Suggested objective performance goals and clinical trial design for evaluating catheter-based treatment of critical limb ischemia

Outcomes of upper extremity interventions for chronic critical ischemia

BACKGROUND

Critical hand ischemia owing to below-the-elbow atherosclerotic occlusive disease is relatively uncommon. The aim of this study was to examine the outcomes in patients presenting with critical ischemia owing to below-the-elbow arterial atherosclerotic disease who underwent nonoperative and operative management.

METHODS

A database of patients undergoing operative and nonoperative management for symptomatic below-the-elbow atherosclerotic disease between 2006 and 2016 was retrospectively queried. Patients with critical ischemia (tissue loss and rest pain) were identified. Three management groups were identified: no revascularization (None), endovascular revascularization (Endo), and open revascularization by bypass (Bypass). Patients with acute embolism, active vasculitis, end-stage renal disease, ipsilateral dialysis access complications of steal, and ipsilateral trauma were excluded.

RESULTS

One hundred eight patients (56% male; average age, 59 years) presented with symptomatic below-the-elbow disease: 93% presented with digital ulceration and the remainder with rest pain. Eighty-one percent had diabetes and 41% had chronic renal insufficiency (not on dialysis). All underwent catheter-based angiography. Fifty-three patients (49%) had no intervention and subsequently were committed to wound care; 26 of these required no further intervention, 10 had an interval palmar sympathectomy, and 17 underwent either a phalanx or digital amputation. Thirty-four patients (31%) underwent an endovascular intervention with a median of 1.5 vessels (ulnar, radial, or interosseous arteries) intervened on. Technical success was achieved in 29 patients (85%). Of the five technical failures, two went on to bypass, one had a focal endarterectomy and patch angioplasty, and one was treated conservatively. Ten patients in the Endo group required either a phalanx or digital amputation. Twenty-one patients (19%) underwent a saphenous vein bypass (reversed or nonreserved) to the radial in 12 and the ulnar in 11 limbs. In follow-up, 11 patients underwent open or endovascular intervention to maintain patency of the bypass. There were nine phalanx or digital amputations in the Bypass group. No below-the-elbow or above-the-elbow amputations were performed within 30 days. The wound healing rate without amputation was 78% (85 of 108). The predictors of wound healing were technical success of the revascularization, intact palmar arch and presence of digital run-off. The presence of an incomplete arch and poor digital run-off were associated with a phalanx or digital amputation.

CONCLUSIONS

Upper extremity interventions for critical ischemia are associated with a high rate of success. Major amputations are rare and the many can be treated nonoperatively. In appropriately selected patients, both endovascular and open interventions have a high rate of success.

Three-Year Outcomes of Surgical Versus Endovascular Revascularization for Critical Limb Ischemia: The SPINACH Study (Surgical Reconstruction Versus Peripheral Intervention in Patients With Critical Limb Ischemia)

Supplemental Digital Content is available in the text.

Background—

The aim of this study was to compare clinical outcomes between surgical reconstruction and endovascular therapy (EVT) for critical limb ischemia (CLI) in today’s real-world settings.

Methods and Results—

This multicenter, prospective, observational study registered and followed 548 Japanese CLI patients. The registration was in advance of revascularization; 197 patients were scheduled to receive surgical reconstruction, and the remaining 351 were scheduled to receive EVT. The primary end point was 3-year amputation-free survival, compared between the 2 treatments in an intention-to-treat manner, using propensity score matching. Interaction analysis was additionally performed to explore which subgroups had better outcomes with surgical reconstruction or EVT. After propensity score matching, the 3-year amputation-free survival was not significantly different between the 2 groups (52% [95% confidence interval, 43%–60%] and 52% [95% confidence interval, 44–60%]; P=0.26). Subsequent interaction analysis identified (1) Wound, Ischemia, and foot Infection (WIfI) classification W-3, (2) fI-2/3, (3) history of ipsilateral minor amputation, (4) history of revascularization after CLI onset, and (5) bilateral CLI as the factors more favorable for surgical reconstruction, whereas (1) diabetes mellitus, (2) renal failure, (3) anemia, (4) history of nonadherence to cardiovascular risk management, and (5) contralateral major amputation were as those less favorable for surgical reconstruction.

Conclusions—

The 3-year amputation-free survival was not different between surgical reconstruction and EVT in the overall CLI population. The subsequent interaction analysis suggested that there would be a subgroup more suited for surgical reconstruction and another benefiting more from EVT.

Clinical Trial Registration—

URL: http://www.umin.ac.jp/ctr/. Unique identifier: UMIN000007050.

Thirty-year trends in aortofemoral bypass for aortoiliac occlusive disease

OBJECTIVE

Endovascular intervention has supplanted open bypass as the most frequently used approach in patients with aortoiliac segment atherosclerosis. We sought to determine whether this trend together with changing demographic and clinical characteristics of patients undergoing aortobifemoral bypass (ABFB) for aortoiliac occlusive disease (AOD) have an association with postoperative outcomes.

METHODS

Using a prospectively maintained institutional database, we identified patients who underwent ABFB for AOD from 1985 to 2015. Patients were divided into two cohorts: the historical cohort (HC) included patients who underwent ABFB for AOD from 1985 to 1999 and the contemporary cohort (CC) who underwent ABFB for AOD from 2000 to 2015. Medical and demographic data, procedural information, postoperative complications, and follow-up data were extracted. Cox proportional hazards regression was used to evaluate associations with the end point of primary patency. A similar analysis was performed for major adverse limb events (MALEs; the composite of above-ankle amputation, major reintervention, graft revision, or new bypass graft of the index limb) in the subset of patients with critical limb ischemia.

RESULTS

There were a total of 359 cases: 226 in the HC and 133 in the CC. The CC had more women (56.4% vs 43.8%; P = .02), smokers (87.2% vs 67.7%; P = .001), and patients who failed prior aortoiliac endovascular intervention (17.3% vs 4.8%; P = .0001), but fewer patients with coronary artery disease (32.3% vs 47.3%; P = .005). Thirty-day mortality was less than 1% in both cohorts, but 10-year survival was higher in the CC (67.7% vs 52.6%; P = .02). Five-year primary, primary-assisted, and secondary patency were higher in the HC (93.3% vs 82.2%; P = .005; 93.8% vs 85.7%; P = .02; 97.5% vs 90.4%; P = .02, respectively). CC membership, decreasing age, prior aortic surgery, and decreasing graft diameter were significant independent predictors of loss of primary patency after adjustment (hazard ratio [HR], 7.03; 95% confidence interval [CI], 2.80-17.63; P < .0001; HR, 0.93; 95% CI, 0.90-0.96; P < .0001; HR, 18.80; 95% CI, 5.94-59.58; P < .0001; and HR, 0.73; 95% CI, 0.55-0.95; P = .02, respectively). Similarly, CC membership, prior aortic surgery, and decreasing graft diameter were significant independent predictors of MALE in the critical limb ischemia cohort after adjustment (HR, 21.13; 95% CI, 4.20-106.40; P = .0002; HR, 40.40; 95% CI, 3.23-505.61; P = .004; and HR, 0.51; 95% CI, 0.30-0.86; P = .01, respectively).

CONCLUSIONS

Compared with the pre-endovascular era, demographic and clinical characteristics of patients undergoing ABFB for AOD in the CC have changed. Although long-term patency is slightly lower among patients in the CC during which a substantial subset of AOD patients are being treated primarily via the endovascular approach, durability remains excellent and limb salvage unchanged. After adjustment, the time period of index ABFB independently predicted primary patency and MALE, as did graft diameter and prior aortic surgery. These changing characteristics should be considered when counseling patients and benchmarking for reintervention rates and other outcomes.

Design Strategies for Global Clinical Trials of Endovascular Devices for Critical Limb Ischemia (CLI) - A Joint USA-Japanese Perspective

For more than 10 years, the Harmonization by Doing (HBD) program, a joint effort by members from academia, industry and regulators from the United States of America (USA) and Japan, has been working to increase timely regulatory approval for cardiovascular devices through the development of practical global clinical trial paradigms. Consistent with this mission and in recognition of the increasing global public health effects of critical limb ischemia (CLI), academic and government experts from the USA and Japan have developed a basic framework of global clinical trials for endovascular devices for CLI. Despite differences in medical and regulatory environments and complex patient populations in both countries, we developed a pathway for the effective design and conduct of global CLI device studies by utilizing common study design elements such as patients' characteristics and study endpoints, and minimizing the effect of important clinical differences. Some of the key recommendations for conducting global CLI device studies are: including patients on dialysis; using a composite primary endpoint for effectiveness that includes 6-month post-procedure therapeutic success and target vessel patency; and using a 30-day primary safety endpoint of perioperative death and major adverse limb events. The proposed approach will be uniquely beneficial in facilitating both the initiation and interpretation of CLI studies and accelerating worldwide CLI device development and innovation.

