Wednesday, September 26, 2018 7:35 AM–9:00 AM ePosters: P24. Matched-pair cohort study of spinal surgery in HIV-infected patients: minimum one-year follow-up

BACKGROUND CONTEXT With the overall advancement in management of patients with human immunodeficiency virus (HIV) infection/AIDS, especially antiretroviral therapy regimens, HIV infection is now considered as a chronic disease and the longevity of these patients has significantly improved for the last two decades. As such, an increasing number of patients with HIV-infection are now potential candidates for elective surgical procedures such as spine surgery. In 2015, an estimated 1.1million adults and adolescents were living with HIV and 39,782 patients were newly diagnosed with HIV infection annually in 2016 (CDC data). Despite this increasing prevalence and incidence of the disease, the literature regarding clinical outcomes of spine surgery in patients with HIV is surprisingly scarce. As is the same as patients with other concurrent immunocompromising co-morbidities such as steroid use, diabetes mellitus, organ recipients, and/or chemo or radiation therapy, postoperative infection is one of the most concerning complications. Furthermore, bone mineral densities of HIV-infected patients are reported to be lower than noninfected controls, which could have some potential indications for worse long-term outcomes such as pseudoarthrosis. Thus, we aimed to characterize clinical outcomes of spine surgery in patients with HIV infection in order to facilitate judicious patient selection and comprehensive informed consent, which are of paramount importance in surgical decision-making processes for this high-risk cohort. PURPOSE Summarize clinical outcomes of spine surgery in patients with HIV, such as readmission rate, infectious complications, fusion rate, and mortality to address surgical indications for this specific cohort. STUDY DESIGN/SETTING Retrospective, single-center, propensity-matched cohort. PATIENT SAMPLE Patients who underwent spine surgery with HIV infection were included and compared with a matched-cohort without HIV infection OUTCOME MEASURES CD4 absolute count/uL, HIV-1 RNA copy numbers/mL, 30-day readmission rate, 90-day medical complication rate, one-year surgical site infectious complication rate, one-year fusion rate, and one-year mortality METHODS Single-center, retrospective data review from 2010 to 2016 yielded a total of 4,968 patients of spine surgery. Amongst those, 45 patients had HIV infection. Patients from the database were propensity-matched for age, sex, diagnoses, procedures, co-morbidities other than HIV at a 1:2 ratio, which yielded 90 matched-patients. Clinical outcomes of (A) 45 patients with HIV infection and (B) 90 matched-patients were compared and statistically analyzed. Intergroup comparison of binary variables was performed via Fisheru0027s exact test. Intergroup comparison of continuous variables was achieved using unpaired t -tests. All reported p values are 2-sided and p values RESULTS No statistically significant differences were noted for baseline characteristics including age, sex, diagnoses, procedures, and co-morbidities. There were no statistically significant intergroup differences in operative data such as operative time and operated levels. the HIV-infected patient group had higher rates of 30-day readmission (11.1% vs. 2.2%, P=.04), one-year surgical site infectious complication (13.3% vs. 3.3%, P=.06), and one-year pseudoarthrosis (17.8% vs. 4.4%, P=.02) as well as longer hospital stay (6.8days vs. 4.6days, p CONCLUSIONS Spinal surgery in HIV-infected patients was associated with worse short- and long-term clinical outcomes, including higher rates of 30-day readmission, one-year infectious complication rate, and one-year pseudoarthrosis rate. Furthermore, CD4 absolute count may have some role in preoperative risk stratification. These results warrant further investigation of this cohort on multicenter, prospective basis, which should facilitate better patient selection for spine surgery and detailed informed consent, thereby potentially benefitting patients with HIV infection in the future.