Injury patterns, management and outcomes of retroperitoneal haemorrhage caused by lower intercostal arterial bleeding at a level-1 trauma centre: A 10-year retrospective review.

OBJECTIVE: Haemorrhagic shock is a life-threatening complication of trauma, but remains a preventable cause of death. Early recognition of retroperitoneal haemorrhage (RPH) is crucial in preventing deleterious outcomes including mortality. Injury to the 9-11th intercostal arteries (i.e. arteries of the lower thoracic region) are complicit in RPH. However, the associated injuries, implications and management of such bleeds remain poorly characterised. METHODS: We performed a retrospective review of the medical records of patients diagnosed with RPH who presented to our level-1 trauma centre (2009-2019). We described the associated injuries, management and outcomes relating to RPH of the lower thoracic region (the 9-11th intercostal arteries) from this cohort to identify potential predictors and evaluate the impact of early identification and management of non-cavitary bleeds. RESULTS: Haemorrhage of the lower intercostal arteries (LIA) into the retroperitoneal space is associated with an increased number of posterior lower rib fractures and pneumothorax/haemothorax. A higher proportion of patients in the LIA group required massive transfusion, angioembolisation or surgical ligation when compared to other causes of RPH. CONCLUSION: The present study highlights the importance of injury patterns, particularly posterior lower rib fractures, as predictors for early recognition and management of RPH in the prevention of deleterious patient outcomes. RPH secondary to bleeding of the LIA may require early and aggressive management of haemorrhage through massive transfusion, and angioembolisation or surgical ligation when compared to RPH because of other causes.

The injury patterns, management and outcomes of retroperitoneal haemorrhage caused by lumbar arterial bleeding at a Level-1 Trauma Centre: A 10-year retrospective review.

PURPOSE: Haemorrhagic shock remains a leading preventable cause of death amongst trauma patients. Failure to identify retroperitoneal haemorrhage (RPH) can lead to irreversible haemorrhagic shock. The arteries of the middle retroperitoneal region (i.e., the 1st to 4th lumbar arteries) are complicit in haemorrhage into the retroperitoneal space. However, predictive injury patterns and subsequent management implications of haemorrhage secondary to bleeding of these arteries is lacking. MATERIALS AND METHODS: We performed a retrospective cohort study of patients diagnosed with retroperitoneal haemorrhage who presented to our Level-1 Trauma Centre (2009-2019). We described the associated injuries, management and outcomes relating to haemorrhage of lumbar arteries (L1-4) from this cohort to assess risk and management priorities in non-cavitary haemorrhage compared to RPH due to other causes. RESULTS: Haemorrhage of the lumbar arteries (LA) is associated with a higher proportion of lumbar transverse process (TP) fractures. Bleeding from branches of these vessels is associated with lower systolic blood pressure, increased incidence of massive transfusion, higher shock index, and a higher Injury Severity Score (ISS). A higher proportion of patients in the LA group underwent angioembolisation when compared to other causes of RPH. CONCLUSION: This study highlights the injury patterns, particularly TP fractures, in the prediction, early detection and management of haemorrhage from the lumbar arteries (L1-4). Compared to other causes of RPH, bleeding of the LA responds to early, aggressive haemorrhage control through angioembolisation. These injuries are likely best treated in Level-1 or Level-2 trauma facilities that are equipped with angioembolisation facilities or hybrid theatres to facilitate early identification and management of thoracolumbar bleeds.

Peripheral vascular trauma - basic management, diagnosis and treatment.

