Superficial temporal artery to middle cerebral artery bypass

The superficial temporal artery to middle cerebral artery bypass is an elegant procedure that was developed and first performed by M. Gazi Ya?argil. It has been used by neurosurgeons for more than 30 years in the management of neurovascular disorders such as cerebrovascular ischemic disease, moyamoya disease, and complex intracranial aneurysms. Mastering the technique requires not only precise and fine skills but also devoted training in the microsurgery laboratory. The technique presented in this article evolved from the long and vast experience of the senior author (DWN) in performing superficial temporal artery to middle cerebral artery bypasses for a variety of cerebrovascular conditions.     

Thyrocervical trunk-external carotid artery bypass for positional cerebral ischemia due to common carotid artery occlusion. Technical note

Medically refractory positional cerebral ischemia (PCI) and concomitant orthostatic hypotension associated with chronic common carotid artery (CCA) occlusion are rare. In this technical report, the authors describe an extracranial bypass in which the thyrocervical trunk was used as a donor vessel to treat three cases of CCA occlusion with PCI. Postoperatively, although orthostatic hypotension remained, ischemia-related symptoms resolved in all three patients and long-term graft patency was demonstrated. It is possible to treat cerebral ischemia due to CCA occlusion with extracranial bypass surgery. In these patients, the thyrocervical trunk proved to be a suitable donor vessel for the reconstitution of blood flow within the external carotid artery.     

Subclavian-external carotid bypass for symptomatic severe cerebral ischemia from common and internal carotid artery occlusion

Occlusion of the common and internal carotid arteries in a patient with symptomatic severe cerebral ischemia, with or without contralateral carotid disease, portends a poor prognosis. The present study has described our experience with subclavian and external carotid artery revascularization for symptomatic severe cerebral ischemia from common and internal carotid artery occlusion. Nine patients (five men and four women) with a mean age of 62 (range 41 to 82 years) were diagnosed as having symptomatic severe cerebral ischemia. All patients had ipsilateral hemispheric symptoms, seven had amaurosis fugax, and two had associated syncope. Four patients (three men and one woman) were hypertensive, four (two men and two women) had diabetes, eight smoked, and all had a history of coronary artery disease. All of the patients had noninvasive laboratory studies and preoperative angiography, and three had postoperative angiography. Five patients were successfully revascularized to a patent external carotid artery despite nonvisualization by angiography. Six patients had unilateral and three bilateral occlusion of the common and internal carotid arteries appropriate to their symptoms. Using regional anesthesia, four patients underwent a subclavian-external carotid bypass with polytetrafluoroethylene; saphenous vein was used in five; and three had concomitant axilloaxillary bypass grafting with polytetrafluoroethylene. Neurologic improvement (that is, no subsequent deficit and no progression of symptoms) was noted in all nine patients with a follow-up of 4 to 28 months (mean 11.2 months). Two patients died from myocardial infarction 4 and 7 months after operation. Subclavian-external carotid artery bypass is a safe addition to the options for the treatment of symptomatic severe cerebral ischemia with occlusion of the common and internal carotid arteries, visualization of a superior thyroid collateral vessel on the recipient end, and nonvisualization of the external carotid artery.     

Anatomic pathways facilitating middle cerebral artery bypass

Occlusion of the middle cerebral artery by thrombi is a relatively common occurrence resulting in stroke. Prompt intervention by dissolution or bypassing the thrombi could reduce the severity of the effects. Here, the anatomic pathways facilitating a bypass are explored. Four possible arteries, the two superficial temporals, left and right, and two middle meningeals, left and right, are in positions adjacent to branches of the middle cerebral arteries, the trunks of which are located in the lateral fissures of the brain. The first possibility is anastomosing a branch of the superficial temporal artery with the middle cerebral artery segment in the lateral fissure where this segment is usually clear of thrombi. The second possibility is anastomosing a branch of the middle meningeal artery with the postthrombotic segment of the middle cerebral artery. These anastomoses are to be done with donor and recipient arteries of the same side. In the unlikely event that these two possibilities are lost, it is still possible to anastomose the affected middle cerebral artery with the superficial temporal or middle meningeal artery of the opposite side using several inches of saphenous vein.     

Complications after subclavian-cortical middle cerebral artery bypass

Subclavian-cortical middle cerebral artery bypass by saphenous vein interposition is an uncommon recent revascularization technique used for immediate volume flow to the brain or when donor arteries are unavailable or inadequate. We used this technique in four cases of symptomatic common carotid artery occlusion. In the last two cases, severe, reversible neurological complications occurred. We think that these complications are due to this particular technique, and more cautious indications than for traditional extra-intracranial arterial bypass are recommended.     

