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Endoscopic approach to cricopharyngeal hypertonicity and hypopharyngeal diverticulum
Operative Techniques in Otolaryngology (2016) ], ]]]–]]]
Endoscopic approach to cricopharyngeal hypertonicity and hypopharyngeal diverticulum Johnathan D. McGinn, MD, FACS From the Division of Otolaryngology—Head & Neck Surgery, Department of Surgery, College of Medicine, The Pennsylvania State University, Hershey, Pennsylvania KEYWORDS hypopharyngeal diverticulum; cricopharyngeus; dysphagia; Zenker’s diverticulum; myotomy
Cricopharyngeal (CP) muscle dysfunction may be an etiology for oropharyngeal dysphagia. The CP muscle may fail to relax fully, or in a coordinated fashion during the swallowing reflex. Alone this may cause dysphagia, but may also precipitate a pulsion diverticulum, known as Zenker’s diverticulum. When symptom severity and radiographic and endoscopic evaluation warrant intervention, endoscopic and open surgical options to manage these issues are available. This article strives to describe the techniques of endoscopic CP myotomy and Zenker’s diverticulostomy. Patient selection, contraindications for the surgery, and potential complications are described. r 2016 Elsevier Inc. All rights reserved.
Introduction Swallowing is a complex synchrony of muscular contraction, relaxation, and neurologic coordination. Dysfunction of this complex reflex may occur at many levels, both intrinsic and extrinsic to the aerodigestive tract. One such level implicated in dysphagia is the upper esophageal sphincter (UES). The UES is primarily made up of the cricopharyngeal (CP) muscle that consists of transverse muscle fibers of the inferior constrictor muscle. Other components include the cricoid cartilage.1 This muscle is tonically contracted, controlling the flow of materials between the pharynx and the esophagus. This valve may serve several purposes, including preventing air entry into the esophagus, preventing refluxant from the esophagus and stomach into the hypopharynx and potentially the airway, and allowing for controlled venting of gas during eructation (belch).2 The CP must relax to allow for the normal bolus Address reprint requests and correspondence: Johnathan D. McGinn, MD, FACS, Division of Otolaryngology—Head & Neck Surgery, Department of Surgery, College of Medicine, The Pennsylvania State University, 500 University Dr, H091, PO Box 850, Hershey, PA 170330850. E-mail address: [email protected] http://dx.doi.org/10.1016/j.otot.2016.04.003 1043-1810/r 2016 Elsevier Inc. All rights reserved.
passage from pharynx to esophagus, and this process must be sufficient in degree, and is properly timed to the remainder of the swallowing reflex. Dysfunction of the CP may arise from incomplete relaxation of the muscle during the swallow reflex, or a mistimed relaxation with the remainder of the swallow sequence. Defective relaxation or fibrosis of this muscle has also been described as contributing to symptomatic cervical dysphagia. With chronic dysfunction of the CP, cervical dysphagia may become a symptom of significant negative quality of life for the patient. Additionally, this dysfunction may contribute to the formation of a hypopharyngeal pulsion diverticulum. The classic hypopharyngeal diverticulum is perhaps best known eponymously as a Zenker’s diverticulum. This is an outpouching of mucosa and submucosa though a region just above the CP, known as Killian dehiscence (Figure 1). This weakness exists between the oblique fibers of the inferior constrictor muscle and the horizontal fibers of the CP. Propulsion of the swallowed bolus via pharyngeal contraction is hindered by the hypertonic or persistently tonically contracted CP, yielding intraluminal pressure increase. This chronic pressure phenomenon yields the prolapse of the mucosa and submucosa and pseudodiverticulum (a true diverticulum has all 3 layers, including muscle) develops.
2
Operative Techniques in Otolaryngology, Vol ], No ], Month 2016 An excellent review of the history of this disorder and the evolution of management is available in an article by Hillel and Flint.6 Current techniques in the management of CP dysfunction and Zenker’s diverticulum are roughly divided into endoscopic and open techniques. Endoscopic techniques have been celebrated as options to reduce the morbidity and potential complications of the open techniques, as well as often reducing the operative time. This article endeavors to discuss the endoscopic options and techniques for both the disorders, given the natural extension from CP dysfunction to Zenker’s diverticulum development. Endoscopic CP myotomy and endoscopic Zenker’s diverticulostomy are described. Another article in this journal edition by Huntley et al describes the open approaches.
Patient selection and indications
Figure 1 Anatomy of the posterior hypopharynx, highlighted area indicating Killian triangle.
Dysphagia arises primarily from the ongoing CP dysfunction, but the pouch, when filled with bolus material, may also impinge on the esophagus externally further contributing to the dysphagia. Regurgitation of the retained food material and secretions may also occur. Symptoms may therefore also include regurgitation of undigested food, halitosis (from stagnant food material), aspiration (primary or secondary from the pouch), and even unreliable medication dosing from retained pills. Patients with Zenker’s diverticulum are often in their 70s and 80s, but earlier presentations are not rare. This disorder was first described by Abraham Ludlow in a postmortem evaluation in 1764, but was incorrectly attributed to a swallowed cherry stone.3 The phenomena was correctly attributed to pharyngoesophageal muscular coordination issues in the early 19th century by Sir Charles Bell,4 but was formally named for the later German pathologist, Freidrich Albert von Zenker, who provided a detailed description in his book Diseases of the Esophagus.5 Surgical management attempts date back to this time frame.
