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Biomedical subjects

W Konertz

Publications and source records attributed to W Konertz.

At least 91 records · Page 5Linked to original sources
PubMed1993

Polycystic disease of the kidneys complicating the diagnosis of myocardial echinococcosis.

The case of a 30-year-old woman with polycystic disease of the kidneys and a large cyst in the interventricular septum is presented. The hypothesis of an echinococcal disease or of a cardiac manifestation of a polycystic disease was raised. The patient's history, serologic data, and the morphological aspect of the cyst did not give evidence for echinococcal disease before surgery. However, the postoperative pathological evaluation confirmed the diagnosis of a single echinococcal cyst. The presented case shows that even in cases without proven diagnosis of echinococcal disease and preexisting hereditary cysts in other organ systems, care should be taken during surgery to avoid anaphylaxis and preoperative spread of the parasite throughout the body.

Adult↗
PubMed1993

Pulmonary artery origin of the left coronary artery: diagnosis by transoesophageal echocardiography in infancy.

In two infants the anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) was detected prospectively by transoesophageal echocardiography (TEE). Colour flow mapping and pulsed Doppler ultrasound revealed a predominant right-to-left shunt from the pulmonary artery to the left coronary artery. These findings were confirmed by angiography. Transthoracic echocardiography (TTE) failed to show the anomalous origin of the left coronary artery or any abnormal pulmonary flow pattern. TEE may be useful in the diagnosis of ALCAPA in selected cases, when TTE is inconclusive.

Coronary Vessel Anomalies↗
PubMed1993

Non-destructive evaluation techniques for prosthetic heart valves based on hologram interferometry. Part II: Experimental results and clinical implications.

Non-destructive evaluation by hologram interferometry of seven mechanical and seven bioprosthetic valves was carried out. Irregular fringe patterns suspect of intrinsic valve anomaly which may lead to later dysfunction were detected in one mechanical and six bioprosthetic valves. Histologic examination of two bioprosthetic valves revealed focal degeneration, especially in the fibrosa, in those parts of the leaflets that had obvious anomalies on the holographic interferograms. It was shown that the flow turbulences caused by prosthetic valves can also be evaluated using hologram interferometry. The experimental results, obtained with six different types of prostheses (Lillehei-Kaster, Bjork-Shiley, Omnicarbon, St. Jude Medical, Carpentier-Edwards S.A.V. and Valcor), demonstrated the applicability of this technique to both mechanical and bioprosthetic valves. Carrying out non-destructive screening tests for heart valve prostheses may prevent the implantation of potentially dysfunctional devices.

Animals↗
PubMed1992

Technique of aortic valve replacement with the Edwards stentless aortic bioprosthesis 2500.

Aortic valve replacement with a stentless device ought to result in superior hemodynamic function, because obstructing stents and sewing rims are eliminated. From 15 June 1991 to 15 October 1991, 15 patients underwent aortic valve replacement with the newly designed Edwards stentless aortic bioprosthesis 2500. Patients' ages ranged from 51 to 70 years (mean 61 years). Preoperatively 4 patients presented with aortic regurgitation, 7 with aortic stenosis and 4 with combined lesions; 7 patients were male and 8 female. No additional cardiac or noncardiac diseases were encountered. The operations were performed under normothermic extracorporeal cardiopulmonary bypass and cold cardioplegic cardiac arrest. The implanted valves ranged from 21 mm to 27 mm in diameter. Ten patients received a subcoronary implantation with the lower row of stitches made up of interrupted sutures and the upper row of a continuous suture. In 5 patients the so-called miniroot technique was used, also with lower interrupted sutures and running upper sutures, after adaptation of coronary ostia to the performed openings in the graft. Aortic cross-clamp time ranged between 73 min and 94 min (mean 82 min). There was no operative mortality or morbidity. Postoperative echocardiography showed no signs of aortic valve regurgation in any patient and continuous wave-Doppler measurements showed that resting pressure gradients across the aortic valve were absent or low. Our preliminary experiences with a stentless aortic xenograft valve show that in presence of an increased cross-clamp time an improved hemodynamic function will be obtained. Further studies will be needed, however, to establish the long-term behavior of this device.

Aortic Valve Insufficiency↗
PubMed1992

Echinococcal cyst of the interventricular septum: a rare cause of myocardial ischemia.

A 30-year-old woman developed ischemia-like chest pain due to myocardial compression by an intracardiac cyst. The cyst was located in the interventricular septum. Its etiology could not be ascertained despite several diagnostic measures but exstirpation was indicated by the clinical symptoms. Intraoperatively the diagnosis of echinococcosis was established. The cyst was extirpated in toto without perforation of the thinned interventricular septum. Postoperatively the patient was symptomfree.

Adult↗
PubMed1992

Aortic annular enlargement with the use of a homograft valve.

