The effect of neck flexion on oesophageal tension in the pig and its relevance to repaired oesophageal atresia.

The indications for postoperative ventilation and paralysis with neck flexion after repair of oesophageal atresia (OA) have been controversial, mainly because of a paucity of information on oesophageal compliance and the influence of posture on anastomotic tension. This study using a pig model demonstrates that 78.8% of oesophageal lengthening occurs between full flexion and the neutral position, contributing to an increase in oesophageal length of about 9%. Compliance of the oesophagus is a linear function of the natural log of the tension applied. These data imply that any postural change (e.g., head and neck flexion) that allows the oesophagus to shorten may produce an exponential reduction in the tension and suggest that the manoeuvre may be appropriate in long-gap OA where there is considerable tension across the oesophageal anastomosis.