Wim-Jan Van Boven

Myocardial oxidative stress, and cell injury comparing three different techniques for coronary artery bypass grafting

OBJECTIVE Oxidative stress as a result of reperfusion injury is a known causative factor of cardiac muscle injury. In the peripheral blood as well in the coronary sinus, oxidative stress parameters and cardiac biomarkers were measured to investigate the different levels of oxidative stress during three different CABG techniques; MCABG (with minimal prime volume and warm blood cardioplegia) that was newly introduced in our hospital, versus OPCAB, versus our current standard, conventional CABG (CCABG, consisting of high volume prime and cold crystalloid cardioplegia). Concomitantly, cardiac biomarkers were measured to detect myocardial cell injury. METHODS Thirty patients scheduled for CABG with the intention to treat three-vessel disease were randomly assigned for CCABG, MCABG or OPCAB. Perioperatively, plasma levels of malondialdehyde (MDA) as a marker of oxidative stress, and the allantoin/uric acid ratio (A/U ratio) as a marker of antioxidant activity were measured in the ascending aorta (Aa), and in the coronary sinus (Cs), simultaneously. Additionally peripheral (Aa) blood levels of heart fatty acid binding protein (HFABP), troponin T, CPK and CKMB as markers of myocardial injury were obtained. RESULTS The MCABG group had significantly lower MDA levels in the Cs compared to the CCABG group, respectively, to the OPCAB group (p=0.04 and p=0.03). At all time points the A/U ratio in the CCABG group remained significantly higher in the Cs as well in the Aa samples compared to the MCABG and the OPCAB group (p<0.001, respectively, p<0.001, for both groups). HFABP and troponin T showed consistent curves compared to the CPK figure over time in all groups. CONCLUSION In this study coronary sinus blood levels of oxidative stress parameters were consistently higher compared to peripheral blood levels. The levels were lowest in the MCABG study group. In this group also the lowest levels cardiac biomarkers of myocardial injury were found.

Surgical management of superior vena cava syndrome after failed endovascular stenting

The superior vena cava syndrome encompasses a constellation of symptoms and signs resulting from obstruction of the superior vena cava. We report a successful surgical management after failed endovascular stenting for superior vena cava syndrome, caused by a postradiation fibrosis after conventional radiotherapy for breast cancer. We emphasize the rarity of this uncommon surgical procedure and the bailout procedure for failed angioplasty and intravascular stenting. Key points of superior vena cava syndrome and its management are discussed.

Minimised closed circuit coronary artery bypass grafting in the elderly is associated with lower levels of organ-specific biomarkers: a prospective randomised study.

