Specific linear left atrial lesions in atrial fibrillation: intraoperative radiofrequency ablation using minimally invasive surgical techniques.

OBJECTIVES: A specific left atrial (LA) linear lesion concept for treatment of paroxysmal and permanent atrial fibrillation (AF) was tested using intraoperative ablation with minimally invasive surgical techniques. BACKGROUND: Curative treatment for patients with chronic AF is among the main challenges of interventional electrophysiology. METHODS: Seventy patients (mean age 53 +/- 10 years) with drug-refractory persistent (n = 28) or paroxysmal (n = 42) AF underwent intraoperative radiofrequency (RF) ablation using video-assisted minimally invasive techniques via a right anterolateral minithoracotomy. Contiguous lesion lines involving the mitral annulus and the orifices of the pulmonary veins were placed with RF energy application under direct vision to prevent anatomically defined LA re-entrant circuits. RESULTS: Mean follow-up was 18 +/- 7 months in patients with permanent AF and 18 +/- 5 months in patients with paroxysmal AF. Antiarrhythmic drug treatment was instituted in patients with postoperative atrial arrhythmias to allow "reverse electrical remodeling" and was discontinued after three months. Six months following ablation, 93% of the patients were in sinus rhythm in both groups, and after 12 months, 95% and 97%, respectively. As major complications, one esophagus perforation and one circumflex coronary artery stenosis were observed. CONCLUSIONS: A pure linear lesion line concept confined to the left atrium targeting specifically at elimination of anatomically defined LA "anchor" re-entrant circuits eliminated AF in >90% of the patients treated with intraoperative ablation using minimally invasive surgical techniques over a mean follow-up of 1.5 years.

Curative treatment of atrial fibrillation with intraoperative radiofrequency ablation: short-term and midterm results.

OBJECTIVE: This report describes the early and midterm results after intraoperative radiofrequency ablation of atrial fibrillation for patients with isolated chronic atrial fibrillation or atrial fibrillation in combination with additional valvular and nonvalvular cardiac diseases. METHODS: From August 1998 to March 2001, a total of 234 patients with chronic atrial fibrillation underwent isolated intraoperative radiofrequency ablation alone (n = 74, 31.6%) or in combination with other cardiac procedures, such as mitral valve reconstruction (n = 57, 24.4%), mitral valve replacement (n = 38, 16.2%), aortic valve replacement (n = 11, 5.1%), coronary artery bypass grafting (n = 8, 5.0%), or a combination of the last with other cardiac procedures (n = 46, 19.7%). In all cases anatomic reentrant circuits confined within the left atrium were eliminated by placing contiguous lesion lines involving the mitral anulus and the orifices of the pulmonary veins through the use of radiofrequency energy application (exposure time, 20 seconds). A median sternotomy was used in 101 cases (43.2%), and video assistance through a right lateral minithoracotomy was used in 133 cases (56.8%). RESULTS: A total of 188 patients (83.9%) were discharged in sinus rhythm, 17 patients (7.6%) had atrial fibrillation, and 19 patients (8.5%) had atypical flutter. Pacemakers were implanted in 23 patients (9.8%). There were 10 in-hospital deaths (4.2%), and 30-day mortality was 5 patients (2.1%). In 3 cases (1.3%) an atrioesophageal fistula developed, necessitating surgical repair. Six months' follow-up was complete for 122 (61.0%) of 200 patients, with 99 patients still in stable sinus rhythm (81.1%, 95% confidence interval 73.1%-89.9%). Twelve months' follow-up was complete for 80 (90.9%) of 88 patients, with 58 patients still in sinus rhythm (72.5%, 95% confidence interval 61.3%-83.2%). CONCLUSIONS: Intraoperative radiofrequency ablation is a curative procedure for chronic atrial fibrillation. It is technically less challenging than the maze procedure and can be applied through a minimally invasive approach. Protection of the esophagus seems mandatory to avoid the deleterious complication of a left atrioesophageal fistula, such as was observed in 3 cases.

Esophageal perforation during left atrial radiofrequency ablation: Is the risk too high?

