Intraoperative assessment of esophageal motility using FLIP during myotomy for achalasia

Endoscopic impedance planimetry versus high-resolution manometry (HRM) for pre-operative motility evaluation in anti-reflux surgery

INTRODUCTION

Pre-operative evaluation of patients with gastroesophageal reflux disease (GERD) includes assessment of esophageal motility. High-resolution manometry (HRM) is the gold standard; endoscopic impedance planimetry (IP) with Endoflip 2.0 is increasingly utilized in esophageal disorders of motility. We hypothesized that normal IP motility would correlate with normal HRM motility and tested this in a prospective cohort study.

METHODS

Patients presenting for surgical evaluation of GERD between 9/2020 and 10/2021 were prospectively enrolled under an IRB-approved protocol. Patients with prior esophageal/gastric surgery, known motility disorders, or large paraesophageal hernias were excluded. All underwent HRM and IP, with normal motility defined by Chicago 3.0 classification for HRM and the presence of repetitive antegrade contractions for IP. Logistic regression and t test were used to analyze the data; p value < 0.05 was considered significant.

RESULTS

Of 63 patients enrolled, 48 completed both IP and HRM testing. The cohort was 50% male with a median age of 52.5 [42.0, 66.0] years, mostly ASA class 1-2 (75.1%, n = 36) and had an average BMI of 31.4 ± 6.3 kg/m2. Normal motility tracings were in 62.5% of IP and 75% of HRM tests. Using HRM as the gold standard, IP detected normal motility with a sensitivity of 65.8% and a specificity of 50% (positive predictive value 83.3%, negative predictive value 27.8%). Normal IP was not statistically significant in predicting normal HRM (OR 3.182, 95% CI 0.826-12.262, p = 0.0926). Tolerability of IP was significantly better than HRM with lower rates of discomfort (10.9% vs. 93.4%, p < 0.0001) and higher willingness to repeat testing (100% vs. 47.8%, p < 0.0001).

CONCLUSION

Esophageal motility testing with Endoflip 2.0 is well tolerated by patients. The low specificity (50%), poor negative predictive value (27.8%), and lack of statistically significant concordance between IP and HRM raises concern for the reliability of this test as a stand-alone replacement for HRM in the pre-operative evaluation for GERD.

The utility of intraoperative endoscopy in esophagogastric surgery

Flexible endoscopy (FE) plays a major role in the diagnosis and treatment of gastrointestinal disease. Although its intraoperative use has spread over the years, its use by surgeons is still limited in our setting. FE training opportunities are different among many institutions, specialties, and countries. Intraoperative endoscopy (IOE) presents peculiarities that increase its complexity compared to standard FE. IOE has a positive impact on surgical results, due to increased safety and quality, as well as a reduction in the complications. Due to its innumerable advantages, its intraoperative use by surgeons is currently a current project in many countries and is part of the near future in others because of the creation of better structured training projects. This manuscript reviews and updates the indications and uses of intraoperative upper gastrointestinal endoscopy in esophagogastric surgery.

Role of short interval FLIP panometry in predicting long-term outcomes after per-oral endoscopic myotomy

BACKGROUND

The Eckardt score (ES) is used to assess symptom response to Per-Oral Endoscopic Myotomy (POEM), but reliable methods to assess physiologic success are needed. Functional lumen imaging probe (FLIP) panometry has a potential role in post-POEM follow-up to predict long-term outcomes. The aim of this study was to assess the correlation between clinical success and FLIP parameters following POEM to determine if short interval FLIP could predict long-term outcomes.

METHODS

This was a prospective study of adult patients who underwent POEM with short interval follow-up FLIP between 11/2017 and 3/2020. Clinical success was defined as post-procedure ES ≤ 3. Physiologic success was based on an esophago-gastric junction distensibility index (EGJ-DI) > 2.8 mm2/mmHg on FLIP.

RESULTS

47 patients (55% female, mean age 55 years) were included in the study. Clinical success after POEM was seen in 45 (96%) patients (mean ES 6.5 ± 2.2 pre and 0.83 ± 1.0 post-POEM, p < 0.001). Physiologic success was noted in 43 (91.5%) patients (mean EGJ-DI 6.1 mm2/mmHg ± 2.5). Among 4 patients not meeting criteria for physiologic success, EGJ-DI was 2.5-2.6. There was no correlation between post-POEM EGJ-DI and ES in the short term or long term. Significant reflux esophagitis was seen in 6 (12.8%) patients with no difference in mean EGJ-DI with vs without esophagitis (5.9 vs 6.1, p = 0.44).

CONCLUSION

Post-POEM endoscopy with FLIP is useful to both assess EGJ physiology and to examine for reflux esophagitis. Short interval FLIP has limited utility to predict long-term patient outcomes or risk of acid reflux.

Achalasia, from diagnosis to treatment

INTRODUCTION

Achalasia is an uncommon esophageal motility disorder and is characterized by alterations of the motility of the esophageal body in conjunction with altered lower esophageal sphincter (LES) relaxation. The clinical presentation of patients with achalasia may be complex; however, the most frequent symptom is dysphagia. The management of patients with achalasia is often challenging, due to the heterogeneous clinical presentation.

