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Table 21.3 Published clinical series on taTME for benign indications
Series Age
(year)
Gender BMI
(kg/m
2
)
Indications Operative
technique
Transanal
platform
Type of resection
De Buck van
Overstraeten
[60]
N =11
34
(22–
66)
M (3),
F (8)
NR UC LA GelPoint
path
Completion proctectomy
Tasende [61]
N =18
40.5
(15.7)
M
(13), F
(5)
26.4
(SD
11.1)
UC LA GelPoint
path
Restorative
proctocolectomy w IPAA
Leo [62]
N =16
46
(26–
70)
M
(10), F
(6)
NR UC LA GelPoint
path
Restorative
proctocolectomy w IPAA
Wolthuis
[63]
N =14
65
(38–
87)
M (5),
F (9)
25 (17–
32)
Fistula (1), IBD (2),
incontinence (1),
circular TVA (2),
complication of
surgery (3), cancer (5)
LA (11),
pure
TAMIS
(3)
GelPoint
path
Coloanal anastomosis (7),
intersphincteric
proctectomy (7)
Bremers [64]
N =9
NR NR NR IBD (6), lynch (1),
collagenous colitis
(1), anastomotic leak
(1)
Transanal TEM Proctectomy
Liyanage
[65]
N =12
66
(SD
13)
M (7),
F (5)
NR IBD (9), neoplasia (2),
proctitis (1)
Transanal TEM Proctectomy
McLemore
[66]
N =6
(22–
74)
M (2),
F (4)
30.5
(22–
51)
Proctitis LA
transanal
GelPoint
path
Completion proctectomy
(2), APR (1), restorative
proctocolectomy with
coloanal anastomosis (1),
restorative
proctocolectomy w IPAA
(1)
Operating
time (min)
Rectal
stump
(cm)
Anastomosis Conversions Intraoperative complications (n) Morbidity
rate
Functional
outcomes
160 (133–
209)
NR Stapled (11) 0 0 2 (18%) NR
170 (90–
300)
NR Stapled (14),
handsewn (2)
0 0 6 (37.5%) Wexner
1.4 (SD
2.9)
247 (185–
470)
NR Stapled (14),
handsewn (2)
3 (18.7%) 0 6 (37.5%) NR
55 (35–
95)
NR handsewn (7),
end-colostomy
(6), end
ileostomy (1)
2 (18%) Maintaining insufflation (2), difficult
view due to bleeding (1), fibrosis due
to prostate radiotherapy (1), rectal
perforation (1),
6 (43%) NR
161 (107–
239)
15 (8–
20)
NR 1 (11%) 0 1 (11%) NR
215 (123–
345)
17.8
(SD
6.1)
NR 1 0 6 (50%) NR
294 (176–
557)
8.5 (8–
15)
NR NR 0 3 (50%) NR
F female; IBD inflammatory bowel disease; LA laparoscopic-assisted; M male; NR not reported; TAMIS transanal minimally
invasive surgery; TEM
transanal endoscopic microsurgery; TVA tubulovillous adenoma; UC ulcerative colitis
21 NOTES Transanal Colorectal Resection 253
mesorectum, or in combination with total
mesorectal dissection.
There have been seven series published on
transanal endoscopic proctectomy for benign indi-
cations, describing outcomes in a total of 86 patients
[60–66]. These have been outlined in Table 21.3.
Procedures performed included completion proctec-
tomy, restorative proctocolectomy with coloanal
anastomosis or ileal pouch-anal anastomosis (IPAA),
and APR. These were performed primarily in hybrid
fashion with transabdominal laparoscopic assistance.
Indications were for refractory diversion and radia-
tion proctitis, ulcerative colitis and Crohn’sdisease,
large carpeting villous adenomas of the rectum, fecal
incontinence, rectal strictures, and complex fistulas
[60–66]. The length of the resected retained rectal
stumps ranged from 8 to 30 cm. There were no
deaths or major procedural complications, but three
patients required conversion to open proctectomy
due to intra-abdominal adhesions [62, 63]. The
cumulative morbidity across the series was 35%
(30/86 cases) and included urinary tract infections,
presacral hematoma, several cases of delayed per-
ineal wound healing, a perineal dehiscence requiring
reoperation, an incarcerated parastomal hernia, and a
colocutaneous fistula to the perineum requiring
reoperation. Although these preliminary reports
demonstrate the feasibility and procedural safety of a
primarily transanal endoscopic approach for distal
rectal dissection in ulcerative colitis, data on
short-term pouch function are lacking.
