Relevance Patients with pancreatic necrosis revealed a high incidence of infection and extention of non-delimiting suppurative destructive process onto parapancreatic fat. These complicated forms of the disease are characterized by severity and high postoperative mortality. Purpose of the study Experimental basis and clinical testing of an original method aimed to form a fibrin delimiting barrier with pancreatic necrosis. Materials and methods For a series of test-tube experiments the following was used : stabilized native plasma, a blood product — plasma cryoprecipitate, standardized preparations: thrombin and thromboplastin, calcium gluconate, aminocaproic acid. As a lysis factor the following was used: native pancreatic juice and officinal drug – himopsin. Experiments to create a fibrin delimiting barrier were being performed on 6 mongrel dogs weighing 15-25 kg. Simulation of focal pancreatic necrosis was performed with intrapleural anesthesia through laparotomic access. Next, parapancreatic fiber in the area of necrosis was infiltrated with a mixture of cryoprecipitate, aminocaproic acid and calcium gluconate (original technology) through puncture. In the chronic experiment, intraoperative biopsies of the gland and the zones of fibrin block were collected with the following histological examination. The results of surgical treatment of 581 patients with necrotizing pancreatitis for the period since 2007-2011 is being researched now. Patients with infected pancreatic necrosis account for 54,8%, out of which – the ones with retroperitoneal phlegmon - 34.4% respectively. Postoperative mortality with phlegmons of retroperitoneal fat was equal to 50,2%. Throughout 2012 in the clinic the patients with necrotizing pancreatitis were being treated by an method of creating a delimiting fibrin barrier — with 19 patients. Four patients had a sterile pancreatic necrosis and were operated endoscopically. In 15 cases - patients having infected necrotizing pancreatitis complicated by the phlegmona of retroperitoneal fat we resorted to open laparotomy. Results and their discussion In the postoperative period data from laboratory studies and special investigation techniques (ultrasound, MSCT) for 13 patients demonstrated regression of phlegmona and the formation of the demarcation zone from the tissue in the form of an inflammatory infiltrate, transforming after 3-4 weeks of observation into a typical area of rumen delimitation (walled-off pancreatic necrosis). Postoperative mortality in this group was 11,8% whereas, in the basic group of patients — 50,2%. Conclusion Laboratory and experimental methods developments have proved the efffectiveness of the use of blood product (plasma cryoprecipitate donors) as implanting artificial source of fibrinogen / fibrin to form fibrin parapancreatic barrier. In the clinic this method was used in the surgical treatment of 19 patients with necrotizing pancreatitis. The use of original technology is more shows in the group of patients suffering from the most severe complications pancreatic necrosis and phlegmon of retroperitoneal fat (15 cases), Postoperative mortality rate was 11,8%.