Introduction
Zenker's diverticulum, a propulsion diverticulum in the pharynx, was first described by Zenker and Ziemssen in 1877.Reference Zenker, Ziemssen and Ziemssen1 It develops due to an inherent pharyngeal weakness, first described by Killian in 1907,Reference Killian2 between the oblique fibres of the thyropharyngeus muscle and the horizontal fibres of the cricopharyngeus muscle.
Endoscopic pharyngeal stapling is a surgical management option widely used within the UK National Health Service, and is considered safe and effective.3 Where endoscopic access to the pouch is difficult, open or external approaches utilising myotomy, inversion, excision or diverticulopexy of the pouch have been described.Reference Weissbrod and Merati4 However, there is no published evidence or recommendation on how to approach diverticula with extension into the mediastinum, a situation for which both endoscopic stapling and traditional cervical approach external pharyngeal pouch surgery will be inadequate.
We describe two such cases in which thoracoscopic mobilisation of the pouch was performed using video-assisted thoracoscopic surgery, together with a traditional transcervical mobilisation and excision of the pouch.
Case reports
Case one
A 32-year-old man presented with a 6-month history of weight loss (10 kg) with longstanding and progressive symptoms of dysphagia, regurgitation and halitosis. He was free from significant cardiovascular, respiratory and neurological comorbidity.
An initial barium swallow study showed a large pharyngeal diverticulum (see Figure 1). Surgical treatment was therefore recommended.
Fig. 1 Barium contrast swallow study for the first case: (a) anteroposterior view; (b) lateral view. A large Zenker's diverticulum is demonstrated.
Because of the patient's young age and large pouch, an external cervical approach with pouch excision and external cricopharyngeal myotomy was discussed with him. A conventional skin crease incision was used, after packing the pouch endoscopically. However, the inferior mediastinal extent of the pouch could not be accessed, preventing delivery of the diverticulum into the surgical field, despite removing the pharyngeal packing. The procedure was abandoned, with no post-operative complication.
A detailed video-fluoroscopic examination and computed tomography (CT) scan of the neck and chest showed the large pouch extending from the level of the seventh cervical vertebra to the fourth thoracic vertebra.
We discussed with the patient a joint procedure involving synchronous thoracoscopically assisted mobilisation of the pharyngeal pouch together with cervical mobilisation plus myotomy and pouch excision. This procedure is described below.
Case two
A 66-year-old man presented to the general ENT clinic with a 4-year history of worsening dysphagia for solids associated with regurgitation of food. This was accompanied by choking and coughing. There was no haemoptysis, weight loss, otalgia or voice change. There was no cardiac, respiratory or neurological comorbidity. Physical examination was normal.
A barium swallow study demonstrated a large pouch with retention of food. The pouch was noted to be compressing the proximal oesophagus and entering the mediastinum. No aspiration of contrast was observed. Cross-sectional CT of the neck and chest was also undertaken.
Due to the size of the pouch, video-assisted thoracoscopic surgery with an external cervical approach was discussed with the patient.
Technique
The external approach pharyngeal pouch excision and cricopharyngeus myotomy with video-assisted thoracoscopic surgery was performed with the patient placed in a supine and reverse Trendelenburg position, with the neck extended on a shoulder roll and head ring. A double lumen endobronchial tube was used to facilitate single lung ventilation.
Rigid pharyngoesophagoscopy identified the pouch, allowing irrigation and removal of food debris together with placement of a nasogastric tube.
A 12-mm EndoPath Xcel bladeless optical trocar (Ethicon Endo Surgery, J & J Medical, Wokingham, UK) was used to access the pleural space via the seventh intercostal space, and was used as the camera port. Two 5-mm operating ports were positioned either side of the camera port, also in the seventh intercostal space (see Figure 2).
Fig. 2 Diagrammatic representation of placement of the thoracoscopic port in the seventh intercostal space, enabling surgical exposure of the trachea (shown in blue), aortic arch (red), oesophagus and Zenker's diverticulum (brown), and vagus nerve and recurrent laryngeal nerve (yellow).
With the lung collapsed, the posterior pleura was incised with a laparoscopic harmonic scalpel. Dissection of the posterior mediastinum and mobilisation of the distal oesophagus was then performed. Endoscopic packing and internal illumination of the pouch aided identification of the diverticulum during thoracoscopic dissection of the superior mediastinum and proximal oesophagus. The great vessels and the left recurrent laryngeal nerve (at its origin from the left vagus nerve) were identified and preserved (see Figure 3). A stay suture was placed in the fundus of the diverticulum to further facilitate thoracoscopic dissection.
Fig. 3 Thoracoscopic image demonstrating the descending aortic arch with the vagus nerve running over it. The recurrent laryngeal nerve (arrow) can be seen just as it divides.
