Ex vivo model for xenotransplantation.
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Acute Disease↗
Biomedical subjects
O Geiran
Publications and source records attributed to O Geiran.
[Endarterectomy of left coronary arteries. An angiographic follow-up study].
From January 1989 to December 1993, 25 patients underwent endarterectomy on the left coronary artery system. Eight of the patients had concurrent endarterectomy of the right coronary artery. The operative mortality consisted of one high-risk patient who died from an intraoperative myocardial infarction. Two patients developed non-fatal perioperative infarction. The follow-up period averaged 27 months (range 4-58 months). At follow-up one patient was lost for evaluation owing to unexpected sudden death, no patients had experienced myocardial infarction, 17 patients (74%) were free of angina, two patients were in NYHA class I and four in NYHA class II. All patients showed an improvement in relation to their preoperative condition. Two asymptomatic patients refused recatheterization, while 21 patients had a control angiographic study. 25 of 34 grafts to endarterectomized vessels were open (patency 74%) compared with 41 of 45 grafts to non-endarterectomized arteries (patency 91%). We find the angiographic and functional results acceptable and they should be acknowledged with reference to patients with diffuse distal coronary artery disease, many of whom would otherwise be considered inoperable.
Adult↗
CarboMedics valve in congenital heart disease. Midterm follow-up study of 14 patients.
In 14 patients aged 5-329 (mean 131) months a CarboMedics valve was implanted because of congenital heart disease. The preoperative NYHA function class was III-IV in ten cases. Seven aortic and seven atrioventricular valves were replaced without early mortality. All patients were followed up, with mean observation time 27 months (total 384 months). One of the 14 patients died of heart failure 10 months postoperatively. Thrombosis occurred in four valves, three in tricuspid and one in mitral position. In all patients who received only warfarin, anticoagulation was demonstrably inadequate. Consequently we now recommend antiplatelet medication in addition to warfarin for children with atrioventricular mechanical valve replacement. In our experience the complication rate with CarboMedics prosthesis is acceptable, provided that anticoagulant therapy is adequate.
Aortic Valve↗
[Lung transplantation].
As alternative methods of lung transplantation are available, in terminal respiratory or combined cardio-respiratory failure, the surgical procedure can be chosen to suit the needs of the individual recipient in accordance with the philosophy of the transplant centre. At one Scandinavian centre the preferred procedure has been en bloc double lung transplantation with bronchial artery revascularisation, whereas at another centre the preference is for single lung transplantation if considered suitable in view of the pathology resulting in respiratory failure. Short-term results compare favourably with international registry standards. Problems commonly occurring in lung transplantation irrespective of the method, are reviewed in the article.
Extracorporeal Circulation↗
[Heart transplantation in terminal heart failure. Still a therapeutic challenge after 10 years].
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Heart Failure↗
Platelets in shed mediastinal blood used for postoperative autotransfusion.
Ten patients undergoing open-heart surgery received postoperative autotransfusion of shed mediastinal blood collected in the cardiotomy reservoir. The number, function and morphology of the platelets found in the shed blood were investigated. Platelets were counted using an electronic counter compared with light microscopy. Morphology of platelets was studied with electron microscopy. Platelet aggregation was studied using an aggregometer. Dense granule secretion was measured as the extracellular appearance of adenosine triphosphate. Enumeration of platelets in shed blood using the two methods gave different results. Thus, the electronic counter gave a mean platelet count of 62 x 10(9).l-1, while light microscopy revealed only a mean platelet count of 10 x 10(9).l-1. Electron microscopy disclosed few platelets, but numerous cytoplasmatic fragments smaller than or up to the same size as platelets. The platelets found were mostly shape-changed, spheroid, characterized by centralization and loss of alpha-granules and dense bodies, all changes that indicated irreversible platelet activation. The platelets failed to aggregate in response to the presence of thrombin, adenosine diphosphate or collagen, and secretion of adenosine triphosphate was absent. Plasma from the shed blood was not capable of inducing spontaneous aggregation in platelet-rich plasma from healthy donors. These results indicate that infusion of larger volumes of autotransfused blood should be supplemented with platelet concentrates.
Adenosine Diphosphate↗
Single lung transplantation. Morphological surveillance by transbronchial biopsy.
