Acta from the EndoFLIP® Symposium

Utility of Functional Lumen Imaging Probe in Long-Term Follow-Up of Children with Esophageal Atresia: A Single-Center Retrospective Study

Long term follow-up of patients with esophageal atresia (EA) may be hampered by esophageal dysmotility, which affects quality of life and might lead to late complications. The endoluminal functional lumen imaging probe (EndoFlip™ Medtronic, Crospon Inc.) is an innovative diagnostic tool that assesses esophageal distensibility. Our aim was to report the use of EndoFlip™ in an EA follow-up, in order to describe distensibility patterns and to determine its possible role for functional evaluation of patients. We retrospectively collected data of EA patients, with a minimum follow-up of 9 years, who required endoscopic evaluation and underwent EndoFlip™. An adaptation of the Medtronic EF-322 protocol was applied and distensibility data were compared to those reported by Pandolfino et al. Nine patients (median age 13 years) were included in the study. The median minimum distensibility was 2.58 mm²/mmHg. Signs of peristalsis were observed in three patients. In one case, the esophagogastric junction (EGJ) after Toupet fundoplication showed low distensibility. EGJ distensibility values of 2.58 mm²/mmHg (median) confirmed both good esophagogastric continence and compliance. Esophagitis and absent peristalsis were found in one patient together with partial stenosis of the fundoplication, confirming the importance of surgical adaptation. Esophageal body distensibility was higher than that of the EGJ. Considering the presence of symptoms, the EndoFlip™ results seem to correlate better with the clinical picture. EndoFlip™ use was safe and feasible in children. It allowed for the measurement of esophageal distensibility and diameter and the acquisition of indirect information on motility with clinical implications. The routine use of EndoFlip™ could be part of EA follow-up, although considerable research is needed to correlate Endoflip™ system measurements to EA patient outcomes.

Impedance planimetry (EndoFLIP™) reveals changes in gastroesophageal junction compliance during fundoplication

INTRODUCTION

Compliance is the ability of a hollow organ to dilate and increase volume with an increase in pressure, an accurate representation of food bolus transit through the gastroesophageal junction (GEJ). Impedance planimetry system can calculate compliance (change in volume over pressure) and distensibility (cross-sectional area over pressure) of the GEJ. We aim to describe the changes in compliance during anti-reflux surgery and hypothesize that compliance is a better predictor of patient outcomes than distensibility (DI).

METHODS AND PROCEDURES

A review of a prospectively maintained quality database was performed. Patients with FLIP measurements during laparoscopic fundoplication between August 2018 and June 2021 were included. GEJ compliance and DI were measured after hernia reduction, cruroplasty, and fundoplication. Patient-reported outcomes were collected through standardized surveys up to 2 years after surgery. A scatter plot was used to identify a correlation between compliance and DI. Comparisons of measurements between time points were made using paired t-tests. Spearman's correlation coefficients (ρ), Wilcoxon rank-sum, and chi-square tests were used to evaluate associations between measurements and outcomes.

RESULTS

One hundred and forty-four patients underwent laparoscopic fundoplication. Compliance is strongly associated with DI (r = 0.96), and a comparison of measurements showed similar trends at specific time points during the operation. After hernia reduction, compliance at the GEJ was 168 ± 74 mm3/mmHg, cruroplasty 79 ± 39 mm3/mmHg, and fundoplication 90 ± 33 mm3/mmHg (all comparisons p < 0.05). GEJ compliance of 80-92 mm3/mmHg after fundoplication was associated with the best patient-reported outcome scores. A compliance of ≤ 79 mm3/mmHg had the highest percentage of patients who reported dysphagia.

CONCLUSIONS

Compliance and DI are strongly associated displaying the same directional change during anti-reflux surgery. GEJ compliance of 80-92 mm3/mmHg revealed the best patient-reported outcome scores, and avoiding a compliance ≤ 79 mm3/mmHg may prevent postoperative dysphagia. Therefore, GEJ compliance is an underutilized FLIP measurement warranting further investigation.

