Reliable Femoral Access is key for Dotter treatment of the legs

Background
In Dotter treatment, also known as PTA, obstructed blood vessels are reopened by devices such as a Dotter balloon or a stent. To get the Dotter balloon in place, a guidewire is used which acts as a rail over which the balloon is routed to the obstruction, which is coloured yellow in both figures above. Obstructions, that lead to an impeded blood supply to the lower leg and foot, are located in the vessel that runs from groin to knee, which vessel is marked with a green arrow in the right figure. Into that vessel the guidewire has to be manipulated in order to properly guide the balloon to the obstruction and perform PTA.

Problem
During the last 40 years Dotter balloons and stents have evolved into highly sophisticated devices. However, the guidewires used to get access - Femoral Access - to the obstructed leg vessels are basically the same as 40 years ago. With standard guidewires, Femoral Access is a difficult and challenging procedure that is prone to complications. The problem is that current guidewires preferentially enter the wrong vessel, which vessel is marked with a red arrow in the left figure above.

Complications
Elaborate manipulations are needed to get the guidewire from the wrong vessel into the right vessel which is marked with the green arrow in the right figure, and such manipulations can result in a complication. Total reported access-related complication rates, including but not limited to groin hematoma, pseudo-aneurysm, and fistula formation, are variable. A systematic review of controlled trials reported a wide range of 2.3 - 33 %. The most frequent complication of Femoral Access performed with current technique is a bleeding that necessitates blood transfusion, occurring in 11.5% of procedures. Due to this well known problem up to 60 supervised procedures are needed for mastering Femoral Access.

Solution
The DFA technique comprises a new device and a highly innovative method. The DFA guidewire finds and enters the desired target vessel by itself as shown in the right figure above. So DFA transforms the currently hazardous Femoral Access into an easy and safe routine procedure. Consequently, implementation of the DFA technique will reduce the long learning curve to master Femoral Access from 60 supervised procedures down to less than 5. In line with expectations routine Femoral Access might reduce complication rates significantly as well.

References

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Biondi-Zoccai et al: Catheter Cardiovasc Interv 2006;68:835.