Intraoperative measurement of esophagogastric junction cross-sectional area by impedance planimetry correlates with clinical outcomes of peroral endoscopic myotomy for achalasia: a multicenter study

Esophageal impedance planimetry during per-oral endoscopic myotomy guides myotomy extent

INTRODUCTION

Peroral endoscopic myotomy (POEM) is the standard treatment for achalasia. Functional luminal imaging probe (FLIP) technology enables objective measurement of lower esophageal sphincter (LES) geometry, with literature linking specific values to improved post-POEM outcomes. Our study assesses FLIP's intraoperative use in evaluating myotomy extent in real-time.

METHODS

Retrospective data from all patients undergoing POEM with intraoperative FLIP measurements were extracted from June 2020 to January 2023. The primary endpoint was intraoperative FLIP measurements, management changes, and symptom improvement (Eckardt score).

RESULTS

Fourteen patients (age 56 ± 14 years, BMI 28 ± 7 kg/m2) were identified. Most patients were female (64%). Predominantly, patients presented with type II achalasia (50%). FLIP measurements were taken before and after myotomy, demonstrating increases in mean distensibility index (DI) 1.6 ± 1. 4 to 5.4 ± 2.1 mm2/mmHg (p < 0.05) and mean diameter (Dmin) 6 ± 1.8 to 10.9 ± 2.3 mm (p < 0.05) at 50 ml balloon fill. Additional myotomy was performed in one patient when an inadequate increase in FLIP values were noted. Mean operative time was 98 ± 28 min, and there were no intraoperative complications. At the 30-day follow-up, median Eckardt score decreased from mean a preoperative score of 7 ± 2 to a post-operative mean of 2 ± 3, with 10 patients (78%) having a score ≤ 2. In total, four patients experienced symptom recurrence, with repeat FLIP values revealing a significant decrease in DI from 7 ± 2.2 post-POEM to 2.5 ± 1.5 at recurrence. FLIP technology identified LES pathology in 3 out of 4 (75%) patients, facilitating referral to LES-directed therapy.

CONCLUSION

Our study adds to the literature supporting the use of FLIP technology during the POEM procedure, with most patients achieving ideal values after a standard-length myotomy. This suggests the potential benefits of shorter myotomies guided by FLIP to achieve comparable outcomes and reduce postoperative GERD risk. Collaborative standardization of study designs and outcome measures is crucial for facilitating prospective trials and cross-setting outcome comparisons.

The effect of per-oral endoscopic myotomy by achalasia subtype as measured by impedance planimetry

BACKGROUND

Achalasia is an esophageal motility disorder with three subtypes based on manometry that can treated with per-oral endoscopic myotomy (POEM). With the advent of impedance planimetry (EndoFLIP®), we hypothesized the three achalasia subtypes would have different pre-POEM EndoFLIP® diameter and distensibility index (DI) measurements but would be similar after POEM.

METHODS

A single-institution, retrospective review of consecutive POEM cases by a single surgeon-endoscopist team from 04/07/2017 to 08/28/2023. Patients with a diagnosis of achalasia were stratified into type 1, 2, or 3 based on pre-POEM manometry. Patient characteristics, Eckardt scores, and pre-and-post-POEM diameter and DI were compared by subtype with descriptive, univariate, and multivariable linear regression statistics.

RESULTS

Sixty-four patients met inclusion criteria, of whom 9(14.1%) had Type 1, 36(56.3%) had Type 2, and 19(29.7%) had Type 3. There were no differences between Types with respect to median pre-POEM Eckardt scores (9[IQR:7-9) vs. 8[IQR:6-9] vs. 7[IQR:5-8], p = 0.148), median post-POEM Eckardt scores (0[IQR:0-1] vs. 0[IQR:0-0] vs. 0[IQR0-0.5], p = 0.112). EndoFLIP® data revealed variation in median pre-POEM diameter and DI between Subtypes (6.9[IQR:6-8.5] vs. 5.5[IQR:5-6.8] vs. 5[IQR:5-6.1], p = 0.025 and 1.8[IQR:1.3-3.2] vs. 0.9[IQR:0.6-1.6] vs. 0.6[IQR:0.5-0.8], p = 0.003, respectively), but not in the change in diameter or DI post-POEM (5.1[IQR:4.3-5.9] vs. 5.1[IQR:4.1-7.1] vs. 5.9[IQR:5-6.4], p = 0.217 and 3.9[IQR:2.5-4.7] vs. 3.4[IQR:2.4-4.7] vs. 2.7[IQR:2.3-3.7], p = 0.461, respectively). However, after adjusting for potentially confounding factors, pre- or post-POEM diameter and DI did not demonstrate statistically significant differences among subtypes.

CONCLUSIONS

Achalasia subtypes did not demonstrate different pre-POEM diameters or DI as measured by EndoFLIP® nor are there differences after POEM completion. While achalasia subtypes may have slightly different pathophysiology based on manometry findings, similar pre- and post-POEM impedance planimetry findings, along with similar Eckardt scores, support the use of POEM in the treatment of any achalasia subtype.

Diagnostic and therapeutic strategies for achalasia of the cardia

The diagnosis of achalasia of the cardidia (AC) is primarily based on clinical symptoms, esophagographic findings, esophagodynamic examination, and upper gastrointestinal endoscopic findings. High resolution manometry is considered the gold standard for diagnosis. With the advan-cement of new technologies, the diagnostic methods for AC have become more diverse, and three-dimensional modeling may facilitate early detection of AC. The use of endoscopic functional intracavity imaging probe can enhance diagnostic accuracy. Common treatment options include endoscopic balloon dilation, laparoscopic Heller myotomy, and peroral endoscopic myotomy (POEM). POEM has emerged as the most widely utilized therapeutic approach currently, significantly improving the clinical success rate in treating AC. This article provides a comprehensive review on recent research progress in the diagnosis and treatment of AC.

POEM in the esophagus - How to deal with the post-POEM reflux

Reflux after peroral endoscopic myotomy (POEM) is arguably one of the greatest concerns related to the procedure. The exact incidence is difficult to establish as reflux symptoms, esophagitis, and abnormal acid exposure correlate poorly, warranting thorough diagnostic investigation. The incidence is, however, higher than after Heller myotomy or pneumatic dilatation across all these three parameters. Although PPI are effective in the resolution of symptoms and healing of esophagitis, refractory patients exist. Esophageal hypersensitivity and acidic fermentation/esophageal stasis are most likely causes and could be diagnosed by manual analysis of pH metry tracings. Long-term complications like peptic stricture and Barrett's esophagus are rare and reported sporadically. Modifications of POEM procedure aiming to decrease post-POEM reflux led to no conclusive preferred technique. Modern investigations like endoluminal functional lumen imaging probe might help to personalize myotomy to the desired distensibility of the lower esophageal sphincter and decrease reflux.

