Central venous catheters may be a potential source of massive air emboli during vascular procedures involving extracorporeal circulation: an experimental study.

Central venous catheters are mandatory during every major procedure involving extracorporeal circulation. Air emboli potentially could enter the circulation through this device when negative pressure is applied in the venous cannula. The following experimental study was initiated by a fatal massive air embolus during a vascular procedure involving cardiopulmonary bypass. An experimental setup was established, simulating a real scenario. The experiment was performed with a 40% glycerol/water mixture which exhibits properties and fluid dynamics close to blood. A heart-lung machine provided circulation of the fluid. The flow was adjusted according to the gravitational status. A triple-lumen central venous catheter with one line open to air was lowered into the liquid. The disconnected lumen of the central venous catheter was manipulated so it approached and was located in close proximity to the venous cannula. An air flow of up to 300 ml/min could be obtained from the central venous catheter with a flow in the cardiopulmonary bypass circuit of 2.3 L/min. A linear relationship was observed between flow in the circuit and air flow. Consecutive measurements proved consistent with acceptable results, proving that a disconnected central venous catheter might, under certain circumstances, be a source of massive air emboli during cardiopulmonary bypass.

Transmyocardial revascularization with CO2 laser in patients with refractory angina pectoris. Clinical results from the Norwegian randomized trial.

OBJECTIVES: The purpose of the study was to evaluate clinical effects, exercise performance and effect on maximal oxygen consumption (MVO2) of transmyocardial revascularization with CO2-laser (TMR) in patients with refractory angina pectoris. BACKGROUND: Transmyocardial laser revascularization is a new method to treat patients with refractory angina pectoris not eligible for conventional revascularization. Few randomized studies comparing TMR with conventional treatment have been published. METHODS: One hundred patients with refractory angina not eligible for conventional revascularization were block-randomized in a 1:1 ratio to receive continued optimal medical treatment (MT) or TMR in addition to MT. The patients were evaluated at baseline and at three and 12 months with end points to symptoms, exercise capacity and MVO2. RESULTS: Transmyocardial laser revascularization resulted in significant relief in angina symptoms after three and 12 months compared to baseline. Time to chest pain during exercise increased from baseline by 78 s after three months (p = NS) and 66 s (p < 0.01) after 12 months in the TMR group, whereas total exercise time and MVO2 were unchanged. No significant changes were observed in the MT group. Perioperative mortality was 4%. One year mortality was 12% in the TMR group and 8% in the MT group (p = NS.) CONCLUSIONS: Transmyocardial laser revascularization was performed with low perioperative mortality and caused significant symptomatic improvement, but no improvement in exercise capacity.

Ultrafiltration after cardiopulmonary bypass in children: effects on hemodynamics, cytokines and complement.

OBJECTIVES: The purpose of the study was to evaluate the clinical and hemodynamic effect of intraoperative extracorporeal ultrafiltration (UF) and its potential in reducing the plasma concentration of circulating cytokines and complement activation products following open heart surgery in children. METHODS: Eighteen children with congenital heart disease were prospectively randomized into a control group (n = 9) and a group who underwent UF (n = 9). Serial plasma samples for measurements of circulating cytokines (interleukin 6 (IL-6), tumor necrosis factor alpha (TNF), and its soluble receptor (sTNF receptor)), and complement factors (C3 activation products (C3a and C3bc) and terminal complement complex (TCC)) were obtained before, during and up to 48 h after cardiopulmonary bypass (CPB). A pulmonary artery thermodilution catheter was introduced preoperatively for hemodynamic monitoring. RESULTS: Postoperative hemodynamics were similar in both groups. Plasma levels of IL-6, sTNF receptors, C3a, C3bc and TCC increased significantly perioperatively (P < 0.01) in both groups. TNF was detected transiently in 16 patients perioperatively and in 4 of the 9 ultrafiltrate samples in concentrations similar to the plasma levels. Complement activating products were not detected in the ultrafiltration samples except for small amounts of C3a in two cases. Compared to the control group the plasma levels of C3a, C3bc and TCC were unaffected by the ultrafiltration procedure. The level of IL-6 and sTNF receptors increased significantly after 15 min of UF but there was no significant difference between the two groups postoperatively. CONCLUSIONS: In this study no clinical or hemodynamic effect was registered after UF. TNF and C3a were occasionally detected in the ultrafiltrate but we were unable to demonstrate reduction of these or any of the other markers tested in the group subjected to ultrafiltration.