Kyoto international consensus report on anatomy, pathophysiology and clinical significance of the gastro-oesophageal junction

OBJECTIVE

An international meeting was organised to develop consensus on (1) the landmarks to define the gastro-oesophageal junction (GOJ), (2) the occurrence and pathophysiological significance of the cardiac gland, (3) the definition of the gastro-oesophageal junctional zone (GOJZ) and (4) the causes of inflammation, metaplasia and neoplasia occurring in the GOJZ.

DESIGN

Clinical questions relevant to the afore-mentioned major issues were drafted for which expert panels formulated relevant statements and textural explanations.A Delphi method using an anonymous system was employed to develop the consensus, the level of which was predefined as ≥80% of agreement. Two rounds of voting and amendments were completed before the meeting at which clinical questions and consensus were finalised.

RESULTS

Twenty eight clinical questions and statements were finalised after extensive amendments. Critical consensus was achieved: (1) definition for the GOJ, (2) definition of the GOJZ spanning 1 cm proximal and distal to the GOJ as defined by the end of palisade vessels was accepted based on the anatomical distribution of cardiac type gland, (3) chemical and bacterial (Helicobacter pylori) factors as the primary causes of inflammation, metaplasia and neoplasia occurring in the GOJZ, (4) a new definition of Barrett's oesophagus (BO).

CONCLUSIONS

This international consensus on the new definitions of BO, GOJ and the GOJZ will be instrumental in future studies aiming to resolve many issues on this important anatomic area and hopefully will lead to better classification and management of the diseases surrounding the GOJ.

Evaluation of post-operative dysphagia following anti-reflux surgery

BACKGROUND

Anti-reflux surgery (ARS) has known long-term complications, including dysphagia, bloat, and flatulence, among others. The factors affecting the development of post-operative dysphagia are poorly understood. We investigated the correlation of intra-operative esophagogastric junction (EGJ) characteristics and procedure type with post-operative dysphagia following ARS.

METHODS

Robotic ARS was performed on 197 consecutive patients with pathologic reflux utilizing EndoFLIP™ technology. Intraoperative EGJ measurements including distensibility index (DI), cross-sectional area (CSA), and high-pressure zone (HPZ) length were collected. Dysphagia was assessed pre-operatively and at 3 months post-operatively.

RESULTS

The median pre-operative DI for all procedures was 2.6 (IQR 1.6-4.5) mm²/mmHg. There was no difference in post-operative DI between procedures [Hill: 0.9 (IQR 0.7-1.1) mm²/mmHg, Nissen: 1.0 (IQR 0.7-1.4) mm²/mmHg, Toupet: 1.2 (IQR 0.8-1.5) mm²/mmHg, Linx: 1.0 (IQR 0.7-1.2) mm²/mmHg, p = 0.24], whereas post-operative HPZ length differed by augmentation type [Hill: 3 (IQR 2.8-3) cm, Nissen: 3.5 (IQR 3-3.5) cm, Toupet: 3 (IQR 2.5-3.5) cm, Linx: 2.5 (IQR 2.5-3) cm, p = 0.032]. Eighty-nine patients (45.2%) had pre-operative dysphagia. Thirty-two patients (27.6%) reported any dysphagia at their 3-month post-operative visit and 12 (10.3%) developed new or worsening post-operative dysphagia [Hill: 2/18 (11.1%), Nissen: 2/35 (5.7%), Toupet: 4/54 (7.4%), Linx: 4/9 (44.4%), p = 0.006]. The median pre-operative and post-operative DI of patients who developed new or worsening dysphagia was 2.0 (IQR 0.9-3.8) mm²/mmHg and 1.2 (IQR 1.0-1.8) mm²/mmHg, respectively, and that of those who did not was 2.5 (IQR 1.6-4.0) mm²/mmHg and 1.0 (IQR 0.7-1.4) mm²/mmHg (p = 0.21 and 0.16, respectively).

CONCLUSIONS

Post-operative DI was similar between procedures, and there was no correlation with new or worsening post-operative dysphagia. Linx placement was associated with higher rates of new or worsening post-operative dysphagia despite a shorter post-procedure HPZ length and similar post-operative DI when compared to other methods of LES augmentation.

