Introduction: Upper renal tract fungal infections, though rare, pose a significant clinical challenge due to their potential for substantial morbidity. The global rise in antifungal resistance underscores the need for effective treatment strategies. Among antifungal agents, fluconazole, voriconazole, amphotericin, and flucytosine have demonstrated sufficient urinary penetration to be considered viable options for urinary tract infections.

We present two cases of resistant upper renal tract fungal infections that necessitated intrarenal antifungal irrigation. A comparison with existing literature was undertaken to evaluate the effectiveness and practicality of this therapeutic approach.

The two patients differed markedly in baseline demographics and fungal species isolated, although both pathogens belonged to the same genus. The antifungal agent used was consistent across cases, but the route of administration varied. Adjunctive systemic antifungal therapies also differed. Literature review revealed similar trends, with intrarenal amphotericin being the most commonly used agent, supported by diverse systemic regimens.

Intrarenal antifungal irrigation appears to be a promising and practical adjunct in the management of resistant fungal infections of the upper renal tract, particularly in immunocompromised individuals. Initiation of intravenous antifungal therapy is recommended prior to considering irrigation. Further multi-centre randomised controlled trials are warranted to establish the efficacy and safety of this modality.