Enhancing Rostral Exposure for Carotid Endarterectomy: Technical Report
Karl A. Greene, MD, PhD*
Joseph M. Zabramski, MD
Robert F. Spetzler, MD
*Institute for Neurosciences and Division of Neurosurgery Conemaugh Memorial Medical Center, Johnstown, Pennsylvania
Division of Neurological Surgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona
Recent studies have demonstrated that carotid endarterectomy significantly reduces the risk of stroke in patients with high-grade stenosis of the carotid artery. Carotid surgery, however, is only beneficial in this group when it can be performed with a combined morbidity and mortality rate below 3% and 5% for asymptomatic and symptomatic patients, respectively. Meticulous technique, which includes adequate exposure of the internal carotid artery distal to the plaque, is key in minimizing the risks of this procedure. This report describes a simple and reliable technique of retracting soft tissue with fishhooks (Codman, Raynham, MA) attached to a Leyla bar (Aesculap, San Francisco, CA) to enhance rostral wound exposure during carotid endarterectomy. Exposure of the distal internal carotid artery is improved, particularly in patients with a high cervical bifurcation. The use of fishhook retraction improves rostral wound exposure during carotid endarterectomy. Soft tissue trauma is minimized, reducing the risk of paresis of the mandibular branch of the facial nerve associated with its compression at the angle of the jaw.
Key Words: carotid artery, endarterectomy, surgical technique
Endarterectomy of the extracranial carotid artery is an effective means of reducing the risk of stroke and death in both asymptomatic and symptomatic carotid artery occlusive disease for patients with 60% and 70% stenosis or greater, respectively.[1-4] To achieve this beneficial effect, however, the procedure must be performed with minimal morbidity and mortality.[1-5] Any surgical technique or method that contributes to the ease and safety of operative dissection and exposure of the carotid artery in the neck should increase the likelihood of uncomplicated and successful outcomes.
Technical issues in carotid endarterectomy have recently been reviewed. The presence of a high carotid bifurcation on preoperative imaging studies, for example, may be a significant risk factor for carotid endarterectomy. We describe a technique for enhancing rostral exposure of the internal carotid artery (ICA) during carotid endarterectomy. This technique exposes the relevant neurovascular structures in patients with a high cervical carotid bifurcation and eases removal of rostral plaque, placement of intraluminal shunts, and reapproximation of the arteriotomy.
|Figure 1. Photographs demonstrating the position of the patient and proper attachment of the Leyla bar to the operating room table. (A) When the head rest has top or side rails, the Leyla bar holder is attached directly to the head rest. (B) When the head rest has no rails, it is removed and the patient is positioned closer to the foot of the table-the Leyla bar holder is then attached to the side rail of the table. Note how in both of these photographs the Leyla bar arches over the top of the patient's head, avoiding any interference with the surgeon's or assistant's access to the surgical field.
Materials and Methods
Figure 2. Intraoperative photograph demonstrating an overview of the setup for using fishhook retraction and the Leyla bar for soft tissue retraction. The rubber bands of the fishhooks are secured to the Leyla bar before the hooks are positioned along the upper margin of the incision. In this case a separate rubber band has been used to help stabilize the Weitlaner retractor. The Leyla bar can be positioned to
alter the final angle and degree of retraction.
Standard instruments used for operative dissection and exposure of the extracranial carotid artery at our institution include Debakey forceps, Metzenbaum and tenotomy scissors, a Shaw hemostatic electrocautery scalpel (Oximetrix, Inc.; Mountain View, CA), bipolar electrocautery forceps (Codman, Raynham, MA), and a pair of small Weitlaner (Codman, Raynham, MA) self-retaining retractors. Rostral exposure of the wound is enhanced when two to three fishhook retractors are attached to rubber bands with interposed strings (Codman, Raynham, MA) and a Leyla bar (Aesculap, San Francisco, CA). The latter instruments are usually reserved for self-retaining retraction of musculocutaneous flaps during craniotomies. A 9-French Microvac multiperforated suction tube (PNT, Inc.; Hopkins, MN) is also used during carotid arteriotomy, plaque dissection, and arteriotomy closure.[7, 9] The combined use of these few instruments is sufficient to expose the ICA even in patients with a high cervical bifurcation.
The details of microsurgical carotid endarterectomy as performed at our institution are described elsewhere.[7, 9] Only those portions of the procedure relevant to rostral wound exposure are emphasized here.
The patient is transferred to the operating room table and positioned to allow attachment of the Leyla bar holder (Fig. 1). The head is turned away from the side of the endarterectomy and extended slightly. The skin incision is outlined along the anterior border of the sternocleidomastoid muscle, beginning about 4 cm above the clavicle and extending rostrally to a point approximately one finger’s breadth lateral to the angle of the mandible (Fig. 1). Combined with the use of fishhook retractors (described below), this incision provides adequate exposure for most cases. When additional exposure is needed, the incision can readily be extended above the angle of the jaw to the level of the mastoid process.
After the skin is opened and the platysma muscle has been divided, small, blunt-tipped, self-retaining Weitlaner retractors are positioned at the superior and inferior margins of the wound and used to help expose the underlying soft tissue and vascular structures. The medial edge of the sternocleidomastoid muscle is dissected free and retracted laterally. The internal jugular and facial veins are identified next, and the facial vein is ligated and divided at its junction with the internal jugular vein. The carotid sheath is exposed by repositioning the lateral blades of the self-retaining retractors so that they displace the internal jugular vein laterally. Care is taken to keep the medial retractor blades superficial to the trachea, avoiding injury to the trachea and recurrent laryngeal nerve.