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294
Fig. 37.6 Transanal Minimally Invasive Surgery
(TAMIS). Instead of a platform containing a rigid proctoscope, a small GelPort (Applied Medical. Rancho Santa
Margarita, CA) is inserted into the anus
alization. Instead of a platform containing a
rigid proctoscope, a small GelPort (Applied
Medical) is inserted into the anus (Fig.37.6),
3 5mm ports are placed through the gel port in
a triangular manor and insufation attached to
one of the ports to distend the rectum. Newer
technology is available to provide balanced
insufation (Air Seal) and smoke evacuation.
When working in small spaces even minimal
amount of suctioning can deate the lumen
and obscure visualization. The ability to provide balanced insufation and smoke evacuation while performing TAMIS has been a
signicant advance over the use of standard
laparoscopic insufators. A 5 or 10mm 30°
laparoscope is inserted through one of the
ports and held by an assistant. Laparoscopic
instruments are placed through the other two
working ports for dissection. Similar to TEM,
the location of the mass determines patient
positioning with TAMIS.The patient should
be positioned so that the mass in the inferior
location. However, unlike TEM, the laparoscope is not xed and can be moved freely.
It is therefore, technically possible, although
potentially more difcult, to resect a mass in
any location with the TAMIS platform while
keeping the patient in the lithotomy position.
This may be advantageous for patients whose
body habitus prohibits prone or lithotomy
positioning. The steps of TAMIS are similar
D. M. Lisle and D. R. Sands
to TEM and involve full thickness excision of
the tumor with a 1cm margin similar to that
method described above.
Anatomical Considerations
inSelecting Method ofLocal
Excision (Refer toTable 37.2)
I. Transanal excision is limited to distal rectal
cancers as proximal and mid rectal cancers
are difcult to visualize through an open
transanal technique even with an anal retrac-
tor device. Some surgeons argue that even
distal rectal cancers are difcult to visualize
and perform sound oncologic local resection
on especially in patients with difcult body
habitus. Several studies have shown higher
recurrence rates with transanal excision com-
pared to radical resection (12.5% vs 6.9%).
However, 5 year overall survival is similar
(77.4% vs 81.7%).
J. TEM is the preferred modality for cancers that
are larger and those above the rst rectal
valve. The TEM platform is able to reach the
more proximal rectum and distal sigmoid
compared to the TAMIS platform due to the
availability of both a 12 and 20cm procto-
scope. The benet of the rigid proctoscope is
not only in proximal reach, it also serves as a
retractor of the rst and second rectal valves
which can hinder visualization when using a
soft platform. This feature can prove invalu-
able in the excision of proximal lesions and
perhaps more importantly, obtaining adequate
closure of the defect in cases of peritoneal
entry. In addition it has the advantage of being
single operator if there is no assistant avail-
able to hold the camera which is necessary for
TAMIS. A Meta analysis comparing TEM to
radical excision for T1N0 rectal cancers
showed equivalent 5year overall survival.
K. TEM or TAMIS is often the preferred plat-
form for small early rectal cancers below the
rst rectal valve. The TEM platform has the
option of a straight edge proctoscope rather
than the beveled edge which can interfere
with the seal at the level of the anus in low
37 Rectal Cancer: Local Therapy
295
lesions. The TAMIS platform is more exible, allowing access to lesions which may be
located in intermediate locations on the rectal
wall, but may overlap the most distal rectal
lesions potentially covering them and obscuring their view. In this case, the dissection may
be initiated with traditional transanal
approach and eversion of the anus. Once the
distal tumor has been mobilized enough to
allow placement of the TAMIS or straight
edge TEM proctoscope advanced endoscopic
assistance can be utilized for the more proximal dissection.
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AC. Meta-analysis of histopathological features of
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C.Selection criteria for local excision with or without
adjuvant radiation therapy for rectal cancer. Cancer.
