Changes in Distensibility Index During an Incremental POEM Myotomy

Reflux after peroral endoscopic myotomy: The dilemma and the options

Per oral endoscopic myotomy (POEM) is rapidly emerging as the treatment of choice for achalasia cardia, but its success is marred by problematic reflux. Although symptomatic reflux rates are low and often comparable to that after laparoscopic Hellers myotomy (LHM), a high incidence of pathologic reflux has been noted after POEM. This poses a dilemma as to what is true reflux, and in determining the indications and optimal endpoints for managing post-POEM reflux. The two pertinent reasons for the difference in reflux rates between LHM and POEM are the variation in length and location of myotomy and the absence of an anti-reflux procedure in POEM. Proton pump inhibitor remains the most sought-after treatment of POEM derived reflux. Nevertheless, modifications in the procedural technique of POEM and the addition of endoscopic fundoplication can probably emerge as a game changer. This article briefly reviews the incidence, causes, controversies, predictive factors, and management strategies related to post-POEM reflux.

Sling fiber preservation during POEM reduces incidence of postoperative reflux symptoms

Gastroesophageal reflux disease (GERD) after peroral endoscopic myotomy (POEM) has been a limiting factor with POEM. Sling-fiber preservation during POEM was reported to reduce postoperative GERD in Japan. This study investigates the efficacy of this technique in a western population. This is a retrospective, single-center study of patients undergoing POEM from October 2017 to January 2023. The initial cohort of patients were treated by conventional POEM, after which a second cohort underwent POEM with sling-fiber preservation. The primary outcome was the incidence of postoperative reflux symptoms. The secondary outcomes were clinical success rate (Eckardt score ≤ 3), procedure time, and adverse events rate. Multivariate regression was then performed to identify factors associated with the incidence of postoperative reflux symptoms. One hundred and forty eight POEM cases (52.5 ± 15.6 y/o, female: 61[43%]) were included. The mean procedure time (108.6 ± 34.5 vs. 109.1 ± 45.7 min, P = 0.93) was similar between the groups. In the sling-fiber preservation group, gastric myotomy length was significantly longer (2.2 ± 0.7 vs. 1.6 ± 0.8 cm, P < 0.05), yet the incidence rate of postoperative reflux symptoms at follow-up was significantly lower (22.4% vs. 42.3%, P < 0.05). The clinical success rate was similar between groups (89.5% vs. 83.1%, P = 0.32), and the rate of adverse events requiring intervention (13.5% vs. 12.2%, P = 0.36) was similar. Regression analysis indicated that, after adjusting for other risk factors of postoperative GERD, sling-fiber preservation during POEM had an odds ratio of 0.24 (95% CI: 0.07-0.85, P < 0.05) for the incidence of reflux symptoms. Sling-fiber preservation during POEM reduces the incidence of postoperative reflux symptoms. As such, sling-fiber preservation may be a useful solution to reduce post-POEM GERD in western populations.

Management of Complications After Per Oral Endoscopic Myotomy

This is a comprehensive review of intraoperative, early postoperative, and late postoperative complications of Per Oral Endoscopic Myotomy with a focus on prevention, intraoperative management, and postoperative management.

Association of gastric myotomy length in peroral endoscopic myotomy (POEM) with gastro-esophageal junction distensibility measured by Endoluminal Functional Lumen Imaging Probe (EndoFLIP)

BACKGROUND

Endoluminal Functional Lumen Imaging Probe (EndoFLIP) is a device that measures gastro-esophageal junction (GEJ) distensibility. However, it is not demonstrated that GEJ distensibility increases proportionally with varying gastric myotomy length in peroral endoscopic myotomy (POEM). This study aimed to investigate the association between gastric myotomy length in POEM and intraoperative EndoFLIP findings.

METHODS

This single-center, retrospective cohort study included patients who underwent POEM with intraoperative EndoFLIP from December 2019 to January 2023. Using EndoFLIP, minimal balloon diameter and its distensibility index (DI) were measured pre- and post-myotomy. Primary and secondary outcomes were the post-myotomy EndoFLIP findings at 30 ml and 40 ml volume fills.

