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
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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.)
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Endoscopic Cricopharyngeal Myotomy
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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.)
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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.)
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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-
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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.
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