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Rectal Conditions: Rectal Cancer—Proctectomy
AaronS.Rickles andFergalJ.Fleming
38
Refer toAlgorithm inFig. 38.1
A. In the current climate of evolving oncologic
therapies, increasing evidence has shown that
a multidisciplinary approach, with surgical
resection at the forefront of curative treatment, improves oncologic, clinical decisionmaking, and functional outcomes for patients
with rectal cancer. For this chapter, we will
be focusing on the surgical therapy for resectable rectal cancer and reserve discussion of
treatment for unresectable disease and disease amenable to local therapies for elsewhere in this text. Quality oncologic resection
requires experience and a deep understanding of the pelvic anatomy in order to yield the
best probability of good oncologic and functional outcomes.
B. In order to determine the most appropriate
treatment options for the patient, a preoperative evaluation must include not only staging
of the cancer according to the TNM classication, but also evaluation of the location of
the tumor relative to the sphincter complex,
involvement of any adjacent structures, and
A. S. Rickles
Rochester Colon and Rectal Surgeons, P.C.
Rochester, New York, NY, USA
e-mail: arickles@rochestercolon.com
F. J. Fleming (*)
Department ofSurgery, University ofRochester
Medical Center, Rochester, NY, USA
e-mail: Fergal_Fleming@URMC.Rochester.edu
proximity or involvement of the circumferential resection margin (CRM).
• Thorough physical examination including
detailed digital rectal examination can
help determine location of the tumor and
proximity to anal sphincters, rmness,
ulceration, and xation.
• Carcinoembryonic Antigen (CEA).
• Colonoscopy, if not already performed, to
exclude proximal synchronous tumor(s), to
obtain histology, and location of tumor
including distance from anal verge or dentate line, as well as circumferential location
as it relates to surrounding structures. A
rigid proctoscope is often preferred in this
setting to more accurately assess tumor distance from the verge and distinguish among
upper, mid, and lower rectal locations.
• Endorectal Ultrasound (ERUS) or
Magnetic Resonance Imaging (MRI) for
local- regional staging. ERUS may have
advantage in evaluating depth of involvement for early stage tumors, whereas MRI
is the only modality that can assess circumferential margin and is the most commonly used method presently. MRI is the
accepted standard by the Commission on
Cancer (CoC). National Accreditation
Program for Rectal Cancer (NAPRC).
• Computed Tomography (CT) of the chest,
abdomen, and pelvis to evaluate for distant metastasis.
© Springer Nature Switzerland AG 2020
S. R. Steele etal. (eds.), Clinical Decision Making in Colorectal Surgery,
https://doi.org/10.1007/978-3-319-65942-8_38
297
298
A. S. Rickles and F. J. Fleming
Fig. 38.1 Algorithm for treatment of rectal cancer–
proctectomy. IMA inferior mesenteric artery, IMV inferior
mesenteric vein, APR abdominal perineal resection, AR
C. Neoadjuvant chemoradiotherapy for locally
advanced rectal cancer (cT3-4, cN0 or any
cT, cN1-2) reduces the risk for local recurrence when compared to surgery alone in
several landmark studies. Chemoradiation
delivered in the neoadjuvant setting is associated with a lower rate of recurrence and
higher treatment completion rates compared
to adjuvant chemoradiation. Short-course
radiation can also be delivered in neoadjuvant setting and shown to signicantly
reduce local recurrence. Neoadjuvant
chemoradiotherapy may also be considered
for those patients with low rectal tumors
where sphincter- preserving surgery would
not yield adequate results without reduction
of the tumor burden. Upper rectal lesions
(above the peritoneal reection) are more
controversial, and in many cases do not
require neoadjuvant therapy and can be
resected primarily.
D. The anatomy of the rectum can be quite vari-
able from patient-to-patient and requires
experience and reliance on key anatomical
constants when operating in a radiated and
occasional difcult anatomical of the pelvis.
The location of the rectal tumor is often measured as the distance from the anal verge or
anterior resection, LAR low anterior resection, TME total
mesorectal excision, taTME transanal total mesorectal
excision
the dentate line, and the height of the rectum
varies between 12 and 15cm by rigid proctoscopy, depending on the type of measurement and size of the patient. Some surgeons
will use the relationship of the tumor to the
rectal valves as a reference point for height of
the tumor (low, middle, and upper rectum).
