Saphenous vein graft for bypass of the maxillary to supraclinoid internal carotid artery: an anatomical short study

Localization of Maxillary Artery for Cerebral Revascularization: L-Shaped Perpendicular Two-Step Drilling Technique Stretching from the Foramen Ovale to Rotundum

BACKGROUND

The use of the maxillary artery (MA) as a donor has increasingly become an alternative method for cerebral revascularization. Localization difficulties emerge due to rich infratemporal anatomical variations and the complicated relationships of the MA with neuromuscular structures. We propose an alternative localization method via the interforaminal route along the middle fossa floor.

METHODS

Five silicone-injected adult cadaver heads (10 sides) were dissected. Safe and effective localization of the MA was evaluated.

RESULTS

The MA displayed anatomical variations in relation to the lateral pterygoid muscle (LPM) and the mandibular nerve branches. The proposed L-shaped perpendicular 2-step drilling technique revealed a long MA segment that allowed generous rotation to the intracranial area for an end-to-end anastomosis. The first step of drilling involved medial-to-lateral expansion of foramen ovale up to the lateral border of the superior head of the LPM. The second step of drilling extended at an angle approximately 90° to the initial path and reached anteriorly to the foramen rotundum. The MA was localized by gently retracting the upper head of the LPM medially in a posterior-to-anterior direction.

CONCLUSIONS

Considering all anatomical variations, the L-shaped perpendicular 2-step drilling technique through the interforaminal space is an attainable method to release an adequate length of MA. The advantages of this technique include the early identification of precise landmarks for the areas to be drilled, preserving all mandibular nerve branches, the deep temporal arteries, and maintaining the continuity of the LPM.

Maxillary artery utilization in subcranial-intracranial bypass procedures: a comprehensive systematic review and pooled analysis

The utilization of the internal maxillary artery (IMAX) in subcranial-intracranial bypass for revascularization in complex aneurysms, tumors, or refractory ischemia shows promise. However, robust evidence concerning its outcomes is lacking. Hence, the authors embarked on a systematic review with pooled analysis to elucidate the efficacy of this approach. We systematically searched PubMed, Embase, and Web of Science databases following PRISMA guidelines. Included articles used the IMAX as a donor vessel for revascularizing an intracranial area and reported at least one of the following outcomes: patency, complications, or clinical data. Favorable outcomes were defined as the absence of neurologic deficits or improvement in the baseline condition. Complications were considered any adverse event directly related to the procedure. Out of 418 retrieved articles, 26 were included, involving 183 patients. Among them, 119 had aneurysms, 41 experienced ischemic strokes (transient or not), 2 had arterial occlusions, and 3 had neoplasia. Furthermore, 91.8% of bypasses used radial artery grafts, and 87.9% revascularized the middle cerebral artery territory. The median average follow-up period was 12 months (0.3-53.1). The post-operation patency rate was 99% (95% CI: 97-100%; I2=0%), while the patency rate at follow-up was 82% (95% CI: 68-96%; I2=77%). Complications occurred in 21% of cases (95% CI: 9-32%; I2=58%), with no significant procedure-related mortality in 0% (95% CI: 0-2%; I2=0%). Favorable outcomes were observed in 88% of patients (95% CI: 81-96%; I2=0%), and only 3% experienced ischemia (95% CI: 0-6%; I2=0%). The subcranial-intracranial bypass with the IMAX shows excellent postoperative patency and considerable favorable clinical outcomes. While complications exist, the procedure carries a minimal risk of mortality. However, long-term patency presents heterogeneous findings, warranting additional research.

Maxillary Nerve as Landmark for Exposure of the Internal Maxillary Artery in Extracranial-Intracranial Bypass Surgery

OBJECTIVE

To establish a new method for fast exposure of the internal maxillary artery (IMA) during extracranial-intracranial bypass surgery.

METHODS

To explore the positional relationship between the IMA and the maxillary nerve and pterygomaxillary fissure, 11 formalin-fixed cadaveric specimens were dissected. Three bone windows of the middle fossa were created for further analysis. Then the IMA length that could be pulled up above the middle fossa was measured after different degrees of removal of bony structure. The IMA branches under each bone window were also explored in detail.

RESULTS

The top of the pterygomaxillary fissure was located 11.50 mm anterolateral to the foramen rotundum. The IMA could be identified just inferior to the infratemporal segment maxillary nerve in all specimens. After drilling of the first bone window, the IMA length that could be pulled above the middle fossa bone was 6.85 mm. After drilling of the second bone window and further mobilization, the IMA length that could be harvested was significantly longer (9.04 mm vs. 6.85 mm; P < 0.001). Removal of the third bone window did not significantly improve the IMA length that could be harvested.

