A O Mansfield

Imperial College London, Londinium, England, United Kingdom

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Publications (49)177.55 Total impact

  • Article: Vascular 07
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    ABSTRACT: Aim: The course of peripheral arterial occlusive disease in patients with isolated SFA occlusion is benign. In light of the atheroprotective role of high shear-stress, we hypothesized that the haemodynamic and shear-stress alterations in distal arteries subsequent to SFA occlusion may confer atheroprotection; we determined the mean-shear-stress in the popliteal artery of stable claudicants with SFA occlusion in comparison with normal controls matched for age and sex.Methods: We measured popliteal artery diameter, mean velocity [MV] and flow [MQ] 2 cm distal to medial femoral condyle, on recumbency, using real-time gated Doppler/duplex in 50 limbs with SFA occlusion and 37 normal control limbs. Blood viscosity was calculated from plasma viscosity and haematocrit. Mean-shear-rate = 4MQ/π (Diameter/2)3; mean-shear-stress[dynes cm−2] = mean-shear-rate• viscosity. Data presented as median (interquartiles).Results: Arteriopaths' plasma viscosity [1.83(1.78–1.94)] mPa s−1 was similar to control [1.78(1.7–1.97)] mPa s−1.Conclusions: Popliteal artery mean-shear-stress in SFA occlusion is significantly higher than in normals, mainly due to higher MV and smaller diameter. Our data suggests that enhancement in haemodynamic shear forces distal to SFA occlusion may act atheroprotectively contributing to the benign vascular outcome in this pattern of disease.
    British Journal of Surgery 01/2009; 89(S1):55 - 55. · 4.84 Impact Factor
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    Article: Vascular 19
    K.T. Delis, D. Bountouroglou, A.O. Mansfield
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    ABSTRACT: Aims: We evaluated long-term impact of iliofemoral thrombosis (IFDVT) on walking capacity, venous haemodynamics, CEAP class, venous-clinical-severity score (VCSS) and quality of life (SF-36), and determined prevalence of venous claudication.Methods: All patients with prior IFDVT at our institution since 1990 were followed up. Excluded were those with walking impairment due to arterial (ABI < 1.0 post-exercise) or unrelated causes, and those thrombectomized or thrombolyzed. Thirty-nine patients (22–83 years) were included. Median follow-up was 5 years (range: 1–23). Investigation included CEAP and VCSS stratification, air-plethysmography (outflow fraction: OF; venous-filling index: VFI; residual-volume fraction: RVF), duplex, treadmill (3.5 km h−1, 10 per cent) to determine initial (ICD) and absolute (ACD) claudication distances, and SF-36 assessment. Non-affected limbs of patients with unilateral IFDVT (37/39) comprised the control group; data presented as median and interquartile range.Results: A total of 75.6 per cent of limbs with IFDVT had superficial and deep reflux and 26.3 per cent superficial reflux; reflux in control limbs was 13.5 and 19 per cent, respectively (P < 0.01); 43.6 per cent (17/39) (95 per cent CI: 27–60 per cent) of patients developed venous claudication ipsilateral to IFDVT (ICD: 130 (105–268) m), compelling 15.4 per cent (6/39) (95 per cent CI: 3.5–27 per cent) to discontinue treadmill (ACD: 241 (137–298) m). Limbs with prior IFDVT had a lower OF (37 (32.2–43) per cent; P < 0.001), abnormally higher VFI (3.8 (2.5–5.7) mL s−1; P < 0.001) and RVF (45 (32.5–51.5) per cent; P = 0.006), and clinical impairment in CEAP and VCSS (P < 0.0001). Patients with IFDVT had impaired physical functioning and role (P < 0.034), general health (P < 0.001), social function (P = 0.047) and mental health (P = 0.043).Conclusions: Of those with prior IFDVT 43.6 per cent developed venous claudication, compelling interruption of walking in 15.4 per cent; prior IFDVT caused outflow impairment, and large residual-venous volume and reflux, resulting in marked clinical and quality-of-life compromise. Standardized challenge enabled discrimination of those with clinically relevant impairment.
