Basic Research And Clinical Observation On Surgical Treatment Of Traumatic Superior Orbital Fissure Syndrome

As early as 1974, Japanese scholars Nakagawa discovered that the clinical manifestations of some traumatic brain injury (TBI) combined with orbital apex fracture patients appeared the same as or similar to "the superior orbital fissure syndrome" caused by tumors and vascular disease. Based on these clinical observations, he first proposed the concept of "Traumatic superior orbital fissure syndrome", and clarified that it was a group of clinical syndrome caused by the fractures of the superior orbital fissure oppressed theⅢ,Ⅳ,Ⅵ,Ⅴ(1) cranial nerves. With the development of TBI treatment, the overall TBI treatment techniques are enhancing rapidly. However, the treatment skills of traumatic superior orbital fissure syndrome had not been dramatically improved for following reasons.①Injury site deep in the skull.②Anatomical structure complex.③Surgery was very difficult.④It is difficult to diagnose exactly by the Interference of the symptoms of TBI. Therefore, surgical treatment has not been extensively carried out, a considerable proportion of patients did not receive treatment timely and effectively.Part 1:Establishment of the Animal Model of Traumatic Superior Orbital Fissure Syndrome[Purpose] To discuss the way of establishing the animal model of traumatic superior orbital fissure syndrome and to provide the model basis for further study of the traumatic superior orbital fissure syndrome. [Methods] The contents of 20 adult SD rats'foramen rotundum (similar to human SOF) were injured by 70g nerve clips through micro-neurosurgery. Record the symptom indexes-direct and indirect light reflex and pupil diameter,24 hours after injury. Pupil diameters were recorded by "Improved camera technology". The animal model were tested and verified by HE staining and electron microscope 1 week,2 weeks and 4 weeks after injury. [Results] Success rate of the model reaches 90%. Pupil diameters of injury group were 3.02±0.45mm and 0.75±0.18mm in control group (P<0.0001). HE staining of nerve showed that nerve denaturation getting worse, nerve regeneration is not obvious and connective tissue hyperplasia along with the time. Electron microscope showed that the nerve compression time getting longer, the hyperplasia of the schwann cells are getting less, and the reproduction speed, quantity, and the thickness of the myelin sheath of the nerve fibers are getting less either. [Conclusion] The animal model of traumatic superior orbital fissure syndrome established by this method can simulate the cause of the traumatic superior orbital fissure syndrome effectively, and also can simulate most of the clinical symptoms. It has certain reference value for the study of the pathological process and the diagnosis of the traumatic superior orbital fissure syndrome. It reduced the mortality rate of the animals for the surgical operation carried out in the extra cranial. The preparation method is easy to master and has strong feasibility. It provides the model basis for further study of the traumatic superior orbital fissure syndrome. The "Improved camera technology" is a convenient and accurate way to measure the pupil diameter of the animals (especially small size animals).Part 2:Related Research of Compression Time and Neurological Recovery[Purpose] To discuss the correlation of the nerve injury time and the neurological recovery and to provide the theoretical basis for further study of the surgical timing for the traumatic superior orbital fissure syndrome. [Methods] 75 adult SD rats were divided into 4 groups. Group A:clamping with 70g nerve clips for 60 seconds then removed them. Group B:clamping with 70g nerve clips and keep them in vivo for 72 hours then removed them. Group C:clamping with 70g nerve clips and keep them in vivo for 1 week then removed them. Group C:clamping with 70g nerve clips and keep them in vivo for 2 weeks then removed them. Record the symptom indexes-direct and indirect light reflex and pupil diameter as well as the CMAP 4 weeks after the clips were removed.Group E: clamping with 70g nerve clips and keep them in vivo for 4 weeks, and do the observation and experiment above directly. [Results] There are great differences among the five groups. Pupil diameters change from 0.91±0.22mm to 3.09±0.40mm. The existing rate of the light reflex changes from 93.33% to 0%. Amplitude of CMAP changes from 7.62±1.78mv to 0.59±0.25mv. Delay of CMAP changes from 3.15±0.68ms to 5.49±0.30ms. The amplitude of injury group are much more flat than that of control group, particularly in group C and D. [Conclusion] Recovery of neurological function in operation group was better than that in non-surgical group. Lifting the compression of the nerves in 72 hours can slow down or even reverse this process. The relationship between nerve oppression time and nerve function is still subject to further study.Part 3:Related Research of Nerve Compression and Pathological Changes[Purpose] To discuss the correlation of the nerve injury time and the pathological changes and to provide the theoretical basis for further study of the surgical timing for the traumatic superior orbital fissure syndrome. [Methods] Observe the morphological changes of the specimen from part 2 using electron microscope and immunohistochemical staining. [Results] ESM suggested that with the nerve compression time getting longer, the hyperplasia of the schwann cells are getting less, and the reproduction speed, quantity, and the thickness of the myelin sheath of the nerve fibers are getting less either. Immunohistochemical staining suggested that with the nerve compression time getting longer, the staining gradually diminished, appear some irregular blocks and beaded pale-brown stain, the staining disappeared in some part finally. [Conclusion] Regeneration of the nerves in operation group was better than that in non-surgical group. Lifting the compression of the nerves in 72 hours can slow down or even reverse this process. The relationship between nerve oppression time and nerve regeneration is still subject to further study.Part 4:Microsurgical Anatomy and Clinical Observation of Traumatic Superior Orbital Fissure Syndrome[Purpose] To discuss the differences between different surgical approaches and to study the microscopic anatomy of the superior orbital fissure (SOF). To provide the theoretical basis for further study of the surgical approach and surgical methods for the traumatic superior orbital fissure syndrome. To compare curative effect of decompression and conservative treatment for traumatic superior orbital fissure syndrome to discuss the operation indications and the operative opportunity for this syndrome. [Methods] 20 specimens of human head (40 sides) were using for this experiment. Open the skull through zygoma approach, measure the degree of the angle and the length between the anterior border of the bone window and SOF. Enlarge the bone window, simulate the modified zygoma approach, measure the angle and the length too. Dissect the SOF under operating microscope, measure the distances from the superomedial to the superolateral edge of the fissure (AB line), the superolateral to the inferior edge (BC line) and the superomedial to the inferior edge (AC line). Data of 12 patients (seven males and five females) with 14 sides were compared to evaluate different curative effect between decompression and conservative treatment so as to optimize the initial corresponding treatment. [Results] The modified zygoma approach can provide anther more operation room by 5.2 degree, meanwhile the distance to the SOF increase 1.2mm. We identified 6 types of SOF, and the most frequently observed was Type VI. The distance from A to B was measured as 16.9±1.80mm mm on the right side and 17.0±1.82mm on the left side, and from B to C as 20.1±2.74mm on the right side and 20.2±2.86mm on the left side. The distance from A to C was measured as 8.9±1.64mm on the right side and 8.9±1.66mm on the left side. No right-left differences were observed for these measurements. The patients were at mean age of 28 years and followed up for mean six months. There was one patient complicated by orbital apex syndrome. CT showed involvement of the superior orbital fissure in seven patients. Of seven patients treated with decompression, six got recovery at different degrees. Meanwhile, three out of five patients treated with conservative treatment recovered to some extent. [Conclusion] The modified zygoma approach is suitable for the surgical treatment of traumatic superior orbital fissure syndrome. For those patient with fracture in SOF, surgical treatment is superior to conservative treatment.3-D imaging reconstruction is helpful to the operation.