Hybrid Totally Thoracoscopic Maze and Catheter Ablation for Persistent Atrial Fibrillation: Initial Experience.

Atrial fibrillation is now a pandemic in our ageing community. Although James L. Cox devised a surgical procedure with near-universal curative success in 1987, catheter-based interventions have flourished. For persistent atrial fibrillation (AF), however, an isolated endocardial approach has limitations: procedural times are long, carry risk, and the outcomes are not durable. By combining left atrial endocardial and epicardial interventions with staged mapping, we optimise the benefits of both approaches. Our initial series of hybrid ablation for persistent atrial fibrillation reports excellent early outcomes, freedom from complications and excellent success at follow-up.

A donor PaO2/FiO2 < 300 mm Hg does not determine graft function or survival after lung transplantation.

BACKGROUND: A donor arterial PO2/FiO2 (P/F ratio) of less than the 300 threshold would frequently result in either exclusion of the donor or placement of the lungs on ex vivo lung perfusion (EVLP). The aim was to investigate the veracity of the P/F ratio threshold of 300 for donor lung acceptability. METHODS: In 93 brain dead lung donors, arterial blood gases were drawn in the intensive care unit (ICU) just before procurement and each of the 4 donor pulmonary veins in the operating room (OR). No donor lungs were rejected for transplantation based on the last ICU or OR P/F ratio, and EVLP was not used. The recipients were followed up 6 and 12 months following transplantation. RESULTS: There were 93 recipients of bilateral lung transplantation. An arterial P/F ratio of < 300 was largely driven by a low P/F ratio in the lower lobes. There were no differences between the recipients receiving donor lungs where the ICU P/F ratio was < 300 compared with ≥ 300 in the time to extubation, grade of primary graft dysfunction, pulmonary function at 6 and 12 months, and 12-month survival. CONCLUSIONS: From this study:(1) If a donor P/F threshold of 300 was adhered to, 36% would have been rejected, and (2) The donor P/F ratio threshold of 300 is excessively conservative and results in the wastage of donor lungs and the application of unnecessary EVLP.

Anterior spinal artery syndrome after double valve replacement and coronary artery bypass surgery.

Spinal infarction is a rare and devastating complication of open-heart surgery, especially in the context of perioperative hemodynamic instability in patients requiring high dose of inotropes and vasoconstrictors. Our report highlights that spinal infarction can occur in such circumstances following a valve replacement surgery.

Lobar torsion following bilateral lung transplantation.

Torsion of lobes of the lung is a rare complication following lung transplantation. We present a case of counterclockwise torsion of the right lung allograft and review of nine additional cases in the literature of lobar torsion following lung transplantation. A high degree of suspicion is needed for early diagnosis with rapid surgical intervention to preserve lung viability.

4D CT and lung cancer surgical resectability: a technical innovation.

A 74-year-old man presents with a left upper lobe lung adenocarcinoma, which demonstrated a wide base intimately with the aortic arch. We utilised 4D CT technique with a wide field of view CT unit to preoperatively determine likely surgical resectability. We propose that 4D CT may be of use in further investigating lung cancer with likely invasion of adjacent structures.

Prophylaxis against atrial fibrillation after cardiac surgery: beneficial effect of perioperative metoprolol.