Impact of peroral endoscopic myotomy on the endoscopic pressure study integrated system

OBJECTIVES

The endoscopic pressure study integrated system (EPSIS) is an endoscopic diagnostic system utilized for evaluation of lower esophageal sphincter function. Although previous studies have determined that EPSIS was effective as a tool for the diagnosis of achalasia, it remains uncertain if EPSIS can detect significant changes before and after peroral endoscopic myotomy (POEM), which is the premier treatment for achalasia. This study aimed to evaluate the effectiveness of EPSIS as an objective diagnostic tool for assessing the clinical effect of POEM.

METHODS

We conducted a retrospective analysis of patients who underwent POEM from January 2022 to December 2023. The patients underwent EPSIS preoperatively and 2 months postoperatively. Intragastric pressure (IGP) parameters, including the maximum IGP, IGP difference, and waveform gradient were compared pre- and post-POEM. These parameters also were compared between two groups: the postoperative gastroesophageal reflux disease (GERD) group and the non-GERD group.

RESULTS

A total of 50 patients were analyzed. The mean maximum IGP was significantly lower postoperatively than preoperatively (15.0 mmHg vs. 19.8 mmHg, P < 0.001). The mean IGP difference and waveform gradient were also significantly lower postoperatively than preoperatively (8.0 mmHg vs. 12.2 mmHg, P < 0.001; and 0.26 mmHg/s vs. 0.43 mmHg/s, P < 0.001, respectively). The mean postoperative waveform gradient was significantly lower in the GERD group (17 patients, 34%) than in the non-GERD group (33 patients, 66%) (0.207 mmHg vs. 0.291 mmHg, P = 0.034).

CONCLUSION

The results supported the use of EPSIS as an effective diagnostic tool for assessing the effect of POEM.

Peroral endoscopic myotomy for spastic esophageal dysmotility among opioid users: a multicenter propensity score matching study

BACKGROUND AND AIMS

Opioid-induced esophageal dysfunction (OIED) often presents as spastic esophageal disorders (SEDs) and esophagogastric junction outflow obstruction (EGJOO). The aim of this study was to evaluate and compare clinical outcomes of peroral endoscopic myotomy (POEM) for SEDs and EGJOO among opioid users and nonusers.

METHODS

This propensity score (PS) matching study included consecutive opioid users and nonusers who underwent POEM for SEDs and EGJOO between January 2018 and September 2022. The following covariates were used for the PS calculation: age, sex, duration of symptoms, Eckardt score, type of motility disorder, and length of myotomy during POEM. Clinical response was defined as a post-POEM Eckardt score ≤3.

RESULTS

A total of 277 consecutive patients underwent POEM during the study period. PS matching resulted in the selection of 64 pairs of patients strictly matched 1:1 (n = 128) with no statistically significant differences in demographic, baseline, or procedural characteristics or in the parameters considered for the PS between the 2 groups. Clinical response to POEM was significantly lower among opioid users (51 of 64 [79.7%]) versus nonusers (60 of 64 [93.8%]) (P = .03) at a median follow-up of 18 months. Among opioid users, higher opioid dose (>60 morphine milligram equivalents per day) was associated with a higher likelihood of failure to respond to POEM (odds ratio, 4.59; 95% confidence interval, 1.31-3.98; P = .02).

CONCLUSIONS

Clinical response to POEM for SEDs and EGJOO is significantly lower among opioid users versus nonusers. There was a dose-relationship between opioids and response to POEM, with higher daily opioid usage associated with a higher likelihood of treatment failure.

Endoscopic pressure study integrated system for the diagnosis of achalasia

OBJECTIVES

The endoscopic pressure study integrated system (EPSIS) is a novel diagnostic tool used to evaluate lower esophageal sphincter (LES) function. EPSIS allows the measurement of intragastric pressure (IGP) during gastric insufflation through esophagogastroduodenoscopy (EGD) and records its pressure waveform. This study aimed to assess the usefulness and applicability of EPSIS as an adjunct diagnostic modality for achalasia.

METHODS

This case-control study was conducted using a database of patients who underwent EGD, barium swallow (BS), high-resolution manometry (HRM), and EPSIS between January 2022 and December 2022. The achalasia (experimental) group (n = 35) consisted of patients with a definitive diagnosis of achalasia. The control group (n = 34) consisted of patients with no abnormalities in EGD, BS, or HRM and no abnormal acid reflux confirmed with 24-h pH-impedance monitoring. EPSIS findings were compared between the two groups and characterized by the waveform pattern (uphill or flat), maximum IGP (IGP-Max), pressure difference, and the gradient of the waveform.

RESULTS

All patients in the achalasia group showed an uphill pattern, in contrast to 21 patients (61.8%) in the control group. IGP-Max demonstrated the best diagnostic accuracy for achalasia, with a cut-off value of 15.8 mmHg (100% sensitivity, 58.8% specificity, and area under the curve [AUC] 0.78). The pressure gradient also demonstrated good diagnostic accuracy, with a cut-off value of 0.40 mmHg/s (80% sensitivity, 61.8% specificity, and AUC 0.76).

CONCLUSION

This study demonstrated that EPSIS can be applied as a diagnostic modality in patients with achalasia.

Anesthesia choice and its potential impact on endoluminal functional lumen imaging probe measurements in esophageal motility disorders

BACKGROUND AND AIMS

The widespread use of peroral endoscopic myotomy (POEM) has revolutionized the management of esophageal motility disorders (EMDs). The introduction of an endoluminal functional lumen imaging probe (EndoFLIP, Medtronic, Dublin, Ireland) can serve as a complementary diagnostic tool to assess the mechanical properties (ie, pressure, diameter, distensibility, topography) of the esophagus. During EndoFLIP measurements, different anesthesia techniques may induce variable degrees of neuromuscular blockade, potentially affecting esophageal motility and altering the results of EndoFLIP metrics. The aim of this study was to compare the impact of using total intravenous anesthesia (TIVA) versus general anesthesia with inhalational anesthetics (GAIA) on diagnostic EndoFLIP measurements.

METHODS

This retrospective study included all adult patients (≥18 years) undergoing EndoFlip during the POEM procedure at our institution between February 2017 and February 2022. Differences in pressure, diameter, and distensibility index were obtained by using propofol-based TIVA versus sevoflurane-based GAIA with a 30 mL and a 60 mL balloon. The differences were divided into terciles and compared between diagnoses by using univariate comparisons and logistic regression models.

