Development and Implementation of Endovascular Capabilities in Wartime

Wartime Endovascular Therapy: A Historical View

Endovascular techniques for managing vascular trauma have become increasingly more common. However, these techniques have had limited application in recent conflicts. Using lessons from 20th century conflicts, the present study aims to highlight how advances made in the past may provide a roadmap to improving surgical capabilities in the future.

Strategies for successful implementation of resuscitative endovascular balloon occlusion of the aorta in an urban Level I trauma center

BACKGROUND

The rationale for resuscitative endovascular balloon occlusion of the aorta (REBOA) is to control life-threatening subdiaphragmatic bleeding and facilitate resuscitation; however, incorporating this into the resuscitative practices of a trauma service remains challenging. The objective of this study is to describe the process of successful implementation of REBOA use in an academic urban Level I trauma center. All REBOA procedures from April 2014 through December 2019 were evaluated; REBOA was implemented after surgical faculty attended a required and internally developed Advanced Endovascular Strategies for Trauma Surgeons course. Success was defined by sustained early adoption rates.

METHODS

An institutional protocol was published, and a REBOA supply cart was placed in the emergency department with posters attached to depict technical and procedural details. A focused professional practice evaluation was utilized for the first three REBOA procedures performed by each faculty member, leading to internal privileging.

RESULTS

Resuscitative endovascular balloon occlusion of the aorta was performed in 97 patients by nine trauma surgeons, which is 1% of the total trauma admissions during this time. Each surgeon performed a median of 12 REBOAs (interquartile range, 5-14). Blunt (77/97, 81%) or penetrating abdominopelvic injuries (15/97, 15%) comprised the main injury mechanisms; 4% were placed for other reasons (4/97), including ruptured abdominal aortic aneurysms (n = 3) and preoperatively for a surgical oncologic resection (n = 1). Overall survival was 65% (63/97) with a steady early adoption trend that resulted in participation in a Department of Defense multicenter trial.

CONCLUSION

Strategies for how departments adopt new procedures require clinical guidelines, a training program focused on competence, and a hospital education and privileging process for those acquiring new skills.

LEVEL OF EVIDENCE

Therapeutic, level V.

A standardized trauma-specific endovascular inventory

We believe that the rapid and widespread adoption of resuscitative endovascular balloon occlusion of the aorta as well as enthusiasm for catheter-based strategies has led to increased interest in basic endovascular techniques among trauma surgeons. The aim of this article was to describe the most commonly performed endovascular procedures for trauma patients, the basic capital equipment and room set up, and a parsimonious inventory of disposable supplies needed to perform each procedure. Together, these make a standardized trauma-specific endovascular inventory. LEVEL OF EVIDENCE: Economic/decision, level V.

Computed tomography correlation of skeletal landmarks and vascular anatomy in civilian adult trauma patients: Implications for resuscitative endovascular balloon occlusion of the aorta

BACKGROUND

Resuscitative endovascular balloon occlusion of the aorta (REBOA) is a valuable resuscitative adjunct in a variety of clinical settings. In resource-limited or emergency environments, REBOA may be required with delayed or absent image-guidance or verification. Catheter insertion lengths may be informed by making computed tomography (CT) correlations of skeletal landmarks with vascular lengths.

METHODS

Between 2000 and 2015 at a single civilian tertiary care center, 2,247 trauma patients with CT imaging were identified, yielding 1,789 patients with adequate contrast opacification of the arterial system in the chest, abdomen, and pelvis. Individual scans were analyzed using MATLAB software, with custom high-throughput image processing algorithms applied to correlate centerline vascular anatomy with musculoskeletal landmarks. Data were analyzed using R version 3.3.

RESULTS

The median centerline distance from the skin access to the aortic bifurcation was longer by 0.3 cm on the right than on the left side. Median aortic zone I length was 21.6 (interquartile range, 20.3-22.9) cm, while zone III was 8.7 (7.8-9.5) cm. Torso extent (TE) correlation to zone I was much higher than that for zone III (R2, 0.58 vs. 0.26 (right) and 0.58 vs. 0.27 (left); p < 0.001). Assuming a 4-cm balloon length, optimal fixed insertion length would be 48 cm and 28 cm for zones I and III (error, 0.4% vs. 33.3%), respectively, although out of zone placements can be reduced if adjusted for TE (error, 0% vs. 26.4%).

