Investigation of colorectal disease

1. Evaluation of Colon, Rectum, and
Anus
Yonas Ademe
August, 2017
1

2. Clinical Assessment
• Obtaining a complete history and performing a
physical examination are the starting points for
evaluating any patient with suspected disease
of the colon, rectum, or anus
2

3. Common Symptoms
Pain
Bleeding
Change in bowel habit (constipation,
diarrhea, tenesmus)
Incontinence
3

4. Pain
• Abdominal pain
– Related to the colon and rectum can result from obstruction,
inflammation, perforation, or ischemia
• Pelvic Pain
– It can originate from the distal colon and rectum or from adjacent
urogenital structures
– Tenesmus may result from proctitis or from a rectal or retrorectal
mass
– Cyclical pain associated with menses, especially when
accompanied by rectal bleeding, suggests a diagnosis of
endometriosis
• Anorectal pain
– Most often secondary to an anal fissure, perirectal abscess
and/or fistula, or a thrombosed hemorrhoid
• Less common causes: peri-anal inflammatory processes, neoplasms
4

5. Lower Gastrointestinal Bleeding
• Acute GI hemorrhage
– The first goal in evaluating and treating a patient
with GI hemorrhage is adequate resuscitation
– The second goal is to identify the source of
hemorrhage
• Because the most common source of GI hemorrhage is
UGI, NG aspiration should always be performed
– If aspiration reveals blood or non-bile secretions, do UGI
endoscopy
– Return of bile suggests that the source of bleeding is distal to
the ligament of Treitz
» Anoscopy OR limited proctoscopy OR colonoscopy (if
patient is hemodynamically stable)
5

6. Cont.
• Cont.
– Colonoscopy may identify the cause of the bleeding,
and cautery or injection of epinephrine into the
bleeding site may be used to control hemorrhage
– Colectomy may be required if bleeding persists
despite these interventions
6

7. Cont.
• Hematochezia
– Commonly caused by hemorrhoids or a fissure
• Sharp, knife-like pain and bright red rectal bleeding with bowel
movements suggest the diagnosis of fissure
• Painless, bright red rectal bleeding with bowel movements is
often secondary to a friable internal hemorrhoid
– In the absence of any sign of obvious fissure or
hemorrhoid, any patient with rectal bleeding should
undergo a careful DRE, anoscopy, and
proctosigmoidoscopy
• Failure to diagnose a source in the distal anorectum should
prompt colonoscopy
7

8. Cont.
• Occult blood loss
– May manifest as IDA or may be detected with FOBT
– Because colon neoplasms bleed intermittently and
rarely present with rapid hemorrhage, the presence
of occult fecal blood should always prompt a
colonoscopy
• Unexplained IDA is also an indication for colonoscopy
8

9. Constipation
• Appropriate definition of constipation is lacking
– Patients may describe infrequent bowel movements, hard
stools, or excessive straining
• It has many causes
– Underlying metabolic, pharmacologic, endocrine,
psychological, and neurologic causes often contribute to the
problem
– A stricture or mass lesion should be excluded by colonoscopy,
barium enema, or CT colonography
• Medical management is the mainstay of therapy for
constipation and includes fiber, increased fluid intake,
and laxatives
9

10. Diarrhea
• It is also a common complaint and is usually a
self-limited symptom of infectious
gastroenteritis
• If diarrhea is chronic or is accompanied by
bleeding or abdominal pain, further
investigation is warranted
10

11. Incontinence
• It ranges in severity from occasional leakage of gas and liquid
stool to daily loss of solid stool
• Causes
– Neurogenic
• CNS, spinal cord, pudendal nerve injury
– Anatomic
• Trauma
• Overflow incontinence secondary to impaction or an obstructing
neoplasm
• Congenital abnormalities
• Procidentia (rectal prolapse)
• Diagnostic adjuncts: anal manometry, defecography,
endoanal ultrasound
11

12. Investigation
12

13. Endoscopy
• Anoscopy
– Anoscopes are made in a variety of sizes and measure
approximately 8 cm in length
– After removing the obturator, the anoscope should be
rotated 90° and reinserted to allow visualization of all four
quadrants of the canal
• Proctoscopy
– The rigid proctoscope is useful for examination of the
rectum and distal sigmoid colon
– It is occasionally used therapeutically
• Polypectomy, electrocoagulation, or detorsion of a sigmoid volvulus
– The standard proctoscope is 25 cm in length and available in
various diameters
13

