8.3 Deep Venous Arterialization for Critical Limb Ischemia

These proceedings summarize the educational activity of the 16th Biennial Meeting of the International Andreas Gruentzig Society held January 31-February 3, 2022 in Punta Cana, Dominican Republic

Faculty Disclosures     Vendor Acknowledgments

2022 IAGS Summary Document

Statement of the problem or issue

Deep venous arterialization (DVA) is a hot topic currently, but it isn’t new. The process was first documented in 1912 by Dr A.E. Halstead, advanced by Dr F. Lengua in Peru, and then recently brought into the endovascular arena by several pioneers in vascular surgery. Initially with this form of treatment, patient selection was considered very conservative, including only Rutherford class 6 limb salvage cases. Based on results from the early pioneers, multiple physicians began arterial-to-venous flow reversal using off the shelf technology. The techniques evolved rapidly over a relatively short period of time. Early on it was learned that the venous valves needed to be addressed and these were treated with balloon angioplasty alone. Valve treatment advanced with the use of cutting balloon angioplasty. Evolution continued with the plantar vein accessed in a retrograde fashion combined with antegrade common femoral artery access. There were other technical variations, all of which led to positive outcomes in terms of limb salvage for patients deemed nonsalvageable. It was learned that higher arterial pressures were necessary to deliver high perfusion pressure into the veins in the foot, otherwise stagnant flow in the foot could lead to higher rates of acute or delayed thrombosis. Today, it is recommended that the inflow for the DVA reversal should be at an arterial conduit level that is viable, contractile, and able to deliver high pressure flow rates. Multidisciplinary collaboration is required to ensure positive patient outcomes, with attention to postprocedure swelling, pain, forefoot surgical debridement, and minor amputation stump management. Wound care specialists and podiatrists must be well-acquainted with the pathophysiology and anatomy in the specific patient setting of swelling and pain. The importance of not transecting the reversed plantar veins is critical. Results from the PROMISE I trial showed high procedural success and improved limb salvage for patients otherwise deemed “no-option” cases.¹ Moving forward, the PROMISE II trial (NCT03970538) has just concluded enrollment.

Gaps in knowledge

We don’t understand completely the exact mechanisms of neovascularization that appear when both antegrade venous flow as well as remnant arterial collateral flow exist. DVA conduit maturation and subsequent tissue perfusion appear to require about 4-6 weeks for tissue granulation to start. Immediately after DVA, symmetric arterial-to-venous flow throughout the foot is seen. But by 6-12 weeks after DVA, both brisk flow and delayed filling of arterialized veins in the digits are noted. We don’t understand the mechanisms for this presently.

We also see delayed arterialization of flow migrating toward the wound area and are unsure whether progenitor cells or signals from the wound are directing angiogenesis toward the area with the highest need for oxygenation. The most curious component of DVA is the fact that, after the procedure is performed and patients’ wounds are healed and doing well, a DVA that then occludes doesn’t seem to make any difference regarding recurrence of ulcers. Interestingly, patients tend to continue to remain asymptomatic and do well clinically. It is not understood why angiography at 6 months and beyond shows the antegrade neovascularization to remain at the highest level despite the DVA conduit being occluded.

The arterialized veins tend to have severely hyperplastic tissue generation right at the junction of the stent grafts and less of it distal from the grafts. It is not understood why the hyperplasia happens in this area. This is one of the Achilles’ heels for DVA.

Possible solutions and future directions

Patient selection for DVA should be expanded beyond “no-option patients.” For example, a patient with a wound in the distribution of one of the tibial arteries and who has failed revascularization by any means should be considered for DVA to ensure oxygenated blood is delivered to the non-healing wound. DVA should be considered for Rutherford class 4 patients. While patients who are Rutherford class 4 may be viewed as “functional patients” to many health care providers, the patients very often do not view themselves the same way. Often these patients can be even less functional than Rutherford class 5 patients who don’t have sensation and therefore have no pain in their feet.

Multidisciplinary DVA teams should be standardized to provide the most efficient long-term benefit to patients who receive the complex DVA procedure. The team should include wound care specialists, podiatry, vascular surgery, endovascular specialists, vascular medicine, and infectious disease. Very importantly, the primary care physician (PCP) must remain involved to address comorbidities, especially chronic kidney disease (CKD) and diabetes, which are prevalent in these patients. It is important to monitor changes in foot tissue color (mottling, cyanosis) after the procedure. Establishing protocols to preserve native arterial perfusion and management of pedal loop outflow is critical during the DVA maturation process.

Reference

1. Clair DG, Mustapha JA, Shishehbor MH, et al. PROMISE I: early feasibility study of the LimFlow System for percutaneous deep vein arterialization in no-option chronic limb-threatening ischemia: 12-month results. J Vasc Surg. 2021;74(5):1626-1635. doi:10.1016/j.jvs.2021.04.057