CIRCUMFERENTIAL SUTURE OF THE MITRAL ANNULUS FOR CORRECTION OF MITRALREGURGITATION IN DOGS

Objective-To develop a method for reducing mitral regurgitation in dog s by positioning and tightening a circumferential suture around the mi tral valve annulus. Study Design-Description of clinical cases. Animal s-15 dogs with spontaneous mitral valve disease, annular dilation, and refractory congestive heart failure treated between 1962 and 1994. Me thods-A composite suture material was constructed using braided Teflon -impregnated polyester sternotomy suture, barium sulfate thread, and S ilastic tubing. Through a left lateral thoracotomy, the suture was pos itioned around the mitral annulus by passing it through the coronary s inus, right atrium, and underneath the left coronary arteries before t ightening it. Results-Six dogs died during surgery because of hemorrha ge from the left atrium, coronary sinus, or left coronary artery. Thre e dogs died postoperatively because of coronary artery compression by the suture. Satisfactory suture placement was achieved in six dogs, th ree of which were long-term survivors (6 to 26 months) before they wer e euthanatized for noncardiac reasons. Conclusions-Reduction of mitral annulus diameter with a circumferential purse-string suture does not require cardiopulmonary bypass. The surgery is technically difficult, and detailed knowledge of coronary artery anatomy is required. The cur rent suture design is inexpensive, radiopaque, and biocompatible; no s pecial instruments are required for placement. Clinical Relevance-Mitr al regurgitation is the most common cardiovascular disorder in dogs an d the most common cause of congestive heart failure. Annular dilation occurs as a consequence of mitral regurgitation. Placement and tighten ing of a circumferential suture around the mitral annulus reduces the degree of mitral regurgitation. (C) Copyright 1998 by The American Col lege of Veterinary Surgeons.