Robot-Assisted Radical Cystectomy: Extracorporeal vs Intracorporeal Urinary Diversion Extracorporeal Diversiondthe Right Choice for Now Robot-assisted radical cystectomy (RARC) has steadily established itself as a standard treatment for muscle invasive bladder cancer which appears comparable to the gold standard of open radical cystectomy with regard to perioperative and oncologic outcomes based on the available intermediate term data. However, the primary morbidity associated with radical cystectomy remains the urinary diversion. Improvements in perioperative and functional outcomes with RARC will ultimately rest on our ability to refine urinary diversion. Forward progress in urinary diversion requires techniques that are reproducible and achieve consistent evidence-based benefits. Extracorporeal urinary diversion (ECUD) in the setting of RARC was first described by Menon et al.1 Prospective, randomized controlled trials seem to demonstrate that ECUD in the setting of RARC is at least comparable to the open gold standard.2,3 As it stands today, intracorporeal urinary diversion (ICUD) is a technically intensive procedure to add to an already complex surgery. The number of cases needed to “pass” the learning curve for RARC has been suggested as 30, looking only at parameters focused on the extirpative portion of the procedure such as operative time, estimated blood loss, lymph node yield and surgical margin status.4 This learning curve estimate does not specifically consider ICUD as the majority of patients had undergone ECUD. The adoption of ICUD would potentially increase the learning curve number dramatically. However, since RARC is not a high volume surgery compared to robot-assisted radical prostatectomy, the adjusted learning curve of RARC plus ICUD may ultimately take years to achieve and be practical only in select centers. A multiinstitutional report from 2 high volume ICUD centers compiled only 132 orthotopic neobladder cases in 10 years.5 A prolonged learning curve would ultimately be justified if prospective, randomized controlled trials showed an obvious advantage to ICUD. However,
0022-5347/15/1935-1467/0 THE JOURNAL OF UROLOGY® © 2015 by AMERICAN UROLOGICAL ASSOCIATION EDUCATION
while data for ICUD continue to mature, standardized analyses and comparative studies remain severely limited. The International Robotic Cystectomy Consortium recently reported their multiinstitutional analysis of perioperative outcomes comparing ICUD and ECUD in 935 RARC cases and found lower readmission rates with ICUD but no difference in overall complication rate or length of stay between the two groups.6 Unfortunately, retrospectively reviewed data are all that exist comparing ICUD and ECUD, which is neither robust nor mature enough to draw definite conclusions and elicit revolutionary changes in surgical technique. The technique of ECUD also continues to evolve. After RARC, some surgeons may simply make a low midline incision and complete the urinary diversion in an open fashion. However, numerous centers are now using hybrid techniques that re-dock the robot to perform the neobladder-urethral anastomosis and sometimes also the ureteroileal anastomoses. At our center we are currently performing the urethral and ureteral anastomoses robotically.7 The rationale behind this approach is that most surgeons make a 6 to 7 cm incision to remove the specimen anyway, and thus performing the bowel anastomoses and pouch construction through this existing incision makes sense. Open bowel work is familiar to urologists whereas laparoscopic bowel work is not. For the urethral anastomosis, closing the incision and re-docking the robot allow efficient and purposeful use of the robot, accessing the deep pelvis and enabling placement of sutures under direct vision. Robotic ureteroileal anastomoses minimize the dissection of the ureters and allow more accurate orientation of the course of the ureters while performing the anastomoses. Another important benefit of ECUD is that it keeps all urinary diversion options available. Bias may creep in if a surgeon becomes proficient at a certain technique such as intracorporeal ileal conduit, which may influence the surgeon to counsel the patient towards ileal conduit, while the patient may in fact be a better candidate for a continent diversion. Additionally, the extracorporeal technique
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keeps the option of continent cutaneous urinary diversion in the discussion of urinary diversion with patients. Currently ICUD is driven by the theoretical advantages of minimizing evaporative fluid losses, quicker return of bowel function, shorter hospital stay, lower complication rates and earlier return of normal activities. With ECUD, the advantages of decreased intraoperative blood loss and other potential benefits associated with RARC still exist, and minimizing the learning curve and operative times should not be understated. The margin of benefit of ICUD over ECUD remains theoretical at this time. Additionally, the size of the incremental benefit, if present, may ultimately not be significant enough to justify ICUD with respect to cost and the learning curve. The work done by leaders in ICUD is truly remarkable and should be applauded. I believe it is possible that with improving robotic platforms and refining surgical techniques, the learning curve may shorten and ICUD may ultimately be adopted at more centers. However, to justify adding the technically challenging ICUD to an already technically intensive operation, we need undeniable, evidencebased benefits. There are also refinements in ECUD under development which may yet improve outcomes. At this time, with the data available, I do not think the universal adoption of ICUD over ECUD is merited. Kevin G. Chan Division of Urology City of Hope Cancer Center Duarte, California
