In addition to the complications already reviewed, patients who have undergone any GI surgery may have intestinal obstruction, intra-abdominal abscess, pancreatitis, cholecystitis, fistulas, and tetanus. Certain procedures, such as anastomoses, bariatric surgery, placement of gastrostomy tubes, biliary tract surgery, other laparoscopic surgery, stoma creation, colonoscopy, and rectal surgery, are associated with specific complications.
Ileus, a functional obstruction of the bowel, is postulated to be the result of stimulation of the splanchnic nerves, leading to neuronal inhibition of coordinated intrinsic bowel wall motor activity. It is expected after any operation in which the peritoneal cavity is violated. After GI surgery, small bowel tone usually returns to normal within 24 hours, and colonic function returns within 3 to 5 days. Ileus can also occur after non-GI procedures and is usually secondary to anesthetic agents; function returns to normal after 24 hours. Prolonged ileus can be caused by peritonitis, intra-abdominal abscess, hemoperitoneum, pneumonia, electrolyte imbalance, sepsis, and medications.
Presenting symptoms of ileus include nausea, vomiting, obstipation, constipation, abdominal distention, and abdominal pain. When these symptoms are present in the first few days after surgery, they are most often due to adynamic ileus. The symptoms of adynamic ileus are most often mild and respond to nasogastric suction, bowel rest, and IV hydration. However, in cases of prolonged ileus, look for an underlying cause. Evaluation includes abdominal radiography to identify air-fluid levels, chest radiography, CBC, measurement of electrolyte levels, and urinalysis to search for secondary causes of ileus.
Mechanical ileus of the bowel is most often secondary to adhesions. Symptoms are abdominal distention and pain. Abdominal radiographs demonstrate multiple air-fluid levels and a paucity of gas in the colon; however, with high obstruction, above the ligament of Treitz, there may be no air-fluid levels. In the ED, differentiating between functional ileus and mechanical bowel obstruction can be difficult. Both disorders result in different degrees of abdominal pain, distention, nausea, vomiting, and failure to pass flatus and/or feces. Abdominal CT scanning is helpful to exclude obstruction due to bowel strangulation.10 Results may have an impact on the decision to manage the obstruction expectantly or not. Once the diagnosis of mechanical obstruction is suspected or confirmed, surgical consultation is indicated.
Intra-abdominal abscess is caused most frequently by preoperative contamination, spillage of bowel contents during surgery, contamination of a hematoma, or postoperative anastomotic leaks. Patients may have abdominal pain, nausea, vomiting, ileus, abdominal distention, fever, chills, anorexia, and abdominal tenderness. If the diagnosis is suspected, obtain CT or US of the abdomen. The patient should receive broad-spectrum antibiotics (see chapter 71, "Acute Abdominal Pain"). Treatment is percutaneous drainage or surgical exploration.
Pancreatitis after abdominal surgery is secondary to direct manipulation or retraction of the pancreatic duct. Pancreatitis most commonly occurs after gastric resection, biliary tract surgery, and endoscopic retrograde cholangiopancreatography. Clinical presentation varies from mild nausea, vomiting, and abdominal discomfort to intracTable vomiting, leukocytosis, and left-sided pleural effusion. Severe hemorrhage can cause lumbar pain accompanied by blue-gray discoloration of the skin in the flank area (Turner sign) or similar changes around the umbilicus (Cullen sign). Although the serum amylase level rises in acute pancreatitis, it is also elevated in patients with severe cholecystitis, renal insufficiency, intestinal obstruction, perforated ulcer, or ischemic bowel. A serum lipase measurement may help to identify those with true pancreatitis, although it may be elevated in a patient with a perforated viscus and other conditions. Abdominal radiographs may show localized ileus in the region of the pancreas (sentinel loop). US and CT are useful in defining pancreatic fluid collections or abscesses. In general, the treatment of postoperative pancreatitis is similar to the treatment of nonoperative pancreatitis (see chapter 79, "Pancreatitis and Cholecystitis").
Postoperative complications related to the gallbladder include biliary colic, acute calculous cholecystitis, or acute acalculous cholecystitis. The cause of these disorders in the postoperative period is not clear. US studies of the gallbladder and pancreas should be performed to aid in the diagnosis.
Acalculous cholecystitis is of particular concern in the postoperative period. The disorder seems to be more common in elderly men, but can occur in any sex and age group. Signs and symptoms are similar to those for calculous cholecystitis. Results of liver function studies and the neutrophil count may be normal. Important findings on US include gallbladder enlargement, wall thickening, and pericholecystic fluid collection, but no gallstones. Hepatobiliary scintigraphy may be helpful. Early diagnosis is critical, because early operative intervention can reduce morbidity and mortality.
