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T V Schroeder

Publications and source records attributed to T V Schroeder.

At least 19 recordsLinked to original sources
PubMed2006

Fluoropolymer-coated dacron versus PTFE grafts for femorofemoral crossover bypass: randomised trial.

OBJECTIVES: To investigate whether patency of a thin walled 8 mm fluoropassivated Dacron graft was similar to that of a standard 8mm PTFE graft for femorofemoral crossover bypass surgery. DESIGN: A randomised multicentre clinical trial comparing two vascular grafts with participation of 10 departments of vascular surgery in Denmark, Sweden and Norway. PATIENTS AND METHODS: 198 patients were randomised to PTFE (n=107) or fluoropolymer-coated Dacron grafts (n=91), 63% underwent surgery for claudication, 27% for ischaemic rest pain and 10% for tissue loss. The median follow-up time was 24 months (IQR 19-26 months). RESULTS: The primary patency rate of the two grafts was similar (log rank test: p=0.35). The primary patency rates (95% CI) for coated Dacron and PTFE grafts were 92% (86-98) and 94% (89-99) at 12 months and 87% (74-95) and 93% (87-99) at 24 months, respectively. CONCLUSION: In patients with unilateral iliac artery disease not amenable to angioplasty, the femoral-femoral bypass is durable and effective. No difference in patency was found between the two graft materials (fluoropolymer coated Dacron and PTFE).

Aged↗
PubMed2005

Identification of patients at risk for ischaemic cerebral complications after carotid endarterectomy with TCD monitoring.

OBJECTIVES: Transcranial Doppler (TCD) monitoring for micro embolic signals (MES), directly after carotid endarterectomy (CEA) may identify patients at risk of developing ischaemic complications. In this retrospective multicentre study, this hypothesis was investigated. METHODS: Centres that monitored for MES after CEA were identified by searching Medline. Individual patient data were obtained from centres willing to collaborate. The number of emboli in 1h was computed. Uni- and multivariate logistic regression analyses were performed for the variables gender, age and number of MES. Discriminative ability of MES monitoring was investigated in a ROC curve. RESULTS: Nine hundred and ninety-one patients were monitored in the first 3h after CEA. Two percent developed ischaemic cerebral complications. Univariate analysis revealed statistically significant associations between ischaemic cerebral complications and both gender and MES, but not age. In a multivariate analysis, > or =8 MES/h showed a statistically significant relationship with cerebral complications (OR 8.1, 95% CI 1.8-36), in contrast to gender (OR 2.2, 95% CI 0.9-5.5). The ROC curve yielded an AUC of 0.83 for monitoring of MES. CONCLUSIONS: These results support the use of TCD monitoring for MES shortly after CEA in order to identify patients at risk of developing ischaemic cerebral complications.

Aged↗
PubMed2004

[Registration of clinical trials: a statement from the International Committee of Medical Journal Editors].

Altruistic motives and trust are central to scientific investigations involving people. These prompt volunteers to participate in clinical trials. However, publication bias and other causes of the failure to report trial results may lead to an overly positive view of medical interventions in the published evidence available. Registration of randomised controlled trials right from the start is therefore warranted. The International Committee of Medical Journal Editors has issued a statement to the effect that the 11 journals represented in the Committee will not consider publication of the results of trials that have not been registered in a publicly accessible register such as www.clinicaltrials.gov. Patients who voluntarily participate in clinical trials need to know that their contribution to better human healthcare is available for decision making in clinical practice.

Clinical Trials as Topic↗
PubMed2004

In-situ bypass surgery on arteriographically invisible vessels detected by Doppler-ultrasound for limb salvage.

AIM: The aim of this paper was to evaluate our primary experience with bypass surgery on arteries only visible on Doppler-ultrasound in patients suffering from critical lower limb ischemia. METHODS: During a study period of 10 months, Doppler-ultrasound routinely supplemented digital subtraction arteriography (DSA) whenever it failed to reveal patent runoff vessels suitable for in-situ saphenous vein bypass surgery. If an arteriographically invisible runoff artery was detected on Doppler-ultrasound and the patient was eligible for surgery, a bypass procedure was performed. All patients were facing a lower limb amputation due to critical limb ischemia (tissue loss, SVS/ISCV-category 5). Postoperatively the patients were followed according to a standard graft surveillance program, including clinical examination, ankle pressure measurements and a color Doppler-ultrasound at discharge and after 1, 6 and 12 months. RESULTS: Fifty-one in-situ saphenous vein bypasses were performed, 5 (10%) on arteriographically occult runoff vessels detected only on Doppler-ultrasound. After a 12-month follow-up, 3 bypasses were still patent and only one patient had an amputation. One bypass occluded after 6 months but the patient stayed asymptomatic. CONCLUSIONS: Doppler-ultrasound permits in-situ by-pass surgery on arteriographically invisible vessels reducing the proportion of inoperable patients by 10%.

