Comparison of balloon angioplasty and Simpson atherectomy for lesions in the femoropopliteal artery: angiographic and clinical results of a prospective randomized trial

Exploring the Reporting Standards of Randomised Controlled Trials Involving Endovascular Interventions for Peripheral Arterial Disease: A Systematic Review

OBJECTIVE

Endovascular technology innovation requires rigorous evaluation in high quality randomised controlled trials (RCTs). However, due to numerous methodological challenges, RCTs evaluating endovascular interventions are complex and potentially difficult to design, conduct, and report. This systematic review aimed to assess the quality of reporting of RCTs for endovascular interventions for lower limb peripheral arterial disease (PAD).

DATA SOURCES AND REVIEW METHODS

A systematic review of Medline, Embase, and the Cochrane Library databases from inception to December 2021 was performed to identify RCTs including participants with PAD undergoing any infrainguinal lower limb endovascular intervention. Study data were extracted and assessed against the Consolidating Standards of Reporting Trials extension for Non-Pharmacological Treatments (CONSORT-NPT) and the Template for Intervention Description and Replication (TIDieR) checklists. Descriptive statistics were used to summarise general study details and reporting standards of the trials.

RESULTS

After screening 6 567 abstracts and 526 full text articles, 112 eligible studies were identified, reporting on 228 different endovascular devices and techniques. Details judged sufficient to replicate the investigated intervention were provided for 47 (21%) interventions. It was unclear whether the description was reported with sufficient details in a further 56 (24%), and the description was judged inadequate in 125 (55%). Any intervention descriptions were provided for 184 (81%), with variable levels of detail (some in 134 [59%] and precise in 50 [22%]). Standardisation of intervention or some aspect of this was reported in 25 (22%) trials, but only one specified that adherence to the study protocol would be monitored.

CONCLUSION

The quality of the reporting standards of RCTs investigating lower limb endovascular treatments is severely limited because the interventions are poorly described, standardised, and reported. PROSPERO registration number: CRD42022288214.

Endovascular revascularization strategies for aortoiliac and femoropopliteal artery disease: a meta-analysis

AIMS

Optimal endovascular management of intermittent claudication (IC) remains disputed. This systematic review and meta-analysis compares efficacy and safety outcomes for balloon angioplasty (BA), bare-metal stents (BMS), drug-coated balloons (DCB), drug-eluting stents (DES), covered stents, and atherectomy.

METHODS AND RESULTS

Electronic databases were searched for randomized, controlled trials (RCT) from inception through November 2021. Efficacy outcomes were primary patency, target-lesion revascularization (TLR), and quality-of-life (QoL). Safety endpoints were all-cause mortality and major amputation. Outcomes were evaluated at short-term (<1 year), mid-term (1-2 years), and long-term (≥2 years) follow-up. The study was registered on PROSPERO (CRD42021292639). Fifty-one RCTs enrolling 8430 patients/lesions were included. In femoropopliteal disease of low-to-intermediate complexity, DCBs were associated with higher likelihood of primary patency [short-term: odds ratio (OR) 3.21, 95% confidence interval (CI) 2.44-4.24; long-term: OR 2.47, 95% CI 1.93-3.16], lower TLR (short-term: OR 0.33, 95% CI 0.22-0.49; long-term: OR 0.42, 95% CI 0.29-0.60) and similar all-cause mortality risk, compared with BA. Primary stenting using BMS was associated with improved short-to-mid-term patency and TLR, but similar long-term efficacy compared with provisional stenting. Mid-term patency (OR 1.64, 95% CI 0.89-3.03) and TLR (OR 0.50, 95% CI 0.22-1.11) estimates were comparable for DES vs. BMS. Atherectomy, used independently or adjunctively, was not associated with efficacy benefits compared with drug-coated and uncoated angioplasty, or stenting approaches. Paucity and heterogeneity of data precluded pooled analysis for aortoiliac disease and QoL endpoints.

CONCLUSION

Certain devices may provide benefits in femoropopliteal disease, but comparative data in aortoiliac arteries is lacking. Gaps in evidence quantity and quality impede identification of the optimal endovascular approach to IC.

Atherectomy for peripheral arterial disease

BACKGROUND

Symptomatic peripheral arterial disease (PAD) has several treatment options, including angioplasty, stenting, exercise therapy, and bypass surgery. Atherectomy is an alternative procedure, in which atheroma is cut or ground away within the artery. This is the first update of a Cochrane Review published in 2014.

OBJECTIVES

To evaluate the effectiveness of atherectomy for peripheral arterial disease compared to other established treatments.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, Cumulative Index to Nursing and Allied Health Literature (CINAHL) and Allied and Complementary Medicine (AMED) databases, and the World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registers to 12 August 2019.

SELECTION CRITERIA

We included all randomised controlled trials that compared atherectomy with other established treatments. All participants had symptomatic PAD with either claudication or critical limb ischaemia and evidence of lower limb arterial disease.

DATA COLLECTION AND ANALYSIS

Two review authors screened studies for inclusion, extracted data, assessed risk of bias and used GRADE criteria to assess the certainty of the evidence. We resolved any disagreements through discussion. Outcomes of interest were: primary patency (at six and 12 months), all-cause mortality, fatal and non-fatal cardiovascular events, initial technical failure rates, target vessel revascularisation rates (TVR; at six and 12 months); and complications.

