Effect of ultrafiltration during cardiopulmonary bypass for pediatric cardiac surgery

The effect of ultrafiltration during cardiopulmonary bypass (CPB) was evaluated for correcting ventricular septal defects with associated pulmonary hypertension in patients less than 18 months old. Interleukin (IL)-6 and IL-8 concentrations in the blood, ultrafiltrate, and urine were measured. The blood IL-6 concentration increased to 128.4+/-20.2 pg/ml by the end of surgery, which is lower than the concentration seen in adult patients (273.1+/-48.2 pg/ml, p < 0.02). The blood IL-8 concentration was not significantly different than that of adults. The total amounts of excreted IL-6 in the ultrafiltrate and urine during CPB were 11.5+/-0.32 pg/kg and 0.32+/-0.07 pg/kg, respectively (p < 0.05). The total amounts of excreted IL-8 in the ultrafiltrate and urine were 4.64+/-0.69 pg/kg and 1.92+/-0.56 pg/kg, respectively (p < 0.05). No differences were seen in these values for excretion between children and adults. We conclude that ultrafiltration during CPB in pediatric patients is more effective in removing proinflammatory cytokines than in adults and more effective than renal filtration alone.     

Minimally invasive coronary artery bypass grafting without cardiopulmonary bypass

To determine the feasibility and the effectiveness of minimally invasive direct coronary artery bypass without cardiopulmonary bypass (MICABG) in patients with left anterior descending (LAD) coronary artery disease, we evaluated 90 consecutive patients who underwent MICABG at the University Hospital of Groningen. PATIENTS: Between January 1995 and December 1996, 50 patients (mean age 60 +/- 10.3 years) with documented myocardial ischemia and isolated stenosis of the LAD were selected for MICABG. Patients with any associated cardiac disease or with acute or evolving myocardial infarction were excluded. METHODS: A small left antero-lateral thoracotomy in the 5th intercostal space was made in all patients, anastomosing the left internal mammary artery (LIMA) to the LAD. A short-term (3 days) postoperative rehabilitation programme was used. Emotional stress (STAY-DY-1 score), wound pain (VAS: visual analogue score) and O2-saturation after a 6 min walking test were measured during hospitalisation and at the first follow-up examination (2.5 week after discharge). RESULTS: Mean operative time was 92 +/- 25 min (range 60-170). We recorded 1 (1.1%) in-hospital death and three cases (3.3%) of perioperative myocardial infarction. In two cases the MICABG was converted to the midline sternotomy. One patient underwent urgent reoperation on postoperative day 1 via midline sternotomy. Mean hospital stay was 4.4 +/- 2 days. Emotional stress was significantly reduced during and after hospitalisation, compared with the admission day. Wound pain was mild (3.5/10 VAS) on postoperative day 1 and reduced significantly during hospitalisation and at first follow-up examination. O2-saturation after a 6 min walking test had significantly improved at the first follow-up examination. CONCLUSION: These results indicate that MICABG is feasible and effective in patients with LAD stenosis and leads to a fast psycho-physical recovery.     

Increasing the colloid osmotic pressure of cardiopulmonary bypass prime and normothermic blood cardioplegia minimizes myocardial oedema and prevents cardiac dysfunction

Various mutations in the fibroblast growth factor receptor 3 (FGFR3) gene have recently been reported in thanatophoric dysplasia (TD). We examined the clinical, radiographic, and histologic findings in 91 cases from the International Skeletal Dysplasia Registry and correlated them with the specific FGFR3 mutation. Every case of TD examined had an identifiable FGFR3 mutation. Radiographically, all of the cases with the Lys650Glu substitution demonstrated straight femora with craniosynostosis, and frequently a cloverleaf skull (CS) was demonstrated. In all other cases, the femora were curved, and CS was infrequently present but was occasionally as severe as TD with the Lys650Glu substitution. Histopathologically, all of the cases shared similar abnormalities, but cases with the Lys650Glu substitution had better preservation of the growth plate. Cases with the Tyr373Cys substitution tended to have more severe radiographic manifestations than the Arg248Cys cases, but there was overlap in the phenotypic spectrum between them. One common classification of TD distinguishes affected infants based on the presence or absence of CS. In contrast, and as originally proposed by Langer et al. [1987: Am J Med Genet 3: 167-179], our data suggest that TD can be divided into at least two groups (TD1 and TD2) based on the presence of straight or curved femora. The variable presence of CS and severity of the radiologic and histologic findings in the other substitutions may be due to other genetic, environmental, or stochastic factors.     

Unusual dyskinesia complicating cardiopulmonary bypass surgery

Four infants developed dyskinesia after cardiopulmonary bypass surgery three to four days postoperatively. The dyskinesia was choreoathetotic, and involved mainly the mouth, tongue and face. It was absent during sleep. Three of these infants improved over periods of several weeks, but one infant remained dyskinetic one year postoperatively. Neuro-imaging studies and EEGs were of little value in determining the cause of the dyskinesia. The factors responsible for the involuntary movements and for their severity remain unexplained.     