RESULTS

A total of 49 patients were included (39% type I achalasia, 43% type II or III achalasia, and 18% jackhammer esophagus [JE]). Compared with spastic disorders (types II and III achalasia and JE), type I had lower values of pressure differences at 60 mL in univariate (3.75 vs 15.20, P = .001) and multivariate (adjusted odds ratio, .89; 95% confidence interval, .82-.978) analyses. Compared with type I, types II and III achalasia had higher rates of pressure differences at 60 mL in the univariate (9.85 vs 3.75, P = .04) analysis and nearly reached significance in the multivariate analysis (1.09; 95% confidence interval, 1-1.20). Compared with type I achalasia, JE exhibited higher values in pressure differences at 60 mL (27.7 vs 3.75, P < .001).

CONCLUSIONS

Esophageal pressure, as measured by EndoFLIP, was significantly reduced when patients were sedated with sevoflurane-based GAIA. The use of sevoflurane-based GAIA for diagnostic EndoFLIP may potentially lead to the misclassification of spastic disorders as type I achalasia. Propofol-based TIVA should therefore be considered over sevoflurane-based GAIA for sedation during the diagnostic test.

Using impedance planimetry to define the end of a peroral endoscopic myotomy

INTRODUCTION

Peroral endoscopic myotomy (POEM) is a minimally invasive endoscopic option for management of achalasia. Adequate distal myotomy is necessary for relief of symptoms, but when too long may also increase risk of reflux. The objective of this study is to evaluate clinical outcomes after POEM and final length of gastric myotomy using impedance planimetry (EndoFLIP).

METHODS

A retrospective review of 34 consecutive patients undergoing POEM with EndoFLIP were included. EndoFLIP measurements, including esophagogastric junction distensibility index (DI), minimum diameter (Dmin), and cross-sectional area (CSA) were recorded at 30- and 40-mL balloon-fill pre- and post- myotomy. The myotomy was considered complete when DI ≥ 3.4 mm2/mmHg. Postoperative Eckardt score (ES) was determined at initial postoperative visit and most recent follow-up. Linear and logistic regression were used to evaluate the association between gastric myotomy length and post-myotomy EndoFLIP measurements on postoperative ES and GERD. Wilcoxon rank-sum test was used to compare gastric myotomy lengths and EndoFLIP parameters in relation to clinical success and development of GERD, and paired t-test to compare EndoFLIP measurements and ES pre- and post-myotomy.

RESULTS

Final length of gastric myotomy measured 1 cm in 1 (2.9%), 1.5 cm in 11 (32.4%), 2.0 cm in 19 (55.9%), and 2.5 cm in 3 (8.8%) patients. Mean preoperative ES was 6.6 ± 2.2. All patients achieved ES < 3 postoperatively, which was maintained in 88.5% of patients at a median of 7.5 months of follow-up. Gastric myotomy length and post-myotomy EndoFLIP values were not associated with postoperative Eckardt scores or GERD.

DISCUSSION

Early and late symptom relief was achieved in 100 and 88.5% of patients, respectively, at a gastric myotomy length of 1-2.5 cm. Using EndoFLIP to define a completed myotomy at DI of 3.4 mm2/mmHg yielded variable lengths of gastric myotomy.

Impedance planimetry during per-oral endoscopic myotomy is associated with decreased inadvertent capnoperitoneum

BACKGROUND

Per-oral endoscopic myotomy (POEM) has become an accepted minimally invasive alternative to Heller myotomy for the treatment of achalasia and other disorders of esophageal dysmotility. One associated adverse event is the inadvertent creation of capnoperitoneum. A proposed mechanism is that extension of the submucosal tunnel below the esophageal hiatus and onto the gastric wall leads to transmural perforation. We hypothesized that the use of impedance planimetry with the endoscopic functional luminal imaging probe (EndoFLIP) more accurately identifies the esophagogastric junction and helps to better define the myotomy's ideal limits, thus lowering the incidence of inadvertent capnoperitoneum.

METHODS

This is a single-center, retrospective review of consecutive POEM cases from 06/11/2011 to 08/08/2022, with EndoFLIP introduced in 2017. Patient and procedural characteristics, including the incidence of clinically significant capnoperitoneum and decompression, were analyzed using univariate and multivariable linear regression statistics.

RESULTS

There were 140 POEM cases identified, 74 (52.9%) of which used EndoFLIP. Clinically significant capnoperitoneum was encountered in 26 (18.6%) cases, with no differences in patient characteristics between those who had capnoperitoneum and those who did not. There was a decreased incidence of capnoperitoneum in cases using EndoFLIP compared to those without (n = 6, 23% vs n = 20, 77%, p = 0.001), with zero instances in the final 56 cases. After adjusting for potentially confounding factors, EndoFLIP use was associated with a - 15.93% (95% confidence interval - 30.68%, - 1.18%) decrease in procedure duration.

CONCLUSIONS

The routine use of EndoFLIP during POEM was associated with decreased incidence of clinically significant capnoperitoneum, potentially due to improved myotomy tailoring and decreased duration of insufflation with shorter procedure times.

Interventional functional diagnostics in gastrointestinal endoscopy: Combining diagnostic and therapeutic tools in the endoscopy suite with the functional lumen imaging probe

With technical progress of gastrointestinal functional testing, there has been a demand for more comprehensive examination of esophageal physiology and pathophysiology beyond high-resolution manometry. A new interventional technology based on impedance planimetry, the functional lumen imaging probe (FLIP), enables intraluminal measurement of distensibility and compliance of hollow organs. EndoFLIP uses balloon catheters to measure diameter and distension pressure to calculate cross-sectional area and distensibility in different organs (mostly esophagus, stomach, anorectal region) and can be used in wide variety of indications (diagnostics, pre- and post-treatment evaluation) and currently serves as a helpful adjunctive tool in ambiguous clinical cases. EsoFLIP is a therapeutic variation that uses a stiffer balloon catheter allowing for dilation. The trend to simplify the clinical process from diagnosis to treatment tends to a one-session procedure combining diagnostics and therapeutic interventions. In specified conditions like e.g. achalasia or gastroparesis, a combination of EndoFLIP and EsoFLIP procedures may therefore be useful. The aim of this narrative review is to introduce the clinical use of FLIP and its potential benefit in combined diagnostic-therapeutic procedures.

