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Biomedical subjects

S M Schellong

Publications and source records attributed to S M Schellong.

At least 19 recordsLinked to original sources

Secondary prophylaxis of venous thromboembolism.

Making decisions about any modality of secondary prophylaxis in patients with venous thromobembolism (VTE) has to balance the risk of bleeding induced by anticoagulants against the benefit of reducing the risk of recurrent disease. It has to be kept in mind that the magnitude of risk is not only defined by the number of events per time period but also by the impact of the event on the fate of the patient. With standard intensity Vitamin K antagonists, the risk of bleeding is more closely related to comorbidities than to other factors, e.g. age. The risk of VTE recurrence differs largely between patient groups. The criterion of presence, or absence of a permanent or transient clinical trigger factor for the actual VTE episode has a greater impact than an abnormal result in thrombophilia testing. The standard period ofsecondary prophylaxis for proximal deep vein thrombosis and for pulmonary embolism is three to six months. The concept of prolonging this period for several months according to the risk of recurrence is seriously challanged by the observation that the prolongation period seems to delay recurrencies rather than truly avoiding them. For this reason, patients who clearly are threatened by recurrent episodes should receive indefinitive secondary prophylaxis. This is the case for cancer patients, patients with the antiphospholipid syndrome, and those who belong to families with severe and symptomatic protein C, protein S, or antithrombin deficiencies. Patients with recurrent VTE, with idiopathic VTE, or with combined thrombophilic conditions may only benefit from indefinitive secondary prophylaxis if the bleeding risk of the anticoagulant regimen under consideration is very low.

Anticoagulants↗

[A huge malignant degenerating neurofibroma of the lower leg coexistent with type 1 Recklinghausen disease].

HISTORY: A 65-year-old man had noted a tumor of the right lower leg that had progressively grown over the last twenty years. He had a dyspnoea on insignificant movement and was relatively immobile because of the extent of the tumor. The tumor had been diagnosed as a Klippel-Trenaunay syndrome. INVESTIGATIONS: Laboratory investigations suggested a hypochromic and microcytic anaemia and an inflammatory constellation. The tumor had no av-fistulas on ultrasonography and angiography, but there were many pathological arteries and tumor nodes. The tumor nodes had been seen also on MRI-biopsy suggested a neurogenic sarcoma. DIAGNOSIS AND TREATMENT: Amputation of the leg was necessary. The histological diagnosis was neurofibrosarcoma with extensive necrotic areas and Recklinghausen disease. Investigation did not reveal any metastasis. Postoperatively the anaemia regressed and the patient learned to walk with a prosthesis. CONCLUSIONS: This history shows the problem of separating clearly the two hereditary diseases. Often there is a different clinical picture in everyday life. One must consider the definitely higher risk of malignant tumors of patients with neurofibromatosis. Ultrasonography is a non-invasive method that can provide morphological information on soft parts and pathology of the vessels. It facilitates the classification of such.

Aged↗

Acute intramural haematoma of the coeliac artery.

The report describes a previously healthy 24-year-old women presenting with acute abdominal pain following a hyperextension manoeuvre. The key finding of a continuous bruit with systolic and diastolic components in the epigastric region subsequently led to the diagnosis of an intramural haematoma of the coeliac artery, that caused a subtotal occlusion of the artery. The diagnosis was achieved by both colour-coded duplex sonography and magnetic resonance angiography. The case shows that a conservative management rather than operative reconstruction is justified in an oligo-symptomatic situation with no signs of end-organ damage as in this patient.

Acute Disease↗

Recurrent isolated calf muscle thrombosis due to a venous aneurysm of the soleal muscle veins.

A rare case of venous aneurysm involving the soleal muscle vein in an 18-year-old woman is presented. The patients showed three episodes of ultrasonographically proven calf muscle thrombosis within 2 years. After a short course of low-molecular-weight heparin at a therapeutic dosage, complete thrombus recanalization was achieved. To prevent further thrombotic episodes, surgery including ligation and resection of the aneurysm was performed. At the 3-month follow-up study the patient had completely recovered.

Adolescent↗

Deep vein and isolated calf muscle vein thrombosis following long-haul flights: pilot study.

