Endovascular techniques in limb salvage: cutting, cryo, brachy, and drug-eluting balloons

A Multidisciplinary Approach to End-Stage Limb Salvage in the Highly Comorbid Atraumatic Population: An Observational Study

Background: The use of free tissue transfer (FTT) is efficacious for chronic, non-healing lower extremity (LE) wounds. The four pillars of managing patient comorbidities, infection control, blood flow status, and biomechanical function are critical in achieving successful limb salvage. The authors present their multidisciplinary institutional experience with a review of 300 FTTs performed for the complex LE limb salvage of chronic LE wounds. Methods: A single-institution, retrospective review of atraumatic LE FTTs performed by a single surgeon from July 2011 to January 2023 was reviewed. Data on patient demographics, comorbidities, preoperative management, intraoperative details, flap outcomes, postoperative complications, and long-term outcomes were collected. Results: A total of 300 patients who underwent LE FTT were included in our retrospective review. Patients were on average 55.9 ± 13.6 years old with a median Charlson Comorbidity Index of 4 (IQR: 3). The majority of patients were male (70.7%). The overall hospital length of stay (LOS) was 27 days (IQR: 16), with a postoperative LOS of 14 days (IQR: 9.5). The most prevalent comorbidities were diabetes (54.7%), followed by peripheral vascular disease (PVD: 35%) and chronic kidney disease (CKD: 15.7%). The average operative LE FTT time was 416 ± 115 min. The majority of flaps were anterolateral thigh (ALT) flaps (52.7%), followed by vastus lateralis (VL) flaps (25.3%). The immediate flap success rate was 96.3%. The postoperative ipsilateral amputation rate was 12.7%. Conclusions: Successful limb salvage is possible in a highly comorbid patient population with a high prevalence of diabetes mellitus, peripheral vascular disease, and end-stage renal disease. In order to optimize patients prior to their LE FTT, extensive laboratory, arterial, and venous preoperative testing and diabetes management are needed preoperatively. Postoperative monitoring and long-term follow-up with a multidisciplinary team are also crucial for long-term limb salvage success.

Treatment of Difficult, Calcified Lesions: Plaque Modification Strategies

Endovascular management of peripheral arterial disease is continually evolving. Most changes focus on addressing the challenges that hinder optimal patient outcomes; one of the most significant is how to best treat calcified lesions. Hardened plaque results in a variety of technical issues including impaired device delivery, decreased luminal revascularization, poor stent expansion, heightened risk of in-stent stenosis or thrombosis, and increased procedural time and cost. For this reason, plaque modification devices have been developed to mitigate this issue. This paper will describe these strategies and provide the reader with an overview of devices that can be used to treat chronically hardened lesions.

Cilostazol as a noninferiority pharmacologic option to paclitaxel in early intimal hyperplasia inhibition after venous balloon angioplasty in a rabbit model: a preliminary study

The development of venous intimal hyperplasia (VIH) has not been fully studied. At present, there are no drugs approved for VIH inhibition; to investigate such alternatives, we aimed to compare paclitaxel with cilostazol in VIH early inhibition in a preliminary experimental model of balloon angioplasty. Twenty-eight male New Zealand rabbits were randomly divided into two groups: cilostazol (A) and paclitaxel (B), which underwent femoral vein barotrauma by a 4 mm balloon angioplasty. The VIH model was previously tested in controls obtaining an 80% increase of subintimal area (SIA) compared with veins without injury (from 0.12 mm² [standard deviation (SD), 0.05] to 0.86 mm² [SD, 0.08]). Group A received 20 mg/kg twice daily; group B angioplasty was performed with a single-dose paclitaxel-coated balloon. Seven days later rabbits were euthanized, and vein tissue samples were taken for histological analysis. The primary end point was SIA measure expressed in mm², and the anticipated difference between treatments was 0.21 mm². Other measurements were immunohistochemistry expression of hypoxia inducible factor-1 alpha, platelet derived growth factor, and smooth muscle actin, as surrogates of cell migration and oxidative stress. SIA of group A was 0.33 mm² (SD, 0.15; 95% CI, 0.24-0.42 mm²), and that of group B was 0.31 mm² (SD, 0.14; 95% CI, 0.22-0.40 mm²). Both drugs showed a reduction of 61% and 63%, respectively, in SIA, compared with controls. The difference between both drugs was 0.0193 mm² (95% CI, −0.1175 to 0.156 mm²); the statistical difference was found in hypoxia inducible factor-1 alpha expression between both groups.

