Michael Appleberg

Ruptured abdominal aortic aneurysms: Who should be offered surgery?

PURPOSE Operation for ruptured abdominal aortic aneurysm is generally still associated with a high mortality rate. A review of our experience over a 9-year period was undertaken to identify factors present on admission associated with 30-day operative mortality. METHODS A retrospective analysis of 154 patients with ruptured abdominal aortic aneurysm submitted for operation in a university teaching hospital between January 1985 and December 1993 was undertaken. RESULTS The hospital mortality rate was 39%. Logistic regression identified a set of five independent preoperative factors associated with mortality: age (> 76 years), creatinine level (> 0.19 mmol/L), loss of consciousness after arrival, Hb (< 9 g%), and electrocardiographic ischemia. In the 52 patients with a single risk factor present, the mortality rate was 37%, with two factors (32 patients) it was 72%, with three or more factors (8 patients), it was 100%, and no patient had all five risk factors. A 16% mortality rate was found in the 62 patients with no risk factors. CONCLUSION These risk factors can be easily determined on admission and may be used to help improve patient selection for surgical intervention. The current operative mortality rate for ruptured abdominal aortic aneurysm remains high, and in some cases health care resources are used in a nonproductive fashion. Restricted patient selection and allocation of scarce resources will bring advantages to both the patient and the community.

Increased synthesis of matrix metalloproteinases by aortic smooth muscle cells is implicated in the etiopathogenesis of abdominal aortic aneurysms.

PURPOSE The objective of this study was to identify the metalloproteinases elaborated by medial smooth muscle cells (SMCs) isolated from abdominal aortic aneurysm (AAA) and control arterial tissues and to ascertain if the levels produced by AAA SMCs were elevated. METHODS SMC monolayers cultured from the outgrowth cells of tunica media explants were established, and their identity was determined by fluorescent microscopy by using a fluorescein isothiocyanate conjugated anti-SMC alpha-actin antibody. Matrix metalloproteinases (MMPs) produced by SMC monolayers in serum-free culture were examined by gelatin zymography and Western blotting with monoclonal antibodies to MMP-2, 3, and 9. RESULTS Serum-free media from AAA SMCs contained metal-dependent elastolytic activity that cleaved the synthetic substrate succinyl trialanyl 4-nitroanilide (pH optima 7.2) and also 14C-insoluble elastin. The level of proteolytic activity found in these cultures was significantly greater than from control SMC media. Zymography established that AAA SMC media samples contained metal-dependent gelatinases of 50 to 64 and 92 kDa, which were identified respectively as MMP-2 and 9 by Western blotting by using monoclonal antibodies to these proteases. CONCLUSION Medial SMCs isolated from AAA tissue produce significantly higher levels of MMP-9 and 2 than SMCs from control arterial tissues. These proteinases have the capacity to degrade elastin and a range of extracellular matrix proteins. From these data, we suggest SMCs may be involved in the abnormal degradation of the aortic wall in AAA through the excessive metalloproteinase activity produced by SMCs.

Carotid intraplaque hemorrhage: The significance of neovascularity

Renewed interest in the neovascularity of atherosclerotic plaques has followed the work of Imparato et al., which confirmed the importance of carotid intraplaque hemorrhage in the production of symptomatic extracranial vascular disease. We have studied the detailed histology of 91 carotid atheromatous plaques with particular regard to hemorrhage and neovascularity and have confirmed the findings of earlier investigators while observing degenerative changes (not previously reported) in these new vessels. The possible role of systemic hypertension in intraplaque hemorrhage and the acceleration of the atherosclerotic process is discussed.

Papillary carcinoma of the thyroid arising in struma ovarii – report of a case and review of management guidelines

Struma ovarii, a cystic teratoma of the ovary predominantly composed of thyroid tissue, is an infrequently encountered clinical entity. Malignant transformation of these tumors is even more uncommon. We report a case of malignant struma ovarii containing foci of papillary carcinoma of the thyroid, which was incidentally found at laparotomy undertaken for repair of an infrarenal abdominal aortic aneurysm.