BACKGROUND Restrictive fluid management may protect organ function and improve postoperative outcome in elderly coronary artery bypass grafting (CABG) patients. OBJECTIVE We assessed organ-specific biomarker release to study the contribution of a fluid restrictive closed circuit concept to organ protection in elderly CABG patients. Cardiac, respiratory and abdominal organ injury was measured during and following minimal fluid coronary artery bypass grafting (mCABG), off-pump coronary artery bypass (opCAB) surgery and conventional CABG with high volume prime and cold crystalloid cardioplegia (cCABG). The results were related to differences in clinical outcome. DESIGN Prospective randomised trial. SETTING Dutch tertiary single centre study. PATIENTS Sixty patients over 70 years of age (38 men and 22 women) were randomised to one of the three different techniques. Inclusion criteria were as follows: first time CABG, elective surgery, ejection fraction more than 30% and multivessel disease. Acetylsalicylic acid and clopidogrel administration or requiring less than three distal anastomoses were an exclusion. MAIN OUTCOME MEASURES Organ-specific markers of the heart – heart fatty acid binding protein (HFABP), troponin T, pro-brain natriuretic peptide (pro-BNP) and creatinine phosphokinase (CPK), lung clara cell 16 protein, pneumoprotein (CC16), intestinal fatty acid binding protein (IFABP) and liver glutathione S-transferase (&agr;-GST) – were measured perioperatively. Postoperative PaO2 levels, ventilation time, blood product consumption and adverse events were noted. RESULTS Myocardial organ-specific biomarker troponin T showed significantly lower median levels during mCABG compared with the cCABG and opCAB groups [troponin 0.25 mg l−1 (interquartile range, IQR 0.18 to 0.40), 0.39 mg l−1 (IQR 0.23 to 0.49) and 0.36 mg l−1 (IQR 0.23 to 0.50), respectively (P <0.003)]. HFABP, IFABP and &agr;-GST levels were significantly higher during cCABG compared with opCAB and mCABG [HFABP 38.6 mg l−1 (IQR 29.6 to 47.1), 23.3 mg l−1 (IQR 16.5 to 31.0) and 21.1 mg l−1 (IQR 15.7 to 28.8; P < 0.001), IFABP 0.57 mg l−1 (IQR 0.37 to 1.11), 0.44 mg l−1 (IQR 0.16 to 0.74) and 0.37 mg l−1 (IQR 0.13 to 1.05; P < 0.02) and &agr;-GST 11.5 mg l−1 (IQR 7.7 to 15.7), 7.0 mg l−1 (IQR 4.5 to 13.8) and 7.3 mg l−1 (IQR 6.2 to 11.2), respectively (P <0.009)]. There was a trend towards higher median CC16 levels in the cCABG group (P <0.07). CPK and pro-BNP were not significantly different. On the first postoperative day, PaO2 levels and duration of mechanical ventilation were significantly improved, and there was lower use of blood products in the mCABG group than in the cCABG and opCAB groups (P <0.05). CONCLUSION Following mCABG with low volume myocardial preservation and restrictive fluid management, early respiratory performance was improved and consumption of blood products reduced compared with opCAB and cCABG.

Phase II Multicenter Clinical Trial of Pulmonary Metastasectomy and Isolated Lung Perfusion with Melphalan in Patients with Resectable Lung Metastases

Introduction: The 5-year overall survival rate of patients undergoing complete surgical resection of pulmonary metastases (PM) from colorectal cancer (CRC) and sarcoma remains low (20–50%). Local recurrence rate is high (48–66%). Isolated lung perfusion (ILuP) allows the delivery of high-dose locoregional chemotherapy with minimal systemic leakage to improve local control. Methods: From 2006 to 2011, 50 patients, 28 male, median age 57 years (15–76), with PM from CRC (n = 30) or sarcoma (n = 20) were included in a phase II clinical trial conducted in four cardiothoracic surgical centers. In total, 62 ILuP procedures were performed, 12 bilaterally, with 45 mg of melphalan at 37°C, followed by resection of all palpable PM. Survival was calculated according to the Kaplan–Meier method. Results: Operative mortality was 0%, and 90-day morbidity was mainly respiratory (grade 3: 42%, grade 4: 2%). After a median follow-up of 24 months (3–63 mo), 18 patients died, two without recurrence. Thirty patients had recurrent disease. Median time to local pulmonary progression was not reached. The 3-year overall survival and disease-free survival were 57% ± 9% and 36% ± 8%, respectively. Lung function data showed a decrease in forced expiratory volume in 1 second and diffusing capacity of the alveolocapillary membrane of 21.6% and 25.8% after 1 month, and 10.4% and 11.3% after 12 months, compared with preoperative values. Conclusion: Compared with historical series of PM resection without ILuP, favorable results are obtained in terms of local control without long-term adverse effects. These data support the further investigation of ILuP as additional treatment in patients with resectable PM from CRC or sarcoma.

