- : A device used to stretch or enlarge an opening. Patients with scarring of the muscular tube through which food passes from the throat to the stomach (esophagus) can require a dilator procedure in order to open the esophagus for adequate passage of food and fluids.
* * *1. An instrument designed for enlarging a hollow structure or opening. 2. A muscle that pulls open an orifice. 3. A substance that causes dilation or enlargement of an opening or the lumen of a hollow structure. SEE ALSO: bougie. SYN: dilatator.- Hegar dilators a series of cylindrical bougies of graduated sizes used to dilate the cervical canal.- hydrostatic d. an instrument for dilating esophageal strictures; fluid pressure is delivered into a flexible area of the instrument placed in the stricture to establish a uniform dilating pressure.- d. iridis SYN: d. pupillae muscle.- pneumatic d. any of a variety of catheters fitted with distal balloons that can be inflated to desired pressures for overcoming obstructions in hollow viscera; most often used to rupture the lower esophageal sphincter to treat achalasia.- Walther d. a gently curved instrument that tapers to an increased diameter, used to dilate the female urethra.
* * *a) an instrument for expanding a tube, duct, or cavity <a urethral \dilator> called also divulsorb) a muscle that dilates a partc) a drug (as a vasodilator) causing dilation
* * *n.1. an instrument used to enlarge a body opening or cavity. For example, the male urethra may become narrowed by disease and it can sometimes be restored to its original size by inserting a dilator. Dilators (such as Hegar's dilator) are also used to enlarge the canal in the cervix of the uterus in the procedure of dilatation and curettage.2. a drug, applied either locally or systemically, that causes expansion of a structure, such as the pupil of the eye or a blood vessel. See also vasodilator.3. a muscle that, by its action, opens an aperture or orifice in the body.
* * *di·la·tor (di-laґtər) (diґla-tər) 1. an instrument used in enlarging a canal, orifice, tube, or vessel by stretching. 2. dilatator (def. 2).
Medical dictionary. 2011.