Photodynamic therapy and endoscopic mucosal resection for Barrett's dysplasia and early esophageal adenocarcinoma

BACKGROUND: Endoscopic mucosal resection (EMR) and endoscopic ablation with porfimer sodium photodynamic therapy (PDT) have recently been combined to improve the accuracy of histologic staging and remove superficial carcinomas. MATERIALS AND METHODS: All patients with Barrett's esophagus and high-grade dysplasia were evaluated with computed tomography and endosonography. Patients with nodular or irregular folds underwent EMR followed by PDT. RESULTS: In three patients, endoscopic mucosal resection upstaged the diagnosis to mucosal adenocarcinoma (T1N0M0). PDT successfully ablated the remaining glandular mucosa. Complications were limited to transient chest discomfort and odynophagia. CONCLUSIONS: The use of EMR resection in Barrett's high-grade dysplasia patients with mucosal irregularities resulted in histologic upstaging to mucosal adenocarcinoma, requiring higher laser light doses for PDT. PDT after EMR appears to be safe and effective for the complete elimination of Barrett's mucosal adenocarcinoma. EMR should be strongly considered for Barrett's dysplasia patients being evaluated for endoscopic ablation therapy.     

Barrett食管的氩离子凝固术或激光治疗

复习国外氩离子凝固术 (Argonplasmacoagulation ,APC)或激光治疗Barrett食管的有关文献资料结果表明 :APC联合高剂量奥美拉唑或腹腔镜抗反流术治疗BE安全、有效 ;单用激光或联合奥美拉唑治疗Barrett食管 (Barrett’sesopha gus ,BE)患者的肠化上皮消失。因此APC或激光可用于BE的治疗     

Curative treatment for high-grade intraepithelial neoplasia in Barrett's esophagus

BACKGROUND AND STUDY AIMS: The incidence of premalignant and malignant lesions in specialized intestinal metaplasia of the esophagus has increased dramatically in the industrialized world in recent years. This report evaluates the efficacy and safety of local endoscopic therapy for high-grade intraepithelial neoplasia (HGIN) in Barrett's esophagus. PATIENTS AND METHODS: Over a 5-year period between October 1996 and September 2001, a total of 379 patients were referred with a suspicion of early Barrett's cancer. In a prospective study, 44 patients with HGIN in Barrett's esophagus were selected for local endoscopic treatment. Endoscopic resection was carried out in 14 patients in whom the HGIN was re-detectable, and 27 patients in whom the HGIN was not re-detectable underwent photodynamic therapy (PDT). Endoscopic resection and PDT were combined in three patients. RESULTS: Complete remission was achieved in 43 of the 44 patients (97.7 %). No major complications occurred. A mean of 1 session was needed to achieve complete local remission. During a mean follow-up period of 36 months (range 7 - 61 months), recurrent or metachronous lesions were observed in six patients (17.1 %), all of whom received a second successful endoscopic treatment. CONCLUSIONS: Endoscopic therapy is a safe alternative treatment regimen for HGIN in Barrett's esophagus, providing a middle way between the widely promulgated options of a "watch-and-wait" policy and radical esophagectomy.     

Is topical delta-aminolevulinic acid adequate for photodynamic therapy in Barrett's esophagus? A pilot study

BACKGROUND AND STUDY AIMS: The methods of endoscopic ablation of metaplastic and dysplastic areas in Barrett's esophagus so far described, are not satisfactory with respect to efficacy and safety. Therefore we investigated whether photodynamic therapy (PDT) with topical delta-aminolevulinic acid (delta-ALA) leads to ablation of specialized columnar epithelium and eradication of low-grade dysplasia while not producing phototoxicity and systemic side effects. PATIENTS AND METHODS: 14 patients with histologically proven Barrett's esophagus, seven of whom had evidence of low-grade dysplasia, underwent endoscopic treatment with topical delta-ALA. Photoactivation (wavelength, 632 nm) was performed at 1.5 - 2 hours after drug administration using an argon dye laser. Patients received omeprazole 80 mg daily for 2 months; thereafter; maintenance therapy depended on reflux symptoms. Patients were endoscopically re-evaluated after 7 days, and subsequently at 3, 6, 12 and up to 48 months (mean follow up 33 months). Re-treatment with high-dose topical delta-ALA was offered to the 11 patients with remaining metaplasia and was carried out in five of them. RESULTS: Low-grade dysplasia was eradicated in all patients. One patient with no dysplasia before PDT developed a high-grade dysplasia after PDT. Complete ablation of Barrett's metaplasia was observed in 21 % of the patients after the first treatment session and in 20 % after the second treatment session. The mean reduction in the length of Barrett's metaplasia was 1.54 +/- 1.29 cm after the first PDT session and 1.02 +/- 0.80 cm after the second PDT session. Post-endoscopic pain and photosensitivity reactions were less frequent with low-dose delta-ALA PDT than with high-dose PDT (pain 15 %, 100 %, respectively; P = 0.001 by Fisher's exact test; phototoxicity, 0 %, 50 %, respectively; P = 0.021 by Fisher's exact test). CONCLUSION: Low-dose topical administration of delta-ALA provides ablation of low-grade dysplasia in the range obtained with oral delta-ALA. In addition, it is safe and well tolerated. Since, however, topical administration of delta-ALA is not able to consistently eradicate Barrett's esophagus, alternative methods will have to be developed.     

