Totally Ultrasound-Guided Percutaneous Nephrolithotomy: How to Improve Success in Patients with Obesity
Year: 2025
Type: article
Study design: Observational Study
Abstract: Introduction: Percutaneous nephrolithotomy (PCNL) is the treatment of choice for kidney stones greater than 2 cm. 1 This procedure in patients with obesity is challenging because obesity is a risk factor for complex access and requires more experience to achieve a successful puncture. 2 – 5 In this video, we demonstrate our technique for totally ultrasound-guided PCNL with two-step tract dilation, our experience, and provide guidance on improving success rates in patients with obesity. Materials and Methods: Surgical technique: With the patient in the supine position, we mobilized fatty tissue; after a proper ultrasound configuration, percutaneous access with a longitudinal freehand technique was obtained. Dilation with a two-step technique 6 Step 1: Creation of a minitract 14Fr to perform antegrade nephroscopy to check the renal cavities and measure the length of the tract; a pair of guides are placed in the ureter, one for definitive dilatation and the other as a safety guide. Step 2: Definitive tract 26Fr, insert the Amplatz dilator 1 cm in addition to the previously measured length of the tract to avoid a short dilation and advance the sheath. Pneumatic fragmentation is performed. Finally, a JJ stent was placed. Case series: Retrospective review of 54 patients treated with totally ultrasound-guided PCNL from July 2021 to June 2023, and we divided the cases according to their BMI: Group 1 included 27 patients with a BMI ≥30 kg/m2 and Group 2 included 27 patients with a normal BMI. Results: Mean age was 46.9 years. The BMI was 36.3 kg/m 2 (±5.9) and 21.7 kg/m 2 (±2.4) ( p = <0.001), respectively. In Group 1, 57% of our patients had Guy’s 3, and 15% had Guy’s 4; 72% of the cases had complex stones. The stone burden was 10,976.43 mm 3 (±11,287.6) and 7,543.0 mm 3 (±10,203.6) ( p = 0.056), with a mean of 12 cm and 8 cm of tract length ( p < 0.001), respectively ( Table 1 ). In the obesity group, the short dilation was more frequent, 63% vs. 26% ( p = 0.013). The stone-free rate was 77.8% in both groups ( p = 1.000), and we found that the stone burden had a more significant effect on the stone-free rate than the BMI ( Fig. 1 ). In Group 1, the complications were 3 (11.1%); 2 patients had fever (Clavien I), and 1 needed a blood transfusion due to anemia (Clavien II), whereas in Group 2 there were 6 (22.2%); 4 had fever (Clavien I), and 2 had urosepsis (Clavien IV) ( p = 0.019). FIG. 1. Relation between stone volume (mm 3 ) and body mass index (Kg/m 2 ) in stone-free status: In blue , the patients with stone-free status, and in red , the patients with residual stone. Table 1. Preoperative and Postoperative Descriptive Data by Group according to BMI Total Group 1: BMI (≥30 kg/m 2 ) Group 2: BMI (≤25 kg/m 2 ) p Value Number of patients 54 27 27 Age, years 48.4 (±11.9) 49.9 (±11.1) 46.9 (±12.7) 0.36 Gender: n (%) Male
Source: Videourology
Institution: Mexican Social Security Institute
Language: English
Subfield: Pulmonary and Respiratory Medicine
Field: Medicine
Domain: Health Sciences
Open Access status: bronze
OpenAlex ID: W4406307854