14. Cont.
• Flexible Sigmoidoscopy and Colonoscopy (both
diagnostic and therapeutic)
– Sigmoidoscopes measure 60 cm in length
• Full depth of insertion may allow visualization as high as the
splenic flexure
• Partial preparation with enemas is usually adequate
• Most patients can tolerate this procedure without sedation
– Colonoscopes measure 100 to 160 cm
• Capable of examining the entire colon and terminal ileum
• A complete oral bowel preparation is usually necessary
• The duration and discomfort of the procedure usually require
conscious sedation
• N.B: electrocautery should generally not be used in the
absence of a complete bowel preparation because of the risk of
explosion of intestinal methane or hydrogen gases 14

15. Cont.
• Capsule Endoscopy
– It is an emerging technology that uses a small
ingestible camera
– After swallowing the camera, images of the mucosa
of the GIT are captured, transmitted by
radiofrequency to a belt-held receiver, and then
downloaded to a computer for viewing and analysis
– Largely has been used to detect small bowel lesions
• However, it has been suggested that this technique might
also be useful for diagnosing colorectal disease
15

16. Imaging
• Plain X-Rays and Contrast Studies
– Plain X-rays of the abdomen (supine, upright, and
diaphragmatic views) are useful for detecting free intra-
abdominal air and bowel gas patterns suggestive of
small or large bowel obstruction
– Contrast studies are useful for evaluating obstructive
symptoms, delineating fistulous tracts, and diagnosing
small perforations or anastomotic leaks
• Although Gastrografin cannot provide the mucosal detail
provided by barium, this water-soluble contrast agent is
recommended if perforation or leak is suspected
• Double-contrast barium enema (use of barium followed by the
insufflation of air into the colon) has been reported to be 70%
to 90% sensitive for the detection of mass lesions greater than
1 cm in diameter
16

17. Cont.
• CT scan
– Its utility is primarily in the detection of extraluminal
disease, such as intra-abdominal abscesses and
pericolic inflammation, and in staging colorectal
carcinoma
• Extravasation of oral or rectal contrast may also confirm
the diagnosis of perforation or anastomotic leak
• A standard CT scan is relatively insensitive for the
detection of intraluminal lesions
– CT colonography (virtual colonoscopy) uses helical CT and three-
dimensional reconstruction to detect intraluminal colonic lesions
with a sensitivity and specificity for detecting 1 cm or larger
polyps of 85% to 90%
17

18. Cont.
• MRI
– The main use of MRI in colorectal disorders is in
evaluation of pelvic lesions
• MRI is more sensitive than CT for detecting bony
involvement or pelvic sidewall extension of rectal tumors
• MRI also can be helpful in the detection and delineation
of complex fistulas in ano
18

19. Cont.
• Positron emission tomography
– It is used for imaging tissues with high levels of
anaerobic glycolysis, such as malignant tumors
– It has been used as an adjunct to CT in the staging of
colorectal cancer and may prove useful in
discriminating recurrent cancer from fibrosis
19

20. Cont.
• Angiography
– Angiography is occasionally used for the detection of
bleeding within the colon or small bowel
– CT and magnetic resonance angiography are also
useful for assessing patency of visceral vessels
20

21. Cont.
• Endoscopic Ultrasound
– Endorectal ultrasound is primarily used to evaluate
the depth of invasion of neoplastic lesions in the
rectum
• The normal rectal wall appears as a five-layer structure
• It also can detect enlarged perirectal lymph nodes, which
may suggest nodal metastases
– Endoanal ultrasound is used to evaluate the layers of
the anal canal
• It is particularly useful for detecting sphincter defects and
for outlining complex anal fistulas
21

22. Laboratory Studies
• Serum tests
– CBC and BG
– OFT
– Electrolytes
– Tumor markers
• CEA may be elevated in 60% to 90% of patients with
colorectal cancer
– Despite this, it is not an effective screening tool for this
malignancy
– It is nonspecific, and no survival benefit has yet been proven
– Genetic Testing (AFP and HNPCC)
22

