Endovascular repair of iatrogenic popliteal artery trauma.

PURPOSE: To evaluate the outcome of the management of iatrogenic arterial injuries following knee arthroplasty using a primary endovascular approach. METHODS: A detailed review of the management of all iatrogenic arterial injuries to the lower limb following total knee arthroplasty (TKA) referred to the Vascular Surgical Unit of a tertiary referral hospital between July 2005 and December 2007 identified from a prospectively maintained database. RESULTS: Of the seven cases referred over a 30-month period, six patients underwent endovascular treatment with successful limb salvage. All seven injuries were related to the popliteal artery behind the knee: pseudoaneurysm (4), intimal flap occlusion (2) and stenosis (1). One patient underwent above-knee amputation. The presentation and pattern of arterial injuries, potential risk factors for their occurrence, measures to reduce their risk and factors that aid in their early recognition are discussed. CONCLUSIONS: An endovascular approach may be considered for the management of these injuries, although it is likely to involve long-term surveillance and may not be appropriate for all cases. Surgeons performing TKA should be aware of the potential risk factors for arterial injury and maintain a high index of suspicion for these infrequent injuries during the post-operative period.

First-principle calculations on the microscopic 57Fe electric-field-gradient tensor of ferrous chloride tetrahydrate: a prototypical Mössbauer species.

Since the pioneering work on the theoretical description of Mössbauer quadrupole line intensities for a single-crystal to elucidate information on the electric-field-gradient (EFG) tensor, ferrous chloride tetrahydrate, FeCl(2)·4H(2)O, has represented a prototypical Mössbauer species. In addition, this species also typifies a so-called ambiguous, low symmetry, iron center where traditionally only macroscopic tensors have been assumed available for determination. Recent experiments on FeCl(2)·4H(2)O have successfully determined physically meaningful spin-Hamiltonian parameters for the (57)Fe microscopic (local) EFG and mean-squared displacement tensors. This paper reports a density functional theory investigation that finds good agreement with experiment. Assuming a gas-phase scaffold cluster approach to describe the crystalline geometry, the sign of the EFG was determined to be positive, in agreement with earlier magnetically perturbed experiments, and the EFG asymmetry parameter η was calculated to be 0.21-0.23 depending on the density functional used, which is in excellent accord with experiment at 0.25(2). By virtue of theoretical and experimental agreement, this work indicates that simultaneous electric-field-gradient-mean-square-displacement Mössbauer determinations can resolve the apparent ambiguity associated with monoclinic, 2/m or 1 Laue class, sites provided there is sufficient anisotropy in the Lamb-Mössbauer recoilless fraction.

Higher-order Zeeman and spin terms in the electron paramagnetic resonance spin Hamiltonian; their description in irreducible form using Cartesian, tesseral spherical tensor and Stevens' operator expressions.

In setting up a spin Hamiltonian (SH) to study high-spin Zeeman and high-spin nuclear and/or electronic interactions in electron paramagnetic resonance (EPR) experiments, it is argued that a maximally reduced SH (MRSH) framed in tesseral combinations of spherical tensor operators is necessary. Then, the SH contains only those terms that are necessary and sufficient to describe the particular spin system. The paper proceeds then to obtain interrelationships between the parameters of the MRSH and those of alternative SHs expressed in Cartesian tensor and Stevens operator-equivalent forms. The examples taken, initially, are those of Cartesian and Stevens' expressions for high-spin Zeeman terms of dimension BS(3) and BS(5). Starting from the well-known decomposition of the general Cartesian tensor of second rank to three irreducible tensors of ranks 0, 1 and 2, the decomposition of Cartesian tensors of ranks 4 and 6 are treated similarly. Next, following a generalization of the tesseral spherical tensor equations, the interrelationships amongst the parameters of the three kinds of expressions, as derived from equivalent SHs, are determined and detailed tables, including all redundancy equations, set out. In each of these cases the lowest symmetry, [Formula: see text] Laue class, is assumed and then examples of relationships for specific higher symmetries derived therefrom. The validity of a spin Hamiltonian containing mixtures of terms from the three expressions is considered in some detail for several specific symmetries, including again the lowest symmetry. Finally, we address the application of some of the relationships derived here to seldom-observed low-symmetry effects in EPR spectra, when high-spin electronic and nuclear interactions are present.