Lower extremity bypass and endovascular intervention for critical limb ischemia fail to meet Society for Vascular Surgery's objective performance goals for limb-related outcomes in a contemporary national cohort

OBJECTIVE

In 2009, the Society for Vascular Surgery (SVS) developed objective performance goals (OPGs) to define the therapeutic benchmarks in critical limb ischemia (CLI) based on outcomes from randomized trials of lower extremity bypass (LEB). Current performance relative to these benchmarks in both LEB and infrainguinal endovascular intervention (IEI) remains unknown. The objective of this study was to determine whether LEB and IEI performed for CLI in a contemporary national cohort met OPG 30-day safety thresholds.

METHODS

SVS OPG criteria were applied to 11,043 revascularizations for CLI performed from 2011 to 2015 in the National Surgical Quality Improvement Program (NSQIP) vascular targeted modules. Primary 30-day safety OPGs including major adverse cardiovascular events (MACEs), major adverse limb events (MALEs), and amputation were calculated for the NSQIP LEB (n = 3833) and IEI (n = 3526) cohorts as well as for subgroups at "high anatomic risk" (infrapopliteal revascularization) and "high clinical risk" (age >80 years and tissue loss). These were compared with SVS OPG benchmarks using χ² comparisons.

RESULTS

Compared with the SVS OPG cohort, both the NSQIP LEB and IEI cohorts had fewer patients at high anatomic risk (LEB, 51%; IEI, 27%; SVS OPG, 60%; both P < .0001). The LEB cohort had fewer patients with high clinical risk than the SVS OPG cohort (LEB, 11%; SVS OPG, 16%; P < .0001). The 30-day MALE was significantly higher in the NSQIP LEB (9.0% [8.7%-9.2%]) and IEI (9.7% [9.4%-10.0%]) cohorts compared with the SVS OPG cohort (6.1% [4.7%-9.0%]; both P ≤ .007), including significantly higher rates of amputation. MACE was significantly lower in the NSQIP LEB (4.2% [4.1%-4.3%]) and IEI (3.1% [3.0%-3.2%]) cohorts compared with the SVS OPG cohort (6.1% [4.7%-8.1%]; both P ≤ .013). Among patients at high anatomic risk, 30-day MALE was significantly higher after LEB (9.5% [9.1%-9.8%]) and IEI (11.1% [10.4-11.8%]) compared with the SVS OPG cohort (6.1% [4.2%-8.6%]; P ≤ .002). Among patients with high clinical risk, IEI was associated with lower MACE compared with the SVS OPG cohort, with similar limb-related outcomes.

CONCLUSIONS

In contemporary real-world practice, LEB and IEI for CLI failed to meet SVS OPG limb-related 30-day safety benchmarks for the entire CLI cohort as well as for the patients at high anatomic risk. Additional investigation using SVS OPGs as consistent end points is required to determine why limb-related outcomes after revascularization for CLI remain suboptimal. LEB and IEI surpassed OPG benchmarks for 30-day cardiovascular morbidity and mortality. OPGs for cardiovascular morbidity in patients undergoing revascularization for CLI deserve re-evaluation using contemporary data.

One-Year Results of First-Line Treatment Strategies in Patients With Critical Limb Ischemia (CRITISCH Registry)

PURPOSE

To examine the outcomes of all first-line strategies for the treatment of critical limb ischemia (CLI), identify factors that influenced the treatment choice, and determine the risk of amputation or death after each treatment.

METHODS

CRITISCH ( ClinicalTrials.gov identifier NCT01877252) is a multicenter, national, prospective registry evaluating all available treatment strategies applied in 1200 consecutive CLI patients in 27 vascular centers in Germany. The recruitment started in January 2013 and was completed in September 2014. Treatment options were endovascular revascularization (642, 53.5%), bypass surgery (284, 23.7%), femoral artery patchplasty (126, 10.5%) with or without concomitant peripheral intervention, conservative treatment (118, 9.8%), and primary major amputation (30, 2.5%). The primary endpoint of this study was amputation-free survival (AFS). The Society of Vascular Surgery's suggested objective performance goal (OPG) for AFS (71%) was used as the effectiveness criterion. Multivariable regression methods were employed to identify variables that influenced the treatment selection and AFS after each treatment; results are presented as the hazard ratio (HR) and 95% confidence interval (CI).

RESULTS

The 12-month AFS estimates following endovascular therapy, bypass grafting, femoral patchplasty, and conservative treatment were 75%, 72%, 73%, and 72%, respectively. Factors influencing treatment choice were age, chronic kidney disease (CKD), diabetes, smoking, prior vascular procedures in the index leg, TransAtlantic Inter-Society Consensus II C/D lesions, and absence of runoff vessels. Cox regression analysis identified CKD (HR 2.07, 95% CI 1.26 to 3.41, p=0.004), the use of a prosthetic bypass conduit (HR 1.97, 95% CI 1.23 to 3.14, p=0.004), and previous vascular intervention in the index limb (HR 1.52, 95% CI 0.94 to 2.43, p=0.085) as independent risk factors for diminished AFS after bypass surgery. CKD (HR 1.47, 95% CI 1.09 to 1.99, p=0.012) and Rutherford category 6 (HR 1.81, 95% CI 1.30 to 2.52, p<0.001) compromised the performance of endovascular revascularization.

CONCLUSION

CRITISCH registry data revealed that all first-line treatment strategies selected and indicated by the treating physicians met the suggested OPGs. CKD was an important determinant of patient prognosis after treatment regardless of the revascularization method.

[Operative treatment of diabetics with vascular complications : Secondary data analysis of diagnosis-related groups statistics from 2005 to 2014 in Germany]

BACKGROUND

In Germany approximately 40,000 amputations per year are performed on patients with diabetes mellitus, often with accompanying vascular complications.

OBJECTIVE

The aim of this study was to present the various degrees of severity of the vascular complications and the temporal changes of the treatment options in diabetics with vascular complications in Germany.

MATERIAL AND METHODS

The microdata of the diagnosis-related groups (DRG) statistics of the Federal Statistical Office were analyzed over the period from 2005 to 2014. All cases were included in which the main or secondary diagnosis of diabetes mellitus with concurrent vascular complications (diabetic angiopathy and peripheral arterial disease) was encrypted.

RESULTS

The median age of the 1,811,422 cases was 73 years and 62% were male. While the total number of amputations remained stable over time, there was a 41% reduction in knee-preserving and a 31% reduction in non-knee preserving major amputations with an 18% increase in minor amputations. Revascularization increased by 33% from 36 procedures in 2005 to 48 procedures per 100,000 inhabitants. The increase in revascularization was evident in the area of endovascular therapy alone where there was an increase of 78%.

CONCLUSION

Due to the significant increase in endovascular revascularization measures, there was a significant increase in the proportion of diabetes patients with vascular pathologies in whom revascularization was carried out. As a result, improved limb preservation was achieved despite equally high amputation rates due to increasing minor amputation rates.

Outcomes of reintervention for recurrent symptomatic disease after tibial endovascular intervention

OBJECTIVE

Tibial interventions for critical limb ischemia are now commonplace. Restenosis and occlusion remain barriers to durability after intervention. The aim of this study was to examine the patient-centered outcomes of open and endovascular reintervention for symptomatic recurrent disease after a primary isolated tibial endovascular intervention.

METHODS

A database of patients undergoing isolated primary lower extremity tibial endovascular interventions between 2006 and 2016 was retrospectively queried. Patients with recurrent critical ischemia (Rutherford 4 and 5) were identified. Outcomes in this cohort were analyzed, and three groups were defined: endovascular reintervention (ie, a repeated tibial or pedal endovascular intervention), bypass (bypass to a tibial or pedal vessel), and primary amputation (ie, above- or below-knee amputation) on the ipsilateral leg. Patient-oriented outcomes of clinical efficacy (absence of recurrent signs or symptoms of critical ischemia, maintenance of ambulation, and absence of major amputation), amputation-free survival (survival without major amputation), and freedom from major adverse limb events (above-ankle amputation of the index limb or major reintervention, such as new bypass graft or jump or interposition graft revision) were evaluated after the reintervention.