    British Journal of Surgery 01/2009; 89(S1):30 - 30. · 4.84 Impact Factor
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    ABSTRACT: We have reviewed our management, of both ruptured and non-ruptured, abdominal and thoraco-abdominal mycotic aneurysms in order to determine the safety and efficacy of in situ and extra-anatomical prosthetic repairs. Data regarding presenting symptoms, investigations, operative techniques and outcome, were collected on patients treated at a singe centre over 11 years. There were 11 men and four women, with a median age of 70 years (range, 24-79). All but one patient were symptomatic and six had a contained leak on admission. In six patients no organisms were identified in either blood or tissue cultures. Pre-operative CT identified; four infra-renal, four juxta-renal, three (Crawford thoraco-abdominal) type IV, three type III and one type II, aortic aneurysms. Thirteen were repaired with in situ prostheses and two required axillo-femoral prosthetic grafts. There were four early deaths. All surviving patients have been followed-up for a median duration of 38 months (range 1/2-112 months). There were two late deaths at 3 months (juxta-renal) and at 2 years (type III), the latter relating to graft infection. In the absence of uncontrolled sepsis, repair of mycotic aortic aneurysms using prosthetic grafts can achieve durable results.
    European Journal of Vascular and Endovascular Surgery 07/2004; 27(6):585-9. · 2.82 Impact Factor
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    ABSTRACT: Intermittent pneumatic compression (IPC) may increase blood flow through infrainguinal arterial grafts, and has potential clinical application as blood flow velocity attenuation often precedes graft failure. The present study examined the immediate effects of IPC applied to the foot (IPC(foot)), the calf (IPC(calf)) and to both simultaneously (IPC(foot+calf)) on the haemodynamics of infrainguinal bypass grafts. Eighteen femoropopliteal and 18 femorodistal autologous vein grafts were studied; all had a resting ankle : brachial pressure index of 0.9 or more. Clinical examination, graft surveillance and measurement of graft haemodynamics were conducted at rest and within 5 s of IPC in each mode using duplex imaging. Outcome measures included peak systolic (PSV), mean (MV) and end diastolic (EDV) velocities, pulsatility index (PI) and volume flow in the graft. All IPC modes significantly enhanced MV, PSV, EDV and volume flow in both graft types; IPC(foot+calf) was the most effective. IPC(foot+calf) enhanced median volume flow, MV and PSV in femoropopliteal grafts by 182, 236 and 49 per cent, respectively, and attenuated PI by 61 per cent. Enhancement in femorodistal grafts was 273, 179 and 53 per cent respectively, and PI attenuation was 63 per cent. IPC was effective in improving infrainguinal graft flow velocity, probably by reducing peripheral resistance. IPC has the potential to reduce the risk of bypass graft thrombosis.