INTRODUCTION: Multiple agents have been investigated to prevent atrial fibrillation (AF) after cardiac surgery. Several studies have investigated the use of ß-blockers such as metoprolol or amiodarone with promising results. We aimed to investigate perioperative pharmacologic prophylaxis against AF using metoprolol, and amiodarone in combination with metoprolol. METHODS: We conducted a prospective, randomised, single-blind, controlled pilot study in patients undergoing elective cardiac surgery. Subjects were randomised pre-operatively to one of three treatment groups: standard therapy (control) or metoprolol (5 mg IV over 5 min on commencement of bypass then 5 mg IV qid for 24h then 25-50 mg tds orally until discharge) or amiodarone (300 mg over 1h starting shortly after the commencement of bypass, then 900 mg over 24h then 400 mg orally tds until discharge) plus metoprolol as above. Patients had ECG monitoring for the occurrence of AF for six days or until discharge. RESULTS: Two hundred and fifteen patients were enrolled. Between-group differences in AF in an intention-to-treat analysis were not significant: control 34% (23-45%), metoprolol 35% (24-46%), combined 22% (12-33%) (p = 0.21). However 87 patients (40%) did not receive the assigned treatment mainly due to side effects, especially bradycardia. The remaining 128 patients were analysed on a per-protocol basis with the overall difference between the three groups bordering on significance: control 34% (23-45%), metoprolol 26% (9-43%), combined 11% (0-23%) (p = 0.06). Logistic regression analysis, correcting for age and gender, was used to separate the individual effects of metoprolol and amiodarone in the presence of metoprolol which showed that compared to control there was a significant effect of metroprolol on AF incidence (O.R. 0.31 (0.10-0.99), p = 0.048) but not of amiodarone (O.R. 0.97 (0.19-5.02), p = 0.97). CONCLUSIONS: (1) Perioperative metoprolol but not amiodarone itself in combination with metoprolol is associated with a significant reduction in postoperative AF. (2) Perioperative administration of metoprolol and combination of metoprolol with amiodarone is associated with a high incidence of side effects, especially bradycardia. (3) Further studies are indicated to confirm these preliminary findings but in the meantime it would not be unreasonable to implement the use of perioperative metoprolol for routine prophylaxis of AF.

Lung T-cell responses to nontypeable Haemophilus influenzae in patients with chronic obstructive pulmonary disease.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is characterized by pulmonary inflammation that persists after the cessation of smoking. T cells have a major role in driving inflammation in patients with COPD and are activated by specific antigens to produce mediators, such as cytokines. The antigens that activate lung T cells have not been clearly defined. Nontypeable Haemophilus influenzae (NTHi) is the dominant bacterium isolated from the lungs of patients with COPD. OBJECTIVE: We sought to measure the response of lung tissue T cells to stimulation with NTHi. METHODS: We obtained lung tissue from 69 subjects having lobectomies for lung cancer. Of the group, 39 subjects had COPD, and 30 without COPD were classified as control subjects. The lung tissue was dispersed into single-cell suspensions and stimulated with live NTHi. Cells were labeled with antibodies for 5 important inflammatory mediators in patients with COPD and analyzed by using flow cytometry. RESULTS: NTHi produced strong activation of both TH cells and cytotoxic T cells in the COPD cohort. The COPD cohort had significantly higher levels of cells producing TNF-α, IL-13, and IL-17 in both T-cell subsets. When control subjects were divided into those with and without a significant smoking history and compared with patients with COPD, there was a progressive increase in the numbers of T cells producing cytokines from nonsmoking control subjects to smoking control subjects to patients with COPD. CONCLUSION: NTHi activates lung T cells in patients with COPD. This proinflammatory profibrotic response might be a key cause of inflammation in patients with COPD and has implications for treatment.

Carbon dioxide insufflation in open-chamber cardiac surgery: a double-blind, randomized clinical trial of neurocognitive effects.

OBJECTIVE: The aims of this study were first to analyze neurocognitive outcomes of patients after open-chamber cardiac surgery to determine whether carbon dioxide pericardial insufflation reduces incidence of neurocognitive decline (primary end point) as measured 6 weeks postoperatively and second to assess the utility of carbon dioxide insufflation in cardiac chamber deairing as assessed by transesophageal echocardiography. METHODS: A multicenter, prospective, double-blind, randomized, controlled trial compared neurocognitive outcomes in patients undergoing open-chamber (left-sided) cardiac surgery who were assigned carbon dioxide insufflation or placebo (control group) in addition to standardized mechanical deairing maneuvers. RESULTS: One hundred twenty-five patients underwent surgery and were randomly allocated. Neurocognitive testing showed no clinically significant differences in z scores between preoperative and postoperative testing. Linear regression was used to identify factors associated with neurocognitive decline. Factors most strongly associated with neurocognitive decline were hypercholesterolemia, aortic atheroma grade, and coronary artery disease. There was significantly more intracardiac gas noted on intraoperative transesophageal echocardiography in all cardiac chambers (left atrium, left ventricle, and aorta) at all measured times (after crossclamp removal, during weaning from cardiopulmonary bypass, and at declaration of adequate deairing by the anesthetist) in the control group than in the carbon dioxide group (P < .04). Deairing time was also significantly longer in the control group (12 minutes [interquartile range, 9-18] versus 9 minutes [interquartile range, 7-14 minutes]; P = .002). CONCLUSIONS: Carbon dioxide pericardial insufflation in open-chamber cardiac surgery does not affect postoperative neurocognitive decline. The most important factor is atheromatous vascular disease.

