V5-04 ROBOTIC-ASSISTED LAPAROSCOPIC PARTIAL NEPHRECTOMY WITH INTRACORPOREAL COOLING FOR A RENAL MASS Dinesh Samarasekera*, Homayoun Zargar, Luis Felipe Brandao, Oktay Akca, Jihad Kaouk, Cleveland, OH INTRODUCTION AND OBJECTIVES: The application of robotics to renal surgery has allowed for re-creation of open surgical principles in a minimally invasive fashion. From open surgery it is known that in-situ renal hypothermia prevents renal ischemic injury during prolonged hilar clamping. A renal temperature of 18-20 C is required for optimal preservation. The aim of this video is to describe our technique for intracorporeal cooling with ice slush during robotic partial nephrectomy, with real time parenchymal temperature monitoring. METHODS: A 74 year-old male presented with an enhancing 3 cm endophytic hilar right renal mass. The R.E.N.A.L. nephrometry
e617
score was 8a. Pre-operative serum Creatinine was 1.32 mg/dL. Decision was made to proceed with a robotic right partial nephrectomy with intracorporeal cooling, given the high complexity of the tumor. The kidney was mobilized and the hilum was dissected. The kidney was then surrounded with an18x4 inch sponge. Ice slush was introduced through an additional 12 mm laparoscopic port placed posterior to the mid axillary line. Ice was placed posterior to the kidney then the hilum was clamped. Additional ice was placed over the medial aspect. After cooling, which was monitored by a thermocouple introduced into the normal kidney parenchyma, tumor excision was initiated, keeping ice covering most of the normal kidney at all times. RESULTS: Operative time was 183 minutes. Total ischemia time was 27 minutes and estimated blood loss was 50 cc. The lowest parenchymal temperature was 14.1 C. The patient’s temperature only dropped by 0.6 C during cooling. There were no intraoperative or perioperative complications. Serum Creatinine one week postoperatively was 1.43 mg/dL. The final pathology was a 2.5cm clear cell renal cell carcinoma, Fuhrman grade 4. The resection margins were negative. CONCLUSIONS: Robotic partial nephrectomy with intracorporeal ice slush cooling is technically feasible. We present our simplified technique with real-time renal parenchymal temperature monitoring. We have performed this technique in 4 patients and were able to achieve renal temperatures of < 18 C consistently during hilar clamping. No post-operative ileus > 2 days was observed. However, further improvements in the ice delivery system are required for universal adaptation of this method. Finally long-term renal functional outcome data is needed to fully validate this technique. Source of Funding: none
V5-05 INTRAOPERATIVE PERIPROSTATIC NERVE ACTION POTENTIAL MONITORING DURING ROBOTIC PROSTATECTOMY Ashutosh Tewari, Ketan Badani*, Paras Singhal, Adnan Ali, Robert Leung, Brian Antonucci, Ruslan Korets, Michael Rothberg, Ari Bergman, Trushar Patel, New York, NY; Dean Myers, Hutchinson, MN; Carol Campbell, Cabot, PA; Wenjeng Li, Bryan Courtney, Jacksonville, FL; Marc Zimmerman, Santa Barbara, CA; Sonny Yamasaki, Jacksonville, FL INTRODUCTION AND OBJECTIVES: Prostate cancer surgery involves interplay between the competing goals of extirpation of cancer, nerve sparing, and postoperative recovery of potency and continence. A surgeon’s task is further complicated by the complexity of periprostatic neuroarchitecture and fine nerves that are not readily visible, which places them at risk of inadvertent injury. Better intra-operative detection of nerve location in the peri-prostatic space can help in better nerve preservation, which is critical for improved functional outcomes after radical prostatectomy. We present a video of an ongoing feasibility clinical study to determine whether intraoperative nerve monitoring can locate these microscopic nerves during robotic radical prostatectomy (RP). METHODS: 28 patients with a Sexual Health Index for Men (SHIM) questionnaire score of 17 or higher were prospectively enrolled into a single study-arm. All study patients received robotic RP with intraoperative nerve monitoring. A bipolar ball-tip probe directed by robotic needle drivers stimulated the periprostatic nerves. A modified Foley catheter with ring electrodes recorded the evoked nerve activity from within the urethra, distal to the apex of the prostate. The nerves were mapped circumferentially in the transverse plane of the prostate. Mapping was also attempted by reversing stimulating and recording electrodes: Stimulating from the Foley catheter ring electrodes and recording the retrograde nerve action potentials from the bipolar ball-tip probe. Following mapping, spontaneous nerve activity during dissection was monitored with the modified Foley catheter. RESULTS: All 28 enrolled patients underwent robotic RP according to the nerve monitoring protocol. In 3 patients (11%), evoked