    British Journal of Surgery 05/2004; 91(4):429-34. · 4.84 Impact Factor
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    ABSTRACT: We evaluated the long-term impact of iliofemoral thrombosis (I-FDVT) on walking capacity, venous hemodynamic status, CEAP class, venous clinical severity, and quality of life, and determined the prevalence of venous claudication. All patients with prior I-FDVT, assessed at our institution since 1990, were called for follow-up. Those with walking impairment due to arterial disease (ABI < 1.0 postexercise) or unrelated causes and those thrombectomized or thrombolyzed were excluded; 39 patients (22-83 years, median 46 years) were included. Median follow-up was 5 years (range 1-23 years). Investigation included classification in CEAP and Venous Clinical Severity Scoring (VCSS) systems, air-plethysmography (outflow fraction [OF], venous filling index [VFI], residual volume fraction [RVF]) and venous duplex, treadmill (3.5 km/h, 10%) to determine initial (ICD) and absolute (ACD) claudication distances, and quality of life assessment (SF-36). Nonaffected limbs of patients with unilateral I-FDVT (37 of 39) comprised the control group. Data are presented as median and interquartile range. A total of 81% of limbs with I-FDVT had superficial and deep reflux and 19% superficial reflux; reflux in control limbs was 29.7% (P < 0.001) and 27% (P > 0.2), respectively; 43.6% (17 of 39; 95% CI, 27-60%) of patients developed venous claudication ipsilateral to I-FDVT (ICD: 130 m, range 105-268 m), compelling 15.4% (6 of 39; 95% CI, 3.5-27%) to discontinue treadmill (ACD: 241 m, range 137-298 m). Limbs with prior I-FDVT had a lower OF (37%, range 32.2-43%; P < 0.001), abnormally higher VFI (3.8 mL/s, range 2.5-5.7 mL/s; P < 0.001), and RVF (45%, range 32.5-51.5%; P = 0.006), and clinical impairment in CEAP and VCSS systems (P < 0.0001). Patients with I-FDVT had impaired physical functioning (P = 0.02) and role (P = 0.033), general health (P = 0.001), social function (P = 0.047), and mental health (P = 0.043). A total of 43.6% of those with prior I-FDVT developed venous claudication compelling interruption of walking in 15.4%. Prior I-FDVT caused outflow impairment and a large residual venous volume and reflux, resulting in marked clinical and quality of life compromise. Standardized challenge enabled discrimination of those with clinically relevant impairment.
    Annals of Surgery 01/2004; 239(1):118-26. · 6.33 Impact Factor
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    ABSTRACT: Elective juxtarenal abdominal aneurysm repair has a significantly lower mortality rate than suprarenal repair. Identification of factors affecting outcome may lead to a reduction in mortality rate for suprarenal repair. Data were collected prospectively between 1993 and 2000 for 130 patients who underwent type IV thoracoabdominal aneurysm (TAA) repair and 44 patients who had juxtarenal aneurysm (JRA) repair. Preoperative risk factors and operative details were compared between groups and related to outcome after TAA repair (there were only two deaths in the JRA group). The in-hospital mortality rate was significantly higher following TAA repair (20.0 per cent; 26 of 130 patients) than JRA repair (4.5 per cent; two of 44). Raised serum creatinine concentration was the only preoperative factor (P = 0.013) and visceral ischaemia the only significant operative factor (P = 0.001) that affected mortality after TAA repair. JRA repair was performed with similar risks to those of infrarenal aneurysm repair. Impaired preoperative renal function was related to death following TAA repair and conservative treatment should be considered for patients with a serum creatinine level above 180 micromol/l. Reducing the duration of visceral ischaemia might improve outcome.
    British Journal of Surgery 10/2003; 90(9):1142-6. · 4.84 Impact Factor
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    ABSTRACT: patients with peripheral arterial disease (PAD) have a threefold increase in cardiovascular mortality. Standard antiplatelet treatment may not confer uniform benefit in different patient groups. This study aimed to compare platelet function in patients with lower limb PAD, carotid disease and abdominal aortic aneurysm (AAA) with age- and sex-matched healthy controls. patients with lower limb PAD (n = 20), carotid disease (n = 40), AAA (n = 13) and age/sex matched healthy controls (n= 20) were studied. Whole blood methods to detect spontaneous platelet aggregation (SPA), and adenosine diphosphate (ADP) and collagen-induced aggregation were used. The detection of platelet P-selectin and the PAC-1 antigen by flow cytometry were also used as markers of platelet activation and aggregation. patients with lower limb PAD or AAA had higher baseline SPA compared to normal controls (p < 0.01). There was significantly higher collagen-induced aggregation in IC patients compared to normal controls (p < 0.01). However, there was no difference in ADP-induced aggregation between lower limb PAD and control patients. There was no difference in PAC-1 binding between control patients and the patients with lower limb PAD, carotid disease or AAA. Patients with carotid disease had a higher expression of P-selectin compared to normal controls (p < 0.05). this study provides further evidence that platelet hyperactivity is present in patients with PAD despite the use of antiplatelet therapy. Further antiplatelet strategies may be indicated to protect these patients.