Cadaveric lobar lung transplantation: technical aspects.

BACKGROUND: The use of lobar transplantation and other size reduction techniques has allowed larger donor lungs to be utilized for smaller recipients who tend to have longer waiting times for transplantation. However, despite these advantages, the techniques have not been widely adopted. We outline the surgical and sizing issues associated with this technique. METHODS: A retrospective review of 23 consecutive patients who received lung transplantation with anatomic lobar reduction was performed, focusing on surgical technique and outcomes. RESULTS: All 23 patients received an anatomic lobar reduction of between 1 and 3 lobes. Survival analysis showed no difference between the lobar reduction cohort and the other historically comparable lung transplant patients from our institution (p=0.115). Percent predicted forced vital capacity and forced expiratory volume in 1 second at 3 months correlated with transplanted donor to recipient total lung capacity ratio, confirming the importance of correct sizing. CONCLUSIONS: Anatomic lobar reduction in lung transplantation is a safe and effective means of transplanting pediatric and small adult recipients, and urgently listed patients.

KRAS mutation is associated with lung metastasis in patients with curatively resected colorectal cancer.

PURPOSE: Oncogene mutations contribute to colorectal cancer development. We searched for differences in oncogene mutation profiles between colorectal cancer metastases from different sites and evaluated these as markers for site of relapse. EXPERIMENTAL DESIGN: One hundred colorectal cancer metastases were screened for mutations in 19 oncogenes, and further 61 metastases and 87 matched primary cancers were analyzed for genes with identified mutations. Mutation prevalence was compared between (a) metastases from liver (n = 65), lung (n = 50), and brain (n = 46), (b) metastases and matched primary cancers, and (c) metastases and an independent cohort of primary cancers (n = 604). Mutations differing between metastasis sites were evaluated as markers for site of relapse in 859 patients from the VICTOR trial. RESULTS: In colorectal cancer metastases, mutations were detected in 4 of 19 oncogenes: BRAF (3.1%), KRAS (48.4%), NRAS (6.2%), and PIK3CA (16.1%). KRAS mutation prevalence was significantly higher in lung (62.0%) and brain (56.5%) than in liver metastases (32.3%; P = 0.003). Mutation status was highly concordant between primary cancer and metastasis from the same individual. Compared with independent primary cancers, KRAS mutations were more common in lung and brain metastases (P < 0.005), but similar in liver metastases. Correspondingly, KRAS mutation was associated with lung relapse (HR = 2.1; 95% CI, 1.2 to 3.5, P = 0.007) but not liver relapse in patients from the VICTOR trial. CONCLUSIONS: KRAS mutation seems to be associated with metastasis in specific sites, lung and brain, in colorectal cancer patients. Our data highlight the potential of somatic mutations for informing surveillance strategies.

Does prior percutaneous coronary intervention adversely affect early and mid-term survival after coronary artery surgery?