CONCLUSION

Computed tomography morphometry suggests that a fixed REBOA catheter insertion length of 48 cm for zone I and 28 cm for zone III is optimal (on average, for average-height individuals), with improved accuracy by formulaic adjustments for TE. High residual error for zone III placement may require redesign of existing catheter balloon lengths or consideration of the relative risk associated with placing the balloon catheter too low or too high.

LEVEL OF EVIDENCE

Prognostic/epidemiological, level III.

Physiologic Considerations in Trauma Patients Undergoing Resuscitative Endovascular Balloon Occlusion of the Aorta

Resuscitative endovascular balloon occlusion of the aorta is a new procedure for adjunctive management of critically injured patients with noncompressible torso or pelvic hemorrhage who are in refractory hemorrhagic shock, ie, bleeding to death. The anesthesiologist plays a critical role in management of these patients, from initial evaluation in the trauma bay to definitive care in the operating room and the critical care unit. A comprehensive understanding of the effects of resuscitative endovascular balloon occlusion of the aorta is essential to making it an effective component of hemostatic resuscitation.

Pitfalls in the management of peripheral vascular injuries

Over the past 65+ years, most civilian peripheral vascular injuries have been managed by trauma surgeons with training or experience in vascular repair or ligation. This is appropriate as the in-hospital trauma team is immediately available, and there are often other injuries present in the victim.

The pitfall to avoid during evaluation of the patient in the emergency center is a missed diagnosis. In the patient without ‘hard’ signs of a peripheral vascular injury, a careful history (bleeding), physical examination including measurement of ankle–brachial (ABI) or brachial–brachial index and liberal use of CT arteriography depending on an ABI <0.9 should essentially make the diagnosis if an arterial injury is present.

At operation, one pitfall is to limit skin preparation and draping, thereby eliminating the option of removing the greater saphenous vein if needed as a conduit from either the groin or ankle of an uninjured lower extremity. Another pitfall is to make a full longitudinal incision directly over a large pulsatile hematoma. Rather, separate shorter longitudinal incisions should be made to obtain proximal and distal vascular control before entering the hematoma. The failure to recognize patients who should be managed initially with insertion of a temporary intraluminal shunt is a major pitfall as well. Not following time-proven and results-proven ‘fine techniques’ of operative repair is another major pitfall. Such techniques include the following: use of small angioaccess vascular clamps or silastic vessel loops; passage of proximal and distal Fogarty catheters; administration of regional or systemic heparin during complex repairs; an open anastomosis technique; and completion arteriography after a complex arterial repair in a lower extremity.

Avoiding pitfalls should allow for success in peripheral vascular repair, particularly since most patients are young with non-diseased vessels.

Emerging Endovascular Therapies for Non-Compressible Torso Hemorrhage

Management of non-compressible torso hemorrhage (NCTH) remains a challenge despite continued advancements in trauma resuscitation. Resuscitative thoracotomy with aortic cross-clamping and recent advances in endovascular aortic occlusion, including resuscitative endovascular occlusion of the aorta, have finite durations of therapy due to the inherent physiologic stressors that accompany complete occlusion. Here, we attempt to illuminate the current state of aortic occlusion for trauma resuscitation including explanation of the deleterious consequences of complete occlusion, potential methods and limitations of existing technology to overcome these consequences, and a description of innovative methods to improve the resuscitation of NCTH. By explaining the complexity and potential deleterious effects of resuscitation augmented with aortic occlusion, our goal is to provide practitioners with a real-world perspective on current endovascular technology and to encourage the continued innovation required to overcome existing obstacles.

Feasibility study of emergency intervention for vascular injury outside the hospital

BACKGROUND

Minimally invasive surgery in the field of traumatic vascular injury diagnosis and treatment has achieved good results. This study was designed to determine whether pre-hospital emergency intervention is feasible for vascular injury in a field intervention cabin under the condition of war or a disaster site.

