bladder is the most common site in the urinary system to be afflicted by cancer . at presentation , approximately 30% of bladder cancers ( bca ) are muscle invasive ; radical cystectomy ( rc ) remains the treatment of choice in these cases . however , in select patients , partial cystectomy ( pc ) may offer equivalent oncological control with superior quality - of - life . pc , when indicated , has most commonly been performed via an open - approach as it permits gross evaluation of the excised specimen and intraoperative assessment of surgical margins . however , techniques of laparoscopic pc ( lpc ) with or without robotic - assistance have been described . .   reported on 4 and 3 cases of robot - assisted pc ( rapc ) , respectively , establishing the feasibility of rapc in management of bladder neoplasms . although , performing pc minimally - invasively may reduce the morbidity of the procedure there is a theoretical risk of inadequate surgical resection that has not been addressed in these previous reports . accordingly , in the current study , we sought to test the feasibility , safety , and reproducibility of a novel ' modification ' of rapc that recapitulates the open technique and allows for intraoperative surgical margin assessment . further , we report on perioperative , oncological , functional , and quality - of - life outcomes in patients undergoing rapc . between 2008 and 2013 , 7 patients consented to undergo rapc , with the latter 5 undergoing modified - rapc ( m - rapc ) using the gelpoint device ( applied medical , rancho santa margarita , ca , usa ) . we have previously demonstrated the efficacy of this technical modification in assessing and reducing positive surgical margins ( psms ) during robotic radical prostatectomy and robotic partial nephrectomy . in the current study , we extend the same principle to the management of bca . for each patient age at surgery , sex , body mass index ( bmi ) , history of abdominal surgery , risk factors for bca , tumor characteristics , perioperative outcomes evaluated included surgery times , blood loss , surgical margins , hospital stay and complications . disease recurrence and survival endpoints were also assessed , with a minimum and median follow - up of 12 and 38.9 months , respectively . lastly , at the time of the last follow - up patients were surveyed to assess regret and satisfaction with treatment using previously validated questionnaires . regret was assessed by the following 3 questions : ( 1 ) the man / woman 's wish that he / she could change his / her mind about the kind of treatment he / she had received ; ( 2 ) his / her feeling that he / she would be better if he / she had chosen another treatment ; ( 3 ) whether he / she was bothered by the fact that others received different treatment for their bca ( the responses were : " none of the time , " " a little of the time , " " some of the time , " " most of the time " or " all of the time " - no regret was defined as " none or a little of the time " ) . satisfaction was assessed by the following 3 questions : ( 1 ) how would you rate your overall satisfaction with your treatment choice ? ; ( 2 ) how would you rate your satisfaction with regards to urinary control ? ; ( 3 ) how would you rate your satisfaction with regards to cancer control ? ( the responses were : " extremely satisfied , " " satisfied , " " unsure , " " dissatisfied " or " extremely dissatisfied " - satisfaction was defined as " extremely satisfied or satisfied " ) . in the 5 patients undergoing m - rapc , the gelpoint device allowed for rapid specimen extraction without compromising the pneumoperitoneum . after induction of general anesthesia , the patient was placed in supine position and the gelpoint access port was inserted supraumbilically through a 4- to 5-cm vertical incision . next , the gelseal cap , prepared with a 12-mm camera port and a 10-mm low profile port ( fig . linear incisions were made in the gelseal at a tangent to the 10-mm port on the gelseal cap to facilitate specimen retrieval postextirpation . the patient was then placed in steep trendelenburg and 5 additional trocars were inserted under direct vision . two 8-mm robotic ports for the left and right robotic arms were inserted along the left and right paramedian lines at the level of the umbilicus , respectively . a 12-mm assistant port was inserted near the right iliac - fossa along the anterior axillary line , and two 5-mm assistant ports were placed ; one for suction in the epigastrium between the gelpoint and the right robotic port , and the other for the left side assistant in the left iliac fossa ( fig . subsequently , the robot was docked in the side - dock position , along the left foot end , to permit intraoperative cystoscopy . robotic instruments included a fenestrated bipolar grasper in the nondominant hand and monopolar curved scissors in the dominant hand ; the latter instrument was exchanged for a robotic needle driver during reconstruction . depending on tumor location ( table 1 ) , the bladder exposure varied . for cases in which the tumor was located at the dome or the anterior wall of the bladder , the bladder was taken down caudally up to the level of the endopelvic fascia freeing the pedicle lateral to the umbilical ligament . in cases where the tumor was located at the lateral wall or near the ureteral orifice , the procedure began with medialization of the sigmoid colon followed by identification of the ureter at the iliac vessel crossing . next , the bladder was filled with normal saline and a flexible cystoscope was introduced for intraoperative tumor localization ( fig . a robotic ultrasound - probe ( bk medical , peabody , ma , usa ) , passed through the 12-mm assistant port , was also utilized for tumor localization in 2 cases allowing for further confirmation and precise localization of the tumor within the bladder ( fig . when tumor location necessitated vascular pedicle control , this was achieved with hem - o - lock clips , and the superior vesical and inferior vesical arteries were clipped and ligated in succession . following this , using cystoscopic assistance , with or without the robotic ultrasound - probe , the margins of the tumor were delineated and the detrusor muscle was scored circumferentially to achieve a 10- to 20-mm margin ( fig . 