gastrointestinal complications from Sabiston textbook of surgery

1. Surgical Complication
• Gastrointestinal complication
Anastomosis leak
Intestinal Fistulas
Acute abdominal compartment syndrome
Stomal complication

2. Anastomotic Leak
• Causes
Numerous factors can cause or are associated with an
increased risk for anastomotic leak .

3. • The level of the anastomosis in the GI tract is important.
• Although small bowel, ileocolic, and ileorectal anastomoses are
considered safe, esophageal, pancreaticoenteric, and colorectal
anastomoses are considered high risk for leakage.

4. • In the esophagus, lack of serosa appears to be a significant
contributing factor.
• In the pancreas, the texture of the gland and size of the pancreatic
duct, the presence of pancreatic duct obstructive lesions, the
experience of the operating surgeon, and probably the type of enteric
anastomosis are implicated.
• In the rectum, the highest leak rate is found in anastomoses in the
distal rectum, 6 to 8 cm from the anal verge.

5. • Adequate microcirculation at the resection margins is crucial for the
healing of any anastomosis.
• Factors interfering with the perianastomotic microcirculation include:
1. smoking,
2. hypertension,
3. locally enhanced coagulation activity as a result of surgical trauma,
4. perianastomotic hematoma, and
5. presence of macrovascular disease.

6. • In colorectal anastomoses, relative ischemia in the rectal remnant is a
factor because its blood supply is derived from the internal iliac artery
via the inferior hemorrhoidal vessels; contribution from the middle
hemorrhoidal artery is minimal and, at best, variable because the
vessels are mostly absent and, when present, are unilateral.
• Total mesorectal excision, neoadjuvant therapy, and extended
lymphadenectomy with high ligation of the inferior mesenteric artery
are additional contributing factors.

7. • Intraluminal distention is believed to be responsible for rupture of an
anastomosis.
• The mechanical strength of the anastomosis is important and, in the
early period, is dependent on sutures or staples, with endothelial
cells and fibrin-fibrinonectin complex additionally contributing to the
tension force.
• Construction of a watertight and airtight anastomosis is essential.

8. • Intra-abdominally placed open rubber drains are not helpful and are
associated with an increased risk of infection if left for more than 24 to
48 hours.
• In the pelvis, drains have been shown in some studies to be associated
with a higher leak rate.

9. • Conversely, drains may remove blood, cellular debris, and
serum that act as good culture media for perianastomotic
sepsis or abscess formation.

10. • Local sepsis affects the integrity of the anastomosis
negatively as it reduces collagen synthesis and increases
collagenase activity, which results in increased lysis of
collagen at the anastomosis.

11. • Defunctioning or protective stomas do not decrease the overall leak
rate, but rather minimize the severity and sequelae of perianastomotic
contamination and decrease the reoperation rate.
• However, defunctioning stomas deprive the colon of shortchain fatty
acids, resulting in exclusion colitis and delay in epithelialization of the
anastomosis, and are associated with altered collagen metabolism
observed in left-sided anastomoses.

12. • Bevacizumab, an angiogenesis inhibitor, is associated with
increased risk for surgical site complications. This agent is a
humanized monoclonal antibody that targets vascular
endothelial growth factor (VEGF). VEGF is a critical factor for
the survival of endothelial cells and is selectively present in
the neovasculature of growing tumors

13. • Bevacizumab binds with high specificity and affinity to VEGF,
inhibiting the binding of VEGF to its receptors and negatively affecting
angiogenesis or the remodeling of the existing network of blood
vessels
• Bevacizumab is used in combination with standard chemotherapy
(irinotecan, 5-fluorouracil, and leucovorin) in the treatment of
patients with metastatic colorectal cancer.

14. • In patients with metastatic colorectal cancer, it increases the
risk of surgical site complications—spontaneous dehiscence
of primary anastomosis and colocutaneous fistula formation
from an anastomosis.
• Such complications may occur 2 years after surgery.

15. The mechanism is probably related to :
• microthromboembolic disease leading to bowel ischemia,
• inhibition of angiogenesis in the microvascular bed of the new
anastomosis,
• inhibition of neoangiogenesis in postradiated tissue, and
• reduction in the number of newly formed vessels in granulation tissue
surrounding anastomotic sites.

16. Emergency bowel surgery is associated with high morbidity and
mortality, in part because of sepsis and anastomotic leakage;
this is related to :
• the poor nutritional status of the patient,
• presence of underlying malignancy,
• immunocompromised state,
• presence of intra-abdominal contamination or sepsis, and
• hemodynamic instability.

17. • Transfusion :
• on the one hand, causes impaired cellmediated immunity and
predisposes to infection and,
• on the other hand, alleviates anemia and improves the oxygen-
carrying capacity of red blood cells that may have a positive impact on
healing.

18. • Obesity :
• increases the difficulty and complexity of the surgery; has been
shown to be associated with increased postoperative complications;
and is an independent risk factor for an increasing leakage rate,
especially after a low colorectal anastomosis.

