Cox Maze Procedure Research Articles

Left atrial mechanical dispersion and left atrial stiffness predicts recurrence of atrial fibrillation: In patients with moderate-severe rheumatic mitral stenosis

AimsThe aim of this study was to evaluate the relationship between preoperative left atrial function and recurrence of atrial fibrillation (AF) after mitral valve surgery and Cox Maze procedure in patients with moderate-to-severe rheumatic mitral stenosis (MS) combined with AF, in order to facilitate clinical risk stratification and to guide treatment strategies. Methods and resultsPatients with moderate-to-severe rheumatic MS attending Beijing Anzhen Hospital of Capital Medical University from April 2022 to September 2023 were prospectively collected, and all of them underwent transthoracic two-dimensional speckle-tracking echocardiography to assess left atrial structure and function before undergoing mitral valve surgery and Cox Maze procedure and postoperative follow-up. 121 patients were enrolled, of whom 77.69 % (94/121) were female, with a median follow-up time of 9.56 ± 1.83 months, and 48 patients (39.7 %, 48/121) had postoperative recurrence of AF. Preoperative left atrial stiffness index (LASI) [3.76(3.10–5.44) vs. 2.41(1.75–3.33), P < 0.001] and left atrial mechanical dispersion (SD-TPS) (15.84 ± 5.92vs. 11.58 ± 5.96, P = 0.001) were significantly higher in the postoperative AF recurrence group than in the without recurrence group; Multivariable cox regression analysis showed that LASI>3.15 and SD -TPS > 13.2 were associated with independent risk factors for AF recurrence (hazard ratio = 2.957, 95 %CI,1.366–6.399, P = 0.006 and hazard ratio = 2.892, 95 %CI,1.381–6.057, P = 0.005). ConclusionLASI and SD-TPS were effective predictors of postoperative recurrence of AF in patients with moderate-to-severe rheumatic MS, and LASI >3.15 and SD-TPS% >13.2 were independent influences on the recurrence of AF after Cox Maze in this group of patients.

Surgical treatment of atrial fibrillation in elderly patients undergoing high risk cardiac surgery

BackgroundEvaluating outcomes of concurrent Cox-Maze procedures in elderly patients undergoing high-risk cardiac surgery.MehodsWe retrospectively identified patients aged over 70 years with Atrial Fibrillation (AF) from 2011 to 2017 who had two or more other cardiac procedures. They were subdivided into two groups: 1. Cox-Maze IV AF ablation. 2. No-Surgical AF treatment. A propensity match score was used to generate a homogeneous cohort and to eliminate confounding variables. Heart rhythm was assessed from Holter reports or 12-lead ECG. Follow-up data was collected through telephone consultations and medical records.ResultsThere were 239 patients. Median follow up was 61 months. 70 patients had Cox-Maze IV procedures (29.3%). Demographic, intra- and post-operative outcomes were similar between groups although duration of pre-operative AF was shorter in Cox-Maze group (p = 0.001). There was no significant 30-day mortality difference in propensity matched cohorts (n = 84. P = 0.078). Sinus rhythm at annual and latest follow-up was 84.9% and 80.0% respectively in Maze group – 160 patients (66.9%) were alive at long-term follow-up with good survival outcomes in Cox Maze group. There was a high proportion of patients in NYHA 1 status in Cox-Maze group. No differences observed in freedom from stroke (p = 0.80) or permanent pacemaker (p = 0.33) between the groups.ConclusionsSurgical ablation is beneficial in elderly patients undergoing high-risk surgery - promoting excellent long-term freedom from AF and symptomatic / prognostic benefits, without added risk. Therefore, surgical risk should not be reason to deny benefits of concomitant AF-ablation.Clinical trial registrationNot required.

Surgical ablation of atrial fibrillation: Rationale and technique.