The superior aspect of the rectum is iden-
tied as the colon passes over the sacral
promontory into the pelvis and the taeniae
coalesce to form a complete layer of longitudinal muscle. The anatomy which comprises
the mesorectal excision can be separated
similarly to how they are encountered surgically, the anterior, posterior, and deep anatomy. From superior to inferior the anterior
excision is comprised of:
• The intraperitoneal anterior wall of the
rectum.
• The peritoneal reection.
• Denonvilliers’ fascia behind the seminal
vesicles and fusing with the fascia on the
back of the prostate in males.
Posteriorly the mesorectum is largely
comprised of a bilobed lipomatous like
structure that lies anterior to the sacrum
and enveloped by the investing visceral fascia of the hindgut. Waldeyer’s fascia invests
38 Rectal Conditions: Rectal Cancer—Proctectomy
299
the front of the sacrum and provides some
protection from the venous plexus and
autonomic nervous plexus of the pelvis.
Between the investing fascia of the mesorectum and the investing fascia of the
sacrum posteriorly is an avascular plane of
dissection that guides the surgeon to a complete mesorectal excision, the so-called
“Holy Plane” of dissection. Distally the
mesorectum narrows or tapers into a
“waist” as the lipomatous lymphatic and
vascular supply tapers and the muscular
wall of the rectum becomes the internal
anal sphincter as it inserts into the pelvic
oor.
Essential to functional outcomes following a TME is an understanding and
awareness of the sympathetic and parasympathetic bers that supply the rectum and
genitourinary tract. The sympathetic or
superior hypogastric plexus arises from
T12-L2 and passes anteriorly over the aortic bifurcation and sacral promontory as it
divides laterally into the right and left
hypogastric nerves. Damage to these nerves
can result in urinary incontinence and retrograde ejaculation. As the superior hypogastric plexus travels inferior and lateral in
the pelvis, posterior to the mesorectum it
joins the pelvic splanchnic nerves, or nervi
erigentes, to form the inferior hypogastric
plexus. Injury to the parasympathetic
nerves when dissecting out the mesorectum
can lead to erectile dysfunction and bladder
dysfunction.
As the TME dissection commences, the
avascular presacral plane will act as a guide
for the rest of the abdominal approach to
the dissection. The plane can reliably be
found by retracting the rectum up and out
of the pelvis and scoring the peritoneum
over the sacral promontory from the right
side of the patient. Care should be taken to
avoid the sympathetic trunks at this location. Once entered, this plane can be followed both distally and laterally to
completely encompass the visceral fascia
of the mesorectum.
E. Consistent with oncologic principles of sur-
gery, the mesentery of the colon and rectum
should be taken en bloc with the specimen.
For rectal cancer, ligation proximal to the
superior rectal artery (low tie) has similar
survival outcomes to ligation of the IMA
proximal to the left colic artery (high tie).
However, a high ligation is often necessary in
order to provide adequate length for a
tension- free anastomosis and should be performed when patients have suspicious lymph
node involvement proximal to the superior
rectal artery. Additionally, a high ligation of
the inferior mesenteric vein is advocated
both for lymph node yield and adequate
mobilization for tension-free anastomosis.
Routine high ligation of the vessels and complete splenic exure mobilization are can be
essential maneuvers to ensuring a tensionfree anastomosis. In those patients with a
redundant and oppy colon who are undergoing a more proximal anastomosis or an
abdominal perineal resection (APR), a
splenic exure mobilization may not be
required.
F. The location of rectal tumors is often
described in reference to the upper (11–
15 cm from anal verge), middle (7–11 cm
from anal verge), or lower third (anorectal
ring to 7cm from anal verge) of the rectum.
The anatomical association to this reference
is that the upper third of the rectum is intraperitoneal and covered by peritoneum anteriorly and laterally. The middle rectum is
anteriorly covered by peritoneum while the
lower third is devoid of peritoneum and is
entirely extraperitoneal.
G. Tumors of the middle and lower third of the
rectum should undergo a complete TME
including anterior dissection through
Denonvilliers’ fascia. This will allow for
complete excision of lymphatic drainage and
minimize risk of local recurrence.
H. Secondary to several anatomic constraints,
tumors of the lower rectum often present the
greatest challenge to successful outcomes.
