Drug-eluting balloon angioplasty versus uncoated balloon angioplasty for the treatment of in-stent restenosis of the femoropopliteal arteries

Rotarex®S rotational atherectomy combined with drug-coated balloon angioplasty for treating femoropopliteal artery in-stent restenosis

OBJECTIVE

This study aimed to analyze the safety and mid-term outcomes of a hybrid treatment method combining rotational atherectomy (RA) with drug-coated balloon (DCB) angioplasty in patients with femoropopliteal artery in-stent restenosis (ISR).

METHODS

This single-center retrospective study enrolled patients from January 2018 to March 2022 who had femoropopliteal artery in-stent restenosis treated by RA and DCB. Preoperative demographics, operative details, and postoperative 12-month follow-up outcomes were analyzed statistically.

RESULTS

38 consecutive patients (31 men; mean age 69.55 ± 9.18 years, range 54-91 years) with Tosaka II (n = 8) and III (n = 30) ISR were treated with RA Most patients had a high prevalence of typical vascular comorbidities. Overall, 50% of patients had chronic limb-threatening ischemia, and the average lesion length was 155.0 ± 54.8 mm. The primary patency rate, assessed by duplex ultrasound at 12 months, was 86.7%; 7.9% (3/38) of patients underwent target lesion revascularization (TLR). The overall mortality rate was 2.6% (1/38), and the ulcer healing rate reached 83.3% (5/6), with none of these patients requiring amputation. Subgroup analysis based on target lesion length (≥ 200 mm) showed that the 12-month primary patency rate was 75.0% for the ≥ 200 mm group and 95.5% for the < 200 mm group. Cox univariate regression analysis did not identify any risk factors affecting primary patency rate and freedom from clinically driven TLR (CD-TLR) at 12 months.

CONCLUSIONS

Rotarex®S combined with DCB seems safe and provides acceptable 12-month primary patency and TLR rates in femoropopliteal in-stent restenosis. Well-designed comparative or large registry studies are necessary to provide high quality and long-term data on this technique to provide firm conclusions on the efficacy of Rotarex®S and DCB in ISR in the femoropopliteal area.

In-stent restenosis

Endovascular arterial recanalization has become the mainstay therapy for peripheral arterial occlusive disease. Although immediate technical success is achieved in greater than 90% of cases, longer-term results continue to vary based on the clinical presentation, and the treated target lesion. In the current era, sustained patency can be expected following intervention in the carotid, coronary, renal, and iliac arteries. However, maintaining patency in the femoropopliteal and tibial arteries continues to be present a significant challenge. Endovascular intervention in the peripheral arteries is met with heavy complex plaque burdens, multiple serial stenoses and occlusions, sluggish blood flow, low mean and oscillatory shear stress, and repetitive axial, radial and torsional deformation that hinder its outcomes. In order to maximize the longevity of endovascular intervention, its therapeutic armamentarium has developed to include vessel preparation, drug delivery, and arterial scaffolding. Nevertheless, in the aggregate of real-world clinical practice, recurrence of stenosis still complicates up to 50% of all infrainguinal endovascular procedures after only one year. Unfortunately, this timeline is often insufficient to reliably address lifestyle limiting symptoms, heal a wound, or save a threatened extremity. The purpose of this review is to discuss the pathophysiology, incidence, risk factors, morphology and treatment of restenosis following peripheral endovascular intervention.

Network Meta-Analysis of All Available Regimens Based on Drug-Coated Balloon Angioplasty and Laser Atherectomy for Femoropopliteal In-Stent Restenosis

PURPOSE

Drug-coated balloon (DCB) angioplasty and laser atherectomy (LA) have been frequently utilized to treat femoropopliteal in-stent restenosis (ISR); however, no studies have concurrently compared available regimens, including DCB, LA+DCB, and LA + plain balloon angioplasty (PB). Therefore, we conducted this network meta-analysis to determine whether there were significant differences in outcomes among these regimens.

MATERIALS AND METHODS

A comprehensive search was conducted in PubMed, EMBASE, and the Cochrane library to identify all randomized controlled trials comparing DCB or LA-based regimes with POBA or each other for treating femoropopliteal in-stent restenosis (ISR) from their inception until March 2021. The primary outcome measure was binary restenosis, and secondary outcome measures were target lesion revascularization (TLR) and mortality, evaluated at 6 and 12 months, respectively. Statistical analysis was performed using Aggregate Data Drug Information System (ADDIS) 1.4 software, and all data were graphically summarized using Microsoft Excel software.

