The effect of vein repair on the risk of venous thromboembolic events: a review of more than 100 traumatic military venous injuries

Assessment and Interventions for Vascular Injuries Associated With Fractures

Vascular injuries associated with fractures are limb-threatening injuries with notable morbidity. The prompt and thorough evaluation of these patients is imperative to diagnose vascular injuries, and coordinated multidisciplinary care is needed to provide optimal outcomes. The initial assessment includes a detailed physical examination assessing for hard and soft signs of arterial injury, and the arterial pressure index can be used to reliably identify vascular compromise and the need for additional assessment or intervention. Advanced imaging in the form of CT angiography is highly sensitive in additional characterization of the potential injury and can be obtained in an expedient manner. The optimal treatment of fractures with vascular injuries includes providing skeletal stability and confirming or reestablishing adequate distal perfusion as soon as possible. Options for vascular intervention include observation, ligation, direct arterial repair, vascular bypass grafting, endovascular intervention, and staged temporary shunting, followed by bypass grafting. Although the optimal sequence of surgical intervention remains an incompletely answered question, the orthopaedic role in the care of patients with these injuries is to provide mechanical stability to the injured limb to protect the vascular repair and surrounding soft-tissue envelope.

Lessons Learned From Treating 114 Inferior Vena Cava Injuries at a Limited Resources Environment - A Single Center Experience

BACKGROUND

The inferior vena cava is the most frequently injured vascular structure in penetrating abdominal trauma. We aimed to review inferior vena cava injury cases treated at a limited resources facility and to discuss the surgical management for such injures.

METHODS

This was a retrospective study of patients with inferior vena cava injuries who were treated at a single center between January 2011 and January 2020. Data pertaining to the following were assessed: demographic parameters, hypovolemic shock at admission, the distance that the patient had to be transported to reach the hospital, affected anatomical segment, treatment, concomitant injuries, complications, and mortality. Non-parametric data were analyzed using Fisher's exact, Chi-square, Mann-Whitney, or Kruskal-Wallis test, as applicable. The Student's t-test was used to assess parametric data. Moreover, multiple logistic regression analyses (including data of possible death-related variables) were performed. Statistical significance was set at P <0.05.

RESULTS

Among 114 patients with inferior vena cava injuries, 90.4% were male, and the majority were aged 20-29 years. Penetrating injuries accounted for 98.2% of the injuries, and the infrarenal segment was affected in 52.7% of the patients. Suturing was perfomed in 69.5% and cava ligation in 29.5% of the patients, and 1 patient with retrohepatic vena cava injury was managed non-operatively. The overall mortality was 52.6% with no case of compartment syndrome in the limbs. A total of 7.9% of the patients died during surgery.

CONCLUSION

The inferior vena cava is often injured by penetrating mechanisms, and the most frequently affected segment was the infrarenal segment. A higher probability of death was not associated with injury to a specific anatomical segment. Additionally, cava ligation was not related to an increased probability of compartment syndrome in the leg; therefore, prophylactic fasciotomy was not supported.

Review article: History of venous trauma

ABSTRACT

This is a literature review on the history of venous trauma since the 1800s, especially that to the common femoral, femoral and popliteal veins, with focus on the early 1900s, World War I, World War II, Korean War, Vietnam War, and then civilian and military reviews (1960-2020). In the latter two groups, tables were used to summarize the following: incidence of venous repair versus ligation, management of popliteal venous injuries, patency of venous repairs when assessed <30 days from operation, patency of venous repairs when assessed >30 days from operation, clinical assessment (edema or not) after ligation versus repair, incidence of deep venous thrombosis after ligation versus repair, and incidence of pulmonary embolism after ligation versus repair.There is a lack of the following in the literature on the management of venous injuries over the past 80 years: standard definition of magnitude of venous injury in operative reports, accepted indications for venous repair, standard postoperative management, and timing and mode of early and later postoperative assessment.Multiple factors have entered into the decision on venous ligation versus repair after trauma for the past 60 years, but a surgeon's training and local management protocols have the most influence in both civilian and military centers. Ligation of venous injuries, particularly those in the lower extremities, is well tolerated in civilian trauma, although there is the usual lack of short- and long-term follow-up as noted in many of the articles reviewed.

LEVEL OF EVIDENCE

Review article, levels IV and V.

