Endovascular Therapy for Vascular Trauma

*Mount Sinai Hospital, Chicago is a Level I Trauma Center and is a Teaching Institution for Finch University of Health Sciences/The Chicago Medical School. For in-depth discussion and case reviews, visit www.peripheralangioplasty.com Recently, however, several new devices like the commercially available covered stent (Wallgraft, Boston Scientific Corporation, Maple Grove, MN) and cross-training of several physician specialties (interventional cardiologists acquiring peripheral vascular interventional skills, surgeons acquiring endovascular skills) have widened the scope of endovascular therapeutics.1 Additionally, widespread availability of digital subtraction imaging with large image intensifiers in combined coronary and vascular laboratories has tremendously improved imaging capabilities. Availability of an on-call team comprising of: an interventionalist; a scrub assistant (trainee fellow or a scrub technologist); a registered nurse; and a radiology technologist (RCIS/RT/CVT), provides the catheterization laboratory a strategic opportunity to manage emergent and potentially life-threatening vascular trauma. The interventionalist could be an interventional cardiologist possessing peripheral vascular skills, interventional radiologist or a vascular surgeon with endovascular training. In the series of patients reported here, an interventional cardiologist was the operator with the on-call team. The scrub assistant was a cardiology fellow-in-training. In non-teaching institutions, an experienced scrub technologist would assume the role of assisting the primary operator. The registered nurse should be well-trained in critical care nursing and emergent management of hemodynamic collapse. Additionally, since the nurse is also the circulating team member in the room, familiarity with endovascular devices is of the utmost importance. At Mount Sinai Endovascular Laboratory, the circulating nurse is fully oriented and familiar with endovascular devices (location in laboratory, names of devices, available sizes, compatibility with guidewires and sheaths, etc). The RT/CVT is typically responsible for operating the hemodynamic monitoring system (which is the WITT Biomedical [Melbourne, FL] at Mount Sinai, Chicago) but is also fully cross-trained as a circulator in the room. In the event of hemodynamic collapse or other crisis during the procedure, the RT/CVT is expected to provide assistance in the room. Since these patients are generally unstable, and rapid diagnosis and therapeutic intervention is crucial, the importance of team effort cannot be stressed enough. A highly trained critical care nurse who is not familiar with the endovascular suite will not be an effective circulator. Similarly, an experienced interventionalist cannot function effectively without a trained and synchronized support team. Trauma coverage is provided by interventional radiology (with radiology on-call team) at most institutions. The cardiac catheterization laboratory (with a separate on-call team) can provide coverage for these procedures, either sharing the coverage time or providing back-up (in busy trauma centers, multiple trauma victims are fairly common!). At Mount Sinai Hospital, Chicago, there are separate on-call teams for interventional radiology and interventional cardiology. The cardiac catheterization laboratory team (with interventional cardiologist) shares primary trauma coverage and provides back-up from time to time as required by trauma service. Trauma to the vascular system may manifest in several ways. The identification of bleeding site in an actively hemorrhaging external wound may be obvious and allows easy hemostasis. However, injury to the vascular system following blunt trauma or penetrating injuries (stab wounds, gunshot wounds) may result in internal injury that may be difficult to recognize and treat.2 The following types of vascular injuries are frequently encountered that require expedient and accurate diagnosis and prompt treatment: 1. Penetrating injuries of large arteries (arch vessels in upper chest and neck, visceral vessels) that cause internal bleeding, vessel thrombosis or intimal dissection; 2. Pelvic fractures with internal hemorrhage; 3. Penetrating or blunt injuries of large blood vessels resulting in pseudoaneurysms or arteriovenous fistulas; 4. Gunshot injuries with retained fragments that may embolize through the vascular tree. The cardiac catheterization laboratory (or the Endovascular Therapeutics Suite, as at Mount Sinai) is capable of supplementing trauma service in the management of traumatic vascular injuries. At institutions that are not trauma centers and do not have an interventional radiology on-call team, but are equipped with catheterization laboratories, the interventional cardiovascular team can provide an important adjunct to the initial care of patients with traumatic vascular injuries. This requires some additional equipment and inventory, and focused training of the interventional cardiovascular team. Since some patients presenting with vascular trauma may be rapidly deteriorating, a well-prepared catheterization suite can be critical in providing initial diagnosis, and in many cases, therapy to stabilize the patients. While non-invasive diagnostic testing is being increasingly utilized in the setting of trauma (ultrasonography, spiral computed tomography and magnetic resonance angiography), contrast arteriography still remains the gold standard for diagnosis, especially since it offers the unique advantage of therapeutic potential.