Two-year Mortality and Functional Outcomes in Combat-related Penetrating Brain Injury: Battlefield Through Rehabilitation

M. Benjamin Larkin, MD, PharmD; Erin K. M. Graves, MD, MA; Jason H. Boulter, MD; Nicholas S. Szuflita, MD, MPH; R. Michael Meyer, MD; Michael E. Porambo, MD; John J. Delaney, MD; Randy S. Bell, MD


Neurosurg Focus. 2019;45(6):e4 

In This Article


Design and Data Collection

This study is a retrospective review of all cases involving US military members who underwent neurosurgical consultation at the Role 3 Multinational Medical Unit at Kandahar Airfield (KAF) in Afghanistan from January 2010 to March 2013. It was conducted in accordance with a protocol approved by the WRNMMC Institutional Review Board. Patients were identified through the US Army Institute of Surgical Research (USAISR) trauma registry. These results were cross-referenced with the Theater Medical Data Store (TMDS) to exclude patients who had sustained head, neck, or facial trauma that did not violate the calvaria, leaving only those with PBI. Records of admission GCS scores were available for only 64 of the 80 patients. Patients without available admission GCS data were not included in associated analyses utilizing admission GCS scores.

Demographical data were collected including branch of service, mechanism of injury, admission Injury Severity Score (ISS), admission GCS score (determined by a neurosurgeon or trauma surgeon upon patient admission), injury characteristics, and surgical interventions (craniotomy, craniectomy, or intracranial pressure [ICP] monitor/external ventricular drain [EVD] placement). GOS scores (present for all patients at all time points) were determined at 6, 12, and 24 months postinjury independently by 2 investigators through a review of the medical records that included inpatient and outpatient neurosurgery evaluations at that time. Notes from multiple disciplines within approximately 1 month of each time point were utilized to minimize error in score determination. Any differences in score assignment were resolved by adjudication from a blinded third investigator.

Outcomes and Statistical Analysis

The primary outcome of interest for the present study was GOS score at 6, 12, and 24 months postinjury. Patients were segregated by mechanism of injury, admission GCS score, admission ISS, and injury characteristics and were evaluated for changes in GOS score as either a continuous or a dichotomized (≥ 4 as "good" and < 4 as "poor") variable at each time point.

Descriptive statistics were calculated as means with standard deviations or counts with percentages where appropriate. Categorical variables were analyzed with Fisher's exact test, and continuous variables were analyzed with Student's t-test and analyses of variance. Statistical significance was set at p < 0.05. All statistics were performed with Microsoft Excel 2013.