Faculty Bibliography

This is a review of the uses, history, and current status of photodynamic therapy for diseases of the esophagus, specifically Barrett's dysplasia and early esophageal carcinoma. This paper describes the clinical experience of photodynamic therapy and compares the use of various photosensitizer drugs. Finally, important biophotonics developments are discussed, including their anticipated impact for improved endoscopic detection of dysplasia and carcinoma. In addition, methods for real-time photodynamic therapy and light dosimetry are provided in order to optimize ablation treatment outcomes while minimizing the risk of complications.

The goal of colonoscopy is to identify and remove premalignant and malignant polyps. During colonoscopy it is not feasible to differentiate with certainty if a polyp is benign or premalignant, resulting in removal of all polyps via polypectomy. In attempts to overcome this clinical dilemma, techniques such as chromendoscopy have been developed to aid in improving the accuracy of identifying precancerous polyps. Chromendoscopy helps detect suspicious polyps using a dye spraying technique, but it is time consuming and causes collateral distortion of the adjacent mucosal field. Recently, narrow band imaging (NBI) has been able to highlight abnormal mucosal topography and microvasculature by illuminating with narrow range blue light. This is achieved with the click of a button on the endoscope, and the accuracy of differentiating between abnormal and normal mucosa is equivalent to chromendoscopy. NBI and other similar technologies will likely provide an electronic, easier alternative to chromoendoscopy to aid the endoscopist in differentiation among benign, premalignant, and malignant mucosal patterns.

Small bowel diverticulosis (SBD) is a rare entity. Most cases of diverticulosis are asymptomatic. SBD is often discovered incidentally during contrast studies and endoscopy. When patients report chronic gastrointestinal symptoms such as abdominal pain, bloating, flatulence, and anemia, SBD is often an overlooked diagnosis. Patients requiring treatment for SBD are those with complications such as malabsorption, hemorrhage, obstruction, and acute inflammation with abscess or rarely perforation. Malabsorption can be managed with broad-spectrum antibiotics and vitamin supplementation. Hemorrhage is treated conservatively with resuscitation efforts, but recurrent bleeding requires surgery. Enteroliths causing obstruction in the duodenum can be relieved by endoscopy, that is, by manipulation, but jejunoileal obstruction requires a resection. Pseudo- obstruction may be managed with prokinetics such as metoclopramide, erythromycin, and the 5-hydroxytryptamine 4 agonist tegaserod. Uncomplicated cases of SBD are treated with bowel rest and antibiotics. However, perforation or abscess formation not amenable to percutaneous drainage mandates surgical resection. Any patient with a triad of anemia, abdominal pain, and an abdominal radiograph with dilated loops of small bowel merits SBD in the differential diagnosis