Advanced pathology under squamous epithelium on initial EMR specimens in patients with Barrett's esophagus and high-grade dysplasia or intramucosal carcinoma: implications for surveillance and endotherapy management

Endoscopic features of buried Barrett's mucosa

BACKGROUND AND AIMS

Buried Barrett's mucosa is defined as intestinal metaplasia that is "buried" under the normal-appearing squamous epithelium. This can occur in Barrett's esophagus with or without previous endoscopic therapy. Dysplasia and neoplasia within buried Barrett's mucosa have also been reported. However, endoscopic features of buried Barrett's mucosa have not been described. At our tertiary referral center for Barrett's esophagus, several endoscopic features have been observed in patients who were found to have buried Barrett's mucosa on histology. These features are squamous epithelium which is (1) darker pink on white-light and darker brown on narrow-band imaging and/or (2) has a slightly raised or nodular appearance. It was also observed that either of these 2 features is frequently seen adjacent to a Barrett's mucosa island. This study aimed to (1) evaluate the diagnostic accuracy of these endoscopic features, and (2) evaluate the frequency of endoscopically identifiable buried Barrett's mucosa in patients with dysplastic Barrett's esophagus, before and after endoscopic eradication therapy.

METHODS

This was a retrospective analysis of a prospectively observed cohort of all cases of dysplastic Barrett's esophagus referred to St Vincent's Hospital, Melbourne. Endoscopy documentation software and histopathology reports of esophageal biopsy and EMR specimens between March 2013 and March 2019 were searched for terms "buried" or "subsquamous" Barrett's mucosa. Endoscopic reports, images, and histopathology reports of suspected buried Barrett's mucosa were then reviewed to apply the endoscopic features and correlate with the histologic diagnosis.

RESULTS

In a cohort of 506 patients with dysplastic Barrett's esophagus, 33 (7%) patients (73% male, median age at referral 70.5 years) had buried Barrett's mucosa on histology. Twenty-seven (82%) patients had previous treatment for dysplastic Barrett's esophagus; radiofrequency in 2 (6%), EMR in 4 (12%), and both modalities in 21 (64%). Six (18%) had no previous treatment. Histologically confirmed buried Barrett's mucosa was suspected at endoscopy in 26 patients (79%). Endoscopic features were (1) darker pink or darker brown mucosa underneath squamous epithelium (24%), (2) raised areas underneath squamous mucosa (27%), and both features present concurrently (27%). These features were associated with adjacent islands of Barrett's esophagus in 48%. Forty-four cases of buried Barrett's mucosa were suspected endoscopically, and these were sampled by biopsy (50%) and EMR (50%). Buried Barrett's mucosa was confirmed in 26 cases, with a positive predictive value of endoscopic suspicion of 59%. Eighteen cases of endoscopically suspected buried Barrett's mucosa had no buried Barrett's mucosa on histology; inflammation or reflux was identified in 12 (67%) patients. Dysplasia was identified within buried Barrett's mucosa in 12 (36%) patients; 5 intramucosal adenocarcinoma, 1 high-grade dysplasia, and 6 low-grade dysplasia. Endoscopic features of buried Barrett's mucosa were observed in 11 of 12 cases harboring dysplasia or neoplasia, compared with 15 of 21 cases of buried Barrett's mucosa without dysplasia.

CONCLUSIONS

In this retrospective analysis of prospectively observed patients with dysplastic Barrett's esophagus, buried Barrett's mucosa was identified in 7%, including treatment-naive patients. The proposed endoscopic features of buried Barrett's mucosa were seen in 79% of patients with histology confirmed disease. These endoscopic features may predict the presence of buried Barrett's mucosa, which may contain dysplasia or neoplasia. An overlap between the endoscopic features of inflammation, reflux, and buried Barrett's mucosa was observed. Future prospective studies are required to develop and validate endoscopic criteria for identifying buried Barrett's mucosa.

Post-ablation buried neoplasia in Barrett's esophagus

Endoscopic eradication therapy (EET) with maximal acid suppression is the cornerstone for the management of patients with Barrett's esophagus (BE) associated dysplasia. The occurrence of buried dysplastic glands after re-epithelialization of a neo-squamous epithelium is of concern for endoscopists. Here, we present a patient with BE and high-grade dysplasia successfully treated by EET who developed buried dysplastic BE during surveillance. A review of literature on buried dysplasia after successful endoscopic therapy of BE is also discussed.

Optimizing Outcomes with Radiofrequency Ablation of Barrett's Esophagus: Candidates, Efficacy and Durability

The treatment of early Barrett's esophagus (BE) has undergone a paradigm shift from surgical subtotal esophagectomy to organ-saving endoluminal treatment. Over the past 15 years, several high-quality studies were conducted to assess safe oncological outcome of endoscopic resection of mucosal adenocarcinoma and high-grade dysplasia. It became clear that add-on ablative therapy with radiofrequency ablation (RFA) significantly reduces recurrence risk of neoplasia after resection. In this review, we highlight the most essential elements to optimize outcomes of RFA of BE, addressing the correct indication and patient selection in combination with the most efficient and safest treatment protocols to obtain long-term durability.

