Lifting Agent Granuloma: Histologic Findings Following Use of ORISE Gel for Endoscopic Resections in the Gastrointestinal Tract

Hypertonic solution as an optimal submucosal injection solution for endoscopic resection of gastrointestinal mucosal lesions: Systematic review and network meta-analysis

OBJECTIVES

Based on different physicochemical properties, common submucosal injection solutions could be classified into three categories: normal saline solution (NS), hypertonic solution (HS), and viscous solution (VS). We compared the efficacy and safety of various categories of solutions in this network meta-analysis of randomized controlled trials (RCTs) to identify the optimal submucosal injection fluid.

METHODS

PubMed, Embase, Web of Science, and the Cochrane Library were searched for RCTs that compared the efficacy and safety of NS, HS, and VS during endoscopic resection for gastrointestinal (GI) mucosal lesions. Pairwise and network analyses were conducted to determine the ranking of different fluids.

RESULTS

Thirteen RCTs were included in the final analysis with 1637 patients (1639 lesions). HS outperformed NS in rates of en bloc (pooled relative risk [RR] 1.50; 95% confidence interval [CI] 1.10-1.90), overall bleeding (pooled odds ratio [OR] 0.33; 95% CI 0.10-0.88; lesions >10 mm OR 4.65 × 10-2; 95% CI 1.10 × 10-3-0.46), and intraoperative bleeding (lesions >10 mm OR 7.10 × 10-6; 95% CI 4.30 × 10-18-0.26). HS showed the highest probability of ranking first in each outcome except for the volume of injection. Although VS was superior to NS in rates of en bloc, overall, and intraoperative bleeding in the lesions >10 mm subgroup, and required less fluid in pooled analysis, it ranked last in cost of submucosal injection solution.

CONCLUSIONS

Both HS and VS were superior to NS in comparisons of efficacy and safety. Considering the better performance and potentially low cost, HS might be an optimal choice during gastrointestinal endoscopic resection, especially for colorectal endoscopic mucosal resection.

Assessment of submucosal distortion and mass effect seen at follow-up after colorectal EMR with ORISE (with video)

BACKGROUND AND AIMS

ORISE (Boston Scientific, Marlborough, Mass, USA) is a viscous gel used for submucosal injection. We noted anecdotally that ORISE is associated with submucosal distortion of EMR scars at follow-up.

METHODS

We blindly reviewed photographs of 30 consecutive EMR scars at follow-up after resections using ORISE and 30 resections using other agents. Distortion was scored on a scale of 0 (no submucosal distortion) to 5 (overt submucosal distortion).

RESULTS

The median submucosal distortion score at follow-up in ORISE cases was 3 (range, 0-5) versus 0 (range, 0-2) with other fluids (P < .001, Mann-Whitney U test) by 1 reviewer and 3 (range, 0-5) versus 2 (range, 0-5), respectively, by a second reviewer (P = .018). The kappa value for agreement in the submucosal distortion scores between the 2 experts was .148 for all photographs and .214 for the ORISE cases (overall minimal agreement).

CONCLUSIONS

ORISE can cause submucosal distortion in the region of EMR scars when they are viewed at follow-up. Such distortions must not be mistaken for submucosal tumor growth.

Randomized controlled trial investigating use of submucosal injection of EverLift™ in rates of complete resection of non-pedunculated 4-9 mm polyps

INTRODUCTION

Currently, cold snare polypectomy (CSP) without submucosal injection is recommended for removing polyps < 10 mm. Use of viscous submucosal agents has not been previously evaluated in CSP. We investigate the potential role of EverLift™ (GI Supply, Pennsylvania) in CSP.

METHODS

The study is a single-center prospective randomized non-inferiority clinical trial evaluating CSP of non-pedunculated 4-9 mm polyps, with or without submucosal injection of EverLift™. Patients 18-80 years of age presenting for colonoscopy were recruited. Eligible polyps underwent block randomization to CSP with or without EverLift™. Following CSP, two biopsies were performed at the CSP site margin. The primary non-inferiority outcome was complete resection rate, defined by absence of residual polyp in the margin biopsies (non-inferiority margin -10%).

