Opposing Views
Radical Cystectomy: Open vs Robotic Approach ROBOTIC APPROACH THE standard of care for the treatment of muscle invasive bladder cancer is open radical cystectomy (ORC), extended lymph node dissection and creation of urinary diversion. Between 2001 and 2010 approximately 7,000 radical cystectomies were performed in the U.S. annually. With the wide adoption of robotic surgery in urological oncology and reconstructive urology, robotic assisted radical cystectomy (RARC) is being performed more often in the U.S. From 2004 to 2010 the percentage of cystectomies performed robotically increased from 0.6% to 12.8%.1 Most academic and referral centers for muscle invasive bladder cancer routinely perform RARC now, and expanding published data are accumulating. Because of the complexity of open radical cystectomy, extended lymph node dissection and creation of urinary diversion, it has been adopted slower than robotic radical prostatectomy and partial nephrectomy. However, the anatomic borders, steps of the operation and oncologic principles are equivalent for both techniques. In fact, the transition from ORC to RARC for urologists who routinely performed robotic surgery and radical cystectomy has been easy. RARC can be performed on octogenarians and those who have undergone previous abdominal surgery or pelvic radiation. The urinary reconstruction is most commonly done through an extracorporeal approach, however some centers are routinely performing this intracorporeally with good early short-term results. With the improved visualization of robotics and tamponading effect of pneumoperitoneum, blood loss has been less with the robotic vs open approach (568 vs 730 ml).2 Consistently, transfusion rates have been higher with the open approach. Although the presence of soft tissue margins is lower for RARC than ORC, the margin rates for pT2 and pT3 disease are similar for both techniques with a tendency to be higher for pT4 disease (39% vs 24%). Lymph node dissection yields are similar with both techniques. For RARC, extended lymph node dissection can be routinely performed cranial up to the inferior mesenteric artery, including
0022-5347/15/1932-0400/0 THE JOURNAL OF UROLOGY® © 2015 by AMERICAN UROLOGICAL ASSOCIATION EDUCATION
400
j
www.jurology.com
AND
RESEARCH, INC.
circumferential dissection of all pelvic and lower retroperitoneal lymph nodes.3 Average nodal counts with dissections to the aortic bifurcation yielded 37 in ORC and RARC cases.4 Although the length of hospital stay varies greatly among institutions due to different practice patterns, comorbidity and use of enhanced recovery after surgery protocols, on average stay is shorter for RARC cases. Standardized reporting of complications has not been done consistently, and complication rates vary between 34% and 80%. The International Robotic Cystectomy Consortium reported complication rates of 41% at 30 days and 48% at 90 days.5 Conversely, in a large single institution series of ORC the complication rate was 64% at 90 days.6 Using the same standardized reporting protocol, a large single institution RARC series had a 90-day complication rate of 77.5% but 70% of these patients had a continent urinary diversion.7 It is difficult to compare all series due to the variance in patient population as well as collection and interpretation of data. Bochner et al performed a single institution, randomized controlled trial comparing ORC and RARC which was powered assuming the study would detect a 20% lower complication rate and shorter length of stay.2 The study was closed when an interim analysis showed no difference in the 90-day Clavien grade 2 to 5 complications. Complication rates were 66% for ORC and 62% for RARC (p¼0.7). Recurrence-free survival is more important than overall survival when examining the oncologic efficacy of the techniques. The 5-year recurrencefree survival for RARC ranges from 52% to 74%, which is similar to open series.8 Long-term data will be needed establish equivalence. During the last decade the number of RARCs performed has increased tremendously, following the minimally invasive urological oncology trends of extirpative treatment of cancer. The ergonomic benefits along with comparable outcomes have created a lot of interest among urologists who perform oncology and robotic surgery. Radical cystectomy is a morbid and complex procedure performed in sick patients at low volume by most urologists. However in a short time RARC has
http://dx.doi.org/10.1016/j.juro.2014.11.079 Vol. 193, 400-402, February 2015 Printed in U.S.A.
