Postgastrectomy Syndromes

Postgastrectomy Syndromes

Postgastrectomy syndromes are iatrogenic conditions that may arise from partial gastrectomies, independent of whether the gastric surgery was initially performed for peptic ulcer disease, cancer, or weight loss (bariatric). The surgical procedures include Billroth-I, Billroth-II, and Roux-en-Y gastric bypass.

History of gastrectomy 1881 Theodor Billroth first to successfully resected the distal stomach Patient had distal gastric cancer Continuity re-established by gastroduodenostomy (Billroth I) Patient recovered, but died 4 months later with abdominal carcinomatosis 1885 Billroth performs successful distal gastrectomy & gastrojejunostomy (Billroth II) for gastric cancer

Billroth I Billroth II

Postgastrectomy syndromes include small capacity dumping syndrome bile gastritis afferent loop syndrome efferent loop syndrome anemia metabolic bone disease.

Dumping syndrome is the effect of altered gastric reservoir function, abnormal postoperative gastric motor function, and/or pyloric emptying mechanism. Clinically significant dumping syndrome occurs in approximately 10% of patients after any type of gastric surgery and in up to 50% of patients after laparoscopic Roux-en-Y gastric bypass. Dumping syndrome can be separated into early and late forms, depending on the occurrence of symptoms in relation to the time elapsed after a meal.

Both forms occur because of the rapid delivery of large amounts of osmotically active solids and liquids to the duodenum. This is a direct result of alterations in the storage function of the stomach and/or pyloric emptying mechanism.

Early dumping Rapid emptying of gastric contents into the small intestine or colon may result in high amplitude propagated contractions and increased propulsive motility, thereby contributing to the diarrhea seen in persons with the dumping syndrome. Symptoms of early dumping syndrome occur 30-60 minutes after a meal. Symptoms are believed to result from accelerated gastric emptying of hyperosmolar contents into the small bowel. This leads to fluid shifts from the intravascular compartment into the bowel lumen, resulting in rapid small bowel distention and an increase in the frequency of bowel contractions.

Early dumping Bowel distention may be responsible for GI symptoms, such as crampy abdominal pain, bloating, and diarrhea. Intravascular volume contraction due to osmotic fluid shifts is perhaps responsible for the vasomotor symptoms, such as tachycardia and lightheadedness.

Early dumping Early dumping systemic symptoms : Desire to lie down Rapid, strong heartbeat Fatigue Faintness Syncope Sweating Headache Flushing Early dumping abdominal symptoms : Epigastric fullness Diarrhea Nausea Abdominal spasm Borborygmi (rumbling or gurgling noise made by the movement of fluid and gas in the intestines).

Late dumping Late dumping occurs 1-3 hours after a meal. The pathogenesis is thought to be related to the early development of hyperinsulinemic (reactive) hypoglycemia. Rapid delivery of a meal to the small intestine results in an initial high concentration of carbohydrates in the proximal small bowel and rapid absorption of glucose. This is countered by a hyperinsulinemic response. The high insulin levels stay for longer period and are responsible for the subsequent hypoglycemia. Intrajejunal glucose induces a higher insulin release than does the intravenous infusion of glucose.

Late dumping symptoms are as follows: Perspiration Shakiness Difficulty to concentrate Decreased consciousness Hunger

Approach Considerations Signs and symptoms can be elicited with the glucose challenge test (50 g oral glucose). A positive result from a hydrogen breath test after ingestion of glucose is also 100% sensitive. A gastric emptying study may be helpful to document rapid gastric emptying. An endoscopy or a barium study can be helpful in discerning the anatomy.

Diet Dietary prohibitions and instructions are very important in the management of dumping syndrome. Note the following: Daily energy intake is divided into 6 meals. Fluid intake during and with meals is restricted. Avoiding liquids for at least half an hour after a meal is helpful. Simple sugars are best avoided. Milk and milk products are generally not tolerated and should be avoided. Because carbohydrate intake is restricted, protein and fat intake should be increased to fulfill energy needs. Most patients have relatively mild symptoms and respond well to dietary manipulations. In some patients with postprandial hypotension, lying supine for 30 minutes after meals may delay gastric emptying and also increase venous return, thereby minimizing the chances of syncope.

Medical Care: Octreotide. Somatostatin and its synthetic analogue octreotide have been used with short-term success in patients with dumping syndrome, but the long-term efficacy of octreotide is much less favorable. They exert a strong inhibitory effect on the release of insulin and several gut-derived hormones. The effectiveness of octreotide in controlling the symptoms of both early and late dumping has been demonstrated in several randomized control trials. The usual initial dose of octreotide is 50 mcg administered subcutaneously 30 minutes prior to each meal. The dose may be increased if smaller doses are not effective; however, higher doses are seldom effective if the smaller doses do not work.

