Resurrection of Chronically Occluded Prosthetic Bypass Grafts in a Single Stage with Suction Thrombectomy and Intervention.

BACKGROUND: Peripheral arterial occlusive disease (PAOD) continues to be a vexing problem despite the advent of endovascular techniques augmenting traditional open repair. At our institution, we have found there is a growing number of patients with PAOD who are vein-challenged and have undergone prosthetic bypass previously for infrainguinal arterial reconstruction. When occluded, these grafts have been abandoned for a new bypass strategy or amputation. We present a novel technique of reestablishing flow through chronically occluded prosthetic bypass grafts. METHODS: A retrospective review of a prospectively maintained database compiled at 2 institutions between 2016 and 2019 was performed. Six patients had previous prosthetic bypass grafts with 4 patients having femoral to popliteal grafts, 1 patient with a femoral to femoral graft, and 1 with a femoral to posterior tibial bypass graft. All patients had an attempted single-stage intervention to clear chronically occluded grafts. RESULTS: A total of 6 patients were included in the study. Indications for intervention were chronic, critical limb ischemia with tissue loss (3), severe claudication (2), and acute on chronic limb ischemia (1). Average time from bypass to suction thrombectomy was 29 months (6-60 months). Mean patency duration is 13 months (1-28 months). Adjunctive procedures include overnight lysis to improve outflow in 1 patient (16.6%), drug-coated balloon angioplasty (83.3%), or stents (83.3%). There were no embolic complications during these procedures. All (2) wounds healed and all are maintained on full-dose anticoagulation and/or antiplatelet therapy. CONCLUSIONS: Often, the timing of bypass graft occlusion is unknown, and the risk of embolism with lysis for chronically occluded bypass grafts is concerning with traditional peripheral intervention techniques. We report a new and unique minimally invasive approach to resurrect chronically occluded prosthetic bypass grafts often successful in just one stage. This tool offers an alternative technique for limb salvage in complex patients and as use increases, requires further interrogation.

Follow-up after carotid endarterectomy and stenting: What to look for and why.

Duplex ultrasound testing after open or endovascular extracranial carotid artery interventions is a clinical practice guideline with a strong recommendation from the Society for Vascular Surgery. Neurologic outcomes are improved by the recognition of repair site stenosis or atherosclerotic disease progression in the unoperated carotid artery. The benefit of surveillance outweighs its risk because duplex testing is free of complications and accurate in the detection of internal carotid artery (ICA) stenosis or occlusion. Surveillance for >70% ICA stenosis is recommended within 30 days of the procedure, then every 6 months for 2 years, and annually thereafter. Repair site and contralateral ICA stenosis classification should be based on angle-corrected pulsed Doppler measurements of peak systolic velocity (PSV), end-diastolic velocity (EDV), and the ratio of PSV at the stenosis to a proximal, nondiseased common carotid artery (CCA) segment (ICA/CCA ratio). Interpretation criteria of PSV >300 cm/s, EDV >125 cm/s, and ICA/CCA ratio >4 predicts >70% repair site stenosis. Endovascular intervention is recommended for a carotid repair site stenosis based on the occurrence of an ipsilateral neurologic event and appropriate anatomy for angioplasty. For asymptomatic restenosis, intervention is based on stenosis progression to elevated PSV and EDV >70% stenosis threshold values and the patient is deemed high risk for stroke due to contralateral ICA occlusion or incomplete functional patency of the circle of Willis.

Aortic aneurysm screening using duplex ultrasound: Choosing wisely who to examine.

The noninvasive vascular laboratory plays a critical role in screening patients at risk for development of abdominal aortic aneurysm (AAA). One-time duplex ultrasound screening reduces aneurysm-related mortality due to rupture and is cost-effective. Population screening based on AAA risk factors is recommended, as it allows for proactive, elective repair of aneurysms at risk for rupture, and surveillance of smaller aneurysms for enlargement. Utilization of societal screening guidelines, such as those published by the Society for Vascular Surgery, can be employed by vascular laboratories to justify individual patient screening, aid primary care physicians to refer patients for testing, and encourage integrated medical health care systems to build prompts in patient electronic health records to ensure compliance with a AAA screening program. Risk factors for developing AAA, that is, age older than 65 years, male sex, family history, and a smoking history of >100 cigarettes, should be used to recommend patient screening, including for women and other elderly (older than 75 years) patients who fall outside of professional societal guidelines.

Vascular surgery resident education and hands-on training in vascular laboratory testing.

