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Biomedical subjects

O R Geiran

Publications and source records attributed to O R Geiran.

36 records · Page 2Linked to original sources
PubMed1998

Minimally invasive direct coronary artery bypass grafting without cardiopulmonary bypass in combination with intraoperative percutaneous transluminal coronary angioplasty for palliative coronary revascularization in a heart transplant recipient.

The use of minimally invasive direct coronary artery bypass grafting without cardiopulmonary bypass in combination with intraoperative percutaneous transluminal coronary angioplasty for myocardial revascularization in a heart transplant recipient is reported.

Angioplasty, Balloon, Coronary↗
PubMed1997

[Extracorporeal heart pump--a bridge to heart transplantation. First Norwegian experiences].

By February 1997, the number of heart transplantations at the National Hospital had reached 265. In our department, the first bridge to transplantation in using Thoratec artificial heart was performed in 1995. A 44 year-old patient with life-threatening heart failure was placed for one week on cardiopulmonary assist with an intra-aortic balloon pump and a veno-arterial cardiopulmonary bypass. Due to unceasing heart failure a Thoratec left ventricular assist device was implanted as a bridge to transplant. The patient was successfully transplanted two days after implantation of Thoratec. After eight months follow-up he is in New York Heart Association (NYHA) functional class I. Another patient, 17 years of age, and with dilated cardiomyopathy, went into cardiogenic shock while awaiting heart transplantation. For three days he had cardiopulmonary assist with intra-aortic balloon pump and venoarterial bypass with an oxygenator. After seven weeks on the left ventricular assist device he was transplanted. Although one episode of severe rejection occurred, be is in NYHA functional class I after four months follow-up. Our early experience is encouraging. Ventricular assist devices should be considered as a life support for patients scheduled for heart transplantation and expected to die within a very short time.

Adolescent↗
PubMed1997

[Transplantation of animal organs (xenotransplantation). Status and future development].

The increasing shortage of human organs for allotransplantation has created intense interest for xenotransplantation. Pig organs have been suggested as suitable grafts for man. However, the immediate problem associated with discordant xenotransplantation is hyperacute rejection. Hyperacute rejection occurs because antibodies become attached to the endothelial cells of the xenotransplant organ, which activates the complement system, attracts platelets etc. This results in endothelial cell damage, oedema, loss of vascular integrity and thus rapid destruction of the graft. Organs from non-human primates often do not cause hyperacute rejection, but will probably not be acceptable donors. Transgenic pigs have been breeded which contain the genes for the human regulators of complement activation. It appears that insertion of such genes into pigs serves to prevent aggressive hyperacute rejection. Understanding the mechanisms of rejection gives cause for optimism. However, there are still many problems to evaluate and solve. One potential danger associated with xenotransplantation is the transmission of infectious disease from animals to man. Other problems relate to physiological adaptation of the xenograft. The legal, ethical, religious and economic aspects must also be taken into consideration. Despite the potential problems, it is likely that a xenotransplant of some kind will soon be attempted in man.

Cost-Benefit Analysis↗
PubMed1997

Intraoperative angiography in minimally invasive direct coronary artery bypass grafting.

Intraoperative angiography in minimally invasive direct coronary artery bypass grafting without cardiopulmonary bypass and in hybrid procedures is reported. Twelve procedures were performed in a specially designed surgical-radiologic suite with a cross-disciplinary organization. In 2 patients the anastomosis was successfully revised on the basis of angiographic findings. In 4 of the 12 patients anastomosis of the left internal mammary artery to the left anterior descending coronary artery performed as a minimally invasive direct coronary artery bypass grafting procedure was combined with percutaneous transluminal coronary angioplasty of lesions in other coronary vessels in the same session. Intraoperative angiography allows a reliable diagnosis of an anastomosis or graft failure and prompt and reliable correction, and it allows the combination of minimally invasive direct coronary artery bypass grafting and angioplasty in one session.

Aged↗
PubMed1997

Homografts for right ventricular outflow tract reconstruction in congenital heart disease.

