Angioplasty of distal venous bypasses: is it worth the cost?

Saphenous vein is the best graft for long term patency infragenicular bypass. During follow-up, stenoses can appear on the graft. Is angioplasty a good solution for the treatment of these lesions? During the follow-up of 612 saphenous bypass with below-knee distal anastomosis, 90 stenoses (over 70%) were discovered. Among them 36 were treated with transluminal angioplasty (34 bypasses). Stenoses were detected at a mean follow-up of 7 months after bypass realization. They were located 17 times on the graft itself and 19 times near the anastomoses and they were never longer than 5 cm. Percutaneous approach was preferred for 11 cases and surgical for the others. Immediate success was obtained in 33 cases (91%). Among the 3 failed cases 2 needed a new bypass. Mean follow-up was 33 months after the initial bypass and 24 months after angioplasty. Graft patency was ensured by a single angioplasty in 18 cases. Assisted primary patency, cumulative patency, limb salvage rate were respectively 65%, 91%, 100% at one year and 53%, 72%, 96% at 2 years. Transluminal angioplasty can be advised for the treatment of short stenosis of infrainguinal vein graft: this technique has a weak risk, little surgical aggressiveness, short hospitalisation. Results are acceptable and not very different with the location of the stenosis.

[Pros and cons of use of collagenated arterial prostheses]. / Pour ou contre l'utilisation des prothèses artérielles collagénées.

Use of bovine collagen for collagen arterial grafts raises the problem of possible contamination with the agents causing subacute spongiform encephalopathy. The safety of these products is the confirmed by the manufacturers and the risk of contamination is practically zero. A prospective non-randomized study conducted from January 1991 to December 1992 compared non-impregnated arterial stents with collagen arterial stents. Among the parameters studied, only the amount of blood transfused was significantly different. Collagen arterial grafts generated less blood loss.

Do collagen-impregnated knitted Dacron grafts reduce the need for transfusion in infrarenal aortic reconstruction?

The purpose of this study was to evaluate the benefits of collagen-impregnated Dacron grafts in patients undergoing infrarenal aortic reconstruction. We therefore prospectively compared two consecutive series of patients undergoing infrarenal aortic reconstruction with Dacron grafts between January 1991 and December 1992. The first group (group A) included 83 high-density knitted prosthetic grafts (Dialine I), whereas the second included 82 grafts of the same type but impregnated with collagen (Dialine II). The two groups were comparable with regard to age, sex, and operative risk factors. They were also comparable in terms of the proportion of patients with occlusive disease or aneurysms, that is, there were 39 and 36 patients with occlusive disease and 44 and 46 patients with aneurysms in groups A and B, respectively. The type of bypass was similar in both groups with 17 and 19 tubular grafts and 66 and 63 bifurcated grafts being inserted in groups A and B, respectively. Thirteen parameters were studied and compared within each group including (1) number of infected grafts, (2) number of postoperative occlusions, (3) maximum postoperative temperature, (4) number of positive postoperative blood cultures, (5) number of postoperative deaths, (6) intraoperative and (7) postoperative quantities of blood transfused, (8) difference between pre- and postoperative hemoglobin concentrations, (9) difference between pre- and postoperative fibrinogen levels, (10) difference between pre- and postoperative platelet counts, (11) duration of aortic clamping, (12) date of return of intestinal function, and (13) mean duration of pre- and postoperative hospital stays.(ABSTRACT TRUNCATED AT 250 WORDS)

[Acute occlusions of the aorta]. / Les aiguës de l'aorte.

Acute occlusion of the aorta is a vascular emergency with high mortality, greater than 30% after revascularization, due to the extent of the ischaemic territory and the haemodynamic consequences. Over a period of 12 years, 34 patients (22 males, 12 females) underwent surgery for acute occlusion of the aorta. Acute bilateral ischaemia was present in 24, unilateral ischaemia in 6 and sub-acute ischaemia in 4. An embolus of cardiac origin was the cause in 13 cases, disease of the aorta itself in 11 cases and hypercoagulability in 10 including 7 due to allergy to heparin. The delay from onset of ischaemia to revascularization was 9 hours (mean). Revascularization was done by simple bifemoral embolectomy in 19 cases, by aortobifemoral bypass in 9 and by extra-anatomic bypass in 6 (3 supra-pubic, 3 axillo-bifemoral). Six patients (18%) died during the post-operative period. Delay to care had been greater than 12 hours in most of these patients. One or more post-operative complications occurred in 18 patients (53 p. 100) including repeated thrombosis, insufficient revascularization, ischaemic neuropathy. Long-term survival at 3 years was 30%. Prognosis might be improved by three elements: reducing the duration of ischaemia by rapid diagnosis and emergency revascularization, better control of metabolic disorders, screening for heparin allergy before thrombotic events occur.

Cryopreserved arterial allografts for limb salvage in the absence of suitable saphenous vein: two-year results in 20 cases.

From January 1992 to November 1992, 20 cryopreserved arterial allografts were used as below-knee bypasses for repeated limb salvage in 18 patients lacking saphenous vein grafts. Arteries were obtained during multiorgan harvesting. A scheduled program of cryopreservation with 15% dimethylsulfoxide was used. Mean storage period was 37 days. All cases were matched for blood group compatibility. Patency was checked at 10 and 90 days and twice a year thereafter. Conventional arteriography was routinely performed 3 months postoperatively. Average follow-up was 26.8 months for the 18 patients and 20.8 months for the 20 bypass grafts. No patients were lost to follow-up. Aneurysmal dilation developed in one graft, which was replaced by another homograft. During follow-up 10 grafts occluded: five once, four twice, and one four times. These 10 grafts underwent a total of 16 reinterventions. Thrombectomy with angioplasty was performed 15 times and graft replacement once because of proximal and distal arterial deterioration. Primary actuarial patency was 68% at 1 year and 42% at 2 years. Secondary actuarial patency was 89% at 1 year and 72% at 2 years. Preliminary results of cryopreserved arterial allografts for repeated limb salvage in the absence of available saphenous veins are encouraging. Further studies are needed to determine the long-term deterioration rate of cryopreserved arterial allografts.

An accurate block-trimming device for ultramicrotomy of selected cells.

A small instrument is described which is operated on the stage of a light microscope to trim resin-embedded specimens to precise levels for subsequent ultramicrotomy and to cut thin pilot sections for light microscopy. The operating procedure and examples of results are given.

Recurrent postpartum painless thyroiditis.

We have presented a case of "painless thyroiditis," a syndrome of transient hyperthyroidism with low 131I uptake and no local thyroid gland symptoms. Although the cause is not known, our patient had recurrences after each of her three pregnancies, strengthening the association of this disorder with the postpartum state.