A lateral cervical skin crease neck incision was used for the lateral pharyngotomy approach. Superior and inferior sub-platysmal flaps were raised in the standard fashion. The inferior portion of the thyroid lobe was mobilised and the recurrent laryngeal nerve identified. The diverticulum, now free from mediastinal attachments (see Figure 4), was delivered into the neck wound with the aid of a stay suture. The neck of the pouch was identified and excised using a linear stapler (TLC 75; Ethicon) and the staple line was oversewn. A myotomy of the cricopharyngeus muscle fibres was performed.
Fig. 4 Thoracoscopic image of the pharyngeal pouch, demonstrating endoscopic illumination from the oral cavity and adhesion of the inferior portion of the pharyngeal pouch.
The lung was then re-inflated and a nasogastric tube and suction drain were placed. In the first case, a suction drain was placed in the neck. In the second case, an additional chest drain was also placed. The wound was closed in layers using standard techniques.
In both cases, the diverticulum was intimately related to the great vessels in the superior mediastinum. Thoracic dissection provided a safe and controlled method of mobilising the Zenker's diverticulum from its mediastinal adhesions.
Results
Case one
During the first post-operative day, the suction drain in the neck was removed. A contrast swallow study performed on the second post-operative day showed no pharyngeal leakage. Sips of water were commenced, and the patient's oral intake was expanded to ‘free fluids’ on the third post-operative day and to a soft diet on the fourth day. An asymptomatic apical right pneumothorax was treated on day 5 with a small (20 Fr) pleural drain, removed on day 6. The patient was discharged on the seventh post-operative day. Reduced movement of the right vocal fold was seen initially following surgery, but this had resolved at the three-month follow-up appointment. Thirty months after surgery, the patient was well and symptom-free.
Case two
In this patient, a nasogastric tube was used to provide enteral nutrition for the first 4 days post-operatively. A contrast swallow study on the fourth post-operative day showed no leakage along the pharyngeal staple line. Sips of fluid were started, with oral intake expanding to a soft diet by the sixth day. The suction chest drain was removed on the fifth day. The patient was discharged home on the seventh post-operative day. Twenty-four months after surgery, he was well and symptom-free.
Discussion
Zenker's diverticulum is estimated to have a prevalence of 2 per 100 000 in the UK population,Reference Siddiq, Sood and Strachan5 although this is believed to be an underestimate. The majority of pharyngeal pouches occur in men in their seventh decade. An endoscopic approach is usually suitable as these patients often have comorbidity and average-sized pouches. In cases of unfavourable anatomy, alternative approaches have been reported, using a combined open and endoscopic approach in the neck.Reference Dale, Burgess and Corbridge6 However, large diverticula present different challenges and risks. The present report describes a new and innovative application of existing techniques, performed with inter-specialty collaboration, in order to surgically treat a large Zenker's diverticulum with mediastinal extension.
The prevalence of large pouches, and pouches with mediastinal adhesions, is not well reported. However, Zenker's diverticula are common, and large Zenker's diverticula are likely to present in the practising lifetime of a head and neck surgeon. It is believed that large diverticulum size is a risk factor for failure of surgery, symptom recurrence and the need for further surgery.Reference Visosky, Parke and Donovan7 What size pharyngeal pouch should be described as large is not widely accepted, but a length of greater than 4 cm has been suggested.Reference Siddiq, Sood and Strachan5 Extremely large or huge pouches are not well reported in the literature; however, Tulinsky and DostalikReference Tulinsky and Dostalik8 have described a diverticulum extending into the right hemi-thorax, treated with open thoracic surgery.
Whilst a thoracoscopic approach to the oesophagus is used regularly by laparoscopic oesophageal surgeons, the use of this approach to treat a Zenker's diverticulum has not previously been described. There are reports of the use of a thoracoscopic approach to access retrosternal thyroid goitres.Reference Oey, Richardson and Waller9, Reference Tsai, Cameron and Wang10 The thoracoscopic approach has the advantage of allowing surgery to be performed without a median sternotomy, decreasing the morbidity of the procedure.
• Zenker's diverticulum occurs in at least 2 per 100 000 in the UK
• Large pouches are thought to have a higher recurrence rate and increased need for revision surgery
• Video-assisted thoracoscopy can be used to safely dissect large diverticula from mediastinal structures, and also facilitates safe excision and myotomy to prevent recurrence
Our cases demonstrate a successful approach to treating huge Zenker's diverticula, with low post-operative morbidity. This method avoids the need for a median sternotomy to access the diverticulum. It provides an example of how close collaboration between specialties enables improvements in the surgical care of patients.
