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422
J. G. Guillem and J. Garcia-Aguilar
ease in a timely and cost-effective manner.
During the initial assessment of primary disease,
our practice is to perform locoregional staging
and assess resectability with a rectal MRI, as well
as obtaining an intravenous contrast-enhanced
CT of the chest, abdomen, and pelvis to assess
for intra-abdominal and lung metastasis. These
studies are consistent with the standards of the
new American College of Surgeons Commission
on Cancer National Accreditation Program for
Rectal Cancer (ACS CoC NAPRC). https://www.
facs.org/~/media/les/quality%20programs/cancer/naprc/naprc%20standards%20manual.ashx.
We selectively obtain PET-CT scans when it is
necessary to further characterize indeterminate
distant lesions found on CT, although modern
high-quality CT scans read by a team of radiologists who are adept at performing oncologic
assessments has enabled us to condently characterize most lesions without needing a PET-CT
in the majority of cases.
Staging
Following the diagnosis of rectal cancer, the
patient is clinically staged by integrating the
history, physical examination, proctosigmoidoscopy ndings, and the results of preoperative
imaging studies. The clinical stage is then used to
select the most appropriate treatment strategy for
each patient. Although the imaging modalities
described above form the current standard of care,
there are clear limitations to these studies, and the
implications of either clinically understaging or
overstaging disease must be recognized.
Denite pathologic staging is carried out after
surgical resection. Currently, the American Joint
Committee on Cancer Tumor, Lymph Node, and
Metastases classication (AJCC TNM) is the
preferred system for the staging of rectal cancer.
The most recent version of the AJCC TNM
staging system further subdivides stages II, III,
and IV disease to more accurately reect
prognosis within these groups (Table23.1). One
notable addition to the 2010 version of the AJCC
staging system is the recognition of satellite
tumor deposits within the subserosa, mesentery,
or nonperitonealized pericolic or perirectal
tissues that do not involve regional lymph nodes.
These lesions are now given the designation N1c,
but their impact on prognosis remains unclear.
The AJCC recommends the histologic examination of at least 12 lymph nodes to adequately assess
nodal status and accurately stage patients. However,
the increased use of neoadjuvant chemotherapy
and/or chemoradiation has prompted a growing
awareness that neoadjuvant treatment may reduce
the number of identiable lymph nodes in the surgical specimen following TME.Therefore, histologic examination of fewer than 12 lymph nodes
may be considered adequate in this setting.
Management Based
onClinical Stage
The complexity of multimodal treatment algorithms for rectal cancer has increased in recent
years, and it is now recommended that most rectal cancer cases be reviewed by a multidisciplinary team after the patient’s initial presentation,
so that to an individualized treatment plan can be
developed. A proposed algorithm for the treatment of patients with rectal cancer is presented in
Fig.23.4.
But even with the advances made in combined
modality therapy, surgery remains the cornerstone of curative treatment for rectal cancer.
Early rectal cancers (stage I) can be denitively
treated by surgery alone; however, patients with
more advanced rectal cancers (stages II and III)
are typically treated with neoadjuvant therapy
(chemotherapy and/or chemoradiation) prior to
surgery to decrease the risk of recurrence and
optimize oncologic outcomes.
