Simultaneous Bilateral Extracorporeal Shock Wave Treatments of the Kidney in a Primate Model

Since the advent of extracorporeal shock wave lithotripsy (SWL) for renal stones, urologists have become more aggressive in using this modality in the treatment of complicated stone disease. Many centers have treated patients with bilateral stones consecutively under a single anesthetic. Concern has arisen regarding this practice because of potential damage to renal function. We used four adult and eight infant Rhesus monkeys that were treated in the Dornier XL-1 experimental Iithotripter and divided into three groups as follows: adults—18 kV, 2000 shocks; low-dose infants—15 kV, 1500 shocks; and high-dose infants—18 kV, 2000 shocks, with the same ketamine anesthetic. The animals were monitored with an indwelling catheter for hematuria. Blood was collected to determine extent of blood loss. Animals were followed with ¹³¹I-Hippuran renal scans to monitor effective renal plasma flow (ERPF) and predicted return (PR). Single and two-tailed t tests were used for statistics. The infants had an overall loss of ERPF by 13.6 ± 6 ml/min per m² over baseline (P = 0.0008). The low-dose animals lost 15.5 ± 4.5 ml/min per m², and the high-dose animals lost 11 ± 7 ml/min per m² (P > 0.1). The adults lost 13.7 ± 30 ml/min per m², which was not different from baseline. In terms of percentage loss, the infants' ERPF declined by 20 ± 8 (NS). We have confirmed that consecutive bilateral SWL treatments may be damaging to renal function. Moreover, this modality may specifically be inappropriate in the pediatrie age group.