Managing waterway health in the Goulburn Broken Catchment, Victoria, Australia.

Historically within most catchments, resource management programs have been planned and implemented in isolation of one another. This was once the case in the Goulburn Broken Catchment, a major catchment of the Murray Darling Basin, Australia. Although only 2% of the Murray Darling Basin's land area, the catchment generates 11% of the basin's water resources. Learning from the past, a cooperative and collaborative approach to natural resource programs has developed. This approach is the envy of many other catchment communities and agencies. Through a combination of "Partnership Programs", "Operational Initiatives" and community involvement, significant programs have been implemented within the catchment, which will benefit not only the local community but communities further afield. The outcomes of the waterway health program highlight the benefits provided through the establishment of cooperative and partnership resource improvement programs. These programs were founded on the ability of the community to recognise the need for integration, base management decisions on best available science and an ability to work together. Their effective delivery has been provided through the resources provided, to the local community, by the Natural Heritage Trust with matching and State and local allocations. While programs have shown success, challenges still face the community. These challenges include verification and implementation of environmental flows, storage of the catchment's vital water resources, and maintaining community involvement and participation in on-going works programs. The Goulburn Broken Catchment community, with the support of Federal, State and Local Governments, is looking at opportunities for continued improvements in waterway health.

Developing a one-stop clinic for leg ulcer patients.

Leg ulceration may be caused by a variety of different factors and specialist assessment is required. Patients with complex leg ulcers in Nottingham are assessed at a one-stop dermatology/vascular clinic. Nurses undertake assessments, provide education and support and liaise with the community nursing services.

Postirradiation aortic sarcoma demonstrated by magnetic resonance angiography.

This is the first ever reported case of a radiation-induced aortic sarcoma. This patient had symptoms and signs initially interpreted as a pulmonary embolus. The extent of the disease was demonstrated with magnetic resonance imaging and magnetic resonance angiography, in particular, allowing rapid surgical intervention.

Large-magnitude high-spin nuclear parameters in a Ti3+ center from X-band EPR measurements at 10 K.

Precise 10 K X-band EPR measurements and subsequent spin-Hamiltonian analysis by direct matrix diagonalization methods are reported for a Ti3+ (S = 1/2) center in tetragonal zircon (zirconium silicate, ZrSiO4). A special, and previously unobserved, feature of the supposedly uniaxial spectrum is the marked angular dependence of the titanium hyperfine lines in the perpendicular, ab crystal plane. As discussed, this can only arise from the presence of high-spin nuclear terms of dimension BIk, SIk (k = 3, 5) in the spin Hamiltonian. Parameters arising from these terms were determined to have magnitudes very much larger than observed previously in first-row transition ions. The consequences of precise determination of these high-spin parameters are significant and several: a precise determination of the nuclear quadrupole tensor leading to a ratio 47P/49P in excellent agreement with the ratio derived from the corresponding nuclear quadrupole moments; an apparent anisotropy in the nuclear Zeeman interaction which can be identified with anisotropy in the chemical shielding "tensor"; a marked hyperfine anomaly. The origin and significance of these observations are discussed.

Early complications of femorofemoral crossover bypass grafts after aorta uni-iliac endovascular repair of abdominal aortic aneurysms.

OBJECTIVE: The following procedures are the 3 main methods of endovascular repair (EVR) of abdominal aortic aneurysms (AAA): aorto-aortic bypass grafting, bifurcated bypass grafting, and aorta uni-iliac grafts. The latter method has the potential disadvantage of requiring an extra anatomic graft (ie, a femorofemoral crossover bypass graft) to maintain contralateral pelvic and limb perfusion. The aim of this study was to assess the complications associated with the femorofemoral crossover bypass graft after aorta uni-iliac EVR of AAA. METHOD: A prospective review was conducted of the complications attributable to the femorofemoral crossover bypass graft in 136 patients who underwent EVR of AAA with an aorta uni-iliac device. RESULTS: During a median follow-up of 7 months (range, 0 to 36 months), 4 patients had superficial wound infections that required antibiotic treatment and 2 patients had bypass graft infections. Nine hematomas developed: 7 (5%) groin hematomas (6 in patients with Dacron bypass grafts), 1 scrotal hematoma, and 1 perigraft hematoma. One bypass graft thrombus developed. CONCLUSION: The femorofemoral crossover bypass graft is a safe and a durable component of EVR of AAA with an aorta uni-iliac device. The results are similar to those with bifurcated devices.

