**2. Achalasia therapeutics**

Different methods have been proposed for the treatment of this condition, none of which seems to be optimal, as they do not act directly on the pathophysiology of the disease [1, 4, 5]. Thus, the main objective this disease treatment is to rescue swallowing and diagnose potential diseases that may occur in the dilated esophagus, consequent to long lasting food stasis.

Extramucosal cardiomyotomy, with its different technical variants, remains the most widely used surgical procedure, and with the advent of minimally invasive surgery today, the endoscopic (POEM) or laparoscopic approach has been widely accepted [2–7].

The good results obtained in myotomy using the minimally invasive technique are for cases of non-advanced achalasia, corresponding to an esophageal diameter that does not exceed 6 cm and that in high-resolution manometry reveals type II Chicago classification [2–4]. This has recently been well demonstrated in a metaanalysis involving 1575 patients with achalasia type II, submitted to laparoscopic myotomy with fundoplication with medium and long-term follow-up, that demonstrated a success rate with adequate rescue of swallowing in 92% of patients [8]. These results confirm what has been previously demonstrated by other authors who made assessments 1 to 18 years after surgery, in a compilation of 39 series with 3,086 patients with non-advanced achalasia undergoing this surgical procedure, who presented an average of 89% of excellent results [9].

Although laparoscopic myotomy is considered the first-line treatment for non-advanced achalasia, it is an invasive procedure though, that requires general anesthesia, which can lead to greater morbidity in the immediate postoperative period, especially in patients with unsatisfactory cardiopulmonary clinical conditions [2, 4, 10].

This is the reason for the advent of endoscopic myotomy, a procedure described by the Japanese school, and which consists, in the realization, under endoscopic vision, of a long extension submucosal tunnel from the end of the middle esophagus to 2 cm below the columnar squamous junction, in order to expose and section more adequately the esophagus circular muscle fibers [11]. The great advantage of this procedure is to minimize the surgical trauma that can potentially occur with more intensity through the laparoscopic approach [2–4, 12].

Some series have shown in a mean 3-year follow-up after surgery that endoscopic myotomy is comparable in terms of good results to 87 to 93% with the laparoscopic route results when evaluated by the ECKARDT score, thus providing good quality of life in patients with non-advanced achalasia [4, 13–16].

Although endoscopic myotomy has the advantage of avoiding further surgical trauma, in an evaluation carried out in the medium and long term, it has been shown, however, that endoscopic myotomy predisposes to greater gastroesophageal reflux when compared to laparoscopic myotomy, since in the latter a partial fundoplication surgery is performed. This has recently been shown in meta-analysis studies with pH monitoring. It was found that the rate of acid exposure can range from 39 to 58% after endoscopic myotomy decreasing to only 7.6% to 16.8% when compared to surgical myotomy [17, 18].

Although surgical/endoscopic myotomy demonstrates good results in the adequate rescue of swallowing in patients with non-advanced achalasia, this is not evidenced though in patients who have this condition with an esophagus diameter greater than 6 cm and in high-resolution manometry having a type I Chicago classification, due to the lack of adequate contractility of the entire esophagus, as has been shown recently [2–4].

Thus, other authors began to standardize cardioplasty procedures for patients with advanced achalasia, in order to promote a more adequate esophageal emptying, mainly by the techniques described by Thal et al., 1965, Hatafuku et al. in 1972, and Serra Doria et al. in 1968, with the experience of the Brazilian surgical school being outstanding, since in this country, advanced achalasia is quite frequent, due to the predominance of the Chagas etiology [19–22].

However, mid-term studies have shown that cardioplasties have not always yielded satisfactory results, mainly due to the difficulty in emptying the esophagus, and due to the gastroesophageal reflux that such procedure can trigger [20, 22–24]. This fact has been well demonstrated more recently by Aquino et al. [25], who evaluated the 5 years late postoperative period in 19 patients with recurrent advanced achalasia who underwent SERRA DORIA cardioplasty and found that only 38.4% of the patients had normal swallowing and 53.8% of them had regurgitation, concluding that this procedure should only be indicated for patients without clinical conditions justifying esophagectomy.

Based on these considerations, the almost total resection of the esophagus began to acquire a new perspective for the treatment of major achalasia, Camara-Lopes [26], concerned with the poor results of conservative therapy for cases of advanced achalasia of Chagas disease etiology, introduced in Brazil in 1958, the subtotal resection of the esophagus via the right transpleural approach. At the same time, he further recommended that the reconstruction of the transit would be performed in a second surgical stage, through a retrosternal gastroplasty, a surgery that became known after his name.

With the best standardization of this procedure, it was recommended that this surgery be performed at the same time, with the gastric transposition to the cervical region performed by the posterior transmediastinal route, demonstrating the advantages of this technical variant over the previous one, mainly because it leaves the stomach in the space previously occupied by the esophagus, preventing the angulation of the esophagogastric anastomosis; in addition two operative times are avoided, which could cause greater morbidity [27–29].

