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Background: The effect of prosthesis-patient mismatch (PPM) on late survival after aortic valve replacement (AVR) in patient with symptomatic severe aortic stenosis (AS) remains unclear. Also, late follow-up in previous studies is confined to only one decade. We aimed to determine the effect of PPM on late survival after isolated AVR for symptomatic severe AS during 25 years of follow-up., Methods: In this retrospective cohort study, Kaplan-Meier survival analysis was performed to determine late survival in 404 consecutive patients with moderate PPM (N.=86), severe (N.=11), or no/mild PPM (N.=307) after isolated AVR for symptomatic severe AS during a mean follow-up of 25.0±2.9 years. Moderate, severe, and no/mild PPM were defined as indexed effective orifice area of >0.65≤0.85, ≤0.65, and >0.85 cm 2 /m 2 , respectively. Multivariable analysis was performed to identify possible independent predictors of decreased late survival, including moderate or severe PPM., Results: Late survival of patients with severe PPM was worse in comparison with those with no/mild PPM: 7.4±2.6 (95% confidence interval 2.2-12.5) vs. 13.6±0.5 (95% confidence interval 12.6-14.6) years, respectively; P=0.020. Late survival of patients with moderate PPM was similar to those with no/mild PPM. Severe PPM was an independent predictor of decreased late survival: hazards ratio 4.002 (95% confidence interval 1.869-8.569); P<0.001. Moderate PPM was not an independent predictor of decreased late survival., Conclusions: Severe PPM was independently associated with decreased late survival after isolated AVR for symptomatic severe AS during a mean follow-up of 25.0±2.9 years. Therefore, severe PPM should be prevented as much as possible.

Objectives: Longer aortic cross-clamp (ACC) time is associated with decreased early survival after cardiac surgery. Because maximum follow-up in previous studies on this subject is confined to 28 months, it is unknown whether this adverse effect is sustained far beyond this term. We aimed to determine whether longer ACC time was independently associated with decreased late survival after isolated aortic valve replacement in patients with severe aortic stenosis during 25 years of follow-up., Methods: In this retrospective cohort study, multivariable analysis was performed to identify possible independent predictors of decreased late survival, including ACC and cardiopulmonary bypass (CPB) time, in a cohort of 456 consecutive patients with severe aortic stenosis, who had undergone isolated aortic valve replacement between 1990 and 1993., Results: Mean follow-up was 25.3 ± 2.7 years. Median (interquartile range) and mean ACC times were normal: 63.0 (20.0) and 64.2 ± 16.1 min, respectively. Age, operative risk scores and New York Heart Association class were similar in patients with ACC time above, versus those with ACC time below the median. Longer ACC time was independently associated with decreased late survival: hazards ratio (HR) 1.01 per minute increase of ACC time (95% confidence interval [CI] 1.00-1.02; P = 0.012). Longer CPB time was not associated with decreased late survival (HR 1.00 per minute increase of CPB time [95% CI 1.00-1.00; P = 0.30])., Conclusions: Longer ACC time, although still within normal limits, was independently associated with decreased late survival after isolated aortic valve replacement in patients with severe aortic stenosis., (© The Author(s) 2020. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.)

Objective: There is a paucity of data on long-term survival of new-onset postoperative atrial fibrillation (POAF) after cardiac surgery. Also, mean follow-up in previous studies is confined to a maximum of one decade. This retrospective, longitudinal cohort study was performed to determine the effect on long-term survival of new-onset POAF after aortic valve replacement (AVR) over a mean follow-up of almost 2 decades., Methods: Kaplan-Meier survival analysis was used to determine long-term survival after AVR, performed between January 1, 1990, and January 1, 1994, in 569 consecutive patients without a history of atrial fibrillation, divided into 241 patients (42.4%) with and 328 patients (57.6%) without new-onset POAF. New-onset POAF was considered in multivariable analysis for decreased long-term survival. After AVR, patients with new-onset POAF were treated with the aim to restore sinus rhythm within 24 to 48 hours from onset by medication and when medication failed by direct-current cardioversion before discharge home., Results: Mean follow-up after AVR was 17.8 ± 1.9 years. Incidence of new-onset POAF was 42.4%. Kaplan-Meier overall cumulative survival rates at 15 years of follow-up were similar in the patients with new-onset POAF versus those without: 41.5% (95% confidence interval [CI], 35.2-47.7) versus 41.3% (95% CI, 36.0-46.7), respectively. New-onset POAF was not an independent risk factor for decreased long-term survival (hazard ratio 0.815; 95% CI, 0.663-1.001; P = .052)., Conclusions: New-onset POAF after AVR does not affect long-term survival when treatment is aimed to restore sinus rhythm before discharge home., (Copyright © 2017 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.)

Background: Mean follow-up in previous studies on the effect of prosthesis-patient mismatch on long-term survival after aortic valve replacement (AVR) is confined to a maximum of one decade. This retrospective longitudinal cohort study was performed to determine the effect on long-term survival of prosthesis-patient mismatch after AVR with a mean follow-up of almost two decades., Methods: Kaplan-Meier survival analysis was used to determine long-term survival after AVR in a cohort of 673 consecutive patients, divided into 163 patients (24.2%) with prosthesis-patient mismatch (indexed effective orifice area ≤ 0.85 cm(2)/m(2)) and 510 patients (75.8%) without prosthesis-patient mismatch (indexed effective orifice area >0.85 cm(2)/m(2)). Effective orifice area values of the prosthetic valves were retrieved from the literature or obtained from the charts of the prosthetic valve manufacturers. Cox multiple regression analysis was used to identify possible independent predictors, including prosthesis-patient mismatch, of decreased long-term survival., Results: Median sizes of the implanted mechanical (n = 430) and biologic (n = 243) prostheses were 25 and 23 mm, respectively. Mean follow-up after AVR was 17.8 ± 1.8 years. Prosthesis-patient mismatch was not an independent predictor of decreased long-term survival (hazard ratio, 0.828; 95% confidence interval, 0.669 to 1.025; p = 0.083). Severe prosthesis-patient mismatch (indexed effective orifice area ≤ 0.65 cm(2)/m(2)), occurring in only 17 patients (2.5%), showed an insignificant trend toward decreased long-term survival (hazard ratio, 1.68; 95% confidence interval, 0.97 to 2.91; p = 0.066)., Conclusions: Prosthesis-patient mismatch was not an independent predictor of decreased long-term survival after AVR., (Copyright © 2016 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

Background: Although younger patients are supposed to be less susceptible to bleeding complications of mechanical aortic valve replacement (mAVR) than older patients, there is a relative paucity of data on this subject. Therefore, it remains uncertain whether younger patients are really at a lower risk of these complications than older patients., Methods: Incidence rates of bleeding events during 15 years of follow-up after mAVR were compared between 163 patients under 60 (group I), 122 patients between 60 and 65 (group II), and 145 patients over 65 (group III) years of age at operation. The target international normalised ratio (INR) was 3.0-4.0., Results: During 15 years of follow-up, the annual incidence rate of major bleeding events (excluding haemorrhagic stroke) was lower in the youngest as compared with the oldest group (3.0 versus 4.7 %, respectively; p = 0.030). However, the annual incidence rate of haemorrhagic stroke was as high in the youngest as in the two older groups (0.6 versus 0.7 % and 0.7 %, respectively; p = 0.928)., Conclusions: With a target INR of 3.0-4.0, patients under 60 years of age are at equally high risk of haemorrhagic stroke after mAVR as older patients. This finding confirms the relevance of a lower target INR as used in international guidelines.