RESULTS

There were 1134 patients (56% male; average age, 59 years) who underwent primary tibial intervention for critical ischemia, and 54% presented with symptomatic restenosis and occlusion. Of the 513 patients with recurrent disease, 58% presented with rest pain and the remainder with ulceration. A repeated tibial endovascular intervention was performed in 64%, open bypass in 19%, and below-knee amputation in 17%. Bypass was employed in patients with a good target vessel, venous conduit, and good pedal runoff. Patient-centered outcomes were better in the bypass group compared with the reintervention group (amputation-free survival, 45% ± 9% vs 27% ± 9% [P < .01]; major adverse limb events, 50% ± 9% vs 31% ± 9% [P < .05]; clinical efficacy, 60% ± 7% vs 30% ± 9% [P < .01], mean ± standard error of the mean at 5 years).

CONCLUSIONS

Tibial interventions for critical ischemia are associated with a high rate of reintervention. In patients with good target vessel, venous conduit, and good pedal runoff, bypass appears more durable than repeated tibial endovascular intervention.

Prior Endovascular Intervention Is Not Detrimental to Pedal Bypasses for Ischemic Wounds

BACKGROUND

Endovascular strategies are often preferred for revascularization of ischemic foot wounds secondary to infrapopliteal disease because of the less invasive technique and faster recovery. Bypass is typically reserved for failures or lesions not amenable to balloon angioplasty. However, the effects of an endovascular-first approach on subsequent bypass grafts are largely unknown. This study evaluates the effects of prior endovascular tibial interventions (PTIs) on successive bypasses to pedal targets.

METHODS

Patients who presented with ischemic tissue loss and tibial arterial occlusive disease to University of Pittsburgh Medical Center between 2006 and 2013 and underwent a surgical bypass to pedal arteries were included in this study. A retrospective chart review was conducted to obtain patient demographics, past medical history, extent of disease, prior tibial endovascular interventions, the treatment intervention, subsequent interventions, wound healing status, limb salvage, and patient survival. The primary outcome was primary patency of the pedal bypass graft.

RESULTS

From 122 eligible patients, 27 had a PTI, whereas 95 had no prior endovascular tibial intervention (nPTI) in the treatment of ischemic pedal wounds with mean follow-up of 24.5 and 20.5 months, respectively (P = 0.36). The 2 groups were largely similar in terms of demographics, comorbidities, wound size, and degree of ischemia. Runoff scores between the 2 groups were also comparable (5.0 ± 1.6 for PTI and 4.8 ± 1.9 for nPTI, P = 0.59). The plantar artery was a more common target vessel in the PTI group, whereas the posterior tibial artery was targeted more often in the nPTI group (P = 0.04). At 12 months, those with a PTI exhibited a shorter primary patency (34.8% vs. 60.2%, P = 0.04). In a multivariate model, PTI was a significant risk factor for primary patency loss (hazard ratio 2.51, P = 0.004). Primary assisted patency and secondary patency were similar between the 2 groups. Wound healing was improved in those patients who had a prior endovascular intervention with 63.8% healed at 1 year compared with only 34.8% of those without intervention (P = 0.01). Amputation-free survival was similar (P = 0.68), as was survival alone (P = 0.50).

CONCLUSIONS

Despite a decrease in primary patency, pedal bypass was not otherwise negatively affected by a PTI. Similar primary assisted patency, secondary patency, wound healing, and survival between the 2 patient populations indicate that an endovascular-first approach is a feasible treatment strategy to achieve similar clinical outcomes in the management of ischemic foot wounds.

Clinical Outcomes after Isolated Infrapopliteal Revascularization in Hemodialysis Patients with Critical Limb Ischemia: Endovascular Therapy versus Bypass Surgery

AIM

To investigate the long-term clinical outcome of endovascular therapy (EVT) or bypass surgery in patients on hemodialysis (HD) with critical limb ischemia due to isolated infrapopliteal disease.

METHODS

We enrolled 254 consecutive HD patients successfully undergoing infrapopliteal revascularization by EVT (126 patients) and bypass surgery (128 patients). They were followed up for five years. Amputation-free survival (AFS) and incidence of any re-intervention were evaluated. A propensity score from all baseline variables was incorporated into Cox analysis.

RESULTS

In the EVT group, age was higher (p=0.039), diabetes and coronary artery disease were more frequent (p=0.004 and p=0.0052, respectively), and tissue loss was more rarely observed (p＜ 0.0001) than in the bypass group. During the follow-up period, 21 major amputations and 64 deaths occurred. The propensity score-adjusted AFS rate at 5 years was comparable between groups (61.0% in EVT group vs. 55.1% in the bypass group, adjusted hazard ratio [HR] 0.87, 95% confidence interval [CI] 0.52-1.42, p=0.58). The adjusted survival rates were also similar between groups for amputation and all-cause mortality. However, freedom from any re-intervention was markedly lower in the EVT than in the bypass group (48.6% vs. 84.6%, adjusted-HR, 3.56, 95% CI 1.95-6.75, p＜ 0.0001).

CONCLUSIONS

The rate of AFS was broadly comparable between the two strategies, although compared with bypass surgery, EVT had much higher rates for re-intervention.

Current Status of Arterial Revascularization for the Treatment of Critical Limb Ischemia in Infrainguinal Atherosclerotic Disease

Critical limb ischemia (CLI) is the most severe form of peripheral arterial disease (PAD) that may result in limb loss and even death; thus, the fast and proper treatment should be employed as earlier as possible to prevent these catastrophic consequences. Arterial revascularization is almost always an indispensable treatment option for CLI. Although both endovascular and surgical revascularization procedures have an important role, nowadays, the hybrid revascularization as a combination of these revascularization procedures has also gained increasing popularity in the treatment of patients with CLI. This review provides an update on the arterial revascularization strategies for the treatment of CLI.

Prognostic Impact of Revascularization in Poor-Risk Patients With Critical Limb Ischemia: The PRIORITY Registry (Poor-Risk Patients With and Without Revascularization Therapy for Critical Limb Ischemia)

OBJECTIVES

The authors sought to investigate the prognostic impact of revascularization for poor-risk CLI patients in real-world settings.

BACKGROUND

Critical limb ischemia (CLI) is often accompanied with various comorbidities, and frailty is not rare in the population. Although previous studies suggested favorable outcomes of revascularization for CLI patients, those studies commonly included the healthier, that is, less frail patients.

METHODS

This was a multicenter prospective observational study, registering patients who presented with CLI and who required assistance for their daily lives because of their disability in activities of daily living (ADL) and/or impairment of cognitive function. Revascularization was either planned (revascularization group) or not planned (non-revascularization group). The primary endpoint was 1-year survival, and was compared between the revascularization and non-revascularization groups, using the propensity score-matching method.

RESULTS

Between January 2014 and April 2015, a total of 662 patients were registered, of those 100 non-revascularization patients were included. A total of 625 patients (94.4%) completed the 1-year follow-up. Death was observed in 223 patients (33.7%). After propensity score matching, the 1-year survival rate was 55.9% in the revascularization group versus 51.0% in the non-revascularization group, with no significant difference (p = 0.120). In the subgroups alive at 1 year after revascularization, health-related quality of life was significantly improved compared with baseline, whereas ADL scores were unchanged from baseline and still remained significantly worse than before CLI onset.

CONCLUSIONS

The 1-year overall survival rate was not significantly different between the revascularization and non-revascularization groups in poor-risk CLI patients. (Poor-Risk Patients With and Without Revascularization Therapy for Critical Limb Ischemia; [PRIORITY Registry]; UMIN000012871).

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.)

Outcomes of tibial endovascular intervention in patients with poor pedal runoff

OBJECTIVE

Tibial interventions for critical limb ischemia are now commonplace. The aim of this study was to examine the impact of pedal runoff on patient-centered outcomes after tibial endovascular intervention.

METHODS

A database of patients undergoing lower extremity endovascular interventions at a single urban academic medical center between 2006 and 2016 was retrospectively queried. Patients with critical ischemia (Rutherford 5 and 6) were identified. Preintervention angiograms were reviewed in all cases to assess pedal runoff. Each dorsalis pedis, lateral plantar, and medial plantar artery was assigned a score according to the reporting standards of the Society for Vascular Surgery (0, no stenosis >20%; 1, 21%-49% stenosis; 2, 50%-99% stenosis; 2.5, half or less of the vessel length occluded; 3, more than half the vessel length occluded). A foot score (dorsalis pedis + medial plantar + lateral plantar + 1) was calculated for each foot (1-10). Two runoff score groups were identified: good vs poor, <7 and ≥7, respectively. Patient-oriented outcomes of clinical efficacy (absence of recurrent symptoms, maintenance of ambulation, and absence of major amputation), amputation-free survival (survival without major amputation), and freedom from major adverse limb events (above-ankle amputation of the index limb or major reintervention [new bypass graft, jump/interposition graft revision]) were evaluated.