Is there a relationship between serum S-100beta protein and neuropsychologic dysfunction after cardiopulmonary bypass?

OBJECTIVES: Over the past decade, the glial protein S-100beta has been used to detect cerebral injury in a number of clinical settings including cardiac surgery. Previous investigations suggest that S-100beta is capable of identifying patients with cerebral dysfunction after cardiopulmonary bypass. Whether detection of elevated levels S-100beta reflects long-term cognitive impairment remains to be shown. The present study evaluated whether perioperative release of S-100beta after coronary artery operations with cardiopulmonary bypass could predict early or late neuropsychologic impairment. METHODS: A total of 100 patients undergoing elective coronary bypass without a previous history of neurologic events were prospectively studied. To exclude noncerebral sources of S-100beta, we did not use cardiotomy suction or retransfusion of shed mediastinal blood. Serial perioperative measurements of S-100beta were performed with the use of a new sensitive immunoluminometric assay up to 8 hours after the operation. Patients underwent cognitive testing on a battery of 11 tests before the operation, before discharge from the hospital, and 3 months later. RESULTS: No significant correlation was found between S-100beta release and neuropsychologic measures either 5 days or 3 months after the operation. CONCLUSION: Despite using a sensitive immunoluminometric assay of S-100beta, we found no evidence to support the suggestion that early release of S-100beta may reflect long-term neurologic injury capable of producing cognitive impairment.

Is atrial fibrillation caused by extracorporeal circulation?

BACKGROUND: Atrial fibrillation is the most common rhythm disturbance encountered after open heart operations, with a reported incidence up to 40%. Despite its high incidence and clinical relevance its etiology remains obscure. It has been hypothesized that atrial fibrillation might be related to extracorporeal circulation. We performed a retrospective study (January 1, 1997 to December 31, 1997) comparing the incidence of atrial fibrillation in 3 groups of patients revascularized with and without extracorporeal circulation. METHODS: The first group comprised patients with coronary artery disease operated on with standard revascularization technique with cardiopulmonary bypass (n = 685). The second group included patients who had minimally invasive coronary artery bypass grafting without the use of extracorporeal circulation (n = 19). Patients in the third group had off-pump transmyocardial laser revascularization (n = 19). RESULTS: There was no significant difference in the incidence of atrial fibrillation in the group that had conventional coronary artery bypass and the group that had minimally invasive coronary artery bypass without cardiopulmonary bypass. The incidence of atrial fibrillation was significantly lower in the transmyocardial laser group compared with the other two groups. CONCLUSIONS: The present study found that postoperative atrial fibrillation is not caused solely by extracorporeal circulation, but patients who had transmyocardial laser revascularization had a significantly lower incidence of atrial fibrillation.

Is there a relationship between cognitive dysfunction and systemic inflammatory response after cardiopulmonary bypass?

BACKGROUND: The systemic inflammatory reaction (SIR) is assumed to be one of the factors that causes cerebral dysfunction after cardiopulmonary bypass (CPB). The aim of the present study was to evaluate the relationship between the SIR and postoperative cognitive performance at 5 days and 3 months. METHODS: One hundred patients undergoing coronary artery bypass grafting were studied. Inflammatory markers and markers of coagulation and fibrinolysis were determined at several time points during and after the operation. Correlation analysis between maximum levels of the different markers and early and late performance was performed. RESULTS: No overall association was found between the maximum levels of the inflammatory markers and early and late function. CONCLUSIONS: Notwithstanding limitations of statistical power established markers of systemic inflammatory reaction showed no relationship with outcome at 5-day or 3-month follow-up in this subset of patients.

