End-Stage Achalasia: Hard to Define, and Even Harder to Treat

About 5% of patients with achalasia will develop endstage achalasia, characterized by progressive dilatation and increasing tortuosity of the esophagus. In their review article, Csendes et al6 outline the diagnosis and therapeutic options for end-stage achalasia, which is often difficult to manage while being debilitating for patients. The management of end-stage achalasia has often required surgical intervention, including esophagectomy, which is associated with significant morbidity and mortality. Since its first description in 2008, per oral endoscopic myotomy (POEM) has emerged as a less invasive alternative to the surgical treatment of achalasia. POEM permits incisionless myotomy of variable length, and has shown efficacy across achalasia subtypes. The risk of gastroesophageal reflux (GERD) post-POEM has, however, tempered enthusiasm for POEM. In a 2019 randomized control trial, Werner et al found that POEM was as effective as laparoscopic Heller myotomy with Dor fundoplication (LHM-DF), but had a higher rate of reflux esophagitis at 3 months (57% vs 20%).1 While this early GERD discrepancy seems large, it may not in fact be clinically relevant, especially for end-stage patients, as the increased risk of GERD after POEM diminished over time as compared to the laparoscopic Heller myotomy group. Importantly, the risk of severe (LA C and D) esophagitis was low and equal in both groups at 2 years. A subsequent analysis using the Lyon Consensus (defining GERD as acid exposure time ≥6%) found no significant difference in GERD after 2 years between POEM and LHM-DF.2 Long term follow up data on POEM remain limited, but reports suggest about a third of patients will develop long term acid reflux.3 It is important to consider that patients with end-stage achalasia have typically struggled with frequent, debilitating symptoms, often for years. For this population, a risk of GERD that may require chronic acid suppression may be clinically acceptable, and certainly should not disqualify POEM as an option, should its efficacy ultimately be proven. As Csendes et al notes, part of the challenge in treating end-stage achalasia is the lack of a diagnostic consensus. The origin of symptoms in end-stage patients is heterogenous, with contributions from persistent outflow obstruction, dilation, diverticula, tortuosity, and angulation. It is likely that POEM will work best in end-stage patents with persistent obstructive physiology. Recent advances in real-time imaging modalities, such as endoluminal functional lumen imaging probes (EndoFLIP), greatly assist in sub-typing these patients. While further studies will be needed to ascertain how to interpret the wealth of data it generates, EndoFLIP may allow surgeons and endoscopists to determine which patients may respond better to specific techniques, including POEM. Current guidelines recommend that esophagectomy be considered in patients who fail a less invasive treatment modality. Esophagectomy carries significant risks, including pneumonia (2%-22%), anastomotic leaks (4%13%), and 2% to 5% risk of mortality.4 While there is paucity of data on the efficacy of POEM in end-stage achalasia patients, early reports of highly selected series have suggested promising efficacy (95% in n = 23) and an 6-point average improvement in post-procedure Eckardt score.5 While complication rates were reported at 43.5% in this series, over half of these reported complications were gas-related complications (ie, subcutaneous emphysema), which resolved without interventions within 3 to 5 days. Of the remaining complications, 1 patient (4.3%) had a tunnel mucosotomy and 3 patients (13%) had reflux esophagitis.5 Certainly, more high quality studies are needed to ascertain the utility of POEM for end-stage achalasia—however, if similar rates and types of complications are seen in future studies, POEM will likely have a more favorable risk profile than esophagectomy and should play a role in the management of the end stage patient in selected patients. One limitation in interpreting the POEM literature, as Dr Csendes notes, is that the bulk of reports have come from Asian institutions. This is in contrast to much of the surgical literature, which has originated predominantly from western countries. We would propose that this geographic discrepancy is likely related to the origins of these techniques. Both Ernest Heller’s original myotomy for achalasia in 1913, and the subsequent video-laparoscopic revolution in the late 1980s, were first pioneered in Europe, with the majority of early reports on the technique coming from western countries. 1137727 GUTXXX10.1177/26345161221137727Foregut article-commentary2022