RESULTS

There were 1134 patients (56% male; average age, 59 years) who underwent tibial intervention for critical ischemia, with a mean of two vessels treated per patient and a mean pedal runoff score of 6 (47% had a runoff score ≥7). Overall major adverse cardiac events were equivalent at 30 days after the procedure in both groups. At 5 years, vessels with compromised runoff (score ≥7) had significantly lower ulcer healing (25% ± 3% vs 73% ± 4%, mean ± standard error of the mean [SEM]) and a lower 5-year limb salvage rate (45% ± 6% vs 69% ± 4%, mean ± SEM) compared with those with good runoff (score <7). Patients with poor pedal runoff (score ≥7) had significantly lower clinical efficacy (23% ± 8% vs 38% ± 4%, mean ± SEM), amputation-free survival (32% ± 6% vs 48% ± 5%, mean ± SEM), and freedom from major adverse limb events (23% ± 9% vs 41% ± 8%, mean ± SEM) at 5 years compared with patients with good runoff (score <7).

CONCLUSIONS

Pedal runoff score can identify those patients who will not achieve ulcer healing and patient-centered outcomes after tibial intervention. Defining such subgroups will allow stratification of the patients and appropriate application of interventions.

A Molecular and Clinical Review of Stem Cell Therapy in Critical Limb Ischemia

Peripheral artery disease (PAD) is one of the major vascular complications in individuals suffering from diabetes and in the elderly that can progress to critical limb ischemia (CLI), portending significant burden in terms of patient morbidity and mortality. Over the last two decades, stem cell therapy (SCT) has risen as an attractive alternative to traditional surgical and/or endovascular revascularization to treat this disorder. The primary benefit of SCT is to induce therapeutic neovascularization and promote collateral vessel formation to increase blood flow in the ischemic limb and soft tissue. Existing evidence provides a solid rationale for ongoing in-depth studies aimed at advancing current SCT that may change the way PAD/CLI patients are treated.

Analysis of wound healing time and wound-free period as outcomes after surgical and endovascular revascularization for critical lower limb ischemia

BACKGROUND

Traditional end points, such as amputation-free survival, used to assess the clinical effectiveness of lower limb revascularization have shortcomings because they do not account independently for wound nonhealing and recurrence or patient survival. Wound healing process and maintenance of a wound-free state after revascularization were not well-studied. The aim of this study was to elucidate the long-term clinical course of ischemic wounds after revascularization. We focused on initial wound healing process as well as the maintenance of a wound-free state after achievement of wound healing. We introduced a wound-free period (WFP; the period during which limbs maintained an ulcer-free state) and Wound Recurrence and Amputation-free Survival (WRAFS) as parameters and tested their effectiveness in evaluating clinical outcomes of limbs treated using endovascular therapy (EVT) and surgical revascularization.

METHODS

The medical records of patients developing lower critical limb ischemia with tissue loss who underwent surgical or endovascular revascularization of the infrainguinal vessels between 2009 and 2013 were reviewed retrospectively. The risk factors for achieving wound healing and WRAFS were analyzed using Kaplan-Meier survival curves and Cox regression model. Risk factors to prolong wound healing time (WHT) and reduce WFP were determined by the least squares method.

RESULTS

In total, 233 patients underwent 278 limb revascularizations; 138 endovascular and 140 surgical procedures were performed as first treatments. The proportion of healed wounds 1, 2, and 3 years after primary revascularization was 64.0%, 69.7%, and 70.5%, respectively. Significant risk factors for wound healing were an EVT-first strategy (risk ratio [RR], 2.47), congestive heart failure (RR, 2.05), and wound, ischemia, and foot infection wound grade (RR, 1.59). The mean WHT was 143.7 days. An EVT-first strategy and wound infection contributed to significantly longer WHT. The mean WFP was 711.0 days. An EVT-first strategy, history of coronary artery disease, and dialysis dependence were associated with significantly shorter WFPs. WRAFS at 1 and 2 years after achievement of wound healing were 76.9% and 64.2%, respectively. Significant risk factors against WRAFS were a history of coronary artery disease (RR, 1.68), dialysis dependence (RR, 2.03), and being wheel chair bound (RR, 1.64).

CONCLUSIONS

EVT revascularization was associated with longer WHT, reduced wound healing rate, and a shorter WFP compared with surgical revascularization. wound, ischemia, and foot infection grade was associated with longer WHT and reduced wound healing rate, but not associated with a shorter WFP. Systemic conditions such as dialysis dependence, congestive heart failure, and being wheel chair bound were associated with reduced wound healing rate and shorter WFP, presumably because they limited life expectancy. WHT and WFP are useful criteria for evaluating limb outcomes in patients with critical limb ischemia.

Clinical Outcomes of Pedal Artery Angioplasty for Patients With Ischemic Wounds: Results From the Multicenter RENDEZVOUS Registry

OBJECTIVES

The aim of this study was to investigate the clinical outcomes of pedal artery angioplasty (PAA) for patients with critical limb ischemia.

BACKGROUND

Pedal artery disease is considered a predictor of delayed wound healing (DH) after endovascular therapy. Adjunctive PAA might improve the speed and extent of wound healing.

METHODS

Consecutive patients with critical limb ischemia (n = 257) presenting with de novo infrapopliteal and pedal artery disease were retrospectively reviewed from a multicenter registry. Patients were divided into 2 groups according to whether PAA was performed (n = 140) or not (n = 117). The rate of wound healing and time to wound healing were compared between these groups. DH score was calculated using the number of independent predictors of DH. Patients were stratified into 3 groups according to DH score: low risk (DH score = 0), moderate risk (DH score = 1 or 2), and high risk (DH score = 3). Estimated efficacy was analyzed for each risk-stratified population.

RESULTS

The rate of wound healing was significantly higher (57.5% vs. 37.3%, p = 0.003) and time to wound healing significantly shorter (211 days vs. 365 days; p = 0.008) in the PAA group. In a multivariate analysis, nonambulatory status, target wound depth (UT grade ≥2), and daily hemodialysis were revealed as predictors of DH. In the moderate-risk population, adjunctive PAA significantly improved the rate of wound healing (59.3% vs. 33.9%; p = 0.001). In the high-risk population, however, PAA did not affect wound healing.

CONCLUSIONS

Patients who underwent PAA showed a higher rate of wound healing and shorter time to wound healing, especially in the moderate-risk population. With regard to wound healing, this aggressive strategy might become a salvage procedure for patients with critical limb ischemia presenting with pedal artery disease.

National Utilization and Outcomes of Redo Lower Extremity Bypass versus Endovascular Intervention after a Previous Failed Bypass

BACKGROUND

Redo lower extremity bypass (LEB) and infrainguinal endovascular intervention (IEI) are options to treat critical limb ischemia after a failed prior LEB, but the utilization and outcomes of each are poorly described. The purpose of this study was to compare 30-day major adverse limb events (MALEs) and major adverse cardiovascular events (MACEs) after LEB and IEI in patients with a failed prior ipsilateral LEB and determine risk factors for each composite outcome.

METHODS

Patients with prior failed ipsilateral LEB who underwent LEB or IEI involving the same arterial segment for critical limb ischemia were identified in the National Surgical Quality Improvement Program (NSQIP) Vascular Targeted File (2011-2014). LEB with single-segment saphenous vein was compared to LEB with alternative conduit (prosthetic/spliced vein/composite) and IEI. Primary outcomes were MALE (untreated loss of patency, reintervention, or amputation) and MACE (stroke, myocardial infarction, or death). Multivariate analysis was utilized to identify independent predictors of MALE and MACE.

