Cryotherapy in the management of esophageal dysplasia and malignancy

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.

Post-ablation lymphocytic esophagitis in Barrett esophagus with high grade dysplasia or intramucosal carcinoma

In patients who have undergone ablation therapy for treatment of Barrett's esophagus with dysplasia, histologic features of eosinophilic esophagitis, but not lymphocytic esophagitis, have been described. We evaluated for histologic evidence of eosinophilic esophagitis and lymphocytic esophagitis and correlated with endoscopic findings in this population. A single-institution Barrett's esophagus registry was searched for patients who had received radiofrequency ablation, cryotherapy, or both for treatment of Barrett's esophagus with dysplasia. Clinical and endoscopic data were collected and biopsies were reviewed for inflammation and reactive changes at three time points: pre-intervention, first surveillance after ablation therapy, and most recent surveillance. Of the 173 patients initially identified, 102 met the inclusion criteria. Intraepithelial eosinophils were increased at first surveillance (60%, P=0.096) and last surveillance (69%, P=0.048) compared with pre-intervention (50%), although histologic evidence of post-ablation eosinophilic esophagitis was not significant. Prevalence of lymphocytic esophagitis was significantly higher at first surveillance (17%, P=0.02) and at last surveillance (43%, P<0.001), compared with pre-intervention (7%). Smoking, hyperlipidemia, and cryotherapy were identified as independent risk factors for developing histologic lymphocytic esophagitis. This is the first report that histologic evidence of lymphocytic esophagitis increased over time in patients undergoing ablation for Barrett's esophagus with dysplasia. Though the pathophysiology of lymphocytic esophagitis remains unknown, patients in our study with a history of smoking, hyperlipidemia, or cryotherapy were more likely to develop post-ablation lymphocytic esophagitis.

Endoscopic management of esophageal cancer after definitive chemoradiotherapy

BACKGROUND

Concurrent chemoradiotherapy (CRT) is a potentially curative non-surgical option for locally advanced esophageal cancer, with pathological complete response (CR) ranging from 13 to 49 %. The rate of persistent and recurrent disease within the esophagus remains high at 40-60 %, and treatment of these tumors may improve disease-free survival. The aim of this review is to assess the efficacy of salvage endoscopic therapies for recurrent esophageal cancer.

METHODS

Medline and Embase were searched for relevant studies published in the English-language literature that reported use of endoscopic modalities, including photodynamic therapy (PDT), endoscopic mucosal resection (EMR), and spray cryotherapy, as salvage therapies for esophageal cancer.

RESULTS

A total of 12 studies were identified. In small case series of PDT, CR varied from 20 to 100 %, with 1-, 3-, and 5-year overall survival rates of 65-80, 34-47, and 36 %, respectively. Data from three studies of EMR in squamous cell cancer show CR in 50 % of cases, with 3- and 5-year overall survival of 56-81 and 49 %, respectively. Endoscopic spray cryotherapy has recently been used in this setting with an observed CR of 37.5 %.

CONCLUSIONS

Endoscopic salvage therapies are options for those patients with disease limited to the superficial esophageal wall and those who are unfit to undergo salvage esophagectomy. Widespread application of endoscopic salvage therapies is limited by the lack of awareness and guidelines for endoscopic surveillance post-CRT and limited data on the effectiveness of endoscopic therapies.

Management strategies of Barrett's esophagus

Barrett’s esophagus is a condition resulting from chronic gastro-esophageal reflux disease with a documented risk of esophageal adenocarcinoma. Current strategies for improved survival in patients with Barrett's adenocarcinoma focus on detection of dysplasia. This can be obtained by screening programs in high-risk cohorts of patients and/or endoscopic biopsy surveillance of patients with known Barrett’s esophagus (BE). Several therapies have been developed in attempts to reverse BE and reduce cancer risk. Aggressive medical management of acid reflux, lifestyle modifications, antireflux surgery, and endoscopic treatments have been recommended for many patients with BE. Whether these interventions are cost-effective or reduce mortality from esophageal cancer remains controversial. Current treatment requires combinations of endoscopic mucosal resection techniques to eliminate visible lesions followed by ablation of residual metaplastic tissue. Esophagectomy is currently indicated in multifocal high-grade neoplasia or mucosal Barrett’s carcinoma which cannot be managed by endoscopic approach.

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

BACKGROUND

Current ablation devices for Barrett's esophagus are effective but have significant limitations.

OBJECTIVE

To evaluate a new ablation device.

