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Biomedical subjects

U Althaus

Publications and source records attributed to U Althaus.

At least 37 records · Page 2Linked to original sources
PubMed1998

Successful heart transplantation in a patient with Ivemark syndrome combined with situs inversus, single atrium and ventricle after total cavo-pulmonary connection.

Heart transplantation represents a valuable therapeutical option for patients with congenital heart disease and end-stage heart failure. We report the case of a young adult patient with a situs inversus and additional complex congenital malformations of the heart who underwent several prior palliative interventions, a biventricular repair being impossible. Orthotopic cardiac transplantation with several technical modifications was performed successfully at the age of 19 years.

Abnormalities, Multiple↗
PubMed1998

Left heart bypass in the pig with a centrifugal pump using cannulae prepared for percutaneous placement.

A rapid and efficient circulatory support system may save a patient in cardiogenic shock. Left heart bypass with percutaneous and trans-septal placement of the aspiration cannula simplifies the circuit and eliminates the need for an oxygenator. In this pre-clinical study we assessed left heart bypass support with a centrifugal pump using new cannulae prepared for percutaneous placement (14 F arterial catheter and 16 F left atrial aspiration line) in 5 anaesthetized pigs. Animals were supported for two hours at a mean flow of 3.2 l/min (4,033 rpm), a mean haematocrit of 29% and low heparinisation (ACT double baseline). Hemodynamic measurements and blood samples were taken at baseline (A), 10 minutes (B), one hour (C) and 2 hours (D) on support. Results show maintenance of hemodynamic parameters throughout the 2 hour support period. Only systolic arterial and left ventricular pressure decreased by 12% and 20% respectively from baseline to the end of the support period with a 13% increase in cardiac output. When the pump was turned on (0-3 l/min) there was usually a decrease in heart rate, systolic pressure and left ventricular pressure, with unchanged cardiac output (non failing model). Potassium increased from 3.9 to 4.2 mmol/l (ns), and plasma hemoglobin from 6.0 to 18.2 mg/dl (p<0.05). Thrombocytes decreased from 187 to 155 10(9)/l (ns). In conclusion, this preclinical study demonstrated the feasibility of an efficient left heart bypass of short duration with a centrifugal pump using cannulae prepared for percutaneous placement. Left heart bypass was well tolerated hemodynamically and no significant laboratory change occurred within the two hours of support. This opens several possibilities for the short term support of patients in cardiogenic shock and eventually also for patients submitted to minimally invasive cardiac surgery.

Animals↗
PubMed1998

Definitive cure of recurrent prosthetic endocarditis using silver-coated St. Jude Medical heart valves: a preliminary case report.

Despite progress in the area of antimicrobial treatment and the surgical use of homografts, prosthetic valve endocarditis (PVE) remains one of the most dangerous complications following heart valve replacement. We present the case of a patient treated for acute endocarditis which affected the mitral valve and who developed recurrent PVE and native aortic valve endocarditis. After multiple valve surgery, the infection was controlled following aortic and mitral valve replacement using silver-coated prostheses. The St. Jude Medical (SJM) mechanical heart valve Masters Series with Silzone coating is intended to protect heart valve patients against microbial infection. The Silzone coating is formed by an ion beam-assisted deposition process that incorporates silver into the sewing cuff of the SJM heart valve. It has also been suggested that silver treatment may improve the healing characteristics of the heart valve sewing cuff. This technology may be a valuable option to prevent or cure PVE, in addition to homografts. Although the present patient is an isolated case, it was encouraging to find not only a well-healed mitral valve silver-coated prosthesis but also no persistent or recurrent infection during a nine-month follow up.

Adult↗
PubMed1997

Outcome of survivors of accidental deep hypothermia and circulatory arrest treated with extracorporeal blood warming.