Clinical Relevance

Although veins have a thinner middle layer compared with arteries, smooth muscle cells appear to play an important role in venous stenosis after angioplasty. The study of smooth muscle cell response after barotrauma may have clinical applications in the endovascular treatment of venous stenosis, because at the moment, there is no medication indicated to prolong patency after venous endovascular procedures, for example in May Thurner syndrome. Paclitaxel and cilostazol seem to have a promising role. Finally, the present study could inspire a research line to reduce stent placement and increase patency after venous angioplasty.

Endovascular balloon angioplasty for infrainguinal arterial occlusive disease: Efficacy analysis

Background

We present early and mid-term clinical outcomes of endovascular revascularization for femoropopliteal involvement of peripheral arterial disease.

Methods

A total of 128 patients (113 males, 15 females; mean age: 63.4±9.9 years; range, 32 to 87 years) who underwent percutaneous transluminal angioplasty for femoropopliteal lesions between August 2016 and April 2018 were analyzed retrospectively. Treatment with Luminor® paclitaxel-coated drug-eluting balloon catheter or bailout therapy with iVolution® self-expanding nitinol stent were performed. Overall patency rates and freedom from reintervention rates were analyzed using the Kaplan-Meier analysis. The primary patency and freedom from reintervention to target lesion rates at 12 and 24 months were evaluated.

Results

Technical success was achieved in 133 (93%) of the interventions with a median follow-up of 11 (range, 1 to 35) months. At 12 and 24 months, the mean overall patency rates were 85.6±3.7% and 66.8±6.7%, respectively and the mean freedom from reintervention to target lesion rates were 91.6±2.9% and 78.1±6.3%, respectively. The primary patency and freedom from reintervention to target lesion rates were significantly higher in the bailout stenting group than the drug-eluting balloon group at 12 months (97.3±2.7% vs. 94.8±6.1%, respectively, p=0.025 and 97.1±2.9% vs. 84.2±5.5%, respectively, p=0.005) and at 24 months (76.9±7.9% vs. 55.8±13.4%, respectively, p=0.025 and 85.2±7.0% vs. 70.2±13.6%, respectively, p=0.005).

Conclusion

Endovascular procedures including drug-eluting balloon and bailout stenting seem to be effective alternative treatment modalities for treatment of infrainguinal peripheral arterial disease and can be also used in patients with long lesions and/or total occlusion of femoropopliteal arteries.

Lin28a up-regulation is associated with the formation of restenosis via promoting proliferation and migration of vascular smooth muscle cells

To explore the potential role of Lin28a in the development of restenosis after percutaneous transluminal angioplasty, double‐balloon injury surgery and mono‐balloon injury surgery were used to establish restenosis and atherosclerosis models, respectively, so as to better distinguish restenosis from atherosclerotic lesions. Immunohistochemical analysis revealed that significantly higher expression of Lin28a was observed in the iliac arteries of restenosis plaques than that of atherosclerosis plaques. Immunofluorescence studies showed the colocalization of Lin28a with α‐smooth muscle actin in restenosis plaques, rather than in atherosclerosis plaques, which suggested that Lin28a might be related to the unique behaviour of vascular smooth muscle cells (VSMCs) in restenosis. To further confirm above hypothesis, Lin28a expression was up‐regulated by transfection of Lenti‐Lin28a and inhibited by Lenti‐Lin28a‐shRNA transfection in cultured VSMCs, and then the proliferation and migration capability of VSMCs were detected by EdU and Transwell assays, respectively. Results showed that the proliferation and migration of VSMCs were significantly increased in accordance with the up‐regulation of Lin28a expression, while above behaviours of VSMCs were significantly suppressed after inhibiting the expression of Lin28a. In conclusion, the up‐regulation of Lin28a exerts its modulatory effect on VSMCs’ proliferation and migration, which may play a critical role in contributing to pathological formation of restenosis.

