Effect on the brain of two techniques of myocardial protection.

This study compared the occurrence of intraoperative microemboli and postoperative changes in neuropsychological performance in 195 patients undergoing coronary artery bypass grafting who were randomized to intermittent crossclamp fibrillation or cardioplegic arrest. Cerebral microemboli were recorded from cannulation to 15 min after decannulation, using transcranial Doppler in 166 patients. Microemboli in relation to 9 surgical events were also noted. Neuropsychological change scores were obtained by comparing cognitive performance preoperatively with that at 6-8 weeks after surgery. The median number of microemboli detected was 105 (range, 9-1,757) in the fibrillation group, and 110 (range, 1-1,306) in the cardioplegia group, with no significant difference between groups. There was also no significant difference between groups in the generation of microemboli during any of the surgical events. Neuropsychological tests were completed postoperatively by 177 participants, with no significant differences in performance found between the 2 groups. Given the equivalence of the effect of intermittent crossclamp fibrillation and cardioplegic arrest on microemboli and neuropsychology, consideration of which form of myocardial protection to employ should perhaps focus more on which method affords most protection to the heart.

An intraoperative assessment of the ascending aorta: a comparison of digital palpation, transesophageal echocardiography, and epiaortic ultrasonography.

OBJECTIVES: There are a number of techniques available to assess the aorta for atheromatous disease in the intraoperative period. This study compared the relationship among the findings of digital palpation (DP), transesophageal echocardiography (TEE), and epiaortic ultrasound (EAU) in the detection of atheroma in the ascending aorta. DESIGN: A prospective, observational study. SETTING: A single-institution, cardiothoracic specialty hospital. PARTICIPANTS: One hundred fifty-four patients undergoing elective cardiac surgery. INTERVENTIONS: The ascending aorta of patients undergoing elective coronary artery bypass surgery was assessed for atheroma by means of the 3 techniques. Atheroma was scored as present or absent. The sensitivity and specificity of the techniques were compared. MEASUREMENTS AND MAIN RESULTS: Assuming EAU provides the "gold standard," the sensitivity of both TEE and DP were low. Digital palpation identified only 20 patients (12%); TEE 31 patients (20%); and, in contrast, EAU detected atheroma in 81 patients (53%). There were 3 and 6 false-positives by DP and TEE, respectively. CONCLUSION: Assuming EAU as the "gold standard" to detect atheroma, this study has shown that when assessing the ascending aorta neither DP nor TEE appear sensitive. This study supports the proposal that detection of atheroma should be performed by EAU.

Malignant pleural mesothelioma: current concepts in treatment.

Malignant pleural mesothelioma (MPM) is a primary and locally aggressive tumor of the pleura. A well defined causal relationship with asbestos exposure, and an overwhelming media interest in the use of asbestos in industrialized countries after World War II, has produced a high level of awareness of this disease. With a peak incidence of MPM expected in Europe, Australia, and the US within the next 15 years, and the failure of current treatment approaches to offer long-term survival and improve quality of life, new therapeutic regimens are warranted. The effects of surgery in terms of survival and symptomatic relief have yet to be defined because of a lack of randomized trials. The role of radiotherapy in the treatment of MPM remains controversial, as the radiosensitivity of malignant mesothelial cells is modest. MPM response to chemotherapy is comparatively poor. The combination of pemetrexed and cisplatin chemotherapy has achieved the best objective responses. Presently, a multimodal approach is considered to be the cornerstone of treatment of MPM. Important ongoing international and national trials are addressing the roles of chemotherapy (e.g. the EAP and MS01 trial), radical surgery (e.g. the MARS trial) and radiotherapy (e.g. the SAKK group phase III study).

An examination of factors influencing the choice of therapy for patients with coronary artery disease.

