Duration Of Aortic Cross-clamping Research Articles

Influence of clamp duration and pressure on endothelial damage in aortic cross-clamping

Aortic cross-clamping during cardiac operations may injure the vessel wall and cause tissue lesions. This experimental study analyses the influence of the intravascular and external pressure and the duration of aortic cross-clamping on endothelial tissue damage. Fresh porcine aortas (n=20) were tested with intravascular pressures from 30 to 80 mmHg. The external clamp pressure, necessary to occlude the aorta, was applied by using the second cog of a commercial aortic clamp and cross-clamping was performed for 1 and 30 min. The observed pressure curves were compared to the histological findings. For occlusion of the aorta, an external pressure of at least 10-fold higher than the intravascular pressure (max. 812 mmHg) had to be applied. After 30 min of clamping, a complete endothelial destruction was observed, irrespective of intra-aortic pressure. The aortic media remained intact. After 1 min clamping, fractions of intact endothelial cells were left, ranging from 40 to 70% at different intra-aortic pressures. These results indicate that endothelial tissue lesions due to aortic cross-clamping are not avoidable, even in moderate clamp application. The duration of aortic cross-clamping but not intravascular pressure is the pivotal factor. The integrity of the aortic media can be preserved if low-force cross-clamping is achieved.

Comparison of S100B and NSE Between Cardiac Surgery and Interventional Therapy for Children

This study aimed to compare the release of S100B and NSE between cardiac surgery and interventional therapy for children and to investigate whether S100B serum concentration correlates with cardiopulmonary bypass in children. For this study, 40 children with congenital heart disease were selected and assigned to two groups: group A (20 children undergoing surgical therapy) and group B (20 children undergoing interventional therapy). In group A, blood samples were drawn 10 min after the induction of anesthesia, immediately after aortic cross-clamping, immediately at the end of cardiopulmonary bypass (CPB), immediately at the end of the operation, then 6 and 24 h after the operation. In group B, blood samples were drawn 10 min after the induction of anesthesia, immediately at the end of the procedure, then 6 and 24 h after the procedure. In group A, S100B plasma levels during the perioperative period and 6 h after the operation were higher than the preoperative level (p < 0.05). The NSE plasma concentrations at the termination of CPB and postoperatively were higher than the preoperative level (p < 0.05). Significant correlation was found between the peak value of S100B at the termination of CPB and the durations of both CPB and aortic cross-clamping. In group B, the differences in S100B and NSE between the post- and preoperative levels were not statistically significant (p > 0.05). The perioperative cerebral impairment indirectly evaluated by the release of NSE and S100B protein is greater in children undergoing CPB than in children undergoing interventional therapy. The release of S100B had a strong correlation with the durations of CPB and aortic cross-clamping in children.

A Comparison of Beating Heart and Arrested Heart Techniques for Mitral Valve Replacement Surgery

Introduction There is growing interest in beating heart cardiac surgery (mainly myocardial revascularization) without aortic cross-clamping and, if possible, without the use of a cardiopulmonary bypass (CPB) pump, since better results can be obtained with this procedure than with conventional myocardial protection techniques using cardioplegic solutions. This led us to considerer mitral valve replacement (MVR) with beating heart and continuous coronary perfusion as a surgical option at the Cardiology and Cardiovascular Surgery Institute (ICCCV) in Havana, Cuba. Objective To assess the safety and potential benefits of beating heart MVR with continuous coronary perfusion compared to the conventional cardioplegic arrested heart MVR procedure. Methods A randomized, controlled intervention study was conducted with a sample of 64 patients referred to the ICCCV for isolated MVR between January 2001 and December 2002. Patients were randomly divided into 2 groups: control group A and study group B. Each group received a specific myocardial protection technique during surgery. Group A underwent MVR using the arrested heart technique with administration of a cold crystalloid cardioplegic solution and with moderately hypothermic CPB. Group B underwent MVR using the beating heart technique with normothermic CPB and continuous coronary perfusion. The following variables were assessed: serum enzyme (CK and CK-MB) and lactate concentrations; duration of aortic cross clamping, CPB, mechanical ventilation support, drainage, postoperative bleeding, stay in the surgical intensive care unit (SICU), and total operation time; amount of blood lost, blood adminstered, and postoperative complications. Quantitative variables were determined using Wilcoxon-Mann-Whitney add Student's t-tests. Results Differences between the two techniques were not found to be statistically significant, which suggests that both are equally safe. However, the differences found are clinically important and favor the beating heart technique, since patients who underwent beating heart MVR had lower serum concentrations of total CK, CK-MB and lactate; less total blood loss, and less need for transfusion. They also required less time on mechanical ventilation support in the SICU, spent fewer days in the hospital, and presented fewer postoperative complications compared to patients who underwent arrested heart MVR. Conclusion The beating heart technique with continuous coronary perfusion proved to be as safe as the conventional arrested heart technique with cardioplegic solutions for MVR surgery in patients with low surgical risk. This procedure is recommended as an alternative method of myocardial protection for this type of surgery in Cuba and may be considered as an option in other limited-resource settings.