Medical Care: Octreotide. The mechanisms of action of octreotide in dumping syndrome are as follows: Delay in the accelerated initial gastric emptying Delay in small intestinal transit time Inhibition of enteral hormone release Induction of a fasting intestinal pattern Inhibition of insulin release Splanchnic vasoconstriction Inhibition of postprandial vasodilation

Surgical Care Several surgical procedures have been designed to rectify the symptoms of dumping: surgical narrowing of the gastrojejunal stoma conversion of Billroth II anastomosis to Billroth I gastroduodenostomy jejunal interposition ( isoperistaltic loop, reversed 10- cm jejunal segments ) conversion to Roux-en-Y gastrojejunostomy pyloric reconstruction.

Summary of remedial operations For patients with prior pyloroplasty, pyloric reconstruction should be the initial remedial operation. For patients with Billroth I and Billroth II gastrectomies, Roux-en-Y reconstruction is the simplest and most effective therapy. For patients who already have a Roux-en-Y reconstruction, a 10-cm antiperistaltic jejunal loop should be interposed.

Conclusion Dumping syndrome is a common postsurgical complication after gastric surgery. The symptoms of dumping produce considerable morbidity. Fortunately, the indications for gastric surgery are declining, although the need for gastric surgery in emergency cases has not changed. Initially, patients with this condition should be treated medically with dietary modifications and octreotide. Close attention should be given to the patient's nutritional status. If medical management fails to provide adequate symptom relief, remedial surgery should be offered with the understanding that even surgical intervention may not be successful.

Afferent loop syndrome (ALS) Afferent loop syndrome (ALS) is a purely mechanical complication that infrequently occurs following the construction of a gastrojejunostomy. Creation of an anastomosis between the stomach and jejunum leaves a segment of the small bowel, most commonly consisting of duodenum and proximal jejunum, lying upstream from the gastrojejunostomy. This limb of intestine transfers bile, pancreatic juices, and other proximal intestinal secretions toward the gastrojejunostomy and is thus termed the afferent loop.

Types of reconstractions after Billroth II gastric resection

Symptoms Symptoms associated with ALS are caused by increased intraluminal pressure and distention due to accumulation of enteric secretions in a partially or completely obstructed afferent limb. ALS is one of the main causes of duodenal stump blowout in the early postoperative period and is also an etiology for postoperative obstructive jaundice, ascending cholangitis, and pancreatitis due to transmission of high pressures back into the biliopancreatic ductal system. High luminal pressures and distention increase bowel wall tension in the afferent loop and can lead to ischemia and gangrene with subsequent perforation and peritonitis.

Secondarily, prolonged stasis and pooling of secretions with partial obstruction facilitate bacterial overgrowth in the afferent loop. [2] Bacteria deconjugate bile acids, which can lead to steatorrhea, malnutrition, and vitamin B-12 deficiency leading to megaloblastic anemia. The severity at presentation mainly depends on the degree and duration of obstruction. The pathophysiology and signs and symptoms associated with ALS result from partial or complete obstruction of the afferent loop. Patients with ALS may present with an acute, completely obstructed form or with a chronic, partially obstructed form. The syndrome can manifest at any time from the first postoperative day to many years after surgery.

Etiology of ALS Each of the following postoperative conditions can cause ALS in a patient with a gastrojejunostomy: Compression of the afferent loop by postoperative adhesions Internal hernia (eg, through a mesocolic defect) Volvulus of the intestinal segment Enteroenteral or enterogastric intussusception Kinking of the afferent limb at the gastrojejunostomy

Patients have an increased chance of developing ALS if one or more of the following conditions is met: The jejunal portion of the afferent limb is longer than 30-40cm in length. The gastrojejunostomy is placed in an antecolic position instead of a retrocolic position. Mesocolic defects are not properly closed after construction of a retrocolic gastrojejunostomy.

Physical Examination Physical examination can reveal one or more of the following findings: An ill-defined mass in the right upper abdominal quadrant may be present in one-third of patients with acute ALS. Localized midepigastric or right upper abdominal quadrant tenderness Peritonitis and/or a rigid abdomen if necrosis or perforation of the bowel wall has occurred Jaundice Signs of pancreatitis (upper abdominal pain radiating to the flank or back)

Surgical treatment Billroth I gastroduodenostomy This procedure creates a direct anastomosis between the stomach and duodenum. It is the most physiologic procedure and is therefore the operation of choice. Several factors may preclude its use, including previous subtotal gastrectomy or extensive scarring around the duodenum. In these situations, the surgeon may be unable to gain enough mobility on the stomach and duodenum to create an anastomosis without excessive tension. Roux-en-Y gastrojejunostomy Jejunal segment interposition (between the gastric remnant and duodenum to create a modified Billroth I type anastomosis) Resection of the redundant portion of the afferent jejunal loop