A review of biological factors implicated in abdominal aortic aneurysm rupture.

Abdominal aortic aneurysm (AAA) rupture is the 13th commonest cause of death in the Western World. Although considerable research has been applied to the aetiology and mechanism of aneurysm expansion, little is known about the mechanism of rupture. Aneurysm rupture was historically considered to be a simple physical process that occurred when the aortic wall could no longer contain the haemodynamic stress of the circulation.

The Surgical Acute Care Unit (SACU): effects on surgical workload and mortality.

Background: A surgical acute care unit (SACU) is designed to provide level 1 care for surgical patients. The aim of the present study was to audit the effects of the introduction of a SACU in a teaching hospital surgical department.

Methods: A retrospective case-note audit of all admissions to the newly established SACU over the first 6 months was performed.

Plasma MMP-9 and MMP-2 following acute myocardial infarction in man: correlation with echocardiographic and neurohumoral parameters of left ventricular dysfunction.

Background: Left ventricular dilatation and elevated plasma natriuretic peptide levels predict adverse prognosis and the development of congestive heart failure after myocardial infarction. Altered matrix metalloproteinase (MMP) activity has been implicated in the structural changes associated with development of heart failure after myocardial injury. The aims of this study were to investigate plasma MMP-2, MMP-9, and tissue inhibitor of metalloproteinase (TIMP)-1 concentrations following acute myocardial infarction and their relationships with measures of left ventricular function.

Unstable carotid plaques exhibit raised matrix metalloproteinase-8 activity.

Background: The fibrous cap of atherosclerotic plaques is composed predominantly of type I and III collagen. Unstable carotid plaques are characterized by rupture of their cap, leading to thromboembolism and stroke. The proteolytic mechanisms causing plaque disruption are undefined, but the collagenolytic matrix metalloproteinase (MMP) -1, -8, and -13 may be implicated.

Comparison of levels of matrix metalloproteinases, tissue inhibitor of metalloproteinases, interleukins, and tissue necrosis factor in carotid endarterectomy specimens from patients on versus not on statins preoperatively.

We performed an observational study on 137 patients undergoing carotid endarterectomy (CEA). Patients on statins were less likely to have had symptoms in the 4 weeks before CEA (p = 0.0049) and were less likely to have spontaneous cerebral embolization detected by transcranial Doppler (p = 0.

Subintimal angioplasty in lower limb ischaemia.

Subintimal angioplasty has been suggested as a treatment option for occlusive disease and has become an established practice in some centres, reducing their operative workload considerably. Others have concerns about the safety and durability of the procedure. This review will focus on the evidence for the use of subintimal angioplasty in lower limb occlusive disease.

Elevation in plasma MMP-9 following carotid endarterectomy is associated with particulate cerebral embolisation.

Objectives: To study plasma MMP-9 levels before and after carotid endarterectomy (CEA).

Design: Observational study.

Methods: Pre-operative (morning of surgery) and post-operative (48 h) plasma samples were obtained from 75 consecutive patients undergoing CEA.

The physiological effects of elevated intra-abdominal pressure following aneurysm repair.

Objectives: Elevated intra-abdominal pressure (IAP) may cause widespread organ dysfunction (abdominal compartment syndrome) through effects on the respiratory, cardiac, renal and gastro-intestinal systems. The aim of this study was to document IAP following aneurysm surgery, and to determine the effect of IAH on outcome.

Design: Prospective observational study.

A systematic review of outcome following synchronous carotid endarterectomy and coronary artery bypass: influence of surgical and patient variables.

Objectives: Outcomes after synchronous carotid endarterectomy (CEA) plus coronary artery bypass (CABG) relative to surgical and patient based variables.

Design: Systematic review of 94 published series (7863 synchronous procedures).

Results: 11.

The abdominal compartment syndrome following aortic surgery.

Background: multi-organ failure is a leading cause of death following aneurysm surgery, especially in the emergency setting. Intra-abdominal hypertension is an important factor in the development of multi-organ failure. Prevention, early recognition and prompt treatment of abdominal hypertension and the abdominal compartment syndrome may reduce mortality following aneurysm surgery.

Prospective, randomized, double-blind trial investigating the effect of doxycycline on matrix metalloproteinase expression within atherosclerotic carotid plaques.

Background And Purpose: Elevated levels of matrix metalloproteinases (MMPs), particularly MMP-1 and MMP-9, have been implicated in plaque rupture. It has been suggested that inhibition of MMPs may stabilize vulnerable atherosclerotic plaques and improve clinical outcome. The aim of the study was to investigate the ability of doxycycline, a nonspecific MMP inhibitor, to reduce MMP concentration in carotid atheroma.

