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Biomedical subjects

R J Hannon

Publications and source records attributed to R J Hannon.

At least 19 recordsLinked to original sources
PubMed2006

Endovenous laser treatment for long saphenous vein incompetence.

BACKGROUND: Endovenous laser treatment is a percutaneous technique used for the treatment of long saphenous vein (LSV) incompetence. This paper presents the results of an uncontrolled case series undertaken to assess the feasibility, safety and efficacy of this technique. METHODS: Some 145 incompetent LSVs in 136 patients with saphenofemoral reflux were treated with endovenous laser. The data were evaluated prospectively. Assessment was carried out at 1 week, 3 and 12 months for LSV occlusion and symptomatic relief. RESULTS: Primary procedural success was achieved in 124 (85.5 per cent) of 145 LSVs. Reasons for primary failure included failed cannulation, failure to pass the guidewire and patient discomfort. At 3 months' follow-up, 105 (89.7 per cent) of 117 veins were totally and nine (7.7 per cent) were partially occluded. At 12 months, 63 (76 per cent) of 83 veins were totally and 15 (18 per cent) were partially occluded. At this stage 73 (88 per cent) of 83 patients remained satisfied, but 26 (31 per cent) had residual or recurrent varicosities. Of these, only five required further treatment. Complications included saphenous nerve injury in one patient and superficial skin burns in a second. CONCLUSION: Endovenous laser treatment for LSV reflux is safe and can be carried out under local anaesthesia in an outpatient setting with good patient satisfaction and low complication rates.

Adult↗
PubMed2005

The effect of pravastatin on intima media thickness of the carotid artery in patients with normal cholesterol.

OBJECTIVE: Carotid intima media thickness (IMT) is a good indicator of the severity of atherosclerotic disease. Statins have been found to reduce carotid IMT in patients with hypercholesterolaemia. The aim of this study was to investigate if pravastatin is effective in reducing IMT in normocholesterolaemic patients with carotid artery disease. METHODS: Patients with carotid artery stenosis and normal cholesterol levels who were not on a statin, were recruited. Patients were randomised to receive pravastatin or placebo daily. Serum concentration of cholesterol and IMT of common carotid arteries were measured before randomisation and at 3 monthly intervals thereafter, for 9 months. IMT was analysed to give the mean of a standardised 2 cm of the common carotid artery (CCA). Results are expressed as median (IQR) and comparison made using the Wilcoxon signed ranks test. RESULTS: Fifty-four patients were examined. Twenty-eight patients were randomised to active treatment. There was no difference in demographic details and co-morbid states between the two groups. A significant reduction in cholesterol concentration was observed from 3 months in patients randomised to the pravastatin group [5.14(4.72-5.88) vs. 4.11(3.44-5.33), p < 0.05], while there was also a significant decrease in combined IMT form 6 months [1.53(1.36-1.87) vs. 1.41 (1.33-1.78), p < 0.05]. CONCLUSIONS: The results demonstrate that pravastatin reduces intima media thickness of the common carotid artery in normocholesterolaemic patients with moderate carotid stenosis.

Aged↗
PubMed2003

Aneurysm of the inferior vena cava.

Aneurysms of the inferior vena cava (IVC) are extremely rare, with a range of reported presentations including deep venous thrombosis. Computerised Tomography (CT) and Magnetic Resonance Imaging (MRI) scans are suggested appropriate diagnostic imaging modalities, but even then it may not be possible to differentiate between an IVC aneurysm and a retroperitoneal tumour. This case illustrates that an IVC aneurysm should be considered in the differential diagnosis of a retroperitoneal tumour.

Adult↗
PubMed2003

The effect of lower limb ischaemia-reperfusion on intestinal permeability and the systemic inflammatory response.

OBJECTIVES: a relationship has been demonstrated between increased intestinal permeability, endotoxaemia and the development of the systemic inflammatory response syndrome (SIRS) after aortic surgery. The aim of this study was to evaluate whether isolated lower limb ischaemia-reperfusion (I/R) injury affects intestinal mucosal barrier function and cytokine release. PATIENTS AND METHODS: four groups of patients were investigated, group I, patients with critical limb ischaemia (CLI) undergoing infra-inguinal bypass surgery (n=18); group II, patients with intermittent claudication (IC) undergoing infra-inguinal bypass surgery (n=14); group III, patients with CLI unsuitable for arterial reconstruction, undergoing major amputation (n=12); and group IV, patients undergoing carotid endarterectomy for symptomatic carotid stenosis (n=13). Intestinal permeability, endotoxaemia and urinary soluble tumour necrosis factor receptors were assessed (p55TNF-R). RESULTS: an increase in intestinal permeability was observed on the 3rd postoperative day only in CLI group. This was found to correlate with arterial clamp time. Patients who had a femoro-distal bypass had significantly higher intestinal permeability compared to those who had femoro-popliteal bypass. Endotoxaemia was not detected in any of the groups. Postoperative urinary p55TNF-R concentrations were significantly higher in CLI group compared to the other groups. These did not correlate with the increased intestinal permeability. CONCLUSIONS: our results support the hypothesis that revascularisation of critically ischaemia limbs leads to intestinal mucosal barrier dysfunction and cytokine release. They also suggest that the magnitude of the inflammatory response following I/R injury is related to the degree of initial ischaemia.

