Surgical-assisted nephroscopic lithotripsy
Surgical-assisted nephroscopic lithotripsy is performed by using a rigid endoscope during an open laparotomy, resulting in
excellent magnification of the renal pelvis for stone retrieval. The same procedure as above (PCNL) can be performed via laparotomy
rather than percutaneously, termed nephroscopic guided lithotripsy.
The greater curvature of the kidney is punctured with a renal puncture needle, and a pyelogram is performed. A guide wire
is then advanced into the renal pelvis with fluoroscopic guidance, and a balloon dilation catheter, preloaded with a matching
sheath, is advanced over the wire and onto nephrolith. The balloon is dilated, and the sheath slides right over the balloon
with a smooth transition. The balloon is withdrawn, and the scope is inserted through the sheath for stone removal.
Little risk of hemorrhage exists when using a balloon-sheath combination since this creates a tamponade effect, and the renal
parenchyma is spread apart with the balloon, not cut with a scalpel blade, making renal damage dramatically less then that
with a nephrotomy. If this is done surgically, then a nephrostomy tube is not necessary because the hole can be closed by
directly suturing the renal capsule to prevent leakage. Because a balloon is used to dilate the renal parenchyma, minimal
nephron loss occurs, and the tissue is compressed via balloon dilation rather than being incised. This is now being performed
routinely on canine kidneys in our practice and has been highly successful.
Unlike a nephrotomy, these minimally invasive procedures do not require transient occlusion of renal vessels and result in
a much smaller hole in the renal parenchyma than a nephrotomy. Placing sutures in the capsule and apposing the small incision
can close the renal access point. Care must be taken to assess all areas of the renal pelvis and renal calyces, as small calculi
can remain if fluoroscopy and contrast nephrography are not used concurrently. We recommend concurrent fluoroscopy, as is
recommended in human urology (Figure 3).
After the procedure, a ureteral stent is placed to protect the ureter from any small fragments that could an obstruction (Figure
4). This stent is then removed four to six weeks later cystoscopically.
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• Raza A, Turna B, Smith G, et al. Pediatric urolithiasis: 15 years of local experience with minimally invasive endourological
management of pediatric calculi. J Urol 2005;174(2):682-685.
• Donner GS, Ellison GW, Ackerman N, et al. Percutaneous nephrolithotomy in the dog: An experimental study. Vet Surg 1987;16(6): 411-417.
• Al-Shammari AM, Al-Otaibi K, Leonard MP, et al. Percutaneous nephrolithotomy in the pediatric population. J Urol 1999;162(5):1721-1724.
• Lennon GM, Thornhill JA, Grainger R, et al. Double pigtail ureteric stent versus percutaneous nephrostomy: effects on stone
transit and ureteric motility. Eur Urol 1997;31(1):24-29.
Dr. Berent is the director of Interventional Endoscopy Services in the Department of Diagnostic Imaging at The Animal Medical
Center in New York City. Dr. Weisse is the director of Interventional Radiology Services in the Department of Diagnostic Imaging
at The Animal Medical Center in New York City.
For a complete list of articles by Drs. Berent and Weisse, visit