The Cox maze procedure is the most effective treatment for atrial fibrillation with the best long-term success rate compared to any other treatment modality, particularly in persistent and long-standing persistent atrial fibrillation. Cardiac surgeons have an unparalleled opportunity to treat atrial fibrillation as a concomitant operation during the treatment of ischemic or valvular disease. In addition, there are many options for surgical ablation of atrial fibrillation. In this review, we share the anatomic basis for surgical atrial fibrillation ablation, focusing on the Cox maze procedure and discuss some key technical points and common pitfalls to provide an effective ablation of atrial fibrillation. These include a discussion of avoidance of pacemaker implantation and other complications, and also how to produce the most effective lesions from a rhythm standpoint.

Concomitant Left Atrial Mass Excision and Bi-Atrial Cox-Maze Procedure

Concomitant Left Atrial Mass Excision and Bi-Atrial Cox-Maze Procedure

Efficacy of a surgical cardiac ablation clamp using nanosecond pulsed electric fields: An acute porcine model

ObjectiveTo examine the effectiveness of a recently developed nonthermal technology, nanosecond pulse-field ablation (nsPFA), for surgical ablation of the atria in a beating heart porcine model. MethodsSix pigs underwent sternotomy and ablation using an nsPFA parallel clamp. The ablation electrodes (53 mm long) were embedded in the jaws of the clamp. Nine lesions per pig were created in locations chosen to be representative of the Cox-maze procedure. Four lesions were intended to electrically isolate parts of the atrium: the right atrial appendage, left atrial appendage, right pulmonary veins, and left pulmonary veins. For these lesions, exit block testing was performed both after ablation and before euthanasia; the time between the 2 tests was 3.3 ± 0.5 hours (range, 2-4 hours). Using purse string sutures, 5 more lesions were created up to the superior vena cava, down to the inferior vena cava, across the right atrial free wall, and at 2 distinct locations on the left atrial free wall. The clamp delivered a train of nanosecond duration pulses, with a total duration of 2.5 seconds, independent of tissue thickness. The heart tissue was stained with 1% triphenyltetrazolium chloride after a dwelling period of 2 hours. Subsequently, each lesion was cross sectioned at 5-mm intervals to assess the ablation depth and transmurality. In some sections, transmurality could not be established on the basis of triphenyltetrazolium chloride staining alone; for these lesions, Gomori-trichrome stains were used, and the histologic sections were evaluated for transmurality. ResultsThe ablation time was 2.5 seconds per lesion, for a total of only 22.5 seconds ablation time to create 9 lesions. A total of 53 lesions were created, resulting in 388 separate histologic sections. Transmurality was established in 386 sections (99.5%). Mean tissue thickness was 3.1 ± 1.5 mm (range, 0.2-8.6 mm). Exit block was confirmed in 23 of the 24 lesions (96%) postablation and 23 of 24 (96%) before the animals were humanely killed. Over the course of the procedure, neither pulse-induced arrhythmias nor any other complications were noted. ConclusionsThe novel nsPFA clamp device was effective in creating acute conduction block and transmural lesions in both the right and left atria in an acute porcine model. This nonthermal energy source has great potential to both shorten procedural time and enable effective ablation in the beating heart.

Pacemaker dependency after Cox Maze procedure concomitant with cardiac surgery, The road between Scylla and Charybdis

Abstract Background The Cox Maze (CM) procedure is a well-established treatment for atrial fibrillation. However, recent trials report alarming rates of pacemaker implantation (PMI) during hospitalization after CM. As PMI, generator replacement and Lead management are sometimes accompanied by complications, such as infection or bleeding and represent a burden for patients and healthcare systems. We thought to investigate the rates of pacemaker dependency 6 months after pacemaker implantation regarding the applied energy source and the performed lesion set, to determine whether PPM implantation timing and specific conduction disturbances as indications are associated with late pacemaker dependency. Methods We performed a retrospective review of 3695 patients underwent elective cardiac surgery in our institution between the years 2005 and 2022. Patients who use of devices for rhythm control, resynchronisation therapy, implantablecardioverter defibrillator (ICD) or both were excluded from the present study. A total of 283 patients met the inclusion criteria; Various energy sources, including cryoablation (n= 123) and radiofrequency (n= 160) were used. Left atrial (n= 228) and biatrial (n= 55) ablation was performed The distribution of the preoperative and perioperative variables was similar. Results There was no statistical difference in the incidence pacemaker dependency regarding the applied energy source whether radiofrequencyablation or cryoablation (25% vs. 30%; p = 0.2 respectively). On the other hand, biatrial ablation led to a significant pacemaker dependency rate compared with isolated left-sided ablation (78,2% vs 14.9%; P = .001 respectively), moreover Sinus node dysfunction as indication for PPM implantation was predictive of being not PPM dependent (OR 6.59; 95% CI, 1.67-26.06; P = .007). Conclusion Concomitant CM procedure showed a pacemaker implantation rate of 7,4%. Univariate and multivariate analysis showed biatrial lesion set as the only statistically significant predictor for pacemaker dependency after CM procedure. Further large-scale randomized controlled studies are needed to elucidate the Impact of the CM on the late pacemaker dependency.

