Vascular Surgery on the Modern Battlefield

Update in combined musculoskeletal and vascular injuries of the extremities

Combined musculoskeletal and vascular injuries of the extremities are conditions in which a multidisciplinary approach is a sine qua non to ensure life initially and limb viability secondarily. Vascular injuries as part of musculoskeletal trauma are usually the result of the release of a high energy load in the wound site so that the prognosis is determined by the degree of soft-tissue damage, duration of limb ischemia, patient's medical status and presence of associated injuries. The management of these injuries is challenging and requires a specific algorithm of action, because they are usually characterized by increased morbidity, amputation rate, infection, neurological and functional deficits, and they could be life threatening. Although vascular injuries are rare and occur either isolated or in the context of major combined musculoskeletal trauma, the high index of suspicion, imaging control, and timely referral of the patient to organized trauma centers ensure the best functional outcome of the extremity in such challenging cases. Even after a successful initial treatment of a combined trauma pattern, long-term follow-up is crucial to prevent and detect early possible complications. The purpose of this manuscript is to provide an update on diagnosis and treatment of combined musculoskeletal and vascular injuries of the extremities, from an orthopedic point of view.

Terrorist attacks: common injuries and initial surgical management

Terrorism-related incidents and shootings that involve the use of war weapons and explosives are associated with gunshot and blast injuries. Despite the perceived threat of terrorism, these incidents and injuries are rare in Germany. For this reason, healthcare providers are unlikely to have a full understanding of the special aspects of managing these types of injuries. Until a clear and complete picture of the situation is available after a terrorist or shooter incident, tactical and strategic approaches to the clinical management of the injured must be tailored to circumstances that have the potential to overwhelm resources temporarily. Hospitals providing initial care must be aware that the first patients who are taken to medical facilities will present with uncontrollable bleeding from injuries to the trunk and body cavities. To improve the outcome of these patients in extremis, the aim of the index surgery is to stop the bleeding and control the contamination. Unlike damage control surgery, which is tailored to the patient's condition, tactical abbreviated surgical care (TASC) is first and foremost adapted to the overall situation. Once the patients are stabilised and all information on the situation is available, the surgical management and reconstruction of gunshot and blast injuries can follow the principles of damage control (DC) and definitive early total care (ETC). The purpose of this article is to provide an overview of the pathophysiology of gunshot and blast injuries, wound ballistics, and the approach and procedures of successful surgical management.

Wartime Vascular Injury

Wartime vascular injury can be particularly challenging due to the complexity of the case, concomitant injuries, resource limitations, and often lack of expertise of the operating surgeon. The proliferation of vascular shunting has been of particular importance as a damage control surgery technique to restore perfusion and temporize the immediate need for definitive repair necessary for limb salvage, particularly in austere locations. Diagnosis of vascular injury can be made using a variety of techniques, from physical examination to ankle-brachial indices to the use of CT angiography or invasive angiographic techniques. Operative planning and judgment are therefore critical in deciding both how and whether to operate. Surgeons likely to deploy should take every opportunity to practice vascular exposures and techniques through clinical practice and laboratory courses.

Management of war-related vascular wounds in French role 3 hospital during the Afghan campaign

OBJECTIVES

To describe the management of war-related vascular injuries in the Kabul French military hospital.

METHODS

From January 2009 to April 2013, in the Kabul French military hospital, we prospectively included all patients presenting with war-related vascular injuries. We collected the following data: site, type, and mechanism of vascular injury, associated trauma, type of vascular repair, amputation rate and complications.

RESULTS

Out of the 922 soldiers admitted for emergency surgical care, we recorded 45 (5%) patients presenting with vascular injuries: 30 (67%) gunshot-related, 11 (24%) explosive device-related, and 4 (9%) due to road traffic accident. The majority of injuries (93%) involved limbs. Vascular injuries were associated with fractures in 71% of cases. Twelve (26.7%) had an early amputation performed before evacuation. Twenty (44.4%) patients underwent fasciotomy and three (6.6%) sustained a compartment syndrome.

