Long-term outcome of infrainguinal bypass grafting in patients with serologically proven hypercoagulability

Aortic endarterectomy in patients with severe multivessel paravisceral and aortoiliac occlusive disease

OBJECTIVE

Aortic endarterectomy (AE), once a treatment of choice for aortoiliac occlusive disease, is now rarely performed in favor of endovascular procedures or open aortobifemoral bypass. However, in select patients with paravisceral or aortoiliac occlusive disease, AE remains a viable alternative for revascularization, either as a primary procedure or after prior interventions have failed. Here, we evaluated outcomes for an extended series of patients undergoing paravisceral or aortoiliac endarterectomy, demonstrating that these procedures can be an excellent alternative with acceptable morbidity and mortality in properly selected patients.

METHODS

A single institution retrospective review of 20 patients who underwent AE from 2017 to 2023 was performed.

RESULTS

Five patients (25%) underwent paravisceral endarterectomy and 15 (75%) underwent aortoiliac endarterectomy. There were no perioperative mortalities. One paravisceral patient died 3 months postoperatively from complications of pneumonia. Three patients in the paravisceral group required reinterventions; one acutely due to thrombosis of the superior mesenteric artery (SMA) requiring extension of the endarterectomy and patch angioplasty on postoperative day 0, one due to stenosis at the distal edge of the endarterectomy 1 month postoperatively, successfully treated with SMA stenting, and one at 10-month follow-up due to SMA stenosis at the distal aspect of the endarterectomy, also successfully treated with SMA stenting. With these reinterventions, the 1-year primary patency in the paravisceral group was 40%, primary-assisted patency was 80%, and secondary patency was 100%. In the aortoiliac group, 1-year primary, primary-assisted, and secondary patency were 91%, 91%, and 100%, respectively. One patient developed iliac thrombosis 10 days postoperatively owing to an intimal flap distal to the endarterectomy site. She and one other patient, a young man with an undefined hypercoagulable disorder, ultimately required neoaortoiliac reconstructions at 18 and 32 months postoperatively, respectively (the latter in the setting of stopping anticoagulation). The remaining 13 patients experienced no complications. All patients had rapid resolution of clinical symptoms, and median postoperative ankle-brachial indexes of 1.06 on the right and 1.00 on the left, representing a median improvement from preoperative ankle-brachial indexes of +0.59 on the right and +0.56 on the left (P < .01 and P < .01).

CONCLUSIONS

In this series of 20 patients undergoing paravisceral and infrarenal aortoiliac endarterectomy, AE was associated with no perioperative mortality, relatively low and manageable morbidity, and excellent clinical outcomes in patients with both paravisceral and aortoiliac occlusive disease. SMA-related early reintervention was not uncommon in the paravisceral group, and attention should be given particularly to the distal endarterectomy site. AE remains a viable treatment for severe multivessel paravisceral or aortoiliac occlusive disease isolated to the aorta and common iliac arteries in select patients.

Predictors of amputation-free survival after endovascular intervention for chronic limb-threatening ischemia in the modern era

OBJECTIVE

Chronic limb-threatening (CLTI) is associated with 25% limb loss and 25% mortality at 1-year. Its lethality increases to 45% in patients subjected to a major amputation. Percutaneous peripheral intervention (PPI) constitutes an attractive and less morbid treatment option for patients with CLTI. The purpose of this study was to assess amputation-free survival in a contemporary cohort treated with endovascular recanalization and assess its predictors.

METHODS

Patients with CLTI undergoing endovascular revascularization at a single regional hospital between 2015-2019 were reviewed. Baseline demographic characteristics, Wound, Ischemia, and foot Infection (WIfI) stage, technical details, and clinical outcomes were tabulated. The primary endpoint was amputation-free survival; a p-value < 0.05 was used for univariate screening and inclusion in a multivariable model.

RESULTS

137 limbs in 111 patients were studied. Comorbidities were prevalent and included diabetes (65%), congestive heart failure (21%), and dialysis dependence (18%). The majority of revascularized limbs presented with advanced wounds (66% WIfI stages 3-4; 47% Rutherford category 6). Presenting WIfI stages were similar across races (p=0.26). Peripheral interventions most commonly targeted femoropopliteal disease (69%) although 26% were multilevel. Percutaneous atherectomy, stenting and paclitaxel-coated or eluting devices were utilized in 68%, 28%, and 15% of cases, respectively. After a median follow-up of 16 months (IQR=4-29 months), significant independent predictors of reduced AFS included non-white race (HR=2.96 [1.42-6.17]; p=0.004) and WIfI stage 4 wounds (HR=2.23 [1.10-4.52]; p=0.026). At one year following successful revascularization, only 59%±1% of patients were alive with their limb intact.

