Outcomes after per-oral endoscopic myotomy for Zenker's diverticula (Z-POEM) and correlation with impedance planimetry (FLIP)

INTRODUCTION

Zenker's diverticulum (ZD) is a false pulsion diverticulum of the cervical esophagus. It is typically found in older adults and manifests with dysphagia. The purpose of this study is to describe our experience with Per-oral endoscopic myotomy for Zenker's (Z-POEM) and intraoperative impedance planimetry (FLIP).

METHODS

We performed a single institution retrospective review of patients undergoing Z-POEM in a prospective database between 2014 and 2022. Upper esophageal sphincter (UES) distensibility index (DI, mm2/mmHg) was measured by FLIP before and after myotomy. The primary outcome was clinical success. Secondary outcomes included technical failure, adverse events, and quality of life as assessed by the gastroesophageal health-related quality of life (GERD-HRQL), reflux severity index (RSI), and dysphagia score. A statistical analysis of DI was done with the paired t-test (p < 0.05).

RESULTS

Fifty-four patients underwent Z-POEM, with FLIP measurements available in 30 cases. We achieved technical success and clinical success in 54/54 (100%) patients and 46/54 patients (85%), respectively. Three patients (6%) experienced contained leaks. Three patients were readmitted: one for aforementioned contained leak, one for dysphagia, and one post-operative pneumonia. Three patients with residual dysphagia underwent additional endoscopic procedures, all of whom had diverticula > 4 cm. Following myotomy, mean DI increased by 2.0 ± 1.7 mm2/mmHg (p < 0.001). In those with good clinical success, change in DI averaged + 1.6 ± 1.1 mm2/mmHg. Significant improvement was found in RSI and GERD-HRQL scores, but not dysphagia score.

CONCLUSION

Z-POEM is a safe and feasible for treatment of ZD. We saw zero cases of intraoperative abandonment. We propose that large diverticula (> 4 cm) are a risk factor for poor outcomes and may require additional endoscopic procedures. An improvement in DI is expected after myotomy, however, the ideal range is still not known.

Impedance planimetry (EndoFLIPTM) and surgical outcomes after Hill compared to Toupet fundoplication

INTRODUCTION

Endoluminal functional lumen imaging probe (EndoFLIP) provides a real-time assessment of gastroesophageal junction (GEJ) compliance during fundoplication. Given the limited data on EndoFLIP measurements during the Hill procedure, we investigated the impact of the Hill procedure on GEJ compliance compared to Toupet fundoplication.

METHODS

Patients who underwent robotic Hill or Toupet fundoplication with intraoperative EndoFLIP between 2017 and 2022 were included. EndoFLIP measurements of the GEJ included cross sectional surface area (CSA), intra-balloon pressure, high pressure zone length (HPZ), distensibility index (DI), and compliance. Subjective reflux symptoms, gastroesophageal reflux disease-health related quality of life (GERD-HRQL) score, and dysphagia score were assessed pre-operatively as well as at short- and longer-term follow-up.

RESULTS

One-hundred and fifty-four patients (71.9%) had a Toupet fundoplication while sixty (28%) patients underwent the Hill procedure. The CSA [27.7 ± 10.9 mm2 vs 42.2 ± 17.8 mm2, p < 0.0001], pressure [29.5 ± 6.2 mmHg vs 33.9 ± 8.5 mmHg, p = 0.0009], DI [0.9 ± 0.4 mm2/mmHg vs 1.3 ± 0.6 mm2/mmHg, p = 0.001], and compliance [25.9 ± 12.8 mm3/mmHg vs 35.4 ± 13.4 mm3/mmHg, p = 0.01] were lower after the Hill procedure compared to Toupet. However, there was no difference in post-fundoplication HPZ between procedures [Hill: 2.9 ± 0.4 cm, Toupet: 3.1 ± 0.6 cm, p = 0.15]. Follow-up showed no significant differences in GERD-HRQL scores, overall dysphagia scores or atypical symptoms between groups (p > 0.05).

CONCLUSION

The Hill procedure is as effective to the Toupet fundoplication in surgically treating gastroesophageal reflux disease (GERD) despite the lower CSA, DI, and compliance after the Hill procedure. Both procedures led to DI < 2 mm2/mmHg with no significant differences in dysphagia reporting (12-24) months after the procedure. Further studies to elucidate a cutoff value for DI for postoperative dysphagia development are still warranted.

