disorders [164].
Endoscopic and surgical management
Endoscopic or surgical therapy can be considered in patients with recalcitrant symptoms. The mainstay of these treatments is aimed at altering the muscle tone of the LES. This can be accomplished with stenting of the LES with balloon dilation, injection of agents directly into the LES, or cutting of the LES muscle fibers through endoscopic or surgical myotomy.
Pneumatic dilation is a well‐established technique where a high‐pressured balloon is positioned across the LES with graded dilation performed in an attempt to stretch, and in some cases tear, muscle fibers. Pneumatic dilation does come with increased risk, namely esophageal perforation, as well as symptomatic heartburn post‐procedure. It was initially used broadly as first‐line therapy for achalasia; however, with the advent of HRM, studies have found that pneumatic dilation may be better suited for achalasia patients with esophageal compression rather than patients with spastic achalasia [165]. Data supporting its use in DES is relatively dated, and with the emergence of per‐oral endoscopic myotomy (POEM), the use of pneumatic dilation has lessened [166].
Direct injection of botulinum toxin type A is another alternative treatment. Botulinum toxin A inhibits the release of acetylcholine, thus promoting smooth muscle relaxation. Patients tend to respond to injection therapy; however, there is a high likelihood of symptom relapse, as its effect is transient [167–170]. The data also suggests botulinum injection can reduce chest pain related to DES [171]. In a meta‐analysis of 5 trials with at least 12 months of follow‐up, botulinum toxin had lower remission rates, higher relapse rates, and a shorter time to relapse than pneumatic dilation [172].
Heller myotomy is a surgical myotomy of the LES, which can be performed open or laparoscopic, and is well‐established in the treatment of achalasia. Here the muscle fibers of the LES are ligated without disruption of the mucosal lining of the esophagus. Several meta‐analyses have demonstrated superiority compared to pneumatic dilation and botulinum toxin injection [172–174]. More recently, endoscopic myotomy known as POEM was introduced in 2008 as an alternative to surgical myotomy for the treatment of achalasia [175]. The use of POEM is discussed in substantial detail in other chapters of the book, but in brief, it creates a submucosal tunnel in the distal esophagus to expose circular muscle fibers beyond the LES, allowing for selective myotomy. Studies comparing Heller myotomy and POEM remain in their infancy; however, the available data suggests that POEM allows for a longer myotomy than a laparoscopic Heller and thus may be more efficacious [176]. POEM has proven to be a safe, less invasive, and effective approach when compared to laparoscopic Heller myotomy, and current literature suggest an excellent two‐ to three‐year durability for POEM with response rates of 94%, 91%, and 90% at 12, 24, and 36 months, respectively [177,178].
Initially used for achalasia, in particular Type III achalasia, POEM has been tried successfully on many spastic disorders of the esophagus [179, 180]. Albers et al. evaluated the efficacy of POEM in esophageal chest pain secondary to hypercontractile esophageal motility disorders (including DES) in which 14 patients underwent POEM, with 12 patients showing significant symptomatic relief with a long‐term clinical success rate of approximately 85% [181]. In a retrospective review of 40 patients undergoing POEM for non‐achalasia motility disorders, Filicori et al. found 90% of patients had improvement in their mean Eckardt scores (5.02 vs. 1.12, p < 0.001), chest pain (1.02–0.36, p = 0.001), and dysphagia (2.20 vs. 0.04, p = 0.001) [182]. A systematic review and meta‐analysis on the use of POEM in spastic esophageal disorders found the pooled clinical success rate was 87% [183]. The weighted pooled response rates were 92% Type III achalasia (116 patients), 88% distal esophageal spasm (18 patients), and 72% jackhammer esophagus (37 patients) [183]. Clinical success was significantly higher for Type III achalasia than for jackhammer esophagus (p = 0.01) [183]. The most recent randomized controlled trial including 130 patients and comparing POEM to pneumatic dilation found POEM was associated with significantly improved Eckardt scores compared to pneumatic dilation (92% vs. 54%; p = 0.01) [184]. Although only 18 of the 130 patients in this study had Type III achalasia, subset analysis of these patients was not provided. It is our current practice to refer Type III patients for POEM whereby a more extended myotomy is performed, as opposed to the more limited myotomy with the Heller procedure. We believe the high reported CP seen following the Heller procedure for these patients is reduced with the POEM related myotomy.
Although there is an excellent clinical response to POEM, a common post‐POEM complication that clinicians should be cognizant of is significant reflux, with GERD and erosive esophagitis occurring in 58% and 23% of patients, respectively [185]. Compared to laparoscopic Heller myotomy, POEM is associated with an odds ratio of 9.31 for the development of erosive esophagitis [186]. This GERD and erosive esophagitis can be safely and effectively managed with antisecretory therapy [187].
Conclusion
Noncardiac chest pain is a frequently encountered clinical scenario, with GI causes implicated for 10–20% of cases, the majority of which are esophageal in origin [3]. Among causes of esophageal chest pain, nearly half the cases are due to GERD [23–25]. Evidence has shown that an empiric trial of a PPI for GERD in patients presenting with ECP can be both therapeutic and diagnostic [31–37]. The prevalence of GERD as the etiologic factor in ECP is so high that, even when patients are not responding to PPI, we advocate for pH‐impedance monitoring as the next step to exclude subclinical reflux as a source of symptoms. For those patients without an anticipated response to PPI without evidence of symptom corresponding reflux on pH‐impedance monitoring, high‐resolution manometry is the most appropriate next step for diagnosis and best‐directed therapy. Among motility disorders, achalasia, jackhammer esophagus, and distal esophageal spasm are most closely associated with ECP. More in‐depth discussion of these treatment options is discussed in separate chapters (Chapters 15, 16, 25, 27, 28, 34, and 35); however, they include medications (calcium channel blockers, nitrates, and phosphodiesterase inhibitors), pneumatic balloon dilation, botulinum toxin injection, and either surgical or endoscopic myotomy. The use of POEM, in particular, for superior treatment of ECP patients with Type III achalasia has a best practice recommendation [177, 178]. Finally, a subset of patients without GERD and with no evidence of motility disorders are characterized by the presence of esophageal hypersensitivity. While the treatment options of esophageal hypersensitivity are varied, they remain largely focused on the overlap with functional gastrointestinal and mental health disorders, relying on antidepressants and non‐pharmacologic behavioral interventions as a mainstay of initial therapy. Certainly, the evaluation of and treatment of ECP can pose a clinical challenge owing to the ambiguity of patient presentation and symptomatic complaints. For this reason, we advocate for the algorithmic approach (Figure 2.1), which tailors the evaluation and treatment in a cost‐effective and evidence‐based rational.
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