Surgical approaches depend largely on the
location and extent of disease, although the
patient’s clinical factors, such as comorbid medical conditions and baseline anorectal function,
are also considered. The most commonly used
transabdominal surgical approaches for rectal
cancers involve en bloc resection of the rectum,
along with the blood vessels and lymphatics that
lay within the mesorectum. Radical resections can
be further subdivided into sphincter-preserving
23 Rectal Cancer: Operative Treatment Transabdominal
423
Table 23.1 AJCC TNM
denitions and staging of rectal
cancer (7th Edition, 2010)
Primary tumor (T)
Tx Primary tumor cannot be assessed
T0 No evidence of primary tumor
Tis Carcinoma in situ: intraepithelial or invasion of lamina
T1 Tumor invades submucosa
T2 Tumor invades muscularis propria
T3 Tumor invades through the muscularis propria into
T4a Tumor penetrates to the surface of the visceral
T4b Tumor directly invades or is adherent to other organs or
Regional lymph nodes (N)
Nx Regional lymph nodes cannot be assessed
N0 No regional lymph node metastasis
N1 Metastasis in 1–3 regional lymph nodes
N1A Metastasis in one regional lymph node
N1b Metastasis in 2–3 regional lymph nodes
N1c Tumor deposit(s) in the subserosa, mesentery, or
N2 Metastasis in four or more regional lymph nodes
N2a Metastasis in 4–6 regional lymph nodes
N2b
Distant metastasis (M)
M0 No distant metastasis
M1 Distant metastasis
M1a Metastasis conned to one organ or site
M1b Metastases in >1 organ/site or the peritoneum
Stage T N M
0 Tis N0 M0
I T1–T2 N0 M0
IIA T3 N0 M0
IIB T4a N0 M0
IIC T4b N0 M0
IIIA T1–T2 N1/N1c M0
IIIB T3–T4a N1/N1c M0
IIIC T4a N2a M0
I VA Any T Any N M1a
IVB Any T Any N M1b
propria
pericolorectal tissue
peritoneum
structures
nonperitonealized pericolic or perirectal tissues without
regional nodal metastasis
Metastasis ≥7 regional lymph nodes
T1 N2a M0
T2–T3 N2a M0
T1–T2 N2b M0
T3–T4a N2b M0
T4b N1-N2 M0
procedures, and procedures in which the
sphincters cannot be salvaged without compromising a negative resection margin, resulting
in a permanent end colostomy. The goals of
surgical resection with curative intent are com-
plete resection of the primary tumor with adequate margins, an anatomically complete
lymphadenectomy of draining lymph nodes,
and en bloc resection of contiguously involved
structures.
424
J. G. Guillem and J. Garcia-Aguilar
Favorable histology
Local Excision
Unfavorable histology
Tl-2,N0
Transabdominal resection (TME)
Clinical
Staging
Cape/RT or
lnf. 5-FU/RT or
Bolus 5-FU/LV/RT
T3, N0 or
T any, N1-2 or T4 and/or
Locally unresectable or
Medically inoperable
FOLFOX or
CapeOX or
-5-FU/LV or
capecitabine
Transabdominal
Resection (TME)
Resection contraindicated
Cape/RT or
lnf. 5-FU/RT or
Bolus 5-FU/LV/RT
Fig. 23.4 Treatment algorithm for nonmetastatic rectal cancer
Transabdominal
Resection (TME)
Cape/RT or
lnf. 5-FU/RT or
Bolus 5-FU/LV/RT
FOLFOX or
CapeOX or
-5-FU/LV or
capecitabine
Transabdominal
Resection (TME)
Resection
contraindicated
Surveillance
Surveillance
Surveillance
Surveillance
Surveillance
Active CT regimen
for advanced disease
Surveillance
Active CT regimen
for advanced disease
T2N0 Rectal Cancer
Although a local procedure that does not include
resection of the mesorectum and draining lymph
channels, such as a transanal excision (TAE), transanal endoscopic microsurgery (TEM), or transanal
minimally invasive surgery (TAMIS), may be performed for a T2N0 rectal cancer, the failure rate for
these procedures is likely to be greater than that for
a properly performed total mesorectal excision
(TME)-based resection. Therefore, most T2N0 rectal cancers are managed with an upfront transabdominal TME-based resection. Details of these
approaches are provided below.
Locally Advanced Rectal Cancer
In patients with transmural and/or node-positive
disease (T3-4/Nx or Tx/N1-2) without evidence
of distant metastases, multimodality therapy
involving a combination of TME, chemoradiation therapy (CRT), and chemotherapy is indicated. Until recently, the standard treatment
regimen involved neoadjuvant CRT, then TME
with either a low-anterior resection or abdominoperineal resection, followed by adjuvant chemotherapy. However, the optimal sequence and
timing of these modalities continues to evolve
and may vary by institution. Major studies leading to the evolution of neoadjuvant therapy
options for rectal cancer are discussed below.
Neoadjuvant andAdjuvant Therapies
The Swedish Rectal Cancer Trial was the rst
randomized trial to assess whether administering
preoperative RT (5 Gy/day × 5 days) within
1week of surgery improved outcomes. The preoperative RT group had decreased local recurrence at ve years (11% vs. 27%, p < 0.01),
increased ve-year overall survival (58% vs.