4a after excision , the tumor was placed in an endo - catch bag ( ethicon surgery inc . , three steps were routinely performed to reduce the potential seeding of the abdominal cavity by cancerous cells ; first , the bladder was drained before entering the mucosa , second , the incised area was held up ( with the help of stay sutures ) until the defect was sutured closed , and lastly , the excised specimen was captured and placed directly into an endo - catch bag without allowing it to touch / rest on adjacent tissue . immediately following excision and extraction of the specimen , the surgeon examined the specimen on - table ( fig . frozen - sections were taken from areas that appeared suspicious for a psm on direct visualization and palpation ( fig . 5c ) , and after being carefully marked for anatomical orientation , were sent for frozen - section analysis ( table 2 ) . if frozen - section yielded unfavorable pathology , more tissue was excised from the in situ complementary site and sent for permanent section . the bladder was then closed in 2 layers using a 3 - 0 barbed suture and left to closed drainage . the robot was then undocked and the fascia and the skin were closed in a standard manner . post operative cystography was performed on all patients on postoperative day 7 prior to foley catheter removal . statistical analyses were performed using stata - se 12 software ( statacorp - lp , college station , tx , usa ) . student t - test was used for continuous variables and a p - value of < 0.05 was considered significant . institutional review board between 2008 and 2013 , 7 patients consented to undergo rapc , with the latter 5 undergoing modified - rapc ( m - rapc ) using the gelpoint device ( applied medical , rancho santa margarita , ca , usa ) . we have previously demonstrated the efficacy of this technical modification in assessing and reducing positive surgical margins ( psms ) during robotic radical prostatectomy and robotic partial nephrectomy . in the current study , we extend the same principle to the management of bca . for each patient age at surgery , sex , body mass index ( bmi ) , history of abdominal surgery , risk factors for bca , tumor characteristics , neo - adjuvant therapy and operative details were recorded . perioperative outcomes evaluated included surgery times , blood loss , surgical margins , hospital stay and complications . disease recurrence and survival endpoints were also assessed , with a minimum and median follow - up of 12 and 38.9 months , respectively . lastly , at the time of the last follow - up patients were surveyed to assess regret and satisfaction with treatment using previously validated questionnaires . regret was assessed by the following 3 questions : ( 1 ) the man / woman 's wish that he / she could change his / her mind about the kind of treatment he / she had received ; ( 2 ) his / her feeling that he / she would be better if he / she had chosen another treatment ; ( 3 ) whether he / she was bothered by the fact that others received different treatment for their bca ( the responses were : " none of the time , " " a little of the time , " " some of the time , " " most of the time " or " all of the time " - no regret was defined as " none or a little of the time " ) . satisfaction was assessed by the following 3 questions : ( 1 ) how would you rate your overall satisfaction with your treatment choice ? ; ( 2 ) how would you rate your satisfaction with regards to urinary control ? ; ( 3 ) how would you rate your satisfaction with regards to cancer control ? ( the responses were : " extremely satisfied , " " satisfied , " " unsure , " " dissatisfied " or " extremely dissatisfied " - satisfaction was defined as " extremely satisfied or satisfied " ) . in the 5 patients undergoing m - rapc , the gelpoint device allowed for rapid specimen extraction without compromising the pneumoperitoneum . after induction of general anesthesia , the patient was placed in supine position and the gelpoint access port was inserted supraumbilically through a 4- to 5-cm vertical incision . next , the gelseal cap , prepared with a 12-mm camera port and a 10-mm low profile port ( fig . linear incisions were made in the gelseal at a tangent to the 10-mm port on the gelseal cap to facilitate specimen retrieval postextirpation . the patient was then placed in steep trendelenburg and 5 additional trocars were inserted under direct vision . two 8-mm robotic ports for the left and right robotic arms were inserted along the left and right paramedian lines at the level of the umbilicus , respectively . a 12-mm assistant port was inserted near the right iliac - fossa along the anterior axillary line , and two 5-mm assistant ports were placed ; one for suction in the epigastrium between