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Biomedical subjects

M P Colgan

Publications and source records attributed to M P Colgan.

At least 37 records · Page 2Linked to original sources
PubMed1994

The comparison of type of incision for transperitoneal abdominal aortic surgery based on postoperative respiratory complications and morbidity.

Equal access to the abdominal aorta can be attained through midline and transverse abdominal incisions. The surgical literature suggests that transverse incisions cause less postoperative pain and morbidity. Fifty patients (10 females and 40 males, mean age 67 years) undergoing abdominal aortic surgery were randomised to a midline (n = 25) or transverse (n = 25) incision. All patients were evaluated preoperatively and postoperatively for seven days. Changes in pulmonary function (FVC and FEV1), time to open and close the incision, analgesia used (morphine mg/kg/h), clinical or X-ray evidence of chest infection, and the duration of ICU stay were recorded. In the transverse group there was a reduction in the incidence of chest complications (20% vs. 28%, p = ns) and these incisions took longer to open (13.9 +/- 4.6 vs. 9.9 +/- 5.1, p < 0.05), but overall there was no significant difference between any other parameter in the two groups. Our results show no statistically significant difference in morbidity or analgesia consumption following transverse or midline abdominal incisions and we conclude that the type of incision used can be left to the surgeon's preference.

Aged↗
PubMed1994

Improved limb salvage and mobility following peroneal artery bypass.

During the 10-year period August 1981 to 1991, 92 consecutive patients underwent revascularisation to the peroneal artery (40 to the upper third, 30 to the mid and 22 to the distal third). The male/female ratio was 1.6:1 and the mean age was 72 years. Thirteen patients had independent mobility preoperatively while 58 had limited mobility and the remaining 18 were bed/housebound. Following surgery the patients were prospectively evaluated and mean follow-up was 25 months. The 1 and 3 year patency rates were 67 and 59% respectively and cumulative limb salvage rates were 75 and 71%. Forty-four patients returned to independent mobility while 36 had limited mobility and 11 remained housebound. Reconstruction to the peroneal artery is a valuable adjuvant for limb salvage providing satisfactory cumulative patency and facilitating improved mobility.

Aged↗
PubMed1993

Contralateral stenosis and stump pressures: parameters to identify the high risk patient undergoing carotid endarterectomy under local anaesthesia.

Carotid endarterectomy (CEA) under local anaesthesia (LA) enables the assessment of the two parameters of stump pressure and contralateral stenosis as predictors of neurological complications both intra- and postoperatively. Over a 7 year period, 175 carotid endarterectomies were performed under LA and of these, stump pressure measurements and angiographic findings were recorded on 99 patients. There were no deaths, two patients (2.0%) suffered a perioperative stroke (CVA) and one (1.0%) a transient ischaemic attack (TIA). An additional eight patients "obtunded" while the internal carotid artery was clamped, with complete resolution upon revascularisation in all but one patient who recovered fully within 24 h. Patients with contralateral occlusion or > or = 80% stenosis were more likely to develop complications (6/25 vs. 5/74 p < 0.03) and stump pressures were significantly lower in patients suffering an event (34.36 +/- 23.15 vs. 55.57 +/- 27.58, p < 0.02). By combining contralateral stenosis (> or = 80%) and stump pressure (< or = 35 mmHg), a "high risk" group of 42 patients in whom eight of the 11 events occurred, were identified. Contralateral stenosis and low stump pressures can be used in combination to identify high risk patients likely to develop neurological complications during or following CEA.

Aged↗
PubMed1993

Observing the brachial artery through a pressure cuff.

A technique is described which enables ultrasonic imaging of the brachial artery whilst pressure is applied via a pressure cuff. This involves a new instrument--a sphygmomanometer, which uses water as opposed to air as the pressure medium, in order to permit ultrasonic imaging through the cuff. The technique was found to be acceptable in the clinical setting, and gave a measurement of the systolic blood pressure which correlated with the conventional cuff measurement in eleven elderly subjects (r = 0.89, p < 0.001). The technique should have an important role to play in studying the origin of differences which occur between direct and indirect blood pressure measurements.

Blood Pressure Determination↗
PubMed1993

Measurement of arterial closing pressure.

