Vessel shape alterations of the vertebrobasilar arteries in Mucopolysaccharidosis type IVa (Morquio A) patients

Classifying vertebral artery anatomy abnormality in children with skeletal dysplasia

PURPOSE

Skeletal dysplasia (SKD) have predictably abnormal occipitocervical skeletal anatomy, but a similar understanding of their vertebral artery anatomy is not known. Knowledge and classification of vertebral artery anatomy in SKD patients is important for safe surgical planning. We aimed to determine if predictably abnormal vertebral artery anatomy exists in pediatric SKD.

METHODS

We performed a retrospective review of CTAs of the neck for pediatric patients at a single institution from 2006 to 2018. CTAs in SKD and controls were reviewed independently in blinded fashion by two radiologists who classified dominance, vessel curvature at C2, direction at C3, and presence of fenestration and intersegmental artery.

RESULTS

14 skeletal dysplasia patients were compared to 32 controls. The path of the vertebral artery at C2 foramen was no different between the cohorts or by side, right (p = 0.43) or left (p = 0.13), nor for medial or lateral exiting direction from C3 foramen on right (p = 0.82) or left (p = 0.60). Dominance was most commonly neutral in both groups (71% in SKD and 63% in controls). There were no fenestrated nor first intersegmental arteries in our cohort.

CONCLUSION

No systematic differences were detected between SKD and control patients with respect to vertebral artery anatomy. Nonetheless, surgically relevant variability was observed in both groups. Paying particular attention to the direction of exit at C3 and curvature at C2 with respect to the foramen and vessel dominance are important and easily classifiable abnormalities that both surgeons and radiologists can use to communicate and employ in pre-operative planning.

LEVEL OF EVIDENCE

III.

Best practice guidelines for management of spinal disorders in skeletal dysplasia

BACKGROUND

Disorders of the spine present a common and difficult management concern in patients with skeletal dysplasia. Due to the rarity of these conditions however, the literature, largely consisting of small, single institution case series, is sparse in regard to well-designed studies to support clinical decision making in these situations.

METHODS

Using the Delphi method, an international, multi-disciplinary group of individuals, with significant experience in the care of patients with skeletal dysplasia, convened to develop multi-disciplinary, "best practice" guidelines in the care of spinal disorders in patients with skeletal dysplasia.

RESULTS

Starting with 33 statements, the group a developed a list of 31 "best practice" guidelines.

CONCLUSIONS

The guidelines are presented and discussed to provide context for clinicians in their decision making in this often-challenging realm of care.

Intravenous Enzyme Replacement Therapy in Mucopolysaccharidoses: Clinical Effectiveness and Limitations

The aim of this review is to summarize the evidence on efficacy, effectiveness and safety of intravenous enzyme replacement therapy (ERT) available for mucopolysaccharidoses (MPSs) I, II, IVA, VI and VII, gained in phase III clinical trials and in observational post-approval studies. Post-marketing data are sometimes conflicting or controversial, possibly depending on disease severity, differently involved organs, age at starting treatment, and development of anti-drug antibodies (ADAs). There is general agreement that ERT is effective in reducing urinary glycosaminoglycans and liver and spleen volume, while heart and joints outcomes are variable in different studies. Effectiveness on cardiac valves, trachea and bronchi, hearing and eyes is definitely poor, probably due to limited penetration in the specific tissues. ERT does not cross the blood-brain barrier, with the consequence that the central nervous system is not cured by intravenously injected ERT. All patients develop ADAs but their role in ERT tolerance and effectiveness has not been well defined yet. Lack of reliable biomarkers contributes to the uncertainties about effectiveness. The data obtained from affected siblings strongly indicates the need of neonatal screening for treatable MPSs. Currently, other treatments are under evaluation and will surely help improve the prognosis of MPS patients.

Cochlear Implantation via the Transmeatal Approach in an Adolescent with Hunter Syndrome-Type II Mucopolysaccharidosis

Type II mucopolysaccharidosis (MPS II) commonly known as Hunter syndrome, is a rare X-linked lysosomal storage disorder caused by iduronate-2-sulfatase deficiency, which in turn causes otorhinolaryngological manifestations, including sensorineural hearing loss (SNHL). Previously, the median survival age of patients with MPS was approximately 13.4 years. However, in the era of enzyme replacement therapy and other multidisciplinary care modalities, the life expectancy has increased. Herein, we report a rare case of an adolescent with MPS II who underwent SNHL treatment with cochlear implantation (CI). Based on unexpected findings of mastoid emissary veins and overgrowth of the vessels around the temporal bone, CI was performed using the transmeatal approach instead of the conventional transmastoid method, to avoid damage to the vessels. The average hearing threshold after CI was 35 dB and no surgical complications were encountered. Adolescent MPS II may present vessel abnormalities, which can reduce the success rate of surgery. In patients with MPS II with SNHL, CI should be performed under careful monitoring of vessel overgrowth. Moreover, with regard to feasibility of CI in adolescent patients with MPS II with SNHL, surgical techniques such as the transmeatal approach should be selected based on adequate assessment of the case.