Wim J. van Boven

Thoracoscopic Video-Assisted Pulmonary Vein Antrum Isolation, Ganglionated Plexus Ablation and Periprocedural Confirmation of Ablation Lesions. First Results of a Hybrid Surgical-Electrophysiological Approach for Atrial Fibrillation

Background—Thoracoscopic pulmonary vein isolation (PVI) and ganglionated plexus ablation is a novel approach in the treatment of atrial fibrillation (AF). We hypothesize that meticulous electrophysiological confirmation of PVI results in fewer recurrences of AF during follow-up. Methods and Results—Surgery was performed through 3 ports bilaterally. Ganglionated plexi were localized and subsequently ablated. PVI was performed and entry and exit block was confirmed. Additional left atrial ablation lines were created and conduction block verified in patients with nonparoxysmal AF. The left atrial appendage was removed. Freedom of AF was assessed by ECGs and Holter monitoring every 3 months or during symptoms of arrhythmia. Antiarrhythmic drugs were discontinued after 3 months and oral anticoagulants were discontinued according to the guidelines. Thirty-one patients were treated (16 paroxysmal AF, 13 persistent AF, 2 long-standing persistent AF). Thirteen patients with nonparoxysmal received additional left atrial ablation lines. After 1 year, 19 of 22 patients (86%) had no recurrences of AF, atrial flutter, or atrial tachycardia and were not using antiarrhythmic drugs (11/12 paroxysmal, 7/9 persistent, and 1/1 long-standing persistent). Three patients had a sternotomy because of uncontrolled bleeding during thoracoscopic surgery. Four adverse events were 1 hemothorax, 1 pneumothorax, and 2 pneumonia. No thromboembolic complications or mortality occurred. Conclusions—Thoracoscopic surgery with PVI and ganglionated plexus ablation for AF is a safe and successful procedure with a single procedure success rate of 86% at 1 year. Electrophysiological guided thorough PVI and additional left atrial ablation line creation presumably contributes in achieving a high success rate in the surgical treatment of AF.

Current management of postoperative chylothorax

BACKGROUND This study was performed to review our experience with postoperative chylothorax and describe our current approach. In addition, we wanted to estimate the impact of video-assisted thoracoscopic surgery (VATS) on our current management policy. METHODS From January 1991 to December 1999, 12 patients developed chylothorax after various thoracic procedures. Their mean age was 61.5 (range 31 to 80 years). The procedures were cardiac, aortic, and pulmonary operations. RESULTS All patients were initially treated conservatively. In addition, 7 patients needed surgical intervention, including one thoracotomy and six VATS. The site of thoracic duct laceration was identified and treated with VATS in 4 patients. In 2 patients, the leak could not be localized by VATS, and fibrin glue or talcage were applied in the pleural space. All patients were discharged without recurrent chylothorax. CONCLUSIONS VATS is an effective tool in the management of persisting postoperative chylothorax. Its easy use, low cost, and low morbidity rate suggest an earlier use of VATS in the treatment of postoperative chylothorax.

Navigating the mini-maze: Systematic review of the first results and progress of minimally-invasive surgery in the treatment of atrial fibrillation

BACKGROUND In this paper we present a systematic literature overview and analysis of the first results and progress made with minimally-invasive surgery using RF energy in the treatment of AF. The minimally-invasive treatment for atrial fibrillation (AF) tries to combine the success rate of surgical treatment with a less invasive approach to surgery. It has the additional potential advantage of ganglion plexus (GP) ablation and left atrial appendage exclusion. Furthermore, additional left atrial ablation lines (ALAL) can be created in non-paroxysmal AF patients. METHODS For the search query multiple databases were used. Exclusion and inclusion criteria were applied to select the publications to be screened. All remaining articles were critically appraised and only relevant and valid articles were included in our results. RESULTS Twenty-three studies were included. In 15 studies GPs around the pulmonary veins were ablated. In four studies ALAL were performed. Single procedure success rate was 69% (95% CI, range 58%-78%) without antiarrhythmic drugs (AAD) and 79% (95% CI, range 71%-85%) with AAD at one year follow-up. Mortality was 0.4%, and various complications were reported (3.2% surgical, 3.2% post-surgical, 2.6% cardiac, 2.1% pulmonary, 1.7% other). CONCLUSIONS Twenty-three studies of minimally-invasive surgery for AF have been reviewed with success rates between that of the standard maze procedure and catheter ablation. These first combined results show promise; however, minimally-invasive surgery is still evolving, for instance by the recent inclusion of electrophysiological endpoints. Furthermore, the type of ALAL and the additional value of GP ablation have to be elucidated.