Malignant Indications
Unlike benign disease, proctectomy for rectal
adenocarcinoma strictly requires TME. Oncologi-
cally adequate resection with a complete
mesorectum and negative margins is critical to
minimize the chance of local recurrence, with the
circumferential resection margin being a major
determinant of overall survival following curative
rectal cancer resection. Of critical importance in
the early stages of adoption of taTME was the
demonstration of the feasibility of achieving ade-
quate mesorectal dissection and satisfactory
short-term oncologic outcomes. The major drive
behind increased adoption on this approach has
been the suggested improvement in access to the
low rectum and mesorectum relative to open and
laparoscopic approaches, and an enhanced view of
dissection planes achieved through the transanal
platforms. This bottom-up approach provides a
less obstructed view and manipulation of the
perirectal and mesorectal planes, facilitating the
mesorectal dissection, especially for low rectal
tumors in patients with a narrow pelvis.
Accepted indications and contraindications for
taTME are consistent with indications for laparo-
scopic or robotic TME. Based on standard tumor
staging, taTME is warranted for resectable T1
tumors with high-risk histologic features, T2 tumors,
and T3 tumors. Although early IRB-approved
taTME protocols excluded node-positive disease
and metastatic disease, the current indications for
taTME have expanded to include these patients if
taTME is performed with curative intent, as well as
following treatment with neoadjuvant therapy when
indicated.
Current indications for taTME also highlight
specific tumor and patient characteristics that are
well suited for a primarily transanal approach.
There is no specified upper BMI limit, but
taTME is becoming the preferred approach in
morbidly obese patients with resectable rectal
tumors. For very low rectal tumors located at or
below the dentate line but not invading the
external anal sphincter, taTME can be performed
in continuity with rectal mucosectomy and par-
tial or total ISR in order to achieve negative
distal margins, followed by handsewn anasto-
mosis. For mid-rect al tumors located > 5 cm
above the anal verge and at least 1 cm above the
top of the anorectal ring, full-thickness rectal
transection can be performed starting just below
a purse-string suture placed to occlude the rec-
tum below the tumor, with preservation of the
anal sphincters, and followed by stapled col-
orectal anastomosis. Transanal TME is not
unanimously believed to provide added benefit
to a laparoscopic or robotic approach for rectal
tumors located >10 cm above the anal verge,
with the obvious exception of the obese male.
For these tumors, in an effort to preserve rectal
function, transanal rectal transection is per-
formed well above the anorectal ring followed
by transanal tumor-specific mesorectal excision
and stapled colorectal anastomosis.
Currently, taTME is contraindicated for T4 dis-
ease and tumors with predicted involved CRM,
254 A.P. D’Andrea and P. Sylla
unless there is evidence of significant downstaging
on restaging MRI following neoadjuvant treatment.
Transanal TME is also contraindicated for com-
pletely or near-completely obstructing rectal tumors.
Another relative contraindication, particularly for
less experienced operators, includes prior prostatec-
tomy or other complex pelvic resection, prior pelvic
radiation for gynecologic or urologic malignancies,
and recurrent rectal cancer. This past history in
patients can substantially complicate identification of
the correct dissection planes from the perineal
approach and may increase the risk of organ injury,
particularly of the bladder and urethra [67].
Patient Selection
Transanal NOTES is appropriate for patients with
benign disease or resectable premalignant and
malignant low-to-mid-rectal tumors. These patients
should have no history of extensive abdominal or
pelvic surgery. Transanal TME is suitable for patients
eligible for low anterior resection for low and
mid-rectal tumors, but it is most ef fective in male
patients with a narrow pelvis and in patients with a
high BMI. Patients with recurrent or T4 disease and
those with threatened circumferential resection mar-
gins and minimal to no response to neoadjuvant
treatment are not usually candidates for taTME with
sphincter preservation and most often require APR or
extralevator APR and/or exenteration to achieve an
R0 resection. Of note, taTME with APR and even
extralevator abdominoperineal excision (ELAPE) can
be performed using a transanal approach, especially if
dif ficulty with the perineal and abdominal dissection
is anticipated, as in obese males with a narrow pelvis.
