A novel device for ablation of abnormal esophageal mucosa (with video)

Safety and efficacy of liquid nitrogen spray cryotherapy in Barrett's neoplasia - a comprehensive review and meta-analysis

Background and study aims  Barrett's esophagus (BE) is a precursor condition to esophageal adenocarcinoma (EAC), resulting in transformation of the squamous epithelium of distal esophagus to columnar-lined epithelium with intestinal metaplasia (IM). Liquid nitrogen spray cryotherapy (LNSC) is a non-contact method of BE eradication and has been used both as primary and salvage therapy. We conducted a systematic review and meta-analysis to assess the safety and efficacy of LNSC. Methods  We searched multiple databases from inception through December 2021 to identify studies on use of LNSC for Barrett's neoplasia. Pooled estimates were calculated using random-effects model and results were expressed in terms of pooled proportions with relevant 95 % confidence intervals (CIs) of complete eradication (CE) of dysplasia(D), high grade dysplasia (HGD) and IM. Results  Fourteen studies with 707 patients were included in our final analysis. Overall pooled rates of CE-D, CE-HGD and CE-IM were 80.8 % (CI 77.4-83.8; I ² 62), 90.3 % (CI 85.2-93.7; I ² 33) and 55.8 % (CI 51.7-59.8; I ² 73) with follow up ranging from 4.25 months to 69.7 months. In patients with follow up beyond 24 months, the rates of CE-D and CE-IM were 83.6 % (CI 77.6-88.2; I ² 60) and 54.7 % (CI 47.6-61.6; I ² 81). Among LNSC naïve patients with prior history of endoscopic resection, the rates were 79.9 % (CI 73.3-85.2; I ² 50) and 67.1 % (CI 59.5-73.8; I ² 0). Pooled rate of therapeutic failures, defined as lack of response to LNSC therapy, was 23.6 % (CI 19.4-28.3; I ² 73). Post LNSC strictures and perforation pooled rates were 4 % and 0.8 %, respectively, which are similar to those previously reported for RFA. Conclusions  Our analysis suggests that liquid nitrogen spray cryotherapy is an acceptable treatment for BE in both ablation naïve and experienced patients.

Comparative outcomes of radiofrequency ablation and cryoballoon ablation in dysplastic Barrett's esophagus: a propensity score-matched cohort study

BACKGROUND AND AIMS

Strong evidence supports the use of radiofrequency ablation (RFA) in the management of dysplastic/neoplastic Barrett's esophagus (BE). Recently, the efficacy of the cryoballoon ablation (CBA) system was demonstrated in multicenter cohort studies. We aimed to assess the comparative effectiveness and safety of these 2 ablation modalities for endoscopic eradication therapy (EET) in a cohort study.

METHODS

Data were abstracted on patients with dysplastic BE or intramucosal carcinoma undergoing EET using RFA or CBA as the primary ablation modality at 2 referral centers. The primary outcome was the rate of complete remission intestinal metaplasia (CRIM). Secondary outcomes were rates of complete remission of dysplasia (CRD) and adverse events. Cox proportional hazards models and propensity scored-matched analyses were conducted to compare outcomes.

RESULTS

Three hundred eleven patients (CBA, 85 patients; RFA, 226 patients) with a median follow-up of 1.5 years (interquartile range, .8, 2.5) in the RFA group and 2.0 years (interquartile range, 1.3, 2.5) in the CBA group were studied. On multivariable analyses, the chances of reaching CRD and CRIM were not influenced by ablation modality. Propensity score-matched analysis revealed a comparable chance of achieving CRIM (CBA vs RFA: hazard ratio, 1.24; 95% confidence interval, .79-1.96; P = .35) and CRD (CBA vs RFA: hazard ratio, 1.19; 95% confidence interval, .82-1.73; P = .36). The CBA group had a higher stricture rate compared with the RFA group (10.4% vs 4.4%, P = .04).

CONCLUSIONS

Histologic outcomes of EET using CBA and RFA for dysplastic BE appear to be comparable. A randomized trial is needed to definitively compare outcomes between these 2 modalities.

Barrett's Esophagus and Intestinal Metaplasia

Intestinal metaplasia refers to the replacement of the differentiated and mature normal mucosal epithelium outside the intestinal tract by the intestinal epithelium. This paper briefly describes the etiology and clinical significance of intestinal metaplasia in Barrett’s esophagus. This article summarizes the impact of intestinal metaplasia on the diagnosis, monitoring, and treatment of Barrett’s esophagus according to different guidelines. We also briefly explore the basis for the endoscopic diagnosis of intestinal metaplasia in Barrett’s esophagus. The identification techniques of goblet cells in Barrett’s esophagus are also elucidated by some scholars. Additionally, we further elaborate on the current treatment methods related to Barrett’s esophagus.

