Does left atrial epicardial conduction time reflect atrial fibrosis and the risk of atrial fibrillation recurrence after thoracoscopic ablation? Post hoc analysis of the AFACT trial.

OBJECTIVES: To determine the association between left atrial epicardial conduction time (LAECT), fibrosis and atrial fibrillation (AF) recurrence after thoracoscopic surgical ablation of persistent AF. SETTING: Single tertiary care centre in the Netherlands. PARTICIPANTS: Patients with persistent AF from the randomised Atrial Fibrillation Ablation and Autonomic Modulation via Thoracoscopic Surgery (AFACT)-trial were included. Patients eligible for thoracoscopic AF ablation were included, full inclusion and exclusion criteria were previously published. All patients underwent thoracoscopic ablation, encompassing pulmonary vein isolation with an additional roof and trigone lesion. In patients with conduction block across the roof and trigone lesion, LAECT was measured. LAECT was defined as the time to local activation at one side of the roofline on pacing from the opposite side. Collagen fibre density was quantified from left atrial appendage histology. OUTCOME MEASURES: Primary outcome: AF recurrence during 2 years of follow-up. RESULTS: 121 patients were included, of whom 35(29%) were women, age was 60.4±7.8 and 51% (62) had at least one AF recurrence during 2 years of follow-up. LAECT was longer in patients with versus without AF recurrence (182±43 ms vs 147±29 ms, p<0.001). LAECT was longer in older patients, in patients with a higher body mass index (BMI) and in patients using class IC antiarrhythmic drugs. LAECT was shorter in patients with higher collagen fibre density. A previously failed catheter ablation, LAECT and BMI were independently associated with AF recurrence. CONCLUSION: LAECT is correlated with collagen fibre density and BMI and is independently associated with AF recurrence in patients with persistent AF. In these patients, LAECT appears to reflect substrate characteristics beyond clinical AF type and left atrial volume. TRIAL REGISTRATION NUMBER: NCT01091389.

Anticoagulant bridging in left-sided mechanical heart valve patients.

BACKGROUND: In preparation for an invasive procedure with a high bleeding risk, patients with a mechanical heart valve temporarily have to discontinue their anticoagulant therapy and are usually bridged with either intravenous unfractionated heparin (UFH) or subcutaneous low-molecular-weight heparin (LMWH). In this study we retrospectively analyzed the safety of UFH versus LMWH as bridging strategy in left-sided mechanical heart valve patients. METHODS: We performed a retrospective multicenter study in four surgical centers in The Netherlands. Patients with a mechanical heart valve implantation bridged from January 2010 until January 2015 were included. The cumulative incidence of adverse events in the 30days following the procedure was recorded. Main outcomes were major bleeding according to International Society on Thrombosis and Haemostasis (ISTH) criteria, symptomatic thromboembolism, and mortality. RESULTS: In total, 238 (174 aortic, 42 mitral, 22 aortic+mitral) bridging episodes were included. The incidence of major bleeding was 16 (19%) events in the UFH group versus 29 (19%) events in the LMWH group (p=0.97). Incidences of thromboembolism were 2 (2.4%) versus 1 (0.6%). The incidence of death was 1 (1.2%) patient in the UFH group versus 3 (1.9%) patients in the LMWH group. More than 50% of all bleeding complications were categorized as a major bleeding. CONCLUSIONS: Bridging anticoagulation in patients with aortic and mitral mechanical valves is associated with considerable risk, but no difference was apparent between UFH and LMWH strategy. The rate of thromboembolism and death was low with either strategy and the vast majority of adverse events were bleedings.

Remifentanil during cardiac surgery is associated with chronic thoracic pain 1 yr after sternotomy.

BACKGROUND: Chronic thoracic pain after cardiac surgery is a serious condition affecting many patients. The aim of this study was to identify predictors for chronic thoracic pain after sternotomy in cardiac surgery patients by analysing patient and perioperative characteristics. METHODS: A follow-up study was performed in 120 patients who participated in a clinical trial on pain levels in the early postoperative period after cardiac surgery. The presence of chronic thoracic pain was evaluated by a questionnaire 1 yr after surgery. Patients with and without chronic thoracic pain were compared. Associations were studied using multivariable logistic regression analysis. RESULTS: Questionnaires of 90 patients were analysed. Chronic thoracic pain was reported by 18 patients (20%). In the multivariable regression model, remifentanil during cardiac surgery, age below 69 yr, and a body mass index above 28 kg m(-2) were independent predictors for chronic thoracic pain {odds ratios 8.9 [95% confidence interval (CI) 1.6-49.0], 7.0 (95% CI 1.6-31.7), 9.1 (95% CI 2.1-39.1), respectively}. No differences were observed in patient and perioperative characteristics between patients receiving remifentanil (58%, n=52) compared with patients not receiving remifentanil (42%, n=38). The association between remifentanil and chronic thoracic pain appeared dose-dependent, both for total dose and for dose corrected for kilogram lean body mass and duration of surgery (P-value for trend: <0.01 and <0.005, respectively). CONCLUSIONS: In this follow-up study in cardiac surgery patients, intraoperative remifentanil was predictive for chronic thoracic pain in a dose-dependent manner. Randomized studies designed to evaluate the influence of intraoperative remifentanil on chronic thoracic pain are needed to confirm these results.

