Noninvasive evaluation for congenital arteriovenous fistulas and malformations.

Although relatively rare, congenital arteriovenous fistulas and other vascular anomalies present a diagnostic challenge to the clinician. The same noninvasive tests that are used for diagnosing arterial occlusive disease in the extremities will also detect arteriovenous fistulas. These tests include segmental limb pressure measurements, segmental plethysmography, and arterial waveform analysis. Additionally, magnetic resonance imaging can be used to determine the extent of these vascular anomalies and the involvement of muscle skin and bone, all of which have a direct bearing on resectability. This article will examine these diagnostic modalities and explain how they can be used in this setting.

Open versus endovascular stent graft repair for abdominal aortic aneurysms: an historical view.

Development of endovascular abdominal aortic aneurysms repair (EVAR), now in its 4th decade, has involved at least 16 different devices, not counting major modifications of some, only 4 of which have emerged from clinical trials and gained US Food and Drug Administration approval. The main impetus behind EVAR has been its potential for significantly reducing procedural mortality and morbidity, but it was also expected to speed recovery and reduce costs through decreased use of hospital resources. At the outset, EVAR was touted as a better alternative to OPEN in high-risk patients with large abdominal aortic aneurysms, and to "watchful waiting" (periodic ultrasound surveillance) for those with small abdominal aortic aneurysms. This new technology has evoked a mixed response with enthusiasts and detractors debating its pros and cons. Bias and conflict of interest exist on both sides. This review will attempt to present a balanced review of the development and current status of this controversial competition between EVAR and OPEN, comparing them in terms of the following key considerations: mortality and morbidity, complications, failure modes and durability, and costs.

Management of the infected aortoiliac aneurysms.

PURPOSE: We have reviewed ruptured and nonruptured infected aortoiliac aneurysms to study the clinical presentation, management and eventual outcome of patients managed with in situ prostheses, axillofemoral prostheses grafts and endovascular reconstruction. DESIGN: A retrospective chart review of 16 cases treated at a single institution. METHODS: From January 2007 to March 2008, a total of 93 patients with aortoiliac aneurysms underwent surgical repair at our institution. Among these, 16 patients (17.2%) were shown to be infected aneurysms of the infrarenal (n = 6), juxtarenal (n = 2), and pararenal aorta (n = 1); the others were 5 common, 1 external, and 1 internal iliac arteries. Fourteen patients were male and 2 were female with the mean age of 66 years (range, 45-79). In all cases, the diagnosis was confirmed by abdominal computed tomography and empirical parenteral antibiotics were administered at least 1 week, unless in patients need emergency operations. At the time of an operation, all were saccular and were classified as primary infected aortoiliac aneurysms. Thirteen patients had surgical debridement with in situ graft interposition and omental wrapping, 2 underwent aneurysm exclusion and extra-anatomic (axillo-femoral) bypass, 1 underwent aneurysmectomy of left external iliac artery and polytetrafluoroethylene (PTFE) graft interposition, and 1 underwent endovascular exclusion. The parenteral antibiotics were continued in the postoperative period for 4-6 weeks. Chronic renal disease was present in 37.5% (6/16), with diabetes mellitus present in 31.25% (5/16). The most common pathogen was Salmonella sp. (n = 6) and E. coli (n = 5). Thirty-seven percent (6/16) of the patients presented late, with a 37.5% (6/16) incidence of ruptured (4 contained, 2 free ruptured) that needed emergency surgery. RESULTS: Disease-specific mortality was 31.25% (5/16). The 30-day mortality rate of ruptured cases is high 67% (4/6), because patients present late in the course of the disease. One patient who underwent aneurysm exclusion and extra-anatomic (axillo-femoral) bypass died 6 months later from burst aortic stump. Salmonella and E. coli are the most common pathogens. CONCLUSIONS: Early diagnosis followed by surgical intervention with proper antibiotic coverage provides the best results. Mortality rate was still high in patients with sepsis and rupture. An in situ graft interposition and omental wrapping is a safe option for revascularization of infected aneurysms of the iliac arteries and infrarenal aorta.

Influence and critique of the PIVOTAL and the EVAR 2 Trials.

Management of a condition that has potentially life-threatening consequences may not lend itself effectively to the scrutiny of a randomized clinical trial when an observation or no treatment option is offered as part of the trial. This type of trial often experiences a significant rate of crossover of subjects from no treatment to treatment, and when results are analyzed on an intent-to-treat basis, they may fail to resolve the issue under study. These trials are frequently used as Level 1 medical evidence and the potential impact on clinical decision-making and reimbursement can be quite significant and long-lasting. The authors observed this phenomenon during participation in the Positive Impact of Endovascular Options for Treating Aneurysms Early (PIVOTAL) trial and have observed it in an analysis of the Endovascular Aneurysm Repair 2 (EVAR 2) trial. Possible solutions to mitigate the high crossover effect are offered for consideration. Some clinical conditions dealing with potentially life-threatening problems probably do not lend themselves to be studied in randomized prospective clinical trials containing an observation or no treatment arm.

