Emerging indications of endoscopic radiofrequency ablation

Safety and efficacy of endoscopic ultrasound-guided radiofrequency ablation for pancreatic insulinoma: A single-center experience

BACKGROUND/OBJECTIVES

Insulinomas are rare, functioning pancreatic neuroendocrine neoplasms (pNEN), whose gold standard therapy is surgical resection. Endoscopic ultrasound-guided radiofrequency ablation (EUS-RFA) is a recent technique that has emerged as a minimally invasive therapeutic option for patients with pancreatic lesions not eligible for surgery. In this study, we aimed to describe a series of patients with unresectable pancreatic insulinoma treated with EUS-RFA.

METHODS

This is a single-center, retrospective study including all consecutive patients with functioning pancreatic insulinoma undergoing EUS-RFA for surgical unfitness or surgery refusal, between March 2017 and September 2021. Technical success (i.e., complete mass ablation), adverse event rate and severity, clinical and radiologic outcomes (i.e., symptom remission with a normal concentration of blood glucose, and the presence of intralesional necrosis), and post-procedural follow-up were assessed.

RESULTS

A total of 10 patients (mean age: 67.1 ± 10.1years; F:M 7:3) were included. The mean size of insulinoma was 11.9 ± 3.3 mm. Technical success and clinical remission were achieved in 100% of patients. Only one (10%) patient was successfully treated with two RFA sessions. Two procedure-related early adverse events occurred, including two (20%) cases of mild abdominal pain. No major complications were observed. The complete radiologic response within 3 months after EUS-RFA was observed in all patients (100%). After a median follow-up of 19.5 (range12-59) months, symptom remission and persistent euglycemia were assessed in all the patients.

CONCLUSIONS

Data from this case series suggest that EUS-RFA is a feasible and safe therapeutic approach for pancreatic insulinomas in patients unwilling or unable to undergo surgery with medium-term efficacy.

Incidence and outcomes of poor healing and poor squamous regeneration after radiofrequency ablation therapy for early Barrett's neoplasia

BACKGROUND

Endoscopic eradication therapy with radiofrequency ablation (RFA) is effective in most patients with Barrett's esophagus (BE). However, some patients experience poor healing and/or poor squamous regeneration. We evaluated incidence and treatment outcomes of poor healing and poor squamous regeneration.

METHODS

We included all patients treated with RFA for early BE neoplasia from a nationwide Dutch registry based on a joint treatment protocol. Poor healing (active inflammatory changes or visible ulcerations ≥ 3 months post-RFA), poor squamous regeneration (< 50 % squamous regeneration), and treatment success (complete eradication of BE [CE-BE]) were evaluated.

RESULTS

1386 patients (median BE C2M5) underwent RFA with baseline low grade dysplasia (27 %), high grade dysplasia (30 %), or early cancer (43 %). In 134 patients with poor healing (10 %), additional time and acid suppression resulted in complete esophageal healing, and 67/134 (50 %) had normal squamous regeneration with 97 % CE-BE. Overall, 74 patients had poor squamous regeneration (5 %). Compared with patients with normal regeneration, patients with poor squamous regeneration had a higher risk for treatment failure (64 % vs. 2 %, relative risk [RR] 27 [95 % confidence interval [CI] 18-40]) and progression to advanced disease (15 % vs. < 1 %, RR 30 [95 %CI 12-81]). Higher body mass index, longer BE segment, reflux esophagitis, and < 50 % squamous regeneration after baseline endoscopic resection were independently associated with poor squamous regeneration in multivariable logistic regression.

CONCLUSIONS

In half of the patients with poor healing, additional time and acid suppression led to normal squamous regeneration and excellent treatment outcomes. In patients with poor squamous regeneration, however, the risk for treatment failure and progression to advanced disease was significantly increased.

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.

Comparison of portal hypertensive gastropathy and gastric antral vascular ectasia: an update

Portal hypertensive gastropathy (PHG) and gastric antral vascular ectasia (GAVE) are two distinct entities that are frequently mistaken with each other, because they present with similar manifestations. This issue may cause catastrophic outcomes, as each one of them has a unique pathophysiology, thereby making their management approaches completely different. There are clinical clues that help physicians distinguish these two. Direct vision via upper endoscopy is often mandatory to establish the diagnosis, and sometimes biopsy is required. In this review, we sought to discuss different aspects of both conditions and highlight clinical evidence that may help in identifying and managing the disease appropriately.

