Cryotherapy in gastrointestinal endoscopy

What Is "Cold" and What Is "Hot" in Mucosal Ablation for Barrett's Oesophagus-Related Dysplasia: A Practical Guide

Over the last two decades, endoscopic eradication therapy has been established as the therapeutic strategy of choice for patients with Barrett's oesophagus-related dysplasia and early oesophageal adenocarcinoma. With a multimodal approach, ablative therapies have been highly effective in achieving remarkable eradication rates of metaplastic epithelium with an acceptable adverse event rate. Among ablative techniques, radiofrequency ablation is currently considered as the first-line option as its efficacy and safety are strongly supported by relevant data. Nevertheless, radiofrequency ablation is costly, and not universally available, or applicable to every situation. Moreover, primary failure and recurrence rates are not negligible. In the last few years, cryotherapy techniques and hybrid argon plasma coagulation have been increasingly assessed as potential novel ablative therapies. Preliminary data have been promising and suggest that they may even have a role as first-line options, alternatively to radiofrequency ablation. The aim of this review is to provide a practical guide for the ablation of Barrett's oesophagus, with emphasis on the different ablative options.

Endoscopic Management of Esophageal Cancer

Advances in technology and improved understanding of the pathobiology of esophageal cancer have allowed endoscopy to serve a growing role in the management of this disease. Precursor lesions can be detected using enhanced diagnostic modalities and eradicated with ablation therapy. Furthermore, evolution in endoscopic resection has provided larger specimens for improved diagnostic accuracy and offer potential for cure of early esophageal cancer. In patients with advanced esophageal cancer, endoluminal therapy can improve symptom burden and provide therapeutic options for complications such as leaks, perforations, and fistulas. The purpose of this review article is to highlight the role of endoscopy in the diagnosis, treatment, and palliation of esophageal cancer.

Outcomes of Radiofrequency Ablation Compared to Liquid Nitrogen Spray Cryotherapy for the Eradication of Dysplasia in Barrett's Esophagus

INTRODUCTION

Current guidelines recommend endoscopic eradication therapy (EET) for Barrett's esophagus (BE) with dysplasia and intramucosal adenocarcinoma using either radiofrequency ablation (RFA) or liquid nitrogen spray cryotherapy (LNSC). The aims of this multicenter study are to compare the rate and number of treatment sessions of RFA vs. LNSC to achieve CE-D and CE-IM and assess outcomes for those who switched therapy.

METHODS

This is a retrospective cohort study of patients with BE undergoing EET. Demographics, baseline variables, endoscopy details, and histology information were abstracted.

RESULTS

One hundred and sixty-two patients were included in this study with 100 patients in the RFA group and 62 patients in the LNSC group. The rate of CE-D and CE-IM did not differ between the RFA group and LNSC group (81% vs. 71.0%, p = 0.14) and (64% vs. 66%, p = 0.78), respectively. The number of sessions to achieve CE-D and CE-IM was higher with LNSC compared to RFA (4.2 vs. 3.2, p = 0.05) and (4.8 vs. 3.5, p = 0.04), respectively. The likelihood of developing recurrent dysplasia was higher among patients who did not achieve CE-IM (12%) compared to those who did achieve CE-IM (4%), p = 0.04. Similar findings were found in those who switched treatment modalities.

DISCUSSION

EET is highly effective in eradication of Barrett's associated dysplasia and neoplasia. Both RFA and LNSC achieved similar rates of CE-D and CE-IM although LNSC required more sessions. Also, achievement of CE-IM was associated with less recurrence rates of dysplasia.

Endoscopic cryotherapy: Indications, techniques, and outcomes involving the gastrointestinal tract

Endoscopic cryotherapy is a technique utilized for the ablation of target tissue within the gastrointestinal tract. A cryotherapy system utilizes the endoscopic application of cryogen such as liquid nitrogen, carbon dioxide or liquid nitrous oxide. This leads to disruption of cell membranes, apoptosis, and thrombosis of local blood vessels within the target tissue. Several trials utilizing cryotherapy for Barrett's esophagus (BE) with variable dysplasia, gastric antral vascular ectasia (GAVE), esophageal carcinoma, radiation proctitis, and metastatic esophageal carcinomas have shown safety and efficacy. More recently, liquid nitrogen cryotherapy (cryodilation) was shown to be safe and effective for the treatment of a benign esophageal stricture which was refractory to dilations, steroid injections, and stenting. Moreover, liquid nitrogen cryotherapy is associated with less post procedure pain as compared to radiofrequency ablation in BE with comparable ablation rates. In patients with GAVE, cryotherapy was found to be less tedious as compared to argon plasma coagulation. Adverse events from cryotherapy most commonly include chest pain, esophageal strictures, and bleeding. Gastric perforations did occur as well, but less often. In summary, endoscopic cryotherapy is a promising and growing field, which was first demonstrated in BE, but the use now spans for several other disease processes. Larger randomized controlled trials are needed before its role can be established for these different diseases.