Objectives: The objective of this study is to develop a simple risk score to predict 30-day mortality of aortic valve replacement (AVR)., Methods: In a development set of 673 consecutive patients who underwent AVR between 1990 and 1993, four independent predictors for 30-day mortality were identified: body mass index (BMI) ≥30, BMI <20, previous coronary artery bypass grafting (CABG) and recent myocardial infarction. Based on these predictors, a 30-day mortality risk score-the AVR score-was developed. The AVR score was validated on a validation set of 673 consecutive patients who underwent AVR almost two decennia later in the same hospital., Results: Thirty-day mortality in the development set was ≤2% in the absence of any predictor (class I, low risk), 2-5% in the solitary presence of BMI ≥30 (class II, mild risk), 5-15% in the solitary presence of previous CABG or recent myocardial infarction (class III, moderate risk), and >15% in the solitary presence of BMI <20, or any combination of BMI ≥30, previous CABG or recent myocardial infarction (class IV, high risk). The AVR score correctly predicted 30-day mortality in the validation set: observed 30-day mortality in the validation set was 2.3% in 487 class I patients, 4.4% in 137 class II patients, 13.3% in 30 class III patients and 15.8% in 19 class IV patients., Conclusions: The AVR score is a simple risk score validated to predict 30-day mortality of AVR.

Objective: To investigate whether supraclavicular ultrasonography of left internal mammary artery (LIMA) to left anterior descending (LAD) area grafts can reliably predict (distal) string sign grafts on arteriography., Methods: Fifty-five patients (42 M, 61 +/- 7 years) with the LIMA to LAD area grafting were prospectively studied. Control arteriography was performed at 1.4 +/- 0.8 years postoperatively. Angiography demonstrated in 46 patients (group I) functional grafts, in 4 patients (group II) sequential distal string sign grafts and in 5 patients (group III) total string sign grafts. Ultrasonography was performed at 1.8 +/- 0.8 year postoperatively and compared with control angiography. Data were tested by unpaired t- and ANOVA tests. The diagnostic accuracy was assessed by the area under the curve of the Receiver Operator Characteristic. A formula was developed to predict the probability of (distal) string sign phenomena of sequential as well as single LIMA grafts., Results: Between the groups all duplex parameters showed a highly significant linear relation (p < or = 0.004) and all parameters between group I and III are significantly different with high Area Under Curve values. The model for the probability of (distal) string sign grafts fitted best with diastolic and systolic peak velocities as the most discriminative factors for (distal) string sign grafts., Conclusions: Postoperative supraclavicular duplex as a method to assess the patency of LIMA to LAD area grafts allows discriminating functional grafts from (distal) string sign grafts.

Aim: To correlate supraclavicular ultrasonography with angiographically patent and string sign left internal mammary artery (LIMA) to left anterior descending artery (LAD) grafts., Methods: Sixteen patients with a single LIMA anastomosis to the LAD were prospectively entered in a follow-up study. The supraclavicular ultrasonography of the LIMA origin was studied preoperatively and at 5.3+/-3.6 months and 1.7+/-0.4 year postoperatively. At the late postoperative ultrasonography electrocardiographically controlled hyperemic response was also studied for 6 min. Control angiography was performed at 1.5+/-0.8 year. Differences within groups were tested with a paired t-test and between groups with an unpaired t-test., Results: Control angiography showed in 13 patients (group I) a patent LIMA graft and in 3 patients (group II) a string sign LIMA graft. Preoperative blood velocities were not significantly different between groups. Postoperatively, both groups revealed higher diastolic and lower systolic blood velocities compared to preoperative values. The blood velocities at rest did not change in group I and all velocities decreased in group II in time postoperatively. The blood velocities in maximal hyperemic response increased significantly within the groups and were not significantly different between the groups. No ischemia could be detected electrocardiographically during hyperemic response and no patient presented angina., Conclusions: Both groups showed a shift towards coronary type diastolic blood velocities at rest and at hyperaemic response. Significant hyperemic response was also present in string sign LIMA grafts and demonstrates response capacity to increased myocardial oxygen demand.

A general analytical framework is presented for the design of birdcage radiofrequency resonators on cylindrical formers having arbitrary cross-sectional shape. The primary objective of such shapes would be to improve the sensitivity of the NMR experiment to noncircular regions of the human anatomy while maintaining field homogeneity and quadrature polarization comparable to those of standard circular birdcage coils. The shape of the corresponding radiofrequency screen, which is required to decouple the coil from the rest of the NMR system and which is key to the performance, is also provided by this methodology. The theory was tested by constructing a 3-T, quadrature, proton coil on a shape conforming to the anthropomorphic mean of the human head, namely, the oval of Cassini. Both bench tests (Q) and in vivo spectral and imaging comparisons of the Cassinian coil with an equivalently dimensioned and constructed circular birdcage coil, respectively, predicted and demonstrated in vivo an improvement in SNR of approximately 24% over the circular section coil. The experimental RF field homogeneity and quadrature performance were comparable for both coil geometries, with the circular coil being marginally superior., (Copyright 2004 Wiley-Liss, Inc.)

The internal mammary artery (IMA) is the conduit of choice in coronary revascularization because of its long-term patency. We analyzed the effect of left internal mammary artery (LIMA) harvesting on sternal perfusion. Diameters and velocity parameters of the nonmobilized right internal mammary artery (RIMA) were noninvasively analyzed with duplex ultrasound in 41 patients with LIMA myocardial revascularization pre- (2.6 +/- 5 days) and postoperatively (4.9 +/- 3.9 months). Data of 41 patients were analyzed; 38 patients underwent all examinations with adequate supraclavicular signals. The proximal RIMA diameter and all velocity parameters increased significantly at follow-up (3.1 +/- 0.6 vs. 3.2 +/- 0.5 mm, p = 0.03; diastolic peak velocity [DPV] 15 +/- 7 vs. 27 +/- 9 cm/sec, p < 0.0001; systolic peak velocity [SPV] 90 +/- 24 vs. 105 +/- 29 cm/sec, p < 0.02). This was more pronounced for the diastolic parameters and for all parameters in the proximal part of the RIMA than in the distal part (DPV 11.9 +/- 10.1 vs. 9.5 +/- 10.2 cm/sec, p = NS; SPV 14.9 +/- 33.9 vs. 7.4 +/- 26.0 cm/sec, p = NS). With longer time intervals of follow-up the increase in all diastolic velocity parameters became less pronounced. As demonstrated in the RIMA velocity parameters, patients with skeletonized LIMA grafts (n = 4) had significantly more flow, suggesting hyperemic flow, than patients with pedicled LIMA grafts (n = 34). Only in diastolic velocity integral (DVI) and systolic/diastolic velocity ratio (SDVRA) were there significant differences between diabetics (n = 9) and nondiabetics (n = 29) and only in DVI between female, (n = 8) and male (n = 30) patients. This study indicates that duplex ultrasound is a useful tool for noninvasive RIMA follow-up in LIMA myocardial revascularization.