Development of Radiofrequency Ablation Generator and Balloon-Based Catheter for Microendoluminal Thin-Layer Ablation Therapy Using the Rat Duodenum as a Model of Low-Impedance Tissue

Radiofrequency ablation (RFA) is a routinely used, safe, and effective method for the tissue destruction. Often, in case of its application in malignant conditions, the extent of tissue destruction is insufficient due to the size of the target lesion, as well as due to the risk of heat-induced damage to the surrounding organs. Nevertheless, there are conditions requiring superficial precise-depth ablation with preservation of deeper layers. These are represented, for example, by mucosal resurfacing in case of Barrett's esophagus or treatment of recurrent mucosal bleeding in case of chronic radiation proctitis. Recently, new indications for intraluminal RFA use emerged, especially in the pancreatobiliary tract. In the case of intraductal use of RFA (e.g., biliary and pancreatic tract), there are currently available rigid and needle tip catheters. An expandable balloon-based RFA catheter suitable for use in such small-diameter tubular organs could be of benefit due to possible increase of contact between the probe and the target tissue; however, to prevent excessive tissue damage, a compatible generator suitable for low-impedance catheter/tissue is essential. This project aimed to develop a radiofrequency ablation generator and bipolar balloon-based catheter optimized for the application in the conditions of low-impedance tissue and (micro)endoluminal environment. Subsequent evaluation of biological effect in vivo was performed using duodenal mucosa in Wistar rat representing conditions of endoluminal radiofrequency ablation of low-impedance tissue. Experiments confirming the safety and feasibility of RFA with our prototype devices were conducted.

Endoscopic treatment for gastric antral vascular ectasia

Gastric antral vascular ectasia (GAVE) is one of the uncommon causes of upper gastrointestinal bleeding. Major treatment of GAVE includes pharmacotherapy, endoscopy, and surgery. The efficacy and safety of pharmacotherapy have not been sufficiently confirmed; and surgery is just considered when conservative treatment is ineffective. By comparison, endoscopy is a common treatment option for GAVE. This paper reviews the currently used endoscopic approaches for GAVE, mainly including argon plasma coagulation (APC), radiofrequency ablation (RFA), and endoscopic band ligation (EBL). It also summarizes their efficacy and procedure-related adverse events. The endoscopic success rate of APC is 40-100%; however, APC needs several treatment sessions, with a high recurrence rate of 10-78.9%. The endoscopic success rates of RFA and EBL are 90-100% and 77.8-100%, respectively; and their recurrence rates are 21.4-33.3% and 8.3-48.1%, respectively. Hyperplastic gastric polyps and sepsis are major adverse events of APC and RFA; and Mallory-Weiss syndrome is occasionally observed after APC. Adverse events of EBL are rare and mild, such as nausea, vomiting, esophageal or abdominal pain, and hyperplastic polyps. APC is often considered as the first-line choice of endoscopic treatment for GAVE. RFA and EBL have been increasingly used as alternatives in patients with refractory GAVE. A high recurrence of GAVE after endoscopic treatment should be fully recognized and cautiously managed by follow-up endoscopy. In future, a head-to-head comparison of different endoscopic approaches for GAVE is warranted.

Role of argon plasma coagulation in treatment of esophageal varices

With the development of endoscopic therapy, argon plasma coagulation (APC) has been widely used by endoscopists. It has many advantages, such as simple to operate, low cost, and minimal invasiveness. Because of its capability of lesion ablation and hemostasis, APC has several indications in the gastrointestinal tract. One of them is esophageal varices. The aim of this review is to summarize the research on APC in this field to provide a reference for clinical practice.

Complications of intracavitary brachytherapy for gynecologic cancers and their management: A comprehensive review

Intracavitary gynecologic brachytherapy in the form of tandem-based brachytherapy and vaginal cylinder-based brachytherapy represents a fundamental component of the treatment of women with cervical or uterine cancer due to the ability to deliver a therapeutic dose of radiation with sharp dose falloff. This results in highly effective treatment in terms of oncologic outcomes with an overall favorable toxicity profile. Still, complications and side effects of brachytherapy do exist. While advances in brachytherapy techniques have led to a significant decrease in the rates of toxicity, a thorough understanding of the potential complications is crucial to ensuring optimal outcomes for women with gynecologic cancer undergoing brachytherapy. Use of equivalent dose at 2 Gy per fraction (EQD2) models has allowed incorporation of external beam radiotherapy dose to the brachytherapy dose leading to development of consolidated dose constraints for organs-at-risk in the modern era. This manuscript offers a comprehensive review of potential complications associated with intracavitary brachytherapy for gynecologic cancer including predictive factors, mitigation tactics, and management strategies.

Liquid Nitrogen Spray Cryotherapy is Associated With Less Postprocedural Pain Than Radiofrequency Ablation in Barrett's Esophagus: A Multicenter Prospective Study

GOALS AND BACKGROUND

Two common endoscopic therapies for eradication of dysplastic Barrett's esophagus are radiofrequency ablation (RFA) and liquid nitrogen spray cryotherapy (LNC). There is no data comparing postprocedural pain. This study aimed to compare the incidence of postprocedural pain between the 2 ablation modalities.

METHODS

This is a multicenter prospective study in which pain intensity scores and the presence of dysphagia were assessed immediately before and after treatment, 48 hours posttreatment and at 3 weeks posttreatment using validated instruments.