RESULTS

The final analysis included 11 studies, of which 6 studies compared DCB with PB, 2 studies compared PB vs LA+PB, 2 studies compared DCB vs LA+DCB, and 1 study compared LA+DCB with LA+PB. DCB was better than PB in decreasing binary restenosis at 6 (odds ratio [OR]: 0.22, 95% credible interval [CrI]: 0.04-0.91) and 12 (OR: 0.26, 95% CrI: 0.12-0.50) months. DCB was associated with lower TLR than PB at 6 months (OR: 0.31, 95% CrI: 0.13-0.69). LA+DCB was also superior to PB in treating binary restenosis at 12 months (OR: 6.10, 95% CrI: 1.94-24.41) and TLR at 6 months (OR: 5.32, 95% CrI: 1.43-28.06). There was no statistical difference in mortality between PB, DCB, and LA+PB. DCB and LA+DCB were the first 2 options for reducing binary restenosis and TLR.

CONCLUSION

The current network meta-analysis demonstrates that both DCB and LA+DCB are superior to PB alone, and that DCB and LA+DCB may be the preferred treatment options for reducing binary restenosis and TLR.

CLINICAL IMPACT

The treatment for femoropopliteal in-stent restenosis (ISR) remains challenging clinical practice. One important reason is that no optimal treatment strategy was available. Drug-coated balloon angioplasty (DCB) and laser atherectomy (LA) have been extensively utilized to treat ISR; however, different combinations of these treatments further confused the clinicians' choices. This network meta-analysis systematically investigated the difference between the currently available treatments regarding therapeutic effects and safety, indicating that DCB and LA+DCB may be the optimal treatment for decreasing the risk of binary restenosis and target lesion revascularization. The results of the current network meta-analysis help to resolve the confusion of clinicians in making the decision.

Efficacy and Safety of TiNO-Coated Stents versus Drug-Eluting Stents in Acute Coronary Syndrome: Systematic Literature Review and Meta-Analysis

(1) Background: Practice guidelines define drug-eluting stents (DES) as the standard of care in coronary percutaneous coronary intervention (PCI), including in acute coronary syndrome (ACS). This is based on comparisons with bare-metal stents (BMS). However, non-drug-eluting titanium-nitride-oxide-coated stents (TiNOS) have not been taken into account. The objective of this study is to determine whether TiNOS can be used as an alternative to DES in ACS. (2) Methods: A prospective systematic literature review (SLR), conducted according to the PRISMA guidelines, was performed, wherein multiple literature databases from 2018 and 2022 were searched. Prospective, randomised, controlled trials comparing outcomes after PCI with TiNOS vs. DES in any coronary artery disease (CAD) were searched. Clinical outcomes were meta-analytic pooled risk ratios (RR) of device-oriented Major Adverse Cardiac Events (MACE) and their components. The analysis stratified outcomes reported with ACS-only vs. ACS jointly with chronic coronary syndrome (CCS). (3) Results: Five RCTs were eligible, comprising 1855 patients with TiNOS vs. 1363 with DES at a 1-year follow-up. Three enrolled patients presented with ACS only and two with ACS or CCS. The latter accounted for most of the patients. The one-year pooled RRs in those three RCTs were as follows: MACE 0.93 [0.72, 1.20], recurrent myocardial infarction (MI) 0.48 [0.31, 0.73], cardiac death (CD) 0.66 [0.33, 1.31], clinically driven target lesion revascularization (TLR) 1.55 [1.10, 2.19], and stent thrombosis (ST) 0.35 [0.20, 0.64]. Those results were robust to a sensitivity analysis. The evidence certainty was high in MACE and moderate or low in the other endpoints. (4) Conclusions: TiNOS are a non-inferior and safe alternative to DES in patients with ACS.