Mechanical bridge to recovery in fulminant myocarditis.

A patient with acute fulminant lymphocytic myocarditis and cardiogenic shock was successfully treated by mechanical off loading of the left ventricle. A nonpulsatile left-heart bypass was undertaken with an implantable centrifugal blood pump. Careful weaning resulted in device removal on the seventh day. Left and right ventricular function is sustained at 7 months. Widespread application of this method depends on the availability of an inexpensive user friendly blood pump, appropriate weaning protocols and emerging strategies to promote sustainable myocardial recovery.

Perioperative cardiac function and predictors for adverse events after transmyocardial laser treatment.

BACKGROUND: Previous studies have reported that mortality and morbidity after transmyocardial laser treatment (TML) mainly occur perioperatively. The present study was designed to evaluate left-ventricular function and identify risk factors for cardiac-related adverse events in this phase. METHODS: Forty-nine patients were studied. The inclusion criteria were angina pectoris Canadian Cardiovascular Society Angina Score (CCSAS) class III and IV refractory to medical therapy and untreatable by coronary artery bypass graft or percutaneous transluminal coronary angioplasty, age less than 75 years, left ventricular ejection fraction greater than or equal to 30%, and myocardial regions with reversible ischemia. Hemodynamic data and cardiac adverse events were registered. The follow-up time was 30 days. RESULTS: A transient decrease in mean cardiac index (CI) was observed, reaching its minimum immediately after end of the surgical procedure (1.8+/-0.4, p<0.01 vs. baseline). Two patients (4%) died during the postoperative period (30 days). Seventeen patients (35%) experienced adverse cardiac-related events, where CCSAS class IV, unprotected left main stem stenosis, and diabetes mellitus were identified as risk factors in a multivariate analysis. CONCLUSIONS: A transient impairment of left ventricular function was observed after TML. The morbidity and mortality after TML were almost exclusively cardiac-related, identifying CCSAS class IV, unprotected left main stem stenosis, and diabetes as risk factors.

The CarboMedics valve: midterm follow-up with analysis of risk factors.

BACKGROUND: This study examined the midterm results with the CarboMedics prosthetic valve. METHODS: From 1987 through 1991 a total of 569 patients received the CarboMedics prosthesis. RESULTS: Early mortality was 4.9% and related to emergency operation, presence of diabetes mellitus, coronary artery disease, preoperative New York Heart Association class, duration of cardiopulmonary bypass, and aortic cross-clamp time. Midterm follow-up with respect to mortality was 100% complete. All patients were followed up in the hospital after 1 year. In addition 86% of the patients responded to a questionnaire. Mean follow-up was 3 years (range, 0 to 5.6 years). Cumulative survival at 1 and 4 years was 91.2% +/- 1.2% and 83.7% +/- 1.8%, respectively. Five patients experienced obstructive valve thrombosis (0.3%/patient-year), 16 patients had major thromboembolic events (0.9%/patient-year), and 10 patients had major warfarin-related bleeding (0.6%/patient-year) requiring hospitalization or blood transfusions. Eight patients were reoperated on for paraprosthetic leak (0.4%/patient-year). Prosthetic valve endocarditis developed in 4 patients (0.2%/patient-year). No structural valve failure was observed. CONCLUSIONS: Midterm follow-up demonstrates that the CarboMedics mechanical prosthesis is reliable and has an acceptable rate of valve-related complications.

Mechanical valve replacement in congenital heart disease.

