Introduction
Hypercontractile esophagus, previously referred to as “nutcracker esophagus,” was
defined manometrically by a mean distal contraction amplitude of 180 mmHg. This definition
was plagued by a lack of specificity and poor symptom correction [1]
[2]. With the introduction of high-resolution manometry (HRM) in 2000, there have been
changes to the manometric criteria for hypercontractile esophagus. The most recent
definition is a distal contractile integer (DCI) of ≥ 8000 mmHg.cm.s in ≥ 20 % of
swallows and has been coined “Jackhammer esophagus.” With this definition, there is
improved specificity and symptom correlation compared with the previous criteria with
standard manometry [3].
Jackhammer esophagus is rare, occurring in approximately 4 % of cases referred to
a tertiary esophageal center [4]. The treatment of Jackhammer esophagus has included oral nitrates, balloon dilation,
and surgical myotomy [5]. Surgical myotomy has not been widely performed due to the usual requirement for
a long myotomy to achieve clinical success, which generally necessitates a combined
abdominal and thoracic approach if a complete myotomy of the LES is to be performed
[6]
[7]
[8]. With peroral endoscopic myotomy (POEM), a long myotomy is possible without increased
morbidity or technical difficulty. However, experience with POEM for Jackhammer esophagus
has been limited due to the rarity of the disorder. In addition, the inclusion/exclusion
of the lower esophageal sphincter (LES) in the myotomy is debated and variably performed,
perhaps contributing to inconsistent clinical outcomes in Jackhammer esophagus [9]
[10]
[11]. POEM was performed on four patients with Jackhammer esophagus at our center. Here
we will present the clinical and manometric results and discuss the treatment implications.
Patients and methods
Between January 2014 and July 2015, four patients underwent POEM for treatment of
Jackhammer esophagus at our center. Written informed consent for POEM was obtained
from all patients. In this series, data was prospectively collected and retrospectively
examined. All patients had undergone a trial of at least 2 weeks on a proton pump
inhibitor (PPI) without improvement in symptoms. Manometry was performed using the
Starlet® system (Star Medical, Tokyo, Japan) (Normal integrated relaxation pressure [IRP]
for Starlet® system 25 mmHg [12]) prior to and 2 months after POEM. The diagnosis of Jackhammer esophagus was based
on the manometric criteria stated above. All patients met the criteria for Jackhammer
esophagus and received a barium esophagram and endoscopic examination prior to POEM.
Furthermore, one patient (Patient 3) received a computed tomography (CT) scan because
of elevated IRP in addition to a distal contractile integral (DCI) ≥ 8000 mmHg.cm.s
in ≥ 20 % of swallows. Follow-up was performed every 3 months for the first year then
annually thereafter or sooner if issues developed.
The POEM procedure was performed as previously described [13]. Briefly, a submucosal bleb was created with saline and indigo carmine. The point
at which the tunnel was started was based on the manometry, barium esophagram, and
endoscopic examination. The objective was to start the myotomy at the most proximal
extent of the hypertensive contractions. A 2- to 3-cm longitudinal mucosal incision
was made, submucosal entry achieved, and the submucosal tunnel was created. When the
LES was included in the myotomy, the tunnel was advanced 2 to 3 cm into the gastric
cardia. The myotomy was advanced from 1 to 2 cm distal to the mucosal incision to
the distal end of the tunnel. However, when the LES was not included the tunnel the
myotomy was only advanced to the distal esophagus. After prophylactic antibiotics
were instilled, the mucosal entry site was closed with hemostatic clips. On Day 1
post-procedure, all patients received a barium esophagram and endoscopy to confirm
the mucosal integrity. The diet was advanced over 4 days and patients were discharged
on day 4 post-procedure.
Results
The manometric and clinical results are summarized in [Table 1] and details about each patient are described below. All patients had uneventful
procedures without any intraoperative or post-procedure complications. Esophageal
manometry, upper endoscopy, and clinical (Eckardt score, gastroesophageal reflux symptoms)
examinations were performed 2 months post-POEM. No patients developed clinical or
endoscopic evidence of reflux.