Devices for esophageal function testing

BACKGROUND AND AIMS

Esophageal function testing is an integral component of the evaluation of refractory GERD and esophageal motility disorders. This review summarizes the current technologies available for esophageal function testing, including the functional luminal imaging probe (FLIP), high-resolution esophageal manometry (HRM), and multichannel intraluminal impedance (MII) and pH monitoring.

METHODS

We performed a MEDLINE, PubMed, and MAUDE database literature search to identify pertinent clinical studies through March 2021 using the following key words: esophageal manometry, HRM, esophageal impedance, FLIP, MII, and esophageal pH testing. Technical data were gathered from traditional and web-based publications, proprietary publications, and informal communications with pertinent vendors. The report was drafted, reviewed, and edited by the American Society for Gastrointestinal Endoscopy Technology Committee and approved by the Governing Board of the American Society for Gastrointestinal Endoscopy.

RESULTS

FLIP is a high-resolution impedance planimetry system used for pressure and dimension measurement in the esophagus, pylorus, and anal sphincter. FLIP provides complementary information to HRM for esophageal motility disorders, especially achalasia. The Chicago classification, based on HRM data, is a widely adopted algorithmic scheme used to diagnose esophageal motility disorders. MII detects intraluminal bolus movement and, combined with pH measurement or manometry, provides information on acid and non-acid gastroesophageal reflux and bolus transit in patients with refractory GERD and for preoperative evaluation for anti-reflux procedures.

CONCLUSIONS

Esophageal function testing techniques (FLIP, HRM, and MII-pH) have diagnostic and prognostic value in the evaluation of esophageal motility disorders and refractory GERD. Newer technologies and classification systems have enabled an increased understanding of these diseases.

Impedance planimetry values for predicting clinical response following peroral endoscopic myotomy

BACKGROUND

There is growing interest in developing impedance planimetry as a tool to enhance the clinical outcomes for endoscopic and surgical management of achalasia. The primary aim of this study was to determine whether impedance planimetry measurements can predict clinical response and reflux following peroral endoscopic myotomy (POEM).

METHODS

A multicenter cohort study of patients with achalasia undergoing POEM was established from prospective databases and retrospective chart reviews. Patients who underwent impedance planimetry before and after POEM were included. Clinical response was defined as an Eckardt score of ≤ 3. Tenfold cross-validated area under curve (AUC) values were established for the different impedance planimetry measurements associated with clinical response and reflux development.

RESULTS

Of the 290 patients included, 91.7 % (266/290) had a clinical response and 39.4 % (108/274) developed reflux following POEM. The most predictive impedance planimetry measurements for a clinical response were: percent change in cross-sectional area (%ΔCSA) and percent change in distensibility index (%ΔDI), with AUCs of 0.75 and 0.73, respectively. Optimal cutoff values for %ΔCSA and %ΔDI to determine a clinical response were a change of 360 % and 272 %, respectively. Impedance planimetry values were much poorer at predicting post-POEM reflux, with AUCs ranging from 0.40 to 0.62.

CONCLUSION

Percent change in CSA and distensibility index were the most predictive measures of a clinical response, with a moderate predictive ability. Impedance planimetry values for predicting reflux following POEM showed weak predictive capacity.