Patients with dysphagia may have been assessed through several means before surgical consultation. Some may have had esophagoscopy, functional endoscopic evaluation of swallowing, or radiographic swallow studies. The most common method of diagnosis for CP dysfunction and Zenker’s diverticulum is radiographic contrast swallow study.7 The classic findings of CP dysfunction are a delay or interference with smooth bolus transit and the posterior indentation of the contracted CP muscle. Hypertonicity and failure of relaxation of the UES may also be noted on esophageal manometry. However, care must be taken to not interpret all CP bars on radiographic studies as the source of patient symptoms.2 A CP bar may be incidentally noted on radiographic studies, and one should consider it a plausible source of the dysphagia only when severe impingement is noted or correlation with esophageal manometry studies. In Zenker’s diverticulum cases, the same UES issues are noted, but the addition of a posterior "sac" is seen originating from above the UES and extending inferiorly, and often toward the left. General patient selection issues are employed regarding degree of patient symptoms that may warrant intervention, patient comorbidities that might interfere with safety of surgery, and surgeon skill set. For CP dysfunction without Zenker’s diverticulum, one can consider more conservative measures, such as botulinum injections of the cricopharyngeus or dilation or both, and reserve myotomy for failures of these techniques. Endoscopic approaches have anatomical restrictions, in which placement of the necessary equipment transorally and visualization of the surgical site may not be possible. Patients with limited neck extension, micrognathia, trismus (o3 cm interincisor distance), narrow dental arch, large torus mandibularis, or prominent central dentition should be considered as potentially unable to undergo an endoscopic approach for endoscopic CP myotomy or endoscopic Zenker’s diverticulostomy. A Zenker’s diverticulum typically must be at least 2 cm in length to allow for the stapler technique as outlined later. Endoscopic options for small Zenker’s diverticulum are
McGinn
Endoscopic CP Myotomy and Zenker Diverticulostomy
Figure 2 Weerda diverticuloscope, partially open. (Color version of figure is available online.)
discussed later. Revision Zenker’s diverticulostomy may also be done endoscopically, even if a previous endoscopic failures occurred.8
Technique—endoscopic Zenker’s diverticulostomy The procedure is performed under general endotracheal anesthesia. After intubation by the anesthesia service and securing of the tube to the left oral commissure, the operating table is rotated such that access from above the patient’s head is available. A small shoulder role may be placed and the top of the patient’s head should be even with the top of the operative table to minimize distance in accessing the oral cavity. The eyes should be padded or surgical goggles used. Draping is performed per surgeon preference, with access to the oral cavity and neck (for manual manipulation of the larynx if needed) maintained. Upper dentition or alveolus or both are protected per surgeon preference. The Weerda rigid endoscope (KARL STORZ Endoscopy America, Inc, El Segundo, CA) is then introduced transorally. Proper atraumatic positioning of this scope is among the key steps in the success of the endoscopic technique. The scope has 2 adjustments knobs —one knob pivots the scope blades apart (ie, “scissors”) and the other knob changes the distance between the blades while maintaining their orientation (Figure 2). The scope should be inserted in a manner to minimize trauma.
3 The scope should be advanced into the postcricoid region, with the goal to have the anterior blade within the esophagus and the posterior blade within the Zenker’s pouch. The intervening wall (including the CP muscle) is then visible in the center of the diverticuloscope. The positioning into the esophagus is typically more challenging; a blunt probe (eg, esophageal suction off suction tubing) or soft orogastric tube may be placed temporarily in the esophagus to confirm the location. The Weerda diverticuloscope may then be placed in suspension. A convenient way to do this is using an OR bed-mounted table and suspension arm (Figure 3). The bed may then be repositioned as needed for surgeon comfort without concern of changing the relationship of the diverticuloscope and patient and potential harm. Once the Weerda diverticuloscope is properly positioned, a 01 or 301 endoscope may be placed through the scope for distal visualization. To assist in maintaining position of the wall between esophagus and diverticulum, one, or a pair, of Endo Stitch (Covidien, Minneapolis, MN) may be placed though the wall to act as traction suture (Figure 4). Division of the wall may then be done with a variety of techniques. An Endo GIA stapler (Covidien, Minneapolis, MN) is a common tool; this creates a staple line on either side and a central division of tissue. Gentle upward traction on the sutures provides wall stability and aids stapler placement (Figure 5). The stapler should be advanced such that the tip sits as far inferior within the pouch as possible, to minimize the portion of the common wall, which is not divided. Visualizing with a 301 scope may be helpful in this task. Some authors advocate modifying the anvil side of the Endo GIA, such that the staple line extends to the distal tip of the anvil.9 This lessens the inferior portion of the wall, which is not stapled when the Endo GIA is utilized. Other devices have been utilized as well, including the carbon dioxide laser10 and Harmonic shears,11-14 although some concerns of higher rates of complications with those techniques has been raised. Once the Endo GIA is deployed, the staple line should be inspected for completeness. If the Zenker’s diverticulum is large, a second insertion and deployment of the Endo GIA can be performed to complete the wall division (Figure 6). Additionally, a carbon dioxide laser may be used to complete the inferiormost wall division.