Objective: (1) To evaluate the quality of life (QoL) scores, assessed with SF36 and EuroQol (EQ-5D), of long term survivors after mechanical aortic valve replacement (mAVR); (2) to study the association of QoL with NYHA score, number of major bleeding and thrombo-embolic events and follow-up time; (3) to compare QoL scores of long term mAVR survivors with QoL scores of other populations., Methods: In total 312 patients had a mAVR between 1964 and 1974 at St. Antonius Hospital Nieuwegein (NL). Mean age at operation was 41 (sd=12). Mean postoperative NYHA class at 1-year follow-up was 1.7 (sd=0.7). In 2001 the survivors (n=78; 25%) were followed-up for late events, NYHA class and QoL scores. 69 patients (93%) returned completed questionnaires., Results: Mean duration of follow-up was 30 years (sd=1.8). Mean age of responders was 65 years (sd=10, range 47-93). In 2001, NYHA class of responders was 2 (sd=0.9). The mean (sd) SF36 scores for responders were: 64 (29) for physical function, 64 (29) for role-physical, 80 (30) for bodily pain, 55 (25) for general health, 63 (23) for vitality, 73 (29) for social functioning, 70 (38) for role-emotional, 76 (18) for mental health. The mean EQ-5D score of responders was: 61 (13). These SF36 and EQ-5D scores are comparable to those of other populations (e.g. cancer, diabetes type-2, migraine, chronic liver disease and iliac artery occlusive disease and Dutch general population). For responders a moderate to high association of SF36 and EQ-5D scores and their NYHA scores (R2=0.36) was found. The number of major bleeding events, age, sex and survival time were not related to QoL., Conclusion: At long term follow-up (mean 30 years) of patients who had mAVR, QoL was relatively high; it was moderately to highly associated with their NYHA class; bleeding and thromboembolic events seem to be of little importance for the QoL at long term follow-up. QoL at long term follow-up of patients who had mAVR is comparable to other cross sectional designed studies with short term follow-up and other population.

In contrast to a previous report [Baertlein et al. (2000)], the transverse electomagnetic resonator used in magnetic resonance imaging is shown to be similar to the high-pass "birdcage" resonator in having an electric field minimum in correspondence with the maximum of the magnetic field. The noise performance of each resonator will, in consequence, be comparable, since at high frequencies patient conductive losses are predominant.

Objectives: To describe morbidity and mortality in patients undergoing the elephant trunk (ET) implantation as the first stage in the repair of their mega aorta and to assess determinants for the occurrence of complications., Methods: One hundred consecutive patients undergoing an ET implantation between 1984 and June 2001 were retrospectively analyzed. The ET was implanted as an extension of an isolated aortic arch (1%), an aortic valve replacement+ascending aorta+arch (14%), a root replacement+ascending aorta+arch (37%) and an ascending aorta+arch (48%). Indications for surgery were acute aortic dissection (1%), an inflammatory aneurysm (3%), chronic post-dissection (31%) or degenerative (65%) aneurysm. Marfan syndrome was present in six patients. For cerebral protection, we used isolated deep hypothermic circulatory arrest (7%), deep hypothermic circulatory arrest combined with uni- or bilateral antegrade cerebral perfusion (18%) or isolated uni- or bilateral antegrade cerebral perfusion (75%). Uni- and multivariate analysis was used., Results: There were no intraoperative deaths. Hospital mortality was 8%. The causes of death were cardiac in one, rupture of a remote aneurysm in three, tamponade in one and sepsis in three. After multivariate analysis, no single factor emerged as a risk factor for hospital mortality. Permanent and transient neurologic dysfunction occurred in 4 and 2%, respectively. Univariate analysis showed the operative period before 1990 (P=0.029) and emergency (P=0.018) as significant factors for postoperative neurologic dysfunction; after stepwise logistic regression analysis, only emergent operation retained significance (P=0.005). Permanent hoarseness, total atrioventricular block requiring pacemaker implantation and re-thoracotomy for bleeding occurred in 17, 2 and 30%, respectively., Conclusions: The first step in the repair of a mega aorta, the implantation of an ET, can be performed with a low mortality and an acceptable morbidity. The risk of central neurologic damage is higher in emergency interventions.

To study echo Doppler characteristics of sequential versus single left internal mammary artery (LIMA) to left anterior descending (LAD) area grafts transthoracic echo Doppler at the LIMA origin and angiography were performed pre- and postoperatively. In 17 patients single LIMA to LAD (group I) and in 45 patients sequential LIMA to LAD area (group II) bypass grafting was performed. All patients show an early postoperative shift towards diastolic coronary Doppler velocity spectra. Only group II shows a further significant late increase in diastolic, velocity time integral and some systolic echo Doppler parameters at rest. Diastolic peak and diastolic as well as total mean and velocity time integral maximal values are significantly higher in group II in late postoperative hyperemic response. Preoperative and late control angiography showed no significant differences in overall grading of native LAD stenosis between both groups. The large coronary reserve in LIMA sequential grafts may contribute to an improved long-term patency.

Objectives: To correlate supraclavicular left internal mammary artery (LIMA) to left anterior descending artery (LAD) area Doppler characteristics with angiographically perfused area., Methods: Sixty patients (50 male, mean age 62+/-7.3 years) with LIMA to LAD area grafting were prospectively entered in a follow up study. Supraclavicular echo Doppler of the LIMA was studied at the LIMA origin preoperatively, and at 4.8+/-3.8 months and 1.8+/-0.9 years postoperatively. The potential area to be revascularized judged from preoperative angiography was called the 'target' area. Control angiography (native and LIMA) was done at 1.5+/-0.9 years. The perfused area % was classified into group I < or =17.0% (n=16), group II >17.0% and <22.50% (n=17), and group III > or =22.50% (n=18) and related to LIMA Doppler characteristics. Multivariate linear regression analyses (MLRA) were performed to assess the relations between Doppler variables and the perfused area, target area and ratio of perfused/target area., Results: At MLRA perfused area was significantly related to the natural logarithm of diastolic peak velocity (DPV) (P=0.013) and diastolic mean velocity (P=0.048) and the ratio only to the degree of LAD stenosis (P=0.004). In hyperaemic response maximal DPV (DPV max) showed significant correlation to the perfused area (P=0.005) as well as to the ratio (P=0.017). When analyzing the additive power of both investigations, only DPV max (P=0.005) correlated significantly to the perfused area and for the ratio only the degree of stenosis of the LAD emerged as significant (P=0.004)., Conclusions: At MLRA the diastolic flow pattern at rest and the maximal DPV in hyperaemic response correlated significantly with the LIMA run-off area whereas the last variable is the strongest predictor of the LIMA run-off area.