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.

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.

Target distensibility index on impedance planimetry during fundoplication by choice of wrap and choice of bougie

INTRODUCTION

Impedance planimetry (FLIP) provides objective feedback to optimize fundoplication outcomes. Ideal FLIP ranges for differing wraps and bougies have not yet been established. We report FLIP measurements during fundoplication grouped by choice of wrap and bougie with associated outcomes.

METHODS

A retrospective review of a prospective gastroesophageal database was performed for all Nissen or Toupet fundoplication with intraoperative FLIP using an 8-cm catheter, 30-mL and/or 40-mL fill and/or 16-cm catheter, 60-mL fill. Surgeons used no bougie, the FLIP balloon as bougie, or a hard bougie. Outcomes included perioperative data, Reflux Symptom Index, GERD-HRQL, Dysphagia scores, need for dilation, postoperative EGD findings, and hernia recurrence. Group comparisons were made using two-tailed Kruskal-Wallis and Fisher's exact tests.

RESULTS

Between 2016 and 2022, 333 patients underwent fundoplication and intraoperative FLIP. Procedures included Toupet with hard bougie (TFHB, N = 147), Toupet with FLIP bougie (TFFB, N = 69), Toupet without bougie (TFNB, N = 78), Nissen with hard bougie (NFHB, n = 20), or Nissen with FLIP bougie (NFFB, N = 19). FLIP measurements at 30-mL/40-mL fills varied significantly between groups, notably distensibility index at crural closure (CCDI) and post-fundoplication (FDI). No significant differences in FLIP measurements were seen between those who developed poor postoperative outcomes and those who did not, including when grouping by choice of wrap and bougie. At a 40-mL fill, abnormal motility patients with CCDI > 3.5 mm2/mmHg developed zero postoperative dysphagia. TFFB abnormal motility patients with CCDI > 3.5 mm2/mmHg or FDI > 3.6 mm2/mmHg developed zero postoperative dysphagia.

CONCLUSION

Intraoperative FLIP measurements vary by fundoplication and bougie choice. A CCDI > 3.5 mm2/mmHg (40 mL fill) should be sought in abnormal motility patients, regardless of wrap or bougie, to avoid postoperative dysphagia. TFFB abnormal motility patients with FDI > 3.6 mm2/mmHg (40 mL fill) also developed zero postoperative dysphagia. FDI > 6.2 mm2/mmHg (40 mL fill) was seen in all postoperative hernia recurrences.

Gastroesophageal Junction and Pylorus Distensibility Before and After Sleeve Gastrectomy-pilot Study with EndoFlipTM

Sleeve gastrectomy (SG) is the most frequently performed bariatric surgical intervention worldwide. Gastroesophageal reflux disease (GERD) is frequently observed after SG and is a relevant clinical problem. This prospective study investigated the gastroesophageal junction (GEJ) and pyloric sphincter by impedance planimetry (EndoFlipTM) and their association with GERD at a tertiary university hospital center. Between January and December 2018, patients undergoing routine laparoscopic SG had pre-, intra-, and postoperative assessments of the GEJ and pyloric sphincter by EndoFlipTM. The distensibility index (DI) was measured at different volumes and correlated with GERD (in accordance with the Lyon consensus guidelines). Nine patients were included (median age 48 years, preoperative BMI 45.1 kg/m2, 55.6% female). GERD (de novo or stable) was observed in 44.4% of patients one year postoperatively. At a 40-ml filling volume, DI increased significantly pre- vs. post-SG of the GEJ (1.4 mm2/mmHg [IQR 1.1-2.6] vs. 2.9 mm2/mmHg [2.6-5.3], p VALUE=0.046) and of the pylorus (6.0 mm2/mmHg [4.1-10.7] vs. 13.1 mm2/mmHg [7.6-19.2], p VALUE=0.046). Patients with postoperative de novo or stable GERD had a significantly increased preoperative DI at 40 ml of the GEJ (2.6 mm2/mmHg [1.9-3.5] vs. 0.5 mm2/mmHg [0.5-1.1], p VALUE=0.031). There was no significant difference in DI at 40 mL filling in the preoperative pylorus and postoperative GEJ or pylorus. In this prospective study, the DI of the GEJ and the pylorus significantly increased after SG. Postoperative GERD was associated with a significantly higher preoperative DI of the GEJ but not of the pylorus.

