2. INCIDENCE AND EPIDEMIOLOGY
• 60% of all cases – older than 65 years
• prior to age 65 - 45% of men and 39% of all women
• Overall survival is higher for patients with rectal cancer (67%) than colon cancer (64%)
• Overall,
• 40% of colorectal tumors are in the proximal colon and
• 60% are in the distal colon and rectum
3. HISTORY
• 1884 – Czérny - first abdominoperineal resection (APR)
• 1885 – Kraske - transsacral approach
• 1908 – Miles - improved on the APR;
• “zone of upward spread”: high ligation of the superior hemorrhoidal artery
• Wide perineal excision: cylindrical resection
• 1980 - William Heald - total mesorectal excision (TME)
• sharp dissection
• complete excision of the mesorectum
• “zone of downward spread”
4. ETIOLOGY AND RISK FACTORS
• First-degree relative with
colorectal cancer
• IBD – UC, Crohn’s colitis
• Genetic risk factors – FAP,
HNPCC
• Dietary fats, especially red-
meat fats
• Alcohol and tobacco -
synergistic effect
5. ANATOMY
• Therapy depends not only on the stage of the tumour but also on its location within the
pelvis and its relation to the anal sphincters.
• The rectum, usually 15 to 20 cm in length, extends from the rectosigmoid junction,
marked by fusion of the taenia coli into a completely circumferential muscular layer, to
the anal canal. (M: 18cm, F: 15cm)
• Transitions from being intraperitoneal to being completely extraperitoneal 10 to 12 cm
from the anus and the root of the sigmoid mesentery is approximately 19 cm from the
anal verge on rigid sigmoidoscopy
• “fixed” posteriorly and laterally by Waldeyer’s fascia
• Male patient, the anterior rectum is fixed to Denonvilliers’ fascia
• Female patient, the peritoneal cavity descends to the pouch of Douglas
6. ANATOMY
• the rectum has three valves of Houston,
the middle of which corresponds to the
anterior peritoneal reflection
• To achieve an adequate distal margin (≥1
cm) with sphincter preservation, the
lower border of a tumor must be located
high enough above the top of the
anorectal ring.
8. ANATOMY
• Lymphatic Drainage
A. Nodes at the origin of the inferior mesenteric artery.
B. Nodes at the origin of sigmoid branches.
C. Sacral nodes.
D. Internal iliac nodes.
E. Inguinal nodes.
• Above the dentate line usually drain via the superior
rectal lymphatics to the inferior mesenteric lymph nodes &
laterally to the obturator and internal iliac nodes
• Below the dentate line, lymph drains primarily to the
inguinal nodes but may empty into the inferior or superior
rectal lymph nodes
9. ANATOMY
• Innervation
• paired hypogastric (sympathetic),
• sacral (parasympathetic), and
• inferior hypogastric nerves
• Fibers from this plexus innervate the
rectum as well as the bladder, ureter,
prostate, seminal vesicles, membranous
urethra, and corpora cavernosa
• Therefore, injury to these autonomic
nerves can lead to impotence, bladder
dysfunction, and loss of normal
defecatory mechanisms.