Esophageal ulcer associated with mild hemophilia A: case report

In this paper, we present the case of a 68-year-old male with personal medical history of coagulopathy issues, who presented to our Emergency Room (Emergency County Hospital, Arad, Romania) with bleeding of the superior tract of the digestive system; the case was difficult to manage, thus warranting the intervention of the Department of Gastroenterology. Endoscopy was performed to localize the site of bleeding and to stop the hemorrhage. This procedure was not successful. The patient was transferred to our Intensive Care Unit where different medications, such as proton pump inhibitor, hemostatic agent and prokinetic drugs were administered. Unfortunately, our attempt to stop bleeding failed; this led us to expand our investigation. We focused on a possible hemophilia as the cause of bleeding, which was confirmed as hemophilia A through the coagulometry test after a period of three days. Patient medical history and coagulation test led us to believe that this is a very rare case of a mild hemophilia A. Finally, the correction of Factor VIII deficiency and repeated endoscopic hemostasis clip was able to stop patients bleeding and ensured a favorable clinical evolution of the patient.

Endoscopic therapies for Barrett's esophagus

The management of Barrett's esophagus (BE) has evolved as newer technologies and novel methods are developed. Endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD) are the initial interventions of choice for nodular BE, with ESD reserved for endoscopists highly trained in the technique and for larger lesions that would warrant en bloc resection. Resection should then be followed by ablative therapy, which remains first line in the treatment of BE with dysplasia. Although there is a myriad of ablation techniques available to the endoscopist, this review has found that radiofrequency ablation (RFA) continues to have the most robust safety and efficacy data to support its use despite a relatively high rate of recurrence. Cryotherapy and Hybrid-APC appear to be safe and effective as RFA alternatives, but further trials are still needed to directly compare their outcomes to RFA and ultimately guide changes in treatment decisions.

The effect of formulation morphology on stimuli-triggered co-delivery of chemotherapeutic and MRI contrast agents

Most conventional chemotherapeutics have narrow therapeutic windows, and thus their delivery remains challenging and often raises safety and efficacy concerns. Theranostic platforms, with simultaneous encapsulation of therapeutic and diagnostic agents, have been proposed as next-generation formulations which can overcome this issue. In this work, we used electrohydrodynamic approaches to fabricate core@shell formulations comprising a pH responsive Eudragit L100 shell embedded with superparamagnetic iron oxide nanoparticles (SPIONs), and a thermo-responsive poly(N-isopropylacrylamide) (PNIPAM)/ethyl cellulose core loaded with the model drug carmofur. By varying the weight ratio of core polymer to shell polymer, the morphology of PNIPAM/ethyl cellulose@Eudragit L100 microparticles could be changed from concave to spherical. Smooth cylindrical fibres could also be generated. All the formulations exist as amorphous solid dispersions of drug-in-polymer, with distinct core@shell architectures. The fibres have clear thermo-responsive drug release profiles, while no thermo-responsive properties can be seen with the particles. All the formulations can protect SPIONs from degradation in gastric fluids (pH ∼ 1.5), and around the physiological pH range the materials offer effective and pH-responsive relaxivity. The r₂ values also display clear linear relationships with drug release data, suggesting the potential of using MRI signals to track drug release in vivo. Mathematical equations were established to track drug release in vitro, with very similar experimental and predicted release profiles obtained.

The role of ablation in the treatment of dysplastic Barrett's esophagus

Endoscopic eradication therapy for Barrett's esophagus has been established as an effective management strategy for patients with Barrett's esophagus with dysplasia and early esophageal cancer. Among the endoscopic therapies, ablation techniques such as radiofrequency ablation and cryoablation are effective primary treatment interventions with acceptable low complication rates forming the spectrum of a multimodal approach. Appropriate selection of patients, high-definition endoscopic evaluation, and dedicated histological assessment are important cornerstones to help navigate to the best effective treatment method. Carefully structured surveillance programs and preventive measures will be needed to provide long-term durability for maintaining complete remission.