Pyloric Functional Lumen Imaging Probe Measurements Are Dependent on Balloon Position

Background/Aims

The functional lumen imaging probe (FLIP) device has been used to assess pyloric dysfunction in patients with gastroparesis. We aim to investigate whether varying FLIP catheter positions affect pyloric FLIP measurements.

Methods

Patients undergoing endoscopy for chronic unexplained nausea and vomiting (CUNV) or gastroparesis were prospectively enrolled. FLIP balloon was adjusted for 3 positions within the pylorus: (1) proximal position, 75% of FLIP balloon in the duodenum and 25% in the antrum; (2) middle position, 50% in the duodenum and 50% in the antrum; and (3) distal position, 25% in the duodenum and 75% in the antrum. Pylorus cross-sectional area (CSA), intra-bag pressure (P), and distensibility indices (DI) were measured for 30, 40, and 50-mL balloon volumes. Fluoroscopic images were obtained to confirm FLIP balloon geometry. Data was analyzed separately using FLIP Analytic and customized MATLAB software.

Results

Twenty-two patients with CUNV (n = 4) and gastroparesis (n = 18) were enrolled. Pressures were significantly higher in the proximal position compared to the middle and distal positions. CSA measurements were significantly higher at the proximal and middle positions for 30-mL and 40-mL volume compared to the distal position values. DI values were significantly lower at the proximal positions for 40-mL and 50-mL distensions when compared to the middle and distal positions. Fluoroscopic images confirmed increased balloon bending when placed mostly in the duodenum.

Conclusions

FLIP balloon position within the pylorus directly affects balloon geometry which significantly affects P, CSA, and DI measurements. Standardized pyloric FLIP protocols and balloon design adjustments are needed for the continued application of this technology to the pylorus.

Endoscopic severity of gastric sleeve stenosis can be quantified using impedance planimetry

BACKGROUND

Gastric sleeve stenosis (GSS) is an adverse event following sleeve gastrectomy for which objective tools are needed for diagnosis and treatment. Endoscopic treatment with serial pneumatic balloon dilation may relieve symptoms and prevent the need for conversion to Roux-en-Y gastric bypass. Endoluminal functional impedance planimetry (EndoFLIP) is an endoscopic tool that measures luminal diameter and distensibility indices (DI) and could be used to characterize severity of GSS.

METHODS

This was a retrospective analysis of a prospective database of patients referred for symptoms suggestive of GSS. Severity was determined at each endoscopy by a bariatric endoscopist blinded to EndoFLIP measurements. Successive pneumatic balloon dilations were performed until symptoms resolved; failure was defined as referral for conversion. EndoFLIP measurements of stenosis diameter and DI were obtained pre- and post-dilation. Primary outcomes were pre- and post-dilation luminal diameter and DI of GSS. Secondary outcomes were endoscopic severity of GSS, patient characteristics, and need for surgical revision.

RESULTS

26 patients were included; 23 (85%) were female. Mean age was 45.3 (± 9.9) years. Mean number of dilations was 2.4 (± 1.3) and 10 (38%) patients were referred for conversion. Mild, moderate, and severe GSS was found in 10 (38%), 6 (23%), and 10 (38%) patients, respectively. Moderate and severe GSS underwent more dilations (2.5 ± 1.0 and 3.2 ± 1.6) than mild GSS (1.8 ± 0.8) and were more likely to be referred for conversion. Both pre- and post-dilation diameters were significantly larger in mild versus moderate or severe GSS. Additionally, pre- and post-dilation DI at 30 ml were significantly higher for mild compared to moderate and severe GSS.

DISCUSSION

EndoFLIP measurements correlate well with endoscopic assessment of GSS. While more data are needed to determine ideal balloon size and threshold measurements, our results suggest EndoFLIP may help expedite diagnosis and treatment of GSS.

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.