In 49 patients aged 2.2-34.8 (mean 11) years, homografts (20 aortic, 29 pulmonary) were implanted in the right ventricular outflow tract as an isolated procedure or part of corrective surgery for congenital heart disease: tetralogy of Fallot with pulmonary stenosis (23 cases), pulmonary atresia with ventricular septal defect (10 cases) truncus arteriosus (8 cases) or transposition of the great arteries with pulmonary stenosis (8 cases). Previous palliative procedures had been performed on 34 patients, and 37 had undergone repair of right ventricular outflow tract, with one to four sternotomies prior to homograft implantation. Homograft valve sizes ranged from 14 to 25 mm internal diameter. Concomitant intra- or extracardiac procedures were performed in 29 cases. Follow-up was complete at a mean of 3 +/- 0.3 (0-8) years. Early and total mortality was 2.0% (1/49), due to sepsis and multi-organ failure unrelated to the homograft. At follow-up all but one of the patients had an improved New York Heart Association function class. Eight patients (16.3%) with a mean age of 9.2 +/- 1.8 (2.8-15.5) years at implantation had homograft malfunction (stenosis in three, regurgitation in two and combined in three) at follow-up, averaging 4.1 +/- 1.0 (0.4-6.9) years, with no significant difference between aorta and pulmonary homograft subsets. Freedom from structural valve deterioration was 46.6 +/- 22% for pulmonary and 32.3 +/- 21.3% for aortic homografts at the 7-year follow-up (difference not significant). In two patients an aortic homograft was uneventfully replaced. In conclusion, homograft implantation in patients with right ventricular outflow tract obstruction improves function class and can entail low mortality and morbidity, even after multiple previous median sternotomies.

Adolescent↗
PubMed1996

[Aortic coarctation and complex heart disease. Surgical treatment during the first year of life].

During the five years 1990 through 1994, 70 neonates and infants had surgery for coarctation of the aorta. 30 patients with complex coarctation of the aorta underwent a first stage correction with supplementary ductus ligation and pulmonary artery banding as needed. The mode of surgical repair of coarctation was end-to-end anastomosis in ten patients and patch graft in 20 patient. Mean follow-up was 766 (range 3-1812) days. Mortality after primary procedure was 16.6% (5/30) and after secondary procedure 11.1% (2/18). Three surviving patient developed recoarctation, but only one patients needed re-operation. In spite of improvement in neonatal cardiac surgery, we conclude that a staged approach is still the current treatment in most cases of complex coarctation of the aorta.

Anastomosis, Surgical↗
PubMed1996

Single lung transplantation for chronic obstructive pulmonary disease: pulmonary function and impact of bronchiolitis obliterans syndrome.

Chronic obstructive pulmonary disease (COPD) is now the most common indication for single lung transplantation. In long-term follow-up, obliterative bronchiolitis is a major problem. The aim of the present study was to perform a long-term follow-up of the pulmonary function and to examine the effect of development of bronchiolitis obliterans syndrome (BOS). Nineteen patients with end-stage COPD underwent single lung transplantation and were followed regularly with pulmonary function tests, and ventilation and perfusion scintigraphy (mean observation time 29 months). They were divided into two categories, with and without BOS, using the definition recommended by the International Society for Heart and Lung Transplantation working group. A mixed model analysis of variance with BOS as co-variate was used to evaluate its effect on pulmonary function. Spirometry, lung transfer factor for carbon monoxide (TLCO), arterial blood gases and 6-min walk test improved significantly (P < 0.001) from before transplantation to 3 months after transplantation. Nine patients developed BOS. Implied by the definition of the syndrome, forced expiratory volume in 1 s (FEV1) was significantly (P < 0.001) lower for patients with BOS while there was no significant effect of BOS category on TLCO corrected for alveolar volume (VA) or perfusion to transplant. Patients without BOS maintained their pulmonary function, and ventilation and perfusion to transplant for more than 3 yr after transplantation. The present results suggest that decreasing FEV1 accompanied by an unchanged TLCO/VA and pulmonary perfusion support the diagnosis of BOS after single lung transplantation for COPD.

Adult↗
PubMed1996

Pulmonary haemodynamics after single-lung transplantation for end-stage pulmonary parenchymal disease.

