Zenker’s Diverticulum
Step 1
Surgical Anatomy
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The upper esophageal sphincter consists of the cricopharyngeal muscle, which courses transversely along the posterior portion of the esophagus. The esophagus borders superiorly with the obliquely coursing inferior constrictor pharyngeal muscles that constitute the hypopharynx. The area between these muscles represents Killian’s triangle. If abnormal relaxation and discoordination of the cricopharyngeal muscle occur during swallowing, this weak area allows the formation of a diverticulum, commonly referred to as Zenker’s , bearing the name of the German pathologist Friedrich Albert von Zenker who first described the underlying pathophysiologic process and reported a series of patients in the 19th century.
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This is the most common diverticulum of the esophagus. It is a false pulsion diverticulum that develops as a protrusion of the mucosal layer through the Killian triangle. The pouch is usually located left posterolaterally. Access to the diverticulum is through an anterior or lateral approach, and in both cases the recurrent laryngeal nerve should be preserved as it courses along the tracheoesophageal groove and enters the larynx between the inferior cornu of the thyroid cartilage and the arch of the cricoid.
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Dysphagia is a common presentation. Halitosis from undigested food and regurgitation of undigested food particles with night cough have also been commonly reported. Because the diverticulum is above the upper esophageal sphincter, tracheobronchial aspiration is a feared complication. Barium swallow is diagnostic for its presence, and no further testing is required.
Step 2
Preoperative Considerations
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The very low morbidity and mortality of excision and myotomy of a Zenker’s diverticulum justifies intervention as soon as its presence is confirmed. Potential complications (e.g., aspiration) carry a higher risk than the procedure itself.
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The pathologic substrate is dysfunction in motility and abnormal relaxation; therefore, the mainstay of the procedure is myotomy. Diverticulectomy alone is associated with a higher incidence of fistulae and should be discouraged. Depending on the size of the diverticulum, this may be left alone if it is smaller than 2 cm or resected if larger. Alternatively, the diverticulum may be fixed in an antigravity position.
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A clear liquid diet is encouraged for 2 to 3 days preceding the procedure. The patient should take nothing by mouth (NPO) after midnight before surgery.
Step 3
Operative Steps—Open Cervical Approach
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Perioperative antibiotics are administered within 1 hour from incision according to institutional policy. Ampicillin and sulbactam for up to 24 hours will provide adequate coverage. The patient is positioned supine on the operating table. General anesthesia is administered, and the airway is controlled via an endotracheal tube. A shoulder roll is placed, and the head is turned to the right side for a left lateral approach.
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An incision, about 5 cm long, is carried along the anterior border of the sternocleidomastoid (SCM) muscle, between the hyoid bone and above the clavicle. Alternatively, the head is extended in midline, and a transverse incision is performed two finger breadths below the prominence of the thyroid cartilage between the anterior borders of both SCM muscles.
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The platysma is divided sharply. Skin hooks are placed and, under gentle traction, subplatysmal flaps are developed. Self-retaining retractors are placed. The sternothyroid and sternohyoid muscles are retracted medially and the omohyoid muscle medially and superiorly ( Fig. 36-1 ). Placement of the medial portion of the retractor should always be superficial to the thyroid gland. Avoid deep placement and injury to the recurrent laryngeal nerve. The lateral portion of the retractor is placed so that it retracts the SCM muscle laterally. The middle thyroid vein is identified just behind the deep cervical fascia over the carotid sheath and divided as lateral as possible. The thyroid gland and the trachea are manually retracted medially. The carotid sheath and the jugular vein are retracted very gently laterally.
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The retropharyngeal space and the diverticulum are exposed. If the omohyoid muscle prevents adequate exposure, it may be divided. The diverticulum is dissected off the surrounding tissue, taking care to maintain a dissection plane very close to the esophageal wall. The neck of the diverticulum is dissected in such a way that the muscle layer is visualized along its entire circumference. The content of the diverticulum is emptied intraluminally.
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A 36 to 44 French bougie is placed in the esophagus, and the myotomy is performed on the side of the diverticulum (i.e., the left posterolateral wall). It extends at least 3 cm in a caudad direction and 2 cm in a cranial direction. A fine right-angle clamp may be used to develop the plane between the mucosa and the muscle and to guide the myotomy site with the electrocautery ( Fig. 36-2 ).