Mini-review: Tailored per-oral endoscopic myotomy for type III achalasia

This mini-review summarizes the most recent literature regarding per-oral endoscopic myotomy for type III achalasia, emphasizing the poorly understood science of tailoring myotomy length during this procedure. In addition, special attention will be placed on the current subjective and objective biomarkers, such as the Eckardt score, used to evaluate treatment outcomes in this population to better contextualize the existing data on patient outcomes, as proposed by Low et al in the current issue of the Journal. Understanding the current treatment landscape for type III achalasia and identifying the key areas of research deficiencies will guide future investigation and management of this disease.

Intraoperative distensibility measurement in POEM for achalasia: impact on patient outcome and associations with other outcome variables at 1-year follow-up

BACKGROUND AND AIMS

The functional luminal imaging probe (FLIP) can provide measurements of lower esophageal sphincter (LES) distensibility. Studies report that use of intraoperative FLIP examination during peroral endoscopic myotomy (POEM) for achalasia is associated with treatment success, but evidence is limited and inconsistent. The main aim of the present study was to assess associations between intraoperative FLIP values and 1-year outcomes. Additionally, associations between 1-year FLIP measurements and other 1-year outcome variables were studied.

METHODS

We performed a single-center prospective study of consecutive achalasia patients treated with POEM with a standardized 1-year follow-up. The inclusion period was from June 2017 to January 2020. We compared 1-year outcomes (FLIP measurement values, Eckardt score (ES), reflux esophagitis, timed barium esophagogram (TBE), and lower esophageal sphincter resting pressure (LES-rp)) in patients with and without intraoperative FLIP examination. We also assessed associations between intraoperative FLIP values, 1-year FLIP values, and other 1-year outcomes. Results are given as median (IQR), and non-parametrical statistical analyses were applied.

RESULTS

Sixty-two patients (27 females) with median age 45 years (35-54) were included. Baseline characteristics were similar in patients with (n = 32) and without (n = 30) intraoperative FLIP examination. In patients with intraoperative FLIP, ES was 2 (1-3) and LES distensibility index (DI) 3.7 (2.6-5.4) after 1 year, compared with ES 2 (1-3) and DI 4.0 (3.1-6.8)) in patients without intraoperative FLIP (ns). Intraoperative DI was not correlated with 1-year ES or DI. One-year DI correlated significantly with 1-year ES (rs - 0.42), TBE (rs - 0.34), and LES-rp (rs - 0.29).

CONCLUSIONS

Use of intraoperative FLIP measurements in POEM for achalasia is not associated with improved 1-year outcome, and the clinical value of intraoperative FLIP in POEM for achalasia is questioned. Follow-up FLIP measurements are moderately associated with symptomatic outcome, and may serve as an additional diagnostic modality in post-treatment evaluation.

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.

Early outcomes following EndoFLIP-tailored peroral endoscopic myotomy (POEM): the establishment of POEM services in two UK centers

Peroral endoscopic myotomy (POEM) is a safe and effective minimally invasive treatment for achalasia. Postoperative reflux rates remain high. The functional luminal imaging probe (FLIP) allows intraoperative measurement of lower esophageal distensibility during POEM. In theory, this enables a tailoring of myotomies to ensure adequate distensibility while minimizing postoperative reflux risk. Two prospectively collected POEM databases were analyzed from two UK tertiary upper GI centers. The operators in each center used FLIP measurements to ensure adequate myotomy. Outcome measures included Eckardt score (where <3 indicated clinical success) and proton-pump inhibitor use (PPI), collected at the first postoperative appointment. Length of stay was recorded as were complications. In all, 142 patients underwent POEM between 2015 and 2019. Overall, 90% (128/142) had postoperative Eckardt scores of <3 at 6 weeks. Clinical success improved to 93% (66/71) in the latter half of each series with a significantly higher rate of complete symptom resolution (53 versus 26%, P = 0.003). In all, 79% of the poor responders had previous interventions compared with 55% of responders (P = 0.09). Median post-myotomy distensibility index was 4.0 mm2/mmHg in responders and 2.9 in nonresponders (P = 0.16). Myotomy length of <7 cm was associated with 93% clinical success and 40% post op PPI use compared with 60% PPI use with longer myotomies. There were two type IIIa, two type IIIb, and one IV Clavien-Dindo complications. This is the largest series of endoluminal functional lumen imaging probe (EndoFLIP)-tailored POEM in the UK to date. The shorter myotomies, allowed through EndoFLIP tailoring, remained clinically effective at 6 weeks. Complete symptom response rates improved in the latter half of each series. More data will be needed from high-volume collaborations to decipher optimal myotomy profiles based on EndoFLIP parameters.

Experience with Impedance Planimetry for Surgical Foregut Disease in 1,097 Cases

BACKGROUND

The geometry and compliance of gastrointestinal sphincters may be assessed by impedance planimetry using a functional lumen imaging probe (FLIP). We describe our institutional foregut surgeon experience using FLIP in 1,097 cases, highlighting instances where FLIP changed operative decision making.

STUDY DESIGN

A retrospective review of an IRB-approved prospective quality database was performed. This included operative and endoscopic suite foregut procedures using FLIP between February 2013 and May 2022.

RESULTS

During the study period, FLIP was used a total of 1,097 times in 919 unique patients by 2 foregut surgeons. Intraoperative FLIP was used during 573 antireflux procedures and 272 endoscopic myotomies. FLIP was also used during 252 endoscopic suite procedures. For those undergoing preoperative workup of GERD, starting in 2021, esophageal panometry was performed in addition to standard FLIP measurements at the lower esophageal sphincter. In 77 cases, intraoperative FLIP changed operative decision making. During antireflux procedures, changes included adding or removing crural sutures, adjusting a fundoplication tightness, choice of full vs partial wrap, and magnetic sphincter augmentation sizing. For endoscopic procedures, changes included aborting peroral endoscopic myotomy or Zenker's peroral endoscopic myotomy, performing a myotomy when preoperative diagnosis was unclear, or performing additional myotomy.

CONCLUSIONS

FLIP is a useful tool for assessing the upper esophageal sphincter, lower esophageal sphincter, pylorus, and secondary esophageal peristalsis that can be used in a wide variety of clinical situations within a foregut surgeon's practice. It can also function as an adjunct in intraoperative decision making.

The Functional Luminal Imaging Probe (FLIP): A Good Tool for Adjustment of anal Canal Dimensions During Operative Management of Fecal Incontinence

PURPOSE

Fecal incontinence is a troublesome problem in the field of colorectal surgery. The main aim of this study was to adjust the anal canal resistance during operative management of anal incontinence using Endo-FLIP.