19. • Steroids :
• affect healing by decreasing collagen synthesis,
• delaying the appearance of the inflammatory reaction,
• and reducing the production of transforming growth factor-β and
insulin-like growth factor in wounds, which are essential for wound
healing.

21. Presentation and Diagnosis
• Anastomotic leak results in sepsis and enteric fistula formation, leads
to reoperation and a possible permanent stoma, and is associated
with decreased survival and increased local recurrence rate after
curative resection of cancer and possibly leads to death.

22. • The clinical manifestations are the result of a cascade of events that
start with loss of integrity of the anastomosis and leakage of intestinal
contents.
• The leakage may be diffuse throughout the peritoneal cavity
(uncontrolled leak) or become walled off by omentum; abdominal
wall; and contiguous loops of bowel, pelvic wall, or adhesions from
prior operations. If a surgical drain is present, intestinal contents are
discharged onto the skin.

23. Intraabdominal fluid collections may contain:
• intestinal contents,
• frank pus, or
• pus mixed with intestinal contents.
• If the fluid collection is drained surgically or percutaneously,
there is an initial discharge of purulent material followed by
feculent material heralding the formation of an
enterocutaneous fistula (controlled fistula).

24. • If allowed to drain through the surgical incision or abdominal wall,
surgical wound infection and dehiscence with evisceration or an
abdominal wall abscess may occur.
• If the fluid collection burrows into a contiguous structure such as the
urinary bladder or vagina, spontaneous drainage occurs, with the
formation of an enterovesical or enterovaginal fistula.

25. • After the index surgery, a patient may have an initial normal
postoperative course or may not have been progressing as expected.
• The early warning signs of anastomotic leak are malaise, fever,
abdominal pain, ileus, localized erythema around the surgical incision,
and leukocytosis.
• Patients may also develop bowel obstruction, induration and erythema
in the abdominal wall, rectal bleeding, or suprapubic pain.

26. • There may be initial excessive drainage from the surgical wound or
surgical wound dehiscence or evisceration or both.
• An intra-abdominal fluid collection or abdominal wall abscess may be
identified and drained surgically or percutaneously.
• Patients may also experience pneumaturia, fecaluria, and pyuria.

27. • Sepsis is a prominent feature of anastomotic leakage and results from
diffuse peritonitis or localized abscess, abdominal wall infection, or
contamination of a sterile site with intestinal contents.
• Abdominal wall infection develops as a result of contact of purulent
material with the muscle and subcutaneous tissue; or contact of
corrosive intestinal juices with the abdominal wall, resulting in
chemical erosion and extension of the infectious process.

28. • Contamination of the urinary bladder with intestinal contents
(enterovesical fistula) results in urosepsis.

29. Treatment
• Treatment of anastomotic leakage starts with prevention.
• In elective cases, nutritional support for 5 to 7 days is appropriate for
patients who are malnourished or have lost significant amounts of
weight.
• Mechanical and chemical bowel preparations are still recommended
by many surgeons before colorectal resection.

30. • In patients receiving or who have received bevacizumab, the
appropriate interval between the last dose administered and the surgery
is unknown.
• The terminal half-life of the medication is long—20 days—so wound-
healing complications are documented 56 days after treatment. It is
advisable to delay elective surgery for at least 4 to 8 weeks or,
preferably, three half-lives (60 days) after treatment.

31. • In emergencies, especially in hemodynamically unstable,
immunocompromised, and nutritionally depleted patients, in the
presence of fecal peritonitis, significant bowel dilation, and edema, an
anastomosis is best avoided because a leak may prove fatal.

32. • Construction of an anastomosis that is at low risk for disruption requires
the following:
• 1. Adequate exposure, gentle handling of tissues, aseptic precaution, and
meticulous, careful dissection
• 2. Adequate mobilization so that the two attached organs have a tension-free
anastomosis
• 3. Correct technical placement of sutures or staples with little variance
• 4. Matching of the lumens of the two organs to be connected, which can be
done by various techniques
• 5. Preservation of the blood supply to the ends of structures to be
anastomosed

33. • Sufficient microcirculation is essential for healing of the
anastomosis.
• In intestinal anastomoses, the marginal artery of the colon
and last vascular arcade of small bowel mesentery must be
preserved.

34. • The small bowel serosa must not be denuded of mesentery
more than 3 to 4 cm for hand-sewn anastomoses.

35. • In the distal colon, the following maneuvers may be required to
ensure a tension-free anastomosis:
• inferior mesenteric artery divided at its origin,
• windows created in the mesentery of the small bowel up to the third
portion of the duodenum, and small branches interrupted between the
arcades creating mesenteric windows and dividing the ileocolic vessels
at their origin.

36. • For intestinal and colorectal anastomoses, there is no difference in the
rate of anastomotic leakage between hand-sewn and stapled
anastomoses and among various stapling techniques,
• The decision to construct a one-layer or two-layer intestinal
anastomosis is a matter of preference. A colorectal anastomosis is
easier to perform in one layer.

