Endoscopic cricopharyngeal myotomy
Transcription
Endoscopic cricopharyngeal myotomy
Operative Techniques in Otolaryngology (2011) 22, 135-141 Endoscopic cricopharyngeal myotomy Michael J. Pitman, MD,a Philip Weissbrod, MDb From the aNew York Eye and Ear Infirmary, Voice and Swallowing Institute, Department of Otolaryngology, New York, New York; and b New York Eye and Ear Infirmary, Department of Otolaryngology, New York, New York. KEYWORDS Endoscopic cricopharyngeal myotomy; dysphagia; Cricopharyngeal achalasia; Cricopharyngeal dysfunction; Cricopharyngeus treatment Endoscopic cricopharyngeal myotomy is becoming an accepted alternative to trancervical myotomy. The operative time is shorter; the morbidity is minimized and complications are comparable if not less frequent and severe than the transcervical approach. An improved understanding of the anatomy posterior to the cricopharyngeus as well as detailed illustration of the surgical technique may serve to decrease surgeons’ hesitancy in adopting this technique and increase its general acceptance as a viable alternative to transcervical cricopharyngeal myotomy. © 2011 Elsevier Inc. All rights reserved. The traditional surgical treatment for upper esophageal sphincter dysfunction involves cricopharyngeal myotomy via a transcervical approach.1-3 An open approach, while effective, carries surgical morbidity, including possible pharyngocutanous fistula, recurrent laryngeal nerve paralysis, hematoma, seroma, and wound infection.4,5 In 1994, endoscopic cricopharyngeal myotomy (ECPM) was developed using direct laryngoscopy with laser incision of the cricopharyngeus (CP) using a potassium-titanyl phosphate laser. Soon after, CO2 laser was employed and has become the laser of choice because of its ability to coagulate small vessels and minimize unintended spread of thermal damage.6 In reviewing the literature, it is apparent that complications from either ECPM or transcervical cricopharyngeal myotomy (TCPM) are few.7 Assessing complications from TCPM alone proves difficult because few series address only TCPM while excluding patients with a Zenker’s diverticulum. Studies that focus on ECPM are few in number and all have relatively small sample sizes. In these studies, the etiology underlying CP dysfunction and presence or ab- Address reprint requests and correspondence: Michael J. Pitman, MD, New York Eye and Ear Infirmary, Voice and Swallowing Institute, Department of Otolaryngology, 310 E. 14th St., New York, NY 10003. E-mail address: mpitman@nyee.edu. 1043-1810/$ -see front matter © 2011 Elsevier Inc. All rights reserved. doi:10.1016/j.otot.2011.01.004 sence of concomitant oropharyngeal dysphagia varies dramatically. As a result, there are multiple confounding factors that make interstudy comparison difficult. It is clear that ECPM offers a shorter operative and anesthesia time, less morbidity, and scar-free surgery. Although it appears that ECPM may have less frequent and less severe complications than TCPM, it is difficult to say this conclusively because of the constraints described above. Indications A patient may be a candidate for a cricopharyngeal myotomy based on the patient’s history and results from manometry, flexible endoscopy, and evidence of a cricopharyngeal bar obstructing greater than 50% of the esophageal lumen on an esophagram. Contraindications to the endoscopic approach are trismus and cervical disease that prevents neck extension. Severe pharyngeal dysfunction is a contraindication to a cricopharyngeal myotomy regardless of approach. Anatomy A brief discussion of facial planes and potential spaces is important in understanding the potential concerns regarding 136 Operative Techniques in Otolaryngology, Vol 22, No 2, June 2011 Figure 1 Surgeon’s view with surrounding anatomy. (Reprinted with permission from Pitman MJ, Weissbrod P: Endoscopic CO2 laser cricopharyngeal myotomy. Laryngoscope 119:45-53, 2009.) violation of fascial planes (Figures 1 and 2). The fascial plane surrounding the esophagus, CP, and inferior pharyngeal constrictor (IPC) is the buccopharyngeal fascia (BPF), the visceral layer of the middle layer of the deep cervical fascia. Its superior limit is the skull base and inferiorly it is continuous with the fibrous pericardium of the mediastinum. Posterior to the BPF is the retropharyngeal space (RPS), which is filled with areolar tissue and defined posteriorly by the alar fascia (AF). The AF fuses with the BPF in the superior mediastinum. Posterior to the AF is the danger space, which is defined