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

INTRODUCTION

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

METHODS AND PROCEDURES

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

RESULTS

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

CONCLUSIONS

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

Crural closure, not fundoplication, results in a significant decrease in lower esophageal sphincter distensibility

INTRODUCTION

The esophagogastric junction (EGJ) is a complex anti-reflux barrier whose integrity relies on both the intrinsic lower esophageal sphincter (LES) and extrinsic crural diaphragm. During hiatal hernia repair, it is unclear whether the crural closure or the fundoplication is more important to restore the anti-reflux barrier. The objective of this study is to analyze changes in LES minimum diameter (D_min) and distensibility index (DI) using the endoluminal functional lumen imaging probe (FLIP) during hiatal hernia repair.

METHODS

Following implementation of a standardized operative FLIP protocol, all data were collected prospectively and entered into a quality database. This data were reviewed retrospectively for all patients undergoing hiatal hernia repair. FLIP measurements were collected prior to hernia dissection, after hernia reduction, after cruroplasty, and after fundoplication. Additionally, subjective assessment of the tightness of crural closure was rated by the primary surgeon on a scale of 1 to 5, 1 being the loosest and 5 being the tightest.

RESULTS

Between August 2018 and February 2020, 97 hiatal hernia repairs were performed by a single surgeon. FLIP measurements collected using a 40-mL volume fill without pneumoperitoneum demonstrated a significant decrease in LES D_min (13.84 ± 2.59 to 10.27 ± 2.09) and DI (6.81 ± 3.03 to 2.85 ± 1.23 mm²/mmHg) after crural closure (both p < 0.0001). Following fundoplication, there was a small, but also statistically significant, increase in both D_min and DI (both p < 0.0001). Additionally, subjective assessment of crural tightness after cruroplasty correlated well with DI (r = - 0.466, p < 0.001) and all patients with a crural tightness rating ≥ 4.5 (N = 13) had a DI < 2.0 mm²/mmHg.

CONCLUSION

Cruroplasty results in a significant decrease in LES distensibility and may be more important than fundoplication in restoring EGJ competency. Additionally, subjective estimation of crural tightness correlates well with objective FLIP evaluation, suggesting surgeon assessment of cruroplasty is reliable.

Impedance planimetry (EndoFLIP™) after magnetic sphincter augmentation (LINX®) compared to fundoplication

INTRODUCTION

Functional luminal imaging probe (FLIP) use during laparoscopic fundoplication (LF) for gastroesophageal reflux disease is well described. However, there is a lack of data on FLIP measurements during magnetic sphincter augmentation (MSA). This study aims to report our institutional experience in performing FLIP during MSA and to compare these measurements to those obtained during Nissen and Toupet fundoplication.

METHODS AND PROCEDURES

A retrospective review of a prospectively maintained quality database was performed. Patients who underwent MSA or LF and had FLIP measurements between April 2018 and June 2021 were included. FLIP measurements at the gastroesophageal junction (GEJ) were recorded without pneumoperitoneum at 40 mL balloon fill after hernia reduction, cruroplasty, and MSA or fundoplication. Reflux symptom index (RSI), GERD-HRQL, and dysphagia score were collected up to 2 years. Group comparisons were made using two-tailed Wilcoxon rank-sum and χ² tests, with statistical significance of p < 0.05.

RESULTS

Twenty-seven patients underwent MSA and 100 patients underwent LF (66% Toupet, 34% Nissen). Type III hiatal hernia was present in 3.7% of MSA patients versus over 50% for fundoplication patients. Minimum diameter, cross-sectional area, and distensibility index (DI) were lower after MSA device placement compared to Nissen or Toupet fundoplication (p < 0.05). Postoperative follow-up showed no differences in RSI, GERD-HRQL, and dysphagia score between MSA and Nissen fundoplication (p > 0.05).

CONCLUSION

Intraoperative impedance planimetry provided objective information regarding the geometry of the GEJ during MSA. The ring of magnetic beads restores the anti-reflux barrier and transiently opens with food bolus and belching. The magnetic force of the beads may explain why the DI after MSA is lower yet postoperative quality of life is no different than Nissen fundoplication.

Impedance Planimetry (Endoflip™) Shows That Length of Narrowing After Fundoplication Does Not Impact Dysphagia

INTRODUCTION

A short floppy fundoplication has been the surgical dogma to prevent dysphagia and gas-bloat after laparoscopic fundoplication while adequately addressing gastroesophageal reflux disease. The literature on the ideal length of narrowing (LON) of the gastroesophageal junction after fundoplication is sparse. The functional luminal imaging probe (FLIP) can be used during anti-reflux surgery to produce a visual representation of the LON. We hypothesize that a longer LON provides relief of GERD symptoms, however worse dysphagia and gas-bloat.

