Percutaneous and laparoscopic-assisted cryoablation of small renal cell carcinomas.
462 Background: To evaluate the complication rate and short term oncological outcome of small renal cell carcinomas treated with cryoablation. Methods: 91 biopsy verified renal cell carcinomas were cryoablated between 2006-11. Patients treated had primarily T1a tumors, but exceptions were made. Patients with tumors not directly accessible percutaneously were selected for laparoscopy. To ensure complete coverage of the tumor, cryoneedle placement and freezing procedure was peroperatively monitored by ultrasound in both modalities. Presice machine with Ice-Seet and Ice-Rod needles from Galil Medical was used. Treatment was considered successful when tumors gradually shrunk and showed no sign of contrast enhancement, assessed by CT or MRI. Results: Mean patient age and tumor size was 65 yr [17 - 83] and 26 mm [10 - 62], respectively [min-max]. Treatment modalities consisted of percutaneous route; n=34 (47%) and laparoscopic guided; n=39 (53%). The mean follow-up time was 19 months [1 - 56]. 18 patients were excluded from follow-up analysis (8 pt. with short observation time, 5 pt. treated despite severe co-morbidity with no planned follow-up, 3 pt. lost to follow-up, 1 pt. emigrated, 1 pt. died as a result of bleeding from perforation of iliac artery by troicar). Residual tumor was diagnosed by imaging in 10 patients (perc n=6 and lap n=4, p>0,05) after a mean follow-up time of 13 months [1 - 31]. Diagnosis was confirmed by biopsy in all but one case, in which the diagnosis was necrosis. Of the 10 patients with residual tumor, 8 patients were reablated and 2 patients were referred to oncological treatment. Cancer specific survival was 100%. Overall survival was 91%. Complications: 8 pt. had minor bleeding in relation to cryoneedle removal, requiring Tachosil. 1 pt. had subcutaneous bleeding, 2 pt. was readmitted due to pain and discharged the following day. No patients required blood transfusion. Conclusions: Although percutaneous and laparoscopic guided cryoablation are minimally invasive procedures and the overall complication rate is low, serious complications may occur. Close follow-up and continuous evaluation of criteria for patient selection and relapse is necessary. An international database is recommended.