Increasing functional status in vascular patients fitted with a prosthesis after amputation was incrementally associated with improved survival, a retrospective analysis of a 10-year experience at a Dallas-based practice showed.
The team at Baylor Scott & White The Heart Hospital-Plano established that as lower extremity amputees referred for an artificial limb progressed through Medicare Functional Classification Levels—known as K-levels—the probability of survival increased.
At the low end, K0 status means a patient has no functional ability with a prosthesis; conversely, K4 status can mean athletic-level ability. Since the Dallas study involved vascular patients, all 123 referred for a prosthesis who were included were K1 to K3 level, explained lead researcher William Shutze, MD, a vascular surgeon with the Texas Vascular Associates practice group. “As patients went from K1 to K2 and up from K2 to K3, that survival curve was sequentially higher statistically,” he told Vascular Specialist. “Our hypothesis initially was that obtaining a prosthetic will improve your survival, but a higher functional level with that prosthetic will even further improve your survival.”
The latest data were presented at the 2024 Southern Association for Vascular Surgery (SAVS) annual meeting held in Scottsdale, Arizona (Jan. 24–27) and are under review for publication in the Journal of Vascular Surgery.
Shutze and colleagues have previously demonstrated that prosthetic referral was an independent predictor of long-term survival among patients who had undergone lower-extremity amputation, finding factors associated with decreased survival were increasing age, higher American Society of Anesthesiologists (ASA) class, Black race, and body mass index (BMI). Prosthesis-referred patients were approximately 50% less likely to experience mortality, they reported in 2021.
With these findings in mind and the latest results from their study of functional status, Shutze said he is now settling on new questions. “Should we really now be taking our patients, after they get their prosthesis, and providing them with more physical therapy to get them to a higher functional level?” he asked. “Should we be encouraging them to get from K1 to K2 or K2 to K3?” K1 status involves a prosthesis-fitted amputee who is able to move around the home on level surfaces; the K2 level involves patients who can ambulate more in the community with the assistance of a wheelchair; and K3 patients have a level of functional independence whereby they can move around in their artificial limb whenever they choose to use it.
“If we could show patients this data and use it to motivate them, to actually see an improvement in their status, then track that person and compare their survival, that would be phenomenal,” Shutze continued.
He now plans to assemble enough partners at other centers in a multi-institutional study to produce more patients who undergo a change in functional status.
But the data out of Dallas are translational right now, Shutze said. “If people really believe the findings, we can start getting more patients into prosthetics and then we can continue to work with them afterward to get them to a higher functional level.”
Prosthetists are important partners in this endeavor, he added. “We know their main focus is on getting these patients a functional limb, but we want to get them as functional as possible with that functional limb.”
All of that said, Shutze lamented his practice’s prosthetic referral rate: it was just 36%. “Even though we are a group that is focused on prosthetics for our vascular patients who lose a limb, our successful referral was less than half. I think that’s a symptom of the barriers in the process of getting a patient from the operating room into the prosthetics office,” he said. “I’d encourage people around the country to look at their own referral rates and see if they are satisfied with those. The literature shows the referral rate at one center was 80%. I think that is a reasonable goal.”
