Prospective, Randomized Single-center Trial to Compare Cryoplasty versus Conventional Angioplasty in the Popliteal Artery: Midterm Results of the COLD Study

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.

Supera stent implantation for the treatment of isolated popliteal artery disease systematic review and evaluation of current endovascular strategies

<b>Introduction:</b> The anatomical location of the popliteal artery is one of the greatest challenges for percutaneous interventions. The biomechanical attributes of the vessel lead to higher rates of restenosis, stent fracture, and occlusion. Some surgeons consider the popliteal artery as a no stenting zone. Many specialists favor percutaneous transluminal angioplasty to be the first line of endovascular treatment in the popliteal artery with bail-out stent implantation if the results are suboptimal. The Supera peripheral stent system is a novel stent that has been manufactured with a high degree of flexibility and supposedly might be appropriate for implantation in the popliteal artery. </br></br> <b>Aim:</b> Evaluation of the performance of Supera stent in isolated popliteal artery disease in comparison to other methods of treatment. </br></br> <b>Methods:</b> As many as 92 articles were found in the databases and after full-text review, 4 studies matched the inclusion criteria and were evaluated. </br></br> <b>Results:</b> Primary patency rates of Supera implantation in an isolated popliteal artery at 12 months ranged from 68% to 90%. In all four studies, no stent fractures were observed. Only one study provided longer follow-up than 12 months and evaluated the performance of the Supera stent 36 months after implantation. </br></br> <b>Conclusion:</b> In conclusion, mentioned studies show promising and superior to other stent patency rates of the Supera stent regarding popliteal artery lesions. What is more, no stent fracture is promising regarding longer follow-up. However, more studies with longer follow-ups and direct comparison to other methods are required to fully evaluate Supera's performance in the popliteal artery.

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.)

One-Year Outcomes Following Directional Atherectomy of Popliteal Artery Lesions: Subgroup Analysis of the Prospective, Multicenter DEFINITIVE LE Trial

Purpose: To report the effectiveness of directional atherectomy for the treatment of popliteal artery occlusive disease. Methods: This subset of the prospective, multicenter, single-arm DEFINITIVE LE trial included 158 patients (mean age 72.0±10.9 years; 82 men) who underwent directional atherectomy in 162 popliteal artery lesions between 2009 and 2011. Forty-eight (30.4%) patients were suffering from critical limb ischemia (CLI). The mean lesion length was 5.8±3.9 cm; 38 (23.5%) arteries were occluded. The primary outcome measure for patients with intermittent claudication (IC) was duplex ultrasound–defined primary patency at 1 year; the outcome for subjects with CLI was freedom from major amputation of the target limb at 1 year. Outcomes and adverse events were independently assessed. Results: Procedure success (≤30% residual stenosis) was achieved in 84.4% of treated lesions; adjunctive stenting was required in 6 (3.7%) of the 162 lesions. The 1-year primary patency rate was 75.0% (IC patients 78.2% and CLI patients 67.5%, p=0.118). The freedom from major amputation in both cohorts was 100%. In both IC and CLI patients, significant improvements were demonstrated at 1 year in the Rutherford category, walking distance, and quality of life in comparison to baseline. Conclusion: This study indicates that directional atherectomy in popliteal arteries leads to favorable technical and clinical results at 1 year for claudicant as well as CLI patients.

Directional Atherectomy With Antirestenotic Therapy vs Drug-Coated Balloon Angioplasty Alone for Isolated Popliteal Artery Lesions

