Serial Transverse Enteroplasty for Management of Refractory d‐Lactic Acidosis in Short‐bowel Syndrome

Abstract

Short-bowel syndrome (SBS) is a relatively common disease of insufficient small-bowel absorptive capacity with an estimated 5-year mortality rate of 37.5%, mostly because of sepsis and liver failure associated with central venous access and parenteral nutrition (1,2). Manifestations of SBS include growth retardation, malnutrition, diarrhea and frequent infection. Sources of infection include central venous access and bacterial overgrowth within chronically dilated bowel. One complication of bacterial overgrowth is d-lactic acidosis, a syndrome of neurological disturbances and acidemia first described in 1979 (3). Patients present with recurrent, often escalating episodes of neurological derangement associated with acidosis, widened anion gap and elevated levels of plasma d-lactic acid. d-Lactic acid, the product of anaerobic carbohydrate metabolism by resident intestinal bacteria, is believed to cause acidosis because it is metabolized much more slowly than l-lactic acid and therefore accumulates if produced in abundance. In the case of SBS, decreased absorption of enteral carbohydrates and bacterial overgrowth are thought to lead to increased bacterial production of lactic acid. The responsible bacteria may colonize the remnant small or large intestine as a result of stasis and dysmotility within chronically dilated bowel or administration of probiotic medications such as the gram-positive anaerobic rod Lactobacillus acidophilus (4,5). Traditional treatment of this disease consists of altering the intestinal flora with antibiotics and minimizing the metabolic substrate by using a low-carbohydrate diet (6). Unfortunately, these therapies are not always successful, and refractory cases are a difficult management problem in this chronically ill patient population. Serial transverse enteroplasty (STEP), which involves sequential linear stapling of the dilated bowel from opposite directions to create a new “zig-zag” lengthened and tapered intestinal channel, has gained acceptance in the treatment of patients with SBS since its introduction in 2003 (7–12). In addition, a recent animal study has shown that the STEP procedure reduces bacterial overgrowth in SBS (13). A potential advantage of the STEP operation compared with conventional tapering is its ability to narrow dilated bowel while preserving small-bowel mucosal mass. Thus, the STEP procedure could be a useful therapy for treatment of SBS patients with refractory d-lactic acidosis. We describe here the case of a patient with SBS who had been relatively well until she developed recurrent episodes of d-lactic acidosis. After failure of medical management, she was successfully treated with the STEP procedure to provide tapering of a massively dilated segment of duodenum that was felt to be a reservoir for d-lactic acid producing bacterial flora.