AREAS COVERED

The diagnosis and management of achalasia has significantly improved in the last years due to the growing availability of high-resolution manometry (HRM) and the implementation in the therapeutic armamentarium of new therapeutic endoscopic procedures. Traditional therapeutic strategies include botulinum toxin injected to the LES and pneumatic balloon dilation. On the other hand, surgical treatments contemplate laparoscopic Heller myotomy and, less frequently, esophagectomy. Furthermore, in the last few years, per oral endoscopic myotomy (POEM) has been proposed as the main endoscopic therapeutic alternative to the laparoscopic Heller myotomy.

EXPERT OPINION

Diagnosis and treatment of achalasia still represent a challenging area. However, we believe that an accurate up-front evaluation is, nowadays, necessary in addressing patients with achalasia for a more accurate diagnosis as well as for the best treatment options.

Changes in impedance planimetry (EndoFLIP) measurements at follow-up after peroral endoscopic myotomy (POEM)

BACKGROUND

Numerous studies show changes in functional lumen imaging probe (FLIP) measurements after myotomy during peroral endoscopic myotomy (POEM), but few report on FLIP measurements at follow-up esophagogastroduodenoscopy (EGD). The purpose of this study was to compare perioperative FLIP measurements to those at follow-up EGD.

METHODS

Patients who underwent POEM with FLIP in the operating room and POEM patients who had EGD with FLIP at follow-up were included. FLIP measurements, including diameter (Dmin), pressure, cross-sectional area (CSA), and distensibility index (DI), were analyzed at a 30-mL balloon fill. Differences between measurements at different timepoints were assessed using a two-tailed Wilcoxon signed-rank test.

RESULTS

A total of 97 patients who underwent POEM and 28 who underwent EGD with FLIP were analyzed. The average age was 63 ± 18 years and 46.4% of the patients were male. Mean preoperative Eckardt score was 6.5 ± 4.8, decreasing to 1.6 ± 2.0 at follow-up. EGDs were performed at a median of 15 months after surgery. When compared to mean measurements obtained post-myotomy, at the time of EGD, pressure was found to be significantly lower (p = 0.007) and DI significantly higher (p = 0.045). Of the patients who underwent EGD, 70.8% had an increase in DI, 55.6% had evidence of reflux esophagitis, and 81.0% met diagnostic criteria for reflux on esophageal pH monitoring. However, there was no correlation with the development of esophagitis or reflux and increase or decrease in DI at follow-up.

CONCLUSIONS

There are significant changes in FLIP measurements between the time of surgery and at follow-up EGD. These results suggest that esophageal remodeling may cause changes in lower esophageal sphincter geometry after POEM and postoperative FLIP targets immediately post-myotomy may need to be adjusted to account for these changes.

Virtual disease landscape using mechanics-informed machine learning: Application to esophageal disorders

Esophageal disorders are related to the mechanical properties and function of the esophageal wall. Therefore, to understand the underlying fundamental mechanisms behind various esophageal disorders, it is crucial to map mechanical behavior of the esophageal wall in terms of mechanics-based parameters corresponding to altered bolus transit and increased intrabolus pressure. We present a hybrid framework that combines fluid mechanics and machine learning to identify the underlying physics of various esophageal disorders (motility disorders, eosinophilic esophagitis, reflux disease, scleroderma esophagus) and maps them onto a parameter space which we call the virtual disease landscape (VDL). A one-dimensional inverse model processes the output from an esophageal diagnostic device called the functional lumen imaging probe (FLIP) to estimate the mechanical "health" of the esophagus by predicting a set of mechanics-based parameters such as esophageal wall stiffness, muscle contraction pattern and active relaxation of esophageal wall. The mechanics-based parameters were then used to train a neural network that consists of a variational autoencoder that generated a latent space and a side network that predicted mechanical work metrics for estimating esophagogastric junction motility. The latent vectors along with a set of discrete mechanics-based parameters define the VDL and formed clusters corresponding to specific esophageal disorders. The VDL not only distinguishes among disorders but also displayed disease progression over time. Finally, we demonstrated the clinical applicability of this framework for estimating the effectiveness of a treatment and tracking patients' condition after a treatment.

Peroral Endoscopy Myotomy (POEM) for Esophageal Motility Disorders

PURPOSE OF REVIEW

This review aims to provide an overview of the current role of per oral endoscopic myotomy (POEM) in the management of primary esophageal motility disorders and treatment of Zenker's diverticulum.

RECENT FINDINGS

POEM has been shown to be an effective treatment for achalasia. Recent research has suggested that the length of myotomy may be tailored to the disease phenotype and that short myotomy may be equally effective compared to long myotomy. The role of intra-operative EndoFLIP has shown promise as a tool to assess of the adequacy of myotomy. Further research is needed to determine the role of POEM in other esophageal motility disorders and for treatment of Zenker's diverticulum. Per oral endoscopic myotomy has been shown to be an effective and durable treatment option for achalasia with additional potential roles for the treatment of other esophageal motility disorders and Zenker's diverticulum.