e616
Vol. 191, No. 4S, Supplement, Monday, May 19, 2014
PD20-12
Renal Oncology/Robotics
EVALUATION OF SUBJECTIVE ASSESSMENT OF NERVESPARING QUALITY ON POSTOPERATIVE ERECTILE FUNCTION IN PATIENTS UNDERGOING ROBOT-ASSISTED LAPAROSCOPIC RADICAL PROSTATECTOMY Pengbo Jiang*, Chris Wright, Newark, NJ; Ihor Sawczuk, Ravi Munver, Hackensack, NJ INTRODUCTION AND OBJECTIVES: The quality of the nerve preservation during nerve-sparing radical prostatectomy is believed to contribute to postoperative erectile function. We report our outcomes of subjective nerve preservation with objective erectile function in patients undergoing bilateral nerve-sparing robot-assisted laparoscopic radical prostatectomy (RALP). METHODS: A review of bilateral nerve-sparing RALP performed at a single institution from 2004 to June 2011 was performed. Eligibility criteria included complete intraoperative data and a minimum 2 year postoperative follow-up. The quality of each nerve-sparing (NS) procedure was subjectively classified on each side and prospectively recorded as good/total athermal NS (3), fair/partial or thermal NS (2), or poor/limited or excessive thermal NS (1). Patients were stratified by their combined score of each side (range 2-6). All patients were followed for a minimum of 24 months for assessment of erectile function. The primary outcome measure of potency was maintenance of an erection sufficient for penetration during vaginal intercourse. 95% confidence intervals were calculated, comparison of proportions was performed, and one-way ANOVA and Tukey HSD test were used to analyze other key characteristics. RESULTS: During the study period, a total of 240 RALPs met the inclusion critera and were subsequently stratified based on their graded nerve-sparing score. Table 1 summarizes key patient characteristics of each group as well as 24-month potency outcomes. Patients with a nerve-sparing score of 6 had a significantly higher potency rate at 24 months as compared to patients with a score of 2 (p<0.0002), 3 (p<0.05), and 4 (p<0.01). Better nerve-sparing grades were associated with decreased estimated blood loss (EBL) (p<0.01) and shorter operative times (p< 0.01) when compared with poor nerve-sparing grades. There was no significant difference in patient age, PSA prior to operation, or prostate volume between the groups. CONCLUSIONS: Subjective assessment of quality of nervesparing during RALP correlates with postoperative erectile function. The quality of the NS procedure, operative time, and EBL, can be important prognostic indicators of postoperative potency. Nerve-
Monday, May 19, 2014
10:30 AM-12:30 PM
V5-01 ROBOT ASSISTED LAPAROSCOPIC RETROPERITONEAL PARTIAL NEPHRECTOMY FOR A POSTERIOR HILAR TUMOR AND A POSTERIOR HORSESHOE KIDNEY TUMOR David Y. Yang, B.S.*, Clinton D. Bahler, M.D., Chandru P. Sundaram, M.D., Indianapolis, IN INTRODUCTION AND OBJECTIVES: Recent reports have demonstrated that in posterior tumors, retroperitoneal (RP) robotic partial nephrectomy (RPN) compared to transperitoneal (TP) RPN resulted in shorter operating time and length of stay without sacrificing margin status or complication rates. We present two cases utilizing RPRPN. The first is a posterior tumor in a horseshoe kidney, which does not allow traditional mobilization and flipping of the kidney, and the second is a posterior hilar tumor in close proximity to the collecting system and renal vasculature. METHODS: The first case is a 1.8 cm mass in the posteromedial aspect of the left renal moiety of a horseshoe kidney with a preoperative R.E.N.A.L. nephrometry score of 5P. The second case is a 2.2 cm hilar right kidney mass with a preoperative R.E.N.A.L. nephrometry score of 8PH. RESULTS: Total case time for the first procedure was 129 minutes. Warm ischemia time (WIT) was 16 min, and estimated blood loss (EBL) was 100mL. At discharge (Post-operative day #2) the patient’s serum creatinine was 0.87 (baseline 0.82) and at one month follow-up the creatinine was 0.95. Total case time for the second procedure was 274 minutes with WIT being 21 min and EBL being 50 mL. At discharge (post- operative day #2) the serum creatinine was 1.08 (baseline 1.26). The one month follow-up creatinine was 1.36. There were no complications in either case. CONCLUSIONS: RP-RPN is a safe and feasible option for posterior hilar masses. For horseshoe kidneys with a posterior mass, the RP approach may be essential. Source of Funding: none
Mean
sparing
Median
Median
Prostate
Mean OR
Mean
Total
(%)
95% CI
Age
PSA
Volume (gm)
Time (min)
EBL (ml)
2
21
4 (19%)
0.08-0.40
60
6.9
65
203
338
3
17
7 (41%)
0.22-0.64
59
5.8
49
182
214
4
55
25 (45%)
0.33-0.58
61
5.8
54
173
201
5
40
21 (53%)
0.38-0.67
58
4.4
45
165
174
6
107
71 (66%)
0.57-0.75
58
5.9
48
159
163
Score
Video
Potency
Source of Funding: None.
