Question:
afferent loop syndrome...has anyone ever heard of this?

   — ANITA W. (posted on April 15, 2002)

May 29, 2002
From http://www.nlm.nih.gov/medlineplus/ency/article/000222.htm - Alternative names: Post gastrectomy syndrome; Stagnant loop; Overgrowth - intestinal bacteria; Gastrojejunal loop obstruction; Afferent loop syndrome; Bacterial overgrowth - intestine Definition: Intestinal bacterial overgrowth occurs when the normal bacterial population of the gut has been eradicated with antibiotics. Other bacteria not normally found in the intestine take the place of the normal bacteria. Abnormal bacteria can cause disease in the bowel including necrotizing enterocolitis and pseudomembranous colitis.
   — Sonya T.

September 8, 2004
Background: The afferent loop syndrome (ALS) is a purely mechanical complication that occurs infrequently following construction of a gastrojejunostomy. Creation of an anastomosis between the stomach and jejunum leaves a segment of small bowel, most commonly consisting of duodenum and proximal jejunum, lying upstream from the gastrojejunostomy. This limb of intestine conducts bile, pancreatic juices, and other proximal intestinal secretions toward the gastrojejunostomy, and is thusly termed the afferent loop. The operations most commonly associated with this complication include distal or subtotal gastrectomies for peptic ulcer disease or gastric malignancies with Billroth II reconstructions, pancreaticoduodenectomies, and gastrojejunostomies performed to bypass other foregut pathology. The pathophysiology and signs and symptoms associated with ALS result from partial or complete obstruction of the afferent loop. ALS is included in the constellation of resectional gastric surgical complications known as the postgastrectomy syndromes. These include: 1. early dumping syndrome (Roberts, 1954)2. late dumping syndrome (Shultz, 1971) 3. postvagotomy diarrhea (Emas, 1985) 4. chronic gastric atony (Hom, 1989) 5. Roux stasis syndrome (Gustavsson, 1988) 6. small gastric remnant syndrome (Delcore, 1991) 7. alkaline reflux gastritis (Ritchie, 1980) 8. afferent loop syndrome (Eagon, 1992) 9. efferent loop syndrome (Eagon, 1992) ALS may present in either an acute, completely obstructed or chronic, partially obstructed form. It can manifest at any time from the first postoperative day to many years after surgery. The acute form usually occurs in the early postoperative period (1-2 weeks), but has been described 30 to 40 years after surgery. McNealy (1942) first described acute ALS as a cause of early postoperative duodenal stump leakage. Lake (1948) is credited with recognizing the chronic form. Roux and coworkers (1950) coined the term "afferent loop syndrome". The first detailed exegesis in the English literature on the etiology, clinical presentation, and treatment of ALS was contributed by Wells and Welbourn (1951). Pathophysiology: An afferent loop is composed of the duodenal stump, remainder of the duodenum and the segment of jejunum located proximal to a Billroth II-type gastrojejunostomy. ALS is caused by complete or partial mechanical obstruction at the gastrojejunostomy or at a point along the jejunal portion of the afferent loop. Causes of afferent loop obstruction are listed in Section 3. Passage of food and gastric secretions through the gastrojejunostomy and into the efferent loop triggers release of secretin and cholecystokinin. These enteric hormones stimulate secretion of bile, pancreatic enzymes, and pancreatic bicarbonate and water into the afferent loop. Under gastrointestinal hormonal influence, up to 1 or 2 liters of pancreatic and biliary secretions can enter the afferent loop daily. Symptoms associated with ALS are caused by increased intraluminal pressure and distension 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. It is also an etiology for postoperative obstructive jaundice (Locke, 1994), ascending cholangitis, and pancreatitis due to transmission of high pressures back to the biliopancreatic ductal system. High luminal pressures and distension increase bowel wall tension in the afferent loop according to the law of LaPlace, and can lead to ischemia and gangrene with subsequent perforation and peritonitis. Secondarily, prolonged stasis and pooling of secretions with partial obstruction facilitates bacterial overgrowth in the afferent loop. Bacteria deconjugate bile acids, which can lead to steatorrhea, malnutrition, and vitamin B12 deficiency. Iron deficiency can occur due to bypassing of the proximal small bowel. Acuity of the presentation depends mainly on the degree and duration of obstruction. Frequency: In the US: ALS affects approximately 1% of patients undergoing gastric resection and Billroth II gastrojejunostomies. This may be an underestimation as this complication is probably underdiagnosed. Overall, the incidence of this complication decreased dramatically during the final quarter of the 20th century as elective gastric surgery for complications of peptic ulcer disease experienced a logarithmic decline (Paimela, 1991; Burkhalter, 1988).
   — Emma B.