Tuncer M. et al., 2021: What is the optimal frequency in shock wave lithotripsy for pediatric renal stones? A prospective randomized study
Tuncer M, Kafkaslı A, Can U, Çoşkun A, Eryıldırım B, Sarica K.
Dr. Lutfi Kirdar Training and Research Hospital Urology Clinic, Cevizli mevkii, Cevizli mah. Şemsi Denizer cad. D 100, Kartal, 34890, Istanbul, Turkey.
2Dr. Lutfi Kirdar Training and Research Hospital Urology Clinic, Cevizli mevkii, Cevizli mah. Şemsi Denizer cad. D 100, Kartal, 34890, Istanbul, Turkey.
3Department of Urology, Biruni University School of Medicine, Istanbul, Turkey.
The aim of the study is to compare the effects of varying frequency rates (60, 90, and 120 SWs/min) on the stone free rate and complication rates of pediatric SWL. 75 children with renal stones were divided into 3 groups depending on the SW frequency applied. Group 1. low (60 SWs/min), Group 2. intermediate (90 SWs/min) and Group 3. high (120 SWs/min) frequency. Patient demographics (age, gender, BMI), stone (location, size, laterality), and SWL (total number of sessions, shock waves, anesthesia time) related parameters were documented. Postoperative success, complication rates, and the need for additional interventions were comparatively evaluated. There was no significant difference regarding the patient demographics, stone characteristics, SWL parameters, postoperative complication rates, need for additional interventions as well as efficacy quotient between all (p > 0.05). The stone free rates were significantly lower in cases with high frequency, whereas there was no statistically significant difference between the intermediate and low frequency groups (p > 0.05). Although not statistically significant; low frequency application may be more advantageous than intermediate as lower number of high energy shock waves required which may cause less tissue damage. On the other hand, despite lack of a statistically significant difference, relatively longer anesthesia time may constitute a disadvantage for lower frequency. We believe that considering the growing nature of the child kidney application of low frequency (60 SWs/min) will be advantageous. However, we believe that further studies with larger series of cases are needed to make a clear-cut differentiation between low and intermediate SW applications.
Urolithiasis. 2021 Mar 11. doi: 10.1007/s00240-021-01246-6. Online ahead of print. PMID: 33704540
Nothing new what is not yet known about this topic. The paper is nevertheless special as it is a prospective randomized study. Some details are questionable.
The treatments were done under sedoanalgesia. “SWL treatment session
was ended when complete fragmentation was noted on USG imaging and when the child became intolerable due to the distressing pain not allowing to stay still.”
I think it is difficult to determine complete fragmentation with ultrasound. It is unclear in how many cases the treatment was prematurely terminated because of pain. There are no data on analgesic needs in the three groups.
Difficult to understand why percutaneous stone removal was finally deemed necessary in 4 of the 25 Group 3 patients. Stone density was not determined before ESWL. “Low dose noncontrast spiral tomography was performed in cases with suspicion of obstruction if needed” Why would one need a CT to find out about obstruction?
Due to the small numbers the efficiency quotients (EQ) of the groups: 1= 41%, 2= 36 %, 3= 17% were not significantly different (5 = 0.143).