Relationship between dysphagia, lower esophageal sphincter relaxation, and esophagogastric junction distensibility

BACKGROUND

It is debated whether high-resolution manometric (HRM) integrated relaxation pressure (IRP) or functional lumen imaging probe (FLIP) distensibility index (DI) is the superior measure of esophagogastric junction (EGJ) opening. We examined the relationship between the DI and IRP and assessed correlations with dysphagia symptoms in patients with achalasia and EGJ outflow obstruction (EGJOO).

METHODS

Patients with achalasia and those with barium tablet retention at the EGJ were grouped as follows: Group 1:Achalasia (IRP ≥ 15 mmHg + complete absence of normal peristalsis); Group 2: Manometric +FLIP EGJOO (IRP ≥ 15 mmHg with some intact peristalsis + DI ≤ 2.8 mm2 /mmHg); Group 3: Abnormal DI only (DI ≤ 2.8 mm2 /mmHg + IRP <15 mmHg); and Group 4: Normal IRP and DI (IRP ≥ 15 mmHg + DI > 2.8 mm2 /mmHg). Correlation between the DI, baseline lower esophageal sphincter pressure (BLESP), IRP, and dysphagia (Eckardt score) was assessed. Multivariable analysis was used to assess variables associated with dysphagia score ≥2.

KEY RESULTS

A total of 79 patients were included: Group 1 (n = 31), Group 2 (n = 33), Group 3 (n = 14), and Group 4 (n = 1). DI did not correlate with BLESP or IRP in the whole sample or subgroups. DI was the only variable associated with dysphagia score ≥2 (p = 0.006). DI < 1.25 mm2 /mmHg had sensitivity of 87% and specificity of 52% (p = 0.0003) for dysphagia score ≥2.

CONCLUSIONS & INFERENCES

DI does not correlate with HRM EGJ measurements and is the metric with the strongest effect on dysphagia severity. The various biological elements that may cause restrictive EGJ function should be the subject of future studies.

The Predictive Value of Intraoperative Esophageal Functional Luminal Imaging Probe Panometry in Patients With Achalasia Undergoing Peroral Endoscopic Myotomy: A Single-center Experience

Background/Aims

We evaluated the clinical significance and prognostic power of functional luminal imaging probe (FLIP) panometry in patients with achalasia treated with peroral endoscopic myotomy (POEM), and examined the clinical parameters associated with symptomatic improvement and the presence of contractility (POC) following POEM.

Methods

We reviewed the electronic medical records of patients with achalasia treated with FLIP panometry and POEM at a tertiary teaching hospital in Seoul, Republic of Korea. Follow-up examination was composed of esophageal manometry and questionnaires on symptoms. We analyzed the FLIP data by interpolating using the cubic spline method in MATLAB.

Results

We retrospectively analyzed 33 men and 35 women (mean age 52 ± 17 years), of whom 14, 39, and 15 patients were diagnosed with achalasia types I, II, and III, respectively. The FLIP panometry diagnoses were reduced esophagogastric junction opening (REO) with a retrograde contractile response (n = 43); REO with an absent contractile response (n = 5); REO with a normal contractile response (n = 11); and a retrograde contractile response (n = 9). Overall, the patients showed improvements in Eckardt scores following POEM from 6.48 ± 2.20 to 1.16 ± 1.15 (P < 0.01). Post-POEM symptomatic improvement was not significantly associated with any of the clinical parameters, including panometry diagnosis. Conversely, post-POEM POC was significantly associated with the presence of repetitive antegrade contractions and achalasia subtypes (both P < 0.01).

Conclusion

While FLIP panometry was not significantly associated with the clinical course of achalasia, FLIP panometry was associated with POC following POEM and may complement manometry in the functional evaluation of esophageal motility disorders.

Functional luminal imaging probe in the evaluation of esophago-gastric junction outflow obstruction

PURPOSE OF REVIEW

Esophagogastric junction outflow obstruction (EGJOO) comprises a heterogeneous group of conditions that demonstrate impaired deglutitive relaxation of the esophagogastric junction (EGJ) with intact esophageal peristalsis on high-resolution manometry. Functional luminal imaging probe (FLIP) panometry is a powerful tool that can help to clarify the etiology of this manometric diagnosis. The aim of this review is to summarize the use of FLIP for the evaluation and management of EGJOO.

RECENT FINDINGS

FLIP panometry provides measures of esophageal compliance at the EGJ and information on esophageal body contractile responses to balloon distention that have important implications for the management of patients with EGJOO. After excluding anatomic causes of impaired EGJ distensibility, FLIP panometry is useful in differentiating true lower esophageal sphincter dysfunction from manometric artifact. FLIP panometry has been shown to be useful in determining the need for invasive treatment in patients with EGJOO, and in intraoperative tailoring of myotomy procedures.

SUMMARY

FLIP panometry is easy to perform during endoscopy and provides useful information for characterizing the EGJOO population. FLIP panometry can be used to guide treatment and improve outcomes in the management of patients with EGJOO.