Electrophysiologic mechanism and ablation strategy for macroreentrant biatrial tachycardias after Cox-maze procedures

BackgroundDifferent types of recurrent atrial tachycardia (AT) after Cox-maze procedures have been reported, whereas biatrial tachycardia (BiAT) has not been systematically analyzed. ObjectiveIn this study, we retrospectively investigated the electrophysiologic characteristics of BiAT after Cox-maze procedures by use of an ultrahigh-density mapping system. MethodsOf a consecutive 76 patients who underwent catheter ablation of AT after Cox-maze procedures, 12 BiATs were identified. High-density activation mapping was performed in both the left atrium and right atrium in combination with entrainment pacing to confirm the circuit. ResultsWe classified these BiATs into 2 groups. In group 1 (7 patients), the bidirectional block of maze linear lesions to prevent the macroreentrant AT was achieved; the posterior interatrial connections were involved in the circuit. In group 2 (5 patients), the bidirectional block of maze linear lesions was not blocked, and the most common gap was located at the end of the linear lesion near the annulus. In group 1, all the ATs were terminated by targeting the corresponding left atrium end of the posterior interatrial connections. In group 2, the ATs were terminated by targeting the gap near the annulus. ConclusionThe optimal ablation strategy for BiATs after the maze procedure should be based on detailed demonstration of the circuit by high-density mapping.

Surgery for Cardiac Arrhythmias: Past, Present, Future.

There is a rich history of surgery for cardiac arrhythmias, spanning from atrial fibrillation and Wolff-Parkinson-White syndrome to inappropriate sinus tachycardia and ventricular tachycardia. This review describes the history of these operations, their evolution over time, and the current state of practice. We devote considerable time to the discussion of atrial fibrillation, the most common cardiac arrhythmia addressed by surgeons. We discuss ablation of atrial fibrillation as a stand-alone operation and as a concomitant operation performed at the time of cardiac surgery. We also discuss the emergence of newer procedures to address atrial fibrillation in the past decade, such as the convergent procedure and totally thoracoscopic ablation, and their outcomes relative to historic approaches such as the Cox maze procedure.

Novel Entropy-Based Metrics for Long-Term Atrial Fibrillation Recurrence Prediction Following Surgical Ablation: Insights from Preoperative Electrocardiographic Analysis.

Atrial fibrillation (AF) is a prevalent cardiac arrhythmia often treated concomitantly with other cardiac interventions through the Cox-Maze procedure. This highly invasive intervention is still linked to a long-term recurrence rate of approximately 35% in permanent AF patients. The aim of this study is to preoperatively predict long-term AF recurrence post-surgery through the analysis of atrial activity (AA) organization from non-invasive electrocardiographic (ECG) recordings. A dataset comprising ECGs from 53 patients with permanent AF who had undergone Cox-Maze concomitant surgery was analyzed. The AA was extracted from the lead V1 of these recordings and then characterized using novel predictors, such as the mean and standard deviation of the relative wavelet energy (RWEm and RWEs) across different scales, and an entropy-based metric that computes the stationary wavelet entropy variability (SWEnV). The individual predictors exhibited limited predictive capabilities to anticipate the outcome of the procedure, with the SWEnV yielding a classification accuracy (Acc) of 68.07%. However, the assessment of the RWEs for the seventh scale (RWEs7), which encompassed frequencies associated with the AA, stood out as the most promising individual predictor, with sensitivity (Se) and specificity (Sp) values of 80.83% and 67.09%, respectively, and an Acc of almost 75%. Diverse multivariate decision tree-based models were constructed for prediction, giving priority to simplicity in the interpretation of the forecasting methodology. In fact, the combination of the SWEnV and RWEs7 consistently outperformed the individual predictors and excelled in predicting post-surgery outcomes one year after the Cox-Maze procedure, with Se, Sp, and Acc values of approximately 80%, thus surpassing the results of previous studies based on anatomical predictors associated with atrial function or clinical data. These findings emphasize the crucial role of preoperative patient-specific ECG signal analysis in tailoring post-surgical care, enhancing clinical decision making, and improving long-term clinical outcomes.

