Esophageal achalasia is a motility disorder characterized by the lack of esophageal peristalsis and failure of the Lower Esophageal Sphincter (LES) to relax.[1] The word achalasia is derived from the Greek khalasis, translated as “not loosening or relaxing.”[2] The clinical presentation is characterized by dysphagia, typically for both solids and liquids, and regurgitation of ingested food or saliva.[1–3] Some patients report retrosternal discomfort, pain, or burning.[4] While achalasia is a rare condition, it is the most common primary motility disorder of the esophagus with a prevalence of 10 cases per 100,000 individuals and an annual incidence of 1.6 per 100,000 individuals.[6–7] The rise in prevalence and incidence was seen in both genders equally.[8–12] However, some investigations have detected a slightly higher incidence in females,[13–15] while the prevalence was noted to be more pronounced in males.[6] A few studies have suggested a bimodal distribution of incidence by age, with peaks at around age 30 and 60 years,[8, 9, 16] while others have pointed towards a generally increased risk of achalasia with advancing age.[10–12]
The etiology of this condition is not entirely known. The possibility of a multifactorial etiology is currently an important topic of study. Evidence suggests that the inflammatory degeneration that occurs in the regulatory neurons of the myenteric plexus has an autoimmune component. Such an autoimmune mechanism would be supported by the presence of circulating anti-nuclear antibodies (present in 56–68% of patients) and the increased prevalence of circulating IgG antibodies against the cytoplasm and nucleus of neuronal cells from the myenteric plexus in most patients with achalasia (54.3–100%).[17] It has been hypothesized that an infectious agent may represent the trigger for an immune reaction in the myenteric plexus. This immune response eventually overcomes the infectious insult, but in genetically predisposed individuals, it may create susceptibility to this disease and damage the ganglion cells. Several studies have suggested that chronic latent or active viral or bacterial infections are associated with achalasia. HSV-1, JC virus, bornavirus, VZV, measles, and HPV are among the possible etiologic factors.[1, 18] Immunohistochemical studies have demonstrated that selective loss of the nitrergic LES nerve fibers occurs in achalasia, thus resulting in unopposed contractile stimuli.[19–21]
It has been previously described that achalasia is a disease that develops slowly.[22, 23] Patients often present late in the course of this disease, when their clinical situation, evidenced by their symptoms as well as their anatomical and physiological abnormalities, have become severe. In some cases, however, it might present in a non-advanced stage.[1] In the less advanced stages, high-resolution manometry (HRM) is considered the gold standard for the diagnosis.[24] However, timed barium swallow (TBS) is used for assessing the esophageal changes such as megaesophagus (> 6 cm in diameter), tortuosity, and angulation.[18, 25–29]
In 1960, Ellis described three stages in the natural history of achalasia in 33 patients.[30] Stage I “onset” is characterized by sudden pain, dysphagia, and regurgitation. Patients treated conservatively then progressed to Stage II “the silent period” which occurs when the symptoms improve due to a dilated esophagus that can accommodate a normal meal without distension and to the techniques that patients learn to facilitate the onward passage of food through into the stomach. Patients in this stage can maintain or even increase their weight. The final stage, “progressive deterioration” occurs 20 years or more after the initial diagnosis, and patients present with severe weight loss, malnutrition, and respiratory infections. Ellis observed that these clinical stages correspond radiologically to progressive dilation, elongation, and tortuosity of the esophagus.[30] Csendes followed 14 patients without surgical treatment and observed a rate of “dilation” of 6.1 mm/year.[31] To date, the factors that might contribute to the progressive esophageal dilation remain unknown. Although we know that patients with achalasia present with progressive esophageal dilation, it is still not clear if this dilation develops proportionally with the duration of symptoms. There are few studies that specifically address the determinants of esophageal dilation in patients diagnosed with achalasia.
Achalasia is a chronic condition without cure.[29] The objective of management is directed toward relieving the esophageal outflow obstruction by lowering the LES tone or disrupting the LES, which thereby leads to an improvement in esophageal emptying and a lessening of the patients’ symptoms.[4] Laparoscopic Heller myotomy (LHM) plus partial fundoplication are among the preferred treatment options for achalasia, with the main objective of eliminating the physiologic barrier at the Esophago-Gastric Junction (EGJ). [29, 32] Most patients respond to this treatment, with an 80%-90% success rate, while only about 5–15% will have persistent symptoms and disease progression to its final stage, as characterized by an unsalvageable esophagus with massive dilatation and/or the loss of the esophageal straight axis.[27, 28, 33, 34] Definitive treatment of such patients involves LHM or esophagectomy. Per 2018 ISDE achalasia guidelines, pneumatic dilation is not recommended as a first line therapy in patients with megaesophagus.[35] Laparoscopic myotomy is more successful than esophagectomy in terms of improving dysphagia, even when the esophagus is larger than 6 cm in diameter and sigmoid-shaped.[18, 25, 26] Because esophagectomy is associated with greater morbidity and mortality than laparoscopic Heller myotomy, it should be reserved as the final option in those patients who have failed all other forms of more conservative therapy.[2, 25, 29]
The aim of the study was to determine if the duration of symptoms is proportionally related to the degree of esophageal dilation. To identify other important factors that might contribute to esophageal dilation and to determine if there are clinical indicators that could help predict its progression.