Allaying uncertainty in diagnosing buried Barrett's esophagus

Subsquamous intestinal metaplasia (SSIM) in the setting of Barrett's esophagus (BE) is a technically challenging diagnosis. While the risk for progression of BE involving the surface mucosa is well documented, the potential risk for development of advanced neoplasia associated with SSIM has been controversial. This study aimed to determine the effects of specimen adequacy, presence of dysplasia, and interobserver agreement for SSIM interpretation. Adult patients (n = 28) who underwent endoscopic therapy for BE with high-grade dysplasia or intramucosal carcinoma (HGD/IMC) between October 2005 and June 2013 were included. Initial evaluation (n = 140 slides) by an experienced gastrointestinal pathologist was followed by an interobserver study by 8 pathologists. Forty-seven (34%) slides had insufficient subsquamous tissue to assess for SSIM. SSIM was found in 19% of all slides and 29% of slides with sufficient subsquamous tissue. At least one slide had SSIM in 54% to 64% of patients. Subsquamous low grade dysplasia (LGD) was found in 4 (15%) slides with SSIM and subsquamous HGD/IMC was found in 5 (19%) slides with SSIM. At the patient level, 8 (53%) had no dysplasia, 4 (27%) had LGD and 3 (20%) had HGD/IMC. Overall agreement for SSIM by slide was 92% to 94% (κ = 0.73 to κ = 0.82, moderate to strong agreement), and by patient was 82% to 94% (κ = 0.65 to κ = 0.87, moderate to strong agreement). This study confirms the need for assessing specimen adequacy and assessing the prevalence of SSIM and is the first to assess interobserver agreement for SSIM and dysplasia within SSIM.

Endoscopic mucosal resection for early esophageal carcinoma is effective and safe but necessitates continued surveillance

BACKGROUND

Endoscopic mucosal resection (EMR) is used for the treatment of early esophageal cancer (EEC).

METHODS

This a retrospective study aimed to study the efficacy, safety, and the recurrence rate of EEC following EMR.

RESULTS

Seventy-nine patients who had undergone EMR for early EEC (T1a andT1b lesions) from 2006 to 2015 were included. EMR alone was considered curative in 51 patients who had T1a lesion. Complete remission was achieved in 50 (98%) patients. Mean number of sessions of EMR was 1.14. Cancer recurred locally in 6 (12%) of 50 patients at a median follow-up of 48 (18-72) months. Endoscopic treatment alone achieved complete remission at last follow up in 47 of 50 patients (94%) who had initial EMR with complete remission, or in 47 of all 51 patients (92%) in whom EMR was considered curative for EC. The Kaplan-Meier cancer-free survival following complete remission with EMR was 94.2% at 1 year and 88.4% at 5 years. Patients with complete eradication of Barrett's had lower risk of recurrence of adenocarcinoma (AC) compared with patients who had persistent Barrett's (p = 0.01). EMR alone was not considered curative in 19 patients, 16 with T1b AC and 3 with T1a squamous cell carcinoma (SCC) invading the muscularis mucosa (m3). Two major adverse events were noted: delayed bleeding requiring hospitalization, and perforation that was closed endoscopically.

CONCLUSION

EMR is effective and safe for the management of early EC. The risk of cancer recurrence, albeit small, warrants surveillance. Complete eradication of Barrett's should be attempted in all patients after EMR of AC.

Radiofrequency ablation compared with argon plasma coagulation after endoscopic resection of high-grade dysplasia or stage T1 adenocarcinoma in Barrett's esophagus: a randomized pilot study (BRIDE)

BACKGROUND AND AIMS

Endoscopic resection (ER) is safe and effective for Barrett's esophagus (BE) containing high-grade dysplasia (HGD) or mucosal adenocarcinoma (T1A). The risk of metachronous neoplasia is reduced by ablation of residual BE by using radiofrequency ablation (RFA) or argon plasma coagulation (APC). These have not been compared directly. We aimed to recruit up to 100 patients with BE and HGD or T1A confirmed by ER over 1 year in 6 centers in a randomized pilot study.

METHODS

Randomization was 1:1 to RFA or APC (4 treatments allowed at 2-month intervals). Recruitment, retention, dysplasia clearance, clearance of benign BE, adverse events, healthcare costs, and quality of life by using EQ-5D, EORTC QLQ-C30, or OES18 were assessed up to the end of the trial at 12 months.

RESULTS

Of 171 patients screened, 76 were randomized to RFA (n = 36) or APC (n = 40). The mean age was 69.7 years, and 82% were male. BE was <5 cm (n = 27), 5 to 10 cm (n = 45), and >10 cm (n = 4). Sixty-five patients completed the trial. At 12 months, dysplasia clearance was RFA 79.4% and APC 83.8% (odds ratio [OR] 0.7; 95% confidence interval [CI], 0.2-2.6); BE clearance was RFA 55.8%, and APC 48.3% (OR 1.4; 95% CI, 0.5-3.6). A total of 6.1% (RFA) and 13.3% (APC) had buried BE glands. Adverse events (including stricture rate after starting RFA 3/36 [8.3%] and APC 3/37 [8.1%]) and quality of life scores were similar, but RFA cost $27491 more per case than APC.

CONCLUSION

This pilot study suggests similar efficacy and safety but a cost difference favoring APC. A fully powered non-inferiority trial is appropriate to confirm these findings. (Clinical trial registration number: NCT01733719.).

Subsquamous intestinal metaplasia is common in treatment-naïve Barrett's esophagus

BACKGROUND AND AIMS

Barrett's intestinal metaplasia may extend beneath normal squamous epithelium at the squamocolumnar junction (SCJ) and therefore escape surveillance biopsy sampling. The prevalence of subsquamous intestinal metaplasia (SSIM) in patients undergoing Barrett's esophagus (BE) surveillance is unknown. Our aim was to examine the prevalence and distribution of SSIM proximal to the SCJ in patients undergoing BE surveillance.