Use of the Functional Lumen Imaging Probe in Clinical Esophagology

The functional lumen imaging probe (FLIP) measures luminal dimensions using impedance planimetry, performed most often during sedated upper endoscopy. Mechanical properties of the esophageal wall and opening dynamics of the esophagogastric junction (EGJ) can be objectively evaluated in esophageal motor disorders, eosinophilic esophagitis, esophageal strictures, during esophageal surgery and in postsurgical symptomatic states. Distensibility index, the ratio of EGJ cross sectional area to intraballoon pressure, is the most useful FLIP metric. Secondary peristalsis from balloon distension can be displayed topographically as repetitive anterograde or retrograde contractile activity in the esophageal body, similar to high-resolution manometry. Real-time interpretation and postprocessing of FLIP metadata can complement the identification of esophageal outflow obstruction and achalasia, especially when findings are inconclusive from alternate esophageal tests in symptomatic patients. FLIP can complement the diagnosis of achalasia when manometry and barium studies are inconclusive or negative in patients with typical symptoms. FLIP can direct adequacy of disruption of the EGJ in achalasia when used during and immediately after myotomy and pneumatic dilation. Lumen diameter measured using FLIP in eosinophilic esophagitis and in complex strictures can potentially guide management. An abbreviated modification of the Grading of Recommendations Assessment, Development, and Evaluation was used to determine the quality of available evidence and recommendations regarding FLIP utilization. FLIP metrics that are diagnostic or suggestive of an abnormal motor pattern and metrics that define normal esophageal physiology were developed by consensus and are described in this review.

Hybrid transgastric approach for the treatment of gastroesophageal junction pathologies

Flexible endoscopy has evolved to the point that it includes many endoluminal procedures that once required open or laparoscopic surgery, for instance, antireflux surgery, pyloromyotomy, mucosal and submucosal tumor resections, and even full-thickness resection. However, these procedures remain technically demanding due to flexible technology issues: difficult imaging, limited energy devices, lack of staplers, unsatisfactory suturing abilities, and so on. Transgastric laparoscopy or hybrid laparoscopy/flex endoscopy has been described for almost two decades as an alternative to a pure endoluminal approach, mainly for pancreatic pseudocyst drainage and full-thickness and mucosal resection of various lesions. The approach has never been widely adopted mostly due to cumbersome and difficult to maintain methods of gastric access. We propose to expand the indications of transgastric laparoscopy by using novel endoscopically placed ports to replicate endoscopic procedures particularly in the difficult to access proximal stomach such as endoluminal antireflux surgery. Under general anesthesia, five female pigs (mean weight: 27.6 kg) had endoscopic placement of 3, 5 mm intragastric ports (Endo-TAGSS, Leakwood KS, USA) using a technique similar to percutaneous endoscopic gastrostomy. A 5-mm laparoscope was used for visualization. Laparoendoscopic-assisted plication of the gastroesophageal junction (GEJ) was performed using 3-0 interrupted sutures (Polysorb®, Covidien, Mansfield, MA, USA). A functional lumen imagine probe (EndoFLIP®, Crospon, Inc., Galway, Ireland) was used to measure diameter, cross sectional area (CSA), distensibility, and compliance of GEJ before and after intervention. Once the TAGSS ports were removed, the gastrotomies were closed by using endoscopic over-the-scope clips. At the end of the procedure, animals were euthanized. Five laparoendoscopic-assisted endoluminal plications were performed. The mean operative time was 65.6 min (Endoscopic evaluation: 3.2 min, TAGSS Insertion: 11 min, EndoFLIP evaluation + GEJ Plication: 43.25 min, gastric wall closure: 15 minutes). In all cases, this technique was effective and allowed to achieve an adequate GEJ plication by endoscopic grading and EndoFLIP measurements. Median pre-plication GEJ diameter (D) and median pre-plication GEJ cross-sectional area (CSA) were 11.42 mm (8.6-13.6 mm) and 104.8 mm2 (58-146 mm2). After the procedure, these values were decreased to 6.14 mm (5.7-6.6 mm) and 29.8 mm2 (25-34 mm2) respectively (p = 0.0079). Median pre-plication distensibility (d) and compliance (C) were 7.87 mm2/mmHg (2.4-22.69 mm2/mmHg) and 190.56 mm3/mmHg (70.9-502.8 mm3/mmHg). After the procedure, these values decreased to 1.5 mm2/mmHg (0.7-2.2 mm2/mmHg) and 52.17 mm3/mmHg (21.9-98.7 mm3/mmHg) respectively (p = 0.0317). No intraoperative events were observed. Endoscopically, all valves were felt to be transitioned from a Hill grade 3 (normal state for the animal model) to a Hill grade 1 at the procedure completion. A hybrid laparoendoscopic approach is a feasible alternative for performing intragastric procedures with the assistance of conventional laparoscopic instruments; especially in cases where the intervention location limits the access to standard endoscopy or where endoscopic technology is inadequate. Further evaluation is planned in survival models and clinical trials.

