Case Reports

Sanjeeta Umbarkar*, EM Santhosh Kumar**

Abstract

This is a case report of Anaesthesia and perioperative management for atlanto-occipital fusion in a child aged 7 years with unstable neck – Morquio’s syndrome under General anaesthesia. Morquio’s disease is Mucopolysaccharidoses type 4 and children with this disease are known for difficult intubation in view of anatomical airway anomalies. The associated multiple congenital anomalies can predispose to cardiovascular and respiratory complications in the perioperative period. Our patient had an uneventful intraoperative course but 24 hours later in postoperative period the child had an episode of endotracheal tube blockade when the child was kept on prophylactic ventilatory support which was managed appropriately.
The child was discharged from the postanaesthesia care unit 48 hours postoperatively and was discharged from the hospital on the 9th postoperative day.

Introduction

This is an account of anaesthesia for atlanto-occipital fusion in a boy aged 7 years who suffers from Morquio’s syndrome. This condition is rare but poses some problems of wider interest to anaesthesiologists.

Morquio and Brailford both described the syndrome independently in 1929.1 The disease is fourth in a group of mucopolysaccharidoses and the metabolic defect is caused by a deficiency of N-acetylhexosamine sulphate sulphatase.

Case Report

The patient, a 7 year old child, was born after a nonconsanguineous marriage, uneventful pregnancy and delivery. He weighed 12 kg and measured 94 cms in height. His elderly female sibling, also a diagnosed case of Morquio’s syndrome, died at the age of 9 years due to respiratory failure. His other female sibling was normal, as were her parents. His deformities were first recognised by an ophthalmologist during school health programme and was later referred to the Paediatric and Orthopaedic clinics.

In early infancy, he was noticed to have a barrel shaped chest (Fig. 1) and later he was of small stature. During early childhood, the skeletal deformities became increasingly evident and he walked with difficulty. He had a flat feet, short neck, and a semicrounching stance. Also had frontal bossing, depressed nasal bridge, exophthalmos, increased intercanthal distance, corneal clouding, lowest ears, and valgus deformities in both upper and lower extremities, dorsolumbar kyphosis, pectus excarinatum, pot belly and umbilical hernia (Fig. 2). He had diminished acuity of vision. However, mental ability remained normal. He had one episode of febrile convulsion at the age of 6 months. Range of movements in shoulder and elbow joints were increased. Cardiovascular, Gastrointestinal and Neurological examinations were clinically normal.

The dentition was normal and was Mallampatti class 3 in airway assessment. Neck movements were adequate except for restricted lateral flexion. Radiology of spine revealed flattened vertebral bodies with anterior and posterior projections involving C1 vertebra (Fig. 3) with mild atlantoaxial dislocation and cord compression. There was partial congenital fusion of C2 and C3 vertebral bodies. Other long and short bones were hypoplastic (Fig. 4). The ribs showed flattening at their anterior ends. Radiology of the skull and brain showed prominence of 4th ventricle (Fig. 3) but no evidence of demyelination or vacculation as expected in the mucopolysaccharidoses. Echocardiography showed thickened aortic valve with good biventricular function.

The child was prepared for elective atlanto-occipital fusion. Written informed high risk consent was taken. As child was cooperative, one peripheral intravenous access was obtained with a 22 G cannula. Intravenous Glycopyrrolate was given for antisialogogue effect. Induction was done with intravenous propofol 2 mg/kg. Laryngoscopy was done and Cormack Lehanne grade 2 visualisation of the laryngeal inlet was obtained. After confirming adequacy of ventilation, intubation was done with a 5.0 portex uncuffed endotracheal tube facilitated by Atracurium. Intravenous Midazolam 0.03 mg/kg and Fentanyl 2 mg/kg were administered postintubation. Sevoflurane and Atracurium were used for maintenance of anaesthesia. Sp02, ETCO2, BP by non-invasive sphygmomanometer and heart rhythm by cardioscope were monitored intraoperatively and in addition arterial blood gases and serum electrolytes were monitored postoperatively. The surgery was done with all reasonable speed by a senior surgeon. Intraoperative course was uneventful.