BACKGROUND: Cardiopulmonary bypass has been used to rewarm victims of accidental deep hypothermia. Unlike other rewarming techniques, it restores organ perfusion immediately in patients with inadequate circulation. This study evaluated the long-term outcome of survivors of accidental deep hypothermia with circulatory arrest who had been rewarmed with cardiopulmonary bypass. METHODS: Deep hypothermia (core temperature, <28 degrees C) with circulatory arrest was found in 46 of 234 patients with accidental hypothermia. In 32 of the 46 patients, rewarming with cardiopulmonary bypass was attempted, resulting in 15 long-term survivors. In most of these patients, deep hypothermia developed after mountaineering accidents or suicide at tempts. After an average (+/-SD) of 6.7+/-4.0 years of follow-up, we obtained the patients' medical histories and performed neurologic and neuropsychological examinations, neurovascular ultrasound studies, electroencephalography, and magnetic resonance imaging of the brain. RESULTS: The average age of the patients was 25.2+/-9.9 years; seven were female and eight were male. The mean interval from discovery of the patient to rewarming with cardiopulmonary bypass was 141+/-50 minutes (range, 30 to 240). At follow-up there were no hypothermia-related sequelae that impaired quality of life. Neurologic and neuropsychological deficits observed in the early period after rewarming had fully or almost completely disappeared. One patent had cerebellar atrophy on magnetic resonance imaging with mild clinical signs, a condition that may have been caused by hypothermia. Other clinical abnormalities were either preexisting or due to injuries not related to hypothermia CONCLUSIONS: This clinical experience demonstrates that young, otherwise healthy people can survive accidental deep hypothermia with no or minimal cerebral impairment, even with prolonged circulatory arrest. Cardiopulmonary bypass appears to be an efficacious rewarming technique.

Accidents↗
PubMed1997

[Acute type B aortic dissection: prognosis after initial conservative treatment and predictive factors for a complicated course].

OBJECTIVE: Today there is still debate concerning the optimal mode of treatment for type B dissection of the aorta. Controversies are mainly due to discordant results regarding survival following medical or surgical treatment. We assessed the early and long-term outcome of acute dissection of the descending aorta after initial conservative treatment. METHODS: Between 1980 and 1995, 225 patients were hospitalized in the medical or surgical department of our institution with the diagnosis of acute type B aortic dissection. 38 patients (16.8%) underwent replacement of the descending aorta within the first week after hospital admission. Primary indications for immediate surgery were rupturing aneurysm in 15 patients, extensive dilatation of the descending aorta in 13, distal malperfusion in 8, and pseudocoarctation syndrome with uncontrollable hypertension in 2. All other patients (n = 187) underwent primary conservative treatment in the intensive care unit, which included appropriate antihypertensive medication. RESULTS: Hospital mortality during and after initial conservative treatment was 17.6% (33/187 patients). Main causes of death were rupture in 14 patients, intestinal malperfusion in 13 and cardiac failure in 3, whereas in 3 patients the cause of death could not be determined. Nine additional patients had to be referred for early surgery during the initial hospitalization because of contained rupture (n = 4), rapidly increasing size of the aorta (n = 2) and suspected intestinal ischemia (n = 3). Hospital mortality after early surgery was 21% (8/38 patients) for the overall time period. After hospital discharge from the initial acute dissection, surgery for chronic dissection was performed in 47 patients, mainly because of expanding descending aortic aneurysm. Hospital mortality was 8% in these patients (4/47). Actuarial survival rates after primary conservative therapy were 76 +/- 5% and 50 +/- 7% after 5 and 8 years respectively. CONCLUSION: Currently, surgery for acute type B dissection is limited to patients with rupturing disease, distal malperfusion or uncontrollable hypertension and pains. Despite aggressive antihypertensive treatment, hospital mortality after primary conservative treatment is still high and a substantial proportion of patients requires surgery during initial hospitalization. Although conservative treatment is recommended in most uncomplicated type B aortic dissections, early surgery should be considered in the following situations: younger patients with 5 cm diameter of the aorta at initial evaluation, as well as those with Marfan syndrome, patients with limited false aneurysm or retrograde dissection into the aortic arch, and those with poor medical compliance or uncontrollable proximal hypertension. Radiographic follow-up for an indefinite period may allow detection of potential late complications and proper planning of elective operations when indicated.

Acute Disease↗
PubMed1997

[Current techniques in heart surgery].

