[Posterior decompression of the craniovertebral junction in syringomyelia combined with Chiari-1 malformation in children]

[Results of surgical treatment of children with Chiari I malformation using differentiated intraoperative tactics of choosing the volume of intervention]

BACKGROUND

Despite the presence of numerous publications and analytical reviews in the foreign literature, there is no universally accepted algorithm for the surgical treatment of Chiari I malformation (MC I) in children. Moreover, in the domestic literature, the number of publications devoted to the problems of surgical treatment of MC I in children is significantly limited, which, in our opinion, this is the reason for the relevance of this work.

OBJECTIVE

To study the results of surgical treatment of children with MC I when applying differentiated tactics of intraoperative choice of intervention volume.

MATERIAL AND METHODS

The results of neurological examination and surgical treatment of 43 patients aged from 1 to 17 years (mean age 8.48 years) were analyzed. The decision on the need for duraplasty was made intraoperatively when signs of persisting compression of subarachnoid spaces after extradural decompression were detected. Clinical manifestations were assessed according to neurological data before discharge, as well as in long-term period with a follow-up from 6 months to 5 years via survey.

RESULTS

Duraplasty was required in 28% of cases. Respiratory disorders disappeared in all patients immediately after surgery and were absent thereafter. Positive dynamics was noted in terms of restoration of the rate of speech development. Headache persisted in 7 (21%) patients, movement, sensation disorders and cerebellar symptoms - in 4 (12%), vomiting and bulbar symptoms - in 2 (6%) patients. There was no difference in the efficacy of surgery with and without duraplasty. None of the parameters evaluated preoperatively had a significant association with the intraoperative decision on the need for duraplasty.

CONCLUSION

In our opinion, final decision on surgical strategy in children with Chiari malformation type I should be made considering intraoperative assessment of extradural decompression. The last one is probably associated with individual characteristics of patients.

Management of Chiari type I malformation: a retrospective analysis of a series of 91 children treated surgically

INTRODUCTION

The diagnosis of Chiari I malformation, its symptomatology, and the results of its surgical management are still discussed. We report a pediatric series of CMI without associated skull base malformations or cerebellar growth anomalies operated between 2001 and 2018.

MATERIAL AND METHODS

Ninety-one children out of 146 surgically treated cases have been included in the study. Age at surgery ranged from 5 months to 17 years clinical data, and complementary examinations leading to the surgical indication have been analyzed together with the surgical outcomes. The average follow-up duration was of 4 years. The occipito-cervical decompression with duraplasty without opening the arachnoid was the procedure of election. Three quarters of patients presented with headaches, 12% with cerebellar syndrome, 13% with vertigo, 26% with nausea or vomiting, 24% with sensorimotor deficits, 11% with cranial nerve deficits, and 29% with other symptoms. Eighteen percent of patients suffered from scoliosis, 47% had an associated syrinx and 16% a ventricular dilation.

RESULTS

After the treatment, the clinical symptomatology improved in about three-quarters of the patients: headache (69.4%), nausea or vomiting (66.7%), sensorimotor deficits (55.6%), and other symptoms (78.3%). Syringomyelic cavities diminished partially in size or disappeared in 58.3% of patients, remained stable in 29.2%, and worsened in 12.5%. Only one-third of children with preoperative scoliosis benefited from the surgical treatment. No clinical signs or symptoms were found to be reliable predictors of surgical success, neither the extent of the cerebellar tonsil descent.

CONCLUSION

Occipito-cervical decompression allows to improve the clinical condition in the majority of children with symptomatic CMI in the absence of associated cervico-spinal junction alterations, craniosynostosis, or cerebellar growth anomalies. No clinical signs or symptoms neither radiological criterion appear to be a specific finding for the surgical indication.

Interlayer dural split technique for Chiari I malformation treatment in adult-Technical note

OBJECTIVE

To present an alternative surgical technique in treating cases of Chiari I Malformation with mild-to-moderate syringomyelia after decompressive suboccipital craniectomy: incising only the outer layer of the dura mater, then dissecting it from the inner layer without opening the latter.

PATIENTS AND METHODS

We utilized this technique in a short series of three cases who were admitted to our department for mild symptoms such as intermittent headache and dissociated sensory loss in the upper limbs, caused by a Chiari Malformation Type I. The patients were placed in the sitting position. We performed a reduced median suboccipital craniectomy and resection of the posterior arch of C1 adapted to the level of tonsil descent, from a limited superior half to complete resection. Afterward, we incised the outer dural layer, while sparing the inner one. Using a fine dissector, we then split apart the outer and inner layers to the margin of the craniectomy. Through the transparency of the inner layer and the arachnoid, the cerebellum and the medulla were visible and pulsating. An autologous fascia duraplasty was then performed.

RESULTS

The postoperative course was favorable in all cases, the patients being discharged without any deficits and with complete symptom resolution. Follow-up at 3, 6, and 12 months after surgery revealed a significant reduction in brainstem compression and syringomyelia.

CONCLUSIONS

Interlayer dural split technique can be used effectively in treating symptomatic cases of type I Chiari malformation in adults, with mild-to-moderate syringomyelia. It is less invasive than opening the dura and possibly more effective than decompressive craniectomy and C1 laminectomy alone. This technique must be validated in a larger case-control series.