Author-
Dr Shikha Rowlak , Senior Resident, Bombay Hospital, Mumbai, India, rowlakshikha@gmail.com, 
ujwal2498@gmail.com 
9304028811 
Guide-Dr Chandrashekhar. E Deopujari -Professor And Head Department of Neurosurgery,  Bombay Hospital Institute of Medical and Sciences,Mumbai,Senior Consultant at Wadia Children's Hospital Mumbai,

Title-Challenges of cavernous sinus invading functional pituitary tumors and increasing role of surgery with Endonasal Endoscopic approach.

Statement of the problem
Cavernous sinus invasion(CSI)is the most difficult feature in achieving remission in functional pituitary adenomas.Endoscopic endonasal inspection best prognosticated by Knosp classification provides direct visualization of its medial wall. Aim of the paper-
The medial wall of the Cavernous sinus can be removed safely favouring GTR and hormonal remission. 
Extension into the cavernous sinus is more in functional pituitary adenomas.
This paper emphasises on variations in corridors for approaching cavernous sinuses according to tumor invasion.These technically challenging cases will be supported by anatomy based stepwise surgical videos. Literature is scarce in these techniques of approaches.Its a technical paper to benefit the academic audience.

Methodology and theoretical orientation 
A total of 181 cases of Pituitary tumors operated in the Department of Neurosurgery, Bombay Hospital, Mumbai, India from December 2019- December 2023 were included.Male:female 117:61. Age 9 yrs to 77 yrs. 49 patients had tumor invading cavernous sinus(Knosp grade 3,4 )and 27 were functional tumors.Remission of hGH in Acromegaly and Cortisol,ACTH in Cushing’s patient were observed according to 14th Acromegaly consensus guidelines.
Findings
Cavernous sinus was invaded in  56%of all functional tumors.Medial wall resected in 37%of all functional cases achieving GTR of 90%and hormonal remission of 88%.GTR was achieved in 76% cases of functional tumors.Hormonal remission was obtained in 74%of all functional tumors and 61%of all CSI tumors with remission in 88%cases of functional tumors invading cavernous sinus after removal of medial wall.No mortality or permanent cranial nerve damage.No requirement of blood transfusion.
Conclusions and significance 
Meticulous and judicious use of the techniques with anatomical considerations and surgical armamentarium(Doppler,Navigation)ensures GTR and biological cure. Knosp Classification confers operability.Favourable outcomes are increasing with Endoscopic instruments and newer corridors for surgery.Our study has better remission rates with lesser complications than contemporary literature because of our technical decisions.