CONCLUSIONS

The maxillary nerve could be used as a reliable landmark for the exposure of the IMA in the pterygopalatine fossa. With our technique, the IMA could be easily exposed and sufficiently dissected without zygomatic osteotomy and extensive middle fossa floor removal.

Sequential approach of internal maxillary-to-middle cerebral artery bypass and endovascular occlusion for giant middle cerebral artery aneurysm: a case report

Background

The combined approach to complex brain МСА aneurysm seems to be generally considered viable. Although it is fairly common, the combinations of modalities, which are suggested in different case reports, vary significantly. This case discusses a sequential approach of reconstructive microsurgery with internal maxillary-to-middle cerebral artery bypass followed by the balloon test occlusion and endovascular embolization of the aneurysm and the MCA. The combined approach together with use of maxillary artery helped minimize the intraoperative and postoperative complications.

Case presentation

A 62-year-old female with rare episodes of headache and depression revealed giant middle cerebral artery aneurysm. The patient underwent a combined operation in a hybrid operating room with no serious neurologic deficit after surgery.

Conclusions

Multimodality management in a hybrid operating room should be considered in case of complex fusiform aneurysm of MCA, which is associated with high risks of clipping. Thus, the sequential procedures will improve patient outcomes in treatment of complex МСА aneurysms.

Minimally Invasive Exposure of the Maxillary Artery at the Anteromedial Infratemporal Fossa

BACKGROUND

The maxillary artery (MA) has been described as a reliable donor for extracranial-intracranial high-flow bypass. Existing techniques to harvest MA require brain retraction and drilling of the middle fossa (with or without a zygomatic osteotomy), carrying the potential risks of venous bleeding, injury to the branches of the maxillary or mandibular nerves, muscular transection, or temporomandibular junction disorders.

OBJECTIVE

To describe a novel technique to expose the MA without bony drilling and with minimal impact to surrounding structures.

METHODS

A conventional curvilinear incision was performed in 10 cadaveric specimens, prior to elevating the scalp to expose the zygomatic root and lateral orbital rim. The sphenozygomatic suture was followed to the anterolateral edge of the inferior orbital fissure (IOF) to locate and harvest the pterygoid segment of the MA. Topographic anatomy was assessed using surrounding landmarks and 3D Cartesian coordinates to define the surgical area. The number of visible MA branches and their lengths were recorded.

RESULTS

The MA was successfully exposed in all specimens. This approach allowed 6 branches of MA to be exposed. The average length of exposure was 23.3 ± 8.3 mm and the average surgical area was 2.8 ± 0.9 cm2. The IOF was 11.5 ± 4.2 mm from the MA.

CONCLUSION

Our technique provides landmarks to identify the distal pterygoid segment of MA as a donor for extracranial-intracranial bypasses without the need for additional craniectomies. Clear anatomical landmarks, including the sphenozygomatic suture, anterolateral edge of IOF, infraorbital artery, and the pterygomaxillary fissure defined a trajectory to efficiently localize the MA with minimal risk to surrounding structures.

Internal Maxillary Artery to Anterior Circulation Bypass with Local Interposition Grafts Using a Minimally Invasive Approach: Surgical Anatomy and Technical Feasibility

BACKGROUND

The internal maxillary artery (IMA) is a reliable donor for extracranial-intracranial high-flow bypasses. However, previously described landmarks and techniques to harvest the IMA are complex and confusing and require extensive bone drilling, carrying significant neurovascular risk. The objective of our study was to describe a minimally invasive technique for exposing the IMA and to assess the feasibility of using the IMA as a donor for anterior-circulation recipient vessels using 2 different local interposition vessels.

METHODS

Via a minimally invasive technique, the IMA was harvested in 10 cadaveric specimens and a pterional craniotomy was performed. Two interposition grafts-the superficial temporal artery (STA) and middle temporal artery-were evaluated individually. Transsylvian exposure of the second segment of middle cerebral artery (M2), the supraclinoid internal carotid artery, and the proximal postcommunicating anterior cerebral artery segment was completed. Relevant vessel calibers and graft lengths were measured for each bypass model.