Purpose: To report a single-center study comparing drug-coated balloon (DCB) angioplasty vs directional atherectomy with antirestenotic therapy (DAART) for isolated lesions of the popliteal artery. Methods: Seventy-two patients were treated with either DCB angioplasty alone (n=31) or with DAART (n=41) for isolated popliteal artery stenotic disease between October 2009 and December 2015. The majority of patients presented with lifestyle-limiting claudication (74% vs 86%, respectively). Vessel calcification (29% vs 29%, respectively), mean lesion length (47 vs 42 mm, respectively), and number of runoff vessels were comparable between the groups. The primary outcome measure was primary patency; secondary outcomes were technical success (<30% residual stenosis or bailout stenting), secondary patency, and freedom from clinically driven target lesion revascularization (TLR). Results: The technical success rate following DCB was 84% vs 93% (p=0.24) after DAART. The 12-month primary patency rate was significantly higher in the DAART group (65% vs 82%; hazard ratio 2.64, 95% confidence interval 1.09 to 6.37, p=0.021), while freedom from TLR did not differ between the 2 treatment strategies (82% vs 94%, p=0.072). Secondary patency at 12 months was identical for both groups (96% vs 96%). Although not statistically significant, bailout stenting was more common after DCB angioplasty (16% vs 5% for DAART, p=0.13) and aneurysmal degeneration of the popliteal artery was seen more often after DAART (7% vs 0% for DCB alone, p=0.25). Popliteal artery injury was observed in 2 patients treated using DAART (5% vs 0% for DCB alone, p=0.5), whereas distal embolization rates were comparable between the groups (3% for DCB alone vs 5% for DAART, p=0.99). Conclusion: In this study, the use of DAART was associated with a higher primary patency rate compared with DCB angioplasty for isolated popliteal lesions. Nonetheless, both treatment options were associated with excellent 12-month secondary patency. Aneurysmal degeneration of the popliteal artery and increased bailout stenting could compromise the outcomes of DAART and DCB, respectively.

Cryoplasty for Canine Iliac Artery Stenosis and its Impact on Expression of TIMP-2 and MMP-2

Objective:

This study was performed to observe the effects of cryoplasty on canine iliac artery stenosis and the expression of tissue inhibition of matrix metalloproteinase 2 (TIMP-2) and matrix metalloproteinase 2 (MMP-2).

Methods:

We produced a reliable canine model to mimic the atherosclerotic stenosis in the iliac artery by suturing the artery followed by vessel ligation to create an injury to intimal and medial walls. Sixteen mongrel dogs with iliac artery stenosis were randomized to conventional balloon angioplasty (n = 8) or cryoplasty (n = 8).

Results:

Four weeks posttreatment, the cryoplasty group with less collagen fibers and smooth muscle demonstrated significantly larger luminal diameter of iliac artery compared to the balloon angioplasty group ( P < .001). Expression of TIMP-2 significantly increased and expression of MMP-2 significantly reduced in iliac artery of the cryoplasty group compared to conventional balloon angioplasty.

Conclusion:

Our study suggests cryoplasty might increase the expression of TIMP-2 and decrease the expression of MMP-2, thereby inhibiting vascular hyperplasia and collagen fibers synthesis of the stenotic vessels.

Comparison of dual-antiplatelet therapy durations after endovascular revascularization of infrainguinal arteries

BACKGROUND

The optimal dual-antiplatelet therapy (DAPT) duration after endovascular revascularization of infrainguinal arteries is uncertain.

METHODS

This study examines DAPT prescription trends and 12-month major adverse limb events (MALEs; a composite of repeat endovascular or surgical revascularization, acute vessel thrombosis, or amputation of the target limb), major adverse cardiovascular events (MACEs; all-cause mortality, nonfatal myocardial infarction [MI], stroke, or coronary revascularization), fatal bleeding events, and those requiring interruption or discontinuation of DAPT (hemorrhagic complications) for patients enrolled into the Excellence in Peripheral Artery Disease (XLPAD) registry.