Seven cases of single lung transplantation are reported. The recipients were all below 60 years of age and severely disabled with end-stage lung disease. Transplantation was performed according to ABO blood group compatibility and negative lymphocytotoxic cross-match between donor and recipient irrespective of HLA mismatch. Recipients' diagnoses were sarcoidosis (3), alfa-1 antitrypsin deficiency (3), and idiopathic emphysema (1). Mean recipient age was 48 +/- 2.4 years (range 45-52). Donor age was 29.7 +/- 5.6 years (range 16-49). The immunosuppressive regimen included cyclosporin A, azathioprine, steroids and rabbit antithymocyte globulin. Excellent graft function was achieved. Six patients survived the postoperative period and are alive 4-18 months posttransplant. One patient died after the operation due to pneumonia with respiratory distress syndrome. Graft function was also monitored by transbronchial biopsy, and 57 biopsy procedures were performed without fatal complications. Acute cellular rejection was seen in 16 biopsy specimens from 5 recipients (grade 1 and 2 rejection in 14, grade 3 rejection in 2). Neither severe rejection with septal necrosis (grade 4) nor obliterative bronchiolitis was seen. The rejection rate was 0.03 episodes per patient/month. In contrast to other reports, episodes of cellular rejection occurred throughout the observation period, and were not mainly limited to the first 4 months posttransplant. Graft vascular occlusive disease or chronic vascular rejection was found in 6 biopsy specimens from one recipient. Five patients experienced 7 episodes of cytomegalovirus infection. The cytomegalovirus infection rate was 0.01 episodes per patient/month. The incidence of infection was significantly lower compared to previous studies of rejection in other lung graft combinations. Both infections and rejection episodes may contribute to the development of obliterative bronchiolitis. Almost one third of the specimens (30%) showed lymphocytic bronchitis without perivascular inflammation. The absence of perivascular infiltrates and exclusion of infectious agents leaves in question the aetiology of this inflammation. The lymphocytic bronchitis could be ischaemic, related to aspiration, or represent recurrent sarcoidosis, or, in fact, express bronchial rejection. All biopsy specimens regarded as rejection with cellular infiltrates in the lung parenchyma also showed a lymphocytic bronchitis. The impact of HLA mismatch on cellular and vascular rejection is unclear. Transbronchial biopsy is a reasonably safe and reliable method in the diagnosis of rejection and infection in single lung transplantation.
Adult↗
Surgical intervention following failed percutaneous coronary angioplasty.
Percutaneous transluminal coronary angioplasty (PTCA) was performed on 725 occasions at the National Hospital of Norway in 1981-1990. Acute surgical intervention was necessary within 24 hours after PTCA in 15 cases, on indications that included coronary artery dissection (8 cases) and acute thrombotic occlusion (5). Electrocardiographic signs of ischemia were present in 11 patients with anginal pain, while two had severe angina but normal electrocardiogram. Two patients had a non-ischemic indication for surgery. Despite surgery, ten of the 15 patients had acute myocardial infarction. One of the ten died. At follow-up nine of 12 patients were free from angina and three had recurrent symptoms.
Angioplasty, Balloon, Coronary↗
Daily home spirometry facilitates early detection of rejection in single lung transplant recipients with emphysema.
Eight single lung transplant recipients with emphysema, aged 40-58 yrs, have been followed up for 90 patient months. Starting 2-4 weeks postoperatively, they recorded their forced vital capacity (FVC), and forced expiratory volume in one second (FEV1), at a fixed time every morning using a Micro Spirometer. They were instructed to contact the hospital if the FVC or FEV1 displayed a persistent (two days or more) decrease of 10%, compared with the average values during the last seven days. Transbronchial biopsies (TBB) were performed regularly in the follow-up, and whenever the patients had respiratory symptoms, or the FVC or FEV1 displayed a persistent decline of more than 10%. We performed 59 TBBs, and 23 biopsy specimens showed rejection. The FVC and FEV1 values on the TBB day were compared with the mean values of the 7 previous days. FVC and FEV1, associated with negative TBBs (16 events), showed no significant changes. However, FVC and FEV1 decreased significantly (p < 0.001, paired t-test) during rejections (mean percentage change 14 and 21% respectively, range +8% to -53%). In 16 of the 23 rejections, the FEV1 decreased by > 10%. We recommend the use of daily home spirometry when monitoring single lung recipients with emphysema, and suggest that a persistent 10% decrease in FEV1 or FVC for at least two days is an indication for hospital admission and possible TBB.