METHODS

This was a prospective cohort study held at Cairo university hospital. Hundred forty-eight incontinent patients treated by different surgical procedures were included. During the procedure the Endo-FLIP was applied to adjust the anal canal dimensions (ACL and ACD) so the ACR could be adjusted based on the flow equation. These were also assessed pre-operatively with Endo-FLIP system and the flow equation calculator. The clinical severity of the disease and outcome after surgical procedures were assessed and correlated to the physiologic parameters.

RESULTS

ACL, ACD and ACR had had significant correlations to the degree of incontinence (P < .001). ACL, ACD and ACR showed statistically significant change with primary repair and gluteus maximus transposition operations. After treatment of fecal incontinence, in good responders' group, the mean resting anal canal resistance increased significantly to 4649.05 ± 1161.49 (postoperative) while in poor responders' group it was 1919.9 ± 1077.73.

CONCLUSIONS

The Endo-flip can be used to measure the anal canal geometric parameters (ACL and ACD) and then anal canal resistance could be calculated by the flow equation - pre-and post-operatively- which help the adjustment of the surgical repair of sphincter injury in fecal incontinence patients which may improve the surgical outcome.

Esophagogastric junction compliance on impedance planimetry (EndoFLIP™) following peroral endoscopic myotomy (POEM) predicts improvement in postoperative eckardt score

BACKGROUND

Peroral endoscopic myotomy (POEM) is a mainstay of treatment for achalasia. Tailored myotomy based on compliance, as measured with impedance planimetry (FLIP), has yet to be described. In this study we describe the associations between Eckardt score, postoperative GERD, and compliance.

METHODS

A retrospective review of a prospectively maintained database was performed, evaluating patients who underwent POEM and intraoperative FLIP between January 2019 and November 2021. Group comparisons were made using two-tailed Wilcoxon rank-sum and Fisher's exact tests. Spearman's correlation coefficients (r) were used to assess the relationship between compliance and outcomes, all with two-tailed statistical significance of p < 0.05.

RESULTS

Thirty five patients underwent POEM with intraoperative FLIP. At a 30 mL and 40 mL fill, respectively, compliance increased by 80% (180 ± 152%) and 77% (177 ± 131%) from pre to post myotomy. Mean Eckardt score improved from 5.5 ± 2.6 preoperatively to 1.3 ± 1.6 and 1.8 ± 1.9 at first and second follow up, respectively. Median times to first and second follow up were 22 days (IQR 16-23) and 65 days (IQR 58-142). A higher compliance at 40 mL fill was moderately associated with lower Eckardt score at first (r = -0.49, p = 0.012) and second (r = -0.64, p = 0.014) follow up. Post myotomy compliance ≥ 125 mm³/mmHg at 40 mL fill was associated with lower Eckardt scores, < 3, at first (0.4 ± 0.5 vs 1.8 ± 1.3, p = 0.008) and second (0.4 ± 0.5, vs 2.0 ± 1.4, p = 0.027) follow up. Compliance ≥ 125 mm³/mmHg performed better than previously defined ideal ranges of DI and CSA in predicting postoperative Eckardt scores. Compliance was not significantly associated with development of postoperative GERD.

CONCLUSIONS

A target post myotomy compliance of ≥ 125 mm³/mmHg at a 40 mL fill is associated with normal Eckardt scores at first and second postoperative visits, and performs better than previously defined ideal ranges of DI and CSA in predicting post-operative Eckardt scores. Compliance is a poor predictor of developing GERD after POEM.

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.

Impedance planimetry (EndoFLIP) assisted laparoscopic esophagomyotomy in pediatric population

INTRODUCTION

Functional lumen imaging probe (EndoFLIP) is a diagnostic technology that assesses esophageal cross-sectional area via impedance planimetry during controlled volumetric distention. The purpose of this study is to evaluate the utility of EndoFLIP intraoperatively during laparoscopic esophagomyotomy.

METHODS

We performed a retrospective cohort study reviewing all patients undergoing EndoFLIP assisted laparoscopic esophagomyotomy for achalasia between January and December 2021 (n = 10). Twenty-two patients with achalasia that underwent traditional laparoscopic esophagomyotomy between July 2014 and September 2019 served as a comparison. Primary outcome evaluated was resolution of symptoms at discharge. Secondary outcomes included change in distensibility index (DI), operative time, length of stay, time to regular diet, and reinterventions.

RESULTS

All patients managed with EndoFLIP assistance had resolution of dysphagia and postprandial vomiting following intervention. Mean change in DI was 5.32 mm²/mmHg with a myotomy length of 3.6 cm. Operative time was shorter in the EndoFLIP cohort (97 min versus 185 min, p = <0.001). Study patients did not undergo an antireflux operation. There was no difference in length of stay or time to soft diet between groups. All patients were discharged on postoperative day 1 tolerating a mechanical soft diet. No acid suppressive medications were prescribed during the observation period. One patient required dilation for recurrent symptoms and one required reoperation for mucosal leak.

CONCLUSION

EndoFLIP assisted laparoscopic esophagomyotomy results in similar short-term outcomes to traditional surgical technique. EndoFLIP allows for focused myotomy length and a shorter operative time.

LEVEL OF EVIDENCE

III.

Comparison of functional lumen imaging probe and high-resolution manometry to assess response after peroral endoscopic myotomy

BACKGROUND AND AIMS

Outcomes after peroral endoscopic myotomy (POEM) are assessed clinically by the Eckardt score (ES) or objectively by high-resolution manometry (HRM) and functional lumen imaging probe (FLIP). This study compared HRM and FLIP to evaluate clinical response after POEM.

METHODS

This was a single tertiary center retrospective study of consecutive patients who underwent POEM for treatment-naive achalasia and with ≥6 months of follow-up. Baseline and follow-up testing in all patients included ES, HRM, and FLIP of the esophagogastric junction (EGJ). A normal post-POEM (or normalized) EGJ distensibility index (EGJ-DI) >2.8 mm²/mm Hg, maximum EGJ diameter (MxEGJD) ≥14 mm, and integrated relaxation pressure (IRP) <15 mm Hg were compared with a clinical response, defined as ES ≤3.

RESULTS

Eighty-seven patients (58% men, mean age 51 ± 17 years) were included. Overall clinical response by ES, IRP, MxEGJD, and EGJ-DI were 97.7%, 86.2%, 75.9%, and 92.0%, respectively. The sensitivity of a normal IRP (87.1% [95% confidence interval {CI}, 78.0-93.4]) was similar to the sensitivity of a normal MxEGJD (75.3% [95% CI, 64.7-84.0], P = .053) and normal EGJ-DI (91.8% [95% CI, 83.8%-96.6%], P = .39) after POEM to predict clinical response. However, the sensitivity of a normal post-POEM EGJ-DI was superior to a normal post-POEM MxEGJD (P = .001) to predict clinical response. There was no difference in the area under the curve of a normal MxEGJD or EGJ-DI to predict a normal IRP (P = .956) after POEM.

