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Michael Luther

Publications and source records attributed to Michael Luther.

4 recordsLinked to original sources
PubMed2007

Risk-scoring method for prediction of 30-day postoperative outcome after infrainguinal surgical revascularization for critical lower-limb ischemia: a Finnvasc registry study.

BACKGROUND: The aim of the present study was to develop a risk-scoring method for prediction of immediate postoperative outcome after infrainguinal surgical revascularization for critical limb ischemia. METHODS: The Finnvasc registry included data on 3,925 infrainguinal surgical revascularization procedures. This database was randomly divided into a derivation and a validation data set of similar sizes. RESULTS: In the overall series, 30-day postoperative mortality and major amputation rates were 3.1% and 6.3%, respectively. The 30-day postoperative mortality and/or limb-loss rate was 9.2%. Diabetes, coronary artery disease, foot gangrene, and urgent operation were independent predictors of 30-day postoperative mortality and/or major lower-limb amputation. A risk score was developed by assigning 1 point each to the latter risk factors. In the derivation data set, the 30-day postoperative mortality/amputation rates in patients with scores of 0, 1, 2, 3, and 4 were 7.7%, 6.4%, 11.1%, 20.4%, and 27.3%, respectively, (P < 0.0001); mortality rates were 1.3%, 2.3%, 4.1%, 7.7%, and 12.1%, respectively, (P < 0.0001); and major amputation rates were 6.4%, 4.3%, 7.1%, 12.7%, and 18.2%, respectively, (P < 0.0001). In the validation data set, the 30-day postoperative mortality/amputation rates in patients with scores of 0, 1, 2, 3, and 4 were 4.8%, 7.5%, 10.1%, 15.9%, and 22.2%, respectively, (P < 0.0001); mortality rates were 0.7%, 2.3%, 4.2%, 5.5%, and 14.8%, respectively, (P < 0.0001); and major amputation rates were 4.6%, 5.3%, 6.4%, 11.0%, and 14.0%, respectively (P = 0.011). CONCLUSIONS: This simple risk-scoring method can be useful to stratify the immediate postoperative outcome of patients undergoing infrainguinal surgical revascularization for critical lower-limb ischemia.

Aged↗
PubMed2006

Adjuvant arteriovenous fistula as means of rescue for infrapopliteal venous bypass with poor runoff.

OBJECTIVE: The aim of this study was to assess the outcome of infrapopliteal bypass when an adjuvant arteriovenous (AV) fistula was reconstructed as means of rescue as a result of poor runoff. The design was a retrospective multicenter case-control study. METHODS: Seventy-seven infrapopliteal vein bypasses required an adjuvant AV fistula among 1813 patients operated on for critical leg ischemia in 3 vascular centers between 1996 and 2003. The mean age was 74 years (range, 39-90 years). A total of 70% of the patients had diabetes, and 24% had undergone previous vascular surgery. In 25% of the bypasses, the distal anastomosis was in a crural artery, in 55% it was in the dorsal pedal artery, and in 20% it was in a plantar artery. An adjuvant AV fistula was reconstructed in all cases because of poor intraoperative arterial status, intraoperative angiography, or low intraoperative flow. A control group was retrieved that matched the study group according to the recipient artery and runoff score. RESULTS: The primary and secondary patency were 61% and 75%, respectively, at 1 year in the AV fistula group and 57% and 71% in the control group. The 3-year patency rates were 49% and 62% for the AV fistula group and 46% and 71% for the control group, respectively. There was a 76% leg-salvage rate at 3 years in the study group, compared with 87% in the control group. There were no major complications related to the AV fistula. Intraoperative flow was increased from a median of 20 mL/min to 115 mL/min by the AV fistula (P = .003). The graft flow was significantly higher in the AV fistula group than in the control group (P = .001). CONCLUSIONS: The adjuvant AV fistula increased graft flow significantly in a poor-outflow venous bypass. In this extreme patient group, acceptable patency and leg salvage was achieved without adverse effects. Despite this, the AV fistula did not improve the outcome.

Adult↗
PubMed2003

Urokinase, tissue-type plasminogen activator and plasminogen activator inhibitor-1 expression in severely stenosed and occluded vein grafts with thrombosis.

Intimal hyperplasia and subsequent thrombotic occlusions limit the success of vascular reconstructive procedures. Plasminogen activation in situ may be an important factor affecting re-stenosis of the graft. Tissue specimens from eight patients with failing or failed infra-inguinal vein bypasses and three specimens from normal veins were harvested to study urokinase-type plasminogen activator (u-PA), tissue-type plasminogen activator (t-PA) and plasminogen activator inhibitor-1 (PAI-1) by in situ hybridization and immunohistochemistry. The possible presence of thrombi was monitored by platelet and fibrin-specific stainings. In occluded grafts, platelet endothelial cell adhesion molecule (PECAM-1) antibody stained the thrombi but not the endothelial area, indicating the absence of endothelium. Platelet glycoprotein (GP) IIb/IIIa co-localized with PECAM-1 and, furthermore, GP IIb/IIIa staining was positive on the vein walls with thrombi and to some extent in the grafts without thrombi. PAI-1 and u-PA were uniformly upregulated in intimal thickening in grafts without thrombus. In organized thrombi, enhanced u-PA, t-PA and PAI-1 reactivity was detected in the ingrowing subendothelium. In non-occluded grafts with small thrombi, u-PA expression was enriched beneath microthrombi co-localizing with the graft wall injury, while PAI-1 was scattered in the (sub)endothelium. We conclude that fibrinolytic system is upregulated at sites of graft stenosis, and local proteolytic degradation of the graft wall associates with thrombus formation.

Aged↗