Baylor University Medical Center Proceedings October 2017 - 420

The per-oral endoscopic
myotomy procedure
The patient is taken to the
operating room in a supine position to undergo endotracheal
intubation and general anesthesia. A bite block is placed
in the patient's mouth, and the
endoscope is used to remove
any bezoar in the esophagus or
stomach. An overtube is used.
Once in place, the overtube is
secured in place at the mouth
and will be used to measure the
anatomic landmarks. The high
pressure zone is identiﬁed and
recorded at the distal esophagus
outlining the hypertensive LES.
Two centimeters is then added
to each end of the high pressure
zone to encompass the length
of the myotomy, usually around
Figure 1. Patients enrolled in the achalasia registry. POEM indicates per-oral endoscopic myotomy; LHM, laparoscopic 6 cm. Four centimeters is then
Heller myotomy.
added to the proximal margin
of the myotomy to identify the
level of the mucosotomy. A solution of diluted methylene blue
pressure, percentage of patients with aperistalsis, and type of
is created containing saline, epinephrine, and methylene blue.
achalasia based on Chicago classiﬁcation. Data on the operaTwo milliliters of concentrated methylene blue is loaded into an
tions included length of procedure and hospital length of stay.
endoscopic needle injector, followed by the dilute solution. The
Adverse events were noted as any event that was a deviation
endoscope is then passed down the esophagus to the stomach
from the normal expected course. Eckardt scores were collected
and, on retroﬂexion, 2 mL of concentrated methylene blue is
preoperatively and postoperatively. The postoperative collection
injected in the submucosa on the lesser curvature of the stomach
was done at an interval of immediately after surgery (<1 month)
2 cm from the LES. This will act to mark the distal extent of
and long-term follow up (>6 months). The Eckardt score is a
the myotomy so it can be seen in the submucosal tunnel. The
validated scoring system to grade symptoms of achalasia patients
endoscope is then withdrawn and a dissecting cap is placed on
on a scale of 0 to 12. There are four components: regurgitation,
the end of the endoscope. It is passed down the esophagus, and
chest pain, dysphagia, and weight loss. The ﬁrst three receive a
a 10 mL injection of dilute methylene blue solution is injected
score of 0 for none, 1 for occasionally, 2 for daily, and 3 for each
into the submucosal plane at the previously obtained mucosomeal. Weight loss receives a score of 0 for no weight loss, 1 for
tomy measurement contiguous with the lesser curvature of the
<5 lb, 2 for 5-10 lb, and 3 for >10 lb (22). Success of myotomy
stomach along the right side of the esophagus. The injection
is based on a total Eckardt score of ≤3 at follow-up (23). Informaserves to separate the mucosa from the circular muscle as the
tion on all complications for the procedures was also collected.
ﬂuid collects in the submucosa.
There were no deﬁnite criteria to determine the surgical
A triangle tip knife is used to incise the mucosa at the level
intervention for each patient. Most patients were oﬀered POEM
of the planned mucosotomy. The endoscope and cap enter the
and LHM and were allowed to choose. However, in some cases
submucosal plane through the mucosotomy; a 3 mL biliary
insurance reimbursement prevented POEM and patients deballoon dilator can be used to assist. Using cautery on the trifaulted to LHM. The redo LHM cohort was not oﬀered POEM
angle tip knife, a submucosal tunnel is created separating the
because their recurrent symptoms appeared to possibly be resubmucosa from the circular muscle down to the concentrated
lated to the fundoplication on preoperative workup as well as
methylene blue mark in the submucosa on the stomach side of
inadequate myotomy.
the LES. Cautery is then used to cut the circular muscle ﬁbers,
We compared characteristics and outcomes of patients who
exposing the longitudinal ﬁbers the length of the predetermined
underwent POEM versus LHM using independent sample t test,
myotomy length. The endoscope is then removed from the subWilcoxon two-sample test, and Fisher's exact test. Paired t test was
mucosal plane and hemoclips are used to close the mucosotomy.
used to assess changes in Eckardt score between preoperative and
In instances of capnoperitoneum and respiratory alterations
postoperative data within procedure groups. Statistical analyses
reported by anesthesia personnel, a Veress needle is used to dewere performed using SAS version 9.4 (SAS Institute, Cary, NC).
compress the peritoneal insuﬄation. The CO2 insuﬄation will
Two-tailed P values < 0.05 were considered statistically signiﬁcant.
420

Baylor University Medical Center Proceedings

Volume 30, Number 4

Table of Contents for the Digital Edition of Baylor University Medical Center Proceedings October 2017