Comparison Of Two Kinds Of Operation Methods For The Treatment Of Arnold-chiari Malformation Typeâ… associated With Syringmyelia Curative Effect

Objective:Arnold-Chiari malformation type I(ACMⅠ) is a kind of posterior fossa congenital malformations disease, often associated with syringomyelia(SM). There are various operation ways to treat this disease, with different curative effects. This study has concluded and compared two operation ways on clinical at present, “External decompression” that is dominated by posterior fossa decompression(PFD)and “Internal decompression” that is dominated by tonsillectomy+ reconstruction of the fourth ventricle outlet. Made an retrospective analysis on curative effects of two operation ways.Methods: A retrospective analysis was made on clinical materials of 68 cases that had been diagnosed for ACMⅠassociated with SM. These patients were divided into two groups according to the different ways of operation. There are 32 cases in Group A. They were treated by posterior fossa decompression, the window of the bone area is 5 cm x 5 cm at least and without durotomy. There are 36 cases in Group B. They were treated by open the window of the bone area is less than 3 cm x 3 cm, then resection the cerebellar tonsillar and the fourth ventricle outflow of membranous structure resection, Release the posterior inferior cerebellar artery, suture the endorachis. 6 cases of the group B are come from group A witch postoperative symptoms and signs suffered from aggravated after the first operation, they get back to the hospital and treated by revision operation. We evaluate the operation curative effects through the following methods:(1)Seven days,3months and 1year after operation the criteria of Tator were introduced to evaluate curative effects;(2)Seven days,3months and 1year after operation cerebellum tonsil retraction, syringomyelia changing condition of patients from two groups were compared through nuclear magnetic resonance(MRI);(3)Neurophysiology were conducted on patients from group A and group B to compare and record the changing condition of somatosensory evoked potential(SEP),of legs and arms, lower cranial nerves(glossopharyngeal nerve, accessory nerve) potential changes;(4)Recorded and compared the postoperative complications in two groups;(5) Compared to the same patient has the efficacy of the two operations. These contents were analyzed to evaluate which operation method had the better curative effect in treating ACMⅠassociated with SM.Results:(1)At 7 days, 3 months and one year after operation, criteria of Tator were adopted to evaluate the t total efficiency rate. The total efficiency rate of group B was higher than that of group A. With the time passing, the total efficiency rate of group B increased while the total efficiency rate of group A decreased. The curative effect of patients from both group had difference(P<0.05);(2) After operation, among 36 patients in group B, the cerebellum tonsil of 32 cases contract to the level above foramen magnum surface(88.89%); among 32 patients in group A, the cerebellum tonsil of 4 cases contract to the level above foramen magnum surface(12.50%).The comparison of both groups had significant difference(P<0.01). Among 36 patients in group B, the syringomyelia of 28 cases decreased or disappeared(77.78%) and there is no one case syringomyelia expanded; among 32 patients in group A, the syringomyelia of 15 cases shrank or disappeared(46.88%) and 3 cases expanded continuously, the comparison of both groups had statistical difference(P<0.05);(3) All of the patients had different degrees of SEP amplitude decreasing in different sites and the latency period prolonged. During the recheck at one year after operation, 22 cases in group B(61.11%) had higher SEP amplitude and shorter latency period and the lower cranial nerve self-generating electricity activity of 4 cases with later cranial nerve symptoms disappeared. At the same time, there only 3 cases in group A(9.38%) had higher SEP amplitude and shorter latency period. Three cases with later cranial nerve symptoms still can be checked out of self-generating electricity activity;(4) Ten cases and fourteen cases got headache separately in group A and group B.9 cases got postoperative fever in group A and 6 cases got postoperative fever in group B. Patients in group B had no difficulty in neck turning while four cases in group A had difficulty in neck turning or neck turning ache. In group B, 3 cases got subcutaneous hydrops or hematocele, 2 cases got leakage of cerebrospinal fluid(CSF) and 2 cases got undesirable healing in incision. In group A, 1 case got subcutaneous hydrops or hematocele, 1 case got undesirable healing in incision, no case got leakage of CSF. There was no case of death in both groups. There is no statistical significance between two groups(>0.05);(5)6 cases of patients who had revision operation, the symptoms, imaging examination and neurophysiology indexes are better than the first time of operation.Conclusion: Both operation ways are safe and effective. Tonsillectomy + reconstruction of the fourth ventricle outlet is superior to PFD in the operation curative effect, but the former one has higher requirements for surgical instruments and surgical technique. Postoperative complication between the group A and B had no Significant difference. Therefore, proper surgical ways shall be chosen according to specific conditions. The neurophysiological results is subjective and correct, so it is the effective way to evaluate the neurophysiological function and it is of great importance during the follow-up visit process of this disease.