Role of dynamic computed tomography scans in patients with congenital craniovertebral junction malformations

AIM To evaluate the role of dynamic computed tomography(CT)scan imaging in diagnosing craniovertebral junction(CVJ)instability in patients with congenital CVJ malformations.METHODS Patients with symptomatic congenital CVJ malformations who underwent posterior fossa decompression and had a preoperative dynamic CT scan in flexion and extended position were included in this study.Measurements of the following craniometrical parameters were taken in flexed and extended neck position:Atlanto-dental interval(ADI),distance of the odontoid tip to the Chamberlain’s line,and the clivus-canal angle(CCA).Assessment of the facet joints congruence was also performed in both positions.Comparison of the values obtained in flexion and extension were compared using a paired Student’s t-test.RESULTS A total of ten patients with a mean age of 37.9 years were included.In flexion imaging,the mean ADI was1.76 mm,the mean CCA was 125.4°and the mean distance of the odontoid tip to the Chamberlain’s line was+9.62 mm.In extension,the mean ADI was1.46 mm(P=0.29),the mean CCA was 142.2°(P<0.01)and the mean distance of the odontoid tip to the Chamberlain’s line was+7.11 mm(P<0.05).Four patients(40%)had facetary subluxation demonstrated in dynamic imaging,two of them with mobile subluxation(both underwent CVJ fixation).The other two patients with a fixed subluxation were not initially fixed.One patient with atlantoaxial assimilation and C23 fusion without initial facet subluxation developed a latter CVJ instability diagnosed with a dynamic CT scan.Patients with basilar invagination had a lower CCA variation compared to the whole group.CONCLUSION Craniometrical parameters,as well as the visualization of the facets location,may change significantly according to the neck position.Dynamic imaging can provide additional useful information to the diagnosis of CVJ instability.Future studies addressing the relationship between craniometrical changes and neck position are necessary.

Endoscopic endonasal approach to the craniovertebral junction

The surgical approach to lesions of the ventral craniovertebral junction(CVJ)has evolved significantly in the last several years with the advent of endoscopic skull base surgery.Differing pathologies of the CVJ can result in irreducible compression of the cervicomedullary region.The endoscopic endonasal approach lends itself well to this region due to the ventral location,and while there is a steep learning curve,is a safe and effective way to perform decompression of the cervicomedullary region.Herein,we discuss the anatomy of the CVJ,preoperative evaluation and surgical considerations,our surgical approach,complications,and outcomes.

Endoscopic endonasal approaches to the craniovertebral junction:The Otolaryngologist’s perspective

Objective:To review indications and techniques for the endoscopic endonasal approach to the craniovertebral junction(CVJ),analyze postoperative outcomes,and discuss important technical considerations.Methods:A retrospective analysis was performed on all patients undergoing endonasal endoscopic approaches to the CVJ from May 2007 to June 2017.Demographic information,presenting symptoms,imaging results,treatment course,postoperative functional status,and followup were recorded.Results:There was a total of 30 patients in this series,with a mean follow-up of 11.7 months.The average age was 33.6 years(range,5e75 years),with 18 females and 12 males.The majority of patients(n Z 22,73.3%)had Chiari malformation type 1 with basilar invagination and symptomatic cervicomedullary compression as the indication for surgery.Intraoperative cerebrospinal fluid leak(CSF)was noted in 3 cases of odontoid resection and a single case of skull base resection.There were no postoperative CSF leaks.Overall,81%of patients resumed regular diet by post-operative day 2(range,0e8 days).Severe postoperative dysphagia occurred in two cases with one requiring gastrostomy tube placement and another utilizing total parenteral nutrition for support prior to eventual gastrostomy.On average,patients were extubated by postoperative day 0.93(range 0e3 days),with 85%extubated by postoperative day 1.A tracheotomy was required in one patient.Conclusion:The endonasal endoscopic approach is a valuable technique for access to the CVJ with minimal disruption of respiratory and alimentary function.