OBJECTIVES: To determine the association between previous percutaneous coronary intervention (PCI) and results after coronary artery bypass graft surgery (CABG). BACKGROUND: Increasing numbers of patients undergoing CABG have previously undergone PCI. METHODS: We analyzed consecutive first-time isolated CABG procedures within the Australasian Society of Cardiac and Thoracic Surgeons Database from June 2001 to May 2008. Logistic regression and propensity score analyses were used to assess the risk-adjusted impact of prior PCI on in-hospital mortality and major adverse cardiac events. Cox regression model was used to assess the effect of prior PCI on mid-term survival. RESULTS: Of 13,184 patients who underwent CABG, 11,727 had no prior PCI and 1,457 had prior PCI. Mean follow-up was 3.3 +/- 2.1 years. Patients without prior PCI had a higher EuroSCORE value (4.4 +/- 3.3 vs. 3.6 +/- 3.0, p < 0.001), were older, and more likely to have left main stem stenosis and recent myocardial infarction. There was no difference in unadjusted in-hospital mortality (1.65% vs. 1.55%, p = 0.78) or major adverse cardiac events (3.0% vs. 3.0%, p = 0.99) between patients with or without prior PCI. After adjustment, prior PCI was not a predictor of in-hospital (odds ratio: 1.22, 95% confidence interval [CI]: 0.76 to 2.0, p = 0.41) or mid-term mortality at 6-year follow-up (hazard ratio: 0.94, 95% CI: 0.75 to 1.18, p = 0.62). CONCLUSIONS: In this large registry study, prior PCI was not associated with increased short- or mid-term mortality after CABG. Good outcomes can be obtained in the group of patients undergoing CABG who have had previous PCI.

What causes post-traumatic empyema?

BACKGROUND: Empyema post chest trauma is a morbid condition requiring operative intervention (thoracotomy and decortication). It is hypothesized that patients who have a complicated initial pleural drainage procedure are at increased risk of developing an empyema. METHODS: All patients who underwent operative decortication for post-traumatic empyema over a 24 month period (July 2003 to June 2005) were included in the study. Data were collected on demographics, intercostal catheter (ICC) insertion, prehospital chest decompression and associated injuries. A matched group of patients who had ICC inserted for chest trauma and did not develop an empyema were used as controls. RESULTS: Fourteen patients had decortications for post-traumatic empyema. Two of three pneumocaths and one ICC were placed within the lung. Five other patients had multiple 'attempts' at ICC insertion. Only two patients had a single uncomplicated ICC inserted. The empyema and control group were well matched in terms of age (mean age 40 years in each group, P = 0.83), injury severity score (36.4 vs 35.3, P = 0.85) and presence of chest, abdominal and multi-system injury. The empyema group had significantly longer median hospital stay (12.8 vs 28.7 days, P = 0.05). The control group had less initial ICC inserted (median of 1.0 vs 2.0, P = 0.02). Only one patient had a complicated ICC insertion, and two uncomplicated pneumocaths were placed. CONCLUSION: Patients with complex chest injuries in whom difficulties in initial pleural drainage are encountered are at increased risk of developing a post-traumatic empyema and have a prolonged hospital stay.

Contemporary results show repeat coronary artery bypass grafting remains a risk factor for operative mortality.

BACKGROUND: Reoperative coronary artery bypass grafting (redo CABG) shows improving outcomes, but with varying degrees of improvement. We assessed contemporary outcomes after redo CABG to determine if redo status is still a risk factor for early postoperative complications and midterm survival. METHODS: Isolated CABG procedures (June 1, 2001 to May 31, 2008) within the Australasian Society of Cardiac and Thoracic Surgeons Cardiac Surgery Database were included. Redo status as a predictor for early outcomes was assessed with logistic regression analysis. Midterm survival was determined from the National Death Index. Effect of redo status on midterm survival was assessed using a Cox proportional hazards model. RESULTS: Inclusion criteria were met by 13,436 patients, and 458 (3.4%) underwent redo CABG. Operative mortality was 4.8% for redo CABG and 1.8% for first-time CABG (p < 0.001). After adjustment, redo status remained a predictor for operative mortality (odds ratio [OR], 2.1; 95% confidence interval [CI], 1.3 to 3.6), myocardial infarction (OR, 2.8; 95% CI, 1.6 to 6.0), and prolonged ventilation (OR, 1.5; 95% CI, 1.1 to 2.0). Unadjusted survival was lower for the redo CABG group vs the first-time CABG group at up to 6 years (p = 0.01, log-rank test. After adjusting for differences in patient variables, redo status was not a predictor of midterm survival (OR, 1.03; 95% CI, 0.78 to 1.35; p = 0.85). CONCLUSIONS: Early postoperative outcomes of redo CABG are encouraging. Midterm survival is excellent; however, redo remains a significant risk factor for operative mortality in contemporary practice.

Pilot study of operative fixation of fractured ribs in patients with flail chest.

