alexander manche - Academia.edu (original) (raw)

Papers by alexander manche

The Journal of Thoracic and Cardiovascular Surgery, Dec 1, 1993

Thromboxane A 2 mediates pulmonary hypertension after cardiopulmonary bypass in the rabbit Clinic... more Thromboxane A 2 mediates pulmonary hypertension after cardiopulmonary bypass in the rabbit Clinically, it is well established that cardiopulmonary bypass results in pulmonary dysfunction. Using a recently developed preparation for cardiopulmonary bypass in the rabbit, we have been able to mimic a similar, but more severe, condition. We found that, despite normal histologic structure of the myocardium, hearts could not be weaned from bypass because of a serious increase in pulmonary vascular resistance. Histologic studies of the lungs showed severe intravascular neutrophil aggregation and marked vasoconstriction. To identify the nature and origin of the mediator responsible for the changes in the pulmonary vasculature, we subjected groups of rabbits (n = 4 per group) to bypass with cooling to 18°C, circulatory arrest for 1 hour, and rewarming on bypass to 33°C. Pulmonary vascular resistance was measured at the same temperature before and after bypass. Four groups were studied: group 1 were untreated controls; group II received the cyclooxygenase inhibitor, indomethacin (0.2 mg/kg intravenously), before operation; group III received the thromboxane A2 synthetase inhibitor, Dazmegral (5 mg/kg intravenously), before operation together with the thromboxane A2 receptor blocker GR 32191B (2 mg/kg per 30 minutes intravenously); and group IV were treated with mustine hydrochloride (1.75 mg/kg intravenously) 3 days before the experiment to deplete the neutrophils by 90 %. During circulatory arrest, the heart was protected with an initial infusion (10 mI at 4°Cover 1 minute) of St. Thomas' Hospital cardioplegic solution. At the end of the experiment, the heart and lungs were histologically examined. In the control group, a significant increase (+395 % when compared with the value recorded before bypass) in pulmonary vascular resistance was observed after bypass. However, in none of the treated groups did pulmonary vascular resistance increase significantly (percentage changes in groups II, Ill, and IV were-24%, 0%, and +33%, respectively). Pulmonary histologic characteristics were normal in all treated groups, and all animals were successfully weaned from bypass. These results indicate that the increase in pulmonary vascular resistance that arises as a consequence of bypass in rabbits is primarily a result of the production of thromboxane A2' a process in which the neutrophil plays a pivotal role.

Charles Ballance was arguably the most eminent surgeon stationed in Malta during the Great War. O... more Charles Ballance was arguably the most eminent surgeon stationed in Malta during the Great War. On the 16 th February 1918 he removed a bullet from the heart of trooper Robert Martin who was shot in the chest in Salonika three months previously. Sadly the patient died of sepsis one month later, a fact that obscured the importance of this landmark operation, the third of its kind worldwide. This paper sets the background to this achievement and celebrates the impact that this surgical pioneer left on our shores.

ICF journal, Feb 4, 2018

Giant coronary artery aneurysms are exceedingly rare. Symptoms are vague and often related to myo... more Giant coronary artery aneurysms are exceedingly rare. Symptoms are vague and often related to myocardial ischaemia or compression of a cardiac chamber. Surgery is indicated when obstruction to the circulation results in heart failure or syncope, as in our case. A clear elucidation of the pathology may not be possible before exploration and the surgical strategy is tailored to the individual case.

Objectives: To evaluate the early outcomes after coronary surgery in the elderly. Methods: A retr... more Objectives: To evaluate the early outcomes after coronary surgery in the elderly. Methods: A retrospective analysis (April 1995-January 2012) of mortality, morbidity and hospital stay, derived from a single surgeon's practice. Outcomes of patients over 70 (group A, n=785) were compared with those of controls under 70 (group B, n=2772). Results: Intervention rate was significantly higher (1502/10 6 vs 467/10 6 , p<0.0001). There were significantly fewer single and quintuple grafts, and significantly more double grafts in group A. The use of an internal thoracic artery (ITA) was lower in group A (748/785, 95.3% vs 2695/2772, 97.2%, p=0.006). Mortality for the entire coronary surgical practice was 1.2%. The overall mortality was 2.7% in group A and 0.8% in group B (p<0.0001). Freedom from any postoperative complication occurred in 57.7% in group A and in 75.6% in group B (p<0.0001). Cardiac complications (except for perioperative MI and atrial flutter) were significantly higher in group A, as were major neurological, renal and respiratory complications, as well as minor wound complications. All complications resulted in patient morbidity but cerebrovascular accident had the worst impact, contributing to perioperative death in 8 of the 18 cases in group A and in 4 of the 24 cases in group B (p=0.049). Average length of stay on intensive care was similar (1.19±1.84 days for group A and 1.13±1.48 days for group B, p=0.38). The average HDU stay was longer in group A (1.43±2.70 vs 0.95±3.68 days, p=0.006) as was the average ward stay (4.00±3.33 vs 3.25±2.23 days, p<0.0001). Conclusions: Although mortality and morbidity remain significantly higher, taken in the context of the overall clinical problem, cardiac surgery has much to offer in this select group of patients.