RESULTS

Among 8,066 revascularizations performed for critical limb ischemia (CLI), 1,606 (461 [28.7%] IEI, 518 [32.3%] LEB saphenous, and 627 [39.0%] LEB alternative) were performed after failed ipsilateral LEB involving the same arterial segment. LEB with saphenous had lower MALE than LEB with alternate conduit and IEI (15.8% IEI, 10.8% saphenous, and 15.5% alternative, P = 0.03). Higher MALE was driven by higher 30-day amputation in IEI (7.8% IEI, 3.7% saphenous, and 5.3% alternative, P = 0.02). Independent predictors of MALE include transfer status (odds ratio [OR] = 1.7, P = 0.01), tobacco use (OR = 1.5, P = 0.02), infrageniculate revascularization (OR = 1.6, P = 0.004), and saphenous conduit (OR = 0.5, P = 0.002). MACE was also different between groups (3.9% IEI, 7% saphenous, and 5.6% alternative, P = 0.049), with no difference in 30-day mortality (P = 0.53). Independent predictors of MACE included congestive heart failure (OR = 3.0, P = 0.01) and dialysis dependence (OR = 2.5, P = 0.02).

CONCLUSIONS

In this large national sample representing routine vascular care of patients with CLI after failed ipsilateral LEB of the same arterial segment, IEI is common and represents 30% of revascularizations in this data set. Redo LEB with saphenous is associated with superior limb-related outcomes, but IEI offers an acceptable potential alternative to bypass in patients who would require alternative conduit. Finally, perioperative care is critical as we demonstrate that patient comorbidities, not the method of revascularization, predicted MACE.

Regional variation in outcomes for lower extremity vascular disease in the Vascular Quality Initiative

BACKGROUND

Increased focus has been placed on perioperative and long-term outcomes in the treatment of peripheral artery disease (PAD), both for purposes of quality improvement and for assessment of performance at a surgeon and institutional level. This study evaluates regional variation in outcomes after treatment for PAD within the Vascular Quality Initiative (VQI). By describing the variation in practice patterns and outcomes across regions, we hope that each regionally based quality group can select which areas are most important for them to focus on as they will have access to their regional data to compare.

METHODS

We identified all patients in the VQI who had infrainguinal bypass or endovascular intervention from 2009 to 2014. We compared variation in perioperative and 1-year outcomes stratified by symptom status and revascularization type among the 16 regional groups of the VQI. We analyzed variation in perioperative end points using χ2 analysis, and 1-year end points were analyzed using Kaplan-Meier and life-table analysis.

RESULTS

We identified 15,338 bypass procedures for symptomatic PAD: 27% for claudication, 59% for chronic limb-threatening ischemia (CLI; 61% of these for tissue loss), and 14% for acute limb ischemia. We identified 33,925 endovascular procedures for symptomatic PAD: 42% for claudication, 48% for CLI (73% of these for tissue loss), and 10% for acute limb ischemia. Thirty-day mortality varied significantly after endovascular intervention for CLI (0.5%-3%; P < .001) but not for claudication (0.0%-0.5%, P = .77) or for bypass for claudication (0.0%-2.6%; P = .37) or CLI (0.0%-5.0%; P = .08). After bypass, rates of >2 units transfused red blood cells (claudication, 0.0%-13% [P < .001]; CLI, 6.9%-27% [P < .001]) varied significantly. In-hospital major amputation was variable after bypass for CLI (0.0%-4.3%; P = .004) but not for claudication (0.0%-0.6%; P = .98), as was postoperative myocardial infarction (claudication, 0.0%-4% [P = .36]; CLI, 0.8%-6% [P = .001]). One-year survival varied significantly for endovascular interventions for claudication (92%-100%; P < .001), bypass for CLI (85%-94% [P < .001]), and endovascular interventions for CLI (77%-96%; P < .001) but not after bypass for claudication (95%-100%; P = .57).

CONCLUSIONS

In this real-world comparison among VQI regions, we found significant variation in perioperative and 1-year end points for patients with PAD undergoing bypass or endovascular intervention. This study highlights opportunities for quality improvement efforts to reduce variation and to improve outcomes.

Usefulness of Lipoprotein(a) for Predicting Clinical Outcomes After Endovascular Therapy for Aortoiliac Atherosclerotic Lesions

PURPOSE

To evaluate the usefulness of serum lipoprotein(a) as a biomarker of clinical outcomes after endovascular therapy (EVT) for atherosclerotic aortoiliac lesions.

METHODS

Serum lipoprotein(a) concentrations were measured at admission in 189 consecutive patients (median age 72 years; 160 men) with peripheral artery disease who underwent EVT for aortoiliac occlusive disease. The patients were dichotomized into 2 groups based on serum lipoprotein(a) levels ≤40 mg/dL (LOW; n=135) or >40 mg/dL (HIGH; n=54). After EVT, the incidences of major adverse limb events (MALE) were analyzed. Predictors of MALE were sought with a Cox proportional hazards analysis; results are presented as the hazard ratio (HR) and 95% confidence interval.

RESULTS

At the median follow-up of 33 months (interquartile range 11, 54), MALE occurred in 44 (23.3%) patients. The MALE-free survival estimate was significantly lower in patients in the HIGH group (55.6% vs 85.2%, p<0.001). Independent predictors of MALE after EVT were hemodialysis (HR 2.23, 95% CI 1.04 to 4.78, p=0.039) and high lipoprotein(a) levels (HR 2.80, 95% CI 1.44 to 5.45, p=0.003).

CONCLUSION

High lipoprotein(a) levels were associated with a higher incidence of MALE after EVT for patients with aortoiliac lesions.

One Year Primary Patency of Infrapopliteal Angioplasty Using Drug- Eluting Balloons: Single Center Experience at King Hussein Medical Center

Objective:

Conventional percutaneous transluminal angioplasty (PTA) for long lesions in the below-the-knee (BTK) arteries in patients presenting with critical limb ischemia (CLI) has high restenosis rates at 1 year. Our goal is to evaluate whether paclitaxel drug-eluting balloons (DEB) have higher 1 year primary patency rates compared to conventional PTA.

Methods:

This is a single-center, prospective, randomized trial that was conducted from June 2013 to December 2015. The aim of the study was to compare 1 year primary patency rates of DEB and PTA in BTK arteries in CLI patients. Inclusion criteria were patients presenting with CLI (Rutherford class 4 or greater), stenosis or occlusion ≥30 mm of at least one tibial artery, and agreement to 12-month evaluation. Exclusion criteria were life expectancy <1 year, allergy to paclitaxel, and contraindication to combined antiplatelet treatment. Follow-up was performed by clinical assessment, ankle brachial pressure index, Doppler ultrasound imaging, and conventional angiogram if indicated. Primary end point was 1 year primary patency, and secondary end points were target lesion revascularization (TLR) and major amputation. Statistical analysis was performed using Fischer's exact test.

Results:

Ninety-three patients with 106 lesions in the BTK arteries were enrolled in this study. One year primary patency was achieved in 26 (65%) and seven (17%) in the DEB and PTA groups (P = 0.006), respectively. TLR was performed in nine lesions (23%) and 29 lesions (71%) in DEB and PTA groups (P = 0.009), respectively. Major amputations occurred in one limb (2%) and two limbs (4%) in DEB and PTA groups (P = 0.6), respectively.

Conclusion:

Paclitaxel DEB has significantly higher 1 year primary patency rate associated with significantly less TLR than conventional PTA, following endovascular recanalization of BTK arteries in patients presenting with CLI.

Long-term outcomes after autogenous versus synthetic lower extremity bypass in patients on hemodialysis

BACKGROUND

Hemodialysis dependence confers unique physiologic conditions. Prior reports of outcomes after infrainguinal open bypass operations in patients on hemodialysis have been based on relatively small sample institutional series. In this study, we evaluate long-term outcomes after open bypass operations in a large contemporary population-based cohort of hemodialysis patients. We studied all hemodialysis patients who underwent infrainguinal open operation using autogenous versus prosthetic conduits in the United States Renal Data System between January 2007 and December 2011.

METHODS

Univariate methods (χ², analysis of variance) were used to compare the characteristics of the patient and type of bypass. Kaplan-Meier, univariate and multivariate logistic, and Cox regression analyses were used to evaluate 30-day postoperative outcomes as well as patency, limb salvage, and mortality in the long term.

