Comparative analysis of anterior petrosectomy and transcavernous approaches to retrosellar and upper clival basilar artery aneurysms.
OBJECTIVE
To compare two techniques, transcavernous approach (TcA) and anterior petrosectomy (AP), used to manage retrosellar and upper clival basilar artery (BA) aneurysms.


METHODS
AP and TcA were carried out on nine sides of cadaver heads. With use of a computerized tracking system, the area of surgical exposure in the ventral surface of the brain stem, the superficial area of exposure, and the linear exposure of the BA were evaluated. The angles of approach in the horizontal and vertical axes were measured using a robotic microscope. The caudal extent of exposure was determined by an aneurysm clip applied to proximal BA, and the distance between the clip and the floor of the sella was quantified after performing TcA.


RESULTS
TcA (1127.3 +/- 438.4 mm2) provided a greater superficial exposure than AP (697.7 +/- 219.1 mm2) (P = 0.01). There were no statistical differences in the deep working exposure (P = 0.303) between TcA (206.9 +/- 40.7 mm2) and AP (260.2 +/- 137.1 mm2). The linear exposure of the BA was greater for AP (22.7 +/- 6.2 mm2) than for the TcA (12.8 +/- 2.9 mm2) (P = 0.004). The caudal extent of exposure averaged 6.1 mm from the floor of the sella. No differences were found in horizontal angles (P = 0.596); however, vertical angles were significantly greater for the TcA than AP (15.2 +/- 3.4) (P = 0.004).


CONCLUSIONS
From an anatomic standpoint, the TcA offers more advantages than the AP, when approaching retrosellar BA aneurysms, except for those cases in which proximal control is the principal issue and the neck of the aneurysm is located more than 6.0 mm below the floor of the sella.
Division of Neurosurgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona 85013, USA.
Eberval Gadelha
EG
Figueiredo
Joseph M
JM
Zabramski
Puspha
P
Deshmukh
Neil R
NR
Crawford
Robert F
RF
Spetzler
Mark C
MC
Preul
D000704:Analysis of Variance; D020771:Anterior Cerebral Artery / Q000473:pathology*; D002102:Cadaver; D002426:Cavernous Sinus / Q000473:pathology*; D003399:Craniotomy / Q000379:methods; D006801:Humans; D002532:Intracranial Aneurysm / Q000473:pathology*; D019635:Neurosurgical Procedures / Q000379:methods