MAIN RESULTS

We included seven studies, with a total of 527 participants and 581 treated lesions. We found two comparisons: atherectomy versus balloon angioplasty (BA) and atherectomy versus BA with primary stenting. No studies compared atherectomy with bypass surgery. Overall, the evidence from this review was of very low certainty, due to a high risk of bias, imprecision and inconsistency. Six studies (372 participants, 427 treated lesions) compared atherectomy versus BA. We found no clear difference between atherectomy and BA for the primary outcomes: six-month primary patency rates (risk ratio (RR) 1.06, 95% confidence interval (CI) 0.94 to 1.20; 3 studies, 186 participants; very low-certainty evidence); 12-month primary patency rates (RR 1.20, 95% CI 0.78 to 1.84; 2 studies, 149 participants; very low-certainty evidence) or mortality rates (RR 0.50, 95% CI 0.10 to 2.66, 3 studies, 210 participants, very low-certainty evidence). One study reported cardiac failure and acute coronary syndrome as causes of death at 24 months but it was unclear which arm the participants belonged to, and one study reported no cardiovascular events. There was no clear difference when examining: initial technical failure rates (RR 0.48, 95% CI 0.22 to 1.08; 6 studies, 425 treated vessels; very low-certainty evidence), six-month TVR (RR 0.51, 95% CI 0.06 to 4.42; 2 studies, 136 treated vessels; very low-certainty evidence) or 12-month TVR (RR 0.59, 95% CI 0.25 to 1.42; 3 studies, 176 treated vessels; very low-certainty evidence). All six studies reported complication rates (RR 0.69, 95% CI 0.28 to 1.68; 6 studies, 387 participants; very low-certainty evidence) and embolisation events (RR 2.51, 95% CI 0.64 to 9.80; 6 studies, 387 participants; very low-certainty evidence). Atherectomy may be less likely to cause dissection (RR 0.28, 95% CI 0.14 to 0.54; 4 studies, 290 participants; very low-certainty evidence) and may be associated with a reduction in bailout stenting (RR 0.26, 95% CI 0.09 to 0.74; 4 studies, 315 treated vessels; very low-certainty evidence). Four studies reported amputation rates, with only one amputation event recorded in a BA participant. We used subgroup analysis to compare the effect of plain balloons/stents and drug-eluting balloons/stents, but did not detect any differences between the subgroups. One study (155 participants, 155 treated lesions) compared atherectomy versus BA and primary stenting, so comparison was extremely limited and subject to imprecision. This study did not report primary patency. The study reported one death (RR 0.38, 95% CI 0.04 to 3.23; 155 participants; very low-certainty evidence) and three complication events (RR 7.04, 95% CI 0.80 to 62.23; 155 participants; very low-certainty evidence) in a very small data set, making conclusions unreliable. We found no clear difference between the treatment arms in cardiovascular events (RR 0.38, 95% CI 0.04 to 3.23; 155 participants; very low-certainty evidence). This study found no initial technical failure events, and TVR rates at six and 24 months showed little difference between treatment arms (RR 2.27, 95% CI 0.95 to 5.46; 155 participants; very low-certainty evidence and RR 2.05, 95% CI 0.96 to 4.37; 155 participants; very low-certainty evidence, respectively).

AUTHORS' CONCLUSIONS

This review update shows that the evidence is very uncertain about the effect of atherectomy on patency, mortality and cardiovascular event rates compared to plain balloon angioplasty, with or without stenting. We detected no clear differences in initial technical failure rates or TVR, but there may be reduced dissection and bailout stenting after atherectomy although this is uncertain. Included studies were small, heterogenous and at high risk of bias. Larger studies powered to detect clinically meaningful, patient-centred outcomes are required.

Initial Clinical Experience with Percutaneous Atherectomy in the Infragenicular Arteries

Purpose:

To evaluate the efficacy and safety of a new atherectomy device for the treatment of infragenicular lesions in arteries with a reference diameter of at least 2.5 mm.

Methods:

Twenty-seven below-the-knee lesions in 17 patients (12 men; mean age 69±12 years) with chronic peripheral arterial occlusive disease were treated with directional atherectomy. The target lesion was in the popliteal artery (segment 3) in 2 (7%) cases, the tibioperoneal trunk in 12 (44%), the peroneal artery in 8 (30%), the anterior tibial artery in 2 (7%), and the posterior tibial artery in 3 (11%). Six (22%) of the lesions were in-stent stenoses. The mean diameter stenosis was 87%±9%, and the mean lesion length was 34±24 mm.

Results:

All but 2 (7%) of the lesions could be treated successfully (residual stenosis <30%) with the atherectomy catheter (93% technical success) using an average of 5±2 (range 1–10) passes of the device. Six lesions (22%) were treated after predilation and 21 (78%) with primary atherectomy. In 8 (30%) lesions, additional balloon angioplasty was performed. The 2 failures were in heavily calcified lesions through which the device could not pass despite predilation. The mean diameter stenosis after atherectomy was 14%±22% (range 0%–90%); after additional balloon angioplasty, the mean residual stenoses reduced to 12%±21% (range 0%–100%). One (6%) of the 2 patients who failed atherectomy sustained a thrombotic occlusion of the target vessel. This complication was treated successfully with local lysis, but the vessel reoccluded 3 days later; a stent was implanted. The mean ankle-brachial index increased from 0.50±0.27 to 0.86±0.40 before discharge.

Conclusions:

Below-the-knee native vessel lesions and in-stent restenoses with a diameter of at least 2.5 mm can be treated successfully and safely with this new atherectomy catheter. Additional balloon angioplasty was necessary in only a few cases.

Two-Year Results after Directional Atherectomy of Infrapopliteal Arteries with the SilverHawk Device

Purpose:

To report the 12- and 24-month results after directional atherectomy (DA) of below-the-knee (BTK) arterial lesions with the SilverHawk device.

Methods:

Forty-nine BTK lesions in 36 patients (58% men; mean age 70611 years) with peripheral occlusive disease of the lower limbs were treated with DA; 19 (53%) of the limbs were classified with Rutherford-Becker 4 or 5 ischemia. Target lesions were in the popliteal artery (n=6, 12%), tibioperoneal trunk (n=25, 51%), peroneal artery (n=10, 20%), anterior tibial artery (n=5, 10%), and posterior tibial artery (n=3, 6%). Nine (18%) lesions were located in a stent. Twelve lesions extended to 2 artery segments. The average degree of diameter stenosis was 89%±10% (range 70%–100%); there were 11 (22%) occlusions. The mean lesion length was 48±28 mm.

Results:

Sixteen (33%) lesions were treated after predilation; 33 (67%) lesions were treated with primary DA. All but 1 (2%) lesion could be treated with DA. In 19 (39%) lesions, additional balloon angioplasty was performed, and 2 (4%) lesions required stent implantation as a result of dissection. The mean stenosis diameter after DA was 12%±18% (range 0%–100%). After additional therapy, the mean stenosis diameter was 8%±9% (range 0%–100%). A residual stenosis ≤30% was achieved in 48 (98%) lesions. The mean ankle-brachial index significantly increased from 0.48±0.26 to 0.81±0.32 (p<0.05) before discharge and remained improved during follow-up. Primary and secondary patency rates were 67% and 91% after 1 year and 60% and 80% after 24 months. The 12-and 24-month cumulative event-free survival rates (primary patency) by Kaplan-Meier analysis were 58%±8% and 46%±9%; at the same time intervals, the cumulative survival rates (secondary patency) were 88%±6% and 73%±9%, respectively.

Conclusion:

BTK lesions can be treated successfully and safely with DA. Midterm clinical results are encouraging.