Consistency and effect of body position change on measurement of upper and lower esophageal sphincter geometry using impedance planimetry in a canine model

The EndoFLIP (Endolumenal Functional Lumen Imaging Probe, Crospon Inc, Galway, Ireland) device uses the technique of impedance planimetry to evaluate dimensions and distensibility of the upper and lower esophageal sphincter. The null hypotheses for this study were that EndoFLIP variables would be stable between anesthestic episodes and would not be affected by body position when evaluating the upper and lower esophageal sphincters in healthy dogs. During each of three consecutive general anesthesia episodes administered to eight healthy adult research colony dogs with a standardized protocol, the EndoFLIP catheter was positioned to measure cross-sectional area, intrabag pressure, upper and lower esophageal sphincter length at two different balloon fill volumes (30 and 40 mL) and two body positions (lateral and dorsal recumbency). From these measured variables, a distensibility index was also calculated. Mixed effect analysis of variance was used to evaluate the fixed marginal and interaction effects of anesthesia episode, body position, and balloon volume on measured and calculated variables. For the upper esophageal sphincter significant interactions were present between anesthetic episode and body position for all variables except intrabag pressure; adjusting for body position significant differences were present between anesthetic episodes for all variables except distensibility index; adjusting for anesthetic episode cross-sectional area, intrabag pressure, upper esophageal sphincter length and distensibility index were all affected by body position. For the lower esophageal sphincter distensibility index was the only variable where a significant interaction between anesthesia episode and body position occurred; cross-sectional area, intrabag pressure, and lower esophageal length were not significantly affected by anesthesia episode when adjusting for body position; distensibility index was the only variable significantly affected by body position. Measurements of the geometry of the lower esophageal sphincter as measured by the EndoFLIP device were consistent under conditions of general anesthesia. Similar measurements taken at the upper esophageal sphincter displayed greater variability between anesthetic episodes and were affected to a greater extent by body position. Body position should be standardized in studies using the EndoFLIP to assess geometric and functional characteristics of the upper and lower esophageal sphincters.

Application of the Functional Lumen Imaging Probe to Esophageal Disorders

OPINION STATEMENT

The functional luminal imaging probe (FLIP) provides a novel method to evaluate esophageal physiology and function in both health and disease. FLIP enables assessment of a previously underexplored component of esophageal function, distensibility, by utilizing high-resolution impedance planimetry to evaluate the relationship of the esophageal luminal geometry with pressure during controlled volumetric distension. Recent studies have described the potential utility of FLIP to evaluate the severity and effectiveness of therapy for esophageal diseases including achalasia, gastroesophageal reflux disease, and eosinophilic esophagitis. This review summarizes these emerging clinical applications of FLIP in the evaluation and management of esophageal diseases.

Effect of changes in intra-abdominal pressure on diameter, cross-sectional area, and distensibility of the lower esophageal sphincter of healthy dogs as determined by use of an endoscopic functional luminal imaging probe

OBJECTIVE To evaluate the effect of intra-abdominal pressure (IAP) on morphology and compliance of the lower esophageal sphincter (LES) by use of impedance planimetry in healthy dogs and to quantify the effect of changes in IAP. ANIMALS 7 healthy, purpose-bred sexually intact male hound-cross dogs. PROCEDURES Dogs were anesthetized, and cross-sectional area (CSA), minimal diameter (MD), LES length, LES volume, and distensibility index (DI) of the LES were evaluated by use of an endoscopic functional luminal imaging probe. For each dog, measurements were obtained before (baseline) and after creation of a pneumoperitoneum at an IAP of 4, 8, and 15 mm Hg. Order of the IAPs was determined by use of a randomization software program. RESULTS CSA and MD at 4 and 8 mm Hg were not significantly different from baseline measurements; however, CSA and MD at 15 mm Hg were both significantly greater than baseline measurements. The LES length and LES volume did not differ significantly from baseline measurements at any IAP. The DI differed inconsistently from the baseline measurement but was not substantially affected by IAP. CONCLUSIONS AND CLINICAL RELEVANCE Pneumoperitoneum created with an IAP of 4 or 8 mm Hg did not significantly alter LES morphology in healthy dogs. Pneumoperitoneum at an IAP of 15 mm Hg caused a significant increase in CSA and MD of the LES. Compliance of the LES as measured by the DI was not greatly altered by pneumoperitoneum at an IAP of up to 15 mm Hg.

