Vasomotor response to CO2 and L-Arginine in patients with severe internal carotid artery stenosis; pre- and post-surgical evaluation with transcranial Doppler.

BACKGROUND AND AIM: Carotid artery disease may cause both thromboembolism and cerebral blood flow disturbances, particularly in subjects with impaired hemodynamic compensatory mechanisms. The aim of this study was to evaluate by transcranial Doppler (TCD) the hemodynamic changes induced by CO2 and L-Arginine stimulation in a selected population with severe unilateral carotid stenosis (70-80%), before and after carotid endarterectomy, in order to determine the effect of surgery in the vascular hemodynamics of these patients. METHODS: We studied 20 subjects (mean age 66.4 years) consecutively admitted to our institute with ischemia and unilateral severe internal carotid artery stenosis (70-80%) detected by Color Doppler. All patients underwent arterial digital subtraction angiography to confirm the ultrasonographic evaluation. TCD was performed bilaterally; blood flow velocity was monitored during CO2 and L-Arginine stimulation both in basal conditions and three months after surgery. RESULTS: After endarterectomy, mean velocity increased in response to both stimuli with a trend toward statistical significance. A significantly lower reactivity to L-Arginine on the stenotic side was found in the pre-operative phase: this asymmetrical reactivity was no longer observable after carotid endarterectomy. CONCLUSIONS: We found a statistically significant difference in L-Arginine reactivity in the stenotic side of patients with severe unilateral internal carotid stenosis. This is probably related to an alteration of the endothelium function due to the carotid pathology, since the abnormalities disappeared three months after endarterectomy.

Ultrasonic endarterectomy: experimental and initial clinical results in carotid stenosis.

PURPOSE: The effects of ultrasonic endarterectomy, evaluated experimentally and clinically, were compared with the results obtained with controversial endarterectomy. EXPERIMENTAL: An ultrasonic vascular dissector with a frequency of 29 kHz was used for ultrasonic endarterectomy. Gross and histologic observation was made on 22 fresh human cadaver atherosclerotic vessels, of which 16 were treated with ultrasound endarterectomy and 6 conventionally. Clinical: Twenty-eight patients requiring carotid endarterectomy were chosen at random. Seven patients underwent ultrasonic endarterectomy after traditional access surgery, while 21 patients were treated with conventional endarterectomy. In the clinical study, an intraoperative gross observation of the endarterectomized surfaces was made, followed by duplex scanning after 18 and 24 months. RESULTS: Histologic observation of the cadaveric revealed particularly smooth surfaces in 87.5%; there was no debris, flaps, or vessel damage in any of the ultrasonically treated samples. In contrast, the traditional technique produced regular surfaces without residual debris in only 50% of the experimental cases. Favorable results were also seen in the clinical carotid experience, in which there was no need to surgically correct the ultrasonically endarterectomized surface in any case. In fact, achieving a satisfactory outcome was greatly facilitated by the use of ultrasound. In the conventionally treated patients, however, only 19% (4) demonstrated a smooth luminal surface on gross observation even after surgical correction. No postoperative complications were encountered in either group, and no restenosis has occurred in ultrasonic endarterectomy-treated patients after 2 years. CONCLUSIONS: Favorable experimental results using ultrasonic endarterectomy prompted the successful clinical application of this new technique in carotid stenosis treatment. Whether or not ultrasonic endarterectomy can reduce postoperative morbidity and restenosis is still under study.

[Intravenous digital angiography in the control of the patency of extra-anatomical bypasses of the legs]. / L'angiografia digitale endovenosa nel controllo della pervietà dei by-pass extraanatomici degli arti inferiori.

The authors report their experience over 58 cases of extra-anatomical by-pass for revascularity of lower limbs (31 axillo-femoral, 21 femoro-femoral, 2 femoro-popliteal, 4 axillo-femoral) checked using intravenous digital angiography (IDA). This method is useful for its poor invasivity. As a matter of fact intravenous peripheral injection of contrast medium is proved to be sufficient. Moreover it allows clear evidence of anastomosis morphology and functionality both peripherally and proximally. Peripheral flow is also well seen when by-pass works. IDA fills now an area where traditional angiography was not employed for the difficulties in using arterial way. Selective catheterization was also necessary for the evidence of the two far-away districts (axillo-femoral).

[Interatrial communications of the ostium secundum type in the adult (author's transl)]. / Le comunicazioni inter-atriali tipo ostium secundum nell'adulto.

On the basis of personal observations made during their first year of activity in cardiac surgery, the authors review the existing literature concerning surgical indications for interatrial communications in the adult. While they recognize that there is a strong correlation between patient age and mortality, they argue that corrective surgery for such defects can be done also in the older patients, with due regard to limiting criteria relative to pulmonary arterial pressure, pulmonary arteriolar resistance, and cardiac failure.

[Myocardial protection during open heart operations]. / La protezione miocardica nel corso di interventi a cuore aperto.

The need for adequate protection of the myocardial tissue during open heart operations has proved to be of considerable importance in view of the conditioning value of the functional anatomical state of the myocardial fibre on the outcome of the surgery itself. After a review and description of the most widely used methods of protection, the Authors draw on the data in literature in order to trace a critical profile of each method, outlining its merits and defects in the light of present experience.

[Technical variants of median sternotomy]. / Varianti tecniche alla sternotomia mediana

Various modifications of the technique of median sternotomy are described. Advantages thus obtained with respective to saving time and better haemostasis are explained.