Enterocutaneous fistulas can occur almost anywhere in the GI tract and are usually the result of technical complications or direct bowel injury. High-output fistulas can result in electrolyte abnormalities and volume depletion. Fistulas involving the proximal GI tract are frequently high output and are of the greatest concern. Sepsis is the other major complication. Most patients require admission, although many fistulas ultimately close spontaneously.
Although most cases of tetanus in the United States occur after minor trauma, there have been numerous reports of tetanus after general surgical procedures.11 Clostridium tetani is found in the GI tract of 1% of the population. During GI surgery, there is spillage of C. tetani. Proliferation of the organism is facilitated by the presence of devitalized tissue, blood clots, and surgical suture. Incubation can take from 0 to 73 days, at which time the toxin leads to clinical tetanus. The classic symptoms of tetanus, trismus, and opisthotonos may not be evident initially. Patients may present with nonspecific symptoms of abdominal discomfort, fever, and abdominal wall rigidity. Diagnosis is based on physical examination and a history of inadequate immunization.
Anastomotic leaks occur most frequently after esophageal and colonic surgeries and least frequently after gastric and small-intestinal anastomoses. The cause of anastomotic leakage is related mainly to surgical technique.
Intrathoracic esophageal anastomotic leaks usually manifest within 10 days of surgery. The presentation is dramatic, with fever, chest pain, tachypnea, tachycardia, and possibly shock. Chest radiograph may reveal a pneumothorax with pleural effusion. Disruption can be confirmed by contrast esophagography using a water-soluble contrast agent. Even with immediate reoperation, morbidity and mortality rates are high.
The signs and symptoms of gastric anastomotic leaks include abdominal pain, fever, leukocytosis, gastric outlet obstruction, hyperamylasemia, hyperbilirubinemia, peritonitis, and shock. Plain radiographs may reveal pneumoperitoneum or air-fluid levels. Provide volume resuscitation, parenteral broad-spectrum antibiotics, and nasogastric tube drainage. Immediate surgery is required.
Small-intestinal anastomoses infrequently leak because of the excellent blood supply and rapid healing of the area. However, if a leak occurs, the patient usually presents with local abscess formation or peritonitis. Treatment is immediate reoperation.
Colorectal anastomoses are prone to disruption because of the large number of pathogenic bacteria found, the propensity for colonic distention, and the presence of only a single thin layer of circular muscle to support sutures. The patients usually present 7 to 14 days postoperatively with fever and abdominal pain. CT confirms the diagnosis. Patients should receive broad-spectrum parenteral antibiotics, nasogastric tube drainage, and adequate fluid resuscitation in preparation for surgery.
BARIATRIC SURGERY COMPLICATIONS
Four main bariatric procedures are currently being performed for morbid obesity: laparoscopic adjusTable gastric banding using the LAP-BAND® device (Allergan, Inc., Irvine, CA), sleeve gastrectomy, Roux-en-Y gastric bypass, and biliopancreatic diversion with duodenal switch (see Figure 298-1 in chapter "The Patient With Morbid Obesity"). Overall operative mortality is <2%, but postoperative complications are common and are likely related to the technical skill of the surgeon.12 Common complications are listed in Table 87-4.13,14
TABLE 87-4Complications of Gastric Bypass Procedures ||Download (.pdf) TABLE 87-4 Complications of Gastric Bypass Procedures
|Complication ||Presentation ||Signs and Symptoms ||Diagnostic Test |
|Anastomotic leak ||0–28 d ||Tachycardia, fever, abdominal pain, nausea, vomiting, hypotension ||Clinical suspicion. CT scan or upper GI study are useful, but may be negative |
|Intra-abdominal bleeding ||0–28 d ||Tachycardia, abdominal pain, hypotension ||CT scan or upper GI study |
|Intraluminal GI bleeding ||Hours to months ||Melena, hematemesis, hypotension, altered mental status ||Emergent endoscopy |
|Ventral hernia ||Anytime ||Pain at incision site or palpable hernia ||Clinical diagnosis |
|Bowel obstruction ||1 week to 8 months ||Nausea, vomiting, abdominal pain ||Plain radiography or CT looking for air-fluid levels |
|Stomal stenosis ||2 months to 1 year ||Postprandial abdominal pain, nausea, vomiting ||Endoscopy or upper GI study |
|Stomal ulcer ||Months to years ||Abdominal pain, upper GI bleed ||Endoscopy |
|Stomal obstruction ||Months to years ||Nausea and vomiting with solids and liquids ||Endoscopy |