Cerebral revascularization: proximal external carotid to distal middle cerebral artery bypass with a synthetic tube graft

A right proximal external carotid to distal middle cerebral artery bypass with a prosthetic tube graft was performed in a patient with intermittent cerebral ischemia due to middle cerebral artery stenosis. The patient was relieved of his symptoms, and he was neurologically normal 3 months after operation. Angiography 3 months postoperatively revealed flow through the graft and excellent filing of the middle cerebral circulation, both retrograde and antegrade. Early results suggest that an expanded polytetrafluoroethylene graft may be useful as a vascular conduit if suitable autogenous vessels are unavailable or have failed.     

Radiologic evaluation of extracranial to Sylvian middle cerebral artery bypass

At this institution a new procedure has been developed that involves anastomosing one of the branches of the superficial temporal artery to one of the major trunks of the middle cerebral artery in the Sylvian fissure. This procedure has been performed in 22 cases to date. Clinical indications for this procedure have fallen into four major categories. This new type of anastomosis produces greater bypass flow than conventional cortical middle cerebral artery anastomoses, and may be a better therapeutic alternative in certain clinical situations. The preoperative and postoperative angiographic evaluation of these patients is discussed. The radiologic results in this series of patients are reviewed.     

An anatomic study for a modified technique for bypass of the external carotid artery to the proximal middle cerebral artery

We aimed to evaluate whether bypass of the external carotid artery (ECA) to the middle cerebral artery (MCA) can be established by a short saphenous vein graft in order to increase the anastomosis patency. The method was performed to ten adult cadaver sides. We described a modified technique for bypass of the ECA to the M2 segment of MCA. The diameters of the vessels and graft length were measured by using an electronic micrometer. The mean diameter of the superior, middle, and inferior trunks of the MCA with trifurcation were 1.7 +/- 0.15, 2.2 +/- 0.25, and 2.0 +/- 0.2 mm, respectively, whereas the mean diameter of the superior and inferior trunks of the MCA with bifurcation were 2.1 +/- 0.2 and 2.3 +/- 0.3 mm, respectively. The mean diameter of the ECA was 3.75 +/- 0.4 mm. The mean length of the saphenous vein graft was 71.5 +/- 3.9 mm. The high-flow ECA to proximal MCA bypass using a short venous graft can supply enough blood flow to establish cerebral revascularization with a straighter route.     

Urgent superficial temporal artery to middle cerebral artery bypass shortly after intravenous rt-PA

Abstract Whether to provide surgical intervention within 24 hours of intravenous recombinant tissue plasminogen activator (rt-PA) treatment is a subject of controversy. In this study, we report a case in which neurological deterioration was prevented by urgent bypass surgery performed shortly after rt-PA treatment.     

Subclavian artery to external carotid artery bypass with saphenous vein graft in the treatment of common carotid artery stenosis

A case of TIAs due to proximal common carotid artery stenosis which was successfully treated with autogenous saphenous vein graft between the subclavian artery and the external carotid artery is presented. A 57-year-old, right handed female was admitted to our hospital for the treatment of left common carotid artery stenosis which was pointed out at a local hospital. She had a 7-years' history of repeated transient right hemiparesis and/or left amaurosis fugax. No neurological deficit was revealed on admission. Angiography showed an 80% irregular stenosis of the left common carotid artery at its origin, hypoplastic A1-portion of the left anterior cerebral artery and hypoplasia of the left posterior communicating artery. No other stenotic lesions were disclosed in a four-vessel study. Several kinds of surgical procedures have been reported for the treatment of common carotid stenotic lesion, in accordance with the site and extension of the lesion and hemodynamic factors. To maintain a sufficient blood flow of the left internal carotid artery, we considered four different operative methods such as (1) endarterectomy of the common carotid artery, (2) subclavian to common carotid artery bypass, (3) subclavian to external carotid artery bypass and (4) subclavian to middle cerebral artery bypass. The first two operative procedures force to clamp the common carotid artery which was the only one feeding artery of the left middle cerebral artery because of poor cross flow in this case. These procedures were thought highly possibly to give rise to cerebral infarction on the left side. The fourth method needs a long graft which has higher risk of bypass occlusion.(ABSTRACT TRUNCATED AT 250 WORDS)     

Automated end-to-side anastomosis to the middle cerebral artery: a feasibility study

