Total autogenous revascularization of an innominate artery occlusive disease

Abstract Severe stenosis of the innominate artery occurs rarely amongst supraaortic occlusive diseases. Patients with hemodynamically significant innominate artery disease may present with hemispheric symptoms such as transient ischemic attacks, amaurosis fugax, or subclavian steal secondary to retrograde flow through a non-dominant right vertebral artery in a right handed individual. Endovascular revascularization or extra-anatomic surgical bypass with prosthetic grafts are the most commonly used techniques for treating these lesions in high-risk patients. Carotid-carotid artery bypass procedure is a durable option in patients who are not candidates for endovascular repair, but like any prosthetic reconstruction it has the potential for graft infection especially in the retropharyngeal space. We present a patient with a subclavian steal syndrome secondary to innominate artery occlusion treated with a total autogenous extra-anatomic revascularization. Introduction Clinically significant occlusive disease is distinctly uncommon in the upper extremity circulation, but especially on the right side. However, when they do occur the innominate artery is most commonly affected. In such cases, blood flow to the arm is reconstituted by reversal of flow through the right vertebral artery, resulting in a steal physiology similar to that seen in patients with lesions of the left subclavian artery. However, in addition to the subclavian steal innominate artery disease also can manifest as atherothromboembolic events both to the hand and the brain. General indications for revascularization include strokes, transient ischemic attacks, and symptoms of vertebrobasilar insufficiency. Although quite rarely performed, in-line ascending aortic bypass grafting combined with endarterectomy may be preferred in patients with multivessel disease and low surgical risk. Extra- anatomic cervical revascularization is a good option in high-risk patients because of decreased morbidity and similar patency rates. Carotid-carotid bypass (CCB) via a retropharyngeal route is a well-described technique that provides a short and straight graft path behind the pharynx, precludes the need for a median sternotomy, and avoids the cosmetically unsightly subcutaneous appearance of a pre-tracheally tunneled graft.1 In the original report of the retropharyngeal tunneling by Berguer, one patient was treated with direct carotid-carotid reimplantation.2 Since then, there have been two case reports3, 4, and one case series5 describing carotid-carotid transposition for cervical debranching in patients undergoing thoracic endovascular aneurysm repair (TEVAR). In 2003 Czerny et al. described combined sequential autologous transposition of the left common carotid artery (LCCA) into the brachiocephalic trunk, and the left subclavian artery into the previously transposed LCCA for aneurysmal disease of the arch through a median sternotomy.6 In our report, we describe a combined sequential transposition of the arch vessels entirely through a cervical approach. Case report A 76-year-old woman presented with dizziness and vertigo. The patient underwent a duplex ultrasound demonstrating severe innominate artery stenosis with reversal of flow in the right vertebral artery. The patient's history was notable for multivessel coronary artery bypass grafting, aortic stenosis, hypertension, hyperlipidemia, and acute right retinal artery occlusion six years prior. The patient was on dual antiplatelet therapy for stroke prevention. The right radial pulse was not palpable and there was a 45 mm Hg pressure gradient between upper extremities. A computed tomography angiography (CTA) of the neck and chest was obtained for case planning, and this actually showed a complete and densely calcified occlusion of the ostium of the innominate artery (Fig 1A). The patient was felt to be a poor candidate for endovascular treatment due to the CTA findings, and a direct transthoracic repair was deemed anatomically high risk due to her prior median sternotomy. Therefore, extra-anatomic revascularization was determined to be most appropriate. Operative Technique The right common carotid artery (RCCA) was exposed through a low, supraclavicular transverse cervical incision down to its origin from the innominate artery. This also afforded excellent exposure of the proximal segment of the right subclavian artery (RSCA). The LCCA was exposed through an oblique cervical incision along the anterior border of the sternocleidomastoid muscle. Both common carotid arteries were unusually redundant and tortuous and nearly entirety of their cervical course was circumferentially mobilized from the surrounding tissues to provide the necessary length for a tension- free anastomosis. The retropharyngeal tunnel was made with blunt dissection from both sides of the neck, following a plane posterior to the esophagus and anterior to the prevertebral fascia. After systemic heparinization, the distal RCCA was clamped distally, and ligated and transected proximally at its origin. The proximal end of the RCCA was then brought through the retropharyngeal tunnel and anastomosed end-to-side to the LCCA. Due to the brief duration of the clamp-time during the anastomosis, no shunt was used, and the mean arterial pressure was maintained greater than 90 mm Hg to maintain collateral cerebral perfusion. Download : Download high-res image (153KB) Download : Download full-size image Figure 1 . Three-dimensional computed tomography angiography (CTA) of the aortic arch vessels. A) Preoperative CTA demonstrating complete occlusion of the innominate artery origin (arrow) and redundant right common carotid artery (asterisk). B) Postoperative CTA demonstrating autogenous revascularization of the right common carotid artery and right subclavian artery via transposed retropharyngeal right common carotid artery (arrow) Next, the RSCA was further exposed through the transverse cervical incision. After division of the vertebral vein, the right vertebral artery (RVA) and RSCA just distal to the RVA origin were exposed. The RSCA was ligated and divided near the innominate bifurcation and clamped distal to the vertebral artery, which was controlled with a vessel loop. The proximal RSCA was directly anastomosed end-to- side to the previously transposed RCCA. The patient was discharged home on postoperative day two and is doing well on follow-up with complete resolution of her previous symptoms. Postoperative CTA at 6 months showed a widely patent right common carotid and subclavian artery tandem transpositions (Fig 1B). The right vertebral artery flow was now antegrade on follow-up duplex ultrasound. Discussion Carotid-carotid bypass is a well-described technique for revascularization of the innominate artery with excellent patency rates approaching 100% at three years.7 However, for retropharyngeal tunnels there is a small but real potential of graft contamination from contact between the prosthesis and the digestive tract with chance of erosion. 8 Transposing one of the carotid arteries to the contralateral artery is an alternative approach that avoids using a prosthetic graft in the retropharyngeal space. Furthermore, when anatomically feasible, performing the double transposition with transposition of the RSCA to the transposed RCCA avoids a bypass graft altogether and may have improved long-term patency compared to carotid-subclavian bypass.9 This technique has some limitations. Sufficient redundancy of the carotid arteries is required to enable mobilization and transposition in a tension-free manner, and therefore this approach can be applied only in selected cases. In conclusion, in select patients with innominate artery occlusive disease not amenable to endovascular repair a totally autogenous extra-anatomic revascularization is possible using carotid-carotid transposition and subclavian-carotid transposition provided these supraaortic branches have sufficient redundancy. This technique avoids a prosthetic graft in the retropharyngeal space, can potentially decrease the risk of infectious complications, and result in improved patency.