Diagnostic testing performed in the noninvasive vascular laboratory is a cornerstone of care for patients with suspected or known vascular disease. The Society for Vascular Surgery has mandated that vascular surgery resident training include mentored experience in performing vascular laboratory testing and interpreting its results. The trainee should be experienced with vascular laboratory instrumentation and testing protocols, be knowledgeable in ultrasound imaging of vascular anatomy, and be competent to classify disease severity relevant to the study indication. The scope of test interpretation should include peripheral arterial, peripheral venous, cerebrovascular, and visceral abdominal testing using duplex ultrasound supplemented by indirect physiologic testing for peripheral arterial and venous disease. The emergence of endovascular therapy has expanded duplex ultrasound applications in the areas of screening, procedural imaging, and surveillance following intervention. Pre-procedure testing to assess disease location and severity, and vein mapping for dialysis access or extremity bypass grafting provide important patient-specific information that can reduce the need for more invasive vascular imaging. It is recommended that trainees acquire the hand-on skills to perform duplex testing in vascular clinic and inpatient sites, such as the emergency department and operating room. Training programs should have a structured vascular laboratory curriculum that documents annual educational milestones that encompass both test interpretation aptitude and hands-on duplex scanning skills. Before completion of training, the resident should acquire documented experience in test interpretation sufficient to take the Physician Vascular Interpretation examination, which is required for American Board of Surgery certification as a vascular surgeon.

The diabetic foot: Pathophysiology, evaluation, and treatment.

The pathophysiology of the diabetic foot ulcer and soft-tissue infection is due to neuropathy, trauma, and, in many patients, concomitant peripheral artery occlusive disease. Diabetic neuropathy results in foot deformity, leading to increased skin pressure with walking. Once a foot ulcer develops, the limb is at high risk for invasive infection and, when combined with peripheral artery occlusive disease, the patient should be considered to have critical limb ischemia. A multidisciplinary approach to care for the diabetic foot is recommended, which includes annual (3-month intervals in high-risk patients) assessments by a primary care physician and referral to a podiatrist and vascular surgeon for diabetics with a foot ulcer for evaluation of foot arterial perfusion and off-loading therapy to reduce plantar skin pressure with walking. When invasive foot infection develops and tissue beneath the fascia is involved, inpatient care is recommended for systemic antibiotic therapy, vascular laboratory testing of artery limb perfusion, and surgical debridement of infected tissue. The goals of treatment are to achieve a healed foot and keep the patient ambulatory.

Intervention after endovascular aneurysm repair: Endosalvage techniques including perigraft arterial sac embolization and endograft relining.

Endovascular aneurysm repair (EVAR) has revolutionized the treatment of abdominal aortic aneurysm (AAA). However, persistent AAA sac endoleak following EVAR can result in sac diameter increase requiring re-intervention in up to one-third of cases and even result in aneurysm rupture. In this case review, we summarize and detail endovascular re-interventions for each type of endoleak. We also detail specific options including stent-graft relining for indeterminate, Type III, and Type IV endoleaks and perigraft arterial sac embolization to induce thrombosis and resolve acute Type I, II, or III endoleaks. Endograft relining involves placement of a new stent-graft-elevating the bifurcation and extending the repair from renal artery to hypogastric arteries; perigraft arterial sac embolization involves placement of a catheter into the excluded sac from common femoral artery access, characterization of the inflow and outflow of the endoleak, and inducing cessation of the blood flow into the sac by the administration of thrombogenic material. Endoleaks range from low-pressure endoleaks, which can be safely monitored in a surveillance program to high-pressure endoleaks, which mandate intervention when associated with AAA sac diameter increase to protect from rupture. The evaluation of new devices and techniques to treat endoleak after EVAR remains an important issue in patient care after EVAR.

ACR Appropriateness Criteria Imaging in the Diagnosis of Thoracic Outlet Syndrome.

Thoracic outlet syndrome is a clinical entity characterized by compression of the neurovascular bundle, and may be associated with additional findings such as venous thrombosis, arterial stenosis, or neurologic symptoms. The goal of imaging is to localize the site of compression, the compressing structure, and the compressed organ or vessel, while excluding common mimics. A literature review is provided of current indications for diagnostic imaging, with discussion of potential limitations and benefits of the respective modalities. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every 3 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment. In this document, we provided guidelines for use of various imaging modalities for assessment of thoracic outlet syndrome.

Estimation of brachial artery volume flow by duplex ultrasound imaging predicts dialysis access maturation.

