S. Franke

Species-dependent premature degradation of absorbable suture materials caused by infection – Impact on the choice of thread in vascular surgery

BACKGROUND In case of infection after vascular reconstruction, preference is often given to absorbable suture material with the aim of preventing persistence of infection. We have investigated the functional deficit of absorbable sutures on incubation with various different bacteria. MATERIAL AND METHODS Four suture materials Dexon bicolor, Vicryl, Maxon and PDS II--were placed in contact with reference bacterial cultures (Staphylococcus aureus, Pseudomonas aeroginosa, E. coli, coagulase-negative staphylococci and Proteus mirabilis). The bacteria were incubated for 7 days at 37 degrees C, together with the suture material. A logarithmic phase (Group A) and a static phase (Group B) were simulated. The linear tensile strength (LTS) of the suture material was measured (Instron Tensiometer). RESULTS In the case of Staphylococcus aureus, a significant decrease in LTS was established for Dexon bicolor (group A: 31%, group B: 22%), and Vicryl (53% and 43%), but not for the monofilament threads. With regard to the other bacteria, a considerably more dramatic effect was observed: in both groups the braided sutures had completely disintegrated after 7 days. The monofilament sutures also revealed a significant loss of function (Maxon: 88%, PDS II 66%). CONCLUSIONS The absorbable sutures revealed a premature, species-dependent loss of function due to the presence of the bacteria. On the basis of our results, the use of absorbable threads for vessel sutures in case of infection cannot be recommended, with the exception of monofilament material in a monocultural Staphylococcus aureus infection.

“Hot Ulcer” of the Hand Caused by Retrograde Flow of Arterialized Blood from an Arteriovenous Fistula A Case Report

Venous hypertension of the hand and forearm is a rare complication of upper extremity arteriovenous (AV) fistula operations for hemodialysis. In severe cases of hand venous hypertension, nonischemic skin ulceration may develop. Our observed case and systematic analysis of the literature show that these venous ulcers of the hand typically are associated with retrograde arterialization of distal fistula vein side branches. We suggest calling these hyperemic skin lesions “hot ulcers” in order to distinguish them from ischemic ulcers. In most instances, hot ulcers are curable by selective ligation of the venous tributaries. If proximal venous outflow is also obstructed, attempts of outflow reconstruction should be undertaken. If this is not feasible, the AV fistula needs to be completely reconstructed.