Eradication of dysplastic Barrett's oesophagus using photodynamic therapy: long-term follow-up

BACKGROUND AND STUDY AIMS: Barrett's oesophagus is a major risk factor for oesophageal adenocarcinoma, a condition which is rapidly increasing in incidence. Photodynamic therapy (PDT) is a developing treatment in which tissue damage is caused by the action of light on a previously administered photosensitizing agent. We present the results of long-term follow-up of its efficacy in patients with dysplastic Barrett's oesophagus. PATIENTS AND METHODS: A total of 40 patients with low-grade dysplasia in Barrett's oesophagus were treated with oral 5-aminolaevulinic acid (ALA) at a dose of 30 mg/kg, followed by laser endoscopy 4 hours later. Patients were treated between December 1995 and December 1998, and all were followed up regularly with endoscopy and biopsies in our surveillance programme. RESULTS: Among the patients, 35 (88%) showed a macroscopic reduction in the area of the columnar epithelium, and in all 40 patients dysplasia was found to be eradicated at 1 month. The effect has been maintained for a median follow-up of 53 months (range 18-68 months), although one patient developed a late carcinoma in an untreated area of Barrett's oesophagus 3 years after the intervention. CONCLUSIONS: Safe and effective ablation of low-grade dysplastic Barrett's oesophagus can be achieved with the use of ALA-induced PDT, and the effects are maintained in the long term.     

Autofluorescence endoscopy in surveillance of Barrett's esophagus: a multicenter randomized trial on diagnostic efficacy

BACKGROUND AND STUDY AIMS: The reference surveillance method in patients with Barrett's esophagus is careful endoscopic observation, with targeted as well as random four-quadrant biopsies. Autofluorescence endoscopy (AFE) may make it easier to locate neoplasia. The aim of this study was to elucidate the diagnostic accuracy of surveillance with AFE-guided plus four-quadrant biopsies in comparison with the conventional approach. PATIENTS AND METHODS: A total of 187 of 200 consecutive Barrett's esophagus patients who were initially enrolled (73 % male, mean age 67 years, mean Barrett's segment length 4.6 cm), who underwent endoscopy for Barrett's esophagus in four study centers, were randomly assigned to undergo either AFE-targeted biopsy followed by four-quadrant biopsies or conventional endoscopic surveillance, also including four-quadrant biopsies (study phase 1). After exclusion of patients with early cancer or high-grade dysplasia, who underwent endoscopic or surgical treatment, as well as those who declined to participate in phase 2 of the study, 130 patients remained. These patients were examined again with the alternative method after a mean of 10 weeks, using the same methods described. The main study parameter was the detection of early cancer/adenocarcinoma or high-grade dysplasia (HGD), comparing both approaches in study phase 1; the secondary study aim in phase 2 was to assess the additional value of the AFE-guided approach after conventional surveillance, and vice versa. Test accuracy measures were derived from study phase 1. RESULTS: In study phase 1, the AFE and conventional approaches yielded adenocarcinoma/HGD rates of 12 % and 5.3 %, respectively, on a per-patient basis. With AFE, four previously unrecognized adenocarcinoma/HGD lesions were identified (4.3 % of the patients); with the conventional approach, one new lesion (1.1 %) was identified. Of the 19 adenocarcinoma/HGD lesions detected during AFE endoscopy in study phase 1, eight were visualized, while 11 were only detected using untargeted four-quadrant biopsies (sensitivity 42 %). Of the 766 biopsies classified at histology as being nonneoplastic, 58 appeared suspicious (specificity 92 %, positive predictive value 12 %, negative predictive value 98.5 %). In study phase 2, AFE detected two further lesions in addition to the initial alternative approach in 3.2 % of cases, in comparison with one lesion with conventional endoscopy (1.7 %). CONCLUSIONS: In this referral Barrett's esophagus population with a higher prevalence of neoplastic lesions, the AFE-guided approach improved the diagnostic yield for neoplasia in comparison with the conventional approach using four-quadrant biopsies. However, AFE alone was not suitable for replacing the standard four-quadrant biopsy protocol.     