Adventitial injection of HA/SA hydrogel loaded with PLGA rapamycin nanoparticle inhibits neointimal hyperplasia in a rat aortic wire injury model

Neointimal hyperplasia is a persistent complication after vascular interventions, and it is also the leading cause of vascular graft restenosis and failure after arterial interventions, so novel treatment methods are needed to treat this complication. We hypothesized that adventitial injection of HA/SA hydrogel loaded with PLGA rapamycin nanoparticle (hydrogel-PLGA-rapamycin) could inhibit neointimal hyperplasia in a rat aortic wire injury model. The HA/SA hydrogel was fabricated by the interaction of hyaluronic acid (HA), sodium alginate (SA), and CaCO₃; and loaded with PLGA rapamycin nanoparticle or rhodamine uniformly. A SD rat aortic wire injury induced neointimal hyperplasia model was developed, the control group only received wire injury, the adventitial application group received 10 μL hydrogel-PLGA-rapamycin after wire injury, and the adventitial injection group received 10 μL hydrogel-PLGA-rapamycin injected into the aortic adventitia after wire injury. Tissues were harvested at day 21 and analyzed by histology and immunohistochemical staining. Hydrogel loaded with rhodamine can be successfully injected into the aortic adventitia and was encapsuled by the adventitia. The hydrogel could be seen beneath the adventitia after adventitial injection but was almost degraded at day 21. There was a significantly thinner neointima in the adventitial application group and adventitial injection group compared to the control group (p = 0.0009). There were also significantly fewer CD68⁺ (macrophages) cells (p = 0.0012), CD3⁺ (lymphocytes) cells (p = 0.0011), p-mTOR⁺ cells (p = 0.0019), PCNA⁺ cells (p = 0.0028) in the adventitial application and adventitial injection groups compared to the control group. The endothelial cells expressed arterial identity markers (Ephrin-B2 and dll-4) in all these three groups. Adventitial injection of hydrogel-PLGA-rapamycin can effectively inhibit neointimal hyperplasia after rat aortic wire injury. This may be a promising drug delivery method and therapeutic choice to inhibit neointimal hyperplasia after vascular interventions.

The Diagnostic Value of Circulating Biomarkers and Role of Drug-Coated Balloons for In-Stent Restenosis in Patients with Peripheral Arterial Disease

Peripheral arterial disease (PAD) is an increasingly pathological condition that commonly affects the femoropopliteal arteries. The current fashionable treatment is percutaneous transluminal angioplasty (PTA), often with stenting. However, the in-stent restenosis (ISR) rate after the stenting of the femoropopliteal (FP) district remains high. Many techniques have been proposed for the treatment of femoropopliteal ISR, such as intravascular brachytherapy, laser atherectomy, second stenting and drug-coated balloons angioplasty (DCB). DCB showed a significantly lower rate of restenosis and target lesions revascularization (TLR) compared to conventional PTA. However, further studies and multi-center RCTs with dedicated long-term follow-up are needed to verify the true efficiency of this approach. Nowadays, the correlation between PAD and inflammation biomarkers is well known. Multiple studies have shown that proinflammatory markers (such as C-reactive proteins) and the high plasma levels of microRNA could predict the outcomes after stent placement. In particular, circulating microRNA-320a, microRNA-3937, microRNA-642a-3p and microRNA-572 appear to hold promise in diagnosing ISR in patients with PAD, but also as predictors of stent patency. This narrative review intends to summarize the current knowledge on the value of circulating biomarkers as predictors of ISR and to foster the scientific debate on the advantages of using DCB in the treatment of ISR in the FP district.

Role of PCK2 in the proliferation of vascular smooth muscle cells in neointimal hyperplasia

