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Biomedical subjects

G Ziemer

Publications and source records attributed to G Ziemer.

At least 37 records · Page 2Linked to original sources
PubMed2001

Influence of high molecular dextrans on lung function in an ex vivo porcine lung model.

BACKGROUND: Extracellular preservation solutions utilizing high molecular agents can reduce intracellular edema during ischemia/reperfusion in lung transplantation. A solution of 40,000 dalton molecular weight (DMW) has already been clinically established (Perfadex). However, it is unclear whether dextrans of this particular size represent the optimal additive for lung preservation solutions. MATERIALS AND METHODS: In a new ex vivo porcine lung model, lungs were each preserved with low-potassium solutions containing 5% dextran with 90,000 DMW (Dex 90) and 160,000 DMW (Dex 160) and with Perfadex (40,000 DMW). After 24 h of cold ischemia, reperfusion was performed employing a roller pump with a pulsatile module. Lungs were perfused with deoxygenated perfusate and ventilated with room air. The oxygenation capacity (Delta pO(2)), peak inspiratory pressure (PIP), and mean pulmonary artery pressure (PAP) were monitored for 60 min. Net weight gain (NWG) and wet-to-dry ratio (W/D ratio) were determined. Free-radical generation was assessed by measuring malondialdehyde (MDA) at 10, 30, and 50 min. RESULTS: PIP and PAP increased in all groups significantly during reperfusion. However, Dex 160-perfused lungs exhibited significantly higher values than those with Dex 90 and Perfadex. Perfadex showed the highest Delta pO(2) throughout the entire reperfusion, while Delta pO(2) was slightly reduced in Dex 160 and significantly lower in Dex 90. In Perfadex the lowest water content was observed assessed by NWG and W/D ratio. The highest MDA values were observed in Dex 90, followed by Dex 160, while the lowest values were seen in Perfadex. CONCLUSIONS: Preservation of the lung with Perfadex exhibited superior postischemic function in contrast to preservation solutions containing dextrans with a higher molecular weight.

Animals↗
PubMed2001

Ventricular septal defect closure in a neonate with combined methylmalonic aciduria/homocystinuria.

Methylmalonic acidemia with associated homocystinuria is a rare inborn error of amino acid metabolism affecting energy supply on the cellular level. Its effects on recovery from surgically induced organ ischemia are largely unknown. We report the successful closure of a nonrestrictive ventricular septal defect by following a normothermic strategy combined with ample metabolic substrate supply.

Amino Acid Metabolism, Inborn Errors↗
PubMed2001

Primary repair of tetralogy of fallot in infancy--the effect on growth of the pulmonary arteries and the risk for late reinterventions.

We sought to analyse the long-term follow-up after primary repair of tetralogy of Fallot in infancy in the first year of life, paying particular attention to growth of the pulmonary arteries and the need for reintervention. We performed a combined retro- and prospective echocardiographic study, including measurements of the pulmonary valve and right and left pulmonary arteries, indexed to the square root of body surface area, in 62 patients prior to primary repair, 18 to 24 months after this event, and at the most recent follow-up, with a mean of 80.4+/-24 months. Of these, 38 patients, with an age at operation of 5.0+/-3.4 months, had presented preoperatively with hypoxic spells or increasing cyanosis. The remaining 24 patients had been asymptomatic, with adequate flow of blood to the lungs. Their age at elective operation was 7.4+/-3.0 months. A transannular patch was needed in 37 patients (63%). There were 3 early postoperative deaths (4.8%). Cross-sectional echocardiography revealed a significantly smaller diameter for the pulmonary valve in patients who had been symptomatic preoperatively compared to the asymptomatic patients (1.09 versus 1.3 cm/BSA0.5; p = 0.019). The diameters of the right and left pulmonary arteries did not differ significantly between the groups. Examination of echocardiographic data obtained 18 to 24 months postoperatively in 43 patients revealed a significant increase in the diameter of the pulmonary arteries; 0.83+/-0.17 cm/BSA0.5 versus 1.1+/-0.26 cm/BSA0.5 for the diameter of the right pulmonary artery, 0.85+/-0.2 cm/BSA0.5 versus 1.0+/-0.25 cm/BSA0.5 for the left pulmonary artery. On comparison between individuals, 18.6% and 25.6% of the patients, respectively, did not show any change in the diameters of their right and left pulmonary arteries, whereas the increase in diameter reached or exceeded the measurements in normal controls in 55.8% and 46.5% of the patients, respectively. On recent follow-up, with a range from 56 to 147 months, no further increase in the indexed diameters of the pulmonaries could be documented in 21 of 33 patients. Of these, 9.1% and 18.2%, respectively, presented with small right and left pulmonary arteries compared with measurements obtained in normal controls. Moderate pulmonary incompetence was found on colour flow mapping in one-third. Of 56 longterm survivors, 8 (14%) had required reinterventions, which were surgical in 6 and achieved by transcatheter techniques in the other 2 patients. Thus, primary correction of tetralogy of Fallot in infancy, with restoration of normal pressures and flows, resulted in sustained increase in the diameters of the right and left pulmonary arteries. It allowed for early normal development of the proximal pulmonary arterial system in most patients regardless of their age and symptomatic status at operation. Patients with persistent subnormal diameter of the pulmonary arteries did not present with significantly elevated right ventricular pressure. Early one-stage repair of tetralogy of Fallot in infancy was associated with a low rate of reinterventions.