Traumatic occlusion of the external iliac artery in a racing cyclist: a cause of ill defined leg pain.

Stenosis of the external iliac artery in healthy athletes, although uncommon, has been reported in competition cyclists. A case of a racing cyclist whose chronic vague leg symptoms were incorrectly attributed to L4/5 nerve root irritation is reported. This highlights the importance of clinical vascular testing when assessing ill defined leg pain. The role of trauma as a causative factor in this condition has not been previously documented.

Early results of endovascular aortic aneurysm surgery with aortouniiliac graft, contralateral iliac occlusion, and femorofemoral bypass.

PURPOSE: The aim of this study was to evaluate the feasibility of endovascular aortic aneurysm repair with use of an aortouniiliac graft secured with self-expanding (Gianturco) stents. METHODS: Thirty patients with a median age of 72 years (age range, 52 to 86 years) and aneurysm diameter of 6.0 cm (range, 4.0 to 9.0 cm) were treated with an aortouniiliac endovascular graft. Of these 30 procedures, 28 were carried out electively and two as emergencies for leaking aneurysm. Of the 30 patients, 21 (70%) were considered to be at high risk for open surgery. A modified Gianturco stent, Dacron graft, and Wallstent were used for these procedures. RESULTS: Endovascular repair was successfully carried out in 25 of 30 (83.3%) patients. All these patients were mobile and had resumed a normal diet within 48 hours of the procedure. The overall 30-day mortality rate was two in 30 (6.6%), but it was one in 28 (3.5%) for the elective cases; all deaths occurred in the group at high risk for surgery. Other complications encountered within 30 days of procedure included myocardial infarction in one patient, pneumonia in two patients, homonymous quadrantanopia in one patient, and colonic ischemia in one patient, giving an overall morbidity rate of four in 30 (13.3%). At a median follow-up of 4 months (range, 1 to 13 months), 27 of 30 (90%) patients remain alive and well. CONCLUSION: Endovascular aortouniiliac repair of abdominal aortic aneurysm with Gianturco stent is feasible in both elective and emergency situations. It appears to be minimally traumatic, and the majority of patients deemed to be at high risk for open surgery can safely undergo endovascular repair. However, data on more patients with longer follow-up is required to determine its role in the management of abdominal aortic aneurysm.

Homocysteine: an independent risk factor for the failure of vascular intervention.

Hyperhomocysteinaemia is an independent risk factor for the early development of arterial disease. Homocysteine and cardiovascular risk factors were assessed in 41 young and 25 older patients with vascular disease. As homocysteine may act by the generation of free radicals, total antioxidant capacity was measured. Hyperhomocysteinaemia was found in 29 per cent of patients but there was no difference between young and older patients. Homocysteine level was unrelated to other cardiovascular risk factors. Young age, diabetes and hyperhomocysteinaemia were independent risk factors for the failure of vascular procedures (P = 0.006). Patients with hyperhomocysteinaemia had raised total antioxidant capacity. The potential of identifying and treating a subgroup of patients with a poor prognosis deserves further study.

Non-invasive aortoiliac assessment.

OBJECTIVES: To assess the accuracy of Duplex ultrasound in the assessment of aortoiliac disease. DESIGN: Prospective, semi-blind study. SETTING: Vascular laboratory and radiology departments, University Hospital. MATERIALS AND METHODS: Ninety-two patients underwent assessment of the aortoiliac segment by femoral pulse palpation, Duplex ultrasound and biplanar arteriography. Of these 184 aortoiliac segments, 68 were also assessed by intraarterial pressure measurements and 80 by magnetic resonance angiography (MRA). MAIN RESULTS: Femoral pulses were abnormal in all 32 occluded aortoiliac segments. Of 152 patent segments, femoral pulse palpation was misleading in 50 (33%). MRA detected all occlusions and had a sensitivity of 71% and specificity of 68% for stenoses, compared to arteriography. Colour flow Duplex misdiagnosed four occlusions as stenoses. Duplex had a sensitivity of 91% and specificity of 93% for stenoses when compared to arteriography. Two stenoses, detected by Duplex and confirmed by pressure gradients, were missed by arteriography. CONCLUSIONS: Pressure measurements remain the gold standard for aortoiliac examination, arteriography providing only morphological information. The limitations of femoral pulse palpation should be appreciated. Although MRA was faster, Duplex examination proved slightly more sensitive to stenoses. At present, colour Duplex provides the best non-invasive assessment of aortoiliac disease and could prevent unnecessary arteriograms.

