When Opening the Carotid Is Anything But Routine
Date: February 28, 2010
Even by the standards of Bruce Perler, this was a challenging case.
Facing Johns Hopkins’ chief of vascular surgery was a 74-year-old man with diffuse, severe cerebral vascular disease manifested in global ischemic episodes who had already been declared inoperable. His right internal carotid was inoperable, 100 percent occluded, and his left carotid was 80 percent narrowed. He also had vertebral artery occlusions.
The condition was so advanced that the patient experienced repeated blackout spells. On one occasion, he blacked out while driving his car and ended up on the side of the road. He became unable to drive or even work around a hot stove and was completely dependent on others.
His overall operative risk was further complicated by severe coronary artery disease with ischemic cardiomyopathy, chronic renal insufficiency, chronic obstructive pulmonary disease and hypertension.
The clear course of action was to remove the plaque from the left carotid with an endarterectomy. But the patient had already been on the operating table in another hospital with poor results. Because of his severe comorbidity, the previous surgeon operated using a local anesthetic. However, as soon as the patient’s carotid artery was clamped, he developed a seizure. They immediately unclamped the artery and aborted the operation.
“Clearly he was dependant on the left carotid artery,” says Perler. “They sent him home and told him it was inoperable and that he had to live like this.”
But the patient’s internist suggested he seek a second opinion from Perler, who has extensive experience in carotid artery surgery and who performs most carotid endarterectomies with the patient under general anesthesia and with intra-operative shunting to perfuse the brain while the artery is clamped.
The method is to clamp the left artery, then quickly place a shunt that routes blood past the blockage. “It’s something we do routinely that optimizes the safety of the procedure,” says Perler. “With this approach, we can do the case using general anesthesia and precisely control the patient’s hemodynamic status.”
It takes Perler less than a minute to clamp the artery, place the shunt and restore blood flow. He then clears the plaque, repairs the artery and removes the shunt before placing the last sutures. The patient is immediately awakened in the operating room, and a neurologic examination is performed to rule out an intra-operative stroke “We wake the patient up as soon as the skin is closed,” says Perler.
Operative risk was further complicated by severe coronary artery disease with ischemic cardiomyopathy, chronic renal insufficiency, chronic obstructive pulmonary disease and hypertension.
In the case of the 74-year-old, the anesthesiologist monitored cerebral perfusion with oximetry and found that when Perler initially clamped the carotid artery, the oxygen tension dropped. It immediately normalized, however, when the shunt was placed. Sensation and motor strength tests, as well as asking the patient a few questions, showed that he had come through without neurologic complications.
He was monitored postoperatively, remained stable from a neurologic and cardiac standpoint, and was discharged home one day after the operation. Nearly a year later, the patient hasn’t had any blackouts and has returned to many of the daily activities he used to enjoy.
“He was definitely a high-risk patient,” says Perler, “but a good example of the kind of difficult cases we do regularly.”