Venous ligation versus venous repair: does the procedure impact venous thromboembolism risk?

Background

Traumatic lower extremity venous injuries are most commonly managed with either a vein ligation or repair procedure. Venous injuries are associated with an increased risk of developing venous thromboembolisms (VTE), but little is understood with regard to how specific surgical treatments may impact the risk of developing either a deep vein thrombosis (DVT) or a pulmonary embolism (PE). In this study of lower extremity venous injuries, we hypothesized that venous ligation would be associated with an increased risk of DVT but a lower risk of PE when compared with venous repair.

Methods

Patients were identified from the National Trauma Data Bank (2008 to 2014) with at least one iliac, femoral, popliteal, or tibial venous injury and who received either a vein ligation or repair. The patients were then compared based on the type of procedure and the location of the injury to assess the risk of DVT and PE between the groups.

Results

A total of 1214 patients were identified. There was no difference between patients who received a vein ligation versus a repair with respect to age, injury severity score, or initial systolic blood pressure. There was no difference in the odds of developing either a DVT or PE between patients who were treated with vein ligation versus repair. There was also no difference in VTE rates when stratified by the location of the injury.

Conclusions

In individuals with lower extremity venous injuries, there is no difference in the rate of DVT or PE complications when comparing venous repair and ligation procedures. The role of anticoagulation remains to be elucidated following operative treatment.

Level of evidence

Therapeutic/Care Management, Level IV.

Presentation patterns and prognosis of 109 isolated venous injuries in 99 patients

Objectives

To identify outcome predictors of isolated venous injuries (VIs).

Methods

Retrospective analysis of prospectively collected information.

Results

A total of 99 patients with 109 isolated VI were included. All-cause mortality was 18/99 (18%) and mortality related to the VI was 10/99 (10%). On multivariate analysis, independent predictors of all-cause mortality included age (odds ratio – OR – 1.06, p = 0.042), external cause – trauma and foreign body retention – of VI (OR 34.62, p = 0.002) and the number of red blood cell units transfused intraoperatively (OR 2.10, p < 0.001), while independent predictors of VI-related mortality included external cause of VI (OR 47.60, p = 0.001) and the number of red blood cell units transfused intraoperatively (OR 1.72, p = 0.003).

Conclusions

VIs due to external causes have a high mortality rate. On the other hand, VIs due to internal causes (iatrogenic injuries during a surgical procedure) are managed promptly and have a very low mortality related to the VI.

The First Aid and Hospital Treatment of Gunshot and Blast Injuries

BACKGROUND

When gunshot and blast injuries affect only a single person, first aid can always be delivered in conformity with the relevant guidelines. In contrast, when there is a dynamic casualty situation affecting many persons, such as after a terrorist attack, treatment may need to be focused on immediately life-threatening complications.

METHODS

This review is based on pertinent publications retrieved by a selective search in Medline and on the authors' clinical experience.

RESULTS

In a mass-casualty event, all initial measures are directed toward the survival of the greatest possible number of patients, in accordance with the concept of "tactical abbreviated surgical care." Typical complications such as airway obstruction, tension pneumothorax, and hemorrhage must be treated within the first 10 minutes. Patients with bleeding into body cavities or from the trunk must be given priority in transport; hemorrhage from the limbs can be adequately stabilized with a tourniquet. In-hospital care must often be oriented to the principles of "damage control surgery," with the highest priority assigned to the treatment of life-threatening conditions such as hemodynamic instability, penetrating wounds, or overt coagulopathy. The main considerations in initial surgical stabilization are control of bleeding, control of contamination and lavage, avoidance of further consequences of injury, and prevention of ischemia. Depending on the resources available, a transition can be made afterward to individualized treatment.

CONCLUSION

In mass-casualty events and special casualty situations, mortality can be lowered by treating immediately life-threatening complications as rapidly as possible. This includes the early identification of patients with lifethreatening hemorrhage. Advance preparation for the management of a masscasualty event is advisable so that the outcome can be as favorable as possible for all of the injured in special or tactical casualty situations.

Venous thromboembolism after major venous injuries: Competing priorities

BACKGROUND

Venous thromboembolism (VTE) after major vascular injury (MVI) is particularly challenging because the competing risk of thrombosis and embolization after direct vessel injury must be balanced with risk of bleeding after surgical repair. We hypothesized that venous injuries, repair type, and intraoperative anticoagulation would influence VTE formation after MVI.

