Introduction: Percutaneous drainage (PCD) is an important initial component of the “step-up” treatment strategy for the management of infected acute necrotic collections consequent to acute necrotizing pancreatitis (ANP). However, PCD alone has a high failure rate and these patients require additional necrosectomy. Delaying necrosectomy can increase morbidity and mortality and therefore, timely intervention is important. Identifying predictors of failure of percutaneous therapy can help in making timely management decisions. In this prospective single-center study, we attempted to identify predictors of failure of PCD in patients with infected ANC. Methods: Twenty-one patients (males:13, mean age:36.05years) (etiology: ethanol-related 47.6% (10/21), GSD related 28.6% (6/21) unknown19% (4/21) PEP 4.8% (1/21)) admitted with infected ANC who were treated with step-up strategy of initial PCD followed by endoscopic or surgical necrosectomy in non-responders were enrolled and studied prospectively. We studied the association between the success of PCD (survival without necrosectomy) & baseline clinical and investigational parameters including etiology, severity scores, C-reactive protein (CRP), computed tomography severity indices (CTSI), and PCD parameters (size of catheter & timing). Results: Nine (42.8%) patients with infected ANC were successfully treated with PCD alone whereas 12 (57.2%) patients either underwent necrosectomy or succumbed to the illness. The frequency of males was significantly higher (83.3% vs 33.33%) in the PCD failure group(p=0.03). The PCD was inserted later in the failure group as compared to the successful group (mean day of insertion of PCD being 20.5 days vs 15.1 days respectively; p=0.023). The mean SIRS score at admission (2.92 vs 2.33; p=0.102) & at 48 hours (3.5 vs 2.89; p=0.12), mean APACHE-II score (7.8 vs 7.0; p=0.508), mean ferritin levels (2916.9 vs 1033.4ng/mL; p= 0.394), and mean CRP levels (249.5 vs 209.6ng/mL; p=0.508.) were higher in the PCD failure group but did not reach statistical significance. The corrected calcium levels were lower(8.3 vs 9.0gm/dL p=0.069) in the PCD failure group. Also, the mean diameter of PCD catheters was more in the success group but the difference was not statistically significant (16.2 vs 14.7F; p=0.277). (Table) Conclusion: Male gender & delayed insertion of PCD seem to be associated with failure of PCD alone in patients with infected necrotic collections. Table 1. - Comparison of parameters between PCD Success and PCD Failure Group Parameter PCD Success group n=9 PCD failure group n=12 P Value Age 37.3±7.5yrs 36.8±13.4yrs 0.65 Males 3(33.33%) 10(83.33%) 0.03 BMI 24.5±4.3Kg/m2 22.4±3.8kg/m2 0.22 TLC 13871±6616.1/mm3 15014.2±7818.6/mm3 0.862 Platelet Count 321666.7±187813.7/mm3 304350.0±155671.1/mm 0.972 Ferritin Level 1033.4±628.2ng/mL 2916.9±2961.8ng/mL 0.394 Corrected Calcium 9.0±0.3gm/dL 8.3±1.2gm/dL 0.069 qCRP Levels 209.6±95.9mg/L 249±107.1mg/L 0.508 SIRS At admission 2.33±0.5 2.92±1.0 0.10 At 48hrs 2.89±0.93 3.50±0.52 0.12 APACHE-II 7.0±3.0 7.8±8.0 0.51 MMS 1.4±0.9 1.7±1.8 0.70 BISAP 2.1±0.3 2.3±0.8 0.55 Size of largest collection on CT 10.3±4.34cm 11.15±3.42cm 0.81 CTSI Score 7.3±2.5 7.8±2.5 0.65 mCTSI Score 8.7±1.7 9.2±1.3 0.60 Day of PCD placement 15.1±4.9 20.5±3.9 0.02 Size of largest PCD in the French scale 16.2±3.1 14.7±4.2 0.28