No abstract

Eversion endarteriectomy has been proposed as a reliable and rapid method for operating on an ulcerated or stenosed internal carotid artery. The surgical technique is presented in detail. The perioperative course is appraised in a series of 60 operations. Irrespective of age and other diseases in the patients and the preoperative state of the ipsilateral and contralateral vessels, a perioperative morbidity of 1.6% (a temporary neurological deficit) and no lethal outcomes were found. Indication for operation on the carotid artery depends on the spontaneous prognosis based on the vascular morphology and the rate of perioperative complications. The method of surgery described establishes favorable conditions for endarteriectomy even in the asymptomatic stage as well as in exulcerative lesions of the carotid wall.

No abstract

The influence of controlled ischemia on myocardial ultrastructure was investigated in isolated, metabolically supported canine hearts. Recovery of functionally normal tissue as indicated by the reversibility of morphological alterations was observed up to 60 minutes of anoxia. It was shown that prolonged reperfusion of the empty beating heart supports the recovery of normal cellular ultrastructure. Severe ischemic damage of mitochondria due to ischemia of 60 minutes was almost completely reversible after a reperfusion period of 50 minutes.

In a consecutive series of 150 patients who underwent open heart surgery, absorbable suture (PDS-Ethicon) were used for the closure of median sternotomy. One patient developed sternal dehiscence; wound complications or incompatibility with the suture material did not occur. With the technique of "double" PDS sutures, rapid and secure sternal closure can be performed even in cases of friability of the sternum without cutting through the sternal bone.

Uneven distribution of temperature and the persistence of electro-mechanical activity after aortic cross-clamping are 2 factors limiting the myocardial protection during cardioplegic arrest, especially in hypertrophied hearts which are known to be extremely vulnerable to ischemia. In the present study regional myocardial temperature (T) was continuously controlled, and the time until arrest occurred (delta t) was determined in 61 patients undergoing aortic valve replacement. In addition, the myocardial contents of high energy phosphates and lactate were assessed. Three different cardioplegic solutions were employed: In the first group we used Bretschneider solution (Br), in the second group St. Thomas' solution (St), and in the third group the so-called "Hamburg cardioplegia" (H). During cardiac arrest the regional myocardial temperature was adjusted to temperatures not exceeding 15 degrees C by intermittent infusions of cold cardioplegic solution. We found a positive correlation between left ventricular muscle mass (LVMM) and delta t. A negative correlation existed between LVMM and adenosine triphosphate (ATP) contents at the end of the ischemic period. The cooling characteristics and delta t were significantly longer and the cooling to 15 degrees C was less rapid when H was used. Adenosine-triphosphate contents were well preserved during ischemia in all 3 groups. We conclude that all 3 cardioplegic solutions tested protect the hypertrophied myocardium adequately if the regional myocardial temperature does not increase above 15 degrees C during cardiac arrest. Hearts with a higher LVMM showed a decreased myocardial ATP content at the end of the ischemic period. Therefore, the LVMM may limit myocardial protection.

ZusammenfassungEs wird über die ersten Erfahrungen mit dem Omnicor-System zur permanenten Elektrostimulation berichtet. Die Funktionsweise des R-Wellen-synchronisierten und R-Wellen-inhibierten Pacemakers werden beschrieben. Vorteile sind in einer prospektiven längeren Lebenserwartung der The advantage of programmable cardiac pacemakers.The first experiences with the new OmnicorSystem for permanent cardiac pacing are discussed. The functioning of the R-wave-synchronous and the R-wave-inhibited pacer are described. An important advantage of the new Heruntergeladen von: University of British Columbia. Urheberrechtlich geschützt.

Cardiac pacing in children still presents problems concerning the most favorable placement of the generator and, in particular, the growth-induced electrode complications. Whereas in infants epicardial implantation is unavoidable, one would prefer transvenous placement in older children to permit replacement or removal without extensive operative measures. The use of actively anchorable endocardial leads seems advantageous because of the possibility of placing long electrode loops in the cavity of the right atrium without increasing the risk of dislodgement. In this way overextension of the lead during growth may be avoided. Since June 1975 we have performed ventricular pacing in 10 children, aged 2 to 9 years, by using a transvenous screw-in electrode (surface 6 mm2). Acute threshold values ranged from 0.4 to 0.7 mA ap a pulse duration of 1.0 msec and sensitivity between 6.5 and 8.7 mV. Electrode function has been without complications up to now. In 6 patients we implanted programmable pacemaker systems which allowed postoperative threshold measurements. The chronic threshold value has not increased above 2.3 mA in any of these cases. In our opinion, actively anchorable endocardial leads present significant advantages for pacing in childhood.