METHODS

A multi-institution, retrospective cohort study of consecutive MVI patients was conducted at three urban, Level I centers (2005-2013). Patients with MVI of the neck, torso, or proximal extremities (to elbows/knees) were included. Our primary study endpoint was the development of VTE (DVT or pulmonary embolism [PE]).

RESULTS

The 435 major vascular injury patients were primarily young (27 years) men (89%) with penetrating (84%) injuries. When patients with (n = 108) and without (n = 327) VTE were compared, we observed no difference in age, mechanism, extremity injury, tourniquet use, orthopedic and spine injuries, damage control, local heparinized saline, or vascular surgery consultation (all p > 0.05). VTE patients had greater Injury Severity Score (ISS) (17 vs. 12), shock indices (1 vs. 0.9), and more torso (58% vs. 35%) and venous (73% vs. 48%) injuries, but less often received systemic intraoperative anticoagulation (39% vs. 53%) or postoperative enoxaparin (47% vs. 61%) prophylaxis (all p < 0.05). After controlling for ISS, hemodynamics, injured vessel, intraoperative anticoagulation, and postoperative prophylaxis, multivariable analysis revealed venous injury was independently predictive of VTE (odds ratio, 2.7; p = 0.002). Multivariable analysis of the venous injuries subset (n = 237) then determined that only delay in starting VTE chemoprophylaxis (odds ratio, 1.3/day; p = 0.013) independently predicted VTE after controlling for ISS, hemodynamics, injured vessel, surgical subspecialty, intraoperative anticoagulation, and postoperative prophylaxis. Overall, 3.4% of venous injury patients developed PE, but PE rates were not related to their operative management (p = 0.72).

CONCLUSION

Patients with major venous injuries are at high risk for VTE, regardless of intraoperative management. Our results support the immediate initiation of postoperative chemoprophylaxis in patients with major venous injuries.

LEVEL OF EVIDENCE

Therapeutic/care management, level IV.

Management of Peripheral and Truncal Venous Injuries

Civilian injuries are increasing according to the World Health Organization, and this is attributed mainly to road traffic accidents and urban interpersonal violence. Vascular injuries are common in these scenarios and are associated with high morbidity and mortality rates. Associated peripheral venous trauma is less likely to lead to death and controversy remains whether ligation or repair should be the primary approach. Conversely, non-compressible truncal venous insult can be lethal due to exsanguination, thus a high index of suspicion is crucial. Operative management is demanding with fair results but recent endovascular adjuncts demonstrate promising results and seem to be the way forward for these serious conditions.

Venous Shunt Versus Venous Ligation for Vascular Damage Control: The Immunohistochemical Evidence

BACKGROUND

To evaluate the expression of immunohistochemical markers of tissue ischemia (iNOS, eNOS, and HSP70) in a vascular damage control experimental model to determine if a venous temporary vascular shunt insertion leads to a better limb perfusion when compared with the ligature of the injured vein.

METHODS

Experimental study in male Sus Scrofa weighting 40 Kg. Animals were distributed into 5 groups: group 1 animals were submitted to right external iliac artery (EIA) shunting and right external iliac vein (EIV) ligation; group 2 animals were submitted to right EIA shunting and right EIV shunting; group 3 animals were submitted to right EIV ligation; group 4 animals were submitted to right EIV shunting; group 5 animals were not submitted to vascular shunting or venous ligation. Transonic Systems flowmeters were used to measure vascular flow on right and left external iliac vessels, and i-STAT (Abbot) portable blood analyzer was used for EIVs blood biochemical analysis. An initial baseline register of invasive arterial pressure, iliac vessels flow, and venous blood analysis was performed. Arterial pressure and iliac vessels flow were taken immediately after right iliac vessels shunting or ligation. Then, hemorrhagic shock was induced by continuous 20 mL/min blood withdraw from the external right jugular vein whereas arterial blood pressure and iliac vessels flow registers were taken every 10 min, and blood samples from EIVs were obtained every 30 min until the vascular flow through right EIA (or through the shunt inserted into the right EIV for group 4 animals) became inexistent or until the animal's death. After the end of the experiments, bilateral hind limb's biopsies were obtained for immunohistochemical analysis. Using image editing and analysis software, the expression of iNOS, eNOS, and HSP70 (3 well-known ischemic associated immunohistochemical markers) was assessed. The mean expression of each marker in the right hind limb was compared between groups. For statistical analysis, Microsoft Office Excel 2007 and BioEstat 5.0 (2007) were used.