RESULTS

There were 9,739 (autogenous: 59%, prosthetic: 49%) infrainguinal open bypass operations performed in this cohort. Of these, 4,717 (48%) were femoral-popliteal, 3,321 (34%) were femoral-tibial, and 1,701 (18%) were popliteal-tibial bypasses. Bypass operations were performed most commonly for critical limb ischemia (72%). Primary patency was 18% for both types of conduits at 5 years (P = .16). Comparing autogenous versus prosthetic conduits, primary-assisted patency was 23% vs 20% at 5 years (P = .98), while secondary patency was 30% for both conduits at 5 years (P = .05). Limb salvage was 35% vs 41% at 5 years (P < .001). Multivariable analyses demonstrated greater patency (adjusted hazard ratio [aHR]: 1.16; 95% confidence interval, 1.05-1.28; P = .003) and limb salvage (aHR: 1.12; 95% confidence interval, 1.01-1.24; P = .03) for autogenous compared to prosthetic bypasses. The advantage conferred by autogenous conduits was most clinically relevant for femoral-tibial (aHR: 1.34; 95% confidence interval, 1.17-1.55; P < .001) and popliteal-tibial (aHR: 1.55; 95% confidence interval, 1.09-2.21; P = .014) configurations.

CONCLUSION

This large study evaluated the long-term outcomes of open bypass operations in patients on hemodialysis. The data confirm the long-term benefits of autogenous conduits compared with prosthetic conduits in this high-risk population of patients, especially for the treatment of distal lesions. Individual patient life expectancy, availability of adequate autogenous conduit options, indication for operation, level of disease, as well as potential need for future options for additional access for dialysis should be taken into consideration when deciding to construct an open bypass in a hemodialysis patient.

The comparative efficacy of angiosome-directed and indirect revascularisation strategies to aid healing of chronic foot wounds in patients with co-morbid diabetes mellitus and critical limb ischaemia: a literature review

BACKGROUND

Ischaemic ulcerations have been reported to persist and/or deteriorate despite technically successful revascularisations; a higher incidence of which affects patients with diabetes and critical limb ischaemia. In the context of wound healing, it is unclear if applications of the angiosome concept in 'direct revascularisation' (DR) would be able to aid the healing of chronic foot ulcerations better than the current 'best vessel' or 'indirect revascularisation' (IR) strategy in patients with co-morbid diabetes and critical limb ischaemia.

METHODS

A literature search was conducted in eight electronic databases, namely AMED, CINAHL, The Cochrane Library, ProQuest Health & Medicine Complete, ProQuest Nursing & Allied Health Source, PubMed, ScienceDirect and TRIP database. Articles were initially screened against a pre-established inclusion and exclusion criteria to determine eligibility and subsequently appraised using the Newcastle-Ottawa Scale.

RESULTS

Five retrospective studies of varying methodological quality were eligible for inclusion in this review. Critical analysis of an aggregated population (n = 280) from methodologically stronger studies indicates better wound healing outcomes in subjects who had undergone DR as compared to IR (p < 0.001; p = 0.04). DR also appears to result in a nearly twofold increase in probability of wound healing within 12 months (hazard ratio, 1.97; 95% CI, 1.34-2.90). This suggests that achieving direct arterial perfusion to the site of ulceration may be important for the healing of chronic diabetic foot ulcerations.

CONCLUSION

Incorporating an angiosome-directed approach in the lower limb revascularisation strategy could be a very useful adjunct to a solely indirect approach, which could increase the likelihood of wound healing. With the limited data currently available, findings appear promising and merit from further investigation. Additional research to form a solid evidence base for this revised strategy in patients with co-morbid diabetes and critical limb ischaemia is warranted.

Bypass Surgery after Endovascular Therapy for Infrapopliteal Lesion Is Not a Poor Outcome Compared with Initial Bypass Surgery by Vascular Surgeons

BACKGROUND

It is unclear whether prior endovascular therapy (EVT) adversely affects bypass surgery. The aim of this study is to investigate treatment outcomes between initial bypass (bypass-first) and bypass surgery after EVT (EVT-first).

METHODS

We conducted a retrospective analysis of critical limb ischemia patients undergoing infrapopliteal bypass between November 2006 and December 2015. Graft patency, limb salvage (LS), amputation-free survival (AFS), and overall survival (OS) were examined between bypass-first and EVT-first groups.

RESULTS

The subjects in this study were 75 patients and 82 limbs in the bypass-first group and 24 patients and 24 limbs in the EVT-first group. The average age was higher in EVT-first group (P = 0.03). The percentage of inframalleolar bypass was higher in the EVT-first group (P = 0.002). Primary patency at 1 and 2 years was 72.0% and 67.5% for the bypass-first group and 53.1% and 47.2% for the EVT-first group, respectively (P = 0.04). Inframalleolar bypass was a risk factor for lower primary patency (hazard ratio 3.07, 95% confidence interval 1.18-8.51, P = 0.02) in multivariate analysis, while there were no differences in secondary patency, LS, AFS, and OS.

CONCLUSIONS

Bypass surgery after EVT has lower primary patency rates in comparison with primary bypass in patients submitted to infrapopliteal revascularization. Although very heterogeneous study population with a lot of bias in the indication of the revascularization, LS, OS and AFS are not affected by previous EVT.

Lower extremity bypass for critical limb ischemia decreases major adverse limb events with equivalent cardiac risk compared with endovascular intervention

OBJECTIVE

Lower extremity bypass (LEB) has traditionally been the "gold standard" in the treatment of critical limb ischemia (CLI). Infrainguinal endovascular intervention (IEI) has become more commonly performed than LEB, but comparative outcomes are limited. We sought to compare rates of major adverse limb events (MALEs) and major adverse cardiovascular events (MACEs) after LEB and IEI in a propensity score-matched, national cohort of patients with CLI.

METHODS

The National Surgical Quality Improvement Program (NSQIP) vascular targeted files (2011-2014) for LEB and IEI were merged. CLI patients were identified by ischemic rest pain or tissue loss. Patients were matched on a 1:1 basis for propensity to undergo LEB or IEI. Primary outcomes were 30-day MALEs and MACEs. Within the propensity-matched cohort, multivariate logistic regression was used to identify independent predictors of MALEs and MACEs.

RESULTS

A total of 13,294 LEBs and IEIs were identified, with 8066 cases performed for CLI. Propensity matching identified 3848 cases (1924 per group). There were no differences in preoperative variables between the propensity-matched LEB and IEI groups (all P > .05). At 30 days, rates of MALEs were significantly lower in the LEB group (9.2% LEB vs IEI 12.2%; P = .003). On multivariate logistic regression, bypass with single-segment saphenous vein vs IEI (odds ratio [OR], 0.7; 95% confidence interval [CI], 0.54-0.92; P = .01), bypass with alternative conduit (prosthetic, spliced vein, or composite) vs IEI (OR, 0.7; 95% CI, 0.56-0.98; P = .04), antiplatelet therapy (OR, 0.8; 95% CI, 0.58-1.00; P = .049), and statin therapy (OR, 0.8; 95% CI, 0.62-0.99; P = .04) were protective against MALEs, whereas infrageniculate intervention (OR, 1.4; 95% CI, 1.09-1.72; P = .01) and a history of prior bypass of the same arterial segment (OR, 1.8; 95% CI, 1.41-2.41; P <. 0001) were predictive. Rates of 30-day MACEs were not significantly different (4.9% LEB vs 3.7% IEI; P = .07) between the groups. Independent predictors of MACEs included age (OR, 1.02; 95% CI, 1.01-1.04; P = .01), steroid use (OR, 1.8; 95% CI, 1.08-2.99; P = .03), congestive heart failure (OR, 1.7; 95% CI, 1.00-1.96; P = .02), beta blocker use (OR, 1.6; 95% CI, 1.09-1.43; P = .01), dialysis (OR, 2.3; 95% CI, 1.55-3.45; P < .0001), totally dependent functional status (OR, 3.1; 95% CI, 1.25-7.58; P = .02), and suboptimal conduit for LEB compared with IEI (OR, 1.6; 95% CI, 1.08-2.36; P = .02).

CONCLUSIONS

Within this large, propensity-matched, national cohort, LEB predicted lower risk-adjusted 30-day MALE rate compared with IEI. Furthermore, there was no difference in 30-day MACE rate between the groups despite higher inherent risk with open surgical procedures. Therefore, this study supports the effectiveness and primacy of LEB for revascularization in CLI.