Efficacy of an intravenous bolus of morphine 2.5 versus morphine 7.5 mg for procedural pain relief in postoperative cardiothoracic patients in the intensive care unit: a randomised double-blind controlled trial.

As pain in the intensive care unit (ICU) is still common despite important progress in pain management, we studied the efficacy of an intravenous bolus of morphine 2.5 vs 7.5 mg for procedural pain relief in patients after cardiothoracic surgery in the ICU. In a prospective double-blind randomised study, 117 ICU patients after cardiothoracic surgery were included. All patients were treated according a pain titration protocol for pain at rest, consisting of continuous morphine infusions and paracetamol, applied during the entire ICU stay. On the first postoperative day, patients were randomised to intravenous morphine 2.5 (n=59) or 7.5 mg (n=58) 30 minutes before a painful intervention (turning of patient and/or chest drain removal). Pain scores using the numeric rating scale (Numeric Rating Scale, range 0 to 10) were rated at rest (baseline) and around the painful procedure. At rest (baseline), overall incidence of unacceptable pain (Numeric Rating Scale ≥4) was low (Numeric Rating Scale >4; 14 vs 17%, P=0.81) for patients allocated to morphine 2.5 and 7.5 mg respectively. For procedure-related pain, there was no difference in incidence of unacceptable pain (28 vs 22%, P=0.53) mean pain scores (2.6 [95% confidence interval 2.0 to 3.2] vs 2.7 [95% confidence interval 2.0 to 3.4]) between patients receiving morphine 2.5 and 7.5 mg respectively. In intensive care patients after cardiothoracic surgery with low pain levels for pain at rest, there was no difference in efficacy between intravenous morphine 2.5 mg or morphine 7.5 mg for pain relief during a painful intervention.

Predicting 30-day mortality of aortic valve replacement by the AVR score.

OBJECTIVES: The objective of this study is to develop a simple risk score to predict 30-day mortality of aortic valve replacement (AVR). METHODS: In a development set of 673 consecutive patients who underwent AVR between 1990 and 1993, four independent predictors for 30-day mortality were identified: body mass index (BMI) ≥30, BMI <20, previous coronary artery bypass grafting (CABG) and recent myocardial infarction. Based on these predictors, a 30-day mortality risk score-the AVR score-was developed. The AVR score was validated on a validation set of 673 consecutive patients who underwent AVR almost two decennia later in the same hospital. RESULTS: Thirty-day mortality in the development set was ≤2% in the absence of any predictor (class I, low risk), 2-5% in the solitary presence of BMI ≥30 (class II, mild risk), 5-15% in the solitary presence of previous CABG or recent myocardial infarction (class III, moderate risk), and >15% in the solitary presence of BMI <20, or any combination of BMI ≥30, previous CABG or recent myocardial infarction (class IV, high risk). The AVR score correctly predicted 30-day mortality in the validation set: observed 30-day mortality in the validation set was 2.3% in 487 class I patients, 4.4% in 137 class II patients, 13.3% in 30 class III patients and 15.8% in 19 class IV patients. CONCLUSIONS: The AVR score is a simple risk score validated to predict 30-day mortality of AVR.

Selective pulmonary artery perfusion: a novel method for the treatment of pulmonary malignancies.

Selective pulmonary artery perfusion (SPAP) is a modality of regional chemotherapy first investigated in the 1950's. A number of studies in animal models documented pharmacokinetic superiority with high-dose local cytostatic drug concentrations when compared to intravenous administration. Blood flow occlusion of the pulmonary artery before or after drug injection results in further increase in local drug concentrations. Animal tumor models with sarcoma and coloncarcinoma confirm anti-tumour efficacy in cytostatic SPAP. In human investigations, feasibility and safety of chemotherapeutic SPAP in humans has been documented. Recent encouraging investigations of SPAP with gemcitabine and blood flow occlusion in a porcine model emphasize the need for further investigations in humans with pulmonary malignancies for safety and efficacy assessments.