Background: The choice of a valve substitute in young adults requires a decision balancing the risks of long-term anticoagulation versus reoperation(s). This article analyzes the long-term risk and determinants of thromboembolic (TE) and bleeding (BLE) complications after mechanical aortic valve replacement (AVR)., Methods: From December 1963 to January 1974, 249 patients survived a mechanical AVR at our institution. Mean age was 41.8+/-12.4 years and 81% (n = 202) were male. Ball valves were implanted in 24% (n = 61) and disc valves in 76% (n = 188). Patients were anticoagulated with vitamin K antagonists and dipyridamole. A total of 4,855 patient-years was available for analysis. Mean follow-up was 19.5+/-9.4 years and was 100% complete. Analyses were performed with Kaplan-Meier and multivariable Cox regression methods., Results: One hundred and two patients had one TE or BLE postoperative event and 58 patients had two postoperative events. Six patients had more than five postoperative events. Freedom from a first postoperative event was 74.8%+/-2.9%, 55.3%+/-3.5%, and 46.8%+/-4.0% at 10, 20, and 30 years, respectively. Freedom from a second postoperative event was 45.4%+/-5.4%, 29%+/-6.0%, and 23.2%+/-7.1% at 10, 20, and 30 years, respectively. Multivariate predictors for TE or BLE complications were ball valve (Odds Ratio (OR) = 2.9), postoperative endocarditis (OR = 2.2), and any surgery (OR = 2.2). The incidence of events was highest the first 5 postoperative years., Conclusions: The risk of adverse events is highest the first 5 postoperative years. Once an event has occurred, the risk for a second event is increased. The incidence and frequency of events is substantial and should be considered in the choice of a valve substitute.

Background: The aim of this study was to determine the durability of aortic valve preservation and root reconstruction in type A aortic dissection with involvement of the aortic root., Methods: From November 1976 to February 1999, 246 patients underwent surgical treatment for acute type A aortic dissection at our institution. In 121 patients (49%), all with acute type A dissection and aortic root involvement, the aortic valve was preserved and one or more of the sinuses of Valsalva were reconstructed. The mean age of this group was 59 +/- 11 years and 70 (58%) were men. Thirty patients (25%) were operated in cardiogenic shock. Criteria for aortic root reconstruction were technical feasibility and surgeon preference. Techniques used for reconstruction were valve resuspension in all patients and additional reinforcement of the aortic root with Teflon (L.R. Bard, Tempe, AZ) felt (n = 21), gelatin-resorcinol-formaldehyde-glue (GRF-glue, Fii, Saint-Just-Malmont, France) (n = 103), or fibrinous glue (Tissu-col, Immuno AG, Vienna, Austria) (n = 5). Mean follow-up was 43.5 +/- 46 months., Results: The operative mortality was 21.5% (n = 26). Actuarial survival was 72% +/- 4%, 64% +/- 5%, and 53% +/- 6% at 1, 5, and 10 years, respectively. Median aortic regurgitation in patients with retained native aortic valve at follow-up was 1+. All root reoperations included aortic valve replacement (n = 12). Freedom from aortic root reoperation was 95% +/- 2% at 1 year, 89% +/- 4% at 5 years, and 69% +/- 9% at 10 years. The incidence of aortic root reoperation was 23%, 11%, and 40%, respectively, when Teflon felt, GRF-glue, and fibrinous glue were used for root reconstruction. Multivariate Cox proportional hazard analysis revealed the use of fibrinous glue (RR = 8.7; p = 0.03) as well as the presence of an aortic valve annulus more than 27 mm (RR = 4.2; p = 0.04) as independent risk factors for aortic root reoperation., Conclusions: Aortic valve preservation in acute type A dissection provides relatively durable results. The use of fibrinous glue for root reconstruction seems to compromise the long-term durability of the repair compared with Teflon felt and GRF-glue. A dilated aortic annulus requires a more extensive root procedure.

Background and Purpose: The outcomes of carotid endarterectomy (CEA) are, in addition to patient baseline characteristics, highly dependent on the safety of the surgical procedure. During the successive stages of the operation, transcranial Doppler (TCD) monitoring of the middle cerebral artery (MCA) was used to assess the association of cerebral microembolism and hemodynamic changes with stroke and stroke-related death., Methods: By use of data pooled from 2 hospitals in the United States and the Netherlands, including 1058 patients who underwent CEA, the association of various TCD emboli and velocity variables with operative stroke and stroke-related death was evaluated by univariable and multivariable logistic regression analyses in combination with receiver operating characteristic (ROC) curve analyses. The impact of basic patient characteristics, such as age, sex, preoperative cerebral symptoms, and ipsilateral and contralateral internal carotid artery stenosis, on the prediction of operative stroke was also evaluated., Results: We observed 31 patients with ischemic and 8 patients with hemorrhagic operative strokes. Four of these patients died. Emboli during dissection (odds ratio [OR] 1.5, 95% CI 0.8 to 2.9) and wound closure (OR 2.3, 95% CI 1.2 to 4.4) as well as > or =90% decrease of MCA peak systolic velocity at cross-clamping (OR 3.3, 95% CI 1.3 to 8.5) and > or =100% increase of the pulsatility index of the Doppler signal at clamp release (OR 7.1, 95% CI 1.4 to 35.7) were independently associated with stroke. The ROC area of this model was 0.69. Of the patient characteristics, only preoperative cerebral ischemia (OR 1.9, 95% CI 1.0 to 3.7) and > or =70% ipsilateral internal carotid artery stenosis (OR 0.5, 95% CI 0.2 to 0.9) were associated with stroke. Adding these patient characteristics to the model, the area under the ROC curve increased to 0.73., Conclusions: In CEA, TCD-detected microemboli during dissection and wound closure, > or =90% MCA velocity decrease at cross-clamping, and > or =100% pulsatility index increase at clamp release are associated with operative stroke. In combination with the presence of preoperative cerebral symptoms and > or =70% ipsilateral internal carotid artery stenosis, these 4 TCD monitoring variables reasonably discriminate between patients with and without operative stroke. This supports the use of TCD as a potential intraoperative monitoring modality to alter the surgical technique by enhancing a decrease of the risk of stroke during or immediately after the operation.

It is demonstrated that birdcage resonators, satisfying conditions of quadrature operation and radiofrequency field homogeneity, can be realized in practice on formers of non-circular cross section described by an equation of the form (x/a)n + (y/b)n = 1 where a and b are constants and n > or = 2 is an integer. Using a ladder network analogous to that of a conventional circular birdcage, optimization algorithms were employed to determine the elemental current distribution on the non-circular cylindrical surfaces. A comparison of circular, elliptical, symmetric and asymmetric fourth-order (n = 4) section birdcage current distributions is presented. A short, asymmetric fourth-order cage was constructed and tested experimentally at 3 T and compared with a conventional circular-section head coil.

