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:
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.Background
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 (2013) 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."
La Meir et al (2013) stated that despite its proven effectiveness, the Cox-Maze III procedure did not gain widespread acceptance for the treatment of stand-alone AF (SA-AF) because of its complexity and technical difficulty. Surgical ablation for SA-AF can now be successfully performed utilizing minimally invasive surgery (MIS). These investigators provided an overview of state-of-the-art MIS for the treatment of SA-AF. Studies selected for this review were identified on PubMed and exclusion and inclusion criteria were applied to select the publication to be screened. A total of 28 studies were included; 27 (96.4 %) were observational in nature whereas 1 was prospective non-randomized. The total number of patients was 1,051 (range of 14 to 114). Mean age ranged from 45.3 to 67.1 years. Suboptimal results were obtained when employing microwave and high focused ultrasound energies. In contrast, MIS ablation of SA-AF achieved satisfactory 1-year results when the bipolar radiofrequency was employed as energy source, with anti-arrhythmic drug-free success rate comparable to percutaneous catheter ablation (PCA). The success rate in paroxysmal was even higher than in PCA. In contrast, ganglionated plexi ablation and left atrial appendage removal seem not to influence the recurrence of AF and the occurrence of post-operative thrombo-embolic events. The authors concluded that minimally invasive surgery ablation of SA-AF achieved satisfactory 1-year results when the bipolar radiofrequency was employed. Nevertheless, the relatively high complication rate reported suggested that such techniques require further refinement. Finally, the authors noted that preliminary results of the hybrid approach are promising but they need to be confirmed.
Ismail et al (2014) presented a novel way to perform the mini-maze procedure through the left atrial appendage. By this way, the usual additional incision of the intra-atrial groove is avoided, especially in patients receiving coronary artery bypass grafting (CABG) or aortic valve replacement without mitral valve disease. These investigators retrospectively analyzed 23 consecutive patients who received this novel mini-maze procedure between 2009 and 2011. In recognition of a learning curve, the authors divided the patients into 2 groups (Group 1: Patients 1 to 11 versus Group 2: Patients 12 to 23), according to the date of operation. In Group 2, 7 patients (58.33 %) were completely free of atrial fibrillation at the time of the follow-up. In Group 1, only 2 (18.18 %) patients were successfully treated resulting in a stable sinus rhythm at the time of the follow-up. The authors concluded that the mini-maze procedure performed through the left atrial appendage is a safe and feasible technique; however, it seems to be less effective than the Cox-maze III procedure and is associated with a learning curve.
Also an UpToDate review on “Surgical approaches to prevent recurrent atrial fibrillation” (Cheng, 2014) states that “The FAST trial randomly assigned 124 patients with antiarrhythmic drug-refractory atrial fibrillation (AF) with left atrial dilatation and hypertension (33 percent) or failed prior RCA [catheter based pulmonary vein radiofrequency ablation] (67 percent) to either minimally invasive surgical ablation or RCA. At 12 months, the primary end point of freedom from left atrial arrhythmia of greater than 30 seconds without antiarrhythmic drugs was significantly higher in the surgical ablation group (65.6 versus 36.5 percent). However, there were significantly more periprocedural complications such as pneumothorax, major bleeding, and the need for pacemaker in the surgical ablation group (35.4 versus 15.9 percent)”.
Pinho-Gomes et al (2014) noted that the first Cox-maze procedure was performed in 1987, demonstrating the feasibility of a non-pharmacological treatment for AF. Since then, surgery for AF has changed over time, in parallel with technological advances. Replacement of surgical incisions with linear ablation lines made a previously cumbersome procedure accessible to most surgeons, without compromising success. On the other hand, new ablation technologies paved the way for the development of minimally invasive surgery, which may potentially extend the scope of surgery to patients who would otherwise be deemed unsuitable. Nonetheless, literature on minimally invasive surgery is still scarce and randomized clinical trials currently under way are expected to shed light on some controversial issues. Moreover, successful AF treatment will probably rely on close collaboration between surgery and electrophysiology. Indeed, the hybrid procedure, though still in its very beginning, seems to combine the best of catheter and surgical ablation. However, further studies are warranted to determine the effectiveness of this promising strategy, especially in patients with persistent and longstanding persistent AF.
