A New Wire-Supported Shunt for CarotidAEndarterectomy John M. Keshishian, M.D., and Stanley Crossland, M.D.
ABSTRACT An intraarterial shunt for cerebral protection during carotid endarterectomy is described. It combines the features of the U-shaped shunt of Hallin and the straight shunt of Sundt, and incorporatesa side-arm that can be used for perfusion, irrigation, and intraarterial pressure. The shunt is a molded Silastic tube with wire coils at each end to prevent collapse, and its funicular collar and rim obviate sudden expulsion. Its use allows endarterectomy to be performed in a deliberate manner, permitting careful attention to prevention of an intimal flap and unhurried repair of the arteriotomy.
Presently, various methods are used for avoiding cerebral insult during carotid endarterectomy. In some instances rapid extraction of the plaque and closure have appeared adequate. In other cases many believe that measurement of "stump" pressures will give substantive evidence that adequate cerebral perfusion exists. There is no consensus on a magic number for stump pressure before the decision whether or not to use a temporary shunt is made. We, like others, have used the temporary intraarterial shunt for the past ten years, in some instances utilizing it in conjunction with local hypothermia. This report describes an intraarterial shunt that combines the features of the U-shaped shunt of Hallin plus the straight shunt of Sundt (Figs 1, 2). It resembles the shunt recently reported by Brener and associates 111 but differs in construction, consisting of a molded Silastic tube with supportive wire coils at each end and a funicular collar rim and side-arm with nipple seal (Fig 1).The shunt is tapered to accommodate to the lumen of the internal and common carotid arteries. The device is available
Fig 1. The shunt. See textfordetails.
From the Department of Surgery, the George Washington University Medical Center, Washington, DC. Accepted for publication June 18, 1976. Address reprint requests to Dr. Keshishian, 2520 L St, NW (at Pennsylvania Ave), Washington, DC 20037.
264
Fig 2 . From top: Sundt shunt, shunts described in t e x t , Hallin shunt.
265
A
How to Do It: Keshishian and Crossland: Shunt for Carotid Endarterectomy
B
Fig3. ( A )Operative field. A bulldog clamp is occluding the external carotid artery. Heavy silk ties are loosely double-looped about the internal and common carotid arteries, w i t h a central "pull-out" tie. (B)T h e carotid artery has been opened and the incision extended above the plaque into the internal carotidartery. Orifices o f t h e external carotid can be seen in the left center o f t h e arteriotomy. An ulceratedstenotic plaque is visible at the base o f t h e thumbforceps on the right. (C) Endarterectorny has been completed with the shunt in the U mode. Patch grafting has been started on the right side of the arteriotomy. T h e s h u n t will be pushedin both directions so as to lieflat before the opposite side issewn.
C
266 The Annals of Thoracic Surgery Vol 23 No 3 March 1977
tive wire prevents occlusion; the collar avoids sudden slippage into the field. Back-bleeding is verified through the side-arm with the common carotid artery side compressed; the same is done for the lower end. Pressures and flow rates can be measured if desired; otherwise, the nipple adapter is closed. With the shunt in place, endarterectomy is begun. Traction sutures on each side enhance exposure. At this time the shunt is used in the U mode. The wire coil assures bending without kinking at the internal carotid. After the plaque has been removed and intimal integrity confirmed, the shunt is slipped down into the Technique common carotid, converting the device into the Figure 3 shows the operative field. A bulldog clamp has been placed on the external carotid linear mode so that it lies within the lumen of the artery. Heavy silk ties are loosely double-looped artery. The arteriotomy can now be closed, with about the internal and common carotid arteries or without patch grafting. We prefer to run a suture from both ends of the arteriotomy site; with a central "pull-out" tie. the shunt may then be withdrawn before the last After the common and internal carotid arteries have been gently occluded, the arteriotomy is few sutures are placed. made and extended up beyond the plaque and into normal internal carotid artery. The preirrigated shunt is then introduced into the internal Reference carotid with simultaneous release of the clamp 1. Brener BJ, Brief DK, Alpert J, et al: A T-shaped carotid shunt. Arch Surg 110:1249, 1975 and tightening of the tourniquet. The suppor-
in sizes as small as 3 mm in internal diameter at the internal carotid artery end. We have used this new shunt in 32 patients without complication. It is our opinion that every surgeon who performs carotid endarterectomy should be able to insert a shunt with a minimum of fuss. Therefore our residents are instructed in its use and become facile in its insertion. We have a simple checklist for shunting and everyone on the team knows his duty, which prevents unexpected and athetoid responses.