RESULTS

The mean caliber of the IMA was 2.7 ± 0.5 mm. Of all 3 recipients, the shortest graft length was seen in the IMA-STA-M2 bypass, measuring 42.0 ± 8.4 mm. There was a good caliber match between the M2 (2.4 ± 0.4 mm) and STA (2.3 ± 0.4 mm) at the anastomotic site. The harvested middle temporal artery was sufficient in length in only 30% cases, with a mean distal caliber of 2.0 ± 0.7 mm.

CONCLUSIONS

This study confirmed the technical feasibility of IMA as a donor for an extracranial-intracranial bypass to the second segment of the anterior cerebral artery, M2, and the supraclinoid internal carotid artery. However, IMA-STA-M2 was observed to be the most suitable bypass model.

The History and Evolution of Internal Maxillary Artery Bypass

Internal maxillary artery (IMA) bypass has gained momentum in the last 5 years for the treatment of complex cerebrovascular disorders and skull base tumors. However, some issues regarding this treatment modality have been proposed. As one of the most experienced neurosurgical teams to perform internal maxillary artery bypass in the world (>100 clinical cases), we reviewed the literature in aspects of basic anatomy of maxillary artery with its variations to the lateral pterygoid muscle, initial anastomosis modalities, and subsequent exposure techniques in cadaver studies, preoperative arterial evaluation methods, optimal interposed graft selections, and surgical outcome in the management of complex aneurysms, skull base tumors, and steno-occlusive disorders.

Microsurgical anatomy of the maxillary artery for extracranial-intracranial bypass in the pterygopalatine segment of the maxillary artery

The extracranial-intracranial (EC-IC) bypass using the maxillary artery (MA) has been successfully completed using a radial artery (RA) graft but the complicated anatomy and narrow exposure make it difficult. The purpose of this article is to define the microsurgical exposure of the MA through the middle fossa and describe the branches, diameter, and length of the MA available for the EC-IC bypass in the sphenopalatine fossa and anterior part of the infratemporal fossa. 5 cadaveric specimens were dissected bilaterally (10 MA dissections) to define the microsurgical anatomy of the MA through an intracranial approach. The exposable branches of the MA at the level of the infratemporal and sphenopalatine fossae were the anterior deep temporal, posterior superior alveolar, and infraorbital arteries. The origin of each branch could be exposed. The available section of the MA for use as a donor vessel is between the origin of the anterior deep temporal artery and the infraorbital artery. The mean exposable length of the MA was 19.4 mm. The mean outer diameter of the donor MA was 3.2 mm. Tension-free EC-IC bypass was possible using a RA graft between the MA and the middle cerebral artery, the MA and the supraclinoid internal carotid artery (ICA), or the MA and the petrous ICA. Exposure of the MA at the infratemporal and sphenopalatine fossae is complicated but provides length and diameter suitable as a donor artery for the EC-IC bypass. Clin. Anat. 31:724-733, 2018. © 2017 Wiley Periodicals, Inc.

Surgical Technique for High-Flow Internal Maxillary Artery to Middle Cerebral Artery Bypass Using a Superficial Temporal Artery Interposition Graft

BACKGROUND: Extracranial-to-intracranial high-flow bypass often requires cranial, cervical, and graft site incisions. The internal maxillary artery (IMA) has been proposed as a donor to decrease invasiveness, but its length is insufficient for direct intracranial bypass. We report interposition of a superficial temporal artery (STA) graft for high-flow IMA to middle cerebral artery (MCA) bypass using a middle fossa approach.

OBJECTIVE: To assess the feasibility of an IMA–STA graft-MCA bypass using a new middle fossa approach.

METHODS: Twelve specimens were studied. A 7.5-cm STA graft was obtained starting 1.5 cm below the zygomatic arch. The calibers of STA were measured. After a pterional craniotomy, the IMA was isolated inside the infratemporal fossa through a craniectomy within the lateral triangle (lateral to the posterolateral triangle) in the middle fossa and transposed for proximal end-to-end anastomosis to the STA. The Sylvian fissure was split exposing the insular segment of the MCA, and an STA-M2 end-to-side anastomosis was completed. Finally, the length of graft vessel was measured.

RESULTS: Average diameters of the proximal and distal STA ends were 2.3 ± 0.2 and 2.0 ± 0.1 mm, respectively. At the anastomosis site, the diameter of the IMA was 2.4 ± 0.6 mm, and the MCA diameter was 2.3 ± 0.3 mm. The length of STA graft required was 56.0 ± 5.9 mm.

CONCLUSION: The STA can be used as an interposition graft for high-flow IMA–MCA bypass if the STA is obtained 1.5 cm below the zygomatic arch and the IMA is harvested through the proposed approach. This procedure may provide an efficient and less invasive alternative for high-flow EC–IC bypass.