Figure 3 Patient positioned with diverticuloscope in position and suspended from the draped bed-mounted table. (Color version of figure is available online.)
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Figure 4 Left—placement of Endo Stitch in the proximal common diverticulum wall, right—operative photograph of sutures in place. (Color version of figure is available online.)
The retention sutures can then be removed by cutting it and pulling through. If the sutures has been accidently included in the staple line, the suture should be cut as short as possible with endoscopic scissors. If the Zenker’s diverticulum is small (less than 2 cm), a carbon dioxide laser technique may be helpful. This may be done via microscope, or using the fiberoptic CO2 laser options with an endoscope. In this, the CO2 laser is used to divide the wall between esophagus and Zenker’s diverticulum in the midline. This is extended to the base of the pouch. With this smaller pouch, the division is likely predominantly the CP muscle alone and the potential for esophageal leak is small. The patient is admitted overnight. Liquid diet is started postoperative day 1, and if this is tolerated with no change in examination or in vital signs, the patient is discharged home later that day. The patient is recommended to take a full liquid diet for 1 week and then advance as tolerated to a regular diet. If any concerns regarding the integrity of the repair is made, a contrast swallow study can be obtained to evaluate, but is not routinely performed. Outpatient follow-up is arranged based on clinical course.
Technique—endoscopic CP myotomy Endoscopic CP myotomy is used in patients with CP dysfunction and in those with smaller Zenker’s diverticulum. The procedure is performed under general anesthesia.
Although the laser is not being used within the airway itself, the use of a laser-safe endotracheal tube is recommended to reduce the risk of airway fire. A preoperative dose of ampicillin and sulbactam is administered before starting the procedure. Patient position is identical to that described earlier for the Zenker’s diverticulostomy. Laser protection, such as placement of wet eye pads and wet towels covering the patient’s head and the use of laser-safe goggles by operating room staff, is required. The Weerda diverticuloscope or operative laryngoscope is placed in the postcricoid region. The diverticuloscope provides the advantage of the expansion of the region and the placement of tissue on stretch. The anterior blade is placed near or within the esophageal introitus, with the posterior blade being placed just superior to the CP muscle. The muscle may be prominent enough to obscure the esophageal introitus, as in some Zenker’s diverticulum. A probe or orogastric tube may again be used to identify the lumen; if used initially, the orogastric tube needs to be removed before laser use, as it is flammable. Some authors advocate using dilation (balloon or guide-wire guided) of the CP before myotomy in those whose esophageal lumen is not easily identified, or in whom access to the CP for laser use is deemed suboptimal.7 The diverticuloscope is then suspended. A 01 endoscope is then used to aid in visualization. A fiberoptic carbon dioxide laser (OmniGuide, Inc, Cambridge, MA) is then used on a continuous setting at 10-15 W to vertically divide the mucosa overlying the CP (Figure 7). The underlying CP
Figure 5 Left—placement of the endoscopic stapler across the wall between Zenker's diverticulum and esophagus, right—intraoperative endoscopic view of same. (Color version of figure is available online.)
McGinn
Endoscopic CP Myotomy and Zenker Diverticulostomy
5
Figure 6 Resultant appearance after endoscopic stapler is removed. Left—artist rendering, right—intraoperative photograph before retention suture removal. (Color version of figure is available online.)
muscle fibers would then be visible. The muscle fibers would retract laterally as they are divided, but additional retraction with a probe may be necessary (Figure 8). Division of the muscle fibers should continue until the buccopharyngeal fascia is exposed. This would appear as a white membranous sheet, overlying the areolar retropharyngeal tissues (Figure 9).1 In some patients, this layer may be less defined. The retropharyngeal space should not be manipulated. Some authors advocate using a pneumatic dilation at near completion of the laser muscle division to avoid exposing the buccopharyngeal fascia with the laser.7 The goal is to minimize manipulation of the layers beyond the buccopharyngeal fascia, which increases the risk of tracking infection and possible mediastinitis. If bleeding is encountered that is not controllable with the CO2 laser, 1:10,000 epinephrine-soaked pledgets can be applied, or an endoscopic bipolar cautery may be used. If concerns regarding a perforation exist, a small feeding tube can be placed under direct visualization into the esophagus and advanced to the stomach. This can be then used if the patient must be kept nothing by mouth (NPO) for a period of time postoperatively, and avoids blind placement in the setting of a perforation. Postoperatively, the patient is admitted to the hospital. A contrast swallowing study is done the next morning to assess for a pharyngoesophageal leak. If nothing is identified, the patient is started on clear liquids and observed
Figure 7
for 24 hours. If no concerns arise regarding leak, with no fever, neck swelling or pain, or chest pain, the patient is discharged home on oral amoxicillin or clavulanate acid suspension for 5 days. A full liquid diet should be used for 3-5 days, then a soft diet for another 10-14 days. This dietary pattern would vary and is at surgeon’s discretion. Outpatient follow-up is as the clinical course demands.
