Aetna considers the Maze procedure, performed with cardiopulmonary bypass on a beating heart, medically necessary for members with atrial fibrillation/flutter when any of the following criteria is met:

• Member can not tolerate the side effects of drug therapy (adequate documentation of the nature and extent of the intolerance is required); or
• Member is suffering the hemodynamic consequences of chronic atrial fibrillation/flutter despite adequate attempts at medical management; or
• Member is at high-risk for thromboembolism as evidenced by either:
  
  
  • A previous episode of thromboembolism when other sources of emboli have been ruled out, or
  • Documented long-standing atrial fibrillation in members with mitral valve disease undergoing open surgical repair of the mitral valve.

Aetna considers the MAZE procedure experimental and investigational for all other indications because its effectiveness for indications other than the ones listed above has not been established.

Aetna considers minimally invasive, off-pump maze procedures, also known as thoracoscopic off-pump surgical ablation (TOPS), experimental and investigational for atrial fibrillation or flutter because there is insufficient evidence of their effectiveness.

See also CPB 0019 - Holter Monitors. 

The Maze procedure is a surgical treatment of atrial fibrillation (AF) in which multiple atrial incisions interrupt the pathogenic reentrant circuits and also direct the sinus impulses to the AV node along a specified route.  In addition, multiple blind "alleys" off the main conduction route allow for activation of the entire atrium.  By eliminating AF, this technique not only addresses the hemodynamic consequences of AF, it also eliminates the threat of thromboembolism AF can cause.

As part of the ongoing study of this procedure, individuals typically undergo a variety of post-operative tests to evaluate the status of the atria.  Unless clinically indicated by the member's signs and symptoms, these tests are considered not routinely medically necessary for post-operative evaluation.  Such tests include: endocardial catheter electrophysiology study; 24-hour Holter monitor; exercise stress test; and color-flow Doppler evaluation of transmitral and transtricuspid valve flow.

Gaynor and co-workers (2005) stated that the Cox maze procedure remains the gold standard for the treatment of AF and has excellent long-term efficacy.  The most significant predictor of late recurrence was duration of pre-operative AF, suggesting that earlier surgical intervention would further increase effectiveness.  This is in agreement with the findings of Chen et al (2005) who noted that the pre-operative left atrial size and duration of AF are primary predictors of sinus conversion by the radiofrequency Maze procedure for patients with persistent AF and mitral valve disease.  Moreover, in a systematic review on surgical treatment of AF, Khargi et al (2005) could not identify any significant difference in the post-operative sinus rhythm conversion rates between the classical "cut and sew" Cox-Maze III technique and the alternative sources of energy (e.g., radiofrequency-microwave and cryoblation), which were used to treat AF.

Thorascopic off-pump (TOP) surgical ablation (also known as mini Maze procedure, absent thoracotomy Maze procedure) is performed on a "beating heart" -- the heart is not arrested via bypass.  Use of a thorascope (a video telescope) helps surgeons guide the energy source to the atria.  Radiofrequency energy applied to the outside of the heart (epicardial ablation) is used for lesion creation.  This approach has many variants, but commonly involves pulmonary vein isolation at a minimum, as well as other potential ablation lines.  Bipolar radiofrequency energy is typically employed, in contrast to the unipolar energy employed in catheter ablation.

Krul et al (2011) presented a systematic literature overview and analysis of the first results and progress made with minimally-invasive surgery using radiofrequency energy in the treatment of AF.  The minimally-invasive treatment for AF tries to combine the success rate of surgical treatment with a less invasive approach to surgery.  It has the additional potential advantage of ganglion plexus (GP) ablation and left atrial appendage exclusion.  Furthermore, additional left atrial ablation lines (ALAL) can be created in non-paroxysmal AF patients.  For the search query ,multiple databases were used.  Exclusion and inclusion criteria were applied to select the publications to be screened.  All remaining articles were critically appraised and only relevant and valid articles were included in the results.  A total of 23 studies were included.  In 15 studies GPs around the pulmonary veins were ablated.  In 4 studies ALAL were performed.  Single procedure success rate was 69 % (95 % confidence interval [CI]: 58 % to 78 %) without anti-arrhythmic drugs (AAD) and 79 % (95 % CI: 71 % to 85 %) with AAD at 1 year follow-up.  Mortality was 0.4 %, and various complications were reported (3.2 % surgical, 3.2 % post-surgical, 2.6 % cardiac, 2.1 % pulmonary, and 1.7 % other).  The authors concluded that the 23 studies of minimally-invasive surgery for AF have been reviewed with success rates between that of the standard maze procedure and catheter ablation.  These first combined results show promise; however, minimally-invasive surgery is still evolving, for instance by the recent inclusion of electrophysiological endpoints.  Furthermore, the type of ALAL and the additional value of GP ablation have to be elucidated.