Minerva jacket was applied for postoperative immobilisation and it was decided to give elective ventilatory support for 24 hours. Inspite of aggressive treatment with antibiotics, suctioning and chest physiotherapy, there were copious secretions and the endotracheal tube was blocked 30 hours postsurgery. The Minerva jacket was cut on emergency basis and reintubation was done nasally and was extubated 48 hours postoperatively after appropriate correction of the acidosis and hypokalaemia which were responsible for the extended elective ventilation. Further course of stay in the hospital was uneventful and the child was discharged on the ninth postoperative day.

Fig. 1 : Patient showing barrel shaped chest	Fig. 2 : Patient showing 1. frontal bossing, 2. flexed neck, 3. pectus excarinatum, 4. cubitus valgus, 5. knock knees alongwith small stature
Fig. 3 : Showing flattened vertebral bodies with anterior and posterior projections involving C1 vertebra. Also showing prominent 4th ventricle	Fig. 4 : Showing flattened ribs at anterior ends

Discussion

Morquio’s syndrome includes the following features: kyphosis, large mobile joints, pigeon chest and most important, an unstable neck due to a degenerate odontoid peg which was liable to cause cord damage.

Other features include – aortic valve disease of varying severity, corneal clouding, and nerve deafness. They are dwarfs with typical knock-kneed gait. Other clinical features include characteristic facies, pectus carinatum, prominent rib margins, thoracic kyphosis, lumbar gibbus, prominent joints and flat feet.1,2 Recurrent umbilical and inguinal herniae are frequent.3 Cardiac involvement is usual. Valve involvement may cause incompetent or stenotic lesions especially of the aortic valve,4,5 whilst myocardial deposits cause reduced compliance.4 Systemic and pulmonary hypertension may occur and death is often due to cardiac or respiratory failure.3

The biochemical abnormalities include positive Berry spot tests and elevated urinary mucopolysaccharides. Roentgenographic criteria6 for diagnosis include universal polyspondyly, odontoid dysplasia, progressive coax valga, dysplastic changes in the femoral capital epiphyses and conical bases of metacarpals.
Spastic quadriplegia and respiratory paralysis are common in late stages of the disease1 which are attributable to compression of the spinal cord secondary to atlanto-axial subluxation due to odontoid dysplasia or hypoplasia. It was stated that if diameter of the spinal cord is 14 mm or less at the level of the odontoid process, cord compression will always supervene;7 but the degree of instability and supervening trauma may be important contributing influences.

The particular dangers facing an anaesthesiologist are the possibility of fatal spinal cord transection if the atlanto-axial joint subluxates because of muscular relaxation, limitation of spontaneous ventilation and postoperative coughing due to kyphosis and pigeon chest, difficulties with intubation due to flattened face, the dangers of low cardiac output due to aortic valve disease, poor vision, deafness, and the mental trauma of multiple hospital admissions, all of which inhibit cooperation.8 The skin is thickened and this combined with stiff joints may make venous access difficult.3 We did not face any difficulties in taking venous access and the child was very cooperative.

An antisialogogue is an essential component of preanaesthetic medication in view of the copious upper airway secretions, and antibiotic prophylaxis is advised in view of the high incidence of cardiac valvular lesions. Inhalational induction is difficult and potentially hazardous because of the problems of venous access and maintenance of an adequate airway. The airway may be improved by placing a sandbag under the patients’ shoulders.3 It is documented that tracheal collapse can occur when the neck is flexed and some of these patients maintain a degree of neck extension.9 Laryngoscopy is usually difficult.3 Intubation has been successful but often a smaller endotracheal tube has had to be used.3 Nasal intubation even for the insertion of a nasopharyngeal airway may be impossible due to the nostrils being blocked with dried secretions.3 Laryngoscopy and intubation were easier in our case and we did a successful nasotracheal intubation when the tube has to be changed in the postanaesthesia care unit.