CONCLUSIONS

This was the first French reported series of war-related vascular injuries during the last decade's major conflicts. The majority of injuries occurred in the limbs. Autologous vein graft remains the treatment of choice for arterial repair. Functional severity of these injuries justifies specific training for military surgeons.

Prosthetic Graft Patency in the Setting of a Polymicrobial Infection in Swine (Sus scrofa)

BACKGROUND

In the setting of vascular injury, vein interposition graft is the preferred conduit, but may have limited availability. This study seeks to develop a large animal model assessing the graft performance of polytetrafluoroethylene (PTFE) and Dacron in the setting of a polymicrobial infection.

METHODS

Thirty-seven animals were placed into 4 groups for a 21-day survival period. Six-millimeter PTFE or Dacron interposition grafts were placed in the right iliac artery with a standardized bacterial inoculation. Native vessel with and without contamination served as control groups. The inoculant was 1 × 10⁷ of genetically labeled Pseudomonas aeruginosa and Staphylococcus aureus. The primary end points were graft patency (determined by duplex ultrasound and necropsy) and graft infection (culture with molecular analysis). Secondary end points included physiological measurements, blood cultures, laboratory data, and histopathology.

RESULTS

PTFE and Dacron had similar infection rates of 85.7% and 75%, respectively. There was no significant difference in infectious organisms between graft materials. PTFE and Dacron exhibited bacterial ingrowth and transmigration to the intraluminal portion of the conduit. Forty-five percent of the Dacron group and 40% of the PTFE group remained patent at postoperative day 21 (P = 0.98). Clinical data, including white blood cell count, percent neutrophils, and lactate, did not vary significantly between groups.

CONCLUSIONS

PTFE and Dacron perform similarly in terms of infection rates and graft failure as both have a propensity toward bacterial ingrowth and occlusion when compared with controls. This is a valid animal model to assess graft performance in the setting of polymicrobial infection and provides an avenue for studying novel prosthetic conduits.

Vascular Injury in Orthopedic Trauma

Vascular injury in orthopedic trauma is challenging. The risk to life and limb can be high, and clinical signs initially can be subtle. Recognition and management should be a critical skill for every orthopedic surgeon. There are 5 types of vascular injury: intimal injury (flaps, disruptions, or subintimal/intramural hematomas), complete wall defects with pseudoaneurysms or hemorrhage, complete transections with hemorrhage or occlusion, arteriovenous fistulas, and spasm. Intimal defects and subintimal hematomas with possible secondary occlusion are most commonly associated with blunt trauma, whereas wall defects, complete transections, and arteriovenous fistulas usually occur with penetrating trauma. Spasm can occur after either blunt or penetrating trauma to an extremity and is more common in young patients. Clinical presentation of vascular injury may not be straightforward. Physical examination can be misleading or initially unimpressive; a normal pulse examination may be present in 5% to 15% of patients with vascular injury. Detection and treatment of vascular injuries should take place within the context of the overall resuscitation of the patient according to the established principles of the Advanced Trauma Life Support (ATLS) protocols. Advances in the field, made mostly during times of war, have made limb salvage the rule rather than the exception. Teamwork, familiarity with the often subtle signs of vascular injuries, a high index of suspicion, effective communication, appropriate use of imaging modalities, sound knowledge of relevant technique, and sequence of surgical repairs are among the essential factors that will lead to a successful outcome. This article provides a comprehensive literature review on a subject that generates significant controversy and confusion among clinicians involved in the care of trauma patients. [Orthopedics. 2016; 39(4):249-259.].