Cardiopulmonary bypass management and acute renal failure: risk factors and prognosis

The aim of the study was to investigate if acute renal failure (ARF) following cardiac surgery is influenced by CPB perfusion pressure and to determine risk factors of ARF. Our research consisted of two studies. In the first study, 179 adult patients with normal preoperative renal function who had been subjected to cardiac surgery on CPB were randomized into three groups. The mean perfusion pressure (PP) during CPB in Group 65 (68 patients) was 60-69.9 mmHg, in Group 55 (59 patients) -- lower than 60 mmHg and in Group 75 (52 patients) -- 70 mmHg and higher. We have analyzed postoperative variables: central venous pressure, the need for diuretics, urine output, fluid balance, acidosis, potassium level in blood serum, the need for hemotransfusions, nephrological, cardiovascular and respiratory complications, duration of artificial lung ventilation, duration of stay in ICU and in hospital, and mortality. In the second study, to identify the risk factors for the development of ARF following CPB, we retrospectively analysed data of all 179 patients, divided into two groups: patients who developed ARF after surgery (group with ARF, n = 19) and patients without ARF (group without ARF, n = 160). We found that urine output during surgery was statistically significantly lower in Group 55 than in Groups 65 and 75. The incidence of ARF in the early postoperative period did not differ among the groups: it developed in 6% of all patients in Group 65, 4% in Group 55 and 6% in Group 75. There were no differences in the rate of other complications (cardiovascular, respiratory, neurological disorders, bleeding, etc) among the groups. There were 19 cases of ARF (10.6%), but none of these patients needed dialysis. We found that age (70.0 +/- 7.51 vs. 63.5 +/- 10.54 [standard deviation, SD], P = 0.016), valve replacement and/or reconstruction surgery (57.9% vs. 27.2%, P = 0,011), combined valve and CABG surgery (15.8% vs. 1.4%, P = 0.004), duration of CPB (134.74 +/- 62.02 vs. 100.59 +/- 43.99 min., P = 0.003) and duration of aortic cross-clamp (75.11 +/- 35.78 vs. 53.45 +/- 24.19 min., P = 0.001) were the most important independent risk factors for ARF. Cardiopulmonary bypass perfusion pressure did not cause postoperative renal failure. The age of patient, valve surgery procedures, duration of cardiopulmonary bypass and duration of aorta cross-clamp are potential causative factors for acute renal failure after cardiac surgery.

Risk Factors for Neurocognitive Dysfunction After Cardiac Surgery in Postmenopausal Women

Women are at higher risk than men for neurologic complications from cardiac operations. This study identified risk factors for neurocognitive dysfunction after cardiac operations in elderly women. One hundred thirteen postmenopausal women undergoing primary coronary artery bypass grafting, with or without valve operation, underwent psychometric testing and neurologic evaluation the day before operation and 4 to 6 weeks postoperatively. Risk factors assessed for neurologic complications included atherosclerosis of the ascending aorta and apolipoprotein epsilon4 genotype. Postoperative neurocognitive dysfunction was defined as the composite end point of a one standard deviation decrement from baseline on two or more psychometric tests or a new neurologic deficit. Neurocognitive dysfunction was present in 25% of the women 4 to 6 weeks postoperatively. Women with a neurocognitive deficit tended to be older than those without a deficit (72.1 +/- 8.1 vs 69.4 +/- 8.9 years, p = 0.144) and were more likely to have mild atherosclerosis of the ascending aorta, a history of congestive heart failure, longer duration of cardiopulmonary bypass (CPB) and aortic cross-clamping, lower nadir blood pressure during CPB, higher rates of postoperative atrial fibrillation, and longer postoperative hospitalization. Mild atherosclerosis of the ascending aorta, duration of CPB, duration of aortic cross-clamping (p = 0.051), and length of postsurgical hospitalization were independently associated with postoperative neurocognitive dysfunction. Mild atherosclerosis of the ascending aorta, duration of CPB, aortic cross-clamping time, and length of hospitalization, but not apolipoprotein epsilon4 genotype, identified risk for neurocognitive dysfunction after cardiac operation in postmenopausal women.

