Robotic assisted cryothermic biatrial Cox-Maze.

INTRODUCTION: Robotic cryothermic Cox-Maze (CM) IV is a minimally invasive procedure that reliably replicates the biatrial lesion set of the CM III by utilizing cryothermia as a single power source. METHODS: Herein we describe a step by step creation of the biatrial CM III lesion sets utilizing the minimally invasive robotic platform. RESULTS: Technical details are reviewed for this single incision, single stage, highly effective option for stand-alone or concomitant surgical ablation of atrial fibrillation (AF). CONCLUSION: Robotic cryothermic CM IV can be safely performed as a stand-alone or concomitant procedure, and offers a comprehensive surgical ablation solution for patients with AF.

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

OBJECTIVE: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Performance of an Irrigated Bipolar Radiofrequency Ablation Clamp on Explanted Human Hearts.

BACKGROUND: Bipolar radiofrequency (RF) clamps are commonly used during surgical ablation for atrial fibrillation (AF). This study examined the efficacy of an irrigated bipolar RF clamp to create transmural lesions in an ex vivo human heart model. METHODS: Ten donor hearts, turned down for transplantation, were explanted and arrested with cold cardioplegia. The ablations of the Cox Maze IV procedure were performed using the Cardioblate LP (Medtronic, Inc) irrigated bipolar RF clamp. In the first 5 hearts, each lesion was created with a single application of RF, whereas in the remaining 5 hearts, each lesion was created with a double application of RF without unclamping. Each lesion was cross-sectioned and stained with 2,3,5-triphenyl-tetrazolium chloride to assess ablation depth and transmurality. RESULTS: A total of 100 lesions were analyzed. In the single-ablation group, 222 of 260 sections (85%) and 37 of 50 lesions (74%) were transmural. The efficacy improved significantly in the double-ablation group, in which 348 of 359 sections (97%, P < .001) and 46 of 50 lesions (92%, P = .017) were transmural. Overall, in nontransmural lesions, the epicardial fat thickness was significantly greater (1.69 ± 0.70 mm vs 0.45 ±0.10 mm, P < .001) than the transmural lesions. CONCLUSIONS: A single ablation on human atrial tissue with an irrigated bipolar RF clamp was insufficient to reliably create transmural lesions, but a double ablation significantly increased the lesion and section transmurality. Nontransmural lesions were associated with significantly thicker layers of epicardial fat, which likely decreased tissue energy delivery due to the higher resistance of fat to current flow.

Surgical Treatment for Stand-Alone Atrial Fibrillation in North America.

BACKGROUND: Surgical treatment of symptomatic atrial fibrillation has been performed for 3 decades. We reviewed trends and outcomes of surgical ablation (SA) for stand-alone atrial fibrillation using The Society of Thoracic Surgeons Adult Cardiac Surgical Database (STS-ACSD). METHODS: The STS-ACSD was reviewed from 2011 to 2017 (N = 7187) for trends. Contemporary data from 2014 to 2017 (n = 3893) were used to compare three subgroups: off pump (n = 3252), on pump (n = 491), and patients with incision conversion or conversion from off pump to on pump (n = 150). Propensity score matching was conducted to balance groups. RESULTS: Annual growth of stand-alone SA was 7%. Median age of patients was 64 years (interquartile range, 57 to 70), and 30% were female. Overall 30-day mortality was 0.8% and perioperative stroke incidence was 0.8%. Most SA procedures were off pump (84%), with 12% greater odds for off pump per year (odds ratio [OR] 1.12, P < .001). The off-pump group had fewer biatrial SA (21% vs 71%, P < .001) and left atrial appendage obliterations (53% vs 95%, P < .001) compared with the on-pump group. After matching, uneventful off-pump SA had similar mortality (0.4% vs 0.9%, P = .292) vs on-pump SA, but reduced incidence of renal failure (0.9% vs 2%, P = .033). After risk adjustment, the conversion group had worse perioperative outcomes vs the off-pump group, including greater incidence of stroke (OR 5.37, P < .001) and operative mortality (OR 9.98, P < .001). Mortality (OR 4.69, P = .011) was also greater for conversion vs on pump. CONCLUSIONS: Steady growth of stand-alone SA operations was noted. Procedures performed either on pump or off pump were relatively safe. However, intraoperative conversion was associated with significantly higher morbidity and mortality. Patient selection, improvement of surgical techniques, and long-term follow-up should be emphasized to improve decision making and outcome.