Continuous, less invasive, hemodynamic monitoring in intensive care after cardiac surgery

The aim of radioimmunotherapy in treating solid tumors is to target tumor sites while sparing normal tissues. This can best be achieved by using a monoclonal antibody (MAb) with high tumor uptake and rapid clearance. Because MAbs are basic, positively charged proteins, and mammalian cells are negatively charged, the electrostatic interactions between the two can create higher levels of background binding resulting in low tumor to normal organ ratios. To overcome this effect, investigators have attempted to improve MAb clearance by using various methods such as secondary agents as well as chemical and charge modifications of the MAb itself. The use of a second agent to remove the MAb involves using a biotinylated MAb followed by treatments with a molecule like avidin. Charge modification can be accomplished by conjugating a chemical moiety with a positive, negative or neutral charge to residues exposed on the surface of MAbs. Experimental results demonstrate that the lowering of the isoelectric point by this method correlates with a decreased clearance time and improved tumor targeting. Altering the pharmacokinetic characteristics of intact MAbs with charge modification can improve their clearance times to rates similar to those of MAb fragments. Several groups have reported on the effects of chemical modification using molecules such as dextran, PEG, lactose and biotin. Some of these modified MAbs retain the antigen binding specificity of the parent molecule and have improved clearance characteristics from blood and other organs. Hence, these methods can be used to improve both the diagnostic and therapeutic potential of MAbs by improving the signal to noise ratio and the absolute tumor accretion of MAb, respectively.     

The acute abdomen following cardiopulmonary bypass surgery

Over a 5-year period, 9 patients (0.85 per cent) developed a major acute abdominal complication after cardiopulmonary bypass surgery. Difficulties in the initial recognition and diagnosis of these complications in sedated, ill patients are highlighted. A high index of suspicion is important in the early diagnosis of these complications. The numbers are too small for statistical analysis, but experience suggests that each case should be dealt with on its merits in accordance with common surgical practice and that operative management should not be rejected because the patient has recently undergone a major cardiac operation.     

Minimally invasive cardiac surgery

In a short period of time, tremendous progress has been made in the field of minimally invasive cardiac surgery. The goal of true "minimally invasive" cardiac surgery should be a totally thoracoscopic or transvascular procedure that allows a very short hospital stay and prompt patient recovery at acceptable costs. To accomplish this goal, efforts to miniaturize and refine instrumentation/cannulae/visualization and the development of innovative new techniques must be pursued. The concept of performing intracardiac repair of a variety of pathologies on the beating heart is under investigation and will require a new generation of technology, which will include through-blood imaging, such as blood displacement videoscopes, and task-specific instruments. Robotics may offer additional assistance in the performance of complex and fine maneuvers.     

Elimination of cardiopulmonary bypass: a prime goal in reoperative coronary artery bypass surgery

OBJECTIVE: The purpose of this study was to evaluate morbidity and mortality in reoperative coronary artery bypass surgery using the New York State database. METHODS: Patients undergoing reoperative coronary artery bypass between January-1995 and December 1996 were included. Patients were operated using cardiopulmonary bypass (CPB group, n = 184) or without cardiopulmonary bypass (non-CPB group, n = 105) by surgeon preference. Groups were compared for preoperative risk factors, postoperative mortality and major complications. RESULTS: Crude mortality was lower in the non-CPB group, despite a higher expected mortality, resulting in a risk-adjusted mortality of 1.3% versus 2.7% for the CPB group (NS). Of non-CPB patients, 91.4% were without complications, while only 72.1% of CPB patients (P < 0.0001) were complication-free. Major complications were significantly reduced in non-CPB patients compared to CPB patients: stroke 0% versus 3.8% (P < 0.04), cardiovascular complications 4.8% versus 15.8% (P < 0.005), other major complications 1.9% versus 10.4% (P < 0.007). Postoperative IABP support was needed in 1.9% of the non-CPB group patients and in 14.2% of the CPB group (P < 0.0007). CONCLUSIONS: The main object of reoperative CABG is to relieve symptoms, since the survival benefit of the procedure has not been demonstrated. Performance of reoperative coronary artery bypass surgery without cardiopulmonary bypass significantly reduces morbidity. We conclude that cardiopulmonary bypass should be avoided whenever possible in reoperative coronary bypass surgery.     