Table 1
Patients with Jackhammer esophagus treated with POEM.
|
Patient
|
Myotomy (cm)
|
LES included
|
Median IRP (mmHg)
|
Mean DCI (mmHg.cm.s)
|
Eckardt score
|
IEM[*]
|
|
|
|
Before
|
After
|
Before
|
After
|
Before
|
After
|
|
|
1
|
20
|
–
|
19.5
|
23.5
|
12 516.5
|
84.2
|
2
|
6
|
+
|
|
2
|
21
|
+
|
16.4
|
10.5
|
18 332.4
|
137.7
|
5
|
0
|
+
|
|
3
|
12
|
+
|
33.8
|
16.2
|
46 700
|
2019.6
|
5
|
0
|
–
|
|
4
|
23
|
+
|
7.3
|
12.4
|
15 388.7
|
234
|
11
|
2
|
+
|
* IEM-ineffective esophageal motility after POEM = ≥ 50 % ineffective swallows (failed
or weak contraction vigor [DCI < 450 mmHg.cm.s])
Patient 1
A 74-year-old man presented with a 15-year history of weekly to daily severe noncardiac
chest pain associated with swallowing. An endoscopy revealed no mucosal pathology
and a small epiphrenic diverticulum. Manometry exhibited multi-peaked contractions
with a mean DCI of 12 516.5 mmHg.cm.s and median IRP of 19.5 mmHg ([Fig. 1]). A 20-cm myotomy was performed, sparing the LES due to lack of its involvement
in the abnormal contractions. The patient’s chest pain completely resolved, but he
developed frequent dysphagia and regurgitation (Eckardt score 6). Six months later,
the patient underwent a second POEM with a 10-cm myotomy that included the LES, resulting
in the resolution of dysphagia and regurgitation (the patient chose to forego repeat
manometry after the second POEM). Clinical follow-up was achieved for a total of 18
and 6 months after the first and second POEM’s, respectively. ([Fig. 1])
Fig. 1 Patient 1 HRM pre- and post-POEM #1. a Multi-peaked contractions with DCI of 12 516.5 mmHg.cm.s and median IRP of 19.5 mmHg.
b Post first POEM showing a lack of abnormal contractions with failed contraction vigor
with a mean DCI of 84.2 mmHg.cm.s and median IRP of 23.2 mmHg.
Patient 2
A 68-year-old man with a 33-year history of regurgitation and dysphagia presented
with progression of symptoms and weight loss (Eckardt score 5). Manometry demonstrated
a mean DCI of 18 332.4 mmHg.cm.s and a median IRP of 16.4 mmHg with inclusion of the
LES in the hypercontractile segment ([Fig. 2]). The patient received a POEM with a 21-cm myotomy that included the LES. After
POEM, the patient’s symptoms completely resolved (Eckardt score 0). The follow-up
HRM demonstrated a DCI of 137.7 mmHg.cm.s and a median IRP of 10.5 mmHg. Clinical
follow-up was achieved for a total of 12 months after POEM. ([Fig. 2])
Fig. 2 Patient 2 HRM pre and post-POEM. a Hypercontractile contractions with a mean DCI of 18 332.4 mmHg.cm.s and median IRP
of 16.4 mmHg b Post-POEM with no abnormal contractions with a weak contraction vigor with a mean
DCI of 137.7 mmHg.cm.s and median IRP of 10.5 mmHg.
Patient 3
An 87-year-old man with a 40-year history of dysphagia presented with symptom progression
leading to weight loss (Eckardt score 5). Manometry demonstrated a mean DCI of 46 700 mmHg.cm.s
with a median IRP 33.8 mmHg with the LES included in the hypercontractile segment
([Fig. 3]). A CT scan was also performed in light of the elevated IRP, which did not reveal
any infiltrative, neoplastic or vascular obstruction at the distal esophagus. The
patient received a 12-cm myotomy that included the LES, which resulted in complete
symptom resolution (Eckardt score 0). Clinical follow-up was achieved for a total
of 12 months after POEM ([Fig. 3])
Fig. 3 Patient 3 HRM pre- and post-POEM. a Hypercontractile contractions with a mean DCI of 46 700 mmHg.cm.s and median IRP
33.8 mmHg b Post-POEM showing no abnormal contractions and a normal contraction vigor with mean
DCI of 2019.6 mmHg.cm.s and median IRP 16.2 mmHg.
Patient 4
A 37-year-old man with a 6-year history of dysphagia, regurgitation, chest pain presented
with deterioration of symptoms resulting in weight loss (Eckardt score 11). HRM showed
DCI of 15 388.7 mmHg.cm.s and median IRP 7.3 mmHg ([Fig. 4]). The patient received a POEM with a 23-cm myotomy that included the LES. After
POEM, the patient regained the weight he had lost and his chest pain completely resolved
with only occasional dysphagia and regurgitation (Eckardt score 2). Clinical follow-up
was achieved for a total of 12 months after POEM ([Fig. 4]) ([Table 1]).
