[Biochemical evaluation of renal lesions produced by electrohydraulic shock waves]. / Evaluation biochimique des lésions rénales produites par les ondes de choc électrohydrauliques.

The authors present a biochemical study of the renal lesions produced during extracorporeal electrohydraulic shock wave lithotripsy (ESWL). The sequential variation (before and after ESWL) of various biochemical parameters of the blood and 24-hour urine was analysed in 50 patients. A significant increase of urinary N-Acetyl-Glucosaminidase (NAG), urinary NAG/urinary creatinine quotient, proteinuria, serum creatinine and potassium was detected during the 24 hours following ESWL. A significant fall in creatinine clearance, urinary osmolarity and uric acid clearance was also detected. A positive correlation was observed between these alterations, the number of shocks and the kilovoltage used. On the 7th and 15th days, no significant difference was observed compared to the baseline values before ESWL. This can be explained by the fact that the lesions caused by shock waves are already in the repair phase.

[Influence of the lithiasic surface on the strategy: complications and results in the treatment of kidney calculi]. / Influencia de la superficie litiásica sobre la estrategia: complicaciones y resultados en el tratamiento de los cálculos renales.

Stone mass is a fundamental parameter that determines the approach to reno-ureteral lithiasis. Reference to stone size based on a single diameter gives us an imprecise idea about stone volume. For this reason, we recommend using the term "stone surface" to express stone mass. Stone surface is obtained by multiplying the longitudinal by the transversal diameter expressed in millimeters, using the plain film for radiopaque and the urogram for radiolucent calculi. Stone surface is a parameter which can be determined easily and is a more reliable way to determine stone volume. In 1,500 renal units with reno-ureteral calculi treated by ESWL and percutaneous techniques, we corroborated that the surface of calculus is directly associated with the number of shock waves required for fragmentation. Thus, as stone surface increases, more shock waves will be required to achieve fragmentation. The surface area of the calculus correlates very significatively with urinary tract obstruction post-ESWL. As the surface of the fragmented stone increases, there exists a higher incidence of obstruction. Obstruction is more severe and more ancillary maneuvers to remove obstruction are warranted. The incidence of renal colic post-ESWL is significantly influenced by the surface area of the calculus. There is a higher incidence of reno-ureteral colic following fragmentation of large stones. Furthermore, stone surface significantly determines the rate at which fragments are passed, and the persistence of stone sand at 3 months. Thus, as stone surface increases, there will be more fragments that can and cannot be spontaneously passed following treatment with ESWL. Finally, it must be emphasized that stone surface is a fundamental parameter that determines the combination of ancillary techniques prior to ESWL and significantly influences the efficacy of the approach in the treatment of reno-ureteral calculi.