INTRODUCTION: Peripheral vascular injuries occur in 1-3% of all traumas in civilian settings. The management of these injuries is often based on experience derived from war medicine where these injuries are more common. The goal of this article is to summarize basic guidelines for the diagnosis and treatment of vascular injuries. METHODS: Western Trauma Association (WTA) and Eastern Association for the Surgery of Trauma (EAST) both have their own guidelines for vascular trauma management. RESULTS: Vascular injuries occur both in penetrating and blunt traumas. Complete vessel disruption occurs more frequently in penetrating traumas. In the case of blunt trauma, intimal defects are more common, resulting in dissection, false aneurysm, or intramural hematoma. The limb is mostly endangered due to ischemia, reperfusion injury and the compartment syndrome. Prompt diagnosis and treatment are paramount. Vascular trauma management is part of the ATLS protocol and life-over-limb principle. The primary goal is to stop the massive external bleeding. Clinical examination and CT angiography are the most helpful for the diagnosis. Surgical revision is indicated when hard signs are present. This can be a damage control surgery with the primary goal to stop the bleeding as quickly as possible. A shunt can be used for temporary reperfusion of the limb. Definitive treatment can take the form of a simple suture, patches or graft interposition; both prosthetic and autologous grafts are used. Sufficient debridement and fasciotomy are important steps in the therapy. In some cases, endovascular treatment can be used. CONCLUSION: Over the last century, the treatment strategy changed dramatically. Data from recent military conflicts show a decrease in amputation rates, and limb salvage has become a standard.

Traumatic arterial injuries in upper and lower limbs: what every radiologist should know.

Traumatic arterial injuries of the extremities are a rare but potentially fatal event. Computed tomography (CT) angiography of the extremities has become the technique of choice and can provide rapid accurate detection and characterization of vascular lesions. Vascular injuries can be classified in active hemorrhage, vasospasm, occlusion, post-traumatic arteriovenous fistula, pseudoaneurysm, and patterns of intimal injuries. The learning objectives of this pictorial essay are to review the normal arterial anatomy of the upper and lower limbs, describe the technique of CT angiography in vascular trauma of the extremities, describe and illustrate the CT-angiography findings of traumatic arterial injuries, and know the potential pitfalls when interpreting a CT-angiography of the extremities.

Lumbar Artery Injury Related to Percutaneous Pedicle Screw Insertion.

A 75-year-old woman underwent L4-L5 lateral interbody fusion for L4-5 foraminal stenosis with the use of percutaneous pedicle screws. On the day after the surgery, she was in shock. Emergency contrast-enhanced CT showed active extravasation from the 4th lumbar artery with a transverse process fracture. A radiologist performed a successful transarterial embolization, and the patient then began walking training on the 4th day post-surgery. Close attention should be paid to the insertion of a percutaneous pedicle screw, as it may cause a lumbar artery injury; in such a case, transarterial embolization is the preferred treatment.

In-hospital outcomes in autogenous vein versus synthetic graft interposition for traumatic arterial injury: A propensity-matched cohort from PROOVIT.

BACKGROUND: The ideal conduit for traumatic arterial repair is controversial. Autologous vein was compared with synthetic interposition grafts in the acute setting. The primary outcome was in-hospital reoperation or endovascular intervention. METHODS: The American Association for the Surgery of Trauma PROspective Observational Vascular Injury Treatment registry from November 2013 to January 2019 was queried for arterial injuries requiring interposition vein or graft repair. Patients with no recorded Injury Severity Score were excluded, and multiple imputation was used for other missing data. Patients treated with synthetic grafts (SGs) were propensity matched to patients with vein grafts (VGs) to account for preoperative differences. RESULTS: Four hundred sixty from 19 institutions were identified, with 402 undergoing VG and 58 SG. In the SG group, 45 were PTFE grafts, 5 were Dacron, and 8 had other conduits. The SG group was more severely injured at admission with more gunshot wounds and higher mean Injury Severity Score, lactate, and first-24-hour transfusion requirement. In addition, the SG cohort had significantly lower admission systolic blood pressure, pH, and hemoglobin. After propensity matching, 51 patients with SG were matched with 87 patients with VG. There were no differences in demographics, clinical parameters, or diagnostic evaluation techniques postmatch. The need for reoperation or endovascular intervention between the matched groups was equivalent (18%; p = 0.8). There was no difference in any secondary outcome including thrombosis, stenosis, pseudoaneurysm, infection, or embolic event, and hospital and intensive care unit length of stay were the same. CONCLUSION: American Association for the Surgery of Trauma PROspective Observational Vascular Injury Treatment registry data demonstrate that SGs are used in more critically ill patients. After controlling for relevant clinical factors and propensity matching, there is no in-hospital difference in rate of reoperation or endovascular intervention, or any secondary outcome between VG and SG. LEVEL OF EVIDENCE: Prognostic and Epidemiolgic, Level III.

