Novel Surgical Procedures Needed to Reduce Amputation Rates

Hello, and welcome to the June 2019 issue of Vascular Disease Management. I have chosen to comment on Gi-Ann Acosta and Dr Richard Neville’s article “Pedal Revascularization: Extending the Limits of Endovascular or Surgical Means to Prevent Amputation.” 

This article discusses the many treatment modalities that are available to revascularize ischemic limbs. It highlights a novel surgical treatment in which thromboendarterectomy and patch of the dorsal pedal artery were utilized to establish flow to a severely ischemic foot as bailout, following failed antegrade interventional attempts at revascularization. The patient had multiple cardiovascular risk factors including diabetes, prior history of coronary artery bypass surgery, and reported renal dysfunction (creatinine of 1.2 mg/dL with no comment on BUN or GFR.) The patient had no suitable foot target arteries initially. Therefore, thrombo-endarterectomy with venous patch of the distal anterior tibial and dorsal pedal artery created adequate outflow. Following this surgical treatment, the patient experienced an improved initial clinical course without long-term follow-up to determine if complete healing was achieved, or to evaluate long-term patency.

Open surgical procedures, particularly distal bypass, have been established as effective therapy in the treatment of critical limb ischemia (CLI). Limitations have typically included the need for adequate inflow (almost always possible), an adequate conduit (clearly preferably long segment autologous vein, but synthetic grafts with a distal venous patch are often effective), and adequate outflow, which often is not present. In addition, access to expert surgical expertise is required. Surgery does not require that the occluded segment be crossed, as the surgeon creates a conduit around the obstruction. In this case, the poor outflow was addressed with a novel technique that allowed successful revascularization in a setting that has historically not been amenable to that therapy. There is no long-term follow-up to determine the durability of this surgical procedure, but if this approach simply allows healing of the foot, long-term foot salvage of the foot may be achieved, because patency and limb salvage are discordant. Perhaps modern medical therapy, including antiplatelet medications and low-dose anticoagulants (Factor X-A inhibitors), coupled with close surveillance, may further improve patency in this case.

I want to comment on the reference to “failed interventional attempt.”  There is a wide variability in reported crossing success and ultimate limb salvage amongst interventionists. There has been great progress in crossing occluded arterial segments related to new improved wires, different access sites including occluded vessels, and new, dedicated crossing and re-entry tools. External duplex guidance has been demonstrated to increase crossing success. Other potential interventional options in this patient would have included retrograde dorsal pedal access and subsequent pedal loop reconstruction via the reconstructed dorsal pedal artery. These interventional options were not attempted. Unfortunately, at this time, the Achilles’ heel of distal arterial intervention is a high restenosis/occlusion rate, which has not been solved. 

Successful revascularization of patients presenting with CLI is improving. Novel surgical and interventional techniques will be required if we are to reduce rates of major amputation secondary to ischemic disorders. Open surgery, interventional therapies, and hybrid techniques will require continued innovation. This novel surgical procedure, as described by Acosta and Neville in their case report, could possibly be one of those innovations.