Preoperative Assessment
and Staging
Evaluation of surgical candidates for transanal
endoscopic proctectomy follows the same principles
as for any other approaches to the rectum. Preoper-
ative workup includes a complete medical and sur-
gical history, colonoscopy with biopsies, and a
comprehensive physical examination, including a
digital rectal examination (DRE). Preoperative
assessment should take into account patients’ base-
line activity level, defecatory function, as well as
urinary and sexual function. For newly diagnosed
rectal cancer, laboratory studies including complete
blood count, serum chemistries, liver function tests,
and baseline serum carcinoembryonic antigen level
should be obtained. Staging CT scans of the chest,
abdomen and pelvis should be completed in addition
to a pelvic MRI for tumor staging and to assess the
status of the mesorectal fascia and predict involve-
ment of the CRM. Endorectal ultrasound can be
performed in conjunction with pelvic MRI, particu-
larly in cases where differentiating between T2 and
T3 disease is equivocal on pelvic MRI. Patients with
locally advanced disease should undergo standard
long-course neoadjuvant treatment, although in some
cases, short-course radiation may be elected, and
neoadjuvant treatment may even be avoided alto-
gether in carefully selected T3a rectal tumors [55].
Preoperative DRE should assess baseline anal
sphincter function, localize the tumor within the
rectum, and determine tumor mobility or fixation,
along with distance from the anorectal ring, dentate
line, and anal verge. Preoperative evaluation should
also include proctoscopy or flexible sigmoidoscopy
to localize the rectal tumor and assist surgical
planning. DRE, office endoscopy, and/or pelvic
MRI may be repeated following completion of
neoadjuvant treatment, to assess tumor response, as
that may impact the operative plan with respect to
sphincter preservation. Transanal proctectomy for
rectal cancer is typically performed 8–12 weeks
following completion of neoadjuvant treatment,
which is the standard of care in the management of
locally advanced rectal cancer.
Candidates for sphincter-preserving proctectomy
using transanal assistance should be extensively
counseled regarding temporary fecal diversion, as
well as anticipated functional disturbances and
quality of life issues following ileostomy closure.
This is particularly important for very low rectal
tumors if radiation was administered preoperatively,
and where partial or complete ISR might be required
to achieve negative resection margins.
Preoperative Preparation
With the exception of completion proctectomy,
patients undergoing transanal endoscopic restorative
proctectomy usually undergo mechanical bowel
preparation the night prior to surgery either with a
21 NOTES Transanal Colorectal Resection 255
combination of oral agents and enemas or with
enemas alone. Standard perioperative antibiotic and
thromboembolic prophylaxis is administered par-
enterally. General anesthesia with paralytics is rec-
ommended to avoid leakage of CO
2
during
procedures. However, the surgical team may consider
preoperative epidural placement versus patient-
controlled analgesia postoperatively or transversus
abdominis plane (TAP) block at the end of the
procedure.
Operative Setup
Ample time should be reserved for setup on the day
of surgery. Regarding intraoperative positioning,
most surgeons perform taTME with the patient in
lithotomy position, but completion proctectomy can
be performed in prone position, which can be helpful
in cases where hip flexion is severely limited [66].
Most authors perform on-table rectal irrigation with
dilute betadine. A Foley catheter is routinely placed,
and the abdomen and perineum are both prepped and
draped to allow simultaneous or sequential access
during hybrid transanal procedures.
The amount of space in the operating room
should be taken into consideration. The majority
of taTME procedures are performed using a
hybrid rather than a pure transanal endoscopic
approach. Therefore, procedures can be per-
formed as either a 1-team approach with a single
team performing the abdominal and transanal
dissection sequentially or a 2-team approach with
a transanal team and an abdominal team working
simultaneously (Fig. 21.1). The 2-team approach
is preferred for reasons of safety and decreased
operative time [43, 53]. If a 1-team approach is
used, then it is recommended to have an assistant
on standby for transanal delivery of the colon.
A 2-team approach at this portion of the case is
meant to assist with reach, to ensure correct
orientation of bowel and mesentery, confirm
adequate blood supply, and reduce tension. There
should be one surgical scrub technician with a
table for the transanal team, and another surgical
technician with a table for the abdominal team.
Fig. 21.1 Operative setup
demonstrating 2-team
approach with a transanal
team and an abdominal
team working
simultaneously
256 A.P. D’Andrea and P. Sylla
Depending on the trans anal platform being used,
there must be enough room for one to two sur-
geons to operate transanally. The TAMIS plat-
form requires a dedicated assistant for camera
control, while the TEO/TEM does not. An opti-
mal high-definition video monitor should have a
moveable screen on swivel. There is typically
one located between the legs facing the transanal
surgeon/team at eye level while not obstructing
the operative field of the abdominal team. The
abdominal team requires a video monitor on the
right side of the patient and another on the left.