Timing is everything: Impact of combined long bone fracture and major arterial injury on outcomes.

BACKGROUND: Timing of extremity fracture fixation in patients with an associated major vascular injury remains controversial. Some favor temporary fracture fixation before definitive vascular repair to limit potential graft complications. Others advocate immediate revascularization to minimize ischemic time. The purpose of this study was to evaluate the timing of fracture fixation on outcomes in patients with concomitant long bone fracture and major arterial injury. METHODS: Patients with a combined long bone fracture and major arterial injury in the same extremity requiring operative repair over 11 years were identified and stratified by timing of fracture fixation. Vascular-related morbidity (rhabdomyolysis, acute kidney injury, graft failure, extremity amputation) and mortality were compared between patients who underwent fracture fixation prerevascularization (PRE) or postrevascularization (POST). RESULTS: One hundred four patients were identified: 19 PRE and 85 POST. Both groups were similar with respect to age, sex, Injury Severity Score, admission base excess, 24-hour packed red blood cells, and concomitant venous injury. The PRE group had fewer penetrating injuries (32% vs. 60%, p = 0.024) and a longer time to revascularization (9.5 vs. 5.8 hours, p = 0.0002). Although there was no difference in mortality (0% vs. 2%, p > 0.99), there were more vascular-related complications in the PRE group (58% vs. 32%, p = 0.03): specifically, rhabdomyolysis (42% vs. 19%, p = 0.029), graft failure (26% vs. 8%, p = 0.026), and extremity amputation (37% vs. 13%, p = 0.013). Multivariable logistic regression identified fracture fixation PRE as the only independent predictor of graft failure (odds ratio, 3.98; 95% confidence interval, 1.11-14.33; p = 0.03) and extremity amputation (odds ratio, 3.924; 95% confidence interval, 1.272-12.111; p = 0.017). CONCLUSION: Fracture fixation before revascularization contributes to increased vascular-related morbidity and was consistently identified as the only modifiable risk factor for both graft failure and extremity amputation in patients with a combined long bone fracture and major arterial injury. For these patients, delaying temporary or definitive fracture fixation until POST should be the preferred approach. LEVEL OF EVIDENCE: Prognostic study, Level IV.

Endothelial Progenitor Cells Modulate the Phenotype of Smooth Muscle Cells and Increase Their Neointimal Accumulation Following Vascular Injury.

BACKGROUND: Smooth muscle cells (SMCs) are the main driver of neointima formation and restenosis following vascular injury. In animal models, endothelial progenitor cells (EPCs) accelerate endothelial regeneration and reduce neointima formation after arterial injury; however, EPC-capture stents do not reduce target vessel failure compared with conventional stents. Here we examined the influence of EPCs on features of SMCs pivotal for their impact on injury-induced neointima formation including proliferation, migration, and phenotype switch. METHODS AND RESULTS: EPCs, their conditioned medium, and EPC-derived microparticles induced proliferation of SMCs while limiting their apoptosis. In transwell membrane experiments and scratch assays, EPCs stimulated migration of SMCs and accelerated their recovery from scratch-induced injury. Treatment of SMCs with an EPC-derived conditioned medium or microparticles triggered transformation of SMCs toward a synthetic phenotype. However, co-cultivation of EPCs and SMCs enabling direct cell-cell contacts preserved their original phenotype and protected from the transformative effect of SMC cholesterol loading. Adhesion of EPCs to SMCs was stimulated by SMC injury and reduced by blocking CXCR2 and CCR5. Interaction of EPCs with SMCs modulated their secretory products and synergistically increased the release of selected chemokines. Following carotid wire injury in athymic mice, injection of EPCs resulted not only in reduced neointima formation but also in altered cellular composition of the neointima with augmented accumulation of SMCs. CONCLUSION: EPCs stimulate proliferation and migration of SMCs and increase their neointimal accumulation following vascular injury. Furthermore, EPCs context-dependently modify the SMC phenotype with protection from the transformative effect of cholesterol when a direct cell-cell contact is established.