Initial multicenter experience with nitrous oxide cryoballoon for treatment of flat duodenal adenomas (with video)

BACKGROUND AND AIMS

EMR is the preferred endoscopic therapy for duodenal adenomas (DAs) but is associated with an overall adverse event rate of 26%. Cryotherapy using a Cryoballoon Focal Ablation System (CbFAS) can safely and effectively eradicate esophageal intestinal metaplasia. We report our first experience with cryoballoon ablation for treatment of flat DAs.

METHODS

This was an American, multicenter, retrospective study involving 5 centers. DAs (Paris 0-IIa and 0-IIb) were treated with nitrous oxide for 5 to 12 seconds using CbFAS. Follow-up EGD was performed at 3 to 12 months.

RESULTS

Seventeen DAs (mean size, 22.7 ± 14.3 mm; 12 tubular, 5 tubulovillous) from 13 patients (mean age, 66.5 ± 9.99 years; 61.5% males) were included in the study. Thirteen of 17 DAs (76.5%) had failed previous treatment, and 4 of 17 (23.5%) were treatment naÏve. All procedures were technically successful and achieved a >50% decrease in size after cryoballoon ablation There was no increase in size or progression of disease for any lesions. Overall, treatment was completed in 15 of 17 patients, and recurrence-free survival was achieved in 12 of 17 (71%) after a median follow-up of 15.5 months (interquartile range [IQR], 6.8-19.4). The median cryoablation time per polyp was 4 minutes (IQR, 1-7.5 minutes), and the median total procedure time was 25 minutes (IQR, 22-30.5 minutes). There were no intra- or postprocedural adverse events.

CONCLUSIONS

Nitrous oxide cryoballoon ablation of nonpolypoid DAs is feasible, with promising safety and efficacy.

Multifocal Cryoballoon Ablation for Eradication of Barrett's Esophagus-Related Neoplasia: A Prospective Multicenter Clinical Trial

INTRODUCTION

Ablation of Barrett's esophagus (BE) is the preferred approach for the treatment of neoplasia without visible lesions. Limited data on cryoballoon ablation (CBA) suggest its potential clinical utility. We evaluated the safety and efficacy of CBA in a multicenter study of patients with neoplastic BE.

METHODS

In a prospective clinical trial, 11 academic and community centers recruited consecutive patients with BE of 1-6 cm length and low-grade dysplasia, high-grade dysplasia (HGD), or intramucosal adenocarcinoma (ImCA) confirmed by central pathology. Patients with symptomatic pre-existing strictures or visible BE lesions had dilation or endoscopic mucosal resection (EMR), respectively, before enrollment. A nitrous oxide cryoballoon focal ablation system was used to treat all visible columnar mucosa in up to 5 sessions. Study end points included complete eradication of all dysplasia (CE-D) and intestinal metaplasia (CE-IM) at 1 year.

RESULTS

One hundred twenty patients with BE with ImCA (20%), HGD (56%), or low-grade dysplasia (23%) were enrolled. In the intention-to-treat analysis, the CE-D and CE-IM rates were 76% and 72%, respectively. In the per-protocol analysis (94 patients), the CE-D and CE-IM rates were 97% and 91%, respectively. Postablation pain was mild and short lived. Fifteen subjects (12.5%) developed strictures requiring dilation. One patient (0.8%) with HGD progressed to ImCA, which was successfully treated with EMR. Another patient (0.8%) developed gastrointestinal bleeding associated with clopidogrel use. One patient (0.8%) had buried BE with HGD in 1 biopsy, not confirmed by subsequent EMR.

DISCUSSION

In patients with neoplastic BE, CBA was safe and effective. Head-to-head comparisons between CBA and other ablation modalities are warranted (clinicaltrials.gov registration NCT02514525).

Cryoballoon ablation for treatment of patients with refractory esophageal neoplasia after first line endoscopic eradication therapy