Vascular smooth muscle cell (VSMC) proliferation is a hallmark of neointimal hyperplasia (NIH) in atherosclerosis and restenosis post-balloon angioplasty and stent insertion. Although numerous cytotoxic and cytostatic therapeutics have been developed to reduce NIH, it is improbable that a multifactorial disease can be successfully treated by focusing on a preconceived hypothesis. We, therefore, aimed to identify key molecules involved in NIH via a hypothesis-free approach. We analyzed four datasets (GSE28829, GSE43292, GSE100927, and GSE120521), evaluated differentially expressed genes (DEGs) in wire-injured femoral arteries of mice, and determined their association with VSMC proliferation in vitro. Moreover, we performed RNA sequencing on platelet-derived growth factor (PDGF)-stimulated human VSMCs (hVSMCs) post-phosphoenolpyruvate carboxykinase 2 (PCK2) knockdown and investigated pathways associated with PCK2. Finally, we assessed NIH formation in Pck2 knockout (KO) mice by wire injury and identified PCK2 expression in human femoral artery atheroma. Among six DEGs, only PCK2 and RGS1 showed identical expression patterns between wire-injured femoral arteries of mice and gene expression datasets. PDGF-induced VSMC proliferation was attenuated when hVSMCs were transfected with PCK2 siRNA. RNA sequencing of PCK2 siRNA-treated hVSMCs revealed the involvement of the Akt-FoxO-PCK2 pathway in VSMC proliferation via Akt2, Akt3, FoxO1, and FoxO3. Additionally, NIH was attenuated in the wire-injured femoral artery of Pck2-KO mice and PCK2 was expressed in human femoral atheroma. PCK2 regulates VSMC proliferation in response to vascular injury via the Akt-FoxO-PCK2 pathway. Targeting PCK2, a downstream signaling mediator of VSMC proliferation, may be a novel therapeutic approach to modulate VSMC proliferation in atherosclerosis.

Efficacy and safety of drug-coated balloon versus non-drug-coated balloon combined with bare metal stent implantation in treatment of patients with occlusions of the superficial femoral artery: a retrospective study in clinical practice

OBJECTIVE

To assess the efficacy and safety of drug-coated balloon and non-drug-coated balloon combined with bare metal stent implantation for the treatment of patients with occlusions of the superficial femoral artery.

METHODS

In this retrospective study, 83 patients with occlusions of the superficial femoral artery were included. Among them, 41 patients received paclitaxel drug coated balloon treatment combined with bare metal stent implantation treatment (experimental group), the remaining 42 received non-drug-coated balloon treatment (control group). Patients were followed up at 1, 6, and 12 months after surgery. The primary clinical assessments, including ankle brachial index (ABI), RutherFord grade, Doppler ultrasound, or CT angiography (CTA), were used to observe the patency of target vessels, perioperative and postoperative complications.

RESULTS

All the diseased vessels were successfully opened. There were no serious intraoperative complications such as vascular rupture or acute thrombosis. There was no significant difference in ankle brachial index, RutherFord grade, and total score between the two groups at one month and six months after operation (P>0.05). There was no significant difference in mortality, amputation rate, or thrombosis between the two groups (P>0.05). Twelve months after the operation, the ankle brachial index, Rutherford grade and total score of the experimental group were better than those of the control group (P<0.05). There was no significant difference in mortality, amputation rate, or thrombosis between the two groups (P>0.05).

CONCLUSION

Paclitaxel coated balloon is safe and effective in the treatment of superficial femoral arteriosclerosis occlusion. It can significantly improve the ABI and Rutherford grades of patients, and it had a higher patency rate and lower reconstruction rate, but it may affect the healing ability of foot ulcer.

Percutaneous Mechanical Atherectomy Plus Thrombectomy Using the Rotarex®S Device Followed by a Drug-Coated Balloon for the Treatment of Femoropopliteal Artery In-stent Restenosis: A Prospective Single-Center, Single-Arm Efficacy Trial (PERMIT-ISR Trial)

Background: Studies investigating debulking devices with drug-coated balloons (DCBs) in the treatment of femoropopliteal (FP) artery in-stent restenosis (ISR) are limited. We aimed to evaluate the safety and midterm outcome of percutaneous mechanical atherectomy plus thrombectomy (MATH) using the Rotarex®S (Straub Medical, Wangs, Switzerland) catheter followed by a DCB in the treatment of FP-ISR. Methods: This study was a single-center single-arm trial. Patients with symptomatic (Rutherford category 2-5) de novo restenosis lesions of FP-ISR were treated with MATH and subsequent DCB. From June 2016 to May 2018, 59 patients with FP-ISR were enrolled. The primary endpoint was target lesion revascularization (TLR) and changes in the Rutherford category of the target limb at 12 months. Secondary endpoints included primary and secondary patency at 12 months, technical success rate, major adverse events, and ankle-brachial index (ABI). Risk factors for TLR were analyzed using Cox proportional hazard model. Results: The average follow-up time was 33 ± 8 months. The rate of technical success was 88.1% (52/59). Nine patients received bailout stenting. The rate of freedom from TLR was 84.7% (50/59) at 1 year, the Rutherford category changed at 12 months were significantly improved from baseline (p < 0.01). The primary patency rates and the secondary patency at the 12-month follow-ups were 82.5 and 92.5%, respectively. The ABI changed at 12 months were significantly improved from baseline (p < 0.01). Global limb anatomic staging system (GLASS) classification III [hazard ratio (HR) 18.44, 95% CI (1.57-215.99), p = 0.020] and postoperative Rutherford classification ≥4 [HR 8.28, 95% CI (1.85-37.06), p = 0.006] were identified as independent predictors of TLR. Conclusion: Our preliminary data suggested that MATH using a Rotarex®S catheter combined with DCB angioplasty is a safe, minimally invasive, and effective treatment for FP-ISR with favorable, immediate, and midterm outcomes. Clinical Trial Registration:http://www.chictr.org.cn, identifier [ChiCTR2000041380].