The reliability of physical examination in diagnosing arterial injury in penetrating trauma to extremities: A first look at different anatomical regions and injury mechanisms.

BACKGROUND: The accuracy of physical examination to exclude arterial injury in penetrating trauma to extremities has been well established. OBJECTIVES: To determine whether the accuracy of physical examination to exclude arterial injury is similar to that of a computed tomography arteriogram (CTA) for different anatomical regions and mechanisms of injury, and in patients with concomitant fractures compared with those without. METHODS: A retrospective review was conducted on all patients who underwent CTA for penetrating injuries to an extremity between 1 June 2016 and 30 June 2017. The presence of arterial injuries was noted, and these were grouped into anatomical areas. Clinical notes were reviewed for the presence of hard signs of arterial injury at initial examination. RESULTS: A total of 220 lower limb and 133 upper limb CTAs were included. The mean patient age was 28.9 years (range 11 - 68). The overall sensitivity of physical examination in detecting a CTA-confirmed arterial injury was 95.3% (95% confidence interval (CI) 88.4 - 98.7), with a specificity of 93.9% (95% CI 90.2 - 96.4). Physical examination of the thigh had the highest specificity of 96.4% (95% CI 91.8 - 98.8), followed by the lower leg at 94.4% (95% CI 81.3 - 99.3), the upper arm at 89.6% (95% CI 79.7 - 95.7) and the forearm at 77.8% (95% CI 40.0 - 97.2). For gunshot wounds the specificity was 96.1% (95% CI 92.4 - 98.3), while for stab wounds it was 86.8% (95% CI 74.7 - 94.5). CONCLUSIONS: This study agrees with current literature indicating that physical examination has high specificity in detecting arterial injury in the setting of penetrating trauma to an extremity. However, it shows that the specificity is not equal for all anatomical regions or mechanisms of injury.

Factores asociados al síndrome de Wellens en pacientes con síndrome coronario agudo sin elevación del segmento ST / Factors associated to Wellens' syndrome in patients with acute coronary syndrome without ST-segment elevation

Introducción: El síndrome de Wellens constituye un equivalente del síndrome coronario agudo con elevación del segmento ST. Este incluye dos patrones electrocardiográficos que sugieren lesión crítica de la arteria descendente anterior. Objetivo: Evaluar probables factores asociados al síndrome de Wellens en pacientes con síndrome coronario agudo sin elevación del segmento ST y lesiones coronarias significativas en la arteria descendente anterior. Material y métodos: Se realizó un estudio observacional, analítico, transversal en pacientes con diagnóstico de síndrome coronario agudo sin elevación del ST y lesión significativa en la arteria descendente anterior, comprobada mediante coronariografía, ingresados en la unidad de cuidados coronarios intensivos del Hospital Clínico-Quirúrgico Manuel Fajardo entre el 2016 y 2019. Resultados: La edad media fue de 66 años, predominó el sexo masculino (53,9 por ciento) y el antecedente de hipertensión arterial (89,5 por ciento). Los pacientes con síndrome de Wellens tuvieron un significativo menor porcentaje de antecedente de cardiopatía isquémica (58,1 por ciento vs. 84,8 por ciento; p = 0,012). Además, el síndrome arrojó asociación estadísticamente muy significativa con la condición de fumador activo (51,2 por ciento vs. 15,2 por ciento; p < 0,01). No se encontró relación estadística significativa entre el síndrome de Wellens y el resultado angiográfico. Conclusiones: La presencia de los patrones electrocardiográficos del síndrome de Wellens se asocia con el hábito tabáquico en pacientes con síndrome coronario agudo sin elevación del segmento ST y lesiones coronarias en la arteria descendente anterior, y su ausencia se asocia con el antecedente de cardiopatía isquémica en el mismo subgrupo de individuos(AU)

