Spontaneous rupture of suprarenal aneurysms: a late sequel to infrarenal aortic aneurysms repair.
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Aged↗
Biomedical subjects
D J Scott
Publications and source records attributed to D J Scott.
The microscopic features of inflammatory abdominal aortic aneurysms: discriminant analysis.
Up to 15% of abdominal aortic aneurysms are designated as inflammatory. They are characterized by marked fibrous thickening of the aneurysmal wall, with the fibrosis extending into the adjacent retroperitoneum. Thirty-five abdominal aortic aneurysms were studied, 15 inflammatory and 20 atherosclerotic. Of the inflammatory group, 10 were symptomatic and five asymptomatic. For each resection specimen, 59 microscopic features (variables) were scored semi-quantitatively. Discriminant function analysis showed that endarteritis obliterans, fibrosis around nerves or ganglia at the outer margin of mural fibrosis, and the thickness of the combined fibrotic media and adventitia gave a satisfactory high discrimination between atherosclerotic and inflammatory aneurysms. When these three variables are used together, a histological diagnosis of inflammatory aneurysm can be made with an expected accuracy in excess of 80%.
Aged↗
Withholding consent for medical care of a child: the ultimate parental decision.
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Adolescent↗
Evidence that conserved residues Cys-62 and Cys-154 within the Azotobacter vinelandii nitrogenase MoFe protein alpha-subunit are essential for nitrogenase activity but conserved residues His-83 and Cys-88 are not.
Metallocluster extrusion requirements, interspecies MoFe-protein primary sequence comparisons and comparison of the primary sequences of the MoFe-protein subunits with each other have been used to assign potential P-cluster (Fe-S cluster) domains within the MoFe protein. In each alpha-beta unit of the MoFe protein, alpha-subunit domains, which include potential Fe-S cluster ligands Cys-62, His-83, Cys-88 and Cys-154, and beta-subunit domains, which include potential Fe-S cluster ligands Cys-70, His-90, Cys-95 and Cys-153, are proposed to comprise nearly equivalent P-cluster environments located adjacent to each other in the native protein. As an approach to test this model and to probe the functional properties of the P clusters, amino acid residue substitutions were placed at the alpha-subunit Cys-62, His-83, Cys-88 and Cys-154 positions by site-directed mutagenesis of the Azotobacter vinelandii nifD gene. The diazotrophic growth rates, MoFe-protein acetylene-reduction activities, and whole-cell S = 3/2 electron paramagnetic resonance spectra of these mutants were examined. Results of these experiments show that MoFe-protein alpha-subunit residues, Cys-62 and Cys-154, are probably essential for MoFe-protein activity but that His-83 and Cys-88 residues are not. These results indicate either that His-83 and Cys-88 do not provide essential P-cluster ligands or that a new cluster-ligand arrangement is formed in their absence.
Amino Acid Sequence↗
Operative assessment of femorodistal bypass grafts using a new Doppler flowmeter.
Operative measurements using a newly developed Doppler flowmeter were made on 47 in situ femorodistal bypass grafts performed for critical ischaemia. Graft blood flow, peripheral resistance and impedance were measured before and after the injection of 15 mg papaverine down the graft. The proportion of retrograde blood flow at the distal anastomosis was also measured. The success of a graft at 1 month was defined by patency on duplex ultrasound scanning, a rise in the Doppler ankle pressures and an improvement in the clinical state of the limb. By these criteria the 1-month primary success rate was 35 out of 47 (74 per cent). Graft blood flow was of little value in predicting graft outcome but, combined with segmental pressures, accurately located six of eight technical problems which were successfully corrected. After papaverine, the peripheral resistance of all the successful grafts fell below one peripheral resistance unit (PRU). No single measurement was able to completely distinguish between success and failure, although discriminant analysis of all measurements was able to predict success with a sensitivity of 100 per cent and specificity of 97 per cent. A simpler combination of a peripheral resistance after papaverine less than 1 PRU and a retrograde blood flow less than 33 per cent predicted success, with a sensitivity of 97 per cent and specificity 83 per cent. These criteria have been validated on a further 26 grafts, achieving a sensitivity of 88 per cent and a specificity of 75 per cent. Simple operative measurements, using a newly developed Doppler flowmeter, enable the detection of technical problems and the accurate prediction of the early outcome of femorodistal grafting.
Adult↗
Abdominal aortic aneurysm repair in the over eighties.
Between January 1980 and September 1988, 34 octogenarians underwent aortic aneurysm repair. There were 26 men and eight women with a median age of 83 years (range 80-88 years). Twenty underwent 'emergency' repair after presenting with pain and/or collapse: 11 with a retroperitoneal rupture, three with an intraperitoneal rupture and six with an expanding aneurysm. The mortality rate for this group was 35 per cent. During the same period 14 patients had an elective repair and there were no deaths within 30 days. The mean hospital stay for the elective group was 14.2 days compared with 17.0 days for survivors in the emergency group. There was no significant difference in terms of risk factors between those who developed postoperative complications and those who did not. These mortality rates compare favourably with our overall mortality results for elective (4.6 per cent) and emergency (31 per cent) surgery. Those patients over 80 years of age with infrarenal abdominal aortic aneurysms should not be refused surgery on the basis of age alone; each patient should be judged individually.