CONCLUSIONS

Despite considerable and consistent advances in urban health care delivery and the techniques of PPI, CLTI remains a morbid and deadly disease. Even in the endovascular era, nearly half of all patients presenting with CLTI will lose their limb and/or life within the first year. Unfortunately, late-stage presentation continues to be commonplace. Although endovascular intervention can reliably restore patency to affected arteries, this appears insufficient to restore most patients to health.

Challenging endovascular treatment for the patient with chronic limb threatening ischemia due to antiphospholipid syndrome

Vascular surgery for chronic limb threatening ischemia (CLTI) in patients with antiphospholipid syndrome (APS) has a poor outcome with a high rate of postoperative thrombotic complications. However, there is little data regarding outcomes of endovascular treatment (EVT). This manuscript reports an interesting case of APS with CLTI in which timely EVT and continuous anticoagulant therapy not only prevented amputation but also thrombotic events over a long period of time. A 41-year-old man with CLTI in the left lower limb was seen and examined. Contrast-enhanced computed tomography revealed thrombotic occlusion in both iliac arteries and the left popliteal artery. Activated partial thromboplastin time was prolonged, and anti-β2 glycoprotein I antibodies and lupus anticoagulants were present. After starting antithrombotic therapy with warfarin, EVT was performed using self-expandable stents in both iliac arterial lesions, and a marked reduction in limb ischemia was observed. Furthermore, the patient was free from thrombotic events for six years until a change in the anticoagulant led to stent thrombosis. This case suggests that EVT using stents along with continuous antithrombotic therapy with warfarin in patients with APS and CLTI could be very effective for immediate relief of ischemia and long-term reduction in thrombotic events. <Learning objective: APS is a rare but important cause of CLTI, and outcomes in patients with APS who receive vascular surgery for CLTI are poor because of a high rate of postoperative thrombotic complications. EVT using a stent can be a useful option if it is coupled with sustained antithrombotic therapy using a vitamin K antagonist, namely warfarin. In addition, administering direct oral anticoagulants as anticoagulant therapy following EVT in APS patients should be very carefully considered.>.

The SELUTION SLR™ drug-eluting balloon system for the treatment of symptomatic femoropopliteal lesions

Endovascular treatment has become first line therapy for the treatment of femoropopliteal disease. Drug-coated devices play a key role in maintaining vessel patency. In the past antiproliferative coating of drug-coated balloons (DCBs) exclusively consisted of paclitaxel. Use of limus drugs was limited by a short residency time in the vessel wall. Besides the drug, the SELUTION SLR™ drug-eluting balloon system consists of a coating formulation of four excipients. The first excipient is a biodegradable polymer (poly(lactic-co-glycolic acid)) that is intermixed with the sirolimus to form micro-reservoirs and regulates drug release via matrix degradation. This review summarizes the existing pre-clinical and clinical literature on treatment of femoropopliteal artery lesions with the SELUTION SLR DCB.

Ischemic Stroke with Protein S Deficiency Treated by Apixaban

A 57-year-old man with atherosclerosis obliterans was admitted with sudden-onset sensory aphasia and right hemiparesis. Brain MRI revealed acute cerebral infarctions in the left temporal lobe and magnetic resonance angiography showed occlusion of the posterior branch of the left middle cerebral artery. Transesophageal echocardiography and ultrasonography respectively confirmed a patent foramen ovale and deep vein thrombosis in the bilateral femoral veins. Blood findings showed low protein S antigen, low protein S activity, and a missense mutation of the PROS 1 gene. The administration of apixaban 10 mg BID prevented ischemic stroke recurrence and decreased the deep vein thrombosis. These outcomes indicated that apixaban may be alternative to warfarin for the secondary prevention of ischemic stroke in a patient with a protein S deficiency.

Hypercoagulability predicts worse outcomes in young patients undergoing lower extremity revascularization

OBJECTIVE

Although we know that young patients with peripheral artery disease (PAD) have worse outcomes than older patients, there is a scarcity of information about the incidence of hypercoagulability in this population. Our aim was to analyze outcomes of young patients diagnosed with a hypercoagulable state (unusual tendency toward thrombosis) after lower extremity revascularization compared with similar patients without hypercoagulability.