Background and study aims  Cryoablation with the Cryoballoon device is a novel ablative therapy that uses cycles of freezing and thawing to induce cell death. This single-center prospective study evaluated the feasibility of the focal cryoablation device for the treatment of areas of refractory esophageal neoplasia in patients who had undergone first line endoscopic eradication therapy (EET). Complete remission of dysplasia (CR-D) and complete remission of intestinal metaplasia (CR-IM) at first follow-up endoscopy, durability of disease reversal, rates of stenosis and adverse events were studied. Patients and methods  Eighteen cases were treated. At baseline, nine patients had low-grade dysplasia (LGD), six had high-grade dysplasia (HGD) and three had intramucosal carcinoma (IMC). Median length of dysplastic Barrett's esophagus (BE) treated was 3 cm. The median number of ablations per patient was 11. Each selected area of visible dysplasia received 10 seconds of ablation. One session of cryoablation was performed per patient. Biopsies were performed at around 3 months post-ablation. Results  CR-D was achieved in 78 % and CR-IM in 39 % of patients. There were no device malfunction or adverse events. Stenosis was noted in 11 % of cases. At a median follow up of 19-months, CR-D was maintained in 72 % of patients and CR-IM in 33 %. Conclusions  Cryoablation appears to be a viable rescue strategy in patients with refractory neoplasia. It is well tolerated and successful in obtaining CR-D and CR-IM in patients with treatment-refractory BE. Further trials of dosimetry, efficacy and safety in treatment-naïve patients are underway.

Safety and effectiveness of balloon cryoablation for treatment of Barrett's associated neoplasia: systematic review and meta-analysis

Background and study aims  Balloon cryoablation (BC) is a novel procedure for endoscopic ablation of Barrett's esophagus (BE- associated neoplasia. We performed a meta-analysis to assess the feasibility, effectiveness, and safety of BC for treatment of BE neoplasia. Patients and methods  Several databases were searched for relevant articles (PubMed, Web of Science, Google Scholar, EMBASE) as well as abstracts of recent gastroenterology meetings. Data extraction was performed by two investigators using standardized forms, including age, gender, length of BE segment, prior treatments, procedural time and number ablation sessions, technical feasibility, adverse events, and eradication rates of intestinal metaplasia (CE-IM) and dysplasia (CE-D) at follow-up. Quality of the studies was assessed using a modified Newcastle Ottawa Scale. Results  Seven studies met inclusion criteria for a total of 548 ablation sessions in 272 patients. The most common histopathology reported prior to BC was high-grade dysplasia (n = 131), followed by low-grade dysplasia (n = 75), and intramucosal adenocarcinoma (n = 52). The pooled rate for technical feasibility was 95.8 % (95 % CI: 93.6-97.5 %; I 2  = 13.2 %; P  = 0.3). Pooled rates of CE-IM and CE-D were 85.8 % (95 % CI: 77.8-92.2 %, I 2  = 55.5 %; p = 0.04) and 93.8 % (95 % CI: 85.5-98.7 %, I 2  = 74.2 %; P  = 0.001), respectively. The overall adverse event (AE) rate was 12.5 % (34 out of 272 patients), of which stricture formation was the most common (5.8 %), followed by mucosal laceration (0.7 %), perforation (0.4 %), and bleeding (0.4 %). All AEs were successfully managed endoscopically. Conclusion  This meta-analysis suggests that BC is a safe and effective ablative technique for treatment of BE neoplasia; future prospective comparative trials are needed to corroborate these initial findings.

Endoscopic therapy for confirmed low-grade dysplasia in Barrett's esophagus

Barrett's esophagus (BE) is a premalignant condition characterized by replacement of the esophageal lining with metastatic columnar epithelium. To date, the management in case of confirmed low-grade dysplasia (LGD) remains controversial. In this article we summarize the available endoscopic options and their results in terms of efficacy and safety in the treatment of confirmed LGD in BE.

Focal cryoballoon versus radiofrequency ablation of dysplastic Barrett's esophagus: impact on treatment response and postprocedural pain

BACKGROUND AND AIMS

Radiofrequency ablation (RFA) is safe and effective for eradicating Barrett's esophagus (BE) but is associated with significant postprocedural pain. Alternatively, balloon-based focal cryoablation (CRYO) has recently been developed, which preserves the extracellular matrix and might therefore be less painful. Although data for CRYO are still limited, uncontrolled studies suggest comparable safety and efficacy to RFA in eradicating limited BE areas. Therefore, secondary endpoints such as pain might become decisive for treatment selection. We aimed to compare efficacy and tolerability between focal CRYO and RFA.

METHODS

We identified BE patients undergoing focal ablation (either RFA or CRYO) of all visible BE from our prospective cohort in 2 Dutch referral centers. After ablation, patients completed a 14-day digital diary to assess chest pain (0-10), dysphagia (0-4), and analgesics use. A follow-up endoscopy was scheduled after 3 months to assess the BE surface regression (blindly scored by 2 independent BE expert endoscopists). Outcomes were BE surface regression; 14-day cumulative scores (area under the curves [AUCs]) for pain, dysphagia, analgesics, and peak pain.