METHODS

We enrolled consecutive patients with biopsy specimen-proven BE. Biopsy specimens were obtained from the squamous epithelium at 5 mm and 10 mm above the SCJ. The primary outcomes were the proportion of patients with SSIM at each level. We further assessed factors associated with SSIM.

RESULTS

We examined 515 squamous epithelial biopsy specimens from 106 BE patients (95% men; mean age, 66 years) with a mean Barrett's length of 3.0 cm. SSIM was present in 39% at 5 mm (95% CI, 29.4-48.6) and 21% (95% CI, 11.7-32.1) at 10 mm proximal to the SCJ. Among all biopsy specimens, 13% (95% CI, 10.6-16.6) contained SSIM: 17% (95% CI, 13-21.6) of biopsy samples at 5 mm and 8% (95% CI, 4.3-12.2) at 10 mm proximal to the SCJ. SSIM was more common in the anterior/right lateral position compared with the posterior/left lateral position (21% vs 11%, P = .001). None of the biopsy specimens showed dysplasia. Length of BE or duration of reflux symptoms were not associated with the presence of SSIM.

CONCLUSIONS

This cross-sectional study found a surprisingly high proportion of SSIM in treatment-naïve patients proximal to the SCJ. These findings raise questions regarding BE management and the prevalence of SSIM in normal-appearing esophagus.

Developments in optical imaging for gastrointestinal surgery

To improve outcomes for patients with cancer, in terms of both survival and a reduction in the morbidity and mortality that results from surgical resection and treatment, there are two main areas that require improvement. Accurate early diagnosis of the cancer, at a stage where curative and, ideally, minimally invasive treatment is achievable, is desired as well as identification of tumor margins, lymphatic and distant disease, enabling complete, but not unnecessarily extensive, resection. Optical imaging is making progress in achieving these aims. This review discusses the principles of optical imaging, focusing on fluorescence and spectroscopy, and the current research that is underway in GI tract carcinomas.

Care of the Postablation Patient: Surveillance, Acid Suppression, and Treatment of Recurrence

Endoscopic eradication therapy is effective and durable for the treatment of Barrett's esophagus (BE), with low rates of recurrence of dysplasia but significant rates of recurrence of intestinal metaplasia. Identified risk factors for recurrence include age and length of BE before treatment and may also include presence of a large hiatal hernia, higher grade of dysplasia before treatment, and history of smoking. Current guidelines for surveillance following ablation are limited, with recommendations based on low-quality evidence and expert opinion. New modalities including optical coherence tomography and wide-area tissue sampling with computer-assisted analysis show promise as adjunctive surveillance modalities.

Different time trend and management of esophagogastric junction adenocarcinoma in three Asian countries

Esophagogastric junction (EGJ) adenocarcinoma has been on the increase in Western countries. However, in Asian countries, data on the incidence of EGJ adenocarcinoma are evidently lacking. In the present review, we focus on the current clinical situation of EGJ adenocarcinoma in three Asian countries: Japan, Hong Kong, and Malaysia. The incidence of EGJ adenocarcinoma has been reported to be gradually increasing in Malaysia and Japan, whereas it has stabilized in Hong Kong. However, the number of cases in these countries is comparatively low compared with Western countries. A reason for the reported difference in the incidence and time trend of EGJ adenocarcinoma among the three countries may be explained by two distinct etiologies: one arising from chronic gastritis similar to distal gastric cancer, and the other related to gastroesophageal reflux disease similar to esophageal adenocarcinoma including Barrett's adenocarcinoma. This review also shows that there are several concerns in clinical practice for EGJ adenocarcinoma. In Hong Kong and Malaysia, many EGJ adenocarcinomas have been detected at a stage not amenable to endoscopic resection. In Japan, histological curability criteria for endoscopic resection cases have not been established. We suggest that an international collaborative study using the same definition of EGJ adenocarcinoma may be helpful not only for clarifying the characteristics of these cancers but also for improving the clinical outcome of these patients.

ADSC-sheet Transplantation to Prevent Stricture after Extended Esophageal Endoscopic Submucosal Dissection

In past years, the cell-sheet construct has spurred wide interest in regenerative medicine, especially for reconstructive surgery procedures. The development of diversified technologies combining adipose tissue-derived stromal cells (ADSCs) with various biomaterials has led to the construction of numerous types of tissue-engineered substitutes, such as bone, cartilage, and adipose tissues from rodent, porcine, or human ADSCs. Extended esophageal endoscopic submucosal dissection (ESD) is responsible for esophageal stricture formation. Stricture prevention remains challenging, with no efficient treatments available. Previous studies reported the effectiveness of mucosal cell-sheet transplantation in a canine model and in humans. ADSCs are attributed anti-inflammatory properties, local immune modulating effects, neovascularization induction, and differentiation abilities into mesenchymal and non-mesenchymal lineages. This original study describes the endoscopic transplantation of an ADSC tissue-engineered construct to prevent esophageal stricture in a swine model. The ADSC construct was composed of two allogenic ADSC sheets layered upon each other on a paper support membrane. The ADSCs were labeled with the PKH67 fluorophore to allow probe-based confocal laser endomicroscopy (pCLE) monitoring. On the day of transplantation, a 5-cm and hemi-circumferential ESD known to induce esophageal stricture was performed. Animals were immediately endoscopically transplanted with 4 ADSC constructs. The complete adhesion of the ADSC constructs was obtained after 10 min of gentle application. Animals were sacrificed on day 28. All animals were successfully transplanted. Transplantation was confirmed on day 3 with a positive pCLE evaluation. Compared to transplanted animals, control animals developed severe strictures, with major fibrotic tissue development, more frequent alimentary trouble, and reduced weight gain. In our model, the transplantation of allogenic ADSCs, organized in double cell sheets, after extended ESD was successful and strongly associated with a lower esophageal stricture rate.