V5-02 COMPLEX ROBOTIC PARTIAL NEPHRECTOMY FOR HILAR MASSES Michael Maddox*, Philip Dorsey, Christopher Keel, Julie Wang, Benjamin Lee, New Orleans, LA INTRODUCTION AND OBJECTIVES: Robotic partial nephrectomy is performed increasingly for complex renal masses. We present technique of addressing a right posterior hilar renal mass abutting the collecting system, as well as the renal hilum. Our objective was to demonstrate our technique for dissection and extirpation of a hilar mass using the robotic-assisted laparoscopic approach. METHODS: The patient was diagnosed with a three centimeter posterior hilar mass found incidentally on a computerized tomography scan. The RENAL nephrometry score for the mass was 9h, demonstrating the significantly complex nature of the lesion. The video demonstrates our technique used to dissect the mass from the hilum and safely reconstruct the kidney without inadvertent injury to the adjacent structures. RESULTS: Following dissection of the renal artery and vein, the kidney is mobilized in its entirety to align the posterior hilar mass to optimize reconstruction. Dissection into the renal sinus is performed off
THE JOURNAL OF UROLOGYâ
Vol. 191, No. 4S, Supplement, Monday, May 19, 2014
clamp. In our experience with hilar lesions, only the renal artery is clamped while the renal vein remains open throughout the procedure. Reconstruction of the kidney is performed with care not to obstruct the renal pelvis post operatively. CONCLUSIONS: Robotic-assisted laparoscopic partial nephrectomy is a safe and feasible option for the treatment of complex renal masses including hilar tumors. Source of Funding: none
V5-03 MINIMIZING WARM ISCHEMIA DURING ROBOTIC ASSISTED PARTIAL NEPHRECTOMY ALAA HAMADA*, Janice C. Santos, Alan M. Nieder, Akshay Bhandari, Miami Beach, FL INTRODUCTION AND OBJECTIVES: To evaluate the efficacy of our approach in minimizing warm ischemia during robotic assisted partial nephrectomy (RAPN). METHODS: We retrospectively evaluated data of patients who underwent RAPN at a single institution by a single surgeon. After IRB approval patient charts were queried for all pertinent patient data which included demographic and perioperative data. Nephrometry score was calculated for all patients. Pathologic data and postoperative complications were also recorded. Patients who underwent an off clamp partial nephrectomy were excluded from analysis. With the intent to minimize warm ischemia Vloc suture was used to over sew the resection bed as well as a single running Vloc suture was used to reapproximate the kidney parenchyma (renorrhaphy) in a horizontal mattress fashion using the sliding hemolok technique. RESULTS: From September 2011 to August, 2013 a total of 48 patients underwent RAPN. The mean age was 67.2 years. Male to female ratio was: 2:1. The average ASA score was 2.6z3: The mean nephrometry score was 6. The median warm ischemia time was 14 minutes and mean estimated blood loss was 129cc. There were no conversions to open however, the procedure was converted to a radical nephrectomy in 3 cases due to concern for incomplete tumor resection. Clear renal cell carcinoma (RCC) was the predominant pathology (68.8%). Positive margin was recorded in 1 (2%) patient. Overall there were two complications (4%) e delayed hemorrhage with negative angiogram and a delayed urinary fistula requiring percutaneous drain placement. By using linear regression analysis, no significant predictive effect of nephrometry score on duration of WIT in our patients (odds ratio: 0.8, 95% CI (0.145 to 1.7), p¼0.094. CONCLUSIONS: Single suture renorrhaphy using Vloc suture performed during robotic partial nephrectomy is helpful in shortening the warm ischemia time with no increased risk of bleeding or urine leak. Source of Funding: None
V5-04 ROBOTIC-ASSISTED LAPAROSCOPIC PARTIAL NEPHRECTOMY WITH INTRACORPOREAL COOLING FOR A RENAL MASS Dinesh Samarasekera*, Homayoun Zargar, Luis Felipe Brandao, Oktay Akca, Jihad Kaouk, Cleveland, OH INTRODUCTION AND OBJECTIVES: The application of robotics to renal surgery has allowed for re-creation of open surgical principles in a minimally invasive fashion. From open surgery it is known that in-situ renal hypothermia prevents renal ischemic injury during prolonged hilar clamping. A renal temperature of 18-20 C is required for optimal preservation. The aim of this video is to describe our technique for intracorporeal cooling with ice slush during robotic partial nephrectomy, with real time parenchymal temperature monitoring. METHODS: A 74 year-old male presented with an enhancing 3 cm endophytic hilar right renal mass. The R.E.N.A.L. nephrometry
