Cumulative risk of bypass, amputation or death following percutaneous transluminal angioplasty

Genetic polymorphisms influence on the response to clopidogrel in peripheral artery disease patients following percutaneous transluminal angioplasty

AIM

To study the association of ABCB1 and CYP2C19 polymorphisms and the clopidogrel response in Spanish peripheral artery disease patients following percutaneous transluminal angioplasty (PTA) and to perform a meta-analysis.

MATERIALS & METHODS

72 patients were recruited and 122 patients included in the meta-analysis. We evaluated the effect of ABCB1 3435 C>T, CYP2C19*2 and CYP2C19*3 and primary end point (restenosis/occlusion of the treated lesions) during 12 months after PTA.

RESULTS

CYP2C19*2 and/or ABCB1 TT patients were associated with primary end point (OR: 5.00; 95% CI: 1.75-14.27). The meta-analysis confirmed the association of CYP2C19*2 and new atherothrombotic ischemic events (OR: 5.40; 95% CI: 2.30-12.70).

CONCLUSION

The CYP2C19 and ABCB1 polymorphisms could be genetic markers of cardiovascular events in peripheral artery disease patients following PTA treated with clopidogrel.

Surgical or endovascular revascularization in patients with critical limb ischemia: influence of diabetes mellitus on clinical outcome

OBJECTIVE

The optimal revascularization strategy in diabetic patients with chronic critical limb ischemia (CLI) is unclear. This study assessed the efficacy of tailored endovascular-first vs surgical-first revascularization stratified for the presence of diabetes.

METHODS

This prospective cohort study, with 1-year follow up, was conducted in a tertiary referral center in a consecutive series of 383 patients (45.7% had diabetes) presenting 426 limbs with chronic CLI. Interventions were endovascular (PTA cohort, 207 limbs) or surgical (SURG cohort, 85 limbs) revascularization. Conservatively treated patients without revascularization (NON REVASC cohort, 108 limbs) were used as a reference. The main outcome measures were sustained clinical success, defined as survival without major amputation or repeated target extremity revascularization (TER), and a categoric upward shift in clinical symptoms according to the Rutherford classification.

RESULTS

Sustained clinical success of revascularization was significantly better in nondiabetic patients (hazard ratio [HR], 0.48; 95% confidence interval [CI], 0.29 to 0.72; P = .001 [SURG cohort]; HR, 0.53; 95% CI, 0.35 to 0.78; P = .002 [PTA cohort]) compared with diabetic patients (HR, 0.78; 95% CI, 0.44 to 1.43, P = .45 [SURG cohort]; HR, 0.83; 95% CI, 0.55 to 1.27, P = .40 [PTA cohort]). Repeated TER significantly improved clinical success, which became equivalent between diabetic and nondiabetic patients (HR, 1.02; 95% CI, 0.7 to 1.4). In multivariate analysis, treatment success was not influenced by mode of initial revascularization, neither in diabetic nor in nondiabetic patients. Cumulative 1-year mortality was 30.4%, with a trend of increased mortality in patients with diabetes (HR, 1.45; 95% CI, 0.98 to 2.17; P = .064). Limb salvage rates were similar in treatment cohorts, also if stratified for diabetes (HR, 1.04; 95% CI, 0.62 to 1.75).

CONCLUSION

Diabetic patients with chronic CLI benefit from early revascularization. To achieve this benefit, multiple revascularization procedures may be required, and close surveillance is therefore mandatory. Choice of initial revascularization modality seems not to influence clinical success.

Evolution of a “falx lunatica” in demarcation of critically ischemic myocutaneous tissue