Post-ablation surveillance in Barrett's esophagus: A review of the literature

Barrett’s esophagus (BE) is a pre-malignant condition affecting up to 15% of patients with gastroesophageal reflux disease. Neoplastic Barrett’s mucosa is defined as harboring high grade dysplasia or intra-mucosal cancer, and carries a high risk of progression to esophageal adenocarcinoma. The rising incidence of Barrett’s lesions along with the high morbidity of surgical approaches has led to the development of numerous validated endoscopic techniques capable of eradicating neoplastic mucosa in a minimally invasive manner. While there has been widespread adoption of these techniques, less is known about optimal surveillance intervals in the post-therapy period. This is due in part to limitations in current surveillance methods, questions about durability of treatment response and the risk of subendothelial progression. As we are now able to achieve organ sparing eradication of superficial neoplasia in BE, we need to also then focus our attention on how best to manage these patients after eradication is achieved. Implementing optimal surveillance practices requires additional understanding of the biology of the disease, appreciation of the limits of current tools and treatments, and exploration of the role of adjunctive technologies. The aim of this article is to provide a comprehensive review of current literature surrounding post-ablation surveillance in neoplastic BE.

Esophageal neoplasia arising from subsquamous buried glands after an apparently successful photodynamic therapy or radiofrequency ablation for Barrett's associated neoplasia

OBJECTIVE

Photodynamic therapy (PDT) and radiofrequency ablation (RFA) are effective non-surgical options for the treatment of Barrett's esophagus (BE) associated neoplasia. Development of subsquamous intestinal metaplasia after successful PDT and/or RFA is a recognized phenomenon; however, the occurrence of neoplasia arising from buried glands is a rare complication.

METHODS

This is a prospective case series of patients treated with PDT and/or RFA from 1999 to 2014 at University College London Hospital for neoplasia associated with BE, whose outcomes were analyzed retrospectively. Prior to any ablative therapy any visible nodularity was removed with endoscopic mucosal resection (EMR). After successful PDT and/or HALO RFA treatment, defined as a complete reversal of dysplasia and metaplasia, patients underwent endoscopic follow up using the Seattle protocol.

RESULTS

A total of 288 patients were treated, 91 with PDT between 1999 and 2010, 173 with RFA between 2007 and 2014, and 24 with both PDT and RFA for neoplasia associated with BE. Subsquamous neoplasia occurred in seven patients (7/288, 2%). The first patient developed subsquamous invasive adenocarcinoma and underwent curative surgery. Another five patients with subsquamous neoplasia (either high-grade dysplasia or intramucosal cancer) were treated successfully with EMR. The final patient developed subsquamous invasive esophagogastric junctional adenocarcinoma with liver metastases.

CONCLUSION

Development of subsquamous neoplasia after an apparently successful PDT and/or RFA is a rare but recognized complication. Clinicians should be aware of this phenomenon and have a low threshold for performing an EMR. Thorough surveillance following successful PDT and/or RFA ensuring high-quality endoscopy is required.

Feasibility of optical coherence tomography for the evaluation of Barrett's mucosa buried underneath esophageal squamous epithelium

OBJECTIVES

The evaluation of Barrett's glands buried underneath esophageal squamous epithelium becomes increasingly important to achieve curative treatments. However, clinically available endoscopies have critical limitations in depicting the subsurface structure, resulting in non-curative treatments. Optical coherence tomography (OCT) can acquire a high-resolution cross-sectional image, equivalent to an 'optical biopsy'. We aimed to assess the feasibility of the in vivo use of probe-type OCT imaging to evaluate Barrett's mucosa buried underneath esophageal squamous epithelium METHODS: We conducted a single-center prospective study with 14 consecutive patients with Barrett's adenocarcinoma from 2008 to 2014. The enrolled patients were examined by a probe-type OCT in vivo, followed by en bloc endoscopic submucosal dissection (ESD) with electric marking. Then, the one-to-one correlations between the OCT images of the buried mucosa and their histological assessment were examined.

RESULTS

The overall accuracy, sensitivity, specificity, positive predictive value and negative predictive value of the buried mucosa in the OCT imaging were 85.7% (12/14), 77.8% (7/9), 100% (5/5), 100% (7/7) and 71.4% (5/7), respectively. However, OCT could not easily distinguish non-dysplastic glands from dysplastic glands. Additionally, the linear distance from the histological squamo-columnar junction in correct cases tended to be longer than that in incorrect cases (mm, median [range]: 2.0 [0.7-7.5] vs. 0.5 [0.5-0.5]).

CONCLUSIONS

We demonstrated, for the first time, that pre-operative OCT imaging might be feasible for detecting the oral side extension of buried Barrett's mucosa to remove the entire area with malignant potential by ESD. This article is protected by copyright. All rights reserved.