Functional Luminal Imaging Probe in the Management of Pediatric Esophageal Disorders

BACKGROUND

Functional luminal imaging probe (FLIP) measures pressure-geometry relationships of digestive luminal space. When used in esophageal disorders, it provides several luminal parameters that help better understand the pathophysiology. Data about the potential utility of FLIP in pediatrics are scarce and there is no standardized use in children. We aim to describe the use of FLIP in our center, its safety, feasibility, and clinical impact in esophageal disorders in children.

METHODS

Consecutive FLIP recordings performed at the Centre Hospitalier Universitaire-Sainte-Justine, Montréal, Canada between February 2018 and January 2021 were extracted. A chart review was conducted for demographics and medical history. Symptomatology after the procedure was evaluated with validated dysphagia scores.

KEY RESULTS

Nineteen patients were included (11 girls, median age 16 years, range 3.2-19.6) with achalasia (n = 5), post-Heller's myotomy dysphagia (n = 3), esophagogastric junction outflow obstruction (n = 3), congenital esophageal stenosis (n = 2); post-esophageal atresia repair stricture (n = 3), and post-fundoplication dysphagia (n = 3). There was no significant correlation between integrated relaxation pressure measured with high resolution manometry and distensibility index (DI). The use of FLIP made it possible to differentiate between dysphagia related to an esophageal obstruction (DI < 2.8 mm2/mmHg) and dysphagia without major motility disorder (DI > 2.8 mm2/mmHg) that guided the indication for dilation. FLIP led to a change in management in 47% of the patients. Forty-seven percent of the patients were symptom free at the time of the evaluation.

CONCLUSIONS INFERENCES

FLIP provides key esophageal luminal values and therefore can play an important role in pediatric esophageal disorders management.

Esophageal Motility Disorders: Are We Missing in Our Busy Endoscopy Practice?

Esophageal motility disorders (EMDs) form a significant part of a busy endoscopist's practice. Endoscopy plays an all-encompassing role in the diagnosis and management of EMDs including achalasia cardia. The focus on in-vogue third-space endoscopic procedures such as per-oral endoscopic myotomy often digresses the important role of endoscopy. Endoscopic evaluation forms the part of standard first-line evaluation of any dysphagia and serves to rule out a secondary cause such as an esophagogastric junction malignancy and eosinophilic esophagitis. Moreover, endoscopic evaluation may itself provide corroborative evidence that may contribute to the diagnosis of the motility disorder. Achalasia cardia may present with a wide spectrum of endoscopic findings from being entirely normal and the well-known and pathognomonic dilated sigmoid-shaped esophagus with food residue, to lesser-known ornate signs. The evidence on the role of endosonography in EMDs is conflicting and largely restricted to evaluation of pseudoachalasia. High-resolution manometry (HRM) remains the gold standard in the diagnosis of EMDs. Endoscopists must also keep abreast of the latest iteration of the Chicago classification version 4.0, which differs significantly from its predecessor in being more stringent in making diagnosis of esophagogastric junction outflow obstruction and disorders of peristalsis since these manometric findings may be seen in normal individuals and may be mimicked by opioid use and gastroesophageal reflux. The latest rendition also includes the use of provocative maneuvers and testing in both supine and sitting posture. Despite being the gold standard, there are certain lacunae in the use and interpretation of the Chicago classification of which the users should be well aware. Emerging technologies such as functional lumen imaging probe and planimetry, and timed barium esophagogram fill the lacuna in diagnosis of these motility disorders, which at times is beyond the resolution of HRM.

Comparison of preoperative, intraoperative, and follow-up functional luminal imaging probe measurements in patients undergoing myotomy for achalasia

BACKGROUND AND AIMS

The functional luminal imaging probe (FLIP) is a novel catheter-based device that measures esophagogastric junction (EGJ) distensibility index (DI) in real time. Previous studies have demonstrated DI to be a predictor of post-treatment clinical outcomes in patients with achalasia. We sought to evaluate EGJ DI in patients with achalasia before, during, and after peroral endoscopic myotomy (POEM) and laparoscopic Heller myotomy (LHM) and to assess the correlation of DI with postoperative outcomes.

METHODS

DI (defined as the minimum cross-sectional area at the EGJ divided by distensive pressure) was measured at 4 time points in patients undergoing surgical myotomy for achalasia: (1) during outpatient preoperative endoscopy (preoperative DI), (2) at the start of each operation after the induction of anesthesia (induction DI), (3) at the conclusion of each operation (postmyotomy DI), and (4) at routine follow-up endoscopy 12 months postoperatively (follow-up DI). Routine Eckardt symptom score, endoscopy, timed barium esophagram, and pH study were obtained 12 months postoperatively.

RESULTS

Forty-six patients (35 POEM, 11 LHM) underwent FLIP measurements at all 4 time points. Preoperative and induction mean DI were similar for both groups (POEM, 1 vs .9 mm²/mm Hg; LHM, 1.7 vs 1.5 mm²/mm Hg). POEM resulted in a significant increase in DI (induction .9 vs postmyotomy 7 mm²/mm Hg, P < .001). There was a subsequent decrease in DI in the follow-up period (postmyotomy 7 vs follow-up 4.8 mm²/mm Hg, P < .01), but DI at follow-up was still significantly improved from preoperative values (P < .001). For LHM patients, DI also increased as a result of surgery (induction 1.5 vs postmyotomy 5.9 mm²/mm Hg, P < .001); however, the increase was smaller than in POEM patients (DI increase 4.4 vs 6.2 mm²/mm Hg, P < .05). After LHM, DI also decreased in the follow-up period, but this change was not statistically significant (5.9 vs 4.4 mm²/mm Hg, P = .29). LHM patients with erosive esophagitis on follow-up endoscopy had a significantly higher postmyotomy DI compared with those without esophagitis (9.3 vs 4.8 mm²/mm Hg, P < .05).