Aged↗
Arteriogram scoring systems and Pulse Generated Run-off in the assessment of patients with critical ischaemia for femorodistal bypass.
Conventional arteriography is the investigation of choice in patients with critical ischaemia to select the site for the distal anastomosis of a femorodistal bypass. Several arteriographic scoring systems have been devised in an attempt to quantify the run-off. More recently Pulse Generated Run-off and intraoperative peripheral resistance measurements have been proposed as better predictors of early graft patency. Eighty-eight consecutive femorodistal bypass grafts were studied using Pulse Generated Run-off (PGR), conventional and intra-arterial digital subtraction arteriography (DSA) and peripheral resistance measurement. Three widely used arteriographic scoring systems were used to grade the arteriographic run-off. There were significant correlations between the scoring systems and the measured peripheral resistance, although PGR correlated better with peripheral resistance than arteriography (rs = -0.59, P less than 0.001). Intra-arterial DSA improved the correlation between the arteriogram scoring systems and the measured peripheral resistance in the distal popliteal artery, but not in single calf vessels. In contrast, PGR correlated much better with peripheral resistance in single calf vessels (rs = -0.82, P less than 0.001). We recommend that selection for femorodistal reconstruction be based on a combination of intra-arterial DSA and PGR. PGR will identify patent distal calf vessels not seen on arteriography and determine their continuity with the pedal arch, two features which are essential prerequisites for successful femorodistal bypass.
Adult↗
Histological appearances of the long saphenous vein.
The long saphenous vein is frequently used as a graft in both coronary artery and femoro-distal bypass surgery. The histological changes which are seen after implantation into the arterial system have been well documented in the past, but little attention has been focused on the histological appearances of the donor long saphenous vein prior to grafting. In this study, samples of the long saphenous vein in excess of that required for bypass have been examined. In none of the veins did the histological appearances conform to the described normal. All showed evidence of intimal fibrosis which contained elastic tissue and enmeshed smooth muscle cells. The longitudinal and circular muscle layers showed evidence of muscle cell hypertrophy with increase in intervening connective tissue. Elsewhere, similar histological changes have been attributed to 'arterialization'. This study shows that many of the changes are present prior to grafting and may be important in graft failure.
Bioprosthesis↗
The non-reversed vein femoro-distal bypass graft: a modification of the standard in situ technique.
The results of 85 in situ vein femoro-distal bypass grafts using a modified technique where the vein was completely mobilised but left "non-reversed" have been reviewed with particular regard to risk factors and complications. The distal anastomosis was to the infrageniculate popliteal artery in 55% and to the tibioperoneal trunk or a single calf vessel in the rest. Arteriographic run-off was by a single vessel in 42%. The primary failure rate at 1 month was 20% and the secondary failure rate 9%; the majority of early failures being due to missed technical errors despite the use of a pulse volume recorder. The cumulative secondary patency rate at 1 and 2 years was 77% and 72%; limb salvage 85% and 77%; and patient survival 89% and 83% respectively. The only significant risk factors were the level of the distal anastomosis and the run-off (P = 0.002 and 0.03 respectively). Complete mobilisation of the vein allows a tension free proximal anastomosis to the common femoral artery and avoids the risk of arteriovenous fistulae. A high vein utilisation rate of 93% was achieved by using a small 2.5 mm Hall valvulotome. Although there was a trend towards lower patency rates in veins with a minimum diameter less than 4 mm the results are still superior to PTFE. Compared to reversed vein the in situ technique has a better utilisation rate and the long-term patency rates are at least as good if not better. Improved methods of haemodynamic assessment during reconstruction to reduce technical errors may be the key to better early patency rates.
Adult↗
Risk factors in selected patients undergoing femoral embolectomy.
Mortality rates after femoral embolectomy (FE) in patients with an acutely ischaemic leg vary from 20-40%. In the last 3 years we have adopted a policy of proceeding directly to femoral embolectomy in those patients with a strong clinical suspicion of an embolus. Where doubt exists about the diagnosis, arteriography is performed in combination with local streptokinase, balloon dilatation and/or reconstruction. In a prospective study between September 1984 and March 1987, 43 patients underwent femoral embolectomy with a limb salvage rate of 87%. The early mortality (within 30 days) was 16%, the late mortality was 26%, with a mean follow-up of 22 months. Of the seven patients who died within 30 days, one had a successful embolectomy but died from a cerebrovascular accident. The remaining six failed to improve clinically, all had poor backbleeding and no return of the peripheral pulses. None of these patients had an amputation. We recommend that femoral embolectomy be performed in those patients with a short history of ischaemia (less than 72 h), a risk factor suggesting an embolic source and no past history of intermittent claudication. If all three criteria are not met, arteriography should be performed with a view to fibrinolytic therapy or vascular reconstruction. In those patients who have had a failed embolectomy or where the circulation cannot be restored promptly, despite fibrinolytic therapy and/or distal reconstruction, early major amputation may be life-saving.