Cell Sheet Transplantation for Esophageal Stricture Prevention after Endoscopic Submucosal Dissection in a Porcine Model

Background & Aims

Extended esophageal endoscopic submucosal dissection (ESD) is highly responsible for esophageal stricture. We conducted a comparative study in a porcine model to evaluate the effectiveness of adipose tissue-derived stromal cell (ADSC) double cell sheet transplantation.

Methods

Twelve female pigs were treated with 5 cm long hemi-circumferential ESD and randomized in two groups. ADSC group (n = 6) received 4 double cell sheets of allogenic ADSC on a paper support membrane and control group (n = 6) received 4 paper support membranes. ADSC were labelled with PKH-67 fluorophore to allow probe-based confocal laser endomicroscopie (pCLE) monitoring. After 28 days follow-up, animals were sacrificed. At days 3, 14 and 28, endoscopic evaluation with pCLE and esophagography were performed.

Results

One animal from the control group was excluded (anesthetic complication). Animals from ADSC group showed less frequent alimentary trouble (17% vs 80%; P = 0.08) and higher gain weight on day 28. pCLE demonstrated a compatible cell signal in 4 animals of the ADSC group at day 3. In ADSC group, endoscopy showed that 1 out of 6(17%) animals developed a severe esophageal stricture comparatively to 100% (5/5) in the control group; P = 0.015. Esophagography demonstrated a decreased degree of stricture in the ADSC group on day 14 (44% vs 81%; P = 0.017) and day 28 (46% vs 90%; P = 0.035). Histological analysis showed a decreased fibrosis development in the ADSC group, in terms of surface (9.7 vs 26.1 mm²; P = 0.017) and maximal depth (1.6 vs 3.2 mm; P = 0.052).

Conclusion

In this model, transplantation of allogenic ADSC organized in double cell sheets after extended esophegeal ESD is strongly associated with a lower esophageal stricture’s rate.

Long-term outcomes of a primary complete endoscopic resection strategy for short-segment Barrett's esophagus with high-grade dysplasia and/or early esophageal adenocarcinoma

BACKGROUND AND AIMS

Complete endoscopic resection (CER) of Barrett's esophagus (BE) with high-grade dysplasia (HGD) and early esophageal adenocarcinoma (EEA) is a comprehensive and precise staging tool and may produce a sustained treatment response, preventing metachronous disease. There are limited data on long-term clinical outcomes and the sustainability of dysplasia eradication after CER. We aimed to describe long-term outcomes of a primary CER strategy of BE with HGD/EEA.

METHODS

Patients with biopsy-proven HGD and EEA in short-segment BE (≤ 3 cm in circumferential length and ≤ 5 cm in maximal length) underwent staged CER by multiband mucosectomy or the cap method. The primary endpoint was remission of HGD or EEA (complete resection of HGD/EEA), dysplasia (complete resection of any dysplasia), and complete resection of intestinal metaplasia.

RESULTS

Of 153 patients (126 HGD, 27 EEA; 83.7% male, median age of 66 years) considered suitable for CER, 138 met all inclusion criteria. CER was technically successful in all patients and was established after a median of 2 sessions. Covert synchronous EEA was found in 1 patient. At a mean follow-up of 40.7 months by intention-to-treat analysis, complete remission of HGD/EEA, dysplasia, and intestinal metaplasia was achieved in 98.5%, 89.1%, and 71.0%, respectively. In 47.1% of patients, CER changed the histological grade compared with pretreatment biopsies (28.1% downstaged and 19.0% upstaged). Esophageal dilation was performed in 36.8% in a mean of 2.5 sessions. At the end of follow-up, 96.4% of patients had no or minimal dysphagia and 90.6% of patients found CER an acceptable treatment.

CONCLUSIONS

On long-term follow-up, a primary CER strategy was a highly effective, safe, and durable treatment for HGD and EEA. Despite the need for post-CER dilation in one-third of patients, the majority found it an acceptable treatment on long-term follow-up.

Sixteen-year follow-up of Barrett's esophagus, endoscopically treated with argon plasma coagulation

OBJECTIVE

The thermal destruction of non-dysplastic Barrett's esophagus (BE) and its replacement by squamous epithelium is an attractive, but unproven strategy to avoid further development of dysplasia or cancer. The goal of this study was to estimate the persistence of restoration of squamous epithelium and the risk of cancer in BE that was eradicated using argon plasma coagulation (APC) in the absence of high-grade dysplasia, 16 years after its application.

DESIGN

We followed 32 patients with BE who underwent eradication of metaplastic epithelium using APC, up to 16 years later.

RESULTS

At the end of the initial treatment, 25 of 32 patients (78%) had complete endoscopic eradication, there was partial squamous re-epithelialization in four patients (13%) and it was absent in three patients (9%). We observed buried metaplastic glands under new squamous epithelium in 6 of the 25 patients who had complete endoscopic eradication. At follow-up, sustained complete endoscopic eradication was observed in 16 of 32 patients (50%), partial eradication in 11 of 32 patients (35%); there were two patients (6%) lost to follow-up and three patients (9%) developed esophageal adenocarcinoma. Two of the latest cases arose from the buried glands under neosquamous epithelium after complete eradication and one arose from a small remaining Barrett's segment.

CONCLUSIONS

We observed long-term re-epithelialization in the majority of patients who had previously had complete eradication of Barrett's esophagus. This did not provide protection against cancer development, as the incidence of cancers arising from buried glands or from residual Barrett's esophagus was similar to that observed in patients undergoing no specific treatment.