e617
score was 8a. Pre-operative serum Creatinine was 1.32 mg/dL. Decision was made to proceed with a robotic right partial nephrectomy with intracorporeal cooling, given the high complexity of the tumor. The kidney was mobilized and the hilum was dissected. The kidney was then surrounded with an18x4 inch sponge. Ice slush was introduced through an additional 12 mm laparoscopic port placed posterior to the mid axillary line. Ice was placed posterior to the kidney then the hilum was clamped. Additional ice was placed over the medial aspect. After cooling, which was monitored by a thermocouple introduced into the normal kidney parenchyma, tumor excision was initiated, keeping ice covering most of the normal kidney at all times. RESULTS: Operative time was 183 minutes. Total ischemia time was 27 minutes and estimated blood loss was 50 cc. The lowest parenchymal temperature was 14.1 C. The patient’s temperature only dropped by 0.6 C during cooling. There were no intraoperative or perioperative complications. Serum Creatinine one week postoperatively was 1.43 mg/dL. The final pathology was a 2.5cm clear cell renal cell carcinoma, Fuhrman grade 4. The resection margins were negative. CONCLUSIONS: Robotic partial nephrectomy with intracorporeal ice slush cooling is technically feasible. We present our simplified technique with real-time renal parenchymal temperature monitoring. We have performed this technique in 4 patients and were able to achieve renal temperatures of < 18 C consistently during hilar clamping. No post-operative ileus > 2 days was observed. However, further improvements in the ice delivery system are required for universal adaptation of this method. Finally long-term renal functional outcome data is needed to fully validate this technique. Source of Funding: none
V5-05 INTRAOPERATIVE PERIPROSTATIC NERVE ACTION POTENTIAL MONITORING DURING ROBOTIC PROSTATECTOMY Ashutosh Tewari, Ketan Badani*, Paras Singhal, Adnan Ali, Robert Leung, Brian Antonucci, Ruslan Korets, Michael Rothberg, Ari Bergman, Trushar Patel, New York, NY; Dean Myers, Hutchinson, MN; Carol Campbell, Cabot, PA; Wenjeng Li, Bryan Courtney, Jacksonville, FL; Marc Zimmerman, Santa Barbara, CA; Sonny Yamasaki, Jacksonville, FL INTRODUCTION AND OBJECTIVES: Prostate cancer surgery involves interplay between the competing goals of extirpation of cancer, nerve sparing, and postoperative recovery of potency and continence. A surgeon’s task is further complicated by the complexity of periprostatic neuroarchitecture and fine nerves that are not readily visible, which places them at risk of inadvertent injury. Better intra-operative detection of nerve location in the peri-prostatic space can help in better nerve preservation, which is critical for improved functional outcomes after radical prostatectomy. We present a video of an ongoing feasibility clinical study to determine whether intraoperative nerve monitoring can locate these microscopic nerves during robotic radical prostatectomy (RP). METHODS: 28 patients with a Sexual Health Index for Men (SHIM) questionnaire score of 17 or higher were prospectively enrolled into a single study-arm. All study patients received robotic RP with intraoperative nerve monitoring. A bipolar ball-tip probe directed by robotic needle drivers stimulated the periprostatic nerves. A modified Foley catheter with ring electrodes recorded the evoked nerve activity from within the urethra, distal to the apex of the prostate. The nerves were mapped circumferentially in the transverse plane of the prostate. Mapping was also attempted by reversing stimulating and recording electrodes: Stimulating from the Foley catheter ring electrodes and recording the retrograde nerve action potentials from the bipolar ball-tip probe. Following mapping, spontaneous nerve activity during dissection was monitored with the modified Foley catheter. RESULTS: All 28 enrolled patients underwent robotic RP according to the nerve monitoring protocol. In 3 patients (11%), evoked