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If the diverticulum is small (i.e., <2 cm), it may be left alone. Larger diverticula are excised. Using a Babcock clamp, the diverticulum is gently lifted, and a linear stapler is fired across, ensuring that the lumen is not compromised and the recurrent laryngeal nerve is not inadvertently included in the staple line. Once the stapler is fired, the site is tested for leaks with intraluminal insufflation while warm saline is poured into the neck wound. Any leak should be repaired with fine absorbable sutures, such as 4-0 polyglactin sutures. Placement of a small drain is optional, and this is placed adjacent to the myotomy site and staple line.
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The platysma is approximated with 3-0 Vicryl interrupted sutures. Skin is approximated with a continuous subcuticular 4-0 Vicryl suture or other similar closure of choice. Steri-strips are applied over the incision, and dressing is usually applied around the drain exit site only. The patient is extubated in the operating room. Some surgeons routinely perform a laryngoscopy to ensure patency of the laryngeal nerves. This is safely accomplished with exchange of the endotracheal tube into a laryngeal mask that allows passage of a pediatric bronchoscope. As the patient becomes more awake, prompt approximation of both vocal cords is documented.
Step 3
Operative Steps—Endoscopic Approach
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The endoscopic approach was popularized with the advent of endoscopic staplers and coagulation devices. After general anesthesia and endotracheal intubation, the patient is placed in the supine sniffing position as for direct laryngoscopy. Adequate head extension is important to assist in smooth introduction of the stapler.
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A Weerda (bivalved) laryngoscope is introduced behind the endotracheal tube. The two valves are positioned in such a way that one is in the diverticulum and the other is in the esophagus, exposing the common wall (“septum”) ( Fig. 36-3 ). Visualization may be enhanced by placement of a small (5 mm or 30-degree) rigid endoscope through the laryngoscope. The esophageal lumen should be clearly seen; occasionally placement of a nasogastric tube will facilitate this and is then removed. Once adequate view is obtained, the laryngoscope is mounted to the chest with a suspension arm to allow the surgeon to work with both hands.
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An endoscopic GIA stapler is introduced with the smaller blade on the side of the diverticulum. Occasionally it is difficult to engage the common wall to the stapler because of inadequate fixation (see Fig. 36-3 ). Endoscopically placed silk sutures to the lateral walls will provide gentle traction. The stapler is then gently angulated anteriorly and fired, dividing the common wall and opening the diverticulum into the esophageal lumen. The stapler should be reapplied and fired again, if necessary, to obtain a common wall smaller than 1 cm long.
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Once this is accomplished, the stay sutures are removed and the laryngoscope is withdrawn. The patient is weaned off anesthesia, and the patient is extubated in the operating room.
Step 4
Postoperative Care
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Postoperatively, a swallow study may be obtained on the day of the surgery or on the first postoperative day. Once this confirms no leak and no risk of aspiration, liquid diet is initiated and slowly advanced as tolerated from mechanical soft to regular diet. For patients with endoscopic repair of the diverticulum, a swallow study is not usually necessary, and liquid diet is initiated on the day of surgery or the first postoperative day.
Step 5
Pearls and Pitfalls
1
Mucosal Entry
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Mucosal injury may be encountered during the attempt to mobilize the diverticulum at the staple line or during an attempt to fix the diverticulum in an antigravity position. This should be repaired primarily with fine absorbable sutures. The omohyoid muscle is divided as lateral as possible and brought over the repaired mucosal site and fixed to the surrounding muscle fibers using fine silk sutures. Alternatively, the mucosal defect is covered by the surrounding muscle.
2
Prevertebral Fascia
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Some advocate the fixation of the diverticulum in antigravity position, which has the advantage of no suture or staple line. If this approach is elected, the diverticulum should be fixed to the superiorly lying muscle fibers, avoiding any sutures and possible contamination of the prevertebral fascia, which may result in descending mediastinitis.
3
Recurrent Laryngeal Nerve Injury
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Potential injury to the recurrent laryngeal nerves is always present, and this is prevented by avoiding any retraction in a medial direction deeper than the thyroid gland with instruments.
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Nerve injury is usually undetected until postoperatively, when voice changes are observed.
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Respiratory distress following extubation should raise suspicion of bilateral injury, which can be confirmed at reintubation. If this is suspected, endoscopy before extubation is mandatory (as described above), and the patient should remain intubated. Tracheostomy may be required to obtain control of the airway.