Brain natriuretic peptide in cardiac surgery — Influence of aprotinin

Background This study was designed to examine plasma concentrations of BNP and its correlations to the perioperative course in patients' cardiopulmonary bypass (CPB). Methods Sixty-five patients with coronary artery disease (CAD) undergoing CPB were examined. Pre, intra and postoperative BNP values and hemodynamic parameters were measured. Results The BNP peak correlated neither with any hemodynamic parameters, with the duration of aortic cross-clamping (AXCL), of the operation or with CBP-time, nor with the use of catecholamines. BNP values were significantly higher with the perioperative use of aprotinin. Conclusion These results confirm that the metabolism and biological activity of BNP may differ following CPB. An additional reason for increased postoperative BNP values might be the use of aprotinin.

Cerebral regional oxygenation during aortic coarctation repair in pediatric population

During repair of aortic coarctation, clamping of the transverse aortic arch proximal to the left common carotid artery occludes blood flow to the left carotid and vertebral arteries. The objective of the present study is to determine whether blood flow through the right carotid and vertebral arteries provides adequate cerebral blood flow during aortic cross-clamping, as assessed by near-infrared spectroscopy. In 11 consecutive children undergoing aortic coarctation repair through a standard posterolateral thoracotomy, regional cerebral oxygen saturation (cSO(2)) was measured using near-infrared spectroscopy. Six patients underwent an extended end-to-end repair, in which the aortic cross-clamp was placed in between the innominate and left common carotid arteries (extended repair group). Five patients underwent a standard end-to-end repair in which the cross-clamp was clamp placed between the left common carotid and subclavian arteries (standard repair group). After aortic clamping, there was a significant decrease in cSO(2) in the extended repair group, whereas the cSO(2) increased in the standard repair group (-9.2+/-12.2 vs 6.0+/-5.1%, extended vs standard repair groups, p=0.03). In the extended repair group, the cSO(2) decreased linearly during the aortic cross-clamping period (r(S)=-0.842, p<0.001), while in the standard repair group, the cSO(2) increased during the same time period (r(S)=0.786, p<0.001). Regression analysis identified the site of aortic cross-clamping as the sole independently significant variable explaining changes in the cSO(2) during aortic cross-clamping (p<0.03), whereas neither age nor duration of aortic cross-clamping was statistically significant. There were no postoperative neurological impairments in either group of patients. During aortic coarctation repair, aortic cross-clamping proximal, as compared to distal, to the left carotid artery is associated with significantly decreased regional cerebral oxygen saturation, as measured by near-infrared spectroscopy. Although no short-term clinical impairments were identified, long-term follow-up in a larger cohort is needed to study the effects of unbalanced cerebral oxygenation during clamping of the transverse arch. These data suggest that cerebral saturation monitoring is warranted, and may be indicative of cerebral hypoperfusion.

Arrhythmias after Fontan operation: comparison of lateral tunnel and extracardiac conduit

Background Arrhythmias are frequent causes of morbidity and mortality in patients with single ventricle physiology after Fontan operation. The aim of this study was to evaluate which type of Fontan procedure—lateral tunnel (LT) or extracardiac conduit (EC)—provides superior outcomes related to the problem of early postoperative and 1-year follow-up arrhythmias. Methods We retrospectively analyzed the incidence, types, and duration of rhythm disorders in 101 consecutive patients who received either LT (n = 60) or EC (n = 41) between April 1997 and March 2006 in Slovak Children's Cardiac Center, Bratislava (Slovakia). Weight, age, sex, and the type of heart morphology did not differ significantly between the 2 groups. The rhythm was monitored and documented perioperatively and postoperatively with standard electrocardiogram (ECG) recording and continual ECG monitoring. Duration of extracorporeal circulation, duration of aortic crossclamp and hemodynamic variables were analyzed with respect to the development of early arrhythmias in both groups. Twenty-four–hour ECG Holter monitoring (DMS 300-7, Holterreader, Producer DMS, Nevada, USA) was used to detect arrhythmias at the 1-year follow-up. Results Early postoperative rhythm abnormalities were identified in 31 patients (52%) who underwent LT and in 22 patients (54%) who underwent EC. The most frequent type of rhythm disturbance was junctional rhythm in both groups. The bivariate analysis revealed that there was no significant difference in the incidence, type, or duration of early onset arrhythmias between the 2 groups. Although, there was no significant difference in the duration of arrhythmia since the admission form the operating room. The need of aortic crossclamp was significantly lower in EC group ( P < .001). However, this did not correlate with lower incidence of early onset arrhythmias with EC modification. At the 1-year follow-up, the prevalence of arrhythmias was similar in both groups. Conclusions Extracardiac conduit as compared with LT does not provide superior outcomes related to the problem of early and 1-year onset arrhythmias. Other factors than the risk of early postoperative and early follow-up arrhythmias should be considered in surgical preference of modification strategy.