Background: This study evaluated the role of left heart bypass on the results of thoracoabdominal aortic aneurysm (TAAA) operations., Methods: Two hundred fifty-eight patients had surgical repair of a thoracoabdominal aortic aneurysm between 1981 and 1998 using the inlay technique. Simple cross-clamping was used in 47.7% and left heart bypass (atriodistal) in 52.3%. Further surgical technique was identical: liberal intercostal or lumbar artery reimplantation, cerebrospinal fluid drainage (since 1989), administration of a renal cooling solution, permissive mild hypothermia, and no pharmacologic protection. Both univariate and multivariate analysis were used., Results: The hospital mortality rate was 10.1% overall: 14.6% in the cross-clamp group, and 5.9% in the bypass group (p = 0.02). The risk of hospital death increased with aneurysm rupture (odds ratio 5.6) and when the patient needed postoperative dialysis (odds ratio 7.5). The use of left heart bypass had a mild protective effect on hospital death (odds ratio 0.56). The incidence of postoperative renal failure requiring dialysis was 8.3% overall: 10.9% in the cross-clamp group, and 5.9% in the bypass group (p = 0.16). After multivariate analysis, a longer operative procedure (odds ratio 1.01 per minute) and a longer reappearance time of blue dye in the urine (odds ratio 1.05 per minute) increased the risk of dialysis, whereas the use of atriodistal bypass reduced that risk (odds ratio 0.08). Paraplegia or paraparesis occurred in 10.9% of patients overall: 13.2% in the cross-clamp group, and 8.8% in the bypass group (p = 0.27). After logistic regression, rupture increased the risk of paraplegia or paraparesis (odds ratio 3.2) and dissection reduced it (odds ratio 0.23)., Conclusions: The use of atriodistal bypass is beneficial in patients who had thoracoabdominal aortic aneurysm repair. Hospital mortality rates, postoperative dialysis, and paraplegia/paraparesis were reduced.

Background: To determine the factors that influence hospital death and neurologic complications after surgery on the thoracic aorta using circulatory arrest and antegrade selective cerebral perfusion., Methods: From May 1989 through April 1997, 106 patients underwent surgery on the thoracic aorta using circulatory arrest and antegrade selective cerebral perfusion. Mean age was 64.0 +/- 11.5 years. Unilateral antegrade cerebral perfusion was used in 37 patients (35%), bihemispheric antegrade cerebral perfusion in 69 patients (65%). Mean antegrade cerebral perfusion time was 50.5 +/- 20.5 minutes. Indication for surgery was atherosclerotic aneurysm in 60 (56.5%) patients, postdissection aneurysm in 26 (24.4%), acute type A dissection in 16 (15.1%), other in 4 (4.0%)., Results: Hospital mortality was 8.5% (n = 9; 70% CL: 5.8%-11.2%). Independent predictors of hospital mortality were rethoracotomy (odds ratio 5.7, p = 0.02), postoperative temporary (odds ratio 17.3, p = 0.02) or permanent (odds ratio 7.5, p = 0.03) neurologic dysfunction, postoperative dialysis (odds ratio 9.9, p = 0.008). Bilateral antegrade selective cerebral perfusion had a favorable impact on hospital mortality (odds ratio 0.08, p = 0.007). Temporary neurologic dysfunction occurred in 3.8% of patients (n = 4; 70% CL: 2.0%-5.6%); preoperative hemodynamic instability (odds ratio 14.8, p = 0.05) and perioperative technical problems (odds ratio 22.2, p = 0.033) were independent determinants of temporary neurologic dysfunction. Permanent central neurologic damage occurred in 5.4% of patients (n = 6; 70% CL: 3.2%-7.6%). Preoperative hemodynamic instability (odds ratio 18.9, p = 0.009) and approach through a left thoracotomy (odds ratio 9.4, p = 0.031) were significant predictors of permanent neurologic damage., Conclusions: Hospital mortality is affected significantly by the choice of technique used for antegrade cerebral perfusion. The incidence of both temporary and permanent postoperative central neurologic damage is influenced by preoperative hemodynamic instability. Duration of cerebral perfusion had no influence on the postoperative neurologic outcome.

Background: This is a retrospective study of early and long-term results of composite valve graft replacement of the aortic root., Methods and Results: Between July 1974 and July 1997, 244 patients underwent aortic root replacement with a composite valve graft. Mean age was 54+/-15 years. The inclusion technique was used in 178 patients (73.0%), the open technique in 65 (26.5%), and the Cabrol II technique in 1 patient (0.5%). Hospital mortality was 7.8% (70% confidence limit, 6.1% to 9.5%). Independent determinants of hospital mortality were preoperative creatinine level more than 150 micromol/L (p = 0.04), prolonged cardiopulmonary bypass time (p = 0.006), intraoperative technical problems (p = 0.048), and year of operation (p = 0.015). Follow-up was 99.6% complete, median 96 months (range, 2 to 256 months). Fifty-seven patients (25.3%; 70% confidence limit, 22.4% to 28.2%) died during follow-up. Cumulative survival at 5, 10, and 20 years was 76%, 62%, and 33%. Independent risk factors for late death were postoperative complications (p = 0.027), technique for coronary reattachment (p = 0.028), and concomitant aortic arch operation (p = 0.01). Twenty patients (8.8%; 70% confidence limit, 7.0% to 10.6%) underwent reoperation on the aortic root. Estimated freedom from reoperation for pseudoaneurysms at 3 years was 96% in the inclusion group and 94% in the open group (p = 0.236)., Conclusions: Aortic root replacement with a composite valve graft can be performed with low hospital mortality and morbidity. Pseudoaneurysms did occur in the inclusion group, but also in the open group.

A 50-year-old man was operated on for acute type I (DeBakey classification) aortic dissection. The supracoronary ascending aorta was replaced with an interposition graft. Postoperative computed tomography and angiography clearly revealed a double-barrelled aortic arch, left common carotid artery and descending thoracoabdominal aorta with contrast filling of both true and false lumen starting from the distal anastomosis. The same finding was noted at 1 year follow-up with severe compression of the true lumen by the false lumen. At this time, anticoagulation therapy was stopped. One year later, computed tomography showed spontaneous resolution of the dissection in the aortic arch, left common carotid artery and descending aorta over its full length. This was confirmed by angiography. This case reports illustrates that spontaneous resolution of a dissected descending aorta can occur late after surgery from type 1 dissection, but it remains very rare.

Aortitis with involvement of the aortic valve is rarely associated with vasculitis syndromes. We present a patient with antibodies to a neutrophil cytoplasmic antigen-associated (ANCA) vasculitis with renal failure who developed aortic incompetence as a result of aortitis which involved the aortic valve. Thickening of the aortic wall also caused stenosis of the left coronary ostium.

Objective: We investigated the clinical outcome of venous coronary artery bypass graft surgery., Methods: A study group consisting of 428 consecutive patients-operated on between 1 April 1976 and 1 April 1977-was followed prospectively. Single or sequential saphenous vein grafts were performed with a mean of 3.2 coronary anastomoses per patient. A left ventricular aneurysmectomy was performed in 25 patients., Results: Complete revascularisation was achieved in 78% of the patients. Follow-up was 99.8% complete and averaged 15.4 years for the survivors. Actuarial survival after 5, 10, and 15 years was 91.4%, 79.9%, and 61.1%, respectively. The cumulative probabilities of event-free survival at 10 years were as follows: cardiac death, 87.3%; acute myocardial infarction, 84.1%; reoperation, 88.6%; coronary artery balloon angioplasty, 94.1%; angina pectoris, 48.7%; and any event, 40.8%., Conclusions: The results are comparable with those of the few other long-term studies that have been published. With isolated venous bypass grafting, satisfactory results can be obtained until approximately 7 years after operation. Thereafter mortality increases, as does the rate of myocardial infarction, reoperation, and balloon angioplasty.