¹ The key elements to successful diagnosis of traumatic injuries to the vascular system are complete and thorough arteriographic evaluation using high quality imaging system. Non-selective arteriography usually fails to identify the precise location of vascular injury. Selective vascular angiography, therefore, is the key element of diagnostic arteriography. Clearly, a thorough understanding of normal and anomalous vascular anatomy, familiarity with devices (coated stents, coils for embolization and intravascular foreign body retrieval devices) and good catheter skills are essential to accomplish diagnostic and therapeutic goals. The following case studies highlight the capabilities of catheterization laboratory in the management of vascular traumatic injuries: Case Report 1: A 43-year-old male presented with penetrating injury to the left shoulder. Initial physical examination revealed intact arterial flow to the left arm. Ultrasound evaluation suggested a pseudoaneurysm of the left subclavian artery. ³ Selective angiography of the left subclavian artery revealed a large pseudoaneurysm (Figure 1). A 9 French, 80 cm long guiding sheath was advanced into the left subclavian artery using a 6 French Judkins Right 4 catheter (Guidant Corporation, Santa Clara, CA) and a 0.035 inch Magic Torque wire (Boston Scientific). A 10 mm x 38 mm Wallgraft was deployed across the origin of the pseudoaneurysm (Figure 2). Digital subtraction angiography revealed complete obliteration of flow into the pseudoaneurysm (Figure 3). The arterial flow to the left arm was intact, including during rotation at the shoulder joint. The patient was treated with aspirin 325 mg and clopidogrel 75 mg daily for 4 weeks. He has remained symptom-free for 2 years post procedure. Case Report 2: A 24-year-old male presented with a gunshot wound to the left side of the neck. There was no neurological deficit suggesting cervical spine injury. Urgent surgical exploration of left side of neck revealed a hematoma with no active hemorrhage. A contusion was identified on the surface of common and internal carotid arteries. The patient was admitted to trauma service and observed clinically. In the hospital, the patient experienced multiple episodes of transient ischemic attacks referable to left carotid artery, despite antiplatelet and anticoagulant therapy. Selective extracranial carotid angiography revealed an intimal dissection in the left internal carotid artery that was felt to be the source of arterial emboli (Figure 4). ^4,5 Intracranial angiography revealed normal left intracranial circulation (Figure 5). Using an 80 cm Shuttle sheath (Cook Inc., Bloomington, IN), a 10 x 20 mm SMART stent (Cordis Endovascular, Warren, NJ) was deployed to tack up the intimal carotid dissection (Figure 6). No further episodes of cerebral ischemia occurred. The patient was treated with aspirin 325 mg and clopidogrel 75 mg (4 weeks) and discharged home 36 hours post-procedure. He has continued to do well at 18 months. Case Report 3: A 29-year-old male presented following a gunshot wound to the abdomen. Plain abdominal radiograph revealed a fragment of the bullet in the region of inferior vena cavae. Emergent exploratory laparotomy including exploration of the inferior vena cava failed to locate the bullet. A repeat chest radiograph in the operating room revealed that the bullet fragment had migrated into the right atrium. Emergent interventional cardiology consultation was obtained in the operating room. The patient was transferred to the catheterization laboratory. Fluoroscopy revealed the bullet fragment freely floating in the right atrium (Fig 7-9). A basket snare was used to secure the bullet fragment (Figure 10), which was withdrawn into the left iliac vein (Figure 11). The bullet was surgically removed from the left iliac vein in the operating room. In order to prevent dislodgement of the bullet during transfer to the operating room, a Trap-ease device (Cordis Endovascular) was used to interrupt the inferior vena cavae (Figure 12). Discussion Cardiac catheterization laboratories have traditionally limited their scope to catheter-based diagnosis and therapy of coronary artery disease. In recent years, treatment of non-coronary occlusive and aneurysmal atherosclerotic disease has been increasingly incorporated into many catheterization laboratories. Catheterization laboratories that are equipped to provide emergent catheter-based therapy round-the-clock to critically ill patients with coronary ischemia are also well-positioned to handle vascular traumatic injuries. This does, however, require additional staff and physician training in vascular angiography (focused at identification of vascular injuries) and equipment required to treat such injuries (coated stents, embolization coils, intravascular foreign body retrieval catheters, etc). Since patients with vascular trauma may require immediate therapeutic intervention and outcome of excessive delays could be detrimental6, catheterization laboratories should consider incorporating these skills to manage such patients. Physicians and laboratories already performing non-coronary angiography are quite familiar with vascular anatomy and possess excellent catheter-based skills. With additional training, incorporating vascular trauma therapy is feasible and should be strongly considered.

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