Risk factors for chronic thoracic pain after cardiac surgery via sternotomy

OBJECTIVE This study examines the influence of patient demographics and peri- and postoperative (<7 days) characteristics on the incidence of chronic thoracic pain 1 year after cardiac surgery. The impact of chronic thoracic pain on daily life is also documented. METHODS A prospective cohort study of 146 patients admitted to the intensive care unit after cardiac surgery via sternotomy was carried out. Pain scores (numeric rating scale 0-10) were recorded during the first 7 postoperative days. One year later, a questionnaire was used to evaluate the incidence in the 2 preceding weeks of chronic thoracic pain (numeric rating scale >0) associated with the primary surgery. RESULTS One year after surgery, 42 (35%) of the 120 responding patients reported chronic thoracic pain. Multivariate regression analysis of patient characteristics revealed that non-elective surgery, re-sternotomy, severe pain (numeric rating scale ≥ 4) on the third postoperative day, and female gender were all independent predictors of chronic thoracic pain. In addition, the chronic sufferers reported more sleep disturbances and more frequent use of analgesics than their cohorts. CONCLUSIONS We have identified a number of factors correlated with persistent thoracic pain following cardiac surgery with sternotomy. Awareness of these predictors may be useful for further research concerning both the prevention and treatment of chronic thoracic pain, thereby potentially ameliorating the postoperative quality of life of a significant proportion of patients. Meanwhile, chronic thoracic pain should be discussed preoperatively with patients at risk so that they are truly informed about possible consequences of the surgery.

Atrial Fibrosis and Conduction Slowing in the Left Atrial Appendage of Patients Undergoing Thoracoscopic Surgical Pulmonary Vein Isolation for Atrial Fibrillation

Background—Atrial fibrosis is an important component of the arrhythmogenic substrate in patients with atrial fibrillation (AF). We studied the effect of interstitial fibrosis on conduction velocity (CV) in the left atrial appendage of patients with AF. Methods and Results—Thirty-five left atrial appendages were obtained during AF surgery. Preparations were superfused and stimulated at 100 beats per minute. Activation was recorded with optical mapping. Longitudinal CV (CVL), transverse CV (CVT), and activation times (>2 mm distance) were measured. Interstitial collagen was quantified and graded qualitatively. The presence of fibroblasts and myofibroblasts was assessed immunohistochemically. Mean CVL was 0.55±0.22 m/s, mean CVT was 0.25±0.15 m/s, and the mean activation time was 9.31±5.45 ms. The amount of fibrosis was unrelated to CV or patient characteristics. CVL was higher in left atrial appendages with thick compared with thin interstitial collagen strands (0.77±0.22 versus 0.48±0.19 m/s; P=0.012), which were more frequently present in persistent patients with AF. CVT was not significantly different (P=0.47), but activation time was 14.93±4.12 versus 7.95±4.12 ms in patients with thick versus thin interstitial collagen strands, respectively (P=0.004). Fibroblasts were abundantly present and were associated with the presence of thick interstitial collagen strands (P=0.008). Myofibroblasts were not detected in the left atrial appendage. Conclusions—In patients with AF, thick interstitial collagen strands are associated with higher CVL and increased activation time. Our observations demonstrate that the severity and structure of local interstitial fibrosis is associated with atrial conduction abnormalities, presenting an arrhythmogenic substrate for atrial re-entry.

Use of minimal invasive extracorporeal circulation in cardiac surgery: principles, definitions and potential benefits. A position paper from the Minimal invasive Extra-Corporeal Technologies international Society (MiECTiS)

Minimal invasive extracorporeal circulation (MiECC) systems have initiated important efforts within science and technology to further improve the biocompatibility of cardiopulmonary bypass components to minimize the adverse effects and improve end-organ protection. The Minimal invasive Extra-Corporeal Technologies international Society was founded to create an international forum for the exchange of ideas on clinical application and research of minimal invasive extracorporeal circulation technology. The present work is a consensus document developed to standardize the terminology and the definition of minimal invasive extracorporeal circulation technology as well as to provide recommendations for the clinical practice. The goal of this manuscript is to promote the use of MiECC systems into clinical practice as a multidisciplinary strategy involving cardiac surgeons, anaesthesiologists and perfusionists.