Complications The most common “complication” encountered with these procedures is inability to perform the endoscopic technique. This has been reported between 7% and 15% of endoscopic procedures.9,15 A plan must be discussed with the patient before the procedure, as to whether the surgery would be aborted at this juncture, or whether an open approach would then be performed. If the plan is to proceed with the open procedure, operative scheduling allowances must be made for the longer procedure. As with other transoral endoscopic procedures, risk of injury to dentoalveolar structures or the oral cavity or oropharynx may occur. The diverticuloscope is a bulkier instrument than those typically used for most laryngoesophageal procedures, and hence the risk of injury corresponds. Perforation from instrument manipulation may occur as well, given the instrument size and occasional challenging exposure. Even with successful exposure, the
Appearance after proper diverticuloscope positioning and early incision of the mucosa overlying the CP muscle.
Operative Techniques in Otolaryngology, Vol ], No ], Month 2016
6
et al18 reported in their long-term follow-up series that those undergoing transcervical techniques had a better long-term complete or improved symptom rate vs the endoscopic approach (93% vs 67%). This concern of recurrence must be weighed against the accepted benefits of the endoscopic technique when counseling patient as to their best options.
Conclusions
Figure 8
CP muscle partially divided with the CO2 laser.
surgery involves violation of the muscular layer of the pharynx and hence the risk of perforation exists. The risk in patients with CP myotomy is higher, given the lack of closure of the muscular injury achieved in the stapler diverticulostomy. The reported series for CP myotomy are all relatively small, but serious complication rates (eg, mediastinitis) are low (2.6%-4.5%).1,7 Management of postoperative leaks may include NPO, intravenous antibiotics, alternate nutritional access, and cervical drainage. Small leaks would likely respond to nonsurgical conservative measures. Recurrent dysphagia is a concerning issue after surgery. The rate of recurrent symptoms with need for further interventions for endoscopic CP myotomy is reported at approximately 14%.7,16 Endoscopic Zenker’s diverticulostomy seems to have a higher rate of recurrent symptoms than the open transcervical technique. This has been theorized to be secondary to incomplete CP myotomies during stapling, especially of smaller diverticula. Symptomatic recurrent dysphagia is reported as high as 39%.17 Seth
Figure 9 Completed endoscopic CO2 laser CP myotomy with exposed buccopharyngeal fascia.
Endoscopic Zenker’s diverticulostomy and endoscopic CO2 laser CP myotomy are good options for many patients with CP dysfunction and symptoms affecting quality of life. Management of these CP entities can improve quality of life, and reduce the morbidity of dysphagia, including weight loss, malnutrition, medication dosage variability, and aspiration. With careful preoperative patient selection and some basic equipment, the endoscopic option is a viable technique for most surgeons to entertain. Postoperative dietary and follow-up measures vary from surgeon to surgeon, often based on experience and confidence with the techniques. Complication rates should be low, but notable severe complications such as mediastinitis are possible and should be a part of the preoperative counseling. Recurrent dysphagia symptoms may occur, possibly at a higher rate than seen in the open counterpart techniques.
Disclosure and conflict of interest The author report no proprietary or commercial interest in any product mentioned or concept discussed in this article. The author has no conflict of interest.
References 1. Pitman M, Weissbrod P: Endoscopic CO2 laser cricopharyngeal myotomy. Laryngoscope 119(1):45-53, 2009 2. Cook IJ: Cricopharyngeal function and dysfunction. Dysphagia 8 (3):244-251, 1993 3. Ludlow A: A case of obstructed deglutition, from a preter-natural dilation of, and bag formed in, the pharynx. Med Obs Inq 3:85, 1767 4. Bell C: Surgical Observations. London, United Kingdom: Longmans, Green & Co; 1816 5. Zenker F, von Ziemssen H: Krankheiten des oesophagus. In: von Ziemssen H, editor. Handbuch Der Speciellen Pathologie und Therapie. Leipzig: FC Vogel; 1877 6. Hillel AT, Flint PW: Evolution of endoscopic surgical therapy for Zenker’s diverticulum. Laryngoscope 119(1):39-44, 2009 7. Bergeron JL, Chhetri DK: Indications and outcomes of endoscopic CO2 laser cricopharyngeal myotomy. Laryngoscope 124(4):950-954, 2014 8. Adam SI, Paskhover B, Sasaki CT: Revision Zenker diverticulum: Laser versus stapler outcomes following initial endoscopic failure. Ann Otol Rhinol Laryngol 122(4):247-253, 2013 9. Weksler B, Cook C, Luketich JD: Endoscopic transoral stapling of Zenker’s diverticula. Multimed Man Cardiothorac Surg 2010 10. Parker NP, Misono S: Carbon dioxide laser versus stapler-assisted endoscopic Zenker’s diverticulotomy: A systematic review and metaanalysis. Otolaryngol Head Neck Surg 150(5):750-753, 2014