METHODS

All patients 50 years of age or younger undergoing an initial procedure for lower extremity PAD from 2000 to 2015 at the Cleveland Clinic were retrospectively analyzed. Patients with a hypercoagulability panel were included and classified into groups as hypercoagulable positive (HP) or hypercoagulable negative (HN). Demographics, preoperative risk factors, form of presentation, level of disease, and type of intervention were analyzed in addition to perioperative complications, early failure, and length of stay. Primary outcomes were limb loss and primary, primary assisted, and secondary patencies. Outcomes were analyzed and Kaplan-Meier curves generated.

RESULTS

Ninety-one patients were included for a total of 118 limbs. Mean follow-up was 32 months; 55% of patients had a hypercoagulable disorder, with 59% having lupus anticoagulant and 32% hyperhomocysteinemia. In the HP group, 71% were men; 49% were men in the HN group. Patients overall had a high prevalence of smoking (86%), hypertension (36%), and hyperlipidemia (33%). Acute limb ischemia was the most common form of presentation for both groups (50% HP, 38% HN). The aortoiliac segment was the most commonly affected (38% HP, 50% HN). The most frequent operation in the HN group was endarterectomy or bypass (32%); in the HP group, it was an endovascular intervention (29%). Perioperative occlusion or failure was 18% in the HN group vs 30% in the HP group (P > .05). Primary patency, primary assisted patency, and secondary patency at 36 months were all better for the HN group (no statistical significance) in all treatment groups. Major amputation at 36 months was significantly worse for the HP group (40% vs 10% in the HN group; P < .005). There was no difference in perioperative complications or length of stay.

CONCLUSIONS

Young patients undergoing lower extremity revascularization for PAD have worse outcomes when associated with hypercoagulability. There are trends to decreased patency of revascularization in these patients, with significantly more major amputations. No clear differences between modalities of treatment were demonstrated.

Use of Femoral and Sciatic Nerve Block Combination in Severe Emphysematous Lung Disease for Femoral Popliteal Arterial Bypass Surgery

Regional anesthesia is a widely used anesthesia technique for high-risk patients with severe vascular or pulmonary diseases in which general anesthesia is considered harmful and should be avoided. In this case, we present the use of femoral-sciatic nerve block combination for a 65-year-old, ASA IV, male patient who had severe emphysematous lung disease and was planned for a right femoral-popliteal arterial bypass surgery. He had severe pulmonary disease, hypertension, peripheral vascular disease, and was on clopidogrel treatment. Due to his existing comorbidities, regional anesthesia was considered the right method. The combination of femoral and sciatic nerve block was successfully used for the operation, which lasted for one hour and fifty minutes under sedation, and was continuously supplied with a propofol infusion. The patient was safely discharged to the surgical ward with no pain. The femoral block and sciatic block combination is described as one of the most useful, and at the same time, the most ignored anesthetic method. This technique is considered a standard technique and is often taught early in training; however, its use seems to be underestimated as there are only a few cases documented in Turkey. The aim of this case is to serve as a reminder of its significant value in patients who are not appropriate for general anesthesia and neuraxial blocks.

Vascular graft thrombosis secondary to activated protein C resistance: a case report and literature review

Hypercoagulability is a well-documented and prominent risk factor for venous thromboembolism. The role of thrombophilia in arterial thrombotic events is less well defined. A 52-year-old male patient with multiple atherogenic risk factors was admitted for non-healing pedal ulcer and absent distal pulses. Based on the clinical presentation, Doppler ultrasound and angiography findings, the patient underwent elective in situ bypass arterial reconstruction. The saphenous vein graft was of satisfactory quality and the procedure went routinely. Acute graft thrombosis on postoperative day 0 was recognized immediately and prompted an emergent surgical revision. No technical errors or anatomical/mechanical causes for failed reconstruction were found and the graft was successfully thrombectomized using a Fogarty balloon-catheter. Graft rethrombosis, however, ensued after several hours. Considering the absence of threatening limb ischemia and the idiopathic recurrent thrombosis, raising suspicion of prothrombotic state, conservative treatment was pursued. Postoperative thrombophilia testing proved positive for activated protein C resistance, mandating introduction of chronic oral anticoagulation. Six months later, the operated extremity is viable. Inexplicable vascular graft thrombosis, particularly if early and recurrent, should raise suspicion of underlying thrombophilia. If confirmed by laboratory testing, long-term secondary antithrombotic prophylaxis may be required.