posteriorly by the prevertebral fascia and runs from the skull base superiorly to the diaphragm inferiorly. Posterior to the prevertebral fascia is the prevertebral space.8,9 Violation of these facial layers may allow pharyngeal contents to pass extraluminally and cause infection. In investigation of ECPM and fascial planes, ECPM was performed with a CO2 laser on cadaveric specimens. Postoperative dissection revealed an intact BPF layer, which correlates to preservation of the fascial layer protecting spread into the RPS.10 In addition, even when the BPF is minimally violated, gross pharyngeal contents are contained by the undisturbed areolar tissue of the RPS. It is a combination of these 2 structures that make ECPM safe and minimizes the risk of mediastinitis. In contrast, with TCPM both areolar tissue of the RPS and the BPF are extensively dissected and violated. Hence, in TCPM, if there is a leak of pharyngeal contents, the anatomic barriers against the spread of these contents and bacteria have been eliminated, increasing risk of mediastinitis. Technique The ECPM technique involves postcricoid placement of a diverticuloscope. A Weerda Diverticuloscope (Karl Storz, Tuttlingen, Germany) or a Slimline Diverticuloscope (Karl Figure 2 Placement of the diverticuloscope and surrounding anatomy. (Reprinted with permission from Pitman MJ, Weissbrod P: Endoscopic CO2 laser cricopharyngeal myotomy. Laryngoscope 119:45-53, 2009.) Pitman and Weissbrod Endoscopic Cricopharyngeal Myotomy 137 Figure 3 Placement of the nasogastric tube helps localize the esophageal entroitus and the cricopharyngeal muscle. (Reprinted with permission from Pitman MJ, Weissbrod P: Endoscopic CO2 laser cricopharyngeal myotomy. Laryngoscope 119:45-53, 2009.) Storz, Tuttlingen, Germany) can be used, with the Slimline being more helpful in patients who are difficult to expose. A nasogastric tube may be placed in the esophagus to help identify the esophageal introitus and guide placement of the diverticuloscope (Figure 3). Visualization of the CP is aided by pressure of the scope on the surrounding tissues. The anterior flange of the diverticuloscope approaches the esophageal introitus and the posterior flange abuts the posterior pharyngeal wall, highlighting the CP (Figure 2). Once the CP is well exposed and the scope is suspended, the nasogastric tube is removed. The mucosa-covered CP is easily identified as the mound of tissue just proximal to the esophageal introitus (Figure 4). The CP is palpated by a right-angle probe. The angle of the probe allows the surgeon to obtain a sense of its mass and depth by palpating the posterior aspect of the CP mound. A transmucosal vertical midline incision is then made with a CO2 laser set in continuous-wave mode at a power of 6 W mechanically pulsed at 0.1 seconds on and 0.3 seconds off (Figure 5). As experience is gained, most of the procedure is performed in a nonpulsed fashion or using an AcuBlade (Yokneam, Israel) scanning CO2 laser (S–CO2) for the increased effi- ciency that is provided by the pattern generator. The overlying mucosa is surprisingly thick. There is a plane between the mucosa and CP that allows retraction of the incised mucosa and improves exposure of the underlying muscle (Figure 6). The mucosal incision should completely transect the overlying mucosa, exposing a substantial amount of the CP before incising the CP in a vertical midline fashion. As the muscle is transected with the laser, there is lateral retraction of visible muscle fibers (Figure 7). As a result, the muscle is easy to discern from the overlying mucosa and underlying fascia. If the lateral retraction is not seen, the position of the scope should be reassessed to confirm that the CP is being addressed, not a constrictor muscle that has buckled up and mimicked the CP. The excellent visualization provided by this approach ensures transection of every fiber of the CP without damage to the underlying BPF. As the BPF is approached, it is recognized as a smooth, translucent or opaque, white/gray plane without the horizontal striations of the CP. When the BPF is identified, the laser should be mechanically pulsed and, if using the S–CO2, the length of incision is minimized. The pulsing and smaller length of incision allows more precise control of the laser. Figure 4 The CP mound is just proximal to the esophageal introitus. (Reprinted with permission from Pitman MJ, Weissbrod P: Endoscopic CO2 laser cricopharyngeal myotomy. Laryngoscope 119:45-53, 2009.) 