Perfusion of individual tissues is a basic physiological process that is necessary to sustain oxygenation and nutrition at a cellular level.
Ischemia, or the insufficiency of perfusion, is a common mechanism for tissue death or degeneration, and at a lower threshold, a mechanism for the generation of sensory signalling including
pain. It is of considerable interest to study perfusion of peripheral abdominal tissues in a variety of circumstances. Microvascular disease of the abdominal organs has been implicated in the pathogenesis of a variety of disorders, including
peptic ulcer disease,
inflammatory bowel disease and
chest pain. The basic principle of
laser Doppler perfusion monitoring (LDPM) is to analyze changes in the spectrum of light reflected from tissues as a response to a beam of monochromatic
laser light emitted. It reflects the total local microcirculatory blood perfusion, including perfusion in capillaries, arterioles, venules and shunts. During the last 20-25 years, numerous studies have been performed in different parts of the gastrointestinal (GI) tract using LDPM. In recent years we have developed a multi-modal
catheter device which includes a
laser Doppler probe, with the intent primarily to investigate patients suffering from functional
chest pain of presumed oesophageal origin. Preliminary studies show the feasibility of incorporating LDPM into such
catheters for performing physiological studies in the GI tract. LDPM has emerged as a research and clinical tool in preference to other methods; but, it is important to be aware of its limitations and account for them when reporting results.