Simple But Effective Modifications to the Cox Maze Procedure Using Only Cryoablation

We describe an effective and practical approach for concomitant ablation that we use in 100% of mitral surgery patients with a history of atrial fibrillation. There are three steps. First the left atrial appendage is closed with a Clip with is highly effective and electrically isolates it. Second, 3 cryoablation lines are used to recreate the key Cox-Maze III lesion set with a total of 8 minutes of ablation time. In some patients, usually with tricuspid regurgitation, 3 right atrial ablations are placed with 6 minutes of ablation time. The procedure added 10.5 minutes and 13.4 minutes of cross clamp and bypass times. For patients with 3-minute box lesion freezes, 12-month freedom from atrial fibrillation off antiarrthymics was 90%. There was no increase in peri-operative complications and late survival was the same as mitral patients without AF and a matched population.

Minimally Invasive Mitral Valve Surgery With Concomitant Cox Maze Procedure Is as Effective as a Median Sternotomy With Decreased Morbidity.

A right minithoracotomy (RMT) is a minimally invasive surgical approach that has been increasingly performed for the concomitant Cox maze IV procedure (CMP) and mitral valve surgery (MVS). Little is known regarding whether long-term rhythm and survival outcomes are affected by the RMT as compared with the traditional median sternotomy (MS) approach. Between April 2004 and April 2021, 377 patients underwent the concomitant CMP and MVS, of whom 38% had RMT. Propensity score matching yielded 116 pairs. Freedom from atrial tachyarrhythmias (ATA) was assessed with prolonged monitoring annually for 8 years. Survival, rhythm, and perioperative outcomes were compared. The unmatched RMT cohort had a greater freedom from ATA recurrence at 1 year (99% vs 90%, P = 0.001) and 3 years (94% vs 86%, P = 0.045). The matched RMT cohort had longer cardiopulmonary bypass (median: 215 [199 to 253] vs 170 [136 to 198] min, P < 0.001) and aortic cross-clamp (110 [98 to 124] vs 86 [71 to 102] min, P < 0.001) times but shorter intensive care time (48 [24 to 95] vs 71 [26 to 144] h, P = 0.001) and length of stay (8 [6 to 11] vs 10 [7 to 14] h, P < 0.001). More pacemakers (18% vs 4%, P < 0.001) and postoperative transfusions (57% vs 41%, P = 0.014) occurred in the MS cohort. The 30-day mortality (P = 0.651) and 8-year survival (P = 0.072) was not significantly different between the cohorts. Early 1-year and 3-year freedom from ATA recurrence was better in the RMT cohort compared with the MS cohort. Despite longer operative times, the RMT cohort had shorter lengths of stay, fewer postoperative transfusions, and fewer pacemakers placed.

Outcome of mitral repair combined with Cox-maze procedure for atrial functional mitral regurgitation with heart failure with recovered ejection fraction.

