Predictors of 1-Year Survival After Endovascular Aneurysm Repair.

OBJECTIVE/BACKGROUND: The purpose of this study was to determine the preoperative variables that best predict 1-year survival following elective endovascular aneurysm repair (EVAR), a period of time that would suggest the patient had benefited from the procedure. Most EVAR survival studies focus on early and late survival; scant information is available for 1-year survival. METHODS: Data from two Australian audits of EVAR (1999-2001 and 2009-13) were combined (n = 1,647). Preoperative variables included routine demographic data, clinical health assessments, computed tomography-derived anatomical data, and all-cause mortality. Univariate and multivariate logistic regressions determined which variables best predicted 1-year survival. RESULTS: One-year survival after EVAR was 93.7% (1,544/1,647) and 30-day survival was 98.4% (1,620/1,647). Univariate analyses found that nine preoperative variables were significantly associated with 1-year survival. Five variables were included in the final multivariate model: American Society of Anesthesiologists physical status, aneurysm diameter, creatinine, respiratory assessment, and severity of iliac artery calcification (receiver-operator curve 0.717, R(2) = .117). Predicted 1-year survival ranged from 98.6% to 68.0%, based on differences in aneurysm size and patient comorbidities. CONCLUSION: Personalised 1-year survival risk enables surgeons and patients to consider seriously the risks and benefits of EVAR prior to surgery.

Personalised predictions of endovascular aneurysm repair success rates: validating the ERA model with UK Vascular Institute data.

OBJECTIVE: The objective of this study was to externally validate the existing Australian Endovascular aneurysm repair Risk Assessment (ERA) Model using data from a major vascular centre in the United Kingdom. METHODS: Data collected from 312 endovascular abdominal aortic aneurysm repair patients at St George's Vascular Institute, London, UK were fitted to the ERA Model. RESULTS: Despite St George's patients being sicker (p < 0.001), having larger aneurysms (p < 0.001) and being more likely to die (p < 0.05) than the Australian patients, their data fitted the ERA Model well for the risk factors early death, aneurysm-related death, three-year survival and type I endoleaks as evidenced by higher area under ROC curves and/or higher R(2) goodness of fit statistics than the Australian data. CONCLUSIONS: The first external validation of the ERA Model using data from St George's Vascular Institute suggests that this tool can be used in different countries and hospital settings. The authors believe the ERA Model is robust and allows valid personalised predictions of outcomes by surgeons treating routine aneurysms as well as those in tertiary referral practices with more adverse outcomes.

Simvastatin plus nitric oxide synthase inhibition modulates remote organ damage following skeletal muscle ischemia-reperfusion injury.

UNLABELLED: Ischemia-reperfusion injury (IRI) to the lower extremities causes both local damage and serious dysfunction to remote organs, including lungs and kidneys. However, effective therapies are not available. This study aims to determine if simvastatin reduced the severity of remote damage following IRI. METHODS: Rats were given simvastatin before hind limb IRI. Lung and kidney tissues were assessed for neutrophil infiltration using myeloperoxidase assays and basement membrane damage by quantitative immunohistochemical measurement of collagen IV. The effect of nitric oxide synthase (NOS) inhibition on remote damage after IRI and simvastatin was assessed using the NOS inhibitor, L-NIO. RESULTS: Simvastatin (2 mg/kg) protected kidneys against IRI-induced neutrophil infiltration. Simvastatin also inhibited the IRI-induced activation of MMP-9 in the lungs. However, paradoxically, simvastatin exacerbated IRI-induced neutrophil infiltration into the lungs. IRI induced collagen IV degradation in the lungs but not in the kidneys. The degree of collagen breakdown in the lungs was significantly ameliorated by 2 mg/kg simvastatin. NOS inhibition markedly protected both the lungs and the kidneys against IRI-induced neutrophil infiltration but did not alter collagen IV degradation. Administration of simvastatin to L-Nio-treated animals enhanced the degree of protection against IRI-induced neutrophil infiltration in the kidneys but not in the lungs. CONCLUSIONS: Simvastatin protects against remote IRI-induced damage in the lungs and kidneys, suggesting statins may reduce the severity of IRI during major vascular surgery.

Preoperative nutritional status predicts the severity of the systemic inflammatory response syndrome (SIRS) following major vascular surgery.

