Endoscopic interventions for preneoplastic and neoplastic lesions: mucosectomy, argon plasma coagulation, and photodynamic therapy

Meta-analysis of endoscopic therapy for low-grade dysplasia in Barrett's oesophagus

Background

The optimal management of patients with Barrett's-associated low-grade dysplasia (LGD) is unclear. The objective of this study was to identify systematically all reports of endoscopic treatment of LGD, and to assess outcomes in terms of disease progression, eradication of dysplasia and intestinal metaplasia, and complication rates.

Methods

A systematic review of articles reporting endoscopic treatment of LGD was conducted in accordance with PRISMA guidelines. MEDLINE and Embase databases were searched to identify the relevant literature. Rates of complete eradication of intestinal metaplasia (CE-IM) and dysplasia (CE-D) were reported. The pooled incidence of progression to cancer was calculated following endoscopic therapy.

Results

Thirty-seven studies met the inclusion criteria, reporting outcomes of endoscopic therapy for 521 patients with LGD. The pooled incidence of progression to cancer was 3·90 (95 per cent confidence interval (c.i.) 1·27 to 9·10) per 1000 patient-years. CE-IM and CE-D were achieved in 67·8 (95 per cent c.i. 50·2 to 81·5) and 88·9 (83·9 to 92·5) per cent of patients respectively. The commonest adverse event was stricture formation.

Conclusion

Reports of endoscopic therapy were heterogeneous and follow-up periods were short. There is a high likelihood of historical overdiagnosis of LGD. Endoscopic therapy, particularly radiofrequency ablation, appears safe and effective at eradicating LGD, but does not eliminate the risk of progression to cancer.

Preemptive surgery for premalignant foregut lesions

INTRODUCTION

Preemptive surgery is the prophylactic removal of an organ at high risk for malignant transformation or the resection of a precancerous or "early" malignant neoplasm in an individual with a hereditary predisposition to cancer. Recent advances in molecular diagnostic techniques have improved our understanding of the biologic behavior of these conditions. Predictive testing is an emerging field that attempts to assess the potential risk of cancer development in predisposed individuals. Despite substantial improvement in these forms of testing, all results are imperfect. This information often becomes an important tool that is used by healthcare providers to evaluate the risk-benefit ratio of various risk modifying strategies (i.e., intensive surveillance or preemptive surgery).

METHODS

A systematic literature review was performed using Medline and the bibliographies of all referenced publications to identify articles relating to preemptive surgery for premalignant foregut lesions.

RESULTS AND DISCUSSION

In this review, we outline the controversies surrounding predictive risk assessment, surveillance strategies, and preemptive surgery in the management of high-grade dysplasia (HGD) in Barrett's esophagus (BE), hereditary diffuse gastric cancer (HDGC), bile duct cysts, primary sclerosing cholangitis (PSC), and pancreatic cystic neoplasms. Resection of BE is supported by the progressive nature of the disease, the risk of occult carcinoma, and the lethality of esophageal cancer. Prophylactic total gastrectomy for HDGC appears reasonable in the absence of accurate screening tests but must be balanced by the impact of surgical complications and altered quality of life. Surgical resection of biliary cysts theoretically eliminates the exposed epithelium to decrease the lifetime risk of cholangiocarcinoma. Liver transplantation for PSC remains controversial given the scarcity of donor organs and inability to accurately identify high-risk individuals. Given the uncertain natural history of pancreatic cystic neoplasms, the merits of selective versus obligatory resection will continue to be debated.

CONCLUSIONS

Preemptive operations require optimal judgment and surgical precision to maximize function and enhance survival. Ultimately, balancing the risk of surgical intervention with less invasive interventions or observation must be individualized on a case-by-case basis.

Gastric full-thickness suturing during EMR and for treatment of gastric-wall defects (with video)

BACKGROUND

The endoscopic full-thickness Plicator device was initially developed to provide an endoscopic treatment option for patients with GERD. Because the endoscopic full-thickness Plicator enables rapid and easy placement of transmural sutures, comparable with surgical sutures, we used the Plicator device for endoscopic treatment or prevention of GI-wall defects.

