Outcomes, complications, and costs of care of Bosniak IIF, III, and IV cystic renal lesions/malignancies: Data from the largest multi-institutional study to date.

Abstract

344 Background: To evaluate outcomes, complications and costs associated with management of Bosniak IIF, III, and IV cystic renal lesions/malignancies. Methods: An IRB-approved HIPAA-compliant multi-institutional retrospective data registry of prospectively classified Bosniak IIF (N=143), III (N=114), and IV (N=29) cystic renal lesions diagnosed in adults between January 2000 and October 2011 at UMMC, UAB, or WFUBMC was performed. Included patients were managed by surgical excision (N=86), ablation (N=19), or imaging-surveillance >1yr (N=181). De-identified coded data was entered into a web-based REDCap database containing 168 fields/patient. Complication severity was assessed using the Clavien classification system. Inpatient/outpatient technical/professional charges from 6 months prior to 6 months after surgery or ablation were gathered. Results: Patient level malignancy on surgical pathology was 38% (3/8) for BIIF, 40% (26/65) for BIII, and 89% (17/19) for BIV lesions. No metastatic BIIF lesions (0/143). One metastatic BIII lesion (1/114) developed after thermal ablation in a patient with a prior history of papillary RCC. One metastatic BIV (1/29) at the time of initial diagnosis (necrotic papillary RCC). Moderate/severe complications in 19%(16/86) of surgical and 5%(1/19) of ablative patients (p = 0.299). 0%(0/181) complications in patients managed by imaging surveillance >1yr. 0%(0/286) deaths for any management strategy. Median charges of $51,902 for partial nephrectomy (N=50), $42,411 for complete nephrectomy (N=36), and $22,442 for ablation (N=19) were significantly different (p < 0.001). Median charges in surgical patients with moderate/severe complications was $80,393 (N=16), significantly higher than $45,024 (N=70) for no/mild complications (p = 0.002). Conclusions: No deaths from Bosniak IIF or III lesions, irrespective of management approach. Imaging surveillance appears to be a safe primary management strategy for Bosniak III lesions. Moderate/severe complications occurred in 19% of surgery and 5% of ablation patients and nearly doubled the charges for surgery.