OPPOSING VIEWS
shown equivalence to ORC in complication rates, lymph node yields, soft tissue margin rates and intermediate term cancer-free survival. The RAZOR (RAndomiZed Open versus Robotic cystectomy) trial, a multi-institutional randomized noninferior phase 3 project comparing ORC to RARC, is under way with data likely available in 2017.9 I believe the outcomes are more a reflection of the skill and experience of the surgical team, coordinated hospital care and commitment to taking care of these patients after surgery than the technology. However, with increased experience, and the development of better robotic instrumentation and platforms, RARC may become the preferred and most commonly used technique of surgical extirpation of muscle invasive bladder cancer. Clayton Stephen Lau Division of Urologic Oncology Department of Surgery City of Hope National Medical Center Duarte, California
OPEN APPROACH Open radical cystectomy remains the gold standard treatment for high grade invasive bladder cancer. With widespread adoption of the robotic surgical platform in urology, robotic assisted radical cystectomy has increased from 0.6% of all cystectomies in 2004 to 12.8% in 2010.1 Whether surgical extirpation is performed through a single open incision or through several small laparoscopic ports likely makes little difference as long as oncologic principles are not compromised. Bladder cancer is an unforgiving disease with poor outcomes associated with positive surgical margins and low lymph node yields. We believe that RARC has yet to demonstrate equivalent oncologic efficacy or improved perioperative morbidity compared to ORC. Lymph Node Yield A meticulous pelvic lymphadenectomy remains an important component in the management of bladder cancer with several studies demonstrating improved staging and potential therapeutic benefit for pathologically proven node positive and node negative cases. Increasing nodal yields of 15, 25 and 45 nodes have been associated with an increasing probability of detecting node positive disease at 50%, 75% and 90%, respectively.10 The International Robotic Cystectomy Consortium demonstrated a median nodal yield of 18 on extended lymph node dissection during RARC.11 Interestingly, 17.1% of patients had fewer than 10 nodes removed and 1.3% had no nodal tissue removed.3 Two single institution randomized trials demonstrated comparable nodal yields between ORC and RARC.12,13 Node counts alone may not be the best
401
surrogate for the completeness or extent of the lymphadenectomy, and more accurate measures are needed to make meaningful comparisons. A prospective study incorporated a second-look open dissection following RARC and demonstrated a median yield of 93% of the total nodes removed.14 The authors noted that depending on the robot model used, lymph node yields were as low as 70% of that with the open second-look dissection. The lymphadenectomy is at risk of being compromised via the robotic approach, which is evident when performed by less experienced surgeons having significantly lower nodal yields on extended lymphadenectomy.3 While the optimal extent of lymphadenectomy continues to be debated, multiple surgical series have demonstrated that long-term recurrence-free survival can be achieved in up to 25% of patients with node positive disease. Perhaps the more important consideration is the commitment of the urological surgeon to performing a meticulous node dissection, regardless of the robot. Positive Surgical Margins Positive surgical margins (PSMs) at the time of cystectomy portend a poor prognosis. Patients with PSMs compared to those with negative margins have decreased 5-year recurrence-free survival, shorter time to recurrence and decreased 5-year disease specific survival.15 Local pelvic recurrences following cystectomy are almost always fatal. Historical rates of PSMs at ORC are around 4.2%, with PSMs occurring primarily in those with extravesical disease.15 Organ confined tumors should have neglible rates of PSMs with either approach. Several studies have indicated comparable overall PSM rates between ORC and RARC, ranging between 0% and 9%.12,13,16 These studies noted only overall PSM status, which precludes stratification of PSMs by pathological stage. Hellenthal et al reported an overall PSM rate for RARC of 6.8%, with 1.6% for organ confined and 16.6% for extravesical disease.17 While we are unable to draw conclusions comparing this study to historical controls, the higher rate of PSMs in the extravesical disease cohort warrants critical investigation, as patients with larger disease burden may not be optimally served by minimally invasive approaches. Perioperative Outcomes Radical cystectomy remains a morbid procedure, with complication rates reported as high as 64%.6 Johar et al demonstrated a 48% overall complication rate, 20% rehospitalization rate and 4.2% mortality rate.5 Styn et al reported a propensity matched analysis of RARC vs ORC, showing no difference in 30-day complications, length of stay or rehospitalizations.18 Similarly, a prospective, nonrandomized