A technique of annular enlargement for use in homograft aortic valve surgery is described. Potential advantages of this technique, that allows convenient valve sizes in small aortic annuli, lie in the pediatric group of patients requiring aortic valve replacement.

Aortic Valve↗
PubMed1992

Gas exchange impairment and pulmonary densities after cardiac surgery.

In 11 patients with impaired respiratory function after coronary artery revascularization surgery, thoracic computed tomography (TCT) and cardiopulmonary profile were obtained. The patients were haemodynamically stable without clinical or radiological signs of lung oedema. Oxygenation was reduced in all patients (alveolo-arterial PO2-difference (PA-aO2) = 37.3 +/- 10.39 kPa, venous admixture (QVA/QT) = 26.4 +/- 4.4%) during mechanical ventilation with positive end-expiratory pressure (PEEP = 5 cmH2O) (0.5 kPa). TCT-scan analysis revealed considerable amounts of crest-shaped bilateral densities in dependent lung regions. There were no differences between the right and left hemithorax. Atelectatic lung tissues were defined as areas presenting with attenuation values of -200 to +20 Hounsfield Units. The magnitude of non-ventilated areas correlated with QVA/QT (r = 0.875, P < or = 0.01), but not with the duration of either extracorporeal circulation, surgical procedure or general anaesthesia. It is concluded that atelectasis in dependent lung areas contributes to impaired gas exchange after cardiac surgery.

Aged↗
PubMed1992

Implantation of a cardioverter/defibrillator in the subpectoral region combined with a nonthoracotomy lead system.

An implantable cardioverter defibrillator was placed into a subpectoral pocket via the incision for cephalic venotomy during implantation of a nonthoracotomy lead system. The approach obviated another incision and subcutaneous tunneling of the leads. There were no perioperative complications and after 6 months of follow-up, the patient continues to tolerate the device satisfactorily.

Electric Countershock↗
PubMed1992

Aortic valve replacement with stentless xenografts.

Between 15th June 1991 and 15th August 1992, 40 patients underwent aortic valve replacement with the newly designed Edwards stentless aortic bioprosthesis 2500. The patients' ages ranged from 24 years to 80 years (mean 60.3 years). Preoperatively, 17 patients presented with pure aortic stenosis, three with aortic regurgitation and 20 with mixed lesion. The operations were performed with normothermic extracorporeal cardiopulmonary bypass and cold cardioplegic arrest. The implanted valves ranged in diameter from 21 mm to 27 mm. Ten patients received a subcoronary implantation, with the lower row of sutures being interrupted and the upper being continuous. The so-called miniroot technique was used in the other 30, also involving lower interrupted and running upper sutures after adaptation of the coronary ostia to the preformed openings in the graft. The aortic cross-clamp time ranged from 51 minutes to 94 minutes (mean 71 minutes). There was no operative mortality but three patients died early after the operation due to cardiac tamponade, sepsis and pneumonia. There was no late mortality or morbidity in the surviving patients up to 16 months postoperatively. Echocardiography, performed at discharge and twice a year thereafter showed no signs of significant valve incompetence in any patient, and continuous wave Doppler measurements indicated that resting pressure gradients across the aortic valve were low or absent. Our preliminary experience with the stentless aortic xenograft shows improved hemodynamic function as compared to stent mounted xenografts or mechanical prostheses. Further studies are needed, however, to establish the long-term performance of this device.

Adult↗
PubMed1991

Implantable cardioverter/defibrillators (ICD): a new lead-system using transvenous-subcutaneous approach in patients with prior cardiac surgery.

The current approach in cardioverter-defibrillator implantation requires placement of epicardial leads which may lead to pericardial and/or pleural effusion and pneumonia during the perioperative period. Although ICD implantation is less invasive than other surgical techniques for the treatment of rhythm disturbances, the perioperative mortality must be considered. Minimizing the operative procedure could lead to a reduction in perioperative mortality. Therefore, we investigated an approach without the need for thoracotomy using a transvenous/subcutaneous lead system. In nine patients with prior cardiac surgery, defibrillator implantation was performed by a transvenous/subcutaneous approach. There was no perioperative mortality. In all patients, a sufficient defibrillation threshold was achieved. The defibrillation pulses were delivered as two sequential pulses between a right ventricular electrode (cathode) and a coronary sinus or superior caval vein electrode (anode 1) and a subcutaneous patch electrode (anode 2). Intubation of the coronary sinus was necessary in 4 patients in order to obtain satisfactory defibrillation thresholds. These data demonstrate that a transvenous/subcutaneous approach is feasible in patients with prior cardiac surgery obviating the need for thoracotomy. Sensing function of the RV-electrode, intubation of the coronary sinus and the intraoperative use of an epicutaneous patch electrode are current problems of this new technique.

Adult↗