METHODS AND PROCEDURES

Prospectively collected data was analyzed. Patients with FLIP measurements during laparoscopic fundoplication between August 2018 and December 2020 were included. FLIP measurements at the gastroesophageal junction were recorded without pneumoperitoneum at 40-mL balloon fill after fundoplication. Reflux Symptom Index (RSI), Gastroesophageal Reflux Disease-Health Related Quality of Life Questionnaire (GERD-HRQL), gas-bloat score, and Dysphagia Score were collected. Comparisons were made using Spearman correlation coefficients (r) and two-tailed Wilcoxon rank-sum tests, with statistical significance set at p < 0.05.

RESULTS

One hundred and eleven patients underwent laparoscopic fundoplication (26% Nissen, 74% Toupet) and had FLIP measurements. Mean LON in this cohort was 2.7 ± 0.8 cm and mean DI was 3.5 ± 1.3 mm²/mmHg. LON is inversely associated with RSI (r =  - 0.29, p = 0.04) and gas-bloat (r =  - 0.30, p = 0.04). There was no association with Dysphagia Score. Patients with a LON of 2.5-4.5 cm and DI of 2.5-3.6 mm²/mmHg after fundoplication reported lower RSI (p = 0.03) and GERD-HRQL (p = 0.04) compared to patients outside of these ranges. There were no significant differences in patient-reported dysphagia or gas-bloat scores at 1 year between these groups.

CONCLUSIONS

Impedance planimetry provides objective real-time measurements and images during anti-reflux surgery, which allows surgeons to measure the length of narrowing after fundoplication. A LON of 2.5-4.5 cm and DI of 2.5-3.6 mm²/mmHg after fundoplication led to better postoperative quality of life at 1 year without an increase in postoperative dysphagia or gas-bloat.

Significant changes in impedance planimetry (EndoFLIP™) measurements after peroral pyloromyotomy for delayed gastric emptying

BACKGROUND

The endoluminal functional lumen imaging probe (FLIP) can be used to obtain real-time measurements of the diameter (D_min), cross-sectional area (CSA), and distensibility of the pylorus before and after peroral pyloromyotomy (POP), an emerging endoscopic treatment for delayed gastric emptying. Our study aims to report our single-center experience in performing POP with FLIP measurements before and after pyloromyotomy.

METHODS

A retrospective review of a prospectively maintained gastroesophageal database was performed. Demographic and perioperative data, including intraoperative FLIP measurements of the pylorus before and after POP, were analyzed. Measurements were compared using paired t tests.

RESULTS

Thirty-four patients underwent POP between February 2017 and July 2020. Twenty-three (67.7%) patients were male and the average age was 59 years. The etiology of delayed gastric emptying was post-vagotomy in 22 patients, idiopathic gastroparesis in 7 patients, and diabetic gastroparesis in 5 patients. There were no significant differences in pre-myotomy or post-myotomy FLIP measurements when comparing the post-vagotomy versus the gastroparesis groups. There were significant increases in D_min, CSA, and distensibility index when comparing pre-myotomy and post-myotomy readings for all patients (all p < 0.001). At follow-up, 64.7% of patients reported resolution of all symptoms.

CONCLUSION

POP is an effective intervention in patients with delayed gastric emptying. Significant changes in FLIP measurements before and after POP suggest that FLIP may be a useful adjunct in guiding the management of delayed gastric emptying.

The impact of pneumoperitoneum on esophagogastric junction distensibility during anti-reflux surgery

OBJECTIVE

We aimed to quantify the contribution of pneumoperitoneum on compliance of the esophagogastric junction (EGJ) during anti-reflux surgery.

BACKGROUND

Compliance of the EGJ is reduced with anti-reflux surgery. EndoFLIP® planimetry can be used to assess dynamic changes of EGJ compliance intraoperatively. It is unclear how pneumoperitoneum impacts intraoperative measurements by EndoFLIP® and the implications thereof on validity of the results. Therefore, determining variability in EndoFLIP® measurements based on pneumoperitoneum is warranted to establish guidelines to interpret clinical outcomes.

