Planimetry System Research Articles

Objective assessment of luminal diameter and distensibility by an impedance planimetry system before and after pneumatic dilation in gastric sleeve stenosis.

Video 1Endoscopic impedance planimetry system measurement and pneumatic balloon dilation of a sleeve gastrectomy stricture.

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

Compliance is the ability of a hollow organ to dilate and increase volume withan 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). 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 2years 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. 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. 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.

Devices for esophageal function testing.

Background and AimsEsophageal 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.MethodsWe 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.ResultsFLIP 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.ConclusionsEsophageal 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.

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

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

Building a Comprehensive Rural Anti-Reflux Center.

Gastroesophageal disease (GERD) is a highly prevalent gastrointestinal disease. In rural areas, general surgeons perform esophagogastroduodenoscopy (EGD) despite its low diagnostic yield. When EGD findings are equivocal, GERD patients are usually referred to tertiary hospitals for further workup. We envisaged establishing a comprehensive anti-reflux program with diagnostic and therapeutic capabilities in a rural setting. This is an IRB approved retrospective chart review of patients who presented with GERD symptoms to a rural anti-reflux clinic between August 2015 and February 2021. Standardized workup included upper gastrointestinal study and EGD with concomitant wireless pH placement. High resolution impedance manometry and gastric emptying scans were selectively utilized initially, then were performed routinely. We used endoFLIP impedance planimetry system starting in February 2019. A total of 830 patients were evaluated. There were 537 (64.6%) females and 293 (35.4%) males. The average age was 57.7 ± 15.2years. The average BMI was 30.8 ± 6.7kg/m2. Approximately one-third of these patients were referred by the primary care provider (PCP) within our health system and a comparable percentage from external PCPs. Self referral was noted in 15.4% and 19.2% were referred by different specialties such as pulmonary (10.7%), surgical for large hiatal hernia (5.8%), inpatient and emergency room (2%), and gastroenterology (0.7%). Rural surgeons with appropriate endoscopic and laparoscopic training can establish a comprehensive anti-reflux program with diagnostic and therapeutic capabilities. It meets the high community need and can expand to be a regional center. The revenues generated are critical for the financial survival of rural hospitals.

Intraoperative Impedance Planimetry (ENDOFLIP)

AbstractThe Endoluminal Functional Imaging Probe (EndoFLIP, Medtronic, Minneapolis, MN) impedance planimetry system provides real-time three-dimensional images of gastrointestinal sphincters of interest, particularly the esophagogastric junction. This allows for real-time objective measurements during the surgical management of foregut diseases such as gastroesophageal reflux and achalasia. Literature continues to grow on how to best utilize this recent technology to improve patient outcomes. This outlines the intraoperative utilization of EndoFLIP.

Experience-based expert consensus on the intra-operative usage of the Endoflip impedance planimetry system.

The Endoluminal Functional Lumen Imaging Probe (Endoflip™) is a balloon-based catheter that provides real-time, objective feedback regarding the distensibility of any sphincter in the gastrointestinal tract. Usage of the Functional Lumen Imaging Probe (FLIP) has not been standardized, which has limited the interpretation and generalizability of published data. The purpose of this consensus statement is to provide a standardized protocol for obtaining FLIP measurements in order to create a more uniform approach to data collection. Five expert foregut surgeons, all of whom utilize the FLIP system in their daily practice, convened on March 19, 2019, to create a standardized protocol for obtaining FLIP measurements during hiatal hernia repair and fundoplication, magnetic sphincter augmentation, laparoscopic Heller myotomy, and peroral endoscopic myotomy. Existing literature was presented and reviewed. Each step of the protocol was discussed in detail until a unanimous consensus was reached. A standardized protocol was developed for obtaining FLIP measurements during hiatal hernia repair and fundoplication, magnetic sphincter augmentation, laparoscopic Heller myotomy, and peroral endoscopic myotomy. The FLIP impedance planimetry system is the only technology available that provides surgeons an objective way to assess the tightness of a fundoplication or adequacy of a myotomy during an operation. While considerable research remains to correlate FLIP measurements to patient outcomes, this consensus statement will provide standardization of data collection among FLIP users that will enhance the understanding of future study results.

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

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. 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 June2019. 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. 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.

Computerized planimetry evaluation of hyperbaric oxygen therapy in the treatment of diabetic foot.