Significant reduction in blood loss in patients undergoing minimal extracorporeal circulation.

Several recent studies have shown differences in blood loss and allogeneic transfusion requirements between on-pump and off-pump coronary artery bypass grafting (CABG). Recently a new concept, the mini-extracorporeal circulation, was introduced to minimize the side effects of extracorporeal circulation. Therefore, there are no data comparing the three techniques with special emphasis to blood loss and transfusion requirements. Two hundred and eighty-five patients undergoing first-time coronary artery bypass grafting were retrospectively matched for number of grafts, age and sex. Ninety-five patients underwent surgery with the off-pump CABG (OPCAB) technique, 97 patients using conventional CABG with cold cardioplegia (CCABG) and 93 patients with the mini-extracorporeal circuit with warm blood cardioplegia (MCABG). Blood loss for the CCABG group with a mean loss of 819 +/- 557 mL and the OPCAB group with a mean loss of 870 +/- 768 mL was significant different compared to the MCABG group with a mean loss of 679 +/- 290 mL. The use of units red blood cell units was significantly higher for CCABG group and OPCAB group compared to the MCABG group. On the day of operation the use of platelet concentrate was significantly higher for the CCABG group compared to MCABG group. As a consequence of improvements of several components of the mini heart lung machine, significantly less blood products are needed in MCABG patients. The expected reduced need for transfusion when the pump was completely avoided could not be confirmed in this single retrospective cohort study.

Combined off-pump coronary surgery and left lung resection through midline sternotomy with a Medtronic Starfish 2 Heart Positioner.

Concomitant lung malignancy and coronary artery disease is uncommon. When the left lung is involved, the approach is considered to be staged or through left thoracotomy. We present a patient who was operated on for left pneumonectomy and off-pump coronary surgery through a midline sternotomy with the use of a Medtronic Starfish 2 Heart Positioner.

Mini extracorporeal circuit for coronary artery bypass grafting: initial clinical and biochemical results: a comparison with conventional and off-pump coronary artery bypass grafts concerning global oxidative stress and alveolar function.

BACKGROUND: The new concept of mini-extracorporeal circulation (MECC) for coronary artery bypass grafts (MCABG) consists of minimal priming volume, a heparin-coated closed circuit, a centrifugal pump, active drainage, blood cardioplegia and a cell-saving device. The potential organ protective effect of this technique during CABG is unknown. Initial clinical outcomes, oxidative stress, alveolar shunting and need for blood transfusion were investigated for MCABG patients. Sub-sets of these data were compared to outcomes of matched groups of patients operated conventionally (CCABG) and off-pump (OPCAB). METHODS: Data of 184 patients were gathered and analysed from a prospective observational database system. This database consists of the initial experience with the first 114 MCABG operations. Of these, the clinical outcome was investigated. In a subset of 60 MCABGs, need for transfusion was monitored and compared to 60 CCABGs. Serum concentrations of malondialdehyde (MDA), allantoin/urate ratios, shunt fractions and lung epithelium-specific proteins (CC16) were measured as biomarkers of damage during MCABG, CCABG and OPCAB (n =30). RESULTS: Patient groups were similar concerning age, risk and number of distal anastomoses. Clinical outcomes are shown for MCABGs only. During MCABG, need for transfusion was significantly reduced compared to CCABG (p < 0.001). Serum concentrations of MDA and allantoin/urate ratios showed significantly reduced oxidative stress during MCABG compared to CCABG. During MCABG, F-shunts were reduced shortly after surgery. Increased concentrations of pneumoprotein CC16 were measured during CCABG compared to MCABG (data submitted). CONCLUSION: Short-term clinical outcomes of MCABG patients are satisfactory. Compared to CCABG the need for transfusion is significantly reduced when a MECC is used. Oxidative stress parameters show a tendency towards improved global organ protection compared to CCABG. F-shunt fractions and CC16 concentrations suggest reduced alveolar damage during MCABG. In a prospective study, the protective effect of mini-CABG has to be confirmed.

Intraaortic filtration captures particulate debris in OPCAB cases using anastomotic devices.