Revision of the venous clinical severity score: venous outcomes consensus statement: special communication of the American Venous Forum Ad Hoc Outcomes Working Group.

In response to the need for a disease severity measurement, the American Venous Forum committee on outcomes assessment developed the Venous Severity Scoring system in 2000. There are three components of this scoring system, the Venous Disability Score, the Venous Segmental Disease Score, and the Venous Clinical Severity Score (VCSS). The VCSS was developed from elements of the CEAP classification (clinical grade, etiology, anatomy, pathophysiology), which is the worldwide standard for describing the clinical features of chronic venous disease. However, as a descriptive instrument, the CEAP classification responds poorly to change. The VCSS was subsequently developed as an evaluative instrument that would be responsive to changes in disease severity over time and in response to treatment. Based on initial experiences with the VCSS, an international ad hoc working group of the American Venous Forum was charged with updating the instrument. This revision of the VCSS is focused on clarifying ambiguities, updating terminology, and simplifying application. The specific language of proven quality-of-life instruments was used to better address the issues of patients at the lower end of the venous disease spectrum. Periodic review and revision are necessary for generating more universal applicability and for comparing treatment outcomes in a meaningful way.

Inherent problems with randomized clinical trials with observational/no treatment arms.

Randomized clinical trials (RCTs) offering an observation/no treatment (OBS/NoRx) arm as control and which are focused on the management of a condition with potentially life-threatening consequences, however small the risk, often experience a significant rate of crossover to treatment by those randomized to the OBS/NoRx arm. Results of these trials when analyzed on intent-to-treat basis often fail to resolve the issue at which they were directed. The authors have observed this in trials of abdominal aortic aneurysms with this design and use these to exemplify the dilemmas RCTs of such design create, with crossovers ranging from 27% to over 60% (EVAR II, UKSAT, ADAM, PIVOTAL). Results of these trials are frequently used as level I medical evidence and their potential impact on clinical decision making and reimbursement can be quite significant and long-lasting. Recommendations regarding trial end points and suggestions to mitigate the high crossover effect are offered. It may be that some clinical conditions dealing with potentially life-threatening problems should not be studied in randomized prospective clinical trials containing an OBS/NoRx arm.

Mycotic abdominal aortic aneurysm due to Streptococcus suis: a case report.

BACKGROUND: Streptococcus suis is a common infection of pigs. Human infection is often related to accidental inoculation through skin injuries during occupational exposure to pigs and pork. The disease may present as meningitis, bacteremia, and less commonly endocarditis, arthritis, or bronchopneumonia. METHODS: Case report and review of the literature. RESULTS: We report a case of bacteremia and severe sepsis caused by S. suis serotype 2 complicated by septic arthritis in a 56-year-old male with history of a prior contact with unprocessed pork. The causative agent was isolated from blood cultures and aspirated synovial fluid. The patient's condition improved after treatment with penicillin, but he was found subsequently to have an abdominal aortic aneurysm, confirmed by computed tomography (CT) scan. The mycotic aneurysm was successfully repaired using an in situ graft reconstruction. Tissue samples analyzed using polymerase chain reaction identified S. suis serotype 2 as the causative organism. After completion of two weeks of parenteral antibiotics, an oral form of ciprofloxacin (0.25 g twice a day) was continued for one month. The patient was discharged from our institution after uncomplicated recovery. Clinical review, a CT scan, and inflammatory markers nine months after surgery revealed no evidence of infection. CONCLUSION: This is the first report of mycotic aneurysm caused by S. suis, which may be an etiologic agent of mycotic aneurysms, especially when complicated by bacteremia in adults with a recent history of contact with pigs or unprocessed pork.

Vascular pythiosis in a thalassemic patient.

