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Common Urological Problems

Urinary Stone Disease Intervention

  • - General Urology - Common Urological Problems - Urinary Stone Disease
  • Jul 25, 2010
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Percutaneous removal of renal and proximal ureteral calculi is the treatment of choice for large (>2.5 cm) calculi; those resistant to ESWL; select lower pole calyceal stones with a narrow, long infundibulum and an acute infundibulo-pelvic angle; and instances with evidence of obstruction; the method can rapidly establish a stone-free status.

Needle puncture is directed by fluoroscopy, ultrasound, or both, and is routinely placed from the posterior axillary line into a posterior inferior calyx.

Superior caliceal puncture may be required, and in such situations care should be taken to avoid injury to the pleura,  lungs, spleen, and liver. Tract dilation is performed by sequential plastic dilators (Amplatz system),  telescoping metal dilators (Alken),  or balloon dilation with a backloaded Amplatz sheath. Tracts placed during open renal procedures are frequently tortuous and suboptimal for subsequent endourologic procedures.

Percutaneous extraction of calculi requires patience and perseverance.  Hardcopy radiographs help to confirm a stone-free status. Remaining calculi can be retrieved with the aid of flexible endoscopes,  additional percutaneous puncture access,  follow-up irrigations,  ESWL,  or additional percutaneous sessions.  Realistic goals should be established. Patients should be informed that complex calculi frequently require numerous procedures.

Urinary Stone Disease

Urinary Stone Disease

Maintenance of body temperature with appropriate blankets during preoperative patient positioning and with warmed irrigation fluids helps to prevent bleeding diatheses associated with hypothermia.  The average blood loss during a percutaneous nephrolithotomy is 2–2.8 g/dL of hemoglobin.  Multiple percutaneous punctures and renal pelvic perforations are associated with a greater blood loss.

Overall, such procedures are safe and effective and have a transfusion rate well <10%.

Open stone surgery is the classic way to remove calculi.

The morbidity of the incision, the possibility of retained stone fragments, and the ease and success of less invasive techniques have made these procedures relatively uncommon when instruments and surgical experience are available.  It is mandatory to obtain a radiograph before the incision is made; calculi frequently move. A variety of incisions to access the kidney are available.

Pyelolithotomy is effective,  especially with an extrarenal pelvis.  A transverse pyelotomy is effective and does not require interruption of the renal arterial blood supply.

Inspection with flexible endoscopes helps ensure a stone free status. Multiple, small renal pelvic calculi and difficult to-access caliceal calculi can be retrieved with the aid of a coagulum. Coagulum was initially produced from pooled human fibrinogen.  The risks of hepatitis and other viral infections have made this method unacceptable. Cryoprecipitate can be obtained from rapid freezing of plasma.

Autologous plasma may be used to decrease the incidence of bloodborne infections. The tensile strength of cryoprecipitate is approximately 10 times that of a blood clot.

Injected into the renal pelvis, endogenous clotting factors result in a Jelly-like coagulum of the collecting system.

Small stones are entrapped and removed with the coagulum.  A variety of Randall stone forceps help gain access into most of the collecting system.

image Figure 16–21.  Plain abdominal radiograph demonstrating complete staghorn calculus with renal pelvic extension into all infundibula and calyces.

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