OBJECTIVE: Intraoperative radiofrequency ablation of atrial fibrillation (IRAAF) is a recently developed procedure being performed in an increasing number of patients. We have performed left atrial IRAAF in 387 patients since August 1998. The purpose of this article is to describe a serious complication of this procedure, namely IRAAF-induced esophageal perforation, in detail to identify possible risk factors. METHODS: Left atrial IRAAF was performed with a commercially available unipolar probe as an isolated procedure (n = 129) or in combination with mitral valve surgery (n = 163) or other surgical procedures (n = 95). Operations were performed either through a conventional sternotomy or right minithoracotomy. RESULTS: Four (1%) patients had esophageal perforation after radiofrequency ablation. All 4 patients presented after an initially unremarkable postoperative course, with sudden neurologic symptoms from esophagoatrial air embolization occurring in 3 of the patients. Three patients were successfully treated with extensive esophageal resection, and one died from massive air embolism. All perforations occurred in patients undergoing minimally invasive IRAAF. Comparison with other patients undergoing isolated minimally invasive IRAAF (n = 129) failed to reveal any reliable predictors of esophageal injury, including patient body size, operating times, or radiofrequency biophysical parameters. CONCLUSIONS: Left atrial IRAAF is associated with a small but definite risk of esophageal perforation. Unfortunately, we were unable to identify any risk factors for this life-threatening complication. A high degree of vigilance must be maintained for esophageal injury after IRAAF, particularly in patients with new neurologic deficits. Until safer methods of ablation are developed, we currently recommend against the use of IRAAF in patients undergoing cardiac surgery.

Skeletonization versus pedicle preparation of the radial artery with and without the ultrasonic scalpel.

BACKGROUND: The radial artery (RA) is increasingly used for myocardial revascularization because of its presumed advantageous long-term patency rates. The vessel can be harvested as a pedicle or skeletonized. The aim of this study was to compare the skeletonization technique with pedicle preparation using either an ultrasonic scalpel or scissors. METHODS: Forty consecutive patients with coronary artery disease undergoing complete arterial revascularization were included in the study. In 20 patients the RAs were prepared using scissors and clips (group 1: skeletonization; group 2: pedicle). In another 20 patients the arteries harvested were prepared using an ultrasonic scalpel (group 3: skeletonization; group 4: pedicle). The RA was treated with papaverine to prevent spasm of the vessel during and after harvesting. Tissue specimens of each RA were taken to analyze endothelial morphology by scanning electron microscopy. After implantation of the RA, graft perfusion was measured with a flow probe. RESULTS: Harvesting the RA as a skeletonized vessel took more time as compared with pedicle preparation (group 1 vs group 2: 37.1 +/- 3.5 minutes vs 24.4 +/- 3.9 minutes; p < 0.001 and group 3 vs group 4: 31.1 +/- 3.5 minutes vs 25.6 +/- 3.7 minutes; p < 0.01). The number of hemostatic titanium clips was similarly higher in group 1 as opposed to group 2 (58.7 +/- 7.1 vs 38.7 +/- 7.1; p < 0.01). However, there was no difference between groups 3 and 4 (p = 0.086). The length of the RA after skeletonization with scissors and clips was 20.8 +/- 1.5 cm in contrast with 19.1 +/- 0.9 cm (p < 0.01) after dissection as a pedicle. In the groups using the ultrasonic scalpel, there was no difference in graft length (p = 0.062). Mean blood flow through the graft after establishing the proximal anastomosis was similar among all groups (groups 1, 2, 3, and 4: 50 +/- 20.1 mL/min, 53.8 +/- 24.3 mL/min, 56.3 +/- 25.1 mL/min, and 51.8 +/- 23 mL/min, respectively). Scanning electron microscopy demonstrated endothelial damage in all patients in groups 1, 2, and 3 and in 7 patients of group 4. Most endothelial lesions were minor except in group 3 in which 1 of 5 endothelial lesions were severe. Statistically significant differences was found between groups 1 and 2, and 3 and 4 with respect to the degree of endothelial damage (p < 0.01). CONCLUSIONS: Skeletonization using scissors and clips is more time consuming and technically more difficult, but yield significantly longer grafts. Skeletonization with an ultrasonic scalpel did not result in additional length and was more frequently associated with severe endothelial damage. Pedicle preparation using scissors or an ultrasonic scalpel is much simpler and faster, and does not jeopardize endothelial integrity.

Intraoperative left atrial ablation (for atrial fibrillation) using a new argon cryocatheter: early clinical experience.