23. Cont.
• Fecal Occult Blood Testing (FOBT)
– It has been used as a screening test for colonic
neoplasms in asymptomatic, average-risk
individuals
– The efficacy of the test is based on serial testing
because the majority of colorectal malignancies will
bleed intermittently
– Any positive FOBT mandates further investigation,
usually by colonoscopy
23

24. Cont.
• Cont.
– It is a nonspecific test for peroxidase contained in
hemoglobin
• Consequently, occult bleeding from any GI source will produce
a positive result
• Similarly, many foods (red meat, some fruits and vegetables,
and vitamin C) will produce a false-positive result
– Increased specificity is now possible by using
immunochemical FOBT
• These tests rely on monoclonal or polyclonal antibodies to
react with the intact globin portion of human hemoglobin and
are more specific for identifying occult bleeding from the colon
or rectum
24

25. Cont.
• Stool Studies
– Stool microscopy
– Stool culture
– Stool toxicology
• C. difficile
– Steatorrhea
• By adding Sudan red stain to a stool sample
25

26. General surgical considerations
26

27. Emergency Resection
• Emergency resection may be required because
of obstruction, perforation, or hemorrhage
• In this setting, the bowel is almost always
unprepared and the patient may be unstable
• An attempt should be made to resect the
involved segment along with its lymphovascular
supply
27

28. Cont.
• If the resection involves the right colon or
proximal transverse colon (right or extended
right colectomy), a primary ileocolonic
anastomosis can usually be performed safely as
long as the remaining bowel appears healthy
and the patient is stable
28

29. Cont.
• For left-sided tumors, the traditional approach has
involved resection of the involved bowel and end
colostomy, with or without a mucus fistula
– Safe and appropriate if the bowel appears compromised
or if the patient is unstable, malnourished, or
immunosuppressed
– There is an increasing body of data to suggest that a
primary anastomosis with or without a diverting
ileostomy, may be equally safe in this setting
• If the proximal colon appears unhealthy (vascular compromise,
serosal tears, perforation), a subtotal colectomy can be
performed with a small bowel to rectosigmoid anastomosis
29

30. Colectomy
• Ileocolic Resection (Ileocecectomy)
– It describes a limited resection of the terminal
ileum, cecum, and appendix with a primary
anastomosis created between the distal small bowel
and the ascending colon
• The ileocolic vessels are ligated and divided
– It is used to remove disease involving these
segments of the intestine
• If curable malignancy is suspected, more radical
resections, such as a right hemicolectomy, are generally
indicated
30

31. Cont.
• Right hemi-colectomy
– It is used to remove lesions or disease in the right colon
and is oncologically the most appropriate operation for
curative intent resection of proximal colon carcinoma
– Approximately 10 cm of terminal ileum are usually
included in the resection
– A primary ileal-transverse colon anastomosis is almost
always possible
– The ileocolic vessels, right colic vessels, and right
branches of the middle colic vessels are ligated and
divided
31

32. Cont.
• Extended Right hemi-colectomy
– It may be used for curative intent resection of lesions
located at the hepatic flexure or proximal transverse
colon
– A standard right colectomy is extended to include
ligation of the middle colic vessels at their base
– The right colon and proximal transverse colon are
resected, and a primary anastomosis is created between
the distal ileum and distal transverse colon
– Such an anastomosis relies on the marginal artery of
Drummond
• If the blood supply to the distal transverse colon is
questionable, the resection is extended distally beyond the
splenic flexure to well-perfused descending colon
32

33. Cont.
• Transverse Colectomy
– Lesions in the mid and distal transverse colon may be
resected by ligating the middle colic vessels and
resecting the transverse colon, followed by a
colocolonic anastomosis
– An extended right colectomy with an anastomosis
between the terminal ileum and descending colon
may be a safer anastomosis with an equivalent
functional results
33

34. Cont.
• Left hemi-colectomy
– For lesions or disease states confined to the distal
transverse colon, splenic flexure, or descending
colon
– The left branches of the middle colic vessels, the
left colic vessels, and the first branches of the
sigmoid vessels are ligated and colocolonic
anastomosis is performed
34

35. Cont.
• Extended left hemi-colectomy
– The left colectomy is extended proximally to include
the right branches of the middle colic vessels
– It is an option for removing lesions in the distal
transverse colon
35

