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Page 2 of 8 Balzano et al. Mini-invasive Surg 2021;5:41 https://dx.doi.org/10.20517/2574-1225.2021.49

status of intracorporeal and extracorporeal continent urinary diversion in the setting of RARC. We evaluate
the most contemporary data examining operative and postoperative metrics used to assess intracorporeal
and extracorporeal approaches to continent diversions.

EXTRACORPOREAL DEFINITION
The definition of an extracorporeal diversion varies among surgeons. For many, this means making a
laparotomy incision and performing the entirety of the procedure open. For others, a more hybrid approach
is used that involves making a much smaller 5-7 cm incision and utilizing the robot to perform the urethral
and/or ureteral anastomoses. This difference cannot be under-emphasized, as the hybrid approach allows
for the possibility of less ureteral mobilization as well as a more precise urethral anastomosis for the
orthotopic diversions. While the literature does not readily differentiate between the two, we will herein
assume they are all the same for the purpose of this discussion.

LEARNING CURVE
The learning curve associated with intracorporeal continent urinary diversion should not be understated.
There have been estimations of the learning curve for RARC and the agreement of 21-30 cases for this
specific procedure has been reached to accomplish a lymph node yield of 20 as well as a positive surgical
[6]
margin rate of 5% or lower . While this may not seem like a large number of cases, “high volume centers”
[7]
are 4-6 cases per year while “very high volume” centers are 7+ RARC/year . This means that for a surgeon
transitioning to intracorporeal diversions, it could take many years to cover the 30 cases required for the
extirpative portion of the surgery alone.

Some groups have attempted to overcome this by having a clear mentor and mentee set-up with a set
[8]
number of cases required to be performed together before operating independently . In addition to this,
some also have a group of nurses and technicians that exclusively work robotic cases and are present for all
their diversion cases. While this would indeed aid with the learning curve, this is not feasible in all
institutions.

OPERATIVE TIME
As we continue to move forward in the robotic era, the ever-pressing question continues to arise, “why
should we continue to perform extracorporeal diversions over intracorporeal?” One of the big arguments is
shorter operative times. Operative times from experienced surgeons range from 265-760 min for
[9]
intracorporeal neobladders, while extracorporeal are 285-401 [10,11] . Even in the most experienced hands,
58%-64% of patients experience a complication within the first 90 days after radical cystectomy regardless of
how the diversion is performed [12,13] .

Zhang et al. recently published their data of 948 patients with 26 months of follow-up looking at
[14]
intracorporeal diversions vs. RARC and open diversion vs. open radical cystectomy with open diversion.
They found that the open radical cystectomy with open diversion had the shortest operative time. This
intuitively makes sense and continues to be a motivating factor towards open diversions to attempt to
[13]
minimize the operative time of an already long procedure. Novara et al. found similar outcomes with
shorter operative times associated with the open cystectomy. Shim et al. looked specifically at
[15]
intracorporeal diversions compared to extracorporeal and found the operative time to also be significantly
longer with the intracorporeal urinary diversion. Lenfant et al. also found that surgeons were less likely to
[10]
offer a patient with an ASA score ≥ 3 an intracorporeal urinary diversion given the potentially longer
exposure to Trendelenburg position with pneumoperitoneum. This difference cannot be ignored when
comparing these two surgical approaches and must remain a continued part of the conversation.