When evaluating patients with possible dysphagic conditions, such as achalasia or esophagitis, gastroenterologists typically have selected bolus movement assessment or high-resolution manometry (HRM) to assess esophageal function.1,2 Despite key advances in these technologies, few novel modalities have been introduced—as either replacements or adjuncts—to provide additional information for diagnosing upper gastrointestinal (GI) disorders.2 However, with FDA clearance of the Endoflip™ impedance planimetry system for motility assessment,3 clinicians and fellows can generate information about lumen diameter, tissue distensibility, and sphincter pressure with one technology, thus providing a new diagnostic tool for upper GI disorders.2

 

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John E. Pandolfino, MD

 

“This is emerging as a disruptive technology and a paradigm shift for the evaluation of patients with a negative endoscopy,” said John E. Pandolfino, MD, the chief of the Division of Gastroenterology and Hepatology at Northwestern University Feinberg School of Medicine, in Chicago, Illinois. Although the sequence in which functional lumen imaging probe (Flip™) technology is employed with other diagnostic tools will vary by patient history and studies already undertaken, the information from Flip™ technology “often can reduce the time to a definitive diagnosis,” Dr Pandolfino added.

Flip™ technology has been in use for other indications, such as bariatric surgery assessment, for many years.4 In early 2017, the Endoflip™ 2.0 impedance planimetry system (Medtronic) received FDA clearance as an adjunct to other diagnostic methods as part of a comprehensive evaluation of patients with symptoms consistent with GI motility disorders.3 It consists of a catheter within a compliant balloon.5 Once placed in the GI tract, the balloon is distended with fixed volumes of fluid to provide controlled dilation. Catheter electrodes allow high-resolution impedance planimetry to measure luminal dimensions and distensibility in real time.6 The data on the mechanical properties of the lumen provide a dimension of information independent of the contractile function measured with manometry.6

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“Demonstrating abnormal distensibility in the esophagus is valuable information when establishing the cause of symptoms suggesting impaired transit in the esophagus. By itself, manometry is not necessarily descriptive of what is happening,” said C. Prakash Gyawali, MD, the director of the Neurogastroenterology Program and the GI Fellowship Training Program at Washington University School of Medicine in St. Louis, Missouri.

Dr Gyawali noted how the ability of Flip™ technology to show abnormal responses to volume distention is capable of shortening the time to diagnosis. According to a clinical practice update issued by the American Gastroenterological Association, the ability of Flip™ technology to characterize the mechanics of the esophagogastric junction is relevant to assessment of conditions in which compliance, rather than patterns of contraction and relaxation, is an important pathologic variable.2 This includes achalasia and eosinophilic esophagitis.2 The applications are continuing to evolve as experience expands.

 

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Amir E. Masoud, MD

 

“With time, I think we will see the applications of Flip™ technology expand. It is already an important tool, but I think it will become a standard of care within the diagnostic algorithm for a number of disorders involving motility in the esophageal body,” said Amir E. Masoud, MD, the associate program director of the Gastroenterology Fellowship Program and director of the Temple Endoscopy Center at Yale School of Medicine, in New Haven, Connecticut. “It is important for fellows with an interest in upper GI disorders to learn this technology.”

HRM is an important and useful tool for evaluating esophageal motility,1 but motility is affected by factors other than peristalsis; according to Dr Masoud, HRM “does not always provide the full story.” “Flip™ technology has been very helpful in patients with a manometry that was inconclusive. Relative to what we had before, this tool provides a direct measure of an abnormal biomechanical reaction to a bolus trigger,” said John O. Clarke, MD, the director of the Esophageal Program at Stanford School of Medicine, in Stanford, California. “We do not have enough data to establish Flip™ as a first-line diagnostic tool, but I have used this at the time of an initial endoscopy in patients with a history of dysphagia to establish a diagnosis of achalasia, avoiding further studies, such as manometry.”