36. Cont.
• Sigmoid colectomy
– For lesions in the sigmoid colon
– The entire sigmoid colon should be resected to the
level of the peritoneal reflection with ligation of the
sigmoid branches and an anastomosis is created
between the descending colon and upper rectum
– Full mobilization of the splenic flexure is often
required to create a tension-free anastomosis
36

37. Cont.
• Total and Subtotal Colectomy
– Occasionally required for patients with fulminant
colitis, attenuated FAP, or synchronous colon
carcinomas
– The ileocolic vessels, right colic vessels, middle colic
vessels, and left colic vessels are ligated and divided
37

38. Cont.
• Cont.
– If it is desired to preserve the sigmoid, the distal sigmoid
vessels are left intact, and an anastomosis is created
between the ileum and distal sigmoid colon (subtotal
colectomy with ileosigmoid anastomosis)
– If the sigmoid is to be resected, the sigmoidal vessels are
ligated and divided, and the ileum is anastomosed to the
upper rectum (total abdominal colectomy with ileorectal
anastomosis)
– If an anastomosis is contraindicated, an end ileostomy is
created, and the remaining sigmoid or rectum is
managed either as a mucus fistula or a Hartmann’s
pouch
38

39. Cont.
• Total Proctocolectomy
– The entire colon, rectum, and anus are removed and
the ileum is brought to the skin as a Brooke
ileostomy
39

40. Cont.
• A→C: Ileocecectomy
• A + B→D: Ascending colectomy
• A + B→F: Right hemicolectomy
• A + B→G: Extended right
hemicolectomy
• E + F→G + H: Transverse colectomy
• G→I: Left hemicolectomy
• F→I: Extended left hemicolectomy
• J + K: Sigmoid colectomy
• A + B→J: Subtotal colectomy
• A + B→K: Total colectomy
• A + B→L: Total proctocolectomy
40

41. Anterior Resection
• Anterior resection is the general term used to
describe resection of the rectum from an
abdominal approach to the pelvis with no need
for a perineal, sacral, or other incision
• 3 types
– High Anterior Resection
– Low Anterior Resection
– Extended low Anterior Resection
41

42. Cont.
• HAR
– Resection of the distal sigmoid colon and upper
rectum
– It is the appropriate operation for benign lesions and
disease at the rectosigmoid junction such as
diverticulitis
– The upper rectum is mobilized, but the pelvic
peritoneum is not divided and the rectum is not
mobilized fully from the concavity of the sacrum
– The IMA and IMV are ligated separately
42

43. Cont.
• LAR
– It is used to remove lesions in the upper and mid
rectum
– The rectosigmoid is mobilized, the pelvic peritoneum is
opened
• The rectum is mobilized from the sacrum by sharp dissection
under direct view within the endopelvic fascial plane
– The rectum and accompanying mesorectum are divided
at the appropriate level, depending on the nature of the
lesion, and a low rectal anastomosis is performed after
mobilization of the splenic flexure
– Both IMV and IMA are ligated
43

44. Cont.
• ELAR
– This is necessary to remove lesions located in the
distal rectum, but several centimeters above the
sphincter
– The rectum is fully mobilized to the level of the
levator ani muscle just as for a LAR, but the anterior
dissection is extended along the rectovaginal
septum in women and distal to the seminal vesicles
and prostate in men
– After resection at this level, a coloanal anastomosis
is performed
44

45. Abdominoperineal Resection
• It involves removal of the entire rectum, anal
canal, and anus with construction of a
permanent colostomy from the descending or
sigmoid colon
• The abdominal-pelvic portion of this operation
proceeds in the same fashion as described for
an ELAR
45

46. Cont.
• The perineal dissection can be performed with the
patient in lithotomy position (often by a second
surgeon) or in the prone position after closure of
the abdomen and creation of the colostomy
– For cancer, the perineal dissection is designed to excise
the anal canal with a wide circumferential margin
including a cylindrical cuff of the levator muscle
– For benign disease, proctectomy may be performed
using an intersphincteric dissection between the
internal and external sphincters
• This approach minimizes the perineal wound, making it easier
to close because the levator muscle remains intact
46

