Manzoor H. et al., 2023: Renal Extracorporeal Lithotripsy
Manzoor H, Saikali SW.
Mayo Hospital Lahore
Clemenceau Medical Center
Abstract
Renal stones pose a significant burden on the health care system. The prevalence of renal stones has increased from 3.8% in 1970 to 8.8% in 2010 in the United States, with annual healthcare costs of USD 3.8 billion. It is estimated that more than half a million people a year visit the emergency room for kidney stone problems. The most common presenting symptoms include hematuria, pain in the flank, groin, or abdomen.
There are many treatment modalities available for managing renal stones. They range from completely non-invasive outpatient procedures to invasive procedures requiring hospital admission and increased risks of complications. Extracorporeal shockwave lithotripsy (ESWL) is a truly non-invasive procedure as opposed to other surgical treatments used, such as retrograde intrarenal surgery (RIRS) and percutaneous nephrolithotomy (PCNL). The efficacy of ESWL lies in its ability to pulverize calculi in vivo into smaller segments, which are them expelled spontaneously by the boy. Shockwaves are generated and are then focused on a point within the body.
The shockwaves propagate through the body with minimal dissipation of energy (and therefore damage) due to minimal difference in density of the soft tissues. At the stone fluid interface, a relatively significant difference in density, combined with a large concentration of multiple shockwaves in a small area, produces a significant dissipation of energy. Through the different mechanisms, this energy can overcome the tensile strength of the stone resulting in fragmentation. Repetition of this process leads to the pulverization of the stone into small fragments that the body then can pass painlessly and spontaneously.
2023 Jul 25. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan–.PMID: 32809722
Comments 1
This article is an educational text obviously intended for health professionals and/or students without knowledge of modern principles of stone removal. Parts of the text also might provide valuable information for patients on what SWL is and how the technique can be used.
It is of note that the authors mention the possibility to use SWL also for stones in the kidney measuring >2 cm if the patient is unfit for general anesthesia. Although repeated treatment sessions will be necessary in these cases, avoiding general anesthesia might be an advantage for quite a large group of patients.
One important statement supported by the reviewer is that: “The provider must be present during the procedure to ensure an optimal SFR”. This is a routine not strictly adhered to in many centers.
Application of adjunctive treatment is emphasized, and that statement comprises several options that can increase the success of SWL while the non-invasive character of SWL is maintained.
Hans-Göran Tiselius