Programmed death-1 mediates venous neointimal hyperplasia in humans and rats

Venous neointimal hyperplasia can be a problem after vein interventions. We hypothesized that inhibiting programmed death-1 (PD-1) can decrease venous neointimal hyperplasia in a rat inferior vena cava (IVC) patch venoplasty model. The rats were divided into four groups: the control group was only decellularized without other special treatment; the PD-1 group was injected with a single dose of humanized PD-1 antibody (4 mg/kg); the PD-1 antibody coated patches group; the BMS-1 (a PD-1 small molecular inhibitor) coated patches group (PD-1 inhibitor-1). Patches were implanted to the rat IVC and harvested on day 14 and analyzed. Immunohistochemical analysis showed PD-1-positive cells in the neointima in the human samples. There was high protein expression of PD-1 in the neointima in the rat IVC venoplasty model. PD-1 antibody injection can significantly decrease neointimal thickness (p < 0.0001). PD-1 antibody or BMS-1 was successfully conjugated to the decellularized rat thoracic artery patch by hyaluronic acid with altered morphology and reduced the water contact angle (WCA). Patches coated with humanized PD-1 antibody or BMS-1 both can also decrease neointimal hyperplasia and inflammatory cells infiltration. PD-1-positive cells are present in venous neointima in both human and rat samples. Inhibition of the PD-1 pathway may be a promising therapeutic strategy to inhibit venous neointimal hyperplasia.

PRISMA 2020 explanation and elaboration: updated guidance and exemplars for reporting systematic reviews

The methods and results of systematic reviews should be reported in sufficient detail to allow users to assess the trustworthiness and applicability of the review findings. The Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) statement was developed to facilitate transparent and complete reporting of systematic reviews and has been updated (to PRISMA 2020) to reflect recent advances in systematic review methodology and terminology. Here, we present the explanation and elaboration paper for PRISMA 2020, where we explain why reporting of each item is recommended, present bullet points that detail the reporting recommendations, and present examples from published reviews. We hope that changes to the content and structure of PRISMA 2020 will facilitate uptake of the guideline and lead to more transparent, complete, and accurate reporting of systematic reviews.

Successful Peripheral Vascular Intervention in Patients with High-risk Comorbidities or Lesion Characteristics

PURPOSE OF REVIEW

Certain comorbidities and lesion characteristics are associated with increased risk for procedural complications, limb events, and cardiovascular events following peripheral vascular intervention (PVI) in patients with peripheral arterial disease (PAD). The purpose of this review is to provide an overview of high-risk modifiable and unmodifiable patient characteristics and its relative impact on clinical outcomes such as amputation risk and mortality. Furthermore, general approaches to potentially mitigating these risks through pre-intervention planning and use of modern devices and techniques are discussed.

RECENT FINDINGS

Diabetes, tobacco use, and older age remain strong risk factors for the development of peripheral arterial disease. Recent data highlight the significant risk of polyvascular disease on major limb and cardiac events in advanced PAD, and ongoing studies are assessing this risk specifically after PVI. Challenging lesion characteristics such as calcified disease and chronic total occlusions can be successfully treated with PVI by utilizing novel devices (e.g., intravascular lithotripsy, re-entry devices) and techniques (e.g., subintimal arterial "flossing" with antegrade-retrograde intervention). Understanding high-risk patient comorbidities and lesion characteristics will improve our ability to counsel and manage patients with advanced PAD. Continued device innovation and novel techniques will aid in procedural planning for successful interventions to improve clinical outcomes.