光动力学疗法治疗Barrett食管和早期食管癌

光动力学疗法(PDT)是治疗Barrett食管(BE)相关的高度不典型增生或早期食管腺癌的有吸引力的一种新技术。通过对国外有关PDT时常用的光敏剂及其在治疗BE及早期食管癌中疗效文献复习发现,PDT治疗BE和早期食管癌安全、有效。     

Long-term follow-up and factors predictive of recurrence in Barrett's esophagus treated by argon plasma coagulation and acid suppression

BACKGROUND AND STUDY AIMS: In several series, argon plasma coagulation (APC) combined with acid suppression has led to short- or medium-term eradication of Barrett's esophagus. The present study was designed to assess the long-term outcome after this treatment. PATIENTS AND METHODS: 39 patients with Barrett's esophagus, seven of them with low-grade dysplasia, underwent APC and received 40 mg omeprazole daily for eradication of the metaplastic epithelium. After the treatment period, patients were randomly assigned to receive 20 or 40 mg omeprazole daily for long-term acid suppression. Histological and endoscopic changes were evaluated annually. Univariate and multivariate analyses were used to test the following 10 variables as predictors of sustained reversal of Barrett's esophagus at the end of follow-up: age, gender, length of diseased segment, presence of hiatal hernia, circumferential nature of lesion, presence of low-grade dysplasia at initial biopsy, number of coagulation sessions, result of pH monitoring under protein pump inhibitor (PPI) treatment, omeprazole dosage, and initial response to therapy (after 1 month). RESULTS: The median follow-up period was 36 months (range 12 - 48). The endoscopic and histological relapse rates at 1, 12, and 24 months, and end of follow-up were, respectively, 30 % and 44 % (12/39 and 17/39), 57 % and 54 % (16/28 and 15/28), 60 % and 57 % (17/28 and 16/28), and 62 % for both rates (23/37). According to multivariate analysis, shorter length of diseased segment and normalization of pH with PPI treatment were the only independent predictors of sustained long-term re-epithelialization. Among the seven patients with low-grade dysplasia, four experienced relapse after 1 month, and during the long-term follow-up, one was lost to follow-up and all the others experienced relapse, but only one developed low-grade dysplasia again. Cancer was found in two cases after 12 and 18 months, respectively. CONCLUSIONS: Persistence of acid reflux and greater length of diseased segment are the major factors associated with a high relapse rate after successful initial reversal. APC for ablation of Barrett's esophagus cannot be recommended.     

Radiofrequency ablation is effective for the treatment of high-grade dysplasia in Barrett's esophagus after failed photodynamic therapy

Endoscopic radiofrequency ablation (RFA) is an effective treatment for high-grade dysplasia in Barrett's esophagus in ablation-na?ve patients, but no studies have evaluated its use in patients in whom ablative therapy has previously failed. We describe 14 patients with residual high-grade dysplasia following aminolevulinic acid or Photofrin (porfimer sodium) photodynamic therapy (PDT). An overall complete reversal of dysplasia was achieved in 86?% with a combination of RFA and rescue endoscopic mucosal resection. The median total follow-up is 19 months. The rate of strictures was 7?% (1/14) and there was a low rate of buried glands (0.5?% follow-up biopsies). These data suggest RFA is both safe and effective for eradication of high-grade dysplasia in patients in whom PDT has failed.     

Mucosectomy for high-grade dysplasia in Barrett's esophagus.

