A modified technique for bypass of the external carotid artery to the proximal posterior cerebral artery: an anatomical and technical study.

CONCLUSIONS: Our results support the proposition that bypass between the external carotid artery (ECA) and proximal posterior cerebral artery (PCA) can be achieved by using a short saphenous venous graft. The diameters of the ECA and vein graft may provide an increased blood flow with a straighter course. This technique may be helpful for management of patients with vertebrobasilar insufficiency or those requiring a high volume blood flow to the posterior circulation. OBJECTIVES: We aimed to describe a modified technique using a short saphenous vein graft for bypass between the ECA and the PCA in order to use a small length of graft material and increase the patency of the anastomosis. MATERIALS AND METHODS: Ten sides of five cadavers were dissected bilaterally. After a frontotemporal craniotomy and zygomatic arch osteotomy, the middle cranial fossa was exposed. A hole located approximately 2-3 cm posterolateral to the foramen rotunda was created extradurally. The sylvian fissure and the interpeduncular and ambient cisterns were opened. The proximal P2 segment of the PCA was identified. The ECA was found through a cervical incision. A short interposition saphenous vein graft was conducted to pass just behind the ramus mandible to the infratemporal fossa. The bypass between the ECA and P2 segment of the PCA was performed by using a short saphenous vein graft. The diameters of the ECA, P2 segment of PCA and both ends of the saphenous vein graft and its length were measured using an electronic micrometer. RESULTS: The mean cross-clamping time of the PCA was 10.4+/-1.8 min. The mean diameters of the P2 segment of the PCA and ECA were 2.2+/-0.15 mm and 3.83+/-0.28 mm, respectively. The mean length of the saphenous vein graft was 88.8+/-3.8 mm.

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.