Atrial functional mitral regurgitation (AFMR) in patients with heart failure with recovered ejection fraction has received insufficient attention. This study analysed the prognosis and outcomes of mitral valve (MV) repair combined with the Cox-maze procedure. A prospective cohort study of patients with AFMR with left ventricular ejection fraction (LVEF) <40% was conducted. All patients received guideline-directed medical therapy. Those with recovered ejection fraction underwent MV repair combined with the Cox-maze procedure. Mortality, atrial fibrillation (AF) recurrence, mitral regurgitation (MR) and postoperative tricuspid regurgitation were assessed using the inverse probability weighting (IPW) method. In total, 312 patients were enrolled in this study between 2010 and 2019, 247 of whom underwent MV repair combined with the Cox-maze procedure [full recovery (LVEF > 50%): n = 132, partial recovery (LVEF of 40-50%): n = 115]. IPW-adjusted survival of patients with LVEF ≥50% and LVEF 40-50% showed no significant difference [hazard ratio (HR): 2.18, 95% confidence interval: 0.46-10.38, P = 0.33]. However, patients with LVEF ≥50% had better IPW-adjusted long-term freedom from recurrent MR [HR: 2.44 (1.28-4.63), P = 0.0065] and AF recurrence [HR: 1.85 (1.06-3.21), P = 0.030] than those with LVEF of 40-50%. MV repair combined with the Cox-maze procedure was effective and feasible in patients with severe AFMR with heart failure with recovered ejection fraction. Additionally, patients with LVEF ≥50% after guideline-directed medical therapy undergoing these combined procedures had better long-term freedom from recurrent AF and MR than those with LVEF of 40-50%.

Impact of pulmonary arterial systolic pressure on patients with mitral valve disease combined with atrial fibrillation.

To determine whether different changes of pulmonary artery systolic pressure (PASP) after surgeries have an impact on the long-term outcomes in patients with rheumatic and degenerative mitral valve (MV) disease and atrial fibrillation. Between 2004 and 2016, 1,188 patients with rheumatic and degenerative MV disease undergoing MV and Cox-Maze procedure were identified. Clinic outcomes, as well as rhythm state and echocardiography indices in long-term follow-up were recorded. Patients were grouped by the changes of PASP (persistently normal, persistently increased, increased, and decreased) from preoperative estimation to follow-up. A complete echocardiography was performed at baseline and after 5 years. During follow-up, free of death and atrial fibrillation (AF) off antiarrhythmic drugs was 90 and 61%, 78 and 41% at 5 and 10 years, respectively. Survival rate was higher in patients with persistently normal and became worse in patients with persistently increased and increased PASP (log-rank 166.0, P < 0.0001). Moreover, the patients with persistently normal PASP had a lowest risk of recurrent AF (SHR: 0817; CI: 0.765-0.872; P < 0.0001) after considering death as a competing risk. A persistently normal PASP at follow-up and degenerative MV disease were associated with improved survival and sinus rhythm (SR) maintenance at multivariable Cox regression analysis (P < 0.05). Patients with degenerative MV disease or have persistently normal PASP during follow-up have better survival and SR maintenance rate than patients with either rheumatic MV disease or persistently abnormal PASP.

Response to correspondence regarding 5-year follow up of the Amaze Randomized Controlled trial of ablation treatment for arrhythmia as an adjunct to cardiac surgery.

We thank Dr Garcia-Villarreal [1] for his comment on our article in which he questions the rate of return to stable sinus rhythm in the Amaze trial [2]. We should like to point out that the Amaze trial [3] was not an evaluation of the complete Cox-maze procedure, but an evaluation of concomitant atrial fibrillation surgery as it is done in the real world. Amongst our findings, we discovered that a large variety of lesion sets were being used and that many surgeons did not complete the full biatrial lesion set in their practice. We also found that there appears to be an ablation ‘dose–response’ in achieving return to sinus rhythm, with the greatest step-up achieved when the left atrial lesion set includes the mitral isthmus lesion. We therefore agree with Dr Garcia-Villarreal that concomitant atrial fibrillation surgery should ideally be as complete as possible, and there may be an argument for concentrating such surgery in the hands of interested and experienced surgeons. Despite this, over 5 years later, we have anecdotal evidence that less complete choices of lesion sets continue to be made. We agree that the experience of surgeons devoted to atrial fibrillation should help in maximizing return to sinus rhythm and may also aid in achieving better atrial function after surgery, which is at least as important for clinical patient outcomes as electrical sinus rhythm restoration (study registration ISRCTN82731440) [4].