Risk factors for lower-extremity vein graft failure

Lower-extremity vein graft failure causes significant morbidity, increases health care costs, and negatively impacts patient quality of life. Identification of risk factors is essential for patient selection, risk factor modification, and identifying individuals who would benefit from more stringent surveillance protocols. Risk factors can be considered as either patient-related or technical. Here we discuss the patient-related risk factors for vein graft failure. Nontechnical factors related to the indication for operation include operation after a previously failed graft, or redo bypass, critical limb ischemia, and infection. Risk factors for vein graft failure are distinct from the risk factors for cardiovascular events. Young age and African American and Hispanic race are risk factors for lower-extremity vein graft failure. Hypercoaguable and inflammatory states also increase risk for vein graft failure. Therapy with statins is indicated in patients with peripheral atherosclerosis and may have beneficial effects on vein graft function, although further studies are needed in this area.

Medical and endovascular management of critical limb ischemia

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

[Thrombophilias and peripheral arterial occlusive disease]

Peripheral arterial occlusive disease is a frequent disease due to the classical vascular risk factors such as smoking, diabetes mellitus, dyslipidemia, and hypertension. Despite these risk factors, many thrombophilias (physiological inhibitors defects, Factor V Leiden and 20210A prothrombin gene variant, antiphospholipid antibodies, mild hyperhomocysteinemia 15-30micromol/l) can be evoked in some clinical forms of peripheral arterial occlusive disease. This paper provides a synthesis of the published data about this topic. Screening for these thrombophilias is justified in patients with venous thromboembolic disease, or signs of antiphospholipid syndrome and possibly in different situations such as premature atheroma of lower limbs, chronic ischaemia, evolutive disease despite adapted treatment and revascularisation failures without evident technical explanation. Except for the antiphospholipid syndrome, there is currently no consensus for systematic screening of thrombophilia and treatment in patients with peripheral arterial occlusive disease.

PEG-hirudin/iloprost Coating of Small Diameter ePTFE Grafts Effectively Prevents Pseudointima and Intimal Hyperplasia Development

OBJECTIVES

Small diameter PTFE grafts are prone to thrombosis and intimal hyperplasia development. Heparin graft coating has beneficial effects but also potential drawbacks. The purpose of this study was to evaluate the experimental efficacy of PEG-hirudin/iloprost coated small caliber PTFE grafts.

METHODS

Thirty-six femoro-popliteal ePTFE grafts (expanded polytetrafluoroethylene, diameter 4 mm) were inserted into 18 pigs. Grafts were randomised individually for each leg and grouped for 3 groups. Group I consisted of native ePTFE grafts, group II were grafts coated with a polylactide polymer (PLA) without drugs and group III grafts were coated with PLA containing a polyethylene glycol (PEG)-hirudin/iloprost combination. The follow-up period was 6 weeks. Patency rates were calculated and development of pseudointima inside the grafts was noted. Thickness of intimal hyperplasia at the distal anastomoses was measured using light microscopy.

RESULTS

Patency rates for group I were 6/9 (67%), for group II 9/10 (90%) and 12/12 (100%) for group III. In groups I and II there was a significant reduction of blood flow proximal to the graft at graft harvest, to 29+/-12 and 28+/-20 ml/min respectively (both p<0.01 versus preoperative value), whilst in group III blood flow, 99+/-21 ml/min, remained at the preoperative level. Subtotal stenosis due to development of pseudointima was noted in each of the native and PLA coated grafts but not in group III grafts. Intimal hyperplasia at the distal anastomosis was lowest in group III.

CONCLUSIONS

The PEG-hirudin/iloprost coating of ePTFE prostheses effectively reduced pseudointima and intimal hyperplasia development and led to superior graft patency.

The prevalence of thrombophilia in patients with symptomatic peripheral vascular disease

Background

The aim of this prospective study was to establish the prevalence of thrombophilia and hyperhomocysteinaemia using a comprehensive screen in patients with peripheral vascular disease.

Methods

A total of 150 patients with peripheral vascular disease (with an ankle brachial pressure index of less than 0·8) underwent thrombophilia screening (protein C and protein S, antithrombin, lupus anticoagulant, activated protein C resistance and factor V Leiden and prothrombin mutations). Fasting homocysteine assays were also performed.

