Pediatric urolithiasis--does body mass index influence stone presentation and treatment?

PURPOSE: Pediatric obesity is a major public health concern in the United States. We investigated the association of body mass index with presentation and outcome in children with urolithiasis. MATERIALS AND METHODS: We identified all patients 2 to 18 years old at our institution with a radiographically confirmed first renal or ureteral stone between January 2003 and June 2008. Data abstracted included demographics, stone characteristics, treatment and metabolic evaluation. Patients were stratified into 3 body mass index categories, including lower (10th percentile or less for age), normal (10th to 85th percentile) and upper (85th percentile or greater) percentile body weight. RESULTS: Of the children 62 boys (55.4%) and 50 girls (44.6%) were evaluable. Mean age at diagnosis was 11.8 years. Body mass index stratification showed lower percentile body weight in 11 patients (9.8%), normal percentile body weight in 55 (49.1%) and upper percentile body weight in 46 (41.1%). Mean stone diameter was 5.0 mm. Of the stones 31 (27.7%) were in the kidney or ureteropelvic junction and 81 (72.3%) were in the ureter. Surgery was done in 87 patients (78.9%) and stone clearance was accomplished by 1 (69.0%) or 2 (31.0%) procedures in all. Lower percentile body weight patients presented earlier than normal and upper percentile body weight patients (9.0 vs 12.2 and 12.0 years, respectively, p = 0.04). Neither stone size nor the number of procedures required for stone clearance differed significantly by body mass index. CONCLUSIONS: Upper percentile body weight was not associated with earlier stone development, larger stones or the need for multiple surgical procedures. In lower percentile body weight patients symptomatic renal stones developed significantly earlier than in normal or upper percentile body weight patients. Stone size and the surgical intervention rate were similar regardless of body mass index. Further research may identify potential factors predisposing children with lower percentile body weight to early stone development.

Single center comparison of laparoscopic cryoablation and CT-guided percutaneous cryoablation for renal tumors.

BACKGROUND AND PURPOSE: Cryoablation has demonstrated therapeutic effectiveness for selected renal tumors. We compared our perioperative and short-term outcomes of laparoscopic (LAP) v percutaneous (PERC) renal cryoablation. PATIENTS AND METHODS: Thirty-four patients (18 men/16 women) underwent a LAP and 26 patients (19 men/7 women) underwent a PERC procedure between September1998 and January 2007. LAP cryoablation was performed transperitoneally with ultrasonographic monitoring. PERC cryoablation was performed with CT guidance. Follow-up imaging was obtained at regular intervals. RESULTS: Mean follow-up was 25 months. Average age (years) was 67.0 for the LAP and 69.7 for the PERC procedure (P = 0.307). Mean body mass index (kg/m(2)) was 29.8 for those undergoing LAP and 28.7 for those undergoing PERC procedures (P = 0.543). Mean tumor size (cm) was 2.9 for LAP patients and 3.1 for PERC patients (P = 0.432). Anterior tumors comprised 61.7% of LAP and 15.4% of PERC procedures (P < 0.001). Posterior tumors comprised 32.4% of LAP and 65.4% of PERC procedures (P = 0.01). Mean procedure time (minutes) was 165.7 for LAP and 106.6 for PERC procedures (P < 0.001). Hospital stay (days) was 2.6 for those undergoing LAP and 1.8 for those undergoing PERC procedures (P < 0.001). Both LAP patients (82.4%) and PERC patients (19.2%) needed postoperative narcotics (P < 0.001). Atelectasis developed in 70.6% of LAP patients and 34.6% of PERC patients (P = 0.005). Residual enhancement was seen in 11.5% of PERC patients and 2.9% of LAP patients (P = 0.192). Complications developed in 14.7% of LAP patients and 26.9% of PERC patients (P = 0.248). 1-year, 2-year, and 3-year disease-specific survival for the two groups was 100%. Tumor size > 4 cm and endophytic location were significantly associated with residual enhancement. CONCLUSIONS: LAP and PERC renal cryoablation have similar short-term outcomes. Significantly more anterior tumors were approached laparoscopically and significantly more posterior tumors were approached percutaneously. The PERC approach may offer advantages regarding hospital stay, narcotic need, and development of atelectasis. Longer-term data are needed to establish success of this approach.