Durable Long-term Patency of Arterial Repairs From Wartime Extremity Vascular Injuries

Abstract

Extremity injuries comprise 50% to 60% of casualties in Iraq/Afghanistan service members. Their 12% overall rate of vascular injury is five times higher than in previous wars, resulting in increased repairs and limb salvage attempts for extremity vascular injuries (EVI). This study examined long-term patency of extremity arterial repairs. We identified service members with EVI undergoing an initial repair attempt using the Department of Defense Trauma Registry and validated by chart abstraction. Our cohort includes those with arterial repair for whom patency data were available. Patency was assessed from duplex ultrasound examination, computed tomography angiography, and angiogram reports. Our cohort comprised the 138 individuals with imaging reports available for review (141 arterial repairs). Most had served in the Army (64%) or Marines (30%); 94% were enlisted. Average age at injury was 25.5 ± 6.9 years (range, 18-56 years). The distribution of race/ethnicity was 77% white, 12% Hispanic, 5% Asian and 4% African-American; >95% were male. Eighty-three percent had a high school education, with 14% having attended some college. The average Injury Severity Score was 17.0 ± 8.9 (range, 4-50) with an Abbreviated Injury Scale-Extremities distribution of 7%, 65%, and 28% for moderate, serious, and severe, respectively. Injury mechanism was predominantly explosions (n = 74 [54%]) and gunshot wounds (n = 56 [41%]) and 70% were discharged/medically retired for disability. Our cohort with patency data was similar compared to the larger population of patients with arterial injury but without patency data (n = 352) except veterans with patency data had higher Injury Severity Scores (P < .03), Abbreviated Injury Scale-Extremities (P < .001) and a higher percentage of gunshot wounds (P < .03). Of the 141 arterial repairs, 82% were vein grafts, 33% were in the upper extremity and 8 repairs occluded or otherwise failed (Table I). Three transtibial amputations were performed for chronic pain and poor function after an average of 27 ± 4 months (range, 24-32 months). Average patency follow-up since injury was 35 ± 40 (range, 1-175 months). Kaplan-Meier analysis of all repairs estimated patency rates of 98%, 96%, 92% and 90% at 6, 12, 24, and 36 months, respectively (Fig 1), with similar results for upper and lower extremity repairs (Table II and Fig 2). Amputations occurring after the 3-month, acute phase of injury were rare and performed for associated fractures and nerve injuries. Arterial repairs for combat EVI have excellent long-term patency with similar patency rates in upper and lower extremity repairs. These results justify continued assertive attempts at vascular repair and limb salvage.Fig 2Patency of upper and lower extremity arterial repairs.View Large Image Figure ViewerDownload Hi-res image Download (PPT)Table IFollow-up (months) and associated injuries of extremity arterial repairsLocation (No. of repairs/No. of patients)Length of follow-upOcclusions, monthsVein graftNerve injuriesBone fracturesOther injured extremitiesAll repairs (141/138)35+40 (1-175)14+11 [8] (2-31)115 (82)53 (38)52 (37)40 (28)Upper (47/47)36+41 (1-137)14+14 [3] (3-31)43 (91)30 (64)15 (32)11 (23)Lower (94/91)35+40 (1-175)14+9 [5] (2-24)72 (77)23 (24)37 (39)29 (31)SD, Standard deviation.Patency includes all arterial repairs with imaging studies documenting patency, occlusions include repairs with imaging documenting patency with subsequent (1) imaging showing occlusion, (2) notes documenting occlusion, (3) amputations including an arterial repair or (4) replacement of an arterial graft.Values are mean ± SD [number] (range) or number (%). Open table in a new tab Table IIPatency analysis for upper and lower extremity arterial repairsInterval, monthsNo. failedNo. censoredNo. remainingCumulative patencyStandard errorUpper extremity 0471.0000 318380.9740.025 817300.9430.039 3119200.8980.058Lower extremity 0941.0000 2113800.9880.012 8119600.9720.020 1419500.9520.027 2319410.9300.035 2418390.9070.041 Open table in a new tab