Age Factors↗
PubMed2001

Incidence and impact of systemic venous collateral development after Glenn and Fontan procedures.

BACKGROUND: Development of systemic venous collaterals after Glenn or Fontan procedures can lead to systemic desaturation and reduction in ventricular function, resulting in impaired everyday performance in patients with univentricular heart disease. METHODS: We analyzed 79 patients who had undergone a Glenn or Fontan procedure between 1995 and 1999 for the incidence and predilection sites of systemic venous collaterals as well as the therapeutic options. RESULTS: In 16/79 (= 20.2%) patients, 19 veno-venous connections were detected 310 days (1-966 days) postoperatively. Locations were: brachiocephalic angles/pericardial veins (7), azygos/hemiazygos system (5), Thebesian veins (2), epidiaphragmatic veins (5). Drainage was to the pulmonary veins in 5, to the "left" atrium in 9, and to the IVC system in 5 patients. An isolated intervention became necessary because of low saturations in 5/16 pts, with improvement in all of them (catheter embolization 4, surgical closure 1). CONCLUSIONS: After Glenn or Fontan operations, the increased central venous pressure may induce recanalization of embryologically preformed and obliterated vessels. Their predilection sites must be carefully evaluated pre- and postoperatively. During surgical procedures, potential venous channels should be ligated. Interventional or surgical closure of collaterals may become necessary.

Adolescent↗
PubMed2001

Correction of anterior thoracic wall deformities: improved planning by means of 3D-spiral-computed tomography.

Surgical correction of anterior thoracic wall deformities is an extensive procedure with considerable operative trauma. The procedure can be markedly supported by means of preoperative 3D spiral-computed tomography for the purpose of improved preoperative planning in order to avoid unnecessary tissue mobilization. It is also helpful to enhance the patients' comprehension regarding the operative requirements.

Adolescent↗
PubMed2001

Peripheral artery occlusion: treatment with abciximab plus urokinase versus with urokinase alone--a randomized pilot trial (the PROMPT Study). Platelet Receptor Antibodies in Order to Manage Peripheral Artery Thrombosis.

PURPOSE: To evaluate the combination of a platelet glycoprotein IIb/IIIa complex receptor inhibitor and urokinase for treatment of recent (<or=6 weeks) arterial occlusion of the legs. MATERIALS AND METHODS: Seventy patients with lower extremity arterial occlusion of less than 6 weeks duration were randomly separated into two treatment groups: urokinase plus abciximab or urokinase plus placebo. Primary end points were the rate of major complications at 30 days after randomization and the rates of amputation-free survival and survival without open surgery or major amputation at follow-up of 90 days. Two readers unaware of the patients' treatment group assignments analyzed digital subtraction angiograms as they related to the study end points, with a final consensus reading. RESULTS: Thrombolysis relative to clot length was faster in the urokinase-plus-abciximab group (odds ratio, 0.52; 95% CI: 0.35, 0.76; P < .001). There were no procedure-related deaths or intracranial hemorrhages, but the rate of nonfatal major bleeding was higher with urokinase plus abciximab (four of 50 patients) than with urokinase alone (none of 20 patients; P = .32). At 90 days, amputation-free survival was 96% (48 of 50 patients) in the urokinase-plus-abciximab group compared with 80% (16 of 20 patients) in the urokinase alone group. The hazard ratio for the two Kaplan-Meier curves was 0.42 (95% CI: 0.16, 0.96; P = .04). CONCLUSION: In patients with lower extremity arterial occlusion who were undergoing urokinase thrombolysis, adjunctive abciximab treatment resulted in faster thrombus dissolution and improved amputation-free survival, despite an increase in major bleeding.

