Risk of Scrotal Hydroceles After Nephrectomy For Kidney Cancer

This population-based study will use provincial health administrative data to examine the risk of hospital admission for hydrocelectomy among males who underwent nephrectomy for kidney cancer, compared with males from the general population with similar baseline health characteristics, who did not undergo nephrectomy. We will use health administrative data from Ontario, Canada, to identify males who underwent nephrectomy for kidney cancer between 2002 and 2024. Four surgical cohorts will be constructed based on procedure type and surgical approach: laparoscopic total nephrectomy, open total nephrectomy, laparoscopic partial nephrectomy, and open partial nephrectomy. A propensity score will be calculated based on sociodemographic characteristics, comorbidities, and health care utilization. For each surgical cohort, patients will be matched to non-nephrectomy male controls (1:4) based on propensity score, age, index date, and modified Charlson Score (excluding cancer). The primary analysis will compare patients undergoing laparoscopic total nephrectomy and laparoscopic partial nephrectomy with matched non-nephrectomy controls from the general population. The primary outcome is hospital admission for hydrocelectomy. Secondary outcomes include diagnosis of hydrocele with receipt of a scrotal ultrasound, and receipt of a scrotal ultrasound. Additional analyses will compare surgical approaches.

\*Laparoscopic total nephrectomy\* Inclusion criteria Male individuals who underwent laparoscopic complete/total nephrectomy between April 1, 2002, and March 31, 2024, with a most responsible diagnosis of malignant kidney, renal pelvis, or ureter cancer at the time of nephrectomy. The index date is defined as the date of the first laparoscopic total nephrectomy during the study period. Exclusion criteria * Individuals with data record errors (e.g., missing or invalid age, sex, or date of birth), who are less than 0 years of age or greater than 105 years of age, with a death record on or before their cohort entry, or have a date of last contact \