Graft replacement remains the procedure of choice for patients with thoracoabdominal aortic aneurysm. Since there is little information regarding the long-term survival following these major vascular operations which may carry a risk of various late complications, a retrospective analysis of 10 years follow-up was undertaken. The results of 172 consecutive operations for thoracoabdominal aortic aneurysm were analysed retrospectively. Hospital mortality rate was 10.5%. Temporary postoperative haemodialysis was necessary in 10.4% of cases and paraplegia occurred in 8.2%. The mean (s.e.) overall cumulative 2-, 5- and 10-year observed survival rate was 76(3.4), 53(4.5) and 19(7)%, respectively while expected survival of a background population at 2, 5 and 10 years was 94%, 85% and 71%, respectively. Reoperation for an early (< 7 days) or late (> 7 days) aortic event was necessary in 31 patients. If performed electively, the hospital mortality rate for late aortic reoperation was only 7% but an emergency reoperation, hospital mortality rate was 100%.

Background: No consistent data are available on the specific coronary artery pathology leading to postinfarction ventricular septal rupture. The benefits and risks of coronary angiography and subsequent coronary artery bypass grafting in these patients is under discussion., Methods: Clinical and coronary angiographic factors were analysed in 109 consecutive patients treated surgically for postinfarction ventricular septal rupture between 1980 and 1992. Coronary angiography was performed in 104 patients, and 92 of the angiograms were available for complete analysis. Factors were related to late cardiac mortality in 79 patients surviving the early period., Results: Single-vessel disease was found in 58 patients (55.8%) and multiple-vessel in 46 (44.2%). In 24 patients (26.1%) there was some collateral circulation to the infarct-related coronary artery. No relationship was found between dominance, occlusion location and early or late outcome. Forty-five patients (41.3%) underwent coronary revascularization in addition to surgical closure of the ventricular septal rupture. Risk factors for late cardiac mortality in patients surviving the early postoperative period were postoperative cardiac failure (P = 0.0089), incomplete coronary revascularization (P = 0.024) and longer aortic cross-clamp time (P = 0.032)., Conclusion: We conclude that concomitant complete revascularization is indicated during surgical repair of postinfarction ventricular septal rupture.

Although it has been the topic of intense medical and surgical attention for over 20 years, the coexistence of severe carotid artery disease in patients undergoing coronary artery bypass graft continues to be a major cause of perioperative morbidity and mortality. Refinements in diagnostic modalities, mainly by duplex ultrasonography, have improved preoperative assessment. Management possibilities vary from ignoring the carotid problem to simultaneous reconstructions. However, the best surgical option for these high-risk patients has yet to be determined because of the lack of controlled, prospective, randomized trials.

Objective: In trying to answer the question about the controversial use of sequential grafts, we determined the long-term clinical outcome of patients in whom coronary artery bypass was done with different types of vein grafts., Methods: A total of 428 consecutive patients who underwent isolated coronary artery bypass with vein grafts between April 1, 1976, and April 1, 1977, were prospectively observed. In these patients three groups could be defined with single grafts only, sequential grafts only, and combined single and sequential grafts. Follow-up was 99.8% complete and averaged 15.4 years for the survivors. The Kaplan-Meier method and multivariate analysis done with the Cox regression model were used for survival, myocardial infarction, reintervention, and "any event.", Results: Perioperative mortality and perioperative myocardial infarction rate were not statistically different among the three groups. During follow-up more myocardial infarctions (hazard ratio: 2.06; 95% confidence interval: 1.08 to 3.93; p = 0.0293) or any events (hazard ratio: 1.54; 95% confidence interval; 1.01 to 2.36; p = 0.0450) occurred in patients with sequential grafts only than in patients with single grafts only., Conclusion: Although more complete revascularization was obtained in patients with sequential vein grafts only, more events during a 15-year follow-up occurred in these patients than in patients with single vein grafts only.

Background: The aim of this study was to identify factors influencing early outcome after surgical treatment of postinfarction ventricular septal rupture. We investigated the influence of proximal or distal rupture location., Methods: Between 1980 and 1992 109 patients were treated surgically for ventricular septal rupture using a standardized technique. A division in time periods was made. The rupture was categorized according to its anterior or posterior site and proximal or distal location., Results: The 30-day mortality rate was 27.5%. Multivariate logistic regression analysis identified preoperative shock (p = 0.0007) and right atrial oxygen saturation less than 60% (p = 0.021) as predictors for early death; the risk for early death declined over the time periods from 50% to 12.8% (p = 0.0007). Proximal ventricular septal rupture location (p = 0.0092) and interval between infarction and ventricular septal rupture less then 1 day (p = 0.034) were risk factors for the occurrence of preoperative shock., Conclusions: Proximal ventricular septal rupture location was the main determinant of preoperative cardiogenic shock, which in turn was the strongest predictor of early mortality. Over the time periods a decrease in early mortality was reached.

Background: In patients with postinfarction sustained ventricular tachycardia showing one or more antiarrhythmic drug failures, the question is how long to proceed with new drug trials before deciding to perform map-guided arrhythmia surgery. Although the techniques of this surgery developed rapidly in the early 1980s, this therapy may be offset by damage to residual left ventricular function. However, surgery has been shown to be very effective in selected groups of patients., Methods: A randomized study was carried out in patients with postinfarction ventricular tachycardia and eligible for arrhythmia surgery based on residual left ventricular function. Therapy failure was defined by the occurrence of the following events: spontaneous recurrence of ventricular tachycardia or ventricular fibrillation, sudden cardiac death, inducibility of sustained ventricular tachycardia or ventricular fibrillation with programmed stimulation of the heart, symptomatic non-sustained ventricular tachycardia requiring therapy or side-effects of antiarrhythmic drugs requiring withdrawal. In the drug limb, failure of the first antiarrhythmic drug was accepted but failure of a second and different drug was regarded as true therapy failure., Results: After randomization, antiarrhythmic drug therapy was administered in 33 patients, and 30 patients underwent surgery. Neither group differed in baseline characteristics, and the mean number of drug failures before randomization was 2.7. The Kaplan-Meier therapeutic failure of antiarrhythmic drugs was 39 +/- 11%, 42 +/- 11% and 51 +/- 18% at 0.5-, 1- and 4-year follow-up, respectively, whereas the therapeutic failure of cardiac surgery was 37 +/- 11%, 37 +/- 11% and 50 +/- 20% at 0.5, 1 and 4 years, respectively, showing no statistical difference. The 1- and 4-year Kaplan-Meier survival of the antiarrhythmic drug-treated group was 91 +/- 6% and 78 +/- 15%, respectively, and of the surgical group 92 +/- 6% and 59 +/- 20%, respectively, and did not differ between either group. However, the relative risk for total cardiac death was higher in the surgical limb than in the drug limb (relative risk 2.2, CI 0.68-7.48)., Conclusion: This study demonstrated no difference between the therapeutic result of continuation of two different antiarrhythmic drugs and that of arrhythmia surgery. Despite the small number of patients studied, it is recommended that drug therapy should continue as long as this regimen is tolerated by the patient. When true drug refractoriness or side-effects of drugs arise, arrhythmia surgery offers a valuable alternative. However, when additional reasons for cardiac surgery exist, arrhythmia surgery should be undertaken earlier and may become the first choice of treatment of postinfarction ventricular tachycardia.

