What is esophageal achalasia and how can it be treated? Our expert in General Surgery in Avellino answers , Dr. Luca Covotta
What is esophageal achalasia?
L ‘ achalasia is a rare disease of the esophagus characterized by an alteration of esophageal peristalsis (movement that allows food to pass from the mouth to the stomach) and the inability to relaxation of the lower esophageal sphincter (valve would be placed between the esophagus and stomach ). Generally, when we swallow, the sphincter is released allowing the food bolus to move into the stomach; but in case of achalasia this always remains tonic and cannot fully relax, causing stagnation of food material in the esophageal lumen. According to estimates, the incidence of achalasia is around 0.6-1 new cases per 100,000 inhabitants per year and mainly affects men and women (without differences) between the ages of 30 and 50.
What can be caused by?
The cause is still poorly understood. According to a rather suggestive hypothesis it seems that an anatomical alteration of the nerve structures of the muscular layer of the esophagus can be determined due to an immune-mediated response to a viral pathogen (for example herpes virus). That is, our immune system, stimulated by this viral infection, attacks the nerve structures of the esophagus thus causing the loss of motor function.
How does it manifest itself?
The typical symptom of achalasia is dysphagia (feeling of food stopping in the esophagus), which occurs with both liquids and solids, although initially it can be paradoxical given that the patient correctly swallows solids and not liquids. Other symptoms include:
- Regurgitation of food (in 70% of cases undigested) which occurs in particular at night and is favored by decubitus;
- Night cough due to regurgitation, which penetrates the respiratory tract;
- Sialorrhea (excessive salivation);
- Halitosis, caused by stagnation of food in the esophagus;
- Chest pain and heartburn may (present in 30% of cases) due to increased esophageal pressure;
- Weight loss.
How is the diagnosis made?
L ‘ endoscopy serves primarily as a differential diagnosis investigation to exclude any mechanical causes of obstruction (eg. Esophageal cancer, inflammatory stenosis). Only in advanced forms can there be a stagnation of food and an increase in the size of the bowel, so much so that in some cases we speak of a “megaesophagus”. In Radiology, by making the patient drink contrast, we evaluate both the conformation of the esophagus and the rapidity with which the esophageal sphincter opens. Also in this method, only in the full-blown pathology, is the so-called characteristic sign of the “mouse tail” visible, ie the enlarged esophagus with the very thin esophagus-gastric passage. Both of these methods are not useful in the early, but already symptomatic, diagnosis of this disorder.
The gold standard detection for early diagnosis is the manometry esophageal, which through a feeding tube in the nose analyzes the motor function of the esophagus and the coordination with the lower esophageal sphincter. In recent times this method has had a great development in terms of sensitivity, so much so that we speak of High Resolution Manometry precisely to differentiate it from the previous one: it consists of a considerable increase in the number of sensors positioned in the tube and sophisticated software for analysis some data.
Thanks to this new method, today we know that there are three subcategories of achalasia:
- Type I (classical) complete absence of peristalsis;
- Type II (with esophageal pressurization) single and sometimes repetitive contractions;
- Type III, characterized by the absence of normal peristalsis and the presence of premature high-amplitude contractions.
This division is extremely important, because it also allows to predict the response of patients to both endoscopic and surgical treatment.
Drug therapy for esophageal achalasia
The therapy aims to reduce the tone of the LES and to eliminate the obstruction that hinders the passage of food in the stomach . Medical therapy involves the intake of calcium channel blockers which, acting on the smooth muscle of the lower sphincter, allow temporary relaxation. These drugs are frequently prescribed for the therapy of cardio-vascular pathologies, with possible side effects such as headache and hypotension, and their use in case of achalasia is very limited, especially in elderly people or in unsuitable general conditions.
What does endoscopic therapy instead provide?
There are three endoscopic methods:
- The injection of botulinum toxin: the action of this toxin is to inhibit the contraction of smooth muscles, therefore a paralysis is induced that counteracts the hypertonicity of the sphincter. The immediate results are good, but relapses frequently occur with the need for repeated injections. In addition, the onset of resistance to therapy occurs in 40-50% of cases;
- The pneumatic dilation of the cardias: it is effective if performed with special cylindrical dilators of variable diameter, but as in the case of botulinum toxin the risk of recurrence remains quite high. The risk of perforation of the esophagus is 2%;
- POEM (per-oral endoscopic myotomy): an innovative endoscopic technique that seeks to reproduce the aims of surgical therapy. In fact, a myotomy (section of the muscle fibers of the esophagus) is performed with a special scalpel introduced through the endoscope. It is an extremely effective technique with a success rate of between 80 and 90%. Also in the case of type III achalasia it is the most successful therapeutic choice. Unfortunately, this method is burdened by a very high percentage of post-treatment gastro-esophageal reflux that reaches 40-50%.
What does the surgery consist of?
It consists of the myotomy called “according to Heller”, that is the section of the smooth muscle of both the terminal esophagus and the first centimeters of the stomach. By reducing the pressure of the esophageal sphincter, the resolution of dysphagia is allowed in most cases but, obviously, the rise of acidic material from the stomach to the esophagus (gastro-esophageal reflux) increases considerably, as in the case of POEM. For this reason, myotomy is associated with a simultaneous operation to reinforce the pressure in the esophagus-gastric junction called “antireflux plastic” or ” funduplication “,positioning the gastric fundus on the area of the myotomy called “partial anterior funduplication according to Dor”. This surgery is performed with a minimally invasive technique in laparoscopy, avoiding the patient the trauma of a large abdominal scar. Furthermore, this approach offers the possibility to the surgeon to have a greater light on the operating field and a greater image amplification, thus reducing the risk of partial myotomies that can expose the patient to annoying relapses.
Surgical treatment has a success rate of over 90% and is therefore still considered the therapy of choice for the treatment of achalasia, in particular of type I and II. Only for type III, a possible superiority in terms of the efficacy of the POEM is to be discussed, but the disadvantage of post-treatment reflux should always be considered.