Proximity to the pelvic oor and sphincter
complex may make satisfactory functional
300
A. S. Rickles and F. J. Fleming
outcomes unobtainable and complete excision
of the tumor may require an abdominalperineal resection (APR) for adequate oncologic and functional outcomes. Additionally,
the natural mesorectal plane narrows deep in
the pelvis making the circumferential margin
at higher risk of being threatened. Extra-organ
involvement is also more likely with tumors in
this location given the proximity of the seminal vesicles, prostate, and vagina.
I. Much controversy exists over the most
appropriate distal margin of resection. Distal
lymphatic or intramural spread of the tumor
presents the potential for a positive distal
margin despite a clear gross margin intraluminally. However, a distal mesorectal margin
of 5 cm for an anterior resection has been
accepted for rectal cancer of the upper third
of the rectum, but should be weighed against
other clinical and pathologic features of the
tumor. A complete posterior and lateral dissection should be performed during this
operation while maintaining the lateral stalks
prior to determining where to divide the distal margin.
J. While concern over technical difculties and
risks for morbidity following increased rates
of anastomotic leaks and pelvic sepsis are
present, middle rectal tumors should undergo
a low anterior resection with total mesorectal excision with a stapled or hand-sewn
anastomosis.
K. When possible, a sphincter-sparing operation
should be the operation of choice for rectal
cancer, including low rectal tumors where
sphincter preservation and reasonable functional outcomes are possible without increasing the risk of unfavorable oncologic
outcomes. Whereas 5cm of distal margin is
ideally accepted for more proximal tumors,
various studies have found that margins of
2 cm or less have resulted in similar oncologic outcomes. When compared to the difference in quality of life between an APR and
a sphincter-sparing operation, a low colorectal or even coloanal anastomosis is often preferred for patients with good preoperative
sphincter function.
Once the oncologic concerns of proper
resection margins have been met and anal
sphincter function accounted for, the greatest
concern in the postoperative period is the risk
of anastomotic leak and pelvic sepsis. The
risk of anastomotic leak in a low pelvic anastomosis can be up to 3–32% depending on
multiple risk factors including tumor height,
receipt of neoadjuvant therapy, and comorbid
conditions. Technical factors increasing the
risk of anastomotic leak include relative ischemia and tension on the anastomosis. Several
meta-analyses have been published evaluating the role of diverting ileostomy for low
anterior resections (LAR) and confer that a
diverting stoma reduces the risk of both anastomotic leak and the need for reoperation by
approximately 60–70%. For this reason the
authors advocate routine diverting loop ileostomy for low and ultra-low anterior resections in addition to leak testing all colorectal
and coloanal anastomoses.
L. Reconstructive options following low and
ultra-low anterior resection include a straight
anastomosis, colonic J-pouch, coloplasty, or
a Baker-type side-to-end anastomosis.
Several factors should be taken into account
when deciding on restorative technique for
optimizing function of the postoperative
neo- rectum. With the loss of the rectum as a
reservoir, and disturbance of the anorectal
reex with low pelvic dissections patients
can experience frequency, urgency, soiling,
and incomplete evacuation, a constellation
of symptoms known as the LAR syndrome.
The risk of these symptoms are increased
with lower anastomoses and with decreased
reservoir compliance. Large systematic
reviews have shown that for the rst 1–2
postoperative years the functional outcomes
for patients are improved following colonic
J-pouch reconstruction compared to straight
coloanal or colorectal anastomosis. For this
reason, when colonic length is adequate, and
the pelvic volume can accommodate a larger
reconstructed reservoir, the authors prefer
where feasible, a colonic J-pouch reconstruction or side-to-end as opposed to a
38 Rectal Conditions: Rectal Cancer—Proctectomy
301
straight anastomosis for low and ultra-low
sphincter- sparing operations. Prior to
advancing the circular stapler or performing
an anastomosis, rectal washout with a
tumoricidal agent may reduce any theoretical risk of exfoliating intraluminal tumor
cells, although data has not consistently
shown benet to this maneuver.