48%, p=0.004), and increased nine-year cancerspecic survival (74% v. 65%, p = 0.002) [4].
This study was followed by the Dutch Colorectal
Cancer Group trial, which also assessed whether
adding preoperative RT (5×5Gy) to TME surgery improved oncologic outcomes in patients
with locally advanced rectal cancers [5].
23 Rectal Cancer: Operative Treatment Transabdominal
425
On long-term follow-up, RT was found to
improve ve-year local recurrence rates (5.6%
for the RT plus TME group vs. 10.9% for the
TME-alone group), but no difference in overall
survival was found. This study established a benet for preoperative RT, even when optimal surgical resection with TME is performed.
The German Rectal Cancer Group compared
preoperative with postoperative CRT (long-course
RT with concurrent chemotherapy) for patients
with stage II or III disease [6]. Preoperative CRT
was found to be associated with fewer acute and
chronic toxicities and an improved ve-year local
recurrence rate (6% vs. 13% for the preoperative
and postoperative groups, respectively). Longterm follow-up data showed that, at 10 years,
there was still a signicant improvement inlocal
control but no effect on overall survival. The
benets of preoperative long-course RT with
concurrent chemotherapy for local control have
been corroborated by others. In a report of 297
consecutive patients with T3-4 and/or N1 rectal
cancer who were treated at Memorial Sloan
Kettering Cancer Center (MSK) with standardized
neoadjuvant CRT regimens followed by a TMEbased resection, the recurrence rate was found to
be 23% (2% local recurrence only, 19% distant
recurrence, and 2% local and distant recurrence)
after a median follow-up of 44months, with an
estimated 10-year recurrence-free survival of
62% and a 10-year overall survival of 58% [7].
There are two options for administering preoperative therapy for locally advanced rectal cancers:
either short-course radiation therapy (5 Gy/
day×5days) followed by surgery within 1week,
or long-course chemoradiation (1.8–2.0 Gy/day
over 5–6weeks to a total dose of 45–50Gy, along
with 5-uorouracil-based intravenous or oral
capecitabine chemotherapy) followed by surgery
8–12 weeks later. Multiple studies comparing
short-course and long-course regimens have
shown that both reduce local recurrence rates by
more than half, but benets for overall survival are
less clear. Short-course radiotherapy remains popular in many European centers, but long-course
chemoradiation has become the preferred treatment regimen within the United States, largely due
to perceived increased local toxicity of the more
concentrated doses of radiation administered with
short-course therapy, as well as the increased
pathologic response rates noted with long-course
chemoradiation over short-course radiation therapy [8, 9].
Ongoing Debates inNeoadjuvant
Therapy forRectal Cancer
Following preoperative long-course RT and concurrent chemotherapy and a TME-based resection,
current guidelines recommend further adjuvant
chemotherapy for all patients with stage III disease, as well as considering it for patients with
high-risk stage II disease. However, less than 50%
of patients will go on to receive the complete
course of chemotherapy without interruptions, and
it is estimated that each 4-week delay in treatment
may decrease overall survival by 14% [10, 11].
These ndings have led some to advocate for
delivering the chemotherapy prior to surgery as
either induction chemotherapy (chemotherapy →
CRT → TME) or consolidation chemotherapy
(CRT → chemotherapy → TME). When compared
with the traditional sequence of CRT followed by
TME then adjuvant chemotherapy, the consolidation chemotherapy approach has been shown in a
prospective clinical trial to be well-tolerated and to
increase the pathologic response rate [12].
