By Philip S K Paty
Strict attention to technical details is the most important aspect of carotid endarterectomy. The ideal carotid endarterectomy technique should make sense intellectually, be easy to perform, be transferrable to other operators, be modifiable depending on the circumstances, and have superior outcomes and a low rate of recurrence. The neck positioning, exposure and dissection for all types of carotid reconstruction including endarterectomy with or without patch, bifurcation advancement and bypass are similar. The devil, so to say, is in the details with regards to handling of the plaque endpoint and method of arterial closure.
An interesting historical note is that Dr DeBakey’s original description of the carotid endarterectomy technique performed in 1959 involved transection of the distal common carotid artery and eversion endarterectomy of the carotid bifurcation. The limitations of this technique were handling of more extensive disease in the internal carotid artery. The current iteration of the eversion carotid endarterectomy involves an oblique transection of the proximal internal carotid artery at the carotid bifurcation, thus isolating eversion of the internal carotid artery from that of common carotid artery and external carotid artery. Transection of the internal carotid artery at the carotid bifurcation simplifies the eversion endarterectomy even in the presence of extensive occlusive disease that spans higher into the internal carotid artery.
As with most surgical techniques, eversion carotid endarterectomy requires careful attention to detail. Aside from preoperative imaging studies, intraoperative visual and tactile clues determine the level of clamp placement. The transition of colour of the distal non-diseased internal carotid artery to a bluish normal tinge is an important visual cue for distal clamp placement. Palpation and compression with a forceps of the common carotid artery determines the proximal level of clamp placement. The technique requires oblique internal carotid artery transection at the bifurcation and circumferential mobilisation to half a centimetre beyond the distal disease. The internal carotid artery plaque is separated with an elevator or fine forceps. Plaque proximally is held by a forceps, gentle downward traction is applied, the adventitia is everted over the plaque like a shirt-sleeve cuff rolling up an arm and the plaque plucked out where it feathers out thinly at the distal end. The endpoint is checked visually and with gently catheter directed irrigation for any loose debris or residual mobile plaque which may embolise or dissect distally. This can be removed by further eversion or stripping debris circumferentially. Alternatively, the plaque can be secured with full thickness tacking sutures. Endarterectomy plane in the common carotid artery is then developed and the plaque cut proximally and removed. External carotid plaque is everted a short distance so that no debris embolises into the internal carotid artery. At this time, redundancy of the internal carotid artery can be excised or the medial wall incised to create a longer patched anastomosis. The internal carotid artery is then sewn to the common carotid artery in an end to side fashion.
Additional measures to deal with extensive internal carotid artery plaque are similar to those used in standard longitudinal carotid endarterectomy and involve division of the ansa hypoglossus, medial and cephalad mobilisation of the hypoglossal nerve and occasionally division of the digastric tendon. Occasionally, reflection of the divided internal carotid artery over the hypoglossal nerve may be required to facilitate eversion. These manoeuvres allow exposure and eversion of the internal carotid artery up to the skull base. If one still cannot obtain a plaque endpoint, the internal carotid artery can be transected and a bypass performed for reconstruction with either a vein or prosthetic graft.
Extensive proximal common carotid artery disease can be managed by encompassing this within a longer caudally directed oblique transection of the carotid bifurcation. Internal carotid artery redundancy and a medial slit often allow a long anastomosis. Alternatively, the usual length oblique transection is made and a longitudinal caudally directed arteriotomy is made. This then is closed with a separate running suture prior internal carotid artery to common carotid artery anastomosis.
If needed, shunt can be placed prior to eversion after internal carotid artery transection. Here the medial internal carotid artery is incised beyond the plaque and the shunt placed in the distal internal carotid artery. The shunt is secured, back bled and air freed, placed in the proximal common carotid artery and flow restored. The shunt then serves as a stabilising point for the distal internal carotid artery facilitating eversion. Alternatively, the internal carotid artery eversion can be performed first, the shunt placed and the internal carotid artery endpoint checked after eversion over the shunt. Either Javid or Pruitt type shunts can be used. The end to side anastomosis is performed around the shunt which is removed prior to complete closure allowing back bleeding and removal of any thrombus.
The currently available carotid stenting options have not achieved equipoise in terms of stroke prevention, risk reduction and recurrent stenosis as compared to open surgery. Carotid endarterectomy, thus, is the best available option currently available. Over the past two decades, we have performed over 11,000 eversion carotid endarterectomy procedures and taught the eversion technique to vascular fellows and residents, the vast majority of whom have adopted this as their go-to technique. The overall incidence of perioperative stroke is <1% for all indications. We perform over 95% of these procedures under cervical block and have routine clamp times of 15 minutes or less.
Implementing a technical change in a vascular surgeon’s “routine” management of carotid disease is difficult and involves assessment of manageable risk. This requires knowledge of tangible benefits of the technique, a plan for implementation and dealing with emotions related to change. This issue has parallels in other innovations such as progressive use of the internet for marketing and sales and remote computer linked workplaces to accommodate lifestyles. Although I would acknowledge that one’s comfort level and experience is important in choice of reconstruction of the internal carotid artery, eversion endarterectomy, as a result of its facile nature, is, in my opinion, the preferred technique.
Philip S K Paty is professor of Surgery, Albany Medical College, Albany, USA, partner, The Vascular Group, PLLC