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Endoscopic CP Myotomy and Zenker Diverticulostomy
11. Fama AF, Moore EJ, Kasperbauer JL: Harmonic scalpel in the treatment of Zenker’s diverticulum. Laryngoscope 119(7):1265-1269, 2009 12. Sharp DB, Newman JR, Magnuson JS: Endoscopic management of Zenker’s diverticulum: Stapler assisted versus Harmonic Ace. Laryngoscope 119(10):1906-1912, 2009 13. May JT, Padhya TA, McCaffrey TV: Endoscopic repair of Zenker’s diverticulum by harmonic scalpel. Am J Otolaryngol 32(6):553-556, 2011 14. Whited C, Lee WT, Scher R: Evaluation of endoscopic harmonic diverticulostomy. Laryngoscope 122(6):1297-1300, 2012
7 15. Verdonck J, Morton RP: Systematic review on treatment of Zenker’s diverticulum. Eur Arch Otorhinolaryngol 272(11):3095-3107, 2014 16. Bachy V, Matar N, Remacle M, et al: Long-term functional results after endoscopic cricopharyngeal myotomy with CO2 laser: A retrospective study of 32 cases. Eur Arch Otorhinolaryngol 270(3):965-968, 2013 17. Shahawy S, Janisiewicz AM, Annino D, et al: A comparative study of outcomes for endoscopic diverticulotomy versus external diverticulectomy. Otolaryngol Head Neck Surg 151(4):646-651, 2014 18. Seth R, Rajasekaran K, Lee WT, et al: Patient reported outcomes in endoscopic and open transcervical treatment for Zenker’s diverticulum. Laryngoscope 124(1):119-125, 2014
Endoscopic approach to cricopharyngeal hypertonicity and hypopharyngeal diverticulum Johnathan D. McGinn, MD, FACS From the Division of Otolaryngology—Head & Neck Surgery, Department of Surgery, College of Medicine, The Pennsylvania State University, Hershey, Pennsylvania KEYWORDS hypopharyngeal diverticulum; cricopharyngeus; dysphagia; Zenker’s diverticulum; myotomy
Cricopharyngeal (CP) muscle dysfunction may be an etiology for oropharyngeal dysphagia. The CP muscle may fail to relax fully, or in a coordinated fashion during the swallowing reflex. Alone this may cause dysphagia, but may also precipitate a pulsion diverticulum, known as Zenker’s diverticulum. When symptom severity and radiographic and endoscopic evaluation warrant intervention, endoscopic and open surgical options to manage these issues are available. This article strives to describe the techniques of endoscopic CP myotomy and Zenker’s diverticulostomy. Patient selection, contraindications for the surgery, and potential complications are described. r 2016 Elsevier Inc. All rights reserved.
Introduction Swallowing is a complex synchrony of muscular contraction, relaxation, and neurologic coordination. Dysfunction of this complex reflex may occur at many levels, both intrinsic and extrinsic to the aerodigestive tract. One such level implicated in dysphagia is the upper esophageal sphincter (UES). The UES is primarily made up of the cricopharyngeal (CP) muscle that consists of transverse muscle fibers of the inferior constrictor muscle. Other components include the cricoid cartilage.1 This muscle is tonically contracted, controlling the flow of materials between the pharynx and the esophagus. This valve may serve several purposes, including preventing air entry into the esophagus, preventing refluxant from the esophagus and stomach into the hypopharynx and potentially the airway, and allowing for controlled venting of gas during eructation (belch).2 The CP must relax to allow for the normal bolus Address reprint requests and correspondence: Johnathan D. McGinn, MD, FACS, Division of Otolaryngology—Head & Neck Surgery, Department of Surgery, College of Medicine, The Pennsylvania State University, 500 University Dr, H091, PO Box 850, Hershey, PA 170330850. E-mail address: [email protected] http://dx.doi.org/10.1016/j.otot.2016.04.003 1043-1810/r 2016 Elsevier Inc. All rights reserved.
passage from pharynx to esophagus, and this process must be sufficient in degree, and is properly timed to the remainder of the swallowing reflex. Dysfunction of the CP may arise from incomplete relaxation of the muscle during the swallow reflex, or a mistimed relaxation with the remainder of the swallow sequence. Defective relaxation or fibrosis of this muscle has also been described as contributing to symptomatic cervical dysphagia. With chronic dysfunction of the CP, cervical dysphagia may become a symptom of significant negative quality of life for the patient. Additionally, this dysfunction may contribute to the formation of a hypopharyngeal pulsion diverticulum. The classic hypopharyngeal diverticulum is perhaps best known eponymously as a Zenker’s diverticulum. This is an outpouching of mucosa and submucosa though a region just above the CP, known as Killian dehiscence (Figure 1). This weakness exists between the oblique fibers of the inferior constrictor muscle and the horizontal fibers of the CP. Propulsion of the swallowed bolus via pharyngeal contraction is hindered by the hypertonic or persistently tonically contracted CP, yielding intraluminal pressure increase. This chronic pressure phenomenon yields the prolapse of the mucosa and submucosa and pseudodiverticulum (a true diverticulum has all 3 layers, including muscle) develops.
