Multiple Tumor Excisions in Ipsilateral Kidney Increase Complications After Partial Nephrectomy

The surgical morbidity of ipsilateral synchronous multifocality (ISM) is poorly characterized. We assessed the impact of ISM on complications after robotic partial nephrectomy (RPN).

We abstracted data on RPN cases performed between 2006 and 2015 at our institution. Multifocal disease was characterized by >1 renal mass on preoperative imaging or >1 mass excision during RPN. The primary outcome was the rate of overall postoperative complications. The association between multifocality and complications was evaluated using univariate and multivariable analyses.

Of 1121 cases, 59 (5.3%) had >1 ipsilateral renal mass and 50 (4.5%) required >1 excision. The overall complication rate was 20.3% (230/1121). The radiographic number of ipsilateral renal masses was not significantly associated with complications (20.2% for 1 mass vs. 25.4% for >1 mass, p = 0.338). However, the actual number of ipsilateral mass excisions performed during RPN was significantly associated with complications (20.2% for ≤2 excisions vs. 42.9% for >2 excisions, p = 0.037). Major complications were higher (14.3% vs. 5.3%) for >2 versus ≤2 excision(s), but this difference was not significant (p = 0.174). The most common complications associated with multiple excisions were transfusion, urine leak, arrhythmia, venous thromboembolism, and ileus. On multivariable analysis, number of excisions independently predicted complications (OR 3.1, 95% CI 1.03-9.33, p = 0.041). Other independent predictors of complications included age, race, Charlson score, body mass index, RENAL score, and surgeon experience.

ISM requiring ≥2 excisions is associated with increased morbidity after RPN. Pending external validation, this information may facilitate clinical decision-making and preoperative patient counseling.