Adult↗
Hemodynamic evaluation of the CarboMedics prosthetic heart valve in the aortic position: comparison of noninvasive and invasive techniques.
Seventy-three patients with a CarboMedics aortic bileaflet valve prosthesis were examined by Doppler ultrasonography, and 27 of them were also assessed by transseptal catheterization. The ultrasonic mean systolic gradient was 17.1 +/- 5.6 mm Hg for valve size 19 mm, falling gradually with increasing valve size to 6.8 +/- 2.5 mm Hg for size 27 mm. The catheter mean systolic gradient was consistently smaller than the ultrasonic gradient (4.3 +/- 4.8 mm Hg), but Tobit regression analysis showed a significant association between the two methods. In all patients both methods revealed negligible to small amounts of retrograde leakage, which is assumed to be a normal finding for this valve. The effective flow areas of the valves calculated from the ultrasonic data were similar to the in vitro calculated flow areas. The hemodynamic potential of this valve is therefore completely utilized in vivo. The effective orifice area corrected for body surface area increased with increasing valve size, which demonstrates a moderate valve-patient mismatch.
Adult↗
Single lung transplantation. Surgical experiences with the first seven patients.
Seven single lung transplants are reported. The patients were severely disabled and oxygen dependent below sixty years of age with a poor prognosis. Diagnosis were alfa 1-antitrypsin deficiency (3), sarcoidosis (3) and idiopathic emphysema (1). Multiorgan-harvesting including six hearts, was performed in local or distant hospitals (3). Partial cardiopulmonary bypass simplified transplantation. The surgical procedure was modified with a direct transpericardial approach. Soft tissue wrapping by a vascularized pedicle secured the bronchial anastomosis. The four drug immunosuppressive regimen included cyclosporin A, azathioprine, steroids and antithymocyte globulin. Primary graft function was excellent. Six patients survived the postoperative period and are alive 5-19 months post transplant. Transbronchial biopsies and lung function studies have been helpful in detecting pulmonary rejections. Patient rehabilitation is satisfactory in most patients with improvement in physiologic parameters.
Adult↗
Morbidity risk factors in human cardiac transplantation. Histoincompatibility and protracted graft ischemia entail high risk of rejection and infection.
Data from the first 103 human heart transplantations performed on 100 recipients (aged 14-62 years) at a single center from November 1983 to January 1990 were analyzed in order to detect morbidity-causing risk factors. Cumulative one- and five-year graft survival was 82% and 68%. Multivariate analysis revealed three independent risk factors for early rejection, viz. HLA-DR and HLA-B mismatches and no prior cardiac surgery. Graft ischemic time exceeding 71 min was an independent risk factor for rejection, especially for moderate or severe events, and for infection. HLA-DR mismatch was an independent risk factor for moderate and severe rejection events and for infections. Finally, patients operated on because of end-stage ischemic heart disease were at significantly higher risk of rejection than those with other cardiac disorders. The study has several implications: Prospective tissue typing for cardiac transplantation and selection of donors may have an impact on graft function: Damage to the graft by prolonged ischemia may be reduced by improved organ preservation.
Adolescent↗
[Gastrointestinal cytomegalovirus infection in patients with heart transplants].
Cytomegalovirus (CMV) infection is a major cause of morbidity in organ transplant recipients. Gastrointestinal CMV disease is a serious and potentially lethal complication requiring treatment with antiviral agents. The symptoms and endoscopic findings are nonspecific. The diagnosis may be decided by histological examination, since CMV inclusions can be verified immunohistochemically in routine sections. In a series of 132 heart transplant recipients, 26 developed CMV-infection. Three of these patients had serious gastrointestinal disease. This report describes the patients with gastrointestinal CMV infection, and briefly discusses symptomatology, diagnostic considerations and suggested treatment.
Adult↗
[Results of 6 1/2 years of heart transplantation at Rikshospitalet].