Regenerative medicine applications in combat casualty care

The purpose of this report is to describe regenerative medicine applications in the management of complex injuries sustained by service members injured in support of the wars in Afghanistan and Iraq. Improvements in body armor, resuscitative techniques and faster transport have translated into increased patient survivability and more complex wounds. Combat-related blast injuries have resulted in multiple extremity injuries, significant tissue loss and amputations. Due to the limited availability and morbidity associated with autologous tissue donor sites, the introduction of regenerative medicine has been critical in managing war extremity injuries with composite massive tissue loss. Through case reports and clinical images, this report reviews the application of regenerative medicine modalities employed to manage combat-related injuries. It illustrates that the novel use of hybrid reconstructions combining traditional and regenerative medicine approaches are an effective tool in managing wounds. Lessons learned can be adapted to civilian care.

Long-term follow-up and amputation-free survival in 497 casualties with combat-related vascular injuries and damage-control resuscitation

BACKGROUND

The effectiveness of damage-control resuscitation (DCR) has been demonstrated in recent US conflicts. Wartime casualties treated for hemorrhagic shock from vascular wounds were studied to report the 24-hour transfusion requirements, graft patency, and amputation-free survival for major vascular injuries.

METHODS

Joint Theater Trauma Registry data from August 2006 to April 2011 (56 months) were retrospectively reviewed. Included were casualties with a vascular injury who presented to US combat support hospitals in Iraq or Afghanistan. Amputation-free survival and graft patency were determined from record and imaging review.

RESULTS

The study group consisted of 497 severely wounded local national and military casualties (mean [SD] Injury Severity Score [ISS], 17 [8.5]) presenting with acidosis (pH 7.29 [0.15]), tachycardia (heart rate, 110 [29.31]), and coagulopathy (international normalized ratio, 1.6 [2.33]). Given DCR and early management of vascular injury, blood pressure, heart rate, temperature, hemoglobin, and base deficit improved promptly (p < 0.05) by intensive care unit admission. Transfusion requirements included packed red blood cells (15 [13] U; range, 1-70 U), fresh frozen plasma (14 [13] U; range, 1-72 U), cryoprecipitate (13 [15] U; range, 1-49 U), and platelets (8 [6] U; range, 1-36 U). Mean operative time was 232 minutes (range, 16-763 minutes). US casualties (n = 111) had limb salvage attempted for 113 extremity vascular injuries (3 [2%] iliac, 33 [30%] femoral, 23 [20%] popliteal, 13 [12%] tibial, 33 [30%] brachial, 4 [3%] ulnar, and 4 [(3%] radial). In this subgroup, 28 (25%) were revascularized by a primary repair or end anastomosis, 80 (71%) were revascularized by saphenovenous grafts, and 15 (3%) [corrected] were revascularized by prosthetic grafts. The follow-up ranged from 29 days to 1,079 days, (mean, 347 days), during which 96 grafts (84.9%) remained patent, 16 casualties (14.2%) required a delayed amputation, and 110 (99.1%) survived. Popliteal injuries had the highest amputation rate (7 of 23, 30.4%). The amputation-free survival was 84%.

CONCLUSION

In severely wounded casualties, wartime surgical strategies to save both life and limb evidently permit definitive procedures at initial surgery with excellent limb salvage results. This outcome analysis in a large cohort can help to refine surgical judgment and support contemporary DCR practices for major vascular injury.

LEVEL OF EVIDENCE

Epidemiologic study, level III; therapeutic study, level V.

Early management of pediatric vascular injuries through humanitarian surgical care during U.S. military operations

BACKGROUND

The objective of this report is to describe our experience of pediatric vascular injuries in a U.S. military combat support hospital in Baghdad, Iraq. A retrospective study was designed using Joint Theater Trauma Registry (JTTR) records in order to evaluate the pediatric (age <18 years) population presenting with vascular trauma to a combat hospital in Baghdad, Iraq between April 2006 and August 2008. Demographic data comprised casualty, age, gender, and mechanism of injury. Physiologic data included presenting vital signs (rectal temperature, blood pressure, and heart rate), arterial pH, base deficit, hemoglobin (g/dL), and international normalized ratio.