402
OPPOSING VIEWS
analysis of RARC and ORC demonstrated no difference in the overall rate of 90-day complications, emergency department visits and readmissions.16 Few randomized trials comparing ORC to RARC have demonstrated similar perioperative outcomes.2,12,13 Bochner et al randomized 58 patients to ORC and 60 to RARC and found no difference in Clavien 2 to 5 complications (66% vs 62%) or mean length of stay (8 vs 8 days).2 Nix12 and Parekh13 et al also reported no difference in complications or length of stay. These studies suggest that there is little benefit to RARC in terms of perioperative complications. Conclusion Invasive bladder cancer is a lethal disease if not treated appropriately. The operative approach may
not necessarily be the most important factor as long as one is committed to adhering to time-honored oncologic principles. The evolution towards a less invasive treatment should not come at the expense of a properly performed lymphadenectomy, wide resection margins or the options for continent lower urinary tract reconstruction. There does not appear to be any clinical benefit to RARC in terms of perioperative outcomes. Ongoing prospective clinical trials, such as RAZOR,9 will hopefully shed light on the lingering question of oncologic efficacy of robotic cystectomy. Robert H. Blackwell and Marcus L. Quek Department of Urology Loyola University Medical Center Maywood, Illinois
REFERENCES 1. Leow JJ, Reese SW, Jiang W et al: Propensitymatched comparison of morbidity and costs of open and robotic assisted radical cystectomies: a contemporary population based analysis in the United States. Eur Urol 2014; 66: 569. 2. Bochner BH, Sjoberg DD and Laudone VP: A randomized trial of robotic assisted laparoscopic radical cystectomy. N Engl J Med 2014; 371: 389. 3. Hellenthal NJ, Hussain A, Andrews PE et al: Lymphadenectomy at the time of roboticassisted radical cystectomy: results from the International Robotic Cystectomy Consortium. BJU Int 2011; 107: 642. 4. Abaza R, Dangle PP, Gong M et al: Quality of lympadenectomy is equivalent in robotic and open cystectomy using the same template. J Urol 2012; 187: 1200. 5. Johar RS, Hayn MH, Stegmann AP et al: Complications after robotic assisted radical cystectomy: results from the International Robotic Cystectomy Consortium. Eur Urol 2013; 64: 52. 6. Shabsigh A, Korets R, Vora KC et al: Defining morbidity of radical cystectomy for patients with bladder cancer using a standardized reporting methodology. Eur Urol 2009; 5: 164.
7. Nazmy M, Yuh B, Kawachi M et al: Early and late complications of robotic assisted cystectomy: a standardized analysis by urinary diversion type. J Urol 2014; 191: 681. 8. Yuh B, Torrey RR, Ruel NH et al: Intermediateterm oncologic outcomes of robotic assisted radical cystectomy for urothelial cancer. J Endourol 2014; 28: 939. 9. Smith ND, Castle EP, Gonzalgo ML et al: The RAZOR trial d randomized open versus robotic cystectomy d study design and trial update. BJU Int 2014; Epub ahead of print. 10. Capitanio U, Suardi N, Shariat SF et al: Assessing the minimum number of lymph nodes needed at radical cystectomy in patients with bladder cancer. BJU Int 2009; 103: 1359. 11. Marshall SJ, Hayn MH, Stegemann AP et al: Impact of surgeon and volume on extended lymphadenectomy at the time of robot-assisted radical cystectomy: results from the International Robotic Cystectomy Consortium (IRCC). BJU Int 2013; 111: 1075. 12. Nix J, Smith A, Kurpad R et al: Prospective randomized controlled trial of robotic versus open radical cystectomy for bladder cancer:
perioperative and pathologic results. Eur Urol 2010; 57: 196. 13. Parekh DJ, Messer J, Fitzgerald J et al: Perioperative outcomes and oncologic efficacy from a pilot prospective randomized clinical trial of open versus robotic assisted radical cystectomy. J Urol 2013; 189: 474. 14. Davis JW and Kamat AM: Lymphadenectomy with robotic cystectomy. Curr Urol Rep 2013; 14: 59. 15. Dotan ZA, Kavanagh K, Yossepowitch O et al: Positive surgical margins in soft tissue following radical cystectomy for bladder cancer and cancer specific survival. J Urol 2007; 178: 2308. 16. Ng CK, Kauffman EC, Lee MM et al: A comparison of postoperative complications in open versus robotic cystectomy. Eur Urol 2010; 57: 274. 17. Hellenthal NJ, Hussain A, Andrews PE et al: Surgical margin status after robot assisted radical cystectomy: results from the International Robotic Cystectomy Consortium. J Urol 2010; 184: 87. 18. Styn NR, Montgomery JS, Wood DP et al: Matched comparison of robotic-assisted and open radical cystectomy. Urology 2012; 79: 1303.