DESIGN AND SETTING

Laboratory and animal model evaluation of the CryoBalloon, a compliant balloon that is simultaneously inflated and cooled by liquid nitrous oxide delivered by using a small, disposable, handheld unit.

INTERVENTION

Cryoablation of esophageal mucosa was performed in 11 swine. Multiple ablations were created in each animal at various ablation times.

MAIN OUTCOME MEASUREMENTS

Animals were euthanized at 4 days (n = 6) or 28 days (n = 5), and histological assessments were performed. At 4 days, the percentage of esophageal mucosa successfully ablated was measured. At 28 days, the circumference of the esophagus at the center of the ablation zone was measured to assess for stricture formation.

RESULTS

The CryoBalloon was simple to operate, and balloon contact with tissue was easily maintained. As the ablation time was increased from 6 to 12 seconds, the percentage of mucosa ablated increased from below 60% to above 90%. Maximal effect on the mucosa was reached at 12 seconds. Ablation of up to 14 seconds resulted in minimal luminal narrowing. As the ablation duration increased from 14 to 22 seconds, there was progressive stricture formation evident at 28 days. All of the animals tolerated the treatments without difficulty and, regardless of ablation duration, were able to continue oral intake and gain weight after the procedure.

LIMITATIONS

Ablation of normal porcine squamous mucosa may differ from that of human Barrett's esophagus.

CONCLUSION

The CryoBalloon device enables circumferential mucosal ablation in a 1-step process by using a novel, through-the-scope balloon. The maximal effect on the mucosa is achieved with a 12-second application time. Because of its ease of use, this new device merits further study so that we can find its possible role in the treatment of Barrett's esophagus.

Cryotherapy for Barrett's esophagus and esophageal cancer

PURPOSE OF REVIEW

To summarize the recent literature on endoscopic spray cryotherapy for the treatment of Barrett's esophagus and esophageal cancer.

RECENT FINDINGS

Endoscopic spray cryotherapy is a relatively new ablative modality for the treatment of gastrointestinal diseases. Spray cryotherapy rapidly cools tissues by spraying them with either liquid nitrogen or rapidly expanding carbon dioxide gas. Initial, nonrandomized and uncontrolled studies show success rates comparable to other ablative modalities for the treatment of Barrett's esophagus with high-grade dysplasia, with complete eradication of dysplasia seen in 87-96% and complete eradication of intestinal metaplasia in 57-96% of treated patients. In early-stage esophageal cancer, spray cryotherapy appears to have a unique role, eliminating mucosal cancer in 75% of patients, including those who have failed other modalities. Patient tolerance of the procedure is very good. Limitations of current studies include small sample sizes and short durations of follow-up, and further studies are needed to validate the promising early results.

SUMMARY

Endoscopic spray cryotherapy is a promising ablative modality for treatment of Barrett's esophagus and esophageal cancer.

State of the art in the endoscopic imaging and ablation of Barrett's esophagus

Barrett's esophagus is the result of long-term acid reflux and is a precursor to esophageal adenocarcinoma. Surgical resection of the esophagus has been the mainstay of treatment for high grade dysplasia and early cancer. However, recent advances in the endoscopic imaging and ablation technologies have made esophagectomy avoidable in patients with dysplasia and superficial neoplasia. In this article, we review the most relevant endoscopic imaging technologies, such as chromoendoscopy, narrow band and autofluorescence imaging, and confocal laser endomicroscopy. We also review the various endoscopic ablation technologies, such as endoscopic mucosal resection, photodynamic therapy, radiofrequency ablation, and cryotherapy. Finally, we focus on the studies that evaluate the efficacy of these imaging and ablation technologies in finding and eradicating neoplastic Barrett's esophagus.

New endoscopic and surgical treatment options for early esophageal adenocarcinoma

Although the outcome for advanced stage esophageal cancer is poor, the early detection and treatment of early stage disease is usually associated with a much better outcome. Until recently, esophagectomy has been the treatment of choice in fit patients. However, morbidity is significant, and this has encouraged the development of newer endoscopic treatments that preserve the esophagus. These techniques include ablation and mucosal resection. Promising results are described, and endoscopic methods might provide a reasonable alternative for the treatment of early esophageal cancer. However, follow-up remains short and endoscopic treatment does not deal with potential lymphatic spread. Hence, careful selection is required. Minimally invasive techniques for esophageal resection have also been shown to be feasible, although there is only limited evidence that they reduce postoperative morbidity. Better data are still required to demonstrate improved outcomes from endoscopic treatment and minimally invasive esophagectomy.