Quantitative common carotid artery blood flow: Prediction of internal carotid artery stenosis *

Common carotid artery (CCA) blood flow was measured noninvasively with a pulsed Doppler duplex scanner modeled after the Octoson (Ultrasonics, Inc., No. Yonkers, N.Y.). The aim of the study was to determine normal values and to assess the accuracy of CCA flow as a predictor of internal carotid artery (ICA) stenosis. One hundred one people who did not have disease were studied; the overall mean flow rate was 395 +/- 79 ml/min (mean +/- S.D.). There was no significant correlation with age, height, or body surface area but there was with body weight (p less than 0.05). A statistically significant difference was evident between men (424 +/- 88 ml/min) and women (371 +/- 62 ml/min) (p less than 0.001). The intrasessional variation (S.D./mean) was 13% and the intersessional variation, 16%. No significant difference was seen between the sides. Ninety-two patients who had carotid angiography were studied and the flow rates compared with the degree of ICA stenosis on each side. The flow rate for mild ICA stenosis (1% to 39%) was 404 +/- 109 ml/min, for moderate stenoses (40% to 69%), 390 +/- 91 ml/min, and for severe stenoses (70% to 99%), 351 +/- 109 ml/min. There was a significant difference in flows only between mild and severe grades of stenosis of the ICA (p less than 0.01). With unilateral stenosis, comparison of flow values in the normal and affected sides showed the greatest discriminatory power when the absolute difference of flow values was taken (p less than 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)

Overcoming aspirin resistance: Increased platelet inhibition with combination aspirin and clopidogrel and high dose aspirin therapy in aspirin resistant patients with peripheral vascular disease

Overcoming aspirin resistance: Increased platelet inhibition with combination aspirin and clopidogrel and high dose aspirin therapy in aspirin resistant patients with peripheral vascular disease -

Aortic Reconstructive Surgery for Limb Ischaemia: Immediate and Long-Term Follow-Up to Provide a Standard for Endovascular Procedures

PURPOSE Aortobifemoral and aortobiliac bypass has been a preferred treatment of severe aortoiliac occlusive disease. Recently, endovascular procedures and unilateral bypass grafting have been introduced. We report the results of aortic reconstructive surgery over a 19-year period (1975-1994). METHODS A total of 285 patients underwent surgery. Follow-up data from clinical notes, general practitioner questionnaire or phone interview was available in 93.3% (266/285). RESULTS Of the total 68% were male (180/226) and the median age was 63 years (range 22-85 years). Indications for surgery were tissue loss/gangrene (n = 32), rest pain (n = 84), severe claudication (n = 40), moderate claudication (n = 110). Total of 177 bifurcated grafts, 51 iliofemoral, eight left/right aortofemoral, and 30 other procedures were performed. The median duration of follow-up was 49.8 months. Cumulative secondary graft patency for 2, 5 and 10 years was 97.7%, 95.9%, and 94.4%. The amputation rate was 4.5% (12/266). Early mortality occurred in eight of 266 patients (3%) and late mortality in 60 patients. The most common cause of late death was ischaemic heart disease (24/60 followed by cancer (14/60). Data was further analysed by type of graft, risk factors, complications and previous and subsequent surgery. In our experience, aortic reconstructive surgery is a successful option for the management of severe aortoiliac occlusive disease. The outcome of other methods of maintaining arterial patency should be measured against this standard.

Carotid redo surgery: both safe and durable.

Aim:  To examine the outcomes and complications of surgery for recurrent carotid stenosis.

Fibromuscular hyperplasia in an aberrant subclavian artery and neurogenic thoracic outlet syndrome: an unusual combination.

An aberrant right subclavian artery arising distal to the origin of the left subclavian artery is the most common anomaly of the aortic arch. Degenerative diseases of aberrant subclavian arteries including aneurysms and occlusive disease have been reported previously. We believe that this case is the first reported case of fibromuscular hyperplasia affecting an aberrant subclavian artery. A 25-year-old woman admitted with a history consistent with neurogenic thoracic outlet syndrome was found to have a reduced pulse and blood pressure on the ipsilateral side caused by fibromuscular hyperplasia of an aberrant subclavian artery. A carotid-subclavian bypass via a supraclavicular incision was performed at the same time as thoracic outlet decompression. Histologic examination confirmed the presence of fibromuscular hyperplasia in the aberrant subclavian artery. This case is discussed with reference to the available literature.

POINT OF CARE TESTING OF ASPIRIN RESISTANCE IN PATIENTS WITH VASCULAR DISEASE

Introduction:  The reported range in rates of aspirin resistance (5.5–60%) may reflect difficulties in studying platelet function and the variety of tests used. This study used a platelet function analyzer (PFA‐100) to prospectively document aspirin resistance in a cohort of patients with arterial disease.