BACKGROUND: Studies associate atheroemboli with neurologic complications following cardiac surgery. The International Council of Emboli Management (ICEM) has demonstrated debris is captured when intraaortic filtration is employed during cardiac surgery. Particulate debris has been extracted from over 98% of ICEM patients and fibrous atheroma from 73%. Anastomotic device use may reduce aortic manipulation, minimizing debris. This study compares particulate capture among three patient groups: Cohort 1 (n = 745) patients receiving on-pump CABG-only procedures; Cohort 2 (n = 24) patients receiving off-pump CABG-only procedures with conventional anastomoses; Cohort 3 (n = 10) patients receiving off-pump CABG-only procedures with automatic proximal anastomoses. METHODS: The intraaortic filter was placed distal to anastomoses, and proximal to the innominate artery. Upon removal, filters were fixed in formalin and shipped to a core lab (Stanford, CA). Demographic, procedural, and outcomes data were collected in the ICEM Registry. RESULTS: Of the 745 patients receiving stopped-heart CABG, complete data on preoperative risk factors was reported for 673 patients. At least 19 patients reported complete data in Cohort 2, and 10 reported in Cohort 3. One adverse outcome, a death, occurred in the 24 off-pump patients reporting (4.2%). Histologic analyses showing the number of filters successfully extracting particles, the number of particles and total particulate surface area per filter, and the ranges are shown in below. Histologic Finding Cohort 1 Cohort 2 Cohort 3 Filters with particles 98% 100% 100% Mean # of particles 8.5 9.6 5.6 Range # of particles 0-76 1-29 2-13 Mean surface area (mm2) 11.8 18.4 6.1 Range surface area (mm2) 0-171 0.5-61 0.2-14 CONCLUSIONS: These data clearly suggest that there is no difference between the amount of particulate debris generated in OPCAB cases versus CPB cases. In OPCAB cases where an anastomosis device was used without a partial clamp, particulate debris may be reduced but not eliminated. These findings may demonstrate the importance of aortic manipulation, particularly clamping, as a source of particulate material in cardiac surgery. However, more study needs to be done to confirm these findings with a larger number of patients.

Early outcome after off-pump versus on-pump coronary bypass surgery: results from a randomized study.

BACKGROUND: The use of cardiopulmonary bypass during coronary artery bypass surgery (CABG) has been associated with substantial morbidity. The recent introduction of cardiac stabilizers facilitates CABG without cardiopulmonary bypass (off-pump CABG), but it is unknown whether cardiac outcome after off-pump surgery is similar to that for the on-pump procedure. METHODS AND RESULTS: In a multicenter trial, 281 patients (mean age 61 years, SD 9 years) were randomly assigned to off-pump or on-pump CABG. In-hospital results and cardiac outcome and quality of life after 1 month are presented. Cardiac outcome was defined as survival free of stroke, myocardial infarction, and coronary reintervention. The mean numbers of distal anastomoses per patient were 2.4 (SD 1.0) and 2.6 (SD 1.1) in the off-pump and on-pump groups, respectively. Completeness of revascularization was similar in both groups. Blood products were needed during 3% of the off-pump procedures and 13% of the on-pump procedures (P<0.01). Release of creatine kinase muscle-brain isoenzyme was 41% less in the off-pump group (P<0.01). Otherwise, no differences in complications were found postoperatively. Off-pump patients were discharged 1 day earlier. At 1 month, operative mortality was zero in both groups, and quality of life had improved similarly. In both groups, 4% of the patients had recurrent angina. The proportions of patients surviving free of cardiovascular events were 93.0% in the off-pump group and 94.2% in the on-pump group (P=0.66). CONCLUSIONS: In selected patients, off-pump CABG is safe and yields a short-term cardiac outcome comparable to that of on-pump CABG.

Off-pump versus on-pump coronary artery bypass grafting: oxidative stress and renal function.