Minimally invasive cardiac surgery: current status and perspective

This study investigated the features of calf deep vein thrombosis (DVT) as a pulmonary embolic source. Fifty-eight lower limbs in 29 patients who were suspected of having DVT distal to the popliteal vein were screened by ultrasonography. Then, ascending venography was performed to confirm the diagnosis. Pulmonary embolism (PE) was diagnosed in suspected patients by use of pulmonary perfusion scanning or pulmonary angiography. Venography revealed calf DVT in 33 limbs in 28 patients. Of 28 patients, six had symptomatic PE. Thrombosis was found in the muscle veins in 18 limbs, the trunk veins in 11, and both veins in four. Isolated single vein thrombosis was found in the soleal vein in 14 limbs (42%), the posterior tibial vein in eight, the peroneal vein in two, and the gastrocnemius vein in two. The overall percentage of soleal vein thrombi was 61%. All six patients with symptomatic PE had isolated soleal vein thromboses. Calf DVT was a pulmonary embolic source when isolated thrombosis of the large soleal vein was more than 7 mm in diameter. Soleal veins were the most frequent and important location of calf DVT, suggesting that these were an occasional embolic source of critical PE.     

Minimally invasive pediatric cardiac surgery

We quantitatively studied the role of periosteum and bone marrow-endosteum during lengthening in 18 growing rabbits, comparing four surgical procedures: 1) periosteum and bone marrow preservation, 2) periosteum preservation, bone marrow destruction, 3) periosteum destruction, bone marrow preservation, 4) periosteum and bone marrow destruction. An external fixator was set on one femur, the other serving as a control. Distraction began on day 5 and stopped on day 25 (0.25 mm/12 hours). On day 30, femora were harvested with a layer of muscle. Area, bone mineral content and density were measured by dual-energy x-ray absorptiometry. Procedure 2 showed the highest increase in bone mineral content around the elongated callus (127%) compared to procedures: 1 (81%), 3 (25%) and 4 (-8%, i.e., resorption of bone ends). A statistically significant effect on bone formation was observed when preserving (vs. destroying): 1) periosteum, 2) bone marrow (effect observed only around the distraction gap), 3) periosteum and bone marrow in combination. Periosteum alone forms a larger callus, with more mineral content than bone marrow alone, and destruction of both results in the absence of bone formation around the distraction area. Careful preservation of periosteum is essential to bone healing. Formation of bone with a large mineral content does not require bone marrow preservation, but there is an interaction effect on healing between bone marrow and periosteum.     

Can retrograde cardioplegia alone provide adequate protection for cardiac valve surgery?

Pretreatment of rats with the extract of Ginkgo biloba termed EGb761 reduced the behavioral sensitization induced by successive D-amphetamine administrations (0.5 mg/kg) as estimated by increasing values of locomotor activity. EGb761 pretreatment also prevented the reduced density of [3H]dexamethasone binding sites in the dentate gyrus and the CA1 hippocampal regions of D-amphetamine treated animals. These observations suggest that EGb761, by reducing glucocorticoid levels, could modulate the activity of the neuronal systems involved in the expression of the behavioral sensitization.     

Uncoupling of human cardiac beta-adrenoceptors during cardiopulmonary bypass with cardioplegic cardiac arrest

BACKGROUND: It is well known that during cardiopulmonary bypass (CPB) with cardioplegic cardiac arrest, catecholamines are vigorously increased. We therefore investigated whether this might cause desensitization of human cardiac beta-adrenoceptors. METHODS AND RESULTS: We assessed in 12 children with acyanotic congenital heart disease who underwent open-heart surgery right atrial beta-adrenoceptor number and subtype distribution [by (-)-[125I]iodocyanopindolol binding] and adenylate cyclase activation [by the beta-adrenoceptor agonist isoprenaline (100 microM) and by the non-receptor-mediated activators 10 microM GTP, 10 mM NaF, 100 microM forskolin, and 10 mM Mn2+] before and after CPB with cardiac arrest by means of St. Thomas' cardioplegic solution. CPB affected neither beta-adrenoceptor number of subtype distribution nor GTP-, NaF-, forskolin-, or Mn(2+)-induced activation of adenylate cyclase. In contrast, activation of adenylate cyclase by 100 microM isoprenaline was significantly (p = 0.0249) lower after CPB than before CPB. CONCLUSIONS: CPB with cardioplegic cardiac arrest decreases beta-adrenoceptor-mediated adenylate cyclase activation in a manner compatible with an uncoupling of beta-adrenoceptors from the Gs-protein-adenylate cyclase complex. Such a beta-adrenoceptor desensitization may be the reason why after CPB many patients need inotropic support but do not respond sufficiently to catecholamines.     