CONCLUSIONS

EGJ DI improved dramatically as a result of both POEM and LHM, with POEM resulting in a larger increase. Mean DI decreased at intermediate follow-up but remained well above previously established thresholds for symptom recurrence. DI at the conclusion of LHM was predictive of erosive esophagitis in the postoperative period, which supports the potential use of FLIP for calibration of partial fundoplication construction during LHM.

Long-term anorectal function in rectal cancer patients treated with chemoradiotherapy and endorectal brachytherapy

AIM

The aim was to study anorectal function in long-term survivors after combined, curatively intended, chemoradiotherapy and endorectal brachytherapy for low rectal cancer.

METHODS

This was a case-control design. We compared anorectal function by anal manometry, anal functional lumen imaging probe (EndoFLIP) and rectal bag distension in rectal cancer patients (RCPs) and healthy, normal subjects (NSs). Symptoms were assessed by the low anterior resection syndrome (LARS) and Wexner faecal incontinence scores.

RESULTS

Thirteen RCPs (12 men, median age 68 years, range 52-92) after 60 Gy radiotherapy, 5 Gy endorectal brachytherapy and oral tegafur-uracil with complete clinical response (median time since treatment 2.8 years, range 2.2-5.6) were compared to 15 NSs (14 men, median age 64 years, range 47-75). RCPs had lower than normal anal resting pressure, 38.6 mmHg (range 8.8-67.7) versus 58.8 mmHg (25.7-105.2) (P < 0.003), and squeeze pressure, 117 mmHg (55.2-203) versus 188 mmHg (103-248) (P < 0.01). Squeeze-induced pressure increase recorded by EndoFLIP was also lower in RCPs (q > 7.56, P < 0.001) as was the anal canal resistance to increasing distension (q = 3.13, P < 0.05). No differences in median rectal volume at first sensation (72 [22-158] vs. 82 [36-190] ml, P = 0.4) or at urge to defaecate (107 [42-227] vs. 132 [59-334] ml, P = 0.2) were found. However, maximum tolerable rectal volume was lower in RCPs (145 [59-319] vs. 222 [106-447] ml, P < 0.02). The median (range) low anterior resection syndrome score was 27 (0-39) for RCPs and 7 (0-23) for NSs (P < 0.001), while the Wexner score was 0 (0-5) versus 0 (0-4) (P = 0.56).

CONCLUSION

Radiotherapy combined with endorectal brachytherapy for rectal cancer causes long-term anorectal symptoms, impaired anal sphincter function and reduced rectal capacity.

Teaching EndoFLIP Impedance Planimetry to Practicing Endoscopists: An "Into the Fire" Approach to Simulation

Background. There are growing interests from practicing endoscopists to implement the functional lumen imaging probe (FLIP) impedance planimetry system. We present a simulation-based curriculum using an "into the fire" approach with hands-on pre- and post-tests to teach the use of this technology. Methods. The curriculum consists of a series of pre-tests, didactic content, mentored hands-on instructions, and post-tests. Pre- and post-testing included a knowledge-based written test, a confidence survey, and an assessment form specific to the hands-on performance of FLIP. Result. Twenty-two practicing physicians completed the curriculum. After course completion, participants had improved knowledge-based written test scores from 6.8±1.7 to 8.9±0.9 (P<0.001), confidence scores from 10.0±5.9 to 22.1±2.6 (P<0.001), and hands-on performance score from 11.4±3.4 to 23.1±2.0 (P<0.001) with significant improvement in all components of the hands-on skills. Conclusion. Our simulation curriculum is effective in improving confidence, knowledge, and technical proficiency when teaching the use of FLIP to practicing physicians.

Outcomes of 100 Patients More Than 4 Years After POEM for Achalasia

OBJECTIVE

We aim to describe the long-term follow-up data from our institution's POEM experience.

SUMMARY BACKGROUND DATA

Per-oral endoscopic myotomy (POEM) is a well-established endoscopic therapy for achalasia with excellent short-term efficacy, but long-term outcomes data are limited.

METHODS

Patients older than 4 years removed from POEM for treatment of achalasia were studied. Clinical success was defined as an Eckardt Symptom (ES) score ≤3 and freedom from reintervention for achalasia. Patients underwent esophagogastroduodenoscopy (EGD), high-resolution manometry, impedance planimetry, and timed barium esophagram (TBE) preoperatively and at least 4 years postoperatively. Objective gastroesophageal reflux disease (GERD) was defined LA Grade B or worse esophagitis on EGD.