BACKGROUND: Flail chest is a serious injury in trauma with a significant mortality rate, and long-term pain and disability. Traditionally, management has consisted of internal pneumatic splinting, leading to prolonged periods of mechanical ventilation, and its attendant complications. The aim of this study was to assess the safety of operative fixation of broken ribs in flail chest using absorbable prostheses. METHODS: Thirteen consecutive patients with severe flail chest injury were enrolled in this pilot study. Surgery was planned after viewing three-dimensional reconstructions of the computed tomography scans of the chest. The plates were applied to the external cortical surface of the rib after reducing the fracture. Segmentally fractured ribs were usually plated only once to convert the flail segment to simple fractured ribs and correct the paradoxical wall motion abnormality. RESULTS: All patients had a good surgical result. On average, four ribs were fixed per patient. All patients were able to be weaned from mechanical ventilation and all patients were discharged from the hospital. There were no deaths. No plates had to be removed. In all patients, the flail chest was successfully stabilized and paradoxical chest wall movement was eliminated. CONCLUSION: This pilot study of operative fixation of broken ribs in patients with flail chest, using absorbable plates and screws, has shown the technique to be safe and effective. On the basis of these results, a prospective randomized trial has commenced at The Alfred Hospital, comparing this management strategy with conservative management.

Epicardial high-intensity focused ultrasound cardiac ablation for surgical treatment of atrial fibrillation.

BACKGROUND: The available alternatives to an effective but technically complex Cox maze procedure for surgical treatment of atrial fibrillation include ablation using radiofrequency, microwave, laser, cryotherapy or ultrasound energy sources. The purpose of this study was to evaluate the safety and efficacy profile of high-intensity focused ultrasound cardiac ablation for the surgical treatment of atrial fibrillation. METHODS: 14 patients underwent epicardial high-intensity focused ultrasound treatment for atrial fibrillation using the Epicor cardiac ablation system between August 2006 and August 2007. The procedure was performed on the beating heart prior to the commencement of cardiopulmonary bypass for concomitant cardiac procedures. Physical examination, electrocardiography and 24-h Holter monitoring were used to determine the postoperative heart rhythm. RESULTS: There were no deaths directly related to the procedure. One patient with myelodysplastic syndrome died of septic complications. Three patients required cardioversion at 1 day, 3- and 4-month intervals postoperatively. The mean follow-up period was 9 months. Currently 10/13 (77%) patients are in sinus rhythm, one patient required insertion of a permanent pacemaker, one patient is in atrial fibrillation and another patient is in atrial flutter. CONCLUSION: Epicardial high-intensity focused ultrasound ablation is a viable alternative to the Cox maze procedure for the surgical treatment of atrial fibrillation. It is a safe and efficient procedure that does not require cardiopulmonary bypass and may potentially be performed using less invasive surgical techniques.

Is informed consent in cardiac surgery and percutaneous coronary intervention achievable?

BACKGROUND: Medical and legal published work regularly discusses informed consent and patient autonomy before medical interventions. Recent discussions have suggested that Cardiothoracic surgeons' risk adjusted mortality data should be published to facilitate the informed consent process. However, as to which aspects of medicine, procedures and the associated risks patients understand is unknown. It is also unclear how well the medical profession understands the concepts of informed consent and medical negligence. The aims of this study were to evaluate patients undergoing coronary artery bypass surgery (CABG) and percutaneous coronary intervention (PCI) to assess their understanding of the risks of interventions and baseline level of understanding of medical concepts and to evaluate the medical staff's understanding of medical negligence and informed consent. METHODS: Patients undergoing CABG or PCI at a tertiary hospital were interviewed with questionnaires focusing on the consent process, the patient's understanding of CABG or PCI and associated risks and understanding of medical concepts. Medical staff were questioned on the process of obtaining consent and understanding of medicolegal concepts. RESULTS: Fifty CABG patients, 40 PCI patients and 40 medical staff were interviewed over a 6-month period. No patient identified any of the explained risks as a reason to reconsider having CABG or PCI, but 80% of patients wanted to be informed of all risks of surgery. 80% of patients considered doctors obligated to discuss all risks of surgery. One patient (2%) expressed concern at the prospect of a trainee surgeon carrying out the operation. Stroke (40%) rather than mortality (10%) were the important concerns in patients undergoing CABG and PCI. The purpose of interventions was only partially understood by both groups; PCI patients clearly underestimated the subsequent need for repeat PCI or CABG. Knowledge of medical concepts was poor in both groups: less than 50% of patients understood the cause or consequence of an AMI or stroke and less than 20% of patients correctly identified the ratio equal to 0.5%. One doctor (2.5%) correctly identified the four elements of negligence, eight (20%) the meaning of material risk and four (10%) the meaning of causation. Thirty doctors (75%) believed that all complications of a procedure needed to be explained for informed consent. Less than 10% could recognize landmark legal cases. CONCLUSION: Patients undergoing both CABG and PCI have a poor understanding of their disease, their intervention, and its complications making the attaining of true informed consent difficult, despite their desire to be informed of all risks. PCI patients particularly were highly optimistic regarding the need for reintervention over time, which requires specific attention during the consent process. Medical staff showed a poor knowledge of the concepts of material risk and medical negligence requiring much improved education of both junior doctors and specialists.