M. Minimally invasive techniques in colorectal
surgery have repeatedly shown benets in
outcomes of early postoperative recovery;
however, studies comparing laparoscopic to
open surgery have less consistency and yield
conicting results for short- and long-term
oncologic outcomes. In the MRC CLASICC
trial, 794 patients in the UK were randomized 2:1 to laparoscopic or open resection for
rectal cancer. The laparoscopic group had a
higher rate of positive CRM; however this
did not translate into long-term differences in
outcomes, with the laparoscopic group have
equivalent overall survival, disease-free survival, and local recurrence rates. The COLOR
II Trial was another randomized controlled
trial comparing the oncologic outcomes of
1044 patients who underwent laparoscopic
or open resection for rectal cancer. In this
large European study, there was no difference in the 3-year locoregional recurrence
rate, disease free survival, or overall survival
between the laparoscopic and open groups.
The ACOSOG Z6051 Trial was a multicenter
randomized controlled trial in the U.S. and
Canada involving 486 patients with Stage II
or III rectal cancer who underwent neoadjuvant therapy. In this study laparoscopic
approach was compared to open approach in
a non-inferiority analysis for pathologic outcomes clear distal and circumferential margins and well as the completeness of the
mesorectal excision. For the authors, the preferred technique remains to be a minimally
invasive approach. Challenges still exist for
treating low rectal tumors, particularly when
operating in a narrow pelvis or on patients
with increased visceral adiposity. Newer
techniques that have growing popularity are
the use of robotic surgery and combined
transanal and transabdominal approach.
Advocates for robotic surgery suggest that
articulating instruments and improved visualization aid in improved dissection in the
difcult pelvis and low-lying tumors.
Proponents of transanal total mesorectal
excision also advocate that this technique
adds benet to improved oncologic specimens primarily for low and ultra-low tumors,
possibly increasing the feasibility of sphincter sparing operations for patients with ultralow cancers, although data on the long-term
value of these techniques are still being
formulated.
N. Sphincter preservation is not advisable for
those patients with poor sphincter control or
who have low tumors invading the levators or
anal sphincters following neoadjuvant treatment. These patients should undergo en bloc
resection of the anus, rectum, and sigmoid
colon with permanent descending colostomy
possibly as an extralevator APR.
O. While APR has long been the gold standard
operation for patients with low rectal cancer,
recent evidence has shown that the improved
oncologic outcomes associated with TME
and neoadjuvant chemoradiation have not
been routinely replicated in patients undergoing APR. Keeping in mind that these
tumors have a higher propensity for local
spread and invasion into adjacent tissues
given the lack of a mesorectum, studies have
shown positive circumferential resection
margin (CRM) rates in the 30% range for
APR compared to 11% for LAR.Additionally,
APR has a higher rate of incomplete dissection and a perforation rate nearly 14% compared to 2.5% for LAR.Some surgeons have
advocated for extralevator APR to combat
the high risk for positive margins or incomplete resections. In this approach the perineal
dissection is started with a wide cylindrical
incision and carried through the ischiorectal
fat and the levator ani divided at the attachment to the sidewall, therefore eliminating
the “waist” associated with the standard APR
specimen and decreasing the risk of a positive CRM.The downside to this technique,
302
A. S. Rickles and F. J. Fleming
however, is the resultant large perineal defect
which often requires a ap for closure and
has a higher rate of wound complications.
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of laparoscopic versus open surgery for rectal cancer.
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Fleshman J, Branda M, Sargent DJ, et al. Effect of
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2015;314:1346–55.
Heald RJ. The ‘Holy Plane’ of rectal surgery. J R Soc
Med. 1988;81:503–8.
Jayne DG, Guillou PJ, Thorpe H, etal. Randomized trial
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Group. J Clin Oncol. 2007;25:3061–8.
Nagtegaal ID, van de Velde CJ, Marijnen CA, et al.
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Taylor FG, Quirke P, Heald RJ, et al. Preoperative high-
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Rectal Conditions: Rectal Cancer—Adjuvant and Neoadjuvant Therapy
TerryZwiep, JulieAnnVan Koughnett,
andPatrickH.D.Colquhoun
39
Refer to Algorithm in Fig. 39.1
A. Introduction
The American Cancer Society predicted an
incidence of rectal cancer of approximately
43,340 patients in United States alone in 2020.
