b'Scientific Session Abstracts SATURDAY APRIL 20, 2024 2: IMPACT OF OBL ON RESIDENT AND FELLOW TRAINING AT A UNIVERSITY VASCULAR SURGERY PROGRAMWilliam Duong, MD, Jesus Ulloa, MD, Nakeisha Favors, MPH,Hugh Gelabert, MDUCLA Division of Vascular SurgeryBackground: The office-based interventional lab (OBL) has become well established in Vascular Surgical practice. Most Vascular Surgery training programs do not offer OBL experience as part of their curriculum. The objective of this report is to describe the impact of an OBL on a University Vascular Surgery Training program by comparing case volumes and trainee experience before and after the establishment of an OBL.Methods: Resident and Fellow training logs were reviewed to assess case volumes and categories from 2004-2023. Two periods of time were compared: before (Period 1, 2004-2013) and after (Period 2, 2014-2023) our OBL was established. A registry of cases performed at our OBL was reviewed for number and types of cases. Resident training logs were compared to the OBL registry. Data is presented as mean and standard deviation and Students T test was used to compare continuous variables. Significance was determined at P 0.05.Results: Over the entire study period (2004-2023), 27 Fellows and Residents graduated: 10 Fellows in P1 and 10 Fellows and 7 Residents in P2. Our Residency program was established in addition to our Fellowship, graduating the first Vascular Surgery Resident in 2017, increasing our annual graduates from 1 to 2. Over the entire study period, 41,700 Vascular (open and endovascular) cases were performed: 17,431 (P1) and 27,385 (P2) (p=0.007), representing a 57% increase of cases from P1 to P2. Over the study period, a total of 17,930 Endovascular cases were completed: 7,039 (P1) and 10,891 (P2) (p=0.031), a 54% increase in endovascular cases form P1 to P2 (Table 1). Over the entire study period, the average Vascular case volume per trainee was 1,659.80 538.81: 1,743.10 427.69 (P1) and 1,610.80 601.66 (P2), (p=0.274). The average number of Endovascular cases per trainee was 664.1 252.86: 703.9 210.75 (P1) and 640 278.12 (P2) (p=0.27). Overall Endovascular cases represented 40.01% of cases: 40.38% in P1 and 39.77 % in P2. For individual trainees, Endovascular cases accounted for 40.01% of cases overall: 40.38% in P1 and 39.73% in P2. OBL cases accounted for 30.212.8%, (range 17.5 to 59.7) of all endovascular cases in P2. OBL endovascular cases accounted for 19.757.1%, (range 11.1 to 33.1) of all cases done by our trainees (Figure 1).36SOUTHERN CALIFORNIA VASCULAR SURGICAL SOCIETY'