Although the subtotal esophagus resection could offer the advantage of trying to completely resolve the dysphagia, by removing the entire denervated area of the organ, with great ectasia, it still caused high morbidity [28–30].

Thus, many authors began to indicate more economical resections, acting exclusively in the esophagus distal third section and in the cardia, locations of greatest importance within the achalasia pathophysiology, due to the evident lack of relaxation at the level of the lower esophageal sphincter. Hence, they recommended the distal resection of the organ or simple cardiectomy, either by left thoracolaparotomy, or laparotomy, reconstructing the transit, either by interposition of a jejunal loop [31–33], or with a colon segment [33, 34] or by means of a valved or non-valved intrathoracic esophagogastric anastomosis [33, 35]. However, mid- and long-term postoperative evaluation with distal esophageal resection showed relapse of dysphagia or gastroesophageal reflux in a significant percentage [31, 32, 34].

Thus, the evaluation, carried out both in anatomical and functional studies, demonstrated with more precision that subtotal esophagectomy was the procedure that was even better suited for the treatment of advanced forms of megaesophagus, despite the great extension of the surgery [36, 37]. In turn, patients with advanced disease, usually malnourished and with difficulty in emptying the esophagus, were predisposed to repeated bronchoaspirations, and may present a significant degree of pulmonary impairment, which causes the transpleural pathway to be predisposed to severe postoperative complications, especially in the pulmonary functions [30, 32, 38].

#### *Dysphagia - New Advances*

In the past, the persistence of great surgeons in trying to solve the problem of pulmonary collapse and pleuromediastinal contamination in cases of esophageal cancer led to the recommendation of successful esophagectomy via the cervicoabdominal extrapleural route, in experimental and clinical studies [39].

Based on this experience and always concerned with the obstacle of thoracotomy, over the years, several authors began to indicate esophagectomy without thoracotomy in a rationalized way, in patients with esophagus, cardia or pharyngoesophageal transition malignancy, or even in the case of esophageal stricture, consequence of caustic esophagitis or gastroesophageal reflux [40–44].

Considering that the results were quite favorable, the possibility of performing it for cases of advanced megaesophagus began to be considered. Ferreira [45], seeking to adapt the advantages of subtotal esophagectomy, through a less traumatic technique, especially for patients with severe esophageal ectasia, potentially malnourished and sometimes with pulmonary affections introduced in Brazil cervicoabdominal esophagectomy without thoracotomy, the phleboextraction method, with transit reconstruction through an esophagogastroplasty through the posterior mediastinum, a technique that became known after its author's name.

Thus, with the better standardization of this surgical technique, several authors from the Brazilian surgical school started to use this procedure as a routine in the treatment of advanced megaesophagus [46–49]. Others advocated the resection of the esophagus through the same route, but by rhombodigital mediastinal dissection and detachment [44, 50].

Pinotti [41] and Pinotti et al. [51], improving the evaluation of both procedures, emphasized that they did not provide an adequate approach of the esophagus, and its resection was carried out practically "blindly". Thus, also wanting to avoid the obstacle of thoracotomy, but to provide a wide view of the organ at the mediastinal level for its resection, he proposed a wide frenotomy in the middle portion of the diaphragm, from the esophageal hiatus to the xiphoid appendix. Thus, for more advanced cases of achalasia, a more rationalized technique through the cervicoabdominal approach was deemed suitable. From then on, this technique became known after the name of the author, and was used by other surgeons [49, 50, 52–54].

More recently, with the advent of minimally invasive surgery, resection of the esophagus has been made possible using video laparoscopy [55–57].

Although the resection of the esophagus without thoracotomy, using any of the three technical variations mentioned, could bring the advantages of avoiding the impairment of pulmonary dynamics, such surgery has not been shown to be completely free from complications. Among these, there is the opening of the pleura and consequent hemo or hydropneumothorax, causing greater postoperative morbidity [46, 50, 51, 53, 58]. This can occur, as advanced esophageal achalasia, due to periesophagitis, causes the esophagus to be adhered to the noble structures of the mediastinum and thus during the dissection procedures it may predispose to lesions.

In addition, it is well known that in advanced megaesophagus, stasis esophagitis, which is usually present, predisposes to the development of preneoplastic lesions, such as leukoplakia, and may even progress to malignancy [3, 4, 23, 59, 60].

In view of these considerations, a method was devised that would allow the removal of the esophagus mucosa and submucosa through the esophagus complete invagination, through the combined cervicoabdominal route without thoracotomy and preserving the entire esophageal muscle tunic. Thus, prophylaxis will be performed with the eradication of preneoplastic mucosal lesions that might exist. In addition dissection and detachment of the esophagus at the level of the mediastinum is avoided.