Cryoplasty for the Treatment of Femoropopliteal Arterial Disease: Extended Follow-up Results

Purpose:

To report the findings from a multicenter study of patients treated with cryoplasty who were then followed for an average of >2 years post-treatment.

Methods:

Extended clinical follow-up was obtained for 70 patients (45 men; mean age 70.5±8.8 years) who originally received cryoplasty therapy to treat symptoms of intermittent claudication as part of a multicenter investigational device exemption (IDE) study. For all subjects, cryoplasty was used to treat stenoses or occlusions ≤10 cm in the femoropopliteal arteries. The original IDE study protocol enrolled 102 patients with a primary endpoint of target lesion patency at 9 months post-treatment. This collection of additional longer term follow-up data was initiated 2.5 years after the onset of study enrollment.

Results:

Extended clinical follow-up ranged from 11 to 41 months (mean 31). The clinical patency rate (freedom from target lesion revascularization) calculated by the Kaplan-Meier method was 83.2% after the original follow-up period of 300 days. After >3 years (1253 days), the clinical patency rate was well maintained at 75.0%.

Conclusions:

Long-term data indicate that cryoplasty is a durable therapy, with relatively low long-term restenosis rates compared to other endovascular treatment approaches.

Atherectomy for peripheral arterial disease

BACKGROUND

Symptomatic peripheral arterial disease may be treated by a number of options including exercise therapy, angioplasty, stenting and bypass surgery. Atherectomy is an alternative technique where atheroma is excised by a rotating cutting blade.

OBJECTIVES

The objective of this review was to analyse randomised controlled trials comparing atherectomy against any established treatment for peripheral arterial disease in order to evaluate the effectiveness of atherectomy.

SEARCH METHODS

The Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (last searched November 2013) and CENTRAL (2013, Issue 10). Trials databases were searched for details of ongoing or unpublished studies.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing atherectomy and other established treatments were selected for inclusion. All participants had symptomatic peripheral arterial disease with either claudication or critical limb ischaemia and evidence of lower limb arterial disease.

DATA COLLECTION AND ANALYSIS

Two review authors (GA and CT) screened studies for inclusion, extracted data and assessed the quality of the trials. Any disagreements were resolved through discussion.

MAIN RESULTS

Four trials were included with a total of 220 participants (118 treated with atherectomy, 102 treated with balloon angioplasty) and 259 treated vessels (129 treated with atherectomy, 130 treated with balloon angioplasty). All studies compared atherectomy with angioplasty. No study was properly powered or assessors blinded to the procedures and there was a high risk of selection, attrition, detection and reporting biases.The estimated risk of success was similar between the treatment modalities although the confidence interval (CI) was compatible with small benefits of either treatment for the initial procedural success rate (Mantel-Haenszel risk ratio (RR) 0.92, 95% CI 0.44 to 1.91, P = 0.82), patency at six months (Mantel-Haenszel RR 0.92, 95% CI 0.51 to 1.66, P = 0.79) and patency at 12 months (Mantel-Haenszel RR 1.17, 95% CI 0.72 to 1.90, P = 0.53) following the procedure. The reduction in all-cause mortality with atherectomy was most likely due to an unexpectedly high mortality in the balloon angioplasty group in one of the two trials that reported mortality (Mantel-Haenszel RR 0.24, 95% CI 0.06 to 0.91, P = 0.04). Cardiovascular events were not reported in any study. There was a reduction in the rate of bailout stenting following atherectomy (Mantel-Haenszel RR 0.45, 95% CI 0.24 to 0.84, P = 0.01), and balloon inflation pressures were lower following atherectomy (mean difference -2.73 mmHg, 95% CI -3.48 to -1.98, P < 0.00001). Complications such as embolisation and vessel dissection were reported in two trials indicating more embolisations in the atherectomy group and more vessel dissections in the angioplasty group, but the data could not be pooled. From the limited data available, there was no clear evidence of different rates of adverse events between the atherectomy and balloon angioplasty groups for target vessel revascularisation and above-knee amputation. Quality of life and clinical and symptomatic outcomes such as walking distance or symptom relief were not reported in the studies.

AUTHORS' CONCLUSIONS

This review has identified poor quality evidence to support atherectomy as an alternative to balloon angioplasty in maintaining primary patency at any time interval. There was no evidence for superiority of atherectomy over angioplasty on any outcome, and distal embolisation was not reported in all trials of atherectomy. Properly powered trials are recommended.

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.

Atherectomy offers no benefits over balloon angioplasty in tibial interventions for critical limb ischemia

BACKGROUND

Endovascular adjuncts, like atherectomy, were developed to improve outcomes of endovascular arterial interventions. The true impact of atherectomy on endovascular outcomes remains to be determined, and little data exist on the influence of atherectomy on tibial interventions. Our study compares early and late outcomes of tibial intervention with angioplasty vs atherectomy-assisted interventions.

METHODS

We completed a retrospective review of all tibial interventions between 2008 and 2010. Outcomes were analyzed using single and multivariate analysis, Cox regression, and Kaplan-Meier curves. Primary outcomes were primary, primary assisted, and secondary patency rates, as well as limb salvage and survival rates.

RESULTS

Over a 2-year period, 480 tibial interventions were completed for 421 patients. Eighty-seven percent (n = 418) of interventions were performed for critical limb ischemia (CLI) and 13% (n = 62) for claudication. The CLI cohort of 418 interventions was analyzed. These patients had a mean age of 71 years with a mean follow-up time of 16 ± 15 months (range, 0-59 months). Of the 418 interventions, 339 underwent percutaneous transluminal angioplasty (PTA): 333 PTA alone, six PTA + stent. The remaining 79 interventions received atherectomy: 33 laser, 13 directional, and 33 orbital either alone or in conjunction with PTA (11 atherectomy only, 68 atherectomy + PTA). The groups did not differ significantly in terms of demographics, risk factors, or technical success. The atherectomy group had more TASC B lesions (54% vs 38%; P = .013), while the PTA-alone group had more TASC D lesions (25% vs 13%; P = .004). TASC A and C lesions did not differ significantly between the groups. No significant differences existed with respect to the early (30-day) outcomes of loss of patency (11% vs 13%; P = .699), complications (8% vs 13%; P = .292), or major amputation (17% vs 13%; P = .344) in the PTA-alone group vs the atherectomy-assisted group. Kaplan-Meier analysis revealed no difference for all primary outcomes of PTA alone vs the atherectomy-assisted group at 12 and 36 months: primary patency (69%, 55% vs 61%, 46%; P = .158), primary assisted patency (83%, 71% vs 85%, 67%; P = .801), secondary patency (94%, 89% vs 95%, 89%; P = .892), limb salvage (79%, 70% vs 81%, 77%; P = .485), or survival (77%, 56% vs 80%, 50%; P = .944).