OBJECT: The treatment of complex cerebrovascular or skull base pathological conditions necessitates a microsurgical blood flow preservation or augmentative revascularization procedure as either an adjunctive safety measure or a definitive treatment. The brain is susceptible to ischemia, and procedure-related risks can be minimized by the reduction of occlusion time or the use of a nonocclusive technique. The authors therefore analyzed the feasibility of an automatic device (C-Port xA, Cardica) designed for constructing an end-to-side anastomosis with or without flow interruption for a middle cerebral artery (MCA) bypass in a human cadaveric model and in an in vivo craniotomy simulation model. METHODS: Four Thiel-fixated human head specimens were prepared using 8 standard pterional craniotomies. The sylvian fissure was opened to access the anterior circulation and in particular the MCA. The length of the individual vessel segments was measured. The C-Port xA was tested on each of the 8 exposures. In addition the C-Port xA was deployed in an in vivo craniotomy simulator model in 10 New Zealand rabbits (a total of 20 anastomoses) by using the abdominal aorta jump graft model. RESULTS: Short-term patency was assessed by angiography and histological findings. In all 8 sylvian exposures, construction of an MCA anastomosis with the aid of the C-Port xA was feasible. All 20 jump graft anastomoses performed in the in vivo craniotomy simulator were found to be patent. CONCLUSIONS: The anatomical studies as well as the in vivo craniotomy simulation studies demonstrated that the dimensions of the automated end-to-side anastomosis device are suitable for an extracranial-intracranial high-flow bypass on the MCA. Further miniaturization and special adaptation of this device would allow bypass procedures to more proximal intracranial vessels.     

Simultaneous superficial temporal artery to middle cerebral or anterior cerebral artery bypass with pan-synangiosis for Moyamoya disease covering both anterior and middle cerebral artery territories

Some patients with moyamoya disease treated by conventional surgical procedures may develop postoperative refractory ischemia and perioperative cerebral infarction in the anterior cerebral artery (ACA) territory. We present a novel operative procedure for moyamoya disease to avoid the risk of ischemia in the ACA territory, which consists of simultaneous superficial temporal artery (STA) to middle cerebral artery (MCA) or ACA bypass with pan-synangiosis, encephalo-duro-arterio-myo-synangiosis for the lateral frontal and temporal areas, and encephalo-galeo-arterio-synangiosis for the medial frontal area. This procedure can establish direct bypass to the ACA territory at the first intervention. Simultaneous STA-MCA and STA-ACA bypasses with pan-synangiosis is suitable for patients with moyamoya disease associated with severely impaired perfusion of the ACA territory requiring direct bypass surgery.     

Axillary-to-carotid artery bypass grafting for symptomatic severe common carotid artery occlusive disease

PURPOSE: Revascularization of the internal or external carotid arteries is occasionally indicated for symptomatic atherosclerotic common carotid artery occlusion or long-segment high-grade stenosis beginning at its origin. I report the outcome of axillary artery-based bypass grafts to the distal common, internal, or external carotid arteries. METHODS: Between 1981 and 1997, 29 axillary-to-carotid bypass grafting procedures were performed on 28 patients, 15 men and 13 women, with a mean age of 68 years. Indications were transient ischemia in nine patients, amaurosis fugax in four patients, completed stroke in six patients, and nonlateralizing global ischemia in nine patients. Twenty-three common carotid arteries were totally occluded, and six had long-segment stenosis of 90% or greater beginning at the origin. Saphenous vein grafts were used in 25 procedures, and synthetic grafts were used in four. Grafts were placed to 13 internal, eight distal common, and eight external carotid arteries. RESULTS: There were no perioperative deaths; one stroke occurred (3.4%). No lymphatic or peripheral nerve complications occurred. In a 1- to 11-year follow-up period (mean, 4.5 years), there were no graft occlusions, one restenosis of 50% or greater, and two restenoses of 70% or greater. The 1-year stenosis-free rate for 50% or greater stenosis was 93%, and the 5- and 10-year rates were 87%. No late ipsilateral strokes occurred. The 5- and 10-year survival rates were 64% and 28%, respectively. Coronary artery disease was the major cause of late mortality. CONCLUSION: Axillary-to-carotid bypass grafting for severe symptomatic common carotid occlusive disease is safe, well tolerated, durable, and effective in stroke prevention. There is a high late mortality rate because of coronary artery disease in patients with severe proximal common carotid occlusive disease.     

Long-term patency of superficial temporal artery to middle cerebral artery bypass for cerebral atherosclerotic disease: factors determining the bypass patent

