Richard F. Neville

Spinal Cord Protection During Surgical Procedures on the Descending Thoracic and Thoracoabdominal Aorta: A Critical Overview

During the past three decades, significant advances have been made in the surgical treatment of the diseases affecting the aorta. Despite these important advances, paraplegia remains a devastating complication of the surgical procedures on the thoracic and thoracoabdominal aorta. Paraparesis and paraplegia occur as a direct result of the interruption of blood flow to the spinal cord during the surgical procedures. A number of techniques have been advocated for the prevention of spinal cord ischemic injury. This article critically reviews our current understanding of the extent of this problem, the mechanism of injury, and the methods that have been devised to reduce the frequency of paraplegia following surgical procedures on the descending aorta.

Endovascular Management of Takayasu Arteritis: Is It a Durable Option?:

Interim outcome of endovascular management of Takayasu arteritis (TA) was determined retrospectively to assess the efficacy of angioplasty and/or stenting in 24 patients with 35 lesions in the chronic inactive stage. The renal (n = 16), subclavian/innominate (n = 11), and carotid (n = 5) arteries and abdominal aorta (n = 3) were treated. Twenty-six lesions achieved excellent to good target lesion revascularization with no residual or only minimal residual stenosis, whereas five had a moderate result. Thirty lesions achieved satisfactory hemodynamic correction. Restenosis was observed in 8 lesions treated with angioplasty alone (n = 18) and in 3 lesions treated with angioplasty and stenting (n = 17). All recurrent stenoses underwent successful reintervention without significant complication. Treatment of inactive stage TA lesions with angioplasty alone or with angioplasty and stenting results in excellent to good clinical improvement in the majority of patients (follow-up at 46.8 months). Endovascular therapy is a durable treatment option in patients with chronic inactive stage TA.

Of Mice and Men: Neuropeptide Y and Its Receptors Are Associated with Atherosclerotic Lesion Burden and Vulnerability

Neuropeptide Y (NPY), a sympathetic and platelet-derived vascular mitogen and angiogenic factor, has been implicated in atherosclerosis in animal and human genetic studies. Here we evaluate its association with human and murine atherosclerosis, and assess the role of platelet-derived NPY in lesion vulnerability. NPY immunoreactivity (NPY-ir) was measured in the platelet-poor and platelet-rich (PRP) plasmas, and NPY receptors (mitogenic Y1R and angiogenic Y2 and Y5Rs), CD26/DPPIV (a protease forming Y2/Y5-selective agonist), CD31-positive vascularity, and lesion morphology assessed by histo- and immunocyto-chemistry—in patients with peripheral artery disease (PAD) and healthy volunteers, and in lard-fed ApoE−/− mice. NPY and NPY-R immunostaining was greater in lesions from PAD patients compared to normal vessels of healthy volunteers (pu2009<u20090.001), and localized to smooth muscle cells, macrophages, and adventitial/neovascular endothelial cells. CD26/DPPIV staining co-localized with CD31-positive endothelial cells only in atherosclerotic lesions. NPY-ir in PRP (but not plasma) and vascular immunostaining was higher (pu2009<u20090.05 and 0.001, respectively) in men (not women) with PAD compared to healthy subjects. A similar gender specificity was observed in mice. PRP NPY-ir levels correlated with lesion area (pu2009=u20090.03), necrotic core area, and the necrotic core-to-lesion area ratio (pu2009<u20090.01) in male, but not female, mice. Also males with neovascularized lesions had higher PRP NPY-ir levels than those lacking lesion microvessels (pu2009<u20090.05). NPY and its Rs are up-regulated in human and murine atherosclerotic lesions suggesting pathogenic role. DPPIV expression by microvascular endothelium in atherosclerotic tissue may shift NPY’s affinity toward angiogenic Y2/Y5Rs, and thus enhance angiogenesis and lesion vulnerability. Remarkably, plaque neovascularization was associated with increased NPY-ir in PRP in males but not females, suggesting that platelet NPY may be a novel mediator/marker of lesion vulnerability particularly in males, for reasons that remain to be determined. Both animal and human data suggest that NPY is an important contributor to, and platelet NPY-ir a marker of, atherosclerotic lesion burden and vulnerability but only in males, perhaps due to androgen-dependent up-regulation of NPY, previously shown in rats.

Primary Lymphedema and Klippel-Trénaunay Syndrome

The majority of primary lymphedemas1,2 are due to a congenital, independent lesion of the lymphatic system resulting in dysfunction. Primary lymphedema due to a truncular lymphatic malformation (LM) has been thoroughly reviewed in Chap. 51.

Primary Lymphedema as a Truncular Lymphatic Malformation

Primary lymphedema has been treated successfully for many decades and is one of the two main types of chronic lymphedema; the other is secondary lymphedema.1,2 Primary and secondary lymphedema are two different diseases with different etiologies, clinical behavior, response to treatment, and prognosis. Throughout the last decade, substantial progress has been made in the understanding of the true nature of primary lymphedema as a type of congenital vascular malformation (CVM)3,4 affecting the lymphatic system.

Contemporary Indications and Controversies

Chronic lymphedema was once considered to be a relatively benign condition of limb swelling associated with minimal morbidity. However, this old concept has been proven to be totally erroneous; the condition is steadily progressive and affects not only the lymphatic system itself, but also the entire surrounding soft xadtissue, resulting in a unique condition of clinically significant dermato xadlipofibrosclerosis.1,2

Vascular reconstructive options in the ischemic foot

Aggressive evaluation and treatment of the patient suffering from lower-extremity ischemia is critical. Vascular reconstruction can be performed to enhance healing and to decrease the incidence of major limb amputation and therefore return these patients to active and productive life.

Current Dilemmas and Controversy

The ideal treatment for the lymphedematous limb should restore both function and a normal cosmetic appearance regardless of its etiology. Unfortunately, it is impossible to achieve these goals with the currently available treatment modalities.1

The clinical impact of risk factor analysis and prophylaxis on pulmonary embolism.

Pulmonary emboli cause 50,000 deaths annually despite, recognized risk factors and methods of prophylaxis. To determine the impact of risk factor analysis and the use of prophylaxis, a retrospective chart review of patients suffering pulmonary embolism (PE) at Georgetown University Hospital was performed. During a fifty-month period, 25,000 surgical and 36,000 nonsurgical admissions included 171 cases of PE. The incidence of PE among surgical patients was 0.24% (n=61) and was 0.30% (n=110) among nonsurgical patients as confirmed in 82% by pulmonary angiography or high-probability ventilation/perfusion scans. PE prophylaxis included pneumatic stockings, low-dose heparin, combination low-dose heparin/stockings, and coumarin. However, prophylactic measures were absent in 23% of the surgical and in all the nonsurgical patients suffering PE. On the basis of established criteria (SVS/ISCVS), 57% of surgical patients suffering PE were considered at high risk as compared with 13% of nonsurgical patients. Conversely, 54% of nonsurgical patients suffering a PE were considered to be at low risk. Standard treatment modalities were instituted after nonfatal PE: anticoagulation (61%), inferior vena cava filter (14%), and anticoagulation/filter (6%) While risk factor analysis identifies high-risk surgical patients, it may be less effective in identifying nonsurgical patients at increased risk for PE.