RESULTS

The study included 44 patients (mean age 53.1 years, 50% female). Chicago classification included achalasia type I (39%), II (41%), III (9%), hypercontractile esophagus (2%), and EGJOO (9%). The mean esophageal myotomy length was 7.5 ± 2.2 cm and gastric myotomy was 2.1 ± 0.6 cm. Simple linear regression analyses indicated that for each 1 cm increase in gastric myotomy length, the DI at 30 ml volume fill was estimated to increase by 2.0 mm2/mmHg (p < 0.05, R2 = 0.41), the minimal diameter at 30 ml volume fill was estimated to increase by 2.4 mm (p < 0.05, R2 = 0.48), and the minimal diameter at 40 ml volume fill was estimated to increase by 1.3 mm (p < 0.05, R2 = 0.09).

CONCLUSIONS

This study demonstrates a significant linear relationship between gastric myotomy length and GEJ distensibility measured by EndoFLIP during POEM. These findings may be useful in clinical practice by enabling EndoFLIP to help calibrate a desired gastric myotomy length to achieve optimal DI and minimal diameter.

What role does the submucosa play in the pathophysiology and treatment of achalasia? An analysis of impedance planimetry during POEM

BACKGROUND

It is thought the therapeutic benefit of per-oral endoscopic myotomy (POEM) in the treatment of esophageal dysmotility disorders is from longitudinal myotomy creation, but it is unknown if the submucosa contributes to the pathophysiology. This study investigates if submucosal tunnel (SMT) dissection alone contributes to POEM's luminal changes as measured by EndoFLIP.

METHODS

A single-center, retrospective review of consecutive POEM cases from June 1, 2011 to September 1, 2022 with intraoperative luminal diameter and distensibility index (DI) data as measured by EndoFLIP. Patients with diagnoses of achalasia or esophagogastric junction outflow obstruction were grouped by those with pre-SMT and post-myotomy measurements (Group 1) and those with a third measurement post-SMT dissection (Group 2). Outcomes and EndoFLIP data were analyzed using descriptive and univariate statistics.

RESULTS

There were 66 patients identified, of whom 57 (86.4%) had achalasia, 32 (48.5%) were female, and median pre-POEM Eckardt score was 7 [IQR: 6-9]. There were 42 (64%) patients in Group 1, and 24 (36%) patients in Group 2, with no differences in baseline characteristics. In Group 2, SMT dissection changed luminal diameter by 2.15 [IQR: 1.75-3.28]cm, which comprised 38% of the median 5.6 [IQR: 4.25-6.3]cm diameter of complete POEM change. Similarly, the median post-SMT change in DI of 1 [IQR: 0.5-1.2]units comprised 30% of the median 3.35 [2.4-3.98]units overall change in DI. Post-SMT diameters and DI were both significantly lower than the full POEM.

CONCLUSIONS

Esophageal diameter and DI are significantly affected by SMT dissection alone, though not equaling the magnitude of diameter or DI changes from full POEM. This suggests that the submucosa does play a role in achalasia, presenting a future target for refining POEM and developing alternative treatment strategies.

The utility of Endoscopic Functional Luminal Imaging (EndoFLIP) in the diagnosis and management of children with achalasia

BACKGROUND

Per-oral endoscopic myotomy (POEM) has is an alternative treatment to laparoscopic Heller myotomy for children with achalasia. The EndoFLIP functional luminal imaging system is used to measure esophagogastric junction (EGJ) distensibility pre- and post-POEM. Previous adult studies have established a correlation between obstructive symptoms and Distensibility Index (DI). Here we analyze the utility of EndoFLIP in diagnosis and management of achalasia in the largest study on pediatric POEM patients and hypothesize that DI may aid diagnosis and treatment of pediatric achalasia.

