Abbas Rashid

Risk of morbidity and in-hospital mortality in obese patients undergoing coronary artery bypass surgery

OBJECTIVES Obesity is often perceived to be a risk factor for adverse outcomes following coronary artery bypass graft (CABG) surgery. Several studies have been unclear about the relationship between obesity and the risk of adverse outcomes. The aim of this study was to examine the relationship between obesity and in-hospital outcomes following CABG, while adjusting for confounding factors. METHODS A total of 4713 consecutive patients undergoing isolated CABG between April 1997 and September 2001 were retrospectively analyzed. Body mass index (BMI) was used as the measure of obesity and was grouped as non-obese (BMI <30), obese (BMI 30-35), and severely obese (BMI > or =35). Associations between obesity and in-hospital outcomes were assessed by use of logistic regression to adjust for differences in patient characteristics. RESULTS A total of 3429 patients were defined as non-obese, compared to 1041 obese and 243 severely obese. There was no association between obesity and in-hospital mortality, stroke, myocardial infarction, re-exploration for bleeding and renal failure. Obesity was significantly associated with atrial arrhythmia (adjusted odds ratio (OR) 1.19, P = 0.037 for the obese; adjusted OR 1.52, P = 0.008 for the severely obese) and sternal wound infections (adjusted OR 1.82, P = 0.002 for the obese; adjusted OR 2.10, P = 0.038 for the severely obese). The severely obese patients were 4.17 (P < 0.001) times more likely to develop harvest site infections. Severely obese patients were also more likely to have prolonged mechanical ventilation and post-operative stays, compared to non-obese patients. CONCLUSIONS Obese patients are not associated with an increased risk of in-hospital mortality following coronary artery bypass surgery. In contrast, there is a significant increased risk of morbidities and post-operative length of stay in obese patients compared to non-obese patients.

A prospective randomised study of continuous warm versus intermittent cold blood cardioplegia for coronary artery surgery: preliminary report.

Between October 1991 and March 1993, 281 consecutive patients underwent non-emergency isolated coronary artery surgery under the care of one surgeon (A.R.). They were prospectively randomised to receive either intermittent cold (Group I-144 patients) or continuous warm (Group II-137 patients) blood cardioplegia for myocardial protection. There were no significant differences in clinical outcome between the two groups, as judged by operative mortality, rates of peri-operative myocardial infarction, blood loss, need for circulatory support, post-operative neurological deficit, or duration of intensive care or hospital stay. However, sinus rhythm returned spontaneously with greater frequency (91.2% vs 45.8%, P < 0.001) in Group II patients. There was greater transmyocardial oxidative stress in Group I patients, as evidenced by a significant rise in oxidised glutathione in coronary sinus blood on myocardial reperfusion. Also, the serum CKMb isoenzyme level 2 h post-operatively was significantly raised in Group I patients, although this difference had disappeared by the day after surgery. In conclusion this preliminary report suggests that continuous warm blood cardioplegia provides comparable myocardial protection to that achieved with standard hypothermic techniques in patients undergoing coronary artery surgery.

Continuous warm versus intermittent cold blood cardioplegia for coronary bypass surgery in patients with left ventricular dysfunction

Between October 1991 and March 1994, 108 consecutive patients with moderate to severe left ventricular dysfunction underwent non-emergency isolated coronary artery surgery under the care of one surgeon (A.R.). They were prospectively randomised to receiving either intermittent cold (Group 1-50 patients) or continuous warm (Group 2-58 patients) blood cardioplegia for myocardial protection. There were no significant differences in clinical outcome between the two groups, as judged by operative mortality, rates of perioperative myocardial infarction, the serum CKMB isoenzyme level at 2 and 18 h after operation, need for circulatory support, postoperative neurological deficit, or duration of hospital stay. Group 2 patients required significantly more potassium (68 vs 29 mmol, P < 0.001) to maintain diastolic arrest and also had higher serum potassium levels after removal of the cross-clamp (P < 0.001). However, sinus rhythm returned spontaneously with greater frequency (91.2% vs 45.8%, P < 0.001) in Group 2 patients. In conclusion this report suggests that retrograde continuous warm blood cardioplegia provides comparable myocardial protection to that achieved with retrograde intermittent cold blood cardioplegia in patients with moderate to severe left ventricular dysfunction undergoing isolated coronary artery surgery.

