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Biomedical subjects

C L McGuinness

Publications and source records attributed to C L McGuinness.

At least 19 recordsLinked to original sources
PubMed2006

Minimally invasive technique for ligation and stripping of the small saphenous vein guided by intra-operative duplex ultrasound.

BACKGROUND: Small saphenous vein (SSV) disconnection and removal are challenging and considered by some authors to have too high a morbidity and failure rate to justify their routine use. Our audited results are at variance with these views. METHODS: We describe a reliable, ultrasound guided, minimally invasive technique for ligation and stripping of the SSV with an incision usually <1 cm. From our total series, 50 random patients attended for ultrasound review. The sapheno-popliteal junction (SPJ), strip track and signs of recurrence were assessed and recorded. RESULTS: Since 1999, 627 patients (679 limbs) have undergone surgery for ultrasound proven SSV reflux. Fifty-two limbs (50 patients) were ultrasound assessed post-operatively. Fifty-one had flush ligation of the SPJ with one showing a 'stump' <1 cm. All showed successful SSV removal. Three limbs had minor strip track revascularisation but none had obvious clinical recurrence. Of the whole series, 11/627 (1.8%) developed proven deep vein thrombosis (DVT). There were six superficial wound infections and one strip track abscess. Sural nerve neurapraxia occurred in 13/627 (2.1%); one showing no sign of recovery at four weeks post-operatively. CONCLUSIONS: Ultrasound guided SSV is a safe, minimally invasive technique with high success and low recurrence and complication rates

Female↗
PubMed2005

The modernisation of the surgical house officer.

INTRODUCTION: There have been considerable changes in the junior doctors' hours and working patterns over the last 4 years. The aim of this study was to assess the effect of these changes on the house officers' surgical experience and to obtain their opinions on the 'Hospital at Night' system, which has recently been introduced at our large teaching hospital. METHODS: A questionnaire was filled out by surgical house officers at the end of their surgical posts in 2001. The same questionnaire was then repeated for house officers completing the same posts in 2005. RESULTS: Pre-registration house officers now see less acute surgical admissions (mean 5 patients in 3 months in 2005 compared with 35 in 2001; P < 0.0001) and spend less time attending theatre than four years ago (mean 12 sessions in 3 months in 2001 compared with 6 in 2005). Despite the reduction in hours, they are still managing to attend educational sessions. Nine out of ten house officers felt that the 'Hospital at Night' system was unsatisfactory. They were unable to see and clerk acute surgical admissions or go to theatre because they were providing cross cover for other specialties. CONCLUSIONS: The full shift system and the introduction of the 'Hospital at Night' team have led to a reduction in acute surgical experience for surgical house officers. The General Medical Council recommendations for reducing non-educational tasks have not been fulfilled despite the evolving role of nurse practitioners.

Attitude of Health Personnel↗
PubMed2003

Randomized clinical trial of three-layer paste and four-layer bandages for venous leg ulcers.

BACKGROUND: Both four-layer and three-layer paste bandages are widely used in the treatment of venous leg ulcers. The aim of this study was to compare the efficacy of these two bandaging regimens. METHODS: The study was a prospective, randomized, open comparison of a consecutive cohort of 133 patients with venous ulcers. Participants were stratified by ulcer size into one of three groups and were randomized within each group to receive either three-layer paste or four-layer bandages. All patients were followed for 1 year. The time taken to complete ulcer healing was the primary endpoint. The time taken to apply the bandages, comfort, tolerability and cost were also assessed. Analysis was performed on the basis of intention to treat. RESULTS: Ulcers healed completely in 51 (80 per cent) of 64 patients treated with three-layer paste bandages compared with 45 (65 per cent) of 69 patients treated with the four-layer regimen (P = 0.031). This difference developed only after 20 weeks of treatment. The median times to complete healing were 12 weeks for three-layer and 16 weeks for four-layer treatment (P = 0.040). Results of venous function tests, including half-refilling times, were similar in the two groups. CONCLUSION: Three-layer paste bandages were significantly more effective at healing venous ulcers than the four-layer regimen in this study.

