Mobilization of the outer cavernous membrane decreases bleeding and improves resection in spheno-clinoidal meningiomas without cavernous sinus extension: A randomized controlled trial.

Objective: The aim of this study was to determine whether adding mobilization of the outer cavernous sinus membrane as a part of the approach, in large spheno-clinoidal meningiomas without cavernous sinus extension, would reduce bleeding and increase the extent of resection.

Methods:: This prospective randomized controlled trial was held between February 2016 and April 2017 at Cairo University Hospitals. The study recruited 94 patients with spheno-clinoidal meningiomas without cavernous sinus involvement. Patients were randomly assigned (by a computer based randomization system) into two groups; the treatment group, in which the patients received mobilization of the outer layer of the lateral wall of the cavernous sinus, prior to opening of the dura; and, the control group, in which the patients were operated by a direct opening of the dura without cavernous sinus dissection. The primary outcome of this study was the difference in the amount of blood lost during surgery between both groups of patients. The secondary outcome variables were the estimated blood loss (EBL) calculated according to Mercurelli's formula, the extent of tumor resection and the amount of blood transfused.

Results:: The amount of blood loss and estimated blood loss (EBL) were significantly less in the "with mobilization group" with the P value being 0.00 and 0.013, respectively. Additionally, the amount of residual tumor was compared between both the groups and it showed that the group of patients who have received mobilization of the outer cavernous sinus membrane had a higher rate of radical resection as expressed by a lower volume of residual tumor (P value 0.005).

Conclusion:: In large spheno-clinoidal meningiomas without cavernous sinus involvement, routine mobilization of the outer cavernous sinus membrane reduces bleeding. This helps in a better visualization of cranial nerves in a relatively avascular field as it enables the performance of neurovascular dissection in an earlier phase of surgery. It also enables a more radical resection.