The using of endoscopic technology in transcranial neurosurgery of tumors chiasmosellar region and arterial anterior ring aneurysm

Objective – to study the experience and technical possibilities of the optimal using of the endoscopic assistance during different stages of intracranial surgical procedures in patients with chiasmal–sellar tumors (CST) and arterial aneurysms (AA) of the anterior circulation (AC). Materials and methods. The results of initial series of 59 patients with CST and 14 patients with AA of the AC who were operated at Romodanov Neurosurgery Institute NAMS of Ukraine between 2012 to August 2017, with the using of endoscopic assistance at the different stages of procedure were analyzed. There were used following methods: clinical and neurological exams, laboratory measurements, instrumental evaluation, neuroimaging (brain Computer Tomography (CT), CT Angiography, brain Magnetic Resonance Imaging (MRA), Magnetic Resonance Angiography (MRA), Digital Subtraction Angiography (DSA) of cerebral vessels), functional (Doppler Ultrasound (DU) of the head and neck vessels), morphological evaluation, electroencephalography, statistical analysis. Results. The choice of surgical tactics and approach for CST was performed considering the localization and expansion of CST on the seller region (ante, retro, para, endosellar) and three-dimensional virtual and material modeling. According to the histological type, distribution of CST was follow: tuberculum and diaphragm sellar meningioma – 22 (37.2%) cases, craniopharyngioma – 15 (25.5%), pituitary adenomas – 14 (23.8%), epidermoid and dermoid cysts – 5 (8.5%), optic nerve gliomas – 3 (5.1%). Craniotomy approaches was follow: supraorbital – in 25 (42.4%) patients, pterional – in 18 (30.5%), modified orbitozygomatic- in 16 (27.1%). In 48 (81.3%) cases, initial removal was done, and in 11 (18.7 %) – repeated surgical interventions (regrowth and residual growth of the pituitary adenoma – 7 (63.6%) cases, craniopharyngioma – 4 (36.4%). Microscopic tumor removal were considered as radical in 46 among 56 patients (82.1%). Postoperative mortality was 2.49% (1 patient). The new onset of diabetes insipidus occurred in 3 (5.1%) observations, transient functional disorders, including cosmetic – in 38 (64.4%). Thirty-two (54.3%) patients showed an improvement of visual function (expansion of vision fields, regression of scotomas and / or increased of visual acuity according to Kadasheva scale assessment). Patients with AA of the AC underwent microsurgical procedure under endoscopic assistance and measuring the depth of the wound and the angles of the surgical field during pterional approach – in 9 (64.3%), orbitozygomatic – in 1 (7.1%), pterional with anterior clinoidectomy – in 2 (14.3%), infratemporal – in 2 (14.3%) cases. The evaluation of results included an assessment of AA clipping: Simple clip – 6 (42.9%), Multiple clips – 8 (57.1%). Following intraoperative complication was seen – AA rupture in 1 (7.1%) case, and secondary postoperative ischemic complication in 1 (7.1%) case. The grade of AA exclusion from the blood flow after clipping was done according to Raymond scale: class I – 13 (92.9%) cases, class II – 1 (7.1%). The quality of life of the surgical treated patients was evaluated using Extended Glasgow Outcome Scale. Full and good recovery was observed in 6 (42.9%) patients, mild dependence in 4 (28.6%), moderate dependence in 4 (28.6%). Conclusions. Endoscopic assistant should be used during tumor inspection, its dissection and for control of radical removal considering the size of the bone window, parameters of surgical approach and quality of microscopic visualization. Extreme importance has the utilization of endoscopic assistance for controlling of tumor removal, since its remaining may be inaccessible for microscopic examination, which is situated in «blind» spots. Endoscopic assistance during different stages of clipping of AA of the AC is accessory technique that improves intraoperative visualization during separation of the affected aneurysmal arterial segment of the AC, determining the anatomical location of the perforating arteries, AA neck regions, assessment of the clip / clips position on the AA neck or AA body without additional traction on the wound margins, and for inaccessible regions for microscope examination