Safety and efficacy of high kV biliary lithotripsy: preliminary experience

Despite intense interest in laparoscopic cholecystectomy, biliary lithotripsy (BL), by avoiding the need for general anesthesia, could remain a useful alternative in approximately 10% of patients with symptomatic gallstones. The poor stone clearance rates reported by the Dornier National Biliary Lithotripsy Study has led to disenchantment with biliary lithotripsy. However, the results may reflect the relatively low kV (18.7 +/- 1.7) used. We have compared symptomatic gallbladder stone/cholecystolithiasis patients with one to five stones of aggregate diameter < 60 mm treated with one to three sessions on an MPLS 9000 (Dornier) lithotripter at moderate kV (22.7 +/- 1.7 kV; mean number of shocks 1473 +/- 356) with a similar group treated with high kV (26 kV, mean number of shocks 1357 +/- 507). Ultrasound stone diameter measurements were made pre- and post-BL; 12-wk results are reported. Treatment safety was assessed by recording adverse experiences and serum, urine, hematology, and chemistry. For patients with single stones, the high kV treatment took significantly (p < 0.05) less time (74 +/- 30 min) than moderate kV treatment (118 +/- 33 min). At 3 months, the moderate kV-treated single-stone group had a residual maximum fragment size of 3.2 +/- 3.3 mm versus 1.8 +/- 2.3 mm in the high kV-treated single-stone group. The 3-month stone-free rate for patients with single stones treated at high kV was 44% compared with 46% for the moderate kV-treated group (NS). At 1 wk, 11 patients had microscopic or macroscopic hematuria and six patients had mildly elevated liver function tests. At 6 wk, however, all urine and hematological measurements had returned to normal. Two patients suffered pancreatitis, one in each group. High kV BL appears to be safe and, for patients with single stones, gives better fragmentation and takes less time to administer than moderate kV. Whether a high kV treatment protocol can achieve improved long-term stone-free rates remains to be assessed.