47. Hartmann’s Procedure
• It refers to a colon or rectal resection without an
anastomosis in which a colostomy or ileostomy is created
and the distal colon or rectum is left as a blind pouch
• The term is typically used when the left or sigmoid colon
is resected and the closed off rectum is left in the pelvis
• If the distal colon is long enough to reach the abdominal
wall, a mucus fistula can be created by opening the
defunctioned bowel and suturing the open lumen to the
skin
47

48. Anastomoses
• Anastomoses may be created between two segments of
bowel in a multitude of ways
• The submucosal layer of the intestine provides the
strength of the bowel wall and must be incorporated in
the anastomosis to assure healing
• Although many surgeons advocate one method over
another, none has been proven to be superior
– Accurate approximation of two well-vascularized, healthy
limbs of bowel without tension in a normotensive,
wellnourished patient almost always results in a good
outcome
48

49. Cont.
• Anastomoses at highest risk of leak or stricture:
– Those involving irradiated or diseased intestine
– Those having perforation with peritoneal soilage
– Those that are in the distal rectal or anal canal
– Those performed in malnourished,
immunosuppressed, or ill patients
49

50. Cont.
• Anastomotic Configuration
– End-to-End
• Can be performed when two segments of bowel are
roughly the same caliber
• Most often employed in rectal resections, but may be
used for colocolostomy or small bowel anastomoses
– End-to-Side
• Useful when one limb of bowel is larger than the other
– This most commonly occurs in the setting of chronic obstruction
50

51. Cont.
• Cont.
– Side-to-End
• It is used when the proximal bowel is of smaller caliber
than the distal bowel
• Ileorectal anastomoses commonly make use of this
configuration
– Side-to-Side
• It allows a large, well vascularized connection to be
created on the antimesenteric side of two segments of
intestine
• Commonly used in ileocolic and small bowel anastomoses
51

52. Cont.
• Anastomotic Technique
– Hand-sutured technique
• Single layer
– Using either running or interrupted stitches
• Double layer
– A continuous inner layer and an interrupted outer layer
– Stapled technique
Suture material may be either permanent or absorbable
52

53. Ostomies
53

54. Classification
• Depending on the clinical situation
– Temporary
– Permanent
• Depending on function
– Decompressive
• Tube cecostomy
• Blow hole colostomy
– Diversion
• End
• Double barrel
• Spectacle
• Depending on construction
– Loop
– End
– Double barrel
– Spectacle
• Depending on anatomic site
– Ileum
– Cecum
– Transverse colon
– Descending colon
– Sigmoid colon 54

55. Location
• A poorly placed stoma can result in leakage and
skin breakdown
– Ideally, a stoma should be placed in a location that
the patient can easily see and manipulate, within
the rectus muscle, and below the belt line
55

56. Cont.
• Because the abdominal landmarks in a supine,
anesthetized patient may be dramatically different from
those in an awake, standing, or sitting patient, the stoma
site should always be marked with a tattoo, skin scratch,
or permanent marker preoperatively, if possible
• In an emergency operation where the stoma site has not
been marked, an attempt should be made to place a
stoma within the rectus muscle and away from both the
costal margin and iliac crest
– In emergencies, placement high on the abdominal wall is
preferred to a low-lying site
56

57. Cont.
• Ideal site for
ileostomy
57

58. Cont.
• For all stomas, a circular skin incision is created and
the subcutaneous tissue dissected to the level of
the anterior rectus sheath
• The anterior rectus sheath is incised in a cruciate
fashion, the muscle fibers separated bluntly, and
the posterior sheath identified and incised
• Care should be taken to avoid injuring and causing
bleeding from the inferior epigastric artery and vein
58

59. Cont.
• The size of the defect depends on the size of the bowel used
to create the stoma, but should be as small as possible
without compromising the intestinal blood supply (usually
the width of two to three fingers)
• The bowel is then brought through the defect and secured
with sutures
– 3 to 4 interrupted absorbable sutures are placed through the edge
of the bowel, then through the serosa, approximately 2 cm
proximal to the edge, and then through the dermis (Brooke
technique)
– After the stoma is everted, the mucocutaneous junction is sutured
circumferentially with interrupted absorbable suture
• The abdominal incision is usually closed and dressed prior to
maturing the stoma to avoid contaminating the wound
59

