Original Articles
 
Effectiveness of POEM in Achalasia Cardia Patients: A Prospective Study from Odisha
 
Manas Kumar Behera1, Jimmy Narayan1, Surendra Nath Swain2, Debakanta Mishra1, Girish Kumar Pati1, Kanishka Uthansingh1, Manoj Kumar Sahu1
1Department of Gastroenterology, 2Department of Medicine, Institute of Medical Sciences & SUM Hospital, Siksha O Anusandhan Deemed to be University, Odisha, India. 


Corresponding Author:
Dr Manoj Kumar Sahu
Email: manojsahu427@gmail.com

Abstract

Background: Per-oral endoscopic myotomy (POEM) is a highly effective and safe technique for the treatment of Achalasia cardia and has gained worldwide acceptance for its promising results. This study aims to evaluate the efficacy of the POEM technique in Indian patients with achalasia cardia.
Methods: Patients with achalasia cardia undergoing POEM between January 2017and March 2019 were prospectively analyzed and were followed up for one year. All of them had high-resolution esophageal manometry before and after the procedure. The outcomes of POEM procedures including improvement in Eckardt score, occurrence of gastroesophageal reflux disease (GERD), and periprocedural complications were compared.
Results: A total of 42 patients underwent POEM for achalasia: Type I (n=10,24%), type II (n=29,69%), and type III (n=3, 7%). The technical success rate of POEM was 98%, and clinical success, defined as Eckardt score=?3 after POEM procedure, was achieved in 38 (92%) patients. The mean age was 37.1 ± 12.3 years; males constitute 66.6% of all cases. The median duration of the disease was three years. The mean pre-POEM Eckardt score was 8.76 ± 1.86, and mean post POEM Eckardt score was 1.78± 0.74 (p<0.001). The mean lower esophageal pressure before and after POEM procedure were 39.6 ± 17.6 and 15.4 ± 7.2, respectively (p<0.001). Eight (19%) patients developed GERD, as documented by clinical and endoscopic evidence of esophagitis.
Conclusion: POEM is a an effective technique, and should be offered as a first treatment option in patients with achalasia cardia and can be safely performed in small tertiary care centers of India.

Introduction

Achalasia cardia (AC) is the most common primary esophageal motility disorder, characterized by absent esophageal peristalsis along with incomplete relaxation of the lower esophageal sphincter (LES) associated with impairment of the deglutitive function. The etiology of achalasia is mostly unknown, however, chronic viral infection along with genetic susceptibility may trigger inflammatory changes and a cascading autoimmune process, leading to loss of inhibitory myenteric plexus ganglions of esophagus.1 No treatment options are currently available that result in regeneration of myenteric neurons to bring back esophageal motility. However, lowering LES pressure by various modalities can significantly decrease the symptoms, leading to improved quality of life. Graded pneumatic balloon dilatation (PBD), laparoscopic Heller’s myotomy (LHM) with fundoplication, and POEM are the currently available modalities to reduce LES pressure.2
Young patients (< 40 years) and with spastic achalasia (type III AC) do not respond as well to PBD, requiring multiple sessions of dilatation3,4  Although LHM is an effective modality for treatment of AC with a durable response. It is associated with significant morbidity, hence, POEM has emerged as a minimally invasive endoscopic treatment modality with excellent results as the treatment of choice for management of achalasia.7,8,9 Patients with AC who failed with prior treatment by LHM or PBD also responds well to POEM.10 Though there are many studies in literature from the country, limited data is available from Eastern India. Hence, we report a prospective pilot study evaluating the efficacy and safety profile of POEM in patients with Achalasia in a tertiary care center from the state of Odisha, India.

