Surgical technique for pituitary adenomas with sphenoid sinus and cavernous sinus

Abstract

Objective. To optimize endoscopic endonasal technique in cases of pituitary adenomas (PA) invasion into the sphenoid sinus (SS) due to using software simulation and intraoperative Doppler ultrasonography control, to evaluate clinical and radiological changes in sphenoid sinus.Materials and methods. We analyzed 82 patients with macro and giant PA with SS extension. 33 (40.2%) and 24 (29.3%) patients had cavernous sinus (CS) invasion Knosp 3, 4, respectively. Knosp 0, 1 and Knosp 2 were found in 4 (4.9%), 5 (6.1%), 16 (19.5%) cases, respectively. In 62 (75.6%) cases PA has extension to SS and CS. PA extension to the CS or SS occurs in 11 (13.4%) and 13 (10%), respectively. Endoscopic endonasal trasphenoidal approach was performed in 51 (62.2%) cases, or extended endoscopic endonasal approach in 31 (37.8%) cases.Results. Depending on the PA extension to SS, the posterior part of the nasal septum was removed: Grade 0 – 3 (3.6%), Grade 1 – 6 (7.3%), Grade 2 – 10 (12.2%), Grade 3 – 26 (31.7%). Additional pre-tumor cavities were created in 45 cases, in 37 cases there was no need. In 21 (36.8% ) cases of Grade 2 and Grade 3 «debulking» technique was performed to create additional pre-tumor cavity in SS. In 28 (66.6%) cases of Knosp 3, 4, with SS extension, intraoperative Doppler ultrasonography was used which allowed avoid ICA injury. GTR was achieved in 51 (62.2%), subtotal resection – in 21 (25.6%), partial resection – in 10 (12.2%) cases.Conclusions. 1. Pituitary adenoma extension into the sphenoid sinus decreases the chance of successful endoscopic endonasal surgery. Classification of PA extension into the sphenoid sinus allows determine indications for surgical approach adaptation with or without posterior septotomy. 2. The posterior nasal septum removal in case of Grade 2 and Grade 3 in several cases for better visualization and easy access is necessary for safe endoscopic endonasal surgery. 3. Using «debulking» technique in Grade 2 and Grade 3 extension to create pre-tumor cavity is possible, especially in cases of dural invasion.