OBJECTIVE

To describe the outcomes and complications of endoscopic full-thickness suturing during EMR and for the treatment of gastric-wall defects.

DESIGN

A report of 4 cases treated with the endoscopic full-thickness suturing between June 2006 and April 2007.

SETTING

A large tertiary-referral center.

PATIENTS

Four subjects received endoscopic full-thickness suturing. The subjects were women, with a mean age of 67 years.

INTERVENTIONS

Of the 4 subjects, 3 received endoscopic full-thickness suturing during or after an EMR. One subject received endoscopic full-thickness suturing for treatment of a fistula.

MAIN OUTCOME MEASUREMENTS

Primary outcome measurements were clinical procedural success and procedure-related adverse events.

RESULTS

The mean time for endoscopic full-thickness suturing was 15 minutes. In all cases, GI-wall patency was restored or ensured, and no procedure-related complications occurred. All subjects responded well to endoscopic full-thickness suturing.

LIMITATIONS

The resection of one GI stromal tumor was incomplete. Because of the Plicator's 60F distal-end diameter, endoscopic full-thickness suturing could only be performed with the patient under midazolam and propofol sedation. The durable Plicator suture might compromise the endoscopic follow-up after EMR.

CONCLUSIONS

The endoscopic full-thickness Plicator permits rapid and easy placement of transmural sutures and seems to be a safe and effective alternative to surgical intervention to restore GI-wall defects or to ensure GI-wall patency during EMR procedures.

Present status of photodynamic therapy for high-grade dysplasia in Barrett's esophagus

GOALS

Review recent developments in Barrett's dysplasia including regulatory approval of porfimer sodium photodynamic therapy.

BACKGROUND

Barrett's esophagus is thought to be the result of long-standing gastroesophageal reflux disease and is known to be the most important risk factor for the development of esophageal adenocarcinoma. The natural history of Barrett's esophagus is not well known, but the annual incidence of invasive adenocarcinoma is estimated to be 0.5% (reported range, 0.2%-2.0%). This represents an increased risk for esophageal cancer of 30 to 60 times higher than normal subjects. As for colorectal cancer, malignant degeneration is Barrett's esophagus is thought to occur through a continuum of histologic stages: metaplasia, dysplasia and neoplasia. Barrett's high-grade dysplasia (formerly referred to as carcinoma in situ) is the histologic stage of disease that immediately precedes the development of invasive carcinoma.

CONCLUSIONS

Previously, Barrett's high-grade dysplasia patients were routinely referred for esophageal resection surgery based upon the assumption of inevitable progression to cancer, the high rate of undiagnosed synchronous cancers, and few treatment alternatives. Important developments in Barrett's high-grade dysplasia include recent publications regarding the natural history of Barrett's high-grade dysplasia and the regulatory approval for endoscopic ablation therapy using porfimer sodium photodynamic therapy (Photofrin PDT).

Confocal laser endoscopy for diagnosing intraepithelial neoplasias and colorectal cancer in vivo

BACKGROUND & AIMS

A confocal laser endoscopy system has recently been developed that may allow subsurface imaging of living cells in colonic tissue in vivo. The aim of the present study was to assess its potential for prediction of histology during screening colonoscopy for colorectal cancer.

METHODS

Twenty-seven patients underwent colonoscopy with the confocal endoscope using acriflavine hydrochloride or fluorescein sodium with blue laser illumination. Furthermore, 42 patients underwent colonoscopy with this system using fluorescein sodium. Standardized locations and circumscript lesions were examined by confocal imaging before taking biopsy specimens. Confocal images were graded according to cellular and vascular changes and correlated with conventional histology in a prospective and blinded fashion.

RESULTS

Acriflavine hydrochloride and fluorescein sodium both yielded high-quality images. Whereas acriflavine hydrochloride strongly labeled the superficial epithelial cells, fluorescein sodium offered deeper imaging into the lamina propria. Fluorescein sodium was thus used for the prospective component of the study in which 13,020 confocal images from 390 different locations were compared with histologic data from 1038 biopsy specimens. Subsurface analysis during confocal laser endoscopy allowed detailed analysis of cellular structures. The presence of neoplastic changes could be predicted with high accuracy (sensitivity, 97.4%; specificity, 99.4%; accuracy, 99.2%).

