Introduction: Nephron-sparing surgery (NSS) is common in the management of small renal masses. In locally advanced tumors, it is typically only considered in cases of a solitary kidney. Robotic and open partial nephrectomy are standard approaches with ex vivo partial nephrectomy rarely reported. This approach was abandoned at Cleveland Clinic in 1986 due to lackluster results. Since then, however, technology has improved with better vessel sealing devices, thrombogenic materials to help pack the defect and reconstruct, and better imaging. Methods: A 44 year old woman was found to have bilateral renal masses on imaging performed during a hypertension workup. The right renal mass was large with inferior vena cava (IVC) tumor thrombus. The left sided mass was central with renal vein thrombus. After undergoing a right radical nephrectomy and IVC tumor thrombectomy, she was treated with 8 weeks of neoadjuvant axitinib on trial to downstage the remaining left renal mass. After considering all options, an ex vivo partial nephrectomy was performed. First, a laparoscopic nephrectomy was performed in similar fashion as to donor nephrectomy. The kidney was then chilled and perfused with Collins' solution before being defatted and small vascular branches ligated. The central mass was then visualized on ultrasound and a portion of parenchyma overlying it excised to allow for hilar and tumor exposure. The renal vein was opened and tumor resected. After oversewing the parenchyma, closing open vessels, and packing the defect with Surgicel Fibrillar, the outer renorrhaphy was performed with 2-0 Chromic sutures. The autotransplantation was then performed with the kidney placed into the left iliac fossa and vascular anastomoses performed to external iliac vessels and ureteral reimplantation onto the bladder dome. Results: The total time in the operating room was 6 hours with 3 hours spent on the bench preparing the kidney and resecting the mass. The estimated blood loss was 500 cc. Final pathology revealed a 7 cm pT3a grade 3 clear cell renal cell carcinoma with negative margins. She experienced acute kidney injury with peak creatinine of 5.91 on post-operative day 3 which improved to 1.54 by 6 weeks. She suffered a pulmonary embolism at that time but has done well on anticoagulation. At 6 months, her creatinine was 1.32 and surveillance imaging was negative for any recurrent disease. Conclusions: The management of bilateral locally advanced renal tumors is complex and challenging. In rare circumstances, ex vivo partial nephrectomy can be considered and performed with good result. SOURCE OF Funding: None