Current Approach to Surgical Ablation for Atrial Fibrillation.

After 4 decades of innovation, surgical ablation for atrial fibrillation is reconverging on the bi-atrial full maze procedure as the most effective approach. Contemporary studies suggest that surgical ablation confers significant rhythm and survival benefits without additional operative risk. Alternative energy sources have become standard, focused primarily on radiofrequency and cryothermic energy. With full bi-atrial lesion sets, long-term sinus conversion rates may now approach 90%. Bi-atrial cryoablation applied in the full maze pattern produces excellent results, and may provide some advantages in simplicity and efficiency. Surgical ablation for atrial fibrillation is being increasingly applied over time for all categories of cardiac operations. Given the known survival advantages of surgical ablation of atrial fibrillation, this trend of increased adoption may contribute to improving long-term outcomes.

Surgical Techniques for Mitral Valve Repair: A Pathoanatomic Grading System.

Mitral valve surgery has evolved over 4 decades from one based on the principles of prosthetic replacement to a subspecialty with a foundation based on the principles of repair. This review will attempt to enumerate the contemporary techniques of mitral valve repair and a pathoanatomically directed approach with which to apply them by focusing on degenerative disease and associated complexities.

Contemporary Surgical Management of Hypertrophic Cardiomyopathy in the United States.

BACKGROUND: The primary surgical therapy for hypertrophic cardiomyopathy with obstruction is septal myectomy (SM). The current outcomes of SM with and without concomitant mitral operations in the United States was examined using The Society of Thoracic Surgeons database. METHODS: From July 2014 through June 2017, 4,274 SM operations were performed. Emergent status, endocarditis, aortic stenosis, and planned aortic valve operations were excluded. In the final cohort of 2,382 patients, 1,581 (66.4%) received SM alone (group 1), and 801 (33.6%) had SM with mitral valve repair or replacement (group 2). Group 2 was subdivided into mitral valve repair (MVr [n = 500]) and mitral valve replacement (MVR [n = 301]). Baseline characteristics were compared and risk-adjusted operative mortality and major morbidity were evaluated between treatment groups. RESULTS: Baseline comorbidity was lower in group 1 versus group 2 and for MVr versus MVR. Operative mortality and major morbidity was lower for group 1 versus 2 (1.6% versus 2.8%, p = 0.046, and 10.9% versus 20.0%, p < 0.001, respectively). For patients with severe 3-4+ mitral regurgitation, SM alone was effective in reducing mitral regurgitation in 85.5% (355 of 415), and SM with MVr was effective in 88.0% (176 of 200; p = 0.4061). After risk adjustment, odds ratio for composite of mortality and major morbidity for group 2 versus group 1 was 1.8 (95% confidence interval: 1.4 to 2.4, p < 0.0001). CONCLUSIONS: Septal myectomy for hypertrophic cardiomyopathy is safe. Septal myectomy alone may have risk-adjusted outcome advantages over SM with mitral valve repair or replacement. Septal myectomy and SM with MVr provide similar reduction in mitral regurgitation. Further longitudinal analyses are required to define technical efficacy and outcomes in selected pathoanatomic groups.

Oral anticoagulation may not be necessary for patients discharged in sinus rhythm after the Cox Maze IV procedure.

