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• Pfannenstiel incision for extraction
• Surgeon and assist on patient’s right side
• Surgical tech and sterile instrument table on patient’s left side
• Monitor angled at left shoulder and left lower extremity
E. M. Haas and A. V. Hayman
Port Placement (Fig.23.2)
• If you prefer a 10mm camera, the umbilical port will need to be upsized to a
12 mm port size. On occasion, placing the camera in another port may be
required, and these ports will also need to be upsized or an additional 5mm cam-
era opened.
• The midline 5mm port can usually be hidden in the upper ridge of the umbilicus;
however, if the distance between the umbilicus and suprapubic region is rela-
tively short, then the optical eld of view may be limited. In these cases, placing
the midline port a few centimeters superior the umbilicus is an option.
• If planning to fashion an ileostomy, the 12mm RLQ can be placed at the lateral
margin of the predetermined ileostomy site. Care should be taken not to place the
Fig. 23.2 Port placement
5 mm
12 mm
5 mm
5 mm
optional
23 Laparoscopic Low Anterior Resection forRectal Cancer: TME Planes andSurgery…
359
12mm RLQ port adjacent to the planned ileostomy site as this may result in dif-
culty pouching the stoma.
• It is recommended to close the fascia on all 12mm port sites due to hernia risk.
Other Equipment/Incisions
• Extraction site: Several options exist for the extraction site. We prefer a
Pfannenstiel incision because it can usually also allow direct access to the anas-
tomosis in cases in which repair of an anastomotic defect is required. It is also
associated with a very low rate of hernia risk. Other extraction sites, however,
can be used such as an umbilical site or the left lower quadrant. In cases in which
we plan to perform an ileostomy, we use the ileostomy site as extraction site.
• Camera: A 5mm 30 degree or exible tip camera is preferred.
• Instruments: Atraumatic bowel graspers are required. It is recommended to have
extended length graspers available.
• Energy devices: Monopolar energy devices include the L or J hook, spatula, or
scissors with cautery. Thermal energy can include various devices designed to
control vessels up to 7mm size, such as a bipolar device or ultrasonic device.
Operative Technique andSurgical Steps
Planes oftheMesorectum
Both medial-to-lateral and lateral-to-medial approaches are utilized during the laparoscopic procedure. The procedure is preferably initiated in a medial-to-lateral fashion to identify the critical landmarks and develop the proper planes of mesenteric
dissection. The medial side of the mesentery is exposed by elevating the rectosigmoid with a bowel grasper to identify the thin base near the sacral promontory. The
peritoneum is carefully scored and the avascular presacral plane is dissected.
Pneumodissection in the alveolar tissue signies the correct plane between presacral fascia and the fascia propria of the rectum. The superior rectal artery (SRA) is
identied and elevated to further expose the plane of dissection (Fig.23.3). The left
ureter and gonadal vessels are exposed very early in the dissection. The avascular
plane is dissected further while elevating the SRA taking care not to injury the
nerves in the deeper plane. Dissection continues laterally in the retroperitoneal
plane toward the white line of Toldt, inferiorly to the level of the sacral promontory
and superiorly toward the base of the IMA.At this level, the peritoneal plane is
scored in an upside-down “U” fashion, starting at the base of the bifurcation, sweeping up as it follows the vessel’s course into the pelvis, and then extending distally to
where the anterior reection terminates laterally in the pararectal gutter.
The plane between the retroperitoneal structures posteriorly and the mesorectum
anteriorly is then developed. Dissection from the CO
tify this avascular plane; after inltrating into the tissues, they appear as white,
insufation again helps iden-
2
360
Fig. 23.3 Medial-to-
lateral dissection with
elevation of the superior
rectal artery (SRA) and
exposure of the
retroperitoneal plane
E. M. Haas and A. V. Hayman
crackly bers. After sweeping over the sacral promontory from right to left, it is
important to remember that the lateral retroperitoneal structures of interest, specically the ureter, gonadal vessels, and internal iliac artery and vein, lie slightly superior to the presacral fascia. Therefore, the surgeon has to be careful to not proceed
in so linear a fashion as to injure these structures. The dissection plane will be
identied quite high on the edge of the mesorectum when dissecting the lateralmost area.
In order to avoid creating a tunnel when performing the above dissection, the
surgeon should periodically reexamine the right peritoneal edge and continue to
open up the triangle that forms between the aorta and IMA pedicle, scoring the
peritoneum in a radial fashion right up to the IMA take off. The surgeon will encounter small bridging nerves in this area. These should be preserved if possible or
ligated as anteriorly as possible.
In order to preserve planes and perform a meticulous dissection, many use hot
scissors, L hook, or thermal energy device tip to carefully dissect between planes.
The use of thermal or bipolar energy is typically not used to establish the planes of
dissection and is reserved to control bleeding or division of vascular pedicles.
