Barrett Esophagus

Barrett esophagus is a metaplastic change in the lining of the distal esophageal epithelium, characterized by replacement of the normal squamous epithelium by specialized intestinal metaplasia. The presence of Barrett esophagus increases the risk of esophageal adenocarcinoma several-fold. Esophageal adenocarcinoma is a malignancy with rapidly rising incidence and persistently poor outcomes when diagnosed after the onset of symptoms. Risk factors for Barrett esophagus include chronic gastroesophageal reflux, central obesity, white race, male gender, older age, smoking, and a family history of Barrett esophagus or esophageal adenocarcinoma. Screening for Barrett esophagus in those with several risk factors followed by endoscopic surveillance to detect dysplasia or adenocarcinoma is currently recommended by society guidelines. Minimally invasive nonendoscopic tools for the early detection of Barrett esophagus are currently being developed. Multimodality endoscopic therapy—using a combination of endoscopic resection and ablation techniques—for the treatment of dysplasia and early adenocarcinoma is successful in eliminating intestinal metaplasia and preventing progression to adenocarcinoma, with outcomes comparable to those after esophagectomy. Risk stratification of those diagnosed with Barrett esophagus is a challenge at present, with active research focused on identifying clinical and biomarker panels to identify those with low and high risk of progression. This narrative review highlights some of the challenges and recent progress in this field.     

Photodynamic therapy for dysplastic Barrett esophagus and early esophageal adenocarcinoma

OBJECTIVE: To evaluate our results using photodynamic therapy (PDT) for the treatment of dysplasia or superficial cancer (T1 N0 M0) in patients with Barrett esophagus. PATIENTS AND METHODS: We retrospectively reviewed our clinical experience with 48 patients (34 patients with high-grade dysplasia and 14 patients with superficial cancer in Barrett esophagus) who had been referred for PDT. Initial evaluation included computed tomography and standard and high-frequency catheter endosonography. Follow-up endoscopy was performed 4 to 6 weeks after PDT with ablation of any residual glandular mucosa, using the argon plasma coagulator. Patients were then followed up indefinitely every 3 to 6 months with computed tomography, endosonography, and endoscopic surveillance. RESULTS: The median series follow-up was 18.5 months (range, 1-56 months). Apparent complete photoablation of Barrett mucosa and/or superficial neoplasm was documented in 47 of 48 cases. Complications included symptomatic strictures (11 patients), photosensitivity (7 patients), atrial fibrillation (1 patient) or recurrent congestive heart failure (1 patient), and self-limited esophageal perforation (1 patient). Failure to ablate T1 N0 M0 adenocarcinoma occurred in 1 patient. CONCLUSIONS: Porfimer sodium PDT appears to eradicate dysplastic Barrett mucosa and neoplasia. These results are promising; however, long-term studies are needed to document the efficacy of PDT in reducing the morbidity and mortality in such patients.     

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.     

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.     

功能性消化不良者心理因素与食管动力的关系

目的探讨心理因素与功能性消化不良(FD)食管动力的关系。方法使用高分辨率旁道灌注测压系统对20例健康对照组及121例FD进行食管动力测定,同时以焦虑自评量表及抑郁自评量表评定两组的心理状态,并观察食管动力与心理状态的联系。结果9.8%(24/121)的FD患者有食管动力障碍,主要表现为非特异性食管动力障碍70.8%(17/24);胡桃夹食管2例、弥漫性食管痉挛5例;60.7%(73/121)的FD者有心理障碍,其中抑郁障碍38.0%(46/121)、焦虑障碍48.8%(59/121),对照组1例有轻度的抑郁障碍,P<0.01。有心理障碍FD者食管动力障碍发生率(26.0%,19/73)比非心理障碍FD者(10.4%,5/48)显著增高(P<0.05),且前者LES压力、食管体蠕动波幅、持续时间均显著高于后者(P<0.05)。结论食管动力障碍是FD重要功能紊乱之一,长期抑郁或焦虑可能影响FD食管动力。     

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.     