CONCLUSIONS

The adjunctive use of atherectomy offered no improvement in primary outcomes over PTA alone in either early or late outcomes in CLI patients who underwent endovascular tibial interventions. Considering the additional cost and increased procedural time, these findings put into question the routine use of adjunctive atherectomy.

Plaque Excision in Management of Lower Extremity Peripheral Arterial Disease with the SilverHawk Atherectomy Catheter

Atherectomy, the removal of plaque from diseased vessels, is theoretically appealing with respect to various procedures used for revascularization of lower extremity vessels. Instead of damaging the native vessel by pushing aside plaque with a balloon or stent, the plaque is removed. Many atherectomy devices have been designed in attempts to achieve this goal. The SilverHawk device is the latest percutaneous device employing this treatment strategy. We discuss patient selection, technical considerations, and strategies for both above and below the knee revascularization, as well as pitfalls in each location based on our experience with over 200 patients.

One-year outcome of percutaneous rotational atherectomy with aspiration in infrainguinal peripheral arterial occlusive disease: the multicenter pathway PVD trial

PURPOSE

To report a safety and efficacy study of a novel rotational atherectomy system with aspiration capabilities for the treatment of infrainguinal arterial lesions.

METHODS

From February 2006 to January 2007, 172 patients (88 women; mean age 72 years, range 51-93; 47% diabetics) with Rutherford class 1-5 lower limb ischemia were enrolled at 9 study sites. Inclusion criteria were atherosclerotic stenoses >70% and up to 10 cm long in the femoropopliteal segment or up to 3 cm long in the infrapopliteal vessels (reference vessel diameter 3.0-5.0 mm). In the study, 210 lesions (mean length 2.7 cm) were treated with the Pathway PV System, including total occlusions (31%), lesions with a moderate to high calcium score (51%), and post-angioplasty (non-stent) restenotic lesions (15%). The primary study endpoint was the 30-day major adverse event (MAE) rate.

RESULTS

Device success was 99% (208/210 lesions). MAE at 30 days was 1% (2 preplanned amputations). Clinically driven target lesion revascularization rates at 6 and 12 months were 15% (25/172) and 26% (42/162), respectively. The 1-year restenosis rate was 38.2% based on duplex imaging. The ankle-brachial index increased significantly from 0.59+/-0.21 at baseline to 0.82+/-0.27 (p<0.05) at 12 months. Mean Rutherford class improved from 3.0+/-0.9 at baseline to 1.5+/-1.3 at 1 year (p<0.05).

CONCLUSION

The use of the Pathway PV System in atherosclerotic lesions appears to be safe and effective in improving stenosis severity, even in the presence of challenging lesion conditions. Vessel patency following intervention appears to be good up to 12 months, and these results translate into clinical benefit.

[Percutaneous mechanical atherectomy for treatment of peripheral arterial occlusive disease]

Peripheral arterial occlusive disease (PAOD) is still an extremely important politico-economic disease. Diverse treatment procedures exist but the pillars of therapy are changes in lifestyle, such as nicotine abstinence and walking exercise as well as drug therapy. Further therapy options are considered after conventional procedures have been exhausted. These further options consist of improvement of the blood supply by surgical or minimally invasive procedures. The latter therapy options include balloon dilatation and stenting as the most widely used techniques. More recent techniques also used are cryoplasty, laser angioplasty, drug-coated stents or balloons as well as brachytherapy or atherectomy, whereby this list makes no claims to completeness. The multitude of different treatment methods emphatically underlines the fact that no resounding success can be achieved with one single method. The long-term results of both balloon dilatation and stenting techniques show a need for improvement, which elicited the search for additional methods for the treatment of PAOD. Atherectomy represents such an alternative method for treatment of PAOD. Basically, the term atherectomy means the removal of atheroma tissue. For percutaneous atherectomy, in contrast to surgical procedures, it is not necessary to create surgically access to the vessel but accomplishes the atherectomy by means of dedicated systems via a minimally invasive access. There are two basic forms of mechanical atherectomy: directional and rotational systems.

Medical and endovascular management of critical limb ischemia

Critical limb ischemia (CLI) is the term used to designate the condition in which peripheral artery disease has resulted in resting leg or foot pain or in a breakdown of the skin of the leg or foot, causing ulcers or tissue loss. If not revascularized, CLI patients are at risk for limb loss and for potentially fatal complications from the progression of gangrene and the development of sepsis. The management of CLI requires a multidisciplinary team of experts in different areas of vascular disease, from atherosclerotic risk factor management to imaging, from intervention to wound care and physical therapy. In the past decade, the most significant change in the treatment of CLI has been the increasing tendency to shift from bypass surgery to less invasive endovascular procedures as first-choice revascularization techniques, with bypass surgery then reserved as backup if appropriate. The goals of intervention for CLI include the restoration of pulsatile, inline flow to the foot to assist wound healing, the relief of rest pain, the avoidance of major amputation, preservation of mobility, and improvement of patient function and quality of life. The evaluating physician should be fully aware of all revascularization options in order to select the most appropriate intervention or combination of interventions, while taking into consideration the goals of therapy, risk-benefit ratios, patient comorbidities, and life expectancy. We discuss the incidence, risk factors, and prognosis of CLI and the clinical presentation, diagnosis, available imaging modalities, and medical management (including pain and ulcer care, pharmaceutical options, and molecular therapies targeting angiogenesis). The endovascular approaches that we review include percutaneous transluminal angioplasty (with or without adjunctive stenting); subintimal angioplasty; primary femoropopliteal and infrapopliteal deployment of bare nitinol, covered, drug-eluting, or bioabsorbable stents; cryoplasty; excimer laser-assisted angioplasty; excisional atherectomy; and cutting balloon angioplasty.