the gelpoint and the right robotic port , and the other for the left side assistant in the left iliac fossa ( fig . subsequently , the robot was docked in the side - dock position , along the left foot end , to permit intraoperative cystoscopy . robotic instruments included a fenestrated bipolar grasper in the nondominant hand and monopolar curved scissors in the dominant hand ; the latter instrument was exchanged for a robotic needle driver during reconstruction . depending on tumor location ( table 1 ) , the bladder exposure varied . for cases in which the tumor was located at the dome or the anterior wall of the bladder , the bladder was taken down caudally up to the level of the endopelvic fascia freeing the pedicle lateral to the umbilical ligament . in cases where the tumor was located at the lateral wall or near the ureteral orifice , the procedure began with medialization of the sigmoid colon followed by identification of the ureter at the iliac vessel crossing . next , the bladder was filled with normal saline and a flexible cystoscope was introduced for intraoperative tumor localization ( fig . a robotic ultrasound - probe ( bk medical , peabody , ma , usa ) , passed through the 12-mm assistant port , was also utilized for tumor localization in 2 cases allowing for further confirmation and precise localization of the tumor within the bladder ( fig . when tumor location necessitated vascular pedicle control , this was achieved with hem - o - lock clips , and the superior vesical and inferior vesical arteries were clipped and ligated in succession . following this , using cystoscopic assistance , with or without the robotic ultrasound - probe , the margins of the tumor were delineated and the detrusor muscle was scored circumferentially to achieve a 10- to 20-mm margin ( fig . the bladder mucosa was then entered and the tumor was excised circumferentially without energy . after excision , the tumor was placed in an endo - catch bag ( ethicon surgery inc . , three steps were routinely performed to reduce the potential seeding of the abdominal cavity by cancerous cells ; first , the bladder was drained before entering the mucosa , second , the incised area was held up ( with the help of stay sutures ) until the defect was sutured closed , and lastly , the excised specimen was captured and placed directly into an endo - catch bag without allowing it to touch / rest on adjacent tissue . immediately following excision and extraction of the specimen , the surgeon examined the specimen on - table ( fig . frozen - sections were taken from areas that appeared suspicious for a psm on direct visualization and palpation ( fig . 5c ) , and after being carefully marked for anatomical orientation , were sent for frozen - section analysis ( table 2 ) . if frozen - section yielded unfavorable pathology , more tissue was excised from the in situ complementary site and sent for permanent section . the bladder was then closed in 2 layers using a 3 - 0 barbed suture and left to closed drainage . the robot was then undocked and the fascia and the skin were closed in a standard manner . post operative cystography was performed on all patients on postoperative day 7 prior to foley catheter removal . statistical analyses were performed using stata - se 12 software ( statacorp - lp , college station , tx , usa ) . student t - test was used for continuous variables and a p - value of < 0.05 was considered significant . institutional review board the mean age was 72.5 years ; 71.4% of the patients were men ( n=5 ) . no patient had a psm ; a potential psm was prevented ( case 6 ) by virtue of m - rapc , as a positive intraoperative frozen - section lead to further tissue excision from the complementary site on the bladder , with subsequent negative surgical margin ( nsm ) ( on the outer side ) on final pathology . one patient developed lymphocele postoperatively requiring drainage ( clavien - dindo grade iiia ) . at a median follow - up of 38.9 months , all patients but one were recurrence free . this patient ( case 6 ) was a high - risk patient who had developed bca secondary to cyclophosphamide therapy for skin lymphoma , and presented with high - grade multiple urothelial carcinomas ( ucs ) clustered together at the dome ( table 1 ) . he developed a superficial recurrence 6 months postsurgery and was managed successfully with transurethral resection of the bladder tumor . he was tumor free at 9-month cystoscopy but had a recurrence again at 12 months . he died the subsequent week from an unrelated condition ( lewy - body disease ) . zero percent of the patients expressed regret and 0% expressed dissatisfaction ( in all 3 domains for both the questions ) . as the incidence of bca continues to rise in the united states and worldwide , pc has gained attention as a potential treatment option for selected patients with muscle invasive bca . to decrease the burden of surgical morbidity , a minimally - invasive approach to pc has been suggested . reported the first case of minimally - invasive pc in a female patient , establishing its feasibility . mariano et al followed suit and reported a case series of 6 patients diagnosed with uc undergoing lpc , with only a single case of recurrence at a median follow - up of 30 months . further established its safety but highlighted that the technical demands of the procedure may limit its adoption . tareen et al .   