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Early Complications in Colorectal Surgery

Mark H. Whiteford, MD, FACS, FASCRS
Clinical Associate Professor, Oregon Health & Science University
Legacy Portland Hospitals , Portland , Oregon  

The surgical literature is a showcase for our successes and innovative ideas. Studies demonstrating mediocrity or below average performance are selected out and are rarely if ever published. Negative outcomes are reserved for the privacy of the weekly morbidity and mortality conferences.  Complications are hard enough for most surgeons to talk about, much less submit them the scrutiny their peers and the permanence of publication. Nothing seems to divert a surgeons decision making skills away from evidence based medicine and back to the dark ages of anecdotal medicine more powerfully than a complication. It is human nature to second guess ourselves and retreat into a more conservative mode from which we may not return.

Complications are best avoided through careful planning and safe surgical technique. Despite this, they still occur, even in the most skilled and experienced hands. Fortunately, most complications in colorectal surgery are not life threatening. For example, the mortality from a colectomy is reported to be less than or equal to one percent. The exact frequency and severity of complications are difficult to determine due to heterogeneous definitions, patient populations, procedures, comobidities, and intensity of follow up.  One perspective of the incidence of complications can be gleaned from four recent randomized controlled trials comparing laparoscopic to open colon resections for cancer. (Table 1). This discussion will focus on a few of these.  

TABLE 1 Complication rates following laparoscopic and open colon resections


Barcelona Trial

COST Trial



Wound Infection





Persistent Ileus













Anastomotic leak



























 URI = urinary tract infection, ARF = acute renal failure, DVT = deep venous thrombosis

Wound infection  

Superficial wound infections are the most common complication of colorectal surgery. Elective colorectal resection in which there is controlled entry into the GI tract, is classified as a clean-contaminated wound with a predicted incidence of surgical site infection of 5-10%. The previously held belief that preoperative cathartic and oral antibiotic bowel preparation was mandatory to prevent post operative infections has recently been debunked by multiple randomized controlled trials 5 .

Superficial wound infections are recognized by any combination of erythema, induration, tenderness, or drainage at the wound site. Systemic signs of fever and tachycardia may also be present. The infection may manifest as an abscess, cellulitis, or a combination of the two. When suspected, the wound should be carefully inspected and when a collection is detected, it is drained by reopening the wound. Gram stain can assist in management and antibiotic selection.  The wound is left open to heal by secondary intention. In most cases, cellulitis associated with an abscess will resolve with drainage alone. Antibiotics are usually unnecessary except in cases of cellulitis or an immunosuppressed host.

Anastomotic leak  

Anatomotic leak is one of the most dreaded early complications of colorectal surgery. It is a common, potentially life threatening complication associated with significant morbidity, increased risk of local recurrence of cancer, decreased functional outcomes, increased length of stay, high risk of (permanent) ostomy, and death.  Leaks are variably defined in the literature, but in general regarded as perianastomotic stool, gas, or abscess, peritonitis, or a fecal fistula. The incidence of anastomotic leak following colectomy is generally reported between 2 and 6%.  Anastomotic leaks present in one of three ways.

  1. Asymptomatic leak

  2. Subtle insidious leak

  3. Dramatic early leak

The asymptomatic leak is incidentally found during endoscopic or radiographic studies. The incidence of radiographically detected leaks is 4-6 times higher than clinically detected leaks. These leaks, which often present weeks or months later, are typically walled off sinuses, and are, as a general rule, harmless. Treatment is rarely necessary. The subtle insidious leak can present perioperatively with nonspecific signs and symptoms common in the post operative period. Such signs include low grade fevers, mild leukocytosis, protracted ileus, and failure to thrive and occur 5-14 days following surgery. Some patients may even have been sent home only to return with vague or progressive symptoms. By this time adhesions have formed to contain the leak into a localized process. Because of the nonspecific signs, early detection may be difficult.  The dramatic early leak can present with any combination of acute abdominal pain, distention, fever, tachycardia, diffuse peritonitis, oliguria, or shock within several days of surgery.  This usually indicates a large, uncontained leak in a patient poorly tolerant to such an insult.

            The goals in management are to effectively treat the leak, control sepsis, and convert and urgent or emergent situation into an elective one. The level and intensity of treatment is individualized to the cause, location, and size of the leak and the condition and comorbidies of the patient.

            Management of the stable patient without signs of peritonitis usually begins with imaging to identify and localize the process. Traditionally, water-soluble contrast enema has been the primary study to identify leaks. Drawbacks include lower sensitivity for right-sided anastomoses as the contrast dilutes out before reaching the proximal bowel. It also provides little information on extracolontic conditions such as ileus and collections. Abdominopelvic CT scan with triple contrast (oral, intravenous, and rectal) has become the imaging modality of choice to evaluate suspected postoperative intraabdominal infection. Specificity during the first five days postop, however, is reduced. During this period, infectious processes may be difficult to differentiate from acute postoperative inflammation and fluid collections. Sensitivity is much improved beyond 5-7 days. CT scan and contrast enema can also be used as complimentary studies.