Another debate in the eld of neoadjuvant therapy for rectal cancer is whether all patients with
locally advanced rectal cancer require neoadjuvant
CRT.Several retrospective analyses suggest that a
subset of patients with low-risk disease (T3N0M0
lesions with negative margins and favorable histologic features) may not derive a signicant benet
from RT [13]. Unfortunately, limitations with current imaging modalities make it impossible to preoperatively select with certainty those patients
with low-risk T3N0 disease. A large multi-institutional study found that 22% of patients who
received preoperative CRT for T3N0 rectal cancer
clinically staged by ERUS or MRI actually had
node-positive disease on pathologic review of
resected specimens [14]. Because preoperative
CRT may reduce the total number of LNs and may
also sterilize mesorectal LNs, the true rate of
patients clinically staged with T3N0 who actually
have node-positive disease may be even higher
[14]. Although the risks of overstaging T3 rectal
cancer have been recognized (e.g., 18% of patients
426
J. G. Guillem and J. Garcia-Aguilar
with clinically staged T3N0 disease actually had
T2N0 disease, according to data from the German
Rectal Cancer Group [6], it is possible that twice
as many of these cancers are understaged based on
the ndings cited above. These data support the
use of preoperative CRT for patients with clinical
T3N0 rectal cancers staged by ERUS or MRI,
because understaged patients would otherwise
require postoperative CRT, which is associated
with inferior local control, higher toxicity, and
poor functional outcomes.
Another ongoing question is whether neoadjuvant chemotherapy can be given alone, without
routine chemoradiation prior to TME.In the phase
II/III PROSPECT trial (Chemotherapy Alone or
Chemotherapy Plus Radiation Therapy in Treating
Patients With Locally Advanced Rectal Cancer
Undergoing Surgery), patients with stage II or
stage III rectal cancer are being randomized to
receive either six cycles of neoadjuvant FOLFOX
followed by immediate TME if the tumor has
responded, or neoadjuvant CRT followed by TME
if the tumor has not responded, or to a control arm
of neoadjuvant CRT for 5.5 weeks immediately
followed by TME and eight cycles of adjuvant
FOLFOX.This trial is still ongoing and nal results
are not yet available, but results from a pilot trial
are encouraging [15].
Distant Metastatic (M1) Disease
Patients with distant metastasis represent a heterogeneous population for whom it is difcult to
dene an all-encompassing strategy. The management of these complex and challenging cases
should be discussed by a multidisciplinary team.
Treatment strategies are based mainly on factors
related to (1) the primary lesion (related symptoms, resectability); (2) the extent of metastases
(sites, resectability); and (3) the patient (age,
comorbidities, the ability to withstand major surgery, preferences regarding quality of life).
A strategy directed at curative intent can be
adopted in patients with a resectable primary
tumor and limited, resectable metastatic disease.
In these patients, systemic chemotherapy is commonly used as the initial treatment modality.
After restaging, resection of the primary and met-
astatic disease can be considered as either combined or staged operations. Alternatively, up-front
surgical resection, as either combined or staged
procedures, can be considered in patients with
limited metastatic disease.
In selected patients with stage IV disease,
systemic chemotherapy may provide effective
palliation that obviates the need for surgery.
However, some patients may present with symptoms such as pain, obstruction, or bleeding that
do not respond to chemotherapy and require a
palliative intervention such as a resection or
diverting ostomy to alleviate symptoms.
Although often utilized in obstructing descending and sigmoid colon cancers, endoscopic
stents are generally avoided in rectal cancer
because these devices tend to migrate and cause
intolerable local symptoms such as pain and
tenesmus.
Because as many as 60% of patients with
colorectal cancer eventually develop liver metastases, the approach to the treatment of colorectal
liver metastases (CRLM) deserves specic attention. With oligometastatic disease in an accessible location, complete resection remains the best
option, with ve-year survival rates of approximately 50%, and a 20% chance of cure. More
commonly, however, patients present with borderline resectable or unresectable disease (80–
90%). Traditional combination chemotherapy
regimens may convert patients who were initially
inoperable to potentially resectable, which results
in 5-year survival similar to that in patients who
were resectable initially. More recently, hepatic
artery infusion (HAI) chemotherapy has emerged
as an attractive adjunct to systemic chemotherapy
and may increase the conversion rate to resectable disease [16, 17].
Surgical Considerations
Radical Resection
Radical resection for rectal cancer involves resection of the tumor and rectum en bloc with its blood
and lymphatic supply, and the surrounding mesorectum. A sphincter-preserving low anterior resection (LAR) is the preferred approach to radical
23 Rectal Cancer: Operative Treatment Transabdominal
427
resection, as long as the procedure is technically
feasible and oncologically appropriate. With
proper patient selection, and surgical training and
experience, the procedure can usually be safely
performed when cancers are located more than
1cm from the upper portion of the anorectal ring.