Instrumentation
The abdominal portion of the case requires instru-
mentation from a standard laparoscopic or robotic
low anterior resection tray, with monopolar hook
and scissors, bipolar vessel sealer, trocars, CO
2
insufflator, suction, irrigation, a pelvic drain, and
supplies to mature a loop ileostomy.
Instrumentation for the transanal portion of
the surgery should include the following:
– Standard anorectal tray with plastic or metal
anoscopes. Our preference is to use the
graduated plastic disposable anoscope that is
part of the procedure for prolapsed hemor-
rhoid (PPH) stapling kit (Medtronic, Min-
neapolis, MN);
– Lone Star disposable retractor;
– Head light;
– TES platform that the operator is familiar
with (TAMIS, TEO, or TEM);
– Monopolar cautery hook or spatula;
– Bipolar device (although dissection with
monopolar cautery is preferred);
– High-flow insufflator and smoke evacuation
system (AirSeal
®
, SurgiQuest, Milford, CT)
has become the preferred system worldwide,
but other high-flow insufflators are available
on the market;
– Suction and irrigation;
– Bariatric length 10-mm camera if a TAMIS
platform is used;
– EEA staplers if a stapled anastomosis is to be
performed;
– Indocyanine green (ICG) fluorescence imag-
ing may be used to assess the perfusion of
colorectal or coloanal anastomoses.
Procedural Steps for taTME
Most surgeons using a 1-team approach will start
with the abdominal dissection, with high ligation
of the inferior mesenteric artery and division of
the inferior mesenteric vein, splenic flexure
takedown, and mobilization of the left colon,
sigmoid, and proximal rectum. The extent of
pelvic dissection is variable, but usually extends
to just above the peritoneal reflection anteriorly,
and to below the sacral promontory posteriorly,
until the deeper mesorectal dissection becomes
technically challenging. The team then transi-
tions to transanal dissection. Occasionally,
transanal dissection will be initiated first, fol-
lowed by abdominal access and dissection.
Whether a 1-team or 2-team simultaneous
approach is utilized, the steps of transanal dis-
section depend on the exact tumor level, i.e.,
distance from the anorectal ring. Following
confirmation of the exact location of the tumor
by digital and visual inspection with anoscopy,
assessment of the required distal margin is made
(Fig. 21.2). For tumors above the anorectal ring,
a purse-string suture is placed 0.5–1 cm below
the rectal tumor. This is completed either directly
through a standard anoscope or endoscopically
through the TES platform (Fig. 21.3). In the
latter case, the transanal platform is inserted first
and then followed by purse-string occlusion of
the rectum. The purse string usually consists of
2-0 Prolene or 2-0 Vicryl sutures based on the
surgeon’s preference. Care must be taken to
ensure that the purse-string suture is airtight to
avoid distention of the proximal colon and spil-
lage of fecal material or tumor cells onto the
operative field (Fig. 21.4).
21 NOTES Transanal Colorectal Resection 257
After purse-string insertion of the transanal
platform and occlusion of the rectum, distention
with CO
2
is achieved to a pressure of 10–12 mm
Hg. The rectal mucosa is scored circumferen-
tially (Fig. 21.5). Full-thickness rectal and
mesorectal mobilization is carried out sequen-
tially using monopolar instruments. Efforts
should be made to avoid the use of bipolar
energy, which is not needed if dissection carries
on along the correct planes. Posterior mesorectal
dissection is carried out along the avascular plane
between the mesorectal fascia and the sacrum,
while anterior dissection is carried between the
rectovaginal or rectoprostatic fascia (Figs. 21.6
and 21.7). Laterally, care must be taken to avoid
dissection of the pelvic sidewall and damage to
Fig. 21.2 View through a plastic anoscope demonstrat-
ing the exact distance between the rectal lesion and the
dentate line
Fig. 21.3 Purse-string suture placement through a plastic
anoscope
Fig. 21.4 Purse-string occlusion of the rectum below the
rectal tumor
Fig. 21.5 Initiation of circumferential rectal transanal
dissection starting just below the purse-string suture
Fig. 21.6 Posterior mesorectal dissection carried out
along avascular plane between the mesorectal fascia and
the sacrum
258 A.P. D’Andrea and P. Sylla
the pelvic plexus (Fig. 21.8). During the antero-
lateral dissection of the rectum and mesorectum,
care must be taken to avoid injury to the neu-
rovascular bundles bilaterally, which may serve
as landmarks for the location of the prostate
when difficulties are encountered durin g anterior
mobilization and identification of the posterior
aspect of the prostate.
