Peroral endoscopic myotomy for the treatment of achalasia in the Unified Healthcare System (SUS): results of a short-term

ABSTRACT Introduction: achalasia is a chronic disease. Since there is no curative treatment, diagnosed patients have pharmacological and/or surgical techniques available, aimed at minimizing the condition. POEM appears as a promising new type of palliative treatment with good rates of symptom improvement. Objective: evaluate the profile of POEM at the Clinical Hospital of the Federal University of Pernambuco (HC - UFPE) and correlate it with the world scenario. Methods: data collection was performed retrospectively from September 2017 to October 2019 with all patients undergoing POEM at the HC - UFPE. Sociodemographic, clinical, and hospital variables were evaluated before and three months after the procedure. Results: of 27 patients (52.41 ± 19.24 years old) who underwent the procedure, 66.7% had idiopathic etiology and 33.3% had etiology secondary to Chagas disease. 48% patients underwent previous procedures, of which seven used some type of medication for symptom control, two underwent pneumatic endoscopic dilation, and four underwent Heller cardiomyotomy with partial fundoplication. 62.5% of the evaluated patients had type II achalasia before the procedure. Seven (25.9%) patients presented the following adverse events: four presented bleeding, two pneumoperitoneum, and one both complications, all being treated conservatively. The Eckardt score reduced from 8.37 ± 1.45 to 0.85 ± 1.06 (p-value <0.001). Conclusion: clinical improvement of symptoms and the patient profile followed the worldwide trend, with emphasis on the etiology secondary to Chagas disease, endemic in Brazil. Gastroesophageal reflux remains the main post-operative symptom.

and/or surgical techniques in order to minimize the clinical condition.Botulinum toxin injection, endoscopic pneumatic dilation and Heller cardiomyotomy with partial fundoplication, which is the gold standard in therapy, are among the options with the best success rates 7,8 .
In this context, a new surgical approach was developed by Inoue and collaborators, the peroral endoscopic myotomy (POEM) 9,10 .The POEM, besides being a safe technique, minimally invasive, and with success rates equivalent to surgery, the existence of previous procedures, both clinical or surgical, do not contraindicate its performance 8,11 .This study evaluates the etiological, sociodemographic, clinical and hospital profile of patients, besides their results immediately and three months after undergoing POEM at the Clinical Hospital of the Federal University of Pernambuco (HC -UFPE).The collected data included sociodemographic, clinical, and hospital variables.Symptoms were evaluated using the Eckardt score in the preoperative period and at the return visit (two to three months later), in which any complications and symptoms were evaluated.This score consists of a self-reported evaluation used to quantify the main symptoms pre-and post-treatment.Active achalasia is considered when the score is higher than three points and treatment effectiveness is considered when the score is lower and/or equal to three [5][6][7] .Regarding the procedure, the following data were evaluated: size of the tunnel and myotomy performed, partial or total section of the circular fibers, and complications during the procedure.

RESULTS
POEM was performed in a total of 27 patients (13 women -48.9% and 14 men -51.1%, with mean age of 52.41 ± 19.24 years old).Clinical and epidemiological data were summarized in Table 1.The predominant etiology was idiopatic, with 18 patients (66.7%), with esophagopathy secondary to Chagas disease being the second most predominant etiology with nine patients (33.3%).Thirteen patients (48%) who underwent POEM had already undergone some type of previous procedure.
Out of these, seven (53.8%) used some type of medication for symptom control, two (15.4%)underwent pneumatic endoscopic dilation, and four (30.8%) underwent Heller cardiomyotomy with partial fundoplication, most of them underwent POEM in Rezende and Mascarenhas' type II (58%).According to Rezende and Mascarenhas's classification, there was a predominance of type II (62.5%), followed by type III (21%), type I (12.5%), and only one patient (4%) had type IV before the procedure.Regarding the etiology, idiopathic and chagasic, most had type II, corresponding to 75% and 56.2%, respectively (Table 4).
Among the 27 patients who underwent POEM, 14 (51.9%)underwent sectioning only of the circular fibers and 13 (48.1%)required total sectioning of the fibers due to technical difficulty or the need for greater relief in the lower esophageal sphincter pressure.Details of the procedure were summarized in Table 2. Mean tunnel length was 12.54 ± 2.09cm and myotomy length was 9.46 ± 1.96cm, with a 1.37 ± 0.51cm section being performed after the cardia. of patients who had complications belonged to types I and III, corresponding to one patient in each (Table 4).
Nabi et al. 12 classified adverse events as major and minor according to their classification.Thus, all events observed in this study were minor.The surgeries were concluded without interruption and all patients who had adverse intraoperative events were treated during the procedure itself, without the need for additional interventions.None of the adverse events had late clinical repercussions.
The 27 patients were followed up on an outpatient basis, on average three months after the procedure.Reduction in the Eckardt score (    França Peroral endoscopic myotomy for the treatment of achalasia in the Unified Healthcare System (SUS): results of a short-term years, ranging from 1.8 to 12.6 per 100,000 individuals, having similar prevalence in most countries 1,2 .Since it is a primary disease, the main cause is idiopathic etiology.
However, the clinical picture can mimic other conditions, such as esophagopathy secondary to Chagas disease.
Since it is a disease without a curative intervention, patients resort to palliative therapies to reduce clinical symptoms.Some techniques have good success rates, including botulinum toxin injection, endoscopic pneumatic dilation, and Heller cardiomyotomy with partial fundoplication, which is the gold standard in therapy 7,8 .A new technique developed by Inoue and collaborators, called peroral endoscopic myotomy, was described in 2010 9,10 .In the present study, sociodemographic, clinical, and hospital variables, besides those related to the POEM technique were evaluated at the HC-UFPE.
The main etiology of achalasia was idiopathic, corresponding to a total of 18 (66.7%)patients, followed by esophagopathy secondary to Chagas disease, with nine (33.3%) patients with positive serology, following the world trend 2,8 .The disease's etiology was defined through epidemiology and positivity Chagas' disease serology; high prevalence of Chagas' disease was already expected, since the northeast of Brazil is still an endemic region despite the combat measures conducted in the last century.In addition, it is known that approximately 15-20% of the population with the disease develops gastrointestinal changes, such as megacolon, and 20-30% after ten years of disease may develop cardiologic alterations, however, as it was not the objective of the study, these alterations were not included in the current study.In patients whose serology was negative, the disease was defined as idiopathic, even though it is known that there are external factors that may influence the development of achalasia, it was not possible to associate such factors due to lack of information in the medical records 3,4,13,14 .
According to the last guideline, the goldstandard to determine the degree and severity of achalasia is the Chicago's Classification using a high-resolution manometry, that is not available in the public health

