Biomedical subjects

N Degrieck

Publications and source records attributed to N Degrieck.

5 recordsLinked to original sources

PubMed1991

Immunosuppressive treatment of venous allografts.

In order to evaluate whether temporary immunosuppressive therapy is able to improve the results obtained with viable venous allografts and achieve better results than with synthetic grafts, 142 arterial reconstructions were performed in mongrel dogs bypassing their ligated femoral arteries. Histological as well as immunological studies were performed and patency determined by weekly palpation and regular angiography. The 6-month cumulative patency rates were: Group I: synthetic grafts (a) Dacron: 48%, (b) plasma-TFE: 53%. Group II: fresh grafts (a) autografts: 100%, (b) allografts: 37%, (c) allografts treated with cyclosporin 4 mg kg-1 daily for 1 month: 74% (100% after 1 month). Group III: grafts preserved in Hanks' solution with 15% DMSO at -160 degrees C for 1 month (a) autografts: 77%, (b) allografts: 35%, (c) allografts treated with methylprednisolone 1 mg kg-1 daily: 38%, (e) allografts treated with cyclosporin and methylprednisolone: 83%. Group IV: human saphenous veins implanted as xenografts and treated with cyclosporin and methylprednisolone: 18%. Immunosuppressive therapy with cyclosporin seems to be able to prevent early thromboses due to rejection seen after implantation of viable fresh or cryopreserved venous allografts, and the results are significantly better than those obtained with synthetic grafts. Tissue matching might further improve these results. This study suggests that cryopreserved venous allografts could be used for the creation of a vein-bank and their use, in combination with tissue typing and temporary immunosuppressive therapy may be warranted for arterial reconstructions when autologous saphenous vein is not available.

Animals↗

PubMedDate not supplied

Venous allografts for vascular reconstructions.

In order to evaluate various protocols for the preservation of venous allografts 162 arterial reconstructions were performed in mongrel dogs bypassing their ligated femoral arteries. The cumulative 6-month patency-rates as determined by weekly palpation and regular angiography were. Group I = Synthetic grafts: (a) Dacron 48%, (b) PTFE 53%. Group II = Fresh venous grafts: (a) autografts 100%, (b) allografts 37%. Group III = Veins preserved in saline at 4 degrees C for 1 month: (a) autografts 44%, (b) allografts 34%. Group IV = Veins preserved in saline at -70 degrees C: (a) autografts 58%, (b) allografts 47%. Group V = Veins preserved in glutaraldehyde solution: (a) autografts 26%, (b) allografts 22%. Group VI = Veins preserved in Hanks-solution with 15% DMSO at -160 degrees C: (a) autografts 77%, (b) allografts 35%. Histological as well as immunological studies suggest that these results are determined by the preservation protocol in Groups III, IV and V and by the presence of rejection in Groups I and VI. As the results with the allografts are not superior to those obtained with synthetic grafts, their use should be confined to those cases where the use of synthetic materials should be avoided at any price. Further experiments with immunosuppression and antigenic matching are indicated to see whether this would improve the results obtained with viable venous allografts.

Animals↗

PubMedDate not supplied

The use of homologous veins in arterial reconstructions. An experimental study.

In order to evaluate under what conditions the use of venous homografts could yield the best results. 230 arterial reconstructions were performed in mongrel dogs bypassing their ligated femoral arteries. Cumulative 6-month patency-rates were: Group 1: Prosthetic materials: a) Dacron grafts: 48%, b) PTFE grafts: 53%. Group 2: Fresh veins: a) autografts: 100%, b) allografts: 37%, c) allografts treated with cyclosporin 4 mg/kg.day for one month: 74% (100% after one month). Group 3: Veins preserved in saline at 4 degrees C. for one month: a) autografts: 44%, b) allografts: 34%. Group 4: Frozen veins preserved in saline at -70 degrees C. for one month: a) autografts: 58%, b) allografts: 47%. Group 5: Veins preserved in glutaraldehyde 0.25% for one month: a) autografts: 26%, b) allografts: 22%. Group 6: Veins preserved in 15% DMSO in Hanks solution at -160 degrees C for one month: a) autografts: 77%, b) allografts: 35%, c) allografts treated with cyclosporin 4 mg/kg.day for one month: 72%, d) allografts treated with methylprednisolone 1 mg/kg.day for one month: 38%, e) allografts treated with cyclosporin 4 mg/kg and methylprednisolone 1 mg/kg daily for one month: 83%. Fresh veins and veins preserved in 15% DMSO at -160 degrees C. are viable but immunologically active grafts. In allografts rejection phenomena cause a relatively high occlusion rate which, however, can be prevented with low dose cyclosporin. The optimal duration of immunosuppressive therapy remains to be determined. Veins stored at 4 degrees C or at -70 degrees C are not viable and only weakly antigenic. Their results are not better than those obtained with prosthetic material.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMedDate not supplied

A critical view on the surgical training.

An inquiry set up in the Flemish- and French-speaking parts of Belgium, shows some deficiencies in surgical training. The training of a general surgeon should not take longer than six years. The first four years should consist in a general training in surgery, the last two years being used for the subspecialization. At the beginning of each year, the trainees should be provided with a list of the operations to be performed by the training surgeon. Each hospital, where the training of surgeons is performed, should have a list of its routine operations. An examination is useful: however this should not be the only way to evaluate a trainee. Lectures during working hours are preferable to those given in the evenings. The residents should be allowed to go off duty after a night on duty, this is already standard practice in several European countries. An independent visitation committee, evaluating the departments, their heads and the resident trainees is needed.

Belgium↗

PubMedDate not supplied

Training in surgery: our constructive propositions.

Several suggestions are presented in order to achieve or to maintain a level of excellence in surgical training, i.e. 1. Interuniversity theoretical teaching; 2. National evaluation; 3. Effective limitation of the number of residents; 4. Residents must be represented in critical organs; 5. A yearly evaluation of the quality of training. These requirements are fulfilled in the USA and Canada.

Belgium↗