Reports on the natural history of high-grade dysplasia (HGD) are sometimes contradictory, but suggest that 10-30% of patients with HGD in Barrett's esophagus (BE) will develop a demonstrable malignancy within five years of the initial diagnosis. Surgery has to be considered the best treatment for HGD or superficial carcinoma, but is contraindicated in patients with severe comorbidities. Non-surgical treatments such as intensive endoscopic surveillance, endoscopic ablative therapies, and endoscopic mucosal resection (EMR) have been proposed. EMR is a newly developed procedure promising to become a safe and reliable non-operative option for the endoscopic removal of HGD or early cancer within BE. It is important to assess the depth of invasion of the lesion and lymph node involvement before choosing EMR. This technique permits more effective staging of disease obtaining a large sample leading to a precise assessment of the depth of malignant invasion. Complications such as bleeding and perforation may occur, but can be treated endoscopically. Trials are needed to compare endoscopic therapy with surgical resection to establish clear criteria for EMR and ablative therapies.     

Argon plasma coagulation in Barrett's esophagus

Argon plasma coagulation (APC) is noncontact electrocoagulation technique that creates tissue damage. Recently, it has been reported that Barrett's esophagus and Barrett's adenocarcinoma in situ could be successfully managed by APC. The aims of this treatment are to prevent the developing of adenocarcinoma and to promote the restitution of normal squamous epithelium. Combined antireflux surgery or proton pump inhibitor therapy are indispensable to this treatment. Shorter length of Barrett's epithelium and normalization in pH with PPI treatment were the independent predictors of sustained long-term restitution of squamous epithelium. In patient with Barrett's esophagus, APC offers an effective, minimally invasive alternative to other treatments previously performed.     

Endoscopic fluorescence detection of intraepithelial neoplasia in Barrett's esophagus after oral administration of aminolevulinic acid

BACKGROUND AND STUDY AIMS: Barrett's esophagus is strongly associated with adenocarcinoma. Early malignant transformation of the Barrett's mucosa is often not visible endoscopically and may remain undetected until the invasive adenocarcinoma stage. Endoscopic surveillance is currently carried out on random four-quadrant biopsies at 1-2 cm intervals. Endoscopic fluorescence detection of protoporphyrin IX induced by 5-aminolevulinic acid can identify premalignant lesions. This study evaluates endoscopic fluorescence detection in patients having Barrett's esophagus and compares the results to those of standard endoscopy with random four-quadrant biopsies. PATIENTS AND METHODS: The study included 30 examinations in 28 patients (22 men, 6 women; age range 37-78 years, mean age 60 years,), with five patients having known intraepithelial neoplasia. A dose of 20 mg/kg of 5-aminolevulinic acid was given orally 5 hours before examination. Random four-quadrant biopsies were performed 4-6 weeks before endoscopic fluorescence detection. RESULTS: Of the biopsies taken during the endoscopic fluorescence detection procedure, 28 % (23/81) were true positives. More than one-third of the false-positive results were due to inflammation. None of the 97 control biopsies taken on nonfluorescing areas during endoscopic fluorescence detection were dysplastic. Endoscopic fluorescence detection showed low-grade intraepithelial neoplasia in five patients which was not diagnosed with random four-quadrant biopsies, while random four-quadrant biopsies alone showed three low-grade intraepithelial neoplasias that were invisible during endoscopic fluorescence detection. All high-grade intraepithelial neoplasias or adenocarcinomas (2/2) were detected with both methods. CONCLUSIONS: Fluorescence detection achieved a similar performance when compared with four-quadrant random biopsy, but resulted in fewer biopsies (81 for endoscopic fluorescence detection vs 531 for random four-quadrant biopsies).     

Poor results of 5-aminolevulinic acid-photodynamic therapy for residual high-grade dysplasia and early cancer in barrett esophagus after endoscopic resection