RESULTS

Immunohistochemical analysis showed no difference regarding the iNOS expression; nevertheless, both eNOS and HSP70 expression were statistically more intense (P < 0.05) on group 1 (eNOS = 1.32; HSP70 = 15.05) than on group 2 (eNOS = 0.018; HSP70 = 8.56).

CONCLUSIONS

The higher expression of eNOS and HSP70 in the right hind limbs of group 1 animals (arterial shunt and venous ligature) than group 2 animals (arterial shunt and venous shunt) suggests that venous ligation is associated with more intense ischemic histological findings than venous shunting.

Risk of pulmonary embolism with repair or ligation of major venous injury following penetrating trauma

BACKGROUND

There are many benefits of repair over ligation of major venous injuries (MVIs) following penetrating trauma, but the risk of pulmonary embolism (PE) is not well defined. We hypothesized that rates of PE are comparable between repair and ligation of MVI.

METHODS

All penetrating trauma patients with MVI requiring an operation from 2003 to 2012 (n = 158) were retrospectively reviewed. Propensity scores were based on a logistic regression model using patient and injury characteristics. A 1:1 fixed ratio nearest neighbor matching was performed to compare outcomes of the repair and ligation cohorts. Data are reported as mean ± SD if parametric, or median (interquartile range) if not, and compared using a t test, Mann-Whitney U-test, χ2, or Fisher's exact test, as appropriate.

RESULTS

The population was 89% male, age 32 ± 12 years, 74% gunshot wound, Injury Severity Score of 19 ± 13, length of stay of 9 (18) days, 3.8% PE, and a mortality of 21.5%. Repair was performed in 37% (n = 59), ligation was performed in 60% (n = 94), and 3% required both. With ligation versus repair, ligation patients were generally more critically injured; 48-hour survival was 78% versus 93% (p = 0.0083), initial Glasgow Coma Scale (GCS) score was 12 ± 5 versus 14 ± 3 (p = 0.003), initial base excess was -9 ± 8 versus -5 ± 5 mEq/L (p = 0.003), more packed red blood cells were transfused (12 (14) U vs. 9 (12) U; p = 0.032), and major arterial injury was more likely (86% vs. 42%, p < 0.001), but the PE rate was identical (5.9%) in propensity-matched cohorts. In those who developed a PE, all were receiving standard thromboprophylaxis.

CONCLUSION

Following penetrating trauma, the risk of PE between repair and ligation of MVI is comparable.

LEVEL OF EVIDENCE

Epidemiologic study, level III.

Limb salvage after vascular reconstruction followed by tissue transfer during the Global War on Terror

BACKGROUND

Combat extremity wounds are complex and frequently require an immediate vascular reconstruction in the operational environment followed by delayed tissue coverage at a stateside medical treatment facility. The purpose of this study was to evaluate limb salvage outcomes after combat-related vascular reconstruction that subsequently required delayed soft tissue coverage during the Global War on Terror.

METHODS

Patients who incurred a war-related extremity injury necessitating an immediate vascular intervention followed by definitive limb reconstruction requiring flap coverage from combat injuries were reviewed. Patient demographics, types of vascular and extremity injuries, and surgical interventions were examined. Outcomes included limb salvage, primary and secondary graft patency, flap outcomes, and complications. Differences between upper extremities (UEs) and lower extremities (LEs) were compared.

RESULTS

From 2003 to 2012, 27 patients were treated for combat-related extremity injuries with an immediate vascular reconstruction followed by delayed tissue coverage. Fifteen LEs and 12 UEs were treated. The mean age was 24 years. An explosion was the cause in 77% of patients, with a mean Injury Severity Score (ISS) of 19. An autogenous vein bypass was the most common reconstruction performed in 20 patients (74%). Other vascular repairs included a primary repair, a patch angioplasty with bovine pericardium, and a bypass with use of a prosthetic graft. Eight patients (30%) had a concomitant venous injury, and 23 (85%) had a bone fracture. Thirty flaps were performed at a mean of 33 days from the original injury. Pedicle flaps were used in 24 limbs and free tissue flaps in six limbs. Muscle, fasciocutaneous, bone, and composite flaps were used for tissue coverage. At a mean follow-up of 16 months, primary patency rates of all arterial reconstructions were 66% in the UE and 53% in the LE (P = .69). Secondary patency rates were 100% in the UE and 86% in the LE (P = .48). The overall limb salvage rate was 81%. Limb salvage rates were 66% in the LE and 100% in the UE (P = .04). Three amputated lower limbs (60%) had inline flow to the foot. The flap success rate was 96%. Reasons for amputation included arterial thrombosis, flap failure, persistent soft tissue infection, osteomyelitis, and debilitating peripheral nerve injuries with associated chronic pain.