Once the vascular pedicle has been adequately skeletonized, and the surgeon has
ensured that the left retroperitoneal structures at risk (i.e., ureter, gonadal vein) are
lateral, the vessel can be divided (Fig.23.4). Either a low (preserving the left colic
(LCA) and/or sigmoid branches) or high ligation of the IMA and inferior mesenteric vein (IMV) is then performed (Table23.1). If performing a low ligation, care
is taken to dissect the mesenteric lymph nodes in the fatty tissue along the base of
the IMA and draw this tissue into the resection margins so as not to leave behind
draining lymph nodes (Fig.23.5).
The surgeon then continues the mesenteric transection up to the site of planned
proximal colonic division, which can be immediately performed via endoscopic
stapler or via the extraction site. In the case of a particularly bulky colorectal
mesentery, early bowel division can improve visualization when performing the
pelvic dissection.
23 Laparoscopic Low Anterior Resection forRectal Cancer: TME Planes andSurgery…
Fig. 23.4 Isolation of the
inferior mesenteric artery
(IMA) with dissection of
the para-aortic lymph
nodes
Table 23.1 Oncologic and functional outcomes of high versus low IMA ligation during LAR for
rectal cancer
Matsuda etal. GI
tumors 2017 [5]
Matsuda etal. BJS
2015 [6]
Fujii, etal. BJS
Open [7]
Mari etal. Ann Surg
2018. (HIGHLOW
trial) [8]
RCT randomized controlled trial, OS overall survival, DFS disease-free survival, FIQOL fecal
incontinence quality of life, NS not signicant, LN lymph nodes
N=100, ‘08-‘11. RCT: high
vs. low ligation in LAR for
rectal cancer
N=100, ‘08-‘11, TCT: high
vs. low ligation in LAR for
rectal caner
N=331, ‘06-‘12, RCT: high
vs. low ligation
N=214, ‘14-‘16, RCT: high
vs. low ligation
NS: OS, DFS (including stage III), # LN
16.7 vs. 14.9
NS: defecatory dysfunction, FIQOL, fecal
incontinence, anastomotic leak, 16% vs.
10% (p=0.42)
NS: anastomotic leak, 17.7% vs. 16.3%
Low ligation: signicant for better
continence, fewer urinary symptoms
(p<0.05 @ 1 and 9months), better QOL
and sexual function
NS: anastomotic leak: 8.1% vs. 6.7%
361
Fig. 23.5 Low IMA
ligation with lymph nodes
in specimen and
preservation of the LCA
362
E. M. Haas and A. V. Hayman
Splenic Flexure Mobilization
Additional length of the proximal colon may be needed to perform the anastomosis in
a tension-free fashion. If so, we generally use the sub-IMV approach, either before or
after IMA ligation, to accomplish this. With this technique, the patient is placed in
slight reverse Trendelenburg position. The key is to carefully sweep the small intestine
right lateral and cephalad to expose the ligament of Treitz. It is helpful to have the
assistant retract the transverse colon cephalad to expose this area. The surgeon then
identies the IMV and incises the peritoneum in a horizontal fashion posterior to the
vein along border of the ligament of Treitz. The retroperitoneal plane deep to the vein
is then developed, and the vein is isolated and divided. The borders of the retroperitoneal dissection plane are the white line of Toldt along the descending colon (lateral),
the inferior border of the pancreas (superior), and the origin the left colic artery (inferior). When dividing the IMV, allow for 1–2cm cuff of vessel to avoid retraction of a
bleeding vein beneath the pancreas should ligation be inadequate. We have found that
the sub-IMV technique allows for easier identication of the dissection planes around
the pedicle. For more details on various approaches for splenic exure take down,
please refer to Chapter 4 on splenic exure release.
Lateral Dissection
Prior to starting the pelvic dissection, we then complete the lateral dissection. We
initiate this dissection along the sigmoid colon and continue in a cranial fashion. If
the sub-IMV approach has been accomplished, the peritoneal attachments will be
well dened and separated from the retroperitoneal plane. The best way to accomplish the lateral dissection is to have the assistant gently retract the proximal colon
medial and cephalad to expose and stretch the peritoneal refection. The surgeon uses
an atraumatic instrument to push the colon medially for counter-traction (it is important to guide trainees with this technique as their instincts are often to traumatically
grasp the mesentery), putting the peritoneal attachments on tension (Fig.23.6). This
Fig. 23.6 The colon is
retracted to stretch the
peritoneal reection for
lateral to medial dissection
along the white line of
Toldt
23 Laparoscopic Low Anterior Resection forRectal Cancer: TME Planes andSurgery…
363
will allow for efcient division of these attachments all the way up to the splenic
exure, staying just medial to Gerota’s fascia.