OBJECTIVE: This study validated duplex ultrasound measurement of brachial artery volume flow (VF) as predictor of dialysis access flow maturation and successful hemodialysis. METHODS: Duplex ultrasound was used to image upper extremity dialysis access anatomy and estimate access VF within 1 to 2 weeks of the procedure. Correlation of brachial artery VF with dialysis access conduit VF was performed using a standardized duplex testing protocol in 75 patients. The hemodynamic data were used to develop brachial artery flow velocity criteria (peak systolic velocity and end-diastolic velocity) predictive of three VF categories: low (<600 mL/min), acceptable (600-800 mL/min), or high (>800 mL/min). Brachial artery VF was then measured in 148 patients after a primary (n = 86) or revised (n = 62) upper extremity dialysis access procedure, and the VF category correlated with access maturation or need for revision before hemodialysis usage. Access maturation was conferred when brachial artery VF was >600 mL/min and conduit imaging indicated successful cannulation based on anatomic criteria of conduit diameter >5 mm and skin depth <6 mm. RESULTS: Measurements of VF from the brachial artery and access conduit demonstrated a high degree of correlation (R(2) = 0.805) for autogenous vein (n = 45; R(2) = 0.87) and bridge graft (n = 30; R(2) = 0.78) dialysis accesses. Access VF of >800 mL/min was predicted when the brachial artery lumen diameter was >4.5 mm, peak systolic velocity was >150 cm/s, and the diastolic-to-systolic velocity ratio was >0.4. Brachial artery velocity spectra indicating VF <800 mL/min was associated (P < .0001) with failure of access maturation. Revision was required in 15 of 21 (71%) accesses with a VF of <600 mL/min, 4 of 40 accesses (10%) with aVF of 600 to 800 mL/min, and 2 of 87 accesses (2.3%) with an initial VF of >800 mL/min. Duplex testing to estimate brachial artery VF and assess the conduit for ease of cannulation can be performed in 5 minutes during the initial postoperative vascular clinic evaluation. CONCLUSIONS: Estimation of brachial artery VF using the duplex ultrasound, termed the "Fast, 5-min Dialysis Duplex Scan," facilitates patient evaluation after new or revised upper extremity dialysis access procedures. Brachial artery VF correlates with access VF measurements and has the advantage of being easier to perform and applicable for forearm and also arm dialysis access. When brachial artery velocity spectra criteria confirm a VF >800 mL/min, flow maturation and successful hemodialysis are predicted if anatomic criteria for conduit cannulation are also present.

Vascular surgical site infection: risk factors and preventive measures.

Surgical site infection (SSI) after arterial intervention is a common nosocomial vascular complication and an important cause of postoperative morbidity. Its prevention requires the vascular surgeon and the health care team to be cognizant of its epidemiology and patient-specific risk factors to apply effective measures to reduce the incidence. The majority of vascular SSIs are caused by Gram-positive bacteria with methicillin-resistant Staphylococcus aureus (MRSA) now a prevalent pathogen that is involved in more than one-third of cases. Nasal carriage of methicillin-sensitive S. aureus or MRSA strains, recent hospitalization, a failed arterial reconstruction, and the presence of a groin incision are major risk factors for developing a vascular SSI. Overall, the SSI rate after arterial intervention is higher than predicted by the Centers for Disease Control and Prevention's National Nosocomial Infections Surveillance Risk Category System, and ranges from 1% to 2% after open or endovascular aortic interventions, to as high as 10% to 20% after lower-limb bypass grafting procedures. Application of perioperative measures to reduce S. aureus nasal and skin colonization in conjunction with appropriate, bactericidal antibiotic prophylaxis, meticulous wound closure, and postoperative care to optimize patient host defense regulation mechanisms (eg, temperature, oxygenation, and blood sugar) can minimize SSI occurrence.

Staged Hybrid Endovascular Repair of a Ruptured Abdominal Aortic Aneurysm with Aortocaval Fistula.

There is a growing body of literature expanding the indication of endovascular aneurysm repair, from prophylactic treatment of aneurysms to other indications such as ruptured and complicated ruptured abdominal aneurysms. Concomitant aortocaval fistula is rare, and reports of open and endovascular repair exist. We report a unique hybrid approach to a case of a ruptured abdominal aortic aneurysm with aortocaval fistula, repaired primarily via endovascular approach in a hybrid, two-staged fashion. Representative images are presented in addition to a short review of this pathology.