Atherectomy for infrainguinal peripheral artery disease

Compared to conventional percutaneous transluminal angioplasty (PTA) and stent implantation for arterial occlusive diseases, atherectomy offers the theoretical advantages of eliminating stretch injury on arterial walls and reducing the, rate of restenosis. Historically, however, neither rotational nor directional atherectomy, whether used alone or with adjunctive PTA, has shown any significant long-term benefit over PTA alone in the coronary or peripheral arteries. However, the SilverHawk Plaque Excision System has produced positive results in single-center prospective registries of patients with femoropopliteal and infrainguinal lesions, with reduced adjunctive PTA, minimal adjunctive stenting, and competitive 6-month and 12-month patency rates. In the observational nonrandomized TALON (Treating Peripherals with SilverHawk: Outcomes Collection) registry, freedom from target lesion revascularization was 80% for 87 patients at 12 months. Questions remaining for further research with this device include more accurate determination of an event rate for distal embolization, the appropriate use of distal protection, the value of and appropriate circumstances for adjunctive angioplasty, and definitive patency and clinical outcomes. Other atherectomy devices are discussed.

Hybrid Revascularization Using Silverhawk Atherectomy and Infrapopliteal Bypass for Limb Salvage

Patients with limb-threatening ischemia and a paucity of ipsilateral greater saphenous vein for conduit represent a challenge for lower extremity revascularization. We present four patients with limited autogenous conduit who underwent hybrid revascularization using the Silverhawk atherectomy device and infrapopliteal artery bypass for limb-threatening ischemia. All patients experienced complete wound healing in early follow-up. Hybrid revascularization appears safe, produces excellent short-term outcomes, and may be appropriate for patients with limited autogenous vein who require lower extremity revascularization.

A novel approach using atherectomy for chronic total occlusion of the brachial artery: a case report

Chronic upper limb ischemia is uncommon, and is most often secondary to subclavian artery stenosis. Percutaneous intervention for subclavian stenosis usually includes balloon angioplasty and stent implantation. Brachial artery stenosis is even more scarce and accounts for approximately 12% of symptomatic upper extremity ischemia. Because it is rare, the optimal treatment strategy for brachial artery stenosis remains uncertain. We describe a case of chronic brachial artery ischemia due to atherosclerotic disease treated with the SilverHawk plaque excision system and review the available data regarding its use.

Percutaneous Rotational and Aspiration Atherectomy in Infrainguinal Peripheral Arterial Occlusive Disease: A Multicenter Pilot Study

PURPOSE

To report a safety and efficacy study of the first rotational aspiration atherectomy system (Pathway PV) for the treatment of arterial lesions below the femoral bifurcation.

METHODS

From December 2005 to February 2006, 15 patients (9 men; mean age 71+/-9 years) with Rutherford stage 2 to 5 lower limb ischemia were enrolled at 3 study sites. Target lesions were in the superficial femoral (n = 7, 47%), popliteal (n = 7, 47%), and posterior tibial (n = 1, 6%) arteries. Mean diameter stenosis was 97%+/-10%; mean lesion length was 61+/-62 mm (range 5-250). The primary study endpoint was the 30-day serious adverse event (SAE) rate.

RESULTS

Interventional success (residual stenosis <30%) was achieved in all lesions (100%). Stand alone atherectomy was performed in 6 (40%) patients, adjunctive balloon angioplasty in 7 (47%), and stenting/endografting in 2 (13%). The SAE rate at 30 days was 20% (3/15), including 1 perforation due to an unrecognized displacement of the guidewire (sealed with an endograft), 1 false aneurysm at the puncture site (successful duplex-guided compression therapy), and 1 dissection in conjunction with a distal embolism (stent implantation and aspiration thrombectomy). Primary patency rates measured by duplex ultrasound at 1 and 6 months were 100% and 73%, respectively; the TLR rate was 0% after 6 months. The ankle-brachial index increased significantly from 0.54+/-0.3 at baseline to 0.89+/-0.16, 0.88+/-0.19, and 0.81+/-0.20 (p<0.05) at discharge, 1 month, and 6 months, respectively. Mean Rutherford categories were 2.92+/-1.19 (range 1-5), 0.64+/-1.12 (range 0-1), and 0.83+/-1.33 (range 0-3) at the same time points (p<0.05).

CONCLUSION

The application of this new atherectomy device was feasible in all cases. The serious adverse event rate was moderate; however, all events were solved during the index procedure. The 0% 6-month TLR rate is promising.

Performance goals and endpoint assessments for clinical trials of femoropopliteal bare nitinol stents in patients with symptomatic peripheral arterial disease

OBJECTIVE

This analysis proposes safety and performance goals for prospective single-arm trials of bare nitinol stents to treat patients with debilitating claudication associated with femoropopliteal (FP) atherosclerotic lesions.

BACKGROUND

To date there have been no analyses of clinical trials data to set efficacy and safety benchmarks for new bare nitinol stents in the treatment of claudication from FP disease. Industry has been reluctant to sponsor studies of nitinol stents due to logistical barriers.

METHODS

VIVA Physician's, Inc. (VPI) analyzed subject-level data from the PTA control arm of three randomized FDA device trials conducted by industry. Subjects with Rutherford category 2-4 claudication and FP lesion lengths 4-15 cm with 12 month duplex ultrasound (DUS) assessment were identified. These data were combined with the results of a survey of the medical literature (1990-2006) for similar subjects.

RESULTS

Analysis of the industry derived control arm PTA data identified 116 patients (mean lesion length 8.7 cm) with a 12 month DUS defined FP patency of 28%. A similar cohort of 191 patients was identified from the medical literature in which the 12-month vessel patency equaled 37%; from these combined patient cohorts, expected vessel patency for PTA was estimated to equal 33%.

CONCLUSION

Based on the PTA performance efficacy rate of 33% derived from industry clinical trial data and the medical literature, and the requirement that the bare nitinol stent 12-month efficacy performance goal be set to equal twice this rate, the patency efficacy goal equals 66%. Additional information is provided on safety and other reporting standards and stent integrity evaluation for bare metal stents.

Peripheral atherectomy in TransAtlantic InterSociety Consensus type C femoropopliteal lesions for limb salvage

BACKGROUND

The optimal therapy for TransAtlantic Societal Consensus (TASC) type C femoropopliteal lesions remains a critical issue in the treatment of infrainguinal occlusive disease. The purpose of this study was to evaluate the outcome of limbs with TASC C femoropopliteal lesions and critical limb ischemia treated with the FoxHollow SilverHawk atherectomy catheter.

METHODS

From September 2004 to September 2005, 18 consecutive femoropopliteal procedures performed in 17 limbs in 16 patients were reviewed. Demographic data, baseline angiographic findings, and indications for the procedures were recorded. Clinical outcomes including symptom resolution and limb salvage were determined for the 17 primary procedures. Hemodynamic improvement was compared by using the paired Student t test. Stenosis-free patency was determined by the Kaplan-Meier method.