It has been suggested that certain artifacts in blood pressure measurement by auscultation stem from stiffness of the tissues underneath the pressure cuff, resulting in a component of cuff pressure being required to overcome resistance to brachial artery collapse. This paper describes a technique for measuring the pressure required to collapse a segment of the brachial artery which has been isolated from central arterial pressure. This measurement is termed the arterial closing pressure. In a study of eleven elderly subjects, the artery collapsed spontaneously (zero closing pressure) after being isolated from central pressure in seven subjects. The remaining four required external pressures ranging from 4.6 to 10.7 kPa (35 to 81 mmHg) in order to collapse the artery. Thus arterial closing pressure may frequently be a significant fraction of arterial blood pressure in the elderly population, and may contribute to error in the measurement of blood pressure by auscultation. Arterial closing pressure may be a useful tool for investigating the origin of differences between indirect and direct blood pressure measurements, and also in the investigation of spontaneous arterial closure.

Aged↗
PubMed1993

New approaches in the medical management of venous ulceration.

This literature survey of the medical treatment of venous ulcers of the lower extremities discusses five classes of agents: (1) fibrinolytics, (2) hydroxyrutosides, (3) prostaglandins, (4) methylxanthines, and (5) others. The authors conclude that all these agents require further research.

Alprostadil↗
PubMed1992

Asymptomatic carotid stenosis: a benign lesion?

Recent reports of the risk of asymptomatic carotid stenosis have been compromised by flawed patient selection or the performance of a large number of carotid endarterectomies during follow-up. We report the natural history of a randomly selected group of asymptomatic patients (n = 188; 114 males and 74 females) with documented carotid artery disease who were prospectively followed without intervention for up to 8 years. Risk factors included ischaemic heart disease in 17%, diabetes in 10%, hypertension in 46% and 88% were smokers. The degree of internal carotid stenosis was classified by duplex scanning and a total of 259 vessels had evidence of atherosclerosis. Study end-points included TIA, CVA and death. At mean follow-up of 4 years 3% of the 96 patients with internal carotid artery stenosis of less than 50% had died and 2% suffered a stroke. Six per cent of patients with a stenosis of 50-79% had died and 4% and 2% had suffered a CVA and TIA, respectively. In the 59 patients with greater than 80% stenosis 7% had suffered a TIA and an additional 7% a CVA, while 2% had died. None of the patients suffering a stroke had an antecedent TIA. Though the incidence of ischaemic events is significantly higher in patients with greater than 80% stenosis the incidence of unheralded stroke remains low. We therefore continue to recommend a conservative approach to the management of asymptomatic carotid stenosis.

Aged↗
PubMed1992

The profunda femoris: a durable outflow vessel in aortofemoral surgery.

Aorta-common femoral artery bypass is the standard operation for relief of aortoiliac occlusive disease. When extensive superficial femoral artery disease coexists, the profunda femoris, even in its distal portion, may be used as the outflow vessel. To test this assumption we compared cumulative patency, limb salvage, and the need for distal bypass of 134 aorta-profunda femoris and 151 aorta-common femoral artery bypasses performed consecutively for aortoiliac occlusive disease over a 12-year period. We also analyzed results of proximal (n = 103) and distal (n = 31) aortoprofunda bypasses. Angiographic and noninvasive studies showed greater disease in limbs undergoing aorta-profunda femoris bypass. However, no difference was observed in cumulative patency (91% +/- 6% vs 96% +/- 3%) or limb salvage (90% +/- 6% vs 94% +/- 3%) at 5 years. Seventeen distal bypasses in the group undergoing profunda femoris bypass and 20 distal bypasses in the group undergoing common femoral artery bypass were required to maintain limb salvage. Proximal and distal aorta-profunda femoris bypasses showed no difference in cumulative patency (91% +/- 9% vs 95% +/- 6%) or limb salvage (94% in each group) at 3 years. Standard aorta-common femoral artery and aorta-profunda femoris bypass provide cumulative patency and limb salvage exceeding 90% at 5 years; concomitant or subsequent distal bypass was required in 12% or limbs undergoing aorta-profunda femoris bypasses. Both proximal and distal profunda femoris arteries provide a durable outflow tract when aortoiliac and femoropopliteal occlusive disease are combined.

Aged↗
PubMed1991

Infrainguinal polytetrafluoroethylene grafts: saved limbs or wasted effort? A report on ten years' experience.