Functional lumen imaging probe: The FLIP side of esophageal disease

PURPOSE OF REVIEW

The aim of this review is to summarize use of the functional lumen imaging probe (FLIP) for the evaluation and management of esophageal diseases.

RECENT FINDINGS

The FLIP utilizes high-resolution impedance planimetry to evaluate the functional geometry and cross-sectional area/pressure relationship (i.e. distensibility) of the esophageal sphincters and body. Recent studies have reported the potential utility of FLIP to evaluate esophageal diseases, such as achalasia, gastroesophageal reflux disease, and eosinophilic esophagitis.

SUMMARY

Esophageal distensibility measures provided by the FLIP will add to our understanding of the contribution of esophageal mechanical properties to esophageal symptoms and function. Application of the FLIP in clinical practice complements the diagnostic evaluation of esophageal function and may also be a valuable tool to help direct and target clinical management of esophageal diseases.

The effect of incremental distal gastric myotomy lengths on EGJ distensibility during POEM for achalasia

BACKGROUND

During peroral esophageal myotomy (POEM) for the treatment of achalasia, the optimal distal gastric myotomy length is unknown. In this study, we used a functional lumen imaging probe (FLIP) to intraoperatively measure the effect of variable distal myotomy lengths on esophagogastric junction (EGJ) distensibility.

METHODS

EGJ distensibility index (DI) (minimum cross-sectional area divided by intrabag pressure) was measured with FLIP after each operative step. Each patient's myotomy was performed in four increments from proximal to distal: (1) an esophageal myotomy (from 6 cm proximal to the EGJ to 1 cm proximal to it), (2) a myotomy ablating the lower esophageal sphincter (LES) complex (from 1 cm proximal to the EGJ to 1 cm distal to it), (3) an initial gastric extension (from 1 cm distal to the EGJ to 2 cm distal), and (4) a final gastric extension (from 2 cm distal to the EGJ to 3 cm distal).

RESULTS

Measurements were taken in 16 achalasia patients during POEM. POEM resulted in an overall increase in DI (pre 1.2 vs. post 7.2 mm(2)/mmHg, p < .001). Initial creation of the submucosal tunnel resulted in a threefold increase in DI (1.2 vs. 3.6 mm(2)/mmHg, p < .001). When the myotomy was then performed in a stepwise fashion from proximal to distal, the initial esophageal myotomy component had no effect on DI. Subsequent myotomy extension across the LES complex resulted in an increase in DI, as did the initial gastric myotomy extension (to 2 cm distal to the EGJ). The final gastric myotomy extension (to 3 cm distal) had no further effect.

CONCLUSIONS

During POEM, creation of the submucosal tunnel prior to myotomy resulted in a marked improvement in EGJ physiology. Myotomy extension across the LES complex and to 2 cm onto the gastric wall resulted in the normalization of EGJ distensibility, whereas subsequent extension to 3 cm distal to the EGJ did not increase compliance further.

Esophagogastric junction distensibility measurements during Heller myotomy and POEM for achalasia predict postoperative symptomatic outcomes

BACKGROUND

The functional lumen imaging probe (FLIP) is a novel diagnostic tool that can be used to measure esophagogastric junction (EGJ) distensibility. In this study, we performed intraoperative FLIP measurements during laparoscopic Heller myotomy (LHM) and peroral esophageal myotomy (POEM) for treatment of achalasia and evaluated the relationship between EGJ distensibility and postoperative symptoms.