Radical Cystectomy: Open vs Robotic Approach ROBOTIC APPROACH THE standard of care for the treatment of muscle invasive bladder cancer is open radical cystectomy (ORC), extended lymph node dissection and creation of urinary diversion. Between 2001 and 2010 approximately 7,000 radical cystectomies were performed in the U.S. annually. With the wide adoption of robotic surgery in urological oncology and reconstructive urology, robotic assisted radical cystectomy (RARC) is being performed more often in the U.S. From 2004 to 2010 the percentage of cystectomies performed robotically increased from 0.6% to 12.8%.1 Most academic and referral centers for muscle invasive bladder cancer routinely perform RARC now, and expanding published data are accumulating. Because of the complexity of open radical cystectomy, extended lymph node dissection and creation of urinary diversion, it has been adopted slower than robotic radical prostatectomy and partial nephrectomy. However, the anatomic borders, steps of the operation and oncologic principles are equivalent for both techniques. In fact, the transition from ORC to RARC for urologists who routinely performed robotic surgery and radical cystectomy has been easy. RARC can be performed on octogenarians and those who have undergone previous abdominal surgery or pelvic radiation. The urinary reconstruction is most commonly done through an extracorporeal approach, however some centers are routinely performing this intracorporeally with good early short-term results. With the improved visualization of robotics and tamponading effect of pneumoperitoneum, blood loss has been less with the robotic vs open approach (568 vs 730 ml).2 Consistently, transfusion rates have been higher with the open approach. Although the presence of soft tissue margins is lower for RARC than ORC, the margin rates for pT2 and pT3 disease are similar for both techniques with a tendency to be higher for pT4 disease (39% vs 24%). Lymph node dissection yields are similar with both techniques. For RARC, extended lymph node dissection can be routinely performed cranial up to the inferior mesenteric artery, including
0022-5347/15/1932-0400/0 THE JOURNAL OF UROLOGY® © 2015 by AMERICAN UROLOGICAL ASSOCIATION EDUCATION
400
j
www.jurology.com
AND
RESEARCH, INC.
circumferential dissection of all pelvic and lower retroperitoneal lymph nodes.3 Average nodal counts with dissections to the aortic bifurcation yielded 37 in ORC and RARC cases.4 Although the length of hospital stay varies greatly among institutions due to different practice patterns, comorbidity and use of enhanced recovery after surgery protocols, on average stay is shorter for RARC cases. Standardized reporting of complications has not been done consistently, and complication rates vary between 34% and 80%. The International Robotic Cystectomy Consortium reported complication rates of 41% at 30 days and 48% at 90 days.5 Conversely, in a large single institution series of ORC the complication rate was 64% at 90 days.6 Using the same standardized reporting protocol, a large single institution RARC series had a 90-day complication rate of 77.5% but 70% of these patients had a continent urinary diversion.7 It is difficult to compare all series due to the variance in patient population as well as collection and interpretation of data. Bochner et al performed a single institution, randomized controlled trial comparing ORC and RARC which was powered assuming the study would detect a 20% lower complication rate and shorter length of stay.2 The study was closed when an interim analysis showed no difference in the 90-day Clavien grade 2 to 5 complications. Complication rates were 66% for ORC and 62% for RARC (p¼0.7). Recurrence-free survival is more important than overall survival when examining the oncologic efficacy of the techniques. The 5-year recurrencefree survival for RARC ranges from 52% to 74%, which is similar to open series.8 Long-term data will be needed establish equivalence. During the last decade the number of RARCs performed has increased tremendously, following the minimally invasive urological oncology trends of extirpative treatment of cancer. The ergonomic benefits along with comparable outcomes have created a lot of interest among urologists who perform oncology and robotic surgery. Radical cystectomy is a morbid and complex procedure performed in sick patients at low volume by most urologists. However in a short time RARC has
http://dx.doi.org/10.1016/j.juro.2014.11.079 Vol. 193, 400-402, February 2015 Printed in U.S.A.