    European Journal of Vascular and Endovascular Surgery 01/2003; 25(1):16-22. · 2.82 Impact Factor
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    ABSTRACT: Background:Immunological factors may play an important role in mediating the progression of atherosclerosis and myointimal hyperplasia, with heat shock proteins being implicated as possible autoantigens. The authors have shown previously that immunomodulation can reduce vascular smooth muscle cell (vSMC) proliferation following balloon injury to rat carotid arteries. The aim of the present study was to examine the effects of immunomodulatory agents on the proliferation of rat aortic vSMCs remote from the area of balloon injury. The agents used were SRL172 (heat-killed Mycobacterium vaccae) and heat shock protein 65 kDa (HSP65) in Freund's incomplete adjuvant. Both these agents are known to influence T-cell responses.Methods:Male Sprague–Dawley rats were used. All immunizations were given subcutaneously. Four groups were studied (ten animals in each group): group 1 animals were immunized with normal saline, group 2 received SRL172, group 3 SRL172 and HSP65–Freund's, and group 4 HSP65–Freund's. Three immunizations were performed as well as carotid balloon injury. Three animals died, leaving 37 for analysis. Some 5 weeks later the animals were killed and the aorta was harvested. Standard explant techniques were applied to grow aortic vSMCs until confluency, passaged three times, quiesced, and fetal calf serum (FCS) of varying concentrations (0·4–10 per cent) was then added, incubated for another 48 h and cell counts carried out.Results:The proliferation rate of aortic vSMCs in the control group was significantly greater than that in the other study groups (Fig.). While all the treatment groups had significantly less proliferation compared with the control group (*P < 0·05, †P < 0·01, Mann–Whitney U test), no statistically significant differences existed between any of the study groups.Conclusion:Immunomodulation may result in a reduction of vSMC proliferation. Although the precise mechanisms involved are unclear, these results are in concordance with previous findings that T-cell immunomodulation decreases the development of myointimal hyperplasia after injury, and suggest that a fundamental phenotypic shift has been produced by these immunizations.
    British Journal of Surgery 12/2002; 88(4):614 - 614. · 4.84 Impact Factor
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    ABSTRACT: To determine changes in platelet activation during carotid endarterectomy (CEA) and the antiplatelet effect of Dextran 40. Prospective study in 40 patients undergoing CEA. Platelet activity was measured by whole blood flow cytometry and platelet aggregometry during CEA. The expression of P-selectin and the PAC-1 antigen were used as markers of platelet activation and aggregation. Patients received aspirin (75-300 mg) preoperatively and 5,000 units unfractionated heparin during surgery. High intensity transient signals (HITS) in the ipsilateral middle cerebral artery were monitored using transcranial Doppler (TCD) perioperatively. P-selectin expression increased after carotid clamping (P < 0.01) and clamp release (P < 0.05). There was higher expression of PAC-1 after carotid clamping (p < 0.05). Spontaneous and ADP-induced platelet aggregation increased after carotid clamping (P< 0.01) and release (P < 0.01). TCD monitoring showed an increased HITS count from preoperative levels, after clamp release (P < 0.01) and during recovery (P < 0.01). After the operation, patients with more than 50 HITS per 30 min were started on an infusion of dextran 40 (n = 6). P-selectin expression decreased 24 h after dextran 40 (P < 0.01). Significant platelet activation and aggregation occurs during CEA despite the current use of antiplatelet treatment. Dextran 40 had an antiplatelet effect after CEA providing further evidence that it may contribute to reducing thromboembolic complications.
