1030. Epidemiology and Microbiologic Characteristics of Post-operative Central Nervous System Infections following Endoscopic Endonasal Surgery

BACKGROUND: Endoscopic Endonasal Surgery (EES) is an innovative surgical technique to remove brain tumors and lesions. Post-operative central nervous system (CNS) infections following EES are poorly described. The objective of this study was to define the epidemiology and characteristics of post-EES CNS infections. METHODS: Adult patients who underwent EES between 1/2010 and 7/2021 were evaluated and included if microbiologically confirmed CNS infection occurred within 30 days of EES. Suspected contaminants, ventricular drain colonization, and pre-EES CNS infections were excluded. RESULTS: Overall, 2005 patients underwent EES; 1.8% (37/2005) developed CNS infection. The median [IQR] age was 51 [42-60] years, 32.4% (12/37) were female, and 54% (20/37) had a prior EES. The most common indications for EES were tumor resection [67.6% (25/37)] and cerebrospinal fluid (CSF) leak repair [24.3% (9/37)]. Post-operative CSF leaks were documented in 70.3% (26/37) of patients and 24.3% (9/37) had an extra-ventricular drain or shunt in place for >48 hours at the time of infection. Ceftriaxone prophylaxis was prescribed in 64.9% (24/37) of cases and other regimens varied. The median [IQR] time from EES to diagnosis of CNS infection was 12 [6-19] days. The most common pathogens were S. aureus, Enterobacterales, and P. aeruginosa(Fig 1). Among 20 patients with prior EES, pathogens included S. aureus (5/20), Enterobacterales (3/20), Enterococcus spp. (3/20) and polymicrobic infections (3/20). Overall, 35.1% (13/37) of patients developed CNS infection due to a pathogen susceptible to pre-EES prophylaxis. Among those colonized with MRSA at time of EES, 75% (3/4) developed MRSA CNS infection compared to 6.1% (2/33) of non-colonized MRSA patients (P=0.005). The overall 30-day mortality rate was 2.7% (1/37). [Figure: see text] A polymicrobic case was defined as >1 pathogen isolated from CSF (n=1) or from rhinocerebral tissue if CSF cultures were negative (n=11). Among polymicrobic cases (n=12), P. aeruginosa (n=5), Enterococcus spp. (n=4). and S. aureus (n=3) were predominant. Cases labeled as other consisted of Trichoderma spp, A. xylosoxidans, P. acnes, S. epidermidis, Peptostreptococcus spp. CONCLUSION: CNS infection post-EES is rare and causative pathogens vary. Given the predominance of S. aureus, antimicrobial prophylaxis should ensure adequate coverage of this pathogen in addition to sinus flora, and programs may benefit from screening patients for MRSA colonization pre-EES. Our data also suggest that prophylaxis should target Gram-negative and other colonizing bacteria among patients with prior EES. DISCLOSURES: Ryan K. Shields, PharmD, MS, Infectious Disease Connect: Advisor/Consultant|Merck: Advisor/Consultant|Merck: Grant/Research Support|Roche: Grant/Research Support.