Transanal TME dissection is carried out cir-
cumferentially, and in a sequential but symmetric
pattern. Every effort should be made to avoid dis-
secting too far along any given plane to avoid loss of
orientation from distorted tissue planes. Posterior
mesorectal dissection is technically the easiest
because the main landmarks, namely the presacral
fascia and the mesorectal fascia, are readily identi-
fiable. Anteriorly, the dif ficultyistoidentifythe
posterior aspect of the vagina or prostate, which can
becomplicatedwhenstartinglowandhavingto
dissect through the perineal body before identifying
the correct anterior mesorectal plane. Ultimately,
anterior dissection is carried out cephalad until the
peritoneal reflection is reached, which is another
landmark that is readily identifiable. Posteriorly,
depending on the angulation of the sacral promon-
tory, transanal dissection cannot be extended beyond
the top of the sacral promontory and must be
assisted by the abdominal team. Even when using a
1-team approach, abdominal assistance during this
step is critical, as it allows two teams to work
simultaneously to complete mobilization of the
rectum and merge the abdominal and transanal
planes of dissection. Peritoneal entry is usually
performed transanally and under laparoscopic visu-
alization from above (Figs. 21.9 and 21.10).
Following complete mobilization of the TME
specimen, the colon is either exteriorized trans-
anally or through an abdominal incision if the
Fig. 21.7 Anterior mesorectal dissection carried out
between mesorectum and retroprostatic fascia
Fig. 21.8 Lateral mesorectal dissection carried out
between mesorectum and pelvic sidewall
Fig. 21.9 Transanal view of peritoneal entry
Fig. 21.10 Laparoscopic view of peritoneal entry
21 NOTES Transanal Colorectal Resection 259
specimen is too bulky to permit transanal
extraction (Fig. 21.11). After transection of the
specimen, a colorectal stapled anastomosis can
be performed if the rectum was transected well
above the dentate line. A double-purse-string,
circular-stapled anastomosis technique is used
with either end-to-end, side-to-end, coloanal
J-pouch or transverse coloplasty [68]. A protec-
tive loop ileostomy is then constructed with
placement of closed pelvic drains.
For tumors below the anorectal ring, either
partial or complete ISR is performed first to
achieve negative distal margins. ISR is per-
formed through a Lone Star retractor with
monopolar instruments. Dissection is extended
cephalad until the puborectalis muscle and the
bottom of the mesorectum are identified, and the
rectovaginal or retroprostatic plane is visualized
anteriorly. The anorectal stump is then closed
with a purse-string suture, and the transanal
platform is inserted. Further dissection is needed
posteriorly through the anococcygeal raphe to
access the presacral space. The inferior aspect of
the mesorectum can be identified posteriorly, and
the rectovaginal or rectoprostatic plane anteri-
orly, and taTME may then proceed as described
previously. The specimen is extracted and a
handsewn coloanal anastomosis is performed
using end-to-end, side-to-end, coloanal J-pouch,
or transverse coloplasty with a protective ileost-
omy (Figs. 21.12 and 21.13).
Fig. 21.11 Transanal
specimen extraction
Fig. 21.12 Handsewn coloanal anastomosis
260 A.P. D’Andrea and P. Sylla
Alternatives
In patients with ulcerative colitis or familial
adenomatous polyposis (FAP), where a transanal
restorative proctocolectomy or proctectomy with
IPAA would be performed, transanal procedures
would commence after mobilization of the colon
and/or rectum and are initiated with a Lone Star
retractor and circumferential rectal mucosectomy
starting at the level of the dentate line. Rectal
transection is then carried out full-thickness
above the anorectal ring with rectal dissection
following along the rectal wall and mesorectal
plane [66]. Alternatively, one may place a
purse-string suture 3 cm above the dentate line
followed by circumferential, full-thickness inci-
sion of the rectal wall and then close rectal dis-
section. IPAA is performed with a single-stapled
technique following specimen extraction [67].