PURPOSE: Recently surgical treatment of atrial fibrillation has gained more popularity and presently is being performed in large numbers of patients. This report describes our early experience in treatment of patients with chronic or paroxysmal atrial fibrillation with a new tool for left atrial cryoablation. DESCRIPTION: From July 2002 through January 2003, 28 patients underwent left atrial cryoablation with the Surgifrost CryoCath. Patients underwent cryotherapy as an isolated procedure (n = 1), in combination with mitral valve surgery (n = 13), or with other surgical procedures (n = 14). In all patients contiguous lesion lines to the orifices of the pulmonary veins connected to the mitral annulus and the atriotomy were created. Surgery was performed through a conventional sternotomy in 8 patients (29%) and a right lateral minithoracotomy using video-assistance in 20 patients (71%). EVALUATION: Postoperatively sinus rhythm was restored in 27 patients (96%). At discharge 82% (23/28) of patients were in sinus rhythm and 18% (5/28) were in atrial fibrillation. Four patients (14%) required pacemaker implantation. There was no in-hospital mortality. At 6-months follow-up (19/28 patients) all were alive and 74% were in stable sinus rhythm, New York Heart Association functional class was 1.2 +/- 0.4. CONCLUSIONS: As indicated by our small and early patient cohort left atrial cryoablation with the Surgifrost argon cryocatheter is effective for the treatment of atrial fibrillation. This new device is technically easy to handle, it can be applied through a median sternotomy or lateral minithoracotomy. Long-term follow-up is necessary to evaluate further rhythm outcome.

Successful coronary artery bypass grafting with the aid of a portable minimized extracorporeal life support system.

Extracorporeal life support system has been successfully used in patients with cardiac failure after open heart surgery, as a bridge to transplantation, and in patients with prolonged cardiogenic shock or cardiopulmonary arrest. This report presents our early experience with the new system Cardiohelp in coronary artery bypass grafting (CABG). Between August 2010 and June 2011, 50 patients underwent CABG with the aid of Cardiohelp. This subgroup was matched for sex and logistic EuroSCORE with 100 patients, who underwent CABG using two different extracorporeal circulation systems, a minimized (MECC) (n = 50) and a conventional (CECC) (n = 50) during the same period. Because of less hemodilution, the intraoperative blood transfusion was significantly lower in the Cardiohelp group (36%) and MECC group (40%) compared with the CECC group (64%). Postoperative release of creatinine kinase and lactate was lower in the Cardiohelp and MECC groups (p < 0.001). Furthermore, these patients had shorter duration of ventilation and lengths of stay at the intensive care unit (p < 0.05). Device-related complications were not observed. A conversion to CECC was not necessary. In conclusion, the Cardiohelp is a safe alternative for CABG surgery. Valid technical innovations and limited number of side effects support its employment as a highly effective device for coronary surgery.

Surgical management of hypoplastic left heart syndrome at the Birmingham Children's Hospital.

Currently, a three-stage surgical palliation remains the treatment of choice at Birmingham Children's Hospital. After initial introduction of the classical Norwood with pulmonary blood flow provided by a modified Blalock-Taussig shunt, a right ventricular to right pulmonary artery conduit at stage 1 Norwood palliation is now used in most cases, a bi-directional 'Glenn' shunt at second stage and an extra-cardiac Fontan completion at third stage. Mortality and morbidity has improved after modification of the technique. Thirty-day mortality was 32.4% (79/244) for the 'classical' Norwood procedure, 25.0% (7/28) for the left-sided RV-PA conduit and 12.7% (22/173) for the right-sided RV-PA conduit. Interstage mortality was 8.6% (21/244) for the 'classical' Norwood procedure, 14.3% (4/28) for the left and 10.1% (15/148) for right-sided RV-PA conduit. After stage II, 30-day mortality was 3.0% (10/335) for all groups. Stage III 30-day mortality was 0.9% (1/115) for all groups.

Beating heart aortic valve replacement after previous coronary artery bypass surgery with a patent internal mammary artery graft.

Re-sternotomy for aortic valve replacement (AVR) in patients with a patent internal mammary artery (IMA) graft may present a challenging surgical problem. Thus, strategies to prevent IMA graft injury include avoiding its dissection and leaving the graft open. However, when aortic cross clamping and cardioplegia are required, this approach may be associated with cardioplegia washout, suboptimal myocardial protection, and anterior myocardial wall injury. We herein describe an alternative technique for AVR on the beating heart in 4 patients with patent IMA grafts. The IMA was left unclamped and continuous retrograde coronary sinus perfusion (RCSP) was administered. Additional simultaneous antegrade venous bypass graft perfusion was established according to the extent of native coronary artery disease as well as patency and level of aortic proximal anastomoses. Using additional coronary ostia backflow control, the aortic valve was successfully replaced on the beating heart in all four cases without perivalvular leak. Postoperatively, low creatine kinase-MB fraction levels and preserved or improved ventricular function suggested very good myocardial protection. No myocardial infarction occurred in any patient. In our experience, aortic valve replacement on the beating heart using simultaneous antegrade-retrograde blood perfusion is a safe and effective method in this challenging subset of patients to prevent myocardial injury and to minimize the risk of patent IMA injury.

Surgical treatment of atrial fibrillation with argon-based cryotechnology.

