Midthoracic diverticulum is a rare disease (15% of all oesophageal diverticula), most commonly secondary to tracheobronchial lymph nodes affected by inflammatory processes. A midthoracic diverticulum is usually a traction diverticulum, produced by continued peristalsis of the oesophagus against a fixed oesophageal adhesion. The majority of these diverticula are the result of oesophageal motility disorders, due to a lack of coordination between the distal oesophagus and lower oesophageal sphincter (LES).¹ The symptoms of midthoracic oesophageal diverticulum vary widely, ranging from primary symptoms, such as dysphagia and regurgitation, to oesophagitis, bleeding and chest pain.^{2 3} Many patients with small diverticula are asymptomatic, and therefore surgical management is usually reserved for patients with larger symptomatic diverticula.⁴ In most published series, oesophageal diverticulectomy has been performed via thoracotomic or thoracoscopic approaches.⁵

Oesophagogastroduodenoscopy and oesophageal barium radiography showed a giant midthoracic oesophageal diverticulum and chest x-ray showed left diaphragmatic relaxation.

The patient (figure 2) underwent a left posterolateral thoracotomy. After division of the triangular ligament, the oesophagus was mobilised (figure 2A) and a giant midthoracic diverticulum was found strictly adherent to the superior vena cava, aorta and right mediastinic pleura. The diverticulum was mobilised from adjacent tissues and the point of origin from the oesophageal muscle was identified. After mobilisation of the neck of the diverticulum, it was excised using a TA55 roticulator (figure 2B). The oesophageal muscle layers over the stump of the diverticular neck were approximated using 3-0 polydioxanone interrupted sutures (figure 2C). Finally, a diaphragmatic plicature using an interrupted non-absorbable suture was performed (figure 2D).

There were no intraoperative complications and the postoperative course was uneventful. A gastrographin swallow did not show any sign of leakage, and chest x-ray showed the left side of the diaphragm had returned to its normal site (figure 3A,B). The patient was discharged in the 11th postoperative day; after 1 year the patient is asymptomatic and has gained 5 kg in weight.

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.