Systemic inflammatory complications after cardiopulmonary bypass (CPB): Influence of cytokines and complement system in correlation to endothelial activation

Objective: To investigate the role of cytokines and complement system in the inflammatory response after CPB we looked for correlations between cytokine-/complement-levels and clinical parameters. Methods: 40 consecutive CABG-patients were included in a prospective study. Blood samples were analyzed for CRP, PCT and for C3a and C5a. We also determined TNF-a, interleukin-1,-6,-8 and -10, as well as ET1, ICAM-1, ICAM-3, VCAM-1 and ELAM-1. Results: IL-1b was not elevated in the plasma at any sample time point. TNF-a was significantly increased in 4 patients after onset of CPB. 3 patients showed a significant TNF-elevation already preoperatively (268.5 pg/ml vs. <10 pg/ml in the other patients). In these 3 patients, which were the only to develop a severe SIRS, we also found significantly higher preoperative levels of ET1 (2.5±0.3 vs. 1.2±0.4 pg/ml), ICAM-1, ICAM-3 and ELAM-1. IL-6 and IL-10 rose significantly and peaked 88 respectively 50 minutes after end of CPB. C3a and C5a were significantly elevated during CPB with maximum levels 30 minutes after CPB. Peak values of IL-6 and -10 could be correlated to the duration of aortic crossclamping. Conclusions: CPB does not induce systemic release of TNF-a and IL-1b. A preoperative TNF-elevation in combination with an activation of the endothelium seems to be an indicator of an increased risk for systemic inflammation. Furthermore our results confirm the presence of complement activation preceding the production of IL-6 and IL-10. IL-6 may contribute to adverse systemic reactions after CPB, since its release could be correlated to the duration of myocardial ischemia.

Root Replacement Using Stentless Valves in the Small Aortic Root: A Propensity Score Analysis

Root replacement using a stentless bioprosthesis may be the optimal approach to avoid patient-prosthesis mismatch in patients with a small aortic root. Primary root replacement, however, is considered to be associated with increased surgical risk. We compared early outcome of full root replacement with a stentless bioprosthesis with that of aortic valve replacement with a stented bioprosthesis using propensity score-matching analysis. Of 231 patients undergoing elective, first-time aortic valve replacement with a small root (< or = 22 mm), 120 patients were selected using propensity score-matching analysis. They underwent either root replacement using a 23-mm stentless bioprosthesis (stentless group, n = 60) or supra-annular aortic valve replacement using a 21-mm stented bioprosthesis (stented group, n = 60). Preoperative characteristics and frequency of concomitant operations were identical. Duration of operation (196 +/- 54 versus 174 +/- 49 minutes), cardiopulmonary bypass (112 +/- 36 versus 91 +/- 33 minutes), and aortic cross-clamping (76 +/- 21 versus 61 +/- 21 minutes) were significantly longer in the stentless group. However, the need for perioperative transfusion and the incidence of postoperative reexploration for bleeding (3% versus 8%) was lower, and ventilation time was shorter. Mean duration of intensive care and hospital stay were also significantly shorter (2.3 +/- 1.7 versus 4.0 +/- 3.9 days, 8.9 +/- 3.1 versus 12.4 +/- 5.7 days). In-hospital mortality was identical (5% each). No independent predictor for in-hospital mortality was identified. Full root replacement using a stentless bioprosthesis does not increase postoperative morbidity or mortality of aortic valve replacement and may be advantageous in patients with a small aortic root.