Significant advances in open heart surgery during the last two decades were achieved in the field of the extracorporal circulation and the preservation of the myocardium. In the last few years, new therapeutical tools were introduced to treat patients with coronary artery disease. The transmyocardial laser revascularization (TMR) technique was introduced for clinical investigation 1990. Despite limited experience with this device in selected patients, some conclusions after a short follow-up period are available. Patients treated with TMR have significantly less anginal pain and need fewer hospitalisations. With PET follow-up studies, a better subendocardial perfusion at the expense of the subepicardial perfusion was demonstrated. On the other hand, there was no substantial increase found in terms of ejection fraction in treated patients. Minimally invasive procedures have also gained acceptance during the last few years, especially the minimally invasive coronary artery bypass procedures (MIDCAB). Introduced initially to treat solitary stenoses of the LAD without cardiopulmonary bypass, this procedure is actually often used in conjunction with PTCA for three-vessel disease in selected patients. Due to the different methods used and summarized under the term of MIDCAB, definite conclusions about the advantages of this method are difficult to formulate. There is a trend to reduced patency rates of the IMA bypasses in MIDCAB procedures compared to the conventional technique due to the difficulty with limited access.

Angioplasty, Balloon, Coronary↗
PubMed1997

Different effects of thrombin receptor activation on endothelium and smooth muscle cells of human coronary bypass vessels. Implications for venous bypass graft failure.

BACKGROUND: Thrombin is implicated in coronary bypass graft disease; it cleaves its receptor's extracellular N-terminal domain and unmasks a new N-terminus as a tethered ligand. We studied the effects of thrombin receptor activation in human internal mammary artery (IMA) and saphenous vein (SV). METHODS AND RESULTS: To study the effects of thrombin receptor activation on vasomotion, isolated blood vessels were suspended for isometric tension recording, and the effects on cell proliferation were studied in cultured smooth muscle cells (SMCs) of IMA and SV. Thrombin receptor expression in IMA and SV was analyzed by reverse transcription polymerase chain reaction and immunohistology. Receptor function was studied by analyzing the activation of mitogen-activated protein kinase (p42MAPK). In IMA thrombin evoked endothelium-dependent relaxations (65 +/- 5%) that were mimicked by thrombin receptor agonist peptide (TRAP) and reduced by the thrombin inhibitors recombinant (r-) hirudin and D-Phe-Pro-Arg-chloromethyl ketone (PPACK) (P < .05). In SV thrombin caused contractions (36 +/- 5% of 100 mmol/L KCl) that were inhibited by r-hirudin or PPACK (P < .05) but not mimicked by TRAP. In SMCs thrombin induced more pronounced [3H]thymidine incorporation (inhibited by r-hirudin or PPACK) in SV than IMA (P < .05), but activation of p42MAPK was similar in both vessels. TRAP induced weaker activation of p42MAPK than thrombin and did not stimulate [3H]thymidine incorporation in SMCs of SV or IMA. Immunohistology and RT-PCR demonstrated that the endothelium and SMCs of IMA and SV express thrombin receptor. CONCLUSIONS: Functional thrombin receptors are present on endothelium and SMCs of IMA and SV. Endothelial thrombin receptors mediate relaxation in IMA but not SV. Thrombin causes much more pronounced contraction and proliferation in SMCs of SV than IMA independent of tethered receptors, suggesting other thrombin receptors exist. These differences of thrombin receptor activation in IMA and SV may be important in the development of and therapy for graft disease.

Amino Acid Chloromethyl Ketones↗
PubMed1997

[Homograft in the therapy of cardiovascular diseases].

Despite considerable progress in prosthetic valve technology, there is actually no ideal artificial heart valve that may be employed in all circumstances, when replacement of a diseased aortic valve is necessary. The choice for optimal valve substitute includes mechanical prosthesis, bioprosthetic xenografts, homografts and pulmonary autografts. More recently an aortic valve sparing operation has been proposed in younger patients presenting with anulo-aortic ectasia. The use of homograft heart valves has now been widely accepted in the treatment of congenital heart defects, as well as for an increasing number of valvular pathologies, especially in infective endocarditis. Heart valve preservation by cryopreservation techniques helps to store the small amount of donor material for special indications without loss of quality, thus permitting elective surgery. In vascular surgery, some concern persists regarding the use of prosthetic material for the treatment of mycotic aneurysms and graft infection. In situ repair with a new vascular prosthesis and resection followed by extra-anatomic reconstruction carry a high peri-operative mortality and substantial morbidity. Cryopreserved vascular homografts represent a valuable alternative in these challenging situations.