Objectives: The aim of this study was to identify factors causing rupture recurrence after surgical repair of postinfarction ventricular septal rupture and to evaluate the indication for reoperation., Patients: Recurrence of rupture was analysed in 25 out of a series of 109 patients who underwent surgical repair for postinfarction ventricular septal rupture between 1980 and 1992 in our institution., Results: The mean interval between initial operation and recurrence was 3.6 days with a median of 2 days. Multivariate logistic regression analysis identified early thrombolysis after infarction (P = 0.0085) as a risk factor for recurrence of the rupture. Rupture recurrence occurred more in the anterior then in the posterior infarction site, although non-significant. Reoperation was indicated in 15 patients, in 13 for postrecurrent cardiac failure. The main determinant of cardiac failure was a large postrecurrent shunt (P = 0.05). The mean interval between initial operation and reoperation was 136 days with a median of 101 days. In 6 patients a combined apical ventricular septal rupture recurrence and anterior ventricular aneurysm was found, in 9 patients the recurrent rupture was proximally located, without concomitant aneurysm formation. Of 15 patients who were reoperated, one died in hospital and three after the in-hospital period. Of 10 patients treated conservatively, one died in hospital and two after the in-hospital period. One residual ventricular septal rupture closed spontaneously., Conclusions: Rupture recurrence is mainly determined by early thrombolysis. Postrecurrent cardiac failure, as the main indication for reoperation, is dependent on postrecurrent shunt size.

Since tibial nerve somatosensory evoked potentials (SEPs) recording is influenced by hemodynamic changes and anesthetics, alterations cannot always be attributed to spinal cord ischemia, so causing false positive results. Additional recording of median nerve SEPs facilitates interpretation. From January 1988 to July 1993, 60 consecutive patients (44 men, 16 women, mean age 66 years, ranging from 26 to 83 years) underwent surgery for an aneurysm of the descending thoracic aorta using a non-heparinized left heart bypass (Biomedicus pump). In 40 patients recording of the tibial and median nerve SEPs was performed intraoperatively by stimulating both nerves alternately. In 32 patients (80%) both recordings were uneventful. In three patients (7.5%) the tibial nerve SEP temporarily disappeared due to peripheral ischemia on termination of the bypass for the creation of an open distal anastomosis. In three patients (7.5%) near loss of both tibial and median SEP recordings was caused by low blood pressure and/or anesthetics. In two patients (5%) isolated loss of the tibial nerve SEP was due to ischemia in the spinal pathway of the tibial nerve. The tibial nerve SEP signal returned to normal: in one patient after reperfusion of intercostal arteries localized within the aneurysm, in the other patient after drainage of cerebrospinal fluid (CSF). Continuous recording of both tibial and median nerve SEPs gives consistent information on spinal cord ischemia, reducing the false positive rate of the lower extremity SEP to 7.5%.

Background: The long-term clinical effects of smoking and smoking cessation after venous coronary bypass surgery have not been well established., Methods and Results: Four hundred fifteen patients who underwent venous coronary bypass surgery between April 1976 and April 1977 were followed up prospectively for 15 years. Multivariate Cox survival analysis revealed that patients who smoked at the time of surgery had no elevated risks for clinical events compared with nonsmokers. However, smoking behavior at 1 and 5 years after surgery appeared to be an important predictor of clinical events during the subsequent follow-up period. Compared with patients who stopped smoking since surgery, smokers at 1 year after surgery had more than twice the risk for myocardial infarction and reoperation. Patients who were still smoking at 5 years after surgery had even more elevated risks for myocardial infarction and reoperation and a significantly increased risk for angina pectoris compared with patients who stopped smoking since surgery and patients who never smoked. Patients who started to smoke again within 5 years after surgery had increased risks for reoperation and angina pectoris. No differences in outcome were found between patients who stopped smoking since surgery and nonsmokers., Conclusions: Our results show that smoking cessation after coronary bypass surgery may have important beneficial effects on clinical events during long-term follow-up.

Objective: To determine the changes in the open heart surgical procedures and hospital mortality between 1982 and 1992., Design: Retrospective investigation., Setting: St. Antonius Hospital, Nieuwegein., Method: A comparison of the open heart surgical procedures, the hospital mortality and the age distribution of the operated patients was made by means of the database of the department of Cardiopulmonary Surgery., Results: The total number of open heart procedures showed a small increase; however, there was a considerable increase in the number of combined procedures of coronary revascularisations with valve surgery, coronary revascularisation reoperations, closure of ventricular septal ruptures, rhythm procedures and reconstruction of the thoracic aorta. Although the mean age of the patients increased by about 6 years, hospital mortality was much lower in 1992., Conclusions: Between 1982 and 1992 mean patient age increased considerably, the open heart procedure became more extensive and the hospital mortality decreased.

Background: Knowledge is still lacking about pre-operative and postoperative factors which predict the long-term prognosis of patients who undergo venous coronary artery bypass graft surgery., Methods and Results: Four hundred and twenty-eight consecutive patients who underwent isolated venous coronary artery bypass graft surgery with or without left ventricular aneurysm surgery between 1 April 1976 and 1 April 1977, were followed prospectively. Follow-up was 99.8% complete and averaged 15.4 years for the survivors. Two prognostic models were set up to illustrate the influence of 21 variables, present at and, 5 years after, surgery, on the occurrence of six different clinical events. Multivariate analysis was performed using the Cox regression model. Age, left ventricular function, pre-operative severity of angina and diabetes mellitus are continuous incremental risk factors for one or more events. Revascularization with sequential grafts only, and obesity at operation are incremental risk factors for acute myocardial infarction. From the 'classical' risk factors present 5 years after surgery hypertension is an incremental risk factor for both overall and cardiac mortality, diabetes mellitus for cardiac mortality, myocardial infarction, balloon angioplasty and smoking for all clinical events except mortality., Conclusions: Well-known pre-operative factors including 'classical' risk factors, present late after surgery, influence the occurrence of clinical events. Treatment of these factors may result in better long-term prognosis after venous bypass graft surgery.

The purpose of this study was to assess the usefulness of left heart bypass in thoracoabdominal aortic aneurysm surgery. Data from 50 patients who underwent thoracoabdominal aortic aneurysm repair between July 1987 and October 1993 were retrospectively reviewed. In all of them a left heart bypass (left atrium to left femoral artery) with a centrifugal pump (without systemic heparinization) was used. Patient-, disease-, and operation-related variables were analyzed using univariate methods. There were no intraoperative deaths. The in-hospital mortality rate was 8% (n = 4). Survival rates were 77% (+/- 6.5) at 2 years and 62% (+/- 8.7) at 5 years. Renal failure requiring dialysis occurred in five (10%) patients and paraplegia in five (10%). Sixteen (32%) patients had respiratory insufficiency requiring prolonged (> 8 days) ventilation. After univariate analysis, the risk factors for developing a need for postoperative dialysis were found to be the preoperative creatinine level (p = 0.002) and the presence of preoperative arterial hypertension (p = 0.018). A history of peripheral vascular occlusive disease (p = 0.008) was an important risk factor for predicting late death. No factors retained significance in the univariate analysis of hospital deaths and postoperative paraplegia. Renal and spinal ischemic times were substantially reduced in comparison to the theoretic times calculated if cross-clamping had been used. Bypass-related complications were completely absent. The use of a left heart bypass during thoracoabdominal aortic aneurysm surgery may not reduce the global complication rate; the results were similar to those achieved using simple cross-clamping. However, this technique appears to be the method of choice for protecting organ systems at risk during difficult repairs.