ABSTRACT An intraarterial shunt for cerebral protection during carotid endarterectomy is described. It combines the features of the U-shaped shunt of Hallin and the straight shunt of Sundt, and incorporatesa side-arm that can be used for perfusion, irrigation, and intraarterial pressure. The shunt is a molded Silastic tube with wire coils at each end to prevent collapse, and its funicular collar and rim obviate sudden expulsion. Its use allows endarterectomy to be performed in a deliberate manner, permitting careful attention to prevention of an intimal flap and unhurried repair of the arteriotomy.
Presently, various methods are used for avoiding cerebral insult during carotid endarterectomy. In some instances rapid extraction of the plaque and closure have appeared adequate. In other cases many believe that measurement of "stump" pressures will give substantive evidence that adequate cerebral perfusion exists. There is no consensus on a magic number for stump pressure before the decision whether or not to use a temporary shunt is made. We, like others, have used the temporary intraarterial shunt for the past ten years, in some instances utilizing it in conjunction with local hypothermia. This report describes an intraarterial shunt that combines the features of the U-shaped shunt of Hallin plus the straight shunt of Sundt (Figs 1, 2). It resembles the shunt recently reported by Brener and associates 111 but differs in construction, consisting of a molded Silastic tube with supportive wire coils at each end and a funicular collar rim and side-arm with nipple seal (Fig 1).The shunt is tapered to accommodate to the lumen of the internal and common carotid arteries. The device is available
Fig 1. The shunt. See textfordetails.
From the Department of Surgery, the George Washington University Medical Center, Washington, DC. Accepted for publication June 18, 1976. Address reprint requests to Dr. Keshishian, 2520 L St, NW (at Pennsylvania Ave), Washington, DC 20037.
264
Fig 2 . From top: Sundt shunt, shunts described in t e x t , Hallin shunt.
265
A
How to Do It: Keshishian and Crossland: Shunt for Carotid Endarterectomy
B
Fig3. ( A )Operative field. A bulldog clamp is occluding the external carotid artery. Heavy silk ties are loosely double-looped about the internal and common carotid arteries, w i t h a central "pull-out" tie. (B)T h e carotid artery has been opened and the incision extended above the plaque into the internal carotidartery. Orifices o f t h e external carotid can be seen in the left center o f t h e arteriotomy. An ulceratedstenotic plaque is visible at the base o f t h e thumbforceps on the right. (C) Endarterectorny has been completed with the shunt in the U mode. Patch grafting has been started on the right side of the arteriotomy. T h e s h u n t will be pushedin both directions so as to lieflat before the opposite side issewn.
C
266 The Annals of Thoracic Surgery Vol 23 No 3 March 1977
tive wire prevents occlusion; the collar avoids sudden slippage into the field. Back-bleeding is verified through the side-arm with the common carotid artery side compressed; the same is done for the lower end. Pressures and flow rates can be measured if desired; otherwise, the nipple adapter is closed. With the shunt in place, endarterectomy is begun. Traction sutures on each side enhance exposure. At this time the shunt is used in the U mode. The wire coil assures bending without kinking at the internal carotid. After the plaque has been removed and intimal integrity confirmed, the shunt is slipped down into the Technique common carotid, converting the device into the Figure 3 shows the operative field. A bulldog clamp has been placed on the external carotid linear mode so that it lies within the lumen of the artery. Heavy silk ties are loosely double-looped artery. The arteriotomy can now be closed, with about the internal and common carotid arteries or without patch grafting. We prefer to run a suture from both ends of the arteriotomy site; with a central "pull-out" tie. the shunt may then be withdrawn before the last After the common and internal carotid arteries have been gently occluded, the arteriotomy is few sutures are placed. made and extended up beyond the plaque and into normal internal carotid artery. The preirrigated shunt is then introduced into the internal Reference carotid with simultaneous release of the clamp 1. Brener BJ, Brief DK, Alpert J, et al: A T-shaped carotid shunt. Arch Surg 110:1249, 1975 and tightening of the tourniquet. The suppor-
in sizes as small as 3 mm in internal diameter at the internal carotid artery end. We have used this new shunt in 32 patients without complication. It is our opinion that every surgeon who performs carotid endarterectomy should be able to insert a shunt with a minimum of fuss. Therefore our residents are instructed in its use and become facile in its insertion. We have a simple checklist for shunting and everyone on the team knows his duty, which prevents unexpected and athetoid responses.
