Background and Aims: With the development of critical care medicine and the update of the surgical concepts and treatment modalities in recent years, the minimally invasive step-up approaches of different types have gradually become the mainstream methods for the treatment of infected pancreatic necrosis (IPN). However, traditional open pancreatic necrosectomy (OPN) still plays an irreplaceable role. This study was conducted to analyze the new characteristics and clinical value of OPN in treatment of IPN in the era of minimally invasive surgery.  
Methods: A total of 140 consecutive patients with IPN treated in Xiangya Hospital of Central South University from January 2014 to May 2019 were reviewed. Of the patients, 24 cases underwent OPN and 116 cases were treated with purely minimally invasive approach, and the main attention was focused on the clinical characteristics, surgical timing, indications and outcomes of the 24 cases undergoing OPN. In the whole group of IPN patients, the therapeutic principle of delayed surgery was implemented. For those failed to antibiotic treatment, surgical intervention was performed after full encapsulation and liquefaction of the pancreatic necrosis by prolongation of the conservative treatment as maximal as possible at least 3 to 4 weeks after the onset. 
Results: The indications or reasons for OPN in the 24 patients included no route for PCD in one case (4.2%), aggressively performed OPN in 5 cases (20.8%), uncontrollable infection after minimally invasive surgery in 6 cases (25.0%), serious associated complications in 9 cases (37.5%) and uncontrollable infection after open surgery in other hospitals in 3 cases (12.5%). All patients undergoing OPN were complicated with severe retroperitoneal and bloodstream infections, of whom, 79.2% (19/24) were multidrug-resistant infections, 58.3% (14/24) were bloodstream infections, 29.2% (7/24) were peripancreatic fungal infections, and 4.2% (1/24) were fungal bloodstream infection. Klebsiella pneumoniae was the most common microorganism isolated from the peripancreatic necrosis. In patients undergoing OPN compared with patients undergoing purely minimally invasive surgery, the proportion of cases with severe illness was high (87.5% vs. 63.8%), the average length of ICU stay was prolonged (26.9 d vs. 17.7 d), the average length of hospital stay after intervention was shortened (24.1 d vs. 42.9 d), and the mortality rate was increased (45.8% vs. 20.7%), and all the differences had statistical significance (all P<0.05); no significant differences in other general data, the interval between intervention and onset, and the main postoperative complications (massive bleeding, intestinal fistula and pancreatic fistula) were noted (all P>0.05). The main causes for postoperative death in patients undergoing OPN included septic shock in 5 cases (45.5%) and hemorrhagic shock in 6 cases (54.5%). 
Conclusion: OPN still plays an irreplaceable role in the treatment of IPN, and sometimes even the only way to save the life of the patients. In the era of minimally invasive surgery, appropriate selection of indications and timing for OPN has great importance in improving the prognosis of the patients with severe acute pancreatitis.