Duplex-derived Evidence of Reflux After Varicose Vein Surgery: Neoreflux or Neovascularisation?

AbstractBackgroundrecurrent varicose veins remain a problem in surgical practice despite improvements to the preoperative investigation of, and surgery for varicose veins. Neovascularisation accounts for some cases of recurrence within a few years of surgery, but other factors relating to disease progression must also play a part. We investigated whether new venous reflux (neoreflux) could occur in the early postoperative period (within 6 weeks) following successful varicose vein surgery.Methodseighteen-month prospective observational study in the dedicated vascular surgery unit of a university teaching hospital. Forty-six patients, with primary saphenofemoral junction reflux, awaiting varicose vein surgery were chosen consecutively from the waiting list. All saphenofemoral surgery was performed in a standardised fashion. Assessments were performed prior to, at 6 weeks and at 1 year after surgery. Duplex ultrasound was used to identify and locate sites of reflux.Resultsneoreflux was present at the 6-week postoperative scan in nine limbs after varicose vein surgery (19.6%), and resolved in 55.6% of patients within 1 year. Neovascularisation was noted in two limbs at the 1-year scan.Conclusionnew sites of reflux, which may resolve spontaneously, occur in the early postoperative period despite adequate varicose vein surgery. It is our hypothesis that this is a manifestation of the effect of altered venous haemodynamics in a system of susceptible veins

The growth companies puzzle: can growth opportunities measures predict firm growth?

While numerous empirical studies include proxies for growth opportunities in their analyses, there is limited evidence as to the validity of the various growth proxies used. Based on a sample of 1942 firm-years for listed UK companies over the 1990-2004 period, we assess the performance of eight growth opportunities measures. Our results show that while all the growth measures show some ability to predict growth in company sales, total assets, or equity, there are substantial differences between the various models. In particular, Tobin's Q performs poorly while dividend-based measures generally perform best. However, none of the measures has any success in predicting earnings per share growth, even when controlling for mean reversion and other time-series patterns in earnings. We term this the 'growth companies puzzle'. Growth companies do grow, but they do not grow in the key dimension (earnings) theory predicts. Whether the failure of 'growth companies' to deliver superior earnings growth is attributable to increased competition, poor investments, or behavioural biases, it is still a puzzle why growth companies on average fail to deliver superior earnings growth

How effective is acute normovolaemic haemodilution in femoro-distal bypass surgery?

Background: Recent guidelines have emphasised the use of autologous blood in the surgical setting. The aim of this study was to analyse the efficacy and efficiency of acute normovolaemic haemodilution (ANH) as a blood conservation intervention in patients undergoing elective femoro-distal surgery for critical limb ischaemia.Methods: Forty patients were studied prospectively. The volume of the blood collected was derived as follows: Blood volume removed = patient's blood volume (initial haematocrit - final haematocrit/average haematocrit) where final haematocrit is 30% and patient's blood volume is 70 and 65 ml/kg for a man and a woman, respectively.Results: Twenty-five patients were suitable for ANH and 15 patients were excluded because of poor ventricular function, anaemia or renal disease. Nine of the 25 patients (44%) had of surgical blood loss and would have avoided homologous blood transfusion (HBT). Four of the patients lost of blood and could not avoid HBT through ANH. Twelve patients had moderate blood loss (950-1400 ml), with eight of these patients requiring transfusion. Four patients avoided exposure to homologous blood.Conclusion: ANH is in evolution and as a single blood conservation intervention, contributes only modestly to blood conservation

Allogeneic versus autologous blood during abdominal aortic aneurysm surgery

Objectives: To determine if cell-salvaged autologous blood can serve as an alternative to homologous blood, and to examine the incidence of infected complications and length of postoperative stay. Design: A prospective randomised study comprising autologous and homologous blood transfections in patients undergoing elective infrarenal abdominal aortic surgery. Methods: Fifty patients undergoing AAA surgery were prospectively randomised to homologous blood (n = 27), or autologous blood transfusion (n = 23), using a cell salvage autotransfusion device. Results: The haemoglobin at the time of hospital discharge was similar for both groups (11.0 vs. 10.8 g/dl) with no difference in perioperative mortality. The length of stay was reduced in those patients who received autologous blood (9 days vs. 12 days, p < 0.05 Mann-Whitney U test). There were four infected cases in the autologous group and 12 in the homologous group (p = n.s., Fisher's exact probability test). However, patients who received 3-4 units of homologous blood had an increased risk of infection compared to those who received a similar amount of autologous blood (50% vs. 0%). Conclusions: Cell salvage autologous blood can safely replace, or at least decrease, exposure to homologous blood transfusion, with a reduction in the mean hospital stay

Ruptured Abdominal Aortic Aneurysm: a Novel Method of Outcome Prediction Using Neural Network Technology

