Simon W. MacGowan

Atrial myxoma: National incidence, diagnosis and surgical management

Despite being the most common benign intracardiac tumour with an excellent prognosis after surgical excision the incidence of atrial myxoma (except at autopsy) is unknown. We reviewed all patients admitted to the National Cardiac Surgery Unit (n=26) with an atrial myxoma over a fifteen year period (1977–1991) to compile national incidence data and assess pre-operative diagnosis, management, surgical technique, and outcome. Preoperative symptoms were: congestive cardiac failure (12 patients), embolism (8 patients), constitutional (3 patients), asymptomatic (2 patients) and tachyarrhythmia (1 patient). The diagnosis was confirmed by 2D echocardiography alone in thirteen patients and by a combination of echocardiography and angiography in thirteen patients. At operation the site of the tumour was left atrial in 24 patients and bi-atrial in two patients. All cases were confirmed by histology. All patients made a good post-operative recovery, although one patient survived a pulmonary embolus and one patient developed a deep venous thrombosis. There has been one late death (five months after surgery) from a cerebrovascular accident. Serial echocardiography has revealed one recurrence to date (8 years after surgery). The surgical incidence of these tumours in the Republic of Ireland over the study period was 0.5 atrial myxomas/million population/year. Although rare atrial myxomas are the most important cardiac tumours to diagnose as the results from surgery are excellent.

Mechanical or bioprosthetic valves in the elderly: a 20-year comparison.

BACKGROUND Our objective was to compare long-term results of mechanical and bioprosthetic valve replacement in patients older than 70 years. METHODS Patients older than 70 years who had either a St. Jude Medical (SJM) mechanical prosthesis or any bioprosthesis (BP) implanted between January 1977 and December 1997 were identified. Alive patients were interviewed by telephone during a closing interval of 130 days. RESULTS Complete follow-up was achieved with a total follow-up of 2,264 patient years. A total of 547 patients had 448 aortic valve replacements (199 SJM and 249 BP) and 99 had mitral valve replacements (76 SJM and 23 BP). A further 30 patients had double valve replacement. One hundred ninety of the 577 patients (33%) had coronary artery bypass grafting in addition to the valve replacement. Survival analysis showed no advantage for either mechanical or bioprosthetic valves. There was also no difference in thromboembolic rates, paravalvular leaks, structural dysfunction, and endocarditis rates. However, patients with mechanical valves had a significantly greater risk of major (p < 0.0001) and minor bleeding (p = 0.002) events. CONCLUSIONS Bioprosthetic valves do not offer a survival advantage over mechanical valves among the elderly. However, anticoagulant-related mortality and morbidity is statistically higher for patients with mechanical valves.

Superoxide radical and xanthine oxidoreductase activity in the human heart during cardiac operations

BACKGROUND The results of clinical trials of xanthine oxidoreductase inhibition in cardiac surgery are encouraging, although studies have failed to localize the enzyme to the human heart and to localize free radical activity to fresh human heart. METHODS We adapted a histochemical staining technique based on the reduction of nitro blue tetrazolium to formazan by superoxide radical. In six samples of right atrium graded blindly on a scale of 0 through 4, strong staining (median grade, 3) of the microvasculature was seen. This was blocked by allopurinol in paired sections (median grade, 1; p < 0.01). Chemiluminescence can be used as an index of superoxide radical activity. Atrial samples were taken from 13 patients at five time points during coronary bypass grafting and placed in buffered luminol. Then chemiluminescence was measured. RESULTS A 15-fold rise in chemiluminescence (295.93 +/- 39.47 mV) was demonstrated during reperfusion compared with the control value (19.06 +/- 0.47 mV). Chemiluminescence at 1 minute after release of the cross-clamp was significantly higher (p < 0.05) by analysis of variance versus values obtained before bypass and 1 minute before and 30 minutes after reperfusion. CONCLUSIONS In this study we have identified superoxide radical activity and a possible generating system (xanthine oxidoreductase) in the human heart.