OBJECTIVES: This study examined the relationship between pre-operative nutritional status and systemic inflammatory response syndrome (SIRS) or sepsis following major vascular surgery. DESIGN AND METHODS: Subjects undergoing open AAA repair, EVAR or lower limb revascularisation were studied prospectively. Pre-operative nutrition was assessed clinically using Mini-Nutritional Assessment (MNA) and body composition was measured by dual energy X-ray absorptiometry (DEXA) scanning. SIRS severity was assessed for 5 post-operative days and sepsis noted within 30 days of surgery. RESULTS: Using MNA, neither SIRS severity nor sepsis occurrence differed significantly between 'well-nourished' subjects and those 'at risk of malnutrition'. Using DEXA, negative associations existed between body mass index and both SIRS score and SIRS duration. Fat free mass (FFM) was negatively associated with SIRS score and duration. Negative associations also existed between skeletal muscle mass (SMM) and SIRS score and duration. SMM was also negatively correlated with post-operative length of stay in hospital. There were no significant correlations between sepsis and any nutritional indices. CONCLUSIONS: Lower pre-operative nutritional indices, indicating protein energy malnutrition, were associated with more severe systemic inflammatory responses following major vascular surgery.

Arm vein as a last autogenous option for infrainguinal bypass surgery: it is worth the effort.

OBJECTIVES: Considerable evidence exists for the use of arm vein conduit in lower limb bypass surgery. The use of arm vein in preference to synthetic conduit as a last autogenous option was assessed for patency and limb salvage outcomes. MATERIALS AND METHODS: A prospective database was interrogated and checked against TQEH operating theatre database to detect all infrainguinal arm vein bypasses performed between 1997 and 2005. Patency, limb salvage and survival data for 37 arm vein bypasses was calculated using the Kaplan-Meier survival estimate method. RESULTS: There were no perioperative deaths. 30 day patency rates were 89% primary, 95% secondary and 95% limb salvage. 12 month patency rates were 56% primary, 79% secondary and 91% limb salvage. 5 year patency rates were 37% primary, 76% secondary and 91% limb salvage. There was no significant patency advantage for primary vs. "redo" grafts (p=0.54), single vessel vs. spliced conduits (p=0.33) or popliteal vs tibial outflow (p=0.80). Patient survival rate was 92% and 65% at 1 and 5 years respectively. CONCLUSION: Lower limb bypasses using arm vein can be performed with favourable patency and limb salvage compared to synthetic conduits. However, secondary interventions are frequently required to maintain patency. We recommend a vigilant surveillance program for early identification of patency threatening disease.

Trends in the presentation and surgical management of the acute diabetic foot.

BACKGROUND: This study examines trends in the presentation and surgical management of acute diabetic foot problems in a single institution. METHOD: Prospective audit of all diabetic patients who had a primary procedure for critical lower limb ischaemia (CLI) and/or foot sepsis between 1st January 1990 and 31st December 2002. Primary and secondary intervention, mortality and limb salvage rate within 6 weeks of the index procedure were recorded. RESULTS: There were 661 patients (417 men and 244 women of median age 69, range 31-99, years) with 799 affected limbs. CLI alone was present in 625 (78%) limbs, combined CLI and foot sepsis in 53 (7%) and foot sepsis alone in 121 (15%). The primary intervention was minor amputation in 323 (40%) limbs, revascularisation in 288 (36%), major amputation in 185 (23%) and sympathectomy in three limbs. Within 6 weeks, 125 (16%) limbs required secondary intervention, the peri-procedural mortality rate was 38 of 924 (4%), and the limb salvage rates for patients with CLI, combined CLI and sepsis and sepsis alone were 66, 66 and 80%, respectively. There was a significant decline in the proportion of patients presenting with CLI alone and a significant increase in the proportion presenting with combined CLI and sepsis and sepsis alone. In patients with CLI alone, there was a significant increase in the primary major amputation rate and a significant decline in the minor amputation rate with no significant change in the revascularisation rate. CONCLUSION: There has been a progressive decline in the proportion of patients presenting with CLI alone and a greater proportion of patients presenting with an element of foot sepsis. In patients with CLI alone, the primary major amputation rate has increased at the expense of a decline in minor amputation rate.

Systematic review of endovenous laser treatment for varicose veins.