Lawrance et al (2015) reviewed the indications, evolution of technique, and results of surgical ablation for AF. With the introduction of the Cox-Maze IV procedure utilizing bipolar radiofrequency ablation and cryoablation, long-term studies have demonstrated a significant decrease in aortic cross-clamp times and major complications with a comparable rate of restoration of sinus rhythm. New hybrid approaches utilizing both catheter-based ablation and minimally invasive surgical approaches have been developed, but have not been standardized. Early studies have demonstrated reasonable success rates of hybrid procedures, with advantages that include confirmation of conduction block, decreased surgical morbidity, and possibly reduced morbidity. However, hybrid approaches have the disadvantage of significantly increased operative times. The authors concluded that the Cox-Maze IV is currently the gold standard for surgical treatment of AF. New hybrid approaches have potential advantages with promising early results, but a standard lesion set, improvement in operative times, and long-term results still need to be evaluated.
Furthermore, an UpToDate review on “Surgical approaches to prevent recurrent atrial fibrillation” (Cheng, 2014) states that "Surgical approaches that are available include the maze and corridor operations as well as radiofrequency or cryoablation. These procedures appear effective in a high percentage of patients. However, the follow-up for many of these studies was limited in scope and did not employ very rigorous arrhythmia surveillance". It does not mention hybrid or convergent maze as a therapeutic option.
|CPT Codes / HCPCS Codes / ICD-10 Codes|
|Information in the [brackets] below has been added for clarification purposes.  Codes requiring a 7th character are represented by "+":|
|ICD-10 codes will become effective as of October 1, 2015 :|
|CPT codes covered if selection criteria are met:|
|33254||Operative tissue ablation and reconstruction of atria, limited (e.g., modified maze procedure)|
|33256||Operative tissue ablation and reconstruction of atria, extensive (eg, maze procedure); with cardiopulmonary bypass|
|+ 33257||Operative tissue ablation and reconstruction of atria, performed at the time of other cardiac procedure(s), limited (e.g., modified maze procedure) (List separately in addition to code for primary procedure)|
|+ 33259||Operative tissue ablation and reconstruction of atria, performed at the time of other cardiac procedure(s), extensive (e.g., maze procedure), with cardiopulmonary bypass (List separately in addition to code for primary procedure)|
|CPT codes not covered for indications listed in the CPB:|
|33255||Operative tissue ablation and reconstruction of atria, extensive (e.g., maze procedure); without cardiopulmonary bypass|
|+33258||Operative tissue ablation and reconstruction of atria, performed at the time of other cardiac procedure(s), extensive (e.g., maze procedure), without cardiopulmonary bypass (List separately in addition to code for primary procedure)|
|33265||Endoscopy, surgical; operative tissue ablation and reconstruction of atria, limited (e.g., modified maze procedure), without cardiopulmonary bypass|
|33266||operative tissue ablation and reconstruction of atria, extensive (e.g., maze procedure), without cardiopulmonary bypass|
|Other CPT codes related to the CPB:|
|62303 - 62305||Myelography via lumbar injection, including radiological supervision and interpretation|
|93015||Cardiovascular stress test using maximal or submaximal treadmill or bicycle exercise, continuous electrocardiographic monitoring, and/or pharmacological stress; with physician supervision, with interpretation and report|
|93224 - 93237||Electrocardiographic monitoring for 24 hours|
|93600 - 93660||Intracardiac electrophysiological procedures/studies|
|ICD-10 codes covered if selection criteria are met:|
|I48.0||Atrial fibrillation [chronic]|
|I48.1||Atrial flutter [chronic]|