Measurement of Blood Flow in an Intracranial Artery Bypass From the Internal Maxillary Artery by Intraoperative Duplex Sonography

This study explored the hemodynamic characteristics of a subcranial-intracranial bypass from the internal maxillary artery by measuring blood flow on intraoperative duplex sonography. The hemodynamic parameters of the internal maxillary artery (n = 20), radial artery (n = 20), internal maxillary artery-middle cerebral artery bypass (n = 42), and internal maxillary artery-posterior cerebral artery bypass (n = 9) were measured by intraoperative duplex sonography. There was no significant difference in the internal diameters of the internal maxillary and radial arteries (mean ± SD, 2.51 ± 0.34 versus 2.56 ± 0.22 mm; P = .648). The mean radial artery graft length for subcranial-intracranial bypasses was 88.5 ± 12.78 mm (95% confidence interval [CI], 80.8-90.2 mm). Internal maxillary artery-middle cerebral artery bypasses required a shorter radial artery graft than internal maxillary artery-posterior cerebral artery bypasses (77.8 ± 2.47 versus 104.8 ± 4.77 mm; P = .001). The mean flow volumes were 85.3 ± 18.5 mL/min (95% CI, 76.6-93.9 mL/min) for the internal maxillary artery, 72.6 ± 26.4 mL/min (95% CI, 64.3-80.9 mL/min) for internal maxillary artery-middle cerebral artery bypasses, and 45.4 ± 6.7 mL/min (95% CI, 40.7-50.0 mL/min) for internal maxillary artery-posterior cerebral artery bypasses. All grafts were opened after the success of the salvage procedures had been established, and the early patency rates (1 month after the operation) were 95% for internal maxillary artery-middle cerebral artery bypasses and 100% the internal maxillary artery-posterior cerebral artery bypasses. Measurement of blood flow by intraoperative sonography can be helpful in decision making and predicting graft patency and success after neurosurgical bypass procedures.

Unilateral Double Great Saphenous Vein: A Clinically Significant Case Report

Great saphenous vein (GSV) is the longest vein in the body originating from the dorsum of the foot at medial malleolus to the level of groin skin crease. It is one among the clinically significant superficial veins of the lower limb. Double or duplication of GSV is considered to be one of its rarest variant forms, which might be often mistaken with the accessory saphenous vein. The overall incidence of duplicated GSV is reported to be 1%. We report herein, a unilateral duplication of GSV with its morphological and clinical perspectives. The major clinical complication that is often encountered from its duplication is recurrent incompetence of the GSV, which predisposes varicosity. Therefore, a thorough knowledge of venous anatomy is important for clinicians and sonographers.

Forearm Cephalic Vein Graft for Short, “Middle”-Flow, Internal Maxillary Artery to Middle Cerebral Artery Bypass

BACKGROUND

The cervical carotid system has been used as a source of donor vessels for radial artery or saphenous vein grafts in cerebral bypass. Recently, internal maxillary artery to middle cerebral artery bypass has been described as an alternative, with reduction of graft length potentially correlating with improved patency.

OBJECTIVE

To describe our experience using the forearm cephalic vein grafts for short segment internal maxillary artery to middle cerebral artery bypasses.

METHODS

All vein grafts were harvested from the volar forearm between the proximal cubital fossa where the median cubital vein is confluent with the cephalic vein and the distal wrist.

RESULTS

Six patients were treated with internal maxillary artery to middle cerebral artery bypass. In 4, the cephalic vein was used. Postoperative angiography demonstrated good filling of the grafts with robust distal flow. There were no upper extremity vascular complications. All but 1 patient (mortality) tolerated the procedure well. The other 3 patients returned to their neurological baseline with no new neurological deficit during follow-up.

CONCLUSION

The internal maxillary artery to middle cerebral artery “middle” flow bypass allows for shorter graft length with both the proximal and distal anastomoses within the same microsurgical field. These unique variable flow grafts represent an ideal opportunity for use of the cephalic vein of the forearm, which is more easily harvested than the wider saphenous vein graft and which has good match size to the M1/M2 segments of the middle cerebral artery. The vessel wall is supple, which facilitates handling during anastomosis. There is lower morbidity potential than utilization of the radial artery. Going forward, the cephalic vein will be our preferred choice for external carotid-internal carotid transplanted conduit bypass.