Establishing diagnostic algorithms in which Flip™ technology can be employed in advance of manometry is attractive, according to Dr Pandolfino. He observed that HRM typically is performed at specialty clinics requiring a separate visit, which can incur costs and cause inconvenience. For patients with a strong likelihood of achalasia, spastic contractions, or other conditions more closely associated with mechanics than contractility alone, Flip™ technology is advantageous. “The color topography can generate very informative images of the contractile response to volume distention, which can be antegrade, retrograde, or absent,” Dr Pandolfino said. “If Flip™ is equivocal, HRM may be needed, but Flip™ is sufficient to diagnose most major esophageal motor abnormalities.”

Overall, relative to HRM, Flip™ technology is easier to employ, less demanding, and more suitable for use outside of specialty centers, according to Dr Clarke, although it should be considered complementary to HRM. It could be used independently of HRM as more experience establishes up-front indications, Dr Clarke noted. As Flip™ technology is performed under sedation, often at the time of endoscopy, patients readily accept this type of evaluation. “The placement of the catheter in the esophagus is technically simple,” Dr Clarke said. He said the learning curve is short for gastroenterologists experienced in HRM or placement of wireless pH probes.

For Dr Masoud, Flip™ technology is drawing attention to the mechanics of esophageal motility, an area that has not received enough attention during fellowship training until now. Dr Pandolfino added, “I could envision that in the future every endoscopy laboratory will have Flip™ technology.” He believes that in cases when Flip™ technology reduces the time to diagnosis, the availability of this tool has implications for quality of care and costs.

References

  1. Hirano I, Richter JE; Practice Parameters Committee of the American College of Gastroenterology. ACG practice guidelines: esophageal reflux testing. Am J Gastroenterol. 2007;102(3):668-685.
  2. Hirano I, Pandolfino JE, Boeckxstaens GE. Functional lumen imaging probe for the management of esophageal disorders: expert review from the clinical practice updates committee of the AGA Institute. Clin Gastroenterol Hepatol. 2017;15(3):325-334.
  3. Crospon. Crospon receives 510(k) FDA clearance for Endoflip® with Flip® Topography Module. www.crospon.com/?news/?company/?crospon-receives-510k-fda-clearance-for-endoflip-with-flip-topography-module. Accessed May 16, 2018.
  4. US Food and Drug Administration. 510(k) summary: EndoFLIP®. www.accessdata.fda.gov/?cdrh_docs/?pdf10/?K102214.pdf. Accessed May 16, 2018.
  5. Crospon. EndoFLIP® system functional lumen imaging probe EF-100 user manual. www.crospon.com/?download/?1226. Accessed May 16, 2018.
  6. Carlson DA, Kahrilas PJ, Lin Z, et al. Evaluation of esophageal motility utilizing the functional lumen imaging probe. Am J Gastroenterol. 2016;111(12):1726-1735.


Indications: The Endoflip™ system is indicated for use in a clinical setting to measure pressure and dimensions in the esophagus, pylorus, and anal sphincters. It is intended to be used as an adjunct to other diagnostic methods as part of a comprehensive evaluation of patients with symptoms consistent with gastrointestinal motility disorders. The EF-325 series of catheters can make pressure and dimensional measurements in the esophagus, pylorus, and anal sphincters, whereas the BF-325 series and EF-825 catheters can make dimensional measurements in the esophagus, pylorus, and anal sphincters. The EF-620 catheter can make dimensional measurements in the esophagus. Other indications for use include:

To estimate the size of a stoma produced by a gastric band (all EndoFLIP™ catheters)

For use as an adjunct to a bougie for measuring the size of a gastric sleeve created during bariatric surgery, where it is suitable for diameter measurements for 22 to 60Fr sleeves (EF-620 catheter)

Contraindications: The Endoflip™ system is contraindicated where endoscopy is contraindicated. The Endoflip™ system is contraindicated for use in patients with actively bleeding varices in the esophagus.

Risks: Similar to most procedures, the products featured here have inherent procedure risks associated. Please refer to the individual product user manuals for detailed information.