Aged↗
PubMed2001

Extraperitoneal approach reduces neutrophil activation, systemic inflammatory response and organ dysfunctionin aortic aneurysm surgery.

OBJECTIVES: to compare the effects of transperitoneal and extraperitoneal approaches on systemic inflammatory response, neutrophil activation and organ dysfunction in elective abdominal aortic aneurysm (AAA) repair. PATIENTS AND METHODS: twenty patients admitted for elective infrarenal AAA repair were prospectively randomised into transperitoneal (n =10) or extraperitoneal ( n =10) groups. Neutrophil activation was assessed by measuring the plasma levels of neutrophil elastase/alpha(1)-anti-trypsin complexes before surgery, intraoperatively and at 6 h, 12 h, 24 h and then daily after surgery. Venous blood samples for estimation of liver function tests, full blood counts, urea and electrolytes and arterial samples for blood gas analysis were taken daily from preoperatively to day 5 after surgery. Multiple organ dysfunction (MOD) and systemic inflammatory response (SIR) scores were calculated daily. RESULTS: the concentrations of neutrophil elastase/alpha(1)-anti-trypsin complexes were significantly higher in the transperitoneal group at 6 h after surgery compared to the extraperitoneal group (799(455-921) ng/ml (median(i.q.r.)) vs 307(171-395) ng/ml, p<0.005), and at 12 h (397(364-936) ng/ml vs 319(134-352) ng/ml, p <0.05). The MOD scores were significantly higher in the transperitoneal group in comparison to the extraperitoneal group at day 1 (2.5(2-3.3) vs 1(0-1), p<0.001) and day 2 (2.5(2-3.3) vs 1(0-1), p <0.001). The SIR scores were also significantly higher at day 1 (1(0-2) vs 0, p <0.01), day 2 (1.5(0-2.3) vs 0, p <0.01), and day 3 (1(0-1) vs 0, p <0.05). CONCLUSIONS: neutrophil activation, systemic inflammatory response and organ dysfunction are increased in elective AAA repair when a transperitoneal approach is used. This may be related to intestinal manipulation and mesenteric traction which are reduced in the extraperitoneal approach.

APACHE↗
PubMed2001

Extraperitoneal approach reduces intestinal and renal dysfunction in elective abdominal aortic aneurysm repair.

BACKGROUND: Intestinal mucosal barrier dysfunction observed in patients undergoing transperitoneal abdominal aortic aneurysm (AAA) repair may contribute to the development of the systemic inflammatory response syndrome and dysfunction of various organs. The aim of this study is to investigate whether an extraperitoneal approach reduces intestinal mucosal barrier and renal dysfunction in elective infrarenal AAA repair. METHODS: Twenty patients admitted for elective infrarenal AAA repair were randomized into either the transperitoneal approach (n=10) or the extraperitoneal approach (n=10). Intestinal permeability was measured preoperatively, and at day 1 and day 3 after surgery using the lactulose/mannitol test by calculating the differential urinary excretion ratio of the two sugars after oral administration. Renal dysfunction was assessed by measuring the urinary albumin/creatinine ratio (ACR) at the same time points. RESULTS: Intestinal permeability was significantly increased in the transperitoneal group at day 1 [0.124+/-0.035 (mean+/-s.e.m.)] compared to the preoperative level (0.020+/-0.003), (p=0.001) and to the extraperitoneal group at day 1 (0.025+/-0.008), (p<0.05) which showed no change in comparison with the preoperative level (0.020+/-0.003). The ACR was also significantly increased in the transperitoneal group at day 1 (16.69+/-5.12) compared to the preoperative level (5.71+/-2.89), (p<0.05) and to the extraperitoneal group at day 1 (4.33+/-1.49), (p<0.05) which showed no significant change at any of the times examined. No correlation was observed between the lactulose/mannitol ratio and the albumin/creatinine ratio, or between age, operating time, aortic clamping time, amount of blood lost or blood transfused. CONCLUSIONS: These results support the suggestion that minimising intestinal manipulation using an extraperitoneal approach in AAA repair preserves intestinal mucosal barrier and renal glomerular functions.

Aged↗
PubMed2000

Intestinal manipulation during elective aortic aneurysm surgery leads to portal endotoxaemia and mucosal barrier dysfunction.