Large-Dose Propofol During Cardiopulmonary Bypass Decreases Biochemical Markers of Myocardial Injury in Coronary Surgery Patients: A Comparison with Isoflurane

We investigated if increasing propofol's dosage to augment its antioxidant capacity during cardiopulmonary bypass (CPB) could confer cardiac protection. Fifty-four coronary artery bypass graft surgery patients were randomly assigned to small-dose propofol (Group P; n = 18), large-dose propofol (Group HiP; n = 18), or isoflurane Group (Group I; n = 18). After the induction, anesthesia was maintained with an inspired concentration of isoflurane 1%-3.5% (Group I) or a continuous infusion of propofol 60 microg x kg(-1) x min(-1) (Group P) throughout the surgery. In Group HiP, this dose of propofol was increased to 120 microg x kg(-1) x min(-1) for 10 min before the onset of CPB until 15 min after aortic unclamping and then decreased to 60 microg x kg(-1) x min(-1) until the end of surgery. The duration of aortic cross-clamping was 83 +/- 24, 88 +/- 22, and 81 +/- 20 min in Group P, Group HiP, and Group I, respectively (P > 0.1). Plasma malondialdehyde, a marker of oxidative stress, was significantly lower at 8 h after CPB, and Troponin I was lower at 24 h after CPB in Group HiP compared with Group P and Group I (P < 0.05). There was a significant reduction in inotropic requirements for separation from CPB in Group HiP compared with Group I. Postoperative systemic vascular resistance was significantly reduced in Group HiP as compared with Group I. Mean cardiac index was significantly higher at 24 h after CPB in Group HiP compared with Group P and Group I (P < 0.05) (Group I, 2.2 +/- 0.1; Group P, 2.3 +/- 0.2; and Group HiP, 2.8 +/- 0.3 L x min(-1) x m(-2), respectively). The duration of intensive care unit stay was significantly shorter in Group Hi-P compared with Group I. We conclude that administration of a large dose of propofol during CPB attenuates postoperative myocardial cellular damage as compared with isoflurane or small-dose propofol anesthesia.

Axillary cerebral perfusion for arch surgery in acute type A dissection under moderate hypothermia

Aortic arch surgery is still associated with increased mortality and morbidity especially in acute type A aortic dissection. Adequate brain protection is essential and commonly performed by either antegrade selective perfusion of the brachiocephalic arteries or an interval of profound hypothermic circulatory arrest. We present our experience for open aortic arch repair with continuous antegrade brain perfusion by means of direct cannulation of the right axillary artery, under moderate hypothermia in patients with acute type A aortic dissection. In, 25 consecutive patients (17 men) with a mean age of 62.6+/-14.8 years, aortic repair extended to the arch, for acute type A aortic dissection, was performed through a midline sternotomy. The right axillary artery was used for arterial systemic and brain perfusion at a rectal temperature of 25-27 degrees C. Mean duration of CPB and aortic cross-clamping was 241+/-55 and 155+/-72 min, respectively. The mean duration of circulatory arrest of the lower body and brain perfusion was 39.7 (range, 24-55 min). All the patients survived the procedure and all but one were discharged from hospital. One patient had left arm paralysis which he recovered the first postoperative month. There were no other transient or permanent neurologic deficits. A CT scan was performed at discharge for routine postoperative evaluation. There were no local neurovascular complications related to the cannulation site except for one local re-exploration for bleeding. The absence of any major permanent neurologic deficit or any visceral damages in our patients suggests that continuous moderate hypothermic cerebral perfusion, with an interval of circulatory arrest of the lower body, is adequate for acute type A aortic dissection surgery, allowing safe open repair of the distal aortic arch.

Mortality and Morbidity in HIV-Infected Patients Undergoing Coronary Artery Bypass Surgery: a Case Control Study

The use of highly active antiretroviral therapy (HAART) in patients with HIV infection has improved survival. This improvement combined with the metabolic effects of treatment has increased cardiovascular risk and the need for cardiac surgery in these patients. We compared morbidity and mortality in HIV-infected patients (cases, n=7) and non-HIV-infected patients (controls, n=21) who underwent isolated coronary artery surgery between 1997 and 2004. The durations of extracorporeal circulation and aortic cross-clamping were shorter in HIV-infected patients (P=.002 and P=.014, respectively). The percentage of patients who experienced complications was similar, at 57.1% in both groups, but there was a slightly higher number of complications per patient in non-HIV-infected individuals. The mean length of total hospitalization was greater in HIV-infected patients (27.1 [13.3] versus 8.8 [5.3] days; P=.003), as was that of postoperative hospitalization (18.2 [15.4] vs 7.9 [4.2] days; P=.08). No HIV-infected patient died or needed a repeat cardiac operation. No progression of the HIV infection was observed. Isolated coronary artery surgery in HIV-infected patients produces good results, and there is no increase in morbidity or mortality. Extracorporeal circulation did not influence disease progression.