Controversies in Barrett esophagus

Barrett esophagus develops when metaplastic columnar epithelium predisposed to develop adenocarcinoma replaces esophageal squamous epithelium damaged by gastroesophageal reflux disease. Although several types of columnar metaplasia have been described in Barrett esophagus, intestinal metaplasia with goblet cells currently is required for a definitive diagnosis in the United States. Studies indicate that the risk of adenocarcinoma for patients with nondysplastic Barrett esophagus is only 0.12% to 0.38% per year, which is substantially lower than previous studies had suggested. Nevertheless, the incidence of esophageal adenocarcinoma continues to rise at an alarming rate. Regular endoscopic surveillance for dysplasia is the currently recommended cancer prevention strategy for Barrett esophagus, but a high-quality study has found no benefit of surveillance in preventing deaths from esophageal cancer. Medical societies currently recommend endoscopic screening for Barrett esophagus in patients with multiple risk factors for esophageal adenocarcinoma, including chronic gastroesophageal reflux disease, age of 50 years or older, male sex, white race, hiatal hernia, and intra-abdominal body fat distribution. However, because the goal of screening is to identify patients with Barrett esophagus who will benefit from endoscopic surveillance and because such surveillance may not be beneficial, the rationale for screening might be made on the basis of faulty assumptions. Endoscopic ablation of dysplastic Barrett metaplasia has been reported to prevent its progression to cancer, but the efficacy of endoscopic eradication of nondysplastic Barrett metaplasia as a cancer preventive procedure is highly questionable. This review discusses some of these controversies that affect the physicians and surgeons who treat patients with Barrett esophagus. Studies relevant to controversial issues in Barrett esophagus were identified using PubMed and relevant search terms, including Barrett esophagus, ablation, dysplasia, radiofrequency ablation, and endoscopic mucosal resection.

Radiofrequency ablation for Barrett's esophagus

PURPOSE OF REVIEW

Several studies published in the last year that have provided evidence on the efficacy, durability and safety of radiofrequency ablation (RFA) in Barrett's esophagus are highlighted in this review.

RECENT FINDINGS

RFA is well tolerated and efficacious in most but not all Barrett's esophagus patients with dysplasia and esophageal adenocarcinoma (EAC). Recent reports have described highly variable rates of disease recurrence. Disease progression may occur during initial therapy or after complete eradication in a small, difficult to identify subset of patients. Studies are underway to help determine the predictors of response and recurrence. Modifications in technique and target populations have been described in the last year as well.

SUMMARY

Endoscopic mucosal resection and RFA are the cornerstones in the management of dysplasia and early EAC in Barrett's esophagus patients today. Despite the encouraging data on the effectiveness and safety of RFA, recurrence and progression of disease remain an issue in a subset of patients who are treated.

Subsquamous extension of intestinal metaplasia is detected in 98% of cases of neoplastic Barrett's esophagus

BACKGROUND & AIMS

Subsquamous intestinal metaplasia (SSIM) has been observed after endotherapy in patients with neoplastic Barrett's esophagus (BE). However, it is not clear whether SSIM occurs in untreated patients. Incompletely eradicated SSIM could provide a source of recurrent disease. We assessed its prevalence in a large cohort of patients who had not received endoscopic therapy.

METHODS

Two experienced pathologists analyzed 138 samples of 506 resection specimens found to contain squamous epithelium from 110 patients with neoplastic BE treated by widespread endoscopic mucosal resection (92 men; mean age, 66 years). The maximum extent of SSIM was measured.

RESULTS

Of the 138 samples analyzed, 124 (89.9%) were found to contain SSIM from 108 of the 110 patients (98.2%). The mean length of SSIM was 3.3 mm (range, 0.2-9.6 mm; 25% ≥ 5 mm); SSIM length correlated with BE length (P < .05). In 83 of 138 samples (60.1%), the SSIM consisted partially or entirely of neoplasias of different grades, with a mean subsquamous extension of 3.3 mm; the extension correlated with grade of neoplasia (P = .0001).

CONCLUSIONS

Most patients with BE with neoplasia (of all grades) have subsquamous extension of intestinal metaplasia, including subsquamous extension of lesions at the squamocolumnar junction. Therefore, biopsy and resection of neoplastic BE should extend at least 1 cm into the squamous epithelium.

Endoscopic Optical Coherence Tomography (OCT): Advances in Gastrointestinal Imaging

In the rapidly evolving field of endoscopic gastrointestinal imaging, Optical Coherence Tomography (OCT) has found many diverse applications. We present the current status of OCT and its practical applications in imaging normal and abnormal mucosa in the esophagus, stomach, small and large intestines, and biliary and pancreatic ducts. We highlight technical aspects and principles of imaging, assess published data, and suggest future directions for OCT-guided evaluation and therapy.

Subsquamous intestinal metaplasia after ablation of Barrett's esophagus: frequency and importance

PURPOSE OF REVIEW

This article reviews reports on the prevalence of subsquamous intestinal metaplasia (SSIM) in patients with Barrett's esophagus, and the implications of SSIM in the neoplastic progression of Barrett's esophagus to esophageal adenocarcinoma.