Routine endoscopic robotic cardiac tumor resection using an 8-mm working port and percutaneous cannulation.

Prior studies have demonstrated robotic excision of cardiac tumors as a safe and effective treatment option. The procedure is performed with five incisions: three robotic arm ports, one atrial retractor port, and one working port. We report our unique initial experience in robotic tumor removal. To our knowledge, this is one of the first reports demonstrating cardiac myxoma and fibroelastoma removal with use of exclusively 8-mm ports. All data for robotic cardiac tumor resection at our institution from June 2019 to December 2021 were retrospectively collected; 18 cases were included, including 13 cardiac myxomas and five fibroelastomas. Baseline demographics, intraoperative characteristics, and surgical outcomes were recorded. Descriptive statistics were calculated; continuous variables were reported as median [interquartile range], and categorical variables were reported as percentages. Median patient age was 64 [55, 70] years old. The cohort consisted of primarily female (67%) and white (83%) patients. Median body mass index was 26.3 [23.0, 31.5] kg/m2 . 11% of patients were current tobacco users and 50% had hypertension. All patients underwent myxoma or fibroelastoma removal with the use of five 8-mm robotic ports. Each patient underwent percutaneous cannulation via the femoral arteries. Aortic occlusion was achieved via an endoaortic balloon (67%) or transthoracic cross-clamp (33%). Cross-clamp time was 30 [26, 41] minutes. Concomitant procedures performed during myxoma removal included patent foramen ovale closure (28%), mitral valve repair (8%), left atrial appendage closure (8%), Cox-maze procedure (6%), and coronary artery bypass grafting (6%). All cardiac tumors were packaged with use of the endo-bag and subsequently removed through the working port. Maximal myxoma and fibroelastoma diameters were 2.5 [1.7, 3.5] and 0.6 [0.4, 0.7] cm, respectively. Procedural cardiopulmonary bypass time was 77 [65, 84] minutes. No intraoperative mortality, reoperation for bleeding, or postoperative cardiac issues were recorded. One in-hospital mortality occurred as the result of a thrombotic event in the context of a hypercoagulable state unrelated to the patient's operation. No other mortalities were observed at 30 days. Hospital length of stay was 4.5 [3.0, 7.8] days. In our study, the robotic platform facilitated safe and effective cardiac tumor excision. Our results highlight the efficacy of 8-mm port sizing and the concurrent use of other minimally invasive techniques, including percutaneous cannulation, in this patient population. In general, patients prefer the least invasive treatment option available. Our findings emphasize the importance of training cardiac surgeons to perform robotic procedures using the least invasive means possible to provide patients with various options for their treatment.

Surgery results of Cox-Maze IV procedure in treatment for atrial fibrillation combined with valve disease at Cardiovascular Center, E hospital

Introduction: Atrial fibrillation is a major cause of stroke, heart failure, and sudden death and is often associated with valve disease. The Maze procedure using the unipolar and bipolar radiofrequency devices is often combined with valvular surgery, especially mitral valve, to treat atrial fibrillation.&#x0D; Method: Cross-sectional descriptive study; 40 patientsss were treated for atrial fibrillation by COX-MAZE procedure combined with heart valve surgery in 2020-2021 at Cardiovascular Center- E Hospital.&#x0D; Result: In 40 patients, 23 males (57.5%), 17 females (42.5%), mean age 53.6 ± 8.3 (36-68) years. Mean time to dêtct atrial fibrillation 3.27 (1-9) years. 05 cases (12.5%) were preopration stroke history. Mean left atrial diameter before surgery 49.2 ± 10.1 (21-70) mm, thrombus in left atrial appendage was 8 cases (20%). All patients had mitral valve disease, accompanied by aortic valve disease 4 cases (10%) and tricuspid valve regurgitation 13 cases (32.5%). 100% of patients underwent COX-MAZE procedure. The rates of free from AF and sinus recovery after surgery 31 cases (77.5%). 02 patients (5%) sinus node dysfunction and 04 patients (10%) atrioventricular block I-II degree but they did not require temporary pacemaker placement, and recovered in 1-3 weeks.&#x0D; Conclusion: The Maze procedure by unipolar devices alone and combination with bipolar devices are effective and safe in patient atrial fibrillation combined with valvular surgery, especially mitral valve surgery.

