Renal mass imaging modalities: does body mass index (BMI) matter?

PURPOSE: Accurate measurement of renal mass size is crucial in the management of renal cancer. With the burdensome cost of imaging yet its need for management, a better understanding of the variability among patients when determining mass size remains of urgent importance. Current guidelines on optimal imaging are limited, especially with respect to body mass index (BMI). The aim of this study is to discern which modalities accurately measure renal mass size and whether BMI influences such accuracy. METHODS: A multi-institutional chart review was performed for adult patients undergoing partial or radical nephrectomy between 2018 and 2021, with 236 patients ultimately included. Patients were categorized by BMI (BMI 1: 18.5-24.9, BMI 2: 25-29.9, BMI 3: 30-34.9, and BMI 4: ≥ 35). The greatest mass lengths were compared between the pathology report and the following: computerized tomography (CT), renal ultrasound, and magnetic resonance imaging (MRI). RESULTS: The difference between greatest length on CT with contrast and MRI were significantly different when compared to pathologic measurement. BMI groups 3 and 4 were found to have a significant difference in size estimates compared to BMI 2 for CT with contrast. No difference was found between size estimates by BMI group for any other imaging modality. CONCLUSION: CT with contrast becomes less accurate at estimating mass size for patients with BMI > 30. While contrast-enhanced CT remains a vital imaging modality for tissue enhancement in the context of unknown renal masses, caution must be used for mass size estimation in the obese population.

Vesicoureteral reflux severity is not associated with unplanned urinary catheterization or length of hospital stay after ureteroneocystostomy.

INTRODUCTION: Vesicoureteral reflux (VUR) is a common urologic condition affecting approximately 1% of all children. Surgical success often depends on the grade of VUR, as patients with grades 4 or 5 have been have a greater risk for postoperative complications. Unplanned urinary catheter placement (UCP) postoperatively and prolonged length of hospital stay (LOS) are indicative of unexpected complications. The association between VUR severity and such metrics remain unclear. OBJECTIVE: The study's objective is to determine if the severity of VUR is associated with higher rates of UCP or prolonged LOS after ureteroneocystostomy (UNC). STUDY DESIGN: The 2020 National Surgical Quality Improvement Program Pediatric database was analyzed for patients with VUR. A total of 1742 patients were initially evaluated with 1373 meeting exclusion criteria. The patients were divided into 3 groups of varying voiding cystourethrogram (VCUG) or radionuclide cystogram (RNC) severity: VCUG Grade 1 or RNC Grade 1 (Group A), VCUG Grade 2 or 3 or RNC Grade 2 (Group B), and VCUG Grade 4 or 5 or RNC Grade 3 (Group C). Basic statistical analysis was performed, and logistic regression was performed with both UCP and LOS as dependent variables. RESULTS: Among the 1373 patients, 2.9% were included in Group A, 32.5% were in Group B, and 64.6% were in Group C. Significant differences were found among the groups for mean age, gender, inpatient status, rate of congenital malformation, ureteral stents, and ASA classification. Regarding surgical treatment, differences were also found comparing mean operative time, LOS, laterality and type of procedure, urine culture results, rates of UTI, surgical site infections, postoperative returns to the emergency department, and unplanned procedures and catheterization. Multivariate analysis demonstrated no significant association between the rate of UCP and VUR severity, while postoperative UTI and unplanned procedure were both independent factors associated with UCP postoperatively. Additionally, postoperative UTI, ASA classification, mean operation time, ureteral stent placement, unplanned procedure, and UCP were independent factors found to contribute to LOS. CONCLUSION: Greater VUR severity does not appear to increase the need for catheterization or prolong hospital stay, while the development of a UTI postoperatively or having an additional unplanned procedure are associated with an increased likelihood of both. The postoperative course after UNC also appears to be influenced more so by other factors such as the operative approach and whether complications arise.

Spontaneous Rupture of the Renal Pelvis Due to Extrinsic Obstruction by Metastatic Retroperitoneal Lymphadenopathy.

Spontaneous rupture of the renal pelvis due to metastatic disease is a rare complication. Renal pelvis rupture often goes undiagnosed in cases of non-traumatic origin due to its vague abdominal and flank symptoms. We present a case of an 81-year-old male with primary non-small cell lung cancer who had renal pelvis rupture due to extrinsic compression of the ureter by retroperitoneal lymphadenopathy secondary to metastatic disease.

Emphysematous Pyelonephritis From a Perinephric Hematoma Complicated by Fournier's Gangrene: A Case Report.

Fournier's gangrene and emphysematous pyelonephritis are rare necrotizing infections of the genitourinary system. Many cases of this rapidly progressive infection occur from abscesses and urinary tract infections; however, Fournier's gangrene secondary to emphysematous pyelonephritis is seldom discussed in the literature. Emphysematous pyelonephritis is defined as a gas-forming, necrotizing infection of the renal parenchyma or its surrounding tissue. Emphysematous pyelonephritis has been observed in high-risk individuals, including those with poor glycemic control and urinary tract obstruction. We present a 61-year-old male with emphysematous pyelonephritis arising from a perinephric hematoma with tracking of the infection to the scrotum, resulting in Fournier's gangrene. The perinephric hematoma most likely developed from increased intrarenal hydrostatic pressure during nephroureteral stent placement. Broad-spectrum antibiotic therapy and surgical debridement of the retroperitoneum, groin, and scrotum were performed ultimately requiring left orchiectomy. We conclude that an existing hematoma can precipitate emphysematous pyelonephritis with tracking from the retroperitoneum to scrotum, causing Fournier's gangrene. High-risk patients with perinephric hematomas can be susceptible to this pathologic transformation.