Endoscopic Approaches to Obesity Management

The field of endoscopic bariatric and metabolic therapy has rapidly evolved from offering endoscopic treatment of weight regain following bariatric surgery to providing primary weight loss options as alternatives to pharmacologic and surgical interventions. Gastric devices and remodeling procedures were initially designed to work through a mechanism of volume restriction, leading to earlier satiety and reduced caloric intake. As the field continues to grow, small bowel interventions are evolving that may have some effect on weight loss but focus on the treatment of obesity-related comorbidities. Future implementation of combination therapy that utilizes both gastric and small bowel interventions offers an exciting option to further augment weight loss and alleviate metabolic disease. This review considers gastric devices and techniques including space-occupying intragastric balloons, aspiration therapy, endoscopic tissue suturing, and plication interventions, followed by a review of small bowel interventions including endoluminal bypass liners, duodenal mucosal resurfacing, and endoscopically delivered devices to create incisionless anastomoses. Expected final online publication date for the Annual Review of Medicine, Volume 73 is January 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Efficacy of Cryotherapy as a Primary Endoscopic Ablation Modality for Dysplastic Barrett's Esophagus and Early Esophageal Neoplasia: A Systematic Review and Meta-Analysis

INTRODUCTION

Cryotherapy is a cold-based ablative therapy used primarily as second line therapy in patients with Barrett's esophagus (BE) who have persistent dysplasia after undergoing endoscopic treatment with radiofrequency ablation (RFA). Few studies have described the use of cryotherapy as a primary treatment modality for dysplastic or neoplastic BE.

AIM

To evaluate the efficacy of cryotherapy as primary treatment of dysplastic and/or neoplastic BE by conducting a systemic review and meta-analysis.

METHODS

A systematic search of Medline, Embase, and Web of Science was performed from January 2000 through March 2020. Articles included were observational studies and clinical trials which included patients who had biopsy confirmed dysplastic or neoplastic BE (i.e., high grade dysplasia (HGD), low grade dysplasia (LGD) or intramucosal adenocarcinoma (ImCA)), underwent ≥1 session of cryotherapy, and had a follow-up endoscopy. Primary outcomes were pooled proportions of patients achieving complete eradication of dysplasia (CE-D) and/or intestinal metaplasia (CE-IM) by using a random effects model.

RESULTS

Fourteen studies making up 405 patients with follow-up ranging from 3-54 months were included. In 13 studies, a total of 321/405 patients achieved CE-D with a pooled proportion of 84.8% (95% confidence interval [CI] 72.2-94.4), with substantial heterogeneity (I² = 88.3%). In 13 studies, a total of 321/405 patients achieved CE-D with a pooled proportion of 84.8% (95% confidence interval [CI] 72.2-94.4), with substantial heterogeneity (I² = 88.3%). Subgroup analysis of only high-quality studies revealed a pooled proportion of CE-D 91.3% (95% CI, 83.0-97.4, I² = 69.5%) and pooled proportion of CE-IM of 71.6% (95% CI, 59.0-82.9, I² = 80.9%). Adverse events were reported in 12.2% patients.

CONCLUSION

Cryotherapy is a safe and effective primary therapy for dysplastic/early neoplastic BE. CE-D and CE-IM rates are comparable to those for other ablation modalities, including RFA. Cryotherapy should be considered for primary therapy of dysplastic BE and early esophageal neoplasia.

Experimental Substantiation of Autoplasma Application as a Haemostatic Agent in Endoscopic Operations in the Digestive Tract

Introduction. In endosurgery of the digestive tract, ‘cellular technologies’ are gaining popularity, including the use of blood components or blood cells with a haemostatic purpose. In this regard, the objective of the study is evaluation of the effectiveness of bleeding control and safety of resection of the hollow organs of the digestive tract in the experimental trauma models of the abdominal organs in laboratory animals.

Materials and methods. The study was conducted in 20 mature male Chinchilla rabbits with the mean body mass of 2450 ± 210 g. All animals were divided into four experimental groups: the control group (without bleeding control); the group that received the infiltration of the wall of a hollow organ with saline; the group in which bleeding was controlled by argon plasma coagulation (APC), and the group wherein animals underwent haemostasis with autoplasma.

Results. In the control group and the physiological saline group, no statistical difference was observed in the time of bleeding control. Autoplasma, due to preventive local administration, is more effective than APC and has a high haemostatic potential.

Conclusion. Autoplasma has been found to be highly effective and safe for bleeding control in the gastrointestinal tract in the experimental model, which has paved the way for new possibilities for operations of various scales, including endoscopic operations.