One helpful tip is that the peritoneum over the lateral retroperitoneal structures appears slightly pink, as opposed to the peritoneum over the colon mesentery which appears slightly yellow. In order to maintain the correct plane, it is
advised to score 1mm on the yellow fat to avoid stripping the peritoneum off the
side wall.
This technique is continued proximally around the splenic exure, staying
close to the colon, to enter the lesser sac. As we approach the splenocolic ligament, we often switch from hot scissors to a thermal energy device such as a
bipolar device or harmonic scalpel to minimize thermal spread and achieve adequate hemostasis. Dissection is continued until entry into the lesser sac is achieved,
usually marked by visualization of the posterior wall of the stomach. If the colon
is closely adhered to the spleen or exposure is otherwise limited, we will change
our approach and attack it proximally. The assistant retracts the mid-transverse
colon omentum cephalad, while the surgeon pulls inferiorly on the transverse
colon tenia. The omentum is then dissected off the colon until the lesser sac is
opened. This dissection plane is carried distally until it meets the descending
colon plane. Typically, there will be a few more attachments anterior to Gerota’s
fascia that will need to be ligated.
Lastly, we return our attention to the rectosigmoid colon and release the lateral
attachments at the intersigmoid fold, taking care to avoid injury to the left gonadal
vein and left ureter. Continue the peritoneal release as distally as possible by retracting the rectum medially and cephalad to expose the left pararectal gutter (Fig.23.7).
We score the peritoneum up and over the lateral edge of sacral promontory, being
careful to stay just medial to the peritoneal edge. We perform the contralateral peritoneal release on the right during the IMA pedicle ligation (Fig.23.8). Remember
from embryology that the colon was a midline structure. Especially for low colorectal anastomoses, splenic exure mobilization is not complete until the colon is able
to be fully mobilized to the midline.
Fig. 23.7 The rectum is
retracted medially to
expose the left pararectal
gutter
364
Fig. 23.8 Exposure and
release of the right
pararectal peritoneal
attachments
Fig. 23.9 Dissection in
the avascular presacral
plane
E. M. Haas and A. V. Hayman
Pelvic Dissection
Dissection continues in the presacral mesorectal plane from the sacral promontory
toward the retrosacral fascia. Care is taken to maintain the correct dissection plane
identied by the avascular alveolar tissue while keeping the investing fascia of
mesorectum intact (Fig.23.9). The surgeon scores the peritoneum where the blood
pools along the right and left pararectal gutters, until the anterior reection is
reached. With the assistant grasping the sigmoid, the surgeon then lifts the rectum
with a blunt instrument and dissects in the posterior plane up and over the sacral
promontory into the pelvis. The lateral stalks of the rectum are divided with hot
cautery. Next, the anterior reection of the rectum is scored and the plane between
the anterior pelvic strictures (seminal vesicles in a man and vagina in a woman) and
the anterior wall of the rectum is developed until the rectum has been adequately
23 Laparoscopic Low Anterior Resection forRectal Cancer: TME Planes andSurgery…
365
mobilized based on the location of the tumor. In the case of an upper rectal tumor,
at least 2 centimeters of distal margin and 5 centimeters of mesenteric margin are
required. A tangential resection across the mesorectum is performed with the aid of
thermal energy device to control the mesenteric vessels. Care is taken to keep the
investing fascia of the mesorectum intact and to avoid the tendency to cone into the
mesenteric envelope.
Dividing theRectum
During specimen division, the surgeon must decide whether to divide the mesentery
or the bowel lumen rst. Typically, the mesentery is initially divided. This is performed in a tangential fashion using thermal energy device with care taken not to
injure the rectal wall. A reticulating linear stapler is placed though the 12mm RLQ
port, and the rectal wall is stapled and divided. It is important to compress the bowel
wall in a linear fashion, and use of a second staple cartridge load is often necessary.
In cases of a particularly bulky mesorectum and/or narrow male pelvis, dividing the
bowel rst can be helpful. A tunnel beneath the bowel wall is carefully created by
developing a plane between the bowel wall and the mesentery. The reticulating linear stapler slides into this plane, and the bowel is then divided in one or two loads.
The mesorectum is now readily exposed for division.
Alternatively, one can widen the Pfannestiel extraction incision and perform
division of the bowel and mesentery under direct nonlaparoscopic access. This
should be reserved for large bulky tumor or otherwise unfavorable anatomy.
The most important aspect of this portion of the case is to maintain adequate
distal and circumferential resection margins. A proper distal margin of at least 2cm
can be ensured by concomitant intraoperative endoscopic visualization of the tumor.
Again, it is important to achieve a 5cm mesenteric margin due to the vagaries of
local lymph node drainage (Fig.23.10).