Adult↗
Adenocarcinoma cell invasion of an obturator artery aneurysm.
Classic teaching implies that arterial walls are a resistance to tumour invasion. We report a case of tumour cell infiltration of an obturator artery aneurysm following an abdomino-perineal excision of rectum.
Adenocarcinoma↗
The characterisation of molecular forms of acetylcholinesterase in Hirschsprung's disease.
Aganglionic rectal tissue from patients with Hirschsprung's disease contains four forms of acetylcholinesterase; the major component has a sedimentation coefficient in the region of 10.0S. Results from gel filtration confirm these findings and, when used in conjunction with the sedimentation data, allow the determination of the molecular mass of these forms. The four species of acetylcholinesterase include: monomer, G1, 74 kDa dimer, G2, 131 kDa; tetramer G4, 275 kDa and an asymmetric form, A12, 811 kDa. Evidence is provided which shows that the major form, G4 interacts with the detergent Triton X-100. Selective measurement of G4-AChE using a suitable assay may provide the basis for improving the existing means of diagnosis of Hirschsprung's disease.
Acetylcholinesterase↗
Pulse-generated runoff: a new method of determining calf vessel patency.
A non-invasive method of determining calf vessel patency before femorodistal bypass has been developed. This pulse-generated runoff (PGR) system generates blood flow in patent calf arteries by means of a pulsatile cuff even if the existing Doppler signal is inaudible. PGR was compared with pre-operative arteriography in 95 ischaemic limbs and both were compared with the peripheral resistance measured at operation in 62 limbs. There was a highly significant correlation between the PGR and arteriogram scores (rs = 0.74, P less than 0.001) but PGR tended to detect more patent vessels than arteriography. The peripheral resistance correlated better with PGR than arteriography (rs = -0.71 and -0.54 respectively, P less than 0.001). PGR is a simple, non-invasive method of determining calf and foot vessel patency pre-operatively.
Adult↗
Pelvic injuries associated with traumatic abduction of the leg.
We report a series of six severe pelvic injuries associated with traumatic abduction of the leg. All sustained a severe fracture of the pelvis associated with a deep perineal wound extending into the anus. Laparotomy was usually required to control haemorrhage and packing was only effective once the pelvis had been stabilized by external fixation. A sigmoid loop colostomy was required in all five initial survivors because of sphincter disruption, but three out of four long-term survivors are now fully continent. If mortality is to be reduced, blood loss must be rapidly controlled and sepsis prevented.
Accidents, Traffic↗
Diagnostic value of acetylcholinesterase/butyrylcholinesterase ratio in Hirschsprung's disease.
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Acetylcholinesterase↗
Does oedema following lower limb revascularisation cause compartment syndromes?
Oedema of the leg, particularly the calf, is a well-recognised complication following lower limb reconstructive vascular surgery, but its effect on the limb is unknown. In this study, anterior compartment pressures and calf circumference were measured in both the operated and non-operated limbs following femoropopliteal bypass in 15 patients. All the patients developed lower limb swelling, which was significantly greater than the non-operated limb, P less than 0.05 paired t test (day 2-5). There was a significant difference in the mean anterior compartment pressures between the operated and non-operated limbs on the third and fourth postoperative days for the overall and below knee group, P less than 0.05 (paired t test). However, none of the patients developed signs, symptoms or pressures indicative of a compartment syndrome. These results suggest that the oedema following reconstructive vascular surgery is subcutaneous rather than compartmental in origin and that compartment pressure measurements should only be undertaken if a fasciotomy is being contemplated.
Adult↗
Diabetic patient discharges from Middlemore Hospital in 1983.
Diabetes mellitus is a significant health problem in south Auckland. A retrospective case note review of all diabetic admissions to Middlemore Hospital in 1983 was performed to establish a database to identify current problem areas and permit ongoing analysis. Three hundred and seventeen admissions from 225 patients using 6086 hospital days were reviewed: 204 diabetes-related admissions occupied 4040 days. One hundred and nine patients were male. One hundred and fifty-seven patients were European, 45 were Maori and 21 were Polynesian. European patients were older (mean age 64 years) and lighter (mean weight 69kg) than the non-European patients (mean age 56 years, mean weight 83kg). One hundred and eighty patients had noninsulin dependent diabetes mellitus: European patients were discharged on insulin treatment in 38% of admissions compared with 17% for nonEuropean patients. The patterns of admission were similar for all racial groups except for admissions for chronic renal failure where 21 of 22 admissions were by nonEuropean patients. A comparative cost analysis was performed: admissions for peripheral vascular disease contributed 34% to the calculated total cost of diabetes-related admissions despite only accounting for 17% of admissions. Further research, especially in the nutritional field, is necessary before realistic cost-benefit interventions can be devised and implemented.
Adult↗