The risk of venous thromboembolism associated with long-haul flights is the subject of controversy. In a prospective, controlled study, we examined 160 passengers before and after return from a long-haul flight and 160 age-matched and sex-matched, non-travelling volunteers using venous compression ultrasound. Deep vein thrombosis was not observed in either group. Isolated calf muscle vein thrombosis (ICMVT) was present in 4/160 (2.5%) flight passengers and in 1/160 (0.6%) controls. All subjects with ICMVT were clinically asymptomatic, and ICMVT was located in the soleal muscle veins in all four subjects. Three of the four passengers with ICMVT had other risk factors for thrombosis.

Adult↗

[Acute limb ischemia].

PATHOPHYSIOLOGY: Signs and symptoms of acute limb ischemia follow the pathophysiology of the disease. If embolism--mainly of cardiac origin--hits a previously unaffected vessel, and if the same embolus occludes the anatomically preexisting collateral vessel, complete ischemia will occur. TREATMENT: Only a revascularization procedure without any delay will be able to avert major amputation; however, once the ischemia/reperfusion cascade has been started, the limb is threatened even after successful revascularization. If acute ischemia results from local arterial thrombosis in an atherosclerotic vessel system a sufficient number of collateral vessels may be recruited within a short time period; thus, borderline compensation of the perfusion is achieved in most cases. This situation allows for thorough angiographic evaluation of the whole arterial tree of the affected limb as well as for perioperative risk assessment of the patient. These are the prerequisites for a technically ambitious revascularization procedure which is needed in most of the older patients with significant comorbidity.

Acute Disease↗

Patients with persistent APC-resistance without factor V Leiden mutation.

BACKGROUND: Activated protein C (APC) resistance and factor V Leiden mutation are major risk factors for deep venous thrombosis. Previous work has led to the view that the coagulation phenotype and the genetic defect are associated in almost all patients. It has been reported about single APC-resistant patients without associated factor V Leiden, but significance and thrombotic risk of this constellation have not yet been established. PATIENTS AND METHODS: We tested 486 consecutive patients with deep venous thrombosis, arterial disease or other than vascular disease for APC-resistance with a factor VIII based assay. RESULTS: 149 patients (31%) showed a pathological APC-ratio. Sensitivity and specificity for detection of factor V Leiden were 100% and 40%, respectively. At 6 months follow-up APC-ratio returned to normal in 55% of the patients with initial pathological APC-resistance. At 12 months follow-up 91% of the patients with persistent APC-resistance showed a pathological ratio as well. CONCLUSIONS: Patients with APC-resistance not due to factor V Leiden can be attributed to one subset with reversible APC-resistance--possibly due to a hypercoagulable state in an acute thrombotic situation, and to another with persistent APC-resistance.

Activated Protein C Resistance↗

Complete compression ultrasound for the diagnosis of proximal and distal deep venous thrombosis--a retrospective outcome study.

BACKGROUND: Compression ultrasound is considered the preferred test for the diagnosis of deep vein thrombosis of the leg (DVT). Since sensitivity for distal thrombosis is low-additional tests are required. We developed a protocol of complete compression ultrasound of all venous segments of the leg (CCUS). A retrospective outcome study was performed to get an estimate of the rate of indeterminate results necessitating repeated testing as well as for the clinical safety of CCUS in a cohort of consecutive, unselected patients. PATIENTS AND METHODS: Case records of all patients referred for clinical suspicion of deep vein thrombosis within a three months period were reviewed. Patients with negative CCUS were followed directly or via the general practitioner in order to know whether an episode of venous thromboembolism had been documented since the initial CCUS. RESULTS: 132 inpatients and 154 outpatients were identified. Clinical probability was high in 50 patients, medium in 142, and low in 94. The first CCUS was negative in 209 cases. Five patients (1.8%) had repeated CCUS within the next 7 days because of incomplete visualisation of the distal veins and turned out to be negative as well. Of all 214 patients with negative CCUS a clinical follow-up information was obtained after 168 +/- 25 days. Five patients had died, none due to pulmonary embolism. In two patients deep vein thrombosis had been documented (0.9% [95% CI: 0.1-3.3%]) 148 and 172 days after CCUS, respectively. CONCLUSION: CCUS for diagnosis of DVT needs to be repeated in very few cases only. Clinical safety seems to fall into the same range as with combined algorithms and should be tested in a prospective design. Patients with medium and high probability showed a very low incidence of DVT within three months following CCUS; therefore, they may be included in a prospective outcome study.

Adolescent↗

Eligibility for home treatment of deep vein thrombosis: a prospective study in 202 consecutive patients.