Management of Barrett’s esophagus with dysplasia refractory to radiofrequency ablation

Radiofrequency ablation (RFA) is very effective for eradication of flat Barrett’s mucosa in dysplastic Barrett’s esophagus after endoscopic resection of raised lesions. However, in a minority of the time, RFA may be ineffective at eradication of the Barrett’s mucosa. Achieving complete eradication of intestinal metaplasia can be challenging in these patients. This review article focuses on the management of patients with dysplastic Barrett’s esophagus refractory to RFA therapy. Management strategies discussed in this review include optimizing the RFA procedure, optimizing acid suppression (with medical, endoscopic, and surgical management), cryotherapy, hybrid argon plasma coagulation, and EndoRotor resection.

Devices for endoscopic hemostasis of nonvariceal GI bleeding (with videos)

BACKGROUND

Endoscopic intervention is often the first line of therapy for GI nonvariceal bleeding. Although some of the devices and techniques used for this purpose have been well studied, others are relatively new, with few available outcomes data.

METHODS

In this document, we review devices and techniques for endoscopic treatment of nonvariceal GI bleeding, the evidence regarding their efficacy and safety, and financial considerations for their use.

RESULTS

Devices used for endoscopic hemostasis in the GI tract can be classified into injection devices (needles), thermal devices (multipolar/bipolar probes, hemostatic forceps, heater probe, argon plasma coagulation, radiofrequency ablation, and cryotherapy), mechanical devices (clips, suturing devices, banding devices, stents), and topical devices (hemostatic sprays).

CONCLUSIONS

Endoscopic evaluation and treatment remains a cornerstone in the management of nonvariceal upper- and lower-GI bleeding. A variety of devices is available for hemostasis of bleeding lesions in the GI tract. Other than injection therapy, which should not be used as monotherapy, there are few compelling data that strongly favor any one device over another. For endoscopists, the choice of a hemostatic device should depend on the type and location of the bleeding lesion, the availability of equipment and expertise, and the cost of the device.

Endoscopic foregut surgery and interventions: The future is now. The state-of-the-art and my personal journey

In this paper, I reviewed the emerging field of endoscopic surgery and present data supporting the contention that endoscopy can now be used to treat many foregut diseases that have been traditionally treated surgically. Within each topic, the content will progress as follows: "lessons learned", "technical considerations" and "future opportunities". Lessons learned will provide a brief background and update on the most current literature. Technical considerations will include my personal experience, including tips and tricks that I have learned over the years. Finally, future opportunities will address current unmet needs and potential new areas of development. The foregut is defined as "the upper part of the embryonic alimentary canal from which the pharynx, esophagus, lung, stomach, liver, pancreas, and part of the duodenum develop". Foregut surgery is well established in treating conditions such as gastroesophageal reflux disease (GERD), achalasia, esophageal diverticula, Barrett's esophagus (BE) and esophageal cancer, stomach cancer, gastric-outlet obstruction, and obesity. Over the past decade, remarkable progress in interventional endoscopy has culminated in the conceptualization and practice of endoscopic foregut surgery for various clinical conditions summarized in this paper. Regarding GERD, there are now several technologies available to effectively treat it and potentially eliminate symptoms, and the need for long-term treatment with proton pump inhibitors. For the first time, fundoplication can be performed without the need for open or laparoscopic surgery. Long-term data going out 5-10 years are now emerging showing extended durability. In respect to achalasia, per-oral endoscopic myotomy (POEM) which was developed in Japan, has become an alternative to the traditional Heller's myotomy. Recent meta-analysis show that POEM may have better results than Heller, but the issue of post-POEM GERD still needs to be addressed. There is now a resurgence of endoscopic treatment of Zenker's diverticula with improved technique (Z-POEM) and equipment; thus, patients are choosing flexible endoscopic treatment as opposed to open or rigid endoscopy options. In regard to BE, endoscopic submucosal dissection (ESD) which is well established in Asia, is now becoming more mainstream in the West for the treatment of BE with high grade dysplasia, as well as early esophageal cancer. In combination with all the ablation technologies (radiofrequency ablation, cryotherapy, hybrid argon plasma coagulation), the entire spectrum of Barrett's and related dysplasia and early cancer can be managed predominantly by endoscopy. Importantly, in regard to early gastric cancer and submucosal tumors (SMTs) of the stomach, ESD and full thickness resection (FTR) can excise these lesions en-bloc and endoscopic suturing is now used to close large defects and perforations. For treatment of patients with malignant gastric outlet obstruction (GOO), endoscopic gastro-jejunostomy is now showing better results than enteral stenting. G-POEM is also emerging as a treatment option for patients with gastroparesis. Obesity has become an epidemic in many western countries and is becoming also prevalent in Asia. Endoscopic sleeve gastroplasty (ESG) is now becoming an established treatment option, especially for obese patients with body mass index between 30 and 35. Data show an average weight loss of 16 kg after ESG with long-term data confirming sustainability. Finally, in respect to endo-hepatology, there are many new endoscopic interventions that have been developed for patients with liver disease. Endoscopic ultrasound (EUS)-guided liver biopsy and EUS-guided portal pressure measurement are exciting new frontiers for the endo-hepatologists.