METHODS

Different types of animal experiments of vascular injury intervention were performed in a field intervention cabin. Treatment capacity was evaluated by data collection, including duration of surgery, clinical evaluation, image clarity, and equipment handling. Environmental adaptability and mobility were evaluated by maneuverability and long-distance mobility.

RESULTS

A total of 56 surgeries (7 types) were performed in the field intervention cabin. Digital subtraction angiography (DSA) had good imaging performance. A total of 4800 km of long-distance mobility was performed, and all the equipment operated normally without any equipment failure. We participated in the medical service maneuver twice. The cabin unfolded and worked properly. There was no equipment damage during the medical service maneuver.

CONCLUSIONS

Use of a field intervention cabin under the conditions of war or disaster is feasible for pre-hospital emergency intervention of vascular injury.

A small case series of aortic balloon occlusion in trauma: lessons learned from its use in ruptured abdominal aortic aneurysms and a brief review

BACKGROUND

EndoVascular and Hybrid Trauma Management (EVTM) is an emerging concept for the early treatment of trauma patients using aortic balloon occlusion (ABO), embolization agents and stent grafts to stop ongoing traumatic bleeding. These techniques have previously been implemented successfully in the treatment of ruptured aortic aneurysm.

AIMS

We describe our very recent experience of EVTM using ABO in bleeding patients and lessons learned over the last 20 years from the endovascular treatment of ruptured abdominal aortic aneurysms (rAAA). We also briefly describe current knowledge of ABO usage in trauma.

METHODS

A small series of educational cases in our hospital is described, where endovascular techniques were used to gain temporary hemorrhage control. The methods used for rAAA and their applicability to EVTM with a multidisciplinary approach are presented.

RESULTS

Establishing femoral arterial access immediately on arrival at the emergency room and use of an angiography table in the surgical suite may facilitate EVTM at an early stage. ABO may be an effective method for the temporary stabilization of severely hemodynamically unstable patients with hemorrhagic shock, and may be useful as a bridge to definitive treatment of the bleeding patients.

CONCLUSION

EVTM, including the usage of ABO, can be initiated on patient arrival and is feasible. Further data need to be collected to investigate proper indications for ABO, best clinical usage, results and potential complications. Accordingly, the ABOTrauma Registry has recently been set up. Existing experiences of EVTM and lessons from the endovascular treatment of rAAA may be useful in trauma management.

A mobile minimally invasive interventional shelter: a new answer to on-spot emergency treatment of large arterial injuries?

BACKGROUND

Severely destructive disasters can often lead to heavy casualties. Large arterial injury in disasters, particularly, often results in high mortality and morbidity. Although minimally invasive intervention has achieved positive effects in diagnosing and treating vascular injuries, it is still unavailable at the disaster area of any country due to lack of on-spot catheterization labs. This study aimed to test the feasibility of adopting interventional techniques to treat haemorrhage of large arterial injuries in remote and austere wild environments after severely destructive disasters, by using a new mobile intervention suite we developed--the mobile minimally invasive interventional shelter (MIS).

METHODS

Large animal models of aortic and femoral arterial injuries were established using a newly developed medium vehicle-mounted digital subtraction angiography (DSA) machine in MIS. The endovascular stent-graft exclusion and balloon occlusion combined with surgical hemostasis were performed respectively following the protocols for rapid interventional therapy. The treatment capacity of the shelter was evaluated based on its stability, surgery duration and the clinical results.

RESULTS AND DISCUSSION

The stability of the medical devices in MIS directly relates to the efficiency and success rate of interventional treatment. The newly developed vehicle-mounted DSA machine showed good imaging performance and the operation of all equipments and devices in MIS were stable in interventional procedures. All the interventional treatments for large arterial injuries were performed smoothly. The average time for treating abdominal aortic injury and femoral arterial injury was 23 ± 11 and 55 ± 17 min, respectively. And the operation success rate reached 100 %.