    Platelets 06/2002; 13(4):231-9. · 2.24 Impact Factor
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    ABSTRACT: Aims: Mycotic aortic aneurysms present a surgical challenge. We reviewed our management of both ruptured and nonruptured, abdominal and thoracoabdominal mycotic aneurysms in order to determine the safety and efficacy of in situ and extra-anatomical prosthetic repairs.Methods: Data regarding presenting symptoms, investigations, operative techniques and outcome were prospectively collected on 15 consecutive patients treated at a single centre from 1991 to 2001 inclusive.Results: There were 11 men and 4 women, with a median age of 70 years (range: 24–79). The median duration of symptoms was 26 days (range: 1–1810). All but one patient were symptomatic. Nine had back pain, five were pyrexial, six had a raised white cell count, six were anaemic, four were septic and six had a contained leak on admission. Blood or tissue cultures isolated Salmonella (n = 3), staphylococci (n = 3), streptococci (n = 1), coliforms (n = 1), Treponema pallidum (n = 1), while in six patients no organisms were identified. Preoperative CT identified four infra-renal, four juxta-renal, three (Crawford thoracoabdominal) type IV, three type III and one type II aortic aneurysms. Thirteen were repaired with in situ prostheses following extensive local debridement and two required axillo-femoral prosthetic grafts. There were four early deaths, two (type IV) relating to blood loss, one secondary to myocardial event (type IV) and one secondary to multiorgan failure (juxta-renal). All surviving patients have been followed up for a median duration of 38 months (range: 1/2–112 months). There were two late deaths at 3 months (juxta-renal) and at 2 years (type III), the latter relating to graft infection.Conclusions: In the absence of uncontrolled sepsis, in situ repair of mycotic aortic aneurysms using prosthetic grafts achieves durable results with only one late infection.
    British Journal of Surgery 12/2001; 89(S1):72 - 72. · 4.84 Impact Factor
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    S Foulds, C Galustian, A O Mansfield, M Schachter
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    ABSTRACT: To examine the role of neutrophil NF kappa B activation in organ dysfunction after major surgery. NF kappa B is a transcription factor involved in the signal transduction of many stimuli that may participate in the pathogenesis of sepsis and resultant multiple organ dysfunction syndrome (MODS). It may therefore be a potential target for modulation in the reduction of postsurgical MODS. Twenty-five patients undergoing major vascular surgery (thoracoabdominal aortic aneurysm repair) were studied. Perioperative levels of neutrophil NF kappa B, CD11b, and glutathione were measured. In vitro inhibition experiments using NF kappa B inhibitors were also performed. No differences in clinical parameters were apparent before surgery between the patients who subsequently developed MODS and those who did not. However, there was a significant difference in preoperative levels of NF kappa B between the patients who developed postoperative organ dysfunction and those who did not. There was also a significant preoperative difference between patients who survived surgery and those who did not. Glutathione levels were reduced both in patients who developed MODS and those who did not at the onset of surgery. NF kappa B inhibitors suppressed patient plasma-stimulated NF kappa B activation in healthy neutrophils. Preoperative neutrophil NF kappa B status may be a marker of postoperative outcome after major surgery, and therapy aimed at attenuating neutrophil NF kappa B activation may reduce postoperative sepsis and organ dysfunction.
    Annals of Surgery 02/2001; 233(1):70-8. · 6.33 Impact Factor
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    Y. C. Chan, J. Lloyd, A. O. Mansfield
    EJVES Extra 01/2001; 1(6):100-103.