|Cholelithiasis/cholecystitis ||Months to years ||Abdominal pain with fatty foods, fever, tachycardia ||US |
|Dumping syndrome ||Anytime ||Diarrhea, abdominal cramps, nausea, vomiting, tachycardia, palpitations, flushing, dizziness, syncope ||Clinical diagnosis or endoscopy |
|Vitamin deficiencies ||Months to years ||Weakness, bone loss, anemia, fractures, neuropathy, hypercalcemia ||CBC, iron studies, parathyroid hormone studies, vitamin levels |
|Gastric slippage ||Days to years ||Abdominal pain, dysphagia, food intolerance, reflux ||Upper GI study |
|Esophageal, gastric pouch dilation ||After band adjustment ||Epigastric abdominal pain, dysphagia, reflux ||Upper GI study |
|Gastric necrosis ||Anytime ||Abdominal pain ||Upper GI study |
Nausea, vomiting, and abdominal pain are common symptoms in ED patients with a history of bariatric surgery. In the first few postoperative weeks, consider life-threatening problems like anastomotic leak and intra-abdominal bleeding. In patients with abdominal pain, tachycardia, or abdominal tenderness in the early postoperative period, a CT scan is often required to rule out these diagnoses.
A common complication of the Roux-en-Y gastric bypass is dumping syndrome, which can occur either right after the meal (early) or 2 to 4 hours later (late). Dumping symptoms occur when the pylorus is bypassed or removed. The hyperosmolar chyme contents of the stomach are dumped into the jejunum, causing rapid influx of extracellular fluid and an autonomic response. Patients experience nausea, epigastric discomfort, palpitations, colicky abdominal pain, diaphoresis, and, in some cases, dizziness and syncope. Patients with early dumping symptoms experience diarrhea, whereas those with late dumping symptoms, 2 to 4 hours postprandially, usually do not. The late dumping syndrome is believed to be due to a reactive hypoglycemia. The mainstay of treatment is dietary modification; consumption of small, dry meals; and separation of solids from liquids. In refractory cases, pyloroplasty can be tried. Most patients with dumping syndrome do not require hospital admission.
Patients with gastroesophageal reflux disease present with burning epigastric pain that is aggravated by meals and unrelieved by vomiting. The syndrome is caused by reflux of bile into the stomach. Diagnosis is made clinically, but other potential diagnoses are often ruled out with endoscopic examination.
Wernicke's encephalopathy is a rare, but serious, complication that must be considered in a patient with a history of bariatric surgery who presents with any cerebellar signs, ophthalmoplegia, weakness, and/or memory disturbances. Although vitamin deficiencies are common with both Roux-en-Y gastric bypass and biliopancreatic diversion, vitamin B12 deficiency is the only one that requires emergent intervention.
NONBARIATRIC GASTRIC SURGERY
Patients who have undergone partial or complete gastrectomy for nonbariatric reasons can present with a few distinct syndromes: dumping syndrome, alkaline reflux gastritis, afferent loop syndrome, and postvagotomy diarrhea. Although these complications are rare, the symptoms can be disabling. Dumping syndrome as a result of nonbariatric gastric surgery is treated in the same way as dumping syndrome after bariatric procedures.
Patients with afferent loop syndrome also develop severe epigastric pain 1 to 2 hours after eating, which is relieved by vomiting. The vomitus is bilious, without food. The syndrome occurs in patients who have undergone gastroenterostomy (Billroth II) reconstruction after partial gastrectomy. Diagnosis is made by contrast radiography or endoscopy. Operative reconstruction is required.
Truncal vagotomy usually results in increased bowel movements, but occasionally results in diarrhea. Diarrhea is variable in occurrence and not associated with food intake. It is often unpredicTable and explosive, which can lead to weight loss, malnutrition, and severe social complications. The incidence of the diarrhea decreases with time, and treatment is mostly symptomatic.
Most gastrostomy tubes are now placed by an endoscopist by percutaneous endoscopy or by a radiologist by percutaneous fluoroscopy. If the patient has undergone a laparotomy, the general surgeon may place a gastrostomy tube at the time of surgery. If the tube was placed by the surgeon and has not been replaced, it will have a bumper holding the tube in place. The tube has to be cut and the bumper allowed to pass, or the bumper has to be removed by endoscopic technique. For further discussion, see chapter 86, "Gastrointestinal Procedures and Devices."