Traumatic penetrating arteriovenous fistulas: a collective review.

INTRODUCTION: Traumatic penetrating arteriovenous fistulas (AVFs) are very rare. The majority of these injuries occur secondary to penetrating trauma. Objectives of this study: review their incidence, clinical presentation, radiologic identification, management, complications and outcomes. METHODS: A literature search was performed on MEDLINE Complete-Pubmed from 1829-2019. PRISMA guidelines were utilized. Of 305 potentially eligible articles, 201 articles were selected. INCLUSION CRITERIA: patients age ≥ 18, articles with title and abstract in English, AVFs secondary to penetrating trauma, articles which specified vessels involved in AVFs, and those reporting complete information on patient presentation, diagnosis, imaging, surgical and/or endovascular surgical management, and outcomes of penetrating AVF's. EXCLUSION CRITERIA: articles reporting blunt or iatrogenic AVFs, pediatric patients, fistulas used for dialysis and their complications, articles lacking complete information, cranial/spinal AVFs or cardiac AVFs, and duplicate articles. Mechanism of injury (MOI), diagnosis, involved vessels, management and outcomes of patients with AVFs secondary to penetrating trauma were recorded. RESULTS: There were a total of 291 patients with AVFs secondary to penetrating injuries. Mechanism of injury (MOI): stab wounds (SW)-126 (43.3%), Gunshot wounds (GSW)-94 (32.3%), miscellaneous-35 (12%), mechanism unspecified-36 (12.4%). Anatomic area: neck-69 (23.7%) patients, thorax-46 (15.8%), abdomen-87 (30%), upper and lower extremities-89 (30.6%). Most commonly involved vessels-vertebral artery-38 (13%), popliteal vein-32 (11.7%). Angiography was diagnostic-265 patients (91.1%). INTERVENTIONS: Surgical- 202 (59.6%), Endovascular-118 (34.8%). Associated: aneurysms/pseudoaneurysms-129 (44.3%). CONCLUSION: Most AVFs occur secondary to penetrating injuries. Stab wounds account for the majority of these injuries. Most frequently injured vessels are vertebral artery and superficial femoral vein. Surgical interventions are the most common mode of management followed by endovascular surgical techniques.

A systematic review and individual patient data meta-analysis of heart failure as a rare complication of traumatic arteriovenous fistulas.

OBJECTIVE: Traumatic arteriovenous fistulas (AVFs) are rare. The vast majority occur secondary to penetrating injuries. High-output cardiac failure is a well-recognized serious complication of AVFs, associated with high morbidity and mortality. The objective of the present study was to identify predictors of heart failure (HF) in patients with traumatic AVF. METHODS: Both PubMed/MEDLINE (Ovid) and CINAHL were searched (up to June 2019) for studies reporting individual patient data on the clinical and demographic characteristics of patients with AVF secondary to penetrating trauma. Exclusion criteria were age <18 years, no specification of symptoms, a cranial, spinal, or cardiac AVF location, and an iatrogenic mechanism of injury. The present study was performed in accordance with the PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) guidelines. RESULTS: A total of 274 AVF patients from 15 case series and 177 case reports were included. The median age at presentation was 32 years (interquartile range, 24-43 years), 90% were men. The most frequent mechanisms of injury were stab wounds (43%) and gunshot wounds (32%). The AVF location was the abdomen (n = 86; 31%), lower limb (n = 79; 29%), neck (n = 61; 22%), thorax (n = 38; 14%), and upper limb (n = 10; 4%). Of the 274 patients, 35 (13%) had presented with HF and 239 (87%) with other symptoms. The risk of HF increased with an increased feeding artery diameter (P < .001). On univariate analysis, HF was significantly associated with a longer median time from injury to presentation with AVF (11.2 years vs 0.1 years; P < .001), older median age at presentation (43 years vs 31 years; P = .002), involvement of a large feeding artery (ie, aorta, pulmonary artery, subclavian artery, external iliac artery; 40% vs 13%; P < .001), shrapnel injuries (11% vs 2%; P = .011), and injuries to the trunk or lower limb (94% vs 71%; P = .004). After adjusting for clinical and demographic patient characteristics, involvement of a large feeding artery (odds ratio, 3.25; 95% confidence interval, 1.26-8.42; P = .015) and every 6 years of delay to presentation (odds ratio, 1.30; 95% confidence interval, 1.03-1.63; P = .026) remained independent predictors for HF. CONCLUSIONS: HF occurs in a small but important fraction of traumatic AVF patients and develops after highly variable latency periods. Large feeding arteries and delayed presentation independently predicted HF in this cohort.