DISCUSSION
Achalasia is a primary esophageal motor disorder whose incidence has remained stable in recent Type IV (dolico-megaesophagus, >10cm) 16 .In a total of 27 patients included in the study, 24 patients had data from these exams in their medical records to calculate the correlation, three patients underwent POEM with only previous endoscopic exams proffing achalasia.
According to the latest recommendations 17,18 , POEM can be indicated for treatment in all stages of the disease, especially for more advanced cases being a less invasive procedure.In our study, 62.5% presented with type II achalasia, 25% with types III or IV, and only three patients (12.5%) in type I.It is worth emphasizing that many patients in the public health system have difficulty to access the most modern therapies, many of them presenting for treatment in more advanced stages of the disease, almost 90% of the sample already had moderate esophageal dilation (> or =4cm) with contrast retention and motility alteration when allocated to the study.
Regardless of the degree of disease involvement, patients of this study were followed up on an outpatient basis at the two following moments: preoperatively and on average two to three months after the procedure.During the follow up, the Eckardt score was applied before and after the POEM, obtaining an average preoperative score of 8.37 (± 1.45) and postoperative of 0.85 (± 1.06).The score is used to evaluate the repercussions of the procedure, with a favorable result being considered if the score is lower and/or equal to three 8 .In the present study, 26 patients had a score compatible with therapeutic success.Only one patient had an Eckardt score greater than three after the procedure and it was a suspicion of esophageal spastic disorder according to pre-procedure endoscopy, who has esophagogram type I.
Despite being limited to assessing short-term follow-up, other recently published studies with longterm follow-up demonstrate that the satisfaction with the technique was reported by more than 90% of the patients followed 19,20 .This fact suggests that POEM is a good long-term option for treating patients with achalasia, guaranteeing good results.studies 21,22 .
Among Eckardt score variables, dysphagia alone contributed most significantly to a higher score, followed by regurgitation.Progressive dysphagia at all meals was reported by 92.6% of patients and regurgitation by 63%.These rates are similar to those observed by Boeckxstaens et al. 3 , who reported dysphagia as the main symptom of achalasia, affecting more than 90% of patients, with regurgitation ranging between 76-91%.Although the Eckardt score is a widely used evaluation tool, with a good level of recommendation by the last guideline for the treatment of achalasia 8 , the study by Taft et al. 6 showed that the weight loss and retrosternal pain variables can decrease the reliability and validity of the score.
The main criticism of this endoscopic technique in the world literature is related to the high rates of gastroesophageal reflux disease when compared with other treatment method 9,[11][12][13][14][23][24] . Duringshort-term follow up, it was observed that 48.1% of patients reported some recurrent symptoms.Symptoms related to gastroesophageal reflux were self-reported by 33.3% of the patients, standing out as a major challenge in the post-operative period.However, the presence of gastroesophageal reflux was identified through the patient's clinical, thereby, the rate of gastroesophageal reflux observed in the study may be underestimated, since diagnostic tests were not performed after symptoms.
Those patients who do not respond to the POEM, others palliative alternatives can be used, as pneumatic dilation to older techniques such as esophagectomy to Thal-Hatafuku 25,26 .
Although relevant perioperative adverse events are uncommon, 25.9% had minor complications, such as controlled bleeding (14.8% of patients) and França Peroral endoscopic myotomy for the treatment of achalasia in the Unified Healthcare System (SUS): results of a short-term pneumoperitoneum (7.4%), with one patient having both, most of them were evidenced in type II patients, probably due to a larger sampling of this group.All adverse events were considered minor according to the classification proposed by Nabi et al. 12 and were treated conservatively during the procedure, without immediate or delayed clinical repercussions.
Despite the above, our work had some limitations the lack of data in the medical records difficulted clarify previous history and etiology.The difficulty of access by the public health system to the gold standard, esophageal manometry, for diagnosis and degree of severity.Many patients lost follow up due to the fact that the Hospital had become a center for the treatment of COVID-19, compromising medium and long-term follow-up.In addition, Hospital das Clínicas is characterized as a tertiary care unit within the Brazilian public health system and only one professional in this service is qualified to perform POEM.