RESULTS

Of 94 patients, 35 underwent LNC and 59 underwent RFA [36 with focal radiofrequency ablation (RFA-F) and 23 with circumferential radiofrequency ablation (RFA-C)]. Immediately posttreatment, patients in the LNC group reported an average Numeric Pain Scale score that was lower than in the RFA groups [LNC 0.41 vs. RFA-F 1.18 (P=0.026), LNC 0.41 vs. RFA-C 1.38 (P=0.010)]. These differences persisted at 48 hours posttreatment [LNC 0.76 vs. RFA-F 1.77 (P=0.013), LNC 0.76 vs. RFA-C 1.73 (P=0.018)]. The odds of pain after RFA were at least 5 times greater than after LNC [immediately posttreatment odds ratio, 5.26 (95% confidence interval, 1.85-14.29) and 48 h posttreatment odds ratio, 5.56 (95% confidence interval, 2.27-14.29)]. There was no difference in dysphagia after treatment in either group, at any time point (P=0.429).

CONCLUSION

LNC was associated with less postprocedural pain when compared with RFA. These results help inform patients and physicians about the expected symptoms after ablative endotherapy.

Case series on multimodal endoscopic therapy for gastric antral vascular ectasia, a tertiary center experience

AIM

To study and describe patients who underwent treatment for gastric antral vascular ectasia (GAVE) with different endoscopic treatment modalities.

METHODS

We reviewed patients with GAVE who underwent treatment at University of Alabama at Birmingham between March 1, 2012 and December 31, 2016. Included patients had an endoscopic diagnosis of GAVE with associated upper gastrointestinal bleeding or iron deficiency anemia.

RESULTS

Seven out of 15 patients had classic watermelon description for GAVE, 1/15 with diffuse/honeycomb pattern and 6/15 with nodular GAVE per EGD description. Seven out of 15 patients required multimodal treatment. Four out of six of patients with endoscopically nodular GAVE required multimodal therapy. Overall, mean pre- and post-treatment hemoglobin (Hb) values were 8.2 ± 0.8 g/dL and 9.7 ± 1.6 g/dL, respectively (P ≤ 0.05). Mean number of packed red blood cells transfusions before and after treatment was 3.8 ± 4.3 and 1.2 ± 1.7 (P ≤ 0.05), respectively.

CONCLUSION

Patients with nodular variant GAVE required multimodal approach more frequently than non-nodular variants. Patients responded well to multimodal therapy and saw decrease in transfusion rates and increase in Hb concentrations. Our findings suggest a multimodal approach may be beneficial in nodular variant GAVE.

Insights into the management of gastric antral vascular ectasia (watermelon stomach)

Gastric antral vascular ectasia (GAVE) is an uncommon but important cause of chronic gastrointestinal bleeding. It is often associated with systemic diseases such as autoimmune diseases, liver cirrhosis, chronic renal insufficiency and cardiovascular disease. The etiology of GAVE has not been fully explored and remains controversial. Diagnosis is mainly based on endoscopic presentation with flat or raised erythematous stripes radiating from the pylorus to the antrum and resembles a watermelon. Clinical presentation may range from iron-deficiency anemia secondary to occult blood loss, melena to hematemesis. In past decades, many therapeutic modalities including medical, endoscopic and surgical intervention have been introduced for GAVE treatment with variable efficacy. Herein, we review the efficacy and safety of these treatment options for GAVE.

Feasibility of liquid nitrogen cryotherapy after failed radiofrequency ablation for Barrett's esophagus

BACKGROUND AND AIM

Radiofrequency ablation (RFA) for dysplastic Barrett's esophagus (BE) is highly effective. RFA failures are infrequent but can be a challenging cohort to manage. There are limited data on the feasibility of liquid nitrogen cryospray ablation for complete eradication of dysplasia (CE-D) and/or intestinal metaplasia (CE-IM) after RFA has failed to achieve CE-IM in patients with dysplastic BE.

METHODS

This is a retrospective review from two medical centers of prospectively maintained databases looking at patients that underwent liquid nitrogen cryospray ablation for refractory intestinal metaplasia post failed RFA.

RESULTS

Eighteen patients were identified that met inclusion criteria. Eleven patients had persistent dysplasia and IM following RFA and seven had persistent non-dysplastic IM. More than 80% of patients were male with long-segment BE (median length 8 cm). Seventy two percent of patients with dysplasia achieved CE-D after cryotherapy. Fifty percent (9/18) of all RFA failures achieved CE-IM with cryotherapy. In comparison, RFA has a CE-IM of 78% in a less challenging treatment naïve cohort from a large-scale meta-analysis of 3802 patients. No adverse events occurred in our cohort.

CONCLUSION

Cryospray ablation is feasible and safe for achieving CE-D and CE-IM after RFA failure. The CE-D rates are high with cryotherapy in this population. CE-IM with cryotherapy is acceptable in this difficult-to-treat cohort when compared to CE-IM rates with RFA in dysplastic BE treatment naïve patients (50% vs 78%).