Systematic evaluation of particle loss during handling in the percutaneous transluminal angioplasty for eight different drug-coated balloons

Paclitaxel drug coated balloons (DCBs) should provide optimal drug transfer exclusively to the target tissue. The aim of this study was to evaluate the particle loss by handling during angioplasty. A robotic arm was developed for systematic and reproducible drug abrasion experiments. The contact force on eight different commercially available DCB types was gradually increased, and high-resolution microscopic images of the deflated and inflated balloons were recorded. Three types of DCBs were classified: no abrasion of the drug in both statuses (deflated and inflated), significant abrasion only in the inflated status, and significant abrasion in both statuses. Quantitative measurements via image processing confirmed the qualitative classification and showed changes of the drug area between 2.25 and 45.73% (13.28 ± 14.29%) in the deflated status, and between 1.66 and 40.41% (21.43 ± 16.48%) in the inflated status. The structures and compositions of the DCBs are different, some are significantly more susceptible to drug loss. Particle loss by handling during angioplasty leads to different paclitaxel doses in the target regions for same DCB types. Susceptibility to involuntary drug loss may cause side effects, such as varying effective paclitaxel doses, which may explain variations in studies regarding the therapeutic outcome.

Drug-Eluting Stents and Balloons-Materials, Structure Designs, and Coating Techniques: A Review

Controlled drug delivery is a matter of interest to numerous scientists from various domains, as well as an essential issue for society as a whole. In the treatment of many diseases, it is crucial to control the dosing of a drug for a long time and thus maintain its optimal concentration in the tissue. Heart diseases are particularly important in this aspect. One such disease is an obstructive arterial disease affecting millions of people around the world. In recent years, stents and balloon catheters have reached a significant position in the treatment of this condition. Balloon catheters are also successfully used to manage tear ducts, paranasal sinuses, or salivary glands disorders. Modern technology is continually striving to improve the results of previous generations of stents and balloon catheters by refining their design, structure, and constituent materials. These advances result in the development of both successive models of drug-eluting stents (DES) and drug-eluting balloons (DEB). This paper presents milestones in the development of DES and DEB, which are a significant option in the treatment of coronary artery diseases. This report reviews the works related to achievements in construction designs and materials, as well as preparation technologies, of DES and DEB. Special attention was paid to the polymeric biodegradable materials used in the production of the above-mentioned devices. Information was also collected on the various methods of producing drug release coatings and their effectiveness in releasing the active substance.

[Recommended interventions for the treatment of peripheral artery disease : Keep the patients moving]

BACKGROUND

Peripheral artery disease (PAD) is often diagnosed in an advanced stage. Accordingly, revascularization is also performed late.

OBJECTIVES

In this paper, the authors describe the progression to critical limb ischemia and cardiovascular risk. Revascularization for secondary prevention is explained. Revascularization strategies according to lesion location and complexity of the stenosis or occlusion are discussed.

MATERIALS AND METHODS

The current guidelines and randomized controlled studies and meta-analyses are analyzed.

RESULTS

PAD is associated with a considerable level of suffering and a high cardiovascular risk. Up to 20% of patients with claudicants will progress to critical limb ischemia. Progression and risk of mortality increase during the course of the disease. Improvement of walking ability by revascularization is a major goal of secondary prevention. In the femoropopliteal segment, drug-coated balloon (DCB) angioplasty and bare-metal stent (BMS) implantation are the methods of choice. In long lesions, spot-stenting should be preferred. For treatment of in-stent restenosis, DCB have proven their effectiveness. In severely calcified or dissected lesions, BMS are well suited. Infrapopliteal lesions should be revascularized to provide in-line flow to the foot through the target arterial path. According to current evidence, DCB or drug-eluting stents are more effective than plain old balloon angioplasty or BMS.

