Obstructive airway in Morquio A syndrome, the past, the present and the future

Abstract

Patients with severe tracheal obstruction in Morquio A syndrome are at risk of dying of sleep apnea and related complications. Tracheal obstruction also leads to life-threatening complications during anesthesia as a result of the difficulty in managing the upper airway due to factors inherent to the Morquio A syndrome, compounded by the difficulty in intubating the trachea. A detailed description of the obstructive pathology of the trachea is not available in the literature probably due to lack of a homogenous group of Morquio A patients to study at any one particular center. We present a series of cases with significant tracheal obstruction who were unrecognized due to the difficulty in interpreting tracheal narrowing airway symptoms. Our goal is to provide the guidelines in the management of these patients that allow earlier recognition and intervention of tracheal obstruction. Sagittal MRI images of the cervical spine of 28 Morquio A patients (12 ± 8.14 years) showed that19/28 (67.9%) patients had at least 25% tracheal narrowing and that narrowing worsened with age (all 8 patients over 15 years had greater than 50% narrowing). Eight out of 28 patients were categorized as severe (>75%) tracheal narrowing when images were evaluated in neutral head and neck position. Of the 19 patients with tracheal narrowing, compression by the tortuous brachiocephalic artery was the most common cause (n = 15). Evidence of such tracheal narrowing was evident as early as at 2 years of age. The etiology of tracheal impingement by the brachiocephalic artery in Morquio A appears to be due to a combination of the narrow thoracic inlet crowding structures and the disproportionate growth of trachea and brachiocephalic artery in relationship to the chest cavity leading to tracheal tortuosity. In conclusion, tracheal narrowing, often due to impression from the crossing tortuous brachiocephalic artery, increases with age in Morquio A patients. Greater attention to the trachea is needed when evaluating cervical spine MRIs as well as other imaging and clinical investigations, with the goal of establishing a timely treatment protocol to reduce the mortality rate in this patient population.

Hematopoietic stem cell transplantation for Morquio A syndrome

“…Respiratory failure with tracheal obstruction and restrictive lung is one of the most important causes of morbidity and mortality in patients with MPS IVA [10, 46]. None of patient treated with HSCT in this study showed any significant tracheal obstruction or respiratory problem until now.…”

Activity of daily living for Morquio A syndrome

“…Four patients completed the ADL study before and after ERT; one before and after HSCT and leg surgery; one before and after ERT and corrective tracheal surgery; and eight untreated patients at different time points. A 16-year-old male patient had been undergoing ERT for over 2.5 years but was experiencing worsening tracheal obstruction and severe respiratory distress (ADL score 30 at 15.9 years [28,70]). Near fatal tracheal obstruction was relieved by urgent trachea vascular reconstruction with marked improvement of his respiratory symptoms (ADL score 50.5 at 17.3 years).…”

“…Accumulation of these GAGs causes incomplete endochondral ossification, leading to characteristic skeletal features such as disproportionate dwarfism with a short trunk and neck, pectus carinatum, joint laxity, kyphoscoliosis, genu valgum, and pes planus [1,2,7–16]. Radiographic findings show dysostosis multiplex with universal platyspondyly, anterior beaking of the lumbar spine, flaring of the rib cage, tilted ulna, coxa valga, flattering femoral head, and epiphyseal dysplasia of joints [2,7,8,17–28]. Most patients become wheelchair-bound in their second decade of life and undergo multiple orthopedic surgeries to alleviate serious medical complications [14,23–25].…”

“…Common mortality and morbidity are due to spinal cord injury that leads to spinal cord compression and instability of C1–C2 joint and later, respiratory failure caused by obstructive trachea and restrictive lung [14,23–25,27–29]. Severe tracheal obstruction leads to a high mortality and morbidity [28,30,31]. Most patients with MPS IVA patients need multiple surgical procedures with a high-risk anesthetic care throughout their lives [32–36].…”

Widespread Vasculopathy in a Patient with Morquio A Syndrome

“…2,7 Vascular disease has also been described in these patients, although it was not present to the extent seen in our patient. 4,5,8 There appears to be a subset of patients with Morquio A syndrome who develop vascular disease, but the actual mechanism of the vascular changes is not known. One potential explanation is that collagen dysplasia of the vessels occurs secondary to the progressive changes in the collagen related to the skeletal system.…”