METHODS

Primary anti-reflux surgery was performed on 39 consecutive patients with pathologic reflux. Intraoperative EGJ measurements including distensibility index (DI), cross-sectional area (CSA), and intrabag pressure were collected using EndoFLIP® at 0, 10, and 15 mmHg of intraperitoneal pressure. Data were acquired pre-procedure, post-hiatal hernia repair, and post-LES augmentation with fundoplications.

RESULTS

Patients underwent Nissen (13.2%), Toupet (68.4%), LINX (10.5%), or Hill-fundoplications (7.9%). There was no difference between 0 and 10 mmHg of pneumoperitoneum in CSA, pressure, or DI measurements pre-procedure; however, there was a difference between 0 and 15 mmHg in pressure (p = 0.016) and DI (p = 0.023) measurements. After LES augmentation, 10 mmHg intraperitoneal pressure reduced DI, though the absolute difference is small (2.0 vs. 1.5 mm²/mmHg, p = 0.002).

CONCLUSION

Pneumoperitoneum affected EGJ distensibility at 15 mmHg, but not 10 mmHg, of insufflation prior to anti-reflux procedures. After anti-reflux surgery, there was a significant variance between 0 and 10 mmHg of pneumoperitoneum in pressure and distensibility. The change in pressure appears linear and needs to be considered if procedural modifications are performed based on intraoperative findings and when evaluating clinical outcomes.

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.

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.

Application of the Functional Lumen Imaging Probe to Esophageal Disorders

OPINION STATEMENT

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

Esophagogastric junction distensibility assessed using the functional lumen imaging probe

AIM

To assess reference values in the literature for esophageal distensibility and cross-sectional area in healthy and diseased subjects measured by the functional lumen imaging probe (FLIP).

METHODS

Systematic search and review of articles in Medline and Embase pertaining to the use of FLIP in the esophagus was conducted in accordance with the PRISMA guidelines. Cross-sectional area and distensibility at the esophagogastric junction (EGJ) were abstracted for normal subjects, achalasia, and gastroesophageal reflux disease (GERD) patients, stratified by balloon length and volume of inflation.

RESULTS

Six achalasia studies (n = 154), 3 GERD (n = 52), and 5 studies including healthy controls (n = 98) were included in the systematic review. Normative data varied widely amongst studies of healthy volunteers. In contrast, studies in achalasia patients uniformly demonstrated low point estimates in distensibility ≤ 1.6 mm²/mmHg prior to treatment that increased to ≥ 3.4 mm²/mmHg following treatment at 40mL bag volume. In GERD patients, distensibility fell to the range of untreated achalasia (≤ 2.85 mm²/mmHg) following fundoplication.

CONCLUSION

FLIP may be a useful tool in assessment of treatment efficacy in achalasia. The drastic drop in EGJ distensibility after fundoplication suggests that FLIP measurements need to be interpreted in the context of esophageal body motility and highlights the importance of pre-operative screening for dysmotility. Future studies using standardized FLIP protocol and balloon size are needed.

Comparison of videofluoroscopy and impedance planimetry for the evaluation of oesophageal stenosis: a retrospective study

Objectives

To compare videofluoroscopy that included a tablet test with impedance planimetry (EndoFLIP^®) for the evaluation of oesophageal stenosis in patients with dysphagia.

Methods

In 56 patients, videofluoroscopic examinations following the transit of a 14-mm tablet were retrospectively reviewed and correlated with impedance planimetry findings, a catheter-based method using impedance planimetry to display the oesophageal diameter estimates. Additional findings assessed were the occurrence of symptoms during tablet passage and evaluation of oesophageal motility.

Results

Impaction of the tablet occurred in 31/56 patients; nine showed a moderate delay (2–15 s), three a short delay (<2 s) and 13 no delay of tablet passage. Both methods showed a significant correlation between tablet impaction and oesophageal diameter <15.1 mm, as measured by impedance planimetry (p = 0.035). The feeling of the tablet getting stuck was reported by seven patients, six showing impaction of the tablet (four with an EndoFLIP-diameter < 13 mm, two with a diameter of 13–19 mm) and one showing delayed passage (EndoFLIP diameter of 17 mm).

Conclusions

Videofluoroscopy and impedance planimetry correlate significantly regarding tablet impaction and residual oesophageal lumen. A standardized 14-mm tablet is helpful in demonstrating oesophageal strictures in dysphagic patients. Triggering of subjective symptoms provides valuable information during a videofluoroscopic study.