BACKGROUND AND STUDY AIMS: The aim of the study was to evaluate the efficacy of photodynamic therapy (PDT) in the treatment of residual high-grade dysplasia or early cancer (HGD/EC) after endoscopic resection in Barrett esophagus. PATIENTS AND METHODS: Study patients were separated into group A, with proven residual HGD/EC, and group B with possible HGD/EC (positive lateral margins in the endoscopic resection specimen, without HGD/EC in the remaining Barrett esophagus). PDT treatment consisted of 5-aminolevulinic (5-ALA) photosensitization (40 mg/kg) followed by illumination of the Barrett esophagus with a total light dose of 100 J/cm (2). Complete remission was defined as the absence of HGD/EC in biopsies taken in two consecutive follow-up endoscopies. The percentage regression of Barrett esophagus, as well as the recurrence rate of HGD/EC, was calculated. RESULTS: 20 patients underwent PDT (group A, 11; group B, 9). Mild complications were seen in 4/26 procedures. The overall success rate was 15/20 (75 %). There was a significant difference in success rate between group A (55 %) and group B (100 %); P = 0.03. All patients had residual Barrett esophagus after PDT; the median regression percentage was 50 % (IQR 25 - 70 %). Recurrence of HGD/EC occurred in four patients (two each in groups A and B) after a median follow up of 30 months. CONCLUSIONS: In this selected group of patients, the addition of 5-ALA-PDT after endoscopic resection for HGD/EC had a disappointing success rate in patients who had residual HGD/EC after endoscopic resection. Most patients undergoing 5-ALA-PDT have residual Barrett mucosa after PDT and 5-ALA-PDT does not seem to prevent recurrences during follow-up.     

Photodynamische Therapie von Dysplasien und Frühkarzinomen bei Barrett-?sophagus mit einem Diodenlasersystem - eine Pilotstudie

Zusammenfassung Hintergrund: Die photodynamische Therapie (PDT) von Dysplasien und Frühkarzinomen des Ösophagus konnte in ersten Studien gute Ergebnisse bezüglich ihres Ablationspotentials zeigen. Die bislang verwendeten teuren und wartungsaufwendigen Farbstofflaser verhinderten einen breiten klinischen Einsatz. Ziel der Pilotstudie war es, die Eignung der neuen preisgünstigen und wartungsfreien Diodenlaser zur PDT von Dysplasien und Frühkarzinomen der Barrett-Schleimhaut zu prüfen. Patienten und Methodik: Acht Patienten mit Barrett-Ösophagus und/oder Frühkarzinomen wurden behandelt. Als Lichtquelle diente ein Diodenlasersystem mit 2 W Leistung und einer Wellenlänge von 633- 3 nm. Ein Patient wurde primär mit Photosan-3^® behandelt, sieben Patienten erhielten initial 5Aminolävulinsäure. Ergebnisse: In allen Fällen ließen sich eine Längenreduktion und/oder ein histologisches Down-Grading erzielen. Bei drei Viertel der Patienten gelang die komplette histologische Eradikation eines Adenokarzinoms. Metaplastisches Zylinderepithel des Barrett-Ösophagus ließ sich ebenfalls komplett eradizieren. Schlussfolgerung: Die PDT mit Diodenlasersystemen bei Barrett-Ösophagus/Adenokarzinom weist eine vergleichbare Effektivität wie die PDT mit Farbstofflasersystemen auf. Es handelt sich dabei um ein wirkungsvolles und schonendes Verfahren mit geringem Nebenwirkungsspektrum. Abstract Background: Photodynamic therapy (PDT) of dysplasia and early cancer of the esophagus could show good results in the potential of ablation. Unfortunately, the existing expensive and temperamental dye laser systems foiled a broad clinical use. In this pilot study, we investigated the feasibility of an inexpensive and maintenance-free diode laser system for PDT of dysplasia and early cancer in Barrett's esophagus. Patients and Methods: Eight patients with Barrett's esophagus and/or early cancer were treated. As light source we used a diode laser system with a maximum power output of 2 W and a wavelength of 633Dž nm. One patient was treated initially with Photosan-3^®, seven patients received 5-aminolevulinic acid. Results: In all patients we could achieve reduction in length and/or histologically proven downgrading. In three quarters of the patients, complete eradication of adenocarcinoma could be attained. Columnar-lined metaplastic epithelium could also be completely eradicated. Conclusion: PDT using a diode laser system is comparably effective in Barrett's esophagus/early cancer as PDT with dye laser systems. PDT is a gentle and effective technique wit little side effects.     

Local treatment of early cancer in short Barrett's esophagus by means of argon plasma coagulation: initial experience.