Accurate prediction of outcome after pediatric forearm fracture.

Factors affecting outcome after pediatric forearm fracture include fracture angulation and fracture position. A new index, axis deviation, combines these factors. Two review studies were performed to determine if axis deviation correlated with outcome. In the first study, 35 subjects were reviewed 2.7 years after fracture without radiographs. In the second study, 152 fractures were reviewed a mean of 4 years after fracture, with 124 patients consenting to undergo radiographs. In both studies, the new index, axis deviation, correlated better with restricted forearm movement than either degree of angulation or fracture position. Midshaft and distal remodeling occurred and could be predicted in terms of axis deviation. We propose that an axis deviation of < 5 at the time of union be the reduction criteria of pediatric forearm-shaft fracture regardless of fracture position.

Radiologic investigation of abdominal aortic aneurysm disease: comparison of three modalities in staging and the detection of inflammatory change.

PURPOSE: The purpose of this study was to compare the ability of ultrasonography (US), contrast-enhanced computed tomography (CT), and magnetic resonance imaging (MRI) to display the anatomy of abdominal aortic aneurysms and to detect the presence of inflammatory change. METHODS: We prospectively studied 79 patients with abdominal aortic aneurysms (64 noninflammatory aneurysms [NIAAs] and 15 inflammatory aneurysms [IAAs]) with US, CT, and MRI. RESULTS: Ultrasonography failed to diagnose the level of the aneurysm neck in three IAAs and 18 NIAAs. It failed to differentiate NIAAs from IAAs and to visualize the origins of the renal arteries in all cases. With CT the level of the aneurysm neck was incorrectly stated as lying above the level of the renal arteries in two cases of IAA and four cases of NIAA, and the renal artery origins were seen in only 10 of 77 patients. Inflammatory change was diagnosed correctly in seven of 15 patients, whereas six NIAAs were falsely diagnosed as inflammatory. MRI successfully diagnosed neck level and inflammatory change in all cases. Of two failures to visualize the renal artery origins, only one was caused by radiologic factors. In addition, characteristic radiologic features were seen in MRI images of IAAs, and these will be described both in vivo and in vitro. CONCLUSIONS: Our results suggest that MRI is superior to other methods in identifying the anatomy of aneurysms and the presence of inflammatory change.

Inflammatory aortic aneurysms: characteristic appearance on magnetic resonance imaging.

Ten to 15% of all aortic aneurysms show inflammatory change. They are characteristically covered on their anterior and lateral sides with thick white fibrous tissue. Peri-aortic fibrosis may spread into the retroperitoneum to encase and obstruct adjacent organs making operative treatment more difficult and increasing the operative morbidity and mortality. Fifteen patients with inflammatory aneurysms and 46 patients with simple non-inflammatory aneurysms were studied prospectively. Each patient underwent magnetic resonance imaging (MRI) using a Picker Vista MR2055 scanner operating at 0.5 tesla. Each scan was reviewed by a radiologist (G.G.H.) preoperatively and a diagnosis of inflammatory or non-inflammatory aneurysm made. At operation, the diagnosis of aneurysm type was made on macroscopic features of inflammatory change, and confirmed histologically using previously published criteria. The radiological diagnosis was found to correspond to the surgical and pathological diagnosis in all cases. In cases of inflammatory aortic aneurysm the aneurysm wall appeared laminated on MRI scan, showing three or more bright, high-signal layers. These appearances of inflammatory change are characteristic, and were present in all 15 patients with such aneurysms. There were no false positives among those patients with simple aneurysms, and no false negatives. Operative specimens of aortic wall were taken from four patients with inflammatory aortic aneurysms and four patients with simple non-inflammatory aortic aneurysms, and subjected to MRI scanning. The characteristic banding appeared only in the inflammatory aneurysm wall samples. Magnetic resonance imaging is a highly sensitive investigative technique for the detection of inflammatory aneurysms, showing characteristic changes. These changes are also seen in in vitro scans of wall samples from inflammatory aneurysms.(ABSTRACT TRUNCATED AT 250 WORDS)

Metabolic activity in inflammatory and non-inflammatory aneurysms of the abdominal aorta.