RESULTS

Data on 368 patients prescribed antiplatelet therapy were analyzed; 8.2% were prescribed antiplatelet monotherapy, 48.6% DAPT for ≤3 months, and 43.2% for >3 months. Patients in the >3 DAPT prescribed group were older, had preexisting coronary artery disease (CAD), and prior MI (all P < 0.001). Overall MALE in the ≤3 and >3-month DAPT prescribed groups were 22.3% and 23.9%, respectively (P = 0.541). Survival analysis showed significantly higher rates of MACE in patients prescribed >3-month DAPT (17.6% vs. 9.5%; P = 0.019). An "as-treated" analysis excluded 10 patients who were prescribed DAPT for >3 months and revealed similar rates of MALE (24.9% vs. 20.8%; P = 0.386) and MACE (12.2% vs. 14.8%; P = 0.443) in patients receiving ≤3 and >3 DAPT. Hemorrhagic complications were similar across all prescribed and "as-treated" DAPT groups.

CONCLUSIONS

After infrainguinal endovascular procedures, patients with underlying CAD were prescribed longer (>3 months) duration of DAPT and experienced more cardiovascular events compared with those prescribed ≤3 months of DAPT. Adverse limb events were similar in both groups.

Stent Placement vs. Balloon Angioplasty for Popliteal Artery Treatment

Purpose: To investigate the 2-year technical and clinical results of primary nitinol stent placement in comparison with percutaneous transluminal angioplasty (PTA) in the treatment of de novo lesions of the popliteal artery. Methods: The ETAP study (Endovascular Treatment of Atherosclerotic Popliteal Artery Lesions: balloon angioplasty vs. primary stenting; www.ClinicalTrials.gov identifier NCT00712309) is a prospective, randomized trial that enrolled 246 patients (158 men; mean age 72 years) who were randomly assigned to receive a nitinol stent (n=119) or PTA (n=127) for lesions averaging 42.3 mm in length. The results of the primary study endpoint were published. Secondary outcome measures and endpoints included primary patency (freedom from duplex-detected target lesion restenosis), target lesion revascularization (TLR), secondary patency, changes in ankle-brachial index and Rutherford class, and event-free survival (freedom from target limb amputation, TLR, myocardial infarction, and death). Results: In total, 183 patients (89 stent and 94 PTA) were available for the 2-year analysis. The primary patency rate was significantly higher in the stent group (64.2%) than in the PTA group (31.3%, p=0.0001). TLR rates were 22.4% and 59.5%, respectively (p=0.0001). When provisional stent placement in the PTA arm was not considered as TLR and loss in patency, the differences prevailed between the study groups but were not significant (64.2% vs. 56.1% for primary patency, respectively; p=0.44). A significant improvement in ABI and Rutherford category was observed at 2 years in both groups. Conclusion: In treatment of obstructive popliteal artery lesions, provisional stenting reveals equivalent patency in comparison to primary stenting. However, the 2-year results of this trial suggest the possibility of a shift toward higher patency rates in favor of primary stenting.

Cryoplasty versus angioplasty in the treatment of arterial restenosis in an experimental model of atherosclerosis in rabbits

Cryoplasty may reduce the incidence of post-angioplasty restenosis in peripheral atherosclerotic arteries. Our study is looking to investigate the mid-term effects (4 weeks) of an FDA-approved cryoplasty catheter (PolarCath(®), Boston Scientific) compared to a conventional angioplasty catheter using a hypercholesterolemic rabbit model of arterial restenosis based on diet plus vessel injury. Thirty-six normolipidemic, 3-month old male New Zealand White rabbits were used. Balloon angioplasty was performed on left external iliac arteries on day 1. Animals were fed with a hypercholesterolemic diet for 60 days. On day 120, three groups of animals were established: conventional PTA (percutaneous transluminal angioplasty) was applied on the PTA group; the CRY group was treated with the PolarCath(®) cryoplasty system and no treatment was given to a control (CTR) group. A broad variety of atheromatous lesions were observed 30 days after treatment, presenting significant differences between groups. Most of the complicated lesions were found in the CRY group, while advanced and early lesions were more often appreciated in the CTR and PTA groups, respectively. The histomorphometric evaluation of the arteries showed significant differences between the CRY group and the other two groups, with the highest percentage of IEM (internal elastic membrane) injury, vascular stenosis and ratio intima/media being registered on animals treated with cryoplasty. Intravascular cryotherapy induces complicated lesions in arterial walls 30 days after treatment in a hypercholesterolemic rabbit model based on diet plus vessel injury. Cryoplasty leads to the production of severe fibrosis and mineralisation and stenosis compared to a conventional angioplasty.