AbstractBackground: reported survival following emergency surgery for ruptured abdominal aortic aneurysm (RAAA) varies widely between institutions. This is largely attributable to differences in case mix. The aim of this study was to identify and evaluate a set of prognostic variables that would accurately predict outcome for individual patients from perioperative indices. Methods: perioperative factors associated with subsequent mortality at our institution were identified by retrospective review of 102 consecutive operations for RAAA over a 7-year period (January 1990 to January 1997). Logistic regression analysis was used to select the most significant variables associated with subsequent mortality. These were used to construct, train, and validate a neural network designed to predict survival from surgery in individual cases on a prospective basis. Results: the 30-day mortality rate was 53%. Multivariate analysis identified four highly significant independent predictors of mortality; preoperative hypotension, intraperitoneal rupture, preoperative coagulopathy, and preoperative cardiac arrest. Using these inputs, the neural network correctly predicted outcome in 82.5% of individual cases. Conclusion: a neural network based on just four perioperative variables can accurately predict outcome of RAAA. Prognostic variables should be reported in studies as a measure of the effect of case mix on survival data. Neural networks have potential to aid decision-making relating to outcome for individual cases

Prospective analysis of quality of life in patients following infrainguinal reconstruction for chronic critical ischaemia

BackgroundThe aims of this prospective study were to analyse the health-related quality of life (QOL) changes associated with infrainguinal arterial reconstruction for chronic critical limb ischaemia (CLI) and to assess the impact of graft patency and limb salvage.MethodsFifty-five consecutive patients, 28 women and 27 men of median age 71 (range 41-86) years, undergoing infrainguinal arterial reconstruction for CLI, consented to participate in the study. QOL was assessed using the Short Form 36 (SF36) health survey questionnaire, which was completed before and at 1, 3, 6 and 12 months following surgery. Graft patency was assessed by duplex imaging at the same postoperative intervals.ResultsCLI severely impaired QOL. Cumulative graft patency at 1, 3, 6 and 12 months after surgery was 82, 78, 76 and 64 per cent respectively. Reconstruction resulted in significant improvements in the SF36 domains Physical Functioning, Pain, Vitality and Social Functioning (P &lt; 0&middot;01). With a patent graft these improvements began soon after surgery and were maintained for the 12 months studied. Following irredeemable graft occlusion, patients who had secondary amputation also described some QOL improvements.ConclusionA patent graft following infrainguinal arterial reconstruction for critical ischaemia results in an immediate and lasting improvement in health-related QOL. &copy; 1998 British Journal of Surgery Society Lt

Does soluble intercellular adhesion molecule-1 (ICAM-1) affect neutrophil activation and adhesion following ischaemia-reperfusion?

Objective: to examine the effect of reperfusion plasma and sICAM-1 on neutrophil integrin expression and neutrophil adhesion to determine if sICAM-1 has a potential role in the regulation of neutrophil adhesion. Materials: twenty-seven patients, 17 men and 10 women undergoing femorodistal surgery. Blood was taken preoperatively and from the femoral vein following the release of the cross-clamp. Neutrophils were obtained from five volunteers and incubated with phosphate buffered saline (PBS), preoperative plasma or reperfusion plasma with and without sICAM-1. Neutrophil expression of CD11b and adhesion were measured. Main results: neutrophil CD11b expression did not change following incubation in the three media. Neutrophil adhesion increased significantly following exposure to reperfusion plasma compared to PBS or preoperative plasma (45.5 adhesion vs. 12.75%, p < 0.01 Mann-Whitney U-test). Soluble ICAM-1 decreased CD11b expression and adhesion in neutrophils exposed to reperfusion plasma only (CD11b expression fell from 15.9 to 3.4 mcf, p < 0.01 Mann-Whitney U-test and adhesion fell to 11.6% cells adhered, p < 0.01). Conclusion: an increase in CD11b expression is not required for an increase in neutrophil adhesion. The change in neutrophil adhesion produced by reperfusion plasma can be blocked by sICAM-1. Soluble ICAM-1 may have a physiological role in the regulation of neutrophil adhesion

Reduced total antioxidant capacity predicts ischaemia-reperfusion injury after femorodistal bypass

BackgroundAntioxidant defence systems are essential to protect the body from harmful free radicals released following ischaemia-reperfusion. The aim of this study was to examine the total antioxidant capacity (TAC) of patients with chronic critical leg ischaemia undergoing femorodistal bypass and to correlate this with lipid peroxidation, changes in capillary permeability and clinical outcome.MethodsTwenty-five patients, 15 men and ten women of median age 71 (range 62-79) years, and 15 matched controls were studied. Blood was taken before operation and after reperfusion, with assays performed for malondialdehyde (a product of lipid peroxidation) and total antioxidant capacity. Changes in capillary permeability were measured by changes in the urinary albumin:creatinine ratio (ACR) following reperfusion of the ischaemic leg and expressed as a percentage increase from the preoperative value. Clinical outcome in terms of the systemic inflammatory response syndrome (SIRS) was recorded.ResultsVascular patients who developed clinical evidence of a systemic inflammatory reaction following revascularization had a significantly reduced TAC compared with the controls (490 versus 860 &micro;mol/l; P &lt; 0&middot;01, Mann-Whitney U test). These patients also demonstrated an increase in lipid peroxidation (0&middot;5 versus 0&middot;25 &micro;mol/l, P &lt; 0&middot;05) and vascular permeability, as measured by the percentage increase in ACR (365 versus 130 per cent, P &lt; 0&middot;01).ConclusionVascular patients with a lower TAC developed increased capillary permeability as a result of ischaemia-reperfusion, which progressed to SIRS. TAC may provide a test to identify &lsquo;at risk' patients. It may be possible to augment their defence with exogenous antioxidants. &copy; 1998 British Journal of Surgery Society Lt