BACKGROUND: The safety and effectiveness of endovenous laser treatment (EVLT) for varicose veins are not yet fully evaluated. METHODS: Medical bibliographic databases, the internet and reference lists were searched from January 1966 to September 2004. Only case series were available for inclusion in the review. RESULTS: : Thirteen studies met the inclusion criteria. Self-limiting features, such as pain, ecchymosis, induration and phlebitis, were commonly encountered after treatment. Deep vein thrombosis and incorrect placement of the laser in vessels were uncommon adverse events. No study has yet assessed the effectiveness of laser therapy in comparison to saphenofemoral junction ligation with saphenous vein stripping. Occlusion of the saphenous vein and abolition of venous reflux occurred in 87.9-100 per cent of limbs, with low rates of re-treatment and recanalization. CONCLUSION: From the low-level evidence available it seems that EVLT benefits most patients in the short term, but rates of recanalization, re-treatment, occlusion and reflux may alter with longer follow-up. The lack of such data, in addition to the small numbers of patients in the available studies, demonstrates the need for a randomized clinical trial of EVLT versus conventional surgery.

Intra-abdominal packing for uncontrollable haemorrhage during ruptured abdominal aortic aneurysm repair.

OBJECTIVE: Intra-abdominal packing is a valuable adjunct in patients with abdominal trauma and uncontrollable bleeding but few data exist regarding early and late outcome associated with this technique in patients with ruptured abdominal aortic aneurysm (AAA). METHODS: Interrogation of a prospective vascular surgical database identified 23 patients (22 men; median age 69, range 59-82, years) with ruptured AAA who required intra-abdominal packing for control of coagulopathic haemorrhage after insertion of an aortic graft between January 1982 and December 2003. Co-morbidity, operative and outcome data were retrieved. RESULTS: Haemostasis was achieved and packs were removed within 48 h in 20 patients. In those patients who had a graft inserted, the peri-operative mortality rate was 12 of 23 (52%) patients (vs. 172 of 455 (38%) patients who were not packed, NS). Three (13%) patients developed early intra-abdominal sepsis, which was universally fatal: graft-enteric fistula, intra-abdominal abscess with necrotizing fasciitis of the abdominal wound, and infected retroperitoneal haematoma. Two of 11 (18%) survivors developed late graft-related infective complications: major aortic graft infection at 6 months and symptomatic infected para-anastomotic aortic false aneurysm at 39 months. Early and late intra-abdominal infective complications were significantly more common in patients who were packed than in those who were not (packed: five of 23, 22% vs. non-packed: five of 455, 1%; p < 0.001). CONCLUSION: These data demonstrate that intra-abdominal packing in coagulopathic patients with ruptured AAA can achieve an acceptable survival rate. However, this technique may be associated with an increased incidence of early and late intra-abdominal infective complications.

The role of statins in vascular disease.

BACKGROUND: Recent publications have highlighted the benefits of statins in non-cardiac occlusive disease but also the failure of vascular surgeons to recognise and treat the risk factors for atherosclerosis, in particular hypercholesterolaemia. The aim of this review is to clarify the current experimental and clinical evidence for the use of statins in vascular disease. METHODS: Literature compiled from an extensive search of Medline and the Cochrane database has been used for the basis of this review. RESULTS: Experimental and clinical evidence consistently reports that statins improve endothelial dysfunction, are anti-inflammatory, anti-proliferative, anti-thrombogenic and anti-proteolytic. These effects are known to inhibit atherogenesis and improve plaque stability. Independent groups support the use of statins in the prevention of both primary and secondary cardiac events. The National Stroke association recommends their use to reduce strokes following myocardial infarction and the Heart Protection Study reports benefits in patients with non-cardiac occlusive disease. CONCLUSIONS: There is substantial evidence advocating the use of statins in patients with clinically significant vascular disease. In the future this may evolve to include those patients at risk from neointimal hyperplasia, aneurysmal disease and ischaemia reperfusion injury.

Up-regulation of MMP-2 and MMP-9 leads to degradation of type IV collagen during skeletal muscle reperfusion injury; protection by the MMP inhibitor, doxycycline.

