OBESITY: A DELICATE ISSUE CHOOSING THE ESWL TREATMENT FOR PATIENTS WITH KIDNEY AND URETERAL STONES?

Urolithiasis and obesity are now public health problems with an increased incidence worldwide. Management of urolithiasis in patients with morbid obesity is usually associated with higher morbidity and mortality compared to non-obese patients. ESWL is a nonsurgical procedure for the treatment of lithiasis. In obese patients the ESWL efficacy is influenced by the skin-to-stone distance or poorer detection of the calculus because of the fatty tissue.

To highlight the overweight or obese lithiasic patient profile that could be best treated by ESWL.

We evaluated ESWL results in 1393 patients with kidney or ureteral stones between 5 and 20 mm. They were divided into 4 groups according to the BMI: Group A-overweight (BMI=25-30 kg/m²); Group B-grade I obesity (BMI=30-35 kg/m²); Group C-grade II obesity (BMI=35-40 kg/m²) and a control group of normal weight (BMI=18-25 kg/m²).

Patients with a higher BMI required a greater number of ESWL sessions. A statistically significant greater number of patients with a waist circumference of >102 cm required more than 2 SWL sessions (p=0.007). Location of the stones in the pelvic ureter had the highest rate of success for obese patients (p=0.00001). The ESWL success rate in overweight and obese patients can be negatively influenced by BMI, abdominal circumference over 102 cm, and hardness of calculi reflected in the radiopacity on KUB.

In patients with grade II obesity, pyelocaliceal calculus and increased hardness, other urological alternatives to lithiasis should be considered from the beginning.