60. Ileostomy
• A temporary ileostomy is often used to “protect”
an anastomosis that is at risk for leakage (low in the
rectum, in an irradiated field, in an
immunocompromised or malnourished patient,
and during some emergency operations)
– In this setting, the stoma is often constructed as a loop
ileostomy
• The advantage of this is that subsequent closure can often be
accomplished without a formal laparotomy
– The loop may be secured with or without an underlying
rod
60

61. Cont.
• A permanent ileostomy is sometimes required
after total proctocolectomy or in patients with
obstruction
– An end ileostomy is the preferred configuration for
a permanent ileostomy because a symmetric
protruding nipple can be fashioned more easily
than with a loop ileostomy
61

62. Colostomy
• Most colostomies are created as end colostomies
rather than loop colostomies and most are on the
left side of the colon
– The bulkiness of the colon makes a loop colostomy
awkward for use of an appliance, and prolapse is more
likely with this configuration
• Closure of an end colostomy has traditionally
required a laparotomy, but increasingly minimally
invasive techniques have been adopted
62

63. Complications of ostomies
• Stoma necrosis
– Usually caused by skeletonizing the distal small
bowel and/or creating an overly tight fascial defect
– Limited mucosal necrosis above the fascia may be
treated expectantly, but necrosis below the level of
the fascia requires surgical revision
• Stoma retraction
– May occur early or late and may be exacerbated by
obesity
– Local revision may be necessary
63

64. Cont.
• Fluid and electrolyte abnormalities
– This is not uncommon in ileostomies
– Ideally, ileostomy output should be maintained at less
than 1500 mL/d to avoid this problem
– Bulk agents and opioids are useful
• Skin irritation
– This can occur, especially if the stoma appliance fits
poorly
– It is less problematic with a colostomy than with an
ileostomy because the stool is less irritating to the skin
than succus entericus
– Skin-protecting agents and custom pouches can help to
solve this problem
64

65. Cont.
• Stoma obstruction
– This may occur intra-abdominally or at the site where the stoma
exits the fascia
• Parastomal hernia
– This is the most common late complication of a colostomy
• Less common after an ileostomy than after a colostomy
– It can cause poor appliance fitting, pain, obstruction, or
strangulation
– If symptomatic, they should be repaired
• Stoma prolapse
– This is a rare and late complication and is often associated with a
parastomal hernia
– This is more common with a loop colostomy
• Interestingly, it is almost always the efferent limb of the loop that
prolapses
65

66. Cont.
• Other
– Colostomy diarrhea
– Psychological impacts
66

67. Bowel Preparation
67

68. Rationale
• The rationale for bowel preparation is that
decreasing the bacterial load in the colon and
rectum will decrease the incidence of
postoperative infection
68

69. Mechanical
bowel preparation
• This uses cathartics to rid the colon of solid stool the
night before surgery
• Arguments in favor of mechanical bowel preparation
include:
– Easier manipulation of an “empty” colon
– Avoidance of a “stool column” above an anastomosis
• Arguments against mechanical bowel preparation
include:
– Dehydration and electrolyte abnormalities that often result
from bowel cleansing
– The risk of spillage of liquid stool left over from the “prep”
– Eradication of normal flora (synthesizers of fatty acids for
colonocytes)
69

70. Cont.
• A recent meta-analysis of 14 randomized
controlled trials suggested that mechanical
bowel preparation does not prevent surgical
site infection and should be abandoned in
clinical practice
70

71. Antibiotic prophylaxis
• Antibiotic prophylaxis also recommended
– A recent analysis of the Surgical Care Improvement Project-1
(SCIP-1) suggests that oral antibiotics do reduce
postoperative wound infection, especially if a mechanical
bowel preparation is not used
• The addition of oral antibiotics to the preoperative
mechanical bowel preparation has been thought to
decrease postoperative infection by further decreasing
the bacterial load of the colon
– However, the regimens used (neomycin, erythromycin, or
metronidazole) frequently caused GI upset that interfered
with the mechanical preparation, and many surgeons have
abandoned oral antibiotic prophylaxis
71

72. Cont.
• Broad spectrum parenteral antibiotic(s) with
activity against aerobic and anaerobic enteric
pathogens should be administered just prior to
the skin incision and redosed as needed
depending on the length of the operation
• There is no proven benefit to using antibiotics
postoperatively after an uncomplicated
colectomy
72

73. End!
73