CONCLUSION
The peroral endoscopic myotomy performed during this study showed excellent results, following the worldwide trend, with improvement in the clinical symptoms of the patients who underwent the procedure.POEM has become a good therapeutic option and more studies are necessary for a better evaluation of patients and maintenance of mediumand long-term follow up.

R E S U M O R E S U M O
Data collection was conducted from September 2017 to October 2019 at the Clinical Hospital of the Federal University of Pernambuco through analysis of medical records of patients undergoing POEM.Patients All patients who underwent the procedure in the period were included in the survey.The sample included 28 patients in a non-random manner, with the volunteers being selected consecutively.The exclusion criteria of this study were, as follows: post-operative period not performed at HC -UFPE, refusal to participate in the collection, unsuccessful contact or incomplete medical records.Only one patient was dismissed from the sample for not performing the post-operative follow-up at HC -UFPE, resulting in a total of 27 patients in this study.For statistical analysis correlating the degree of achalasia by the esophagogram, a total of 24 patients were used, three patients were excluded from the correlation because did not have preoperative esophagograms in their medical records, only previous digestive endoscopy.This study was submitted to the Ethics and Research Committee of HC -UFPE was approved CAAE No. 27695320.4.0000.8807.Procedures All procedures were performed by the same specialist with extensive experience in interventional endoscopy.Under CO 2 insufflation, the tunnel was started with mucosotomy approximately 10cm away from the cardia, located at the five o'clock position, with the patient in supine position and under general anesthesia.The submucosal plane close to the muscle was dissected until reaching 2.0cm below the cardia, followed by myotomy of the circular muscle layer, initiated 2.0cm below the mucosotomy.Sectioning of the longitudinal esophageal musculature was necessary in cases of fibrosis with difficulty in separating the elements or in very intense hypertonias of the lower esophageal sphincter.Myotomy included an inch or two from the stomach muscles.The tunnel was sealed with the closure of the mucosotomy by endoscopic clips (Figures 1 to 6).

Figure 1 .
Figure 1.Stasis is present in most POEMs.Orotracheal intubation should consider the high risk of bronchoaspiration.

Figure 2 .
Figure 2. Dilated esophagus showing edematous mucosa and effacement of the vasculature.

Figure 4 .
Figure 4. Submucosal tunneling close to the muscle.

Figure 5 .
Figure 5. Myotomy of the circular layer with preservation of the longitudinal layer.
system in Pernambuco.This classification was created in 2011 by the International High Resolution Manometry Working Group 15 as a way of classifying the degree

Figure 7 .
Figure 7.Comparison between pre-and post-POEM parameters.

França
Peroral endoscopic myotomy for the treatment of achalasia in the Unified Healthcare System (SUS): results of a short-term of esophageal diseases through manometry.For that reason, it was decided to use the Rezende e Mascarenhas' Classification, which uses the esophagogram to define the severity of achalasia.The classification determines four degrees: Type I (unchanged caliber, discreet contrast retention, <4cm); Type II (moderate increase of caliber, contrast retention and tertiary waves, 4-7cm); Type III (large increase of caliber and hypotonia, 7-10cm); and Six patients followed had already been treated previously, either by surgical or endoscopic treatment, and showed no significant difference in the post-POEM Eckhart Score when compared to patients who were not treated previously, which is in agreement with what Tan et al. and Sanaka et al. stated in their most recent

Table 1 -
Clinical and epidemiological data of patients who underwent POEM.

Table 2 -
Data of the procedures performed.
FrançaPeroral endoscopic myotomy for the treatment of achalasia in the Unified Healthcare System (SUS): results of a short-term Adverse events were observed in seven (25.9%) patients.Out of these, four (57.1%) presented controlled bleeding, two (28.6%)pneumoperitoneum and one (14.3%)both complications.Most of the operative complications occurred in patients with type II achalasia (71%), which may be related to the fact that this group comprised the largest sample.The other 28%

Table 3 -
Eckardt score before and after treatment with POEM.

Table 4 -
Degree of achalasia and its correlations.