✓ Spinal arteriovenous malformations (AVM's) can present with symptoms of neurogenic claudication indistinguishable from those of lumbar spondylosis. Spinal AVM's occur most frequently in males of middle age or older; lumbar spondylosis is often also present in these patients. The myelographic appearance of the abnormal vessels may resemble that of the dilated veins or redundant nerve roots sometimes seen adjacent to regions of spinal block, obscuring the diagnosis. Two patients are described who presented with clinical histories and myelographic findings that led to laminectomies for presumed spinal stenosis; ultimately, both were found to have an AVM. Treatment of the AVM arrested the neurological decline in one patient, and resulted in dramatic improvement in the other. A hypothesis related to hemodynamic consequences of venous hypertension is presented in an attempt to link the pathophysiology of the two conditions.
Report of two cases
Joseph R. Mausen and Roberto C. Heros
Bradford B. Walters, Robert G. Ojemann, and Roberto C. Heros
✓ A retrospective review of carotid endarterectomies performed by the Neurosurgical Service at Massachusetts General Hospital from July, 1976, through December, 1985, disclosed 64 procedures that were performed on an emergency basis. The patients included 40 men and 24 women, with a mean age of 64 years (range 32 to 87 years). Correlation of angiographic findings with outcome revealed that of the 27 patients with severe stenosis, usually with delay in blood flow, 25 (93%) were the same or improved postoperatively; of the 11 patients with stenosis and an intraluminal filling defect (six of whom had an intraluminal clot), eight (73%) were the same or improved after surgery; of the 16 patients with complete occlusion, 14 (88%) were the same or improved (backflow was established in all cases); and of the 10 patients with moderate to severe stenosis and/or severe ulceration (including three with transient ischemic attacks who were receiving heparin), eight (80%) were the same or improved.
Pre- and postoperative clinical status were graded into five categories: intact; mild deficit; moderate deficit (significant impairment but able to perform activities of daily living); severe deficit (requiring assistance for daily activities); and death. Of the 36 patients who preoperatively were intact or had mild deficits, 33 (92%) were the same or improved postoperatively, three were worse, and there were no deaths. Among 15 patients presenting with moderate deficits, 12 (80%) were the same or improved, two were worse, and one died. Of the 13 patients with severe deficits, 10 (77%) were the same or improved and three died. Two patients with sudden severe deficits associated with loss of contralateral bruit were operated on without angiography and were intact postoperatively. Of the four deaths in the total series, two were attributed to cardiac causes and two to unrelated disease processes. The indications for emergency carotid endarterectomy are discussed.
Kevin M. McGrail, Roberto C. Heros, Gerard Debrun, and Brian D. Beyerl
✓ A 44-year-old man experienced the sudden onset of horizontal diplopia and hemifacial numbness. Arteriography demonstrated a left intrapetrous carotid artery aneurysm. The patient was successfully treated with a left superficial temporal artery to middle cerebral artery bypass followed by balloon entrapment of the aneurysm.
There have been at least 40 previously reported cases of aneurysms of the petrous portion of the carotid artery. These aneurysms can be mycotic, traumatic, or developmental in origin. They can present with massive otorrhagia or epistaxis from acute rupture or with decreased hearing and paresis of the fifth through eighth cranial nerves and, less frequently, of the ninth, 10th, and 12th cranial nerves caused by direct pressure. They can also produce pulsatile tinnitus, and sometimes they are discovered as a retrotympanic vascular mass during otological examination. The treatment of choice is carotid artery occlusion. Trapping of the aneurysm by detachable balloons eliminates immediately the risk of hemorrhage, offers the possibility of test occlusion of the internal carotid artery with the patient awake prior to permanent occlusion, and should also reduce the risk of thromboembolism. It should be preceded by a bypass procedure when preliminary evaluation indicates that the patient will not tolerate internal carotid artery occlusion.
Roberto C. Heros
✓ A modification of the unilateral suboccipital approach is elaborated and illustrated. This modification is useful for aneurysms of the vertebral artery, the vertebrobasilar junction, and the proximal basilar trunk, and for arteriovenous malformations of the inferolateral cerebellum. It entails extreme lateral removal of the rim of the foramen magnum toward the condylar fossa and posterolateral removal of the arch of the atlas toward the exposed vertebral artery. This extra bone removal allows an approach to the front of the brain stem from inferolaterally, after gentle upward and medial retraction of the tonsil, with minimal or no retraction of the medulla.
Karl W. Swann, Roberto C. Heros, Gerard Debrun, and Curt Nelson
✓ A case of middle cerebral artery embolism by a detachable intra-arterial balloon is presented. The balloon migrated after being detached in an effort to occlude the internal carotid artery proximal to an unclippable giant paraclinoid aneurysm. Volume expansion, induced hypertension, anticoagulation therapy, rapid middle cerebral artery embolectomy, and good collateral circulation are factors that may have contributed to the patient's complete recovery from hemiplegia.
Roberto C. Heros, Gerard M. Debrun, Robert G. Ojemann, Pierre L. Lasjaunias, and Pierre J. Naessens
✓ A patient presenting with progressive paraparesis was found to have a spinal arteriovenous fistula at the T3–4 vertebral level. The lesion consisted of a direct communication of the anterior spinal artery with a very distended venous varix that drained mostly superiorly to the posterior fossa and simulated a posterior fossa arteriovenous malformation (AVM) on vertebral angiography. The patient was treated by surgical ligation of the fistula through an anterior transthoracic approach. He deteriorated abruptly on the 4th postoperative day, probably because of retrograde thrombosis of the enlarged anterior spinal artery. Over the next few months, he improved to the point of being able to walk with crutches. He has also regained sphincter control.
The different types of spinal AVM's are reviewed. Our case does not fit into any of these groups. A new category, Type IV, is proposed to designate direct arteriovenous fistulas involving the intrinsic arterial supply of the spinal cord.
Report of two cases
Karl W. Swann and Roberto C. Heros
✓ Two patients who had an accessory nerve palsy following carotid endarterectomy are presented. Both patients had high carotid bifurcations necessitating unusually high retraction and dissection. The ipsilateral accessory nerve was injured in the anterior cervical triangle in both cases. It is believed that vigorous lateral retraction of the superior aspect of the sternocleidomastoid muscle led to a stretch injury of the nerve. The symptoms completely resolved in both patients within 6 months.
Roberto C. Heros and Ali M. Ameri
✓ A patient with a giant aneurysm of the top of the basilar artery presented with severe progressive symptoms of brain-stem compression. There was inadequate collateral circulation to the upper basilar system. She underwent exploration of the aneurysm and, after it was found to be impossible to clip, a tourniquet was placed on the basilar artery for future occlusion with the patient awake. A saphenous vein graft was interposed between the left external carotid and the left posterior cerebral arteries. The previously unruptured aneurysm bled fatally 36 hours after surgery, just before intended occlusion of the basilar artery.