Materials and Methods

We prospectively collected data of all patients with AC who presented to the gastroenterology department of IMS and SUM Hospital, Bhubaneswar, and underwent POEM. They were diagnosed and classified by Chicago classification using High resolution Manometry (HRM). All patients underwent esophagogastroduodenoscopy to assess for LES and esophagus. Eckardt score was calculated to assess the symptom severity before POEM and on follow up. The Eckardt score comprises 4 components: dysphagia, chest pain, regurgitation, and weight loss with each component having a score from 0 to 3 based and total score ranging from 0 to 12. Intraoperative details like duration of procedure, site and length of incision, number of clips, and mucosal bleeding were recorded. Postoperatively, pneumoperocardium, pneumoperitoneum, pleural effusion, length of hospital stay, and submucosal fibrosis were evaluated. Post procedure, all patients were kept nil per oral for 48 hrs. Barium esophagogram was done on post-operative day 1 to assess for leak. They were started on liquid diet after 48 hrs and on soft diet after 72 hrs. Clinical success after POEM was defined as Eckardt score =3 on follow-up. Informed consent was taken from all the patients in the study.
Exclusion criteria included pulmonary disease, significant coagulation disorder, severe erosive esophagitis and past history of endoscopic mucosal resection (EMR) or radio frequency ablation (RFA) as they alter the mucosal integrity. The endoscopist performing POEM (MKS) received adequate training of POEM in porcine model, attended several live workshops, and observed numerous procedures performed by experienced operators. The operator has performed more than 100 POEM procedures, with initial 30 cases performed under supervision by an experienced operator.

Procedure of POEM

Upper GI endoscopy was performed prior to POEM to remove food remnants and clean the esophagus. POEM procedure was performed under general anesthesia in supine position. A forward viewing gastroscope with distal transparent cap was used. CO2 insufflation was performed through the endoscope to reduce the risk of mediastinal emphysema and air embolization. The electrosurgical triangle tip knife with integrated water jet function (KD-645L; Olympus Corp, Tokyo, Japan) was used for myotomy. It was done in either anterior or posterior approach, depending on the patient status. A mixture of saline and indigo carmine was injected into the submucosal space. 
A 1.5 cm longitudinal mucosal incision was made in the wall of mid esophagus. Then, submucosal tunnel was made till 2-3 cm into gastric cardia using the technique of endoscopic submucosal dissection. Myotomy started from oral side of the esophageal body, and the end point was the incision from the LES to the gastric side of the sphincter. Once inside the submucosal tunnel, dissection of circular muscle was started using the triangular tip knife around 2 cm distal to mucosal incision, complete myotomy was done at EG junction. The dissection was done using spray coagulation which helps in avoiding major bleeding from the intra-muscular vessels. Sphincter muscle dissection is continued from the proximal side up to 2 or 3 cm into the cardia. Larger vessels in the submucosa were coagulated using the Coagrasper forceps in the soft coagulation mode, and adequate hemostasis achieved inside the tunnel. The location  of EGJ could be determined once the palisade vessels became visible and the wide-open submucosal space beyond cardia. By retroflexion, the location of the distal tunnel margin was verified from within the gastric lumen. As the myotomy was completed, the passage of endoscope through the EGJ improved. The esophageal mucosa overlying the tunnel was inspected for any thermal injury and finally the site of entry of mucosal incision was closed with hemoclips.

Statistics

The data was collected before and after the POEM procedure. Those are presented as median (range) or mean ± standard deviation. Continuous variables were evaluated by the paired t-test and categorical variables by proportion test. A p value < 0.05 was considered statistically significant.

Results

Patient Characteristics

The baseline characteristics of 42 patients who underwent POEM in our department is depicted in Table 1. The mean age of Achalasia patients  was 33.5 ± 11.2 years with male predominance  (n=28.67%). They were classified as achalasia cardia according to Chicago Classification11 as type I (n=10, 24%), type II (n=29, 69%), and type III (n=3, 7%). Prior treatment for AC had been provided to 6 patients such as balloon dilation (n=3), botulinum toxin injection (n=1), and LHM(n=2). Pre-POEM clinical and HRM parameters are detailed in Table 1.




Procedure Characteristics

The operative findings and adverse events of POEM were depicted in Table 2. POEM was performed by anterior approach (2’0 clock) in 37 patients (88%) and rest by posterior approach (5’0 clock). The median procedural time was 90 minutes. Median length of esophageal and gastric myotomy among these patients were 8 cm (range 4-13) and 2 cm (range 1-4), and median number of clips required for closure was 8. Mean hospital stay in these patients was 4 days. The technical success rate for POEM in this study is 98% and this rate did not differ among treatment naive & previously treated patients. Six patients (14.2%) developed capnoperitoneum requiring drainage, 2 patients (4.7%) each had developed capnothorax and 6 patient (14.2%) developed self-limiting subcutaneous emphysema, these resolved spontaneously in all these patients. Four patients (9.5%) developed retroperitoneal air requiring temporary stoppage of procedure. There was no clinically significant bleeding defined as bleeding  episodes requiring blood transfusion.




