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.

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.

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.