Early cuff anchorage for tunneled central venous catheters using a buried absorbable suture.

PURPOSE: Long-term tunneled cuffed central venous catheters (CVC) are widely used for the administration of chemotherapy, parenteral nutrition, and fluids. External migration and displacement of catheters have been reported to occur in 2.4% to 24% of cases, prompting the development of various anchoring strategies. We report an adaptation of previous techniques, where the cuff of a tunneled catheter is prevented from moving outwards by inserting a buried absorbable purse string suture around the catheter. Its effectiveness in catheter fixation has been assessed in a prospective audit. METHODS: The effectiveness of the anchoring suture was assessed in a cohort of 101 oncology chemotherapy patients using specific measurements of catheter movement (Dacron cuff to suture distance, Dacron cuff to exit site distance, and external catheter length), taken at catheter insertion and removal. RESULTS: Catheters were placed in situ for a median of 16 weeks. Displacement was found in 19% to 36% of lines (depending on the specific measurement taken), with a median cuff to exit site movement of 7.5 mm (range 5 to 40 mm) and a median length of external line movement of 10 mm (range 5 to 70 mm). The suture had good cosmetic results. CONCLUSIONS: This is, to our knowledge, the first study to attempt to quantify CVC movement. Our data suggest that this suture technique provides an effective and safe additional strategy for cuffed tunneled CVC fixation.

Common variation in the C-terminal region of the fibrinogen beta-chain: effects on fibrin structure, fibrinolysis and clot rigidity.

Fibrinogen BbetaArg448Lys is a common polymorphism, positioned within the carboxyl terminus of the Bbeta-chain of the molecule. Studies suggest that it is associated with severity of coronary artery disease and development of stroke. The effects of the amino acid substitution on clot structure remains controversial, and the aim of this study was to investigate the effect(s) of this polymorphism on fibrin clot structure using recombinant techniques. Permeation, turbidity, and scanning electron microscopy showed that recombinant Lys448 fibrin had a significantly more compact structure, with thin fibers and small pores, compared with Arg448. Clot stiffness, measured by means of a novel method using magnetic tweezers, was significantly higher for the Lys448 compared with the Arg448 variant. Clots made from recombinant protein variants had similar lysis rates outside the plasma environment, but when added to fibrinogen-depleted plasma, the fibrinolysis rates for Lys448 were significantly slower compared with Arg448. This study demonstrates for the first time that clots made from recombinant BbetaLys448 fibrinogen are characterized by thin fibers and small pores, show increased stiffness, and appear more resistant to fibrinolysis. Fibrinogen BbetaArg448Lys is a primary example of common genetic variation with a significant phenotypic effect at the molecular level.