How to Optimize DCB Results in BTK Arteries: ‘Deep Drug Delivery Is Key!’

Francesco Liistro (San Donato Hospital, Arezzo, Italy) returned to the LINC podium yesterday to share a pragmatic, mechanics-first approach to drug-coated balloon (DCB) therapy in below-the-knee (BTK) arteries. Drawing on his experience with complex chronic limb-threatening ischemia, he walked delegates through how meticulous vessel preparation, physiologically guided optimization, and a disciplined inflation technique could transform the effectiveness of current DCB platforms. His talk focused less on headline results and more on the practical steps that, in his view, make “deep drug delivery” a realistic goal in heavily diseased BTK vessels.

Speaking to LINC Today, Professor Liistro began by explaining why BTK angioplasty still fails for mechanical reasons, and how these failures can be tackled. “Atherosclerotic disease of BTK vessels is characterized by a large plaque burden with a thick fibrocalcific intimal layer, which is responsible for vessel recoil, residual critical stenosis after ballooning and reduced drug transfer,” he began.

In a previous study, Professor Liistro and colleagues defined mechanical target-lesion revascularization (TLR) as a reintervention within the first month after angioplasty that was related to a suboptimal angioplasty result rather than failure of the drug-eluting device. The suboptimal result could be due to residual critical stenosis, vessel recoil, or a flow-limiting dissection. They showed that outcomes of balloon angioplasty could be improved using extravascular ultrasound guidance, which measures flow velocity in residual stenoses or dissected segments, helps select the appropriate balloon size, and supports long inflations (5–7 minutes) in segments with flow-limiting dissection.

Sharing his ideal vessel-preparation sequence in BTK before DCB use, Professor Liistro described starting with balloon angioplasty using a 1:1 vessel-to-balloon size ratio and a slow increase in inflation pressure up to 16–18 atm, noting that this gradual escalation helps to reduce dissection. If the stenosis does not yield, he enlarges the balloon diameter and shortens the balloon length; if this still fails to achieve an adequate result, he then considers adjunctive plaque-modifying tools such as atherectomy or Shockwave devices.

Professor Liistro explained that he considered a BTK lesion ready for DCB treatment only after achieving what he defined as an optimal balloon angioplasty result, characterized by less than 30% residual stenosis on angiography and no flow-limiting dissection on extravascular ultrasound, including a normal flow pattern and a peak systolic velocity ratio below 1.5.

When asked whether DCB failure in calcified BTK disease was primarily a drug problem or a mechanics problem, Professor Liistro stressed that both aspects are important, and that this issue has not yet been resolved. “We hope that orbital atherectomy and temporary spur stent coupled with DCB may increase immediate and long-term efficacy. In a small, randomized pilot study, DEBATE-BTK SHOCK, we tested intravascular lithotripsy prior to DCB in BTK intervention but the results were no better compared to DCB alone. In The OPTIMIZE BTK randomized pilot study there was a trend for higher patency in favor of atherectomy plus DCB.”

Professor Liistro explained that when optimizing DCB delivery in BTK disease, especially in the context of chronic limb-threatening ischemia, the choice of endpoint depends on the question being asked. “If we want to test DCB efficacy we should be focusing on patency,” he said, noting that all other clinical endpoints were heavily influenced by baseline patient characteristics, the consistency of wound care and surveillance, and the availability of a fast-track pathway for reintervention. Wound healing, time-to-heal, limb salvage and similar measures were therefore critical from a clinical perspective but less reliable as pure read-outs of DCB performance. He added that centers performing BTK interventions should work within a multidisciplinary team structure to manage these multiple moving parts effectively.

Looking at the longer-term evidence base, he acknowledged that BTK DCB data had been mixed historically, but saw a clear pattern emerging from studies such as DEBATE-BTK and other datasets. According to Professor Liistro, DCBs tended to provide better patency in BTK arteries for roughly 18–24 months, after which a late catch-up phenomenon reduced the patency advantage, so that by three years there was no longer a significant difference versus plain balloon angioplasty. “However, the advantage in TLR remains, and this is the most important value of using DCB,” he commented, emphasizing the ongoing reduction in clinically driven reinterventions as the key rationale for BTK DCB use.

On drug choice, he advised caution in drawing simple conclusions from early comparisons of paclitaxel- and sirolimus-based BTK DCBs. Paclitaxel and sirolimus are fundamentally different types of anti-restenotic drug, noted Professor Liistro, and current DCB platforms used distinct coating and elution technologies tailored to each compound. For that reason, he felt “the results of any comparison should be confined to the technologies used rather than the drug itself.” He pointed to the DEBATE-BTK DUELL pilot, which showed no significant difference in TLR between a paclitaxel DCB (Litos, Acotec) and a sirolimus DCB (Magic Touch, Concept Medical), although there was a trend towards lower reocclusion with paclitaxel. He noted that core-laboratory angiographic analyses were expected to report during 2026, which might further clarify these early observations.