Drug-eluting balloon: design, technology and clinical aspects

A drug-eluting balloon is a non-stent technology in which the effective homogenous delivery of anti-proliferative drugs is processed by the vessel wall through an inflated balloon. This is done to restore luminal vascularity in order to treat atherosclerosis, in-stent restenosis and reduce the risk of late thrombosis without implanting a permanent foreign object. The balloon technology relies on the concept of targeted drug delivery, which helps in the rapid healing of the vessel wall and prevents the proliferation of smooth muscle cells. Several drug eluting devices in the form of coated balloons are currently in clinical use, namely DIOR^®, PACCOCATH^®, SeQuent^®Please and IN.PACT™. The device varies in terms of the material used for making the balloon, the coating techniques, the choice of coated drug and the release pattern of the drug at the site. This review gives an insight into the evolution, rationale and comparison of the marketed drug-eluting balloons. Here, different coating techniques have been analysed for the application and critical analysis of available DEB technologies, and a technical comparison has been done.

When Are Endovascular and Open Bypass Treatments Preferred for Femoropopliteal Occlusive Disease?

Several meta-analyses and multicenter trials have shown that chronic limb ischemia did not occur for up to 5 years in 50%–70% of patients who underwent saphenous vein grafts, with limb salvage and perioperative mortality rates of >80% and 3%, respectively. However, open surgical bypass can have limitations, including postoperative morbidity/wound complications of 10%–20% and prolonged length of hospital stay and outpatient care. Several studies have analyzed clinical outcomes for patients with critical limb ischemia treated with endovascular therapies, but they have been mainly retrospective with significant heterogeneity or were single center. Only few randomized trials have compared surgical vs. endovascular therapy. These included the Bypass vs. Angioplasty in Severe Ischemia of the Leg (BASIL) trial, with no differences found in amputation-free or overall survival rates at 1 year; however, late outcomes favored the surgical group. The Bypass or Angioplasty in Severe Intermittent Claudication (BASIC) trial concluded that the 1-year patency rates were 82% and 43% for bypass and angioplasty, respectively. The BEST Endovascular vs. Best Surgical Therapy in Patients with Critical Limb Ischemia (BEST-CLI) trial is currently enrolling patients. This review analyzed studies comparing open vs. endovascular therapy in patients with femoropopliteal disease. (This is a review article based on the invited lecture of the 45th Annual Meeting of Japanese Society for Vascular Surgery.)

Drug delivering technology for endovascular management of infrainguinal peripheral artery disease

Endovascular intervention has become a well-recognized treatment modality for peripheral artery disease; however, mid- and long-term outcomes have been plagued by limited durability. Plain balloon angioplasty and bare-metal stents have historically suffered from high restenosis rates leading to the need for frequent repeat revascularization procedures. The innovation of locally administered, drug-delivering balloons and stents has been a direct result of technological innovations directed toward prevention and treatment of this limitation. Over the last 5 years, numerous clinical trials investigating the use of drug-coated stents and drug-coated balloons indicate a significant improvement in endovascular treatment durability and outcomes. This review provides an up-to-date assessment of the current evidence for the use of drug-coated stents and drug-coated balloons in the treatment of femoropopliteal and infrapopliteal peripheral artery disease. Additionally, it provides an overview of the development of this technology, highlights landmark ongoing and completed clinical trials, examines evidence to support the use of drug-coated technologies in combination with other modalities, and examines promising new technological developments. Last, it summarizes the challenges and safety concerns that have delayed U.S. Food and Drug Administration approval of these devices.

