Influence of Different Types of Catheters on the Development of Diseases of the Jugular Vein in 45 Horses

[Venous catheters in horses - early ultrasonographic venous abnormalities and evidence of biofilms]

OBJECTIVE

Complications associated with indwelling intravenous catheters vary from minor to severe. Changes in tissue architecture and vein structure may be detectable prior to clinical alterations. The aim of the study was to characterize and compare changes in a catheterized vein and surrounding tissue by clinical and ultrasonographic examination. Microbiological infestation of catheter specimens was assessed.

MATERIAL AND METHODS

In this prospective, observational, clinical study 55 horses with an indwelling intravenous catheter have been included. Subsequent to catheter placement, vein and surrounding tissue were daily examined clinically and by ultrasonographic examination at predetermined localizations. After sterile removal of the catheters, specimens underwent microbiological testing and scanning electron microscopy. Obtained data were analyzed via descriptive statistics. Thickness of the venous wall was compared at predetermined localizations and time points for several parameters with the help of non-parametric tests (level of significance at p < 0.05, post-hoc Bonferroni correction).

RESULTS

Overall, in 41.8 % of the horses transient alterations (swelling) of the surrounding tissue occurred during catheterization. Median catheterization was 69.5 hours (19 hour-10 days). With ultrasonography, venous valves and collateral vessels could be detected reliably. Significant alterations in wall thickness during catheterization were associated with various factors (location site [p ≤ 0.001], season [p = 0.006], anesthesia [p ≤ 0.001]).Microbiological analysis revealed a positive result in 23.5 %, 12 of the 51 samples; raster electron microscopy showed presence of bacteria in 25.0 %, 4 of the 16 investigated catheter samples.

CONCLUSION AND CLINICAL RELEVANCE

Local tissue changes at the insertion site of the catheter are commonly associated with catheterization, and are easily detectable with ultrasonography. Despite the easy performance in a clinical setting, the benefit of routine ultrasonographic monitoring of catheterized veins might be questionable with regard to early identification and prediction of catheter-associated venous disease. Bacteria might be detectable morphologically on the catheter but frequently lack a positive result from standard bacterial cultivation.

Unilateral jugular vein stenosis in five horses and experience with percutaneous transluminal angioplasty

BACKGROUND

Venous stenosis, a possible cause of jugular dilatation and congestion, is well known in human medicine but has poorly been described in horses.

OBJECTIVE

To report unilateral jugular vein stenosis as a cause of jugular vein dilatation in horses and describe treatment by percutaneous transluminal angioplasty (PTA).

STUDY DESIGN

Case report.

METHODS

Details of horses diagnosed with unilateral jugular stenosis were retrieved from medical records.

RESULTS

Five horses were presented with a non-painful, unilateral dilatation of the jugular vein of which two horses showed headshaking during exercise. In one horse an indwelling catheter had been used and jugular dilatation developed 4 weeks later. In the other horses, no intravenous injections had been administered in the months before jugular dilatation developed. Ultrasonographic examination revealed venous stenosis in all horses approximately 5-10 cm cranial to the thoracic inlet. The internal diameter at the level of this stenosis was only 1-3.1 mm. The length of the stenosis was about 15-19 mm with a markedly thickened intima and media on ultrasonography. After enoxaparin treatment, PTA was performed in three horses. During the procedure the stenotic vein was dilated three times with progressively increasing pressures up to 12 atm. The stenotic diameter increased to a maximum of 4.9 mm with improved jugular blood flow. Aftercare included anti-inflammatory and anti-thrombotic therapy.

CONCLUSION

Jugular vein stenosis occurs in horses and should be included in the differential diagnoses of unilateral jugular vein dilatation. It may present in the absence of previous intravenous treatment. PTA of the jugular vein is feasible to improve jugular blood flow.

Cranial superficial epigastric vein phlebitis and septicemia in dairy cows in Brazil

Cases of cranial superficial epigastric vein (CSEV) phlebitis with subsequent septicemia were observed in dairy farms in Minas Gerais, Brazil. Autopsy on 4 affected cows, from 2 farms, revealed CSEV thrombophlebitis with perivascular abscesses, pulmonary abscesses, valvular endocarditis, arthritis, thromboembolic nephritis, and renal infarcts. Microscopic examination revealed fibrosing and lymphoplasmacytic phlebitis with occasional endothelial loss, subendothelial areas of necrosis, and abundant fibrin deposition. Trueperella pyogenes, Escherichia coli, and Staphylococcus aureus were isolated from lesions of 3 different cows. Thrombophlebitis of the CSEV is a rare condition in dairy cows; however, it has become more frequent in dairy farms in southeastern Brazil after repeated venipuncture of this vein, likely with contaminated needles used for administration of oxytocin.