METHODS

Distensibility index (DI) (defined as the minimum cross-sectional area at the EGJ divided by distensive pressure) was measured with FLIP at two time points during LHM and POEM: (1) at baseline after induction of anesthesia, and (2) after operation completion.

RESULTS

Measurements were performed in 20 patients undergoing LHM and 36 undergoing POEM. Both operations resulted in an increase in DI, although this increase was larger with POEM (7 ± 3.1 vs. 5.1 ± 3.4 mm(2)/mmHg, p < .05). The two patients (both LHM) with the smallest increases in DI (1 and 1.6 mm(2)/mmHg) both had persistent symptoms postoperatively and, overall, LHM patients with larger increases in DI had lower postoperative Eckardt scores. In the POEM group, there was no correlation between change in DI and symptoms; however, all POEM patients experienced an increase in DI of >3 mm(2)/mmHg. When all patients were divided into thirds based on final DI, none in the lowest DI group (<6 mm(2)/mmHg) had symptoms suggestive of reflux (i.e., GerdQ score >7), as compared with 20 % in the middle third (6-9 mm(2)/mmHg) and 36 % in the highest third (>9 mm(2)/mmHg). Patients within an "ideal" final DI range (4.5-8.5 mm(2)/mmHg) had optimal symptomatic outcomes (i.e., Eckardt ≤ 1 and GerdQ ≤ 7) in 88 % of cases, compared with 47 % in those with a final DI above or below that range (p < .05).

CONCLUSIONS

Intraoperative EGJ distensibility measurements with FLIP were predictive of postoperative symptomatic outcomes. These results provide initial evidence that FLIP has the potential to act as a useful calibration tool during operations for achalasia.

An extended proximal esophageal myotomy is necessary to normalize EGJ distensibility during Heller myotomy for achalasia, but not POEM

BACKGROUND

For laparoscopic Heller myotomy (LHM), the optimal myotomy length proximal to the esophagogastric junction (EGJ) is unknown. In this study, we used a functional lumen imaging probe (FLIP) to measure EGJ distensibility changes resulting from variable proximal myotomy lengths during LHM and peroral esophageal myotomy (POEM).

METHODS

Distensibility index (DI) (defined as the minimum cross-sectional area at the EGJ divided by pressure) was measured with FLIP after each operative step. During LHM and POEM, each patient's myotomy was performed in two stages: first, a myotomy ablating only the EGJ complex was created (EGJ-M), extending from 2 cm proximal to the EGJ, to 3 cm distal to it. Next, the myotomy was lengthened 4 cm further cephalad to create an extended proximal myotomy (EP-M).

RESULTS

Measurements were performed in 12 patients undergoing LHM and 19 undergoing POEM. LHM resulted in an overall increase in DI (1.6 ± 1 vs. 6.3 ± 3.4 mm(2)/mmHg, p < 0.001). Creation of an EGJ-M resulted in a small increase (1.6-2.3 mm(2)/mmHg, p < 0.01) and extension to an EP-M resulted in a larger increase (2.3-4.9 mm(2)/mmHg, p < 0.001). This effect was consistent, with 11 (92%) patients experiencing a larger increase after EP-M than after EGJ-M. Fundoplication resulted in a decrease in DI and deinsufflation an increase. POEM resulted in an increase in DI (1.3 ± 1 vs. 9.2 ± 3.9 mm(2)/mmHg, p < 0.001). Both creation of the submucosal tunnel and performing an EGJ-M increased DI, whereas lengthening of the myotomy to an EP-M had no additional effect. POEM resulted in a larger overall increase from baseline than LHM (7.9 ± 3.5 vs. 4.7 ± 3.3 mm(2)/mmHg, p < 0.05).

CONCLUSIONS

During LHM, an EP-M was necessary to normalize distensibility, whereas during POEM, a myotomy confined to the EGJ complex was sufficient. In this cohort, POEM resulted in a larger overall increase in EGJ distensibility.