In recent years endoscopically controlled local therapeutic methods, such as photodynamic therapy, mucosectomy, or laser therapy, have been used with a curative aim for the destruction of early esophageal or gastric cancers. We report on our experience of treating histologically proven mucosal cancer in Barrett's esophagus with argon plasma coagulation (APC), in three patients. All the mucosal esophageal cancers, with a mean diameter of 4 mm, were successfully destroyed after one or two treatment sessions. Additionally, in two of the three patients the specialized columnar epithelium was replaced by normal squamous cell epithelium when APC treatment was combined with omeprazole. In the third patient with Barrett's esophagus, a partial squamous cell re-epithelialization was induced. No method-related mortality and morbidity were observed. During the mean follow-up of 24.3 +/- 1.1 months (range 23-25 months) one tumor recurrence developed which was successfully treated with photodynamic therapy. In patients with small early Barrett's carcinoma APC might offer an effective, minimally invasive alternative to mucosectomy or photodynamic therapy, as the treatment procedure is less cumbersome and the equipment less expensive.     

High-resolution endoscopy plus chromoendoscopy or narrow-band imaging in Barrett's esophagus: a prospective randomized crossover study

BACKGROUND AND STUDY AIMS: High-resolution endoscopy (HRE) may improve the detection of early neoplasia in Barrett's esophagus. Indigo carmine chromoendoscopy (ICC) and narrow-band imaging (NBI) may be useful techniques to complement HRE. The aim of this study was to compare HRE-ICC with HRE-NBI for the detection of high-grade dysplasia or early cancer (HGD/EC) in patients with Barrett's esophagus. PATIENTS AND METHODS: Twenty-eight patients with Barrett's esophagus underwent HRE-ICC and HRE-NBI (separated by 6 - 8 weeks) in a randomized sequence. The two procedures were performed by two different endoscopists, who were blinded to the findings of the other examination. Targeted biopsies were taken from all detected lesions, followed by four-quadrant biopsies at 2-cm intervals. Biopsy evaluation was supervised by a single expert pathologist, who was blinded to the imaging technique used. RESULTS: Fourteen patients were diagnosed with HGD/EC. The sensitivity for HGD/EC was 93 % and 86 % for HRE-ICC and HRE-NBI, respectively. Targeted biopsies had a sensitivity of 79 % with HRE alone. HGD was diagnosed from random biopsies alone in only one patient. ICC and NBI detected a limited number of additional lesions occult to HRE, but these lesions did not alter the sensitivity for identifying patients with HGD/EC. CONCLUSIONS: In most patients with high-grade dysplasia or early cancer in Barrett's esophagus, subtle lesions can be identified with high-resolution endoscopy. Indigo carmine chromoendoscopy and narrow-band imaging are comparable as adjuncts to high-resolution endoscopy.     

A new long-range through-the-scope balloon applicator for photodynamic therapy in the esophagus and cardia.

BACKGROUND AND STUDY AIMS: Photodynamic therapy (PDT) is a new local, endoscopically controlled therapeutic technique based on the sensitization of malignant and precancerous lesions prior to light-induced tissue destruction. PDT of Barrett's esophagus with severe dysplasia, or of mucosal carcinomas and superficial squamous-cell cancer of the esophagus, requires light application devices allowing homogeneous illumination of the tissue surface in spite of esophageal motility and respiratory movement. On the basis of a commercially available through-the-scope balloon system, we developed a long-range light applicator for homogeneous and circumferential irradiation during PDT, and describe here the initial clinical experience with the device. PATIENTS AND METHODS: The new balloon applicator consists of a flexible cylindrical diffuser fiber with a length of up to 10 cm, depending on the lesion to be illuminated, and an inflatable balloon based on the type of balloon used for esophageal dilation. The balloon is made of a transparent polyurethane membrane with negligible absorption (<5%) at lambda = 600-700 nm, and it can be positioned through the biopsy channel of a conventional endoscope, with direct endoscopic visualization of the targeted lesion. The light intensity distribution perpendicular to the optical axes of the diffuser was measured for red laser light (lambda = 632.8 nm) and for green laser light (lambda = 542 nm). The study of photodynamic treatment included two women and four men (aged 48-79 years) with histologically proved high-grade dysplasia (n = 2) or mucosal cancer in Barrett's esophagus (n = 2) and superficial squamous-cell cancer (SCC) (n = 2), who had undergone EUS staging showing uT0 or uT1N0. Laser light irradiation was conducted after oral ingestion of 5-aminolevulinic acid (5-ALA) or intravenous administration of meta-(tetrahydroxyphenyl)chlorin (mTHPC). RESULTS: Both in vitro and in vivo, precise positioning of the new application system at the targeted tissue and homogeneous illumination were feasible, safe and effective. The total efficiency of transmitted light at wavelengths of lambda = 632.8 nm and lambda = 542 nm was 85-90%. A high degree of homogeneity was measured with applicator lengths of between 15 mm and 95 mm, and the maximum deviation from the mean intensity extended over a range of 40% over the total length of 80 mm. High-grade dysplasia was eradicated in all patients, and in addition mucosal cancer was successfully destroyed in three-quarters of them, requiring an average of 1.3 treatment sessions, with a mean follow-up of 12 months (range 10-15 months). CONCLUSIONS: This centering balloon system may in the future be capable of improving light application techniques during esophageal photodynamic therapy, making PDT a more reliable alternative modality for minimally invasive treatment of high-grade dysplasia and early Barrett's esophagus or squamous-cell carcinoma, as compared with esophagectomy.     