Generally, slender patients with wide pelvises provide more favorable conditions for sphincter-preserving surgery, and obese patients and those with
long, narrow pelvises pose a technical challenge
that can preclude a restorative procedure.
Contraindications to LAR include tumor invasion into the anal sphincter or levator muscles.
Signicantly impaired preoperative anorectal
function is a relative contraindication, because it
often leads to poor postoperative bowel function.
An abdominoperineal resection (APR) is preferred
in situations where a margin-negative resection
would result in loss of anal sphincter function,
leading to fecal incontinence. In radical surgery
for rectal cancer, the following factors should be
considered: (1) total mesorectal excision (TME),
(2) autonomic nerve preservation, (3) negative
circumferential and distal margins, and (4)
sphincter preservation and restoration of bowel
continuity and function, when possible. The
following sections discuss each of these factors.
Total Mesorectal Excision
TME has consistently been associated with signicantly lower locoregional failure rates, ranging
from 3 to 7%, compared with historic and contemporary controls. The markedly low local recurrence rates associated with TME have made it the
standard of care in the surgical management of
rectal cancer. TME is dened as complete excision
of the visceral mesorectum, which refers to the
fatty tissue that encompasses the rectum, contains
the lymphatic drainage from the rectum, and is
encased by visceral fascia (Fig.23.5). When properly performed, TME results in en bloc removal of
the primary rectal cancer and mesorectum as an
intact “package,” which is associated with high
negative circumferential resection margin (CRM)
rates. TME also facilitates the identication and
preservation of the pelvic autonomic nerves. For
most middle and low rectal cancers, the entire
a
b
Fig. 23.5 Anterior (a) and posterior (b) views of a com-
plete mesorectal excision specimen
mesorectum is mobilized and resected. Cancers in
the upper rectum, usually located above 10 cm
from the anal verge, can be treated with a tumorspecic excision in which the mesorectum is
divided at a right angle to the bowel 5cm distal to
the mucosal edge of the tumor. TME is one of the
fundamental cornerstones of the American College
of Surgeons (ACS) Commission on Cancer (Coc)
National Accreditation Program for Rectal Cancer
(NAPRC) [18]. Numerous studies have found that
performance of a complete or near-complete TME
is associated with lower local recurrence rates than
is an incomplete TME [19]. However, it has been
found that this association is only valid when the
pathologist and the surgeon assesses the quality/
completeness of TME [20].
Circumferential Resection Margin
Circumferential resection margin (CRM) status
refers to the adequacy of the surgical resection
margin relative to the 360° radial extension of the
primary tumor, which may include extension into
the mesorectum and adjacent extrarectal soft tissue. The prognostic signicance of a negative
CRM in the presence of an intact mesorectum has
been well established [21]. In general, strive for a
2 mm or greater circumferential margin. When
428
J. G. Guillem and J. Garcia-Aguilar
MRI indicates a threatened margin, preoperative
neoadjuvant chemoradiotherapy may help
achieve a tumor-free CRM.
Distal Resection Margin
Distal resection margins (DRMs) of 2–5cm have
been the traditional standard in surgery for rectal
cancer. However, recent whole-mount pathologic
analyses of specimens from selected patients
who underwent CRT followed by resection found
intramural extension beyond the gross mucosal
edge of residual tumor in only 2 (1.8%) of 109
patients. Moreover, when extension was present,
it was limited to a distance of 0.95mm or less
[22]. Retrospective data suggest that margins as
small as 1 cm may not compromise oncologic
outcomes. A review from our institution found
that local control and recurrence-free survival
(RFS) with three years of follow-up after neoadjuvant CRT and TME-based resection were not
signicantly different when patients with DRMs
less than or equal to 1cm were compared with
those of patients with DRMs greater than 1cm
[23]. We advocate striving for a DRM of at least
2 cm for most rectal cancers, even after
preoperative CRT.However, a histologically negative DRM less than 1cm is acceptable in carefully selected patients in the absence of adverse
histologic features, particularly in situations in
which an APR may be required to achieve a wider
margin. In cases in which the DRM status is
uncertain, we suggest obtaining an intraoperative
frozen section of the distal margin. The editor
(SDW) does not nd intraoperative frozen sections valuable [24].