A young female patient was involved in a head-on collision and sustained a rupture of the aortic ... more A young female patient was involved in a head-on collision and sustained a rupture of the aortic isthmus. She underwent emergency surgical repair of an aortic pseudoaneurysm with an interposition graft. She made a good post-operative recovery and represents the first such case in Malta.

Malta Medical Journal, 2010

Aim: The aim of this retrospective study was to assess the impact of a growing percutaneous coron... more Aim: The aim of this retrospective study was to assess the impact of a growing percutaneous coronary intervention (PCI) program on our coronary artery bypass graft (CABG) practice. Method: The data were collected from 300 consecutive surgical patients from January 2000 (early series) and from a similar number from July 2008 (recent series). Results: Our recent series presented an increased risk (mean Parsonnet scores rose from 5.5 to 7.3, mean euroSCORE rose from 2.4 to 3.1). The mean age increased from 60.3 to 63.8 years, with the percentage of patients over 70 rising from 14.3 to 29.1%. The proportion of females increased from 15.1 to 18.6%. Mean number of vessels grafted diminished from 3.24 to 3.02 per case. Fewer coronary arteries over 3mm diameter were grafted and more advanced atheroma was encountered at the site of grafting in the recent series. Conclusion: The rise in PCI was associated with a smaller surgical population presenting an increased risk and challenge to the cardiac surgical team.

European Journal of Cardio-Thoracic Surgery, 1995

This case report describes the occurrence of a supraventricular arrhythmia in a patient with a la... more This case report describes the occurrence of a supraventricular arrhythmia in a patient with a large epiphrenic oesophageal diverticulum. The arrhythmia was precipitated by meals and was thought to result from pressure effects on the left atrium. Medical therapy did not control the arrhythmia. Excision of the diverticulum combined with oesophageal myotomy resulted in a dramatic relief of symptoms.

European Journal of Cardio-Thoracic Surgery, 1999

Objectives: Several studies have shown angiotensin-converting enzyme (ACE) inhibitors to confer s... more Objectives: Several studies have shown angiotensin-converting enzyme (ACE) inhibitors to confer significant mortality and morbidity benefits in heart failure. First-dose hypotension may necessitate interruption of such therapy. This is more likely to occur if the ACE inhibitor is administered early after coronary artery bypass grafting (CABG). The purpose of this study was to analyse the haemodynamic tolerance to early post-operative treatment with perindopril and enalapril in patients with impaired renal and ventricular function. Methods: Eighty one consecutive CABG patients with a previous myocardial infarction, impaired pre-operative left ventricular ejection fraction (LVEF) on ventriculography and moderately impaired renal function (serum creatinine of 115-150 mmol/l) were randomised into three groups to receive oral placebo, perindopril (4 mg) or enalapril (5 mg) once daily. Groups were subdivided into those with mild ventricular dysfunction (LVEF = 35-65%, n = 20) and significant ventricular dysfunction (LVEF Ͻ 35%, n = 7). Exclusion criteria included oliguria (Ͻ0.5 ml/kg per h) or inotrope dependance at the point of entry on the first post-operative day. Intolerance to ACE inhibitor was defined as hypotension (Ͻ95 mmHg systolic blood pressure or a decrease exceeding 25 mmHg in systolic blood pressure) leading to oliguria (Ͻ0.5 ml/kg per h) which was unresponsive to intravenous furosemide (20 mg). In such cases ACE inhibitor treatment was discontinued and patients commenced on dopamine. Results: In the groups with mild ventricular dysfunction (LVEF = 35-65%) perindopril was discontinued in 1/20 and enalapril in 4/20 patients (P = n.s). However, in the groups with significant ventricular dysfunction (LVEF Ͻ 35%) perindopril was discontinued in 2/7 and enalapril in 7/7 patients (P = 0.02). Conclusion: Our results suggest that after CABG, patients with moderately impaired renal function and significant ventricular dysfunction do not tolerate ACE inhibitors well when these were commenced on the first post-operative day. However, perindopril was associated with less haemodynamic deterioration than enalapril and consequently may be advantageous in this setting.