With transanal endoscopic proctectomy or
proctocolectomy with APR, the colon is mobi-
lized followed by ligation of the inferior
mesenteric vessels, and TME dissection initiated
using an open, laparoscopic- or robotic-assisted
transabdominal approach. The anus is sutured
closed followed by intersphincteric or standard
proctectomy, which may be carried out simulta-
neously (2-team) or sequentially with the
abdominal dissection (1-team). Transanal dis-
section continues cephalad with division of the
perineal body until the rectoprostatic or recto-
vaginal plane is clearly identified. Posterior dis-
section is then carried out until the puborectalis is
visualized. The transanal platform is then inser-
ted with CO
2
insufflation, and rectal dissection is
advanced endoscopically. The posterior dissec-
tion can be carried out close to the rectal wall
within the mesorectal plane, or along the plane
between the mesorectum and presacral fascia
Fig. 21.13 Anterior and
posterior views of complete
TME specimen
21 NOTES Transanal Colorectal Resection 261
depending on the pathology and surgeon’ s pref-
erence. After proctectomy, the specimen is then
extracted followed by closure of the perineal
wound in layers.
Another alternative to transanal completion
proctectomy for benign disease is to initiate
transanal, endoscopic, full-thickness, rectal tran-
section through the transanal platform starting
well above the dentate line. The rectal dissection,
mesorectal dissecti on, and exteriorization of the
specimen are then performed, and intersphinc-
teric dissection of the short anorectal stump is
then carried out, followed by extraction of the
new specimen and perineal wound closure [64].
Postoperative Care and Follow-Up
A Foley catheter is typically kept in place for at
least two days after the procedure given the rel-
atively high incidence of postoperative u rinary
retention following perineal dissection, espe-
cially in males [ 36 , 44, 47]. One to two doses of
parenteral antibiotics are administered postoper-
atively. Patients are often managed using
enhanced recovery protocols with immediate
initiation of oral intake as tolerated, and pain
control with aggressive, non-narcotic regimens.
Patients are extensively counseled regarding
ostomy management prior to discharge.
Postoperative visits and evaluation following
taTME are the same as any rectal cancer resec-
tion. In patients with locally advanced rectal
cancer undergoing adjuvant treatment, ileostomy
closure is usually deferred until completion of
adjuvant therapy. Endoscopic and radiographic
evaluation of the coloanal anastomosis is per-
formed prior to reversal, and anastomotic com-
plications such as strictures, leaks, and fistulas
are managed using standard protocols. Oncologic
surveillance following rectal cancer resections
typically follows NCCN guidelines. Regarding
functional outcomes, patients who have under-
gone partial or complete ISR are at increased risk
for poor functional outcomes and require
long-term monitoring of their defecatory function
and aggressive management of their fecal
incontinence.
Complications
Complication rates reported with taTME per-
formed either in pure or hybrid fashion with
abdominal assistance mirror complications rates
associated with open or laparoscopic TME and
include intraoperative bleeding, organ injury
(including rectal perforation, ureteral, and ure-
thral injury), vaginal wall injury, and prostatic
injury. Conversion to laparoscopic and/or open
techniques is always possible and represents
good surgical judgment rather than a complica-
tion. Conversion rates can be expected to be
higher during a surgeon’s early experience.
Maintaining pneumorectum is a technical
issue unique to taTME. When encountering loss
of pneumorectum, the surgeon should trou-
bleshoot, check for leaks in the platform, and
confirm muscle paralysis. One should avoid
premature peritoneal entry during the transanal
approach and defer this step until complete cir-
cumferential TME has been extended as far
cephalad as possible.
Urethral injury is not a reported complication
of open and laparoscopic TME, and it is a rare
complication during difficult APR, with an esti-
mated incidence of 1.5–2% [69, 70]. Although
rarely reported in current taTME series, urethral
injury has emerged as the most concerning
procedure-specific morbidity associated with
taTME. Although only four urethral injuries have
been described in our review of over 500 pub-
lished taTME cases to date, the actual incidence
of urethral injury is not yet defined. Based on
personal communications, there have been more
cases of urethral injuries during taTME than have
been voluntarily entered in the LOREC interna-
tional taTME registry, which will soon publish
the findings of the first 720 taTME cases entered.
The risk of urethral injury seems to be highest
during the surgeon’s early experience, during
difficult anterior dissection, and in patients with
bulky anterior rectal tumors or enlarged prostate
[47, 48, 53, 71].
To avoid urethral injury, the surgeon must be
familiar with the pre-prostatic anatomy from the
taTME point of view. The neurovascular bundle
of Walsh contains paired arterial vessels that can
262 A.P. D’Andrea and P. Sylla