BACKGROUND: A diverse range of factors influence clinicians' decisions regarding the allocation of patients to different treatments for coronary artery disease in routine cardiology clinics. These include demographic measures, risk factors, co-morbidities, measures of objective cardiac disease, symptom reports and functional limitations. This study examined which of these factors differentiated patients receiving angioplasty from medication; bypass surgery from medication; and bypass surgery from angioplasty. METHODS: Univariate and multivariate logistic regression analyses were conducted on patient data from 214 coronary artery disease patients who at the time of recruitment had been received a clinical assessment and were reviewed by their cardiologist in order to determine the form of treatment they were to undergo: 70 would receive/continue medication, 71 were to undergo angioplasty and 73 were to undergo bypass surgery. RESULTS: Analyses differentiating patients receiving angioplasty from medication produced 9 significant univariate predictors, of which 5 were also multivariately significant (left anterior descending artery disease, previous coronary interventions, age, hypertension and frequency of angina). The analyses differentiating patients receiving surgery from angioplasty produced 12 significant univariate predictors, of which 4 were multivariately significant (limitations in mobility range, circumflex artery disease, previous coronary interventions and educational level). The analyses differentiating patients receiving surgery from medication produced 14 significant univariate predictors, of which 4 were multivariately significant (left anterior descending artery disease, previous cerebral events, limitations in mobility range and circumflex artery disease). CONCLUSION: Variables emphasised in clinical guidelines are clearly involved in coronary artery disease treatment decisions. However, variables beyond these may also be important factors when therapy decisions are undertaken thus their roles require further investigation.

A prospective clinical study of cerebral microemboli and neuropsychological outcome comparing vent-line and auto-venting arterial line filters: both filters are equally safe.

INTRODUCTION: Microemboli are the main implicated cause of neuropsychological (NP) impairment after cardiac surgery. This prospective clinical trial compared the effect of an auto-venting arterial line filter on intraoperative cerebral microemboli and NP outcome compared to an arterial line filter with a vent line, in patients undergoing elective coronary artery bypass graft (CABG) surgery. METHODS: One hundred and ten patients received either an Avecor Affinity (n =73) or Pall AV-6 (n =37) control filter. Cerebral microemboli during cardiopulmonary bypass were recorded by transcranial Doppler monitoring of the right middle cerebral artery. Evidence of cerebral impairment was obtained by comparing patients' performance in a NP test battery (nine tests) administered 6-8 weeks postoperatively with their preoperative scores. RESULTS: During cardiopulmonary bypass, the median number and range of microemboli were 67 (5-846) and 55 (2-773) for the Avecor and AV-6 groups, respectively (p = 0.47). There was no difference in NP outcome. CONCLUSION: There is no difference in the filtering ability of vent-line and auto-vent filters as assessed by cerebral microemboli. This, together with the similar NP outcome, suggests that both types of filter are equally safe for clinical use.

A single-center experience of the Sorin Bicarbon heart valve prosthesis: long-term clinical, hematological and hemodynamic results.

BACKGROUND AND AIM OF THE STUDY: The Sorin Bicarbon (SB) bileaflet valve, available since 1990, has a good clinical safety profile. The study aim was to assess the long-term clinical results following implantation, plus hemodynamic and hematological aspects of the valve. METHODS: A total of 195 SB prostheses (100 aortic, 67 mitral, 14 double valve replacements) was implanted in 181 patients (108 males, 73 females) since 1991. RESULTS: Mean age at implantation was 60.5 +/- 10.8 years. Actuarial analysis at 9.0 years showed an overall survival of 63.9 +/- 5.5%; 28.2% of deaths were early (n = 11), and 71.8% late (n = 28). Freedom from thrombosis was 99.4 +/- 0.6% (one early event, successfully reoperated on), and from embolic events was 86.3 +/- 4.7%. Freedom from endocarditis and hemorrhagic complications were respectively 98.1 +/- 1.1% and 98.6 +/- 0.9%. No occurrence of hemolysis was reported. Freedom from non-structural valve dysfunction was 98.7 +/- 0.9%, and from reoperation was 96.1 +/- 1.6%. Hemodynamic evaluation by echocardiography and hematological testing was performed at 7.0 +/- 1.3 years (range 5-9 years) in a subset of 31 patients (20 males, 11 females). Mean valve size was 23.9 mm for aortic mitral. Echocardiography showed that aortic valves had a mean effective orifice area (EOA) of 2.26 +/- 1.28 cm2, with peak and mean pressure gradients of 23.6 +/- 14.6 and 12.9 +/- 8.1 mmHg, respectively. The mean EOA of mitral valve prostheses was 2.67 +/- 0.66 cm2, with peak and mean pressure gradients of 12.2 +/- 4.5 and 3.8 +/- 1.6 mmHg, respectively. Overall mean hemoglobin was 13.4 +/- 1.35 g/dl, and serum lactate dehydrogenase 630 +/- 13 IU/l. Serum haptoglobin was detectable in one patient only, and the mean reticulocyte count was 1.24 +/- 0.51%. CONCLUSION: In the present authors' experience, the Sorin Bicarbon prosthesis has low complication rates and maintains an excellent hemodynamic function over time. Hemolytic potential is insignificant with this valve.

