Abstract
Objective: To assess the effect of spinal surgery and nocturnal ventilation on lung function and survival in patients with scoliosis secondary to Duchenne Muscular Dystrophy.
Study design: Prospective, observational study by a single observer (Research Physiotherapist).
Subjects: 80 patients with Duchenne Muscular Dystrophy were treated between 1986 and 2002. During this period 40 patients underwent a spinal fusion at a mean age of 14.05y (95 % CI 13.6 – 14.6). Nocturnal ventilation was commenced when symptoms and signs of respiratory failure were evident. The mean FVC at commencement of nocturnal ventilation was 0.41 litres. The patients were divided into 2 groups based on whether they received nocturnal ventilation. A total of twenty eight patients received nocturnal ventilation and 52 did not. The groups were further sub-divided based on whether they had spinal fusion. There were fourteen patients in each sub-group of the ventilated group and 26 patients in each sub-group of those that were not ventilated.
Outcomes: Serial forced vital capacity (FVC) measurements and survival measured by Kaplan Meir survival analysis.
Results: The mean vital capacity dropped from 1.41 l (95 % CI 1.21 – 1.61) to 1.13 (95 % CI 0.893 – 1.37), a year post-operatively. This was not associated with the development of respiratory compromise. The vital capacity improved gradually, reaching the pre-operative level before it declined again. The shortest survival was seen in patients who received neither surgery nor ventilation (median survival 19.7y). The patients who received surgery but no ventilatory support were not as good as the patients that were ventilated but did not have surgery (median survival 24.3y). The best results were seen in the patients who had both surgery and ventilation (median survival 26.4y). The worst prognosis is in patients with early onset symptomatic cardiomyopathy (6 patients, with a median survival of 16.3y).
Conclusion: Nocturnal ventilation is the most important factor in the improvement in survival of patients with Duchennes muscular dystrophy. Spinal surgery is also beneficial and the best results are in those patients who have both.
The abstracts were prepared by Mr Peter Millner. Correspondence should be addressed to Peter Millner, Consultant Spinal Surgeon, Orthopaedic Surgery, Chancellor Wing, Ward 28 Office Suite, St James’ University Hospital, Beckett Street, Leeds LS9 7TF.