A reinforced sternal wiring technique for transverse thoracosternotomy closure in bilateral lung transplantation: from biomechanical test to clinical application.

OBJECTIVES: A high incidence of failure of transverse thoracosternotomy closure, involving the loops of wire cutting through the sternum, remains a significant morbidity after bilateral lung transplantation. We postulated that placing peristernal wires inside the usual longitudinal wires could prevent the longitudinal wires from cutting through the sternum. The aims of this study were to investigate the biomechanical and clinical efficacy of the proposed reinforced sternal closure technique. METHODS: In vitro, 24 artificial sternal models were wired with the reinforced or conventional wiring techniques and were tested either by means of longitudinal distraction or anterior-posterior shear (n = 6 per group). In vivo, the 6-month outcomes of 70 bilateral lung transplantations, including 27 reinforced and 43 conventional wiring techniques, were assessed. RESULTS: Reinforced wiring was stronger than conventional wiring for both longitudinal distraction (yield load: 585 +/- 60 vs 334 +/- 21 N [P = .03]; maximum load: 807 +/- 60 vs 525 +/- 34 N [P = .03]; postyield stiffness: 91.0 +/- 22.0 vs 32.8 +/- 11.8 N/mm [P = .04]) and anterior-posterior shear (yield load: 405 +/- 9 vs 364 +/- 16 N [P = .03]; postyield stiffness: 47.4 +/- 6.1 vs 27.5 +/- 5.1 N/mm [P = .04]). In multivariate analysis, the use of the conventional wiring technique (odds ratio, 5.38; P = .04) and osteoporosis (odds ratio, 18.31; P = .0005) were significant risk factors associated with sternal dehiscence. In the patients with osteoporosis (n = 25), the incidence of sternal dehiscence in the reinforced wiring group (4/16 [25%]) was significantly lower than that in the conventional wiring group (7/9 [78%], P = .02). CONCLUSION: Osteoporosis is a significant risk factor for sternal dehiscence after bilateral lung transplantation. The new reinforced sternal wiring technique provides biomechanically superior fixation of the sternum and clinically reduces the incidence of sternal dehiscence in high-risk osteoporotic patients undergoing bilateral lung transplantation.

Fast-track cardiac surgery: application in an Australian setting.

In response to the current state of healthcare in Australia, our unit has employed a fast-track policy for low-risk cardiac surgery patients since January 2000. This study was designed to examine the safety and efficacy of this policy. From July 2001 to June 2004, 342 (23%) of 1,488 patients undergoing cardiac surgery were identified preoperatively as suitable for fast-track recovery. There was a significantly shorter median time to extubation (4 hr vs 9 hr), reduced intensive care unit stay (8 hr vs 26 hr), and a lower rate of readmission to the intensive care unit (0.6% vs 4.2%) for those fast tracked compared to the other patients. The fast-track group had a lower incidence of complications and significantly decreased median length of hospital stay (5 vs 7 days). We concluded that this policy accurately identifies the low-risk cardiac surgery patients suitable for less intensive postoperative recovery.