Pythium insidiosum is a fungus that causes disease in both animals and humans. Human pythiosis is an emerging disease in the tropical, subtropical, and temperate regions of the world, occurring in localized and systemic or vascular forms. Most patients with arterial pythiosis have an underlying hemoglobinopathy, such as thalassemia. A case is presented of a thalassemic horse stable worker who developed an ulcerative cutaneous lesion on the lower left leg followed by progressive ascending involvement of the arteries of that extremity with a necrotizing arteritis with aneurysm formation. P. insidiosum was not isolated from the ulcer by culture or wet potassium hydroxide preparations but was diagnosed by histopathologic study of a biopsy. P. insidiosum infection was quickly confirmed by immunoblot method, aiding in preoperative decision making. Many systemic antibiotics or antimycotics have not been effective in the treatment of systemic pythiosis, and radical surgical removal of all infected tissue is the only method to ensure patient survival. An orally administered saturated solution of potassium iodide, amphotericin B-oral solution, and terbinafine has succeeded only in the cutaneous form but had no favorable effect on vascular pythiosis. It is likely that immunotherapy, successfully used in animal pythiosis, may be beneficial in the treatment of human vascular pythiosis.

Clinical staging of acute limb ischemia as the basis for choice of revascularization method: when and how to intervene.

In acute lower limb ischemia, there are basically three management options: (1) clot removal by catheter-directed thrombolysis with or without percutaneous mechanical thrombectomy, (2) surgical thromboembolectomy followed by correction of underlying arterial lesions, and (3) anticoagulation with continued observation. Arterial embolic occlusion presents more abruptly and with more severe ischemia than arterial thrombosis, which occurs in narrowed arterial segments that have generally developed some degree of collateral circulation. The appropriate choice of treatment for acute limb ischemia depends to a great extent on the severity of the ischemia. Level of ischemia is readily determined by examining for sensory loss or motor deficit and interrogating the distal arteries and veins for audible flow signals with a handheld Doppler velocity detector. After clot removal, appropriate management of the responsible underlying lesion depends on its characteristics, best determined by vascular imaging. Staging the severity of ischemia according to clinical classification levels in the current reporting standards for lower extremity ischemia continues to serve as the basis for logical management decisions. This approach is outlined in algorithmic form and alternative pathways are discussed in this article.

Updated terminology of chronic venous disorders: the VEIN-TERM transatlantic interdisciplinary consensus document.

Non-uniform terminology in the world's venous literature has continued to pose a significant hindrance to the dissemination of knowledge regarding the management of chronic venous disorders. This VEIN-TERM consensus document was developed by a transatlantic interdisciplinary faculty of experts under the auspices of the American Venous Forum (AVF), the European Venous Forum (EVF), the International Union of Phlebology (IUP), the American College of Phlebology (ACP), and the International Union of Angiology (IUA). It provides recommendations for fundamental venous terminology, focusing on terms that were identified as creating interpretive problems, with the intent of promoting the use of a common scientific language in the investigation and management of chronic venous disorders. The VEIN-TERM consensus document is intended to augment previous transatlantic/international interdisciplinary efforts in standardizing venous nomenclature which are referenced in this article.

Management of abdominal aortic aneurysms: which risk factors play a role in decision-making?

There are three choices for management of abdominal aortic aneurysms (AAA), ie, endovascular repair (EVAR), open repair (OR), and continuing surveillance (OBS). The treating physician must weigh the risk of no intervention, in terms of ultimate death from rupture, against the more immediate risk associated with either form of repair, considering in the process those risk factors that directly or indirectly relate to outcome. These risk factors include AAA size and the patient's comorbidities, age, gender, and AAA anatomy, as well as the skills and experience of the treating physicians and the health care environment in which the patient is treated. While individualization is clearly required, a generalizable platform for decision-making derived from past trials and other pertinent observational studies is also useful. This article attempts to present pertinent background information and develop it into generally applicable guidelines.

The impact of recent European trials on abdominal aortic aneurysm repair: is a paradigm shift warranted?

Recent reports, following upon the reported outcomes of European randomized prospective trials of endovascular abdominal aortic aneurysm repair (EVAR), have brought into question the appropriateness of some of the trials' main conclusions, particularly in patients deemed at high-risk for surgical intervention. Based on the data of these trials, specifically EVAR 2, it has been suggested that EVAR should not be performed in high-risk individuals due to the likelihood of poor outcomes and the lack of improved survival, both associated with higher costs. In addition, certain aspects of the trials involving those deemed fit for open repair (the EVAR 1 and Dutch Randomized Endovascular Aneurysm Management trials) deserve qualified reservations. Although prospective, randomized United States trial data on such patients are not currently available, some large retrospective studies and registry reviews provide a basis for comparison of these trials with US EVAR experiences. In this review, the European EVAR trials are analyzed along with these other US studies and the rationale for modifying some of the conclusions drawn from the trials is presented and general guidelines for the selective management of abdominal aortic aneurysm patients presenting with potential indications for intervention are proposed.

Chronic subcritical limb ischemia: a poorly recognized stage of critical limb ischemia.

