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Biomedical subjects

R Frisch

Publications and source records attributed to R Frisch.

At least 19 recordsLinked to original sources

Attachment of hyaluronic acid to polypropylene, polystyrene, and polytetrafluoroethylene.

Surfaces of polypropylene (PP), polystyrene (PS) and polytetrafluoroethylene (PTFE) were activated with radio frequency plasmas Ar and NH3 to aminate the polymer surface and were subsequently reacted with hyaluronic acid (HA) in one of the three different attachment schemes. Results show that ammonia plasma treated polymers were more reactive toward HA attachment. The three chemistry schemes consisted of two distinct approaches: (1) direct attachment of the HA to the aminated surface, and (2) extending the reactive group away from the surface with succinic anhydride and then reacting the newly formed carboxylic acid group with an adipic dihydrazide modified HA (HA-ADH). The latter scheme proved to be more effective, suggesting that steric effects were involved with the reactivity of the HA with surface groups. These HA-coated polymers are a candidate for cell attachment and growth.

Ammonia↗

Long-term results of thrombectomy for late occlusions of aortofemoral bypass.

Sixty-two first episodes of aortofemoral (eight patients) or aortobifemoral (42 patients) bypass thrombosis were operated upon in 50 patients between 1980 and 1985. There were 47 men and three women whose mean age was 58 years. Retrograde thrombectomy through the distal anastomosis was achieved in all cases by using either a balloon catheter or Vollmar rings. If thrombectomy was impossible, revascularization was ensured by an extraanatomic bypass or complete replacement of the graft. Angioplasty, repeat distal anastomosis or femoropopliteal bypass of the native runoff artery were done in 55 (89%) operations. The cause of thrombosis was elucidated in 45 cases. Suture line stenosis and atheromatous stenosis of the native runoff artery were the two most common causes. Three patients died and two required above-knee amputation in the immediate postoperative period. Contralateral embolism occurred in two patients undergoing retrograde thrombectomy. Mean follow-up was 47 months. Thrombectomy was possible in 51 or 62 prosthetic thromboses (Group I). Thirty-nine of these grafts have remained patent. Twelve instances of repeat thrombosis occurred, requiring either repeat thrombectomy or a new bypass. Primary patency in group I was 97.8%, 81.2%, and 71.3% at one, three, and five years, respectively. Thrombectomy was impossible in 11 graft thromboses (Group II). A new bypass was performed in all 11 cases. Primary patency in Group II was 100%, 75% and 50% at one, three, and five years, respectively. Retrograde thrombectomy combined with treatment of native runoff artery anomalies can restore long-term patency when thrombosis occurs late after aortofemoral bypass and is associated with low mortality and morbidity.

Adult↗

Persistent proatlantal artery associated with carotid artery stenosis treatment by percutaneous transluminal balloon angioplasty.

A 58-year-old man had an asymptomatic tight stenosis of the internal carotid artery associated with a persistent proatlantal artery. This as well as other compositional arterial anomalies of the basilar artery were discovered on arteriograms. The stenosis was successfully treated by percutaneous transluminal balloon angioplasty. Therapeutic choices are discussed in this setting because of the risk of carotid clamping in the presence of persistent carotid-basilar anastomoses.

Angioplasty, Balloon↗

[Thrombectomy or thrombolysis in the treatment of proximal phlebitis. Functional long term results].

MATERIALS AND METHODS Between 1981 and 1985, 78 iliocaval thrombi were treated by aggressive therapy: 52 surgical thrombectomies were performed by a femoral approach associated, depending on the case, with a caval approach; and 26 iliofemoral thrombi were lysed according to a protocol in which urokinase and plasminogen were used over a 48-h period. Subsequent functional evaluation was based on clinical scoring (0 to 9 points) taking into account functional impairment, edema and trophic disorders. Patency of trunks and the deep valvular state were assessed by Doppler examination and plethysmography. RESULTS In the surgical group, 3 early deaths occurred, only one of which could be attributed to an embolic course. Six weeks after surgery the rate of recurrence of iliac thrombosis was 50% (25% postoperative + 25% secondary). Beyond this period, there were no recurrences of thrombosis. There was a direct, statistically significant relation between the degree of iliac patency and the realization of an ideal thrombectomy on a nonadherent fresh clot. The functional results, assessed after four and a half years of follow-up, are satisfactory (score less than 3) in 80% of patients. The poor results with venous claudication or varicose ulcer all occurred in the case of massive persistent thrombi of the femoral confluence. Valve lesions were signaled in 46% of patients by a massive backflow in orthostatism. In the medical group, a major hemorrhagic complication occurred under urokinase therapy in 11% of patients, including one for whom it was fatal. Sixty percent of patients showed immediate radiological improvement allowing partial or total freeing of a venous confluence. The functional results after 4 years of follow-up were nondisabling in 85% of patients. No leg ulcers were detected. Late iliac patency was low (26%), whereas at the femoral level almost all of the thrombi which remained after lysis became patent again spontaneously. Valve failure was found in 37% of patients. Both groups had very similar late functional results despite rather different anatomical conditions. The iliac patency rate was higher in the surgical group (50% vs 26%), but plethysmographic study showed that in case of therapeutic failure devalvulation was greater after surgery (46% vs 37%).

Femoral Vein↗

Per-operative uncontrollable bleeding at polyester (Dacron) arterial prosthesis implantation.

An aortobifemoral knitted polyester graft was placed in a 58-year-old woman with aorto-iliac occlusive disease. Although the prosthesis was preclotted in the usual manner, it never became impervious to blood under normal intra-arterial pressure. Examination of the graft showed lipid infiltration not ordinarily seen. We recommend that when a knitted prosthesis fails to preclot a woven graft should be used instead.

Blood Coagulation↗

[The course of Cockett's disease (author's transl)].

The term of Cockett's syndrome stands for a lower limb dysfunction with venous stasis originating from the left common iliac compression by the right common iliac artery at the pelvic inlet level. For the authors, there are three evolutive stages. -- first stage: a simple compression without any anatomic venous parietal lesion. -- second stage: to the previous, are added left common iliac vein lesions consisting of an inner vascular band formation. -- third stage: final evolution: ilio-femoral thrombosis. Therefore, the diagnosis must be done as early as possible. It lies on the left lower limb phlebography.

Constriction, Pathologic↗

[Chemodectomas of the vagus nerve. Pathogenic hypothesis based on a review of 100 cases].

In connection with a personal case, 100 chemodectomas of the vagus described in the literature have been collected: revealing themselves in 75p. 100 of the cases in the form of cervical and pharyngeal tumours, 50p. 100 of the tumours of the vagal glomus involve some neurological manifestations mainly in the form of lesion of the lower cranial nerves. These appear to be either affected in isolation (41 p. 100) or in a dissociated manner (59 p. 100). Intra-cranial extension is rare (7 p. 100 of the cases) and delayed. Carotid angiography is characteristic. 76 p 100 are intra-vagal, 24 p. 100 are para-vagal and 60 p. 100 are located in the plexiform ganglion. Multifocal forms which account for 17 p. 100 of the cases are more usually, but not exclusively, familial. Surgical treatment is followed by sequelae or complications in more than half the cases. Close attention has been paid to pathogenetic theories: chemodectomas of the vagus may develop from type I chemoreceptor cells of the carotid glomera or from distinct cells with different properties (S.I.F. cells). They may equally well develop from nonchromaffin paraganglionic cells which have not migrated in the normal manner. The finding of such cells in the nerves of new-born babies and adults supports this theory, at least for some chemodectomas of the vagus.

Female↗