METHODS

Demographics, preoperative basal and residual pressures measured on manometry, and EndoFLIP measurements pre- and post-POEM were recorded for children that underwent POEM. Pearson correlation coefficient and T-scores were used to assess for correlation between manometry measurements and pre-POEM DI. Linear regression was conducted to analyze the relationship between pre-POEM DI, Eckardt scores, and manometry pressures.

RESULTS

Of 33 patients that underwent POEM and EndoFLIP since 2014 (21 male, 12 female), the median pre-POEM Eckardt score decreased from 7 to 1 post-POEM. The median basal pressure was 50 ± 25 mmHg, pre-POEM DI was 0.9 (0.8-1.6) mm²/mmHg and the post-POEM DI was 3.8 (3.2-4.4) mm²/mmHg. There was no correlation between DI and basal pressure or residual pressure, though there was a strong negative correlation between Eckardt scores and DI.

CONCLUSION

The EndoFLIP system is a valuable tool in adult patients in diagnosing achalasia and defining the endpoint of the POEM procedure. We find that there is a role for EndoFLIP in the pediatric population in diagnosis and management of the disease.

TYPE OF STUDY & LEVEL OF EVIDENCE

Study of diagnostic test; Level IV.

Advances in the Diagnosis and Management of Achalasia and Achalasia-Like Syndromes: Insights From HRM and FLIP

High-resolution manometry, Chicago Classification v4.0, the functional lumen imaging probe, Panometry, and peroral endoscopic myotomy (POEM) are all now integral parts of the landscape for managing achalasia or, more precisely, achalasia-like syndromes. This narrative review examines the impact of these innovations on the management of achalasia-like syndromes. High-resolution manometry was the disruptive technology that prompted the paradigm shift to thinking of motility disorders as patterns of obstructive physiology involving the esophagogastric junction and/or the distal esophagus rather than as siloed entities. An early observation was that the cardinal feature of achalasia-impaired lower esophageal sphincter relaxation-can occur in several subtypes: without peristalsis, with pan-esophageal pressurization, with premature (spastic) distal esophageal contractions, or even with preserved peristalsis (esophagogastric junction outlet obstruction). Furthermore, there being no biomarker for achalasia, no manometric pattern is perfectly sensitive or specific for 'achalasia' and there is also no 'gold standard' for the diagnosis. Consequently, complimentary physiological testing with a timed barium esophagram or functional lumen imaging probe are employed both to improve the detection of patients likely to respond to treatments for 'achalasia' and to characterize other syndromes also likely to benefit from achalasia therapies. These findings have become particularly relevant with the development of a minimally invasive technique for performing a tailored esophageal myotomy, POEM. Now and in the future, optimal achalasia management is to render treatment in a phenotype-specific manner, that is, POEM calibrated in a patient-specific manner for obstructive physiology including the distal esophagus and more conservative strategies such as a short POEM or pneumatic dilation for obstructive physiology limited to the lower esophageal sphincter.

Submucosal endoscopy: the present and future

Submucosal endoscopy or third-space endoscopy utilizes the potential space between the mucosal and muscularis layers of the gastrointestinal tract to execute therapeutic interventions for various diseases. Over the last decade, endoscopic access to the submucosal space has revolutionized the field of therapeutic endoscopy. Submucosal endoscopy was originally used to perform endoscopic myotomy in patients with achalasia cardia, and its use has grown exponentially since. Currently, submucosal endoscopy is widely used to resect subepithelial tumors and to manage refractory gastroparesis and Zenker's diverticulum. While the utility of submucosal endoscopy has stood the test of time in esophageal motility disorders and subepithelial tumors, its durability remains to be established in conditions such as Zenker's diverticulum and refractory gastroparesis. Other emerging indications for submucosal endoscopy include esophageal epiphrenic diverticulum, Hirschsprung's disease, and esophageal strictures not amenable to conventional endoscopic treatment. The potential of submucosal endoscopy to provide easy and safe access to the mediastinum and peritoneal spaces may open doors to novel indications and rejuvenate the interest of endoscopists in natural orifice transluminal endoscopic surgery in the future. This review focuses on the current spectrum, recent updates, and future direction of submucosal endoscopy in the gastrointestinal tract.