Introduction: Wellens' syndrome is equivalent to acute coronary syndrome with ST-segment elevation. It includes two electrocardiographic patterns suggesting a critical lesion in the anterior descending artery. Objective: Evaluate probable factors associated to Wellens' syndrome in patients with acute coronary syndrome without ST-segment elevation and significant coronary lesions in the anterior descending artery. Methods: A cross-sectional observational analytical study was conducted of patients diagnosed with acute coronary syndrome without ST-segment elevation and significant lesion in the anterior descending artery verified by coronary arteriography, admitted to the intensive coronary care unit at Manuel Fajardo Clinical Surgical Hospital in the period 2016-2019. Results: Mean age was 66 years, with a predominance of the male sex (53.9 percent) and a history of hypertension (89.5 percent). Patients with Wellens' syndrome had a significantly lower percentage of ischemic heart disease antecedents (58.1 percent vs. 84.8 percent; p = 0.012). A very significant statistical association was observed between the syndrome and active smoking (51.2 percent vs. 15.2 percent; p < 0.01). A significant statistical relationship was not found between Wellens' syndrome and angiographic results. Conclusions: The presence of electrocardiographic patterns of Wellens' syndrome is associated to smoking in patients with acute coronary syndrome without ST-segment elevation and coronary lesions in the anterior descending artery, whereas their absence is associated to a history of ischemic heart disease in the same subgroup of individuals(AU)

Terapia endovascular en trauma periférico: una alternativa a la cirugía abierta tradicional / Endovascular therapy in peripheral trauma: our experience

Resumen Introducción: La terapia endovascular ha demostrado ser una buena alternativa de tratamiento en las enfermedades arteriales y venosas. Asimismo, en trauma vascular periférico constituye una excelente opción, especialmente en sitios anatómicos difíciles de acceder y con lesiones complejas como seudoaneurismas, fístulas arteriovenosas (FAV) o la combinación de ambos, con numerosas ventajas. Objetivo: Evaluar los resultados del tratamiento endovascular en trauma vascular penetrante por agresiones y iatrogenias. Materiales y Método: Revisión retrospectiva de todos los pacientes con trauma vascular periférico sometidos a terapia endovascular. Resultados: Entre abril de 2011 y mayo de 2020 se trataron 30 pacientes, 28 hombres y 2 mujeres. Con edades fluctuantes entre 17 y 84 años. La causa del trauma fue 20 penetrantes y 10 iatrogenias. Los vasos afectados fueron arteria femoral superficial 6, femoral profunda 2, subclavia 9, axilar 1, poplítea 4, ilíacas 1, peronea 1, tibial anterior 5, tronco venoso braquiocefálico 1. Diecisiete pacientes fueron tratados con endoprótesis, 9 con embolización y 4 con cierre percutáneo en relación con catéteres arteriales en subclavia. No hubo mortalidad, pero dos pacientes requirieron reparación abierta: un seudoaneurisma poplíteo gigante y un seudoaneurisma de tibial anterior, en ambos se constató sección completa de ambas arterias. El seguimiento clínico ha sido entre 30 días y 3 años. Conclusiones: En esta serie de casos, la terapia endovascular en lesiones de trauma vascular periférico ofrece excelentes resultados con baja morbimortalidad y permeabilidad aceptable a corto y mediano plazo.