CONCLUSION

It is feasible to perform interventional operations to control haemorrhage of large arterial injuries in MIS outside hospital. The MIS has a great potential to save patients from dying of hemorrhagic shock due to lack of effective treatment devices and approaches in remote and austere wild environments, such as in disaster areas.

Patient demographics and cardiovascular risk factors differentially influence geometric remodeling of the aorta compared with the peripheral arteries

BACKGROUND

Detailed knowledge of the dimensions and shape of the main arteries of the body and how they change with age and disease is important for understanding arterial pathophysiology and improving minimally invasive devices to treat arterial diseases. Our goal was to describe and compare geometric remodeling of the aorta and peripheral arteries in the context of patient demographics and cardiovascular risk factors.

METHODS

Three-dimensional reconstructions of computed tomography angiography scans were performed in 122 subjects 5-93 years of age (mean 47 ± 24 years, 64 M/58 F). Best-fit arterial diameters, lengths, and tortuosity for the principle named arteries in the chest, abdomen, pelvis, and upper thigh were measured, and multiple linear regression analysis was performed to examine how these morphologic parameters associate with patient demographics and risk factors.

RESULTS

Large elastic arteries increased their diameter, length, and tortuosity with age, whereas muscular arteries primarily became more tortuous. Demographics and risk factors explained >70% of the variation in diameters of the abdominal aorta, paravisceral aorta, and the aortic arch; and >75% of variation in tortuosity from the profunda femoris to the brachiocephalic artery. Male sex, larger body mass index, and hypertension contributed to larger diameters, whereas the presence of diabetes was associated with somewhat-straighter arteries. Overall, the effects of cardiovascular risk factors on geometric remodeling were small compared with those of demographics.

CONCLUSION

The geometry of the vascular tree is greatly affected by aging, demographics, and some risk factors. Elastic and muscular arteries remodel differently, possibly as the result of differences in their microstructure.

VA Vascular Injury Study (VAVIS): VA-DoD extremity injury outcomes collaboration

BACKGROUND

Limb injuries comprise 50-60% of U.S. Service member's casualties of wars in Afghanistan and Iraq. Combat-related vascular injuries are present in 12% of this cohort, a rate 5 times higher than in prior wars. Improvements in medical and surgical trauma care, including initial in-theatre limb salvage approaches (IILS) have resulted in improved survival and fewer amputations, however, the long-term outcomes such as morbidity, functional decline, and risk for late amputation of salvaged limbs using current process of care have not been studied. The long-term care of these injured warfighters poses a significant challenge to the Department of Defense (DoD) and Department of Veterans Affairs (VA).

METHODS/DESIGN

The VA Vascular Injury Study (VAVIS): VA-DoD Extremity Injury Outcomes Collaborative, funded by the VA, Health Services Research and Development Service, is a longitudinal cohort study of Veterans with vascular extremity injuries. Enrollment will begin April, 2015 and continue for 3 years. Individuals with a validated extremity vascular injury in the Department of Defense Trauma Registry will be contacted and will complete a set of validated demographic, social, behavioral, and functional status measures during interview and online/ mailed survey. Primary outcome measures will: 1) Compare injury, demographic and geospatial characteristics of patients with IILS and identify late vascular surgery related limb complications and health care utilization in Veterans receiving VA vs. non-VA care, 2) Characterize the preventive services received by individuals with vascular repair and related outcomes, and 3) Describe patient-reported functional outcomes in Veterans with traumatic vascular limb injuries.

DISCUSSION

This study will provide key information about the current process of care for Active Duty Service members and Veterans with polytrauma/vascular injuries at risk for persistent morbidity and late amputation. The results of this study will be the first step for clinicians in VA and military settings to generate evidence-based treatment and care approaches to these injuries. It will identify areas where rehabilitation medicine and vascular specialty care or telehealth options are needed to allow for better planning, resource utilization, and improved DoD-to-VA care transitions.

