Comparative Study Of Jugular Foramen Surrounding Structures In Two Kinds Of Operation Position

BackgroundJugular foramen refers to the potential gap, surrounded by the petrous temporal bone, mastoid, occipital, temporal mandibular joint, ramus and cervical vertebrae bony structures, it is not only start-stop muscles complex, but also adjacent to the labyrinth, cochlear and other important anatomical structure, and facial nerve, vestibular cochlear nerve, glossopharyngeal nerve, vagus nerve, accessory nerve, hypoglossal nerve, internal carotid artery, internal jugular vein and vertebral artery etc. important structures in which to walk through, that caused huge difficulties giving the regional lesion surgery. Jugular foramen (jugular foramen, JF) is located between the lateral occipital and petrous temporal bone, surrounded by the petrous temporal bone and occipital neck, the long axis inclined from the outside after to forward, JF is a channel from the bottom of the front side of the brain to extracranial.The two hole protrusions formed temporal and occipital bone is called the temporal and occipital process respectively, both is connected to the fiber or bone bridge, constituting a nerves and blood vessels separation inside the hole. JF is divided into two parts by jugular vein crest and fibrous septa, the anteromedial nerve section for the Traveling ninth cranial nerve; posterolateral vascular department, within which is the jugular bulb and10,11cranial nerves. All along, the jugular foramen has been one of the hot spot of neurosurgery, Head and Neck Surgery, ENT and surgical oncology etc. multidisciplinary joint attention. The structure of jugular foramen is complex, Rhoton thinks this can be attributed to the following aspects:(1) the size and shape of each is not the same and very irregular;(2) a number of important organizational structures walk through;(3) deep, adjacent to the complex. Although the research of microsurgical techniques, neuroimaging, intraoperative neurological monitoring and other related fields has made great development recently, the surgery treatment of the jugular foramen tumors is still one of the most difficult surgery in the surgical field. Only a detailed understanding of the anatomy structure of the jugular foramen, to determine the nature of the lesions and the development direction of the tumors, then choosing the most appropriate surgical approach is likely to make the operation achieve better results.Siefert first reported in1934the surgical removal of jugular bulb lesions, since neurotology and neurosurgeon used a variety of surgical approaches to deal with JF lesions. House and Hitselberger in1976the cochlea into the road and lost in1978reached the slopes and the internal auditory canal; Fish made the temporal fossa approach in1997;1986Pellet lost by the pillow under the combined approach,1988AI. Merry, Samii down through the mastoid and canopy combined approach to remove jugular foramen tumor (JFT). Subsequently, after the epidural occipital bone rock combined approach, near the occipital condyle into the road and so on several of the proposed approaches to remove JFT. With the development of the microscope, imaging and neuroendoscopic, a large number of research workers have been on the jugular foramen surgical approach and made a lot of anatomical simulations.Early researchers have carried on the detailed description for anatomical signs of jugular foramen, for example the transverse process of the atlas (TPA), the cephalic rectus, digastric groove and jugular process, the length and width of the inside and outside mouth of the jugular foramen, the diameter of adjacent structures of the jugular foramen (hypoglossal canal mouth,the inside and outside mouth of condyle tube, carotid canal mouth, petrosal sinus, inferior petrosal sinus and sigmoid sinus), the outside mouth of jugular foramen and adjacent structures (foramen magnum, occipital condyles, hypoglossal canal, mouth, mastoid tip, stem milk hole, mastoid roots condyle outside the mouth and the star point) hole spacing and the jugular vein and the inner door opening, the mouth hypoglossal canal, vestibular pitch aqueduct the outside mouth of the corpse’s head objectively measure. With the clinical application of surgical microscope, the researchers observed and measured for the jugular foramen and adjacent structures in the body and human head under the operating microscope. Although the microscopic anatomy of jugular foramen have been numerous studies, for the research of three-dimensional anatomical relationship of important nerves,blood vessels and the bone of the skull base structure is relatively less. With the progress of CT scanning