RESULTS

Twenty-five children, median age 14 years (range, 5-17 years), median weight 48 kg (range, 15-80 kg) sustained 18 (72%) blast and 7 (28%) gunshot wounds. The mean Injury Severity Score was 25 ± 16.2. The median operative time for the vascular repairs was 189 minutes (range, 41-505 minutes). Patients were tachycardic (mean ± standard deviation, 136 ± 29 bpm), hypotensive (109/63 ± 29/19 mm Hg), and acidemic (pH 7.26 ± 0.07; BD -5.57 ± 5.1 mEq/L) on arrival to the emergency department and were physiologically improved upon admission to the intensive care unit 3 hours later. Repair techniques were ligation (14; 39%), saphenous graft (11; 31%), lateral suture (7; 19%), end anastomosis (2; 5%), patch (1; 3%), and thrombectomy (1; 3%). Twenty-four hour mean transfusion requirements included crystalloid 102 mL/kg (range, 19-253), transfused blood 47 mL/kg (range, 0-119), fresh frozen plasma 14 mL/kg (range, 0-68), and apheresis platelets (1.2 ± 3.68 units). Over a follow-up of 22 ± 5.5 days, the amputation-free survival was 80%.

CONCLUSIONS

This is the largest reported wartime series to demonstrate in children that damage control resuscitation despite high injury severity permits simultaneous limb salvage.

Management of combat vascular injuries using modern imaging: are we getting better?

Background. Vascular injuries often result in life threatening hemorrhage or limb loss. When they present with a single entry or exit wound, surgery is immediately indicated. With multiple injuries, however, imaging such as CTA is necessary for diagnosis and choice of treatment. Methods. For all combat-related vascular cases admitted to our medical center during the Lebanon wars in 1982 and 2006, we compiled and compared presenting signs and symptoms, means of diagnosis, treatments, and results. Results. 126 patients with vascular injuries were admitted (87 in 1982, 39 in 2006). 90% were male; mean age of 29 years (range 20-53). All injuries were accompanied by insult to soft tissue, bones, and viscera. 75% presented with injury to arteries in the extremities. 75% of these patients presented with limb ischemia, and 25% sustained massive blood loss. Treatments included venous interposition graft, end-to-end anastomosis, venous patch, endovascular technique (only in 2006), and ligation/observation. Complications included thrombosis and wound infections. Mortality and amputations occurred only in 1982, and this may be attributed to the use of imaging, advanced technique, and shorter average time from injury to hospital (7 hours). Conclusions. We recommend CTA as the first line modality for diagnosis of vascular injuries, as its liberal use allowed for early and appropriate treatment. Treatment outcomes improved with fast and effective resuscitation, liberal use of tourniquets and fasciotomies, and meticulous treatment by a multidisciplinary team.

The increasing rate of secondary amputation in popliteal arterial injury associated with multi-organ injuries and hypotension

OBEJECTIVES

To study the role of hypotension and associated injuries in increasing the chances of secondary amputation in lower limb with vascular injuries.

METHODS

This study was conducted in the Department of cardiovascular and thoracic surgery( CVTS ), Sher-i- Kashmir Institute of Medical Sciences, ( SKIMS ) Srinagar Kashmir India and comprised all patients sustaining vascular injury due to different causes like road traffic accident, fire arm and blast injuries or falling from height during the last five years. Following admission to our Department, the patients were divided into two groups. The first group with associated injuries was hemodynamically unstable during vascular repair or in post-operative period and the second group had no associated injuries and was hemodynamically stable during vascular repair and in post-operative period.