Aged↗
PubMed2002

Value of isotope lymphography in the diagnosis of lymphoedema of the leg.

BACKGROUND: Isotope lymphography has largely replaced contrast lymphography in the diagnosis of lymphoedema. Its accuracy has only been assessed in small studies and it is not known if it can identify patients with a proximal lymphatic obstruction who may be suitable for lymphatic bypass surgery. METHODS: Three hundred and ninety-five patients suspected to have lymphoedema were investigated by isotope lymphography between 1985 and 1995. Contrast lymphography was also carried out in 29 of these patients because the isotope results were thought to be misleading, or because lymphatic bypass surgery was being considered. RESULTS: In the 29 patients who had both investigations isotope lymphography detected 20 of 24 abnormal lymphatic systems. Four legs with obstructed groin lymphatics were reported as normal. Two legs with normal contrast lymphograms were erroneously diagnosed as having lymphoedema in the isotope study. Detectable groin nodes on the scintigrams were indicative of either normal lymphatics or proximal lymphatic obstruction. An increase in isotope uptake over 30-60 min of less than 50 per cent, or a total absence of isotope within groin nodes, was a sensitive indicator that patients were unsuitable for lymphatic bypass surgery. CONCLUSION: Isotope lymphography is a moderately sensitive test for lymphoedema, which will mistakenly classify some normal legs as lymphoedematous. It will usually correctly identify patients who are suitable for lymphatic bypass surgery.

Contrast Media↗
PubMed2002

Incidence and pattern of long saphenous vein duplication and its possible implications for recurrence after varicose vein surgery.

BACKGROUND: The incidence of long saphenous vein (LSV) duplication has not been clearly established. This anomaly could have implications for recurrence after varicose vein surgery. METHODS: Some 103 saphenograms obtained in 85 patients being considered for peripheral arterial bypass surgery were reviewed. Non-ionic contrast medium was injected directly into the vein or its tributaries at the ankle. Duplications of the LSV and their relation to thigh and calf perforator veins were assessed and recorded by two independent observers. RESULTS: There was evidence of duplication of the LSV in 50 (49 per cent) of the 103 saphenograms. Most duplications were present in the thigh (88 per cent) and the most common pattern was a closed loop (54 per cent). Perforator veins were connected to one branch of the duplication in 42 per cent of the legs (20 per cent of all 103 legs); in half the perforator vein was connected to the non-dominant branch of the duplication. Only ten of the 18 patients who had bilateral saphenograms had duplications in both legs, and only one patient had the same pattern of duplication on both sides. CONCLUSION: The incidence of LSV duplications is higher than previously reported.

Adult↗
PubMed2001

Value of intraoperative duplex imaging during supervised carotid endarterectomy.

BACKGROUND: For overall benefit, carotid endarterectomy requires low perioperative morbidity and mortality rates. Carotid thrombosis is usually secondary to technical error, which may be related to the experience of the operator. In this retrospective study the clinical and technical outcome of carotid endarterectomies performed by one consultant and five trainees were compared. METHODS: Some 149 patients underwent carotid endarterectomy; 89 were operated on by the consultant and 60 by trainees. Intraoperative duplex imaging of the carotid repair was performed before wound closure, and re-exploration was carried out when there was a residual severe stenosis associated with an intimal flap. RESULTS: There was no significant difference in clinical outcome between operations done by consultant or trainees. There was a significant increase in the number of stenoses, kinks and flaps in carotid endarterectomies performed by trainees compared with those of the consultant both before (chi2 = 12.0, 1 d.f., P < 0.001) and after (chi2 = 10.1, 1 d.f., P < 0.001) correction. CONCLUSION: Intraoperative duplex imaging may facilitate training by providing an objective assessment of the quality of the operation.