Over the past several years numerous attempts have been made to treat atrial fibrillation surgically. The most effective of all such surgical treatments has been the Maze operation, developed by James Cox in the 1980s. The Maze operation has demonstrated excellent long-term results. The procedure is based on a complex surgical technique, thus is it not easily being reproduced by every surgeon. Different attempts have been made to simplify the original Maze technique. In 1999, the electrophysiologists at the authors' institution outlined a lesion concept for left atrial ablation in the treatment of atrial fibrillation. In 387 patients, the authors used intraoperative radiofrequency ablation to cure AF. The results were comparable to the maze procedure. This concept was very effective but after a time period of 4 years in 1% of patients esophagus perforations occurred. In a quest to identify other energy sources to produce good ablation results with less possible complications, intraoperative cryoablation has been developed. In the following study conducted the authors were able to use a new flexible cryocatheter (Cryocath Surgifrost). Sinus rhythm was achieved in 71% after a 1 year follow-up period with low morbidity and comparable mortality, which was due to the concomitant cardiac pathologies and operative procedures. In conclusion, thus far from this series of patients presented, the authors have demonstrated that cryoablation with Argon-cryotechnology is efficacious and safe.

Three-dimensional echocardiography for planning of mitral valve surgery: current applicability?

BACKGROUND: Two-dimensional transesophageal echocardiographic (2D TEE) assessment of the mitral valve requires mental integration of a limited number of 2D imaging planes. Structural display in three dimensions from any perspective may be of advantage to the surgeon for better judgment and planning. METHODS: Feasibility, accuracy, and limitations of preoperative three-dimensional transesophageal echocardiography (3D TEE) was assessed in 51 patients with mitral valve disease. The width of the anterior mitral valve was measured with either method and compared with the operative finding. Three-dimensional dynamic sequences of the reconstructed mitral valve were shown preoperatively to the surgeon and later compared with the intraoperative finding. RESULTS: The quality of the 3D reconstruction was graded as good in 25 patients (49.0%), fair in 16 patients (31.4%), and poor in 10 patients (19.6%) where atrial fibrillation did not allow ECG gating. Thirty-nine patients had successful mitral valve repair and twelve patients required valve replacement. Based on intraoperative findings, sensitivity for the diagnosis of mitral valve prolapse using 2D TEE and 3D TEE was 97.7% and 92.9% (p = ns) respectively and specificity was 100% by both methods. Sensitivity for the diagnosis of rupture of chordae tendineae using 2D TEE and 3D TEE was 92.3% and 30.8% respectively (p < 0.05) and specificity was 100% by both methods. CONCLUSIONS: Dynamic 3D echocardiography is feasible and can provide good insight into valvular motion and allows adequate preoperative planning when reconstruction is being considered. However dynamic 3D reconstruction is currently limited by the quality of the original 2D echo cross sectional images which can be adversely affected by minimal patient movements, breathing, or cardiac arrhythmia, thus limiting accuracy of the 3D TEE significantly compared with 2D TEE.

Temporary extracorporeal membrane oxygenation in patients with refractory postoperative cardiogenic shock--a single center experience.

BACKGROUND: Approximately 1% of patients require temporary circulatory support due to refractory cardiogenic shock following cardiac surgery. Such patients are at very high risk for subsequent morbidity and mortality. We evaluated the results of temporary extracorporeal membrane oxygenation (ECMO) support in patients with postcardiotomy cardiogenic shock. METHODS: From November 1997 to February 2000, 7900 patients underwent cardiac surgery in our institution. Ninety-five patients (1.2%) (CABG, n = 63; AVR, n = 16; CABG and AVR, n = 8; other procedures, n = 8) required temporary postoperative ECMO support. ECMO implantation was performed via the femoral vessels or via the right atrium and ascending aorta. Intraaortic balloon counterpulsation was employed in all patients. RESULTS: Mean duration of ECMO support was 2.8 +/- 2.1 days. Forty-five patients (47%) were successfully weaned from ECMO. Of these, 28 patients were discharged from hospital 35.8 +/- 20.8 days post-ECMO support. Overall hospital mortality for all ECMO patients was considerable at 71%. Mortality rate in the combined CABG and AVR group was 100% (P < 0.05 versus the other surgical groups). ECMO support was complicated by renal failure in 64% of patients, bleeding requiring mediastinal reexploration in 62%, ischemia of the lower limbs in 16%, cerebral edema in 6%, and cerebral hemorrhage in 3%. CONCLUSIONS: ECMO is a suitable technique for short-term treatment of refractory postoperative low cardiac output. Mortality rates are comparable to other cardiac assist devices, with approximately 30% of patients able to be discharged from hospital.