Risk Stratification in Kidney Stone Disease: Environmental Drivers and Perioperative Infectious Outcomes

Abstract

Kidney stone disease represents a growing global health burden, with rising incidence observed across diverse populations and geographic regions (1). Increasing attention has focused on identifying determinants of risk that operate at multiple stages of the disease process, from environmental exposures that influence stone formation to clinical factors that shape treatment outcomes and complications (2–4). This thesis explores nephrolithiasis through a multilevel lens, examining both population-level drivers of disease presentation and perioperative determinants of infectious severity. The first paper examines the relationship between ambient temperature and kidney stone risk through a systematic review of observational studies that assess temperature exposure and healthcare utilization for nephrolithiasis. Although seasonal variation in renal colic has been widely described, a comprehensive synthesis of the available evidence has been lacking. By consolidating findings across diverse climates and populations, this review helps shift the framework from traditional geographic constructs such as the “stone belt” toward a more dynamic understanding centered on heat exposure as a modifiable risk factor. The second paper examines the risk of infection after percutaneous nephrolithotomy, a key surgical treatment for complex stone disease. Specifically, it assesses whether bacterial species found in preoperative urine cultures are associated to an early inflammatory response, measured by Quick Sepsis-related Organ Failure Assessment (qSOFA) positivity, and to significant clinical outcomes like intensive care unit admission. This study goes beyond simple culture positivity to explore how different organisms influence postoperative risk.