Does Bowel Stimulation Before Loop Ileostomy Closure Reduce Postoperative Ileus? A Multicenter Randomized Controlled Trial

Low anterior resection with total mesorectal excision is the standard operative treatment for mid and some low rectal cancers.The most dreaded and morbid complication of this procedure is anastomotic leak,with a varied incidence of 3-32%,and which can result in pelvic abscess and sepsis,re-operation,and death.The creation of a loop ileostomy is the only measure proven to reduce the morbidity and septic complications of anastomotic leakage. With the current trend towards sphincter-preserving surgery and the performance of ultra-low anastomoses for low rectal cancers, anastomotic dehiscence is increasingly being observed.That, in addition to the frequent use of neoadjuvant radiotherapy has contributed to a greater use of diverting ostomies. Furthermore, the use of a protective loop ileostomy is not limited to oncologic surgeries, and is often performed during colonic resection for complicated diverticular disease.

However, the formation of a loop ileostomy comes at a price as it requires a second surgery typically 12 weeks after the initial operation to restore intestinal continuity. The incidence of complications following ileostomy closure is certainly not negligible, at a highly variable range of 11-45%. A systematic review of 48 studies including 6,107 cases reported a 17.3% morbidity rate and a 3.7% re-operation rate. Of all complications, postoperative ileus (POI) is the most commonly observed morbidity following ileostomy closure, with rates typically reported between 15-32 %. POI can lead to increased patient discomfort, postoperative morbidity, prolonged hospital stay, increased risk for nosocomial infections,and ultimately higher health care costs.

Transient gut dysmotility can be expected after abdominal surgery. However, in the case of an ileostomy, the defunctionalized segment of bowel undergoes a series of structural and functional changes that may increase the time it takes for motility to resume after closure. Studies performed in animals have shown that defunctionalization of the ileum leads to atrophy of its villi and muscular layers.This was confirmed in humans by Williams et al.,who demonstrated a significant loss of muscular contractility and atrophy of intestinal villi following the creation of a diverting ileostomy.Oh et al. also revealed lower concentrations of peptide YY secreted in the mucosa of the ileum and colon distal to a loop ileostomy,the function of which is to inhibit gastric motility and promote water and electrolyte absorption in the colon.Thus, the absorptive capacity of the colon is reduced following reconstruction of the bowel.

It would appear that changes in the defunctionalized segment of bowel might leave it functionally unprepared for intestinal transit, contributing to the development of POI. A group in Spain proposed that preoperative stimulation of the excluded intestine might reverse those changes and improve its absorptive and motor function prior to restoring intestinal continuity, thus reducing the incidence of POI.They published a randomized controlled trial of 70 patients, of which 35 patients underwent daily stimulation with a thickened saline-based solution via the efferent limb of the ileostomy for two weeks. Following ileostomy closure, they observed reduced rates of POI, earlier return to oral intake and passage of flatus or stool, and shorter hospital stays in the group of patients that underwent stimulation. While their results are promising, t was a single-institution study in a European patient population, perhaps limiting its generalizability to our practice. Furthermore, while randomization should allow for equal distribution of confounders amongst the two groups, they did not report on electrolyte imbalances, narcotic use, and other variables known to influence the development of POI. Miedema and colleagues were the only other group to apply a similar technique of bowel stimulation before ileostomy closure, and found no benefits in intestinal absorptive function or postoperative bowel function. However, they only had six patients in their stimulated group, and all had undergone a restorative proctocolectomy with ileoanal J pouch, thus only a short segment of distal ileum was stimulated.

The idea of stimulating defunctionalized bowel to reduce POI is theoretically plausible, but is lacking in evidence. To our knowledge, this study would be the first of its kind in North America, and would complement the work done in Europe.The potential benefits of this intervention are numerous, including the patient's overall postoperative outcome, a postoperative course with a potential two-day reduction in length of stay and its associated health care costs. If such findings are observed, the use of preoperative bowel stimulation could be incorporated in Enhanced Recovery After Surgery (ERAS®) pathways for patients undergoing ileostomy closure.