CONCLUSIONS

Immediate vascular repair followed by delayed tissue coverage can be performed with a high (>80%) limb salvage rate after combat trauma. Limb salvage rates were higher in the UE despite equivocally high arterial patency rates. Wounded warriors can expect limb salvage by use of this international algorithm.

Intraoperative injuries during liver resection: analysis of 1,005 procedures

PURPOSE

Risk of liver resection has been well investigated in many studies. However, the problem of intraoperative injuries is rarely mentioned. The aim of this study was to assess the incidence, the type, and management of intraoperative injuries during liver resection.

METHODS

A total of 1,005 liver resections between 2004 and 2009 were included in this retrospective investigation. We analyzed the incidence of intraoperative injuries, risk factors, and an impact on patients' clinical outcome.

RESULTS

The overall incidence of intraoperative injuries was 4.4% (44 of 1,005). Injuries of the diaphragm (1.6%, 16 of 1,005) and hepatocaval junction (1%, 10 of 1,005) were the most frequent. In multivariate analysis, tumor recurrence (p = 0.0199) and tumor size (p = 0.0317) were the only independent risk factors for diaphragm injuries, whereas the extent of resection (p = 0.0007) was the only independent risk factor for caval or hepatic vein injuries. Injuries of the inferior vena cava or hepatic veins significantly increased perioperative mortality (p = 0.0005).

CONCLUSIONS

Minor injuries causing no significant complications were the most frequent. However, prevention and proper management of the rare injuries of hepatocaval junction are essential to avoid increased mortality in major liver resections.

Handlebar injury to femoral vein: case report and review

Handlebar injury varies from minor trauma to life-threatening visceral and vascular damage resulting in a significant morbidity among children. Femoral vein injuries secondary to handlebar trauma are rare but potentially serious. Venous continuity should be restored and several techniques for repair of femoral injuries have been described. We reported a case of femoral vein injury secondary to handlebar trauma in a child and we described techniques used for its repair.

Popliteal artery repair in massively transfused military trauma casualties: a pursuit to save life and limb

BACKGROUND

Popliteal artery war wounds can bleed severely and historically have high rates of amputation associated with ligation (72%) and repair (32%). More than before, casualties are now surviving the initial medical evacuation and presenting with severely injured limbs that prompt immediate limb salvage decisions in the midst of life-saving maneuvers. A modern analysis of current results may show important changes because previous limb salvage strategies were limited by the resuscitation and surgical techniques of their eras. Because exact comparisons between wars are difficult, the objective of this study was to calculate a worst-case (a pulseless, fractured limb with massive hemorrhage from popliteal artery injury) amputation-free survival rate for the most severely wounded soldiers undergoing immediate reconstruction to save both life and limb.

METHODS

We performed a retrospective study of trauma casualties admitted to the combat support hospital at Ibn Sina Hospital in Baghdad, Iraq, between 2003 and 2007. US military casualties requiring a massive transfusion (> or = 10 blood units transfused within 24 hours of injury) were identified. We extracted data on the subset of casualties with a penetrating supra or infrageniculate popliteal arterial vascular injury. Demographics, injury mechanism, Injury Severity Score, tourniquet use, physiologic parameters, damage control adjuncts, surgical repair techniques, operative time, and outcomes (all-cause 30-day mortality, amputation rates, limb salvage failure, and graft patency) were investigated.