We discuss our experience from 6 1/2 years of orthotopic heart transplantation at Rikshospitalet (the National Hospital). 112 grafts were performed on 109 patients (19 women and 90 men), mean age 47 years (range 14-63). In the first nine patients the immunosuppressive regimen consisted of cyclosporine A and prednisolone, and in the last 100 azathioprine was added (triple medication). There was no operative mortality. 21 patients died, giving an 81% cumulative survival, with a significantly better prognosis among those who received triple immunosuppressive regimen. The main complications were rejection, infection and arrhythmia. Since our main problem was rejection it is concluded that careful supervision, concentrated on as few cardiologists as possible, and a liberal indication for myocardial biopsy, are decisive for the prognosis.
Adolescent↗
[Single lung transplantation as treatment of terminal lung diseases].
The article describes the first cases of single lung transplantation in Norway. The indication for surgery was end-stage pulmonary disease (1 sarcoidosis, 2 emphysema) in three severely disabled patients requiring administration of oxygen. The operation necessitated cardiopulmonary bypass in all patients. Primary graft function was excellent. Epidural analgesia, peripheral pulse oxymetry and continuous monitoring of mixed venous oxygen saturation aided early extubation. The initial postoperative course with a four drug immunosuppressive regimen has been encouraging. Rejection is monitored by clinical examination, chest x-ray, serial pulmonary function tests and transbronchial biopsies.
Adult↗
Risk factors for total and cause-specific mortality in human cardiac transplantation. Prolonged extracorporeal bypass time: a high risk factor for rejection and infection.
Data from the first 103 human heart transplantations in 100 recipients performed at a single centre from November 1983 to January 1990 were analysed to detect risk factors for overall and cause-specific mortality. Twenty-two patients died. Cumulative 1 year graft survival was 82% and 5 year, 68%. Acute and chronic rejection was the cause of death in 9 patients, disseminated infection in 8 and cancer in 3. One patient died from cerebral haemorrhage and 1 from acute cardiac failure. The mean observation time was 803 days (range: 1-2 308 days). Total follow-up was 226.6 graft years. Risk factors were analysed by univariate and multivariate methods. The type of immunosuppression regimen and recipient age above 50 years were independent risk factors for mortality. Histocompatibility mismatching (HLA-DR) and type of immunosuppression were independent risk factors for lethal rejection and a female recipient was an independent risk factor for lethal infection. Prolonged time on extracorporeal bypass was an independent risk factor for both lethal rejection and infection, and also for overall mortality. The impact of extracorporeal bypass time on rejection and infection is discussed, and the importance of prospective HLA matching in heart transplantation is stressed. The association between recipient female sex and infection remains uncertain.
Adolescent↗
Haemodynamic effects of heparin during coronary bypass surgery.
Heparin has been suggested as an activator of the plasma kallikrein-kinin system, with possible formation of bradykinin, a potent vasodilator. Haemodynamic effects and changes in the kallikrein-kinin system were studied after heparin- and saline-injections in ten patients undergoing coronary bypass surgery. A moderate decrease in mean arterial pressure was found in all patients in the observation period, but significantly more at 2 and 3 min after heparin-injection compared with saline-injection. None of the other haemodynamic variables measured were significantly different when comparing heparin- to saline-injection. Heparin-injection resulted in significant changes in the kallikrein-kinin system, with a marked increase in spontaneous kallikrein-like activity as the most prominent feature, while no changes were found after saline-injection. Liberation of bradykinin would be expected to give a decrease in systemic vascular resistance with an increase in cardiac output. The results indicate that the plasma kallikrein-kinin system, though apparently activated after heparin-injection, does not contribute significantly to the decrease in arterial pressure in the patients studied.
Blood Pressure↗
Duration of cardiopulmonary bypass compared with changes in the plasma protease systems.
Forty patients undergoing elective coronary artery bypass grafting were investigated concerning association between duration of cardiopulmonary bypass (CPB) and changes in the plasma protease systems. Spontaneous enzyme activity, proenzymes and functional inhibition capacities in the fibrinolytic, plasma kallikrein-kinin and coagulation systems were measured before, during and after CPB and in the immediate postoperative period. No clear relationship was revealed between changes in the measured variables and the duration of CPB.
Blood Coagulation↗