The Anatomy Of Cavernous Sinus And Related Veins And Its Application In Endovascular Therapy

Objective:Now many knowledge has been available on the anatomy of cavernous sinus,internal carotid artery,cranial nerves,while that of CS and related veins were rarely studied and individual variation was great.Therefore,a good grasp of the anatomy and conception of CS and related veins contributes not only has the very important significance to the department of Neurosurgery surgery,also has the important guiding function to the clinical intervention treatment.The present study aims to(1)investigate the relationships between CS and related veins,as well as the shape,size,length and location of related veins;(2)Combined with the anatomical results and imaging data,we can provide guidance for the treatment of carotid cavernous fistula and improve the success rate of treatment and reduce the risk of treatment.Methods: The subject is divided into two parts :1 5 cases(10 sides)of adult skull specimens,fixed by formalin,were infusedintravenously with blue latex.The skulls were splited along the boundary between skull base and calvarium with the meninges left.Venoussystem involving facial vein,superior ophthalmic vein,inferior ophthalmic vein,sylvian vein,inferior petrosal sinus and superior petrosal sinus were carefully separated and observed with naked eye and surgical microscope for the morphology and structure of CS and related veins,and measured with vernier caliper for diameter and length of veins.2We researched part of the case of Dural arteriovenous fistula and traumatic carotid cavernous fistula in Shanghai Changzheng Hospital from February 2012 to January 2016,discussed the guiding role of anatomy of CS and related veins in interventional therapy.Results: 1.Anatomy: The CS and its adjacent structures in 5 cases(10 sides)of adult wet head specimens were dissected in detail.The results were as follows:(1)The scope of CS: the anterior cavernous sinus extended into the medial margin of anterior clinoid process and superior orbital fissure.The posterior CS is behind the posterior clinoid process.The upper wall is composed of dura mater below anterior clinoid process,posterior clinoid process and petrous apex.The medial and lateral wall of CS converge below to form the lower edge of CS,which is beneath the internal carotid artery.(2)Thedivision of CS: CS is divided into the anterior-inferior space,the posterior-superior space,the medial space and the lateral space using the internal carotid artery as the boundary.(3)CS and related structures of 5 adult skull specimens were fully viewed via surgical microscope.The distance between the midline and the medial walls of CS on both sides are as follows: on the medial margin of pituitary fossa: 7.36 ± 1.01 mm,7.58 ± 1.98 mm;on the medial margin of upper sphenoid sinus: 13.76 ± 0.87 mm,12.56 ± 1.08mm;on the medial margin of lower sphenoid sinus: 22.96 ± 2.23 mm,23.05 ± 1.15 mm.(4)Related veins or venous sinus: basilar sinus is wide and located on the slopes.It is connected to CS,superior and inferior petrosal sinus on both sides.The ophthalmic vein flows into the CS in the lower anterior space of CS.The lateral fissure vein flows directly into CS in 5 sides,into the sphenoidal sinus and then drains into CS in 4 side.There was no inlet point in 1side.The inferior petrosal sinus originated from the posterior CS,including vertical and horizontal segments.The inferior petrosal sinus in 10 sides in our study flow directly to the jugular bulb.2.Clinical treatment:(1)A total of 47 patients were collected,including a total of 21 males and a female of 26.The age ranged from 16 to 70 years with an average age of 49.30±13.88.Symptoms: conjunctival hyperemia of up to 47 the number of cases,followed by 45 the number of cases,exophthalmos,conjunctival edema in 31 cases.Another vascular murmur in 15 cases,9 cases of headache and diplopia in 14 cases,decreased visual acuity in 6 cases,3 cases of ptosis,1 cases with tinnitus.In this study,Among 15 patients with t CCF,12 cases were treated with arterial balloon embolization,and 3 of them underwent combined arterial coil and ONYX embolization after failure using balloon embolization;among 32 patients with CDAVF,3 cases were treated with arterial Onyx embolization,19 cases were treated by intravenous coil embolization,and 10 cases underwent intravenous embolization using coils and ONYX.14 of 15 cases with t CCF patients obtained successful embolization of the fistula,and 1 case had unsuccessful balloon embolization and no further treatment due to economic reasons.Among 32 cases of DCAVF receiving embolization,29 cases obtained satisfactory recovery,with 1 case obtaining non-imaging ophthalmic vein and imaging lateral fissure vein,and 2 cases obtaining ophthalmic veins and imaging inferior petrosal sinus.After treatment,5 cases developed ipsilateral abducens nerve palsy,1 case developed eyelid edema,which were significantly improved after active management.For the remaining 40 cases,no symtom was detected at discharge.Among 46 cases(except for suspension of treatment due toeconomic reasons),1 case of lateral fissure vein development were followed up 3 months of which one was completely non-developed.2 cases of the development of inferior petrosal sinus were followed up for 3 months of which one was completely non-developed.The remaining patients were uneventful at follow-up.(2)Clinical application of anatomical knowledge: We have good grasp of the anatomical concept,such as the scope and division of CS,the correlations with internal carotid artery,bony signs,and openings and course of the ocular vein,lateral fissure vein,which benefit a lot in the treatment of related diseases.This study provided more important anatomical basis for complex cases,such as nonimaging inferior petrosal sinus,the existence of intercavernous sinus,microcatheter placing difficulties and multiple venous intubation due to various reasons.Conclusions:Related data of anatomy of cavernous sinus and related veins is important to study the interventional treatment of carotid cavernous fistula(such as intubation of micro catheter and embolization).It can significantly improve the success rate of interventional catheterization and embolization and reduce the risk of operation.