Significant morbidity is associated with proximal fecal diversion among high-risk patients who undergo colectomy: A NSQIP analysis

Major renal morbidity following elective rectal cancer resection by the type of diverting ostomy

AIM

Patients with rectal cancer often undergo faecal diversion, yet the existing literature cursorily reports renal sequelae by the type of ostomy. We aimed to determine whether the presence of an ileostomy or colostomy was associated with postoperative renal morbidity.

METHODS

We identified patients with rectal cancer undergoing elective resection with primary anastomosis without diversion, with an ileostomy and with a colostomy by 21 possible procedures in the colectomy- and proctectomy-specific National Surgical Quality Improvement Program files. The odds of major renal events (renal failure [dialysis initiated] or progressive renal insufficiency [>2 mg/dl increase in creatinine without dialysis]), progressive renal insufficiency alone and readmissions were assessed using propensity score weighting and logistic regression.

RESULTS

Of 15 075 patients (63.7% Stage II-III, 85.7% creatinine values obtained ≤30 days preoperatively), 37.7% were not diverted, 39.5% had an ileostomy and 22.9% a colostomy. Compared to non-diverted patients, diversion was associated with major renal events (ileostomy, odds ratio [OR] 2.1, 95% confidence interval [CI] 1.6-2.9; colostomy, OR 1.8, 95% CI 1.3-2.5), progressive renal insufficiency (ileostomy, OR 2.5, 95% CI 1.7-3.5; colostomy, OR 2.0, 95% CI 1.4-2.9), readmissions for renal failure (ileostomy, OR 3.2, 95% CI 2.1-5.0; colostomy, OR 2.5, 95% CI 1.6-4.1) and readmissions for fluid/electrolyte abnormalities (ileostomy, OR 2.3, 95% CI 1.6-3.3; colostomy, OR 1.8, 95% CI 1.2-2.6).

CONCLUSION

Diverting ostomies after elective rectal cancer resection are strongly associated with renal morbidity. The decision to divert is complex, and it is unclear whether select patients may benefit from a colostomy from a renal perspective.

Overuse of Proximal Fecal Diversion in Colorectal Surgery

Many surgeons tend to overuse proximal fecal diversion in the setting of colonic surgery. The decision to proximally divert an anastomosis should be made with careful consideration of the risks and benefits of proximal diversion. Proximal diversion does not decrease the rate of anastomotic leak, but it does decrease the severity of leaks. Anastomotic height for low pelvic anastomoses, hemodynamic instability, steroid use, male sex, obesity, malnutrition, smoking, and alcohol abuse increase the rate of anastomotic leak. Biologics, most immunosuppressive agents, unprepped colons, and radiation for rectal cancer do not contribute to increased rates of anastomotic leak. Proximal fecal diversion creates additional potential morbidity, higher rates of readmission, and need for a subsequent hospitalization and operation for reversal. Additionally, diverted patients have higher rates of anastomotic stricture and delayed recognition of chronic leaks. These downsides to diversion must be weighed with a patient's perceived ability to handle the physiologic stress and consequences of a severe leak if reoperation is required. When trying to determine which patients can handle a leak, the modified frailty index can help to objectively determine a patient's risk for increased rate of morbidity and failure to rescue in the event of a leak. While proximal diversion is still warranted in many cases, we find that certain clinical scenarios often lead to overuse of proximal diversion. The old surgical adage "If you are considering diverting, you should probably do it" should be tempered by an understanding of the risk and benefits of diversion.