OBJECTIVES: Oxidative stress and renal dysfunction occur in patients undergoing coronary artery bypass grafting with cardiopulmonary bypass (on-pump CABG). Whether the same adverse effects also occur during off-pump CABG is the question in this study. METHODS: Forty patients, 27 men and 13 women, undergoing elective CABG were included; 20 patients underwent on-pump CABG and 20 patients underwent off-pump CABG. Renal and ischemia/reperfusion injury parameters were studied, as well as malondialdehyde as a parameter for oxidative stress. RESULTS: The renal function measured as the mean urinary creatinine excretion decreased significantly during surgery for the on-pump CABG group from 7.62+/-4.74 before surgery to 3.07+/-1.49 mmol/l after surgery, whereas no changes occurred in the off-pump CABG group. The mean urinary concentrations of hypoxanthine, xanthine and malondialdehyde expressed as creatinine ratios for the on-pump group increased significantly from 1.92+/-1.36, 6.06+/-3.62 and 0.21+/-0.07 before surgery to 11.88+/-5.77, 13.11+/-6.61 and 0.57+/-0.31 mmol/mol creatinine, respectively at arrival to the intensive care unit (ICU). During the next time-points, the purines and malondialdehyde decreased to 9.21+/-7.46, 7.55+/-3.95 and 0.32+/-0.13 mmol/mol creatinine, respectively after a 20 h stay at the ICU. For the off-pump CABG group, the mean ratios also increased significantly from 1.71+/-1.38, 2.01+/-0.96 and 0.16+/-0.10 before surgery to 4.73+/-3.19, 5.15+/-3.74 and 0.23+/-0.17 mmol/mol creatinine, respectively at arrival to the ICU. During the next time-points, the ratios of xanthine and malondialdehyde decreased to 3.80+/-2.92 and 0.24+/-0.13 mmol/mol creatinine, respectively. The ratio for hypoxanthine reached the highest ratio (6.97+/-5.67 mmol/mol creatinine) after a 9 h stay at the ICU, after which the ratio decreased to 5.98+/-5.56 mmol/mol creatinine after a 20 h stay at the ICU. However, all ratios from the on- and off-pump CABG patients still remained elevated compared with preoperative ratios. In addition, all ratios for the on-pump CABG group were elevated significantly at all time-points for xanthine, at time-points T2 and T4 for hypoxanthine and at time-point T2 for malondialdehyde as compared with the off-pump CABG group. CONCLUSIONS: Only mild signs of oxidative stress and no renal dysfunction were found during and after off-pump CABG compared with on-pump CABG.

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.

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.

Wedge carinal resection for closure of the main bronchus after pneumonectomy.

Closure of the bronchial stump after pneumonectomy can be challenging. Some special situations such as tumor extension, technical pitfalls, or poor tissue quality of the bronchial stump may preclude safe closure of the airway with standard techniques. We describe here a technique of wedge carinal resection that provides the surgeon an alternative whenever the standard closure of the stump is inapplicable. This technique has been successfully used in a series of 4 patients.

Allograft root on closed pulmonary valve for subaortic obstruction in double-inlet left ventricle with transposition of the great arteries.

BACKGROUND: Until recently closure of the pulmonary valve during staged Fontan-type palliation in the setting of double-inlet left ventricle with an unrestrictive or adequately enlarged ventricular septal defect and transposition of the great arteries with the aorta on a left-sided outflow chamber was regarded as an appropriate part of surgical treatment. Lately, however, an increased incidence of subsequent subaortic obstruction has been described in this regard. METHODS: Allograft root placement on the previously closed pulmonary orifice in combination with a modified Damus-Kaye-Stansel procedure is described to create an unobstructed outflow from the main ventricle to the systemic circulation. This procedure was done in 3 patients. One root placement was combined with the construction of the bidirectional superior cavopulmonary connection, one was done as an intermediate step before completion of the cavopulmonary connection, and one was combined with completion of total cavopulmonary connection. RESULTS: Immediate relief of the subaortic obstruction was achieved in all 3 patients. Ventricular hypertrophy, echocardiographically assessed by diastolic posterior wall thickness, regressed to normal in all 3 within 6 to 12 months. CONCLUSIONS: Allograft root placement on the reopened pulmonary orifice in double-inlet left ventricle with a ventricular septal defect and transposition of the great arteries appears technically feasible and functionally adequate on short-term follow-up. This procedure should result in regression of ventricular hypertrophy to allow eligibility for a Fontan-type palliation again. To what extent possible failure of the allograft increases the risk of an adverse outcome of this palliation may be a matter of concern.

Late follow-up after surgical correction of atrial septal defect of the secundum type.

From more than 500 survivors of surgery for atrial septal defect of the secundum type (ASD II) operated upon between 1953 and 1965, 50 consecutive patients with an age of less than 6 years at the time of operation and 50 consecutive patients with an age of over 20 years at time of operation were chosen. Minimum follow-up in all cases was 20 years. In the younger age group there was a greater return to normal ECG and normal chest x-ray and patients had a normal exercise tolerance at late follow-up. When surgery was performed at an adult age fewer patients had normal ECGs and chest x-ray postoperatively, and overall there was a lower functional class postoperatively. There was, however, still a good longterm survival. Atrial arrhythmias developed in a considerable number of patients postoperatively and can develop even late after surgery in all age groups.