Risk factors for wound complications and 30-day mortality after major lower limb amputations in patients with peripheral arterial disease

Purpose Risk factors for wound complications or 30-day mortality after major amputation in patients with peripheral arterial disease remain unclear. We investigated the outcomes of major amputation in patients with peripheral arterial disease. Methods Patients who underwent major amputation from 2008 to 2015 were retrospectively analyzed. The main outcome measures were risk factors for wound complications and 30-day mortality after major lower limb amputations. Major amputation was defined as above-knee amputation or below-knee amputation. Wound complications were defined as surgical site infection or wound dehiscence. Results In total, 106 consecutive patients underwent major amputation. The average age was 77.3 ± 11.2 years, 67.9% of patients had diabetes mellitus and 35.8% were undergoing hemodialysis. Patients who underwent primary amputation constituted 61.9% of the cohort, and the proportions of above-knee amputation and below-knee amputation were 66.9% and 33.1%, respectively. The wound complication rate was 13.3% overall, 10.3% in above-knee amputation, and 19.5% in below-knee amputation. Multivariate analysis showed that the risk factors for wound complications were female sex (hazard ratio, 4.66; 95% confidence interval, 1.40-17.3; P = 0.01) and below-knee amputation (hazard ratio, 4.36; 95% confidence interval, 1.20-17.6; P = 0.03). The 30-day mortality rate was 7.6%, pneumonia comprised the most frequent cause of 30-day mortality, followed by sepsis and cardiac death. Multivariate analysis showed that a low serum albumin concentration (hazard ratio, 3.87; 95% confidence interval, 1.12-16.3; P = 0.03) was a risk factor for 30-day mortality. Conclusions Female sex and below-knee amputation were risk factors for wound complications. A low serum albumin concentration was a risk factor for 30-day mortality after major amputation in Japanese patients with peripheral arterial disease.

Lifelong limb preservation: A patient-centered description of lower extremity arterial reconstruction outcomes

BACKGROUND

Life expectancy is short for patients with critical limb ischemia (CLI), many of whom may fear amputation more than death. In light of the reduced life expectancy of these patients, the traditional 5-year freedom from amputation (FFA) statistic may not accurately address their concern. We developed a more relevant patient-centered calculation of major amputation risk during a patient's remaining lifetime to better answer the question, Will I ever lose my leg?

METHODS

We identified all limbs undergoing first-time intervention for CLI in a large institutional database from 2005 to 2013. We calculated the traditional metrics of amputation-free survival (AFS, for which failure is death or amputation) and FFA (for which failure is amputation but deaths are censored and removed from further analysis). In addition, we propose a new term, lifelong limb preservation (LLP). LLP defines amputation as failure, but deaths are not censored and therefore reflect that LLP has been achieved. All deaths before 30 days were considered a failure in all three metrics, reflecting the risk of surgery.

RESULTS

There were 1006 limbs identified as having first-time intervention for CLI (22% rest pain, 45% ulcer, 27% gangrene; 46% treated by angioplasty with or without stenting, 54% bypass). Using life-table analysis, 7-year AFS was 14% (561 events), FFA was 78% (123 events), and LLP was 86% (123 events). LLP was similar between patients undergoing angioplasty with or without stenting and bypass (7-year rates, 86% and 85%, respectively). For patients undergoing intervention for rest pain, 7-year rates were 14% for AFS, 84% for FFA, and 92% for LLP. For those undergoing treatment for ulcer, 7-year rates were 14% for AFS, 77% for FFA, and 86% for LLP. Finally, in those with gangrene, rates were 10% for AFS, 67% for FFA, and 79% for LLP. Using LLP, patients presenting with an ulcer can be told that although we cannot guarantee how long they will live, with revascularization there is approximately an 86% chance they will not lose the leg.

CONCLUSIONS

These results show that the durability of our limb preservation efforts often exceeds the life expectancy of our patients. Using LLP as an outcomes assessment provides a more accurate and patient-centered answer to the question, If I have this procedure, will I ever lose my leg?

Outcomes of Isolated Tibial Endovascular Intervention for Rest Pain in Patients on Dialysis

BACKGROUND

Tibial interventions for critical limb ischemia are frequent in patients with end-stage renal disease (ESRD) presenting with critical ischemia. The aim of this study was to examine impact of ESRD on the patient-centered outcomes following tibial endovascular Intervention for rest pain.

METHODS

A database of patients undergoing lower extremity endovascular interventions between 2006 and 2016 was retrospectively queried. Patients with rest pain (Rutherford 4) were identified. Patients with claudication (Rutherford 1 to 3) and tissue loss (Rutherford 5 and 6) were excluded. Patients were categorized by the presence or absence of ESRD. Patient-orientated outcomes of clinical efficacy (CE; absence of recurrent symptoms, maintenance of ambulation, and absence of major amputation), amputation-free survival (AFS; survival without major amputation), and freedom from major adverse limb events (MALEs; above ankle amputation of the index limb or major reintervention new bypass graft, jump/interposition graft revision) were evaluated.

RESULTS

A total of 829 patients (56% male, average age 59 years; 658 nonhemodialysis [non-HD] and 171 HD) underwent isolated tibial intervention in one leg for rest pain. Technical success was 99% with a median of 2 vessels treated per patient. There was no difference in the distribution of Trans-Atlantic Inter-Society Consensus I lesions, but both the modified Society for Vascular Surgery (SVS) runoff score and the pedal runoff score were worse in the HD group. The 30-day major adverse cardiac events and 30-day MALEs were equivalent in both groups. CE was 38 ± 9% and 19 ± 8% at 5 years for the non-HD and HD groups, respectively (P < 0.01). Overall, AFS was 45 ± 8% and 18 ± 9% at 5 years for the non-HD and HD groups, respectively (P < 0.01). Freedom from MALE was 41 ± 9% and 21 ± 8% at 5 years for the non-HD and HD groups, respectively (P < 0.01).

CONCLUSIONS

Patients with ESRD who present with rest pain have equivalent short-term outcomes to those not on dialysis but do not achieve long-term satisfactory CE and AFS after isolated tibial intervention for rest pain.

Rationale and design of the MarrowStim PAD Kit for the Treatment of Critical Limb Ischemia in Subjects with Severe Peripheral Arterial Disease (MOBILE) trial investigating autologous bone marrow cell therapy for critical limb ischemia

OBJECTIVE

Critical limb ischemia (CLI) continues to place a significant encumbrance on patients and the health care system as it progresses to limb loss and long-term disability. Traditional methods of revascularization offer a significant benefit; however, for one-third of CLI patients, these surgical options are not technically possible or patency is severely limited by disease burden (deemed "poor-option" for revascularization). In a previous phase I trial, we demonstrated intramuscular injection of concentrated bone marrow aspirate (cBMA) via MarrowStim (Zimmer Biomet, Warsaw, Ind) harvest is safe and may decrease major amputation in patients with CLI unfit for surgical revascularization. Therefore, we describe and rationalize the MarrowStim PAD Kit for the Treatment of Critical Limb Ischemia in Subjects with Severe Peripheral Arterial Disease (MOBILE) trial, a study geared to provide the pivotal proof of efficacy of cBMA in CLI.

METHODS

MOBILE is a multicenter, randomized, double-blind, placebo-controlled trial designed to assess the efficacy of intramuscular injections of cBMA in promoting amputation-free survival in patients with poor-option CLI. Patients (aged >21 years) with rest pain or tissue loss resulting from advanced peripheral arterial disease, as characterized by ankle-brachial index (<0.6), toe-brachial index (<0.4), or transcutaneous pressure of oxygen (<50 mm Hg), were eligible for inclusion if surgical revascularization was not possible secondary to advanced disease.

RESULTS

Treatment and 1-year follow-up of 152 patients enrolled in MOBILE are completed. Long-term follow-up is ongoing. Currently, we are in the process of unblinding the initial results for preliminary data analysis.

CONCLUSIONS

If successful, MOBILE could add definitive, high-quality evidence in support of cBMA for the treatment of poor-option CLI patients and provide an additional modality for patients who face amputation secondary to advanced limb ischemia.

Safety and Effectiveness of Bone Marrow Cell Concentrate in the Treatment of Chronic Critical Limb Ischemia Utilizing a Rapid Point-of-Care System

Critical limb ischemia (CLI) is the end stage of lower extremity peripheral vascular disease (PVD) in which severe obstruction of blood flow results in ischemic rest pain, ulcers and/or gangrene, and a significant risk of limb loss. This open-label, single-arm feasibility study evaluated the safety and therapeutic effectiveness of autologous bone marrow cell (aBMC) concentrate in revascularization of CLI patients utilizing a rapid point-of-care device. Seventeen (17) no-option CLI patients with ischemic rest pain were enrolled in the study. Single dose of aBMC, prepared utilizing an intraoperative point-of-care device, the Res-Q™ 60 BMC system, was injected intramuscularly into the afflicted limb and patients were followed up at regular intervals for 12 months. A statistically significant improvement in Ankle Brachial Index (ABI), Transcutaneous Oxygen Pressure (TcPO₂), mean rest pain and intermittent claudication pain scores, wound/ ulcer healing, and 6-minute walking distance was observed following aBMC treatment. Major amputation-free survival (mAFS) rate and amputation-free rates (AFR) at 12 months were 70.6% and 82.3%, respectively. In conclusion, aBMC injections were well tolerated with improved tissue perfusion, confirming the safety, feasibility, and preliminary effectiveness of aBMC treatment in CLI patients.

