Percutaneous nephrolithotomy with renal angiomyolipomas: a rare challenge.

Renal angiomyolipomas (AML) are vascular tumors associated with a risk of spontaneous bleeding. Renal trauma may also initiate such hemorrhage. We present a case in which we initially avoided direct puncture and the possible risk of bleeding through extensive renal AMLs and then subsequently performed a direct puncture through the tumors. A 21-year-old obese male patient with tuberous sclerosis and mental retardation presented to our institution with left renal colic and was found to have a staghorn calculus. A CT scan revealed extensive bilateral renal AMLs. The patient had previously undergone renal angioinfarction for an enlarging right-sided AML, and nuclear renography demonstrated 70% function from the left side. The patient had a nephrostomy access created on the morning of a scheduled percutaneous nephrolithotomy under three-dimensional CT guidance. There was no clinically significant bleeding. Intraoperatively, a second access site was required in order to render the patient stone free. This was done using standard biplanar fluoroscopic technique and traversed an AML. Both tracts were balloon dilated prior to placement of a 34F Amplatz sheath. Postoperatively, the patient had an uneventful recovery. A CT scan performed 1 day postoperatively revealed no retroperitoneal collection. This case demonstrates that renal access can be achieved with remarkable accuracy using 3D CT imaging. Furthermore, although this approach seems most prudent in the case of extensive renal AMLs, fluoroscopically guided renal access and dilation to 34F was not associated with bleeding in this patient.