Postoperative Considerations

Recovery may be slow and is often accompanied by periods of breath holding, bronchospasm and cyanosis. One of the reasons for elective postoperative ventilation is susceptibility to prolonged effects of nondepolarising muscle relaxants. There have been several documented cases of postoperative respiratory obstruction,10,11 which may be fatal.10 An anaesthetic sequence that ensures the early return of consciousness and airway reflexes is therefore recommended. These children are mouth breathers, as the nose is often blocked by secretions. They are predisposed to frequent chest infections and it is important to keep the patients well hydrated perioperatively and arrange for regular chest physiotherapy. Early use of antibiotics to control chest infections is recommended.3 Tracheostomy may be difficult due to short neck and abnormal trachea.3

Conclusion

The operation advocated by most authors for atlanto-axial instability is posterior cervical fusion.13-15 Because posterior cervical fusion is often done with immobilisation of head and neck, the risks in small children15 must be considered along with the dangers inherent in operating on a neck that is unstable. The risks must be weighed against the probability that cord damage will eventually occur if the instability is left untreated.

References

1. 1. Mckusick V. Heritable diseases of Connective tissue. 4th edn, Mosby, St.Louis, Missouri, USA. 1972 : p.583.
2. Spranger JW, Langer LO,JR, Weidemann HR. Bone dysplasias. An Atlas of Constitutional Disorders of Skeletal Development. Philadelphia.W.B.Saunders, 1974.
3. King DH, Jones RM, Barnett MB. Anaesthetic considerations in the Mucopolysaccharidoses. Anaesthesia 1984; 39 : 126-31.
4. Renteria VG, Ferrans VJ, Roberts WC. The heart in the Hurler syndrome. The American Journal of Cardiology 1976; 38 : 487-501.
5. Ireland MA, Rowlands DB. Mucopolysaccharidosis type 4 as a cause of mitral stenosis in an adult. British Heart Journal 1981; 46 : 113-15.
6. Stephen J Lipson, Boston, Massachusetts. Dysplasia of the odontoid process in Morquio’s syndrome causing Quadriparesis. The Journal of Bone and Joint Surgery 1977; 3 : 340-44.
7. Greenberg AD. Atlanto-Axial Dislocations. Brain 1968; 91 : 655-84.
8. Keith J Birkinshaw. Anaesthesia in a patient with an unstable neck; Morquio’s syndrome. Anaesthesia 1975; 30 : 46-49.
9. Pritzker MR, King RA, Kronenberg RS. Upper airway obstruction during head flexion in Morquio’s disease. The American Journal of Medicine 1980; 69 : 467-70.
10. Woolley MM, Morgan S, Hays DM. Heritable disorders of Connective tissue, Surgical and anaesthetic problems. Journal of Pediatric Surgery 1967; 2 : 325-31.
11. Suzuki M, Tsukakoshi M, Ashizawa N, Fukunaga A. The anesthetic management of mucopolysaccharidosis. Japanese Journal of mucopolysaccharidosis. Japanese Journal of Anesthesiology 1976; 25 : 977-81.
12. Kopitz SE, Perovic MN, Mckusick Victor, Robinson RA, Bailey JA 3. Congenital Atlantoaxial dislocations in various forms of Dwarfism. In proceedings of the American Academy of Orthopaedic Surgeons. J Bone and Joint Surg 1972; 54-A : 1349-50.
13. Minderhoud JM, Brackman R, Penning L. Os Odontoideum. Clinical, Radiological and Therapeutic aspects. J Neurol Sciences 1969; 8; 521-44.
14. Wadia NH. Myelopathy Complicating Congenital Atlanto-Axial Dislocation (A study of 28 cases). Brain 1967; 90 : 449-72.
15. Kopits SE, Steingass MH. Experience with the “Halo-Cast” in small children. Surg Clin North America 1970; 50 : 935-43.