Open bypass surgery results in better outcomes for certain patients with severe forms of peripheral artery disease

Open bypass surgery results in better outcomes for certain patients with severe forms of peripheral artery disease

Performing open bypass surgery to restore circulation in people with a severe form of peripheral artery disease (PAD) — a condition that restricts blood flow to the legs and feet — resulted in better outcomes for certain patients compared to a less invasive procedure, a National Institutes of Health-supported clinical research study has found.

More than 8.5 million adults in the United States live with PAD, a condition in which blood flow to one or both legs is reduced due to a buildup of fatty plaque in the arteries. One in 10 develops a severe form of PAD called chronic limb-threatening ischemia (CLTI), a painful and debilitating condition that, if left untreated, can lead to amputation. Up to about 22 million people worldwide have CLTI, which is also associated with an increased risk of heart attack, stroke and death.

Given the projected increase in the number of patients with chronic, limb-threatening ischemia, it is critical that we understand the full impact of our interventions for this disease. These results help and can also support doctors and nursing staff in providing patients with the best possible care.”

Matthew Menard, MD, study author and associate professor of surgery and co-director of the endovascular surgery program at Brigham and Women's Hospital, Boston

The Best Endovascular versus Best Surgical Therapy for Patients with CLTI (BEST-CLI) trial is a landmark study supported by the National Heart, Lung, and Blood Institute (NHLBI). The results were published in the New England Journal of Medicine and presented as the latest research at the American Heart Association's 2022 Scientific Sessions.

To better understand the effectiveness of two common treatments for CLTI, researchers enrolled 1,830 adults who were planning to undergo revascularization, a procedure to restore blood flow to their blocked arteries, and who were eligible for both treatment strategies.

One treatment strategy was open bypass surgery, in which blood is rerouted around the blocked leg artery using a section of a healthy vein. The other strategy was an endovascular procedure - one performed inside the blood vessels, where a balloon is dilated and/or a stent is inserted into the blocked segment of the artery to improve blood flow. To compare the surgical strategy with the less invasive endovascular approach, researchers randomized participants to one of two parallel trials conducted between 2014 and 2021 at 150 medical centers in the United States, Canada, Finland, Italy and New Zealand.

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The first study, defined as Cohort 1, included 1,434 adults who were considered the best candidates for bypass surgery because they had a sufficient amount of an optimal vein (the unipartite great saphenous vein) that was preferred for the procedure. Participants were then randomly assigned to either a surgical bypass or an endovascular procedure. Researchers followed study participants for up to seven years.

The second study, defined as Cohort 2, included 396 adults who were not the best candidates for open bypass because they did not have sufficient volume of the preferred saphenous vein. They were randomly assigned to undergo either an endovascular procedure or a bypass using alternative graft material instead of the saphenous vein. The researchers followed the study participants for up to three years.

At the end of the study, researchers found that participants in Cohort 1 who received the bypass were 32% less likely to have serious medical events related to CLTI than those who underwent endovascular surgery. This result was due to a 65 percent reduction in major repeat operations or procedures to maintain blood flow in the lower leg and a 27 percent reduction in major amputations. No differences were found in mortality rates between participants who received bypass surgery and those who received an endovascular procedure.

Adults in Cohort 2 – those who did not have the optimal vein for bypass – had no significant differences in outcomes based on an open bypass or an endovascular procedure.

“Our results support the complementary role of these two treatment strategies and emphasize the need for preoperative planning to assess patients and inform which treatment will be selected,” said co-principal investigator Alik Farber, MD, chief of the Division of Vascular and Endovascular Surgery at Boston Medical Center.

“This study is an excellent example of how comparative effectiveness research can show us the most promising surgical interventions to improve quality of life and long-term outcomes for those suffering from the most severe cases of PAD,” said NHLBI Director Gary H. Gibbons, MD

Common symptoms of CLTI include leg and foot pain, foot infections, and open sores on the leg and foot that do not heal completely. Without a procedure to redirect or open blocked blood flow to the lower body, about 4 in 10 adults with CLTI have a below-knee or foot amputation.

BEST-CLI is the largest CLTI clinical trial to date and builds on previous research aimed at answering questions about the risks and benefits of revascularization strategies for CLTI.

Source:

NIH/National Heart, Lung and Blood Institute

Reference:

Farber, A., et al. (2022) Surgery or endovascular therapy for chronic limb-threatening ischemia. New England Journal of Medicine. doi.org/10.1056/NEJMoa2207899.

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