Internal maxillary artery-middle cerebral artery bypass: infratemporal approach for subcranial-intracranial (SC-IC) bypass

BACKGROUND:

Internal maxillary artery (IMax)–middle cerebral artery (MCA) bypass has been recently described as an alternative to cervical extracranial-intracranial bypass. This technique uses a “keyhole” craniectomy in the temporal fossa that requires a technically challenging end-to-side anastomosis.

OBJECTIVE:

To describe a lateral subtemporal craniectomy of the middle cranial fossa floor to facilitate wide exposure of the IMax to facilitate bypass.

METHODS:

Orbitozygomatic osteotomy is used followed by frontotemporal craniotomy and subsequently laterotemporal fossa craniectomy, reaching its medial border at a virtual line connecting the foramen rotundum and foramen ovale. The IMax was identified by using established anatomic landmarks, neuronavigation, and micro Doppler probe (Mizuho Inc. Tokyo, Japan). Additionally, we studied the approach in a cadaveric specimen in preparation for microsurgical bypass.

RESULTS:

There were 4 cases in which the technique was used. One bypass was performed for flow augmentation in a hypoperfused hemisphere. The other 3 were performed as part of treatment paradigms for giant middle cerebral artery aneurysms. Vein grafts were used in all patients. The proximal anastomosis was performed in an end-to-side fashion in 1 patient and end-to-end in 3 patients. Intraoperative graft flow measured with the Transonic flow probe ranged from 20 to 60 mL/min. Postoperative angiography demonstrated good filling of the graft with robust distal flow in all cases. All patients tolerated the procedure well.

CONCLUSION:

IMax to middle cerebral artery subcranial-intracranial bypass is safe and efficacious. The laterotemporal fossa craniectomy technique resulted in reliable identification and wide exposure of the IMax, facilitating the proximal anastomosis.

ABBREVIATIONS:

EC-IC, extracranial-intracranial

IMax, internal maxillary artery

MCA, middle cerebral artery

SC-IC, subcranial-intracranial

STA, superficial temporal artery

KIS, Zhang Y, Zhou Z, Sun Y. Bypass of the maxillary to proximal middle cerebral artery or proximal posterior cerebral artery with radial artery graft

The authors report three cases of radial artery (RA) graft bypass from the maxillary artery (MA) to either the middle cerebral artery (MCA) or the posterior cerebral artery (PCA). The first two cases presented with the features of basal ganglion ischemia, and magnetic resonance imaging (MRI) revealed left and right basal ganglion ischemia respectively, whereas angiogram showed MCA occlusion. Computed tomography angiography (CTA) of the third case, who presented with headache and dysphasia, showed a giant basilar artery aneurysm with an absence of the left posterior communicating artery (PComA). The first two cases underwent MA-MCA graft bypass and the third case underwent MA-posterior cerebral artery (PCA) RA graft bypass, followed by clipping of the left dominance vertebral artery and a sub-occipital decompressive craniotomy. Postoperative angiogram disclosed patent RA graft and refilling of the ischemic segment. Follow-up at 7-9 months showed marked clinical improvement in all cases. To our knowledge, MA bypass has not been performed clinically till the date and this method may be a safe, effective and new surgical technique for the extracranial-intracranial (EC-IC) bypass surgery.

Short Segment Internal Maxillary Artery to Middle Cerebral Artery Bypass: A Novel Technique for Extracranial-to-Intracranial Bypass

BACKGROUND:

Traditional high-flow extracranial-to-intracranial (EC-IC) bypass procedures require a cervical incision and a long (20–25 cm) radial artery or saphenous vein graft. This technical note describes a less invasive, EC-IC bypass technique using a short-segment (8–10 cm) of the radial artery to anastomose the internal maxillary artery (IMAX) to the middle cerebral artery.

CLINICAL PRESENTATION:

Anatomic dissections were performed on 6 cadaveric specimens to assess the location of the IMAX artery using an extradural middle fossa approach. Subsequently, the procedure was implemented in a patient with a giant fusiform internal carotid artery aneurysm.

TECHNIQUE:

A straight line was drawn anteriorly from the V2/V3 apex along the inferior edge of V2. The IMAX was found 8.6 mm on average anteriorly from the lateral edge of the foramen rotundum. We drilled to a depth of 4.2 mm on average to find the medial extent of the artery and then lateral and deep drilling exposed an average of 7.8 mm of graft. The IMAX was consistently found running just anterior and parallel to a line between the foramens rotundum and ovale. In the clinical case presented, both intraoperative indocyanine green and postoperative conventional angiography revealed a patent graft. The patient did well clinically without any new deficits.