Surgical resection remains the mainstay of
curative therapy for rectal cancer in most
patients; however, the treatment algorithms for
rectal cancer are complex when the roles of
neoadjuvant and adjuvant treatments are considered. The appropriate use of neoadjuvant
and adjuvant therapies requires proper workup
and staging. A multidisciplinary approach is
critical to account for these treatment nuances
and ensure optimal patient outcomes.
B. Staging
Staging of rectal cancer is multifactorial and
utilizes a combination of magnetic resonance
imaging (MRI), endorectal ultrasound
(ERUS), computed tomography (CT), colonoscopy, and serum carcinoembryonic antigen (CEA) level. The AJCC staging system is
standardly accepted for colorectal cancer and
is shown in Table 39.1. T and N stage are
determined by clinical impression on digital
rectal examination (DRE), endoscopy, and
T. Zwiep · J. A. Van Koughnett
P. H. D. Colquhoun (*)
Department ofSurgery, London Health Sciences
Center University Hospital, London, ON, Canada
e-mail: Patrick.Colquhoun@lhsc.on.ca
MRI or ERUS.DRE has been shown by the
MERCURY group to be fairly accurate in
locally staging a rectal mass in experienced
hands, but is not adequate as the sole modality to determine local stage; rather, it can be
helpful to provide a clinical impression and
guide further staging. There was debate in the
past about the best form of local staging with
MRI or ERUS. MRI has been denitively
established as the superior method for local
staging in most situations. MRI provides both
T stage and N stage, and even more importantly visualizes the proximity of the tumour
and involved lymph nodes to the mesorectal
fascia (circumferential radial margin—
CRM). It also offers better visualization of
potential invasion of surrounding structures
in the case of locally advanced disease, such
as the pelvic side wall and sphincters. MRI is
thus preferred for routine staging of rectal
cancer in order to best determine CRM status
and mesorectal and extramesorectal pelvic
lymph nodes. In addition, experienced radiologists and improved MRI techniques have
now allowed for the detection of extramural
vascular invasion, tumor budding, and extrarectal tumor deposits, all of which may more
accurately guide the recommendation for the
role of neoadjuvant chemoradiotherapy. The
use of ERUS without MRI for rectal cancer
should be limited to early T stage tumors or
very advanced adenomas, where it may provide better resolution. It must be noted that
© Springer Nature Switzerland AG 2020
S. R. Steele etal. (eds.), Clinical Decision Making in Colorectal Surgery,
https://doi.org/10.1007/978-3-319-65942-8_39
303
304
T. Zwiep et al.
Fig. 39.1 Algorithm for management of a complete clinical response after neoadjuvant treatment. TME total mesolec-
tal excision
the accuracy and utility of both MRI and
ERUS staging are highly dependent on the
expertise of the interpreter, and one must
account for local expertise when choosing the
staging modality and considering their
results. A CT of the thorax, abdomen, and
pelvis is recommended for assessment of any
metastatic disease. Extramesorectal disease
may be surgically resectable and should
involve input from a multidisciplinary tumor
board in choosing the sequence of potential
treatments. The concepts of resectable and
curable metastatic rectal cancer have resulted
in major shifts in treatment paradigms and
heavily utilize both neoadjuvant and adjuvant
treatment. This issue will be discussed in further detail later in the chapter.
C. Neoadjuvant Chemoradiotherapy
Following staging, a decision must be made
about the need for neoadjuvant chemoradio-
therapy. According to the National
Comprehensive Cancer Network (NCCN)
guidelines for the treatment of rectal cancer, all
patients who are locally staged as T3 N0, or
Tany N1-2, or T4 should undergo neoadjuvant
therapy. However, the benet of radiation in
patients with a clear CRM and no suspicious
lymph nodes on staging MRI is limited. As
mentioned earlier, MRI has been demonstrated
to be highly accurate in the interpretation of
the CRM status. Radiation is not benign or
without potential morbidity. Complications of
radiation include diarrhea, radiation enteritis,
radiation proctitis, perianal skin irritation,
anastomotic leak, and secondary malignancies. Neoadjuvant therapy can also alter nal
pathology and make the role for adjuvant therapy questionable in those who have seemingly
been downstaged on nal surgical pathology,
when compared to pre-operative MRI stage of