American Journal of Surgery, May 1, 1993

Since 1972, 17 patients have been surgically treated for double aortic arch at our institution. T... more Since 1972, 17 patients have been surgically treated for double aortic arch at our institution. The procedure became necessary before 12 months of age in 11 patients and before 24 months in 16 patients. The major symptoms were respiratory distress, noisy breathing, and respiratory infections; four patients also had dysphagia. A high degree of clinical suspicion should warrant further investigation. Barium swallow and bronchoseopy were diagnostic and revealed extrinsic compression of the esophagus and trachea, respectively. Division of the anterior arch was pedormed in 16 patients; the right (posterior) arch was divided in the remaining patient. Kommerell's diverticulum was found in four patients and was resected in order to avoid recurrence of dysphagia by compression. A vascular suspension procedure was necessary in 13 patients to further release the trachea and eosphagus. There was no mortality in this series, and symptomatic improvement was achieved in all patients. A degree of tracheomalacia may be responsible for some residual symptoms in four patients.

European Journal of Cardio-Thoracic Surgery, 1993

The protective effects of sanguineous and asanguineous St. Thomas' cardioplegia (SCP and ACP) on ... more The protective effects of sanguineous and asanguineous St. Thomas' cardioplegia (SCP and ACP) on postischemic vasodilator responsiveness, left ventricular developed pressure and end-diastolic pressure (LVDP and LVEDP), tissue adenosine triphosphate (ATP) and creatine phosphate (CP) contents were compared in the isolated blood-perfused rat heart. Five groups of hearts were studied: the controls (n = 8) perfused with blood (from a support rat) for 50 min (37'C), versus hearts (n = 14/group) arrested by a single infusion of either cardioplegic solution (15'C) prior to global ischemia (15OC) and blood reperfusion (37'C). After 2 or 4 h of ischemia and 50 min of reperfusion, endothelium-dependent vasodilator acetylcholine (1 pg) induced a 10 _+ 0.5 and 8.5 f 0.5% reduction, respectively, in coronary resistance, in the SCP groups, but only a 6.5 f 0.6 and 4.5 f 0.5% reduction (P < 0.05), respectively, in the ACP groups. However, there were no significant differences in LVDP, LVEDP, tissue ATP and CP contents, and endothelium-independent vasodilator response to nitroglycerin between the two cardioplegic groups. In a further study, rat hearts (n = 8/group) were arrested with SCP (magnesium concentration < 0.5,5.0 or 16.0 mmol/l, in groups 1,2 and 3) and subjected to 4 h of global ischemia (15°C) followed by 50 min of blood reperfusion (37'C). At the end of reperfusion, LVDP (at a ventricular volume of 180 pl) was 60 f 3.4,72 + 3.5 and 70 f 3.2 in groups 1,2 and 3, respectively. There were no significant differences in LVEDP or tissue ATP and CP contents. In conclusion : (1) SCP provided better preservation of endothelium-dependent vasodilator response than ACP; (2) the two cardioplegic solutions achieved comparable preservation of contractile function, ATP and CP contents; and (3) added magnesium enhanced the protective properties of SCP with regard to contractile function. [Eur