  • British Journal of Surgery 05/2000; 87(4):520-1. · 4.84 Impact Factor
  • Y C Chan, D Valenti, A O Mansfield, G Stansby
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    ABSTRACT: Warfarin induced skin necrosis is a rare complication with a prevalence of 0.01-0.1 per cent. It was first described in 1943. A literature review was undertaken using Medline; all relevant papers on this rare compli-cation of warfarin therapy were used. There are several adverse skin manifestations associated with the use of oral anticoagulants, ranging from ecchymoses and purpura, haemorrhagic necrosis, maculopapular vesicular urticarial eruptions to purple toes. This article concentrates mainly on warfarin induced skin necrosis. The syndrome typically occurs during the first few days of warfarin therapy, often in association with the administration of a large initial loading dose of the drug. Although the precise nature of the disease is still unknown, advances in knowledge about protein C, protein S and antithrombin III anticoagulant pathways have led to a better understanding of the mechanisms involved in pathogenesis. Differential diagnosis between warfarin induced skin necrosis and necrotizing fasciitis, venous gangrene and other causes of skin necrosis may be difficult; the disease may also be confused with other dermatological entities. Warfarin induced skin necrosis, while rare, is an important complication. All surgeons should be aware of its existence.
    British Journal of Surgery 04/2000; 87(3):266-72. · 4.84 Impact Factor
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    ABSTRACT: The purpose of this study was to examine the effects of major aortic surgery and its associated oxidative stress and injury on the myocardium. Plasma from 27 patients who underwent thoracoabdominal aortic aneurysm (TAAA) repair and 17 patients who underwent infrarenal aortic aneurysm (AAA) repair was collected at incision, aortic crossclamping, and reperfusion and 1, 8, and 24 hours thereafter. Samples were assayed for the myocardial specific protein troponin-T, total antioxidant status, and lipid hydroperoxides. Ten patients experienced cardiac dysfunction in the first 24 hours after surgery (eight patients in the TAAA group and two patients in the AAA group). Immediately after reperfusion, total antioxidant status levels dropped in all patients with TAAA and with AAA; this was more marked in patients with TAAA, leading to a significant difference between the two groups at this time point and for up to 1 hour thereafter (P <.01). Patients with TAAA showed a sharp rise in lipid hydroperoxide levels immediately after reperfusion, and levels were significantly higher than in patients with AAA (P =.0007). In patients with AAA, no significant change in troponin-T was observed throughout the study period; whereas in patients with TAAA, levels were significantly elevated at 8 and 24 hours after reperfusion (P <.01). Troponin-T levels significantly correlated with total antioxidant status (r = -0.5) and lipid hydroperoxides (r = 0.78) but not with systolic blood pressure. Supracoeliac aortic crossclamping is associated with a significant release of the myocardial injury marker troponin-T. This seems to correlate with the severity of oxidative rather than hemodynamic stresses. Ameliorating oxidative injury during TAAA surgery may therefore have a cardioprotective effect.
    Journal of Vascular Surgery 04/2000; 31(4):742-50. · 2.88 Impact Factor
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    ABSTRACT: Monocyte CD14 and its soluble form (sCD14) mediate the proinflammatory response to endotoxemia. The aim of this study was to measure the changes to these factors after major aortic surgery and the possible inhibitory role of transforming growth factor-beta(1) (TGF-beta(1)) during these procedures. Twenty-four patients with supraceliac aortic crossclamping during thoracoabdominal aortic aneurysm (TAAA) repair and 12 patients with infrarenal aortic crossclamping as part of infrarenal aneurysm repair (AAA) were studied. Blood was collected at incision, aortic clamping, and reperfusion and at 1, 8, and 24 hours after reperfusion. Samples were assayed for endotoxin, peripheral blood monocyte CD14 expression, sCD14, tumor necrosis factor-alpha, and TGF-beta(1). Although there was significant endotoxemia on reperfusion in both groups of patients, peak plasma endotoxin levels were significantly higher in patients with TAAA (P =.001). Monocyte CD14 and plasma sCD14 were significantly decreased in patients with TAAA at reperfusion and 1 hour after reperfusion (P <.01, both points). In patients with AAA, a significant upregulation of CD14 was observed at 24 hours after reperfusion (P <.01), but no significant changes in sCD14 were observed. TNF-alpha showed no significant changes during the study period in both groups. In patients with TAAA, TGF-beta(1) showed significant elevation at all time points (P <.01); whereas in patients with AAA, TGF-beta(1) showed no significant changes. Splanchnic ischemia reperfusion in patients who undergo supraceliac aortic clamping is associated with peripheral blood monocyte CD14 suppression and significant elevation of TGF-beta(1). TGF-beta(1) may play an important role in modulating the immune response to endotoxemia during major aortic aneurysm surgery.