Purpose: Carotid endarterectomy (CEA) performed with continuous transcranial Doppler monitoring provides a unique opportunity to determine the number of cerebral microemboli and to relate their occurrence to the surgical technique. The purpose of this study was to assess in CEA the impact of cerebral microembolism on clinical outcome and brain architecture. We also evaluated the influence of the audible transcranial Doppler signal on the surgeon and his or her technique., Methods: In a prospective series of 301 patients, CEA was monitored with electroencephalography and transcranial Doppler ultrasonography of the ipsilateral middle cerebral artery. Preoperative and intraoperative risk factors were entered in a logistic regression analysis program to assess their correlation with cerebral outcome. To evaluate the impact of cerebral microembolism on brain architecture, we compared preoperative and postoperative computed tomography scans or magnetic resonance images of the brain in two subgroups of 58 and 40 patients, respectively., Results: Seven (2.3%) patients had intraoperative transient ischemic symptoms, three (1%) had intraoperative strokes, 1 (0.3%) had transient ischemic symptoms after operation, and 10 (3.3%) had postoperative strokes. Four (1.3%) patients died. Microemboli (> 10) noticed during dissection were related to both intraoperative (p < 0.002) and postoperative (p < 0.02) cerebral complications. Microemboli that occurred during shunting were also related to intraoperative complications (p < 0.007). Microembolism never resulted in new morphologic changes on postoperative computed tomography scans. On the contrary, the phenomenon of more than 10 microemboli during dissection was significantly (p < 0.005) related to new hyperintense lesions on postoperative T2-weighted magnetic resonance images., Conclusions: During CEA the presence of microembolism (> 10 microemboli) during dissection shows a statistically significant relationship with perioperative cerebral complications and with new ischemic lesions on magnetic resonance images of the brain. Moreover, microembolism during shunting is also related to intraoperative complications. Surgeons can be guided by the audio Doppler and emboli signals by changing their technique. This change may result in a decrease of microembolism and consequently in a decline of the intraoperative stroke rate.

Background and Purpose: The main purpose of carotid endarterectomy (CEA) for neurologically symptomatic high-grade extracranial carotid artery stenosis is to remove the suspected source of cerebral microemboli. Transcranial Doppler (TCD) ultrasonography has the potential for detecting solid microemboli in the basal cerebral arteries. Therefore, TCD monitoring provides the opportunity to assess the rate of microemboli to the brain in patients with symptomatic high-grade carotid artery stenosis and to verify whether these phenomena have ceased after CEA., Methods: TCD monitoring was performed in 41 patients to detect high-intensity transient signals indicating microemboli in the middle cerebral artery before and after CEA. In the event that, within 1 week after CEA, TCD monitoring revealed ongoing cerebral microemboli on the side of surgery, the examination was repeated 3 months later., Results: High-intensity transient signals were detected preoperatively on the side of the affected carotid artery in 22 patients (54%; mean, 10.2 per hour; range, 1 to 88). Linear regression analysis demonstrated a trend toward an inverse relationship between the number of high-intensity transient signals per hour and the time interval since the last episode of neurological symptoms (P < .1). CEA resulted in a significant reduction in the number of high-intensity transient signals per hour 7 days after surgery (mean, 6.0 versus 0.4 per hour; median, 0 versus 0; n = 37; P < .005) and 3 months later (mean, 6.3 versus 0 per hour; median, 1.3 versus 0; n = 41; P < .0001)., Conclusions: Clearly, TCD monitoring can be helpful in assessing the effect of CEA in removing the suspected source of cerebral microemboli. Ongoing microemboli to the brain should prompt reassessment of the operated carotid artery or a search for other potential sources of cerebral embolism. Carotid artery plaques seem to produce cerebral microemboli for a limited period, which implies that the prophylactic effect of CEA might decrease if the operation is delayed.

Forty-three patients undergoing repair of a thoracoabdominal aortic aneurysm were monitored to evaluate spinal cord ischemia, as evidenced by somatosensory evoked potentials (SEPs). All patients were operated on using left heart bypass. In 34 patients (80%), staged clamping was used. Except for cerebrospinal fluid (CSF) drainage in 15 patients (35%), no other protective measures to preserve spinal cord function were used. The overall incidence of immediate onset paraplegia was 7%, and of immediate onset paraparesis was 5%; neither was limited only to those patients in whom potentials were lost. In 18 patients (42%), no change in the evoked potentials occurred; one of these patients (5%) awoke paraplegic after operation, and two others had a delayed onset paraplegia. In 13 patients (30%), evoked potentials were lost despite adequate perfusion; in 12 of them, potentials returned gradually, with one immediate paraplegia (8%), and in one potentials did not return at all, with subsequent immediate paraplegia (100%). In 12 patients (28%), evoked potentials decreased without being lost completely, and then recovered; in this group there were no immediate paraplegias. No relationship could be demonstrated between the extinction time, the recovery time, or the duration of loss of evoked potentials with postoperative neurological outcome. Intraoperative monitoring of SEPs is a good indicator of spinal cord ischemia, although we found a 5% incidence of false negatives. SEP monitoring offers an improvement in surgical strategy, and allows safer operations for thoracoabdominal aneurysms.

Background: This study was performed to assess the initial results and long-term follow-up of Morrow septal myectomy for patients with hypertrophic obstructive cardiomyopathy (HOCM)., Methods and Results: We studied 38 consecutive patients with HOCM (age, 13 to 74 years) who underwent a Morrow septal myectomy between 1977 and 1992. There were no perioperative deaths, and the postoperative course was uneventful for all except 2 of the patients. One patient required implantation of a pacemaker due to a complete heart block, and in 1 patient a small ventricular septal defect was caused. Follow-up (mean, 6.8 years) was 100% complete. No patient was reoperated for recurrent HOCM. All except 1 patient experienced a major functional improvement with a decrease of the mean New York Heart Association functional class from 3.0 before operation to 1.5 at follow-up (P < .001). Symptoms persisting during follow-up were angina pectoris in 3 of 22 patients (14%), dyspnea in 6 of 30 patients (20%), dizzy spells in 2 of 12 patients (17%), and syncope in 2 of 10 patients (20%). During follow-up no HOCM related death occurred. All patients were restudied by Doppler echocardiography. The peak gradient in the left ventricular outflow tract decreased from 72 +/- 30 mm Hg (range, 31 to 144 mm Hg) to 6 +/- 4 mm Hg (range, 0 to 20; P < .001). A systolic anterior movement was seen in 8 patients (21%) compared with 32 patients (97%) before the operation (P < .001). The left ventricular outflow tract diameter increased from 17 +/- 3 mm (range, 10 to 23 mm) to 22 +/- 3 mm (range, 15 to 33 mm; P < .001), and the mean subaortic septal thickness decreased from 23 +/- 5 mm (range, 15 to 35 mm) to 15 +/- 6 mm (range, 8 to 30 mm; P < .001)., Conclusions: Morrow septal myectomy for patients with HOCM is a safe procedure with an excellent clinical and Doppler echocardiographic long-term follow-up.