Activation of Fibrinolytic Pathways Is Associated With Duration of Supraceliac Aortic Cross-Clamping

Activation of Fibrinolytic Pathways Is Associated With Duration of Supraceliac Aortic Cross-Clamping

Risk Factors Associated With Arterial Switch Operation for Transposition of the Great Arteries

The present study was undertaken to determine the risk factors for early mortality following an arterial switch operation. From January 1994 through October 2003, 78 pediatric patients underwent surgical repair. Simple transposition was present in 48 patients (61.5%), 29 (37.2%) had an associated ventricular septal defect, and one had a Taussig-Bing anomaly. The risk factors analyzed were: the patient's age and weight at the time of the intervention, repair of a coexisting ventricular septal defect, coronary artery anatomical pattern, duration of cardiopulmonary bypass, duration of aortic cross-clamping, and duration of circulatory arrest. All factors were evaluated for strength of association with the duration of mechanical ventilation, the length of intensive care unit stay, and mortality. Overall, the early mortality rate was 9% (7/78). Some 14 patients (17.9%) underwent simultaneous repair of a ventricular septal defect. Patients with an intramural coronary artery (n=3, 3.8%) or a single coronary ostium (n=5, 6.4%) were the only ones who had a significant (P<.05) mortality risk, at 50% (4/8). Circulatory arrest was implemented in 53 (68%) patients. There were significant correlations between the duration of circulatory arrest and the ventilator support time (r=0.3, P<.05) and the duration of stay in the intensive care unit (r=0.3, P<.05). The risk of early death was increased when more complex coronary artery anatomical variants were present. As the period of circulatory arrest lengthened, the mechanical ventilation time and duration of intensive care unit stay increased.

The Effect of Concomitant Radiofrequency Ablation and Surgical Technique (Repair Versus Replacement) on Release of Cardiac Biomarkers During Mitral Valve Surgery

All patients undergoing heart surgery experience a certain amount of nonspecific myocardial injury documented by the release of cardiac biomarkers and associated with poor outcome. We investigated the role of unipolar radiofrequency ablation of atrial fibrillation on the release of cardiac biomarkers in 71 patients undergoing mitral valve surgery and concomitant left atrial ablation case-matched with 71 patients undergoing isolated mitral surgery. The study was powered to detect a 3 ng/mL difference. There was no difference between the 2 groups in terms of cardiac troponin I (10 +/- 5.3 versus 12 + 10.4 ng/mL; P = 0.7) or creatine kinase-MB (50 +/- 21.8 versus 57 +/- 62.0 ng/mL; P = 0.5) release. Postoperative peak cardiac troponin I levels had univariate associations with the duration of cardiopulmonary bypass (P = 0.002) and aortic cross-clamping (P = 0.001) and with the surgical technique (15 +/- 12 ng/mL for mitral valve replacement versus 9 +/- 4.8 for mitral valve repair; P = 0.0007) at univariate analysis. Mitral valve replacement was the only independent predictor of postoperative peak release of cardiac troponin I identified with multivariate analysis (P = 0.005). Radiofrequency ablation of atrial fibrillation does not significantly increase cardiac biomarker release compared with isolated mitral surgery; mitral valve repair is associated with less release of cardiac biomarkers compared with mitral valve replacement.