Aged↗
PubMed2001

Thoracic aortic stent grafts--early experience from two centres using commercially available devices.

OBJECTIVES: open surgical intervention for aneurysms of the distal arch and descending thoracic aorta is associated with high morbidity and mortality. Stent grafts offer an attractive alternative treatment for these aneurysms. The aim of this study was to assess the morbidity and mortality of endovascular treatment for these aneurysms with stent grafts. DESIGN, PATIENTS AND METHODS: a prospective observational study was performed of 37 consecutive patients treated from July 1997 to October 2000 (30 at Guy's and St. Thomas' and 7 at Sheffield). Indications included degenerative aneurysms (n=18), false aneurysm (5), acute dissection (4), aortic transection (4), aneurysm related to previous surgery for coarctation (3), chronic dissection (2) and traumatic dissection (1). Nineteen were performed as elective and 18 as non-elective procedures. RESULTS: three non-elective patients died in hospital (in-hospital and 30-day mortality 8%) and one suffered a stroke with spontaneous full recovery. No elective patient died. One patient with a persistent proximal endoleak required conversion to open repair at 6 weeks. Two patients with persistent flow into the sac at 24 h spontaneously thrombosed at subsequent 3 month follow-up. Two further patients developed new distal endoleaks at 3 months and required distal extension cuffs. One patient died at 28 months of aortic rupture. Serial CT scans had shown prolapse of the stent graft into the aneurysm sac and the patient died just before planned endovascular repair. No patient suffered paraplegia or renal failure. Intensive care facilities were only required for patients who needed them preoperatively. CONCLUSIONS: thoracic stent grafts can be performed with low morbidity and mortality. They offer a realistic alternative to open surgery. Long term follow up is required to assess their durability.

Aged↗
PubMed2001

Clinical grading of the upper palpebral conjunctiva of non-contact lens wearers.

PURPOSE: To categorize the appearance of the normal upper palpebral conjunctiva using a grading scale and to investigate interobserver agreement with a grading scale modified to include decimal increments. METHODS: Upper palpebral conjunctival appearance of 96 non-contact lens wearing subjects aged 18 to 75 years was assessed using a photographic grading scale that has a generic (zero to four) scale to score redness and roughness of the palpebral conjunctiva. RESULTS: Median redness and roughness was about 1.25 units. About 5% of subjects had redness or roughness >2.0 units. Interobserver agreement improved during the study. By the end of the study, the standard deviation of the discrepancy scores was 0.12 to 0.19 units. CONCLUSIONS: Upper palpebral conjunctival redness or roughness >2.0 units are unusual. The grading scale can be used successfully with decimal rather than integer scale increments. For experienced clinicians, a change in grade of > or =0.5 units may be significant.

Adolescent↗
PubMed2001

Lymphoedema.

Explore the source record for details and available documents.

Diagnosis, Differential↗
PubMed2001

Repair of secondary aortoesophageal fistula by endoluminal stent-grafting.

PURPOSE: To describe a case of secondary aortoesophageal fistula that was treated with an endoluminal stent-graft. CASE REPORT: A 58-year-old woman presented with hematemesis and melena. In 1974 she had an interposition graft repair of an aortic transection sustained during a traffic accident. At the examination in 1998, angiography demonstrated a mechanical disruption of the proximal anastomosis forming an aortoesophageal fistula. A 28-mm x 3.75-cm AneuRx stent-graft was introduced via a right femoral arteriotomy and deployed across the defect. Follow-up CT scans at 18 months showed exclusion of the false aneurysm with no evidence of infection; the patient remains well at >2 years after stent-graft implantation. CONCLUSIONS: Endoluminal repair can be successful in achieving a satisfactory midterm outcome in cases of secondary aortoesophageal fistula.

Anastomosis, Surgical↗
PubMed2001

Multiple aneurysms associated with congenital rubella.