The effect of cryothermic and radiofrequency Cox maze IV ablation on atrial size and function assessed by 3D echocardiography, a randomized trial. To freeze or to burn

Abstract Background The Cox maze procedures have been shown to be safe methods for restoring sinus rhythm (SR) in patient with atrial fibrillation and often performed concomitant to mitral valve (MV) surgery. Cryothermy (Cryo) and Radiofrequency (RF) are available techniques to achieve atrial linear scars. The differences between the effect of these energy sources on late left atrial (LA) reverse remodeling are not fully described. Purpose This study aims to compare the impact of Cryo and RF procedures on left atrial (LA) size and function one year after Cox-maze IV concomitant to MV surgery using 3-dimensional echocardiography (3DE). Methods Seventy-two patients with MV disease and atrial fibrillation were randomized to either Cryo (35) or RF (37) ablation. Another 33 patients were enrolled according to the protocol without concomitant ablation (NoMaze group). All patients had an echocardiogram before and one year after surgery. Results The 42 ablated patients who recovered sinus rhythm (SR) one year after surgery had comparable left and right systolic ventricular function and a mean reduction of LA size by 23% (LA volume index decreased from 66±24 to 54±13ml/m2, p=0.004). The 3DE extracted reservoir and booster function showed higher values after RF ablation compared to Cryo (37±10% vs 26±6%; p&amp;lt;0.001 resp. 18±9 vs 7±4%, p&amp;lt;0.001), while passive conduit function was comparable (24±11 vs 20±8%; p=0.17). Patients with restored SR without ablation had more preserved systolic atrial function but similar LA size reduction as those who underwent maze surgery. Conclusions SR restoration after MV surgery and maze results in LA size reduction irrespective of the energy source used. By 3DE we could show that, compared to RF maze, the extension of ablation area produced by Cryo implies a major LA structural remodeling affecting LA systolic function. The reverse size remodeling seems to be the least, the longer AF history. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): ALF funding for clinical research-Sweden

Efficacy of a Novel Bipolar Radiofrequency Clamp: An Acute Porcine Model.

Expert consensus guidelines recommend surgical ablation (SA) for patients with symptomatic atrial fibrillation (AF), but less than half of patients with AF undergoing cardiac procedures receive concomitant SA. Complete isolation of the left atrial posterior wall (LAPW) has been shown to be the most critical part of the Cox maze procedure. The purpose of this study was to investigate the performance of a novel radiofrequency (RF) bipolar device, EnCompass™ (AtriCure, Inc., Mason, OH, USA), designed to isolate the LAPW in a single application. Five adult pigs underwent SA in a beating heart model. After a single ablation, the heart was arrested, explanted, and stained with triphenyl-tetrazolium-chloride for histological assessment. Each lesion was sectioned, and the ablation depth, muscle, and fat thickness were determined. The lesion width, energy delivery, and ablation times were compared with those from a reference RF clamp (Synergy™, AtriCure). Transmurality was documented in 100% of lesions (5 of 5) and cross sections (160 of 160). Electrical isolation was documented in every instance. There was no evidence of clot, charring, or pulmonary vein stenosis. Compared with the reference clamp, the lesions created by the EnCompass™ clamp were 1.5 times wider on average. The average energy delivered was 5 times higher over a duration that was 4.5 times longer due to the increased volume of tissue ablated. The EnCompass™ clamp reproducibly created transmural isolation of the LAPW with a single application. This may allow for simplification of the SA strategy and increased adoption of AF treatment during concomitant surgery.

Two hundred robotic mitral valve repair procedures for degenerative mitral regurgitation: the Yale experience.