Two-hundred and twenty-four infrainguinal polytetrafluoroethylene reconstructions were performed for critical ischemia over a 10 year period: 48 to the above-knee popliteal artery, 113 to the below-knee popliteal artery, and 63 to the tibial vessels. The cumulative patency rates were 84 +/- 6% and 63 +/- 9% for above-knee popliteal, 53 +/- 5% and 35 +/- 7% for below-knee popliteal, 45 +/- 6% and 30 +/- 9% for tibial vessels at one and five years respectively. Limb salvage rates were 81 +/- 6% and 73 +/- 9% (above-knee popliteal), 69 +/- 5% and 57 +/- 9% (below-knee popliteal), 64 +/- 7% and 32 +/- 10% (tibial vessels) at one and five years respectively. Graft occlusion did not result in limb loss in 32 cases. Preoperatively, 54% of the patients had limited mobility while 43% were regarded as severely restricted. At follow-up, 57% of the patients were considered to be independent, 26% had limited mobility, and 17% were still severely restricted. Polytetrafluoroethylene provides good short-term limb salvage and improved mobility in patients with critical ischemia and poor life expectancy. Its use is well worth the effort.

Activities of Daily Living↗
PubMed1991

Upper limb embolus: a timely diagnosis.

In a ten year period, 36 patients were treated surgically for embolic occlusion of upper limb vessels. The sources of embolus were cardiac (58%), peripheral aneurysm (22%) and unknown (20%). Brachial embolectomy was performed in all cases. Six out of eight peripheral aneurysms were resected. A patency rate of 94% was achieved at five years. Hospital mortality and morbidity rates were 3% and 10%, respectively. One patient died of a myocardial infarct one week postoperatively. Three patients suffered ischemic contracture or amputation; all three presented after 36 hours. We conclude that upper limb emboli are usually easy to recognize and treat. Prompt surgery (less than 24 hours) produces the most satisfactory results. Late presentation or delay in treatment can result in limb loss.

Acute Disease↗
PubMed1991

Histologic characteristics of carotid artery plaque.

Carotid plaque characteristics associated with the production of symptoms were identified with quantification of carotid plaque constituents in high-grade stenotic asymptomatic (n = 8) and symptomatic (n = 44) plaques. Asymptomatic plaques contained significantly more fibrous/collagen material (88%) than symptomatic plaques (66%) (p less than 0.05). Hemorrhage constituted 2% and 1% of asymptomatic and symptomatic plaques, respectively. The predominant nonfibrous material was a pink amorphous material mixed with cholesterol, which composed 7% of asymptomatic and 27% of symptomatic plaques (p less than 0.05). No relationship was found between plaque composition and the number of ipsilateral ischemic neurologic events, nor was there evidence of a healing process. B-mode ultrasound scanning had a sensitivity of 94% in identifying plaque with greater than 80% fibrous content. We believe that plaque composition may be a useful discriminating factor in selecting asymptomatic patients for carotid endarterectomy.

Arteriosclerosis↗
PubMed1990

Oxpentifylline treatment of venous ulcers of the leg.

OBJECTIVE: To determine the effect of oxpentifylline on the healing of venous ulcers of the leg. DESIGN: Double blind, randomised, prospective, placebo controlled, parallel group study. SETTING: Four outpatient clinics treating leg ulcers in England and the Republic of Ireland. PATIENTS: 80 Consecutive patients with clinical evidence of venous ulceration of the leg in whom appreciable arterial disease was excluded by the ratio of ankle to brachial systolic pressure being greater than 0.8. INTERVENTIONS: All patients received either oxpentifylline 400 mg three times a day by mouth or a matching placebo for six months (or until their reference ulcer healed if this occurred sooner) in addition to a locally standardised method of compression bandaging. MAIN OUTCOME MEASURES: The primary end point was complete healing of the reference ulcer within six months. The secondary end point was the change in the area of the ulcer over the six month observation period. RESULTS: Complete healing of the reference ulcer occurred in 23 of the 38 patients treated with oxpentifylline and in 12 of the 42 patients treated with a placebo. Life table analysis showed that the proportion of ulcers healed at six months was 64% in the group treated with oxpentifylline compared with 34% in the group treated with a placebo (log rank test chi 2 = 4.78, p = 0.03), which was significant (odds ratio = 1.81, 95% confidence interval 1.20 to 2.71). CONCLUSION: Oxpentifylline used in conjunction with compression bandaging improves the healing of venous ulcers of the leg.

