Objective To explore the indications, methods and prognosis of spinal caverno-thoracic shunt for the treatment of spinal cavern. Methods Twenty-six patients with spinal cord cavitation treated with spinal cord cavitation-thoracic shunt from 2008 to 2012 were retrospectively analyzed. The preoperative diagnosis was confirmed by magnetic resonance imaging (MRI) and the modified Japanese Orthopaedic Association spinal cord function score (mJOA score) was accepted. All cases underwent spinal cord caverno-thoracic shunt surgery, and the MRI was reviewed two weeks after the surgery and the mJOA score was performed. Long-term follow-up was performed after the patients were discharged from the hospital. RESULTS Twenty-four patients (92.3%) showed significant improvement in clinical symptoms after surgery, with no change in one case, deterioration in one case, and no deaths or infections. After two weeks of postoperative MRI review, 25 patients showed different degrees of reduction in the segment or diameter of the cavity, and the mJOA score increased by 1-3 points; 1 patient’s postoperative cavity was similar to the preoperative one, and the mJOA score was unchanged. 26 patients were followed up for a period of 3-38 months, with an average follow-up period of 13.5 months, and the follow-up methods used were telephone follow-up of the mJOA score (24 patients) and MRI examination (2 patients). MRI examination (2 cases). mJOA scores of 24 patients at the time of follow-up did not fluctuate up or down by more than 1 point compared with the two weeks after the operation; MRI examination at the time of follow-up of 2 patients suggested that the cavities were further reduced and the mJOA scores were improved. The mJOA scores of all patients before and after surgery were statistically studied, and the results suggested a statistical difference (P<0.001). < span="">Conclusion The choice of spinal cord caverno-thoracic shunt is undoubtedly a reasonable and effective surgical procedure for some patients with unexplained spinal cord cavities or those who have already undergone suboccipital decompression surgery and failed to achieve the desired result, and postoperative complications are relatively rare. 【Keywords】 spinal cord cavern; spinal cord cavern shunt; spinal cord cavern-thoracic shunt (Report of 26 cases) ‘s syrinx and scores had no change. All patients were available for follow-up with All patients were available for follow-up with duration between 3 and 38 months, the mean duration of 13.5 months. MJOA scores of 24 cases at the time of follow up showed fluctuated no more than 1 point compared with the 2-weeks post follow-up. MJOA scores of 24 cases at the time of follow up showed fluctuated no more than 1 point compared with the 2-weeks postoperative scores. 2 cases took the MRI during the follow up period, indicating the further narrowing of the cavity and Results (preoperative mJOA scores and 2-week postoperative scores) were statistically significant (p<0.001< span="">) Spinal cord cavitation (syringomyelia, SM) is a chronic, progressive degenerative disease of the spinal cord caused by a variety of reasons, which can exist alone or in combination with other diseases, such as Chiari malformation, base of skull depression, spinal cord tumors, spinal cord embolism, spinal cord post-traumatic adhesion, scoliosis deformity, and arachnoiditis of the spinal cord, etc. However, the pathogenesis of SM has not yet been clarified, and the related theories are more diverse. However, the pathogenesis of SM has not yet been clarified, and the related theories and doctrines are numerous, which determines the diversification and diversity of its treatment methods.1,2,3 From 2008 to 2012, we used spinal cord caverno-thoracic shunt to treat a total of 26 patients with spinal cord cavernosis, and achieved good results. Here we retrospectively analyze the indications for surgery, key points of surgery, and prognosis of this group of cases, which are reported as follows: Data and methods General data: From 2008 to 2012, we used spinal cord caverno-thoracic shunt (SPS) to surgically treat 26 patients with spinal cord cavernous, of which 16 were male and 10 were female, aged 18-61 years old, with a mean age of 40.5 years. 40.5 years old. The average age was 40.5 years. The duration of the disease ranged from 2 to 10 years, with an average of 6 years. 7 patients had undergone posterior occipital decompression surgery for Chiari malformation, 6 patients had a history of spinal cord trauma (spinal cord trauma and spinal cord tumor resection), 6 patients had suffered from encephalo(spinal) meningitis, 4 patients had combined presence of scoliosis deformity, and 3 patients had simple spinal cord cavernous cavity. All patients were objectively evaluated preoperatively according to the modified Japanese Orthopaedic Association Spinal Cord Function Scoring Criteria (mJOA Score). mJOA Score: 7-13, Mean Score: 10.71.7 . Clinical manifestations: The first symptom was neck pain in 1 case, chest and back pain in 2 cases, segmental sensory detachment disorder in 23 cases. 