10. ANATOMY
• Fascial Planes: the endopelvic/parietal fascia
• The fascia propria: forms the lateral
stalks
• Waldeyer’s fascia: anteroinferior fascial
reflection of the presacral fascia
• Denonvilliers’ fascia: separates the
anterior rectal wall
11. DIAGNOSIS AND EVALUATION
• History
• Rectal bleeding, a change in bowel habits or stool caliber, rectal pain, a sense of
rectal “fullness,” weight loss, nausea, vomiting, fatigue, or anorexia
• Tenesmus: possibly fixed stage II or III cancer
• Pain with defecation suggests involvement of the anal sphincters
• Preoperative sexual function is important
• Family history or factors predisposing the patient to rectal cancer, such as FAP,
HNPCC, MUTYH, and IBD, are important
12. DIAGNOSIS AND EVALUATION
• Physical Examination
• digital rectal examination (DRE) is critical
• tumor size, mobility and fixation,
• anterior or posterior location,
• relationship to the sphincter mechanism and top of the anorectal ring, and distance
from the anal verge
• Rigid proctoscopy is mandatory, Flexible sigmoidoscopy is not used routinely
• A complete colonoscopy to the cecum is essential to rule out synchronous cancers
• For anterior lesions, women should undergo a complete pelvic examination to
determine vaginal invasion
13. DIAGNOSIS AND EVALUATION
• Preoperative Staging
• Abdominal and pelvic computed
tomography (CT) scans:
• If a node is seen on CT scan, it
should be presumed to be
malignant because benign
adenopathy is not normally seen
around the rectum
• Lateral pelvic sidewall invasion
must be ascertained
• Endorectal ultrasound (ERUS)
• MRI
• FDG-PET
• LABORATORY STUDIES
• Complete blood count and electrolytes
• LFT
• serum carcinoembryonic antigen
(CEA): greater than 5 ng/mL
(preoperative) signify a worse
prognosis
16. PRINCIPLES OF TREATMENT
• Surgical resection is the cornerstone of curative therapy
• Superficially invasive, small cancers may be managed effectively with local excision
• However, most patients have more deeply invasive tumors that require major surgery,
such as low anterior resection (LAR) or APR
• Bowel Preparation:
• a clear-liquid diet 24 hours prior to surgery, laxatives and/or enemas,
• oral antibiotics (erythromycin base and neomycin base) and
• gastrointestinal tract irrigation with a solution of polyethylene glycol electrolyte
lavage.
17. Goals of Surgery
• Complete eradication of the primary tumor along with the adjacent mesorectal tissue
and the superior hemorrhoidal artery pedicle
• Cancer removal should not be compromised in an attempt to avoid a permanent
colostomy
• Resection Margins
• DISTAL MARGINS: controversial - a 1-to 2-cm distal margin is acceptable for
resection of rectal carcinoma, although a 5-cm proximal margin is still
recommended
• RADIAL MARGINS: circumferential radial margin (CRM) is more critical than the
proximal or distal margin for local control
18. LOCAL EXCISION
• CHARACTERISTICS OF TUMORS AMENABLE TO LOCAL EXCISION
• T1N0 or T2N0 lesion
• <4 cm in diameter
• <40% circumference of the lumen
• <10 cm from dentate line
• Well- to moderately differentiated histology
• No evidence of lymphatic or vascular invasion on biopsy
• Patients with extensive metastatic disease and poor prognosis who require local
control
19. LOCAL EXCISION
• Technique: There are four approaches to local excision
• Transsphincteric – less preferred
• Transanal - 6 to 8 cm above the anal verge/ 3 to 4 cm above the anorectal ring
• Transcoccygeal - larger or more proximal lesions, 4.8 cm from the dentate line
• TEM - lesions in the mid and proximal rectum
• 3 cm from the dentate line but not invading the sphincters : transanal procedure
• 5 cm from the dentate line: transcoccygeal approach or TEM
• 7 to 10 cm from the dentate line: TEM or LAR
20. Transanal Excision
• Approach to transanal excision of a rectal
tumor.
A. A 1- to 2-cm margin is marked
circumferentially with Bovie
electrocautery on the rectal mucosa.
B. Full-thickness excision down to
perirectal fat is performed.
C. The specimen is oriented for the
pathologist.
21. Transcoccygeal Excision
• Kraske approach to an anterior lesion.
The coccyx is excised, the levator is split
in the midline, and the rectum is
mobilized. The posterior rectal wall is
opened to expose an anterior lesion
22. Transcoccygeal Excision
• Kraske approach to a posterior lesion.