RESULTS

Forty-six massively transfused male casualties, median age 24 years (range, 19-54 years; mean Injury Severity Score, 19 +/- 8.0), underwent immediate orthopedic stabilization and vascular reconstruction. There was one early death. The median operative time for the vascular repairs was 217 minutes (range, 94-630 minutes) and included all damage control procedures. Combined arterial and venous injuries occurred in 17 (37%). Ligation was performed for no arterial and 9 venous injuries. Amputations (transtibial or transfemoral) were considered limb salvage failures (14 of 48, 29.2%) and were grouped as immediate (< or = 48 hours, 5), early (>48 hours and < or = 30 days, 6), or late (>30 days, 3). Limb losses were from graft thrombosis, infection, or chronic pain. Combined arterial and venous injuries occurred in 17 (37%). Ligation was performed for no arterial and nine venous injuries. For a median follow-up (excluding death) of 48 months (range, 23-75 months), the amputation-free survival rate was 67%.

CONCLUSIONS

This study, a worst-case study, showed comparable results to historical controls regarding limb salvage rates (71% for Iraq vs. 56-69% for the Vietnam War). Thirty-day survival (98%), 4-year amputation-free survival (67%), and complication-free rates (35%) fill knowledge gaps. Guidelines for managing popliteal artery injuries show promising results because current resuscitation practices and surgical care yielded similar amputation rates to prior conflicts despite more severe injuries. Significant transfusion requirements and injury severity may not indicate a life-over-limb strategy for popliteal arterial repairs. Future studies of limb salvage failures may help improve casualty care by reducing the complications that directly impact amputation-free survival.

Issues in revascularization of the ischemic foot and ankle war injury

The battlefield has provided a multitude of advancements in the management of hemorrhage and vascular repair. Basic understanding of the anatomy and exposures of lower extremity injuries is essential to any surgeon caring for these patients. The techniques of repair and potential adjunctive measures (eg, shunts) available should always be considered when approaching a vascular injury. The most important concept from a vascular standpoint is the fact that a multidisciplinary approach to these complex patients is required with maximal tissue preservation when feasible and safe.

The use of prosthetic grafts in complex military vascular trauma: a limb salvage strategy for patients with severely limited autologous conduit

BACKGROUND

The use of prosthetic grafts for reconstruction of military vascular trauma has been consistently discouraged. In the current conflict, however, the signature wound involves multiple extremities with significant loss of soft tissue and potential autogenous venous conduits. We reviewed the experience with the use of prosthetic grafts for the treatment of vascular injuries sustained during recent conflicts in Iraq and Afghanistan.

METHODS

Trauma registry records with combat-related vascular injuries repaired using prosthetic grafts were retrospectively reviewed from March 2003 to April 2006. Data collected included age, gender, mechanism of injury, vessel injured, conduit, graft patency, complications, including amputation and eventual outcome of repair.

RESULTS

Prosthetic grafts were placed in 14 of 95 (15%) patients undergoing extremity bypass for vascular injuries. Patients were men with an average age of 25 years (range, 19-39 years). All prosthetic grafts in this series were made of polytetrafluoroethylene. Mechanism of injury included blast (n = 6), gunshot wounds (n = 6), and blunt trauma (n = 2), resulting in prosthetic repair of injuries to the superficial femoral (n = 8), brachial (n = 3), common carotid (n = 1), subclavian (n = 1), and axillary (n = 1) arteries. Mean evacuation time from injury to stateside arrival was 7 days (range, 3-9 days). Twelve grafts were placed initially at the time of injury, and two after vein graft blow out with secondary hemorrhage. The mean follow-up period was 427 days (range, 49-1,285 days). Seventy-nine percent of prosthetic grafts stayed patent in the short term, allowing patient stabilization, transport to a stateside facility, and elective revascularization with the remaining autologous vein graft. Three prosthetic grafts were replaced urgently for thrombosis. The remaining seven grafts were replaced electively for severe stenosis (3) or exposure (4) with presumed infection. There were no prosthetic graft blow outs or deaths in this series. No patients required amputation because of prosthetic graft failure. Three (21%) patients went on to have elective lower extremity amputation, despite patent grafts for nonsalvagable limbs.

CONCLUSIONS

When managing patients with multiple extremity trauma and limited noninjured autogenous venous conduits, emergent use of prosthetic grafts may provide an effective limb salvage strategy. Despite being placed in multisystem trauma patients with large contaminated soft tissue wounds, emergent revascularization with polytetrafluoroethylene allowed patient stabilization, transport to a higher echelon of care, and elective revascularization with remaining limited autologous vein.