Endovascular therapy in trauma

The practice of medicine has experienced a revolution in the use of catheter-based or endovascular techniques to manage age-related vascular disease over the past 15 years. In many scenarios the less invasive, endovascular method is associated with reduced morbidity and mortality than the traditional open surgical approach. Although somewhat delayed, the use of endovascular approaches in the management of certain trauma scenarios has also increased dramatically. With improvements in catheter-based and imaging technologies and a broader acceptance of the value of the endovascular approach, this trend is likely to continue to the benefit of patients. The use of endovascular techniques in trauma can be considered in three broad categories: (1) large-vessel repair (e.g. covered stent repair), (2) mid- to small-vessel hemostasis (e.g. coils, plugs, and hemostatic agents), and (3) large-vessel balloon occlusion for resuscitation (e.g. resuscitative endovascular balloon occlusion of the aorta). While not exclusive, these categories provide a framework from which to consider establishing a trauma-specific endovascular inventory and performance of these techniques in the setting of severe injury. The aim of this review is to use this framework to provide a current appraisal of endovascular techniques to manage various forms: vascular injury, bleeding, and shock; including injury patterns in which an endovascular approach is established and scenarios in which it is nascent and evolving.

Endovascular Skills for Trauma and Resuscitative Surgery (ESTARS) course: curriculum development, content validation, and program assessment

BACKGROUND

The management of hemorrhage shock requires support of central aortic pressure including perfusion to the brain and heart as well as measures to control bleeding. Emerging endovascular techniques including resuscitative endovascular balloon occlusion of the aorta serve as potential lifesaving adjuncts in this setting. The Endovascular Skills for Trauma and Resuscitative Surgery (ESTARS) course was developed to provide fundamental endovascular training for trauma surgeons.

METHODS

ESTARS 2-day course incorporated pretest/posttest examinations, precourse materials, lectures, endovascular and open vascular instruments, Vascular Intervention System Trainer endovascular simulator, and live animal laboratories for training and testing. Curriculum included endovascular techniques for trauma; review of wires, sheaths, and catheters; as well as regional vascular injury management. Animal laboratories integrated arterial access, angiography, coil embolization, resuscitative endovascular balloon occlusion of the aorta, control of iliac artery injury, and vascular shunt placement. Students completed a knowledge test (precourse/postcourse) and a summative skills assessment. The test measured knowledge and judgment in vascular injury management as defined in the course objectives. Vascular Intervention System Trainer and animal laboratory were used for final examinations. Subjective performance was graded by expert observers using a global assessment scale and performance metrics.

RESULTS

Four pilot ESTARS courses were completed, with four participants each. Knowledge and performance significantly improved after ESTARS. Mean test examination scores increased by 77% to 85%, with a mean change of 9 percentage points [paired t (15) = 7.82, p < 0.0001]. The test was unidimensional (Cronbach's α = 0.67). Technical skill significantly improved for both endovascular simulation and live animal laboratory examinations. All participants passed the live animal laboratory practical examination.

CONCLUSION

The ESTARS curriculum is effective at teaching a basic set of endovascular skills for resuscitation and hemorrhage control to trauma surgeons. ESTARS was confirmed as a stepwise and hierarchical curriculum demonstrating measurable improvements in performance metrics and should serve as a model for future competency-based structured training in endovascular trauma skills.

A clinical series of resuscitative endovascular balloon occlusion of the aorta for hemorrhage control and resuscitation

BACKGROUND

A requirement for improved methods of hemorrhage control and resuscitation along with the translation of endovascular specialty skills has resulted in reappraisal of resuscitative endovascular balloon occlusion of the aorta (REBOA) for end-stage shock. The objective of this report was to describe implementation of REBOA in civilian trauma centers.

METHODS

Descriptive case series of REBOA (December 2012 to March 2013) used in scenarios of end-stage hemorrhagic shock at the University of Maryland, R. Adams Cowley Shock Trauma Center, Baltimore, Maryland, and Herman Memorial Hospital, The Texas Trauma Institute, Houston, Texas.