OBJECTIVES: Oral anticoagulants have inherent risks. In the absence of clear evidence, anticoagulant use after surgical ablation for atrial fibrillation remains variable. This study examined patient outcomes with and without oral anticoagulants after successful surgical ablation. METHODS: From October 2011 to April 2016, 239 consecutive patients underwent biatrial Cox Maze IV operations for persistent atrial fibrillation. All patients received endocardial left atrial appendage obliteration. All patients discharged in sinus rhythm not requiring anticoagulation for preexisting or mechanical prosthetic reasons received antiplatelet therapy only. Neurologic end points were defined as any deficit of abrupt onset not resolving within 24 hours. RESULTS: Of 233 patients discharged, 57 received oral anticoagulants and 176 did not. Thirty-day mortality was 2.9%. Follow-up was 2.2 ± 1.3 years. During follow-up, 46 of 176 patients received anticoagulation, and 130 of 176 patients did not. In patients without mechanical valves, 87% were off anticoagulation at 1 year, 77% were off anticoagulation at 2 years, and 81% were off anticoagulation at 3 years. Return to sinus rhythm off antiarrhythmic drugs at 1, 2, and 3 years was 81%, 77%, and 68%, respectively. Of patients receiving anticoagulation during follow-up, 11 of 103 (11%) had major bleeds (1 fatal) and 2 (1.9%) developed stroke. In patients without anticoagulation for the entirety of follow-up, 1 stroke occurred at 21 months and 1 stroke occurred at 23 months postoperatively. Cumulative 4-year freedom from stroke in patients without anticoagulation was 97.5%. CONCLUSIONS: Discharging patients who underwent Cox Maze IV in sinus rhythm without oral anticoagulants seems to be safe with a stroke rate of less than 1% per year. This management strategy will need further validation by prospective investigation.

Robotic mitral valve operations by experienced surgeons are cost-neutral and durable at 1 year.

BACKGROUND: Robotic mitral valve surgery has potential advantages in patient satisfaction and 30-day outcome. Cost concerns and repair durability limit wider adoption of robotic technology. This study examined detailed cost differences between robotic and sternotomy techniques in relation to outcomes and durability following robotic mitral program initiation. METHODS: Between April 2013 and October 2015, 30-day and 1-year outcomes of 328 consecutive patients undergoing robotic or sternotomy mitral valve repair or replacement by experienced surgeons were examined. Multivariable logistic regression informed propensity matching to derive a cohort of 182 patients. Echocardiographic follow-up was completed at 1 year in all robotic patients. Detailed activity-based cost accounting was applied to include direct, semidirect, and indirect costs with special respect to robotic depreciation, maintenance, and supplies. A quantitative analysis of all hospital costs was applied directly to each patient encounter for comparative financial analyses. RESULTS: Mean predicted risk of mortality was similar in both the robotic (n = 91) and sternotomy (n = 91) groups (0.9% vs 0.8%; P > .431). The total costs of robotic mitral operations were similar to those of sternotomy ($27,662 vs $28,241; P = .273). Early direct costs were higher in the robotic group. There was a marked increase in late indirect cost with the sternotomy cohort related to increased length of stay, transfusion requirements, and readmission rates. Robotic repair technique was associated with no echocardiographic recurrence greater than trace to only mild regurgitation at 1 year. CONCLUSIONS: Experienced mitral surgeons can initiate a robotic program in a cost-neutral manner that maintains clinical outcome integrity as well as repair durability.

The Society of Thoracic Surgeons 2017 Clinical Practice Guidelines for the Surgical Treatment of Atrial Fibrillation.