Mean arterial pressure maintenance following spinal cord injury: Does meeting the target matter?

INTRODUCTION: Neurosurgical guidelines recommend maintaining mean arterial pressure (MAP) between 85 and 90 mm Hg following acute spinal cord injury (SCI). In our hospital, SCI patients receive orders for MAP targeting for 72 hours following admission, but it is unclear how often the patient's MAP meets the target and whether or not this affects outcome. We hypothesized that the proportion of MAP measurements ≥85 mm Hg would be associated with neurologic recovery. METHODS: Spinal cord injury patients with blunt mechanism of injury admitted between 2014 and 2019 were identified from the registry of a level 1 trauma center. Proportion of MAP values ≥85 mm Hg was calculated for each patient. Neurologic improvement, as measured by positive change in American Spinal Injury Association (ASIA) impairment scale by ≥1 level from admission to discharge was evaluated with respect to proportion of elevated MAP values. RESULTS: A total of 136 SCI patients were evaluated. Average proportion of elevated MAP values was 75%. Admission ASIA grades were as follows: A, 30 (22.1%); B, 20 (14.7%); C, 28 (20.6%); and D, 58 (42.6%). One hundred six patients (77.9%) required vasopressors to elevate MAP (ASIA A, 86.7%; B, 95.0%; C, 92.9%; D, 60.3%). Forty patients (29.4%) were observed to have improvement in ASIA grade by discharge (admission ASIA A, 15%; B, 33%; C, 40%; D, 13%). The proportion of elevated MAP values was higher for patients with neurologic improvement (0.81 ± 0.15 vs. 0.72 ± 0.25, p = 0.014). Multivariate modeling demonstrated a significant association between proportion of elevated MAP values and neurologic improvement (p = 0.028). An interaction revealed this association to be moderated by vasopressor dose (p = 0.032). CONCLUSION: The proportion of MAP measurements ≥85 mm Hg was determined to be an independent predictor of neurologic improvement. Increased vigilance regarding MAP maintenance above 85 mm Hg is warranted to optimize neurologic recovery following SCI. LEVEL OF EVIDENCE: Therapeutic/care management, level IV.

Penetrating Internal and Common Carotid Artery Injuries Shunts versus no shunts during repair effect on neurological outcomes.