RESULTS

During the past five years, 95 patients were operated for lower limb vascular injury in our department. Of these 25 patients had associated multi-organ injuries and were hemodynamically unstable and needed intensive care monitoring after surgical intervention. Additionally, 10 patients died due to associated multiple organ injuries, 10 needed amputation due to recurrent thrombosis of their anastomosis, and in five patients limb salvage was achieved. Seventy patients who had isolated limb vascular injuries with no associated injuries or hypotension were hemodynamically stable and were kept in low dependency unit after vascular repair. Only Four patients from this group needed amputation for thrombosis of the anastomosis.

CONCLUSION

[corrected] Patients with shock and related injuries face significant rate of amputation. These patients whether with multi-organ injuries or isolated vascular injuries need judicious treatment for hypovolumic shock during surgical intervention and in post-operative period.

Microvascular porcine model for the optimization of vascularized composite tissue transplantation

BACKGROUND

Devastating extremity injuries are prevalent but most often survivable on the modern battlefield. The complexity of these injuries requires advanced methods of reconstruction. This study is designed to validate the feasibility of gracilis myocutaneous flap transplantation via microvascular free tissue transfer in a porcine model. This model will facilitate study of autotransplant physiology as well as vascularized composite allotransplantation as an evolving method for reconstructing previously nonreconstructable injuries.

MATERIAL AND METHODS

A donor gracilis myocutaneous flap is procured from Yorkshire swine. The right external carotid artery and internal jugular vein are prepared as the recipient axis for microvascular anastomoses. Group 1 undergoes immediate microvascular anastomosis with resultant 1-h ischemic period. Group 2 undergoes delayed anastomosis with 3-h ischemic period. Markers of ischemia-reperfusion injury are evaluated after anastomosis and on postoperative days 1, 2, 7, and 14.

RESULTS

A novel porcine model for microvascular composite tissue transplantation is demonstrated. Ischemia period-dependent elevations in circulating biomarkers (lactate dehydrogenase [LDH], creatine kinase [CK], and aspartate transaminase [AST]) demonstrate the effects of prolonged ischemia. Both groups showed marked LDH elevation without significant statistical intergroup difference (P=0.250). The difference in CK and AST levels at 24h showed strong significance (P<0.0001).

CONCLUSIONS

A novel method of vascularized gracilis myocutaneous flap transplantation was validated in the Yorkshire swine. Assays for skeletal muscle tissue injury (LDH, CK, and AST) showed ischemia period-dependent response providing assessment of ischemia-reperfusion injury at the cellular level. Subsequent studies will evaluate agents that mitigate ischemia-reperfusion injury and transition these findings to potentiate vascularized composite allotransplantation.

Vascular injuries in an urban combat setting: experience from the 2006 Lebanon war

Vascular injuries are manifested by life-threatening hemorrhage or limb loss and their diagnosis and treatment are challenging. Angiography is beyond the capability of available teams during wartime. Thus, computed tomographic angiography (CTA) may become a major triage tool. This study reports on the presentation, diagnosis, management and outcome of combat vascular injuries with emphasis on the utility of CTA. Presenting signs and symptoms, means of diagnosis, treatments and results of all combat sustained vascular cases were collected and compiled with follow-up. Of 511 patients, 39 patients (7.6%) with vascular injuries were admitted. Injuries were penetrating and accompanied by soft tissue and bone insult. Diagnosis was made by CTA in 62% and by surgical exploration in 38%. Extremity arteries were injured in 72% of cases. Treatment included surgical and endovascular techniques.

COMPLICATIONS

one late amputation, 5% thrombosis, 24% wound infections with no mortalities or early amputations. Although similarities exist between this experience and recent wartime reports, differences are apparent including the effectiveness of CTA. High index of suspicion and liberal use of CTA allows for an early and accurate diagnosis of a vascular injury resulting in high rates of limb salvage and low mortality. CTA should be the first line modality for diagnosis of vascular injuries, reserving angiography for endovascular treatment.

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.