Normothermic arrest with continuous hyperkalaemic blood : initial experience

The requirement for hypothermia in myocardial protection has recently been questioned. Between October 1990 and May 1991, diastolic arrest was achieved using continuous perfusion with normothermic, hyperkalaemic blood in 257 consecutive patients undergoing cardiac surgery. The mean age was 59.8 +/- 9.3 years (range 28-84 years). Coronary artery surgery was performed in 210 patients, valve replacements in 18, combined procedures in 22, and 7 patients had miscellaneous procedures. Eleven patients (4.3%) had undergone previous cardiac surgery, and 65 (25.3%) required urgent or emergency operations. Hyperkalaemic blood (7-20 mmol/l) was delivered antegradely in 190 (72.8%) patients (mean aortic root pressure 60-80 mmHg), retrogradely in 62 (25.3%) patients (mean coronary sinus pressure less than 40 mmHg), and by a combined route in 5 (1.9%). Sinus rhythm returned immediately after removal of the aortic clamp in 235 (91.4%) patients. Weaning from bypass was achieved without circulatory support in 207 (82.5%) patients. Of 233 patients undergoing non-emergency coronary artery surgery, single valve or combined procedures, 11 died, giving an operative mortality of 4.7%. Of 155 patients with good left ventricular function requiring coronary artery surgery, 3 (1.9%) died. The in-hospital mortality for the group as a whole was 7.3%. Sixteen (6.2%) patients sustained perioperative myocardial infarctions; of these 6 died. We conclude that continuous, normothermic, hyperkalaemic arrest is a simple and safe method of myocardial protection. It may avoid the damage associated with hypothermia, ischaemia and reperfusion.

Left circumflex coronary artery to left atrial fistula in a patient with mitral regurgitation after excision of a left atrial myxoma

Acquired coronary artery to left atrial fistulas are rare and previously only described in mitral stenosis associated with left atrial thrombus or coronary arteriosclerosis. We present the case of a patient who developed a left circumflex coronary artery to left atrial fistula associated with mitral regurgitation 12 years after excision of a left atrial myxoma. This was successfully ligated at the time of mitral valve replacement.

Hybrid theatres: nicety or necessity?