RECENT FINDINGS

Endoscopic eradication therapy for dysplastic Barrett's esophagus has become an encouraging alternative to esophagectomy or continued endoscopic surveillance. However, the presence of SSIM before and after ablation is concerning because this tissue may have potential for malignant progression, is not visible by conventional endoscopy, and may evade detection by random esophageal biopsy sampling methods. Advances in endoscopic high-resolution three-dimensional optical coherence tomography recently have revealed SSIM in a majority of patients both before and after complete eradication of Barrett's esophagus by radiofrequency ablation. Studies suggest that although cells of Barrett's glands are highly proliferative, the cells of these buried glands are more dormant. Nevertheless, the malignant potential of SSIM cells remains undetermined.

SUMMARY

Novel endoscopic imaging demonstrates that SSIM is present in the majority of patients with Barrett's esophagus, both before and after ablative therapy. Although these subsquamous cells exhibit less proliferative activity than those of typical surface Barrett's glands, the malignant potential of the buried glands, especially when challenged by injurious factors, remains largely unknown. Future methods to detect subsurface dysplasia will be needed.

Endoscopic management of Barrett's esophagus: advances in endoscopic techniques

Barrett's esophagus (BE) is a well-known premalignant condition that can be associated with the development of dysplasia and adenocarcinoma. In the past, esophagectomy was the standard treatment for patients with BE with high grade dysplasia (HGD) and early cancer (EC). However, esophagectomy is not necessarily the only treatment response to HGD and EC anymore. Over the past decade, a number of endoscopic therapies have been developed for management of BE. These include endoscopic mucosal resection, thermal ablation techniques that use laser irradiation, multipolar electrocoagulation, argon plasma coagulation, photodynamic therapy, and the recently developed cryotherapy and radiofrequency ablation.

Characterization of buried glands before and after radiofrequency ablation by using 3-dimensional optical coherence tomography (with videos)

BACKGROUND

Radiofrequency ablation (RFA) is an endoscopic technique used to eradicate Barrett's esophagus (BE). However, such ablation can commonly lead to neosquamous epithelium overlying residual BE glands not visible by conventional endoscopy and may evade detection on random biopsy samples.

OBJECTIVE

To demonstrate the capability of endoscopic 3-dimensional optical coherence tomography (3D-OCT) for the identification and characterization of buried glands before and after RFA therapy.

DESIGN

Cross-sectional study.

SETTING

Single teaching hospital.

PATIENTS

Twenty-six male and 1 female white patients with BE undergoing RFA treatment.

INTERVENTIONS

3D-OCT was performed at the gastroesophageal junction in 18 patients before attaining complete eradication of intestinal metaplasia (pre-CE-IM group) and in 16 patients after CE-IM (post-CE-IM group).

MAIN OUTCOME MEASUREMENTS

Prevalence, size, and location of buried glands relative to the squamocolumnar junction.

RESULTS

3D-OCT provided an approximately 30 to 60 times larger field of view compared with jumbo and standard biopsy and sufficient imaging depth for detecting buried glands. Based on 3D-OCT results, buried glands were found in 72% of patients (13/18) in the pre-CE-IM group and 63% of patients (10/16) in the post-CE-IM group. The number (mean [standard deviation]) of buried glands per patient in the post-CE-IM group (7.1 [9.3]) was significantly lower compared with the pre-CE-IM group (34.4 [44.6]; P = .02). The buried gland size (P = .69) and distribution (P = .54) were not significantly different before and after CE-IM.

LIMITATIONS

A single-center, cross-sectional study comparing patients at different time points in treatment. Lack of 1-to-1 coregistered histology for all OCT data sets obtained in vivo.

CONCLUSION

Buried glands were frequently detected with 3D-OCT near the gastroesophageal junction before and after radiofrequency ablation.

Cervical inlet patch-optical coherence tomography imaging and clinical significance

AIM: To demonstrate the feasibility of optical coherence tomography (OCT) imaging in differentiating cervical inlet patch (CIP) from normal esophagus, Barrett’s esophagus (BE), normal stomach and duodenum.

METHODS: This study was conducted at the Veterans Affairs Boston Healthcare System (VABHS). Patients undergoing standard esophagogastroduodenoscopy at VABHS, including one patient with CIP, one representative patient with BE and three representative normal subjects were included. White light video endoscopy was performed and endoscopic 3D-OCT images were obtained in each patient using a prototype OCT system. The OCT imaging probe passes through the working channel of the endoscope to enable simultaneous video endoscopy and 3D-OCT examination of the human gastrointestinal (GI) tract. Standard hematoxylin and eosin (H and E) histology was performed on biopsy or endoscopic mucosal resection specimens in order to compare and validate the 3D-OCT data.

RESULTS: CIP was observed from a 68-year old male with gastroesophageal reflux disease. The CIP region appeared as a pink circular lesion in the upper esophagus under white light endoscopy. OCT imaging over the CIP region showed columnar epithelium structure, which clearly contrasted the squamous epithelium structure from adjacent normal esophagus. 3D-OCT images obtained from other representative patients demonstrated distinctive patterns of the normal esophagus, BE, normal stomach, and normal duodenum bulb. Microstructures, such as squamous epithelium, lamina propria, muscularis mucosa, muscularis propria, esophageal glands, Barrett’s glands, gastric mucosa, gastric glands, and intestinal mucosal villi were clearly observed with OCT and matched with H and E histology. These results demonstrated the feasibility of using OCT to evaluate GI tissue morphology in situ and in real-time.

CONCLUSION: We demonstrate in situ evaluation of CIP microstructures using 3D-OCT, which may be a useful tool for future diagnosis and follow-up of patients with CIP.