Barrett's esophagus: treatment with 5-aminolevulinic acid photodynamic therapy

Barrett's esophagus has been identified as the premalignant precursor of esophageal adenocarcinoma. The eradication of metaplastic or dysplastic columnar-lined (Barrett's) esophagus may prevent progression to esophageal adenocarcinoma. 5-Aminolevulinic acid photodynamic therapy is a simple method for the mucosal ablation of the abnormal segment. Areas of metaplastic epithelium may remain buried after treatment and continued surveillance is necessary. Repeated treatments often are necessary but are very well tolerated with few complications.     

Mucosal ablation therapy of barrett esophagus

Barrett esophagus is defined by the metaplasia of existing squamous mucosa into a specialized intestinal-type mucosa. The importance of this metaplasia is the association of this condition with the development of adenocarcinoma of the esophagus. Elimination of the metaplastic mucosa may decrease the cancer risk. Currently, several forms of therapy have evolved with the goal of replacing the specialized mucosa with normal squamous mucosa. These proposed treatments include photodynamic therapy and thermal techniques. The effectiveness of photodynamic therapy varies depending on the pharmaceutical photosensitizer used and the wavelength of light applied to activate the drug. Thermal techniques include multipolar coagulation, argon plasma coagulation, KTP:YAG laser therapy, Nd:YAG laser therapy, and argon laser therapy. Finally, mucosal resection has been attempted through the endoscope to remove large areas of the Barrett mucosa. All of these ablative strategies attempt to destroy the metaplastic mucosa and promote the regrowth of squamous epithelium. These therapies have demonstrated the ability to "reverse" the metaplasia to varying degrees, but a decrease in cancer risk has not been demonstrated conclusively with any of these treatment methods.     

An educational tool for photodynamic therapy of Barrett esophagus with high-grade dysplasia: from screening through follow-up.

Photodynamic therapy using a centering balloon was recently approved by the Food and Drug Administration for ablation of Barrett esophagus with high-grade dysplasia. This article is an educational tool for the photodynamic therapy team, addressing four important steps involved with photodynamic therapy: screening for potential patients, patient education, treatment using the centering balloon, and follow-up after treatment. Each step ensures proper care for the patient requiring photodynamic therapy.     

Management of gastroesophageal reflux disease

Gastroesophageal reflux disease is the most common and expensive digestive disease with complex and multi-factorial pathophysiologic mechanisms. Transient inappropriate relaxation of the lower esophageal sphincter is the predominant mechanism in the majority of patients with mild to moderate disease. Hiatal hernias and a reduced lower esophageal sphincter pressure have a significant role in patients with moderate to severe disease. Typical manifestations of gastroesophageal reflux disease include heartburn, regurgitation, and dysphagia. Atypical symptoms, such as noncardiac chest pain, pulmonary manifestations of asthma, cough, aspiration pneumonia, or ENT manifestations of globus and laryngitis, can be seen in patients with or without typical symptoms of gastroesophageal reflux disease. Endoscopy and ambulatory pH tests are best to evaluate the anatomic and physiologic impact ofgastroesophageal reflux disease. Complications of chronic gastroesophageal reflux disease include peptic strictures and Barrett metaplasia. Barrett esophagus is a major risk factor for esophageal adenocarcinoma, and upper endoscopy with surveillance biopsies is recommended for patients with Barrett esophagus. Medical therapy with anti-secretory agents (H2 blockers and proton pump inhibitors) is effective for most patients with gastroesophageal reflux disease. Surgical fundoplications and endoscopic treatment modalities are mechanical treatment options for patients with gastroesophageal reflux disease.     