In recent years there has been a convergence of approaches to the treatment of cardiovascular disease with combined cardiology, radiology and surgical multidisciplinary team (MDT) based management. This is particularly true with the advent of transcatheter (transfemoral and transapical) aortic valve replacement1 as well as the new combined open and endovascular approaches to thoraco‐abdominal aneurysms,2 including single stage combined coronary artery bypass grafting (CABG) and abdominal aortic endovascular aneurysm repair (EVAR).3 However, there has also been a more longstanding, and commonly although not exclusively, staged hybrid approach in the form of combining percutaneous coronary intervention (PCI) with surgical coronary revascularization and surgical valve repair or replacement in appropriate patients.4–6 As such, it is inevitable new operating enviroments have emerged in the form of so‐called ‘hybrid theatres’ allowing single stage, hybrid endovascular and open intervention for a range of morbidities in children and adults.7,8 This manuscript discusses briefly the design and function of a hybrid theatre, including its perceived advantages and disadvantages. By way of example we review our activity in this environment over the first year of opening. We discuss whether this resource is a nicety or necessity in adopting hybrid approaches. Design and function of the hybrid theatre As part of the development of a regional thoracic aortic aneurysm service a purpose‐built hybrid theatre was constructed (Philips) and opened in Liverpool in April 2007. A number of detailed descriptions of hybrid theatres exist8–10 and we therefore restrict the discussion here to a brief overview. Broken down into its basic structural components, the hybrid theatre is simply an operating theatre with built‐in radiological screening capabilities. In truth, however, the hybrid theatre is more than simply the sum of its parts. The bespoke C‐arm image intensifier is built into the ceiling of the operating room and able to move both longitudinally and rotate around the axis of the patient (Figures 1a and b). As such, the theatre complex is designed with ample space, allowing for dedicated cardiopulmonary bypass equipment as well as the paraphernalia associated with general anaesthesia. Other equipment, including transoesophageal echocardiography, cell salvage, electrocautery and pacing, are easily accommodated. Multiple monitors allow easy access to data at all points around the table. High quality overhead lights allow for good visibility. Consistent with a normal catheter laboratory the theatre is designed with a control/viewing room with dedicated image processing, as well as catheter store room, surgical scrub room and anteroom. Lead aprons are available. Other devices such as contrast injector and defibrillator are stored in theatre. It is not only the close proximity of this multidisciplinary equipment which makes this a unique environment, but the fact that it engenders a collaborative approach to the management of complex disease. Figure 1a and 1b Hybrid theatre showing the theatre table, roof-mounted C‐arm, perfusion, anaesthetic and surgical equipment Hybrid approaches to elective cardiovascular disease The hybrid activity in the theatre is coordinated by two MDT meetings attended regularly by consultant representation from cardiology and radiology, as well as both vascular surgery and cardiac surgery, and intensive care medicine. The specialization of these two groups centres on endovascular approaches to thoraco‐abdominal aortic disease and transfemoral/transapical aortic valve replacement. Hybrid thoracic endovascular aneurysm repair (TEVAR)/open procedures A team of three cardiac surgeons with an interest in thoraco‐abdominal aneurysms attend a weekly thoracic aneurysm clinic, with regional and supra regional referrals from the full range of medical specialties. Complex cases requiring endovascular solutions or combined endovascular/open approaches (hybrid or staged) are referred to a monthly MDT meeting attended by cardiac and vascular surgeons with input from both interventional and non-interventional radiologists. During the first year of coming online, a range of truly hybrid interventions have been performed. These include abdominal endovascular aneurysm repairs (EVAR) with simultaneous coronary artery bypass grafting (CABG), arch-related TEVAR with arch vessel bypass, TEVAR with femoral–femoral cross‐over graft, as well as a full range of isolated TEVAR procedures ( Table 1). Table 1 Surgical activity 2007–2008 Transfemoral and transapical aortic valve replacement A regular MDT comprising interventional cardiologists, cardiac surgeons and anaesthetists/intensivists discusses possible suitable patients for this approach. To date we have early experience with transfemoral and transpical aortic valve replacement and found the hybrid theatre exceptionally well suited for this activity.

True Aneurysm of a Dacron Tube Graft 19 Years After Repair of Coarctation of the Aorta

We report a 31-year old woman who presented with acute onset of shortness of breath 19 years after multiple repairs of a preductal coarctation of the aorta using a Dacron tube graft. Imaging studies showed an aneurysm had developed in the tube graft. The aneurysmal tube graft was replaced during an open repair.

Coincidence of spinal canal stenosis and thoracoabdominal aortic aneurysm.

We report a case in which a thoracoabdominal aneurysm was present in association with previously unknown critical spinal canal stenosis. In spite of using left heart bypass, systemic hypothermia, and controlled cerebrospinal fluid drainage for spinal cord protection, the patient developed paraplegia following aortic aneurysm repair. Computed tomography scan revealed critical stenosis of the spinal canal that was thought to be sufficient to produce spinal cord compression syndromes including paraplegia.

Liverpool Aortic Surgery Symposium V: New Frontiers in Aortic Disease and Surgery

Aortic aneurysm disease is a complex condition that requires a multidisciplinary approach in management. The innovation and collaboration among vascular surgery, cardiothoracic surgery, interventional radiology, and other related specialties is essential for progress in the management of aortic aneurysms. The Fifth Liverpool Aortic Surgery Symposium that was held in May 2013 aimed at bringing national and international experts from across the United Kingdom and the globe to deliver their thoughts, applications, and advances in aortic and vascular surgery. In this report, we present a selected short synopsis of the key topics presented at this symposium.

Esophageal carcinoma invading a Kommerell's aneurysm.

A 67-year-old man presented with increasing dysphagia and loss of appetite for 3 months, and history of hypertension and abdominal aortic aneurysm for 5 years. Esophagoscopy revealed a mass in the cervical esophagus, measuring 4 4 cm, with signs of external invasion; a biopsy identified squamous cell carcinoma. Computed tomography of the chest and abdomen was performed for staging (Figure 1, 2). This revealed that the esophageal carcinoma had invaded an aneurysm of a diverticulum arising from an aberrant right subclavian artery (Kommerell’s aneurysm). The tumor was considered unresectable on the basis of invasion of an unrecorded vascular structure. The patient was started on palliative chemotherapy.