In a prospective study, we investigated the effect of single-lung transplantation (SLT) on pulmonary haemodynamics and the relationship between pulmonary hypertension (PH) and the fraction of perfusion to the transplant in patients with end-stage pulmonary parenchymal disease. Twenty four SLT recipients were included in the study, 19 with chronic obstructive pulmonary disease (COPD), two with sarcoidosis and three with fibrosing alveolitis. Spirometry, determination of arterial blood gas values, perfusion scintigraphy and right heart catheterization were performed before and 1, 6, 12 and 24 months after transplantation. Patients with a mean pulmonary artery pressure (Ppa) > or = 20 mmHg before transplantation were defined as having PH (PH group, 15 patients) and the remainder (9 patients) constituted the non-PH group. In the PH group, Ppa and pulmonary vascular resistance (PVR) were significantly decreased after transplantation: 28 +/- 2 to 18 +/- 1 mmHg and 288 to 161 +/- 11 dyne.s-1.cm-5, respectively (mean +/- SEM). In the non-PH group, the haemodynamic parameters were unchanged after transplantation. Over the 2 year follow-up period, no significant change was found in Ppa and PVR, nor any difference between the PH and non-PH group. There was no significant difference between the two groups in terms of pulmonary perfusion to the graft. In conclusion, patients with pulmonary hypertension obtain pulmonary haemodynamics within the normal range after single-lung transplantation. Presence or absence of pulmonary hypertension before transplantation does not influence perfusion to the graft. These findings persist up to 2 yrs, despite the coexistence of an "end-stage" native lung and a lung transplant.

Adult↗
PubMed1996

Release of interleukin-8 and calprotectin during and after paediatric cardiopulmonary bypass with and without ultrafiltration.

Release of calprotectin and interleukin-8 (IL-8), changes in leukocyte counts and subsets and influence of extracorporeal ultrafiltration were evaluated during and after cardiopulmonary bypass (CPB) in 18 children undergoing open-heart surgery for congenital heart anomalies. Ultrafiltration was used in nine cases and nine were controls. Calprotectin concentration rose after start of CPB, peaking 48 hours postoperatively, with no significant intergroup difference. Positive correlation was found between duration of CPB and calprotectin (peak level and accumulated total). Circulating IL-8 was detected in all patients perioperatively, peaking at wound closure in the ultrafiltration group and at termination of bypass in the controls. CPB duration correlated significantly to peak level and accumulated total of IL-8. Seven of nine ultrafiltrate samples contained IL-8 at levels similar to the plasma concentration. Changes in white cell counts were mainly attributable to neutrophils. The two subgroups did not differ significantly in neutrophil counts. Neutropenia found after 10 minutes of CPB was replaced by neutrophilia, with maximal values postoperatively. Calprotectin and IL-8 thus were released into the circulation during CPB in children. Ultrafiltration did not affect the plasma concentrations of these substances, and only IL-8 was detected in the ultrafiltrate.

Calcium-Binding Proteins↗
PubMed1996

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.

Cardiopulmonary Bypass↗
PubMed1995

Complement activation and release of tumour necrosis factor alpha, interleukin-2, interleukin-6 and soluble tumour necrosis factor and interleukin-2 receptors during and after cardiopulmonary bypass in children.

C3 activation products, terminal complement complex (TCC), and cytokines including interleukins 6 and 2 (IL-6, IL-2) and tumour necrosis factor-alpha (TNF), and the soluble IL-2 and TNF receptors were determined serially during and up to 48 h after open heart surgery in children. Significant increases were noted in soluble TNF and IL-2 receptor levels postoperatively (p < 0.05). No significant increase over preoperative levels was seen in the cytokines, except for IL-6 which was significantly increased postoperatively (p < 0.01), reaching a maximum 2 h postoperatively. C3 activation products and TCC levels increased significantly after weaning from cardiopulmonary bypass (p < 0.05). The IL-6 response lagged behind the complement activation. We found a significant correlation between duration of cardiopulmonary bypass and IL-6 levels 48 h postoperatively (r = 0.852, p < 0.05). We conclude that the concentration of complement activation products, IL-6 and the soluble TNF and IL-2 receptors are significantly increased after open heart surgery in children. The cytokine receptor response probably reflects some sort of regulatory mechanism.

Cardiopulmonary Bypass↗
PubMed1995

Activation of the fibrinolytic, coagulation and plasma kallikrein-kinin systems during and after open heart surgery in children.

Activation of the fibrinolytic, coagulation and plasma kallikrein-kinin systems may be responsible for some of the coagulation disorders and inflammatory sequelae seen after extracorporeal circulation. The activation pattern of these systems was studied in 10 children undergoing open heart surgery with extracorporeal circulation. Blood samples were drawn serially before, during and up to 48 h after surgery. The heparin injection induced a significant elevation of plasmin (PL) (p < 0.05) which stayed elevated during extracorporeal circulation. Antiplasmin (AP) values were reduced at wound closure, while the levels were significantly elevated 48 h postoperatively (p < 0.05). alpha 2-antiplasmin-plasmin (APP) increased significantly perioperatively peaking 10 min after the initiation of cardiopulmonary bypass (p < 0.05). The coagulation markers thrombin-antithrombin (TAT) and the prothrombin fragment F1 & 2 increased significantly, peaking at wound closure and at termination of bypass respectively (p < 0.05). Plasma kallikrein (KK) values increased significantly with subsequent decreased levels of prekallikrein (PKK) and kallikrein inhibitor (KKI) after heparin injection. The KK level stayed elevated during cardiopulmonary bypass (CPB). The proenzyme functional inhibition index (PFI index), defined as the sum of deviations from the control values for proenzyme and functional inhibition values of the coagulation, fibrinolytic and plasma kallikrein-kinin systems, correlated significantly to the duration of cardiopulmonary bypass (p < 0.05). We conclude that open heart surgery in children activates the fibrinolytic, coagulation and plasma kallikrein-kinin systems.