Atrial Fibrillation Catheter Ablation Versus Surgical Ablation Treatment (FAST)

Background— Catheter ablation (CA) and minimally invasive surgical ablation (SA) have become accepted therapy for antiarrhythmic drug–refractory atrial fibrillation. This study describes the first randomized clinical trial comparing their efficacy and safety during a 12-month follow-up. Methods and Results— One hundred twenty-four patients with antiarrhythmic drug–refractory atrial fibrillation with left atrial dilatation and hypertension (42 patients, 33%) or failed prior CA (82 patients, 67%) were randomized to CA (63 patients) or SA (61 patients). CA consisted of linear antral pulmonary vein isolation and optional additional lines. SA consisted of bipolar radiofrequency isolation of the bilateral pulmonary vein, ganglionated plexi ablation, and left atrial appendage excision with optional additional lines. Follow-up at 6 and 12 months was performed by ECG and 7-day Holter recording. The primary end point, freedom from left atrial arrhythmia >30 seconds without antiarrhythmic drugs after 12 months, was 36.5% for CA and 65.6% for SA (P=0.0022). There was no difference in effect for subgroups, which was consistent at both sites. The primary safety end point of significant adverse events during the 12-month follow-up was significantly higher for SA than for CA (n=21 [34.4%] versus n=10 [15.9%]; P=0.027), driven mainly by procedural complications such as pneumothorax, major bleeding, and the need for pacemaker. In the CA group, 1 patient died at 1 month of subarachnoid hemorrhage. Conclusion— In atrial fibrillation patients with dilated left atrium and hypertension or failed prior atrial fibrillation CA, SA is superior to CA in achieving freedom from left atrial arrhythmias after 12 months of follow-up, although the procedural adverse event rate is significantly higher for SA than for CA. Clinical Trial Registration— URL: http://clinicaltrials.gov. Unique identifier: NCT00662701.

Electrophysiologically Guided Thoracoscopic Surgery for Advanced Atrial Fibrillation

Patients with symptomatic atrial fibrillation (AF) may require catheter or surgical ablation after antiarrhythmic drugs (AAD) have failed. Thoracoscopic surgical approaches aim to combine the reported efficacy of Cox-Maze procedures with less invasiveness, but long-term follow-up is unavailable. We

Surgical Left Atrial Appendage Exclusion Does Not Impair Left Atrial Contraction Function: A Pilot Study

Background. In order to reduce stroke risk, left atrial appendage amputation (LAAA) is widely adopted in recent years. The effect of LAAA on left atrial (LA) function remains unknown. The objective of present study was to assess the effect of LAAA on LA function. Methods. Sixteen patients with paroxysmal AF underwent thoracoscopic, surgical PVI with LAAA (LAAA group), and were retrospectively matched with 16 patients who underwent the same procedure without LAA amputation (non-LAAA group). To objectify LA function, transthoracic echocardiography with 2D Speckle Tracking was performed before surgery and at 12 months follow-up. Results. Mean age was 57 ± 9 years, 84% were male. Baseline characteristics did not differ significantly except for systolic blood pressure (p = 0.005). In both groups, the contractile LA function and LA ejection fraction were not significantly reduced. However, the conduit and reservoir function were significantly decreased at follow-up, compared to baseline. The reduction of strain and strain rate was not significantly different between groups. Conclusions. In this retrospective, observational matched group comparison with a convenience sample size of 16 patients, findings suggest that LAAA does not impair the contractile LA function when compared to patients in which the appendage was unaddressed. However, the LA conduit and reservoir function are reduced in both the LAAA and non-LAAA group. Our data suggest that the LAA can be removed without late LA functional consequences.

