Transcranial epidural approach to pituitary tumors extending beyond the sella.

Abstract

The treatment of residual and/or recurrent pituitary tumors, initially operated on through transsphenoidal and/or transcranial approaches, required a new single approach that would make it possible to excise the tumor from the sella and from the neighboring regions. Surgical complications, such as pneumatocephalus, cerebrospinal fluid leak, mechanical lesion of the internal carotid artery and/or visual apparatus, and failure to remove the tumor completely, supported the need for an approach that would guarantee a much higher rate of completeness of resection of tumours and also avoid the risk of occurrence of complications. This report does not address endocrinological disorders before surgical treatment of pituitary tumors nor is its aim to present the functional efficacy of surgical treatment relating to hormones. The anatomic relationships of the sellar and parasellar regions were studied using central cranial base specimens. Previous anatomic studies of the triangles of the lateral wall of the cavernous sinus (including anteromedial, paramedial, and Parkinson's triangles) and practical experience dealing with tumors in the region led to the use of the triangular windows as key access to the pituitary tumors in the enlarged sella and in the neighboring area(s). During the past 15 years, 210 patients with pituitary tumors extending into the parasellar and other regions beyond the sella were operated on using the transcranial approach. In Group I (consisting of 120 patients), complete removal was achieved in 66.5% of the patients by using the classical approach. Postoperative cerebrospinal fluid leak occurred in 8% and impairment of the visual function in 6% of the patients. With the new approach being used during the last 5 years in Group II (consisting of 90 patients), postoperative impairment of the visual function occurred in only 1 patient and cerebrospinal fluid leak occurred in only 1 other patient. Complete excision was achieved in 92.5% of the patients in Group II. Postoperative improvement of the visual function(s) was achieved for 26% of the patients in Group I and 525 of the patients in Group II. There was no mortality in either the first or the second group. The results led to the conclusion that the new approach to pituitary tumors extending beyond the sella (regarding the rate of completeness of the tumor resection) is superior to the previous transcranial approach. Using the new approach, the risks of surgical complications can be avoided by preserving, intact, the diaphragm sellae and the dura covering the central cranial base around the sella.