RESULTS

We identified 46 patients (20 CRYO, 26 RFA) with similar baseline characteristics. The BE regression was comparable (88% vs 90%, P = .62). AUCs for pain, dysphagia, and analgesics were significantly smaller after CRYO versus RFA (all P < .01). Peak pain was lower after CRYO (visual analog scale 2 vs 4, P < .01), and the duration of pain was also shorter after CRYO (2 vs 4 days, P < .01). CRYO patients used analgesics for 2 days versus 4 days for RFA (P < .01).

CONCLUSIONS

In this multicenter, nonrandomized cohort study, we found no differences in efficacy after a single treatment with CRYO and RFA for short-segment BE. Patients reported less pain after CRYO as compared with RFA. Moreover, CRYO patients used fewer analgesics. Our results suggest a different pain course favoring CRYO over RFA, but a randomized trial is needed for definitive conclusions. (Clinical trial registration number: NCT02249975.).

Multifocal nitrous oxide cryoballoon ablation with or without EMR for treatment of neoplastic Barrett's esophagus (with video)

BACKGROUND AND AIMS

Endoscopic cryotherapy can eradicate neoplastic Barrett's esophagus (BE). A new contact cryoballoon focal ablation system (CbFAS)) freezes esophageal mucosa with nitrous oxide. We studied the safety and efficacy of CbFAS for complete eradication of neoplastic Barrett's esophagus.

METHODS

In a prospective clinical trial, consecutive BE patients with confirmed neoplasia (low-grade dysplasia [LGD], high-grade dysplasia [HGD], and/or intramucosal adenocarcinoma [ImCA]), at least 1 cm of BE, with or without prior ablation, were treated with a dose 10 seconds of spray per site. EMR was performed for nodular lesions. Treatments were repeated every 10 to 12 weeks until complete eradication, with a maximum of 5 treatments. Primary outcomes were complete eradication of all dysplasia (CE-D) and complete eradication of intestinal metaplasia (CE-IM) at 1 year (intention-to-treat analysis).

RESULTS

Forty-one assessable patients (22 treatment naive, 19 previously ablated) with LGD (n = 13), HGD (n = 23), or ImCA (n = 5) were treated. The median procedure time was 30 minutes. The median number of ablation procedures for CE-IM was 3 (interquartile range, 2-4). Overall 1-year CE-D and CE-IM rates were 95% and 88%, respectively. CE-D rate was significantly lower (67%) in those with ultra-long BE compared with those with <8 cm (100%, P = .02). Median pain scores were zero at day 1. Four patients (9.7%) developed mild dysphagia from stenoses requiring dilation. One patient on aspirin developed upper GI bleeding that did not require therapy.

CONCLUSIONS

Multifocal nitrous oxide cryotherapy using CbFAS is a promising, highly effective, and safe endoscopic treatment for primary or rescue therapy of BE-associated neoplasia and IM. (Clinical trial registration number: NCT02534233.).

Nitrous oxide cryotherapy for treatment of esophageal squamous cell neoplasia: initial multicenter international experience with a novel portable cryoballoon ablation system (with video)

BACKGROUND AND AIMS

Early esophageal squamous cell neoplasia (ESCN) can be successfully treated by EMR, endoscopic submucosal dissection (ESD), or radiofrequency ablation. A new portable, battery-powered cryotherapy system using nitrous oxide (cryoballoon focal ablation system [CbFAS]) has been used for Barrett's esophagus. It consists of a small hand-held device containing liquid nitrous oxide, which converts to gas within a low-pressure-compliant through-the-scope balloon and freezes targeted mucosa in contact with the balloon. This study evaluated the feasibility of endoscopic eradication of early ESCN with the CbFAS.

METHODS

Patients with early ESCN (defined as low-grade intraepithelial neoplasia [LGIN], high-grade intraepithelial neoplasia [HGIN], or early T1 squamous mucosal cancer) were treated with the CbFAS. After chromoendoscopy, all Lugol's unstained lesions (USLs) were targeted with 8, 10, or 12 seconds of ice per site, and treatment was repeated until biopsy samples demonstrated eradication of ESCN. Postprocedure adverse events were recorded.

RESULTS

Ten patients (4 men; median age, 69.5 years) with LGIN (n=2), HGIN (n=7), or esophageal squamous cell carcinoma (ESCC; n=1, after EMR) in 24 USLs were treated. The median maximum diameter of the largest USL was 1.5 cm (interquartile range, 1-2 cm), and median total length of all neoplastic USLs was 2 cm (range, 1-10 cm). Patients with focal disease received a median of 2 cryoablations, whereas 4 patients with large and/or multifocal circumferential neoplasia had 6 to 12 ablations per procedure. The median procedure time was 34 minutes (range, 18-57 minutes). Treatment was completed in all patients. No major adverse events occurred. Four patients developed mild self-limited chest pain requiring narcotic analgesics immediately after the procedure. Two patients who received circumferential ablation developed a stricture responding to dilation, with no recurrence. Complete endoscopic and pathologic response was achieved in all patients at 3 months. One year follow-up biopsy specimens in 7 patients showed no USL or ESCN. All patients were disease free at last visit, with a median follow-up time of 10.7 months (interquartile range, 4-14 months).