Introduction: Endovascular therapy has proven to be a good treatment alternative in arterial and venous diseases. Likewise, in peripheral vascular trauma it is an excellent option, especially in anatomical sites that are difficult to access and with complex lesions such as pseudoaneurysms, arteriovenous fistulas (AVFs) or the combination of both, with numerous advantages. Aim: To evaluate the results of endovascular treatment in trauma Penetrating vascular injury and iatrogenesis. Materials and Method: Retrospective review of all patients with peripheral vascular trauma undergoing endovascular therapy. Results: Between April 2011 and May 2020, 30 patients were treated, 28 men and 2 women. With fluctuating ages between 17 and 84 years. The cause of the trauma was 20 penetrating and 10 iatrogenic. The affected vessels were superficial femoral artery 6, deep femoral 2, subclavian 9, axillary 1, popliteal 4, iliac 1, peroneal 1, anterior tibial 5, brachiocephalic venous trunk 1. Seventeen patients were treated with endoprosthesis, 9 with embolization and 4 with percutaneous closure in relation to arterial catheters in the subclavian. There was no mortality but two patients required open repair: a giant popliteal pseudoaneurysm and an anterior tibial pseudoaneurysm in which both sections of both arteries were found to be complete. Clinical follow-up was between 30 days and 3 years. Conclusión: In this serie, endovascular therapy in peripheral vascular trauma lesions offers excellent results with low morbidity and mortality and acceptable patency in the short and medium term.

Posterior Wall Acetabulum Fracture with a Persistent Sciatic Artery: A Case Report.

CASE: We report the case of a patient who sustained a left posterior wall acetabular fracture with an ipsilateral persistent sciatic artery (PSA). The PSA was diagnosed preoperatively on lower extremity computed tomography angiogram. He was treated with open reduction internal fixation through a Kocher-Langenbeck approach. The PSA and sciatic nerve were identified and protected throughout the case. There were no neurovascular complications. CONCLUSION: PSA in the setting of posterior wall acetabulum fractures has not been reported previously. Orthopaedic surgeons who treat these injuries should be aware of PSA anatomic variants so that they can be identified and protected during surgery.

Factors Affecting the Re-Endothelialization of Endothelial Progenitor Cell.

The vascular endothelium, which plays an essential role in maintaining the normal shape and function of blood vessels, is a natural barrier between the circulating blood and the vascular wall tissue. The endothelial damage can cause vascular lesions, such as atherosclerosis and restenosis. After the vascular intima injury, the body starts the endothelial repair (re-endothelialization) to inhibit the neointimal hyperplasia. Endothelial progenitor cell is the precursor of endothelial cells and plays an important role in the vascular re-endothelialization. However, re-endothelialization is inevitably affected in vivo and in vitro by factors, which can be divided into two types, namely, promotion and inhibition, and act on different links of the vascular re-endothelialization. This article reviews these factors and related mechanisms.

Three-Dimensional Computed Tomography of the Detoured Facial Artery: Variations and Implications for Nasojugal Groove Correction.

BACKGROUND: When performing filler injection procedures to the nasojugal groove, there is the risk of iatrogenic damage to the detoured facial artery. OBJECTIVE: To determine the 3-dimensional location of the detoured facial artery. MATERIALS AND METHODS: The branches of the facial arteries from 118 cadaveric hemifaces were scanned using computed tomography and reconstructed using the Mimics software program. RESULTS: Detoured facial arteries were found in 47 of the 118 hemifaces (39.8%). Two main arterial patterns were identified: in Type I (29 of 47 cases), there were both detoured and nasolabial trunks where the facial artery originated, whereas in Type II (18 of 47 cases), there was only a detoured trunk. The detoured trunk originated 32.0 ± 5.3 mm from the midsagittal line, 5.0 ± 2.8 mm from the occlusion plane, and 5.9 ± 3.5 mm below the skin layer; the inflection of the detoured trunk was located 30.0 ± 5.6 mm laterally, 26.2 ± 4.4 mm superiorly, and 5.7 ± 2.6 mm deep. The meeting point with the inferior orbital rim plane was located 17.1 ± 3.4 mm laterally, 43.4 ± 3.1 mm superiorly, and 2.8 ± 1.7 mm deep. CONCLUSION: The 3-dimensional location of the detoured facial artery as reported here will help clinicians to avoid iatrogenic damage when they are performing filler injection procedures.

