Current management of calculi in horseshoe kidneys

Objectives: To assess treatment options for calculi in horseshoe kidneys an d the impact of extracorporeal shockwave lithotripsy (ESWL) on the manageme nt of renal stones. Material and methods: From June 1971 to January 1998, 5 2 patients with horseshoe kidneys and calculi received treatment at our Uro logic Stone Unit. There were 40 men (77%) and 12 women (23%). Average patie nt age was 41 years (range: 10-70 years). Clinical onset, treatment receive d and outcome were evaluated retrospectively. A successful outcome was defi ned as a patient without residual calculi or with fragments <0.4 cm in size . Results: Clinical onset was mainly low back pain in 37 patients (71%). Ei ghty-nine stones were treated, i.e, an average of 1.7 treatments per patien t. Before the ESWL era (May 1987), we performed two heminephrectomies, 16 p yelolithotomies, 12 pyelolithotomies combined with ureteropyeloplasty and o ne percutaneous nephrolithotomy. Since the advent of ESWL, seven pyeloliths tomies and three pyelolithotomies combined with ureteropyloplasty have been done. ESWL was used to treat 48 calculi. In three cases the patient was pl aced in the prone position due to difficulties in stone focusing. In 37 cas es (77%) patients were either rendered stone-free or had residual fragments <0.4 cm in size. Urinary diversion for obstruction was carried out in two cases (4%). Conclusions: At present ESWL is the first-choice treatment for calculi in horseshoe kidneys. It involves no significant focusing difficult ies and is associated with a low incidence of obstructive complications. Op en surgery is indicated in cases of stone-related pyeloureteral stenosis an d in the presence of calculi >2-2.5 cm in size.