The effect of leucocyte-depleting arterial line filters on cerebral microemboli and neuropsychological outcome following coronary artery bypass surgery.

OBJECTIVES: A randomised clinical trial sought evidence as to whether leucocyte-depleting (LD) arterial line filters added a further degree of neuroprotection in patients undergoing elective coronary artery bypass graft (CABG) surgery. METHODS: One hundred and ninety-two patients were randomised to the use of a Pall Leukoguard-6 LD filter or either an Avecor Affinity or Pall Autovent-6 control filter. Cerebral microemboli during surgery were recorded by transcranial Doppler (TCD) monitor over the right middle cerebral artery. Evidence of cerebral impairment was obtained by comparing patients' performance in a neuropsychological (NP) test battery (nine tests) administered 6-8 weeks post-operatively with their pre-operative scores. RESULTS: The groups proved well balanced in pre-operative variables. During cardiopulmonary bypass (CPB) the median number and range of microemboli was 15 (3-180) in the LD group compared to 67 (5-846) and 55 (2-773) for the Avecor and AV6 groups, respectively (P<0.0001). One hundred and sixty-two patients completed all the NP tests. The LD group showed better post-operative performance in all but one of the nine tests although the difference in a total change score just failed to reach significance (P=0.07 one-tailed t-test). CONCLUSIONS: LD filtration during CABG reduced the number of cerebral microemboli recorded by TCD and showed a strong trend towards improving NP performance post-operatively. These findings suggest that the use of such filters in CABG surgery may offer increased neuroprotection.

Correction of ionized plasma magnesium during cardiopulmonary bypass reduces the risk of postoperative cardiac arrhythmia.

UNLABELLED: We conducted this randomized controlled trial to determine whether the intraoperative measurement and correction of ionized plasma magnesium can reduce the risk of cardiac arrhythmia after cardiopulmonary bypass. Eighty-five patients presenting for coronary artery bypass grafting were randomly assigned either to the magnesium-corrected group, which received magnesium sulfate on the basis of measured levels of ionized plasma magnesium (n = 43), or to the control group, in which magnesium levels were identified but not corrected (n = 42). Ionized magnesium was determined with an ion-selective electrode with minimal delay, and further samples were taken for laboratory analysis of total plasma magnesium. All patients had Holter electrocardiogram monitoring for 72 h after surgery. Total hypomagnesemia (45 patients; 53% of all patients) was more common than ionized hypomagnesemia (11 patients; 13%) before cardiopulmonary bypass. Both total and ionized magnesium levels declined further during the course of cardiopulmonary bypass in the control group. The incidence of ventricular tachycardia in the first 24 h was less frequent in the magnesium-corrected group (3 patients; 7%) than the control group (12 patients, 30%; P < 0.01). Patients in the magnesium-corrected group were more likely to display continuous sinus rhythm (Lown Grade 0) in the first 24 h (14 patients; 34%) than patients in the control group (2 patients, 5%; P < 0.001). Our results suggest that the intraoperative correction of ionized magnesium is associated with a reduction in postoperative ventricular arrhythmia in cardiac surgical patients. IMPLICATIONS: In this study the correction of ionized plasma magnesium during cardiopulmonary bypass was guided by measurements from an ion-selective electrode. This intervention resulted in a reduction in the incidence of postoperative ventricular tachycardia and an increased frequency of continuous sinus rhythm. Ion-selective electrodes constitute a convenient near-patient test, providing a basis for the targeted replacement of ionized plasma magnesium.