RESULTS

A total of 291 eligible polyps underwent CSP, with 142 removed using EverLift™. There was similar polyp size and distribution of pathology between the two groups. Overall, there was a low rate of positive margins with (1.4%) or without submucosal injection (2.8%), with no significant difference in complete resection (difference 1.28%, 95% CI: -2.66 to 5.42%), demonstrating non-inferiority of EverLift™ injection. Use of EverLift™ significantly increased CSP time (109.8 vs 38.8 s, p < 0.0001) and frequency of use of hemostatic clips (13.4 vs 3.6%, p = 0.002).

CONCLUSION

Submucosal injection of EverLift™ was non-inferior to CSP of 4-9 mm polyps without injection and increased time for resection as well as use of hemostatic clips to control acute bleeding. Our results suggest that polypectomy of 4-9 mm polyps can be safely performed without submucosal injection of EverLift™.

New Kids on the Block

CONTEXT.—

With the increasing development and use of iatrogenic agents, pathologists are encountering more novel foreign materials in retrieved gastrointestinal specimens. These colorful and unusual-appearing foreign materials can pose a diagnostic dilemma to those unaware of their morphology, especially if the relevant clinical history is lacking.

OBJECTIVE.—

To discuss the histopathologic features, clinical scenarios and significance, and differential diagnosis of relatively recently described, yet quickly expanding, family of iatrogenic agents that can present as foreign materials in gastrointestinal specimens-pharmaceutical fillers (crospovidone and microcrystalline cellulose), submucosal lifting agents (Eleview and ORISE), lanthanum carbonate, hydrophilic polymers, OsmoPrep, yttrium 90 microspheres (SIR-Sphere and TheraSphere), and resins (sodium polystyrene sulfonate, sevelamer, and bile acid sequestrants).

DATA SOURCES.—

We collate the findings of published literature, including recently published research papers, and authors' personal experiences from clinical sign-out and consult cases.

CONCLUSIONS.—

Correct identification of these iatrogenic agents is important because the presence of some novel agents can explain the histopathologic findings seen in the background specimen, and specific novel agents can serve as diagnostic clues to prompt the pathologist to consider other important and related diagnoses. Awareness of even biologically inert agents is important for accurate diagnosis and to avoid unnecessary and expensive diagnostic studies.

Histologic mimics and diagnostic pitfalls of gastrointestinal endoscopic lifting media, ORISE™ gel and Eleview®

Synthetic lifting media, ORISE™ gel and Eleview®, are increasingly used in gastrointestinal endoscopy, but neither comparative features nor pitfalls are well-established. Media histopathology, morphologic mimics, and complications are described, along with helpful stains and endoscopist media preference. A 3-year retrospective search was performed. A total of 123 cases (108 endoscopies and 15 subsequent surgeries) were identified. ORISE gel was used in 86 (79.6%), Eleview in 20 (13.9%), and others in 7 (6.5%). ORISE gel was histologically identified in 58.1% (n = 50) of endoscopic specimens and all 15 resections. Eleview media were not detected histologically. ORISE gel mimicked mucin in hematoxylin and eosin-stained biopsies, concerning for adenocarcinoma misdiagnosis and/or upstaging, but did not stain for mucin. Acid-fast bacterial staining highlights ORISE gel for specific and definitive identification. In resections, ORISE evolves into an amorphous eosinophilic material, often with exuberant giant cell reaction and transmural bowel penetration. Polyp formation leads to polypectomy in one patient, and operative lesions concerning for adenocarcinoma resulted in frozen sections in two patients. ORISE gel mimics mucin, malignant masses, amyloid, pulse granulomata, elastofibromas, and infectious granulomata. No significant endoscopist media preference was identified. Recognition of ORISE gel in tissues eliminates multiple pitfalls. Eleview was not detectable, yielded none of the pitfalls seen with ORISE gel, and, on our survey, has equivalent endoscopist acceptance. In this largest published series to date, Eleview is clearly preferable to ORISE gel.

Endoscopic mucosal resection of large colonic laterally spreading tumors using a dedicated viscous solution for submucosal injection (ORISE gel): a short case series (with video)

OBJECTIVE

Endoscopic mucosal resection (EMR) of large (>20 mm) laterally spreading tumors (LSTs) was usually rescheduled to guarantee experienced operator and enough endoscopic schedule time. The use of viscous solutions allows a reduction in repeated injections, snare resections and procedural time. The aim was to describe the outcome of EMR of large LSTs performed at the time of index colonoscopy, using ORISE gel (Boston Scientific).

