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.

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.

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.

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.

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.

Urgent and emergency coronary artery bypass grafting for acute coronary syndromes.

BACKGROUND: Urgent and emergency coronary artery bypass grafting may be associated with significant mortality and morbidity. We report our recent experience with this group of patients. METHODS: A retrospective analysis of 441 patients undergoing urgent and emergency surgery over a 3-year period was carried out. Multivariate analysis was used to identify subgroups of patients who were most at risk of death. RESULTS: The 30-day mortality was 3.3 and 16.3% in the urgent and emergency groups, respectively. Urgent surgery was associated with significantly shorter duration of ventilation (16 h vs 69 h) and stay at the intensive care unit (31 h vs 102 h). The incidence of pneumonia, pulmonary embolism, renal failure and neurological events were also less in the urgent group. The preoperative use of the intra-aortic balloon pump was low (0.8% in the urgent group and 4.8% in the emergency group). Multivariate analysis showed that patients over 70 years of age (odds ratio 3.2, 95% confidence interval 1.1-9.5) with left main stenosis (odds ratio 4.4, 95% confidence interval 1.5-12.4) complicated by cardiogenic shock (odds ratio 17.8, 95% confidence interval 5.2-61.1) were at highest risk of death. Patients transferred directly to theatre from cardiac catheter laboratory following failed percutaneous interventions were found to be most at risk. Mortality in this group was 29%, with 50% patients being in shock and 36% having left main stenosis. CONCLUSION: Satisfactory results have been obtained in urgent coronary artery bypass grafting, but acute coronary syndromes complicated by cardiogenic shock remain a high-risk group. Further studies are needed to define the optimal operative management in this group of patients.

Experience with unipolar radiofrequency ablation for atrial fibrillation.

BACKGROUND: The cut and sew Cox maze procedure for atrial fibrillation (AF), although effective, is not widely used because of technical complexity, prolonged duration and significant risk of postoperative bleeding. This study reviews our experience with the unipolar radiofrequency ablation (RFA) procedure, which was used to create a modified maze to treat AF. METHODS: A retrospective review of 31 patients undergoing consecutive cardiac surgery who had concomitant RFA for AF over a 16-month period was carried out. A Cobra unipolar RFA probe (EPT; Boston Scientific, San Jose, CA, USA) was used to create a standard set of lesions. RESULTS: There were 20 men and 11 women (mean age, 66 +/- 9 years; range, 48-87 years). AF was continuous in 21 patients and intermittent in 10. The median duration of AF leading up to surgery was 48 months (range, 6 months-20 years). Left atrium was enlarged in 81% of the patients. Operations included mitral valve repair (7 patients), replacement (5), coronary artery bypass (10), aortic valve replacement (1) and combined procedures (8). There were no complications directly attributable to RFA. There were three early deaths. One patient required a permanent pacemaker. Median follow up was 22 months (range, 12-30 months). One patient died 2 years after the operation from a stroke. Cardioversion was attempted in five patients within 3 months of operation and was successful in four. At 2 years following the procedure, the probability of the patient remaining in sinus rhythm was 0.71 +/- 0.15. CONCLUSION: Surgical RFA can be carried out as a useful adjunct to conventional cardiac surgery. Although the results were satisfactory in this series, further studies are needed to refine the indication of the procedure and to assess its longer-term efficacy.

The outcome of cardiac surgery in dialysis-dependent patients.

BACKGROUND: Patients on dialysis for end-stage renal failure (ESRF) are undergoing cardiac surgery with increasing frequency. Furthermore, ESRF is known to be an important risk factor for complications of cardiac operations performed with cardiopulmonary bypass. AIMS: To evaluate the outcome of dialysis-dependent patients undergoing cardiac surgery at one institution. METHODS: A retrospective analysis was performed on consecutive patients with ESRF dependent upon maintenance haemodialysis or peritoneal dialysis who underwent cardiac surgery from January 1998 to August 2002. RESULTS: Thirty-eight patients on dialysis underwent cardiac surgery during this time period (1.5% of total cases). The most common cause for ESRF was diabetic nephropathy (n = 12). Operations performed included isolated coronary artery bypass grafting (CABG, n = 22), CABG and valve surgery (n = 8), and valve surgery alone (n = 6). When allowing for age, sex, surgeon and operative category, the odds ratio for mortality risk of dialysis patients, compared with all others, was 4.9 (95% confidence interval (CI): 1.7-13.9, p = 0.003), and for morbidity risk, was 2.8 (95% CI: 1.4-5.4, p = 0.003). CONCLUSIONS: Patients on dialysis have an increased morbidity and mortality following cardiac surgery, however we believe ESRF should not be regarded as an absolute contraindication to cardiac surgery or cardiopulmonary bypass.