Disparate response of high-frequency ganglionic plexus stimulation on sinus node function and atrial propagation in patients with atrial fibrillation

BACKGROUND In patients with atrial fibrillation (AF), the autonomic nervous system is supposed to play an role in triggering AF; however, little is known of the effect on atrial conduction characteristics. OBJECTIVE The purpose of this study was to study the effect of ganglionic plexus (GP) stimulation during sinus rhythm on atrial and pulmonary vein conduction in patients during thoracoscopic surgery for AF METHODS: In 25 patients, the anterior right ganglionic plexus (ARGP) was stimulated (16 Hz, at 1, 2, and 5 mA). Epicardial electrograms were recorded using a 48-electrode map from the right pulmonary vein (RPV) or right atrial (RA). Intra-atrial activation time (IAT), local activation time (LAT), and inhomogeneity of conduction (IIC) were determined. ECG parameters (P-P, P-R interval) were measured. RESULTS P-P interval was 956 ± 157 ms (range 768-1368 ms), and P-R interval was 203 ± 37 ms (range 136-280 ms). After ARGP stimulation, a short-lasting increase of P-P interval was observed, more prominent at higher output (1 mA = 82 ms, 2 mA = 180 ms, 5 mA = 268 ms, all P <.01 vs baseline). P-R interval remained unchanged. IAT was 34.4 ms (range 5.6-50.3 ms) at the RA and 105.8 ms (range 79.7-163.3 ms) at the RPV. After 1-mA stimulation IAT increased, in patients taking beta-blockers (P = .001), or it decreased, and this change persisted after subsequent stimulation at higher current (1 mA, P = .001; 2 mA, P = .401; 5 mA, P = .593). Similar changes were observed for LAT and IIC. CONCLUSION ARGP stimulation results in a short-lasting, output-dependent decrease in sinus node frequency due to a parasympathetic response. Stimulation of the ARGP induced a prolonged increase or decrease in conduction characteristics in patients with AF, consistent with a persistent differential parasympathetic and/or sympathetic response.

Closed chest lobectomy with subxyphoid retraction.

An important disadvantage of the video-assisted thoracoscopic surgery (VATS) lobectomy technique remains the minithoracotomy for specimen removal resulting in some degree of traction on the ribs even without the usage of a rib retractor. We describe a new technique of VATS lobectomy in supine position consisting of complete lymph node dissection and subxyphoidal removal of the lobe(s) preventing any degree of rib traction.

The change in circulating galectin-3 predicts absence of atrial fibrillation after thoracoscopic surgical ablation

Aims Galectin-3 (Gal-3) is an important mediator of cardiac fibrosis, particularly in heart failure. Increased Gal-3 concentration (Gal-3), associated with increased risk of developing atrial fibrillation (AF), may reflect atrial fibrotic remodelling underlying AF progression. We aimed to investigate whether the change in serum Gal-3 reflects alterations of the arrhythmogenic atrial substrate following thoracoscopic AF surgery, and predicts absence of AF. Methods and results Consecutive patients undergoing thoracoscopic AF surgery were included. Left atrial appendages (LAAs) and serum were collected during surgery and serum again 6 months thereafter. Gal-3 was determined in tissue and serum. Interstitial collagen in the LAA was quantified using Picrosirius red staining. Ninety-eight patients (76% male, mean age 60 ± 9 years) underwent thoracoscopic surgery for advanced AF. Patients with increased Gal-3 after ablation compared to baseline had a higher recurrence rate compared to patients with decreased or unchanged Gal-3 (HR 2.91, P = 0.014). These patients more frequently had persistent AF, longer AF duration and thick atrial collagen strands (P = 0.049). At baseline, Gal-3 was similar between patients with and without AF recurrence: 14.8 ± 3.9 µg/L vs. 13.7 ± 3.7 µg/L, respectively in serum (P = 0.16); 94.5 ± 19.4 µg/L vs. 93.3 ± 30.8µg/L, respectively in atrial myocardium (P = 0.83). There was no correlation between serum Gal-3 and left atrial Gal-3 (P = 0.20), nor between serum Gal-3 and the percentage of fibrosis in LAA (P = 0.18). Conclusion The change of circulating Gal-3, rather than its baseline value, predicts AF recurrence after thoracoscopic ablation. Patients in whom Gal-3 increases after ablation have a high recurrence rate reflecting ongoing profibrotic signalling, irrespective of arrhythmia continuation.