138 Operative Techniques in Otolaryngology, Vol 22, No 2, June 2011 Figure 5 Initial mucosal incision. (Reprinted with permission from Pitman MJ, Weissbrod P: Endoscopic CO2 laser cricopharyngeal myotomy. Laryngoscope 119:45-53, 2009.) Use of the laser at this point is very deliberate to avoid injury to the BPF. The specific micromanipulator or pulsing regimen, whether super pulse, ultra pulse, or mechanically pulsed, is not of significant importance. While the variability in the effect of these pulsing regimens is important when operating on the sensitive and layered structure of the vocal fold, the small differences in-depth of injury are not significant here because the structures are larger and more tolerant of injury. The goal is to use a regimen and equipment that the surgeon is familiar with so there is a level of comfort with the laser and an understanding of the effects of the laser strike for the particular settings chosen. More important than which particular instrument and settings used is the ability to recognize when the BPF has been reached so that it can be kept free from trauma. Considering the importance of the IPC in the function of the upper esophageal sphincter, some promote including transection of its inferior aspect.11 After complete transection of the CP, repositioning the diverticuloscope proxi- mally allows for this to be performed. Often, as dissection approaches the IPC from the CP, bleeding is encountered. If hemostasis beyond the capabilities of a CO2 laser is needed, a neuropledget soaked with epinephrine diluted to 1:10,000 will stop most bleeding, while suction cautery is occasionally necessary. Following transection of the muscle fibers of the CP, the intact BPF is nearly always visible as a contiguous sheet overlying the areolar tissue of the RPS (patient A; Figure 8). However this layer is not consistent. Figure 9, which was extracted from the surgical video, is an example of a patient (patient B) where the BPF is extremely thin to nonexistent. The areolar tissue of the RPS is immediately encountered after CP transection. Despite the presence or absence of BPF, the RPS should not be disturbed and the AF should never be violated. Disruption of these tissue barriers will substantially increase the risk of mediastinitis. At the completion of the procedure, the mucosa, completely transected CP, BPF, and underlying areolar tissue of the RPS are easily discernible (Figure 10). Figure 6 A plane between the mucosa and underlying CP allows retraction of the mucosa to better visualize the muscle and confirm the incision depth. (Reprinted with permission from Pitman MJ, Weissbrod P: Endoscopic CO2 laser cricopharyngeal myotomy. Laryngoscope 119:45-53, 2009.) Pitman and Weissbrod Endoscopic Cricopharyngeal Myotomy 139 Figure 7 The CP muscle fibers retract laterally with each laser pulse. They are easily discernible from the mucosa and underlying fascia. (Reprinted with permission from Pitman MJ, Weissbrod P: Endoscopic CO2 laser cricopharyngeal myotomy. Laryngoscope 119:45-53, 2009.) Figure 8 Intact buccopharyngeal fascia after complete transaction of the cricopharyngeus muscle in patient A. (Reprinted with permission from Pitman MJ, Weissbrod P: Endoscopic CO2 laser cricopharyngeal myotomy. Laryngoscope 119:45-53, 2009.) Figure 9 In patient B the BPF was extremely thin to nonexistent and the areolar tissue of the RPS is immediately encountered upon complete transaction of the CP. (Reprinted with permission from Pitman MJ, Weissbrod P: Endoscopic CO2 laser cricopharyngeal myotomy. Laryngoscope 119:45-53, 2009.) As seen in Figures 8, 9, and 10 the RPS is not empty but filled with areolar tissue. As a result, as demonstrated by patient B’s early postoperative gastrograffin swallow, gross pharyngeal contents will be confined to the area directly involved in the surgery even when the buccopharyngeal fascia is not present or has been minimally disrupted (Figure 11). Although gross pharyngeal contents are contained, air may still track through the RPS. It should be noted that as with patient A, when the BPF is present and undamaged, air does not leak into the RPS (Figure 12). Hence we recom- 140 Operative Techniques in Otolaryngology, Vol 22, No 2, June 2011 Figure 10 At the completion of the procedure, the mucosa, completely transected CP, BPF, and underlying areolar tissue of the RPS are easily discernible. (Reprinted with permission from Pitman MJ, Weissbrod P: Endoscopic CO2 laser cricopharyngeal myotomy. Laryngoscope 119:45-53, 2009.) mend avoiding positive pressure mask ventilation at the end of the