Large collections are often amenable to percutaneous, transgluteal, or transanal image guided catheter drainage. The images should be reviewed with an interventional radiologist to identify a safe window of access that avoids vascular structures and other organs. Abscesses less than 3-4 cm are too small for most pigtail catheters and will often resolve with a course of antibiotics. In the era of modern CT scanning and interventional radiology, the routine practice of repeat laparotomy, abdomial washouts, large sump drains, and open abdominal wound management is rarely necessary and can be reserved for patients who fail to respond to, deteriorate following, or are not candidates for percutaneous drainage.

             Management of the patient with progressive generalized peritonitis with or without septic shock requires resuscitation, broad spectrum antibiotics and urgent laparotomy. Laparoscopic management may be considered if the surgeon has sufficient laparoscopic skills and reoperative experience. At the time of surgery, the anastomosis should be scrutinized for signs which led to its failure. This can guide the appropriate method of repair.

            If the findings at operation show ischemia and necrosis of greater than one third of the anastomosis, the anastomosis should be resected with creation of a stoma. If the mucous fistula can be brought up to the skin, it should ideally be fashioned through the same site as the proximal ostomy. When performed in this fashion, subsequent ostomy reversal can be done via a circumstomal incision, obviating the need for formal laparotomy and its associated morbidity. If the findings at operation identify a smaller leak with healthy bowel, the anastomosis can usually be salvaged with suture repair, proximal diversion, and washout of the distal segment. Our preferred diversion is a loop ileostomy.

Early post operative small bowel obstruction

Early postoperative bowel obstruction is rare, occurring in 1% of patients following intestinal surgery 6 . This time period accounts for 5-29% of all small bowel obstructions 6-8 . Most obstructions are caused by adhesions which form within 72 hours of surgery then become very dense and vascular after two weeks. Obstructions are more common following colorectal and gynecological procedures than following appendectomy or procedures located above the transverse colon. Signs and symptoms of early postoperative small bowel obstruction are similar to and hard to differentiate from the more common paralytic ileus. Patients typically develop abdominal distention, nausea, and vomiting, but cannot tolerate nasogastric tube clamping or removal. Most patients have a slow, smoldering course with emergencies being the exception.

There is a fine balance between waiting for the obstruction to resolve and rushing a patient to the operating room. In the first week following surgery, obstruction is hard to differentiate from ileus. Between 2 weeks and 2 months postop, adhesions become thick, vascular and obliterate natural planes making surgery much more difficult and prone to complications. The decision to operate should, therefore, occur between 7-14 days.

Plain films readily diagnose most small bowel obstructions. Oral administration of water soluble contrast followed by an abdominal plain film or CT scan 4 hours later is good predictor of resolution of a small bowel obstruction. Contrast in the colon indicates the obstruction is likely to resolve with non-operative means. CT scan may be useful in identifying signs of ischemia, other intraabdominal processes and in localizing the site of obstruction for operative planning.

Management of the stable patient involves fluid and electrolyte replacement, bowel rest, nasogastric tube drainage, and a nutritional evaluation. Total parenteral nutrition should be started after 7 days. Operation is advised for high grade or complete bowel obstruction, concern for strangulated bowel, or unresolved small bowel obstruction despite prolonged NGT decompression.

Most patients resolve with non-operative management. If surgery becomes necessary, it should occur prior to the two week mark after which the acute adhesions become dense, vascular, and problematic. Surgery involves careful re-exploration and lysis of adhesions. Operative findings usually reveal either a single adhesive band or multiple matted adhesions, each occurring with similar frequency.

Laparoscopic exploration and adhesiolyis is being increasingly utilized for small bowel obstructions 9 . Advanced laparoscopic skills and experience are a prerequisite. Poor candidates for laparoscopic management include patients with signs of peritonitis, multiple previous operations for small bowel obstruction, small bowel diameter greater than 4 cm, or other medical contraindication to laparoscopy. Pneumoperitoneum should be established with an open technique at a site remote from the previous incision. Atraumatic graspers are used to explore the bowel in a retrograde fashion beginning with decompressed bowel at the ileocecal valve. Distended bowel is fragile and should not be graped: grasping the adjacent mesentery reduces the risk of inadvertent bowel perforation. Adhesiolysis is best performed with scissors or bipolar cautery devices to reduce the risk of adjacent bowel injury. Conversion rates range from 7-43%. Proactive reasons to convert include poor visualization, non-viable intestine, multiple dense adhesions, deep pelvic adhesions, and failure to progress in a reasonable time.


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