BackgroundRobotic surgery has gained popularity over the past two decades due to the benefits related to smaller surgical incisions, enhanced technical dexterity and better intraoperative visualization. We present the Yale experience of the first two hundred totally endoscopic, robotic-assisted mitral valve repair procedures for the treatment of degenerative mitral regurgitation.MethodsWe performed a retrospective cohort study of patients undergoing totally endoscopic, robotic-assisted isolated or concomitant mitral valve repair for degenerative mitral regurgitation at Yale-New Haven Hospital from October 2018 to April 2022. Mitral valve repair procedures for rheumatic or secondary functional mitral regurgitation and planned robotic-assisted mitral valve replacement cases were excluded.ResultsTwo hundred consecutive procedures were performed. The median age was 65 years (interquartile range, 58–73 years). Six patients (3.0%) had a history of mediastinal radiation, four patients (2.0%) had previous cardiac surgery, and one patient (0.5%) had cardiac dextroversion. Median cardiopulmonary bypass and aortic cross-clamp times were 122 and 79 minutes, respectively. Femoral vessel cannulation was performed percutaneously in 57 (28.5%) patients with no major access-site related complication. Aortic cross-clamping was performed with the endoaortic balloon occlusion device in 151 (75.5%) patients. No conversions to sternotomy occurred. Satisfactory repair was achieved in 100% of cases, with 184 (92.0%) and 16 (8.0%) of patients having trace/none or mild residual mitral regurgitation, respectively. Forty-two patients (21.0%) underwent concomitant Cox-maze procedure and 25 patients (12.5%) underwent concomitant tricuspid valve repair. Thirty-day mortality rate was 0.5%, with an observed-to-expected ratio of 0.53. Two patients (1.0%) underwent re-exploration for bleeding, one had early postoperative stroke (0.5%), five developed pneumothorax (2.5%) and two required dialysis for acute renal failure (1.0%). The median length of hospital stay was four days.ConclusionsExcellent short-term outcomes can be achieved in experienced centers for the treatment of degenerative mitral regurgitation with a totally endoscopic, robotic-assisted approach.

Comparing mid-term outcomes of Cox-Maze procedure and pulmonary vein isolation for atrial fibrillation after concomitant mitral valve surgery: A systematic review.

Although concomitant pulmonary vein isolation (PVI) is used more frequently than the Cox-Maze procedure, which is currently the gold standard treatment for atrial fibrillation (AF), data on the comparative effectiveness of the two procedures after concomitant mitral valve (MV) surgery are still limited. We conducted a systematic review to identify randomized controlled trials (RCTs) and observational studies comparing the mid-term mortality and recurrence of AF after concomitant Cox-Maze and PVI in patients with AF undergoing MV surgery based on 12-month follow-up. Medline, EMBASE databases, and the Cochrane Library were searched from 1987 up to March 2022 for studies comparing concomitant Cox-Maze and PVI. Additionally, a meta-analysis of RCTs was performed to compare the mid-term clinical outcomes between these two surgical ablation techniques. Three RCTs and three observational studies meeting the inclusion criteria were included in this systematic review with 790 patients in total (532 concomitant Cox-Maze and 258 PVI during MV surgery). Most studies reported that the concomitant Cox-Maze procedure was associated with higher freedom from AF at 12-month follow-up than PVI. Regarding AF recurrence, estimates pooled across the three RCTs indicated large heterogeneity and high uncertainty. In the largest and highest quality RCT, 12-month AF recurrence was higher in the PVI arm (risk ratio = 1.58, 95% CI: 0.91-2.73). In two out of three higher-quality observational studies, 12-month AF recurrence was higher in PVI than in the Cox-Maze arm (estimated adjusted probabilities 11% vs. 8% and 35% vs. 17%, respectively). RCTs demonstrated comparable 12-month mortality between concomitant Cox-Maze and PVI, while observational studies demonstrated the survival benefit of Cox-Maze. Concomitant Cox-Maze in AF patients undergoing MV surgery is associated with better mid-term freedom from AF when compared to PVI with comparable mid-term survival. Large observational studies suggest that there might be a mid-term survival benefit among patients after concomitant Cox-Maze. Further large RCTs with longer standardized follow-up are required to clarify the benefits of concomitant Cox-Maze in AF patients during MV surgery.