ABSTRACT
Objective: To investigate anatomic and morphological distribution characteristics of the torcular herophili of the intracranial venous system and to provide reference for the treatment and evaluation of common diseases related to the venous system. Method: From January 2016 to July 2018, 2 668 inpatients with cerebrovascular disease related symptoms admitted in Department of Neurology and the other departments, the First Medical Center of the PLA General Hospital were retrospectively recruited. These patients included 1 572 men and 1 096 women. The ages ranged from 11 to 82 years, with an average of (54 ± 14) years old. According to the anatomic morphology and drainage channel of the straight sinus,bilateral or unilateral transverse sinuses,superior sagittal sinus and other blood vessels in the sinus confluence area (occipital protuberance),the anatomic morphology of the torcular herophili from DSA results can be divided into type I (complete torcular herophili type),type II (incomplete torcular herophili type, including II1A,II1B,II2,II3,II4 and II 5 five subtypes), type III (no torcular herophili). Type I refers to venous confluence of the superior sagittal sinus, straight sinus and bilateral transverse sinuses in the occipital protuberance;Type II refers venous confluence of any three of the superior sagittal sinus, straight sinus and bilateral transverse sinuses in the occipital protuberance, and it must contain the superior sagittal sinus and the straight sinus not directly connected with bilateral transverse sinuses; Type III refers to confluence of the straight sinus alone into the one side of the transverse sinus-sigmoid sinus,but without drainage from the contralateral veins and no communication between bilateral transverse sinuses. Results: (1) Among the 2 668 patients admitted to the hospital due to cerebrovascular disease related symptoms and completed DSA examination, the proportion of different anatomic types torcular herophili from high to low was type II 56. 4% (1 504 cases), type I 39. 0% (1 040 cases) and type ID 3.7% (100 cases). (2) Among five subtypes of type II, the proportion of II 1A was 20.4% (544/2 668), II 1B 5. 7% (152/2 668), II2 19. 8% (528/2 668), II3 2. 8% (76/2 668), II4 4. 3% (116/2 668) and II5 3. 3% (88/2 668). (3) The proportion of right dominant drainage was the highest,accounting for 50. 5% (1 348/2 668),followed by bilateral balanced drainage,accounting for 36. 4% (972/2 668). The left dominant drainage was the lowest, accounting for 12. 1% (324/2 668). Conclusions: There are great morphological variations in the sinus confluence of the intracranial venous system. Understanding of the anatomical features of the sinuses and assessment of the drainage characteristics of the venous sinuses could provide references for diagnosis and treatment of venous system diseases.