Tips for improving access in endoscopic stapling of pharyngeal pouch

Abstract

Endoscopic stapling is the preferred technique for treatment of symptomatic pharyngeal pouches. The use of stapling with a standard pharyngoscope can be successful in difficult access patients. This modification of the technique can prevent the conversion of an endoscopic approach to an open approach.

Background

Zenker’s diverticulum (ZD) is an acquired outpouching through Killian’s dehiscence in the inferior constrictor muscle bounded by the oblique thyropharyngeus fibres superiorly and the transverse fibres of the cricopharyngeus inferiorly. It is a typical pulsion diverticulum (a false diverticulum is formed of mucosa and submucosal layers only) occurring dorsally. The first description of ZD was in 1769 by Ludlow, however, the pathologist Friedrich Albert von Zenker, recognised the pathophysiology in 1877.¹ The current treatment options are rigid endoscopic transoral stapling, CO2-laser myotomy or Dohlman’s procedure, endoscopic harmonic scalpel diverticulotomy, flexible transoral diverticulotomy or cricopharyngeal myotomy and an open approach repair. The first option is recognised as the standard approach by the National Institute for Health and Care Excellence.²

Rigid endoscopy is difficult in patients with short necks, decreased hyomental distance, prominent cervical osteophytes, poor dentition, fused cervical vertebrae, high body mass index and insufficient protection of the diverticulum sac by the dorsal oesophageal wall.^{3 4} The Weerda diverticuloscope is a popular instrument used for position and access to the pharyngeal diverticulum. However, it is bulky and can be extremely difficult for the operator to position adequately and safely in difficult access neck.⁴ The endoscopic approach has failed in 16%–68% of patients.³ In a series of 337 patients, 3.9% of surgeries were abandoned due to inadequate exposure.⁵

Case presentation

A 57-year-old man presented to the ENT clinic with a history of progressive dysphagia and regurgitation. His barium swallow confirmed a 5 cm pharyngeal pouch (large according to Morton’s system) occupying two cervical vertebrae (C5, 6). He had two unsuccessful attempts for endoscopic stapling of the pouch by two different surgeons using Weerda diverticuloscope under general anaesthesia. The first surgery was abandoned as for difficult access due to prominent teeth, limited mouth opening, a receding mandible and cervical spondylosis. The second attempt was done by a head, neck surgeon who did not achieve complete satisfactory stabling of the pouch. The patient had persistent symptoms of dysphagia, cough and weight loss postoperatively. After his second surgery, the head, neck surgeon relisted him again for an open approach after discussing the risks and recurrence rate compared with the endoscopic approach. The patient has been consented for the external approach with the agreement to attempt the modified endoscopic technique at the beginning of the surgery before proceeding with the external approach.

Treatment

A Negus pharyngoscope (figure 1) is advanced until the distal end of the instrument rests in the oesophagus. A 0° 4 mm Sorz Hopkin rod is introduced initially through the lumen of the endoscope to confirm depth and length of the pouch (5 cm) and its healthy surface mucosa. The shaft of the stapling device (Ethilcon endopath ETS Flex 45) is rotated 180°, and advanced down the pharyngoscope. The 0° rod is then introduced transorally alongside the pharyngoscope to visualise the pouch (figure 2) and the shorter blade of the stapler to ensure full engagement of the cricopharyngeal bar within the jaws of the stapler. The fine staple blade (anvil jaw) is inserted into the pouch and the upper stubbier, longer blade (cartridge jaw) follows the pharyngoscope and passes into the oesophagus. The gun is then activated (figure 3).

Figure 1.

Standard pharyngoscope used to visualise pharyngeal pouch.

Figure 2.

The use of 0° endoscope alongside the pharyngoscope in the oropharynx.

Figure 3.

The Modified endoscopic technique showing successful stapling.

Outcome and follow-up

The surgery was successful without the need for the open approach. The Negus endoscope allowed better visualisation of the pouch and full engagement of the stapler into cricopharyngeal bar. The patient’s symptoms resolved postoperatively at the follow-up appointment. No further recurrence of the symptoms in the following 2 years.

Discussion

Pharyngeal pouches are developed from incoordination in pharyngeal contraction and increased intrabolus pressure.³ Morton system classified pouches into small (less than 2 cm), medium (2–4 cm) and large (larger than 4 cm).⁶ Another radiological correlation scheme by Brombart was designed to assess the response to treatment where type I is the visible pouch during contraction of upper oesophageal sphincter and type IV is the large, compressing pouch to the surrounding.³ The main goal of surgery is cricopharyngeal myotomy.³ Weerda diverticuloscope can still be challenging in the difficult access neck despite modification and shortening of the anvil jaw of the stapling device.^{4 6} The redundant 5 mm distal tip of the stapler could give false impression of residual pouch on the postoperative barium swallow.⁶ The endoscopic visualisation of the pouch with Hopkin rod is essential before the application of the stapler. It is interesting to note that Martin-Hirsch and Newbegin described a Negus pharyngoscope in their original operation for pharyngeal pouches before the Dohlman pharyngoscope was available at the time.⁴ A similar technique has been reported in the literature 12 years ago. However, the author recommended passing a 0° 4 mm telescope down the sidearm of the Negus pharyngoscope.⁴ We found this difficult as the shaft of the stapler (12 mm diameter) filled all the lumen of the pharyngoscope (internal diameter 13 mm), precluding the insertion of the endoscope and visualisation of the pouch. This modification was helpful in aiding visualisation during stapling in difficult access patients. An alternative scope would have been the Oxford Universal Pouch Scope (Roberts Surgical Healthcare) which was not available in our trust. It is designed to insert the Hopkin rod alongside the stapling gun. Bola et al recommended the initial use of oxford pouch scope in the stapling of pharyngeal diverticulum then Weerda scope if limited visualisation; finally reserving the Negus scope for the most difficult access.⁶ This recommendation is consistent with our choice of Negus scope as a last attempt to overcome the previous failure with Weerda diverticuloscope. Other known options would have been the CO2 Laser or harmonic scalpel.³ It would have been difficult to focus the micromanipulator beam indicator of the microscope on the cricopharyngeal bar due to difficult access, thus, complete laser myotomy could have been challenging as well. It is recommended in the consent process of revision previously failed endoscopic stapling to highlight possibility of external approach. Bola et al reported 17% failure rate for endoscopic stapling regardless the type of the scope.⁶

Learning points.

• Endoscopic stapling is the preferred technique for treatment of symptomatic pharyngeal pouches.

• The use of stapling with a standard pharyngoscope can be successful in difficult access patients.

• This modification of the technique can prevent the conversion of an endoscopic approach to an open approach.

• There are variety of scopes in addition to different techniques in endoscopic stapling of pharyngeal pouch. These should be familiar to any surgeon performing the procedure as the failure rates are significant.