Long-term patency of superficial temporal artery to middle cerebral artery (STA–MCA) bypass surgery for atherosclerotic disease and associated risk factors for loss of patency have rarely been discussed. We retrospectively analyzed long-term patency following STA–MCA bypass and evaluated various demographic and clinical factors to identify the ones predictive of postsurgical loss of patency using records of 84 revascularization procedures (58 patients, 45 males; mean age at surgery 63.6 years, range 31–78 years). Bypass patency was diagnosed based on magnetic resonance angiography or three-dimensional computed tomography. The mean follow-up period was 24.7 months (range 6–63 months). Decreased bypass patency was observed in 4 of 58 patients (6.9 %) who collectively underwent 6 bypasses (7.1 %) of 84. All cases of decreased bypass patency were first detected within 6 months of surgery. Bypass patency was not correlated with age, sex, number of anastomoses, postoperative cerebral infarction, or control of postoperative diabetes mellitus. We found a significant association of bypass patency with hyperperfusion (p?=?0.01) and postoperative smoking (p?=?0.0036). Furthermore, we found a significant association of hyperperfusion with STA diameter (p?<?0.0001), location of anastomosis (p?=?0.075), and preoperative cerebral blood flow (p?=?0.0399). In our retrospective study, hyperperfusion and smoking after surgery may be risk factors for decreased bypass patency in cerebral atherosclerotic disease patients. Careful monitoring of patency to prevent hyperperfusion and cessation of smoking are recommended, particularly within 6 months of the surgery.     

Monitoring middle cerebral artery blood velocity during carotid endarterectomy

Transcranial pulsed Doppler ultrasound and spectral analysis were used to monitor blood velocities in the middle cerebral artery of nineteen patients (mean age 61 +/- 9 years) during carotid endarterectomy. A Javid shunt was used in all patients. The intensity weighted mean Doppler frequency for each spectral sweep (at 5 ms intervals) was time-averaged over the cardiac cycle to obtain a mean value for blood velocity in the middle cerebral artery. The range of such values found in the 19 patients was: 12-38 cm s-1 after anaesthesia (baseline); 12-69 cm s-1 during diathermy; 0-30 cm s-1 during carotid clamping; 16-32 cm s-1 during shunting and 18-60 cm s-1 in the recovery room. The average change in middle cerebral artery blood velocity from baseline values showed significant increases during diathermy (P less than 0.005), shunting (P less than 0.05) and in the recovery room (P less than 0.005). Clamping of the internal carotid artery showed a significant decrease in middle cerebral artery blood velocities of all patients (P less than 0.005), three of whom showed no flow in the middle cerebral artery during clamping. Abnormally high amplitude Doppler signals at the commencement of shunting were detected in 17 of the 19 patients. Such Doppler signals are consistent with turbulent blood flow or the introduction of micro-air bubbles by the shunt. Backbleeding in the internal carotid artery before insertion of the shunt was associated with diminished flow in the ipsilateral middle cerebral artery of ten patients, oscillatory forward/reverse flow in three patients and cessation of flow in the remaining six patients.     

Cardiopulmonary bypass via common carotid artery cannulation in redo sternotomy

There are certain situations in redo cardiac surgery in adults where it may not be possible to use alternate arterial cannulation sites like the common femoral artery and axillary artery. We report a case where we established safe cardiopulmonary bypass with common carotid artery cannulation in an adult patient. The patient underwent aortic valve replacement for severe aortic regurgitation 8 months after repair of type A aortic dissection plus aortic valve resuspension.     

Transcranial Doppler ultrasound in internal carotid artery and middle cerebral artery disease

Using noninvasive transcranial Doppler sonography, we studied cerebral collateral patterns in 30 patients with stenosis and/or occlusion of the extracranial internal carotid artery (ICA). All patients with unilateral ICA stenosis ⩽ 80% had normal transcranial Doppler findings. 80% of patients with unilateral and 50% of patients with bilateral ICA stenosis of more than 80% including those with occlusion showed a collateralization via the ipsilateral anterior and/or posterior cerebral artery. 20% of patients with unilateral and 50% of patients with bilateral ICA stenoses of more than 80% (including occlusion) had two or three collateral pathways, including the ophthalmic artery. Another ten patients with stenosis or spasm of the middle cerebral artery (MCA) showed increased flow velocities with turbulence in the narrow segment. In four patients with severe MCA disease with a systolic peak velocity of more than 200 cm/s, the Doppler waveform distal to the lesion was damped. Decreased regional cerebral blood flow (rCBF) measured by^99mTc-HMPAO-SPECT was found in two patients with severe MCA stenosis. Another patient with moderate MCA stenosis with a systolic peak velocity of 140 cm/s showed a normal cerebral perfusion pattern.     

Femoro-internal carotid artery bypass for cerebral ischemia in takayasu's arteritis

In two patients with Takayasu's arteritis, severe cerebral ischemia was successfully treated by femoral to internal carotid artery bypass using a polytetrafluoroethylene (PTFE) graft through a subcutaneous tunnel. All of the arch branches were critically stenotic or occluded in both patients. The entire thoracic aorta was affected by the active inflammation process in one patient and there was marked calcification in the other patient. In these situations we hesitate to use the thoracic aorta as the donor site of bypass. Considering that Takayasu's arteritis affects the thoracic aorta and the proximal portions of its branches, the femoro-internal carotid artery bypass can be constructed without involving severely diseased vessels and can be expected to result in good cerebral revascularization.