Diabetic foot ulcer is one of the major complications of diabetes mellitus in adults. The aim of the study was to conduct a planimetry evaluation of the effectiveness of hyperbaric oxygen therapy (HBOT) in the treatment of patients with vascular disorders caused by diabetic foot. The study included 94 patients, 30 females (32%) and 64 males (68%), aged 33-76 years, with diabetes lasting 1.5-32 years, who underwent HBOT due to diabetic foot. All patients from that group underwent vascular procedures prior to HBOT. In qualifying patients for hyperbaric oxygen therapy, transcutaneous oximetry method was applied (30-60 exposures in hyperbaric oxygen at pressure of 2.5 ATA). Progress in wound healing was evaluated by computerized planimetry system IRIS 4. In 26 patients the wounds were completely closed and in 37 patients the topical state was significantly improved - the wound surface decreased by 34% in average. During the treatment, in 11 patients amputation of fingers and metatarsal necrotic bones was performed, while in 9 patients amputation was prevented. A planimetry evaluation showed that the application of HBOT in the treatment of diabetic foot enhances foot ulcer healing, reduces tissue damage, contributes to the reduction of complications related to soft tissue and bone infections.

Image acquisition and planimetry systems to develop wounding techniques in 3D wound model

Abstract Wound healing represents a complex biological repair process. Established 2D monolayers and wounding techniques investigate cell migration, but do not represent coordinated multi-cellular systems. We aim to use wound surface area measurements obtained from image acquisition and planimetry systems to establish our wounding technique and in vitro organotypic tissue. These systems will be used in our future wound healing treatment studies to assess the rate of wound closure in response to wound healing treatment with light therapy (photobiomodulation). The image acquisition and planimetry systems were developed, calibrated, and verified to measure wound surface area in vitro. The system consists of a recording system (Sony DSC HX60, 20.4 M Pixel, 1/2.3″ CMOS sensor) and calibrated with 1mm scale paper. Macro photography with an optical zoom magnification of 2:1 achieves sufficient resolution to evaluate the 3mm wound size and healing growth. The camera system was leveled with an aluminum construction to ensure constant distance and orientation of the images. The JPG-format images were processed with a planimetry system in MATLAB. Edge detection enables definition of the wounded area. Wound area can be calculated with surface integrals. To separate the wounded area from the background, the image was filtered in several steps. Agar models, injured through several test persons with different levels of experience, were used as pilot data to test the planimetry software. These image acquisition and planimetry systems support the development of our wound healing research. The reproducibility of our wounding technique can be assessed by the variability in initial wound surface area. Also, wound healing treatment effects can be assessed by the change in rate of wound closure. These techniques represent the foundations of our wound model, wounding technique, and analysis systems in our ongoing studies in wound healing and therapy.

Emerging Roles of the Endolumenal Functional Lumen Imaging Probe in Gastrointestinal Motility Disorders.

Gastrointestinal sphincters play a vital role in gut function and motility by separating the gut into functional segments. Traditionally, function of sphincters including the esophagogastric junction is studied using endoscopy and manometry. However, due to its dynamic biomechanical properties, data on distensibility and compliance may provide a more accurate representation of the sphincter function. The endolumenal functional lumen imaging probe (EndoFLIP) system uses a multi-detector impedance planimetry system to provide data on tissue distensibility and geometric changes in the sphincter as measured through resistance to volumetric distention with real-time images. With the advent of EndoFLIP studies, esophagogastric junction dysfunction and other disorders of the stomach and bowels may be better evaluated. It may be utilized as a tool in predicting effectiveness of endoscopic and surgical treatments as well as patient outcomes.

Effectiveness of the Frequency Rhythmic Electrical Modulation System for the Treatment of Chronic and Painful Venous Leg Ulcers in Older Adults

Frequency rhythmic electrical modulation system (FREMS) is an innovative type of transcutaneous electrotherapy used in a rehabilitation setting for the treatment of pain, especially in diabetic patients. In a randomized clinical trial, we tested the hypothesis that FREMS is effective in the treatment of chronic and painful venous leg ulcers in 20 older patients. Group A (10 patients) received FREMS and topical treatment, whereas group B (10 patients) received topical treatment alone. Over a period of 3 consecutive weeks, 15 treatment sessions were done for each group. Wound healing and tissue repair were evaluated with the Visitrack digital planimetry system and photos. Pain was evaluated using the Visual Analogic Scale (VAS). The measurements were done at baseline and after 5, 10, and 15 days of treatment, with follow-up measurements after 15 and 30 days from the last treatment session. Group A showed a statistically significant decrease in ulcer area during the treatment and follow-up. The VAS score showed a statistically significant decrease after 5 and 10 days of treatment. Group B showed a statistically decrease in ulcer area after 5, 10, and 15 days of treatment with a reduction of VAS score only at 15 days of follow-up. At the end of the treatment, the comparison of the change in ulcer area and the change in VAS score of each group showed a statistically significant difference between groups, suggesting the therapeutic and analgesic efficacy of FREMS in reducing pain and area of chronic venous leg ulcers in older adults. Further investigation is needed to determine its reproducibility in larger case series or randomized clinical trials with longer follow-up periods.

