June 09, 2015
Let's review the basic principles for performance of a carotid endarterectomy. This is a 61 year old male who presented with an asymptomatic left sided high-grade stenosis. The imaging, again, demonstrates the extent of stenosis on the CT angiogram. Let's go ahead and review patient positioning. Obviously, the supine position is used, the incision marks the anterior border of the sternocleidomastoid muscle. The incision curves posteriorly, just at the angle of the jaw. Following the initial dissection, the anterior belly and border of the sternocleidomastoid muscle is exposed. Here's the anterior belly of the sternocleidomastoid muscle. The common facial vein is isolated. Two sutures are used to ligate this vein. Often the two sutures can be passed simultaneously. After the vein is ligated, it can be transected, therefore further expanding our operative corridor, toward the carotid sheath. Here again, following the medial belly of the sternocleidomastoid muscle, fish hooks may be used on the muscle, but not on the jugular vein. Here's the carotid sheath that is being opened. And so surfacalis is mobilized anteriorly, it joins the hypoglossal nerve. I also place sutures or fish hooks into the carotid sheath when this sheath is robust in order to elevate the carotid artery out of its groove. This maneuver significantly facilitates the exposure of the carotid artery and decreases the working distance of the operator. Next dissection follows the route of the internal carotid artery, as well as the proximal part of the external carotid artery. Blunt and sharp dissection techniques are used to expose the artery thoroughly. Obviously the extent of exposure should be just to the level or the distal level of the carotid plaque. Here is another suture to further immobilize the carotid sheath. Visa loops are placed around all the vessels for vascular control. The internal carotid artery is circumferentially dissected. So that vascular control is secured, especially just to a distal level of the plaque in the vessel. Dissection in the area distal to the ICA has to be carefully performed more superficially so that the hypoglossal nerve is not injured. There's usually a vein just around the nerve. This vein can be isolated if necessary, coagulated and cut, one can also follow the route of the inside surfacalis and find the hypoglossal nerve. The nerve itself can be mobilized, generously more superiorly and potentially anteriorly, here again, you can see the nerve. I try to avoid disconnecting it's connection to the inside surfacalus. Now the nerve is being undermined so additional distal exposure is secured. Using the soft tissue around the nerve, I translocate the nerve anteriorly and follow the posterior border of the nerve so that the more distal aspect of the internal carotid artery is available. So now their control appears to be adequate based on palpation of the plaque within the ICA. Here's control circumferentially around the external carotid artery. So vessel loops can be passed around, again, aggressive manipulation of this area should be avoided. Now the common carotid artery and the bifurcation is being circumferentially dissected. A temporary clip was placed around the superior thyroid artery. Now vessel loops are placed around the internal as well as the external carotid arteries. And also a vessel clamp is placed just distal to the edge of the plaque over the internal carotid artery. So the initial occlusion is performed over the internal carotid artery followed by common and then external. This provides the necessary local circulatory arrest so that arteriotomy can begin. So the initially arteriotomy starts at the level of the common carotid artery and continues over the internal carotid artery. One has to avoid the temptation to create a zigzag arteriotomy line because of the angle of the internal carotid artery in relation to the bifurcation. If the plaque is calcified and the scissors are not effective, I use a 10 blade knife to cut through the plaque. To continue the arteriotomy to the level where the plaque joins the normal wall of the vessel, or one may say they're relatively normal wall of the vessel. A plane is created between the intima of the artery and the plaque on both sides of the common and internal carotid artery. I first dissect away from the origin of the ECA and avoid injuring the wall during dissection. Next the dissection continues to the other edge of the vessel. This dissection will be halted or stopped by the entry of the plaque into the external carotid artery. When this happens, I divert my attention more proximally into the common carotid artery where circumferential disconnection of the plaque continues. Now I continued to mobilize the plaque that enters into the ECA. Next, I disconnect the plaque from its attachment into the common carotid artery. Obviously a normal vascular wall is not available and the plaque has to be disconnected. At some point after the proximal portion of the plaque is disconnected, I divert my attention into the ECA lumen where the proximal part of the plaque into this artery is circumferentially disconnected as this totally as possible into the ECA and the plaque into the ECA is avulsed, as distally as possible to avoid any thrombogenic surfaces entering into the internal quartered artery lumen or their level of the bifurcation. Here the loop, the vessel loop around the ECA is lucent. Now here is the critical part of the operation where all the loose intimal flaps or the flaps from the plaque are carefully removed. Ample amount of heparin irrigation is used to identify these plaques via their mobilization. Some of the plaques or flaps have to be dissected along the edge and pulled across the circumference of the vessel until the vesent is clearly clean off any thrombogenic surfaces of the plaques or the flaps. Any extra trimming of their plaque proximally may be necessary to make sure again, there is no free floating edges of the flap into the lumen of the vessel. Here again is the maneuver of using the irrigation, heparin irrigation to identify the free floating flap, especially at the edges of their common carotid artery. Next, the plaque is disconnected into the internal carotid artery. It is often a natural plan where the plaque wants to disconnect. Micro scissors are used to, again, trim down the edges of the plaque into the ICA avoiding presence of any free floating flaps in this area. The lumen of the vessel appears relatively clean. We're just about ready to start our arteriotomy closure. I'm conducting my final inspection of the ICA. The IC was quite generous in its lumen in this case, therefore patching was then not necessary. The initial suture is important. It's from outside to inside and then inside to outside. And this initial suture tacks down all the edges of the plaque. I continue to suture the edges of the arteriotomy using a non-absorbable suture in this case, you can see a high magnification on the microscope, as I was tacking down of the plaque, making sure that no free floating edges are apparent. The initial bites are relativity exact within the ICA to make sure the lumen of the ICA is not as stenosed. However, when suturing moves onto the common, more generous bites of the vessel wall can be taken so that the lumen on the vessel remains very clean, free of any rugged edges of the vascular wall. The closure also is performed at the proximal end of the arteriotomy. The same technique was used outside to inside and inside to outside to tack down all the edges of the plaque. The initial suture stopped in the middle, from distal to proximal. And this second suture continuous from proximal to distal meeting the first suture in the middle. Heparin irrigation is used continuously to clear the operative field, generous bites are taken at this point. Since the vessel is quite redundant at the level of the common carotid artery in this patient, the order of re instituting flow is as follows. The ICA is opened last to avoid any debris from being directed into this vessel. Before we complete the knot, further irrigation into the vessel is conducted, the back bleeding has to be performed. So as mentioned, the internal is opened last, the external and common are instituted first, but for the back bleeding, as you can see the IC is back bled. And the common is back bled, a couple of times and next the final knot is completed. And after the arteriotomy is finished, and for it's closure, again the flow is re-instituted with the common and external face first and internal last. Here's some bleeding from the arteriotomy closure site. After the flow was re-instituted. I placed a single suture to close the bleeding site. Obviously hemostasis is quite important to avoid formation of an acute hematoma. That can be quite life-threatening. The single suture was quite effective. Here is the final result, the vessel is nicely positile. Thank you.
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