RESULTS

One hundred and nineteen consecutive patients were included. Five patients died or had catastrophic events unrelated to achalasia or POEM. One hundred of the remaining patients (88%, 100/114) had long-term data available. Clinical follow-up for all patients was greater than 4 years postoperatively and the mean was 55 months. Mean current ES was significantly improved from preop (n = 100, 1 ± 1 vs 7 ± 2, P < 0.001). Overall clinical success was 88% and 92%. Five patients had a current ES >3 and 4 patients required procedural reintervention on the lower esophageal sphincter. Reinterventions were successful in 75% of patients (3/4), with current ES ≤3. The rate of objective GERD was 33% (15/45). Esophageal physiology was improved with a decrease in median integrated relaxation pressure (11 ± 4 vs 33 ± 15 mm Hg, P < 0.001), a decrease in median TBE column height (3 ± 3 vs 13 ± 8 cm, P < 0.001), and an increase in median distensibility index (5.1 ± 2 vs 1.1 ± 1 mm2/mm Hg, P < 0.001).

CONCLUSIONS

POEM provides durable symptom relief and improvement in physiologic esophagogastric junction relaxation parameters over 4.5 years postoperatively. Reinterventions are rare and effective.

Clinical utility of cricopharyngeal distensibility measurements during endoscopic myotomy for Zenker's diverticulum

BACKGROUND AND AIMS

Flexible endoscopic cricopharyngeal myotomy (FECM) allows minimally invasive treatment of patients with Zenker's diverticulum (ZD); however, retreatment rates are substantial. We hypothesized that the functional lumen imaging probe (FLIP) may provide insight into ZD pathophysiology and serve as an intraprocedural guide to adequacy of myotomy.

METHODS

We prospectively evaluated 11 ZD patients undergoing FECM and compared the baseline cricopharyngeal (CP) distensibility with 16 control subjects. Intraprocedural CP distensibility was measured immediately pre- and postmyotomy. The CP distensibility index (CP-DI) was defined as a ratio of the narrowest cross-sectional area (nCSA) and the corresponding intrabag pressure at 40 mL distension. Same-procedure myotomy extension was undertaken in a subgroup if threshold distensibility changes were not met.

RESULTS

ZD patients had reduced baseline nCSA and CP-DI compared with control subjects, (169.6 vs 227.5 mm² [P < .001] and 3.8 vs 7.6 mm²/mm Hg [P < .001], respectively). After CP myotomy, both nCSA and CP-DI increased significantly by an average of 74.2 mm² (95% confidence interval [CI], 35.1-113.3; P = .002) and 2.2 mm²/mm Hg (95% CI, .6-3.8; P = .01), respectively. In the subgroup with no significant change in CP distensibility after initial myotomy (n = 6), myotomy extension resulted in significant increases in both mean nCSA and CP-DI of 66.6 mm² (95% CI, 16.4-116.8; P = .03) and 1.9 mm²/mm Hg (95% CI, .4-3.3; P = .015), respectively. There were no adverse events.

CONCLUSIONS

CP distensibility is reduced in ZD patients and is partially reversible by FECM. An intraprocedural FLIP CP distensibility measurement is safe and sensitive in detecting myotomy-induced changes. These findings support using FLIP to optimize FECM outcome. Further studies are required to derive precise metrics predictive of clinical response.

The Modern Age of POEM: the Past, Present and Future of Per-Oral Endoscopic Myotomy

BACKGROUND

Per-oral endoscopic myotomy (POEM) has gained widespread enthusiasm amongst foregut specialists since its introduction in the mid 2000s as an effective and less invasive treatment option for achalasia. As more than 6000 POEM procedures have been performed to date throughout the world, we aim to summarize the history and current state of POEM in the treatment of esophageal motility disorders.

METHODS

We performed a comprehensive review of the published literature focusing on the history and development of the POEM procedure, and its most current applications and outcomes.

RESULTS

Multiple favorable long-term studies have been published advocating for the use of POEM as a valid and perhaps the most valid treatment option for achalasia. The procedure is also increasingly being applied to a wider spectrum of esophageal motility disorders including type III achalasia, spastic esophageal disease or isolated lower esophageal sphincter (LES) dysfunction, as well as new endoluminal procedures such as submucosal tumor endoscopic resection (STER), endoscopic fundoplications (POEM-F) and peroral pyloromyotomy (POP or G-POEM).

CONCLUSIONS

While POEM is a proved and valid procedure, its further adoption is being threatened by external factors: challenges related to teaching, institutional support (politics) and insurance reimbursement. While this technique has come an incredible distance in its relatively short lifespan, the future of POEM in the USA will depend on the support from surgical societies to validate it as a valuable tool in the esophageal specialist's armamentarium, and to encourage a commitment to training in endoluminal surgery.