Reconstruction Options Following Low Anterior Resection
Reconstruction techniques following a low anterior resection (LAR) may include straight coloanal anastomoses (SCA) in either an end-to-end
or side-to-end fashion, or the creation of a colonic
reservoir with either a colonic J-pouch (CJP) or a
transverse coloplasty pouch (TCP). Multiple prospective randomized studies have compared these
options, and the majority shows better short-term
(within the rst postoperative year) functional
outcomes in terms of urgency and number of
bowel movements per day with CJPs; however,
there do not seem to be any long-term (>1year
postoperatively) differences in terms of continence, leak rate, and overall quality of life [25].
In general, we consider a CJP after a very low
anterior resection if the patient’s pelvic anatomy
is appropriate for this procedure (narrowed colon
lumen, limited colonic mesenteric fat, and a wide
pelvis). However, when a CJP is not technically
feasible, we favor performing a SCA.
Temporary Diversion Following Low Anterior Resection
Although exceptions may occur, we tend to perform
a diverting loop ileostomy on most LARs with a
low anastomosis (within 5cm from the anal verge
or within 2 cm above the anorectal ring), and on
most patients with a LAR following preoperative
RT.The ileostomy reversal is usually scheduled by
the authors at 3 months after surgery. However,
when postoperative chemotherapy is required,
reversal is postponed for several weeks beyond
completion of chemotherapy. In all patients, an
interim ofce visit with DRE and an enema study
with water-soluble contrast are recommended to
ensure that the anastomosis has remained patent,
has not narrowed, and that there is no evidence of
leakage prior to closure of the ileostomy.
A different approach is utilized by one of the
editors (DEB). The option of early ileostomy closure is discussed with patients. In those choosing
this option, the diverting ileostomy is closed
5–6weeks after the rectal resection and before the
chemotherapy, which can be started 3weeks after
the ileostomy closure. This editor performs the
rectal resection approximately 6 weeks after the
chemoradiotherapy in patients where maximal
tumor shrinkage is not needed. These patients then
start their chemotherapy 16–18weeks after starting their chemoradiotherapy. A retrospective
review of patients with rectal cancer who underwent a low anterior resection with diverting loop
ileostomy followed by adjuvant chemotherapy
from 2005 to 2013 identied 22 patients whose
stomas were closed before chemotherapy (BC)
and 50 whose stomas were closed after adjuvant
23 Rectal Cancer: Operative Treatment Transabdominal
429
chemotherapy (AC) [26]. Comparing the two
groups, there was no difference in mean age (or
preoperative clinical stage). Follow-up revealed a
similar mean duration from surgery to last contact
(BC 50.6—23.6months vs AC 43.5—22.1months,
P=0.23), and similar overall survival (BC 86% vs
AC 70%, P= 0.23) between groups. While this
study was underpowered, it supports individualizing the timing of ileostomy closure.
Abdominoperineal Resection
The abdominoperineal resection (APR) refers to
a combined abdominal and perineal approach to
resecting the rectum, mesorectum, anus, surrounding perineal soft tissue, and pelvic oor
musculature en bloc. An APR is indicated if the
tumor directly involves the sphincter muscles, if
adequate margins cannot be obtained during a
restorative resection, or if the patient already suffers from fecal incontinence preoperatively.
Beginning in 2007, several European centers
began reporting on a more radical resection of the
perineal component of the APR [27]. With this
approach, the patient is placed in the prone position for the perineal dissection, which is carried
widely along the levator muscles to the point at
which they originate on the pelvic sidewall before
traversing the levators and joining the mesorectal
dissection (Fig. 23.6). This approach leaves the
levators in their anatomic location attached to the
rectal wall and creates a more cylindrical surgical
specimen (Fig.23.7).
Surgeons who utilize this cylindrical or extralevatory abdominoperinal excision (ELAPE)
technique believe that the more cylindrical specimen decreases the rate of tumor perforation and
positive CRM, thereby improving outcomes.
