A Novel Minimally Occlusive Microvascular Anastomosis Technique Using a Temporary Intraluminal Shunt: A Prospective Technique to Minimize Brain Ischemia Time during Superficial Temporal Artery-to-Middle Cerebral Artery Bypass

The clinical utility of the Kopitnik arteriovenous malformation microclip during STA-MCA bypass surgery

Purpose

Yasagil temporary clips have been widely used in extracranial-intracranial (EC-IC) arterial bypass surgery. However, the extremely delicate vessels involved often require the application of finer clips. We report on the use of the Kopitnik arteriovenous malformation (AVM) microclip system for superficial temporal artery-middle cerebral artery (STA-MCA) bypass.

Methods

Kopitnik AVM microclips are new mechanical devices that are used during AVM surgery. They exert a pre-defined closing force of 50–70 g, and also feature a special, pyramid-shaped structure stamped on inner surfaces of the blades. These characteristics avoid vascular intimal injury and provide a secure grip. We prospectively studied their use in 15 patients requiring STA-MCA anastomosis.

Results

Clinical results were excellent and there were no new ischemic events during 6-months’ follow-up.

Conclusions

Kopitnik AVM microclips have several advantages; they have small and variously sized clip blades (2, 3, 4 and 5 mm), and the small clip head allows the operator an excellent view of the pathology and clip status. The Kopitnik AVM microclip appears to be clinically effective and safe for EC-IC bypass surgery, especially when smaller vessels are involved.

Risk of intraoperative ischemia due to temporary vessel occlusion during standard extracranial–intracranial arterial bypass surgery

Object

Standard extracranial–intracranial (EC–IC) arterial bypass surgery represents a well-recognized procedure in which the aim is to augment distal cerebral circulation. The creation of the bypass requires temporary occlusion of the recipient vessel. Thus, there exists controversy about the risk of standard EC–IC arterial bypass surgery causing ischemic complications due to temporary vessel occlusion. In this prospective study, the incidence of intraoperative ischemia was investigated in symptomatic patients with steno-occlusive cerebrovascular disease and existing hemodynamic insufficiency.

Methods

Twenty consecutive patients (14 women and 6 men; mean age 46 ± 11 years) suffering from recurrent transient ischemic attacks due to occlusive cerebrovascular disease and proven hemodynamic compromise in functional blood flow studies were enrolled in this study. The underlying pathological condition was internal carotid artery (ICA) or middle cerebral artery (MCA) occlusion in 6 cases and ICA or MCA stenosis in 3 cases, whereas 11 patients presented with moyamoya syndrome or moyamoya disease. The surgical procedure consisted of the establishment of a standard superficial temporal artery (STA)–MCA bypass, and was performed while a strict intraoperative management protocol was applied. Patients underwent clinical examination and magnetic resonance (MR) imaging within 48 hours before and after surgery.

Results

The incidence of reversible clinical signs of ischemia was 2 (10%) of 20 patients. Postoperative MR imaging revealed signs of diffusion disturbances in 2 (10%) of 20 cases. The observed diffusion-weighted imaging changes, however, were situated within the dependent vascular territory at risk for ischemia in 1 patient only. No permanent neurological deficit occurred. The temporary vessel occlusion time ranged between 25 and 42 minutes (mean 33 ± 7 minutes). All means are expressed ± the standard deviation.

Conclusions

Temporary vessel occlusion during standard STA–MCA arterial bypass surgery carries a low risk of intraoperative ischemia when a strict perioperative management protocol is applied.