Midthoracic oesophageal diverticula represent 15% of all oesophageal diverticula. Most previous studies highlight the importance of a traction mechanism in the pathogenesis of oesophageal diverticula, especially in the middle third of the oesophagus because of its proximity to the tracheobronchial lymph nodes affected by inflammatory processes. The aetiology of diverticula has been clarified recently, and the association between midthoracic oesophageal diverticula and motor disorders, secondary to increased intraluminal pressure, has been stressed.
In the present case we hypothesise that the oesophageal diverticulum was related to relaxation of the diaphragm. The rise of the left hemidiaphragm would cause lack of space and consequently increased pressure in the left hemithorax. This would create a siphon-shaped angle at the gastro-oeosphageal junction, causing an increase in intraluminal oesophageal pressure. The subsequent disturbance in the movement of the oesophagus would induce the oesophageal diverticulum through a pulsion mechanism, on the right side because the left hemidiaphragm is affected. Due to the pathogenesis of the diverticulum, we did not perform anti-reflux surgery. We chose a left thoracotomic approach, even though the diverticulum was on the right side of the oesophagus, because we also had to perform the left diaphragmatic plicature.
This report demonstrates an association between left diaphragmatic relaxation and a midthoracic oesophageal diverticulum, not previously described in the literature, due not to specific motor disorders but to obstruction of the distal oesophagus as a result of diaphragmatic relaxation causing a siphon-shaped angle at the gastro-oesophageal junction. The particular ethiopathogenesis with a pulsion mechanism in this case shows that the relaxation is the main cause of this condition.
Plication is a valuable treatment for unilateral diaphragmatic paralysis, which improves patients’ dyspnoea and work ability. Because of the risk of aspiration and potential life-threatening pulmonary complications in some patients, surgery should be undertaken in all patients with thoracic oesophageal diverticula regardless of the presence or absence of symptoms. We did not perform a fundoplication or a myotomy but rather treated the diaphragmatic relaxation with plication because the relaxation was the first cause of the diverticulum and accompanying symptoms.
- Some midthoracic oesophageal diverticula are congenital in origin, others are caused by traction from contiguous mediastinal inflammation and adenopathy, while others, as in our case, have a different aetiology.
- Aspiration pneumonia may accompany large symptomatic diverticula, so surgery should be undertaken in all patients with thoracic oesophageal diverticula regardless of the presence or absence of symptoms.
- Surgical options usually include diverticulectomy with myotomy.
- In our case we did not perform a fundoplication or a myotomy but instead treated the diaphragmatic relaxation with plication because it was the first cause of the diverticulum and accompanying symptoms.