Login to Access Video or Poster Abstract: MP100-16
Sources of Funding: None

Introduction

Review of 15 year, single surgeon experience using laparoscopic cryoablation (LCA) and real-time intraoperative thermal monitoring for the management of small renal masses. We present treatment success and perioperative outcomes.

Methods

We retrospectively analyzed 143 renal masses (128 patients) treated with LCA from 2001-2011, allowing for 5 year follow-up. Patients underwent retroperitoneal (RP) or transperitoneal (TP) LCA with objective thermal monitoring. After cryoneedle insertion, ≥2 thermal probes were placed within the tumor and outside the tumor margin to quantitatively assess temperatures. All tumors had ≥2 freeze cycles with a goal of achieving ≤-25°C at the periphery. Core tumor biopsies (3-6) were taken under direct vision during the first freeze cycle. _x000D_ _x000D_ Follow-up was recommended at least annually. Patient characteristics, operative details, pathology and perioperative labwork were analyzed. All cases of post-ablative radiologic persistence (lesion at ablation site) and recurrence (lesion outside of ablation site) were confirmed with biopsy or pathology from additional surgery._x000D_

Results

Of 128 LCA patients (75 female, 53 male), mean age was 63 (30-83) years and BMI was 31.3kg/m2. Median ASA score was 3. Comorbidities included: hypertension (82/128), renal insufficiency (33/128), diabetes (28/128), ischemic cardiac disease (17/128) and solitary kidney (11/128)._x000D_ _x000D_ RP approach was used in 30/78 right vs 38/65 left-sided tumors with TP in the remainder. Mean tumor size was 3.0 (+/- 1.1) cm and surgical time was 211.1 (+/- 63.4) min. Two freeze cycles were performed in 97/143 tumors and mean freeze cycle duration was 11.0 (+/- 8.3) min. Mean EBL was 164.6mL and postop discharge was ≤24 hrs and ≤48 hrs in 45/133 and 84/133 of cases, respectively. Average hematocrit and eGFR change from pre- to postop was -5.1 mg/dL and 3.96 mL/min/1.73m2, respectively._x000D_ _x000D_ Intraoperative biopsy (n=143) showed malignancy in 97 (67.8%) or oncocytic neoplasm in 21 (14.7%) cases. Of the remainder, 18 were benign (12.6%) and 6 were angiomyolipoma (4.2%). One sample was lost._x000D_ _x000D_ Surgical limitations to tumor treatment were noted in only 3/143 (2.1%) tumors using our LCA technique. Of patients with biopsy-proven renal cancer or oncocytic neoplasm, 113/118 (95.8%) had no tumor persistence (mean radiologic follow-up 49.4 (+/-28.4) months (0.4-131.8 months)). Only 7/128 (5.5%) patients had recurrence._x000D_

Conclusions

Using objective thermal monitoring may improve intraoperative tumor control and decrease the likelihood of oncologic persistence when compared to traditional LCA.

Funding

None