Abciximab↗
PubMed2001

Oxygenator thrombosis: worst case after development of an abnormal pressure gradient--incidence and pathway.

The development of an abnormally high pressure gradient (APG) before the membrane oxygenator (MO) is a complication that occurs during some extracorporeal circulation (ECC) procedures. The present study deals with the incidence of an APG and discusses a probable causative pathway by comparing surface-coated and uncoated oxygenation systems. Five thousand six hundred and seventeen adult ECCs were carried out (2,581 without and 3,036 with surface coatings). The incidence of an APG, therefore, amounted to 0.03% in the group with coated systems and 4.3% in the uncoated group. In addition, an in vitro study demonstrated significantly reduced adhesion and activation of platelets and leucocytes when the surfaces of the MOs were coated with heparin or polypeptides. The advantages of coating surfaces of ECC devices possibly depend on the selective adsorption of particular plasma proteins. These will presumably form a biocompatible membrane on the surface, and minimize pathological deposit of fibrin, platelets and other blood cells, and, therefore, implicate the prevention of an oxygenator failure.

Blood Platelets↗
PubMed2001

MRI diagnosis of a previously undiagnosed large trabecular ventricular septal defect in an adult after multiple catheterizations and angiocardiograms.

Ventricular septal defect (VSD) is the most frequent congenital heart disease (25-30%). The diagnosis of VSD is usually made echocardiographically by means of colour Doppler ultrasound, and is confirmed by angiocardiography in most cases. We describe a case in which an additional large trabecular VSD was demonstrated by MRI after previous cardiac catheterizations and angiocardiography in various hospitals. MRI allows an exact presentation of the anatomy, including areas that are difficult to assess, for instance the apical septum. Determination of cardiac output, regurgitation volume and the Qp/Qs quotient in patients with shunt volume in heart defects is also possible with one examination.

Adult↗
PubMed2001

Primary cardiac leiomyosarcoma originating from the pulmonary valve. Case report and review of the literature.

Primary cardiac tumours are rare findings (incidence 0.02% according to a recent meta-analysis) with dismal prognosis. Approximately 25% are malignant, mostly represented by sarcomas. Among these, leiomyosarcomas are exceptional. Treatment for primary cardiac leiomyosarcomas consists of radical surgical resection followed by adjuvant radiation therapy and/or chemotherapy. The mean survival after surgery and adjuvant therapies is 6.8 months. We present a rare case of a 40- year-old male patient with a primary cardiac leiomysarcoma originating from the pulmonary valve. This patient died after surgery and implantation of a homograft of the pulmonary trunk. Furthermore, the literature has been reviewed.

Adult↗
PubMed2000

S-100 after correction of congenital heart defects in neonates: is it a reliable marker for cerebral damage?

BACKGROUND: Newborns undergoing cardiac operation may acquire some extent of neuronal damage. An early diagnosis is especially hard regarding neonates. In the past years, S-100 has been widely discussed as a marker revealing perioperative damage to the brain. METHODS: Sequential blood samples from 33 neonates undergoing repair of congenital heart disease were taken perioperatively. Samples of 12 healthy neonates were taken at birth as a control group. The newborns were divided into four groups: cyanotic and acyanotic disease operated on in deep hypothermic circulatory arrest, operation without deep hypothermic cardiac arrest, and operation without extracorporeal circulation. RESULTS: Even in healthy neonates, serum S-100 levels were at 10-fold values compared with adults. On admission, S-100 values in the operative groups were similar. During extracorporeal circulation, levels rose to a certain degree. Cyanotic newborns operated on in deep hypothermic cardiac arrest had significantly higher S-100 levels compared with acyanotic newborns also operated on in deep hypothermic cardiac arrest (p < 0.001). Two newborns who experienced seizures postoperatively had the highest absolute S-100 levels. One child with a poor neurologic outcome but no seizures did not have different values when compared with her group. CONCLUSIONS: In this study, S-100 seemed to be a possible marker for a certain degree of neurologic deficit after cardiac operation in neonates, especially regarding postoperative seizures. The missing peaks of this protein in one newborn with poor neurologic outcome show that it is not possible to exclude damage to the brain with normal postoperative values. These results suggest that the mechanism of cerebral damage and S-100 release into the blood in neonates with a developing central nervous system and blood-brain barrier is not fully understood.

Adult↗
PubMed2000

Successful weaning of a transplanted heart from biventricular assist device.