15 patients had different degrees of muscle strength loss, and combined with muscle atrophy in 8 cases. There were 4 cases of urinary and faecal disorders. Imaging data All patients were diagnosed by magnetic resonance imaging (MRI) before surgery, which showed long T1 and long T2 signals in the spinal cord, with different degrees of thickening and thinning of the spinal cord. Among them, there were 8 patients with total spinal cord cavitation, 16 patients with cervicothoracic segmental cavitation, and 2 patients with thoracic segmental cavitation. Surgical methods Surgery was performed in the left lateral position under general anesthesia, and double incisions were made, i.e., a posterior median straight incision on the back of the chest was made at the thinnest part of the spinal cord (based on preoperative MRI localization), and the transverse expansion was avoided as much as possible; a lateral incision was made at the junction of the right midaxillary line and the 8-9th rib space or the upper edge of the 9th rib, which was mainly based on the shape of the lower border of the lungs and the position of the pleural cavity. During surgery, we mostly use single-segment laminectomy, and if necessary, 1/2 segment can be explored upward or downward, which aims to minimize the disruption of the continuity and stability of the spine under good surgical field of view and operation range. After removing the vertebral plate and opening the dura mater, the spinal cord was seen to be thickened, hypertonic, and poorly pulsed in all the patients with cavities. The structures on the surface of the spinal cord were carefully identified under the microscope, and spinal cord dissection was made along the posterior median sulcus of the spinal cord in 18 cases (Posterior Midline (PML)), and dissection was made along the dorsal root entry zone (DREZ) of the spinal cord in 8 cases (DOR), and dissection was made along the length of the spinal cord. The length of the incision was 2-3mm, and after the incision, clear cerebrospinal fluid was seen to flow out. The “T-end” of the T-shunt tube was placed inside the cavity, and its own elasticity was utilized to stretch the arms to a tension-free state, and the soft spinal cord and arachnoid membrane were closed with 5-0 absorbable sutures to fix the shunt tube, and the dura was tightly sutured to fix the shunt tube once again. The shunt was fixed, the dura was tightly sutured, the shunt was fixed again, and the distal end of the shunt was inserted into the pleural cavity through a subcutaneous tunnel, and the exposure of the pleural cavity was not repeated here. Results: 1 patient with a history of tuberculous pleurisy (92.3%) had different degrees of postoperative symptomatic improvement, 1 patient with no change, 1 patient with deterioration, and 1 patient with no death or infection. 1 patient with a history of tuberculous pleurisy did not have good postoperative symptomatic improvement, and it was found that the pleura was thickened, adherent, and it was difficult to insert the drain tube. 1 patient had significant symptomatic improvement two weeks after SPS, and it was found that the shunt tube was placed into the pleural cavity through a subcutaneous tunnel. In one case, the patient’s symptoms improved significantly two weeks after SPS, but deteriorated one month later, and exploratory surgery was performed, during which inflammatory lesions were found around the epidural T-tube, and the patient’s symptoms improved after removal of the inflammatory lesions and adjustment of the drainage tube. According to the MRI results two weeks after the operation, the spinal cord cavity segments or diameters of 25 patients were reduced to different degrees (Figure 1), and the mJOA score was improved by 1-3 points; 1 patient’s postoperative cavity situation was similar to that before the operation, and there was no change in the mJOA score; 23 patients underwent postoperative mJOA scoring of 8-15 points, with a mean score of 12.82.1 points. 2 patients experienced postoperative complications, one of which was mainly manifested by the presence of inflammation around the epidural T-tube, and one of which was mainly manifested by the presence of inflammation around the epidural T-tube. Two patients had postoperative complications, one of which was mainly “numbness in the trunk” and the other was “discomfort in the right side of the chest”, and neither of them received any special treatment, and the discomfort symptoms gradually disappeared after long-term follow-up. 26 patients were followed up for 3-38 months. The average follow-up time was 13.5 months (3-38 months). mJOA score (24 patients) and MRI examination (2 patients) were used for follow-up by telephone, and the results showed that the mJOA score of 24 patients fluctuated up and down by no more than 1 point compared with that of two weeks after the operation, with an average score of 12.62.4 points; MRI examination of the 2 patients at the time of follow-up suggested that the spinal cord cavities had shrunk further (Figure 2), and the mJOA score improved. ), and the mJOA score improved. Statistical analysis of the mJOA score scores of the 26 patients preoperatively and two weeks postoperatively was performed using the nonparametric rank sum test, and the results