Antifibrinolytic Agents↗
PubMed1994

[Tetralogy of Fallot. A 20-year material].

Surgical repair of tetralogy of Fallot may be a first stage palliation with secondary physiologic correction or repair as a primary procedure. The aim of palliation is to increase the pulmonary blood flow. Since 1981 we have used an interposition shunt between the subclavian and the pulmonary artery for this purpose. Repair comprises closure of the ventricular septal defect and relief of the pulmonary stenosis. A primary repair may be performed if the pulmonary arteries have reached a certain size. The size and function of the left ventricle must also be able to cope with the increased work load. During the last 20 years, 333 operative procedures have been performed in patients with tetralogy of Fallot. This material comprises 107 shunts and 226 repairs. The total mortality while in hospital was 6%. During the last period from 1990 until January 1993 the mortality in hospital was 3% after operative repair. There have been no mortality following palliative procedures during the same period.

Angiocardiography↗
PubMed1993

Complement activation during extracorporeal circulation. In vitro comparison of Duraflo II heparin-coated and uncoated oxygenator circuits.

The degree of complement activation during cardiopulmonary bypass is considered a valuable parameter of biocompatibility of the extracorporeal circuit. In an in vitro setting with a heart-lung machine primed with fresh whole blood and saline solution, the C3 activation products C3b, iC3b, and C3c and the terminal complement complex were measured in double-antibody enzyme immunosorbent assays. No differences were found between seven sets treated with Duraflo II heparin coating and seven uncoated sets after 2 hours of circulation. C3 activation products (expressed as median and 95% confidence intervals) increased from 4.5 AU (2.8 to 12.3 AU) to 16.5 AU (10.0 to 19.4 AU) in the uncoated sets (p = 0.02) and from 4.6 AU (2.2 to 5.8 AU) to 19.3 AU (3.5 to 27.1 AU) in the coated sets (p = 0.02). Terminal complement complex increased from 5.7 AU (2.7 to 11.3 AU) to 13.6 AU (8.2 to 17.8 AU) in the uncoated sets (p = 0.02) and from 7.9 AU (4.6 to 11.4 AU) to 17.3 AU (9.4 to 35.1 AU) in the coated sets (p = 0.02). A significant drop in thrombocyte levels was observed in both coated and uncoated sets. In a supplementary series, the sterilization process did not influence the results. Although Duraflo II heparin coating is considered highly effective in preventing coagulation, it did not prevent complement activation in the present in vitro study. We hypothesize that the mode by which the heparin molecule is bound to the surface may be essential to obtain effects on both coagulation and complement system.

Biocompatible Materials↗
PubMed1986

Prognostic factors in blunt chest trauma. Analysis of 652 cases.

All records of 652 patients treated for blunt chest trauma at Ullevål Hospital, Surgical Department 3, during the period 1973-1981 were analyzed for factors predictive of prognosis. Mortality for the whole group was 7.7%. Age, blood pressure on admission, the number of fractured ribs, the need for blood transfusions and the need for artificial ventilation were the most important predictors of prognosis. Mortality increased significantly when at least two extrathoracic injuries were present (22.6%). Intrathoracic injuries did not increase mortality in cases of isolated thoracic injuries. Combined thoraco-abdominal injuries carried a high mortality (25%), especially when the injury had resulted in rupture of the diaphragm (57.1%). There were no sex-related differences. The majority of the patients could be handled adequately with oxygen support, chest drainage, physiotherapy and pain relief. The incidence of bronchial infection, septicaemia and hypercoagulability was significantly higher for patients on ventilators than for patients breathing spontaneously. Mortality increased when septicaemia or bronchial infection was present (30.8 and 21.9%, respectively). The injury severity score (ISS) for the 50 patients who died in the hospital was similar to that of some other reports.

Abdominal Injuries↗