2
Operative Techniques in Otolaryngology, Vol ], No ], Month 2016 An excellent review of the history of this disorder and the evolution of management is available in an article by Hillel and Flint.6 Current techniques in the management of CP dysfunction and Zenker’s diverticulum are roughly divided into endoscopic and open techniques. Endoscopic techniques have been celebrated as options to reduce the morbidity and potential complications of the open techniques, as well as often reducing the operative time. This article endeavors to discuss the endoscopic options and techniques for both the disorders, given the natural extension from CP dysfunction to Zenker’s diverticulum development. Endoscopic CP myotomy and endoscopic Zenker’s diverticulostomy are described. Another article in this journal edition by Huntley et al describes the open approaches.
Patient selection and indications
Figure 1 Anatomy of the posterior hypopharynx, highlighted area indicating Killian triangle.
Dysphagia arises primarily from the ongoing CP dysfunction, but the pouch, when filled with bolus material, may also impinge on the esophagus externally further contributing to the dysphagia. Regurgitation of the retained food material and secretions may also occur. Symptoms may therefore also include regurgitation of undigested food, halitosis (from stagnant food material), aspiration (primary or secondary from the pouch), and even unreliable medication dosing from retained pills. Patients with Zenker’s diverticulum are often in their 70s and 80s, but earlier presentations are not rare. This disorder was first described by Abraham Ludlow in a postmortem evaluation in 1764, but was incorrectly attributed to a swallowed cherry stone.3 The phenomena was correctly attributed to pharyngoesophageal muscular coordination issues in the early 19th century by Sir Charles Bell,4 but was formally named for the later German pathologist, Freidrich Albert von Zenker, who provided a detailed description in his book Diseases of the Esophagus.5 Surgical management attempts date back to this time frame.
Patients with dysphagia may have been assessed through several means before surgical consultation. Some may have had esophagoscopy, functional endoscopic evaluation of swallowing, or radiographic swallow studies. The most common method of diagnosis for CP dysfunction and Zenker’s diverticulum is radiographic contrast swallow study.7 The classic findings of CP dysfunction are a delay or interference with smooth bolus transit and the posterior indentation of the contracted CP muscle. Hypertonicity and failure of relaxation of the UES may also be noted on esophageal manometry. However, care must be taken to not interpret all CP bars on radiographic studies as the source of patient symptoms.2 A CP bar may be incidentally noted on radiographic studies, and one should consider it a plausible source of the dysphagia only when severe impingement is noted or correlation with esophageal manometry studies. In Zenker’s diverticulum cases, the same UES issues are noted, but the addition of a posterior "sac" is seen originating from above the UES and extending inferiorly, and often toward the left. General patient selection issues are employed regarding degree of patient symptoms that may warrant intervention, patient comorbidities that might interfere with safety of surgery, and surgeon skill set. For CP dysfunction without Zenker’s diverticulum, one can consider more conservative measures, such as botulinum injections of the cricopharyngeus or dilation or both, and reserve myotomy for failures of these techniques. Endoscopic approaches have anatomical restrictions, in which placement of the necessary equipment transorally and visualization of the surgical site may not be possible. Patients with limited neck extension, micrognathia, trismus (o3 cm interincisor distance), narrow dental arch, large torus mandibularis, or prominent central dentition should be considered as potentially unable to undergo an endoscopic approach for endoscopic CP myotomy or endoscopic Zenker’s diverticulostomy. A Zenker’s diverticulum typically must be at least 2 cm in length to allow for the stapler technique as outlined later. Endoscopic options for small Zenker’s diverticulum are
McGinn
Endoscopic CP Myotomy and Zenker Diverticulostomy
Figure 2 Weerda diverticuloscope, partially open. (Color version of figure is available online.)
discussed later. Revision Zenker’s diverticulostomy may also be done endoscopically, even if a previous endoscopic failures occurred.8
Technique—endoscopic Zenker’s diverticulostomy The procedure is performed under general endotracheal anesthesia. After intubation by the anesthesia service and securing of the tube to the left oral commissure, the operating table is rotated such that access from above the patient’s head is available. A small shoulder role may be placed and the top of the patient’s head should be even with the top of the operative table to minimize distance in accessing the oral cavity. The eyes should be padded or surgical goggles used. Draping is performed per surgeon preference, with access to the oral cavity and neck (for manual manipulation of the larynx if needed) maintained. Upper dentition or alveolus or both are protected per surgeon preference. The Weerda rigid endoscope (KARL STORZ Endoscopy America, Inc, El Segundo, CA) is then introduced transorally. Proper atraumatic positioning of this scope is among the key steps in the success of the endoscopic technique. The scope has 2 adjustments knobs —one knob pivots the scope blades apart (ie, “scissors”) and the other knob changes the distance between the blades while maintaining their orientation (Figure 2). The scope should be inserted in a manner to minimize trauma.