Drug-eluting balloon angioplasty versus uncoated balloon angioplasty for the treatment of in-stent restenosis of the femoropopliteal arteries

BACKGROUND

Stents are placed in the femoropopliteal arteries for numerous reasons, such as atherosclerotic disease, the need for dissection, and perforation of the arteries, and can become stenosed with the passage of time. When a stent develops a flow-limiting stenosis, this process is known as "in-stent stenosis." It is thought that in-stent restenosis is caused by a process known as "intimal hyperplasia" rather than by the progression of atherosclerotic disease. Management of in-stent restenosis may include performing balloon angioplasty, deploying another stent within the stenosed stent to force it open, and creating a bypass to deliver blood around the stent. The role of drug-eluting technologies, such as drug-eluting balloons (DEBs), in the management of in-stent restenosis is unclear. Drug-eluting balloons might function by coating the inside of stenosed stents with cytotoxic chemicals such as paclitaxel and by inhibiting the hyperplastic processes responsible for in-stent restenosis. It is important to perform this systematic review to evaluate the efficacy of DEB because of the potential for increased expenses associated with DEBs over uncoated balloon angioplasty, also known as plain old balloon angioplasty (POBA).

OBJECTIVES

To assess the safety and efficacy of DEBs compared with uncoated balloon angioplasty in people with in-stent restenosis of the femoropopliteal arteries as assessed by criteria such as amputation-free survival, vessel patency, target lesion revascularization, binary restenosis rate, and death. We define "in-stent restenosis" as 50% or greater narrowing of a previously stented vessel by duplex ultrasound or angiography.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase, and CINAHL databases and the World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registers to November 28, 2017. Review authors also undertook reference checking to identify additional studies.

SELECTION CRITERIA

We included all randomized controlled trials that compared DEBs versus uncoated balloon angioplasty for treatment of in-stent restenosis in the femoropopliteal arteries.

DATA COLLECTION AND ANALYSIS

Two review authors (AK, WA) independently selected appropriate trials and performed data extraction, assessment of trial quality, and data analysis. The senior review author (AD) adjudicated any disagreements.

MAIN RESULTS

Three trials that randomized a combined total of 263 participants met the review inclusion criteria. All three trials examined the treatment of symptomatic in-stent restenosis within the femoropopliteal arteries. These trials were carried out in Germany and Austria and used paclitaxel as the agent in the drug-eluting balloons. Two of the three trials were industry sponsored. Two companies manufactured the drug-eluting balloons (Eurocor, Bonn, Germany; Medtronic, Fridley, Minnesota, USA). The trials examined both anatomical and clinical endpoints. We noted heterogeneity in the frequency of bailout stenting deployment between studies as well as in the dosage of paclitaxel applied by the DEBs. Using GRADE assessment criteria, we determined that the certainty of evidence presented was very low for the outcomes of amputation, target lesion revascularization, binary restenosis, death, and improvement of one or more Rutherford categories. Most participants were followed up to 12 months, but one trial followed participants for up to 24 months.Trial results show no difference in the incidence of amputation between DEBs and uncoated balloon angioplasty. DEBs showed better outcomes for up to 24 months for target lesion revascularization (odds ratio (OR) 0.05, 95% confidence Interval (CI) 0.00 to 0.92 at six months; OR 0.24, 95% CI 0.08 to 0.70 at 24 months) and at six and 12 months for binary restenosis (OR 0.28, 95% CI 0.14 to 0.56 at six months; OR 0.34, 95% CI 0.15 to 0.76 at 12 months). Participants treated with DEBs also showed improvement of one or more Rutherford categories at six and 12 months (OR 1.81, 95% CI 1.02 to 3.21 at six months; OR 2.08, 95% CI 1.13 to 3.83 at 12 months). Data show no clear differences in death between DEBs and uncoated balloon angioplasty. Data were insufficient for subgroup or sensitivity analyses to be conducted.

AUTHORS' CONCLUSIONS

Based on a meta-analysis of three trials with 263 participants, evidence suggests an advantage for DEBs compared with uncoated balloon angioplasty for anatomical endpoints such as target lesion revascularization (TLR) and binary restenosis, and for one clinical endpoint - improvement in Rutherford category post intervention for up to 24 months. However, the certainty of evidence for all these outcomes is very low due to the small number of included studies and participants and the high risk of bias in study design. Adequately powered and carefully constructed randomized controlled trials are needed to adequately investigate the role of drug-eluting technologies in the management of in-stent restenosis.