Effect of recombinant factor VIIa as an adjunctive therapy in damage control for wartime vascular injuries: a case control study

OBJECTIVES

Military casualties with vascular injuries often present with severe acidosis and coagulopathy that can negatively influence limb salvage decisions. We previously reported the value of a damage control resuscitation (DCR) strategy that can correct physiologic shock during simultaneous vascular reconstruction. The effect of recombinant factor VIIa (rFVIIa) on the repair of injured vessels and vascular grafts when used as an adjunctive therapy during DCR is unclear in the setting of wartime vascular injuries. The primary aim of this study was to assess the effect of rFVIIa use during DCR for vascular trauma and the impact on vessel repair.

METHODS

A retrospective two cohort case control study was performed using the Joint Theater Trauma Registry to identify patients with major vascular injury and DCR. Group 1 (n = 12) had DCR and repair of the injured vessels. Group 2 (n = 41) included early rFVIIa as an adjunctive therapy with DCR to control bleeding and perform simultaneous vascular reconstruction.

RESULTS

Age, injury severity score, presenting physiology, and operative time were similar between groups. Postoperative data show that early physiologic recovery from acidosis, coagulopathy, and anemia was associated with rFVIIa and DCR. Extremity graft failures in groups 1 and 2 (follow-up range, 10-26 months) were either from early thrombosis (1 vs. 5 p = 1), graft dehiscence (1 vs. 2 p = 0.55), or infection (1 vs. 1 p = 0.41) and were the result of inadequate soft tissue coverage or technical factors that eventually resulted in eight (15%) amputations. All cause mortality (group 1: 0% vs. group 2: 7.3%, p = 1) and amputation rates (group 1: 25% vs. groups 2: 12.2%, p = 0.36) were similar between the two groups.

CONCLUSIONS

DCR using rFVIIa is effective for controlling hemorrhage and reversing coagulopathy for severe vascular injuries. Early graft failures seem unrelated to rFVIIa use in the setting of wartime vascular injuries. No differences in amputation rate or mortality were seen. Although rFVIIa may be a useful damage control adjunct during vessel repair, the overall impact of this strategy on long-term outcomes such as mortality and limb salvage remains to be determined.

The role of SVS volunteer vascular surgeons in the care of combat casualties: results from Landstuhl, Germany

With a shortage of active duty vascular surgeons in the military, Society for Vascular Surgery (SVS) members have been called upon to perform short-term rotations at Landstuhl Regional Medical Center (LRMC), the US military's receiving facility for combat injuries sustained in the Iraq and Afghanistan conflicts. From September 2007 to May 2008, 20 SVS vascular surgeons have performed 2-week rotations at LRMC through American Red Cross and US Army sponsorship. Volunteers were surveyed for previous military and/or trauma experience. In addition to reporting number and types of procedures performed, volunteers were queried on their experience and impression of the rotation. Several volunteers have had prior military experience and all have had vascular trauma experience through residency, fellowship, and current practices. With most definitive vascular repairs being done in theater, SVS members were most often called upon for clinical expertise in the care of combat casualties and evaluation of revascularization procedures. The volunteers contributed to daily rounds, patient care, and teaching conferences, as well as actively participated in surgical procedures with the most common being wound examinations under anesthesia for which intraoperative vascular consultation was occasionally requested (5-20 per volunteer). Additional procedures that volunteers performed included: inferior vena cava (IVC) filter placement, thrombectomy, revision of lower and upper extremity interposition vein grafts, retroperitoneal spine exposures, diagnostic and therapeutic angiograms, iliac stenting, and duplex ultrasound scan interrogation of vascular repairs, suspected arterial injuries, and deep vein thrombosis. All volunteers described the experience as valuable and will return if needed. With a limited number of military vascular surgeons and the unpredictable need for a vascular specialist at LRMC, civilian volunteers are playing an important role in providing high-quality vascular care for the nation's wounded soldiers by expanding vascular and endovascular capability at LRMC and contributing to general surgical critical care. As volunteers, SVS members are carrying on a tradition started by our surgical forefathers during previous US military conflicts.