Impedance Planimetric Description of Normal Rectoanal Motility in Humans

Manometry and pressure-volume measurements are commonly used to study anorectal physiology. However, the methods are limited by several sources of error. Recently, a new impedance planimetric system has been introduced in a porcine model. It allows simultaneous determination of anorectal pressures and multiple rectal luminal cross-sectional areas. This study was designed to study normal human rectoanal motility by means of impedance planimetry with multiple rectal cross-sectional areas and rectal and anal pressure. Twelve healthy volunteers (10 females), aged 24 to 53 years, were studied during one-hour fasting and one hour after a meal. Rectal cross-sectional areas were determined at five levels each 2 cm apart, as well as rectal and anal pressure. A number of rectoanal motility patterns were observed. A total of 25 episodes with very localized cyclic rectal contractions detected at only one of five channels were observed lasting two to four minutes with a median frequency of three per minute (range, 2-6). A total of 44 episodes of cyclic rectal contractions propagating over two or more channels were detected lasting 2 to 36 minutes. Most were associated with contractions of the anal canal. A significant increase in rectal contractile activity was observed after the meal (P < 0.05). Single rectal contractions were observed in 11 subjects, and the majority were located to one channel and lasted less than 40 seconds. In two subjects who felt a need to defecate during the experiment, the cross-sectional area at all channels showed strong cyclic contractile activity and the anal pressure increased by approximately 100 percent. The new rectal impedance planimetry system allows highly detailed description of rectoanal motility patterns. It has promise as a new method for description of rectoanal motility in further studies.

Use of a nanocrystalline silver dressing on lymphatic ulcers in patients with chronic lymphoedema

A prospective evaluation to explore the effect of treating patients with chronic lower limb lymphoedema and lymphatic ulcers using a nanocrystalline dressing and multilayer bandaging. Ulcers were cleansed and dressed with a nanocrystalline silver dressing, an alginate dressing and a hydrocellular dressing, followed by multilayer short-stretch compression bandages. A digital planimetry system was used to calculate the ulcer surface area. In cases of multiple ulcers, the areas were added together. Eight patients with chronic lower limb lymphoedema plus ulcers were included. Median age was 53.7 years (range 39.2-72.3). Mean ulcer size was 10.5cm2 (range: 0.8-33.8). All ulcers completely healed after one to nine weeks of treatment. This protocol has been effective in healing lymphatic ulcers and was well accepted by patients. There were no adverse effects or withdrawals. Further studies with larger numbers of patients are required to support these results.

A new method for evaluation of intestinal muscle contraction properties: studies in normal subjects and in patients with systemic sclerosis

Systemic sclerosis is a connective tissue disease that involves the gastrointestinal (GI) tract. Seventy-five per cent of systemic sclerosis patients experience symptoms arising from oesophagus. The intestine has less frequently been subject for studies than the oesophagus. When the small intestine becomes involved, nausea, vomiting, bloating, diarrhoea and malabsorption may occur. Previous studies have shown decreased and abnormal intestinal motility, dilatation and a stiffer wall. The aim was to study muscle mechanics in systemic sclerosis patients using novel analysis of intestinal muscle contraction force-velocity and power. A volume-controlled duodenal ramp-distension protocol was used in nine patients and eight healthy controls. The wall stretch ratio, tension, shortening velocity and muscle power were computed from pressure and cross-sectional area data recorded by an impedance planimetry system. The tension-stretch ratio relation obtained in patients was shifted to the left, indicating a stiffer wall. The in vivo tension-shortening velocity relationship was quantified using Hill's equation. The maximum preload tension (tension at zero velocity) was lower in the patients than in the healthy controls (P < 0.001). The muscle power was lowest in the patients. An association was found between the duration of the disease and the maximum stretch ratio (P < 0.05). The study represents the first data with application of in vivo muscle force-velocity relations in patients with gastrointestinal diseases. Systemic sclerosis patients had increased stiffness and impaired muscle dynamics of the duodenum. Decreased muscle function and increased wall stiffness may explain the GI symptoms reported in this patient group.