Key Points

• A 14-mm tablet can demonstrate oesophagogastric junction narrowing in patients with dysphagia.

• Type of passage of a tablet enables estimation of oesophageal luminal diameter.

• Videofluoroscopy and impedance planimetry correlate significantly regarding tablet impaction and residual oesophageal lumen.

Intraoperative assessment of the effects of laparoscopic sleeve gastrectomy on the distensibility of the lower esophageal sphincter using impedance planimetry

BACKGROUND

Laparoscopic sleeve gastrectomy (LSG) has emerged as an effective weight-loss procedure for morbid obesity that is also effective for treating comorbidities such as diabetes. However, it has been associated with the development of GERD postoperatively. The pathophysiology of post-LSG GERD is unknown, and current studies have shown conflicting results. The aim of our study is to shed light on this issue by investigating the effect of LSG on the lower esophageal sphincter (LES) function and the relationship of LES function to GERD symptoms.

METHODS

A prospective study of patients undergoing LSG from 10/2013 to 8/2014 at a single academic tertiary referral center was carried out. Patients undergoing a concomitant procedure such as hiatal hernia repair or laparoscopic gastric band removal were excluded. Distensibility of the LES was measured after pneumoperitoneum and after LSG. Baseline GERD-HRQL was obtained with follow-up GERD-HRQL and weight at 3 and 6 months. The primary outcomes measured were LES distensibility and GERD-HRQL scores after LSG. Our secondary outcome was a correlation between LES distensibility and GERD-HRQL scores after LSG.

RESULTS

Fifteen subjects were enrolled (5M/10F). Mean age was 51 years (30-71 years), and mean BMI 45 kg/m² (30-58). We were able to obtain follow-up data for all patients at 3 months. Mean LES distensibility increased from 1.2 before LSG to 2.2 after LSG (p = 0.017). Median GERD-HRQL was 0 before LSG and remained essentially negative at 1 and 0 (3 and 6 months postoperatively, respectively). Three (27 %) of the patients had de novo GERD at 3 months following LSG. One (25 %) patient had remission of GERD. There was no correlation between LES distensibility and GERD symptoms.

CONCLUSION

While LSG weakens the LES immediately, it does not predictably affect postoperative GERD symptoms; therefore, distensibility is not the only factor affecting development of postoperative GERD, confirming the multifactorial nature of post-LSG GERD.

Pyloric sphincter therapy: botulinum toxin, stents, and pyloromyotomy

Gastroparesis is a syndrome characterized by delayed gastric emptying with associated symptoms. Gastric emptying is a complex process and pyloric dysfunction may play a key role in select subsets of patients with gastroparesis. Diagnostic tests to measure pyloric physiology are now available and have the potential to be more widely used in clinical practice. Targeted therapies including botulinum toxin, transpyloric stent placement, surgical pyloroplasty and endoscopic pyloromyotomy have been developed. Data are emerging regarding efficacy and durability, but these therapies may play a prominent role in select patients with gastroparesis and pyloric dysfunction.

Measuring mechanical properties of the esophageal wall using impedance planimetry

The mechanical properties of the esophagogastric junction (EGJ) are of major importance for the competence of the EGJ. Although manometry reliably measures sphincter pressure, no information is provided on distensibility, a crucial determinant of flow across the EGJ. Recently, a new technique, impedance planimetry, was introduced allowing accurate measurement of compliance or distensibility. This review discusses the recent advances in this area and highlights the clinical relevance of this new technique evaluating the mechanical properties of the esophageal wall and EGJ.

Uses of esophageal function testing: dysphagia

Esophageal function testing should be used for differential diagnosis of dysphagia. Dysphagia can be the consequence of hypermotility or hypomotility of the muscles of the esophagus. Decreased esophageal or esophagogastric junction distensibility can provoke dysphagia. The most well established esophageal dysmotility is achalasia. Other motility disorders can also cause dysphagia. High-resolution manometry (HRM) is the gold standard investigation for esophageal motility disorders. Simultaneous measurement of HRM and intraluminal impedance can be useful to assess motility and bolus transit. Impedance planimetry measures distensibility of the esophageal body and gastroesophageal junction in patients with achalasia and eosinophilic esophagitis.