BACKGROUND AND AIMS OF THE STUDY: Mechanical valves are the prosthesis of choice in valve replacement in children. However, the problem of somatic growth leading to patient-valve mismatch remains present, and the appropriate anticoagulation regimen remains controversial. We present our experience of valve replacement in a young population over 20 years. MATERIALS AND METHODS: Between 1972 and 1992, 48 patients (34 males and 14 females), mean age 11.2 years (range 0.4-27.4 years), underwent mechanical valve replacement at our institution. Aortic valve replacement was performed in 28 patients (58.3%), mitral valve replacement in 13 (27.1%), tricuspid valve replacement in six (12.5%) and pulmonary valve replacement in one patient (2.1%). The prostheses used were: St. Jude Medical (n = 2), Björk-Shiley (n = 14), Medtronic Hall (n = 16), Duromedics (n = 2) and CarboMedics (n = 14). Early mortality was 14.3%, 10.7% for aortic valve replacement and 30.8% for mitral valve replacement. Mean follow up for all patients was 8.3 years (range 0-22 years), with a total of 398 patient-years. RESULTS: Seven patients died during the follow up (17.1%). Survival after 10 years, including operative mortality, was 81% for aortic valve replacement, 33% for mitral valve replacement, 83% for tricuspid valve replacement and 100% for pulmonary valve replacement. All patients were anticoagulated with warfarin. In eight patients (16.7%) an antiplatelet drug (aspirin or dipyridamole) was added. Major events included paravalvular leak in six patients (1.5%/pty), valve thrombosis in five (mitral position in two, tricuspid in three) (1.3%/pty) and endocarditis in one patient (0.3%/pty). Minor thromboembolic events occurred in three patients (0.8%/pty) and minor hemorrhagic events in three (0.8%/pty). No patients developed hemolytic anemia and there was no case of structural failure. CONCLUSIONS: In our experience, mechanical prostheses in congenital heart disease were associated with significant morbidity and mortality, however long term survival after aortic valve replacement was good (81% at 10 years). Thromboembolic and hemorrhagic events were of minor significance. Atrio-ventricular valve replacement carried the highest risk of valve thrombosis and we now give warfarin and an antiplatelet drug to children undergoing mechanical valve implantation in this position.

Spondyloarthritis: a strong predictor of early coronary artery bypass grafting.

OBJECTIVES: The main aim of the study was to examine whether patients with spondyloarthritides underwent their first coronary artery bypass grafting (CABG) at a younger age than those without spondyloarthritides. METHODS: Patients who underwent their first CABG at the Feiring Heart Clinic during 2001-2005 were preoperatively screened for spondyloarthritides, and the cardiological assessment was registered. We compared the characteristics of patients with and without spondyloarthritides. RESULTS: Of the 3852 patients undergoing their first CABG, 30 (0.78%) had spondyloarthritides. No statistically significant differences in traditional cardiovascular risk factors were found. The mean ages of patients with and without spondyloarthritides were 60.1 (SD = 8.7) and 66.9 (SD = 10.1) years, respectively. Spondyloarthritis was found by multivariate analysis to be a stronger independent predictor of early CABG than traditional cardiovascular risk factors [adjusted beta -6.2, p<0.001, 95% confidence interval (CI) -9.5 to -2.8]. Sixty per cent of spondyloarthritis patients and 52% of control patients had already suffered a myocardial infarction (p = 0.4). CONCLUSION: Spondyloarthritis was a stronger predictor of early CABG than most of the registered traditional cardiovascular risk factors. The prevalence of spondyloarthritis seemed to be higher in the CABG population than in the general population. These findings may indicate accelerated coronary artery disease (CAD) in spondyloarthritides.

[Serious complications related to use of corn starch powder on surgical gloves]. / Alvorlige komplikasjoner ved bruk av maisstivelse på kirurgiske hansker.

Cornflour has been used as a lubricant on surgical gloves since 1947. Serious complications have been reported after deposition of cornflour powder in the human body. The best known complication is granulomatous peritonitis, but cornflour granulomas have also been found in the heart, the kidneys and the central nervous system. Maltesercross, when seen in polarized light in the microscope, is pathognomonic. Malignancy and other granulomatous inflammations are actual differential diagnoses. Nowadays gloves free of lubricating powder are commercially available.