Adult↗
PubMed2003

Ultrasound contrast-agent improves imaging of lower limb occlusive disease.

OBJECTIVES: to evaluate if ultrasound contrast-agent infusion could improve duplex-ultrasound imaging of peripheral arterial disease (PAD) and increase the agreement with digital subtraction arteriography (DSA). DESIGN: prospective and consecutive study. MATERIAL: of 60 consecutive PAD patients, 15 were found to have an inconclusive duplex-ultrasound scan of the trifurcation and were included in the study. All 15 patients (53% male) were scheduled for DSA, all being candidates for vascular surgery due to claudication (n = 3, 20%), rest pain (n = 5, 33%) and tissue loss (n = 7, 47%). METHODS: on the day before DSA, a duplex-ultrasound scan of the trifurcation was performed. If the duplex-ultrasound scan was found inconclusive, it was repeated during continuous ultrasound contrast-agent infusion. DSA was performed unaware of the duplex-ultrasound results and served as the gold standard. RESULTS: after contrast-agent administration, the number of inconclusively diagnosed segments was significantly reduced by 26 (70%), from 37 to 11(p < 0.001). In 19 segments (73%) contrast-agent infusion changed the diagnosis in accordance with the DSA (p < 0.05). Values of sensitivity and positive predictive value were improved from 0.20 (0.04-0.62) to 0.47 (0.26-0.69) and 0.50 (0.10-0.91) to 0.80 (0.49-0.93), respectively. Specificity and negative predictive value were unchanged. Agreement between duplex-ultrasound and DSA were improved from poor (kappa = 0.18 (95% CI: 0-0.82)) to moderate (kappa = 0.45 (0.17-0.74)) (p = 0.44). CONCLUSION: ultrasound contrast-agents improve the diagnostic ability of duplex-ultrasound when scanning difficult arterial segments in patients suffering from PAD.

Adult↗
PubMed2002

The haemodynamic effect of carotid endarterectomy.

OBJECTIVES: to assess the haemodynamic effect of carotid artery surgery, and to relate postoperative changes to the state of cerebral circulation before revascularisation. MATERIALS AND METHODS: using transcranial Doppler we studied bilateral middle cerebral artery (MCA) flow velocities before and on 1st day, 2nd or 3rd day and 4th or 5th day and 3 months after carotid surgery in 61 patients. In addition, ipsilateral MCA flow velocity was monitored continuously during surgery. Data were related to the internal carotid artery (ICA) perfusion pressure (cerebral perfusion pressure index, CPPI), measured directly before ICA clamping. RESULTS: postoperatively, MCA flow velocities increased significantly overall (p<0.01), mainly due to pronounced and longer lasting flow velocities in the group of 18 patients with CPPI<0.7 (p<0.05). Flow velocities peaked - absolute as well as relative - on the first postoperative day and then gradually levelled off to reach preoperative values after 4-5 days in patients with high CPPI, whereas MCA flow velocities remained increased in the group of patients with low CPPI. At 3 months flow velocities in both groups were normalised. New neurological symptoms occurred in four patients, who all had low CPPI preoperatively (22% (4/18) vs 0%; Fisher's exact test: p=0.006). CONCLUSION: some degree of hyperperfusion was seen in most patients, but the changes were significantly more pronounced in patients with preoperative hypoperfusion, who also suffered significantly more neurological complications.

Aged↗
PubMed2002

Ultrasound imaging of infrainguinal arterial disease has a high interobserver agreement.

OBJECTIVES: to evaluate and compare the operator dependency of duplex ultrasound and digital subtraction arteriography (DSA) in patients suffering from chronic lower limb ischaemia. DESIGN: prospective and blinded validation study. MATERIAL: twenty-six consecutive patients (13 male and 13 females) with severe claudication (n=6, 23%), rest pain (n=7, 27%) or tissue loss (n=13, 50%). METHODS: two physicians independently performed a duplex scan of the lower limb from groin to foot (15 segments). Segments were classified as insignificantly (<50% stenosis) or significantly (>50% stenosis or occlusion) diseased. DSA was performed within 24h of the duplex scanning and was independently reported by two radiologists in the same manner. Interobserver agreement was assessed for both diagnostic methods. After 10 months the arteriograms were reassessed and the intraobserver agreement calculated. RESULTS: for the limb as a whole the interobserver agreement was good and similar for both duplex and DSA, with kappa-values of 0.79 (95%-CI: 0.72-0.86) and 0.80 (0.74-0.87). In the femoral, crural and pedal segments the interobserver agreement was similar for both methods. The intraobserver agreement between the two DSA readings was 0.84 (0.79-0.90). CONCLUSION: ultrasound is comparable to arteriography when visualising arterial occlusive disease in patients with chronic lower limb ischaemia.

Adult↗
PubMed2001

Ultrasonic echolucent carotid plaques predict future strokes.