Aortic Valve↗
PubMed1997

[Myocardial revascularization in geriatric patients].

The results of percutaneous transluminal coronary angioplasty (PTCA) in 71 patients over 75 years of age were retrospectively analyzed and compared with those of 55 patients aged over 75 who underwent surgical revascularization (CABG) during the same time period (1992-1995). The main indication for revascularization was unstable angina. The clinical success in PTCA patients was 92%, with a lesion success rate of 93%. Major cardiac complications occurred in 5% of patients with an in-hospital mortality of 1%. The mean hospital stay was 4 days. During a follow-up period of 16 (range 1-36) months, 23% of patients treated with PTCA needed repeat revascularization (17% PTCA, 6% CABG) and 4 patients (6%) suffered nonfatal myocardial infarction. In-hospital mortality and complications were higher among the surgically treated patients (mortality 7%, major complications 45%), a fact probably related to their poorer clinical condition preoperatively. Repeat revascularization rate in the surgically treated group was 2%. The long-term mortality rate in both groups was 10%. Among long-term survivors, 92% of patients indicated that revascularization (PTCA or CABG) improved their quality of life. More than 80% led normal lives, and > 90% would undergo a second procedure if needed. In selected patients aged over 75, PTCA has a high immediate success rate with low complications and mortality. Long-term recurrence rate is high, however, and repeat revascularizations are frequent. Patient satisfaction after myocardial revascularization (PTCA or CABG) is excellent and the majority of elderly patients can lead an active and independent life.

Aged↗
PubMed1997

VATS-guided epicardial pacemaker implantation. Hand-sutured fixation of atrioventricular leads in an experimental setting.

BACKGROUND: In neonates and infants epicardial stimulation may be preferred to endocardial stimulation because of growth-associated lead problems and the risk of vascular complications associated with transvenous electrodes. This study analyzes the feasibility of atrioventricular implantation of a new epicardial lead using the video-assisted thoracic surgical (VATS) technique in an animal model. METHODS: Bipolar steroid-eluting epicardial leads were implanted in seven young white pigs. In five animals bipolar atrial and ventricular pacing leads (n = 10) were inserted and fixed by the VATS technique, while two animals served as controls and underwent implantation through anterolateral thoracotomy. Surgical feasibility, pacing, and sensing thresholds of the leads as well as hemodynamic parameters during pacing were studied. Histological changes beneath the electrodes were evaluated 1 week after the implantation. RESULTS: All animals survived the pacemaker lead implantation. One animal which underwent thoracotomy died because of irreversible ventricular fibrillation induced by rapid ventricular pacing. One animal in the VATS group exhibited intraoperative herniation of the heart through the pericardial window. All animals with left-sided VATS implantations demonstrated good individual pacing and sensing threshold values. The mean cardiac output was 1.6 times higher during AAI-mode pacing as compared to VVI-mode pacing at a heart rate of 140/min. One animal died postoperatively due to respiratory failure. No displacements of the pacemaker leads were observed in the survivors. CONCLUSION: While VATS-guided implantation of epicardial, atrial, and ventricular leads is feasible, technical improvements of the system are mandatory for safe clinical application.

Animals↗
PubMed1997

Extension of the "elephant trunk" technique in complex aortic pathology: the "bidirectional" option.

BACKGROUND: The "elephant trunk" technique, using a free-floating vascular prosthesis, was originally described to facilitate a subsequent operation on the downstream aorta. We developed an additional refinement of this technique, called the "bidirectional elephant trunk." This option may represent an interesting tool in more complex aortic operations, especially when the descending aorta has to be replaced first in patients with concomitant pathology of the ascending aorta or of the aortic arch. METHODS: The initial operation is performed through a left thoracotomy. The proximal elephant trunk is created by invaginating the future aortic arch graft into the descending aortic graft. The proximal anastomosis between the doubled graft and the proximal descending aorta is performed first. During construction of the distal anastomosis, a distal elephant trunk may be inserted likewise. If the aortic arch and ascending aorta have to be replaced later, this second step is performed through a median sternotomy. The free-floating arch graft is pulled out of the proximal descending aorta with a nerve hook, unfolded, and used for total arch replacement. RESULTS: This technique was used successfully in 3 patients without mortality. No major complications were observed excepted persistent hoarseness in a patient with preoperative paresis of the recurrent nerve. No perfusion problems due to the unfolding of the free-floating graft occurred during the second operation. CONCLUSIONS: The bidirectional elephant trunk technique is an interesting option that may be suitable for patients presenting with a complex pathology of the whole thoracic aorta when the descending segment has to be replaced first.

