Shock wave lithotripsy for renal stones is not associated with development of hypertension in Chinese/Taiwanese population

Purpose: Shock wave lithotripsy (SWL) is highly available due to its accessible of use, noninvasive nature, and highly effective in fragmentation the stones. Some reports showed the SWL may develop new onset of hypertension. The association between SWL and development of new hypertension has become a matter of debate due to controversial data have become available. We aimed to determine whether the SWL increased the development of hypertension with controls matched for age, gender, obesity, diabetes mellitus and hyperlipidemia by using the Taiwan National Health Insurance (NHI) database.

Materials and Methods: Data sourced from the “Longitudinal Health Insurance Database” (LHID200) of our country (Taiwan, Republic of China) compiled by the NHI from 1996 to 2010. The LHID200 include medical records for 1,000,000 individuals randomly sampled from all enrollers in NHI. Cases of renal stones were defined by the ICD-9 diagnostic codes as 592. Patients with newly onset of hypertension was defined as ICD-9 diagnostic codes 401 to 405 with hypertension medication. For the study group, we only include the renal patients underwent SWL, patients with diagnosis of renal stone who underwent either percutaneous nephrolithotomy (PCNL; procedure code: 76016B) or ureterorenoscopic lithotripsy (URSL; procedure code: 77026B, 77027B, 77028B) were precluded in our cohort. For control group, we included the patients with renal stones diagnosed but did not receive the SWL, PCNL and URSL. The Kaplan-Meier analysis was applied to estimate the effect of SWL on hypertension free rates.

Results: We included 464 patients with SWL and 1,160 patients with comparison. There were no difference in age, gender, urbanization, monthly income, and co-morbidities between the two groups. There was no difference between the incidence of newly hypertension between SWL and comparison group. The incidence rate of newly hypertension during the follow up period was 30.3 (95% CI: 0.69–1.17) per 1,000 person-years and 30.2 (95% CI: 1.13–1.95) per 1,000 person-years for the SWL and comparison cohort, respectively. Interestingly, the average newly hypertension onset time was faster in the SWL groups than those in the control groups

Conclusion: On the basis of our results, SWL is a safe procedure for the nephrolithiasis patients under the proper management.