Bypass surgery linked to fewer amputations in people with severe peripheral artery disease

Reviewed by Emily Henderson, B.Sc.Nov 7 2022

People with severe peripheral artery disease, or PAD, who received bypass surgery to improve blood flow to their legs and feet had 65 percent fewer repeat procedures and 27% fewer amputations than those who had minimally invasive procedures such as angioplasty and stenting, according to preliminary late-breaking research presented today at the American Heart Association's Scientific Sessions 2022. The meeting, held in person in Chicago and virtually, Nov. 5-7, 2022, is a premier global exchange of the latest scientific advancements, research and evidence-based clinical practice updates in cardiovascular science.

PAD occurs when the arteries that carry blood away from the heart to the head, arms, legs and feet become narrow due to a build-up of fatty plaque. It affects more than 200 million people worldwide, and its prevalence is increasing because people are living longer, and more people have Type 2 diabetes, a major risk factor for PAD. The artery build-up results in ischemia, or poor blood flow, to the legs and feet. People with severe PAD may develop chronic limb-threatening ischemia (CLTI), which leads to a high risk for limb amputation and causes pain even while at rest, nonhealing wounds or ulcerations, and tissue damage to the foot and leg.

Re-opening or bypassing the blocked arteries, also called revascularization, is imperative for people with CLTI; without treatment, 20-40% of those with CLTI risk having a major leg amputation. The risk of death also increases for people with CLTI who do not receive proper treatment.

CLTI is treated with bypass surgery, which creates a passage around the blocked arteries using a patient's leg vein or an artificial blood vessel, or a minimally invasive endovascular procedure such as angioplasty and stenting. In this procedure, a thin balloon-tipped catheter is inserted into the blockage to widen it, and a stent is placed to keep the artery open.

The study authors note, however, that while both procedures are considered standard of care, there is little data or guidance on which revascularization procedure is better for these patients. A 2021 American Heart Association scientific statement highlighted the need for more studies comparing surgical vs. endovascular treatment for PAD and CLTI.

Procedure preference may vary by institution and by health care professional based on expertise and training, or availability of technology. As minimally invasive techniques became more available two decades ago, there was a trend toward less bypass surgery. However, it is not clear what is best for people with chronic limb-threatening ischemia in whom the stakes are high."

Alik Farber, M.D., M.B.A., principal investigator, associate chief medical officer for surgical services and chief of the division of vascular and endovascular surgery at Boston Medical Center

The Best Endovascular versus Best Surgical Therapy for Patients with Chronic Limb Threatening Ischemia (BEST-CLI) Trial enrolled 1,830 people with CLTI in 150 centers in the U.S., Canada, Italy, Finland and New Zealand beginning in 2014. Researchers compared the clinical, safety, quality of life and cost outcomes between those who had bypass surgery and those who had endovascular treatment. The study aimed to clarify the appropriate role for both treatment strategies to determine an evidence-based standard for this patient population.

The study participants were an average age of 67 years, 28% were female and 72% were white. Participants included 36% who smoked; 69% with diabetes (with and without insulin dependence); and 11% with end-stage kidney disease. About 22% of study participants reported leg pain at rest as a primary symptom.

The study divided patients into groups and subgroups:

• Group 1 included 1,434 patients whose large leg veins (great saphenous veins) were suitable for bypass surgery. The people in Group 1 were then randomly assigned into two subgroups by their treatment team to undergo either bypass surgery or an endovascular procedure to restore blood flow to the leg.

• Group 2 included 396 patients who did not have saphenous veins that were suitable for surgery. Each participant in Group 2 was then randomly assigned to one of two subgroups to either have bypass surgery using an arm vein or artificial blood vessel or undergo an endovascular procedure.

The researchers compared the outcomes of the subgroups within each larger group. The study was not designed to compare results between Group 1 (those with suitable leg veins) and Group 2 (without suitable leg veins). Major adverse limb events were compared, including the number of major repeat vascular procedures or amputations above the ankle on the limb that had been treated. The study also measured safety by assessing the rate of death, heart attacks or strokes among participants. Participants were followed up to seven years in Group 1, and up to five years in Group 2.

The study found:

• Group 1 results: Among the participants who received bypass surgery using their great saphenous vein, there was a 33% reduction in major adverse limb events compared to the group who received endovascular treatment. There were 65% fewer major interventions and 27% fewer above-ankle amputations than in the endovascular subgroup. There was no difference in the number of patient deaths, heart attacks or strokes between the two subgroups.

• Group 2 results: There was no statistical difference in repeat interventions or amputations between the people who had bypass surgery using an arm vein or an artificial blood vessel and those who had endovascular procedures.

"The results we found within Group 1 are interesting in that there were significantly fewer amputations and major reoperations performed in the people who had bypass surgery, and there was no difference between the treatment groups in the number of patient deaths," said Farber, who is also a professor of surgery and radiology at Boston University School of Medicine. "This information debunks the idea that CLTI patients who need revascularization should have an endovascular procedure first due to concern that bypass surgery may be potentially more dangerous. In this group of people, who were at acceptable risk for surgery and had a good vein available, we determined that surgical bypass led to better outcomes."

The study did have some limitations. The results may have been influenced by selection bias because each study location chose which patients were good candidates for revascularization. Additionally, each investigator selected the specific equipment and methods of treatment, therefore, the surgical and endovascular techniques were somewhat diverse. In addition, the percentage of females in the study was less than expected.

Co-principal investigators are Matthew Menard, M.D.; Kenneth Rosenfield, M.D.; Taye Hamza, Ph.D.; Mark J. Cziraky, Pharm.D., FAHA; and Niteesh Choudhry, M.D., Ph.D. Authors' disclosures are listed in the abstract.

The study was funded initially by the National Heart, Lung, and Blood Institute, a division of the National Institutes of Health. Funding during the follow-up period (2019-2021) was provided by Vascular InterVentional Advances (VIVA), the Society for Vascular Surgery, the New England Society for Vascular Surgery, the Western Vascular Society, the Eastern Vascular Society, the Midwest Vascular Surgery Society, the Southern Association of Vascular Surgeons, the Canadian Society for Vascular Surgery, the Society for Clinical Vascular Surgery, the Society of Interventional Radiology, the Vascular and Endovascular Surgery Society, the Society for Vascular Medicine; Janssen; Gore; Becton Dickinson and Company; Medtronic; Cook; Boston Scientific; Abbott; Cordis; and Cardiovascular Systems, Inc.