Clinical and scientific considerations in leech therapy for the management of acute venous congestion: an updated review.

Any surgical intervention that involves the manipulation of veins, large or small, carries the risk of acute venous congestion. Venous congestion is the product of an imbalance between arterial inflow and venous outflow, and results in the stasis of blood in the tissues that are normally drained by the affected veins. The resultant lack of tissue perfusion causes hypoxia, acidosis, and arterial thrombi formation, which can potentially progress to tissue necrosis and wet gangrene. In the past several decades, the use of leeches (Hirudo medicinalis) has been rediscovered as an effective method of relieving acute venous congestion. This updated review of leech therapy focuses on the use of medicinal leeches in a variety of clinical conditions characterized by acute venous congestion, and points out the experimental use of leeches in other pathological entities. A discussion of the recent scientific findings that explain the possible mechanisms of action of leech therapy is also provided.

Local gene delivery: arterial thrombosis model for endothelial cell-targeted thrombolytic gene therapy research.

The authors describe a rabbit arterial thrombosis model that employs vessel division followed by microsurgical anastomosis and transluminal sutures, to reliably induce thrombus formation in the common femoral artery (CFA). Using two objective measures, "evacuation/refill" evaluation of patency and computer-aided histomorphometric analysis of the thrombus area, thrombus formation was confirmed and characterized in the model at both short- and long-term observation time-points. In addition, a gene delivery method was developed in the CFA that employs an adenoviral vector solution injected through the inferior epigastric artery (IEA). Using this method, a marker transgene (beta-galactosidase) was delivered to endothelial cells locally and without trauma. By subsequently performing beta-galactosidase staining, effective endothelial transfection was demonstrated simultaneously with endothelial viability, with preserved endothelial synthetic function in the immediate environment of the occluding thrombus. The results suggest that these two techniques can be used together in one model, to effectively introduce a foreign therapeutic transgene into endothelial cells and to evaluate the effect of the expressed protein product in a consistent in vivo thrombosis system. This combined model may be used as one of several assays of efficacy in future endothelial cell-targeted thrombolytic/antithrombotic vascular gene therapy research.