[Microsurgical anatomy of the perforating arteries in the superior space of the internal carotid artery through a pterional approach].

OBJECTIVE: To study the microanatomy of the perforating arteries in the superior space of the internal carotid artery visualized through a pterional approach. METHODS: Twelve (24 sides) perfused cadaver heads were dissected via the pterional approach, and the perforating arteries in the superior space of the internal carotid artery were studied under microscope. The diameter, course and distribution in the anterior perforated substance of the perforating arteries were recorded. RESULTS: All the perforating arteries exposed lied on the side of the brain tissue. The carotid bifurcation on 8 sides had perforating arteries, and 11 sides showed medial lenticulostriate artery of the middle cerebral arteries, with short course and overlapped with another perforating arteries upon entry into the anterior perforated substance. On 4 sides, the medial lenticulostriate artery coincided with the perforating arteries in A1. All 24 sides showed middle lenticulostriate artery and lateral lenticulostriate artery of the middle cerebral arteries. Most of the lenticulostriate arteries originated from the anterior segment of the bifurcation of the middle cerebral arteries. The earlier bifurcation occurred in M1 of the middle cerebral arteries, the more perforating arteries originated. On 22 sides, the anterior cerebral arteries had perforating arteries with many branches, and fewer perforating arteries in a main artery were associated with greater diameter of them. CONCLUSION: The superior space of the internal carotid artery allows a space for operation, and in some cases, part of the medial leticulostriate arteries and A1 perforating arteries can be severed to obtain larger space for the operation.

[Anatomical study of venous spaces in transsphenoidal approach for cavernous sinus surgery].

OBJECTIVE: To study the anatomical and morphological characteristics of the venous spaces involved in surgery via transsphenoidal approach to the cavernous sinus (CS). METHODS: Ten fixed cadaver heads (six male, four female) with red and blue latex injected in the arteries and veins, respectively, were used to perform the transsphenoidal approach. The anterior wall of the sphenoidal sinus and the floor of sellar turcica were opened as much as possible to expose the dura mater at the sellar floor and the inferior wall of CS, and the location of the anterior and inferior intercavernous sinuses were observed carefully. All the spaces of CS were observed and measured. According to the observations, the venous spaces available for operation were identified and analyzed. RESULTS: In all the cadaver heads, 4 anterior and 5 inferior intercavernous sinuses were found, with the former locating below the optic protuberance, while the latter situated at the turn of the sellar protuberance at the clival indentation. CS was subdivided into medial space, inferolateral space, and dorsolateral space. CONCLUSIONS: In transsphenoidal approach, opening of anterior and inferior intercavernous sinus is liable to result in intra- and postoperative venous bleeding, and understanding of the location of the intercavernous sinus and appropriate utilization of these CS may help reduce intraoperative vascular and nerve injury.