We describe the case of a woman with congenital rubella who presented with backache. Plain abdominal X-ray revealed calcification of a superior mesenteric artery aneurysm. Intra-arterial digital subtraction angiography demonstrated multiple aneurysms of the arteries to the upper and lower limbs and the viscera. We have not found another report in the literature of the association of congenital rubella with multiple aneurysms.

Adult↗
PubMed2001

Recruitment of labelled monocytes by experimental venous thrombi.

OBJECTIVE: Infusing monocytes that have been stimulated to produce fibrinolytic activators and factors that regulate cell proliferation, migration and maturation, might enhance venous thrombus resolution. The aim of this study was to determine the time course of infused monocyte recruitment into venous thrombus in an appropriate model of this disease. DESIGN AND METHODS: Thrombus was induced in the inferior vena cava of male Wistar rats using reduced flow (80-90% stenosis). The vessel wall was examined at 1hr by scanning electron microscopy. Resolving thrombi with surrounding vena cava were obtained at 1, 7, 14 and 21 days after induction (n = 8). Sections, taken at 0.5 mm intervals (10-15 sections per thrombus), were stained using haematoxylin, Martius Scarlet Blue and antibodies against monocytes, platelets and fibrin. Sections from human venous thrombi (n = 4) were similarly stained. The area occupied by monocytes (in relative pixel units, RPU) was determined using computer aided image analysis. Peripheral rat blood monocytes were extracted, fluorescently labelled and injected intravenously into 7 rats prior to thrombus induction, Vena cava with thrombus was harvested 1 h, 2, 3, 4, 7, 14 and 25 days after induction and their fluorescence measured. The fluorescent content of the caval wall and thrombus was analysed in greater detail at 2 and 25 days after thrombus induction (n = 4 at each time interval). RESULTS: Experimental thrombi were structurally similar to human thrombus and resolved within 14-21 days. Scanning electron microscopy showed minimal endothelial damage at 1 h with signs of early thrombus formation (platelet, red cell leukocyte and fibrin deposition). Neutrophils were the predominant leukocyte in the thrombus at 1 day, with monocytes making up only 0.3% (0.04% sem) of the area of the thrombus. There was a steady increase in thrombus monocyte content and by 21 days the percentage area of thrombus covered by monocytes had increased by over 35 fold to 11.5% (2.3% sem) (p <0.001). Initially, monocytes appeared around the edge of the thrombus and became more evenly distributed through the thrombus as resolution progressed. Labelled monocytes could be found in the circulation up to 1 week after infusion. The fluorescent content (RPU) of the thrombus increased over 25 days (mean RPU At 2 days 0.012, sem 0.005; mean RPU at 25 days 1.062, sem 0.252, p = 0.008). The number of labelled monocytes in the vessel wall peaked at 2 days and decreased thereafter. CONCLUSION: The structure of thrombi produced by this model was comparable to that of human venous thrombi. Endogenous and injected monocytes migrated into the thrombus during natural resolution, possibly via the vein wall. Monocyte targeting could therefore be used to develop novel treatments for venous thrombosis, with the aim of reducing post-thrombotic complications.

Animals↗
PubMed1999

Monocyte chemotactic protein-1 (MCP-1) accelerates the organization and resolution of venous thrombi.