Fig. 4 Patient 4 HRM pre- and post-POEM. a Hypercontractile contractions with a mean DCI of 15 388.7 mmHg.cm.s and median IRP
7.3 mmHg b Post-POEM showing no abnormal contractions with a weak contraction vigor with a mean
DCI of 234 mmHg.cm.s and median IRP 12.4 mmHg.
Discussion
With inclusion of the LES in POEM for Jackhammer esophagus, Patients 2, 3, and 4 had
excellent clinical results. In contrast, Patient 1 in whom LES was not included in
the myotomy developed regurgitation and dysphagia. However, after the second POEM
that included the LES, his symptoms of dysphagia and regurgitation resolved. With
Patient 1, the HRM was consistent with Jackhammer esophagus, with a mean DCI of 12 516.5 mmHg.cm.s
and a normal IRP. However, the IRP was in the upper range of normal and one could
speculate that the patient was progressing to achalasia and had a variant of “incompletely
expressed” or “early” achalasia.
The progression from hypercontractile esophagus or diffuse esophageal spasm (DES)
to achalasia has previously been described, suggesting that the spastic esophageal
motor disorders may represent a spectrum of a single disease entity [14]
[15]. Interestingly, there have been no reports of progression from one spastic disorder
to another demonstrated with HRM. This may be due to the previous misdiagnosis with
standard manometry, the superior sensitivity and specificity of HRM, and the new Chicago
classification. That, on the other hand, would support the notion that the spastic
esophageal motor disorders are separate entities rather than a spectrum of a single
pathology. The successful treatment of Jackhammer esophagus usually requires a long
myotomy, often two-thirds or more the length of the esophagus, which can often result
in iatrogenic ineffective esophageal motility [16]. This was demonstrated in our series by the fact that all patients with a myotomy
20 cm or longer developed ineffective esophageal motility (≥ 50 % ineffective swallows),
while the patient with a 12-cm myotomy had persevered contraction vigor. Without involvement
of the LES in the hypercontractile segment, inclusion of LES in the myotomy has been
a contentious topic. However, we postulate that routine inclusion of the LES in POEM
for Jackhammer esophagus should be performed for the following reasons:
-
Patients with Jackhammer esophagus typically require a long myotomy, which results
in diminished contraction vigor and in many cases iatrogenic ineffective esophageal
motility. In some patients, gravity and the remaining propulsive force is inadequate
to propagate the food bolus across the preserved LES. Without the inclusion of the
LES in the myotomy to further reduce outflow resistance, symptoms analogous to achalasia
may develop (regurgitation, dysphagia, and chest pain). Thus, there is a critical
(currently unknown) length of esophageal myotomy that once exceeded, results in ineffective
esophageal motility, inadequate food bolus propulsion, and symptom development. The
importance of LES inclusion was demonstrated in a case report by Badillo et al., in
which a 50-year-old woman received POEM for Jackhammer esophagus, resulting in worsening
symptoms post-POEM. She subsequently presented with continued deterioration in symptoms
and was found to have an 8-cm anterolateral diverticulum with moderate narrowing of
the gastroesophageal junction. [17] Based on her immediate post-POEM symptom deterioration and subsequent development
of the diverticulum, it is highly likely the LES was not included in the myotomy analogous
to, although more dramatic, than our Patient 1.
-
There is evidence that the non-achalasia spastic esophageal motility disorders can
progress to achalasia. Albeit rare, if there is progression to achalasia and the LES
is preserved, symptom development would occur and the patient would require additional
treatment.
-
The risk of complicated reflux developing due to myotomy of the LES is negligible.
Although there is indeed a significant risk of reflux after POEM (up to 50 %), there
are no cases of reflux refractory to PPI, and only one report of a peptic stricture.
[18]
[19]
[20]
In conclusion, POEM is a suitable treatment for patients with Jackhammer esophagus.
Based on our clinical experience and physiologic and manometric observations, we speculate
that the obligatory inclusion of the LES is justified. Inclusion of the LES minimizes
the risk of symptom development from iatrogenic ineffective esophageal motility or
subsequent progression to achalasia. Furthermore, from our experience, in addition
to the thousands of cases of POEM published, the risk of reflux-related complications
has been shown to be marginal. Thus, it appears that the risks associated with LES
exclusion are far greater than the risks of reflux-associated complications of LES
inclusion. However, given the low incidence of Jackhammer esophagus, an international,
multicenter randomized trial is required in order to obtain a definitive evidence-based
answer to whether routine inclusion/exclusion of the LES in the application of POEM
for Jackhammer esophagus is warranted.