Fig. 23.10 Tumor-specic
mesorectal excision for
showing 5cm mesenteric
margin
366
E. M. Haas and A. V. Hayman
Specimen Extraction andCreating theAnastomosis
We utilize a small Pfannenstiel incision for our extraction site to minimize pain,
hernia rate, and improve cosmesis. Generally, we also place and secure the anvil of
the circular stapler into the proximal end of colon via this site. The assistant then
places the circular stapler through the rectum and opens the stapler just anterior to
the rectal staple line. The anvil is then attached to the head of the stapler, which is
closed and then actuated. The patient is then taken out of Trendelenburg and the
pelvis lled with saline, submerging the anastomosis. The assistant advances a exible or rigid endoscope past the anastomosis under direct visualization to assess for
anastomotic integrity and hemostasis while insufating. The operating surgeon
assesses for any bubbling from the anastomosis, indicating a potential leak.
Generally, for upper and mid-rectal tumors, we do not perform a diverting loop
ileostomy unless there are poor prognostic features of healing, most commonly in
the background of a radiated eld.
Pitfalls andTroubleshooting
When toConvert
Typically, the most difcult portion of the case is the pelvic dissection, especially when
operating in a postradiated or postoperative eld or in the presence of a bulky, locally
advanced, or previously perforated tumor. In these cases, we still commence the procedure with a minimally invasive approach performing the splenic exure, sub-IMV dissection and colon mobilization laparoscopically, then performing the remainder of the
pelvic dissection and specimen extraction through the Pfannenstiel extraction incision.
Although for novices, laparoscopic dissection and exposure of challenging anatomy or
splenic exure takedown may be daunting and result in early conversion to open surgery, with experience this approach will become more routine. However, as with difcult low pelvic dissections, although conversion to open may allow for more effective
retraction and counter-traction, visualization is often sacriced, due to the loss of magnication and high-denition imaging supplied by modern laparoscopes. Therefore, in
order to minimize the morbidity of an open incision, whenever possible, we attempt to
keep our incisions subumbilical even when we need to convert.
Another tool that aids in anatomic identication is preoperative cystoscopy and
ureteral catheter placement by urology. If preoperative ureteral catheters are utilized, intraoperative identication can be accomplished laparoscopically by injecting 25mg of indocyanine green in 10mL of saline via a Luer lock attachment into
each catheter and performing intraoperative uorescence imaging utilizing Spy or,
if using the robot, FireFly technology. This will allow the ureters to light up green
throughout the duration of the case (Fig. 23.11a, b). However, if these tools are
insufcient to allow safe visualization, or if at any point the surgeon is concerned
about safely proceeding with the procedure, the surgeon should consider conversion
to an open or, when possible, a hand-assisted approach.
23 Laparoscopic Low Anterior Resection forRectal Cancer: TME Planes andSurgery…
367
ab
Fig. 23.11 (a, b) Intraoperative localization of the left ureter using Firey uorescence and ICG
injection into the left ureteral stent. (Courtesy of Josh Wallet, MD)
The laparoscopic surgeon should be constantly vigilant about avoiding intraoperative injury to major vascular structures (IMA, iliac vessels, pelvic side wall vessels, and presacral venous plexus) or adjacent organs (small intestine, spleen,
bladder). One tip is to alert the operating room staff prior to a critical portion of the
procedure (IMA ligation, splenic exure takedown) and ensure that any potential
equipment needed in the event of an unintended injury is immediately available. In
the event of IMA stump bleed, a large plastic clip or looped laparoscopic ligature
may be helpful in controlling bleeding. Hollow organ injury (bladder, small intestine) can be repaired, either denitely or for temporary control, via laparoscopic
suturing with an absorbable suture. Although a detailed discussion about managing
intraoperative splenic bleeding is beyond the scope of this chapter, briey, the laparoscopic surgeon must be aware that any undue traction on the splenocolic ligament
can result in splenic bleeding. If just a subcapsular tear, a useful tool for managing
this can be intraoperative placement of an absorbable hemostatic knit mesh, along
with extended pressure.
Outcomes
Every prospective proctectomy patient should be asked about any baseline bowel,
sexual, or urinary dysfunction. They should be counseled about the risk of surgery
including low anterior resection syndrome (LARS), incontinence, impotence, bladder dysfunction, and others especially in those who will undergo neoadjuvant radiation therapy.
There are debates about the risk versus benet ratio of high versus low ligation
of the IMA during LAR; one must balance oncologic outcomes (i.e., overall land
disease-free survival) with functional outcomes (defecatory, urinary, and sexual
function). Some purists insist that it is essential to perform a full lymphadenectomy
for LAR completed for malignancy, up to just after the takeoff of the IMA from the
aorta and cephalad to the aortic bifurcation. However, other surgeons have argued
that this adds unnecessary risk of injury to the autonomic nerves, specically the