ABSTRACT
Objective: To examine the feasibility, safety, and efficacy of mobilization of the vertebral artery for C2 pedicle screws in cases with high-riding vertebral artery (HRVA). Methods: The clinical data of 12 patients with basilar invagination and atlantoaxial dislocation underwent atlantoaxial reduction and fixation in the Department of Neurosurgery, the First Affiliated Hospital of University of Science and Technology of China between January 2020 and November 2021 were retrospectively analyzed. All patients had high-riding vertebral artery on at least one side that prohibited the insertion of C2 pedicle screws. There were 2 males and 10 females aged (48.0±12.8) years (range: 17 to 67 years). After correction of vertical dislocation during the operation, the C2 pedicle screw insertion and occipitocervical fixation and fusion were performed using the vertebral artery mobilization technique. Neurological function was assessed using the Japanese Orthopedic Association (JOA) scale. The preoperative and postoperative JOA score and the main radiological measurements, including the anterior atlantodental interval (ADI), the distance of the odontoid tip above the Chamberlain line, the clivus-canal angle, were collected and compared by paired t-test. Results: Mobilization of the high-riding vertebral artery was successfully completed, and C2 pedicle screws were then fulfilled after the vertebral artery was protected. There was no injury to the vertebral artery during the operation. Meanwhile, no severe surgical complications such as cerebral infarction or aggravated neurological dysfunction occurred during the perioperative period. Satisfactory C2 pedicle screw placement and reduction were achieved in all 12 patients. All patients achieved bone fusion 6 months after surgery. No looseness and shift in internal fixation or reduction loss was observed during the follow-up period. Compared to the preoperative, the postoperative ADI decreased from (6.1±1.9) mm to (2.0±1.2) mm (t=6.73, P<0.01), the distance of the odontoid tip above Chamberlain line decreased from (10.4±2.5) mm to (5.5±2.3) mm (t=7.12, P<0.01), the clivus-canal angle increased from (123.4±11.1) ° to (134.7±9.6) ° (t=2.50, P=0.032), the JOA score increased from 13.3±2.1 to 15.6±1.2 (t=6.99, P<0.01). Conclusion: The C2 pedicle screw insertion assisted by mobilization of the vertebral artery is safe and considerably effective, providing a choice for internal fixation in cases with high-riding vertebral arteries.
ABSTRACT
Objective To provide the anatomical data for single-nostril transsphenoidal microsurgery for pituitary adenoma.Methods Microanatomic structures were observed and measured in 20 cadaveric a- dults heads.Results(1)The diaphragmal opering was 5 mm or greater broad in 90%.The mean thick- ness of the diaphragma sellae was (0.18?0.08)mm.(2) A sphenoid sinus with complete pneumatization was named as all-sellae type,its percentage in all specimens was 85%,85% sphenoid sinus had middle sep- tum of which only 18.8% located in the medial sagital section.(3)The meant thickness of the sellar floor was (0.81?0.34) mm,70% of which were not more than 1 mm.Of the sellar floors,that the shape was flatness reach 15%.(4) The relationship between ICA and sphenoid sinus had two aspects,one was to be mutually apart (55%),the other was to communicate (45%),which formers carinae on the lateral wall of the sphe- noid sinus,espeially in the superior surface of posterior part.The relationship between optic nerve and sphe- noid sinus,one was to be mutually apart (27.5%),the other was to communicate (72.5% ),which formers carinae on the lateral wall of the sphenoid sinus,especially in the superior surface of anterior part.(5) Three main types of the intercavernous sinus were the anterior intercavernous sinus,present in 80%,the inferior in- tercavenous sinus (25%),and the posterior intercavenous sinus (15%).Conclusion The knowledge of the anatomy of the sellar region and sphenoid sinus is helpful to safe operation in the single-nostril transsphe- noidal approach for pituitary,adenoma microsurgery.