The Journal of Thoracic and Cardiovascular Surgery, Oct 1, 1998

Circulation, Aug 1, 1995

Background The present study was designed to explore the relation between the duration of ischemi... more Background The present study was designed to explore the relation between the duration of ischemia and the rate and extent of myocardial functional recovery after reperfusion. Methods and Results Isolated rat hearts were perfused with blood from a support animal for 15 minutes (flow rate, 2.5 mL/min; perfusion pressure, 60.1±1.3 mm Hg). Control left ventricular developed pressure (LVDP) was measured, and the hearts (six per group) were subjected to 10, 20, 30, 40, 50, 60, 70, or 80 minutes of global ischemia (37°C) and 60 minutes of reperfusion. Pacing (320 beats per minute) was instituted before and after ischemia. In all groups, transient arrhythmias occurred at the onset of reperfusion, to be followed by an early phase of recovery that peaked after 2 to 3 minutes of reperfusion. The relation between the extent of this initial recovery and the duration of preceding ischemia was described by a bell-shaped curve. Thus, the maximum initial mean recovery after 10, 20, 30, 40, 50, 60, 70, or 80 minutes of ischemia was 97%, 108%, 145%, 154%, 118%, 34%, 41%, and 24%, respectively, of preischemic LVDP. Possibly indicative of reperfusion-induced injury, LVDP then declined in all groups so that after 20 minutes of reperfusion, the mean recovery was 63%, 53%, 48%, 50%, 56%, 12%, 9%, and 5%, respectively. In the 10-, 20-, 30-, and 40-minute ischemia groups, there then was a secondary increase in LVDP, possibly indicating the start of recovery from stunning. After 60 minutes of reperfusion, the mean recovery of LVDP was 82%, 65%, 59%, 54%, 47%, 9%, 7%, and 4%, respectively; this second phase of recovery was inversely proportional to the duration of ischemia. To define the early phase of recovery that had been obscured by reperfusion-induced arrhythmias, we repeated the experiments with the inclusion of a cardioplegic infusion (St Thomas’ solution for 2 minutes before ischemia). This significantly reduced the incidence of ventricular fibrillation during early reperfusion. The extent of the initial postischemic recovery of LVDP was similar to that observed without cardioplegia; however, the mean secondary recovery was greater in all groups. Again, the relation of early transient (2 to 5 minutes) recovery to the duration of ischemia was represented by a bell-shaped curve, whereas the secondary recovery was inversely related. Conclusions Although the results of the present study confirm the protective properties of cardioplegia, they also shed some light on the nature of reperfusion-induced injury and myocardial stunning and their complex relation to the severity of the preceding ischemia.

Early (one year) and late (15 year) outcomes after heart transplantation in Malta were evaluated ... more Early (one year) and late (15 year) outcomes after heart transplantation in Malta were evaluated by means of a retrospective analysis of mortality and morbidity, derived from the transplant database. Fifteen transplants were performed with an 87% operative and one-year survival and an 80% 15-year survival. Four patients experienced complications necessitating major surgical interventions and 5 further patients required hospital admission for other complications. Four patients never required hospital admission after their transplant. Twelve longterm survivors enjoy an unrestricted life, whereas one patient is troubled with recurrent gout. Results of heart transplantation can be gratifying, even when performed in a low-volume centre.

Coronary artery fistulae involve a communication between a coronary artery and a heart chamber or... more Coronary artery fistulae involve a communication between a coronary artery and a heart chamber or part of the pulmonary circulation. Most are asymptomatic and discovered incidentally, whilst larger ones may cause coronary steal syndrome. Fistulae may produce continuous murmurs and are diagnosed at echocardiography or angiography. Treatment is by percutaneous coil embolisation or open surgery. We review four cases treated with surgical closure. All patients were asymptomatic and diagnosed incidentally at angiography. One case involved a failed attempt at percutaneous coil embolization requiring immediate open surgery. The other three cases required other operative procedures and the fistulae were oversutured during the same procedure.

Propeller blade injuries to the chest are uncommon but can result in devastating injuries. We des... more Propeller blade injuries to the chest are uncommon but can result in devastating injuries. We describe a case of a 44 year-old male scuba diver who was dragged by sea currents into the propeller of a speedboat. He suffered extensive chest wall trauma but narrowly escaped damage to major organs and vessels. He was admitted directly to the operating theatre. There was significant loss of bone from the manubrium, costal cartilages, overlying skin and muscle which were stripped off in 3 horizontal bands. During reconstruction the bony fragments were anchored to the nearest stable sternal or costal cartilage entities using steel wires, to achieve stability. The overlying muscle and skin were sutured directly to its opposite edge in layers and in an interdigitating fashion following the shape of the propeller blade lacerations. The patient remained intubated for 3 days in ITU and was transported back to his home country. He required a small skin graft to one area of necrosis but eventually made a full recovery with only his scars as a reminder of his accident. There have been other cases of propeller injuries in Malta but this is unique in being a severe injury to the chest, in which the patient made a full recovery. This report highlights the importance of legislation in preventing propeller injuries by restricting swimmer zones and introducing propeller guards or jet drive systems.

Spontaneous pneumothoraces occur mostly in tall thin young males due to a congenital bulla bursti... more Spontaneous pneumothoraces occur mostly in tall thin young males due to a congenital bulla bursting.peer-reviewe