Neutrophil-to-lymphocyte ratio is effective prognostic indicator for post-amputation patients with critical limb ischemia

To confirm whether neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) are indicators for the prognosis of post-amputation patients with critical limb ischemia (CLI). Methods: In this retrospective observational study a total 270 post-amputation patients with CLI were included between January 2010 and December 2014 in the First Hospital of Jilin University, Changchun, China. The neutrophil and lymphocyte counts were recorded before amputations. Neutrophil-to-lymphocyte ratio was calculated and NLR ≥8.08 was defined as elevated. Logistic regression analysis was conducted to test the prognostic value. Results: According to the statistical analysis, it was indicated that NLR ≥8.08 (odds ratio [OR]: 26.228, 95% confidence interval [CI]: 5.801-118.583, p less than 0.001), PLR ≥237.14 (OR: 3.464, 95% CI: 1.289-9.308, p=0.014) and coronary heart disease (OR: 2.739, 95% CI: 1.060-7.082, p=0.038) were the independent prognostic indicators for the patients. Conclusion: Neutrophil-to-lymphocyte ratio, PLR, and coronary heart disease are independent prognostic indicators for post-amputation patients with CLI.

Drug-Eluting Balloon Angioplasty for Below the Knee Lesions in End Stage Renal Disease Patients with Critical Limb Ischemia: Midterm Results

BACKGROUND

The 1-year restenosis rate after standard balloon angioplasty (BA) of long lesions in below-the-knee arteries may be as high as 70%. Our aim was to investigate the efficacy and safety of paclitaxel drug-eluting balloon (DEB) for treatment of below the knee lesions in end stage renal disease patients (ESRD) with critical limb ischemia (CLI).

METHODS

Our study is a retrospective, single-center study. Inclusion criteria were ESRD, critical limb ischemia (Rutherford class 4 or higher) and significant stenosis or occlusion of at least 1 below-the-knee vessel. Target vessel restenosis and reocclusion at 1-year follow-up was the primary end point. Major amputation, was the secondary end point.

RESULTS

From July 2012 to February 2015, 50 patients identified with ESRD, with CLI, treated with DEB angioplasty. Six patients were lost to follow-up, leaving 44 patients with 55 vessels (mean age, 58.0 ± 6.9 years; 54.5% male). The mean lesion length was 113.4 ± 55.4 mm. BA confined to the infra-popliteal segment alone in 81.8% of cases. Primary patency was 90.4% at 6 months and 62.2% at 12 months. At a mean follow-up of 13.9 ± 3.5 months all cause mortality was 8.1% (N = 3). The ankle brachial index increased from 0.45 ± 0.04 preoperative to 0.88 ± 0.07 postoperative. There was one major amputation (2.7%) and 5 minor amputations at one year (13.5%).

CONCLUSION

DEB is effective in the treatment of below the knee critical stenosis and occlusions in ESRD patients with critical limb ischemia.

Incidence and clinical outcomes of the slow-flow phenomenon after infrapopliteal balloon angioplasty

OBJECTIVE

This study investigated the incidence and clinical relevance of the slow-flow phenomenon after infrapopliteal balloon angioplasty.

METHODS

This retrospective, single-center study included 161 consecutive patients with critical limb ischemia (173 limbs) who underwent endovascular treatment for infrapopliteal lesions between January 2012 and May 2015. The overall technical success rate was 88%. Of these lesions, 30 limbs presented with slow flow after angioplasty.

RESULTS

Total occlusion (90% vs 63%; P < .01) and severe calcification (43% vs 8%; P < .01) were more common in the slow-flow group. Kaplan-Meier curve analysis revealed that freedom from major amputation (60% vs 86%; log-rank, P < .01) and wound healing at 2 years (77% vs 91%; log-rank, P = .03) were significantly less common in the slow-flow group. Univariate Cox proportional hazard analysis identified Rutherford class 6 (hazard ratio [HR], 6.4; 95% confidence interval [CI], 2.8-15.8; P < .01), the slow-flow phenomenon (HR, 3.9; 95% CI, 1.6-8.9; P < .01), and hemodialysis (HR, 3.2; 95% CI, 1.2-11.1; P = .02) as independent predictors of major amputation and Rutherford class 6 (HR, 0.3; 95% CI, 0.2-0.6; P < .01), the slow-flow phenomenon (HR, 0.5; 95% CI, 0.3-0.9; P = .02), and pedal arch (HR, 1.6; 95% CI, 1.0-2.5; P = .04) as predictors of wound healing.

CONCLUSIONS

The slow-flow phenomenon after infrapopliteal balloon angioplasty occurred in 18.6% of limbs. This phenomenon may result in poor outcomes.

Rationale and Design of Randomized Clinical Trial for the Assessment of Macitentan Efficiency as Coadjuvant Treatment to Open and Endovascular Revascularization in Critical Limb Ischemia

INTRODUCTION

Critical limb ischemia (CLI) is defined by ischemic rest pain, tissue loss, or both, secondary to arterial insufficiency, and its prevalence is increasing mainly as a result of the worldwide high prevalence of diabetes. Currently, there are no available conclusive data on the efficacy of any coadjuvant therapy after revascularization procedure benefiting amputation and patency rates. Macitentan is an orally active dual endothelin (ET) receptor antagonist that may contribute to reduce the amputation rate and improve revascularization patency in CLI.

METHODS/DESIGN

REVASC is a proposed pilot, open-label, controlled, randomized, single-center clinical double-blind trial to be conducted in Spain on a study population of European patients with CLI, which will compare the clinical outcomes and cost-effectiveness of macitentan coadjuvant treatment after limb revascularization with the standard antiplatelet treatment strategy for severe limb ischemia. Patients are randomized 1:1 to receive macitentan or placebo for 12 weeks. The primary clinical end point will be amputation-free survival rate at 12 months, defined as the time to major (above the ankle) amputation for the index (trial) limb or death from any cause, whichever comes first. Secondary outcomes include overall survival, quality of life, in-hospital mortality and morbidity, repeat interventions, healing of tissue loss, and hemodynamic changes following revascularization. Sample size is estimated as 120 patients. The economic analysis will consist of two components: a "within-study" analysis, which will be based on study end points; and a "model-based" analysis, which will extrapolate and compare costs and effects likely to accrue beyond the study follow-up period.

DISCUSSION

The REVASC trial is designed to be pragmatic and represents current practice of the real-world population management after limb revascularization for CLI due to atherosclerosis. Current evidence does not support any coadjuvant treatment. A new pathway of treatment may be opened with the use of ET receptor antagonists in these patients.

Management of Critical Limb Ischemia

Critical limb ischemia (CLI) is a clinical syndrome of ischemic pain at rest or tissue loss, such as nonhealing ulcers or gangrene, related to peripheral artery disease. CLI has a high short-term risk of limb loss and cardiovascular events. Noninvasive or invasive angiography help determine the feasibility and approach to arterial revascularization. An endovascular-first approach is often advocated based on a lower procedural risk; however, specific patterns of disease may be best treated by open surgical revascularization. Balloon angioplasty and stenting form the backbone of endovascular techniques, with drug-eluting stents and drug-coated balloons offering low rates of repeat revascularization. Combined antegrade and retrograde approaches can increase success in long total occlusions. Below the knee, angiosome-directed angioplasty may lead to greater wound healing, but failing this, any straight-line flow into the foot is pursued. Hybrid surgical techniques such as iliac stenting and common femoral endarterectomy are commonly used to reduce operative risk. Lower extremity bypass grafting is most successful with a good quality, long, single-segment autogenous vein of at least 3.5-mm diameter. Minor amputations are often required for tissue loss as a part of the treatment strategy. Major amputations (at or above the ankle) limit functional independence, and their prevention is a key goal of CLI therapy. Medical therapy after revascularization targets risk factors for atherosclerosis and assesses wound healing and new or recurrent flow-limiting disease. The ongoing National Institutes of Health-sponsored Best Endovascular Versus Best Surgical Therapy in Patients With Critical Limb Ischemia (BEST-CLI) study is a randomized trial of the contemporary endovascular versus open surgical techniques in patients with CLI.