OPPOSING VIEWS
shown equivalence to ORC in complication rates, lymph node yields, soft tissue margin rates and intermediate term cancer-free survival. The RAZOR (RAndomiZed Open versus Robotic cystectomy) trial, a multi-institutional randomized noninferior phase 3 project comparing ORC to RARC, is under way with data likely available in 2017.9 I believe the outcomes are more a reflection of the skill and experience of the surgical team, coordinated hospital care and commitment to taking care of these patients after surgery than the technology. However, with increased experience, and the development of better robotic instrumentation and platforms, RARC may become the preferred and most commonly used technique of surgical extirpation of muscle invasive bladder cancer. Clayton Stephen Lau Division of Urologic Oncology Department of Surgery City of Hope National Medical Center Duarte, California
OPEN APPROACH Open radical cystectomy remains the gold standard treatment for high grade invasive bladder cancer. With widespread adoption of the robotic surgical platform in urology, robotic assisted radical cystectomy has increased from 0.6% of all cystectomies in 2004 to 12.8% in 2010.1 Whether surgical extirpation is performed through a single open incision or through several small laparoscopic ports likely makes little difference as long as oncologic principles are not compromised. Bladder cancer is an unforgiving disease with poor outcomes associated with positive surgical margins and low lymph node yields. We believe that RARC has yet to demonstrate equivalent oncologic efficacy or improved perioperative morbidity compared to ORC. Lymph Node Yield A meticulous pelvic lymphadenectomy remains an important component in the management of bladder cancer with several studies demonstrating improved staging and potential therapeutic benefit for pathologically proven node positive and node negative cases. Increasing nodal yields of 15, 25 and 45 nodes have been associated with an increasing probability of detecting node positive disease at 50%, 75% and 90%, respectively.10 The International Robotic Cystectomy Consortium demonstrated a median nodal yield of 18 on extended lymph node dissection during RARC.11 Interestingly, 17.1% of patients had fewer than 10 nodes removed and 1.3% had no nodal tissue removed.3 Two single institution randomized trials demonstrated comparable nodal yields between ORC and RARC.12,13 Node counts alone may not be the best
401
surrogate for the completeness or extent of the lymphadenectomy, and more accurate measures are needed to make meaningful comparisons. A prospective study incorporated a second-look open dissection following RARC and demonstrated a median yield of 93% of the total nodes removed.14 The authors noted that depending on the robot model used, lymph node yields were as low as 70% of that with the open second-look dissection. The lymphadenectomy is at risk of being compromised via the robotic approach, which is evident when performed by less experienced surgeons having significantly lower nodal yields on extended lymphadenectomy.3 While the optimal extent of lymphadenectomy continues to be debated, multiple surgical series have demonstrated that long-term recurrence-free survival can be achieved in up to 25% of patients with node positive disease. Perhaps the more important consideration is the commitment of the urological surgeon to performing a meticulous node dissection, regardless of the robot. Positive Surgical Margins Positive surgical margins (PSMs) at the time of cystectomy portend a poor prognosis. Patients with PSMs compared to those with negative margins have decreased 5-year recurrence-free survival, shorter time to recurrence and decreased 5-year disease specific survival.15 Local pelvic recurrences following cystectomy are almost always fatal. Historical rates of PSMs at ORC are around 4.2%, with PSMs occurring primarily in those with extravesical disease.15 Organ confined tumors should have neglible rates of PSMs with either approach. Several studies have indicated comparable overall PSM rates between ORC and RARC, ranging between 0% and 9%.12,13,16 These studies noted only overall PSM status, which precludes stratification of PSMs by pathological stage. Hellenthal et al reported an overall PSM rate for RARC of 6.8%, with 1.6% for organ confined and 16.6% for extravesical disease.17 While we are unable to draw conclusions comparing this study to historical controls, the higher rate of PSMs in the extravesical disease cohort warrants critical investigation, as patients with larger disease burden may not be optimally served by minimally invasive approaches. Perioperative Outcomes Radical cystectomy remains a morbid procedure, with complication rates reported as high as 64%.6 Johar et al demonstrated a 48% overall complication rate, 20% rehospitalization rate and 4.2% mortality rate.5 Styn et al reported a propensity matched analysis of RARC vs ORC, showing no difference in 30-day complications, length of stay or rehospitalizations.18 Similarly, a prospective, nonrandomized