Minimally invasive direct coronary artery bypass surgery

Traditional coronary artery bypass surgery involves a median sternotomy and the use of a heart-lung machine to stabilize the heart during suturing. Minimally invasive coronary artery surgery employs small incisions directly over the target vessels and avoids the use of a heart-lung machine, which can cause postoperative complications. The target coronary vessels are stabilized in alternative ways, potentially hazardous manipulation of the ascending aorta is avoided, and the subclavian and axillary arteries provide alternative inflow sources. Other new techniques used in minimally invasive procedures include a coronary artery cannula to avoid intraoperative ischemia and wound irrigation catheters to administer postoperative bupivacaine hydrochloride. Perioperative nurses need to become familiar with these new techniques to be able to plan and implement effective patient care.     

Complement activation, cytokines, and adhesion molecules in children undergoing cardiac surgery with or without cardiopulmonary bypass

Although obsessive-compulsive disorder (OCD) is often considered a heterogeneous condition, there is no generally accepted subtype typology. Cluster analysis was used to identify definitive symptom-based groupings of 106 OCD patients. A stable cluster solution was achieved and five patient subgroups were identified based on their pattern of symptoms on the Yale-Brown (Y-BOCS) symptom checklist: harming, hoarding, contamination, certainty and obsessionals. The five subgroups were characterized by dominant symptom patterns and significant secondary concerns reflecting the symptom heterorgenaity often seen in the clinical presentation of obsessional patents. Between cluster differences on multiple symptom measures were evaluated and several meaningful differences were identified. Cluster analytic procedures may prove to be a useful tool for identifying a functional taxonomy of OCD subtypes.     

Assessing postoperative cognitive change after cardiopulmonary bypass surgery.

Cognitive decline after cardiopulmonary bypass (CPB) surgery has been a concern since the advent of CPB procedures. A primary focus of many studies on this topic has been to quantify the incidence of post-CPB cognitive impairment. However, studies that have used traditional parametric statistics have generally failed to confirm that long-lasting (–- I month) cognitive declines occur reliably after CPB surgery. For the present study, the authors used a split-plot analysis of variance model that revealed preoperative memory impairments in the CPB patients and new postoperative impairments of attention. The authors discuss the assumptions of, and problems associated with, analysis methods that are often used to quantify the incidence of cognitive impairment following CPB surgery. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Necrotizing enterocolitis after open heart surgery employing hypothermia and cardiopulmonary bypass

Three patients, 1-11 months of age, who underwent open heart surgery with cardiopulmonary bypass and profound hypothermia, developed necrotizing enterocolitis postoperatively leading to death. Pneumatosis intestinalis and portal vein gas were demonstrated radiographically. Necrotizing enterocolitis has not been previously reported as a complication of cardiopulmonary bypass and profound hypothermia.     

Platelets and cardiopulmonary bypass

Exposure of blood to an extracorporeal circulation, such as CPB, causes a variety of physiological responses. Haematological derangements are just one of many potential dangers to the patient who undergoes CPB. The paradox of CPB-related problems with the haematological system is that there are some factors tipping the balance towards a bleeding tendency, and others that favour a prothrombotic state. Both of these issues must be dealt with independently to create the safest environment for surgery. It has been demonstrated that platelets play a key role in both haemostatic dysfunction and thrombotic complications of CPB. Much has been achieved, both clinically and in the laboratory, in the understanding of the precise role platelets play in these events, but the exact mechanisms involved have yet to be completely identified. As research progresses, our understanding will increase, but until then clinical practice must be dictated by the current evidence available.     

Facile minimally invasive cardiac surgery via ministernotomy

BACKGROUND: The public's and surgeons' perception of minimally invasive operations are frequently at odds. Nevertheless, real or perceived benefits may result from limiting skin and skeletal trauma. METHODS: Beginning in January 1996, we began approaching most infant and pediatric open heart procedures through an upper sternal split incision using a 1- to 3-inch skin opening and then extended this technique using a 2.5- to 3.5-inch incision for adult aortic and mitral valve replacement. RESULTS: A total of 82 patients, 57 infants and children and 25 adults, have been operated on using this approach (age range, newborn to 81 years). Operations accomplished through ministernotomy have included aortic valvotomy, arterial switch, tetralogy of Fallot, atrial or ventricular septal defect closure, aortic valve replacement, mitral valve replacement and repair, redo aortic or mitral valve replacement, double valve replacement, aortic root replacement, and complex arch reconstruction. In adults, the sternum was divided and then a T incision was made at the second, third, or fourth intercostal space. The mitral valve was reached through the roof of the left atrium. In children, a lower sternal split was used for atrial septal defect repairs. All cannulas were introduced through the ministernotomy incision, eliminating femoral cannulation. No new instruments, retractors, or ports were used. Mediastinal drainage was accomplished through a Blake drain connected to Heimlich-valved grenade suction. All but 2 patients were extubated immediately. Hospital stay was from 1 to 20 days (median 2 days). Patient and family acceptance is very high. CONCLUSIONS: On the basis of this initial experience, we attempt all congenital cardiac and isolated adult valve operations through ministernotomy.