Laparoscopic Partial Nephrectomy at the Mayo Clinic Arizona: Follow-up Surveillance of Positive Margin Disease

Objectives: There is no consensus as to the management of positive surgical margins after laparoscopic partial nephrectomy (LPN). A recent study revealed no evidence of malignancy in radical nephrectomy specimens removed for this reason, pointing out that a positive margin does not always translate to residual disease. We present results from our institution for the first 80 LPN performed with minimum 2 years' follow-up, focusing on patients with malignancy noted to have positive margin on final pathology. Methods: We performed a retrospective chart review for patients who had undergone laparoscopic partial nephrectomy for malignancy and a minimal follow-up of 2 years. Patient demographic, operative, and perioperative data were collected. Those cases with positive margins were selected for specific oncologic analysis. Results: Of the 80 LPN performed, 50 were performed for malignancy. Mean tumor size was 2.2 cm. Five patients were found to have positive margin for renal cell carcinoma. All five of these masses were excised without hilar clamping using thermal dissection with energy ablation of the tumor bed. All patients underwent surveillance with a mean follow-up of 56.4 months with no recurrences. One patient with a negative surgical margin experienced a metachronous lesion in the contralateral kidney 3 years later. Conclusions: Surveillance in selected patients may be adequate without sacrificing oncologic control. However, long-term follow-up is essential. Hilar clamping may allow optimal visualization for tumor excision and allows excision to be performed without energy, potentially decreasing the rate of true- and false-positive margins.