Wound measurement comparing the use of acetate tracings and VisitrakTM digital planimetry

This study aimed to compare acetate tracing with the new digital planimetry system Visitrak (Smith + Nephew). It also aimed to compare the percentage change in wound size after four weeks using both methods. There is a need for development and more widespread use of objective tools in wound management. Wound measurement is an integral part of wound assessment and provides possibly the most objective tool available. To achieve this, practitioners use a variety of methods including acetate tracing and digital planimetry. Studies have demonstrated good inter- and intrarater reliability using both methods. A retrospective, random selection of wound tracings of superficial leg ulcers was completed until 25 tracings of <10 cm2 and 25 tracings of >10 cm2 were obtained. Wound area was calculated firstly by manually counting squares completely within the wound border and those half or more within the border as 1 cm2. The area was then calculated using the Visitrak system. The difference between the acetate and Visitrak for wounds <10 cm2 not significant (P = 0.330). For wounds >10 cm2 the difference between both methods was significant (P = 0.008). After four weeks the number of tracings available was too small for any conclusions to be made. Wound measurement should become part of routine practice. Acetate offers a good indicator of wound size and digital planimetry can enhance the precision of the measurement. Accurate and objective wound measurement is a vital component of wound management. It is essential that nurses have adequate training and skills in wound measuring to assess wounds correctly and objectively. Findings from this study can be used when deciding which method should be used in a particular setting when outcomes and cost have been considered. Accurate on-going wound measuring contributes to improved quality of patient care, more effective communication between professionals, as a predictor to wound healing, to document progress and assess treatment efficacy.

Sensory-motor responses to mechanical stimulation of the esophagus after sensitization with acid

Sensitization most likely plays an important role in chronic pain disorders, and such sensitization can be mimicked by experimental acid perfusion of the esophagus. The current study systematically investigated the sensory and motor responses of the esophagus to controlled mechanical stimuli before and after sensitization. Thirty healthy subjects were included. Distension of the distal esophagus with a balloon was performed before and after perfusion with 0.1 mol/L hydrochloric acid for 30 min. An impedance planimetry system was used to measure cross-sectional area, volume, pressure, and tension during the distensions. A new model allowed evaluation of the phasic contractions by the tension during contractions as a function of the initial muscle length before the contraction (comparable to the Frank-Starling law for the heart). Length-tension diagrams were used to evaluate the muscle tone before and after relaxation of the smooth muscle with butylscopolamine. The sensitization resulted in allodynia and hyperalgesia to the distension volumes, and the degree of sensitization was related to the infused volume of acid. Furthermore, a nearly 50% increase in the evoked referred pain was seen after sensitization. The mechanical analysis demonstrated hyper-reactivity of the esophagus following acid perfusion, with an increased number and force of the phasic contractions, but the muscle tone did not change. Acid perfusion of the esophagus sensitizes the sensory pathways and facilitates secondary contractions. The new model can be used to study abnormal sensory-motor mechanisms in visceral organs.

Accuracy of aortic valve area calculation using a computer-based planimetry system in the cathererization laboratory

Accuracy of aortic valve area calculation using a computer-based planimetry system in the cathererization laboratory

A longitudinal study of cortical cataracts using retroillumination photographs

The National Eye Institute (NEI) computer planimetry system has been shown to have good reproducibility in assessing the size of cortical cataracts from retroilluminatin photographs. In this study, we determined the usefulness of this system in monitoring cortical cataract changes over time. Using the Neitz Kawara retroillumination camera, retroillumination photographs of cortical cataracts in 81 eyes were obtained every six months for an average of 31 months. As previously described, the cortical cataract outlines were traced in a masked fashion onto transparent plastic overlays, and the tracings then digitized into a Macintosh Quadra computer using a computer scanner. Cortical cataract area was then determined using a specially developed software program. For each eye, the rate of cortical area change was determined by the slope of the regression line fitted to the follow-up measurements. Cataract progression was classified to be significant if the slope exceeded a critical value. Of the 81 eyes, 24 (30%) had significant cataract progression, while 57 (70%) did not progress. This study presents data on progression of the area of cortical cataracts and suggests the usefulness of the NEI computer planimetry system for monitoring such changes from retroillumination photographs. The slope-based test can also play a useful part in longitudinal studies with irregular time intervals and variable number of visits.

Oral epithelial response to experimental chronic alcohol ingestion in hamsters

The purpose of this study was to assess the effect of alcohol on oral epithelium by quantifying epithelial compartment thicknesses after chronic alcohol ingestion with the use of a computerized planimetry system. A 10% solution of absolute alcohol in water was given as the sole source of drinking fluid to young adult Syrian hamsters over a period of 9 months. Quantitative histologic analysis showed significant atrophy of the posterior lateral tongue epithelium. The epithelium of the dorsal tongue showed an increase in the thickness percentage of keratin. No significant change was found in the ventral aspect of the tongue epithelium. It was concluded that such alcohol-related atrophy may render the lateral margins of the posterior tongue more susceptible to carcinogenesis.