CONCLUSIONS

Normal FLIP metrics ≥6 months after POEM for achalasia show good to excellent sensitivity but are equivalent to a normalized IRP by HRM to predict clinical response by ESs. FLIP may be used as an alternative to HRM to assess lower esophageal sphincter response to POEM in these patients. (Clinical trial registration number: NCT02770859.).

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.

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.

Per-oral Endoscopic Myotomy: State of the Art

For more than a decade, per-oral endoscopic myotomy (POEM) has been performed for the treatment of achalasia and other dysmotilities of the esophagus. POEM has become an accepted alternative to Heller myotomy, a salvation technique for patients not responding to Heller myotomy and the favorite intervention for diffuse esophageal spasm and jackhammer esophagus. POEM paved the way for endoscopic pyloromyotomy, Zenker's diverticulum myotomy, and submucosal tunneling with endoscopic resection. This review will cover the technique and the most current literature of this revolutionary third space technique.

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.

Use of the functional luminal imaging probe in pediatrics: A comparison study of patients with achalasia before and after endoscopic dilation and non-achalasia controls

BACKGROUND

Achalasia is an esophageal motility disorder characterized by esophagogastric junction (EGJ) dysfunction and impaired esophageal peristalsis with significant impact on quality of life. While the functional luminal imaging probe (FLIP) has been used to assess EGJ distensibility in achalasia, its clinical utility in pediatrics is limited due to absence of normative values and correlations with clinical outcomes in children. Thus, we sought to evaluate FLIP's use in a pediatric achalasia cohort undergoing dilations and non-achalasia controls.

METHODS

We conducted a retrospective study of pediatric patients with achalasia who underwent FLIP before and immediately after balloon dilations and compared to a non-achalasia cohort.

KEY RESULTS

Thirty patients with achalasia (mean age, 15.2 years; 40% female), including fourteen treatment-naïve and thirteen controls (mean age, 7.9 years; 61% female) were identified. Median EGJ distensibility index (EGJ-DI) 2.07 mm²  mmHg^-1 and diameter (9.23 mm) in treatment-naïve patients were significantly lower compared to controls (EGJ-DI 6.8 mm²  mmHg^-1 ; diameter 18.61 mm; (p < 0.001). Balloon dilations resulted in a significant increase in EGJ-DI immediately after the dilation, particularly in treatment-naïve patients (p < 0.001), and a significant improvement in Eckardt scores (p < 0.001).

CONCLUSIONS & INFERENCES

Functional luminal imaging probe measurements of EGJ-DI in pediatric patients with achalasia are mostly consistent with adult findings. However, normal EGJ-DI is seen in symptomatic patients, including treatment-naive, highlighting the need for pediatric reference data. Balloon dilations achieve a significant increase in EGJ-DI with improvement in Eckardt scores, confirming the therapeutic value of dilations in achalasia management.

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.

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.

Insights into the endoscopic management of esophageal achalasia

Achalasia is a primary esophageal motility disorder characterized by the loss of inhibitory neurons in the myenteric plexus, resulting in impaired relaxation of the esophagogastric junction. Achalasia is an incurable disease, and the treatment modalities are aimed at disruption of the esophagogastric junction and vary widely from pharmacological to endoscopic to surgical. Traditional endoscopic therapy includes pneumatic dilation, botulinum toxin injection, and peroral endoscopic myotomy. This review aims to provide an overview of the endoscopic management of achalasia, while focusing on the utilization of peroral endoscopic myotomy and other novel approaches.

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.

Changes in impedance planimetry metrics predict clinical response to flexible endoscopy in Zenker's diverticulotomy

Background and study aims  Various techniques have been described for flexible endoscopic therapy for Zenker's diverticulum (ZD). Objective methods to assess myotomy effectiveness are lacking. We assessed the utility of impedance planimetry in flexible endoscopic ZD therapies and correlation with a validated symptom score. Patients and methods  Patients undergoing endoscopic therapy for symptomatic ZD from February 2019 to March 2020 were included. Intraprocedural impedance planimetry was performed pre- and post-myotomy to assess esophageal diameter and distensibility index (DI). Eating Assessment Tool (EAT)-10 scores were assessed preintervention and post-intervention. Descriptive statistics were calculated. Results  Thirteen patients (46 % women; mean age 80 years; 77 % peroral endoscopic myotomy technique) were included. Technical and clinical success was 100 %. No adverse events occurred. At 40 mL and 50 mL, the diameter improved (mean 2.3 mm and 2.6 mm, respectively). At 40 mL and 50 mL, the DI improved (mean 1.0 mm ² /mmHg and 1.8 mm ² /mmHg, respectively). EAT-10 scores improved by a mean of 15 points. Mean follow-up was 97 days. Conclusions  Intraprocedural impedance planimetry may provide objective data to define success for flexible endoscopic ZD. Further research is required to corroborate these results.

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.

ACG Clinical Guidelines: Clinical Use of Esophageal Physiologic Testing

Esophageal symptoms are common and may indicate the presence of gastroesophageal reflux disease (GERD), structural processes, motor dysfunction, behavioral conditions, or functional disorders. Esophageal physiologic tests are often performed when initial endoscopic evaluation is unrevealing, especially when symptoms persist despite empiric management. Commonly used esophageal physiologic tests include esophageal manometry, ambulatory reflux monitoring, and barium esophagram. Functional lumen imaging probe (FLIP) has recently been approved for the evaluation of esophageal pressure and dimensions using volumetric distension of a catheter-mounted balloon and as an adjunctive test for the evaluation of symptoms suggestive of motor dysfunction. Targeted utilization of esophageal physiologic tests can lead to definitive diagnosis of esophageal disorders but can also help rule out organic disorders while making a diagnosis of functional esophageal disorders. Esophageal physiologic tests can evaluate obstructive symptoms (dysphagia and regurgitation), typical and atypical GERD symptoms, and behavioral symptoms (belching and rumination). Certain parameters from esophageal physiologic tests can help guide the management of GERD and predict outcomes. In this ACG clinical guideline, we used the Grading of Recommendations Assessment, Development and Evaluation process to describe performance characteristics and clinical value of esophageal physiologic tests and provide recommendations for their utilization in routine clinical practice.

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.

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.