RESULTS

REBOA was performed by trauma and acute care surgeons for blunt (n = 4) and penetrating (n = 2) mechanisms. Three cases were REBOA in the descending thoracic aorta (Zone I) and three in the infrarenal aorta (Zone III). Mean (SD) systolic blood pressure at the time of REBOA was 59 (27) mm Hg, and mean (SD) base deficit was 13 (5). Arterial access was accomplished using both direct cutdown (n = 3) and percutaneous (n = 3) access to the common femoral artery. REBOA resulted in a mean (SD) increase in blood pressure of 55 (20) mm Hg, and the mean (SD) aortic occlusion time was 18 (34) minutes. There were no REBOA-related complications, and there was no hemorrhage-related mortality.

CONCLUSION

REBOA is a feasible and effective means of proactive aortic control for patients in end-stage shock from blunt and penetrating mechanisms. With available technology, this method of resuscitation can be performed by trauma and acute care surgeons who have benefited from instruction on a limited endovascular skill set. Future work should be aimed at devices that allow easy, fluoroscopy-free access and studies to define patients most likely to benefit from this procedure.

LEVEL OF EVIDENCE

Therapeutic study, level V.

Acute ischemia of the lower limb after injury by gunshot: case report and review of literature

INTRODUCTION

Civilian and military vascular trauma has evolved dramatically. It is estimated that 80% of all cases of vascular injuries are due to peripheral vascular trauma, most involving the lower extremities. Arterial below-knee injuries by gunshot still remain a challenge, with an associated rate of amputation of 20-54%.

MATERIAL AND METHODS

This case reports a 48 year-old male patient who sustained a gunshot below his left knee. At hospital admission, loss of substance and hemorrhage at the medial and lateral faces of the upper third of his left leg were present with signs of distal ischemia. Arteriography revealed infra-popliteal arterial lesions of the three arterial axes. Two reversed great saphenous vein interposition grafts were performed into the anterior and posterior tibial arteries with immediate revascularization of the left leg and foot. Later, soft tissue reconstruction was accomplished by a split-thickness skin graft.

RESULTS

At the fifth month of follow-up, the left leg and foot were viable with good healing, without limitations and with controlled pain. Posterior tibial and dorsalis pedis pulses were palpable.

CONCLUSION

This case report shows the importance of an adequate team approach for treatment of a gunshot extremity injury with vascular lesion. The authors want to highlight the scientific background evidence and the value of comparing worldwide civilian trauma center outcomes, mostly reported previously from the military field.

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.

False aneurysm of the interosseous artery and anterior interosseous syndrome--an unusual complication of penetrating injury of the forearm: a case report

BACKGROUND

Palsies involving the anterior interosseous nerve (AIN) comprise less than 1% of all upper extremity nerve palsies.

OBJECTIVES

This case highlights the potential vascular and neurological hazards of minimal penetrating injury of the proximal forearm and emphasizes the phenomenon of delayed presentation of vascular injuries following seemingly obscure penetrating wounds.

CASE REPORT

We report a case of a 22-year-old male admitted for a minimal penetrating trauma of the proximal forearm that, some days later, developed an anterior interosseous syndrome. A Duplex study performed immediately after the trauma was normal. Further radiologic investigations i.e. a computer-tomographic-angiography (CTA) revealed a false aneurysm of the proximal portion of the interosseous artery (IA). Endovascular management was proposed but a spontaneous rupture dictated surgical revision with simple excision. Complete neurological recovery was documented at 4 months postoperatively.

CONCLUSIONS/SUMMARY

After every penetrating injury of the proximal forearm we propose routinely a detailed neurological and vascular status and a CTA if Duplex evaluation is negative.

Varied presentations of missile emboli in military combat

Fragment embolization is a rare phenomenon in trauma patients. Although surgical and endovascular management of vascular injuries have evolved significantly, the detection and management of fragment emboli remain a formidable challenge. We reviewed our experience with this entity from December 2001 to March 2008. During this time period, four (1.1%) of 346 US soldiers evacuated to Walter Reed with arterial or venous injuries were discovered to have suffered missile emboli. Venous emboli were treated with anticoagulation and arterial emboli were treated with standard embolectomy techniques with good result. The presentation, diagnosis, and surgical management of these cases are described.