surgery, especially in the presence of thin BPF or if the fascia has been inadvertently violated. Some authors recommend sealing the surgical site with fibrin glue or even closure of the mucosa.12 This may not be necessary unless the RPS is exposed but does provide an extra level of security and comfort to the surgeon. Placement of 1 suture in the mucosa creates a pocket that holds the fibrin glue after its application. This technique seems to most effectively seal the RPS without the need to endure placement of numerous sutures, which alone are unlikely to result in a watertight seal and may pull the muscle edges together, reestablishing a functional CP. As with TCPM, there is a wide array of postoperative protocols as to timing of postoperative swallow studies, length of hospital stay, time to oral feeding, and advancement of diet. Convincing studies that evaluate the optimal protocol do not exist. We place patients on ampicillan/ sulbactam and perform a thin barium swallow on the morning of postoperative day 1. If no leak is noted then, patients begin a clear liquid diet. If the diet is tolerated and no complications arise, the patient is discharged home that evening on amoxicillin/clavulinic acid elixir for 5 days. Patients will advance to full liquids on postoperative day 3, maintain a soft diet from postoperative day 5 to 7, and then begin a regular diet. Figure 11 Patient B gastrograffin swallow postoperative day 1. Note containment of contrast by RPS with minimal tracking of air through the space. (Reprinted with permission from Pitman MJ, Weissbrod P: Endoscopic CO2 laser cricopharyngeal myotomy. Laryngoscope 119:45-53, 2009.) Figure 12 Patient A gastrograffin swallow postoperative day 1. Note containment of contrast by RPS in surgical area. Due to intact BPF, there is no evidence of air entry into the RPS. (Reprinted with permission from Pitman MJ, Weissbrod P: Endoscopic CO2 laser cricopharyngeal myotomy. Laryngoscope 119:45-53, 2009.) Pitman and Weissbrod Endoscopic Cricopharyngeal Myotomy An annotated video displaying the technique described above is available for viewing at http://www.nyee.edu/ swallowing.html. 141 employed using the skills already in the armamentarium of most otolaryngology surgeons. Appendix. Supplementary data Complications As discussed above, complications are relatively rare. In 164 patients minor complications consisting of 2 fevers of unknown origin and 1 chest pain were reported as well as major complications consisting of 2 esophageal perforations, 1 prolonged intubation, and 1 suspicion of mediastinitis, which was negative, as well as 1 patient with subcutaneous emphysema. This results in a minor and major complication rate of 1.8% and 3%, respectively, which appears to compare favorably with the complication rate of TCPM, which ranges from 3.7% to 12%.3-5 Mediastinitis due to ECPM has not been described. Much of the attendant morbidity secondary to cricopharyngeal myotomy is due to the age and medically fragile state of many of these patients, highlighting the benefits of minimizing anesthesia time. Discussion When considering surgical treatment for CP dysfunction, ECPM is a safe, reliable, and possibly more attractive option than TCPM. Either approach for myotomy has a relatively low risk of major postoperative complications and good functional outcome. The endoscopic approach is favorable considering the reduced surgical time, reduced recovery time, decreased morbidity, lack of external scar, minimal risk of recurrent laryngeal nerve injury (especially in a revision operation), and most likely a lower overall complication rate. Mediastinitis has not been reported after ECPM. The technique described herein is such that it can be Supplementary data associated with this article can be found, in the online version, at doi:10.1016/j.otot.2011.01.004. References 1. Goyal RK, Martin SB, Shapiro J, et al: The role of cricopharyngeus muscle in pharyngoesophageal disorders. Dysphagia 8:252-258, 1993 2. Kaplan S: Paralysis of deglutition, a post-poliomyelitis complication treated by section of the cricopharyngeus muscle. Ann Surg 133:572573, 1951 3. McKenna JA, Dedo HH: Cricopharyngeal myotomy: Indications and technique. 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Brondbo K: Treatment of cricopharyngeal dysfunction by endoscopic laser myotomy. Acta Otolaryngol Suppl 543:222-224, 2000 12. Richtsmeier W: Simple primary mucosal closure in endoscopic cricopharyngeal myotomy, in Orlando, FL, Triological Society, Combined Sections Meeting; 2010