Lithotripsy Does Not Promote Diabetes or Hypertension

Researchers at the University of British Columbia (Vancouver, Canada) conducted a retrospective review of 727 patients who underwent SWL at Vancouver General Hospital (Canada) between 1985 and 1989. The researchers compared the prevalence of hypertension and DM in patients treated with an unmodified HM-3 lithotripter (USWL) and a second-generation modified HM-3 lithotripter (MSWL) to determine whether the type of lithotripter was differentially associated with the development of these sequelae. The response rate was 37.3%.

The results showed a greater proportion than average of overweight and obese individuals in the study group; hypertension was more prevalent in all lithotripsy subjects. In univariate analysis, lithotripsy with an USWL was associated with a higher rate of DM than the provincial rate, whereas lithotripsy with the MSWL was not; on multivariate analysis, however, the type of lithotripter was not associated with the development of either outcome. The researchers therefore postulated that the development of renal calculi was more indicative of an overall metabolic syndrome not related to shockwave lithotripsy, but rather to a systemic metabolic dysfunction. The study was published in the June 2, 2011, issue of BJU International.

“What we can tell our patients is that shockwave lithotripsy to treat kidney stones is safe and that it does not cause diabetes or hypertension,” said lead author Ben Chew, MD, of the department of urologic sciences. “Patients with kidney stones should be monitored closely for the development of hypertension and diabetes. Overweight patients should be counseled to lose weight and exercise.”

Shockwave lithotripsy is a noninvasive treatment of kidney stones and biliary calculi using an acoustic pulse. The pulses are initially administered at a slow rate for more effective comminution of the stone and to minimize morbidity; power levels are then gradually increased, so as to break up the stone. The final power level usually depends on the patient's pain threshold and the observed success of stone breakage. The successive shock wave pressure pulses result in direct shearing forces, as well as cavitation bubbles surrounding the stone, which fragment the stones into smaller pieces that then can easily pass through the ureters or the cystic duct. The process takes about an hour.

Related Links:
University of British Columbia
Vancouver General Hospital