Subsquamous intestinal metaplasia: implications for endoscopic management of Barrett's esophagus

Buried Barrett's, or subsquamous intestinal metaplasia (SSIM), is defined as the presence of metaplastic, columnar tissue beneath overlying squamous epithelium. Therefore, SSIM cannot be detected by endoscopic visual examination alone; it is detectable only by tissue biopsy. SSIM can develop in patients with Barrett's esophagus (BE) after chronic pharmacologic suppression of gastric acid; it has been identified before and after endoscopic ablative therapies in cohort studies. It is important to determine the malignant potential of SSIM and the effects of endoscopic therapy for BE on development of SSIM; answers to these questions could affect long-term endoscopic surveillance and ablation strategies for patients with BE.

Buried metaplasia after endoscopic ablation of Barrett's esophagus: a systematic review

OBJECTIVES

Endoscopic ablation of Barrett's esophagus can bury metaplastic glands under a layer of neosquamous epithelium. To explore the frequency and importance of buried metaplasia, we have conducted a systematic review of reports on endoscopic ablation.

METHODS

We performed computerized and manual searches for articles on the results of photodynamic therapy (PDT) and radiofrequency ablation (RFA) for Barrett's esophagus. We extracted information on the number of patients treated, biopsy protocol, biopsy depth, and frequency of buried metaplasia.

RESULTS

We found 9 articles describing 34 patients with neoplasia appearing in buried metaplasia (31 after PDT). We found five articles describing a baseline prevalence of buried metaplasia (before ablation) ranging from 0% to 28%. In 22 reports on PDT for 953 patients, buried metaplasia was found in 135 (14.2%); in 18 reports on RFA for 1,004 patients, buried metaplasia was found in only 9 (0.9%). A major problem limiting the conclusions that can be drawn from these reports is that they do not describe specifically how frequently biopsy specimens contained sufficient subepithelial lamina propria to be informative for buried metaplasia.

CONCLUSIONS

Endoscopic ablation can bury metaplastic glands with neoplastic potential but, even without ablation, buried metaplasia often is found in areas where Barrett's epithelium abuts squamous epithelium. Buried metaplasia is reported less frequently after RFA than after PDT. However, available reports do not provide crucial information on the adequacy of biopsy specimens and, therefore, the frequency and importance of buried metaplasia after endoscopic ablation remain unclear.

Does ablative therapy for Barrett esophagus affect the depth of subsequent esophageal biopsy as compared with controls?

BACKGROUND

Photodynamic therapy (PDT) and radiofrequency ablation (RFA) are associated with high rates of complete eradication of Barrett esophagus (BE). However, if ablation were to induce fibrosis in the regenerated squamous epithelium, then postablation biopsies may not penetrate deeply enough to detect subsquamous intestinal metaplasia (SSIM) and, therefore, complete response rates could be over-estimated.

GOALS

To assess the depth of esophageal biopsies from the squamous epithelium of ablation-naive controls and from the neosquamous epithelium of post-PDT and post-RFA patients to determine if prior ablation results in a reduced proportion of biopsies containing lamina propria (LP) as compared with controls.

STUDY

Review of archived esophageal specimens from a prospective multicenter cohort study (post-RFA) and 2 retrospective consecutive case series (ablation-naive controls, post-PDT).

SETTING

Eight US centers and 1 US gastrointestinal pathology laboratory.

PATIENTS

Ablation-naive controls with GERD, dyspepsia, and/or BE. Post-PDT and post-RFA BE patients with biopsies more than 6 months after achieving complete eradication of BE.

INTERVENTIONS

Review of endoscopic biopsies from ablation-naive controls, post-PDT patients, and post-RFA patients.

MAIN OUTCOME MEASUREMENTS

One GI pathology lab processed all tissue and slides. One expert GI pathologist, blinded to cohort, graded the depth of each esophageal specimen as: partial epithelium, full epithelium, LP, muscularis mucosae, or submucosa. Each specimen was also evaluated for SSIM.

RESULTS

There were 82 patients [ablation-naive (12), post-PDT (10), post-RFA (60)] with 899 biopsy specimens. The proportion of specimens containing "LP or deeper" was similar between groups: ablation-naive (88%), post-PDT (88%), post-RFA (91%) (P>0.05). No SSIM was detected in any group.

CONCLUSIONS

There is no difference in esophageal biopsy depth between ablation-naive squamous epithelium and post-PDT/post-RFA neo-squamous epithelium, thus refuting the concern of ablation-induced mucosal resistance to procurement of adequate biopsy specimens. Most biopsies (88% to 91%) from both ablation cohorts were deep enough to detect SSIM, in that they included "LP or deeper."

Optimal endoluminal treatment of Barrett's esophagus: integrating novel strategies into clinical practice

Endoluminal therapy has become the first-choice treatment over the last 5 years for early Barrett's neoplasia limited to the mucosa. Long-term follow-up data on endoscopic resection have demonstrated the oncological safety of endoscopic resection in comparison to surgery. However, there is a high rate of recurrent disease, which can be avoided using additional ablation of the remaining Barrett. Radiofrequency ablation was recently introduced as an efficacious means to ablate Barrett's epithelium with a better safety profile than older ablation techniques. Recent studies show that endoscopic resection can be safely combined with radiofrequency ablation for treating dysplastic Barrett's after removal of visible lesions. This constitutes a completely new treatment paradigm that will be integrated in routine clinical practice in the forthcoming years.