BACKGROUND: Penetrating Carotid artery injuries are rarely encountered even in busy in urban Trauma Centers. Repair is preferred over ligation for Internal (IC) and Common Carotid (CC) arteries. To date, the use of temporary shunts correlated to neurological outcomes has not been reported. OBJECTIVES ARE TO SPECIFICALLY ADDRESS THE QUESTION: In patients with penetrating IC or CC injury requiring repair, does use of temporary shunts decrease mortality and/or improve neurologic outcomes? We hypothesized that the use of temporary shunts during revascularization might produce improvements in both areas. METHODS: A literature search was performed through Medline Complete-PubMed, Cochrane, Ovid, and Embase for the period of 1900-2019. PRISMA guidelines were utilized. Thirty-two articles met inclusion criteria, ranging from 1960-2018. These were analyzed to determine whether surgical repair was performed with or without the use of temporary shunts. External Carotid artery injuries were excluded. Pre- and postoperative neurological outcomes and overall outcomes were analyzed. Non-parametric data were analyzed with Fisher's Exact or Chi-square tests as applicable. Statistical significance was set to a p-value < 0.05. RESULTS: There were a total of 973 patients with penetrating IC and CC injuries; 136 (14%) patients underwent ligation and were excluded. Our study population consisted of 837 patients; 126 (15.1%) with shunts (WS), 711 (84.9%) without shunts (WOS). Mortality stratified to patients repaired WS versus WOS was 5.6% versus 11.1% (p=0.058). Neurological improvement was noted to be similar for patients undergoing repair WS - 14.2% versus WOS - 13.7% (p=0.8). Worsening neurological status for patients shunted WS - 3.4%, versus WOS - 9.0% (p=0.038). Data were analyzed for outcome variables including neurological deficits with or without mortality. Patients shunted had an improved and/or unchanged neurological outcome compared to patients not shunted during repair - 91.3% versus 80.9% (p=0.0047). CONCLUSIONS: Patients sustaining penetrating Internal and Common Carotid injuries repaired with temporary shunts have a slightly lower mortality rate and similar or unchanged neurological outcomes versus those repaired without shunts. Based on this evidence, we recommend thoughtful interoperative consideration for the use of temporary shunts for patients requiring complex repairs of these injuries.

Popliteal artery injuries. Less ischemic time may lead to improved outcomes.

BACKGROUND: Popliteal artery injuries are rare. They have high amputation rates. OBJECTIVES: To report our experience, identify predictors of outcome; mechanism of injury (MOI), Mangled Extremity Severity Score (MESS) score and length of ischemic time. We hypothesized that ischemic time as close to six hours results in improved outcomes. METHODS: Retrospective 132-month study. All popliteal artery injuries. Urban Level I Trauma Center. OUTCOME MEASURES: MOI, ISS, MESS, ischemic time, risk factors for amputation, role of popliteal venous injuries, and limb salvage. STATISTICAL ANALYSIS: univariate and multivariate. RESULTS: 76 patients - 59 (76.1%) males and 17 (22.4%) females. MOI: penetrating - 54 (71%). MESS for penetrating injuries - 5.8 ± 1.5, blunt injuries - 5.6 ± 1.8. Admission-perfusion restoration (n = 76) - 5.97 hours (358 minutes). Ischemic time was not predictive of outcome (p = 0.79). Ischemic time penetrating (n = 58) 5.9 hours (354 ± 209 minutes), blunt 6.1 hours (371 ± 201 minutes). Popliteal arterial repairs: RSVG 44 (58%), primary repair 21 (26%), PTFE 3 (4%), vein patch 2 (2%), ligation 2 (3%), exsanguinated 4 (6%). No patients underwent stenting. Popliteal Vein: Repair 19 (65%), ligation 10 (35%). Fasciotomies 45 patients (59%). OUTCOMES: Limb salvage - 90% (68/76). Adjusted limb salvage excluding intraoperative deaths - 94% (68/72). Selected patient characteristics; MOI: penetrating vs. blunt - age (p <0.0005). Amputated vs. non-amputated patients, age (p < 0.05). ISS (p < 0.005) predicted amputation, MESS (p = 0.98) did not. Mean ischemic time (p = 0.79) did not predict amputation. Relative risk of amputation, MOI - blunt (p = 0.26, RR 4.67, 95% CI: 1.11 - 14.1), popliteal artery ligation (p = 0.06, RR 3.965, 95% CI: 1.11 - 14.1) as predictors of outcome. Combined artery and vein injuries (p = 0.25) did not predict amputation. CONCLUSIONS: Decreasing ischemic time from arrival to restoration of perfusion may lead to improved outcomes and increased limb salvage. MESS is not predictive for amputation. Blunt MOI is a risk factor for amputation. Maintaining ischemic times as close to six hours as possible may lead to improved outcomes.

Brachial Artery Injuries Operative Management and Predictors of Outcome.