Exceptionally few cases worldwide have survived weaning from a biventricular assist device following heart transplantation in contrast to those who underwent early retransplantation. We present a successful outcome after biventricular assist device implantation following initial biventricular failure after heart transplantation. Weaning could be performed after 1 week, although pulmonary vascular resistance remained markedly elevated.

Adult↗
PubMed2000

A patient with five primary tumours of the aerodigestive tract and the kidney. The Interdisciplinary Tumour Board, Tübingen.

We report the case of a 65-year-old male who developed an oropharyngeal carcinoma, an oesophageal carcinoma and two primary bronchial carcinomas in combination with a renal cell carcinoma as an additional primary entity. By means of an aggressive diagnostic regimen including radiological and nuclear imaging techniques all carcinomas were detected early and could be treated with curative intention.

Bronchial Neoplasms↗
PubMed2000

[Pulsed spray lysis with reteplase in peripheral arterial occlusions--technique and initial results].

PURPOSE: Urokinase followed by rt-PA are the most frequently used drugs approved for thrombolysis in peripheral arteries in the USA and Europe. We wanted to test the safety and efficacy of low-dose reteplase administered by pulsed spray technique. MATERIALS AND METHODS: 10 patients with acute or subacute occlusion of a peripheral artery (n = 8) or graft (n = 2) were treated (history 8 +/- 17 days; occlusion length 4-60 cm, mean 23 cm). Reteplase was administered as an intra-arterial (i.a.) bolus (0.5 U/10 cm of occlusion length) followed by pulsed spray lysis (1 U/h for the first 2 h, then 0.5 U/h). The catheter was placed into the occlusion. In addition the patients received heparin (i.a.) and aspirin (oral). The site of puncture was closed with a percutaneous suturing system prior to discontinuation of heparin treatment. RESULTS: A total dose of 3.3 +/- 1.2 U reteplase was administered. The primary success rate was 7/10. Two distal embolizations and two bleeding complications were observed (one minor bleeding at the site of puncture and one rupture of the suture which had to be treated surgically). CONCLUSION: With regard to our limited data, low-dose i.a. reteplase seems to be safe and effective. Two bleeding complications were observed which both occurred at the site of puncture. Discontinuation of heparin treatment prior to sheath removal is recommended. Fibrinolysis with reteplase may be an alternative to urokinase or rt-PA.

Aged↗
PubMed2000

Evaluation of protein S-100 serum concentrations in healthy newborns and seven newborns with perinatal acidosis.

UNLABELLED: We measured Protein S-100 serum levels in 66 healthy newborns during the first week of life and in 7 newborns with perinatal acidosis. Normal values (n = 66) constantly ranged between 0.66 and 3.33 microg/l (2.5 and 97.5 percentiles) during the evaluation period. CONCLUSIONS: Newborns with signs of hypoxic-ischaemic encephalopathy (HIE) after perinatal acidosis showed elevated Protein S-100 serum levels, whereas newborns without these signs had normal concentrations. S-100 might thus be a marker of central nervous system damage in newborns. Key words: Asphyxia, brain damage, neonate

Acidosis↗
PubMed2000

The significance of preformed aprotinin-specific antibodies in cardiosurgical patients.

UNLABELLED: Acute hypersensitivity reactions are serious complications of reexposure to aprotinin. Previous contact via infusions or fibrin tissue adhesives can induce specific antibodies. In this study, we aimed to elucidate the preoperative prevalence of aprotinin-specific antibodies in patients scheduled for cardiac operations. Sera of 520 consecutive cardiosurgical patients were collected preoperatively and screened retrospectively for aprotinin-specific IgG using a standard enzyme-linked immunosorbent assay (ELISA). Positive sera were analyzed also for aprotinin-specific IgA (ELISA) and IgE (fluorescence enzyme immunoassay). The histories of all patients were reviewed with focus on aprotinin preexposure. Of 520 patients, 22 (4%) had specific IgG. Only three of these had a documented aprotinin preexposure. Of 448 patients exposed to aprotinin intraoperatively, 15 had preformed specific antibodies. The only patient presenting with severe anaphylaxis was positive for both IgG and IgE, and had a recent IV preexposure in cardiovascular surgery. The presence of aprotinin-specific IgG alone seems not to induce adverse reactions on exposure. Exposure history alone is not sensitive enough to identify patients with aprotinin-specific antibodies. IMPLICATIONS: Anaphylaxis on IV reexposure to aprotinin is a medical emergency. The clinical significance of preformed aprotinin-specific IgG remains questionable, whereas preformed IgE was present in the only patient who suffered from severe anaphylaxis on reexposure to aprotinin. Preformed antibodies are not reliably predicted by exposure history.

Aged↗