Clinical impact of conventional endosonography and endoscopic ultrasound-guided fine-needle aspiration in the assessment of patients with Barrett's esophagus and high-grade dysplasia or intramucosal carcinoma who have been referred for endoscopic ablation therapy

BACKGROUND AND STUDY AIMS: Endoscopic mucosal resection and photodynamic therapy are exciting, minimally invasive curative techniques that represent an alternative to surgery in patients with Barrett's esophagus and high-grade dysplasia or intramucosal adenocarcinoma. However, there is lack of uniformity regarding which staging method should be used prior to therapy, and some investigators even question whether staging is required prior to ablation. We report our experience with a protocol of conventional endoscopic ultrasound staging prior to endoscopic therapy. PATIENTS AND METHODS: A total of 25 consecutive patients with a diagnosis of high-grade dysplasia or intramucosal adenocarcinoma in Barrett's esophagus who had been referred to the University of Chicago for staging in preparation for endoscopic therapy between March 2002 and November 2004 were included in the study. All 25 patients underwent repeat diagnostic endoscopy and conventional endosonography with a radial echo endoscope. Any suspicious lymph nodes that were detected were sampled using endoscopic ultrasound-guided fine-needle aspiration. RESULTS: Baseline pathology in the 25 patients (mean age 70, range 49-85) revealed high-grade dysplasia in 12 patients and intramucosal carcinoma in 13 patients. Five patients were found to have submucosal invasion on conventional endosonography. Seven patients had suspicious adenopathy, six regional (N1) and one metastatic to the celiac axis (M1a). Fine-needle aspiration confirmed malignancy in five of these seven patients. Based on these results, five patients (20%) were deemed to be unsuitable candidates for endoscopic therapy. CONCLUSIONS: By detecting unsuspected malignant lymphadenopathy, conventional endosonography and endoscopic ultrasound with fine-needle aspiration dramatically changed the course of management in 20% of patients referred for endoscopic therapy of Barrett's esophagus with high-grade dysplasia or intramucosal carcinoma. Based on our results, we believe that conventional endosonography and endoscopic ultrasound with fine-needle aspiration when nodal disease is present should be performed routinely in all patients referred for endoscopic therapy in this setting.     

Intraepithelial high-grade neoplasia and early adenocarcinoma in short-segment Barrett's esophagus (SSBE): curative treatment using local endoscopic treatment techniques

BACKGROUND AND STUDY AIMS: In recent years, short-segment Barrett's esophagus (SSBE) has attracted increasing attention in the context of reflux disease. However, there is continuing controversy regarding its potential for malignant transformation. PATIENTS AND METHODS: Between October 1996 and September 1999, 50/115 patients (43 %) with intraepithelial high-grade neoplasia or early Barrett's adenocarcinoma, who underwent local endoscopic treatment, had developed a malignant lesion in an (SSBE). In the framework of a prospective observational study, 28 patients were treated with endoscopic mucosal resection (EMR), 13 with photodynamic therapy, and three with argon plasma coagulation; six patients received combinations of these treatments. RESULTS: Complete local remission was achieved in 48/49 patients (98 %). One patient switched to surgery after the first EMR, because there was submucosal tumor infiltration, and in one patient out of 50 local endoscopic treatment failed. A mean of 1.7 +/- 1.4 treatment sessions was required for local endoscopic treatment. The method-associated mortality was 0 %. The rate of relevant complications (stenosis, bleeding) was 6 % (3/50 patients). No cases of severe hemorrhage (Hb fall >2 g/dl) or perforation occurred. During a mean follow-up period of 34 +/- 10 months, metachronous intraepithelial high-grade neoplasms or early adenocarcinomas were seen in 11/48 patients (23 %), who received further successful endoscopic treatment. Four patients died during the follow-up period, but in only one patient was this due to his Barrett's adenocarcinoma (this was the patient who underwent esophageal resection). CONCLUSIONS: The malignant potential of short-segment Barrett's esophagus must not be underestimated. Organ-preserving local endoscopic treatment shows good acute-phase and long-term results. Local endoscopic treatment represents an alternative to esophageal resection in the case of intraepithelial high-grade neoplasia and selected early adenocarcinomas in Barrett's esophagus.     