ACR Appropriateness Criteria® nontraumatic aortic disease.

The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every 3 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment. In this document we provided guidelines for use of various imaging modalities for assessment of nontraumatic aortic diseases.

Therapeutic angiogenesis for critical limb ischemia.

The application of gene- and cell-based therapies to promote angiogenesis is a novel concept to treat lower-limb critical limb ischemia (CLI) and may provide an unmet need for patients with no options for revascularization. Proof of concept was demonstrated in animal models resulting in clinical trials that have confirmed the feasibility and short-term efficacy of intramuscular injection of angiogenetic tissue growth factors or bone marrow stem cells. The safety of these biologic therapies has been demonstrated in randomized clinical trials with no "off-target" angiogenesis, growth of occult tumors, or progression of diabetic retinopathy. Current phase III randomized clinical trials using a DNA plasmid with the hepatocyte growth factor gene or bone marrow aspirate concentrate of mesenchymal cells are designed to address several crucial issues, including proper patient selection criteria, relevant clinical endpoints, and long-term efficacy. Because effectiveness of these novel therapies remains to be established, ongoing and future randomized clinical trials should be placebo-controlled, investigator-blinded, and have amputation-free survival as the primary endpoint. Further development of efficient gene transfer techniques and keeping transplanted stem cells healthy have the potential to make biologic therapies more robust in promoting angiogenesis, tissue regeneration, and resolution of CLI symptoms. If sustained efficacy can be demonstrated, new therapeutic strategies for patients with CLI will be available for clinicians, ie, limb revascularization using angiogenic gene or stem cell therapy alone, or in conjunction with endovascular intervention.

Surveillance and follow-up after revascularization for critical limb ischemia.

The purpose of a structured and cost-effective surveillance program after surgical or endovascular intervention for critical limb ischemia is to optimize limb salvage and preserve arterial repair function. Surveillance programs should include clinical, vascular laboratory, and radiographic follow-up, and, when a high-grade progressive stenosis is identified, appropriately timed intervention should be performed. Because many patients with critical limb ischemia are older and many are frail with limited mobility, optimizing the durability of arterial intervention and keeping these patients ambulatory is an important factor in retaining an independent lifestyle and quality of life. Despite the importance of surveillance after arterial intervention, there is a lack of consensus in the literature regarding the efficacy of surveillance, how it should be performed, and well-defined evidence-based guidelines. This review provides an up-to-date scrutiny on this topic and provides recommendations for optimal testing methods, limitations of surveillance testing, and when and how to intervene. These recommendations should be considered in the care of the patient with critical limb ischemia, but with the understanding that patients vary widely and care should be individualized.

The comparative effectiveness of surgeons over interventionalists in endovascular repairs of abdominal aortic aneurysm.

OBJECTIVE: Comparative effectiveness research has mostly been focused on comparison of treatment techniques. The goal of the present study was to extend the research to physician specialty. BACKGROUND: Both surgeons and interventionalists (cardiologists and radiologists) are involved in endovascular repairs (EVAR) of aortic aneurysms, with different residency education, operative experience, preoperative assessment and patient selection, and postoperative continuity of care. METHODS: Retrospective analysis was performed using the Nationwide Inpatient Sample from 1998 to 2009. Patients undergoing EVAR for abdominal aortic aneurysm were identified with International Classification of Diseases, Ninth Revision, procedure code 39.71. Using physician identifiers available in the database, surgeons were identified by case experience in the same calendar year with elective open AAA repairs, arteriovenous fistula repairs, or carotid endarderectomy. Multivariate analysis adjusted for physician volume, AAA ruptured status, patient demographic and comorbidities, and hospital characteristics. RESULTS: A total of 28,094 EVARs were analyzed. Unadjusted mortality rates, length of stay, and total hospital charges were significantly higher for patients treated by interventionalists than those by surgeons (all Ps < 0.001). This difference persisted on multivariate analysis, where interventionalists were associated with increased likelihood of mortality (odds ratio = 1.39; 95% confidence interval, 1.04-1.89), longer length of stay (1.32 days; 95% confidence interval, 1.03-1.62), and higher total hospital charges ($19,312; 95% confidence interval, 16,471-22,153). CONCLUSIONS: Physician specialty is associated with patient outcomes. Surgeons are associated with improved outcomes, with lower mortality, shorter length of stay, and lower charges for EVAR cases, when compared with interventionalists. This finding has significant implications for future comparative effectiveness research and potential policy changes in patient referrals or physician admitting privileges.