However, this procedure creates a larger perineal defect that typically requires tissue-ap
reconstruction of the pelvic oor and is associated with increased morbidity, especially in the
setting of neoadjuvant therapy. Although randomized data comparing traditional APR with
ELAPE are limited, a retrospective review of the
Swedish Colorectal Cancer Registry reported
fewer intraoperative perforations during ELAPE
compared with conventional APR (7% vs. 16%,
p=0.043), but only among the subset of tumors
located within 4 cm of the anal verge [28].
However, ELAPE was associated with a signicantly higher risk of postoperative wound infections (20% vs. 12%, p = 0.01). A similar
retrospective review from the Danish Colorectal
Cancer Group database found that CRM positivity was more common following ELAPE, compared with traditional APR (16% vs. 7%,
p=0.01) [29]. Although there is still no consensus on the optimal approach, this debate further
abc
Fig. 23.6 Extralevator abdominoperineal excision of the rectum, showing dissection along the sphincter complex (a),
division of the levator muscle at the apex of the ischiorectal fossa (b), and the perineal defect (c)
430
Fig. 23.7 Cylindrical abdominoperineal excision of the
rectum specimen
underscores the importance of achieving a negative CRM and maintaining precise surgical technique when performing any type of APR.
Extent ofResection
When performing a resection for rectal cancer,
the most commonly involved adjacent structures
are located anteriorly: the prostate in men or the
posterior wall of the vagina in women. If prostatic involvement is suspected and an en bloc
prostatectomy/APR is required, the postoperative
function of the bladder is likely to be very poor,
and urinary diversion with an ileal conduit is
often needed. If the posterior vaginal wall is
involved, an en bloc anterior vaginectomy can be
performed and the defect closed with a perineal
ap. Another potential concern is pelvic sidewall
lymphadenopathy. In these cases, an extended
pelvic sidewall dissection and lymphadenectomy
can be of benet in carefully selected patients.
Abdominal Dissection: Minimally Invasive Versus Open Technique
The abdominal portion of a rectal cancer resection can be performed through a laparotomy, or
by using minimally invasive techniques. Four
large multicenter, prospective randomized trials
have compared open and laparoscopic TME for
rectal cancer.
In the COREAN (Randomized Prospective
Trial for Laparoscopic vs Open Resection for
Rectal Cancer) trial, 340 patients who had
received neoadjuvant CRT were randomly
assigned to either open or laparoscopic surgery.
Three-year DFS and OS were also similar
J. G. Guillem and J. Garcia-Aguilar
between the groups, although the study was powered to detect only a non-inferiority margin of
15% for DFS [30].
In the COLOR II (Laparoscopic Versus Open
Rectal Cancer Removal) trial, a study in which
30 international centers participated, 1044
patients with solitary rectal cancers within 15cm
of the anal verge were randomized to either open
or laparoscopic surgery. At 3years, local recurrence (5% vs. 5%), DFS (75% vs. 71%), and OS
(87% vs. 83%) were nearly identical in the laparoscopic and open groups, respectively [31].
However, the rates of tumor-free CRMs and local
recurrence for patients with mid-rectal tumors
was superior in the laparoscopic group.
A third prospective multicenter trial sponsored by the American College of Surgeons
Oncology Group (ACOSOG Z6051) randomized
486 patients with stage II or III rectal cancer
within 12cm of the anal verge to either laparoscopic or open resection after completion of neoadjuvant therapy. The primary outcome assessing
efcacy was a nonvalidated composite of circumferential radial margin (CRM) >1mm, negative
distal margin, and completeness of
TME. Successful resection occurred in 82% of
laparoscopic resections and 87% of open resections, which did not support non-inferiority.