Using intravital microscopy in a chronic in vivo mouse model, we studied the demarcation of myocutaneous flaps and evaluated microvascular determinants for tissue survival and necrosis. Chronic ischemia resulted in a transition zone, characterized by a red fringe and a distally adjacent white falx, which defined the demarcation by dividing the proximally normal from the distally necrotic tissue. Tissue survival in the red zone was determined by hyperemia, as indicated by recovery of the transiently reduced functional capillary density, and capillary remodeling, including dilation, hyperperfusion, and increased tortuosity. Angiogenesis and neovascularization were not observed over the 10-day observation period. The white rim distal to the red zone, appearing as “falx lunatica,” showed a progressive decrease of functional capillary density similar to that of the necrotic distal area but without desiccation, and thus transparency, of the tissue. Development of the distinct zones of the critically ischemic tissue could be predicted by partial tissue oxygen tension (Pt[Formula: see text]) analysis by the time of flap elevation. The falx lunatica evolved at a Pt[Formula: see text] between 6.2 ± 1.3 and 3.8 ± 0.7 mmHg, whereas tissue necrosis developed at <3.8 ± 0.7 mmHg. Histological analysis within the falx lunatica revealed interstitial edema formation and muscle fiber nuclear rarefaction but an absence of necrosis. We have thus demonstrated that ischemia-induced necrosis does not demarcate sharply from normal tissue but develops beside a fringe of tissue with capillary remodeling an adjacent falx lunatica that survives despite nutritive capillary perfusion failure, probably by direct oxygen diffusion.

Gender Differences in Patients Treated for Critical Limb Ischemia

OBJECTIVE

To investigate, in patients treated for critical limb ischemia, how pre-operative conditions, localisation of lesions and outcome varied according to gender.

DESIGN

Retrospective cohort study.

METHODS

Medical records were analysed for all patients treated with vascular reconstruction or PTA for critical limb ischemia 1993-1994 (119 women, 115 men) at the Karolinska Hospital. All events such as secondary intervention, amputation and death occurring until 2003 were included in the analysis.

RESULTS

The preoperative conditions were similar between women and men apart from higher mean age (74 years in women vs 69 in men, p=0.0002), fewer subjects with a smoking history (63 vs 82%, p=0-005) and diabetic disease (22 vs 43%, p=0.0004) among females. More interventions were performed suprainguinally in women (44% in women vs 19% in men). Amputation and survival rates were similar in women and men, even after matching for age and diabetes.

CONCLUSION

Women were older, had a lower frequency of diabetes, smoked less and had more proximal lesions than treated men. Outcome was identical for both genders. Biological and anatomical differences could possibly explain several of the found gender differences. Gender differences in risk factors and possibly in the selection process also may have contributed to our findings.

Complications in Peripheral Vascular Interventions: Emerging Role of Direct Thrombin Inhibitors

Unfractionated heparin is associated with a high rate of bleeding and thrombotic complications during peripheral vascular interventions (PVIs). Newer anticoagulants such as direct thrombin inhibitors might offer significant advantages over heparin. Early data with bivalirudin in the peripheral circulation are promising. Bivalirudin appears safe and effective when used during PVIs. Data with the use of other direct thrombin inhibitors (hirudin, r-hirudin, argatroban, and melagatran) in peripheral interventions are still lacking. Among these, argatroban and melagatran have pharmacologic properties that might offer some advantages in PVI, but further studies are needed to demonstrate their safety and effectiveness.

The role of infrapopliteal angioplasty

Infrapopliteal percutaneous transluminal angioplasty (PTA) is currently indicated in patients with critical limb ischaemia (CLI). It may be performed after femoral angioplasty or bypass surgery, to improve outflow and hence patency of the proximally treated segment. Patients with CLI are typically elderly with multiple co-morbidities and limited life expectancy and therefore, a procedure, which is minimally invasive with reduced morbidity and mortality but lesser long-term patency, may be more appropriate than a more invasive procedure with better long-term patency. Clinical success is superior to angiographic patency, because once healing has occurred, should the artery restenose or occlude, collateral flow can be sufficient to preserve tissue integrity if there is no further injury. Although no prospective randomized trials have been performed, the reported limb-salvage rates of PTA are comparable with surgery. As PTA carries a lower morbidity and mortality, shorter hospital stay and does not preclude surgery, it is ideal for this group of patients who are high-risk surgical candidates. Improvements in guide-wire and catheter technology and recanalization techniques mean that very long stenoses or occlusions, and multiple lesions can be treated successfully. At the current time, PTA is the treatment of choice for infrapopliteal occlusive disease; experience with the use of stents in this territory is increasing but currently insufficient to justify their primary use.

Outcome of Conservative Therapy of Patients with Severe Intermittent Claudication

BACKGROUND

Intermittent claudication due to peripheral artery disease (PAD) can be treated conservatively, or by revascularization.