Glue aortoplasty repair of aortic dissection after coronary angioplasty

Aortic dissection complicating percutaneous transluminal coronary angioplasty is rare. We report the case of a 45-year-old man who after right coronary artery angioplasty with stenting, dissected that vessel to involve the aorta to the bifurcation. Surgical repair with Gelatin-Resorcinol-Formaldehyde (GRF) glue as opposed to prosthetic graft replacement of the ascending aorta was successful. The use of GRF glue is effective in the surgical treatment of aortic dissection after coronary angioplasty.

Aortic Valve Replacement in Osteogenesis Imperfecta—Technical and Practical Considerations for a Successful Outcome

Abstract  Osteogenesis imperfecta is a connective tissue disorder that is rarely associated with isolated aortic insufficiency. Surgery on such patients carries high morbidity and mortality, which are mostly associated with bleeding tendencies secondary to increased tissue and capillary fragility. We report a 42‐year‐old male with isolated aortic incompetence, who underwent aortic valve replacement (AVR) with a mechanical prosthesis. The postoperative course was uneventful, and the patient was discharged home on the seventh postoperative day (POD 7). He remains well on follow‐up 6 months later. We highlight the importance of a meticulous surgical technique, together with a strategy for management of anticipated perioperative complications to ensure a successful outcome. (J Card Surg 2003;18:554‐556)

Self-managed anticoagulation is safe and effective

We read with interest the article by Christensen et al. [1] and agree with their conclusion that self-managed anticoagulation is an effective method of managing oral anticoagulation therapy. In their review of the literature, we were surprised that they did not include a prospective randomised trial from our unit [2]. Our own program was initiated after a presentation by Dr. Hasenkam at the EACTS meeting in 1996 [3]. We believe that our study answers some of the questions that may be raised by readers. One of the concerns clinicians may have about selfmanaged anticoagulation is that it only suits younger patients. In our study, the mean age of patients was 66 years. This is much higher than that of the group in the study by Christensen et al. (mean age 47.6). Furthermore, Christensen et al. discuss the question of time in therapeutic range. Although we demonstrated very similar times in therapeutic range to their figures and to the literature (self-managed group: 76% and control group: 64%) we believe that sometimes these comparisons with the literature can be biased as the therapeutic ranges are not equivalent; a larger proportion of patients will be in therapeutic range if this is wider. There are many approaches to training patients for selfmanaged anticoagulation. A very important component of the training is to educate patients, make them aware that they are actually responsible for their management and stress the importance of their decisions as to dosing. Our current training program is very structured. A specialist nurse provides training during two sessions lasting 3 h each, usually a week apart. Patient education includes theoretical knowledge (at layperson level) on the coagulation process, the action of warfarin, the concept of therapeutic range, effects of over and under dosing, and the effects of other drugs, diet and alcohol. In the practical component of the training, patients carry out five supervised tests in the first week and four supervised and one unsupervised test the following week. They then have to pass a simple exam before they are allowed to practise self-managed anticoagulation. Lastly, in the conference discussion [1], Dr. Sergeant suggests that there is a safety issue regarding self-management with inappropriate family practitioner supervision. We would argue that properly trained patients, using a single coagulometer, and adjusting their own dosing, based on their own experience may be a system where many variables (such as different coagulometers, different methods of blood collection and different clinicians changing the dose of warfarin), have been eliminated and should be safer.

Traumatic Aortic Rupture During Pregnancy

Abstract  A 29‐year‐old woman, in her third trimester of pregnancy, underwent emergency Caesarian section for placental abruption following a road traffic accident. Following transfer, an abrupt change in the diameter of the aorta was noted on CT scan. Aortography confirmed aortic rupture distal to the left subclavian artery and Dacron graft replacement of this segment was carried out, utilizing a left atrial to descending aorta partial bypass through a centrifugal pump. The mother is alive and well at 4 months follow‐up. (J Card Surg 2003;18:557‐561)