BACKGROUND: We tested prospectively the hypothesis that stroke development can be predicted by echolucency of carotid atherosclerotic plaques in previously symptomatic and asymptomatic patients. METHODS AND RESULTS: We followed incidence of ipsilateral ischemic strokes for 4.4 years in 111 asymptomatic and 135 symptomatic patients with >/=50% relevant carotid artery stenosis. At inclusion, echogenicity of carotid plaques and degree of stenosis were evaluated with high-resolution B-mode ultrasound with computer-assisted image processing and Doppler ultrasound, respectively. We observed 44 ipsilateral ischemic strokes. In symptomatic patients, relative risk of ipsilateral ischemic stroke for echolucent versus echorich plaques was 3.1 (95% CI, 1.3 to 7.3), whereas for 80% to 99% versus 50% to 79% stenosis, the relative risk was 1.4 (95% CI, 0.7 to 3.0). Relative to symptomatic patients with echorich 50% to 79% stenotic plaques, those with echorich 80% to 99% stenotic plaques, echolucent 50% to 79% stenotic plaques, and echolucent 80% to 99% stenotic plaques had relative risks of ipsilateral ischemic strokes of 3.1 (95%CI, 0.7 to 14), 4.2 (95% CI, 1.2 to 15), and 7.9 (95% CI, 2.1 to 30), equivalent to absolute risk increases of 11%, 18%, and 28%. This was not observed in previously asymptomatic patients. CONCLUSIONS: Echolucent plaques causing >/=50% diameter stenosis by Doppler ultrasound are associated with risk of future stroke in symptomatic but not asymptomatic individuals. This suggests that measurement of echolucency, together with degree of stenosis, may improve selection of patients for carotid endarterectomy.

Adult↗
PubMed2001

[Do Scandinavian physicians understand each other's languages?].

BACKGROUND: The national medical journals in Denmark, Norway, and Sweden publish selected papers from the other journals in their original languages. We wanted to know how well Scandinavian general practitioners understand their neighbour languages and English, today the "lingua franca" in medical publishing. MATERIAL AND METHODS: 111 doctors (36 Norwegians, 32 Danes, 43 Swedes) completed a questionnaire in which they rated their own subjective understanding of Danish, Norwegian, Swedish, and English on a five point Likert scale. RESULTS: The Norwegian doctors rated their understanding of Danish significantly higher than Swedish (p < 0.01) and English (p < 0.01). The Swedish doctors rated English significantly higher than Danish (p < 0.01) and Norwegian (p = 0.01) and Norwegian significantly higher than Danish (p = 0.02). The Danish doctors did not rate the foreign languages differently. INTERPRETATION: Particularly because of the Swedish doctors' incomplete understanding of Danish and to some extent Norwegian, there is a risk that future communication between doctors in these countries will be conducted in the English language.

Adult↗
PubMed2001

[Can ultrasonography replace arteriography in arteriosclerosis of the lower limb?].

Arteriography is the imaging modality of choice before lower limb revascularization, because it allows pinpointing of the diseased arteries and planning of the treatment strategy, be it PTA or bypass grafting. However, a 2-3% risk of complications, makes assessment of non-invasive alternatives mandatory. Insufficient contrast filling of infrapopliteal arteries distal to severe lesions have also challenged the status of arteriography as the gold standard before revascularisation. The use of duplex arterial mapping is a promising alternative, as it has the highest agreement in the femoral segment and the lowest in the infra-popliteal segment. Duplex arterial mapping is a reliable means of predicting whether patients will require a bypass graft or an endovascular procedure, and, if surgery is required, in predicting the actual location of both anastomoses.

Anastomosis, Surgical↗
PubMed2001

Intraoperative endothelial damage is associated with increased risk of stenoses in infrainguinal vein grafts.

OBJECTIVES: Saphenous vein injury is believed to predispose to vein graft stenoses. The aims of this study were to assess the endothelial injury associated with infrainguinal vein bypass surgery by serial measurements of serum thrombomodulin concentration as well as by platelet scintigraphy, and to relate these findings with the postoperative development of stenoses. METHODS: In 35 patients undergoing vein bypass surgery serum thrombomodulin concentration was measured pre- and postoperatively. Autologous 111-indium labelled platelets were administered into the common femoral artery immediately after restoration of flow in the graft and scintigraphic images were obtained 4 and/or 24 h later. RESULTS: Serum thrombomodulin increased markedly from median 17 ng/ml preoperatively to 32 ng/ml 1 day after surgery (p =0.00002). Platelet scintigraphy revealed a total of 62 focal activity accumulations, the majority being located in the anastomotic regions. Among the 30 patients with grafts remaining patent at 30 days stenoses occurred in nine (16%) of 55 regions with scintigraphic platelet accumulations as compared to only four (4%) of 94 regions without platelet accumulations (p =0.03). CONCLUSIONS: The very high predictive value of a negative platelet scintigraphy (96%) strongly suggests that localised perioperative endothelial injury is an important pathogenetic factor in the development of vein graft stenoses.

Adult↗