Esophageal POEM: the new standard of care

Since its introduction into clinical practice nearly a decade ago, per-oral endoscopic myotomy (POEM) has now become an accepted minimally invasive approach for the treatment of achalasia with excellent short- and mid-term clinical outcomes in both treatment naïve and those who have failed prior therapy. POEM is comparable to laparoscopic Heller myotomy (LHM) in terms of efficacy and safety, with less procedural pain and faster recovery time. Recent data also reveals that POEM may be more effective and durable than pneumatic dilation (PD) for the treatment of achalasia, with similar safety profile. Preliminary data on POEM for spastic esophageal disorders (SED) is promising yet scarce. Post-POEM gastroesophageal reflux disease (GERD) is common but asymptomatic in most patients, further highlighting the need for ongoing research in this field and the importance of long-term surveillance of these patients.

Using a standardized intra-operative endoflip protocol during fundoplication to identify factors that affect distensibility

INTRODUCTION

The Endoluminal Functional Lumen Imaging Probe (Endoflip) can be used to provide objective measurements of the gastroesophageal junction during fundoplication, and recent publications have suggested that this device could improve surgical outcomes. However, the impact of operative variables has not been clearly reported. The aim of this study is to determine the effect of these variables on functional lumen imaging probe (FLIP) measurements.

METHODS

Following implementation of a standardized operative FLIP protocol, all data were collected prospectively and entered into a quality database. This database was queried for patients undergoing hiatal hernia repair and fundoplication. The protocol utilized various balloon volumes (30 and 40 ml), patient positions (flat and reverse Trendelenburg) and amounts of insufflation (15 mmHg pneumoperitoneum and no pneumoperitoneum).

RESULTS

Between August 2018 and February 2020, 97 fundoplications were performed by a single surgeon. Multivariable analysis without interactions demonstrated that a 40 ml volume fill resulted in significantly higher minimum diameter (Dmin), cross-sectional area (CSA), intra-balloon pressure (IBP) and distensibility index (DI) compared to a 30 ml volume fill (p < 0.001). While reverse Trendelenburg positioning resulted in a significantly higher Dmin, IBP and CSA compared to the flat position (all p < 0.05), there was little impact of positioning on DI. Lastly, pneumoperitoneum significantly increased IBP (p < 0.001) but did not affect Dmin (p = 0.697) or CSA (p = 0.757), which resulted in a significant decrease in DI (p < 0.001) when compared to measurements without pneumoperitoneum. Multivariable analysis allowing for interactions demonstrated significant two-way interactions between balloon volume and pneumoperitoneum (p = 0.047), as well as patient position and pneumoperitoneum (p < 0.001).

CONCLUSION

Surgeons should consider balloon volume and the presence or absence of pneumoperitoneum when interpreting distensibility during or after fundoplication. Additionally, we suggest a formal standardized protocol for FLIP measurements to utilize a 40 ml volume fill in reverse Trendelenburg without pneumoperitoneum.

EndoFLIP in the Esophagus: Assessing Sphincter Function, Wall Stiffness, and Motility to Guide Treatment

The functional luminal imaging probe (FLIP) uses high-resolution planimetry to provide a three-dimensional image of the esophageal lumen by measuring diameter, volume, and pressure changes. Literature surrounding use of FLIP has demonstrated its clinical utility as a diagnostic tool and as a device to guide and measure response to therapy. FLIP can assess and guide treatments for esophageal disease states including gastroesophageal reflux disease, achalasia, and eosinophilic esophagitis. FLIP may become the initial test for patients with undifferentiated dysphagia at their index endoscopy. This article summarizes use of FLIP in assessing sphincter function, wall stiffness, and motility to guide treatments.

The use of impedance planimetry (Endoscopic Functional Lumen Imaging Probe, EndoFLIP® ) in the gastrointestinal tract: A systematic review

BACKGROUND AND PURPOSE

The EndoFLIP® system is a method of delineating impedance and was first designed to investigate the characteristics of the esophago-gastric junction. In the last decade, its use was widened to investigate other sphincteric and non-sphincteric systems of the gastrointestinal tract. The objective of the present systematic review was to summarize the available data in literature on the use of the EndoFLIP® system in the gastrointestinal tract, including sphincteric and non-sphincteric regions. We performed a systematic review in accordance with recommendations for systematic review using PRISMA guidelines without date restriction, until June 2020, using MEDLINE-PubMed, Cochrane Library, and Google Scholar databases. Only articles written in English were included in the present review. Five hundred and six unique citations were identified from all database combined. Of those, 95 met the inclusion criteria. There was a lack of standardization among studies in terms of anesthetic drugs use, probe placement, and inflation protocol. In most cases, only small cohorts of patients were included. Most studies investigated the EGJ, with a potential use of the EndoFLIP® to identify a subgroup of patients with achalasia and for intraoperative assessment of treatment efficacy in achalasia. However, the use of EndoFLIP® in the esophageal body (esophageal panometry), other esophageal diseases (gastro-esophageal reflux disease, eosinophilic esophagitis), and other sphincter regions (anal canal, pylorus) will need further confirmatory studies. The EndoFLIP® system provides detailed geometric data of the gastrointestinal lumen but further works are needed to determine its use in clinical practice.

Esophageal Functional Lumen Imaging Probe (FLIP): How Can FLIP Enhance Your Clinical Practice?

