Stroke prevention following modified endoscopic ablation and appendectomy for atrial fibrillation

The Mei mini-maze procedure

Atrial fibrillation is a common clinical arrhythmia with high morbidity and a risk of stroke. The Cox-maze IV procedure that uses radiofrequency energy for ablation is established as an effective way to eliminate atrial fibrillation. Compared to the Cox-maze IV procedure, the video-assisted Wolf mini-maze procedure is associated with reduced surgical trauma, but still requires bilateral thoracotomies, and the ablation line connecting the right and left pulmonary vein isolations cannot be created with a bipolar ablation clamp. We have developed a novel video-assisted mini-maze technique that uses a unilateral (left chest) thoracoscopic approach (the Mei mini-maze procedure).

Cerebral oxygen desaturation in patients with totally thoracoscopic ablation for atrial fibrillation: A prospective observational study

BACKGROUND

Epicardial radiofrequency ablation for stand-alone atrial fibrillation under total video-assisted thoracoscopy has gained popularity in recent years. However, severe cardiopulmonary disturbances during the surgery may affect cerebral perfusion and oxygenation. We therefore hypothesized that regional cerebral oxygen saturation (rSO2) would decrease significantly during the surgery. In addition, the influencing factors of rSO2 would be investigated.

METHODS

A total of 60 patients scheduled for selective totally thoracoscopic ablation for stand-alone atrial fibrillation were enrolled in this prospective observational study. The rSO2 was monitored at baseline (T0), 15 min after anesthesia induction (T1), 15 minute after 1-lung ventilation (T2), after right pulmonary vein ablation (T3), after left pulmonary vein ablation (T4) and 15 minute after 2-lung ventilation (T5) using a near-infrared reflectance spectroscopy -based cerebral oximeter. Arterial blood gas was analyzed using an ABL 825 hemoximeter. Associations between rSO2 and hemodynamic or blood gas parameters were determined with univariate and multivariate linear regression analyses.

RESULTS

The rSO2 decreased greatly from baseline 65.4% to 56.5% at T3 (P < .001). Univariate analyses showed that rSO2 correlated significantly with heart rate (r = -0.173, P = .186), mean arterial pressure (MAP, r = 0.306, P = .018), central venous pressure (r = 0.261, P = .044), arterial carbon dioxide tension (r = -0.336, P = .009), arterial oxygen pressure (PaO2, r = 0.522, P < .001), and base excess (BE, r = 0.316, P = .014). Multivariate linear regression analyses further showed that it correlated positively with PaO2 (β = 0.456, P < .001), MAP (β = 0.251, P = .020), and BE (β = 0.332, P = .003).

CONCLUSION

Totally thoracoscopic ablation for atrial fibrillation caused a significant decrease in rSO2. There were positive correlations between rSO2 and PaO2, MAP, and BE.

Concomitant thoracoscopic surgery for solitary pulmonary nodule and atrial fibrillation

OBJECTIVES

The incidence of both solitary pulmonary nodules (SPN) and non-valvular atrial fibrillation (NVAF) has increased over the past decade. We performed concomitant video-assisted thoracoscopic surgery with modified epicardial radiofrequency ablation procedure for NVAF and SPN resection.

METHODS

Sixteen patients (7 men, mean age 62.6 ± 11.2 years) with SPN and NVAF underwent this procedure. Of these patients, 10 had paroxysmal atrial fibrillation and 6 persistent atrial fibrillation. A modified epicardial radiofrequency ablation combined with pulmonary vein isolation, circumferential left atrial ablation, ganglionic plexus ablation and left atrial appendage resection was performed for all patients. Left pulmonary surgery was carried out subsequently.

RESULTS

The mean procedure duration was 203.1 ± 15.6 (range 177-224) min. All patients successfully underwent this procedure with no conversion to sternotomy or pacemaker implantation. Of the 16 included patients, 13 received lobectomy and 3 received wedge resection. No severe complications occurred postoperatively. The mean length of hospital stay was 9.1 ± 1.4 (range 7-11) days with a mean follow-up period of 18.7 ± 6.7 (range 8-32) months. One patient had AF recurrence 6 months postoperatively. No pulmonary vein stenosis was detected at the 3rd postoperative month. There were no deaths or thromboembolic events during follow-up.

CONCLUSIONS

This concomitant therapy proved to be safe and yielded good clinical outcomes. Therefore, it deserves to be considered as a treatment for patients with SPN and NVAF.

Right minithoracotomy versus conventional median sternotomy for patients undergoing mitral valve surgery and Cox-maze IV ablation with entirely bipolar radiofrequency clamp

Cox-maze IV ablation by bipolar radiofrequency clamp was considered to be only performed through median sternotomy (MS), but impossible through right minithoracotomy (RM). Now, we developed a novel technique of performing Cox-maze IV ablation entirely by bipolar clamp through RM. To compare the outcomes of RM or MS for patients undergoing mitral valve surgery and concomitant Cox-maze IV ablation with entirely bipolar clamp. All 152 patients underwent mitral valve surgery and concomitant Cox-maze IV ablation with bipolar clamp through RM (n = 69) or MS (n = 83) were analyzed for outcome differences. The etiology of mitral valve disease was rheumatic (n = 97) and degenerative (n = 55). All patients had long-standing persistent atrial fibrillation (AF). Diameter of left atrium ranged from 42 to 60 mm. All patients successfully underwent Cox-maze IV ablation by bipolar clamp. RM group had longer cardiopulmonary bypass time (130.3 ± 17.7 vs 115.3 ± 14.4 min; P < 0.001) and aortic cross-clamp time (91.8 ± 12.7 vs 74.6 ± 9.3 min; P < 0.001). But mechanical ventilation time (14.2 ± 6.6 vs 21.3 ± 9.0 h; P < 0.001) and hospital length of stay (9.3 ± 2.6 vs 11.7 ± 3.0 days; P < 0.001) were shorter in RM group. At discharge, the maintenance of normal sinus rhythm (NSR) was 94.2% in RM group and 95.1% in MS group (P = 1.000). Cumulative maintenance of NSR at 2 years postoperatively was 85.1 ± 5.8% in RM group and 88.6 ± 3.6% in MS group (P = 0.767). RM can achieve similar therapeutic effect to MS for patients undergoing mitral valve surgery and concomitant Cox-maze IV ablation with entirely bipolar clamp. In addition, patients through RM had faster recovery.