The role of matrix metalloproteinases in vascular disease.

There is growing interest in the role of matrix metalloproteinases in vascular diseases. These conditions are often characterized by excessive tissue remodelling, and increased matrix metalloproteinase activity has been demonstrated in aneurysms, intimal hyperplasia and atherosclerotic plaque disruption. These enzymes represent a potential target for therapeutic intervention to modify vascular pathology.

Matrix metalloproteinases and atherosclerotic plaque instability.

Background: There is growing interest in the role of matrix metalloproteinases in atherosclerosis. Excessive tissue remodelling and increased matrix metalloproteinase activity have been demonstrated during atherosclerotic plaque disruption, a frequent predeterminant of ischaemic cardiac events and stroke. These enzymes represent a potential target for therapeutic intervention to modify vascular pathology.

Amputations: no longer the end of the road.

Background: The aim of this prospective study was to assess the effect of an intensive in-patient rehabilitation programme upon the mobility of amputees.

Methods: All major lower limb amputations between 1997 and 1999 received a pre-operative mobility assessment and, where appropriate, were referred for a vigorous rehabilitation programme.

Results: 92 lower limb amputations were performed in 87 patients (57 below knee, 33 above knee, two hip disarticulations).

Plasma MMP-9 - a marker of carotid plaque instability.

Objectives: to investigate whether peripheral blood levels of matrix metalloproteinases (MMPs) or their inhibitors are altered in patients with particulate cerebral embolisation.

Design: a prospective study.

Materials And Methods: using sandwich enzyme immunoassay, plasma levels of MMPs-1, -2, -3 and -9, plus TIMPs-1 and -2 were quantified in 70 consecutive patients undergoing carotid endarterectomy.

A comparison of colour duplex ultrasonography, papaverine testing and common femoral Doppler waveform analysis for assessment of the aortoiliac arteries.

Objective: to study the "accuracy" of aortoiliac colour duplex ultrasonography.

Design: prospective study.

Setting: vascular laboratory, University Hospital.

Endovascular repair of an innominate artery false aneurysm following blunt trauma.

Purpose: To describe a case of endovascular graft exclusion of an innominate artery pseudoaneurysm arising from blunt trauma.

Methods And Results: A 21-year-old patient was admitted following a major road accident. Computed tomography (CT) and aortography on admission disclosed an isolated innominate artery pseudoaneurysm.

Marimastat inhibits neointimal thickening in a model of human arterial intimal hyperplasia.

Objective: matrix metalloproteases (MMPs) produced by vascular smooth-muscle cells (VSMCs) degrade extracellular matrix and facilitate the migration of these cells. This is a fundamental process in arterial intimal hyperplasia. This study investigated whether Marimastat (a selective but non-specific MMP inhibitor) can prevent intimal hyperplasia in cultured human internal mammary artery (IMA).

Increased matrix metalloproteinase-9 activity in unstable carotid plaques. A potential role in acute plaque disruption.

Background And Purpose: Acute disruption of atherosclerotic plaques precedes the onset of clinical syndromes, and studies have implicated a role for matrix metalloproteinases (MMPs) in this process. The aim of this study was to establish the character, level, and expression of MMPs in carotid plaques and to correlate this with clinical status, cerebral embolization, and histology.

Methods: Plaques were obtained from 75 consecutive patients undergoing carotid endarterectomy and divided into 4 groups according to symptomatology (group 1, asymptomatic; group 2, symptomatic >6 months before surgery; group 3, symptomatic within 1 to 6 months; group 4, symptomatic within 1 month).

Quality control during endovascular aneurysm repair: monitoring aneurysmal sac pressure and superficial femoral artery flow velocity.

Purpose: To use intraoperative aneurysmal sac pressure measurement and flow monitoring of the superficial femoral artery (SFA) to ensure complete exclusion of the aneurysm from the circulation.

Methods: A 5F catheter was positioned in the aneurysmal sac of 15 consecutive patients undergoing endovascular aortomonoiliac aneurysm repair between February and September 1997. The catheter was connected to an external pressure transducer allowing pressure monitoring throughout the operation and for 24 hours postprocedurally.

Marimastat inhibits elastin degradation and matrix metalloproteinase 2 activity in a model of aneurysm disease.

Background: Abdominal aortic aneurysms are characterized by degradation of the extracellular matrix, with a reduction in the elastin concentration of the arterial media. These changes have been linked to increased levels of endogenous metalloproteinases (MMPs) within the aorta, particularly MMP-2 and MMP-9. This provides a potential therapeutic target for pharmacological agents aimed at reducing the growth rate of small aneurysms.