Frequency of Barrett's neoplasia after initial negative endoscopy with biopsy: a long-term histopathological follow-up study

BACKGROUND: Barrett's adenocarcinoma is being diagnosed increasingly. We examine possible differences between long segment and short-segment Barrett esophagus (LSBE and SSBE) in long-term follow-up on the basis of our histopathology registry. METHODS AND PATIENTS: All Barrett's esophagus patients diagnosed histologically between 1990 and 1995 (n = 1071) were selected. Long-term follow-up data from endoscopy with biopsy were sought on all patients without neoplasia on initial endoscopic biopsy (n = 1003). A total of 255 individuals (25.4 %) were regarded as drop-outs (201 lost and 54 without further endoscopy). Of the remaining 748 patients with follow up for more than 5 years, 315 had documented LSBE, 246 had SSBE, and 187 had no length of Barrett esophagus recorded (NLBE). RESULTS: In the study cases (male : female ratio 2.1 : 1, mean age +/- SD 60.9 +/- 14.2 years), the biopsy procedure was fully compliant with guidelines in only 32.5 %. Only 5 cases (0.6 %) had visible lesions reported on endoscopy, but all were negative for neoplasia. Over a mean follow-up of 78.2 +/- 35.6 months (range 0-240), 7 new cases of low grade intraepithelial neoplasia (LGIN) and 15 cancer cases developed, accounting for a yearly incidence of 0.2 % (LGIN) or 0.4 % (cancer) after an initial negative endoscopy. When the cases with initial diagnosis of neoplasia were included, this yearly incidence rose to 0.5 % (LGIN), 0.3 % (high grade intraepithelial neoplasia [HGIN]) or 1.7 % (cancer). Differences between SSBE and LSBE were only encountered for cancer incidence. CONCLUSION: The yearly incidence of Barrett esophagus cancer varies between 0.4 % and 1.7 %. Despite the limitations of this retrospective and pathology-based study, the observed risk of developing cancer in Barrett esophagus without neoplasia is comparable to that found in other studies, mainly from the US and the UK, and varies between 0.7 % and 1.0 % of yearly incidence.     

Barrett esophagus: update for radiologists

Barrett esophagus is a well-recognized entity in which there is progressive columnar metaplasia of the lower esophagus due to longstanding gastroesophageal reflux and reflux esophagitis [1]. This condition is important because it is associated with an increased risk of developing esophageal adenocarcinoma by a well-established sequence from dysplasia to carcinoma [2]. During the past decade, however, an explosion of new data has dramatically affected our understanding of Barrett esophagus. Not only have revised histopathologic criteria been developed for this condition, but it is currently believed that patients with Barrett esophagus should be classified as having short-segment or long-segment disease based on the extent of columnar metaplasia in the distal esophagus. This distinction has important implications for the risk of developing esophageal adenocarcinoma and subsequent need for endoscopic surveillance. The purpose of this article is to present these new concepts about Barrett esophagus and provide radiologists with a more current framework for diagnosing this condition.     

The fetal esophagus: anatomical and physiological ultrasonographic characterization using a high-resolution linear transducer.

OBJECTIVE: To study the sonographic anatomy and physiology of the human fetal esophagus during the mid-trimester of pregnancy using a high-resolution linear transducer. METHODS: This was a prospective observational study of the fetal esophagus between 19 and 25 weeks' gestation. The study was performed in 60 consecutive fetuses, after a normal anatomy scan, using a 5-13-MHz matrix array wide-band transducer. During the examination the collapsed esophagus was first visualized, and followed by a 5-min video recording in order to demonstrate luminal patency and peristaltic waves. RESULTS: Complete anatomical visualization of the esophagus was possible in 52 (86.7%) patients and at least partial visualization in 58 (96.7%) patients. Three different patterns of esophageal motility were observed: a simultaneous and short opening of the whole esophagus was found in 35 (58.3%) fetuses; a segmental, peristalsis-like movement from the pharynx, through the mediastinum, and into the stomach was found in 18 (30%) fetuses; and in one fetus reflux-like passage of solid contents from the stomach was observed. The mean time required for demonstration of esophageal patency was 96.1 (range, 10-300) s. CONCLUSIONS: Demonstration of normal anatomy and physiological activity of the fetal esophagus is feasible using appropriate transducers. The most commonly observed pattern of esophageal motility in the mid-trimester of pregnancy is the simultaneous relaxation of the upper and lower esophageal sphincters with concurrent opening of the esophageal lumen from the upper thorax to the stomach. Demonstration of a patent esophagus may be helpful in fetuses with suspected esophageal atresia.     