Sunderland et al (2011) examined if left atrial size reduction compared to maze surgery alone improve maze surgery success in adults undergoing a maze procedure for AF.  A total of 58 papers were found using the reported search, of which 8 represented the best evidence to answer the clinical question.  The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers were tabulated.  Four out of 8 papers compared a volume reduction technique as an adjunct to the maze procedure to a maze procedure alone -- all 4 papers reported that atrial volume reduction significantly increased restoration of sinus rhythm: 89.3 % versus 67.2 %, p < 0.001; 85 % versus 68 %, p < 0.05; 84 % versus  68 %, p < 0.05; 90 % versus 69 %, p < 0.05.  Three out of 8 papers had no control group but reported good rates of sinus rhythm restoration at last follow-up – 90 %, 92 % and 89 %, respectively -- despite the study population including atrial enlargement, a risk factor for failure of a maze procedure.  One paper reported no benefit of an atrial reduction plasty in patients with a left atrium (LA) greater than 70 mm.  An enlarged LA is a risk factor for failure of a maze procedure, and various models of AF suggested that reducing atrial mass and/or diameter may help to abolish the re-entry circuits underlying AF.  Furthermore, AF is uncommon when left atrial diameter is less than 40 mm, so there is at least some physiological basis for atrial reduction surgery in aiding the success of a maze procedure.  The evidence suggested that patients with an enlarged (greater than or equal to  55 mm) or giant (greater than or equal to 75 mm) LA who are at risk of failing to obtain sinus conversion after a standard maze procedure may derive benefit from concomitant atrial reduction surgery using either a tissue excision or a tissue plication technique.  However, the authors concluded that the evidence is not strong since the papers available are not readily comparable owing to substantial variations in the populations and procedures involved.  They therefore, emphasized the need for prospective, randomized studies in this area.

Bum Kim et al (2012) noted that the long-term benefits of the maze procedure in patients with chronic AF undergoing mechanical valve replacement who already require lifelong anti-coagulation remain unclear.  These investigators evaluated adverse outcomes (death; thromboembolic events; composite of death, heart failure, or valve-related complications) in 569 patients with AF-associated valvular heart disease who underwent mechanical valve replacement with (n = 317) or without (n = 252) a concomitant maze procedure between 1999 and 2010.  After adjustment for differences in baseline risk profiles, patients who had undergone the maze procedure were at similar risks of death (hazard ratio, 1.15; 95 % CI: 0.65 to 2.03; p = 0.63) and the composite outcomes (hazard ratio, 0.82; 95 % CI: 0.50 to 1.34; p = 0.42) but a significantly lower risk of thromboembolic events (hazard ratio, 0.29; 95 % CI: 0.12 to 0.73; p = 0.008) compared with those who underwent valve replacement alone at a median follow-up of 63.6 months (range of 0.2 to 149.9 months).  The effect of superior event-free survival by the concomitant maze procedure was notable in a low-risk EuroSCORE (0 to 3) subgroup (p = 0.049), but it was insignificant in a high-risk EuroSCORE (greater than or equal to 4) subgroup (p = 0.65).  Furthermore, the combination of the maze procedure resulted in superior left ventricular (p < 0.001) and tricuspid valvular functions (p < 0.001) compared with valve replacement alone on echocardiographic assessments performed at a median of 52.7 months (range of 6.0 to 146.8 months) after surgery.  The authors concluded that compared with valve replacement alone, the addition of the maze procedure was associated with a reduction in thromboembolic complications and improvements in hemodynamic performance in patients undergoing mechanical valve replacement, particularly in those with low-risk of surgery.

With thorascopic “off-pump” (TOP) surgical ablation, the heart is not arrested via bypass, and minimally-invasive techniques are used. Radiofrequency energy applied to the outside of the heart (epicardial ablation) is used for lesion creation. This approach has many variants, but typically involves pulmonary vein isolation at a minimum, as well as other potential ablation lines. An assessment by the Institute for Clinical and Economic Review (2010) found that the evidence for TOP surgical ablation was particularly scant; the ICER review identified no randomized controlled trials, and the remaining case series and cohort studies varied significantly in technical approach, outcome measurement, and level of reporting detail. The ICER review stated: "Thorascopic, off-pump surgical ablation is an emerging surgical technique, as there are many variations in how the procedure is performed, there is no evidence on longer term outcomes, and what evidence is available on intermediate or surrogate outcomes is limited to a few surgical case series."