Nutritional status affects post-cystectomy outcomes

Washington-Preoperative hypoalbuminemia is a risk factor for complications following radical cystectomy, say researchers from the University of North Carolina, Chapel Hill.

Study authors, led by Angela Smith, MD, assistant professor of urology, and reported by urology resident David C. Johnson, MD, MPH, extracted data from a retrospective review of the American College of Surgeons National Quality Improvement Program (ACS-NSQIP) data files for 2005-2011. A total of 1,092 patients were included, of whom 575 (53%) developed a complication within 30 days of surgery.

Three variables were investigated as measurable markers of nutritional status: preoperative hypoalbuminemia (<3 g/dL), weight loss >10% in the 6 months before surgery, and nonoptimal weight (body mass index <30 kg/m² vs. ≥30 kg/m²). In a multivariate analysis controlling for age, resident involvement in surgery, operation year, and surgical history, among others, hypoalbuminemia, which was present in 8% of the population, was associated with a statistically significant, twofold increased likelihood of experiencing a postoperative complication.

Preoperative weight loss >10%, found in 5% of the population, showed a trend to statistical significance as an independent risk factor for complications. BMI dichotomized using a cut-off of 30 kg/m² was not associated with complications.

“An association between a patient’s nutritional status and morbidity and mortality following urologic surgical procedures has not been well-studied. However, it is of particular interest as it pertains to radical cystectomy because it is associated with a high rate of complications and the population undergoing the procedure is at increased risk for malnutrition, considering these patients are older on average and have a malignant disease,” Dr. Johnson said.

Findings suggest targeting nutrition

“Our study corroborates the high morbidity of radical cystectomy and supports targeting nutritional status as a modifiable risk factor to potentially improve patient outcomes,” added Dr. Johnson, who presented the findings at the 2013 American College of Surgeons Clinical Congress in Washington.

Dr. Johnson explained that the NSQIP dataset was chosen as a resource for the study because it is a powerful, validated database that prospectively collects information on a large number of preoperative, intraoperative, and postoperative variables, including complications through 30 days. Hypoalbuminemia was investigated as a potential predictor of complications because two previous studies in the urologic literature found it to be a significant predictor of all-cause mortality. Weight loss >10% in the 6 months prior to surgery was chosen to identify patients who might have experienced unintentional weight loss. Although the investigators wanted to investigate being underweight (BMI <18.5 kg/m²) as a risk factor for complications, the study was underpowered for that analysis, as very few patients were underweight.

Dr. Johnson noted that the question remains as to whether the information from the study can be applied to improve outcomes after radical cystectomy.

“There have been studies showing that interventions, including screening for patients at high risk for nutritional deficiency, increasing protein and carbohydrate intake preoperatively, and counseling by registered dietitians preoperatively and during the postoperative hospital stay, can correct nutritional deficiencies. Whether that translates into reduced postoperative complications after cystectomy is not known,” he said.

However, considering the potential significant benefit of nutritional intervention and the fact that it has minimal downsides, urologists at the University of North Carolina are collaborating with colleagues at Carolinas Medical Center in Charlotte, NC to implement a nutrition protocol for patients undergoing radical cystectomy. The program is focusing on improved screening and the development of individualized strategies to improve patient nutrition pre- and postoperatively.UT

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