An overview of optimal endovascular strategy in treating the femoropopliteal artery: mechanical, biological, and procedural factors

Treatment of the femoropopliteal (FP) artery remains a challenge to the endovascular specialist. Long-term patency is low with a high rate of target lesion revascularization. The true patency rate varies considerably between studies partly because there is a lack of uniform performance criteria and reporting standards in peripheral arterial interventions. Literature review supports three principles that emerge as important components of an optimal strategy in treating the FP artery: (1) improving vessel compliance and subsequently less dissections and bailout stenting, (2) reducing smooth muscle cell proliferation, and (3) protecting outflow vessels from distal embolization. In this overview, we examine current data that support the validity of this strategy.

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

The complex pathophysiology response to injury of the lower-extremity arteries has prompted the development of several unique balloon technologies to overcome initial technical failures and short-term intimal hyperplasia. Cryoplasty alters the cellular and mechanical properties of the vessel wall during angioplasty. Cutting balloons incise the wall, preventing elastic recoil and allowing expansion of the lumen at a lower pressure, thus limiting barotrauma. Drug-eluting balloons actively transfer inhibitory compounds to the wall during the initial therapy, while brachytherapy balloons allow for localized delivery of radiation to inhibit the proliferative response seen after angioplasty. These platforms provide unique means to enhance immediate and short-term results and also reduce stent usage in the lower extremity.

Cryoplasty for peripheral arterial disease

BACKGROUND

Percutaneous balloon angioplasty is an endovascular technique for restoring blood flow through an artery that has become narrowed or blocked by atherosclerosis. Narrowing of the artery following angioplasty (restenosis) is the major cause of long-term failure. Cryoplasty offers a different approach to improving long-term angioplasty results. It combines the dilation force of balloon angioplasty with cooling of the vessel wall. This systematic review evaluated cryoplasty in peripheral arterial disease and provides focus for further research in the field. This is an update of a review first published in 2007.

OBJECTIVES

To assess the efficacy of, and complications associated with, cryoplasty for maintaining patency in the iliac, femoropopliteal and crural arteries in the short and medium term.

SEARCH METHODS

For this update the Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (last searched October 2012) and CENTRAL (2012, Issue 10). Trial databases were searched for ongoing or unpublished studies. We also searched the reference lists of relevant articles.

SELECTION CRITERIA

All randomised controlled trials in which participants with peripheral arterial disease (PAD) of the lower limbs, or lower limb bypass graft stenoses, were randomised to cryoplasty with or without another procedure versus a procedure without cryoplasty were considered. This included trials where all participants received angioplasty and the randomisation was for cryoplasty versus no cryoplasty and trials where cryoplasty was used as an adjunct to conventional treatment (for example stenting) against a control.

DATA COLLECTION AND ANALYSIS

Two review authors independently reviewed, assessed and selected trials, extracted data and assessed risk of bias.

MAIN RESULTS

Seven trials (six primary cryoplasty and one adjunctive cryoplasty trial) with a combined total of 478 patients were included in this review. The trials reported patency and restenosis either by participant, lesion or vessel location. Follow-up ranged from 30 days to three years.Target lesion patency measured at various time points in two primary cryoplasty trials showed no statistically significant difference between the treatment groups. The adjunctive cryoplasty study showed that cryoplasty was associated with improved patency only at six months (OR 5.37, 95% CI 1.09 to 26.49, n = 90).Restenosis measured per patient (two primary cryoplasty trials) showed no statistically significant difference between the treatments. Restenosis measured by lesion (two primary cryoplasty trials) showed a statistically significant difference only within 24 hours of the procedure (OR 0.08, 95% CI 0.04 to 0.18, n = 192) favouring cryoplasty.Need for re-intervention was not significantly different in primary cryoplasty trial participants (per participant: OR 0.27, 95% CI 0.05 to 1.52, n = 241, I(2) = 89%; per lesion: OR 0.59, 95% CI 0.06 to 5.69, n = 307, I(2) = 94%). The adjunctive cryoplasty trial did not report on need for intervention.Immediate success of procedure (within 24 hours) was not significantly different in primary cryoplasty trial participants (per participant: OR 1.63, 95% CI 0.14 to 19.55, n = 340, I(2) = 95%; per lesion: OR 1.81, 95% CI 0.19 to 17.36, n = 397, I(2) = 90%). The adjunctive cryoplasty trial reported 100% success.Limb loss, deaths from all causes and the risk of complications immediately after treatment showed no statistically significant differences between the treatments.