It is well-known that critical limb ischemia is associated with high mortality and amputation risk. Chronic subcritical limb ischemia, however, represents a subgroup of patients with critical limb ischemia in whom severely reduced circulation to the foot does not manifest as rest pain, ischemic ulceration, or ischemic gangrene. Admittedly, there is a paucity of data describing the fate of this patient subset, and little evidence to support appropriate treatment. To better understand the distinctive characteristics and clinical outcomes of this population, a cohort of 20 patients was examined. During the mean follow-up of 1.9 years, there were no deaths or major amputations, and only one patient progressed to surgical intervention. This review describes the characteristics and outcomes of this patient cohort and discusses the clinical implications. These findings suggest that attentive medical care and risk-reduction strategies may reduce mortality and alter progression of limb ischemia to amputation in patients with chronic subcritical limb ischemia.

The hemodynamics and diagnosis of venous disease.

The venous system is, in many respects, more complex than the arterial system and a thorough understanding of venous anatomy, pathophysiology, and available diagnostic tests is required in the management of acute and chronic venous disorders. The venous system develops through several stages, which may be associated with a number of development anomalies. A thorough knowledge of lower extremity venous anatomy, anatomic variants, and the recently updated nomenclature is required of all venous practitioners. Effective venous return from the lower extremities requires the interaction of the heart, a pressure gradient, the peripheral muscle pumps of the leg, and competent venous valves. In the absence of pathology, this system functions to reduce venous pressure from approximately 100 mm Hg to a mean of 22 mm Hg within a few steps. The severe manifestations of chronic venous insufficiency result from ambulatory venous hypertension, or a failure to reduce venous pressure with exercise. Although the precise mechanism remains unclear, venous hypertension is thought to induce the associated skin changes through a number of inflammatory mechanisms. Several diagnostic tests are available for the evaluation of acute and chronic venous disease. Although venous duplex ultrasonography has become the standard for detection of acute deep venous thrombosis, adjuvant modalities such as contrast, computed tomographic, and magnetic resonance venography have an increasing role. Duplex ultrasonography is also the most useful test for detecting and localizing chronic venous obstruction and valvular incompetence. However, it provides relatively little quantitative hemodynamic information and is often combined with measurements of hemodynamic severity determined by a number of plethysmographic methods. Finally, critical assessment of venous treatment modalities requires an understanding of the objective clinical outcome and quality of life instruments available.

Randomized EVAR trials and advent of level i evidence: a paradigm shift in management of large abdominal aortic aneurysms?

The recent endovascular aneurysm repair (EVAR) 1 and 2 and Dutch Randomized Endovascular Aneurysm Management (DREAM) trials addressed management of abdominal aortic aneurysms (AAAs) larger than 5.5 cm in diameter. The DREAM and EVAR 1 trials randomized patients appropriate for open repair between endovascular repair (EVAR) and open repair (OR), and the EVAR 2 trial randomized patients unfit for OR between EVAR and conservative nonoperative management (No Rx). The EVAR 1 trial showed a 3% lower initial mortality for EVAR, with a persistent reduction in aneurysm-related death at 4 years. Improvement in overall late survival was not demonstrated. Similarly, the DREAM trial observed an initial mortality advantage for EVAR, but overall 1-year survival was equivalent in both groups. Both trials found significantly higher complication and intervention rates and higher hospital costs with EVAR, and by 1 year a quality of life (QOL) benefit was not evident. The EVAR 2 trial did not demonstrate a survival advantage of EVAR with respect to nonoperative management, while noting that EVAR was associated with greater likelihood of treatment complications, subsequent interventions, and threefold higher costs. Both EVAR trials were limited by long delays between randomization and treatment. Moreover, 27% of patients in EVAR 2 crossed over from nonoperative to endovascular repair, and these patients had a lower procedure mortality from EVAR than those originally assigned to it (2% v 9%). These 47 cases, and the exclusion of 14 patients dying while waiting for EVAR, appears to confer a survival advantage to those receiving EVAR over those receiving no treatment in a post-hoc analysis, but per-protocol analysis of the EVAR 2 trial data performed by the EVAR investigators did not show a significant difference in either all-cause or aneurysm-related mortality. Thus, outcomes of the EVAR 2 trial have not settled the choice between EVAR and no treatment in this scenario to everyone's satisfaction. In patients with large AAAs who are fit for OR, EVAR offers an initial mortality advantage over OR, with a persistent reduction in AAA-related death at 4 years. However, EVAR offers no overall survival benefit, is more costly, and requires more interventions and indefinite surveillance with only a brief QOL benefit. It may or may not offer a mortality benefit over nonoperative management in patients with large AAAs who are unfit for open repair, but the statistical significance of this comparison is inconclusive.