OBJECTIVES: to determine the role of matrix metalloproteinases, MMP-2 and MMP-9, in reperfusion injury following skeletal muscle ischaemia and whether inhibition of MMPs by doxycycline protects against tissue damage. METHODS: rats were anaesthetised and a tourniquet applied to the proximal thigh to occlude blood flow. Four hours of ischaemia was followed by reperfusion for 0, 4, 24 or 72 h. Two further groups received doxycycline for 7 days prior to bilateral ischaemia and 24 h reperfusion. Skeletal muscle from both limbs, kidneys and lungs were harvested for zymography and immunohistochemical staining for type IV collagen. RESULTS: upregulation of MMP-2 and MMP-9 was detected by zymography in the ischaemic leg and lung but not in the kidney. Quantitative immunohistochemical analysis showed marked degradation of type IV collagen in reperfused muscle, lung and kidney. Doxycycline-treated rats showed significant preservation of type IV collagen in skeletal muscle and a trend towards preservation in kidney and lung. CONCLUSIONS: MMP-2 and MMP-9 are strongly upregulated in skeletal muscle ischaemia/reperfusion injury and are also upregulated in remote organs, leading to degradation of basement membranes. Inhibition of MMP activity may therefore be potentially therapeutically useful in reducing the severity of reperfusion injury.

Proximalized lateral tunnel for the bypass to the dorsalis pedis artery -- a safe way to go.

BACKGROUND: Wound complications associated with bypass grafting to the dorsalis pedis artery are frequent, and threaten the viability of the bypass and the limb. METHODS: The long saphenous vein can be tunneled from its bed down the lateral side of the anterior margin of the tibia for subsequent anastomosis with the dorsalis pedis artery. CONCLUSION: The proximalized lateral tunnel for the bypass to the dorsalis pedis artery has the advantage of protecting the bypass graft from exposure if the patient develops wound breakdown.

Apoptotic cell death makes a minor contribution to reperfusion injury in skeletal muscle in the rat.

OBJECTIVE: to determine if apoptotic cell death contributes to skeletal muscle reperfusion injury. METHODS: leg ischaemia was induced in rats with a tourniquet and maintained for 4 h before reperfusion for 24 or 72 h. Apoptosis was assessed by morphology, in situ end labelling of DNA fragments, DNA laddering, expression of p53 mRNA and detection of caspase-3-like proteolytic activity. RESULTS: increased caspase-3-like activity was detected in muscle following ischaemia and zero, 24 h or 72 h of reperfusion. Levels remained relatively low but with a highly significant difference in enzyme activity between the ischaemic and non-ischaemic legs (p <0.0001, Repeated Measures Analysis of Variance). Morphological examination showed considerable oedema, disruption of muscle fibres and infiltration of white cells into tissues. Muscle nuclei did not show any morphological evidence of apoptosis and were negative for DNA fragmentation, while occasional neutrophils contained fragmented DNA. Expression of p53 was not induced by ischaemia and reperfusion and DNA ladders were not detected. CONCLUSIONS: the cells undergoing apoptosis were infiltrating neutrophils rather than muscle cells and reperfused muscle was damaged largely by an inflammatory process involving considerable oedema.

Carotid bifurcation CT angiography: assessment of interactive volume rendering.

PURPOSE: The purpose of this study was to compare the accuracy of CT angiography (CTA) for the assessment of carotid bifurcation stenosis, using interactive volume rendering (VR), maximum intensity projection (MIP), and 2D transverse CT technique (t-CT). METHOD: Nineteen consecutive patients were prospectively studied with CTA and selective digital subtraction angiography (DSA). There were 13 men and 6 women from 51 to 84 years old (mean 70 years). Results of DSA were compared with those of interactive VR, MIP, and conventional t-CT results, using North American Symptomatic Carotid Endarterectomy Trial criteria for stenosis grading. RESULTS: There were a total of 38 carotid bifurcations studied, with 9 mild, 10 moderate, and 15 severe stenoses and 4 occlusions. Overall agreement with DSA for VR was achieved in 76%. Eighty percent of the severe stenoses were correctly predicted by VR. The overall agreement between t-CT and DSA was 89%. MIP images, when analyzed independently, showed an overall agreement with angiography of only 71%. VR was not significantly different from MIP (p = 0.60). The difference between VR and t-CT had borderline significance (p = 0.09). MIP had significantly poorer agreement with angiography than t-CT (p = 0.02). CONCLUSION: CTA has a high degree of accuracy for the assessment of carotid artery disease compared with catheter angiography. Interactive VR increases the accuracy of diagnosing carotid stenosis and decreases the number of unsatisfactory studies as compared with MIP. Further advances in computation speeds and improvements in software may dramatically alter the future use of VR for the communication of results to clinicians; however, careful analysis of transverse sections is essential to accurate CT interpretation.