    Journal of Vascular Surgery 03/2000; 31(3):520-31. · 2.88 Impact Factor
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    ABSTRACT: Purpose: Monocyte CD14 and its soluble form (sCD14) mediate the proinflammatory response to endotoxemia. The aim of this study was to measure the changes to these factors after major aortic surgery and the possible inhibitory role of transforming growth factor-β1 (TGF-β1) during these procedures.Methods: Twenty-four patients with supraceliac aortic crossclamping during thoracoabdominal aortic aneurysm (TAAA) repair and 12 patients with infrarenal aortic cross-clamping as part of infrarenal aneurysm repair (AAA) were studied. Blood was collected at incision, aortic clamping, and reperfusion and at 1, 8, and 24 hours after reperfasion. Samples were assayed for endotoxin, peripheral blood monocyte CD14 expression, sCD14, tumor necrosis factor-α, and TGF-β1.Results: Although there was significant endotoxemia on reperfusion in both groups of patients, peak plasma endotoxin levels were significantly higher in patients with TAAA (P = .001). Monocyte CD14 and plasma sCD14 were significantly decreased in patients with TAAA at reperfusion and 1 hour after reperfusion (P < .01, both points). In patients with AAA, a significant upregulation of CD14 was observed at 24 hours after reperfusion (P < .01), but no significant changes in sCD14 were observed. TNF-α showed no significant changes during the study period in both groups. In patients with TAAA, TGF-β1 showed significant elevation at all time points (P < .01); whereas in patients with AAA, TGF-β1 showed no significant changes.Conclusion: Splanchnic ischemia reperfusion in patients who undergo supraceliac aortic clamping is associated with peripheral blood monocyte CD14 suppression and significant elevation of TGF-β1TGF-β1 may play an important role in modulating the
    Journal of Vascular Surgery - J VASC SURG. 01/2000; 31(3):520-531.
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    ABSTRACT: There is considerable debate over the management of infected infrainguinal grafts. This report describes recent experience in this field and documents the change in clinical practice needed to deal with methicillin-resistant Staphylococcus aureus (MRSA). All infected infrainguinal grafts between January 1991 and July 1997 were reviewed. In the light of the findings, clinical practice was modified considerably. A further 1 year was audited prospectively up to August 1998. Twenty-six patients were treated for 27 infrainguinal graft infections (25 prosthetic, two vein). Twenty were treated by complete graft excision as the initial therapy; graft preservation was attempted in six patients. Before 1995, the infecting organisms were predominantly Pseudomonas aeruginosa or methicillin-sensitive staphylococci. Subsequently all 14 patients treated up to 1997 had infection with MRSA. The overall amputation rate was 17 of 26; ten amputations were in patients with MRSA. Four patients died, all with MRSA sepsis. As a result of this experience a policy of complete isolation was adopted for all patients infected with MRSA. In the 12 months since this policy was introduced, 77 infrainguinal grafts (61 vein, 16 prosthetic) have been inserted. Two grafts (3 per cent) have become infected, necessitating graft excision and amputation. MRSA infection of an infrainguinal graft is a serious complication with high associated amputation and mortality rates. Isolation and barrier nursing appeared to contain the problem.