Results

A thrombophilia defect was found in 41 patients (27·3 per cent). The commonest was protein S deficiency, found in 17 patients (11·3 per cent). Others included factor V Leiden mutation, found in 10 (6·7 per cent) and protein C deficiency, found in six (4·0 per cent). Lupus anticoagulant and prothrombin mutation were both found in six (4·0 per cent). One patient had an antithrombin deficiency. Only the presence of critical ischaemia was associated with a positive thrombophilia screen on single variable analysis (P = 0·03). Hyperhomocysteinaemia was present in over a third of the study group (37·3 per cent): 45 defined as moderate and 11 as intermediate.

Conclusion

A quarter of patients with peripheral vascular disease had evidence of thrombophilia, and a third had hyperhomocysteinaemia.

Protein C and/or S deficiency presenting as peripheral arterial insufficiency

Although protein C and/or S deficiency has frequently been associated with venous thromboembolic events, instances of arterial thromboses have been reported. However, the exact incidence of protein C and/or S deficiency in patients with peripheral arterial insufficiency has not been established. Furthermore, given the lack of adequate studies to define the natural history and angiographic findings of these patients, the treatment has not been well delineated. Therefore, we conducted a prospective study to investigate the prevalence, characteristic angiographic findings and optimal treatments in patients with peripheral arterial insufficiency associated with protein C and/or S deficiency. Between September 2000 and August 2004, 133 patients who presented with peripheral arterial insufficiency underwent hypercoagulability tests before the initiation of any treatments. Of these, 11 patients (8.3%) with protein C and/or S deficiency were included in this study. There were nine males and two females. The ages ranged from 38 years to 72 years (mean 57 years). All patients showed characteristic angiographic findings: long segment thrombotic occlusion of a main peripheral artery without evidence of atherosclerosis or with mild atherosclerotic changes in the aorta and other major arterial trees. Surgical or endovascular procedures were performed in nine patients: bypass graft in four, thrombectomy in four and catheter-directed thrombolysis in one. Conservative treatment with full anticoagulation was performed in two patients. All patients received pre- and post-operative anticoagulation. Except for one amputated case, clinical and vascular laboratory improvements were achieved in 10 patients. Mean follow-up period was 21 months (range 4-45 months). However, one patient, in whom re-vascularization surgery was performed successfully, discontinued warfarin therapy himself at 10 months after surgery, graft occlusion and limb loss occurred at 30 months after surgery. This initial experience suggests that protein C and/or S deficiency may be an independent risk factor for peripheral arterial insufficiency. Patients who present with peripheral arterial insufficiency and protein C and/or S deficiency demonstrate characteristic angiographic findings. Once the diagnosis of protein C and/or S deficiency is made, patients should be treated with life-long anticoagulation.

Prevalence and Risk of Thrombophilia Defects in Vascular Patients

This paper reviews the available data on the prevalence of thrombophilia defects in patients with peripheral vascular disease (PVD) and attempts to delineate the risk of failure of vascular intervention in these patients. The prevalence of thrombophilia in stable claudicants is 25% and increases to 40% in those requiring revascularisation, compared to only 11% in the control group. The overall prevalence of thrombophilia defects in patients with premature atherosclerosis appears to be between 15 and 30%. The prevalence in the typical cohort of patients with PVD appears to be similar. All these studies have recruited patients with symptoms significant enough to warrant intervention. The overall prevalence of thrombophilia calculated from these trials, therefore, may not be truly indicative of the general vascular population who may not even present primary or secondary healthcare. The risk of thrombotic occlusion following arterial revascularisation in patients with an identified thrombophilia defect appears to be almost three times that of patients with no evidence of a thrombophilia defect. The best management of these patients has not been determined and needs to be evaluated by prospective randomized trials.

Watering down the clots, or are we?

Fluid resuscitation is an essential part of managing patients with major trauma, as well as in the perioperative setting. Common misconceptions exist regarding the role of fluid therapy in maintaining, enhancing or inhibiting normal coagulation and haemostasis. This review provides an overview of the basic coagulation processes, as well as the influence of intravenous crystalloid and colloid preparations on haemostasis and coagulation. The use of point-of-care devices is encouraged as a feasible way of monitoring these effects in the acute setting.