3 The scope should be advanced into the postcricoid region, with the goal to have the anterior blade within the esophagus and the posterior blade within the Zenker’s pouch. The intervening wall (including the CP muscle) is then visible in the center of the diverticuloscope. The positioning into the esophagus is typically more challenging; a blunt probe (eg, esophageal suction off suction tubing) or soft orogastric tube may be placed temporarily in the esophagus to confirm the location. The Weerda diverticuloscope may then be placed in suspension. A convenient way to do this is using an OR bed-mounted table and suspension arm (Figure 3). The bed may then be repositioned as needed for surgeon comfort without concern of changing the relationship of the diverticuloscope and patient and potential harm. Once the Weerda diverticuloscope is properly positioned, a 01 or 301 endoscope may be placed through the scope for distal visualization. To assist in maintaining position of the wall between esophagus and diverticulum, one, or a pair, of Endo Stitch (Covidien, Minneapolis, MN) may be placed though the wall to act as traction suture (Figure 4). Division of the wall may then be done with a variety of techniques. An Endo GIA stapler (Covidien, Minneapolis, MN) is a common tool; this creates a staple line on either side and a central division of tissue. Gentle upward traction on the sutures provides wall stability and aids stapler placement (Figure 5). The stapler should be advanced such that the tip sits as far inferior within the pouch as possible, to minimize the portion of the common wall, which is not divided. Visualizing with a 301 scope may be helpful in this task. Some authors advocate modifying the anvil side of the Endo GIA, such that the staple line extends to the distal tip of the anvil.9 This lessens the inferior portion of the wall, which is not stapled when the Endo GIA is utilized. Other devices have been utilized as well, including the carbon dioxide laser10 and Harmonic shears,11-14 although some concerns of higher rates of complications with those techniques has been raised. Once the Endo GIA is deployed, the staple line should be inspected for completeness. If the Zenker’s diverticulum is large, a second insertion and deployment of the Endo GIA can be performed to complete the wall division (Figure 6). Additionally, a carbon dioxide laser may be used to complete the inferiormost wall division.
Figure 3 Patient positioned with diverticuloscope in position and suspended from the draped bed-mounted table. (Color version of figure is available online.)
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Figure 4 Left—placement of Endo Stitch in the proximal common diverticulum wall, right—operative photograph of sutures in place. (Color version of figure is available online.)
The retention sutures can then be removed by cutting it and pulling through. If the sutures has been accidently included in the staple line, the suture should be cut as short as possible with endoscopic scissors. If the Zenker’s diverticulum is small (less than 2 cm), a carbon dioxide laser technique may be helpful. This may be done via microscope, or using the fiberoptic CO2 laser options with an endoscope. In this, the CO2 laser is used to divide the wall between esophagus and Zenker’s diverticulum in the midline. This is extended to the base of the pouch. With this smaller pouch, the division is likely predominantly the CP muscle alone and the potential for esophageal leak is small. The patient is admitted overnight. Liquid diet is started postoperative day 1, and if this is tolerated with no change in examination or in vital signs, the patient is discharged home later that day. The patient is recommended to take a full liquid diet for 1 week and then advance as tolerated to a regular diet. If any concerns regarding the integrity of the repair is made, a contrast swallow study can be obtained to evaluate, but is not routinely performed. Outpatient follow-up is arranged based on clinical course.
Technique—endoscopic CP myotomy Endoscopic CP myotomy is used in patients with CP dysfunction and in those with smaller Zenker’s diverticulum. The procedure is performed under general anesthesia.
Although the laser is not being used within the airway itself, the use of a laser-safe endotracheal tube is recommended to reduce the risk of airway fire. A preoperative dose of ampicillin and sulbactam is administered before starting the procedure. Patient position is identical to that described earlier for the Zenker’s diverticulostomy. Laser protection, such as placement of wet eye pads and wet towels covering the patient’s head and the use of laser-safe goggles by operating room staff, is required. The Weerda diverticuloscope or operative laryngoscope is placed in the postcricoid region. The diverticuloscope provides the advantage of the expansion of the region and the placement of tissue on stretch. The anterior blade is placed near or within the esophageal introitus, with the posterior blade being placed just superior to the CP muscle. The muscle may be prominent enough to obscure the esophageal introitus, as in some Zenker’s diverticulum. A probe or orogastric tube may again be used to identify the lumen; if used initially, the orogastric tube needs to be removed before laser use, as it is flammable. Some authors advocate using dilation (balloon or guide-wire guided) of the CP before myotomy in those whose esophageal lumen is not easily identified, or in whom access to the CP for laser use is deemed suboptimal.7 The diverticuloscope is then suspended. A 01 endoscope is then used to aid in visualization. A fiberoptic carbon dioxide laser (OmniGuide, Inc, Cambridge, MA) is then used on a continuous setting at 10-15 W to vertically divide the mucosa overlying the CP (Figure 7). The underlying CP
Figure 5 Left—placement of the endoscopic stapler across the wall between Zenker's diverticulum and esophagus, right—intraoperative endoscopic view of same. (Color version of figure is available online.)