Arteriography in chronic renal failure: a case for carbon dioxide.

PURPOSE: The aim of this study was to assess the utilisation of carbon dioxide arteriography, performed with a simple injection system, as the imaging technique of choice in patients with chronic renal failure. METHODS: Patients with chronic renal impairment who required arterial imaging or intervention were recruited for carbon dioxide angiography. Demographic data were prospectively recorded and pre- and post-arteriogram renal function was quantified. Radiographic images were graded by an independent radiologist. RESULTS: Twenty-eight patients underwent renal or aorto-femoral studies with only one failure. There were no cases of contrast-induced nephropathy. Twenty-two of the films (79%) were graded as excellent or good, four as acceptable and two were considered to be poor (non-diagnostic). CONCLUSIONS: This study has demonstrated that carbon dioxide angiography is a safe and clinically effective procedure in patients with chronic renal failure.

A prospective randomized trial evaluating the haemodynamic role of incompetent calf perforating veins.

AIM: This study was undertaken to determine the haemodynamic effect of incompetent calf perforating veins in patients with uncomplicated varicose veins and long saphenous incompetence. METHODS: Thirty-eight limbs from 35 patients were studied. All patients had uncomplicated varicose veins with both long saphenous and calf perforator incompetence on duplex ultrasonography. Patients were randomized to have incompetent calf perforators ligated or left intact, in addition to saphenofemoral junction ligation, strip of long saphenous vein to knee and stab avulsion of any visible varicosities in the leg. Patients were assessed with air plethysmography pre-operatively and 3 months postoperatively. RESULTS: Superficial venous surgery improved venous volume, venous filling index and ejection fraction in the patient cohort. No significant haemodynamic difference was demonstrated between the two groups of patients who were randomized. CONCLUSIONS: At present, the results of this study do not support the use of routine perforator ligation during superficial surgery for uncomplicated varicose veins.

Deregulation of apoptosis in colorectal carcinoma: theoretical and therapeutic implications.

Apoptosis, or programmed cell death, maintains the structure of the colonic crypts by providing a balance to the rate of cell proliferation. Colorectal carcinoma arises partly from a disruption in this balance in the favour of uncontrolled growth. Until recently, most research into colon cancer has focused on the molecular regulators of cell-cycle progression and proliferation, but it is now evident that apoptosis is also defective. A failure of cells to die in response to premalignant damage may allow the progression of the disease and maintain the resistance of cancer cells to cytotoxic therapy. This review outlines the importance of apoptosis in the normal colon and presents recent studies that demonstrate that induction of apoptosis is defective in colonic tumours. When the molecular regulation of apoptosis is better understood, this knowledge may lead to the earlier detection of patients at greater risk of developing colorectal carcinoma, and also to the development of more effective therapies.

Upper extremity arterial injuries: experience at the Royal Adelaide Hospital, 1969 to 1991.

PURPOSE: A review of upper extremity arterial injuries managed at the Royal Adelaide Hospital between 1969 and 1991 was undertaken because the optimal management of complex upper extremity trauma, particularly in proximal injuries, remains unclear. METHODS: Patients were identified from the computer registry of patients treated by the vascular unit at the Royal Adelaide Hospital. They were studied in three groups: (1) subclavian and axillary artery, (2) brachial artery, and (3) radial and ulnar artery injuries. The mechanism of injury, associated injuries, treatment and outcome were reviewed. RESULTS: There were 114 patients with upper extremity arterial injuries: 28 with subclavian and axillary, 62 with brachial, and 24 with radial and ulnar artery injuries. Good upper limb function was obtained in 32% of subclavian and axillary artery injuries, 79% of brachial artery injuries, and all radial and ulnar artery injuries. Amputation was performed in 14% of the proximal injuries and 8% of the brachial artery injuries. Three deaths occurred in this study group. CONCLUSION: Blunt proximal injuries were usually associated with neurologic, soft tissue, and bony damage, which was responsible for the poor functional outcome. Critical limb ischemia or severe hemorrhage rarely occurred. Complete brachial plexus lesions resulted in uniformly poor outcomes. More distal injuries were associated with fewer nerve and soft tissue injuries, resulting in a more satisfactory outcome.