Anastomosis, Surgical↗
PubMed1997

Early and late outcome of operated and non-operated acute dissection of the descending aorta.

OBJECTIVE: At present debate continues concerning the optimal mode of treatment for type B dissections. Controversies are mainly due to discordant results regarding survival following medical or surgical treatment. We assessed early and long-term outcome of acute dissection of the descending aorta treated by emergency aortic replacement, medical treatment or delayed surgery. METHODS: Between 1980 and 1995, 225 patients were hospitalized in the medical or surgical department of our institution with the diagnosis of acute type B aortic dissection. A total of 38 patients (16.8%) underwent replacement of the descending aorta within the first week after hospital admission. Primary indications for immediate surgery were: rupturing aneurysm (n = 15), diameter of the descending aorta (n = 13), malperfusion of the thoracoabdominal aorta (n = 8) and pseudocoarctation syndrome with uncontrollable hypertension (n = 2). All other patients (n = 187) underwent primary conservative treatment on the intensive care unit, including appropriate anti-hypertensive medication. In 12 of them, surgery was denied because of age or significant concomitant diseases. RESULTS: Hospital mortality after urgent or emergency surgery was 21% (8/38 patients) for the overall time period. There has been a significant decrease in hospital mortality during the last 5 year-period (12% versus 30% between 1980 and 1994). Causes of death were: cardiac failure in 3, bleeding complications in 2, postoperative mesenteric ischemia in 2 and septicemia in one patient. From the 30 operative survivors, 9 (30%) patients required further surgery on the native aorta after a mean follow-up of 48 +/- 13 months. Hospital mortality during conservative treatment was 17.6% (33/187 patients). Main causes of death were rupture in 14, thoraco-abdominal malperfusion in 13 and cardiac failure in 3 patients, whereas in 3 patients, the cause of death could not be evaluated. In this group, 9 patients had to be shifted to early surgery during the initial hospitalization because of impending rupture (n = 4), rapidly increasing diameter (n = 2) and suspicion of intestinal ischemia (n = 3). After hospital discharge, surgery for chronic dissection was performed in 47 patients, mainly because of expanding descending aortic aneurysm. Hospital mortality was 8% (4/47 patients). Actuarial survival rates after surgery during the first admission were 85 +/- 6% at 5 years and 61 +/- 8% at 10 years, versus 76 +/- 5 and 50 +/- 7% respectively, following conservative treatment (P < 0.001). CONCLUSION: Nowadays, acute type B dissection can be treated surgically with a reasonable perioperative risk. Despite aggressive anti-hypertensive treatment, hospital mortality of primary conservative treatment is still high and a substantial percentage of patients requires surgery during initial hospitalization. Main causes of death in both groups are rupture and abdominal malperfusion: therefore, closed clinical and radiologic assessment of the whole thoraco-abdominal aorta is of utmost importance. Long-term results are satisfying; unlimited radiographic follow-up allows for detection of potential severe complications and for proper planning of elective reoperations when indicated.

Acute Disease↗
PubMed1997

Thoracotomy and thoracoscopy: postoperative pulmonary function, pain and chest wall complaints.