After the rectum has been exposed, the
surgeon may palpate the distal margin of
the tumor. The tumor is excised with a 1-
cm margin
23. Transanal Endoscopic Microsurgery
• useful for small benign and malignant
lesions in the mid and proximal rectum
that are too high for a traditional
transanal excision
• specialized instrumentation includes a 4-
cm Wolf operating proctoscope in lengths
of 12 and 20 cm with a flat or beveled
end
• equipped with a binocular microscope and
videoscope attachment for viewing on a
standard laparoscopy tower
• follows the same principles as transanal
excision
24. LOW ANTERIOR RESECTION WITH TOTAl MESORECTAL
EXCISION
• TME involves sharp dissection under direct vision in the avascular, areolar plane
between the fascia propria of the rectum, which encompasses the mesorectum, and the
parietal fascia overlying the pelvic wall structures
• emphasizes autonomic nerve preservation (ANP), complete hemostasis and avoids
violation of the mesorectal envelope
• Quality of Life: significant incidence of
• Impotence
• Retrograde ejaculation, and
• urinary incontinence/retention
25. Technique of Total Mesorectal Excision
• The patient is placed in a modified lithotomy position
• A low midline incision is made between the umbilicus
and the pubis
• The abdomen is explored to search for metastatic
disease in the liver, pelvic organs
• The sigmoid colon is mobilized laterally &
identification of left ureter
• The colon usually is divided proximal to the
rectosigmoid junction
• The superior hemorrhoidal artery is then divided at
the junction with the left colic artery
• The presacral fascia is incised down to Waldeyer’s
fascia, and the dissection is carried inferiorly to the
tip of the coccyx
• The anterior and lateral dissections are then started
26.
27. Technique of Total Mesorectal Excision
• POINT OF TRANSECTION:
• upper rectum (>10 cm from the anal
verge) - extended to 5 to 6 cm, rectum
and mesorectum at the same level
• Once the rectum has been mobilized, a
tumor measured at 5 cm by rigid
proctoscopy often may be moved to 8
cm from the dentate line
• When the distal extent of the tumor and
the site of transection have been
established, electrocautery is used to
dissect the mesorectal fat away from
the rectum.
28. Technique of Total Mesorectal Excision
• TA linear stapler or a curved 40-mm contour stapler (Ethicon,
USA) is used to staple the rectum
• The specimen is handed off the field
• a tension-free anastomosis should be followed using a end-to-
end anastomosis (EEA) circular stapler
• A diverting loop ileostomy should be considered in any low
anastomoses (<5cm) from the dentate line
• Side-to-end reconstruction or a colon J-pouch reconstruction:
superior function over a straight coloanal anastomosis
29. ABDOMINOPERINEAL RESECTION
• distal rectal cancers have been treated with an abdominoperineal resection (APR)
• En bloc resection of the tumor as well as the surrounding lymph nodes and the anal
sphincters, resulting in a permanent colostomy.
• The dissection proceeds down to the striated muscles of the levator ani
• the colostomy is created and the abdominal cavity is closed
• The perineal dissection is then performed
30.
31. OTHER SURGICAL OPTIONS
• EN BLOC EXCISION WITH RECTUM
• Posterior Vaginectomy
• Prostatectomy
• Pelvic Exenteration
• PALLIATIVE RESECTION IN STAGE IV DISEASE
• LAPAROSCOPIC SURGERY
• ROBOTIC SURGERY
32. CHEMORADIATION
• Adjuvant Chemoradiation
• The goal is to eliminate the micrometastatic disease present at the time of surgery
• Radiation therapy used alone may improve local recurrence but not survival rates
• Neoadjuvant Chemoradiation
• Advantages:
• ability to deliver higher doses,
• tumor downstaging,
• radiating tissues with a greater oxygen supply then creating the neorectum with
nonirradiated colon,
• small intestine has not fallen into the pelvis
34. SURVEILLANCE
• Postoperatively at 2 weeks and then every 3 months for 2 years
• At each visit, the patient undergoes DRE & sigmoidoscopy, & a CEA level is
obtained
• At 1 year post-resection a colonoscopy & CT scans of the chest, abdomen, and
pelvis
• A CT scan is performed annually until 3 to 5 years postoperatively
• After the initial 2 years: every 6 months with CEA levels & physical examinations until
5 years