Review <p>A best evidence topic in cardiothoracic surgery was written<br />according to a structured protocol. The question addressed<br />was: In [adults undergoing a maze procedure for atrial fibrillation<br />(AF)], [does left atrial size reduction] compared<br />to [maze surgery alone] improve [maze surgery success]?<br />A total of 58 papers were found using the reported search,<br />of which eight represented the best evidence to answer the<br />clinical question. The authors, journal, date and country of<br />publication, patient group studied, study type, relevant outcomes<br />and results of these papers are tabulated. Four out<br />of eight papers compared a volume reduction technique<br />as an adjunct to the maze procedure to a maze procedure<br />alone - all four papers reported that atrial volume reduction<br />significantly increased restoration of sinus rhythm:<br />89.3% vs. 67.2%, P&lt;0.001; 85% vs. 68%, P&lt;0.05; 84% vs.<br />68%, P&lt;0.05; 90% vs. 69%, P&lt;0.05. Three out of eight papers<br />had no control group but reported good rates of sinus<br />rhythm restoration at last follow-up -90%, 92% and 89%,<br />respectively - despite the study population including atrial<br />enlargement, a risk factor for failure of a maze procedure.<br />One paper reported no benefit of an atrial reduction plastyin patients with a left atrium (LA) &gt;70 mm. An enlarged<br />LA is a risk factor for failure of a maze procedure, and various<br />models of AF suggest that reducing atrial mass and/or<br />diameter may help to abolish the re-entry circuits underlying<br />AF. Furthermore, AF is uncommon when left atrial<br />diameter is &lt;40 mm, so there is at least some physiological<br />basis for atrial reduction surgery in aiding the success of a<br />maze procedure. The evidence suggests that patients with<br />an enlarged ( 55 mm) or giant ( 75 mm) LA who are at<br />risk of failing to obtain sinus conversion after a standard<br />maze procedure may derive benefit from concomitant atrial<br />reduction surgery using either a tissue excision or a tissue<br />plication technique. However, the evidence is not strong<br />since the papers available are not readily comparable owing<br />to substantial variations in the populations and procedures<br />involved. We therefore, emphasise the need for prospective<br />randomised studies in this area. Keywords: Atrial fibrillation;<br />Cox maze; Left atrial size reduction; maze, Minimaze;<br />Recurrence of atrial fibrillation</p> - 0 0 http://www.iscs.org.ir/journals/vol.3/no.3/360/