Risk factors for prolonged ICU stay in patients following coronary artery bypass grafting with a long duration of cardiopulmonary bypass

Risk factors for prolonged stay in the intensive care unit (ICU) in patients following coronary artery bypass grafting (CABG) have been reported in many previous studies. However few have focused on circulatory and respiratory status as immediate postoperative risk factors. Therefore we examined immediate postoperative risk factors for prolonged ICU stay after CABG with a long duration of cardiopulmonary bypass (CPB). We studied retrospectively 100 consecutive patients undergoing elective CABG with CPB. Patients were excluded from this study if the duration of aortic cross-clamping was less than 60 min. Patients were divided into three groups according to the duration of the ICU stay. Patients in group A (n = 68) were discharged from the ICU on the next morning after surgery, those in group B (n = 19) stayed for 3 days, and group C (n = 13) stayed for more than 3 days. Perioperative variables were compared among the three groups and we demonstrated risk factors for prolonged (more than 3 days) ICU stay. There were significant differences in duration of CPB (157 +/- 34 versus 184 +/- 48 minutes, P < 0.05) and aortic cross-clamping (119 +/- 32 versus 141 +/- 40 min) between groups A and B. On the other hand, there were significant differences in age (62.8 +/- 7.8 versus 67.4 +/- 6.2 years), mean pulmonary artery pressure (MPAP) (17 +/- 2 versus 22 +/- 3 mmHg), and Pa(O2)/FI(O2) (PF ratio) (409 +/- 94 versus 303 +/- 108 mmHg) on admission to the ICU between groups A and C. There were no significant differences in intraoperative fluid balance and duration of CPB. Multiple logistic regression analysis identified age (>65 years), MPAP (>21 mmHg), and PF ratio (<300 mmHg) as independent risk factors for more than a 3-day ICU stay. Advanced age, increased MPAP, and decreased PF ratio on admission to the ICU were significant risk factors for a prolonged ICU stay of more than 3 days.

Diaphragmatic Paralysis after Endovascular Stent Grafting of a Thoracoabdominal Aortic Aneurysm

Diaphragmatic Paralysis after Endovascular Stent Grafting of a Thoracoabdominal Aortic Aneurysm

Myocardial Protection Using HTK Solution in Minimally Invasive Mitral Valve Surgery

Minimally invasive cardiac surgery (MICS) is a safe and satisfactory approach used mainly in mitral valve surgery with excellent results in many centers. Cardioplegia administration can be still a problem, especially when an endoaortic clamp is used. We retrospectively analyzed our early results with histidine-triptophane-ketoglutarate (HTK) solution used for myocardial protection in MICS. Between February 2003 and February 2004, 8 patients underwent mitral valve surgery using an endo- cardiopulmonary bypass (CPB) system and HTK solution as myocardial protection. The mean patient age was 67.7 +/- 9.2 years, and the preoperative ejection fraction was normal in all patients. Three patients had valve repair and 5 had valve replacement. Mean CPB time was 129.2 +/- 19.4 minutes, and aortic cross-clamp duration was 88.5 +/- 15.4 minutes. In every case HTK solution was used for only a single dose for cardioplegia at the beginning of the procedure, without any recalls. The heart restarted spontaneously at reperfusion in 6 of 8 cases (75%), and there were no significant modifications in electrocardiogram results or myocardial cytonecrosis enzymes (creatine kinase and its MB fraction) during the postoperative period. HTK solution is a cold crystalloid cardioplegia solution that has demonstrated its utility in MICS because it provides a safe long cardioplegic arrest time and it reduces the risk of inadequate coronary perfusion due to dislodgement of the endoaortic clamp.

Elective open abdominal aortic aneurysm repair: a seven-year experience

The seven-year experience of elective abdominal aortic aneurysm (AAA) repair of a vascular surgical unit in a teaching hospital was reviewed to determine the factors associated with in-hospital mortality. All patients who underwent elective open repair of an AAA between July 1, 1991, and June 30, 1998, were identified using International Classification of Diseases Ninth Revision (ICD-9) codes. Twenty-four variables were selected for investigation by reviewing the published literature and by discussion with local vascular surgeons. Data were obtained by retrospective medical record review. Variables were first analysed by univariate analysis, and those with a p-value up to 0.25 were included in multivariate analysis. Of the 219 patients reviewed, 8 (3.7%, 95% confidence interval, 1.6%, 7.1%) died during the admission. The mean age of patients was 69.9 years, and 81% of them were male. Univariate analysis found that female sex, renal artery involvement in the aneurysm, and aortic cross-clamp duration of 90 min or greater were significantly associated with mortality. Multivariate analysis found that female sex, use of a bifurcated graft, and performance of an additional procedure at the time of operation were the only variables independently associated with mortality. Use of a bifurcated graft was a significant prognostic variable on logistic regression analysis confirming that the technical difficulty of the operation and the morphology of the aneurysm are important factors in determining mortality. Why women may be at higher risk for death is unclear. This study also highlights that caution is required when interpreting raw audit data.