An evaluation of the Doppler-laser system in monitoring the free skin flap in the rat.

The authors discuss their experience in monitoring the free skin flap in the rat with a newly-conceived Doppler-Laser system. The results obtained are compared with a method which is currently used as skin thermometry and the influence in the clinical field is evaluated.

Laser-Doppler versus fluorometry in the postoperative assessment of a cutaneous free flap.

To find the optimal means for monitoring the vascularity of a cutaneous free flap in the postoperative period, we have experimentally compared laser-Doppler velocimetry and fluorometry. Using the rat groin model, five groups were evaluated: 1. flap isolation without division of the pedicle vessels (island flap); 2) flap isolation, division, and repair of the pedicle artery and vein (free flap); 3) flap isolation, with ligation of the pedicle artery immediately or 1 hour later; 4) flap isolation, with ligation of the pedicle vein immediately or 1 hour later; 5) flap isolation, with ligation of the pedicle artery and vein immediately or 1 hour later.

[Progressive complications associated with polyester arterial prostheses. Study of 61 specimens following surgical excision].

Reports of individual surgical cases tend to be anecdotal because of the unique circumstances surrounding the patient, the surgeon, the intervention and, where applicable, the prosthetic device. To overcome this limitation the authors have taken a wider collaborative approach and report the analysis of 61 explanted polyester arterial prostheses associated with delayed complications on 53 patients reoperated upon in six different French hospitals. One advantage of such an independent and centralized retrieval programme is that the impact of centre specific factors, such as patient selection and surgical techniques, is minimized.

Chemically fixed human umbilical cord vein grafts as arterial substitutes: potential and limits.

In spite of reported successes, synthetic fabric grafts and microporous and plain synthetic conduits have proven unsuitable for aorto-coronary bypasses and showed weaknesses below the knee. Readily available and uniform diameter vascular substitutes with biological and mechanical properties comparable to human vessels would be of paramount interest. Following reported successes with chemically fixed human umbilical veins (HUV), we have attempted to develop smaller diameter blood conduits and have improved the currently prevalent techniques of fixation, preparation and storage to generate more convenient surgical products.

Gastric stress ulcer of the rat: relative contribution of the pyloric sphincter, HCO3- bile reflux and mucosal blood flow.

Gastric ulceration has been induced after stress, combining 24 h of fasting and 48 h of restraint in 9 groups of 20 rats with or without a pyloroplasty or a pylorojejunostomy combined with atropine and gastric infusion of NaHCO3 or taurocholic acid. After death or sacrifice at 48 h, ulcer index and blood in the jejunum were determined. Gastric mucosal blood flow was measured semi-continuously by a laser Doppler velocimeter.

A new laser Doppler interface for the continuous measurement of the rat gastric mucosal blood flow.

The laser Doppler system (LD) has been proposed for a tissue blood flowmetry. However, its accuracy is dependent on the pressure and direction of the laser probe. Therefore, we have devised a new interface for the measurement of the gastric mucosal blood flow in rats keeping the probe constant in pressure and direction.

A method of exocrine pancreatectomy in the rat.

The abdominal cavity of male albino rats, average weight 250 g, was opened and the duodenum approached where the ductus choledochus joins. Pancreatic ducts empty into the lower third of the choledochus. The ductus choledochus was cannulated with a Teflon catheter beneath the liver and its other end was brought out at the neck of the rat.

[Glutaraldehyde - fixed human umbilical cord vein as a small diameter arterial substitute. Experimentation on the monkey].

Autologous saphenous veins, the preferred substitute material for aorto-coronary, femoro-popliteal and femoro-tibial by-pass, are usable in only 70% of individuals in need of such procedures. The development of small diameter substitute arteries is therefore essential to broaden the pool of patients who could benefit from this class of cardiovascular surgery. Existing substitutes, however, present major difficulties and have had limited success.

New alternatives in the preparation of chemically fixed human umbilical veins as arterial substitutes.

Following reports of the successful use of chemically processed human umbilical veins as medium and small diameter arterial substitutes, the development of new and improved techniques for the preparation, fixation and storage of these bioprostheses has been attempted. A series of physical and "in vitro" tests was undertaken to predict the "in vivo" performance of these devices. The results indicate that the new techniques are not only technically feasible but may provide a more convenient, versatile and effective surgical product.

[Urokinase (in situ) in the case of acute ischemia of the lower limbs (author's transl)].

Eighteen patients with severe, acute ischemia of the lower limbs were treated with an arterial perfusion of the ischemic leg with Urokinase. This was associated, in thirteen patients, with a limited attempt of revascularization. The result of this treatment was an immediate improvement in twelve cases, which lasted, more than six months, in six patients.

Processes human umbilical veins as arterial substitutes--evaluation in canine models.

Human umbilical cord vein segments have been used as vessel substitutes for damaged or occluded arteries, as aorto-coronary by-passes and as arterio-venous fistulae for dialysis. The Dardik-Biograft fixed with glutaraldehyde and the Mindich-Bioflow, fixed with ethanol and dialdehyde starch, are commercially available. They were implanted in dogs as replacements for a segment of the abdominal aorta.