BACKGROUND: Brachial artery injuries are rare. The objectives of the study are to report our experience and identify predictors of outcome. The hypothesis of the study is that maintaining ischemic times less than six hours results in improved outcomes. METHODS: This is a retrospective 118-month study. The outcome measure is total operative time from admission to restoration of blood flow, and outcomes are survival and limb salvage. Statistical analyses used in the study are univariate and multivariate stepwise logistic regression. RESULTS: There were 124 patients with 131 brachial artery injuries. Mechanism of injury (MOI) included the following: penetrating: 108 (87%) and blunt: 16 (13%). Operative management included the following: 77 (62%) reverse saphenous vein interposition grafts, 37 (29.8%) end-to-end anastomosis, and 4 (3.2%) ligation. Fasciotomies were performed in 23 (19.2%) patients. Outcomes of the study were as follows: 120 patients survived and the overall survival rate was 96.8%, adjusted survival rate excluding intraoperative deaths was 100%, overall limb salvage/amputation rate was 95.1%/4.9%, and adjusted limb salvage/amputation rates excluding intraoperative deaths were 98.3%/1.67%. Univariate analysis showed the mean ischemic times for survivors as 5 ± 3.1 hrs (300 ± 186 min) versus ischemic times for non survivors as 3 ± 2.2 hrs (180 ± 132 min) (P = 0.017); Injury Severity Score (ISS) (P = 0.002); and estimated blood loss (EBL) (P = 0.024). Logistic regression identified independent predictors of outcome for survival: MOI: penetrating [P = 0.015, RR - 4.29, 95% CI: 1.49-12.36]; Glasgow Coma Score < 7 [P < 0.001, RR - 21.71, 95% CI: 9.37-50.32]; ISS > 15 [P < 0.005, RR - 4.98, 95% CI: 1.68-14.73]; and patients not requiring ED thoracotomy [P = 0.009, RR - 7.48, 95% CI: 2.58-21.69]. CONCLUSIONS: Brachial artery injuries are rare. For patients not requiring ED thoracotomy, Glasgow Coma Score, ISS, and EBL predicted survival. The adjusted limb salvage rate was 98.3%. Patients with brachial artery injuries die from associated injuries, experiencing less ischemic times than survivors who are able to undergo repairs.

Are all trauma centers created equal? Level 1 to level 1 trauma center patient transfers in the setting of rapid trauma center proliferation.

BACKGROUND: Level 1 trauma centers should provide definitive care for every aspect of injury. However, in environments that have experienced trauma center proliferation, not all level 1 centers may have the resources or expertise needed for every patient, necessitating transfer to another trauma center. The purpose of this study was to assess the incidence of such transfers and associated impact on patient outcome and burden on the receiving level 1 center. METHODS: In a metropolitan area experiencing trauma center proliferation, we performed a 5.5-year review of patient transfers to an established level 1 (index center) from other state designated level 1 centers. American College of Surgeons verification level was identified for each facility. Comparisons were performed between the cohort of transferred patients and patients with similar demographics, injury patterns, and severity managed at the index center using propensity score matching. RESULTS: A total of 104 patients were received from other state level 1 centers (39% American College of Surgeons level 2, 61% American College of Surgeons level 1). Nearly 70% of patients were transferred for definitive evaluation and/or management of brain, spine, or cerebrovascular injury. For 76% of this subgroup, specialty consultation was available, but the injury was deemed beyond their capability. Comparison of the transfer cohort propensity score matched to the control cohort (93 vs. 558 patients) demonstrated increased length of stay (6.5 days vs. 4.6 days, p = 0.001) and cost (US $36,027 vs. US $30,654, p = 0.033) associated with the transfer cohort, with similar mortality (12.1% vs. 9.7%, p = 0.492). CONCLUSION: The number of level 1 to level 1 transfers observed imply a disparity in resources and capability among level 1 trauma centers in the region. The majority of transfers were for neurosurgical care, suggestive of a deficit of adequate neurosurgical coverage in the setting of trauma center proliferation. Both patients and established trauma centers bear the burden for these transfers with respect to increased cost and length of stay. LEVEL OF EVIDENCE: Care management, level IV.