Inflammatory aneurysms of the abdominal aorta (IAA) comprise 10-15% of all aortic aneurysms (AA) but their aetiology and pathogenesis are obscure. Destruction of mural elastin is a prominent feature of IAA, and both increased elastolysis and decreased inhibition of elastolysis have been implicated. In order to study these factors, we have examined the peripheral blood of three groups of patients; 15 with inflammatory aortic aneurysms (IAA), 61 with simple aortic aneurysms (SAA) and 35 with aorto-iliac occlusive disease (OD). In all cases, alpha-1-anti-trypsin (A-1-AT), alpha-2-macroglobulin (A-2-MG), elastase inhibitory activity (E.I.A.), elastase-anti-trypsin complex, C-reactive protein (CRP), caeruloplasmin (CP) and plasma viscosity were measured. Patients with IAA had a significantly higher plasma viscosity (Mann-Whitney, p less than 0.05), E.I.A. (Mann-Whitney, p less than 0.01) and levels of A-1-AT, CRP, CP and elastase/anti-trypsin complex (Mann-Whitney, all p less than 0.05) than patients in the other two groups. There was no difference in the levels of A-2-MG between any of the groups. This study refutes the theory that reduced inhibition of elastase activity predisposes to the formation of SAA. In patients with IAA, raised marker levels indicate ongoing destruction of elastin, and suggest a difference in pathogenesis between IAA and SAA. The study also suggests that IAA are highly active metabolically, as opposed to the more degenerative SAA.

Bath scalds in children in the south-east of Scotland.

Scalds caused by domestic hot tap water constitute a significant but preventable hazard in childhood. We have reviewed some of the factors contributing to such injuries, and the experience of a regional paediatric burn unit in their treatment. There were 91 children with bath water scalds and 667 children with thermal injuries from other sources included in this study. In the former group, scalds were more common on the limbs, including the hands and feet. Scalds involving over 40% of body surface area were more common in children with bath water injuries; however, there was no difference between the groups with regard to hospital stay or requirement for skin grafting. Parents ran the bath responsible for scald production in most cases, but single parenthood did not appear to be a risk factor. First aid application made no significant difference to eventual burn area or hospital stay. It appears from this study that reduction of domestic hot water temperature is necessary. Statutory control is likely to offer the best solution to the problem of domestic hot tap water scalds in childhood.

Impedance analysis to identify the at risk femorodistal graft.

Computer-assisted impedance analysis is a newly developed technique to identify femoropopliteal and distal vein graft stenoses before failure. Pulsatile flow is measured from the proximal and distal graft by use of an 8Mhz Doppler velocimeter. A pulse volume recorder measures pulsatile pressure within the thigh and calf. Fourier transfer analysis is performed on paired Doppler pulse volume recorder waveforms and an impedance score derived for the thigh and calf, respectively. In a retrospective review of 50 nonreversed femoropopliteal/distal grafts performed for limb salvage, postoperative biplanar intraarterial digital subtraction arteriography was compared with impedance analysis. Arteriography showed graft or runoff stenoses in 22 grafts (at risk) and 28 normal grafts (controls). Impedance scores were significantly higher in the at risk group (0.58 + [0.43 to 0.72]*), when compared with the controls (0.34 + [0.30 to 0.38], p less than 0.001*). A thigh or calf impedance score of greater than 0.45 was able to detect 20 of 22 stenoses, including 6 lesions in grafts with normal resting and postexercise ankle pressures. This score was then applied prospectively and compared with serial biplanar digital subtraction arteriography in a further 56 femoropopliteal/distal bypasses for limb salvage. Thirty-three of 34 lesions were successfully predicted and impedance scores were significantly higher in the at risk limbs (0.56 + [0.44 to 0.68]*) when compared with the controls (0.38 + [0.35 to 0.41], p less than 0.001*). In this series impedance analysis proved more sensitive than resting or stressed ankle pressures and, unlike Duplex scanning, was able to detect runoff as well as graft stenoses.(ABSTRACT TRUNCATED AT 250 WORDS)