OBJECTIVES

To assess the short-term outcome of conservatively-treated claudicants, and determine predictors for clinical improvement. Design. A retrospective cohort study.

METHODS

We evaluated Fontaine stage, walking distance and ankle brachial index (ABI) at baseline and after median 9 months (interquartile range (IQR) 6-24) in 181 patients with severe claudication.

RESULTS

We found clinical improvement by at least one Fontaine stage in 38 patients (21%) with an increased walking distance from baseline median 100 m (IQR 50-150) to follow-up median 650 m (IQR 300 to unlimited; p<0.001), but without changes in ABI (median 0.57, IQR 0.48-0.73 vs. median 0.54, IQR 0.45-0.81; p=0.10). One hundred and thirty-eight patients (76%) remained clinically and hemodynamically stable. A worsening of the clinical stage but without amputation was recorded in five patients (3%). Female gender (hazard ratio (HR) 0.51, p=0.052), diabetes (HR 0.35, p=0.020), and baseline ABI below 0.44 (HR 0.31, p=0.019) were associated with a reduced probability of clinical improvement.

CONCLUSION

Certain patients with intermittent claudication show substantial clinical improvement with conservative medical therapy, despite any lack of hemodynamic improvement. Given the low number of patients with clinical deterioration in the short term, primarily conservative therapy should be the preferred initial option for most claudicants.

The final outcome of primary infrainguinal percutaneous transluminal angioplasty in 100 consecutive patients with chronic critical limb ischemia

PURPOSE

This study was performed to determine final outcomes in patients treated with infrainguinal percutaneous transluminal angioplasty (PTA) for chronic critical limb ischemia (CLI).

MATERIALS AND METHODS

The study population consisted of 100 consecutive patients (mean age, 72 y; range, 38-90 y; 40 men and 60 women) with 116 treated limbs. CLI was defined as rest pain or ischemic tissue defect combined with an ankle systolic pressure < or = 50 mm Hg. Indication for treatment was rest pain in 23 limbs (20%), ischemic ulcer in 50 (43%), and gangrene in 43 (37%). All patients were followed until they had met the study endpoints: major amputation or death. The mean follow-up period was 38 months (1-119 mo). Limb salvage, survival, and life with limb rates were determined along with their determinants.

RESULTS

On average, 1.9 invasive procedures were required during the lifespan of a critically ischemic limb, including primary PTA and 32 repeat PTA procedures, 11 surgical revascularizations, and 51 amputations. The major amputation rate was 32% (n = 37). Limb salvage for endovascular treatments at 3, 5, and 8 years was 65%, 60%, and 60%, respectively (SE of estimate [SEE] <or = 0.06), and the corresponding life with limb rates were 29%, 18%, and 6% (SEE < or = 0.05). A greater number of diseased vessels in the treated limb was associated with poorer limb salvage (P =.004). Survival rates were 41%, 26%, and 14% (SEE < or = 0.05) at 3, 5, and 10 years. The 10-year survival rate was markedly poorer than that in the age- and sex-matched control population. Coronary artery disease (P =.001) and poor peripheral runoff (P =.02) were associated with decreased survival.

CONCLUSIONS

Infrainguinal PTA in patients with CLI results in acceptable limb salvage with a low number of additional revascularization treatments, but patient survival is poor.

Percutaneous Transluminal Angioplasty of Crural Arteries: Diabetes and other Factors Influencing Outcome

OBJECTIVE

to evaluate the efficacy of percutaneous transluminal angioplasty (PTA) of the crural arteries.

PATIENTS AND METHODS

a retrospective review of patients treated with PTA of at least one crural artery during an 8-year period (1990--1997).

RESULTS

one hundred and fifty-five legs in 140 consecutive patients (mean age 74 years, range 38--91 years) were treated. In 76% a more proximal lesion was also treated. After 1 year, results were significantly better in non-diabetics (improvement rate of 66% vs 32%p <0.05). The outcome for patients with a combination of diabetes, heart disease and renal disease was significantly worse compared to all other patients with an improvement rate of only 9% after 1 year. Patients alive and not amputated at 1 year were significantly more common (p <0.05) among non-diabetics (90%), compared to diabetics (66%). The 1-year mortality for the whole group was 15%, significantly higher for diabetic patients (p =0.04).