CONCLUSION:

The advantages of this new technique include the avoidance of a long cervical incision and potentially higher patency rates secondary to shorter graft length than currently practiced.

Superficial temporal artery graft for bypass of the maxillary to proximal middle cerebral artery using a transantral approach: an anatomical and technical study

CONCLUSION

Using a transantral approach, we examined a new bypass of the maxillary artery (MA) to proximal middle cerebral artery (MCA). The caliber of the MA was suitable to provide sufficient blood flow. The length of the graft was shorter and it had a straighter course in the new technique than in previously described techniques.

OBJECTIVE

To examine a new bypass of the MA to proximal MCA using a transantral approach as an alternative to other forms of anterior circulation bypass surgery.

MATERIAL AND METHODS

The method was applied to five adult cadavers bilaterally. The MA and its branches were easily found after removal of the posterior sinus wall using a transantral approach. Then, a hole was created in the sphenoid bone 5-6 mm lateral to the posteroinferior edge of the superior orbital fissure extradurally. After the carotid and sylvian cisternae had been opened, the M2 segment of the MCA was exposed. The MA was transected just before the origin of the descending palatine artery branch. After opening the dura over the hole, the MA was passed through the hole to reach the intracranial cavity. The proximal side of the superficial temporal artery graft was anastomosed end-to-end with the MA and the distal side was anastomosed end-to-side with the M2 segment of the MCA.

RESULTS

The mean caliber of the MA was 2.4+/-0.3 mm before the origin of the descending palatine artery branch. The mean caliber of the largest trunk of the M2 segment of the MCA was 2.3+/-0.3 mm. The average length of the graft was 24+/-3 mm.

Radial Artery Graft for Bypass of the Maxillary to Proximal Middle Cerebral Artery: An Anatomic and Technical Study

OBJECTIVE

In this study, we aimed to investigate the use of a radial artery graft for bypass of the maxillary artery (MA) to the proximal middle cerebral artery (MCA) as an alternative to superficial temporal artery-to-MCA anastomosis or extracranial carotid-to-MCA bypass using long grafts.

METHODS

Five adult cadavers were used bilaterally. After a frontotemporal craniotomy and a zygomatic arch osteotomy, the MA was found easily 1 to 2 cm inferior to the infratemporal crest. A hole was created with a 4-mm-tip drill in the sphenoid bone 2 to 3 mm lateral to the foramen rotundum extradurally, and the dura over the hole was opened. After the carotid and sylvian cisterns had been opened, the M2 segment of the MCA was exposed. The graft was passed through the hole to reach the M2 segment. Then, the MA was freed from the surrounding tissue and was transected before the infraorbital artery branch. The radial artery graft was anastomosed end-to-end to the MA proximally and end-to-side to the M2 segment of the MCA distally.

RESULTS

The mean thickness of the MA before the infraorbital artery branch was 2.6 ± 0.3 mm. The mean thickness of the largest trunk of the MCA was 2.3 ± 0.3 mm. The average length of the graft was 36 ± 5.5 mm.

CONCLUSION

MA-to-MCA bypass is as feasible as proximal MCA revascularization using long vein grafts. The thickness of the MA provides sufficient flow; the length of the graft is short, and it has a straight course. MA-to-proximal MCA bypass may be an alternative to superficial temporal artery-to-MCA as well as extracranial carotid-to-MCA bypasses.

Proximal superficial temporal artery to proximal middle cerebral artery bypass using a radial artery graft: an anatomic approach

We present the use of radial artery graft for bypass of the proximal superficial temporal artery to the proximal middle cerebral artery. Six adult cadaver sites were used bilaterally. After apterional incision, 2x2-cm minicraniectomy was performed which began 2 cm behind the zygomatic process of the frontal bone. The superficial temporal artery was transsected before exposing the zygomatico-orbital artery branch. The proximal side of the radial artery graft was anastomosed end-to-end to the proximal superficial temporal artery and the distal side end-to-side to the proximal middle cerebral artery. The mean calibers of the proximal superficial temporal artery and largest trunk of the middle cerebral artery were 2.25+/-0.35 mm and 2.3+/-0.3 mm, respectively. The average graft length was 85+/-5.5 mm. We conclude that such bypasses are simpler than proximal middle cerebral artery revascularization using long vein grafts. This method proves that the caliber of the proximal superficial temporal artery is more suited to providing sufficient flow than the distal superficial temporal artery, and the graft is short. Such bypasses to the middle cerebral artery may be an alternative to those from the distal superficial temporal artery or extracranial carotid artery.