AUTHORS' CONCLUSIONS

The benefit of cryoplasty over conventional angioplasty cannot be established as the number of randomised controlled trials is small and their quality is not sufficiently high. The technical success and primary patency rates seen in these trials are inconsistent and do not necessarily suggest a future role for cryoplasty in the treatment of PAD, but they cannot be reliably interpreted. Currently there are insufficient data to support the routine use of cryoplasty over conventional balloon angioplasty in the treatment of PAD.

Cost-effectiveness analysis of enhancements to angioplasty for infrainguinal arterial disease

Background

The aim was to perform an economic evaluation of the cost-effectiveness of endovascular enhancements to percutaneous transluminal balloon angioplasty (PTA) with bail-out bare metal stents for infrainguinal peripheral arterial disease.

Methods

The following interventions were considered: PTA with no bail-out stenting, PTA with bail-out drug-eluting stents, drug-coated balloons, primary bare metal stents, primary drug-eluting stents, endovascular brachytherapy, stent-grafts and cryoplasty. A discrete-event simulation model was developed to assess the relative cost-effectiveness of the interventions from a health service perspective over a lifetime. Populations of patients with intermittent claudication (IC) and critical leg ischaemia (CLI) were modelled separately. Univariable and probabilistic sensitivity analyses were undertaken. Effectiveness was measured by quality-adjusted life-years (QALYs).

Results

For both patient populations, the use of drug-coated balloons dominated all other options by having both lower lifetime costs and greater effectiveness. For willingness-to-pay thresholds between £0 and £100 000 per additional QALY, the probability of drug-coated balloons being cost-effective was at least 58·3 per cent for patients with IC and at least 72·2 per cent for patients with CLI. Sensitivity analyses showed that the results were robust to different assumptions regarding the clinical benefits attributable to the interventions.

Conclusion

The use of drug-coated balloons represents a cost-effective alternative to the use of PTA with bail-out bare metal stents.

Systematic review and meta-analysis of additional technologies to enhance angioplasty for infrainguinal peripheral arterial occlusive disease

Background

There are several additional techniques designed to enhance conventional percutaneous transluminal balloon angioplasty (PTA). This systematic review assessed current evidence on the clinical effectiveness of additional techniques for infrainguinal peripheral arterial occlusive disease (PAD).

Methods

Relevant electronic databases, including MEDLINE, were searched in May 2011. The population comprised participants with symptomatic PAD undergoing endovascular treatment for disease distal to the inguinal ligament. Interventions were additional techniques compared with conventional PTA. Main outcome measures were restenosis and need for reintervention. Randomized clinical trials (RCTs) of clinical effectiveness were assessed for quality and data were extracted. Where appropriate, meta-analysis was undertaken to produce risk ratios (RRs).

Results

Forty RCTs were selected. Meta-analysis showed a significant benefit in reducing restenosis rates at 6 months for self-expanding stents (RR 0·49) and drug-coated balloons (RR 0·40), and at 12 months for endovascular brachytherapy (RR 0·63). There was also evidence that use of a stent-graft significantly reduced restenosis compared with PTA, as did drug-eluting stents compared with bare-metal stents. Meta-analysis showed that use of drug-coated balloons was associated with significantly lower reintervention rates than PTA alone at 6 months (RR 0·24) and 24 months (RR 0·27) of follow-up. There was also evidence of significantly lower reintervention rates for self-expanding stents at 6 months. Other techniques did not show significant treatment effects for restenosis or reintervention.