CONCLUSIONS

Confocal laser endoscopy is a novel diagnostic tool to analyze living cells during colonoscopy, thereby enabling virtual histology of neoplastic changes with high accuracy. These newly discovered diagnostic possibilities may be of crucial importance in clinical practice and lead to an optimized rapid diagnosis of neoplastic changes during ongoing colonoscopy.

Ablative procedures for prevention and treatment of esophageal adenocarcinoma

Ablation of Barrett's mucosa by endoscopic resection, photodynamic therapy or thermoablative methods in combination with adequate acid suppression leads to mucosal replacement largely by squamous epithelium. In appropriately selected cases, these methods have the potential to cure superficial Barrett's neoplasia. Endoscopic resection is an alternative to surgical resection of high-grade intraepithelial neoplasia or early esophageal adenocarcinoma, if the tumor is less than 20 mm in size, is not ulcerated, and does not exhibit differentiation grade 3 or lymph vessel infiltration on histological examination. In the presence of submucosal infiltration, the likelihood of lymph node infiltration is related to the infiltration depth. The risk of a noncurative endoscopic ablative approach has to be weighted against the general risk of surgery. With photodynamic or thermoablative treatment, the completeness of destruction of neoplastic tissue can only be judged at follow-up. These methods are therefore restricted to cases that have an increased surgical risk. Ablation of non-neoplastic Barrett's mucosa is currently not indicated.

Interventional endoscopy

PURPOSE OF REVIEW

This review provides an updated summary of gastric interventional endoscopy. Relevant original articles and topic reviews are highlighted in the areas of infection control, light sedation, hemostasis, endoscopic mucosal resection, and endoscopic placement of enteric devices.

RECENT FINDINGS

Several key findings are worth noting: the increased use of propofol by nonanesthesiologists for deep sedation with minimal adverse side effects, the adaptation of tissue adhesive agents for the treatment of bleeding gastric varices, the successful treatment of early gastric cancer by endoscopic mucosal resection, and the development of direct percutaneous endoscopic jejunostomy tubes for patients at high risk of aspiration.

SUMMARY

These recent developments in the field of interventional endoscopy have already made a great impact on clinical care. More advanced procedures can be performed safely while the patient is under deep sedation. Yet, these developments have not slowed down the need for improvement in interventional endoscopy. Researchers continue to look for smaller instruments, better optics, and more advanced accessories. This constant state of flux marks the field of interventional endoscopy and ensures its progress.

Approach to early Barrett's cancer

Because of effective surveillance programs in patients with known Barrett's esophagus, adenocarcinoma of the distal esophagus is increasingly diagnosed at early stages. With the introduction of limited surgical and endoscopic treatment modalities, the need for radical esophagectomy and extensive lymphadenectomy in such patients has been questioned. When selecting the approach to early Barrett's cancer, the precancerous nature of the underlying Barrett's esophagus, the frequent multicentricity of neoplastic alterations within the Barrett mucosa, the inaccuracy of current staging modalities, and the presence of lymph node metastases should be taken into account. Invasiveness and morbidity of the procedures, as well as quality of life aspects, should also be considered. From an oncologic point of view the minimum extent of a resection for early Barrett's cancer should include a full-thickness removal of the entire segment of the distal esophagus covered by intestinal metaplasia together with a regional lymphadenectomy. In appropriately selected patients this can be achieved by a limited surgical procedure involving transhiatal resection of the distal esophagus, but not by endoscopic mucosal ablation or endoscopic mucosa resection. Our experience with 49 limited surgical resections with regional lymphadenectomy indicates that this procedure is oncologically adequate and safe. Reconstruction with an interposed jejunal loop prevents postoperative gastroesophageal reflux and is associated with good quality of life. In contrast, endoscopic interventions are plagued by a high tumor recurrence rate, probably from persistence of Barrett's mucosa and gastroesophageal reflux.