OBJECTIVES: to investigate the effect of intestinal manipulation on intestinal permeability and endotoxaemia during elective abdominal aortic aneurysm (AAA) surgery. DESIGN: prospective randomised controlled study. PATIENTS AND METHODS: fourteen patients undergoing elective infrarenal AAA repair were randomised into either the transperitoneal (n=7) or extraperitoneal approach (n=7). Intestinal permeability was measured preoperatively (PO), and at day 1 (D1) and day 3 (D3) after surgery using the lactulose/mannitol absorption test. Portal and systemic blood samples were taken before clamping, at completion of proximal and distal anastomoses and immediately before abdominal wound closure, for endotoxin measurement using the chromogenic limulus amoebocyte lysate assay. RESULTS: intestinal permeability was significantly increased at D1 (0.107+/-0.04 (mean+/-S.E.M.)) in the transperitoneal group compared to the PO level (0.020+/-0.004, p<0.05) and to the extraperitoneal group at D1 (0.020+/-0.004, p<0.05) which showed no change in comparison with the PO level. No correlation was seen between increased intestinal permeability and aortic clamp time, operation time, amount of blood lost or transfused. However, a significantly higher concentration of portal endotoxin was detected intraoperatively in the transperitoneal group of patients in comparison to the extraperitoneal group (p<0.05). There was a significant positive correlation between portal endotoxaemia and intestinal permeability (r(s)=0.955 p=0.001). CONCLUSION: an increase in intestinal permeability and a greater degree of portal endotoxaemia are observed during transperitoneal approach to the aorta. This suggests that intestinal manipulation may impair gut mucosal barrier function and contribute to the systemic inflammatory response seen in AAA surgery.

Aged↗
PubMed1996

Aortic prosthetic infection: 50 patients treated by radical or local surgery.

Fifty patients with aortic prosthetic infection were managed in a period of 10 years from 1983 to 1993. Twenty-five patients had recurrent sepsis after local surgery (group 1) and 22 of these eventually required radical surgery. Twenty-five patients had radical graft excision as the first procedure (group 2). Group 1 contained an excess of patients with local groin symptoms (11 in group 1 versus five in group 2, P = 0.03) and in this group fewer radiological techniques were used to document the extent of graft infection. The perioperative mortality rate was similar in both groups (seven in group 1 versus five in group 2). The number of amputations was also similar (five in group 1 versus four in group 2). The triad of occlusive disease, aortobifemoral bypass and groin symptoms was associated with eight of nine amputations. While the authors would consider using local techniques if the anastomosis was intact, the graft remained patent and infection appeared to be confined to the groin, this combination is uncommon and radical graft excision remains the preferred treatment.

Amputation, Surgical↗
PubMed1992

Prophylactic extrapleural chest drainage following repair of esophageal atresia: is it necessary?

In a review of 110 cases of esophageal atresia (EA) and tracheoesophageal fistula (TEF), 15 patients (13.6%) developed anastomotic leakage. All patients had extrapleural surgical exposure and prophylactic extrapleural chest drainage (PEPCD). Despite this precaution, all patients with anastomotic leaks developed a pneumothorax with or without a pleural effusion. This required insertion of an additional drain in 12 (80%) cases. PEPCD following repair of EA and TEF does not appear to prevent pneumothorax or pleural effusion when anastomotic leakage occurs.

Drainage↗
PubMed1990

Fluid and ion redistribution in skeletal muscle in an animal sepsis model.

The redistribution of fluid and electrolytes was investigated in a hyperdynamic sepsis animal model using cecal ligation and puncture (CLP) in Wistar rats. Hyponatremia was not observed. There was a significant shift of sodium, chloride, and water from the extracellular into the intracellular space as early as 12 hours following CLP. These data suggest that the mechanism by which hyponatremia occurs in clinical sepsis is not caused by shift of fluid from the intracellular to the extracellular space as proposed by the sick cell theory. This is more likely to result from fluid retention and dilution of the extracellular space possibly on the basis of antidiuretic hormone secretion.

Animals↗
PubMed1990

Hyponatraemia and intracellular water in sepsis: an experimental comparison of the effect of fluid replacement with either 0.9% saline or 5% dextrose.

Hyponatraemia associated with sepsis is known to have an increased morbidity and mortality. The cause of this phenomenon is unknown, but may be related to dilution of the extracellular space with retained exogenous fluid. Fluid and ion redistribution across the cell membrane of striated muscle was investigated in an animal sepsis model and compared with sham controls. The objective was to study the effect of different volumes of fluid replacement with either 0.9% saline or 5% dextrose. Significant shifts of sodium, chloride, and water occurred into the cell in all septic animals but not in controls. This trend was exacerbated by the use of dextrose for intravenous replacement even when the estimated normal fluid requirements had not been exceeded. Hyponatraemia and plasma hypoosmolality were induced only in septic animals, which received 100% of their fluid requirements as dextrose. These animals at the same time had significantly reduced extracellular and increased intracellular volumes compared with controls and the septic animals that received saline replacement. It is concluded that the hyponatraemia and plasma hypoosmolality that occurs in these animals is caused by a combination of intracellular shift of sodium and water, and dilution of the extracellular space, probably on the basis of physiological antidiuretic hormone (ADH) secretion. Dextrose (and by implication 4% dextrose/0.18% saline) is inappropriate, potentially dangerous, and should be avoided in these circumstances.

Analysis of Variance↗