EXECUTIVE SUMMARY: Surgical ablation for atrial fibrillation (AF) can be performed without additional risk of operative mortality or major morbidity, and is recommended at the time of concomitant mitral operations to restore sinus rhythm. (Class I, Level A) Surgical ablation for AF can be performed without additional operative risk of mortality or major morbidity, and is recommended at the time of concomitant isolated aortic valve replacement, isolated coronary artery bypass graft surgery, and aortic valve replacement plus coronary artery bypass graft operations to restore sinus rhythm. (Class I, Level B nonrandomized) Surgical ablation for symptomatic AF in the absence of structural heart disease that is refractory to class I/III antiarrhythmic drugs or catheter-based therapy or both is reasonable as a primary stand-alone procedure, to restore sinus rhythm. (Class IIA, Level B randomized) Surgical ablation for symptomatic persistent or longstanding persistent AF in the absence of structural heart disease is reasonable, as a stand-alone procedure using the Cox-Maze III/IV lesion set compared with pulmonary vein isolation alone. (Class IIA, Level B nonrandomized) Surgical ablation for symptomatic AF in the setting of left atrial enlargement (≥4.5 cm) or more than moderate mitral regurgitation by pulmonary vein isolation alone is not recommended. (Class III no benefit, Level C expert opinion) It is reasonable to perform left atrial appendage excision or exclusion in conjunction with surgical ablation for AF for longitudinal thromboembolic morbidity prevention. (Class IIA, Level C limited data) At the time of concomitant cardiac operations in patients with AF, it is reasonable to surgically manage the left atrial appendage for longitudinal thromboembolic morbidity prevention. (Class IIA, Level C expert opinion) In the treatment of AF, multidisciplinary heart team assessment, treatment planning, and long-term follow-up can be useful and beneficial to optimize patient outcomes. (Class I, Level C expert opinion).

Early Results of the Modified Right Atrial Lesion Set for the Cox-CryoMaze Procedure.

OBJECTIVE: The standard right atrial lesion (RAL) set, as originally outlined in the Cox-Maze III procedure, can be technically challenging when using a cryoprobe to create the lesions. We report our initial experience with an alternative set of RALs for the surgical treatment of atrial fibrillation (AF). METHODS: Between September 2011 and January 2015, a total of 112 patients underwent a CryoMaze procedure with biatrial lesions using argon-based cryoablation (cryoprobe temperature, -160°C). Although the standard left atrial lesion set was used, the RAL pattern was modified in this cohort of patients. The intracaval superior vena cava-inferior vena cava lesion was performed as in the pattern described for the standard Cox-Maze III procedure. In addition, a horizontal atriotomy incision (the "T" lesion) in the mid free wall of the right atrium was based roughly in the midintercaval line and extended medially as a linear cryolesion to the lateral tricuspid annulus at the so-called 2-o'clock position as in the Cox-Maze III lesion pattern. Ordinarily, a linear cryolesion would be placed from the tip of the right atrial appendage (RAA) to the anterior tricuspid annulus at the so-called 10-o'clock position to prevent macro re-entry around the base of the RA appendage. Our modification consisted of, instead, a linear cryolesion directed perpendicularly from the mid portion of the atriotomy (T lesion) to the tip of the RA appendage, which simply interrupted RAA re-entry at another point. RESULTS: The mean ± standard deviation age was 72.7 ± 10.6 years, 56.3% were males, and 63.1% had long-standing persistent AF. There were three operative deaths (2.6% with an observed over expected of 0.58), all in the concomitant procedures with associated cardiac disease. Overall follow-up was 91.3%. Freedom from AF at discharge, 1-, 3-, 6-, 12-, 24-month, and last follow-up [16.1 ± 11.3 months (range, 0.4-43 months)], was 100%, 76.3%, 84.2%, 98.3%, 89.5%, 89.2%, and 90.5%, respectively. Similarly, freedom from antiarrhythmic drugs was 74% and 81%, whereas freedom from anticoagulants was 72% and 78% at 12 and 24 months, respectively. CONCLUSIONS: These results suggest the modified RAL set to be an effective alternative to the traditional RALs of Cox-Maze III. By substituting this lateral RAA lesion for the more technically difficult medial lesion, the procedure becomes easier to perform and favorably impacts operative time while achieving comparable results in reducing AF burden.