Uncovering Silent Fungal Infections complicating Obstructive Uropathy due to Renal Papillary Necrosis in Diabetic patients – A step towards preventing Recurrent Obstructive Uropathy.

Introduction and Objectives: Renal papillary necrosis is one of the common causes of obstructive uropa-thy in diabetic patients. During removal of necrosed renal papilla, many patients were observed to have fluffy necrotic material in the ureter, and renal pelvis, and a few among them present again with recurrent episodes of obstructive uropathy and sepsis following DJ stent removal. Our study aimed to identify thesignificance of this fluffy necrotic material and its evaluation by histopathological examination (HPE). Materials and Methods: This is a prospective observational study done in our institute by compiling data of 56 patients admitted with obstructive uropathy secondary to renal papillary necrosis who underwent a protocol-based treatment from 2016 to 2019. All these patients underwent initial DJ stenting followed by check flexible ureteroscopy or nephroscopy after 6 weeks. The white, necrotic fluffy material collected during initial DJ stenting or with subsequent flexible ureteronephroscopy was sent for HPE. All these patients were followed up for 1-3 years. Results: Out of 56 patients, 15 patients had fluffy necrotic material in the bladder on initial cystoscopy, of which 1 patient was diagnosed with aspergillosis and 1 patient with candida infection on HPE. During check flexible ureteroscopy (FU), 19 patients had minimal burden of fluffy necrotic material in renal pelvis, of which one patient was diagnosed with aspergillosis, one with candida (same patient diagnosed on cystoscopy), and one patient with both aspergillus and candida colonies on HPE. 5 patients had the significant burden of fluffy necrotic material in the renal pelvis, requiring removal via percutaneous nephroscopic access. Among these 5 patients, 2 were diagnosed with aspergillosis and 1 with candida infection on HPE. A total of 32 patients had single papilla, and 24 had multiple papillae in the pelvicalyceal system. 5 out of 7 patients with positive fungal pathology had negative fungal cultures. Compared to our historical data of 4% mortality and 22% recurrent obstructive uropathy in the 3 years preceding the adoption of this protocol, with the present protocol, no patient developed recurrent pyelonephritis during follow-up of 1–3 years after DJ stent removal following complete evacuation of necrotic material and appropriate antifungal treatment. Conclusion: This study highlights the need for check ureterorenoscopy and removal of all necrotic papillae and debris to establish a microbiological and histopathological diagnosis along with proper antifungal treatment to prevent episodes of recurrent pyelonephritis and obstructive uropathy.