RESULTS

The mean age was 72.5 years (range, 47-88 years). Fifty percent of the patients had four or more of the following risk factors: hypertension, diabetes, tobacco use, hyperlipidemia, renal insufficiency, and coronary artery disease. The indication was tissue loss in 13 limbs and rest pain in 4. All patients had a second level of disease, either inflow or tibial/pedal, which was treated concurrently when appropriate. Initial resolution of symptoms was achieved in 12 limbs, and partial healing was achieved in 2 others. Early amputation was necessary in the remaining three patients, but this was likely due to severe inframalleolar disease and advanced forefoot ischemia at the time of presentation. Five patients have remained symptom-free without restenosis at a mean follow-up of 6 months. Two patients have required late amputation for hemodynamic failure. The ankle-brachial index improved from 0.39 +/- 0.08 (mean +/- SEM) before surgery to 0.75 +/- 0.08 in the immediate postoperative period (P = .02). However, it returned toward baseline at 6 months after surgery, with a mean of 0.48 +/- 0.07. Stenosis-free patency of the femoropopliteal segment was 22% at 12 months.

CONCLUSIONS

Peripheral atherectomy can achieve good early clinical and hemodynamic success in patients with TASC C lesions and critical limb ischemia. However, mid-term restenosis rates are high in this challenging cohort of patients.

Long-term results after directional atherectomy of femoro-popliteal lesions

OBJECTIVES

Our objective in this research was the evaluation of the long-term results after directional atherectomy using the Silverhawk device (FoxHollow Technologies, Redwood City, California) of femoro-popliteal lesions.

BACKGROUND

Considering reports on stent fractures in femoro-popliteal arteries, atherectomy may be a valuable alternative to stenting.

METHODS

Eighty-four patients with 100 legs and 131 lesions with peripheral occlusive disease Rutherford categories 2 to 5 were included in a prospective registry. Forty-five lesions were de novo lesions (group 1; 34%), 43 lesions native vessel restenoses (group 2; 33%), and 43 lesions in-stent restenoses (group 3; 33%). Additional low pressure balloon angioplasty was used in 78 of 131 lesions (59%) and stenting in 8 lesions (6%).

RESULTS

Technical success rate was 86% for atherectomy only and 100% after additional therapy. Mean lesion length was 43 +/- 54 mm, 105 +/- 122 mm, and 131 +/- 111 mm for group 1, group 2, and group 3, respectively (p < 0.001). Primary patency, defined as freedom of a >50% restenosis detected by duplex, was 84%, 54%, and 54% at 12 months (p = 0.002) and 73%, 42%, and 49%, at 18 months (p = 0.008); secondary patency rates were 100%, 93%, and 91% at 12 months (p = NS) and 89%, 67%, and 79% at 18 months (p = 0.001), respectively; and target lesion revascularization rate was 16%, 44%, and 47% at 12 months and 22%, 56%, and 49% at 18 months (p = 0.003 each) for group 1, group 2, and group 3, respectively. The only independent predictor for restenosis was treatment of restenotic lesions. Ankle-brachial index was significantly improved after 12 months and 18 months in all groups.

CONCLUSIONS

Long-term technical and clinical results after directional atherectomy of femoro-popliteal lesions are in favor of de novo lesions compared with restenotic lesions.

Critical limb ischemia: will atherectomy and laser-directed therapy be the answer?

The interventional treatment of peripheral atherosclerotic occlusive disease is increasingly becoming accepted as an appropriate initial form of therapy. Standard methods of treatment include balloon angioplasty and stent assisted angioplasty. Laser catheters and mechanical atherectomy catheters are newer tools, which can be utilized to assist in achieving and maintaining patency in these vessels. In this report, we review the efficacy, safety, and potential advantages of these ablative devices when used for the treatment of peripheral arterial occlusive disease.

Procedural and Clinical Outcomes With Catheter-Based Plaque Excision in Critical Limb Ischemia

PURPOSE

To examine the safety and efficacy of catheter-based plaque excision as an alternative therapy to surgery, conventional angioplasty, and/or stenting in high-risk patients with critical limb ischemia (CLI).

METHODS

Between August 2003 and August 2004, a prospective evaluation was conducted of consecutive patients with CLI (Rutherford category>or=5) who were treated with endovascular plaque excision at 7 institutions. This study enrolled 69 patients (37 women; mean age 70+/-12 years, range 43-93) with CLI involving 76 limbs. Clinical outcomes were prospectively followed for 6 months. The primary endpoint was major adverse events (death, myocardial infarction, unplanned amputation, or repeat target vessel revascularization) at 30 days. Visible healing of ulcerated tissue, avoidance of any amputation, and performance of less extensive amputation than initially planned were also assessed.

RESULTS

Procedural success was achieved in 99% of cases. Major adverse events occurred in 1% of patients at 30 days and 23% at 6 months. The target lesion revascularization rate was 4%, and there were no unplanned limb amputations. Amputation was less extensive than initially planned or avoided altogether in 92% of patients at 30 days and 82% at 6 months.

CONCLUSION

Catheter-based plaque excision is a safe and effective revascularization method for patients with CLI. These findings support further study of this modality as a singular or adjunctive endovascular therapy for limb salvage in CLI.

Functional and clinical outcomes of nitinol stenting with and without abciximab for complex superficial femoral artery disease: A randomized trial

OBJECTIVE

To evaluate the effect of glycoprotein IIb/IIIa inhibition during nitinol stenting, of superficial femoral occlusive disease.

BACKGROUND

Stent implantation in the superficial femoral artery has been associated with suboptimal results while Glycoprotein IIb/IIIa inhibitors have shown improved procedural results during coronary intervention. We evaluated abciximab infusion during (Smart Stent) implantation in superficial femoral obstructions.

METHODS

We conducted a randomized placebo controlled trial. The two primary end points include: (1) 9-month restenosis defined as a decrease in ankle brachial index and in-stent duplex ultrasound restenosis: (2) adverse events defined as death (30 days) or repeat revascularization within 9 months.

RESULTS

Twenty-seven patients were randomized to abciximab and 24 patients to control (placebo). The primary end point of cumulative restenosis occurred in 15.4% of patients administered abciximab and in 12% administered placebo (P = 0.873). The primary restenosis endpoint in diabetics and total occlusions were similar at 14.3% and 15.4% respectively. The composite end point of 30-day mortality and 9-month revascularization occurred in 5.8% abciximab and 0% (P = 0.274) placebo with no 30-day deaths. Graded treadmill time and Rutherford class were all significantly improved in both groups, but the abciximab group did not appear to demonstrate any identifiable effect.

