The effect of urinary diversion on long-term kidney function after cystectomy.

OBJECTIVES: Cystectomy with urinary diversion is associated with decreased long-term kidney function due to several factors. One factor that has been debated is the type of urinary diversion used: ileal conduit (IC) vs. neobladder (NB). We tested the hypothesis that long-term kidney function will not vary by type of urinary diversion. METHODS AND MATERIALS: We retrospectively identified all patients who underwent cystectomy with urinary diversion at our institution from January 1, 2007, to January 1, 2018. Data were collected on patient demographics, comorbid conditions, perioperative radiotherapy, and complications. Creatinine values were measured at several time points up to 120 months after surgery. Glomerular filtration rate (GFR) (ml/min per 1.73 m2) was calculated using the Chronic Kidney Disease Epidemiology Collaboration equation. A linear mixed model with inverse probability of treatment weighting (IPTW) was used to compare GFR between the IC and NB cohorts over time. Multiple sensitivity analyses were performed based on 2 different calculations of GFR (Chronic Kidney Disease Epidemiology Collaboration equation vs. Modification of Diet in Renal Disease), with and without excluding patients with preoperative GFR less than 40 ml/min per 1.73 m2. RESULTS: Among 563 patients who underwent cystectomy with urinary diversion, a NB was used for 72 (12.8%) individuals. Patients who had a NB were significantly younger, had a lower American Society of Anesthesiologists score, greater baseline GFR, better Eastern Cooperative Oncology Group performance status, lower median Charlson comorbidity index, and were less likely to have received preoperative abdominal radiation (all P < 0.05). Both NB and IC patients had decreased kidney function over time, with mean GFR losses at 5 years of 17% and 14% of baseline values, respectively. The IPTW-adjusted linear mixed model revealed that IC patients had slightly more deterioration in kidney function over time, but this was not statistically significant (estimate, 0.12; P = 0.06). The sensitivity analyses yielded a similar trend, in that GFR decrease appeared to be greater in the IC cohort. This trend was statistically significant when using Modification of Diet in Renal Disease (P = 0.04). CONCLUSIONS: Among highly selected patients with an NB, deterioration of kidney function may potentially be lower over time than among IC patients. However, the statistical significance varied between analyses and we cautiously attribute these observed differences to patient selection.

How the Beneficial Effects of Alvimopan Differ With Surgical Approach for Radical Cystectomy.

OBJECTIVE: To assess whether the beneficial perioperative effects of alvimopan differ with surgical approach for patients who undergo open radical cystectomy (ORC) vs robot-assisted radical cystectomy (RARC). METHODS: This retrospective study reviewed all patients who underwent cystectomy with urinary diversion at our institution between January 1, 2007, and January 1, 2018. Data were collected on demographic characteristics, comorbidities, surgical approach, alvimopan therapy, hospital length of stay (LOS), days until return of bowel function (ROBF), and complications. Outcomes and interactions were evaluated through regression analysis. RESULTS: Among 573 patients, 236 (41.2%) underwent RARC, 337 (58.8%) underwent ORC, and 205 (35.8%) received alvimopan. Comparison of 4 cohorts (ORC with alvimopan, ORC without alvimopan, RARC with alvimopan, and RARC without alvimopan) showed that patients who underwent ORC without alvimopan had the highest rate of postoperative ileus (25.6%, P = .02), longest median hospital LOS (7 days, P < .001), and longest time until ROBF (4 days, P < .001). On multivariable analysis, the interaction between surgical approach and alvimopan use was significant for the outcome of ROBF (estimate, 1.109; 95% confidence interval, 0.418-1.800; P = .002). In the RARC cohort, multivariable analysis showed no benefit of alvimopan with respect to ileus (P = .27), LOS (P = .09), or ROBF (P = .36). Regarding joint effects of robotic approach and alvimopan, RARC had no effect on gastrointestinal tract outcomes. CONCLUSION: We observed a diminished beneficial effect of alvimopan among patients undergoing RARC and a statistically significant benefit of alvimopan among patients undergoing ORC. The implications of these findings may permit more selective medication use for patients who would benefit the most from this drug.