Intracorporeal DiversiondCompleting the Learning Curve Although the number of robot-assisted radical cystectomies performed in the United States is steadily increasing, less than 20% are currently performed robotically.8 The majority of these procedures continue to be completed with an extracorporeal urinary diversion.9 A recent review panel concluded that although oncologic data remain immature, lymph node yields and positive surgical margin rates were similar between open and robotassisted radical cystectomy.10 The centers with followup to 5 years showed similar results to open series for cancer specific survival and overall survival. While these reports are optimistic about the future of RARC, they also highlight that RARC is evolving and gradually being adopted. There remains ongoing debate as to whether the urinary diversion in RARC is best completed extracorporeally or intracorporeally. Two important aspects fundamental to this debate are 1) is it technically
feasible to routinely perform an intracorporeal urinary diversion that does not result in increased complication rates and 2) most importantly, is it advantageous to the patient? A recent report assessing the learning curve for totally intracorporeal RARC with intracorporeal neobladder concluded that it can be introduced and performed safely at a high volume center without compromising perioperative and pathological outcomes if a standardized approach is adopted within an experienced robotic team.11 These authors also concluded that an experienced team and mentor can impact the learning curve of a new surgeon, resulting in decreased operation times early in the series, and reducing conversion and complication rates. Important aspects were noted to be quality measuring, data sharing and replicating identified technical modifications that resulted in superior outcomes. However a commonly held perception remains that an intracorporeal approach is more complex surgery, associated with higher complication rates. To understand the origin of this perception we need to look at the history of the technique. When the pioneers of minimally invasive surgery first performed laparoscopic radical cystectomy, there were significant complications associated with intracorporeal urinary diversion, leading surgeons to conclude that an intracorporeal approach should be avoided.12 However, this conclusion was based on standard laparoscopic surgery outcomes and not robotic surgery, and the results reflected the early learning curve (discovery curve) in a pioneering laparoscopic procedure. The evidence and opinion in the literature are gradually changing. As previously mentioned, the International Robotic Cystectomy Consortium found no difference in reoperation rates between ECUD and ICUD at 30 days.6 However, patients who underwent ICUD were at a lower risk of experiencing a postoperative complication at 90 days (odds ratio 0.68, 95% CI 0.50e0.94, p¼0.02) and gastrointestinal complications were significantly lower in those patients (p 0.001). So what oncologic and functional outcomes could an intracorporeal approach potentially effect and improve? The 3 primary components of RARC are radical cystectomy, extended pelvic lymph node dissection and urinary diversion. As the oncologic part of the operation is completed before urinary diversion, it is unlikely that the approach to urinary diversion will impact oncologic outcomes. A recent review of various centers at which extracorporeal or intracorporeal urinary diversion is performed supports this view, showing no significant differences in positive surgical margin rates, lymph node yields or cancer specific and overall survival estimates among the various centers.10
A completely intracorporeal RARC approach avoids a mini-laparotomy. The aforementioned decreased gastrointestinal complications in the intracorporeal group may be related to reduced bowel handling and exposure. Other potential advantages include less intraoperative blood loss, quicker return of bowel function, shorter hospital stay and earlier return to normal activities, all of which would theoretically allow more timely administration of adjuvant chemotherapy when required. There are also differences in the ureteroileal anastomosis. While ECUD requires the anastomoses to be made outside of the abdominal cavity, an intracorporeal approach enables the anastomoses to be made at the position they will remain in after the operation is completed, resulting in less mobilization of the ureters and less tension. Ureteral strictures and ileal ureteral leaks are recognized complications associated with ureteral ischemia and trauma, both of which may be more readily avoided with an intracorporeal approach. Using an intracorporeal approach at our institution the postoperative ureteral stricture rate was