CONCLUSION

(Smart Stent) nitinol stenting of the superficial femoral artery was associated with favorable functional outcomes at 9 months. Adjunctive abciximab did not appear to demonstrate any identifiable effect.

The Use of Femoropopliteal Stent-Grafts for Critical Limb Ischemia

Peripheral vascular disease of the femoropopliteal segment is one of the most common anatomic locations leading to patient symptoms. Traditional open surgical bypass has started to be supplanted by a surge in lower risk endovascular procedures. Though midterm results of endovascular therapy have been acceptable, longer term results, especially in long diffuse disease, appear to be less durable than their surgical alternatives. Recently the Viabahn, a percutaneously placed PTFE stent-graft, has been approved for use in the femoropopliteal artery. Though the majority of the data for this stent-graft has been derived from patients with complex (>10 cm length) lesions, most of the patients have been claudicants. The population with critical limb ischemia is at particularly high risk for cardiovascular mortality and may benefit from this less invasive approach. However, stent-graft utilization is more complex and many variables must be evaluated before and during the procedure to allow for optimal procedural outcomes.

Midterm results after atherectomy-assisted angioplasty of below-knee arteries with use of the Silverhawk device

PURPOSE

Prospective evaluation of the 3- and 6-month results after atherectomy of below-knee arterial lesions with a reference diameter of at least 2.0 mm with use of the Silverhawk device.

MATERIALS AND METHODS

Fifty-two below-knee lesions in 33 patients (61% men; mean age, 70 years +/- 11) with chronic peripheral occlusive disease of the lower limbs were treated with directional atherectomy. Target lesions were the popliteal artery (segment 3), n = 4 (8%); tibioperoneal trunk, n = 22 (42%); peroneal artery, n = 18 (34%); anterior tibial artery, n = 5 (10%); posterior tibial artery, n = 3 (6%); and in-stent lesions, n = 8 (16%). All interventions were performed via a 6-F sheath. The average degree of diameter stenosis was 89% +/- 10% (range, 70%-100%; n = 12 [23%] occlusions) and the mean lesion length was 48 mm +/- 28.

RESULTS

All but one lesion (2%) could be treated with the atherectomy catheter. After additional balloon angioplasty, all but one lesion was treated, with a residual stenosis no greater than 30% (98%), with 7.2 passes per lesion +/- 2.8 (range, 1-12) performed with the device. Fifteen lesions (29%) were treated after predilation and 37 (71%) were treated with primary atherectomy. In 15 lesions (29%), additional balloon angioplasty was performed, and two lesions required stent implantation as a result of dissection. The mean stenosis diameter after atherectomy was 12% +/- 18% (range, 0-100%). After additional therapy, the mean stenosis diameter was 6% +/- 9% (range, 0%-30%). A residual stenosis no greater than 30% was achieved in 50 lesions (96%). The mean ankle-brachial index significantly increased from 0.46 +/- 0.27 to 0.80 +/- 0.34 before discharge and remained improved during follow-up. One procedural complication (3%) was observed in which an intermittent occlusion of the target vessel occurred after an unsuccessful attempt to cross the lesion with the atherectomy device; this was then treated successfully with local lysis. One patient with one treated lesion died during follow-up. The rates of restenosis of at least 70% (diagnosed by duplex ultrasonography) were 14% (seven of 51 lesions) after 3 months and 22% (11 of 51) after 6 months. The 3-month and 6-month cumulative event-free survival were 91% +/- 4.1% and 76.9% +/- 5.8% and the 3-month and 6-month cumulative patency rates were 98% +/- 1.9% and 94.1% +/- 3.3%, respectively.

CONCLUSION

Below-knee native vessel lesions with a diameter of at least 2.0 mm can be treated with the Silverhawk catheter with a high success rate and a low complication rate. Midterm technical and clinical results are encouraging. Additional balloon angioplasty might be necessary in selected cases.

Percutaneous Peripheral Atherectomy of Femoropopliteal Stenoses Using a New-Generation Device:Six-Month Results From a Single-Center Experience

PURPOSE

To report the early and 6-month results after atherectomy of femoropopliteal lesions using a new atherectomy device compatible with a 7-F sheath.

METHODS

Fifty-two patients (36 men; mean age 67+/-7 years) with stable, chronic lower limb occlusive disease were enrolled prospectively in a study of percutaneous directional atherectomy using the SilverHawk Atherectomy Catheter. The 71 femoropopliteal stenoses were grouped for analysis according to pathology: 30 (42%) primary stenoses, 27 (38%) native vessel restenoses, and 14 (20%) in-stent restenoses. The overall average stenosis length was 48+/-64 mm (range 10-300). There were more diabetics in the primary lesion cohort, whereas the lesion length of the in-stent restenoses was nearly twice as long as the other groups.

RESULTS

After atherectomy alone, residual stenosis was < or =50% in 68 (96%) lesions and < or =30% in 54 (76%). Additional balloon angioplasty was used in 41 (58%) lesions, primarily to smooth the arterial contour; stents were implanted in 4 (6%) arteries. Acute results after atherectomy and additional therapy were identical for the 3 groups (mean residual stenosis 15% in primary lesions, 8% in restenoses, and 14% in in-stent lesions). At the beginning of the study, 5 cases of tissue embolism were successfully treated with aspiration (device modification solved this problem). Restenosis rates after 6 months were not significantly lower in primary lesions (27%) compared with the other groups (41% for restenoses and 36% for in-stent restenoses). Reintervention after 6 months was also lowest for primary lesions (20% versus 37% for restenoses and 29% for in-stent lesions; p=NS). The ankle-brachial index was significantly improved after 6 months in all groups. At the 6-month follow-up, >80% of all patients were symptom free or had no lifestyle-limiting claudication.

CONCLUSIONS

Short and medium-length femoropopliteal lesions can be treated successfully and safely in most cases with this new atherectomy catheter. Technical and 6-month clinical outcomes seem to favor primary lesions compared with restenoses.

Balloon dilation and stent implantation for treatment of femoropopliteal arterial disease: meta-analysis

PURPOSE

To perform a meta-analysis of long-term results of balloon dilation and stent implantation in the treatment of femoropopliteal arterial disease.

MATERIALS AND METHODS

The English-language literature was searched for studies published between 1993 and 2000. Inclusion criteria for articles were presentation of long-term primary patency rates, standard errors (explicitly reported or derivable), and baseline characteristics of the study population. Two reviewers independently extracted data, and discrepancies were resolved by consensus. Primary patency rates were combined by using a technique that allows adjustment for differences across study populations. Analyses were adjusted for lesion type and clinical indication.