402
OPPOSING VIEWS
analysis of RARC and ORC demonstrated no difference in the overall rate of 90-day complications, emergency department visits and readmissions.16 Few randomized trials comparing ORC to RARC have demonstrated similar perioperative outcomes.2,12,13 Bochner et al randomized 58 patients to ORC and 60 to RARC and found no difference in Clavien 2 to 5 complications (66% vs 62%) or mean length of stay (8 vs 8 days).2 Nix12 and Parekh13 et al also reported no difference in complications or length of stay. These studies suggest that there is little benefit to RARC in terms of perioperative complications. Conclusion Invasive bladder cancer is a lethal disease if not treated appropriately. The operative approach may
not necessarily be the most important factor as long as one is committed to adhering to time-honored oncologic principles. The evolution towards a less invasive treatment should not come at the expense of a properly performed lymphadenectomy, wide resection margins or the options for continent lower urinary tract reconstruction. There does not appear to be any clinical benefit to RARC in terms of perioperative outcomes. Ongoing prospective clinical trials, such as RAZOR,9 will hopefully shed light on the lingering question of oncologic efficacy of robotic cystectomy. Robert H. Blackwell and Marcus L. Quek Department of Urology Loyola University Medical Center Maywood, Illinois
REFERENCES 1. Leow JJ, Reese SW, Jiang W et al: Propensitymatched comparison of morbidity and costs of open and robotic assisted radical cystectomies: a contemporary population based analysis in the United States. Eur Urol 2014; 66: 569. 2. Bochner BH, Sjoberg DD and Laudone VP: A randomized trial of robotic assisted laparoscopic radical cystectomy. N Engl J Med 2014; 371: 389. 3. Hellenthal NJ, Hussain A, Andrews PE et al: Lymphadenectomy at the time of roboticassisted radical cystectomy: results from the International Robotic Cystectomy Consortium. BJU Int 2011; 107: 642. 4. Abaza R, Dangle PP, Gong M et al: Quality of lympadenectomy is equivalent in robotic and open cystectomy using the same template. J Urol 2012; 187: 1200. 5. Johar RS, Hayn MH, Stegmann AP et al: Complications after robotic assisted radical cystectomy: results from the International Robotic Cystectomy Consortium. Eur Urol 2013; 64: 52. 6. Shabsigh A, Korets R, Vora KC et al: Defining morbidity of radical cystectomy for patients with bladder cancer using a standardized reporting methodology. Eur Urol 2009; 5: 164.
7. Nazmy M, Yuh B, Kawachi M et al: Early and late complications of robotic assisted cystectomy: a standardized analysis by urinary diversion type. J Urol 2014; 191: 681. 8. Yuh B, Torrey RR, Ruel NH et al: Intermediateterm oncologic outcomes of robotic assisted radical cystectomy for urothelial cancer. J Endourol 2014; 28: 939. 9. Smith ND, Castle EP, Gonzalgo ML et al: The RAZOR trial d randomized open versus robotic cystectomy d study design and trial update. BJU Int 2014; Epub ahead of print. 10. Capitanio U, Suardi N, Shariat SF et al: Assessing the minimum number of lymph nodes needed at radical cystectomy in patients with bladder cancer. BJU Int 2009; 103: 1359. 11. Marshall SJ, Hayn MH, Stegemann AP et al: Impact of surgeon and volume on extended lymphadenectomy at the time of robot-assisted radical cystectomy: results from the International Robotic Cystectomy Consortium (IRCC). BJU Int 2013; 111: 1075. 12. Nix J, Smith A, Kurpad R et al: Prospective randomized controlled trial of robotic versus open radical cystectomy for bladder cancer:
perioperative and pathologic results. Eur Urol 2010; 57: 196. 13. Parekh DJ, Messer J, Fitzgerald J et al: Perioperative outcomes and oncologic efficacy from a pilot prospective randomized clinical trial of open versus robotic assisted radical cystectomy. J Urol 2013; 189: 474. 14. Davis JW and Kamat AM: Lymphadenectomy with robotic cystectomy. Curr Urol Rep 2013; 14: 59. 15. Dotan ZA, Kavanagh K, Yossepowitch O et al: Positive surgical margins in soft tissue following radical cystectomy for bladder cancer and cancer specific survival. J Urol 2007; 178: 2308. 16. Ng CK, Kauffman EC, Lee MM et al: A comparison of postoperative complications in open versus robotic cystectomy. Eur Urol 2010; 57: 274. 17. Hellenthal NJ, Hussain A, Andrews PE et al: Surgical margin status after robot assisted radical cystectomy: results from the International Robotic Cystectomy Consortium. J Urol 2010; 184: 87. 18. Styn NR, Montgomery JS, Wood DP et al: Matched comparison of robotic-assisted and open radical cystectomy. Urology 2012; 79: 1303.
