Results of extracranial-intracranial arterial bypass for bilateral carotid occlusion.

The results of superficial temporal to middle cerebral artery bypass surgery for bilateral internal carotid artery occlusion were reviewed in 39 patients. Preoperative symptoms included recurrent transient ischemic attacks (TIA's) in 31 patients (80%) and mild or moderate stroke in 15 (29%). Deficits were unilateral in 23 cases and bilateral in 14. Dementia or personality changes were observed in 19 patients (49%). Operative morbidity occurred in six of 39 cases and was neurological in one; the surgical mortality rate was 8% (three of 39 patients), including two cases of cerebral hemorrhage. The outcome was good or excellent (relief of TIA's and reduction of neurological deficit) in 82% of patients over a follow-up period of 3 to 139 months. Five patients had a late postoperative stroke, which occurred in the unoperated hemisphere in each case; one patient had an ipsilateral TIA 6 years after the bypass procedure. These results suggest that an extracranial-intracranial arterial bypass procedure to augment collateral cerebral blood flow can be performed safely in patients with bilateral internal carotid artery occlusion and may be associated with relief of ischemic symptoms. Future studies may document a role for this procedure in the prevention of stroke.

Extracranial-intracranial arterial bypass for middle cerebral artery stenosis and occlusion. Operative results in 65 cases.

Forty-seven patients with middle cerebral artery (MCA) stenosis and 18 patients with MCA occlusion underwent extracranial-intracranial arterial bypass procedures. Patients presented with a history of transient ischemic attacks (TIA's), reversible ischemic neurological deficits, TIA's after initial stroke, stroke-in-evolution, or completed stroke. Angiography revealed that the MCA stenosis ranged from 70% to over 95%. Two patients (4.3%) in the stenosis group had a perioperative stroke (within 30 days of operation). There was no perioperative mortality. In the occlusion group, no patient had a perioperative stroke, and one patient (5.5%) died from a non-neurological disease. The TIA's resolved completely in 90% of the patients with stenosis and in 91.6% of those with occlusion. No patient with MCA stenosis had a late ipsilateral stroke, although five had a contralateral or vertebrobasilar stroke. One patient with MCA occlusion had a late ipsilateral stroke. The bypass patency rate at late follow-up review was 100%. The results of intracranial-extracranial arterial bypass procedures appear to be similar for patients with either stenosis or occlusion of the MCA. Symptomatic relief of TIA's was excellent and, in two patients with progressive stroke-in-evolution, the deficit was stabilized. The incidence of postoperative ipsilateral stroke was low in patients with TIA's alone or with TIA's after an initial stroke, but among patients with completed stroke, improvement was confined to slight reduction in the neurological deficit.

Results of extracranial-intracranial arterial bypass for intracranial internal carotid artery stenosis: review of 105 cases.

Extracranial-intracranial arterial bypass was performed for intracranial internal carotid artery stenosis in 105 patients who had ischemic symptoms 1 to 3 months before operation. The degree of stenosis, measured angiographically, was 60 to 98%. The postoperative bypass patency rate, determined angiographically or by Doppler examination, was 97%. The surgical mortality rate was 1%, and the permanent surgical morbidity rate was 2%. During a mean follow-up period of 54 months, 22 patients died; 10 deaths were caused by cardiac disease and 3 were related to stroke, 2 of which were ipsilateral to the bypass. One patient was lost to follow-up. Seventy-three of the 82 survivors (89%) had no further transient ischemic attacks or stroke after operation. Seven patients had a late stroke: 5 were ipsilateral, 1 was contralateral, and 1 was vertebrobasilar. Three of these strokes were fatal. The overall late death rate was 4% per year, and the late death rate from neurological causes was 0.6% per year. The late stroke rate was 1.5% per year, and the rate of ipsilateral late stroke in patients who had a patent bypass was 0.6% per year. We conclude that extracranial-intracranial arterial bypass for symptomatic intracranial internal carotid artery stenosis is a reasonably safe and technically satisfactory procedure that has a potential for improving outcome, compared with the natural history of the disease.

Giant aneurysm and cerebral ischemia.

A case is reported of a patient harboring a giant aneurysm of the left middle cerebral artery who presented with a reversible ischemic neurological deficit. The etiology of the cerebral ischemia is discussed, with reference to the literature. In addition, results obtained from evaluation of the luminal surface of the aneurysmal dome with the scanning electron microscope are described.

Revascularization of the scalp by microsurgical techniques after complete avulsion.

A total scalp replantation was performed after a complete traumatic avulsion of the scalp with skull fracture. Multiple arterial and venous anastomoses were required. Satisfactory healing occurred, and the patient has had a subsequent uneventful cranioplasty to fill a bony defect, with normal scalp healing.

Successful replantation of two avulsed scalps by microvascular anastomoses.

Two cases of immediate replantation of avulsed scalps by microvascular anastomosis are presented. This method of treatment seems to offer significant economic, social, and psychological advantages over split-skin grafting of the calvarium, or other presently used treatments. The need for secondary reconstructive procedures after a successful replantation is minimal, or nil. The mechanism of scalping is reviewed, and it is related anatomically to the structure of the galea aponeurotica. Specific recommendations are made regarding the immediate care of the avulsed scalp and the denuded calvarium, the value of a team approach in replantation, and various technical aspects of the procedure and postoperative management. The more frequent use of interpositional vein grafts is urged.

Reconstruction of extensive tissue defects of the scalp by microsurgical composite tissue transplantation.

Two cases of severe and extensive electrical burns of the scalp and skull are presented. Large segments of composite groin tissue were successfully transplanted to cover the scalp defects. Microvascular surgical techniques were employed. Both patients had short postoperative hospitalizations. It is possible that a cranioplasty may now be performed as a second stage under the healed full-thickness skin. The advantages of providing a thick protective skin cover in a single operation are outlined.

A scanning electron microscopy study of micro-arterial damage and repair.

The effects of microvascular clamps on the femoral vessels of rats were studied, using the SEM. The early changes observed were (1) local fusiform dilatation of the area secondary to necrosis of the muscular wall, (2) flattening of the longitudinal ridges in the endothelial (3) loss of laminar flow, (4) endothelial sloughing, (5) platelet aggregation, and (6) leukocyte adherence and diapedesis. The repair of the endothelium occurred by an early replication of the adjacent undamaged endothelial cells -- with their subsequent migration across a platelet bed. The coverage was complete in one week, although reorientation of the neo-endothelial cells took longer. On the basis of this study and our clinical experience, we think the ideal microvascular clamp would possess the following characteristics: small size, light weight, mechanical simplicity, flat jaws (one to two mm in diameter) coated with a non-slip surface, and calibrated to produce a pressure less than 30 gm per mm2. In addition the clamp should be unaffected by blood, autoclaving, or repeated use. No such clamp is commercially available now, but we hope that one will be available in the near future.