CONCLUSIONS

We report the first application of nitrous cryoballoon ablation for curative treatment of early primary or recurrent ESCN. Our initial experience suggests that efficacy is high and the safety profile is reasonable. Prospective trials are needed to optimize cryogen dosimetry and assess safety and efficacy.

Endoscopic Management of Early Adenocarcinoma and Squamous Cell Carcinoma of the Esophagus: Screening, Diagnosis, and Therapy

Because the esophagus is easily accessible with endoscopy, early diagnosis and curative treatment of esophageal cancer is possible. However, diagnosis is often delayed because symptoms are not specific during early stages of tumor development. The onset of dysphagia is associated with advanced disease, which has a survival at 5 years lower than 15%. Population screening by endoscopy is not cost-effective, but a number of alternative imaging and cell analysis technologies are under investigation. The ideal screening test should be inexpensive, well tolerated, and applicable to primary care. Over the past 10 years, significant progress has been made in endoscopic diagnosis and treatment of dysplasia (squamous and Barrett's), and early esophageal cancer using resection and ablation technologies supported by evidence from randomized controlled trials. We review the state-of-the-art technologies for early diagnosis and minimally invasive treatment, which together could reduce the burden of disease.

Optical coherence tomography in gastroenterology: a review and future outlook

Optical coherence tomography (OCT) is an imaging technique optically analogous to ultrasound that can generate depth-resolved images with micrometer-scale resolution. Advances in fiber optics and miniaturized actuation technologies allow OCT imaging of the human body and further expand OCT utilization in applications including but not limited to cardiology and gastroenterology. This review article provides an overview of current OCT development and its clinical utility in the gastrointestinal tract, including disease detection/differentiation and endoscopic therapy guidance, as well as a discussion of its future applications.

Cryotherapy for Barrett's Esophagus

Cryotherapy or cryoablation involves the freezing of tissues to destroy unwanted tissue or to control bleeding. Endoscopic cryotherapy has been developed for gastrointestinal application by through-the-scope noncontact delivery of compressed carbon dioxide gas or liquid nitrogen (cryospray) or contact balloon cryoablation. The mechanism of cryotherapy ablative effects includes immediate injury as well as coagulation necrosis occurring over several hours and days, unlike heat-based thermal ablation. This article reviews the basis, technique, safety, efficacy, and durability for the use of endoscopic cryotherapy in Barrett's esophagus and esophageal adenocarcinoma.

Circumferential cryoablation in a strictured esophagus: a feasibility and dose-finding study in a porcine model after inducing stenosis by endoscopic mucosal resection

In the treatment of early esophageal Barrett's neoplasia, radiofrequency ablation may be hindered by stenosis due to prior endoscopic resection (ER). The flexible balloon-based circumferential CryoBalloon Ablation System (CBAS) may overcome this problem by the conformability of the compliant balloon which might enable circumferential cryoablation in a stenosis. The aim of the current study was to evaluate the feasibility of the CBAS as well as the dose-response effect of cryoablation in a strictured esophagus model. In six pigs, a stenosis was induced by ER (3 cm in length, 75% of circumference) in the proximal, mid, and distal esophagus. After 28 days, cryoablation with the CBAS was performed, with the length of ablation time (6, 8, or 10 seconds) randomly assigned per stricture location within the esophagus. Four days post-ablation, the esophagi were harvested for histopathological assessment of the percentage of the total circumference affected by cryoablation and the maximum depth of necrosis. At 28 days, all 18 ER areas had transformed into strictures with ±50% of its original diameter remaining. In 9 of 18 strictures, more than one attempt for cryoablation was necessary due to displacement of the balloon. Histopathological evaluation showed a wide range in circumferential uniformity (0-100%) and maximum necrosis depth (epithelium to external proper muscle layer) of cryoablation, both independent of ablation times. Deepest ablation effects were seen at the center of the resection-induced scar. This first generation CryoBalloon Focal Ablation System was not feasible for ablation within severe stenoses, since it results in inconsistent circumferential uniformity of cryoablation with subsequent differences in depth of ablation. Further research with a next generation CBAS in a more realistic stricture model is warranted.