Recent innovations in esophageal diagnostic testing have enhanced gastroenterology clinical practice by facilitating more nuanced and advanced evaluation of esophageal symptoms. Among these pivotal advances is the FDA-approved functional lumen imaging probe (FLIP), which utilizes impedance planimetry via volumetric distension of a catheter-mounted balloon at the time of sedated upper endoscopy, to acquire esophageal dimensions and pressures. In real time, FLIP can display cross-sectional areas (CSA) and distensibility indices (ratios of CSA to intra-balloon pressures) throughout the esophagus, most notably at the esophagogastric junction, as well as secondary peristaltic esophageal body contractile patterns. As the use of FLIP has progressively spread and permeated into the practice of clinical gastroenterology since its introduction, increasing data on and experiences with its applications have accumulated to guide its utility in clinical practice. In this current review developed for gastroenterologists and foregut surgeons across clinical practice, we provide an introduction to FLIP technology and metrics and discuss the clinical scenarios in which performance of or referral for FLIP may be helpful in the evaluation and management of patients with commonly encountered esophageal symptoms and disorders. Specifically, we discuss the potential applications and limitations of FLIP as a complementary diagnostic modality in patients with non-obstructive dysphagia, established or suspected achalasia spectrum disorders, eosinophilic esophagitis, gastroesophageal reflux disease and those undergoing esophageal surgery.

The functional lumen imaging probe in gastrointestinal disorders: the past, present, and future

The functional lumen imaging probe (FLIP) is a diagnostic tool that utilizes impedance planimetry to allow the assessment of luminal diameter and distensibility. It has been used primarily in esophageal diseases, in particular, in the assessment of achalasia, esophagogastric junction outflow obstruction, and eosinophilic esophagitis (EoE). The usage and publications have increased over the past decade and it is now an essential tool in the armamentarium of the esophagologist. Indications are emerging outside of the esophagus, in particular with regard to gastroparesis. Our paper will review the history of FLIP, optimal current usage, data for key esophageal disorders (including achalasia, reflux, and EoE), data for nonesophageal disorders, and our sense as to whether FLIP is ready for prime time, as well as gaps in evidence and suggestions for future research.

Impedance in the evaluation of the esophagus

The aim of this paper is to review esophageal electrical impedance technologies and to discuss the use of these technologies for physiological measurements, diagnostics, and therapy of esophageal disease. In order to develop a better understanding of the pathophysiology of and improve the diagnosis of esophageal disorders, such as gastroesophageal reflux disease (GERD) and achalasia, several new diagnostic tests, including intraluminal impedance, esophageal mucosal impedance, and the functional luminal imaging probe, have been developed. These technologies have proven valuable for assessment of the esophagus in recent years. They provide information on esophageal flow properties, mucosal integrity, lumen shape, and distensibility in esophageal disorders, in particular for GERD and achalasia. Despite their promise and novel clinical studies, the potential of these technologies has been far from realized. New multidisciplinary approaches will contribute to our understanding and interpretation of esophageal impedance data and disease mechanisms.

Applying the Functional Luminal Imaging Probe to Esophageal Disorders

PURPOSE OF REVIEW

The functional luminal imaging probe (FLIP) uses high-resolution planimetry to provide a three-dimensional image of the esophageal lumen by measuring diameter, volume, and pressure changes. The goal of this review is to summarize the most recent advances in applying the (FLIP) to esophageal disorders.

RECENT FINDINGS

The FLIP has been studied in esophageal disease states including gastroesophageal reflux disease (GERD), achalasia, and eosinophilic esophagitis. It has also been used in the investigation of dysphagia. The FLIP is a valuable tool for the diagnosis of esophageal diseases as well as guiding treatments and predicting treatment response. As further research is done, the FLIP may become the initial test for the patient with undifferentiated dysphagia at the time of their index endoscopy.

Comparison of peroral endoscopic myotomy between de-novo achalasia and achalasia with prior treatment

Peroral endoscopic myotomy has been recognized as an effective treatment for patients with achalasia. Prior treatment may affect the outcome of subsequent treatment. We aimed to compare the safety and efficacy of POEM in treatment-naive patients vs. those with prior treatment failure. We retrospectively analyzed the data of achalasia patients who underwent POEM from November 2011 to January 2018. A comparative analysis was performed between De-Novo (DN) and Prior Treatment Failure (PTF) cases. Technical and clinical success, adverse events, operative time for POEM, hospital stay were compared between the two groups Overall, 209 patients with achalasia underwent POEM during the studied period, including 113 patients (54%) in the DN group and 96 patients (45%) in the PTF group. The baseline characteristics of the DN and PTF groups were not significantly different except for duration of disease. The PTF group had longer disease duration than the DN group. (7.92 ± 9.28 vs 4.45 ± 5.67 years, respectively, p = 0.005). Both groups were technically successful. Operative time was longer in the PTF group than that in the de-novo group, but the difference was not significant. The occurrence rates of complications were similar in both groups. Changes in the Eckardt score were comparable in the DN and PTF cases. IRP and LES pressure decreased after POEM. After 6 months, more patients suffered from reflux symptoms in the PTF group, but DeMeester score and endoscopic evaluation were not significantly different POEM is safe and equally effective for patients with prior treatment failure as well as de-novo patients up to 6 months post treatment.