Conclusion

The conclusions of this review should be tempered by small sample sizes, lack of clinical outcome measures and differing outcome definitions, making direct comparison across trials difficult. However, self-expanding stents, drug-eluting stents and drug-coated balloons appeared to be the most promising technologies worthy of future study.

Stent Placement Versus Balloon Angioplasty for the Treatment of Obstructive Lesions of the Popliteal Artery

Background—

Stenting has been shown to improve patency after femoral artery revascularization compared with balloon angioplasty. Limited data are available evaluating endovascular treatment for obstructive lesions of the popliteal artery.

Methods and Results—

This prospective, randomized, multicenter trial compared primary nitinol stent placement to percutaneous transluminal balloon angioplasty in patients with peripheral artery disease Rutherford-Becker class 2 to 5 who had a de novo lesion in the popliteal artery. The primary study end point was 1-year primary patency, defined as freedom from target-lesion restenosis (luminal narrowing of ≥50%) as detected by duplex ultrasound. Secondary end points included target-lesion revascularization rate and changes in Rutherford-Becker class. Provisional stent placement was considered target-lesion revascularization and loss of primary patency. Two hundred forty-six patients were included in this trial. The mean target-lesion length was 42.3 mm. One hundred ninety-seven patients were available for the1-year follow-up. The 1-year primary patency rate was significantly higher in the group with primary nitinol stent placement (67.4%) than in the percutaneous transluminal balloon angioplasty group (44.9%, P =0.002). Target-lesion revascularization rates were 14.7% and 44.1%, respectively ( P =0.0001); however, when provisional nitinol stent placement was not considered target-lesion revascularization and loss in patency, no significant differences prevailed between the study groups (67.4% versus 65.7%, P =0.92 for primary patency). Approximately 73% of patients in the percutaneous transluminal balloon angioplasty group and 77% in the nitinol stent group showed an improvement of ≥1 Rutherford-Becker class ( P =0.31).

Conclusions—

Primary nitinol stent placement for obstructive lesions of the popliteal artery achieves superior acute technical success and higher 1-year primary patency only if provisional stenting is considered target-lesion revascularization. Provisional stenting as part of a percutaneous transluminal balloon angioplasty strategy has equivalent 1-year patency and should be preferred over primary stenting.

Clinical Trial Registration—

URL: http://www.clinicaltrials.gov . Unique identifier: NCT00712309.

Pilot trial of cryoplasty or conventional balloon post-dilation of nitinol stents for revascularization of peripheral arterial segments: the COBRA trial

OBJECTIVES

The purpose of this study is to compare post-dilation strategies of nitinol self-expanding stents implanted in the superficial femoral artery of diabetic patients with peripheral arterial disease.

BACKGROUND

Endovascular treatment of superficial femoral artery disease with nitinol self-expanding stents is associated with high rates of in-stent restenosis in patients with diabetes mellitus.

METHODS

We conducted a prospective, multicenter, randomized, controlled clinical trial of diabetic patients to investigate whether post-dilation of superficial femoral artery nitinol self-expanding stents using a cryoplasty balloon reduces restenosis compared to a conventional balloon. Inclusion criteria included diabetes mellitus, symptomatic peripheral arterial disease, and superficial femoral artery lesions requiring implantation of stents>5 mm in diameter and >60 mm in length. Primary endpoint was binary restenosis at 12 months, defined as ≥2.5-fold increase in peak systolic velocity by duplex ultrasonography.