OBJECTIVE: Two different surgical accesses combined with standard pain management procedures are compared regarding early and intermediate pulmonary function and pain relief. METHODS: In a prospective study, 15 consecutive patients undergoing video-thoracoscopy for pulmonary wedge resection (group 1) were matched to 15 patients undergoing standard postero-lateral thoracotomy for lobectomy (group 2) according to age, gender and preoperative pulmonary function. Postoperative pain control consisted of patient controlled analgesia in group 1 and epidural analgesia in group 2. Pain intensity was scored from 0-4. The predicted postoperative pulmonary function (FVC and FEV 1) after lobectomies was calculated from the preoperative value according to the extent of resection. A clinical measurement was obtained after a mean follow-up time of 4.2 months. RESULTS: The ratios of postoperative measured to predicted values of FVC and FEV1 for group 1 compared with group 2 were 0.64 +/- 0.15 and 0.65 +/- 0.14 compared with 0.60 +/- 0.19 and 0.59 +/- 0.13, resp. (both n.s.) at the first day postoperative; 0.92 +/- 0.18 and 0.95 /- 0.17 compared with 0.76 +/- 0.20 (P < 0.05) and 0.83 +/- 0.23 (n.s.), resp. at hospital discharge; 0.98 +/- 0.10 and 0.94 +/- 0.14 compared with 1.01 +/- 0.17 (n.s.) and 1.10 +/- 0.17 (P < 0.05), resp. at follow-up. Pain intensity score one day after surgery ranged from 0.4 (resting position) to 1.6 (coughing) for group 1, and from 0.3 to 1.2 for group 2. Thirty-six percent of the thoracoscopy patients and 33% of the thoracotomy group complained of persistent pain or discomfort on the site of the operation after 3-18 months. CONCLUSION: Post-thoracotomy pain can be effectively controlled with epidural analgesia and pain intensity is no higher than in patients after thoracoscopy who are managed with patient controlled analgesia. FVC is slightly more decreased after thoracotomy during the early postoperative period. FVC and FEV 1 approach the predicted values after four months in both groups. The rate of persistent pain is similar after thoracoscopy and thoracotomy.

Adult↗
PubMed1997

Experimental assessment of photodynamic therapy with chlorins for malignant mesothelioma.

OBJECTIVE: Photodynamic therapy (PDT) with two chlorin sensitisers was assessed on nude mice bearing human mesothelioma xenografts, and on intrathoracic tissues of minipigs with the same drug-light conditions to optimise the antitumour activity of PDT while preventing photosensitising injury to normal tissues. METHODS: Laser light (20 J/cm2) at 652 nm was delivered to the xenografts 1-4 days after i.p. administration of 0.1 mg/kg m-tetrahydroxyphenyl-chlorin (mTHPC) or an equimolar dose of polyethylene glycol-derived mTHPC (pegylated mTHPC), respectively. The extent of tumour necrosis was assessed by histomorphometry. Intraoperative PDT was then performed to the thoracic cavity of minipigs through a sternotomy with the same drug-light conditions at drug-light intervals ranging from 12 h to 6 days after i.v. administration of mTHPC and pegylated mTHPC, respectively. RESULTS: Both, mTHPC and pegylated mTHPC, resulted in photosensitised necrosis of mesothelioma xenografts at drug-light intervals from 1 to 4 days but the extent of necrosis was significantly larger by use of pegylated mTHPC instead of mTHPC at a drug-light interval of 3 and 4 days. The optimal tumourcidal effect was achieved with pegylated mTHPC at a drug-light interval of 4 days. The photosensitising effect of mTHPC on intrathoracic tissues of minipigs revealed severe damage of virtually all tissues except nerves at short drug-light intervals. Tissue damage gradually became less at longer drug-light intervals and was absent at intervals of 3 days and longer. In contrast, pegylated mTHPC resulted in no obvious change to any structure at any drug-light interval assessed. CONCLUSIONS: PDT with pegylated mTHPC reveals the potential of selective tumour destruction in this experimental setting and deserves further evaluation for intraoperative application in patients with malignant mesothelioma.

Animals↗
PubMed1997

Spontaneous pneumothorax from radiographically occult metastatic sarcoma.

We present two cases of spontaneous pneumothorax secondary to metastatic synovial cell sarcoma. Radiographic techniques initially did not suggest lung nodules in either patients; thoracoscopy allowed sequential bilateral detection of small pulmonary metastases in one case and confirmed the diagnosis during treatment of recurrent pneumothorax in the second case. This report underlines that pneumothorax may be the first clinical manifestation of metastatic sarcoma and can occur even if current imaging techniques are not indicative of metastatic disease. In the latter instance, thoracoscopic exploration has to be envisaged in order to rule out the possibility of metastatic lung involvement.