Double-Blind Method↗
PubMed1990

"Haemorrhagic" carotid plaque does not contain haemorrhage.

The presence of haemorrhage in carotid bifurcation atheromatous plaques is widely believed to be associated with the production of ischaemic neurological events. This study set out to characterise plaque composition in symptomatic (SYM) and asymptomatic (ASYM) patients and to identify, if possible, the origin of intra-plaque haemorrhage. Fifty-nine plaques (50 SYM and 9 ASYM) were serially sectioned and examined for haemorrhage, haemosiderin, fibrin, cholesterol and collagen. Immunoperoxidase and electron microscopy studies were carried out on sections from five plaques in order to identify blood breakdown products. Intra-plaque haemorrhage was identified in 40 (68%) plaques and was similar in SYM and ASYM plaques. In only one did it constitute more than 15% of plaque content, and in the remainder it consisted of small collections of erythrocytes constituting greater than 1% of plaque content in only 21 (35%) plaques. The predominant non-fibrous component was a pink amorphous material mixed with cholesterol. Apart from traces of platelet breakdown products there was no evidence of haemorrhage in this pink material. Plaque roof rupture or ulceration was seen in 39 (66%) and in almost all cases overlay the amorphous/cholesterol material. Blood vessels were identified in 51 87%) plaques but were in close proximity to haemorrhage in only nine (15%).

Arteriosclerosis↗
PubMed1989

Ultrasonic screening for the detection of abdominal aortic aneurysms.

Detection of aortic aneurysms before they rupture is imperative if the mortality rate from this disease is to be reduced. Although large aneurysms frequently are palpable, small aneurysms--especially in obese patients--are seldom recognized on physical examination. Ultrasound, which is noninvasive, relatively inexpensive, and nearly 100 per cent accurate in identifying the presence or absence of aneurysms, is well suited to screening. In high-risk populations (patients over the age of 50 with coronary artery or peripheral vascular disease), ultrasonic screening is probably cost-effective.

Adult↗
PubMed1989

Carotid stump syndrome: a colour-coded Doppler flow study.

Colour-coded Doppler flow imaging (angiodynography) was performed on 29 patients with 30 internal carotid artery occlusions. Large internal carotid stumps were revealed as intravascular cul-de-sacs demonstrating vortices of blue flow reversal. Large carotid stumps or significant external carotid stenoses were present in nine patients (9 arteries). Such patients were significantly more likely to develop symptoms of cerebral ischaemia during follow up which averaged 18 months (P = 0.016; Fisher exact). These results support the concept of embolisation from the carotid bifurcation (residual stump or external stenosis) as a cause of episodic cerebral ischaemia following internal carotid occlusion. Angiodynography may prove to be a useful tool for selecting appropriate patients for treatment.

Adult↗
PubMed1989

Relationship of severity of lower limb peripheral vascular disease to mortality and morbidity: a six-year follow-up study.

Among the considerations affecting the therapeutic approach to patients with atherosclerosis of the lower extremities is their associated risk of death, myocardial infarction, stroke, and limb loss. To investigate the relationship of these events to the severity of peripheral vascular disease we undertook a 6-year review of 247 consecutive patients undergoing lower extremity noninvasive vascular assessment. There were 130 men and 117 women with a mean age of 65 +/- 15 years. Patients were categorized into four groups according to their ankle-brachial pressure indexes at their first visit. Ninety-seven patients had normal indexes (greater than or equal to 0.92), 86 had indexes of 0.50 to 0.91, 39 had indexes of 0.31 to 0.49, and 25 had indexes within the ischemic range, less than or equal to 0.30. At 6 years 64% of the patients with ischemic indexes were dead. This incidence was significantly higher than that of any other patient category (p less than 0.01). Diabetes also had a significantly adverse effect on survival. The incidence of stroke and myocardial infarction was similar for all disease groups. Thirteen percent and 32% of patients with indexes of 0.31 to 0.49 and less than or equal to 0.30, respectively, underwent limb amputation. We conclude that patients with evidence of mild to moderate peripheral vascular disease have a survival rate and risk of vascular-related disorders similar to those of patients of similar age with little evidence of disease, whereas an ankle-brachial pressure index less than or equal to 0.30 is associated with a malignant prognosis.

Adolescent↗