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.

Can a hydrophilic guidewire be resterilized?

The Glidewire (Microvasive, Natick, MA) or Terumo wire (Terumo, Japan) is constructed with a hydrophilic polymer surface that enables easier passage through narrowed lumens in the urinary tract. This study examined the effects of gas sterilization on Glidewire surface structure, slipperiness, and ability to support bacterial growth. Light microscopy at 100x and 400x and scanning electron microscopy at 100 to 1300x were used to compare the surface tips of five new 0.038-inch Glidewires with those resterilized one or three times. The tips were immersed in water prior to standard gas sterilization for operating room equipment. Subjective evaluation of slipperiness involved asking 10 blinded urologists to assess the nature of new and resterilized wires by feel. Support of bacterial growth was assessed by comparing cultures performed on new wires (control) with those of wires incubated with Bacillus stearothermophilus. Microscopy, reviewed by a pathologist, revealed no perceivable surface differences after one and three gas sterilizations. Eight of the urologists noted similar or improved slipperiness of resterilized wires compared with new wires. Bacterial cultures of intentionally infected wire segments showed no growth after standard gas sterilization in all cases. In this study, gas sterilization did not adversely affect the lubricious nature or the surface coating of the hydrophilic coating of Glidewires. Also, gas resterilization was bactericidal to new and used wires that had been infected with a heat-tolerant organism.

Novel hemostatic nephrostomy tube.

Significant hemorrhage from the access site is an infrequent complication of percutaneous renal surgery. We developed a novel nephrostomy tube that combines the benefits of the re-entry Malecot design with those of the Kaye tamponade catheter. The new nephrostomy tube was successful in preventing significant bleeding in high-risk patients who had this tube placed after percutaneous nephrostolithomy. All of the patients tolerated the tube without complications. Preliminary results show that this tube is easy to insert, well tolerated by patients, and effective in preventing and stopping bleeding from a percutaneous access site and that it maintains ureteral access.

Techniques for stenting the normal and obstructed ureter.

Ureteral obstruction is a common cause of urologic morbidity requiring quick and effective treatment, as prolonged obstruction can cause pain, infection, and eventual loss of renal function. Few would argue that initial drainage or bypassing of the obstruction is favorable initial management; however, urologists are often-times faced with technically difficult cases not responsive to the standard operative maneuvers. Recognizing the diversity of pathology and the potentially complicating issues, urologists should have in their armamentarium a systematic approach or algorithm for dealing with these common dilemmas, as well as an understanding of various tricks of the trade. This knowledge will prevent heightened anxiety at the time of surgery and will ensure the availability of the proper operative equipment. This article outlines an approach and discusses the obstacles and options in stenting the obstructed ureter.