    British Journal of Surgery 12/1999; 86(11):1433-6. · 4.84 Impact Factor
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    ABSTRACT: there is recent evidence that the immune system plays an essential role in the pathogenesis of atherosclerosis, with both cellular and humoral mechanisms being involved. Heat-shock proteins (HSPs) have been detected in atherosclerotic lesions, and antibodies to HSPs have also been found to be raised in patients with carotid stenoses. The aim of our study was to examine the level of anti-HSP70 antibodies in patients with other vascular diseases. a questionnaire was designed for the subjects in the study, with documentation of clinical details and ankle-brachial pressure index. Patients with concomitant infection, malignancy, hepatorenal failure, or recent surgery were excluded. Enzyme-linked immunosorbent assay (ELISA) was used to identify anti-HSP70 antibodies in the sera in different dilutions. Graphs of optical density (OD) vs. negative log dilution were plotted, the gradient of which was taken to be the estimated optical density for each subject (proportional to antibody level). Our groups consisted of controls (n =21, mean age 59.0+/-19.2), lower limb claudicants ( n =19, mean age 60.0+/-12.6), patients with lower-limb critical ischaemia ( n =22, mean age 68.5+/-10.07), and patients with abdominal aortic aneurysms ( n =20, mean age 69.9+/-6.2). we found no correlation between age and the estimated OD in our subjects (Spearman's correlation coefficient ( r )=0.123, one-tailed p value was 0.135). Patients with intermittent claudication, critical lower limb ischaemia, and aneurysms had higher estimated OD, and therefore higher anti-HSP70 antibody levels, than controls (Mann-Whitney test p =0.0127, 0.0037, 0.0008, respectively). our data provide the first evidence of a correlation between anti-HSP70 antibodies and different types of vascular diseases, suggesting that HSP70 might be involved in the pathogenesis and propagation of atherosclerosis. Since the immune response to HSPs can be modulated, this opens up the possibility of new therapeutic approaches.
    European Journal of Vascular and Endovascular Surgery 11/1999; 18(5):381-5. · 2.82 Impact Factor
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    ABSTRACT: The risks and benefits of operating on patients with ruptured thoracoabdominal aortic aneurysm (TAAA) have not been defined. The aim of the present study is to report this unit's experience with operations performed for ruptured TAAA over a 10-year period. Interrogation of a prospectively gathered computerised database. Between 1 January 1983 and 30 June 1996, 188 consecutive patients with TAAA were operated on, of whom 23 (12%) were operated for rupture. There were nine survivors (40%). Patients whose preoperative systolic blood pressure remained above 100 mmHg were significantly more likely to survive (4/8 vs. 13/15, p = 0.03 by Fisher's exact test). Survival was also related to Crawford type: type I (two of three survived); II (none of six); III (two of six); and IV (five of eight). All non-type II, non-shocked patients survived operation. Survivors spent a median of 28 (range 10-66) postoperative days in hospital, of which a median of 6 (range 2-24) days were spent in the intensive care unit. Survivor morbidity comprised prolonged ventilation (> 5 days) (n = 3); tracheostomy (n = 1); and temporary haemofiltration (n = 2). No survivor developed paraplegia or required permanent dialysis. Patients in shock with a Crawford type II aneurysm have such a poor prognosis that intervention has to be questioned except in the most favourable of circumstances. However, patients with types I, III and IV who are not shocked on presentation can be salvaged and, where possible, should be transferred to a unit where appropriate expertise and facilities are available.
    European Journal of Vascular and Endovascular Surgery 03/1999; 17(2):160-5. · 2.82 Impact Factor

Publication Stats

893 Citations
177.55 Total Impact Points

Institutions

  • 1997–2009
    • Imperial College London
      Londinium, England, United Kingdom
  • 1993–2004
    • Saint Mary's Hospital Center
      Montréal, Quebec, Canada
  • 2001
    • Queen Mary, University of London
      Londinium, England, United Kingdom
  • 1995–1996
    • Imperial College Healthcare NHS Trust
      Londinium, England, United Kingdom