Purpose: This study aims to identify determinants of pericardial effusion (PCE) in patients with renal cancer and predictors of in-hospital mortality in patients with renal cancer and PCE. Materials and Methods: We conducted a retrospective cohort study using National Inpatient Sample of patients with primary malignant renal cancer data from 2016–2020. A total of 85,288 patients were included in the analysis, of which 763 (0.90%) presented with PCE. The main outcomes of interest were the presence of PCE and the in-hospital mortality rate in patients with renal cancer and PCE. Results: The majority of our cohort are aged ≥40 years (96.79%) and males (64.57%). In the bivariate analysis, patients <40 years had higher odds of PCE (adjusted odds ratio [aOR], 1.82; 95% confidence interval [CI], 1.23–2.63). Non-Hispanic Black (aOR, 1.59; 95% CI ,1.30–1.94) and Hispanic patients were associated with an increased odd of PCE odds ratio. Higher Elixhauser comorbidity index (≥4: aOR, 2.27; 95% CI, 1.66–3.08), hypoproteinemia (aOR, 1.49; 95% CI, 1.22–1.81), heart failure (aOR, 2.15; 95% CI 1.83–2.55), metastatic disease (aOR, 1.36; 95% CI, 1.15–1.62), and severe disease presentation (aOR, 6.35; 95% CI, 4.82–8.36) were also significant predictors of PCE. Private insurance was associated with higher PCE odds (aOR, 1.43; 95% CI, 1.20–1.70). Among PCE patients, the in-hospital mortality rate was 13.37%. Self-pay insurance status (aOR, 3.82; 95% CI, 1.05–13.95), metastatic disease (aOR, 1.76; 95% CI, 1.07–2.96), and severe disease presentation (aOR, 3.46; 95% CI, 1.05–8.58) significantly predicted increased mortality. Conclusion This study identifies crucial demographic, clinical, and healthcare system factors associated with PCE and in-hospital mortality in renal cancer patients. These findings highlight the need for increased vigilance and tailored surveillance for vulnerable groups and those with higher comorbidity burdens.

The current standard of care for patients with end-stage renal disease (ERSD) is a kidney transplant or dialysis when a donor organ isnot available. The growing gap between patients who require a kidney transplant and the availability of donor organs as well as thenegative effects of long-term dialysis, such as infection, limited mobility, and risk of cancer development, drive the impetus to developalternative renal replacement technology. The goal of this review is to assess the potential of two of the most recent innovations inkidney transplant technology—the implantable bioartificial kidney (BAK) and kidney regeneration technology—in addressing the aforementionedproblems related to kidney replacement for patients with ERSD. Both innovations are fully implantable, autologous, personalizedwith patient cells, and can replace all aspects of kidney function. Not only do these new innovations have the potential toimprove the possibility of transplantation for more patients, they also have potential to improve the outcome of transplantation or dialysis-related renal cancer diagnosis. A major limitation of the current technology is that both implantable BAK and kidney regenerationtechnology are still in preclinical stages, and thus their potential effects cannot be comprehensively generalized to human patients.