showed P<0.001. The preoperative and 2-week postoperative periods and follow-up of the 26 patients in this group were summarized (see Table 1). Discussion The pathogenesis of spinal cord cavitation is based on the theory of cerebrospinal fluid circulation disorders, and the current theory of intramedullary pulsatile pressure is relatively more convincing.3 The surgical treatment of spinal cord cavitation varies according to the etiology of the disease. However, the aim of all surgical procedures is to reduce the size of the cavity while stabilizing or improving the symptoms and slowing or stopping the progression of the disease. According to the literature and our own clinical practice, the surgical treatments for spinal cord cavities are broadly categorized into two groups. The first type of surgery is mainly for patients with spinal cord cavitation combined with atlanto-occipital malformations, including decompression of the posterior cranial fossa, transoral resection, and release of dural and arachnoid adhesions.1, 4-5 6 The purpose of this type of surgery is to restore the cerebrospinal fluid circulation in the craniocervical border area or the subarachnoid space of the spinal cord and the central canal, and to reestablish the homeostasis of the cerebrospinal fluid circulation. And the purpose of the second type of surgery is to rebuild the discharge system of the fluid in the cavity sac lumen, which mainly includes: spinal cord cavity shunt, the indications of which are mostly, patients who exclude the possibility of the first type of surgery, or those who have already received the first type of surgery and have poor therapeutic effect. Currently, the main cavity shunts used at home and abroad include: "cavity-subarachnoid shunt, cavity-abdominal shunt, cavity-thoracic shunt".1,2,9 Among the many shunt procedures, the pressure gradient of the shunt is the key factor that affects the amount of shunt flow and maintains the smoothness of the drainage.10 Gao Yongzhong9 et al. have investigated the spinal cord cavity shunts in 26 patients with spinal cord cavities, and found that the pressure gradient of the shunt was the key factor that influenced the amount of shunt flow and maintained the smoothness of the drainage.10 Gao Yongzhong9 et al. Gao Yongzhong9 et al. measured the pressure in the cavity of 26 patients with spinal cord cavities and found that the average pressure was 109.2 mmH2O2, whereas the pressure in the pleural cavity fluctuates from -5H202 to -8H2O2, which is much smaller than the pressure in the cavity. Cacciola 10 et al. suggested that in spinal cord cavity-subarachnoid shunt surgery, the pressure in the subarachnoid space was almost equal to the pressure in the cavity, resulting in poor drainage and poor surgical results. In spinal caverno-peritoneal shunt surgery, the pressure in the peritoneal cavity is not constant and is often greater than the pressure in the cavernous capsule, which increases the incidence of blockage of the peritoneal end of the drain. Also, Oldfield11 et al. showed that when excess cerebrospinal fluid is present in the subarachnoid space of the spinal canal, it can re-enter the central canal of the spinal cord through the perivascular space and the nerve root cuffs, resulting in the formation of a cavity, thus the long-term efficacy of spinal cavernosus -subarachnoid shunt is also questionable. Of the 26 patients in this group, 19 had simple spinal cord cavities (without atlanto-occipital deformity), and SPS was the treatment of choice. The remaining 7 patients had undergone postoperative occipital decompression surgery due to the presence of Chiari malformation, and the spinal cord cavitation failed to improve or even worsened after the surgery. Considering that it was difficult to perform postoperative occipital decompression surgery again and the efficacy was not certain, and that the clinical symptoms of all the patients mainly consisted of the "clinical manifestations of spinal cord cavernous disease", we considered SPS as a remedial surgical measure for the treatment. The patients' clinical symptoms were mostly characterized by the "clinical manifestations of spinal cord cavernous disease". Therefore, we do not recommend SPS as the first choice of treatment for all patients with spinal cord cavernous disease, especially when combined with Chiari malformation, decompression of the posterior cranial fossa, resection of subcerebellar herniation, and relaxation of the central canal of the spinal cord should be the first choice of treatment, which is also the view of Zhang Yuqi12 et al. in China. Only through individualized assessment and analysis of the etiology of spinal cord cavitation patients, and then through the selection of a reasonable surgical approach, can patients receive effective treatment. In this group of cases, two patients had numbness and sensory abnormalities in the trunk after SPS, which might be related to the location and length of the spinal cord incision point, but after long-term follow-up, the discomfort tended to improve gradually. one patient had discomfort and pain in the right side of the chest after surgery, which was initially considered to be due to