Adult↗
PubMed1997

Qualitative assessment of blood washing with the continuous autologous transfusion system (CATS)

A number of different blood-processing methods can be used at the end of cardiopulmonary bypass (CPB) to improve the quality of autologous blood. They include centrifugation, hemofiltration and cell-washing. They differ in processing time required, cost of disposables and the quality of the processed autologous blood product. The newly developed continuous auto-transfusion system (CATS: Fresenius AG, Bad Homburg) uses a continuous cell-washing method. In a prospective study, the oxygenator blood of 10 patients was processed at the end of cardiac surgery with CATS and the quality of autologous blood before and after processing was compared. The processing volumes and the time required were recorded. The concentrations and elimination rates of blood parameters and waste products such as activated coagulation and complement products were measured. At the end of CPB a mean volume of 1,010 +/- 174 ml diluted oxygenator blood was processed and concentrated to 310 +/- 88 ml in 11.0 +/- 2.2 mins. Cellular elements such as erythrocytes and leucocytes were mostly retained and their concentration showed a significant increase after processing (250% and 210% respectively; p < 0.01). Thus, the blood processing with CATS resulted in an excellent hemoconcentration (hematocrit 62 +/- 3 vs. 24 +/- 4% before processing) with a consistent reproducibility. On the other hand, the CATS concentrate showed a significant loss of autologous plasma proteins. Likewise, all water soluble elements such as waste products are significantly lower in concentration after processing and, if calculated by quantity, they show a high elimination rate (> 93%). In conclusion, the continuous autologous transfusion system permits an automated, rapid and continuous processing of autologous blood yielding a standardised high quality erythrocyte concentrate.

Aged↗
PubMed1997

Early experience with the new Masters series of St. Jude Medical heart valve: in vivo hemodynamic and clinical results in patients with narrowed aortic annulus.

BACKGROUND AND AIMS OF THE STUDY: Aortic valve replacement in the small aortic root results in a heart-prosthesis mismatch in a significant number of patients. The new Masters series of St. Jude Medical (SJM) valves represents the company's most recent innovation, combining the beneficial Hemodynamic Plus (HP) characteristics with rotatability. Thus, this valve allows for a larger valve orifice area with an equivalent tissue annulus diameter and reduces the potential interferences of subannular tissue with leaflet mobility. METHODS: We compared prospectively the hemodynamic characteristics and the early clinical results in four groups of 25 patients each who received either the 21 Masters-HP, the 21 Standard, the 21 HP or the 23 Standard SJM valves. Patients were selected from our database and matched rigorously for age, gender, body surface area, NYHA functional class, underlying lesion, native valve opening area and left ventricular function, as well as preoperative peak and mean valve gradients. Postoperative evaluation included clinical examination and echocardiographic studies before hospital discharge and at six months. RESULTS: Short-term clinical follow up was marked by a complete absence of valve-related complications in all groups. Doppler-derived mean and maximal pressure gradients were significantly lower in the 21 HP (8.7 +/- 3.1 mmHg and 15.1 +/- 4.0 mmHg, respectively) and 21 Masters-HP groups (8.9 +/- 2.6 mm +/- Hg and 14.5 +/- 3.8 mmHg) than those in the 21 Standard group (15.1 +/- 3.2 mmHg and 22.5 +/- 6.1 mmHg; p = 0.002 and p = 0.004, respectively). These results confirm that the superior hemodynamic performance of the HP series is maintained in the Masters-HP valve, despite the introduction of a new cuff design allowing rotatability. Pressure gradients did not differ significantly between the 21 HP, the 21 Masters-HP and the 23 Standard groups. CONCLUSIONS: The hemodynamic performance of the 21 Masters-HP SJM valve corresponds closely with that of the 21 HP and 23 Standard valves and is substantially better than that of the 21 Standard valve. The Masters-HP valve will continue to reduce cardiac-prosthesis mismatch in normal-sized patients with a narrowed aortic root; its performance index is equal to that of the 21 HP valve and significantly higher than that of the 21 Standard valves. The valve will also further reduce the need for aortic annulus enlargement.

Aged↗