Critical Limb Ischemia and Below Knee PTA

Speaker:         Robert Bersin
Moderator:      James Benenati
Panelists:        James Zidar
                      Tyrone Collins

Endovascular strategies for critical limb Ischemia are in a state of growth and evolution. The are a number of therapeutic options for endovascular revascularization  of tibial vessels but to date controversy remains regarding the optimal techniques for providing long term clinical benefits.  Revascularization strategies including angioplasty, stenting, drug eluting stents, atherectomy and combinations of the above are widely debated as being the optimal methods.  Access to the target vessels remains challenging in some patients, leading to operator preferences towards retrograde contralateral femoral, antegrade ipsilateral femoral and retrograde tibial access.  Outcomes are difficult to define since patency and clinical outcomes may not coincide in limb salvage situations. Therefore, this growing and vitally important area of endovascular therapy lacks consensus in approaches  and strategies to treat infrpopliteal arterial occlusive disease. 

Unfortunately, there is a paucity of data supporting any one therapy over another.  Secondly, we do not have technology available to us in the U.S. that is available in Europe and in other  countries.  Fortunately, there are trials that have either started or will soon start that will measure outcomes for critical limb ischemia using different techniques for revascularization.  These data will be necessary to validate and justify the time and expense that these procedures require.  There are currently some data with drug eluting stents using coronary drug eluting devices off label in the tibial circulation. These data support the use of these devices over bare metal counterparts.  These devices however have some major limitations. They were not designed for the tibial vessels and therefore are short in length and cannot be used for long segment disease.  Soon, drug-eluting balloon data will begin to be available as trials either enrolling or soon to enroll will accumulate data. The concept of angiosome revascularization is also becoming more popular and there is now data accumulating to support this concept. As more data on techniques and outcomes become available we will be able to refine and develop evidence-based algorithms for the treatment of critical limb ischemia.

At this time the recommendations for the revascularization for critical limb ischemia are primarily based on lower levels of evidence but there is a strong consensus that this growing area of therapy is extremely important for limb salvage and limb preservation.  Current techniques work well with limitations but until better data are available there is no real way to standardize protocols or techniques for these procedures.  Currently, atherectomy, angioplasty and stenting are the primary techniques and depending on operator preference and experience, reasonable results  can be achieved. The use of retrograde pedal access has helped to achieve good results in patients in whom we would previously have failed.