PURPOSE: Organization, recanalization, and contraction are common to wound healing and thrombus resolution. Monocytes are essential to wound healing and are also found in venous thrombi. We measured endogenous levels of the monocyte chemotactic protein-1 (MCP-1) in naturally resolving venous thrombi and determined the effect of injecting MCP-1 into newly formed thrombus. METHODS: Endogenous MCP-1 levels were estimated in rat blood, thrombi, and the adjacent vessel wall after thrombus formation, in cohorts of eight animals at 1, 7, and 14 days. In another group (n = 10), 1 microgram of MCP-1 was injected into newly formed thrombi. Carrier was injected into the thrombi of control animals (n = 10). Thrombi and adjacent vein walls were obtained for histology at 7 days. Thrombi were given an arbitrary organization score based on erythrocyte and extracellular matrix content, which was assessed by means of computerized and observer analysis. Specimen weight, thrombus area, and cellular and monocyte content were measured. RESULTS: Endogenous MCP-1 increased between days 1 and 7 in the thrombus (1-day median, 1.1 ng/g wet wt; 1-day range, 0.8 to 1.4 ng/g wet wt; 7-day median, 5.4 ng/g wet wt; 7-day range, 1.5 to 7.4 ng/g wet wt; P <.0001) and vein wall (1-day median, 1.5 ng/g wet wt; 1-day range, 0.8 to 4.3 ng/g wet wt; 7-day median, 3.3 ng/g wet wt; 7-day range, 2.7 to 8.3 ng/g wet wt; P <. 05). At 14 days, thrombus was incorporated in the vein wall, and total MCP-1 levels remained high (median, 3.9 ng/g wet wt; range, 1.1 to 7.4 ng/g wet wt). Less MCP-1 was found in the thrombus than the adjacent vessel wall at day 1 (P <.05), but there was no difference at day 7. MCP-1 could not be detected in the blood. MCP-1 injection into thrombus increased the computer (P =.016) and observer (P =.004) organization scores, reduced the thrombus area (from median, 3. 4 mm(2), and range, 1.5 to 5.7 mm(2), to median, 0.2 mm(2), and range, 0.02 to 2.6 mm(2); P =.048), and increased the surrounding vessel wall monocyte content (P =.008). Specimen weights of treated animals were lower than those of control animals (P <.02). CONCLUSION: Venous thrombus MCP-1 levels increase during natural resolution. MCP-1 treatment increased the organization and resolution of thrombi. MCP-1 may therefore be of therapeutic use.

Animals↗
PubMed1998

The role of the monocyte in the generation and dissolution of arterial and venous thrombi.

Monocyte infiltration into forming thrombus has been demonstrated in experimental models of venous thrombosis developed in our laboratories. These cells produce and release plasminogen activators as the thrombus organises and resolves. Monocytes are also capable of assembling and releasing procoagulant factors and the evidence for their importance in thrombogenesis is reviewed. The ability of monocytes to maintain this fibrinolytic balance suggests that they may have a role in both thrombosis and thrombus resolution. Control of the mechanisms which regulate these activities may therefore be important in preventing thrombus formation or stimulating its resolution.

Animals↗
PubMed1997

High and constant plasma levels of tissue plasminogen activator and PEG-hirudin can be achieved by subcutaneous delivery.

Intramural thrombosis is a consistent finding in the arteries of patients who die following coronary angioplasty. This thrombosis is thought to have a role in restenosis, which is a common complication of coronary angioplasty. It has been hypothesised that antithrombotics such as hirudin or tissue-type plasminogen activator (tPA), may be therapeutically useful following angioplasty. This report describes the bioavailability of both agents following subcutaneous (sc) injection in cholesterol-fed rabbits. Intravenously delivered tPA has a half-life of 3-5 minutes. The half-life of intravenously administered hirudin is less than one hour in many species. In order to prolong the duration of action recombinant hirudin was conjugated to polyethylene glycol (PEG). Polyethylene glycol conjugated recombinant hirudin (PEG-rH) (0.7 mg/kg) antigen and activity were measurable after just 1 hr, reaching a maximum (663 and 884 ng/ml respectively) at 12 hours. Significant levels were present in rabbit plasma 24 hours after injection. Subcutaneously delivered recombinant (r-tPA) (1 mg/kg) was present in significant amounts 1 hr after injection, reaching a maximum (92 IU/ml) at 2 hours. Levels of tPA at 9 hours were approximately 80x normal circulating levels. High and constant levels of functional activity of both PEG-rH and r-tPA in rabbit plasma are achieved by subcutaneous delivery.

Animals↗