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.     

24h食管pH监测和食管测压及奥美拉唑治疗试验在食管原性胸痛中的应用

目的 :探讨 2 4 h食管 p H监测和食管测压及奥美拉唑治疗试验在食管原性胸痛中的诊断价值。方法 :对食管原性胸痛 6 8例行内镜、食管测压、2 4 h食管 p H监测及 7d的奥美拉唑 (2 0 mg,2次 / d)治疗试验 ,治疗后症状评分比治疗前降低超过 75 %者则为治疗试验阳性。结果 :食管原性胸痛 6 8例中 5 5例 (81% )符合胃食管反流病 (GERD) ,胡桃夹食管 2例 ,早期贲门失驰缓症 3例 ,弥漫性食管痉挛 3例 ,无效食管运动 (IEM) 5例。GERD5 2例测压分析 ,35例(6 7% )符合 IEM诊断标准。奥美拉唑治疗试验对诊断 GERD的敏感性为 93% ,特异性为 85 %。结论 :GERD是食管原性胸痛的主要原因。 2 4 h食管 p H监测和食管测压是诊断食管原性胸痛的主要检查手段 ,奥美拉唑治疗试验是临床诊断GERD简便而实用的方法。     

Barrett's esophagus occurring as a complication of scleroderma

Two patients had both scleroderma and a columnar epithelium-lined lower esophagus (Barrett esophagus). Features of Barrett's esophagus included high esophageal strictures in both patients and ulcer craters in the columnar area of one. Biopsy confirmed columnar epithelium in the lower esophagus of each patient. In these patients, the Barrett esophagus probably was a complication of scleroderma and resulted from long-standing gastroesophageal reflux.     

Optimization of the diameter of a radial irradiation device for photodynamic therapy in the esophagus

BACKGROUND AND STUDY AIMS: Photodynamic therapy (PDT) is a local therapeutic technique based on the photosensitization of lesions using a dye prior to light-induced tissue destruction. PDT of intraepithelial neoplasia in Barrett's esophagus, or of early squamous-cell carcinoma of the esophagus, requires light application devices that allow homogeneous and well-defined illumination of the tissue surface. Such devices must be large enough to induce complete unfolding of the esophagus in spite of esophageal motility and elasticity. The aim of this study was therefore to determine the optimal diameter of a cylindrical illumination device for PDT in this organ. PATIENTS AND METHODS: The study included nine patients (aged 49-72 years) who underwent panendoscopy. Flexible transparent hollow tubes with diameters ranging from 13 to 19 mm were successively introduced into the esophagus, and the esophageal wall was viewed from the inside through the tube using a flexible small-diameter endoscope. The number of folds was counted. Observations of the upper, middle, and lower thirds of the esophagus were recorded. The radial location of the folds was also recorded, and defined as follows: anterior wall (up), posterior wall (down), side walls (right, left). RESULTS: No significant difference in the number of folds between the lower and middle parts of the esophagus was noticed. However, the upper third had significantly fewer folds (about 30 %) than the other two parts. For diameters above 17 mm, this difference was less dramatic. The number of such folds was shown to decrease with the increasing diameter of the device. CONCLUSIONS: It appears that 18 mm or more is the optimal diameter for a fixed-geometry cylindrical photodynamic therapy irradiating device for the patient category considered in this study. It was also observed that most folds were located on the side walls of the esophagus.     

Biology of Barrett's esophagus and esophageal adenocarcinoma

The past few years have brought new advances in our understanding of the molecular mechanisms underlying the development of Barrett's esophagus and esophageal adenocarcinoma. Although knowledge of the genetic basis for these conditions has not yet translated into clinically useful biomarkers, the current pace of biomedical discovery holds endless possibilities for molecular medicine to improve the diagnosis and management of patients with these conditions. This article provides a useful conceptual basis for understanding the molecular events involved in the making of Barrett metaplasia and in its neoplastic progression, and provides a rationale for evaluating studies on the application of molecular medicine to the diagnosis and management of patients with Barrett's esophagus and esophageal adenocarcinoma.