Intraoperative use of FLIP is associated with clinical success following POEM for achalasia

BACKGROUND

Esophagogastric junction distensibility index (DI), measured using the functional luminal imaging probe (FLIP), correlates with symptomatic outcomes after interventions for achalasia. The objective of this study was to determine if the intraoperative measurement of DI using FLIP was associated with improved clinical outcomes following per-oral endoscopic myotomy (POEM) for achalasia when compared with procedures in which FLIP was not utilized.

METHODS

Patients undergoing POEM from 2012 to 2017 at a single institution by a single surgeon were studied. Use of FLIP during this time period was based on catheter and technician availability, resulting in two patient cohorts. In patients in whom FLIP was used, operative video recordings were reviewed to determine when DI measurements led to the performance of additional myotomy. Postoperative Eckardt symptom scores (ES) at 12 months and postoperative physiologic studies were compared between patients with and without intraoperative FLIP. Associations were assessed using Mann-Whitney U and Chi-square tests.

RESULTS

143 patients were included in the analysis (61 with intraoperative FLIP and 82 without FLIP). Video recordings were available for 85% of the FLIP cohort. Review of these operative recordings revealed that 65% of patients who underwent FLIP had additional myotomy performed following the initial postmyotomy FLIP measurement. At 12 months after POEM, the FLIP cohort had significantly more clinical successes (defined as ES ≤ 3) than patients in whom FLIP was not used (93% vs. 81%, p < 0.05).

CONCLUSIONS

Use of intraoperative FLIP during POEM resulted in the surgeon performing additional myotomy in over half of cases and was associated with improved clinical outcomes. This study demonstrates the potential for a FLIP-tailored myotomy to improve outcomes in patients undergoing surgical myotomy for achalasia.

Intraoperative FLIP distensibility during POEM varies according to achalasia subtype

BACKGROUND

The functional luminal imaging probe (FLIP) can be used to measure the esophagogastric junction distensibility index (DI) during myotomy for achalasia and increased DI has been shown to predict superior clinical outcomes. The objective of this study was to determine if the intraoperative DI and the changes produced by per oral endoscopic myotomy (POEM) differed between achalasia subtypes.

METHODS

FLIP measurements were performed during POEM for achalasia at a single institution. DI (defined as the minimum cross-sectional area (CSA) at the EGJ divided by distensive pressure) was measured at three time points: after induction of anesthesia, after submucosal tunneling, and after myotomy. Measurements were reported at the 40 mL fill volume for the 8 cm FLIP (EF-325) and at the 60 mL fill volume for the 16 cm FLIP (EF-322). Measurements were compared using chi-square and Kruskal-Wallis tests.

RESULTS

142 patients had intraoperative FLIP performed during POEM for achalasia between 2012 and 2019 (30 type I, 68 type II, 27 type III, and 17 variant). Patients with type I achalasia had a significantly higher induction DI (median 1.7 mm²/mmHg) than type II (0.8 mm²/mmHg), type III (0.9 mm²/mmHg), and variants (1.1 mm²/mmHg; p < 0.001). These differences persisted after submucosal tunneling and final DI after myotomy was also significantly higher in type I patients (median 8.0 mm²/mmHg) compared to type II (5.8 mm²/mmHg), type III (3.9 mm²/mmHg), and variants (5.4 mm²/mmHg; p < 0.001). Achalasia subtypes were found to have similar CSA at all time points, whereas pressure differed with type I having the lowest pressure and type III the highest.

CONCLUSION

The DI at each operative step during POEM was found to differ significantly between achalasia subtypes. These differences in DI were due to pressure, as CSA was similar between subtypes. Achalasia subtype should be accounted for when using FLIP as an intraoperative calibration tool and in future studies examining the relationship between DI and clinical outcomes.

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.

Intraoperative use of a functional lumen imaging probe during peroral endoscopic myotomy in patients with achalasia: A single-institute experience and systematic review

Aim

The functional lumen imaging probe (FLIP) is a recently developed technique to evaluate the esophagogastric junction (EGJ) distensibility. Unlike timed barium esophagogram (TBE) and high-resolution manometry (HRM), FLIP can be used during peroral endoscopic myotomy (POEM). The aim of this study was to evaluate the association of intraoperative FLIP parameters with clinical outcomes as recorded in a single-center database and to investigate a systematic review of literatures.

Methods

We reviewed consecutive patients diagnosed with achalasia and scheduled for POEM between June 2016 and March 2019 in our tertiary referral hospital. All patients underwent intraoperative FLIP assessment during POEM. The final FLIP measurements were compared between the patients with good and poor clinical response. We comprehensively reviewed studies evaluating whether intraoperative FLIP measurements reflected clinical outcomes.

Results

We evaluated 23 patients with achalasia who underwent intraoperative FLIP before and after POEM. Two exhibited poor clinical responses after 3 months (Eckardt scores = 3). The final distensibility index (DI) did not differ significantly between good and poor responders (5.01 [4.52] vs. 4.91 [3.63–6.20] mm²/mmHg at a balloon distension of 50-mL, median [IQR], P = 0.853). The final DI did not differ significantly between post-POEM reflux esophagitis and non-reflux esophagitis groups (6.20 [5.15] vs. 4.23 [1.79] mm²/mmHg at a balloon distension of 50-mL, median [IQR], P = 0.075).

Conclusions

A systematic review of both prospective and retrospective studies including our data indicated that the final intraoperative FLIP measurements did not differ significantly between good and poor responders. Further study with more patients is necessary to explore whether FLIP can predict short- and long-term clinical responses.

Using Impedance Planimetry (EndoFLIP) to Evaluate Myotomy and Predict Outcomes After Surgery for Achalasia

BACKGROUND

The functional lumen imaging probe (FLIP) is an innovative tool that uses impedance planimetry to assess esophageal geometry in real time. It has been used to diagnose achalasia and evaluate treatment failure after laparoscopic Heller myotomy (LHM) and peroral endoscopic myotomy (POEM). We hypothesize that impedance planimetry can be utilized intra-operatively to assess adequacy of myotomy and assist in predicting patient outcomes.

METHODS

A prospectively maintained patient database at a single center was queried. Seventy-seven patients with achalasia underwent POEM or LHM by a single surgeon. The FLIP was used to measure cross-sectional area (CSA), minimum diameter (D_min), balloon pressure, and distensibility index (DI) of the lower esophageal sphincter (LES) before and after the procedure. Clinical outcomes were measured up to 2 years after treatment.

RESULTS

Post-operative CSA, D_min, balloon pressure, and DI values were significantly different from pre-operative values (p < 0.001). Patients with a post-operative Eckardt score ≥ 3 were significantly more likely to have a final DI ≤ 3.1 mm²/mmHg (p = 0.014) or a change in DI ≤ 3.0 mm²/mmHg (p = 0.010). Additionally, a final CSA > 96 mm² or D_min > 11.0 mm was predictive of worse reflux at 2 years (p = 0.01).