Intravascular brachytherapy for peripheral vascular disease

BACKGROUND

Interventional treatment of arteries that are narrowed and obstructed by atherosclerosis involves either bypassing the blockage using a graft; widening the artery from the inside with a balloon, a procedure known as percutaneous transluminal angioplasty (PTA); or providing a strut to hold the vessel open, known as a stent. All of these treatments are, however, limited by the high numbers that fail within a year. Intravascular brachytherapy is the application of radiation directly to the site of vessel narrowing. It is known to inhibit the processes that lead to restenosis (narrowing) of vessels and grafts after treatment. This is an update of a review first published in 2002.

OBJECTIVES

To assess the efficacy of, and complications associated with, intravascular brachytherapy (IVBT) for maintaining patency after angioplasty or stent insertion in native vessels or bypass grafts of the iliac or infrainguinal arteries.

SEARCH METHODS

For this update the Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched their Specialised Register (last searched August 2013) and CENTRAL (2013, Issue 7).

SELECTION CRITERIA

Randomised controlled trials of the use of brachytherapy as an adjunct to the endovascular treatment of people with peripheral arterial disease (PAD) or stenosed bypass grafts of the iliac or infrainguinal arteries versus the procedure without brachytherapy.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and two other review authors independently extracted the data. Adverse event information was collected from the trials.

MAIN RESULTS

Eight trials with a combined total of 1090 participants were included in this review. All included studies used the femoropopliteal artery. We did not identify any studies that used the iliac arteries. All studies compared PTA with or without stenting plus IVBT versus PTA with or without stenting alone. No trials were found comparing IVBT to technologies such as drug eluting stents or balloons, or cryoplasty. Follow-up ranged from six months to five years. The quality of the included trials was moderate with our concerns relating to the difficulty of blinding due to the nature of the procedures and the small sample sizes for some studies. Primary outcomes (patency or restenosis and need for re-intervention) were reported in the majority of the trials, but reporting at various time points and the use of multiple definitions of the outcomes by the included studies meant that not all data were available for pooling. The secondary outcomes were not reported in many of the included studies.For brachytherapy, cumulative patency was higher at 24 months (odds ratio (OR) 2.36, 95% confidence interval (CI) 1.36 to 4.10, n = 222, P = 0.002). A statistically significant difference was found for restenosis at six months (OR 0.27, 95% CI 0.11 to 0.66, n = 562, P = 0.004), 12 months (OR 0.44, 95% CI 0.28 to 0.68, n = 375, P = 0.0002) and 24 months (OR 0.41, 95% CI 0.21 to 0.78, n = 164, P = 0.007) in favour of IVBT. No difference was found after five years as measured in one study. The need for re-interventions was reported in six studies. Target lesion revascularisation was significantly reduced in trial participants treated with IVBT compared with angioplasty alone (OR 0.51, 95% CI 0.27 to 0.97, P = 0.04) at six months after the interventions. No statistically significant difference was found between the procedures on the need for re-intervention at 12 and 24 months after the procedures.A statistically significant lower number of occlusions was found in the control group at more than three months (OR 11.46, 95% CI 1.44 to 90.96, n = 363, P = 0.02) but no differences were found at less than one month nor at 12 months after the procedures making the clinical significance uncertain. Ankle brachial index was statistically significantly better for IVBT at the 12 month follow-up (mean difference 0.08, 95% CI 0.02 to 0.14, n = 100, P = 0.02) but no statistically significant differences were found at 24 hours and at six months.Quality of life, complications, limb loss, cardiovascular deaths, death from all causes, pain free walking distance and maximum walking distance on a treadmill were similar for the two arms of the trials with no statistically significant difference found between the treatment groups.

AUTHORS' CONCLUSIONS

The evidence for using peripheral artery brachytherapy as an adjunct to percutaneous transluminal angioplasty to maintain patency and for the prevention of restenosis in people with peripheral vascular disease is limited, mainly due to the inconsistency of assessment and reporting of clinically relevant outcomes. More data are needed on clinically relevant outcomes such as health related quality of life (HRQOL) or limb salvage and longer-term outcomes, together with comparisons with other techniques such as drug eluting balloons and stents. Adequately powered randomised controlled trials, health economics and cost-effectiveness data are required before the procedure could be recommended for widespread use.