ABSTRACT
Objective: To explore the clinical characteristics of various types of infected pancreatic necrosis(IPN) and the prognosis of different treatment methods in the imaging classification of IPN proposed. Methods: The clinical data of 126 patients with IPN admitted to the Department of Pancreatic and Biliary Surgery, the First Affiliated Hospital of Harbin Medical University from December 2018 to December 2021 were analyzed retrospectively. There were 70 males(55.6%) and 56 females(44.4%), with age(M(IQR)) of 44(17)years (range: 12 to 87 years). There were 67 cases(53.2%) of severe acute pancreatitis and 59 cases (46.8%) of moderately severe acute pancreatitis. All cases were based on the diagnostic criteria of IPN. All cases were divided into Type Ⅰ(central IPN)(n=21), Type Ⅱ(peripheral IPN)(n=23), Type Ⅲ(mixed IPN)(n=74) and Type Ⅳ(isolated IPN)(n=8) according to the different sites of infection and necrosis on CT.According to different treatment strategies,they were divided into Step-up group(n=109) and Step-jump group(n=17). The clinical indicators and prognosis of each group were observed and analyzed by ANOVA,t-test,χ2 test or Fisher exact test,respectively. Results: There was no significant difference in mortality, complication rate and complication grade in each type of IPN(all P>0.05). Compared with other types of patients, the length of stay (69(40)days vs. 19(19)days) and hospitalization expenses(323 000(419 000)yuan vs. 60 000(78 000)yuan) were significantly increased in Type Ⅳ IPN(Z=-4.041, -3.972; both P<0.01). The incidence of postoperative residual infection of Type Ⅳ IPN was significantly higher than that of other types (χ2=16.350,P<0.01). There was no significant difference in the mortality of patients with different types of IPN between different treatment groups. The length of stay and hospitalization expenses of patients in the Step-up group were significantly less than those in the Step-jump group(19(20)days vs. 33(35)days, Z=-2.052, P=0.040;59 000(80 000)yuan vs. 122 000(109 000)yuan,Z=-2.317,P=0.020). Among the patients in Type Ⅳ IPN, the hospitalization expenses of Step-up group was significantly higher than that of Step-jump group(330 000(578 000)yuan vs. 141 000 yuan,Z=-2.000,P=0.046). The incidence of postoperative residual infection of Step-up group(17.4%(19/109)) was significantly lower than that of Step-jump group(10/17)(χ2=11.980, P=0.001). Conclusions: Type Ⅳ IPN is more serious than the other three types. It causes longer length of stay and more hospitalization expenses. The step-up approach is safe and effective in the treatment of IPN. However, for infected lesions which are deep in place,difficult to reach by conventional drainage methods, or mainly exhibit "dry necrosis", choosing the step-jump approach is a more positive choice.