excessive drainage, resulting in pleural effusion, and was later treated with pulmonary surgery. "At first, we thought that the pleural effusion might be caused by excessive drainage, but after lung CT, we confirmed that only a small amount of effusion existed (less than 100 ml), so we could not rule out the possibility that the cerebrospinal fluid irritated the pleura and caused the above clinical manifestations, but the symptom gradually disappeared in 3-7 days after the operation. There was only one case in which the patient's condition gradually deteriorated 1 month after SPS, and inflammatory lesions around the epidural T-tube were found during exploratory surgery, and the patient's symptoms improved after removal of the inflammatory lesions and adjustment of the drainage tube. None of the operated patients were re-visited for obstruction or displacement of the drainage tube. ROTH14 et al. suggested that the incision point of the spinal cord should be chosen in the dorsal root entry zone (DERZ) of the spinal cord to minimize damage to the spinal cord, and POTH14 et al. suggested that the incision point of the spinal cord should be chosen in the dorsal root entry zone (DERZ) of the spinal cord to minimize damage to the spinal cord. minimize damage to the spinal cord, and Prestor15 et al. have confirmed the same by studying the functional electrophysiological testing of the spinal cord. It has also been suggested that the dorsal posterior median fissure (PML) of the spinal cord can also be used as a point of incision of the spinal cord, which is also minimally traumatic to the spinal cord and is easily recognizable.16 In our cases, the DERZ incision was chosen in 8 patients and the PML incision in 18, with the selection of the method being based on whether or not the spinal cord cavernous capsule lumen was lateralized or centered. When making spinal cord incision, the cervical pontine region should be avoided, and the length of incision should not be too long (≤3mm). This shows that when patients with spinal cord cavitation exclude surgical procedures aimed at restoring the cerebrospinal fluid circulation pathway (e.g., decompression surgery of the posterior cranial fossa, etc.), or when such surgical treatments have already been performed but are ineffective, the choice of spinal cord cavitation-thoracic shunt is undoubtedly a reasonable and effective surgical procedure. Through the literature and our own practice, we found that the theoretical basis of spinal cord caverno-thoracic shunt is more reasonable, the efficacy is more certain, and the postoperative complications are relatively rare. However, this still needs a large number of case data to confirm so, and should be compared with other cavity shunts in order to be more convincing. Figure 1: Female patient, 40 years old, with numbness and weakness of both upper limbs with pain and hypothermia for 10 years. She underwent two postoperative occipital decompression surgeries for "spinal cord cavern, Chiari malformation," but the results were unsatisfactory. a. The patient's preoperative MRI (T2) showed the presence of a spinal cord cavern in the C1-T11 spinal cord, dilatation of the spinal cord's central canal with hydrocele, and thinning of the spinal cord, and the mJOA score was 8 points. b. B1 and b. B2. The patient was rechecked two weeks after the surgery. MRI (T2), suggesting complete disappearance of the cavities in the lower cervical and upper thoracic segments, mJOA score: 10 points. Figure 2: Figure 2: The patient was a 57-year-old male with progressive left-sided trunk distension and numbness and weakness for more than 8 months. He had a history of spinal cord trauma.A. The patient's preoperative MRI (T2) suggested the presence of a spinal cord cavity, mJOA score: 7. B. Postoperative MRI (T2) was reviewed 2 weeks after surgery, suggesting that the cavity was reduced compared with the preoperative period, and there was a decrease in the spinal cord tension. mJOA score: 8. C. The patient's postoperative follow-up of 23 months was reviewed by MRI (T2), which suggested the complete disappearance of the cavity in the cervical and upper thoracic segments, mJOA score: 10 points. Table 1: Case summary table Preoperative 2 weeks postoperative Postoperative follow-up Basic information Patient: 26 cases Male: 16 cases Female: 10 cases Age: 18-61 years old Mean age: 41 years old Clinical symptoms Improvement: 24 cases Deterioration: 1 case No change: 1 case Complications: 3 cases Mean follow-up time: 13.5 months Follow-up methods: telephone follow-up (24 cases). Examination (2 cases). а Examination All cases were diagnosed with spinal cord cavitation by MRI of the spinal cord. In 25 cases, the segment or diameter of the cavity was reduced to different degrees. In one case, the postoperative condition of the cavity was similar to that before surgery. MRI was performed in the follow-up of the case patient, suggesting further reduction of the cavity. Mean mJOAβ score а. MRI (Magnetic Resonance Imaging)-approved magnetic resonance imaging. β. mJOA (modified Japanese Orthopedic Association Scores)-Modified Japanese Orthopedic Association Scores for functional status of the spinal cord.