Surgery in intestinal pseudo-obstruction: pro.

Unnecessary surgeries should be avoided. Everybody agrees with this aphorism. It is on the definition of ‘‘unnecessary’’ that different physicians hold daily, often acrimonious discussions. Indeed, if a ‘‘chance to cut is a chance to cure’’ one may also argue that a chance to cut is a chance to hurt. This is particularly true in the somewhat mysterious entity of intestinal pseudo-obstruction. There is no definitive diagnostic test or medical cure for pseudoobstruction, a condition that continues to be associated with high morbidity and mortality in children (1). In this condition, surgery may be used to aid in diagnosis and to improve symptoms. In pseudo-obstruction symptoms are generated by the failure of the intestinal pump, leading to stasis of intestinal content, much like it happens in subjects presenting with a bowel obstruction. As the term implies, to diagnose pseudo-obstruction one needs to conclusively rule out a physical obstruction. Radiology, endoscopy and manometry may all fail to detect a structural bowel occlusion. Contrast material may become diluted in the fluid-filled dilated bowel loops making arduous to detect a narrowing within the intestinal lumen. The lesion may be well beyond the reach of the endoscope. Manometry is particularly helpful in ruling out pseudo-obstruction when one finds a normal pattern of contractions (2), but may be abnormal in patients with an obstructive lesion (3), especially when the bowel is dilated. Thus, surgical exploration may be the only technique that can conclusively confirm or rule out a bowel obstruction. During surgery, if an occlusion is not found, one should obtain full thickness biopsies which may clarify the etiology of the motility disorder. Improved histo-pathologic techniques now allow detection of subtle abnormalities in the enteric nervous system and may uncover deficiencies in specific neuropeptides and neurotransmitters. In the past, the use of surgery just to obtain bioptic specimens was discouraged in patients with pseudo-obstruction, because it was felt that the information obtained would have had little impact on the treatment (4). Also, any surgery may predispose to the development of adhesions making it very challenging to differentiate future pseudo-obstructive crises from bowel occlusions. More recently, the use of laparoscopy to obtain serial biopsies (5) has reduced the morbidity of surgery and may have lessened the risk of causing adhesions. The diagnosis of pediatric forms of pseudo-obstruction due to autoimmune processes (6) or mitochondrial diseases (7), conditions that are associated with specific treatments may lead to a reassessment of the role of diagnostic surgery in pseudo-obstruction. At present, success of medical treatment in pseudoobstruction remains limited (8) and most children with the most severe forms of the disease require parenteral nutrition (9). Treatment is directed towards improving the function of the gastrointestinal pump. When this is unsuccessful, a reduction in the ‘‘after-load’’, much like it happens in heart failure, may be beneficial. This can be accomplished by ‘‘shortening’’ the gut by feeding distally to the stomach and diverting the fecal stream proximally to the colon with the creation of an ileostomy (10). Bowel decompression through a gastrostomy or a jejunostomy has been reported to be the most beneficial intervention in pseudo-obstruction patients (11). Venting ostomies improve symptoms by decreasing the frequency of vomiting or alleviating retching in patients who have had antireflux surgery. Gastrointestinal motility may improve as venting reduces bowel dilation. Gastrostomies and jejunostomies allow administration of drip feedings which may be better tolerated in a gastrointestinal tract which has a suboptimal function. Drip feedings should always be attempted before considering parenteral nutrition. Surgical bypass of diseased segments (12) and use of loop enterostomies (13) have been shown to benefit carefully selected patients. The best results occur in the rare situations where the disease is limited to an isolated segment of the bowel. Cecostomies have been used to administer antegrade enemas when constipation appears to be the predominant symptom. Surgical implantation of gastric and intestinal pacemakers aimed at improving motility constitutes a promising investigational approach in patients with severe motility disorders. Use of the gastric pacemaker has been associated with significant improvement in nausea and vomiting (14). Less impressive has been the effect on gastric emptying, suggesting that the electrical stimulation may act upon sensory rather than motor nerves. Small bowel pacing is more challenging due to the length and complex function of the organ to be stimulated and it is still in its infancy. At the present time, small bowel transplantation represents the only definitive cure for patients with chronic pseudo-obstruction. All children with pseudo-obstruction receiving total parenteral nutrition with frequent sepsis, Carlo Di Lorenzo, MD (e-mail: dilorenc@pediatrics.ohio-state.edu). Journal of Pediatric Gastroenterology and Nutrition 41:S64–S65 September 2005 Lippincott Williams & Wilkins, Philadelphia