Effects of age and coronary artery disease on cerebrovascular reactivity to carbon dioxide in humans.

Alterations in cerebrovascular reactivity to CO2, an index of cerebrovascular function, have been associated with increased risk of stroke. We hypothesised that cerebrovascular reactivity is impaired with increasing age and in patients with symptomatic coronary artery disease (CAD). Cerebrovascular and cardiovascular reactivity to CO2 was assessed at rest and during hypercapnia (5% CO2) and hypocapnia (hyperventilation) in subjects with symptomatic CAD (n=13) and age-matched old (n=9) and young (n=20) controls without CAD. Independent of CAD, reductions in middle cerebral artery blood velocity (transcranial Doppler) and cerebral oxygenation (near-infrared spectroscopy) were correlated with increasing age (r = -0.68, r = -0.51, respectively, P < 0.01). In CAD patients, at rest and during hypercapnia, cerebral oxygenation was lower (P < 0.05 vs. young). Although middle cerebral artery blood velocity reactivity was unaltered in the hypercapnic range, middle cerebral artery blood velocity reactivity to hypocapnia was elevated in the CAD and age-matched controls (P < 0.01 vs. young), and was associated with age (r = 0.62, P < 0.01). Transient drops in arterial PCO2 occur in a range of physiological and pathophysiological situations, therefore, the elevated middle cerebral artery blood velocity reactivity to hypocapnia combined with reductions in middle cerebral artery blood velocity may be important mechanisms underlying neurological risk with aging. In CAD patients, additional reductions in cerebral oxygenation may place them at additional risk of cerebral ischaemia.

New shapes and sizes: a T-tube coronary conduit.

A novel type of coronary artery graft named a T-tube conduit is described. This reversed saphenous graft, coming in three different variations, is useful at long arteriotomies, at revision redo anastomoses, and when size mismatch exists between vein and artery.

Fractured rib with penetrating cardiopulmonary injury.

Described is an unusual injury, arising from a motorized vehicle accident, in which a detached fractured rib from a flail chest caused lung perforation and hemopericardium. The full diagnosis was only appreciated on computed tomography. Therefore, thoracotomy averted potential disaster.

Long-term function in University of Cape Town prostheses in the tricuspid position.

A 55-year-old woman undergoing triple-valve replacement was found at operation to have a well preserved and functioning University of Cape Town prosthesis that had been inserted 18 years earlier for tricuspid stenosis. Case reporting, valve reappraisal, and factual updating on another case, the world's first documented tricuspid valve replacement for Ebstein's anomaly, are presented. These two remarkable in vivo successes speak well for this historic collar stud valve.

Mammary artery grafts: a new no-touch technique for anastomosis.

Reported techniques for mammary artery-coronary artery anastomosis involve instrumental damage to one or all three layers of the mammary artery during surgical connection. Described herein is an atraumatic method of suturing that achieves a precise and highly accurate anastomosis.

Transesophageal echocardiography in acute aortic transection.

Confirming the diagnosis of acute transection of the descending aorta can be problematic. Unnecessary patient movement and time delay are often associated with conventional investigations. We describe a patient in whom such an injury was clearly and quickly defined at the bedside by transesophageal echocardiography.

Placement of an apical chest tube by a posterior intercostal approach.

Apical pneumothorax due to incomplete expansion of the lung is not uncommon following thoracotomy and also occurs in some patients with recurring spontaneous pneumothorax. Standard methods of intercostal drainage may be unsatisfactory because of difficulty in placing an intercostal tube safely and accurately within the apical air space.

Tracheal stenosis caused by congenital vascular ring anomaly misinterpreted as asthma for 45 years.

Dyspnoeic conditions simulating asthma are not uncommon in adult and paediatric practice. Vascular ring anomalies in particular may be misdiagnosed, resulting in unnecessary delay before corrective surgery. We report a rare case of symptomatic double aortic arch in an adult which emphasises the above points.

Bronchopleural fistula. A novel type of window thoracostomy.

Bronchopleural fistula usually associated with chronic empyema after lung operations continues to occur in modern surgical practice. Successful treatment depends to a large extent on adequate dependent drainage of the empyema space. Tube thoracostomy, although useful initially, is unacceptable as long-term treatment. Window thoracostomy as currently performed is effective but unnecessarily extensive. We describe a simpler procedure, triangular window thoracostomy, for use as a permanent pleurocutaneous stoma or as an interim measure before definitive surgical treatment.

Oesophago-pericardial fistula and cardiac tamponade after oesophagoscopy.

A case of oesophago-pericardial fistula following oesophagoscopy and dilatation is reported. This is a rare and usually fatal complication of oesophageal instrumentation. This case is of further interest as cardiac tamponade following a Niopam swallow subsequently occurred, and the patient survived emergency surgery.

Pericardial hemangiopericytoma as a cause of dysphagia.

A 68-year-old woman was seen with recent-onset dysphagia. Investigations suggested a large retrocardiac tumor. At thoracotomy, a highly vascular tumor was found, involving the posterior and left aspect of the pericardium with attachment to the heart. The lesion was partially removed, and histopathological analysis revealed a malignant hemangiopericytoma. To our knowledge, this tumor site and its presentation have not been reported before.