Management of Inadvertent Supra-aortic Arterial Lesions During Central Venous Access Procedures: Report of Six Cases and Proposed Algorithm.

Accidental supra-aortic arterial cannulation during central venous catheter (CVC) insertion is a rare and serious complication associated with risk of vascular and neurologic complications. The aim of this study is describing our 6 cases experience and propose a management algorithm. We retrospectively evaluated the diagnosis and treatment of six patients arrived at our Department for accidental supra-aortic arterial cannulation during CVC insertion. They underwent Doppler Ultrasonography (DUS) or Computed Tomography Angiography (CTA) to confirm the arterial damage and to decide the correct therapeutic pathway. Four patients underwent DUS as the shallow location of injured arteries and 2 patients CTA because of the arterial damage deeply located. Surgical procedure with direct arterial suture was performed in four patients. Endovascular treatment with stent graft deployment was carried out in two patients. All procedures were conducted successfully: technical success (immediate hemostasis and vessel patency) was obtained in 100% of the cases. Postoperative imaging (DUS or CTA) confirmed the absence of arterial bleeding and the arterial patency. No perioperative mortality or complications occurred. After a careful review of literature and our case series, we proposed an algorithm to delineate the optimal treatment strategy, explaining that early and careful diagnosis (by DUS or CTA) and prompt repair appear crucial to achieve good outcomes and clarifying that an endovascular technique (stent graft placement or vascular closure device) seems to be the best treatment in these cases. Finally, an open surgical technique could be indicated in case of common carotid artery injury and concurrent catheter passing through the target vein.

Outcomes of Arterial Grafts for the Reconstruction of Military Lower Extremity Arterial Injuries.

INTRODUCTION: Lower extremity (LE) arterial injuries are common in military casualties and limb salvage is a primary goal. Bypass grafts are the most common reconstructions; however, their specific outcomes are largely unreported. We sought to describe the outcomes of LE arterial grafts among combat casualties and their association with limb loss. METHODS: Retrospective cohort study of 2004-2012 Iraq/Afghanistan casualties with LE arterial injury undergoing bypass graft from a database containing follow-up until amputation, death, or military discharge. Primary outcome was composite graft complications (GC-thrombosis, stenosis, pseudoaneurysm, blowout, and/or arteriovenous fistula). RESULTS: Two hundred and twenty-two grafts were included (99 femoral, 73 popliteal, 48 tibial). 56 (26%) had at least one GC; thrombosis was most common in femoral, stenosis most common in popliteal and tibial. GC was not associated with graft level but was associated with synthetic conduit (P = 0.01) and trended towards an association with multiple-level arterial injuries (P = 0.07). Four of eight (50%) synthetic grafts had amputations, all within 72h. Two of the eight synthetic grafts thrombosed, and both limbs were amputated. There were 52 total amputations. Amputation was performed in 13 (23%) of limbs with a GC and 24% of those without (P = 0.93) Overall, 24 (11%) of grafts thrombosed, 16 within 48h and 13 (25%) in limbs undergoing amputation (P = 0.001 for association of thrombosis with amputation). CONCLUSION: GC are common among LE bypass grafts in combat casualties but are not associated with limb loss. Thrombosis is predominantly early and is associated with amputation. Closer attention to ensuring early patency may improve limb salvage.