Operative time was signicantly longer for laparoscopic resections (266 min vs. 220 min,
p<0.001), but there were no signicant differences in length of stay, readmission, major complications, negative CRM, negative distal margin,
or completeness of TME.The authors concluded
that laparoscopic resection failed to meet the criterion for non-inferiority for pathologic outcomes
and therefore should not be used in these patients
[32]. A fourth study, the ALaCaRT randomized
trial, examined patients with T1-T3 rectal cancers and also failed to demonstrate noninferiority
of laparoscopic surgery compared with open surgery [33]. However, the subsequent two-year follow up study [34] found no differences in
oncologic outcomes between the open and laparoscopic group. The problem with the Z-6051
study was not the technique of laparoscopy
between the use of a never before used non-validated composite score. Sadly, but not surprising,
using this score awed composite score, the
AlaCart study reached the same non-inferiority
23 Rectal Cancer: Operative Treatment Transabdominal
431
conclusions relative to short term surrogate
pathologic parameters.
Recently there has been increasing interest in
adopting the robotic surgical platform for the surgical treatment of rectal cancer. However, critics
cite the high cost of purchasing and maintaining
the robotic platforms, as well as the lack of haptic
feedback inherent in robotic surgery, as reasons
why they hesitate to convert from conventional
laparoscopy to robotic surgery. The literature to
date comparing conventional laparoscopy to
robotic surgery is limited to retrospective reviews
and institutional case series, with most studies
reporting that robotic surgery is associated with
increased operative time, decreased blood loss,
decreased conversion to open surgery, and similar oncologic outcomes [35]. The ROLARR trial
(Robotic Versus Laparoscopic Resection for
Rectal Cancer) also failed to demonstrate any statistically signicant advantage of robotic as compared to laparoscopic TME [36].
Our preference is to utilize, whenever possible, the robotic platform for all pelvic work, as
the visualization and dexterity are much improved
in comparison with traditional laparoscopy.
Robotic techniques above the level of the pelvis
can be challenging in obese patients, as achieving
exposure and retraction of the intra-abdominal
contents is sometimes difcult, and an experienced assistant is extremely helpful. Male
patients with a narrow pelvis and large mesorectum can be challenging using any technique, but
the laparoscopic approach in these patients may
be particularly difcult because of the straight
instruments and limited range of motion. One of
the editors prefers the laparoscopic approach and
has shown its superiority to laparotomy [37].
Perineal Dissection: Prone Versus Lithotomy Positioning
For perineal dissection, putting the patient in the
prone jackknife position facilitates maximum
exposure, keeps the dissection away from the table
edge, and increases access for a lateral-most dissection of the levator muscles. Although the
“upside down” view may be challenging, there are
distinct advantages to this approach, especially in
anteriorly located low rectal cancers in men.
Very obese patients may not tolerate the prone
jackknife position because their large abdomen
may lead to restricted ventilation. In these
patients, a left lateral (Sims) position, with the
knees tucked and the right buttock taped up and
away, allows exposure without restricting ventilation. The high lithotomy, also known as the
Lloyd-Davies position, is another alternative that
is ideal when a two-team approach is planned, so
that perineal dissection and abdominal dissection
can take place synchronously. Similarly, the plastic surgery team can harvest the rectus abdominus ap while the perineal portion of the APR is
completed.
When the perineal portion of the operation is
performed with the patient in the prone position,
it is important to discuss the specic sequence of
steps of the operation with the surgery, anesthesia, and nursing teams before the procedure to
maximize timing and uency and minimize overall operative time. For example, if a ventral rectus
abdominis ap is planned, the tissue will need to
be dissected, mobilized, and sutured to the proximal rectum prior to closing of the abdomen and
maturing of the ostomy—all of which is done
before the patient is turned to the prone position.
However, one of the editors (SDW) prefers to
perform the APR or ELAPR in the supine position. Data from the Cleveland Clinic Foundation
found no differences in outcomes between the
prone and supine positions [38].
Perineal Reconstruction Options
Primary closure of the perineal wound is associated with a signicant risk of wound infection,
dehiscence, and possible perineal hernia.
Reconstruction of the perineum using a number of
aps may reduce these risks, particularly in
patients undergoing an extended perineal resection. Unfortunately, these reconstructive procedures are themselves associated with specic
morbidity. The use of a rectus muscle ap can
lead to abdominal wall hernias at the midline incision or parastomal hernias. The use of gluteal
rotational aps is an alternative option, although
this procedure can lead to permanent changes in
mobility in the lower legs. A gracilis muscle ap
is yet another option, but often this approach is