Follow Up Data After One Year

The comparison of pre-POEM and post-POEM characteristics at 12 months follow up as shown in table 3 revealed that there was significant reduction of Eckardt score  after POEM(post: 1.78 ± 0.74vs.pre: 8.76 ± 1.86;p <0.001), IRP (post: 10.19 mm Hg ± 3.12 vs pre: 25.91 ± 7.02 mm Hg, p<0.001), and LES pressure (post: 15.43 ± 7.2mmHg vs.pre 39.5 ± 17.6 mmHg). The incidence of clinically significant gastroesophageal reflux disease (GERD) as found by presence of heart burn & endoscopic evidence of reflux esophagitis was found to be 19% after one year of POEM.



Discussion

In this study, we reported the safety and success of POEM in patients with AC. There are various treatment modalities available for the treatment of AC including various drugs (calciumchannel blockers, nitrates, 5-phosphodiesterase inhibitors, anti-cholinergic, beta adrenergic agonists and theophylline), botulinum toxin injection, PBD and surgical open or laparoscopic myotomy.12 POEM has emerged as the superior technique for the treatment of AC in recent years. The lack of external incision, extensive dissection of esophageal hiatus in POEM, along with lesser hospital stay makes it as the preferred upfront therapeutic option for many patients with AC.13 In this present study, patients with failed balloon dilatation & hellers myotomy were also offered POEM.
In this study, technical success was achieved in 41 out of 42 patients (98%), and could not be completed in one patient due to severe submucosal fibrosis by prior pneumatic balloon dilatation. POEM procedure has been successfully carried out in patients with sigmoid esophagus with 100% technical success, although sigmoid esophagus is usually difficult to treat variety of AC.14 Another advantage of POEM is that it can be done with a fair success rate in patients who had failed previous endoscopic or surgical procedures,15,16 with efficacy similar to treatment naive cases, which is observed in our present study. The safety profile in this present study is >90%. Capnoperitoneum and submucosal emphysema are unavoidable consequences of the procedure which can be explained to the patient and be easily managed during the procedure if clinically significant.17
Clinical success, as defined by  post procedure Eckardt = 3, was achieved in 38 patients (92%) who underwent POEM, indicating that this procedure is a highly effective treatment modality for management of AC. Despite significant proportion of sigmoid esophagus and prior treatment failure with pneumatic balloon dilatation and heller’s myotomy,we were able to achieve clinical success rate of more than 90% in terms of improvement in Eckardt score and significant reduction of LES pressure in esophageal manometry, as found in previous studies.18,19,20 POEM is found to be superior to LHM in patients with type III achalasia cardia, though they require longer length of myotomy to relieve the dysphagia.18,21 Clinically relevant GERD (heartburn and/or endoscopic evidence of esophagitis) after POEM was observed in nine  patients (18%), similar to other reports from India.21 Previous literature suggested that GERD is less common in anterior approach than posterior approach, however we could not find compare this difference because majority of our patients underwent POEM  by anterior approach due to technical convenience.
The major imitation of the present study is its small sample size. GERD was diagnosed only by clinical and endoscopic evaluation; we did not perform pH studies for the assessment of GERD. We also did not measure percentage emptying of barium at 5 min on timed barium swallow to assess for efficacy of myotomy after POEM procedure. The strengths of this study are it’s prospective design and follow up for 1 year.

Conclusion 

In this study, POEM in patients with Achalasia cardia demonstrated excellent results in terms of symptom resolution, decrease in LES pressure by HRM after 1 year of follow up. POEM is a safe & better modality of treatment than LHM in Type III AC. It can safely & effectively performed in tertiary care hospitals of peripherally located smaller cities by experienced operators.

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