[Treatment of lithiasis in horseshoe kidney with extracorporeal shock-wave lithotripsy]

The horseshoe kidney is the most frequent renal anomaly. As a consequence of impaired urinary drainage, urolithiasis is present in 20% of the cases. Indications for extracorporeal shock wave lithotripsy (ESWL) in the treatment of patients with anomalous kidneys is still the subject of controversy.

To evaluate ESWL efficacy in the treatment for lithiasis in horseshoe kidney.

Between april 1988 and december 1999 a total of 32 symptomatic lithiasis in 30 patients with horseshoe kidneys were managed by 65 sessions with ESWL. Until march 1999 a Dornier HM-4 electrohydraulic lithotripter was used. Posteriorly, two treatments was performed with an electromagnetic Dornier Lithotripter S. These procedures have been performed without anaesthesia or sedation for the Dornier HM-4 equipment. Analgesia with Meperidine was used for the Dornier Lithotripter S. Diuresis was not forced during or after treatment with diuretics or serotherapy. Treatments was conducted in an outpatient clinic in all cases.

Treatment/lithiasis rate was 2.03. Following treatment 16 patients (54%) were stone-free by X-ray, 9 patients (30%) had residual fragments and in 5 patients (16%) no sign of stone disintegration was observed. Open surgery was performed in three of this patients. Better results was achieved in stones located in the renal pelvis and stone size is 10 mm or less. Clinical evolution: free of symptoms in 20 patients; chronic vague flank pain in 5 patients and acute renal colic with or without hematuria in 5 patients. No major complication was observed in our compilation.

These results suggest that ESWL is the method of primary choice in the treatment for small lithiasis (10 mm or less) in horseshoe kidney.