RESUMEN
Esophageal infarction or acute necrotizing esophagitis is a rare condition that has a dramatic endoscopic appearance of a "black esophagus." The esophageal involvement can vary from the distal third to the total esophagus. Excluding corrosive injury and other well-known rare causes of black esophagus, the etiology of this condition is unknown. Ischemia due to hypoperfusion state is thought to play a central role in the pathogenesis. The treatment is supportive with acid suppression and gastrointestinal rest. Mortality is high due to comorbid conditions.
RESUMEN
In up to 10% to 20% of colonoscopies, complete intubation of the colon may be considerably difficult. A principal cause of difficulty is looping of the endoscope shaft in a floppy, often tortuous segment of the colon that typically happens in the sigmoid colon. Also, if looping is not recognized and the scope is advanced with abandon, the risk of perforation will rise. Special "variable stiffness" colonoscopies are expensive and have not been unequivocally shown to be useful in preventing looping. The simplest approach to prevent looping is perhaps the use of an over-tube to prevent the shaft from bowing out. The ShapeLock could offer an ideal over-tube that is flexible enough to safely and easily negotiate bends in the colon but when needed be rigid enough to prevent looping with just a snap of its handle. It also has potential other applications including enteroscopy, transgastric endoscopy and access to difficult regions of the upper gastrointestinal tract.