technology and the development and utilization of computer software,3D-CT helical scanning and image reconstruction techniques have been successfully applied in the field of neurosurgery.3D-CT helical scan can accurately depict the three-dimensional relationship between the lesions of the skull base and surrounding skull, falx, tentorium, blood vessels, and thus make up for the shortage of the conventional two-dimensional CT, with the help of three-dimensional images, we can make comfortably preoperative preparation and choose the best surgical approach to reduce side injury and reduce disability. In addition, the application of3D-CT helical scan can accurately diagnose the site of skull base fracture and injury, for the past some diagnosis relied on experience to make provides a scientific and objective criteria. Then combined imaging and neurosurgery workers in the two-dimensional and three-dimensional reconstruction of high-resolution CT had made simulation studies, and observed with intraoperative microdissection, no significant differences. By a comparative study of jugular foramen surgical approach of preoperative cranial CT three-dimensional reconstruction, jugular foramen CT reconstruction of preoperative jugular foramen tumors in patients has important clinical significance.However, at home and abroad preoperative3D-CT reconstruction simulation postural guiding the surgical approach of jugular foramen tumors is still lack of systematic and comprehensive clinical studies. Therefore, I has carried on comparative studies for using head CT reconstruction technique in two positions on the surrounding structures of jugular foramen. Conventional suboccipital far lateral approach is used to remove jugular foramen tumors, using lateral position (ie, the middle cranial flexion), you need to go far foramen magnum lateral bone resection after Cl arch and side pieces and expose the extracranial vertebral arteries, jugular foramen structure can be revealed from the external and below, but reveal fully and effectively structures in front of the brainstem on the premise of not pull brainstem. But the process exposed jugular foramen in the far lateral approach will be the same restrictions for the posterior arch of the atlas, the vertebral artery, occipital condyle and near the condyle bony protrusions, hindering the operative field, increasing traction of brain tissue and brain injury. Using oblique supine position, we now has successfully processed the jugular foramen tumors, found that the transverse process of the atlas is not worn out, do not shift the vertebral artery, it can better reveal the jugular foramen, and can safe to access through the jugular foramen fossa along the carotid sheath. Therefore, we hope to find a more suitable surgical position and summarize its clinical advantages.ObjectiveComparative study of the middle cranial supine and oblique supine with the revelation extent of structures surrounding the jugular foramen, for the regional surgical approaches and the protection of the relative structures provide the anatomical basis.Methods41cases of healthy adults were confirmed by PHILIPS Brilliance64-slice CT machine according to the conditions in1mm thick bone window in a simulated lateral position, respectively (ie, the middle cranial flexion supine position) and oblique supine position with continuous axial scanning, scan range includes horizontal canal to C3levels bony landmarks. The scanned images input Philips Extended Brilliance Workspace CT reconstruction of multi-plane (MPR) and measure the data.ResultsIn the simulated lateral position (ie, the middle cranial flexion supine position) when measured the distance of transverse process atlas (C1) to the ipsilateral mastoid tip, tip of the styloid process, the midpoint of the outer edge in occipital condyle anatomical landmarks, they were respectively20.99±4.18mm,20.49±5.47mm,22.035±4.27mm. Measured in supine oblique the distance of transverse process atlas to the ipsilateral mastoid tip, tip styloid process, the midpoint of the outer edge in occipital condyle anatomical landmarks, they were respectively22.795±3.29mm,22.315±5.48mm,23.025±3.91mm. Using a paired t-test, compared to the measured data in the supine position and the middle cranial supine, p<0.05, the difference was statistically significant.ConclusionsIn the surgical approach of jugular foramen, supine oblique can change the relative spatial relationship of correlative structure, increase the exposure of the jugular vein area fully, so that the facial nerve, vertebral artery and extracranial posterior brain structures were protected, it also reduces the damage to surrounding structural tissues and complications.