METHODS

A retrospective analysis was performed retrieving patients who underwent EMR of large colonic LSTs at the time of index colonoscopy. EMR was performed after dynamic injection of ORISE gel to create a submucosal cushion. Procedural parameters, together with pathological and endoscopic outcomes, were analyzed.

RESULTS

Five patients [three males, median age 65 (45-70) years] were included. Median LST size was 35 mm (25-40). Median procedure time was 8 min (range 3-13). En bloc resection was achieved in one out of five cases; four out of five were planned as piecemeal resections. A median of 10 mL (10-20) of viscous solution was injected. R0 resection was achieved in the single case who underwent en bloc EMR, whereas it was not assessable in the case of piecemeal resections. One self-limiting bleeding was observed.

CONCLUSION

The use of ORISE gel allows a well-tolerated and rapid performance of EMR of large colonic LSTs even at the time of index colonoscopy. In our opinion, in these specific situations, the use of viscous solutions is advisable and also affordable.

Histologic changes caused by injection of a novel submucosal lifting agent for endoscopic resection in GI lesions

BACKGROUND AND AIMS

ORISE Gel is a recently introduced, U.S. Food and Drug Administration-approved submucosal lifting agent used in endoscopic resection of GI lesions. Histologically evident gel deposits in resected specimens may pose a potential diagnostic pitfall. To aid in recognition of this procedure-related artifact, we report the largest histologic series of ORISE Gel in endoscopic and surgical resection specimens to date.

METHODS

Fifty-eight EMR/endoscopic submucosal dissection (ESD) specimens with ORISE Gel injection and 5 interval surgical resection specimens with previous ORISE Gel injection were included. Patient demographics and endoscopy reports were obtained. Histologic slides from all cases were reviewed. Histochemical stains were performed on select cases.

RESULTS

Fifty-one EMR and 7 ESD specimens were identified. In 51 of 58 (88%) endoscopic resection specimens, amorphous, pale blue-gray, finely granular material was evident in the submucosa, as well as focally within the mucosa in 4 cases. Most cases showed homogeneous near-complete filling of the submucosa with this material, whereas a few demonstrated areas of condensation and retraction. Mucicarmine and periodic acid-Schiff stains were negative for mucin. Interval surgical resection specimens revealed extensive deposition of dense, eosinophilic material with associated multinucleated giant cells in the submucosa in all cases, with transmural extension in 3 cases.

CONCLUSION

ORISE Gel injection during endoscopic resection of GI lesions results in deposition of amorphous, blue-gray material seen in histologic sections, whereas interval surgical resection specimens demonstrate dense, eosinophilic material with an associated giant cell reaction. Awareness of these artifacts will help avoid misinterpretation of their presence as pathologic findings.

Features of endoscopic procedure site reaction associated with a recently approved submucosal lifting agent

Endoscopic resection techniques, such as endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD), are frequently aided by injection of submucosal lifting solutions that create a plane for dissection and protect deeper mural layers. ORISE™ gel is a recently approved synthetic lifting solution that produces a localized inflammatory reaction associated with retained gel at the injection site. We describe a series of six cases of ORISE™-associated inflammatory lesions in patients who underwent endoscopic resections. Deposits comprised pale fibrillary or hyalinized eosinophilic material, depending on their age. All cases were associated with an inflammatory reaction composed of foreign-body giant cells and scattered eosinophils. ORISE™ gel extended laterally and deeply beyond residual tumors in all cases. Histochemically, the material proved to be negative for Congo Red, and mucicarmine, faint blue with Alcian blue, but positive for PAS and PAS-D. It stained blue with trichrome. Such deposits were absent in cases, wherein other widely-available lifting solutions were used. We compared ORISE™ deposits to histologically similar extracellular deposits, namely amyloid and pulse granulomata. Unlike ORISE™ material, amyloid deposits appear as waxy, more densely eosinophilic material, and stain positive with Congo Red. Amyloid demonstrated prominent intramucosal and perivascular distributions, features not seen in this series of ORISE™ deposits. Hyalinized pulse granulomata showed strong overlap with ORISE™ deposits, since they also comprise eosinophilic material associated with giant cell reaction. On the other hand, they form ribbons of glassy material in circumscribed lobules, unlike the ill-defined ORISE™ deposits. In summary, we describe the pathologic findings at injection sites in patients who underwent endoscopic procedures aided by the recently approved lifting agent, ORISE™. Pathologists should be aware of its appearance and associated reaction to avoid confusion with other common extracellular deposits seen in the gastrointestinal tract.