Image analysis for classification of dysplasia in Barrett's esophagus using endoscopic optical coherence tomography

Barrett's esophagus (BE) and associated adenocarcinoma have emerged as a major health care problem. Endoscopic optical coherence tomography is a microscopic sub-surface imaging technology that has been shown to differentiate tissue layers of the gastrointestinal wall and identify dysplasia in the mucosa, and is proposed as a surveillance tool to aid in management of BE. In this work a computer-aided diagnosis (CAD) system has been demonstrated for classification of dysplasia in Barrett's esophagus using EOCT. The system is composed of four modules: region of interest segmentation, dysplasia-related image feature extraction, feature selection, and site classification and validation. Multiple feature extraction and classification methods were evaluated and the process of developing the CAD system is described in detail. Use of multiple EOCT images to classify a single site was also investigated. A total of 96 EOCT image-biopsy pairs (63 non-dysplastic, 26 low-grade and 7 high-grade dysplastic biopsy sites) from a previously described clinical study were analyzed using the CAD system, yielding an accuracy of 84% for classification of non-dysplastic vs. dysplastic BE tissue. The results motivate continued development of CAD to potentially enable EOCT surveillance of large surface areas of Barrett's mucosa to identify dysplasia.     

Argon plasma coagulation for treatment of watermelon stomach

BACKGROUND AND STUDY AIMS: Watermelon stomach or gastric antral vascular ectasia (GAVE) is a rare but well-recognized cause of gastrointestinal blood loss, which typically affects elderly women. Historically patients were treated with antrectomy but this has been largely replaced by endoscopic therapy such as Nd:YAG laser. Argon plasma coagulation (APC) is a new noncontact electocoagulation technique which has several theoretical advantages over laser. The objective of this study was to assess the efficacy of APC in treating GAVE. PATIENTS AND METHODS: We retrospectively reviewed the case-records of five patients (four women, one man) with iron deficiency anaemia or gastrointestinal blood loss due to GAVE who were treated with APC and for whom a follow-up of more than 12 months was available. Four patients were transfusion-dependent. Their mean age was 71 years (range 58 - 83). The mode of presentation, number of treatment sessions, response to therapy and recurrence (if any) were recorded. RESULTS: A mean of 2.6 treatment sessions per patient were required. All patients had an endoscopically observed response to therapy and all patients had a sustained rise in hemoglobin level after treatment. Transfusion dependence ceased in all patients. After a mean follow-up of 20 months GAVE recurred in two patients (40 %). Both patients responded to further APC treatment. No major complications were recorded. CONCLUSION: APC is a safe and effective short-term treatment for GAVE. The natural history of the condition is uncertain, and at medium-term follow-up GAVE is found to recur in a substantial number of patients treated with APC. Re-treatment with APC is an option in these patients.     

The role of radiofrequency ablation in the management of Barrett's esophagus

Studies in the last several years have consistently shown radiofrequency ablation (RFA) to be effective, safe, and well tolerated in the treatment of nondysplastic and dysplastic Barrett's esophagus (BE). The results found at academic medical centers have been reproduced in the community setting. RFA provides a safe and cost-effective alternative to surgery or surveillance in the management of high-grade dysplasia (HGD). RFA should be given serious consideration as first-line therapy for HGD. This article reviews the evidence behind RFA to differentiate it from other management strategies in terms of efficacy, durability, safety, tolerability, and cost-effectiveness. The role of RFA in the management of BE is described, including endoscopic resection. Future directions are identified for research that will help to better define the role of RFA in the management of BE.