RESUMO
BACKGROUND: Radical cystectomy (RC) is the primary surgical treatment for muscle-invasive urothelial carcinoma of the bladder. This major operation is typically associated with an extended hospital stay, a prolonged recovery period and potentially major complications. Nutritional interventions are beneficial in some people with other types of cancer and may be of value in this setting too. OBJECTIVES: To assess the effects of perioperative nutrition in people undergoing radical cystectomy for the treatment of bladder cancer. SEARCH METHODS: We performed a comprehensive search using multiple databases (Evidence Based Medicine Reviews, MEDLINE, Embase, AMED, CINAHL), trials registries, other sources of grey literature, and conference proceedings published up to 22 February 2019, with no restrictions on the language or status of publication. SELECTION CRITERIA: We included parallel-group randomised controlled trials (RCTs) of adults undergoing RC for bladder cancer. The intervention was any perioperative nutrition support. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed studies for inclusion, extracted data, and assessed risk of bias and the quality of evidence using GRADE. Primary outcomes were postoperative complications at 90 days and length of hospital stay. The secondary outcome was mortality up to 90 days after surgery. When 90-day outcome data were not available, we reported 30-day data. MAIN RESULTS: The search identified eight trials including 500 participants. Six trials were conducted in the USA and two in Europe.1. Parenteral nutrition (PN) versus oral nutrition: based on one study with 157 participants, PN may increase postoperative complications within 30 days (risk ratio (RR) 1.40, 95% confidence interval (CI) 1.07 to 1.82; low-quality evidence). We downgraded the quality of evidence for serious study limitations (unclear risk of selection, performance and selective reporting bias) and serious imprecision. This corresponds to 198 more complications per 1000 participants (95% CI 35 more to 405 more). Length of hospital stay may be similar (mean difference (MD) 0.5 days higher, CI not reported; low-quality evidence).2. Immuno-enhancing nutrition versus standard nutrition: based on one study including 29 participants, immuno-enhancing nutrition may reduce 90-day postoperative complications (RR 0.31, 95% CI 0.08 to 1.23; low-quality evidence). These findings correspond to 322 fewer complications per 1000 participants (95% CI 429 fewer to 107 more). Length of hospital stay may be similar (MD 0.20 days, 95% CI 1.69 lower to 2.09 higher; low-quality evidence). We downgraded the quality of evidence of both outcomes for very serious imprecision.3. Preoperative oral nutritional support versus normal diet: based on one study including 28 participants, we are very uncertain if preoperative oral supplements reduces postoperative complications. We downgraded quality for serious study limitations (unclear risk of selection, performance, attrition and selective reporting bias) and very serious imprecision. The study did not report on length of hospital stay.4. Early postoperative feeding versus standard postoperative management: based on one study with 102 participants, early postoperative feeding may increase postoperative complications (very low-quality evidence) but we are very uncertain of this finding. We downgraded the quality of evidence for serious study limitations (unclear risk of selection and performance bias) and very serious imprecision. Length of hospital stay may be similar (MD 0.95 days less, CI not reported; low-quality evidence). We downgraded the quality of evidence for serious study limitations (unclear risk of selection and performance bias) and serious imprecision.5. Amino acid with dextrose versus dextrose: based on two studies with 104 participants, we are very uncertain whether amino acids reduce postoperative complications (very low-quality evidence). We are also very uncertain whether length of hospital stay is similar (very low-quality evidence). We downgraded the quality of evidence for both outcomes for serious study limitations (unclear and high risk of selection bias; unclear risk of performance, detection and selective reporting bias), serious indirectness related to the patient population and very serious imprecision.6. Branch chain amino acids versus dextrose only: based on one study including 19 participants, we are very uncertain whether complication rates are similar (very low-quality evidence). We downgraded the quality of evidence for serious study limitations (unclear risk of selection, performance, detection, attrition and selective reporting bias), serious indirectness related to the patient population and very serious imprecision. The study did not report on length of hospital stay.7. Perioperative oral nutritional supplements versus oral multivitamin and mineral supplement: based on one study with 61 participants, oral supplements compared to a multivitamin and mineral supplement may slightly decrease postoperative complications (low-quality evidence). These findings correspond to 135 fewer occurrences per 1000 participants (95% CI 256 fewer to 65 more). Length of hospital stay may be similar (low-quality evidence). We downgraded the quality of evidence of both outcomes for study limitations and imprecision. AUTHORS' CONCLUSIONS: Based on few, small and dated studies, with serious methodological limitations, we found limited evidence for a benefit of perioperative nutrition interventions. We rated the quality of evidence as low or very low, which underscores the urgent need for high-quality research studies to better inform nutritional support interventions for people undergoing surgery for bladder cancer.