Depressed thyroid function following paediatric cardiopulmonary bypass: association with interleukin-6 release?

Cellular activation with release of cytokines such as interleukin-6 (IL-6) occurs during cardiopulmonary bypass. IL-6 regulates a number of physiologic processes, and a possible role of IL-6 was recently postulated in the pathogenesis of changes in serum thyroid hormone concentrations in patients with nonthyroidal illness. The perioperative concentrations of triiodothyronine (T3) and IL-6 were determined in ten children undergoing open-heart surgery. Significant fall in T3 concentration was found postoperatively, while IL-6 increased significantly, peaking 2 hours postoperatively. The total accumulated IL-6 level 2 hours postoperatively was correlated to postoperative T3 concentration. A significant inverse correlation was found between T3 levels 24 and 48 hours postoperatively and total accumulated IL-6, and also between the percentage decrease in T3 concentrations and total accumulated IL-6. IL-6 release thus correlated inversely to T3 levels after cardiopulmonary bypass.

Pericardio-peritoneal window for recurrent postoperative effusion. Case report.

A pericardio-peritoneal window was created to relieve cardiac tamponade by recurrent effusion after heart transplantation. The effect was echocardiographically evaluated. The technique is described. It requires no sternal splitting for pericardial access and no foreign materials such as drains or shunts. The method should be considered for immunologically compromised, infection-prone patients with heart transplantation.

[Ogilvie syndrome]. / Ogilvies syndrom.

Ogilvie's syndrome, or acute colonic pseudo-obstruction, is clinically impossible to differentiate from mechanical colonic ileus. Ogilvie's syndrome is associated with several conditions but the most common associated factor is surgery. Earlier, coecostomi or colostomy was the treatment of choice but most experts will agree that, although several methods of treatment have been proposed, the one now to be preferred is deflation by a colonoscope.

[Treatment of rectal prolapse. Perineal rectosigmoidectomy using a suture machine]. / Behandling av rectumprolaps. Perineal rektosigmoidektomi med suturmaskin.

More than 50 operations designed for the treatment of complete rectal prolapse have been reported. Perineal rectosigmoidectomy using autosuture devices was first described by Vermeulen et al in 1983. During the last two years we have used this technique at Gjøvik County Hospital. We believe it to be a good alternative in patients where a transabdominal approach is unsuitable. The method is described in detail and illustrated by figures.

[Thrombolysis in acute tricuspid valve thrombosis]. / Trombolyse ved akutt trombosert trikuspidalventil.

The usual treatment of acute heart valve thrombosis is thrombectomy or heart valve replacement. During the last 20 years there have been a few reports of thrombolytic treatment for heart valve thrombosis. We report the successful treatment of two patients with a thrombosed tricuspid heart valve. Both patients received streptokinase. The diagnosis of heart valve thrombosis was based on the clinical status of the patients, cineradiology and echocardiography. Both patients received the combination of salicylic acid and warfarin after streptokinase treatment. Follow-up has shown well functioning heart valves in both patients.

[Placebo effect in research related to surgery and technical procedures]. / Placeboeffekt ved kirurgisk og prosedyrerelatert klinisk forskning.

BACKGROUND: Development of new technology has led to the introduction of many new high-tech surgical treatment modalities. It has been claimed that the use of high-tech medicine is a potent inductor of placebo effect; in fact, many new treatment modalities have been established before they have been evaluated in placebo-controlled trials. However, there are several ways to minimize the confounding effects of placebo in surgical trials. MATERIAL AND METHODS: This is a review based on a thoroughly performed search on Medline of Norwegian and English language publications published up until August 2000. RESULTS: Several studies have demonstrated that surgical treatment induces significant placebo effect. To minimize the confounding effects of placebo in trials evaluating new surgical modalities, it is important to use adequate blinding, neutral patient information, objective end-points, and correction for estimated placebo effects. The use of placebo surgery has been a source of lively controversy; many consider it ethically unacceptable.