reported primarily on the utility of rapc in management of benign bladder neoplasms ( 3 out of 4 cases ) while all 3 patients in study by allaparthi et al . underwent rapc for a malignant indication . in our study also , all 7 patients underwent rapc for a malignant indication and we believe this represents the largest experience of rapc in patients with cancer of the bladder . the biggest drawback of rapc , to date , has been the inability to retrieve tissue specimens prior to undocking the robot . intraoperative tissue evaluation is important as it allows the surgeon to inspect the specimen margins grossly as well as send tissue for preliminary pathology review ensuring nsms . the significance of achieving nsms was demonstrated by ashley et al .   in their study of 130 patients undergoing pc ; the authors noted that in multivariable analysis , nsm was one of only 2 predictors that were significantly associated with improved survival . the m - rapc technique overcomes the aforementioned drawback of standard - rapc , and provides the surgeon with the ability to extract the specimen without undocking the robot and send tissue for frozen - section analysis during cystorrhaphy / pelvic lymphadenectomy . by performing cystorrhaphy / pelvic lymphadenectomy while waiting for the results of frozen - section analysis allows the procedure to be completed in a timely fashion . accordingly , we did not note any increase in operative ( p=0.67 ) or console time ( p=0.81 ) for the five m - rapc cases as compared to the 2 standard rapc cases ( table 2 ) . further , all seven patients had favorable perioperative outcomes including minimal blood loss , 1- to 2-day hospital stay , unremarkable cystograms and negative tissue margins . long - term oncological outcomes were also favorable with only 1 patient experiencing a superficial recurrence at a median follow - up of 38.9 months , corroborating previous findings . lastly , we show that patients undergoing rapc have excellent functional outcomes and quality - of - life ( table 2 ) , which to the best of our knowledge has not been reported before for pc patients . the issue of satisfaction and regret becomes important when several potentially equally - efficacious choices exist for management of a particular disease ; in such scenarios , clear portrayal of risk and benefits of each approach and involving patient in the decision making process might lead to higher patient satisfaction and lower regret post - therapy . this is demonstrated in our study by example of patient 6 , as despite having an early recurrence , the patient expressed no regret or dissatisfaction . despite its merits , first , the study represents a retrospective review of prospectively collected data and thus is subject to the biases inherent to retrospective study designs . second , the regret and satisfaction survey results were not obtained at a constant time - interval from the date of surgery for each patient , which might have confounded the survey results . lastly , the sample size is limited . however , this study was done with the aim of testing the feasibility and safety of our new modification to rapc and reporting the early outcomes in the initial patients . nonetheless , keeping in mind these drawbacks and in an effort to overcome them , we hope to pursue a prospective development study ( ideal phase 2a study ) in the near future following the ideal ( idea , development , exploration , assessment and long - term monitoring ) guidelines of surgical innovation proposed by the balliol collaboration . in conclusion , the m - rapc technique is technically feasible , safe , and reproducible ; further , rapc leads to favorable oncological , functional and quality - of - life outcomes in patients eligible for pc .
purposeto describe a novel modification to robot - assisted partial cystectomy ( rapc ) that allows for intraoperative surgical margin assessment by bimanual - examination and frozen - section analysis.materials and methodsa total of 7 patients underwent rapc at a single tertiary - care institution between 2008 and 2013 . 
 the technique evolved over the study - period and permitted real - time intraoperative surgical margin evaluation in the last 5 patients via bimanual - examination and frozen - section analysis , utilizing the gelpoint platform ( a hand - assist device ) . 
 the gelpoint platform was placed through a 4- to 5-cm vertical supraumbilical incision and allowed for rapid retrieval of the bladder specimen without compromising the pneumoperitoneum or prolonging the operative time . 
 perioperative , oncological and functional outcomes were evaluated ; all patients had a minimum 12-month follow - up . at the time of last follow - up , a cross - sectional survey of patients was performed to evaluate regret / satisfaction utilizing validated questionnaires.resultsthe mean age was 72.5 years ; 71.4% of the patients were men ( n=5 ) . 
 all patients underwent rapc for a malignant indication . 
 the mean operative and console times were 291 and 217 minutes , respectively . 
 no patient had a positive surgical margin . 
 mean length - of - stay was 1.7 days . at a median follow - up of 38.9 months 
 , 1 patient experienced a local recurrence 6 months postsurgery . 
 the only mortality was secondary to lewy - body disease , in the same patient , 1 year postoperatively . 
 patient assessment of regret and satisfaction indicated 0% regret and 0% dissatisfaction.conclusionsthe ' modified ' technique of rapc is technically feasible , safe , and reproducible ; further , rapc leads to favorable oncological , functional and quality - of - life outcomes in patients eligible for partial cystectomy .