Leong WS et al, 2013: Does Simultaneous Inversion During Extracorporeal Shock Wave Lithotripsy Improve Stone Clearance: A Long-term, Prospective, Single-blind, Randomized Controlled Study
Leong WS, Liong ML, Liong YV, Wu DB, Lee SW
Department of Urology, Lam Wah Ee Hospital, Penang, Malaysia
OBJECTIVE: To determine the efficacy of a combination of simultaneous shock wave lithotripsy (SWL), hydration with controlled inversion therapy compared with SWL with hydration alone in patients with lower pole calyx stones.
METHODS: Patients with lower pole stones (4-20 mm) were randomized to SWL or SWL with simultaneous inversion therapy (30° head down Trendelenburg position). Standardized shock waves were given to all patients stratified according to stone size. Subsequent standardized shock waves were given to patients with stone fragments determined by plain abdominal radiography and ultrasound by 2 radiologists blinded to treatment at day 1, weeks 2, 4, 12, 24, and at 1 year. The primary endpoint is stone-free rate (SFR) at week 12.
RESULTS: A total of 140 patients were recruited into the study. Patients were comparable with respect to age, sex, race, and stone parameters at baseline. The overall SFR at week 12 was 72% (n = 49 of 68) in patients with SWL and 76% (n = 54 of 71) in SWL with simultaneous inversion at the end of study (P = .591). There was a trend for SFR to improve over time with >80% of patients being stone-free after 1 year in both groups. No significant adverse effects were noted in both groups of patients.
CONCLUSION: Although not statistically significant, SWL with simultaneous inversion is a valuable adjunct in assisting the passage of lower pole renal stones with a SFR of 76%. In clinical practice, this also translates to a 1.28 times improvement in SFR with no or minimal additional costs.
Urology. 2013 Sep 14. pii: S0090-4295(13)00989-8. doi: 10.1016/j.urology.2013.08.004
PMID:24044912 [PubMed - as supplied by publisher]
A well conducted study. My conclusion is: Inversion does not improve the SWL results.
The retreatment rate is high:
Concerning the technique of retreatment the authors only state: "If the patient had significant residual lithiasis, SWL was repeated, with 1000 SW delivered." They unfortunately do not indicate if the retreatment was also done under inversion and when the retreatment was done. To find out if some of the numerous retreatments were unnecessary it would need another prospective study.