Combined off-pump coronary surgery and right lung resections through midline sternotomy

Concomitant severe coronary artery disease and lung malignancies are uncommon. Combining conventional coronary surgery with cardiopulmonary bypass with lung resection is still a controversial issue. Conversely, combining off-pump coronary surgery with right lung resections through a midline sternotomy can be an attractive approach. Off-pump coronary surgery avoids the risks of cardiopulmonary bypass, reduces systemic inflammatory response and does not affect the immune system. We report a series of three patients successfully operated using this approach.

Combined coronary artery bypass grafting and aortic valve replacement with minimal extracorporeal closed circuit circulation versus standard cardiopulmonary bypass

Isolated aortic valve replacement (AVR) or coronary artery bypass grafting (CABG) using minimized extracorporeal circulation (MECC) has been shown to have less deleterious effects than standard cardiopulmonary bypass (CPB). In this prospective cohort study, we evaluated and compared clinical results of combined AVR with CABG using MECC. We prospectively collected preoperative, intraoperative, postoperative and follow-up data of 65 patients who underwent combined AVR with CABG using MECC and compared these with 135 patients undergoing combined AVR with CABG using standard CPB. No significant differences were seen in patients demographic characteristics or intraoperative data. Patients in the MECC group experienced a smaller preoperative haemoglobin drop (4.5±0.8 g/dl vs. 5.0±0.5 g/dl, P=0.002) resulting in higher haemoglobin at discharge (11.3±1.3 g/dl vs. 10.8±1.1 g/dl, P=0.03). They had decreased blood products requirements (P=0.004) compared to patients in the standard CPB group. No differences were noted in pulmonary complications, neurological events or mortality. We present for the first time data showing that combined AVR with CABG using MECC is feasible and provides better clinical results compared to standard CPB with regard to blood products requirements, without compromising operative morbidity or mortality.

Isolated lung perfusion for pulmonary metastases, a review and work in progress

Pulmonary metastasectomy is a widely accepted treatment for many patients with pulmonary metastases from various solid tumors. Nevertheless, 5–year survival is disappointing, with rates of 25–40%, and many patients develop recurrences. Isolated lung perfusion (ILuP) is a promising new technique to deliver high–dose chemotherapy to the lungs, while minimising systemic toxicities. This procedure is technically safe and feasible; however, clinical value and efficacy remain unclear. The aim of this paper is to give a review of literature on ILuP in humans, and to describe the development of the perfusion procedure in our institute.

Epicardial confirmation of conduction block during thoracoscopic surgery for atrial fibrillation--a hybrid surgical-electrophysiological approach.

Abstract Background: Totally thoracoscopic epicardial pulmonary vein ablation is an emerging treatment of atrial fibrillation (AF). A hybrid surgical-electrophysiological procedure with periprocedural confirmation of conduction block might reduce recurrences of AF or atrial tachycardia and improve surgical success. Methods and results: We report our joint surgical-electrophysiological approach for confirmation of conduction block across pulmonary vein ablation lines and those compartmentalizing the left atrium during totally thoracoscopic surgery. A diagnostic electrophysiology (EP) catheter positioned under the left atrium is used as reference and a custom-made multi-electrode for recording. Determination of conduction block across the pulmonary vein (PV) ablation lines requires measurement of activation time differences of milliseconds. Second, a stable reference electrogram to which to relate local activation time is required. Third, the recording electrode terminals and the inter-electrode distance should be small to prevent recording of far field activity and to allow recording of very small electrograms. We confirm entry and exit block and determine conduction block across linear ablation lines with differential pacing. Conclusion: A joint surgical-electrophysiological protocol for confirmation of conduction block across PV isolation lines and left atrial ablation lines is feasible and might prevent recurrences and further improve the success of minimally invasive surgery for AF.