CASE
Our patient was an 85-year-old male with hypertension and a history of peptic ulcer disease who now presented with a several-week history of epigastric pain. He had completed a course of Prevpac (lansoprazole, amoxicillin, and clarithromycin) combination therapy after serum test results were positive for Helicobacter pylori. Although the pain resolved with treatment, it quickly returned. The patient was referred to our surgical service for an outpatient upper GI endoscopy. He was found to have a large antral ulcer with chronic appearance and severe diffuse gastritis. Biopsy revealed focal, poorly differentiated adenocarcinoma involving the lamina propria and moderate chronic inflammation of the antral mucosa with no evidence of H pylori.
Preoperative positron emission tomography (PET)/CT showed no abnormal uptake, and laboratory test results were within normal limits. The patient underwent diagnostic laparoscopy, which showed no evidence of carcinomatosis or intraperitoneal spread of the malignant process. Laparotomy and distal gastrectomy were performed with a Billroth II gastrojejunostomy reconstruction. No obvious nodal spread was found. A nasogastric tube and a urinary catheter were placed during the procedure, and a feeding jejunostomy tube was placed prior to closure.
The final pathology report confirmed adenocarcinoma of the gastric antrum extending into the subserosal layer. All margins were negative for tumor, and no tumor involvement was seen in five lesser curvature lymph nodes and two greater curvature nodes. No lymphatic, vessel, or perineural invasion was identified. The tumor stage assigned was stage IIa (T3N0M0).
Full-strength tube feeding was started the morning following surgery via the feeding jejunostomy tube at a low rate (25 cc/hour). Maintenance IV fluids were continued. At 48 hours after surgery, an upper GI study with water-soluble contrast confirmed good emptying of the gastrojejunostomy anastamosis (Figure 1). However, the tube feeding infusions were discontinued 24 hours after institution because the patient developed intolerance with nausea, abdominal pain, and abdominal distention.
The patient rapidly deteriorated over the next few hours, showing signs of septic shock. Metabolic acidosis was found. Fluid resuscitation and BP support with dopamine were started. Emergency CT of the abdomen showed signs of bowel ischemia and small and large bowel distention (Figure 2), pneumatosis intestinalis (Figure 3), and portal venous gas (Figure 4). The patient was taken to the OR immediately for surgical exploration. Surgery was performed within 24 hours of the onset of intolerance to the enteral feedings.
Emergency laparotomy revealed total infarction of the entire small bowel, right colon, and gallbladder (Figure 5). There was no leakage at the gastrojejunostomy or the jejunal feeding tube site. No viable small bowel remained to sustain life, and so the abdomen was closed. A conference was held with the patient's family to discuss the operative findings and the probable etiology of the bowel infarction. The futility of any further aggressive efforts was openly discussed, and the family understood the situation. The patient was then transferred to the ICU and died several hours later with his entire family at the bedside. Information was provided to the family, some of whom were health care workers, regarding the unusual but documented occurrences of bowel ischemia secondary to the utilization of enteral feedings.
DISCUSSION
Jejunostomy after gastrectomy is typical. The most frequent complication specific to gastrectomy is dehiscence of the anastomotic site, which occurs in up to 15.8% of cases. Although the occurrence rate is not exceedingly high, the mortality rate for this complication is 50%.1 Water-soluble contrast study of the stomach is used to verify that there is no leak and that the anastamosis is patent before initiating oral feedings. The jejunostomy feeding tube allows for early enteral feedings, which is more beneficial than parenteral feedings after GI surgery. Placing the feeding tube distal to the anastamosis is invaluable if edema at the gastrojejunostomy anastamosis prevents oral feedings in the immediate postoperative period, which occurs frequently. Other specific complications include pancreatic fistula, hepatic necrosis, and intestinal perforation.
Irritation and inflammation at the site from the tube can result in tissue erosion. Inadequate nutritional support can occur if the tube lumen becomes blocked, and dislodgement may cause peritonitis, which will make tube replacement more difficult and fraught with complications. Intolerance of a nutrient component can lead to nausea, vomiting, diarrhea, and the rare but serious mesenteric ischemia. Up to 20% of all patients and 50% of critically ill patients will experience intolerance. Nutrient imbalances are always a risk; therefore, serum levels of electrolytes, glucose, magnesium, and phosphate should be obtained daily for at least the first week.2
Prevention of ischemic complications of enteral tube feeding can be as simple as infusing a more dilute feeding solution. Typical small bowel contents are not hyperosmolar solutions. An enteral diet exposes the bowel mucosa to nonphysiologic osmolar loads. During a period of disordered peristalsis, as in the postoperative patient, the feedings may remain in the lumen, increasing mucosal exposure to the hyperosmolar solutions. Rapid fluid shifts into the lumen causes bowel distention, capillary backup (sludging), and perfusion difficulties.3 With greater dilutions and smaller volumes, the risk of osmotic effect is lower. Pure water, either tap or distilled, should never be infused directly into the bowel lumen. Water injures the epithelium and should therefore always be mixed with a nutritional supplement.4 Jejunostomy tube feedings usually start at a concentration of 0.5 kcal/mL or less and at a rate of 25 mL per hour. Concentration and volume can be increased to meet calorie and water goals after a few days. The maximum that can typically be tolerated is 0.8 kcal/mL at a rate of 125 mL per hour, which provides a daily diet of 2,400 kcal.2
Bowel ischemia is a severe complication of postoperative enteral feeding. Incidence is usually much less than 1% but can occur in 0.3% to 3.8% of patients receiving small bowel tube feedings.5 Ischemic bowel is most often reported in conjunction with surgical jejunostomies.5,6 The benefits of jejunostomy are believed to outweigh the risks, as overall occurrence of necrosis is rare. When it does occur, however, early diagnosis is challenging, and prognosis is always poor. The mortality rate can approach 100%.7 Previous research has indicated that the splanchnic circulatory system is responsible for the redistribution of blood flow during feeding and exercise.8 Splanchnic blood flow decreases with increasing age.9 Feeding and digestion is accompanied by an increase in splanchnic and intestinal oxygen consumption. The metabolic demands of absorption are increased proportionally greater than the increase in splanchnic blood flow, implying that an oxygen deficit occurs.10