CONCLUSION

Impedance planimetry using the FLIP can offer intra-operative feedback about the geometry of the LES. The most useful parameters in predicting patient outcomes have yet to be clearly defined, but our results demonstrate that final DI and CSA are predictive of post-operative treatment response.

Use of Impedance Planimetry (Endoflip) in Foregut Surgery Practice: Experience of More than 400 Cases

BACKGROUND

We provide a comprehensive report of our institution's experience with the endoluminal functional lumen imaging probe (Endoflip) impedance planimetry system, a device that can be used intraoperatively to objectively evaluate the distensibility of any sphincter of the gastrointestinal tract. We aim to describe the variety of ways in which the Endoflip can be used in a foregut surgeon's practice.

STUDY DESIGN

This is a retrospective review of a prospectively maintained quality database of all patients in which the functional lumen imaging probe (FLIP) system was used between February 2013 and June 2019.

RESULTS

During the study period, 402 FLIP cases were performed: 226 fundoplications, 94 peroral endoscopic myotomies, 15 peroral pyloromyotomies, 12 antireflux mucosectomies, 11 magnetic sphincter augmentations, 9 laparoscopic Heller myotomies, 8 pre-esophagectomy esophagogastroduodenoscopies (EGDs), 4 diagnostic EGDs, 8 endoscopic Zenker's diverticulotomies, 5 post-peroral endoscopic myotomy EGDs, 8 EGDs with dilations, and 2 transoral incisional fundoplications.

CONCLUSIONS

Within a foregut surgeon's practice, the FLIP can be used to measure the upper esophageal sphincter, lower esophageal sphincter, and pylorus in a variety of clinical scenarios and settings.

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.

Updated Systematic Review of Achalasia, with a Focus on POEM Therapy

AIM

To systematically review clinical presentation, diagnosis, and therapy of achalasia, focusing on recent developments in high-resolution esophageal manometry (HREM) for diagnosis and peroral endoscopic myotomy (POEM) for therapy.

METHODS

Systematic review of achalasia using computerized literature search via PubMed and Ovid of articles published since 2005 with keywords ("achalasia") AND ("high resolution" or "HREM" or "peroral endoscopic myotomy" or "POEM"). Two authors independently performed literature searches and incorporated articles into this review by consensus according to prospectively determined criteria.

RESULTS

Achalasia is an uncommon esophageal motility disorder, usually manifested by dysphagia to solids and liquids, and sometimes manifested by chest pain, regurgitation, and weight loss. Symptoms often suggest more common disorders, such as gastroesophageal reflux disease (GERD), thus often delaying diagnosis. Achalasia is a predominantly idiopathic chronic disease. Diagnosis is typically suggested by barium swallow showing esophageal dilation; absent distal esophageal peristalsis; smoothly tapered narrowing ("bird's beak") at esophagogastric junction; and delayed passage of contrast into stomach. Diagnostic findings at high-resolution esophageal manometry (HREM) include: distal esophageal aperistalsis and integrated relaxation pressure (trough LES pressure during 4 s) > 15 mmHg. Achalasia is classified by HREM into: type 1 classic; type 2 compartmentalized high pressure in esophageal body, and type 3 spastic. This classification impacts therapeutic decisions. Esophagogastroduodenoscopy is required before therapy to assess esophagus and esophagogastric junction and to exclude distal esophageal malignancy. POEM is a revolutionizing achalasia therapy. POEM creates a myotomy via interventional endoscopy. Numerous studies demonstrate that POEM produces comparable, if not superior, results compared to standard laparoscopic Heller myotomy (LHM), as determined by LES pressure, dysphagia frequency, Eckardt score, hospital length of stay, therapy durability, and incidence of GERD. Other therapies, including botulinum toxin injection and pneumatic dilation, have moderately less efficacy and much less durability than POEM.

CONCLUSION

This comprehensive review suggests that POEM is equivalent or perhaps superior to LHM for achalasia in terms of cost efficiency, hospital length of stay, and relief of dysphagia, with comparable side effects. The data are, however, not conclusive due to sparse long-term follow-up and lack of randomized comparative clinical trials. POEM therapy is currently limited by a shortage of trained endoscopists.

Functional lumen imaging probe in gastrointestinal motility diseases

Dysfunction of gastrointestinal (GI) sphincters, including the lower esophageal sphincter (LES) at the esophagogastric junction (EGJ) and the pyloric sphincter, plays a vital role in GI motility disorders, such as achalasia, gastroesophageal reflux disease (GERD), gastroparesis, and fecal incontinence. Using multi-detector high-resolution impedance planimetry, the functional luminal imaging probe (FLIP) system measures simultaneous data on tissue distensibility and luminal geometry changes in the sphincter in a real-time manner. In this review we focus on the emerging data on FLIP, which can be used as an innovative diagnostic method during endoscopic or surgical procedures in GI motility disorders. Subsequent large, prospective, standardizing studies are needed to validate these findings before it can be put to routine clinical use.

How I Approach Dysphagia

PURPOSE OF REVIEW

This review presents an overview of the diagnostic approach to esophageal dysphagia and summarizes recent epidemiological trends and technical advancements.

RECENT FINDINGS

The evaluation of dysphagia begins with a detailed history followed by endoscopy to evaluate for any structural abnormalities including malignancy. This is especially true given the emergence of eosinophilic esophagitis (EoE) as a dominant cause of esophageal dysphagia. In fact, it is now standard practice to obtain esophageal biopsies during endoscopy performed to evaluate dysphagia, since EoE can present without the characteristic mucosal features of rings, furrows, and exudate. Achalasia is also more frequently encountered since the introduction of high-resolution manometry (HRM) and the Chicago Classification into clinical practice. The Chicago Classification provides a stepwise diagnostic algorithm for evaluating HRM studies and systematically diagnosing esophageal motility disorders. Lastly, the functional lumen imaging probe (FLIP) is a novel technology that has added insight into both achalasia and EoE. Measuring esophageal distensibility with FLIP has useful prognostic implications for both diseases, and FLIP can identify motility abnormalities in achalasics not detected with HRM. A careful history is key to the efficient evaluation of dysphagia, and endoscopy is usually the first diagnostic study to obtain. For patients with prominent reflux symptoms, an empiric trial with proton pump inhibitors is reasonable then because reflux disease is such a common cause of dysphagia. Thereafter, patients should undergo HRM to evaluate for a motility disorder, and FLIP can provide complementary data to guide management.