37. • However, since the advent of stapling devices, an anastomosis deep in
the pelvis has most commonly been stapled.
• The technique is not only faster but also improves asepsis because the
anastomosis is performed in a closed fashion compared with a hand-
sewn anastomosis, which is considered an “open anastomosis” and
allows for more contamination

38. • In low anterior resection, the omentum may be advanced to the pelvis
and placed around the colorectal anastomosis. This maneuver may
reduce the rate of anastomotic leak or disruption but mostly appears to
decrease the severity of the complication.

39. • Drainage of a colorectal anastomosis is advisable in difficult cases
and when technical problems are encountered or when neoadjuvant
therapy has been used.
• Defunctioning stomas are used for extraperitoneal anastomoses, when
technical difficulties are encountered, or after neoadjuvant therapy.

40. • The routine placement of drains in proximity to pancreatic
anastomoses is controversial.
• Drains and octreotide can be used when an anastomosis is performed
to a soft pancreas with a small duct and in centers with lower surgical
volume or centers with a high leak rate (>10%).

41. • Pancreatic duct stents (placed intraoperatively) continue to be used,
despite the lack of data to suggest that they decrease the leak rate.
• A pancreatic stent placed before a distal pancreatectomy
decompresses the pancreatic duct by abolishing the pressure gradient
between the pancreatic duct and duodenum and may decrease the risk
of fistula formation, allowing the site of a leak to seal.

42. • When an anastomotic leak is suspected or diagnosed,
resuscitation is started immediately because patients are in
the postoperative period and have been without nutrition.
Furthermore, they have a contracted intravascular volume
because of third spacing and lost intestinal contents and may
have an electrolyte imbalance.

43. • Intravascular volume is restored with crystalloid fluids and a
blood transfusion if anemia is present, and electrolyte
imbalances are corrected.
• Oral intake is stopped, and the bowel is put at rest to
decrease luminal contents and GI stimulation and secretion.
• An NG tube is placed if obstructive symptoms are present
• Infected surgical wounds are opened, and any abdominal wall
abscesses are incised and drained.

44. • Reoperation is indicated if there is :
1. diffuse peritonitis,
2. intra-abdominal hemorrhage,
3. suspected intestinal ischemia,
4. major wound disruption, or
5. evisceration.
• Reoperation is a major undertaking and is associated with significant
mortality and morbidity.
• Primary closure of the leaking point only is avoided because failure is
certain.

45. • The management of duodenal and proximal jejunal leaks is
challenging.
• In these situations, transgastric placement of a jejunal tube helps divert
gastric and biliopancreatic secretions, and placement of drains in close
proximity to the leak allows external drainage of the intestinal
contents.
• Pyloric exclusion and gastrojejunostomy should be used judiciously in
these situations.

46. . Management of jejunal, ileal, and colorectal leaking anastomoses
depends on :
• the severity and duration of contamination,
• condition of the bowel, and
• hemodynamic stability of the patient.

47. • In a critically ill and unstable patient, especially a patient with fecal
peritonitis, a damage control type of procedure is performed :
1. the anastomosis is taken down,
2. the ends of the bowel are stapled,
3. peritoneal lavage is performed, and
4. the incision is left open.
5. A second-look laparotomy with stomal formation is performed in 24
to 48 hours or when the patient is more stable.

48. • Otherwise:
• in the small bowel, an anastomosis may be performed or the
ends of the bowel are delivered as stomas;
• in the colon, the proximal end of the colon is brought out as
a colostomy, and the distal end is closed or brought out as a
mucous fistula; and
• in the rectum, the distal end is closed, and the proximal end
of the colon is delivered as a stoma.

49. • In the absence of diffuse peritonitis and evisceration, a CT scan may
identify single or multiple abscesses, pneumoperitoneum, ascites, and
sometimes extravasation of oral contrast agent into the peritoneal
cavity.
• Multiple abscesses require open drainage,
• a single intra-abdominal abscess can be drained percutaneously, and
• a pelvic abscess can be drained transrectally or transvaginally

50. • An external fistula may develop after drainage.
• If percutaneous drainage fails to control sepsis, reoperation is
indicated.
• At the time of open drainage of a pelvic abscess, if there is any doubt
about the origin of the abscess (de novo abscess versus abscess
secondary to a small anastomotic leak that has sealed), a defunctioning
stoma is constructed, unless there is complete disruption of the
anastomosis. In that case, the ends of the bowel are exteriorized as a
stoma.

51. • A pancreaticojejunostomy leak, if small, can be treated by placing a
drain next to the leak. However, for an anastomosis that has almost
fallen apart, the patient would probably require completion
pancreatectomy.
• A patient who has a bile duct leak requires drainage of the infection
and placement of a drain next to the leak or, in the case of a large leak,
may require bile duct reconstruction.