Simple enucleation for the treatment of renal angiomyolipoma

To report on the role of simple enucleation for treating renal angiomyolipoma (AML) in a series of patients treated in our department.

We retrospectively reviewed the data of all 37 patients with a histopathological diagnosis of renal AML who had either radical nephrectomy (three) or nephron-sparing surgery by simple enucleation (34) between January 1986 and December 2005. Indications for intervention included either symptomatic AML or a tumour of >4 cm, regardless to the presence of symptoms or renal masses suspicious of malignancy. The patients' status was evaluated last in October 2006.

The mean (sd, median, range) pathological tumour size was 5.2 (3.4, 4.8, 1.5-15) cm; five patients (15%) were affected by tuberous sclerosis. Simple enucleation was successful in all patients but in three (9%) a sharp dissection a few millimetres from the tumour was used during critical steps of the procedure where it seemed difficult to define the right plane of enucleation. Warm ischaemia was used in 79% of patients, with a mean ischaemic time of 11.2 min. Two patients (6%) required renal hypothermia. A simple parenchymal compression was used in five cases (15%). The mean (range) intraoperative blood loss was 170 (70-650) mL. None of the patients had postoperative bleeding requiring re-intervention but one (3%) required two units of blood after surgery. There were no major complications, e.g. prolonged acute tubular necrosis/chronic renal insufficiency and urinary leakage/urinoma, but two patients had urosepsis not associated with perirenal fluid collection and that required targeted antibiotic therapy. At a mean (median, range) follow-up of 56 (50.5, 10-120) months none of the patients had local tumour recurrence. Two patients had a small AML elsewhere in the operated kidney, detected 18 and 36 months after surgery, with a kidney recurrence rate of 6%.

Our data confirm the optimum results of simple enucleation for renal AMLs; this technique provides excellent long-term local control and no patient had urinary leakage/fistula afterward.