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Endoscopic CP Myotomy and Zenker Diverticulostomy
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Figure 6 Resultant appearance after endoscopic stapler is removed. Left—artist rendering, right—intraoperative photograph before retention suture removal. (Color version of figure is available online.)
muscle fibers would then be visible. The muscle fibers would retract laterally as they are divided, but additional retraction with a probe may be necessary (Figure 8). Division of the muscle fibers should continue until the buccopharyngeal fascia is exposed. This would appear as a white membranous sheet, overlying the areolar retropharyngeal tissues (Figure 9).1 In some patients, this layer may be less defined. The retropharyngeal space should not be manipulated. Some authors advocate using a pneumatic dilation at near completion of the laser muscle division to avoid exposing the buccopharyngeal fascia with the laser.7 The goal is to minimize manipulation of the layers beyond the buccopharyngeal fascia, which increases the risk of tracking infection and possible mediastinitis. If bleeding is encountered that is not controllable with the CO2 laser, 1:10,000 epinephrine-soaked pledgets can be applied, or an endoscopic bipolar cautery may be used. If concerns regarding a perforation exist, a small feeding tube can be placed under direct visualization into the esophagus and advanced to the stomach. This can be then used if the patient must be kept nothing by mouth (NPO) for a period of time postoperatively, and avoids blind placement in the setting of a perforation. Postoperatively, the patient is admitted to the hospital. A contrast swallowing study is done the next morning to assess for a pharyngoesophageal leak. If nothing is identified, the patient is started on clear liquids and observed
Figure 7
for 24 hours. If no concerns arise regarding leak, with no fever, neck swelling or pain, or chest pain, the patient is discharged home on oral amoxicillin or clavulanate acid suspension for 5 days. A full liquid diet should be used for 3-5 days, then a soft diet for another 10-14 days. This dietary pattern would vary and is at surgeon’s discretion. Outpatient follow-up is as the clinical course demands.
Complications The most common “complication” encountered with these procedures is inability to perform the endoscopic technique. This has been reported between 7% and 15% of endoscopic procedures.9,15 A plan must be discussed with the patient before the procedure, as to whether the surgery would be aborted at this juncture, or whether an open approach would then be performed. If the plan is to proceed with the open procedure, operative scheduling allowances must be made for the longer procedure. As with other transoral endoscopic procedures, risk of injury to dentoalveolar structures or the oral cavity or oropharynx may occur. The diverticuloscope is a bulkier instrument than those typically used for most laryngoesophageal procedures, and hence the risk of injury corresponds. Perforation from instrument manipulation may occur as well, given the instrument size and occasional challenging exposure. Even with successful exposure, the
Appearance after proper diverticuloscope positioning and early incision of the mucosa overlying the CP muscle.
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et al18 reported in their long-term follow-up series that those undergoing transcervical techniques had a better long-term complete or improved symptom rate vs the endoscopic approach (93% vs 67%). This concern of recurrence must be weighed against the accepted benefits of the endoscopic technique when counseling patient as to their best options.
Conclusions
Figure 8
CP muscle partially divided with the CO2 laser.
surgery involves violation of the muscular layer of the pharynx and hence the risk of perforation exists. The risk in patients with CP myotomy is higher, given the lack of closure of the muscular injury achieved in the stapler diverticulostomy. The reported series for CP myotomy are all relatively small, but serious complication rates (eg, mediastinitis) are low (2.6%-4.5%).1,7 Management of postoperative leaks may include NPO, intravenous antibiotics, alternate nutritional access, and cervical drainage. Small leaks would likely respond to nonsurgical conservative measures. Recurrent dysphagia is a concerning issue after surgery. The rate of recurrent symptoms with need for further interventions for endoscopic CP myotomy is reported at approximately 14%.7,16 Endoscopic Zenker’s diverticulostomy seems to have a higher rate of recurrent symptoms than the open transcervical technique. This has been theorized to be secondary to incomplete CP myotomies during stapling, especially of smaller diverticula. Symptomatic recurrent dysphagia is reported as high as 39%.17 Seth
Figure 9 Completed endoscopic CO2 laser CP myotomy with exposed buccopharyngeal fascia.
Endoscopic Zenker’s diverticulostomy and endoscopic CO2 laser CP myotomy are good options for many patients with CP dysfunction and symptoms affecting quality of life. Management of these CP entities can improve quality of life, and reduce the morbidity of dysphagia, including weight loss, malnutrition, medication dosage variability, and aspiration. With careful preoperative patient selection and some basic equipment, the endoscopic option is a viable technique for most surgeons to entertain. Postoperative dietary and follow-up measures vary from surgeon to surgeon, often based on experience and confidence with the techniques. Complication rates should be low, but notable severe complications such as mediastinitis are possible and should be a part of the preoperative counseling. Recurrent dysphagia symptoms may occur, possibly at a higher rate than seen in the open counterpart techniques.
Disclosure and conflict of interest The author report no proprietary or commercial interest in any product mentioned or concept discussed in this article. The author has no conflict of interest.
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