Cryotherapy in the management of premalignant and malignant conditions of the esophagus

Endoscopic cryotherapy is a relatively new thermal ablative modality used for the treatment of neoplastic lesions of the esophagus. It relies on cycles of rapid cooling and thawing to induce tissue destruction with a cryogen (liquid nitrogen or carbon dioxide) leading to intra and extra-cellular damage. Surgical treatment was once considered the standard therapeutic intervention for neoplastic diseases of the esophagus and is associated with considerable rates of morbidity and mortality. Several trials that evaluated cryotherapy in Barrett’s esophagus (BE) associated neoplasia showed reasonable efficacy rates and safety profile. Cryotherapy has also found applications in the treatment of esophageal cancer, both for curative and palliative intent. Cryotherapy has also shown promising results as salvage therapy in cases refractory to radiofrequency ablation treatment. Cryoballoon focal ablation using liquid nitrogen is a novel mode of cryogen delivery which has been used for the treatment of BE with dysplasia and squamous cell carcinoma. Most common side effects of cryotherapy reported in the literature include mild chest discomfort, esophageal strictures and bleeding. In conclusion, cryotherapy is an effective and safe method for the treatment of esophageal neoplastic processes, ranging from early stages of low grade dysplasia to esophageal cancer.

Endoscopic therapy for Barrett’s esophagus and early esophageal cancer: Where do we go from here?

Since Barrett’s esophagus is a precancerous condition, efforts have been made for its eradication by various ablative techniques. Initially, laser ablation was attempted in non-dysplastic Barrett’s esophagus and subsequently, endoscopic ablation using photodynamic therapy was used in Barrett’s patients with high-grade dysplasia who were poor surgical candidates. Since then, various ablative therapies have been developed with radiofrequency ablation having the best quality of evidence. Resection of dysplastic areas only without complete removal of entire Barrett’s segment is associated with high risk of developing metachronous neoplasia. Hence, the current standard of management for Barrett’s esophagus includes endoscopic mucosal resection of visible abnormalities followed by ablation to eradicate remaining Barrett’s epithelium. Although endoscopic therapy cannot address regional lymph node metastases, such nodal involvement is present in only 1% to 2% of patients with intramucosal adenocarcinoma in Barrett esophagus and therefore is useful in intramucosal cancers. Post ablation surveillance is recommended as recurrence of intestinal metaplasia and dysplasia have been reported. This review includes a discussion of the technique, efficacy and complication rate of currently available ablation techniques such as radiofrequency ablation, cryotherapy, argon plasma coagulation and photodynamic therapy as well as endoscopic mucosal resection. A brief discussion of the emerging technique, endoscopic submucosal dissection is also included.

Nitrous oxide cryotherapy ablation for refractory gastric antral vascular ectasia

Background

Argon plasma coagulation (APC) is typically the first-line therapy for gastric antral vascular ectasia (GAVE). However, many patients are refractory to APC ablation.

Objective

We examined the safety and efficacy of nitrous oxide CryoBalloon cryotherapy ablation for GAVE refractory to APC.

Methods

This is a retrospective review of patients with refractory GAVE treated with the CryoBalloon system. Technical success was defined as successful ablation of the visualized GAVE. Clinical success was defined by transfusion independence and percentage of GAVE that was eradicated.

Results

Twenty-three patients with GAVE were included, of whom 16 patients (70%) had two treatments with the CryoBalloon and seven patients (30%) had one treatment. Technical success was achieved in all patients. At six months, 19/23 (83%) were transfusion independent, while 20/23 (87%) had more than 75% of the GAVE eradicated. Patients were transfused an average of 1.8 units/month one year prior to cryotherapy and an average of 0.3 units/month up to six months post-cryotherapy (p < 0.001). The average increase in mean hemoglobin at six months was 2.55 g/dl. No acute or late adverse events were reported.

Conclusions

CryoBalloon ablation is an efficacious and safe modality for the treatment of GAVE. Prospective studies need to be conducted to determine comparative results to standard therapies.