RESULTS

Seventy-four patients, with 90 stented superficial femoral artery lesions, were randomly assigned to post-dilation using cryoplasty (n=45 lesions) or conventional balloons (n=45 lesions). Mean lesion length was 148±98 mm, mean stented length was 190±116 mm, mean stent diameter was 6.1±0.4 mm, and 50% of the lesions were total occlusions. Post-dilation balloon diameters were 5.23±0.51 mm versus 5.51±0.72 mm in the cryoplasty and conventional balloon angioplasty groups, respectively (p=0.02). At 12 months, binary restenosis was significantly lower in the cryoplasty group (29.3% vs. 55.8%, p=0.01; odds ratio: 0.36, 95% confidence interval: 0.15 to 0.89).

CONCLUSIONS

Among diabetic patients undergoing implantation of nitinol self-expanding stents in the superficial femoral artery, post-dilation with cryoplasty balloon reduced binary restenosis compared to conventional balloon angioplasty. (Study Comparing Two Methods of Expanding Stents Placed in Legs of Diabetics With Peripheral Vascular Disease [COBRA]; NCT00827853).

Efficacy of endoluminal interventional therapy in diabetic peripheral arterial occlusive disease: a retrospective trial

Background

The purpose of this study was to assess the efficacy of interventional therapy for peripheral arterial occlusive disease and the difference between diabetic patients and non-diabetic patients.

Methods

139 consecutive patients between September 2006 and September 2010 who underwent percutaneous lower extremity revascularization for arterial lesions were divided into diabetes group (n = 62) and non-diabetes group (n = 77). Before intervention, rest ankle brachial indexes and three dimensional computed tomography angiography from abdominal aorta to tiptoe were performed. The interventional treatments included angioplasty with or without stenting. The clinical outcomes included rest ankle-brachial indexes, primary patency rates, secondary patency rates and limb-salvage rates for 6-month, 12-month, 24-month and 36-month after treatment. The primary and secondary patency rates of all interventions and the limb-salvage rates of the patients are illustrated by Kaplan-Meier curves and compared by log-rank analysis.

Results

The interventional operation success rates were 98.4% (61/62) in diabetes group and 100% (77/77) in non-diabetes group. The re-interventional operation success rates were 85.7% (18/21) in diabetes group and 76.9% (20/26) in non-diabetes group. The mean value of ankle brachial indexes was significantly increased after intervention (0.397 ± 0.125 versus 0.779 ± 0.137, t = -25.780, P < 0.001) in diabetes group and (0.406 ± 0.101 versus 0.786 ± 0.121, t = -37.221, P < 0.001) in non-diabetes group. Perioperative 30-day mortality was 0%. Major complications included groin hematoma in 7.2%, and pseudoaneurysm formation 2.2%. In diabetes group, 6, 12, 24, and 36-month primary patency rates were 88.7% ± 4.0%, 62.3% ± 6.6%, 55.3% ± 7.0%, and 46.5% ± 7.5%; secondary patency rates were 93.5% ± 3.1%, 82.3% ± 5.1%, 70.8% ± 6.5%, and 65.7% ± 7%; limb-salvage rates were 95.2% ± 2.7%, 87.7% ± 4.4%, 85.5% ± 4.8%, and 81.9% ± 5.8%. In non-diabetes group, 6, 12, 24, and 36-month primary patency rates were 90.9% ± 3.3%, 71.8% ± 5.4%, 71.8% ± 5.4%, and 60.9% ± 6.2%; secondary patency rates were 96.1% ± 2.2%, 91.6% ± 3.3%, 82.7% ± 4.8%, and 71.8% ± 6.2%; limb-salvage rates were 97.4% ± 1.8%, 94.4% ± 2.7%, 90.6% ± 3.7%, and 83.1% ± 5.4%. The differences between two groups were not significant (P > 0.05).

Conclusion

With a low risk of morbidity and mortality, the percutaneous revascularization accepted by patients does not affect ultimate necessary surgical revascularization and consequently should be considered as the preferred therapy for chronic lower extremity ischemia. The efficacy and prognosis of interventional therapy in diabetic patients is similar that in non-diabetic patients.