CONCLUSION

PTA of crural arteries produces reasonably good results in non-diabetic patients. Diabetic patients were doing worse than non-diabetics after a year, though 1-month results were not significantly different. Patients with diabetes, heart disease and renal disease make a high-risk group that has a significantly worse outcome.

Prospective trial of infrapopliteal artery balloon angioplasty for critical limb ischemia: angiographic and clinical results

PURPOSE

To evaluate the safety and efficacy of infrapopliteal percutaneous transluminal angioplasty (PTA) as a primary treatment of chronic critical limb ischemia in a prospective trial.

MATERIALS AND METHODS

Infrapopliteal PTA was performed on 72 limbs of 60 patients (mean age, 72 y; range, 38-92 y) and patients were followed for 12-24 months.

RESULTS

The primary angiographic success rate for the stenoses was 84% (102 of 121) and that for the occlusions was 61% (41 of 67) with corresponding restenosis rates of 32% and 52% at follow-up angiography performed a mean of 10 months after primary PTA. The rate of major complications was 2.8% (access site pseudoaneurysms in two patients). The primary clinical success was 63% (45 of 72). A 48% cumulative primary patency rate, a 56% secondary patency rate, and a 80% cumulative limb salvage rate were registered at 18 months, as determined with use of Kaplan-Meier analysis. Lack of angiographic improvement at the site of the most severe ischemia and renal insufficiency (serum creatinine level > 130 micromol/L) were independent predictors of poorer long-term clinical results, as determined with use of Cox multiple regression analysis.

CONCLUSIONS

Infrapopliteal PTA is a feasible primary treatment of chronic critical limb ischemia with moderate primary angiographic and clinical success, a low complication rate, and a cumulative limb salvage rate comparable with surgical techniques.

Minimally invasive superficial femoral artery endarterectomy: early experience with a modified technique

OBJECTIVES

To describe our experience of a modified technique for carrying out remote endarterectomy for superficial femoral artery occlusive disease.

METHODS

A 4-French arterial dilator is inserted using a Smart needle into the popliteal artery below the occlusion. A remote endarterectomy is carried out through an arteriotomy in the proximal superficial femoral artery. The atheroma is cut distal to the lower extent of disease using a Moll ring cutter. The lower flap of atheroma is secured with an intraluminal stent inserted from the arteriotomy in the superficial femoral artery. The arteriotomy is extended into the common femoral artery and closed with a vein patch.

RESULTS

The procedure was completed in 21 of 26 limbs. In 18 cases the superficial femoral artery remained patent at 30 days. Of the 21 cases all but four stayed in hospital for one night. A successful femoropopliteal bypass was carried out in the five patients in whom the procedure was not completed.

CONCLUSION

Insertion of the dilator into the popliteal artery distal to the occlusion before carrying out the remote endarterectomy has two advantages. Firstly, the stent insertion is carried out in the correct plane and prevents dissection of the distal cut atheroma when attempting to pass the guidewire from above. Secondly, the procedure can be carried out under simple image intensification without sophisticated radiological equipment. The early results are encouraging and further evaluation of the technique is justifiable.

Early experience with stenting for iliac occlusive disease

OBJECTIVES

To review our experience of iliac artery stenting for occlusive disease.

DESIGN

Prospective study of 50 consecutive patients with iliac occlusive disease, November 1993-November 1996. The indications for stenting were complete iliac occlusion (37) restenosis (four), donor site inflow for bypass grafting (four) and difficult stenoses (> 90% and/or > 5 cm) (five). The majority of patients (41) presented with intermittent claudication.

RESULTS

All 13 stenoses were successfully stented. One occluded but the rest remain patent. There were no other complications. By contrast, it was not possible to place a stent across 10 of the 37 complete iliac occlusions. In this group there were nine major complications, including five patients who required early embolectomy (four femoral, one brachial) and one patient who developed a false aneurysm at the site of the stent. The "intention to treat" primary cumulative patency for iliac occlusions was 65% at 2 years but after excluding technical failures was 88%.

CONCLUSIONS

There is a sharp learning curve and significant complication rate associated with stenting complete occlusions. However, following successful stenting patency rates are around 90% for both iliac stenoses and occlusions.