RESULTS

Nineteen studies met the inclusion criteria, representing 923 balloon dilations and 473 stent implantations. Combined 3-year patency rates after balloon dilation were 61% (standard error, 2.2%) for stenoses and claudication, 48% (standard error, 3.3%) for occlusions and claudication, 43% (standard error, 4.1%) for stenoses and critical ischemia, and 30% (standard error, 3.7%) for occlusions and critical ischemia. The 3-year patency rates after stent implantation were 63%-66% (standard error, 4.1%) and were independent of clinical indication and lesion type. Funnel plots demonstrated an asymmetric distribution of the data points associated with stent studies.

CONCLUSION

Balloon dilation and stent implantation for claudication and stenosis yield similar long-term patency rates. For more severe femoropopliteal disease, the results of stent implantation seem more favorable. Publication bias could not be ruled out.

Predictors of long-term patency after femoropopliteal angioplasty: results from the STAR registry

PURPOSE

To identify variables predictive of long-term patency after femoropopliteal angioplasty.

MATERIALS AND METHODS

The primary patency of 219 limbs in 205 patients from a multicenter registry who underwent femoropopliteal angioplasty between January 1, 1992, and December 31, 1994, was prospectively monitored with a combination of angiography, noninvasive hemodynamic testing, and clinical outcome. Patient demographic, angiographic, and hemodynamic variables were examined alone and in combination to determine effect on long-term primary patency. Each limb was graded as Category 1-4 according to the American Heart Association (AHA) criteria for arterial lesions, and differences in outcome for each category were examined. Primary patency and intergroup analysis were determined with use of the Kaplan-Meier method and log-rank test, respectively. Cox proportional hazards models were used to calculate relative risks for predictive variables.

RESULTS

Primary patency rates for all limbs (on an intent-to-treat basis) at 12, 24, and 36 months were 87% +/- 3%, 80% +/- 3%, and 69% +/- 5%, respectively. Primary patency at 48 and 60 months was 55% +/- 7%. Poor tibial runoff (single tibial vessel with 50%-99% stenosis or occlusion) was most predictive of occlusion (relative risk 8.5, P <.0001). The presence of diabetes or renal failure was associated with lower long-term patency (relative risk 5.5 and 4.0, P <.0001 and.0002, respectively). Long-term patency was higher with AHA Category 1 lesions (P =.006), and no significant difference in patency was observed between Category 2 and 3 lesions (P =.65). A multivariate Cox proportional hazards model showed only the stratified runoff score and the presence of diabetes to be significant determinants of long-term patency.

CONCLUSION

Poor tibial runoff is most predictive of lower long-term patency rates. Diabetes is also independently associated with lower long-term patency rates. The criteria that distinguish Category 2 and 3 lesions do not predict differences in long-term patency, nor do they serve to identify lesions best treated with surgical bypass. This suggests that indications for femoral angioplasty can be extended to include longer and more complex Category 3 lesions.

Transcatheter interventions for the treatment of peripheral atherosclerotic lesions: part I

Transcatheter endovascular procedures are increasingly used to treat symptomatic peripheral atherosclerosis. This two-part review identifies the existing evidence supportive of the application of transcatheter treatments for peripheral atherosclerotic lesions. The first part addresses the treatment of obstructive lesions that cause limb claudication and critical ischemia, renovascular hypertension and azotemia, and mesenteric ischemia. Studies were identified via a search of MEDLINE (January 1993 through April 1999) and reference lists of identified articles. When multicenter prospective randomized trials or other high-quality studies were unavailable, a preference was given to studies with at least 50 patients per treated group and a minimum mean follow-up duration of 6 months. Data presented in tables are proportionally weighted averages from included studies. For each application, the authors assessed the quality of evidence (QOE; efficacy, safety, and, where available, cost-effectiveness) and made recommendations with appropriate caveats. There is higher QOE supporting the more established treatments such as lower limb percutaneous transluminal angioplasty (PTA) with stent placement and thrombolysis. Treatments such as renal artery PTA and stent placement and mesenteric and brachiocephalic PTA are in wide use, but high QOE supporting general application is lacking. Blanket recommendations based on established efficacy and cost-effectiveness cannot be made. However, the use of transcatheter therapies can be supported in specific circumstances based on an expected reduction in procedure-related morbidity and/or mortality rates. It is hoped that the identification of deficiencies in the literature will inform and inspire critically needed research in this area.

Peripheral directional atherectomy evaluated with a rotational digital angiography system

BACKGROUND

One of the factors that affect the recurrence rate after peripheral directional atherectomy (DA) is the degree of residual stenosis. A new method of peripheral DA to reduce residual stenoses was evaluated with a rotational digital angiography (RDA) system that provides both angiography and fluoroscopy at multiple projections within 360 degrees.

PATIENTS AND METHODS

Between March 1995 and July 1999, severe short segmental stenoses of six iliac arteries and two superficial femoral arteries (SFA) in eight patients were treated with the Simpson DA catheter under RDA system guidance. After pre-procedural RDA evaluation, the first series of DA were performed under ordinary PA fluoroscopic guidance. The residual stenoses were evaluated with RDA. If the residual stenoses exceeded 30%, a second series of DA were performed covering the residual plaque with the cutter window of the DA catheter. To this purpose the fluoroscopy of the RDA system was fixed in the direction in which the residual stenoses were largest and most eccentric. The end point was defined to be a residual stenosis of less than 30% evaluated with the RDA system, and the procedures were repeated until the end point was achieved.

RESULTS

Five of six iliac artery lesions were curved at the pre-procedural RDA evaluation. After the first series of DA, only two of six iliac lesions but all SFA lesions achieved the end point. Among the four other iliac lesions, three achieved the end point with one or two additional series of DA using the RDA system guidance to control the selective cuts of the residual plaques. One patient had a residual stenosis of 50% because the procedure could not be completed by balloon rupture of the DA catheter. In the patients with iliac stenoses, there was no final residual stenosis in one, and the range was from 20% to 25% in the four patients. The residual stenoses were located on the greater curvature side of the curved artery in three of these four patients.

CONCLUSION

The RDA system is a valuable tool in aiding reduction of the residual stenoses during peripheral DA. Minimal stenoses often remain on the greater curvature side of the wall because the rigid and straight metallic capsule (cylindrical housing) of the Simpson DA catheter does not completely fit the curved wall. This phenomenon was thought to be a mechanical limitation of this device.