PolarCath cryoplasty enhances smooth muscle cell apoptosis in a rabbit iliac artery model: an experimental in vivo controlled study

PURPOSE

To in vivo investigate the histological response after single and double cryoplasty therapy in a rabbit iliac artery model.

MATERIALS AND METHODS

In total, 40 New Zealand White rabbits underwent percutaneous transluminal angioplasty of the iliac artery using either PolarCath balloon or a conventional angioplasty balloon of equal diameter. Arterial injury, inflammatory response and smooth muscle cells (SMC) apoptosis with the TUNEL (Terminal deoxynucleotidyl transferase dUTP Nick End Labeling) immunohistochemical assay were analyzed. Rabbits were divided between single or double balloon inflation and histological results were compared between cryoplasty and control angioplasty both at 30 min and 72 h.

RESULTS

Arterial injury and wall inflammation scores were low and similar between cryoplasty and control groups after single and double balloon inflation. Compared to conventional balloon angioplasty, Polarcath cryoplasty demonstrated superior SMC apoptosis after single inflation at 30 min [12.0±1.2 cells/(0.025 mm)2 vs 7.0±1.5 cells/(0.025 mm)(2), p=0.002], single inflation at 72 h [9.0±1.0 cells/(0.025 mm)(2) vs 5.4±1.4 cells/(0.025 mm)(2), p=0.001], double inflation at 30 min [11.6±1.5 cells/(0.025 mm)(2) vs 6.8±1.4 cells/(0.025 mm)(2), p=0.001] and double inflation at 72h [9.2±0.8 cells/(0.025 mm)(2) vs 5.0±0.7 cells/(0.025 mm)(2), p=0.001]. There were no significant differences in apoptosis between single and double cryoplasty application at 30 min and 72 h.

CONCLUSION

Cryoplasty demonstrated superior rates of SMC apoptosis at 30 min and 72 h and was associated to relatively low arterial injury and inflammation scores. An immediate second PolarCath inflation did not achieve superior apoptosis.

Cryoplasty versus conventional balloon angioplasty of the femoropopliteal artery in diabetic patients: long-term results from a prospective randomized single-center controlled trial

The purpose of this study was to investigate the immediate and long-term results of cryoplasty versus conventional balloon angioplasty in the femoropopliteal artery of diabetic patients. Fifty diabetic patients (41 men, mean age 68 years) were randomized to cryoplasty (group CRYO; 24 patients with 31 lesions) or conventional balloon angioplasty (group COBA; 26 patients with 34 lesions) of the femoropopliteal artery. Technical success was defined as <30% residual stenosis without any adjunctive stenting. Primary end points included technical success, primary patency, binary in-lesion restenosis (>50%), and freedom from target lesion recanalization. Cox proportional hazards regression analysis was performed to adjust for confounding factors of heterogeneity. In total, 61.3% (19 of 31) in group CRYO and 52.9% (18 of 34) in group COBA were de novo lesions. More than 70% of the lesions were Transatlantic Inter-Society Consensus (TASC) B and C in both groups, and 41.4% of the patients in group CRYO and 38.7% in group COBA suffered from critical limb ischemia. Immediate technical success rate was 58.0% in group CRYO versus 64.0% in group COBA (p = 0.29). According to 3-year Kaplan-Meier estimates, there were no significant differences with regard to patient survival (86.8% in group CRYO vs. 87.0% in group COBA, p = 0.54) and limb salvage (95.8 vs. 92.1% in groups CRYO and COBA, respectively, p = 0.60). There was a nonsignificant trend of increased binary restenosis in group CRYO (hazard ratio [HR] 1.3; 95% CI 0.6-2.6, p = 0.45). Primary patency was significantly lower in group CRYO compared with group COBA (HR 2.2; 95% CI 1.1-4.3, p = 0.02). Significantly more repeat intervention events because of recurrent symptoms were required in group CRYO (HR 2.5; 95% CI 1.2-5.3, p = 0.01). Cryoplasty was associated with lower primary patency and more clinically driven repeat procedures after long-term follow-up compared with conventional balloon angioplasty.