AIM: To evaluate the effi cacy of continuous regional arterial infusion therapy (CRAI) with gabexate mesilate and antibiotics for severe acute pancreatitis (SAP). METHODS: We conducted a prospective study on patients who developed SAP with or without CRAI. Out of 18 patients fulf illed clinical diagnostic criteria for SAP in Japan, 9 patients underwent CRAI, while 9 patients underwent conventional systemic protease inhibitor and antibiotics therapy (non-CRAI). CRAI was initiated within 72 h of the onset of pancreatitis. Gabexate mesilate (2400 mg/d) was continuously administered for 3 to 5 d. The clinical outcome including serum infl ammation-related parameters were examined. RESULTS: The duration of abdominal pain in the CRAI group was 1.9 ± 0.26 d, whereas that in the non-CRAI group was 4.3 ± 0.50. The duration of SIRS in the CRAI group was 2.2 ± 0.22 d, whereas that in the non- CRAI group was 3.2 ± 0.28. Abdominal pain and SIRS disappeared signifi cantly in a short period of time after the initiation of CRAI using gabexate mesilate. The average length of hospitalization signifi cantly differed between the CRAI and non-CRAI groups, 53.3 ± 7.9 d and 87.4 ± 13.9 d, respectively. During the first two weeks, levels of serum CRP and the IL6/IL10 ratio in the CRAI group tended to have a rapid decrease compared to those in the non-CRAI group. CONCLUSION: The present results suggest that CRAI using gabexate mesilate was effective against SAP. AIM: To evaluate the effi cacy of continuous regional arterial infusion therapy (CRAI) with gabexate mesilate and antibiotics for severe acute pancreatitis (SAP). METHODS: We conducted a prospective study on patients who developed SAP with or without CRAI. Out of 18 patients fulf illed clinical diagnostic criteria for SAP in Japan, 9 patients underwent CRAI while 9 patients under conventional systemic protease inhibitor and antibiotic therapy (non-CRAI). CRAI was initiated within 72 h of the onset of pancreatitis. Gabexate mesilate (2400 mg / d) was continuously administered for 3 to 5 d. The clinical outcome including serum infl ammation-related parameters were examined. RESULTS: The duration of abdominal pain in the CRAI group was 1.9 ± 0.26 d, then that that the non-CRAI group was 4.3 ± 0.50. The duration of SIRS in the CRAI group was 2.2 ± 0.22 d, that that of the non-CRAI group was 3.2 ± 0.28. Abdominal pain and SIRS disappeared signifi cantly in a short period of tim e after the initiation of CRAI using gabexate mesilate. The average length of hospitalization signifi cantly differed between the CRAI and non-CRAI groups, 53.3 ± 7.9 d and 87.4 ± 13.9 d, respectively. During the first two weeks, levels of serum CRP and the IL6 / IL10 ratio in the CRAI group tended to have a rapid increase compared to those in the non-CRAI group. CONCLUSION: The present results suggest that CRAI using gabexate mesilate was effective against SAP.