PURPOSE: Home treatment of deep vein thrombosis (DVT) has been shown to be safe and effective. However, this conclusion has been drawn from studies with predefined patient selection criteria. Eligibility for home treatment has never been properly assessed. METHODS: In a 9-month period, we prospectively evaluated the possible reasons for hospital treatment in consecutive patients with acute DVT by using a check list that included medical reasons, home care situation, preferences, and hospital service logistics. Treatment consisted of low-molecular-weight heparin and concomitant oral vitamin K antagonists and compression therapy. A 3-month follow-up examination included assessment of recurrent venous thromboembolism (VTE), bleeding events, and mortality. RESULTS: A total of 202 patients were included in the study; 117 patients (58%) were outpatients and 85 patients (42%) were hospitalized before DVT diagnosis. Of the 117 outpatients, 95 (81%) were considered eligible for home treatment. Only two patients (1.7%) were admitted to the hospital for DVT-related morbidity, one (0.85%) because of comorbidity, 11 (9.4%) for home care reasons, and eight (6.83%) because of hospital service logistics. Of the hospitalized patients, 79 (92.94%) remained inpatients, and six (7.05%) could be discharged within 48 hours. The only reason for hospitalization was pre-existing comorbidity. In outpatients, the outcome after 3 months showed a 4% rate of recurrent VTE, no major bleeding, and an 8% mortality rate; 75% of deaths were caused by cancer. No patient died of VTE. In inpatients, a statistically significant higher mortality rate was found (8% vs 19%; P < .02). CONCLUSION: Less than 3% of patients with DVT who were outpatients had to be hospitalized because of DVT morbidity. For the entire DVT population, the main reason for hospital treatment is comorbidity, rather than management issues or DVT morbidity.

Adult↗

Therapy of isolated calf muscle vein thrombosis with low-molecular-weight heparin.

There are no data from prospective studies concerning the treatment of isolated calf muscle vein thrombosis (soleal and gastrocnemial muscle veins), found in 20-40% of patients with lower extremity thrombosis of the calf. We investigated the outcome in two cohorts of consecutive patients, the first receiving low-molecular-weight heparin for 10 days at therapeutic doses and compression therapy; the second cohort, compression therapy alone. In patients on therapeutic heparin (n = 52), no progression to deep vein thrombosis occurred [0%; 95% confidence interval (CI), 0-6.8%]. Patients without anticoagulation (n = 32) showed a statistically significant higher percentage of progression into the deep calf veins (25%; 95% CI, 11.5-43.4%) as well as recurrent muscle vein thrombosis. No symptomatic pulmonary embolism or bleeding event occurred; one patient died in each group, both related to malignancy. The data suggest a need for short-term anticoagulation in such patients to prevent further thromboembolic complications. Randomized prospective studies are now warranted in a larger study population.

Adolescent↗

Investigation of genotype-dependent differences in factor V activity as well as response to activated protein C by application of different methods.

Coagulation factor V has been at the centre of investigation for several years. In addition to factor V Leiden, various other polymorphisms are becoming the object of interest. Different results have been published about the association of the HR2 haplotype with decreased factor V levels and with reduced response to activated protein C (APC). Due to the central position of factor V in the clotting process, its activity can be determined in both thromboplastin-based and activated partial thromboplastin time (aPTT)-based assays. A multitude of assays are known for the determination of APC response. The aim of our study was to investigate whether different methods disclose genotype-dependent differences in factor V activity as well as APC response. Three wild-type carriers, three carriers homozygous for the R2 allele (4070G), and three carriers homozygous for the G allele (2391G, 2663G, 2684G, 2863G) were investigated. For each individual plasma sample, the factor V activity was determined using 12 different reagent combinations of three different thromboplastins, three different aPTT reagents, and two different factor V deficient plasma sources. The determination of factor V activity in the thromboplastin system revealed differences between the genotypes. These differences were independent of the thromboplastin reagent and the factor V-deficient plasma. The aPTT system exhibited a dependency on the aPTT reagent and the factor V-deficient plasma. Analysis of APC response disclosed genomic differences in specific test systems only. One type of assay could be more appropriate than other types in dependence of the position of genomic variations. Therefore, the applied assay is an important influential factor in investigations of functional consequences of genomic variations.

Alleles↗

[The concept of ambulatory therapy of proximal deep venous thrombosis].

In recent studies outpatient treatment of proximal deep venous thrombosis with low-weight-molecular heparin is shown as safe and effective as the treatment within the hospital. The incidence of recurrent thromboembolism, major bleeding and mortality is not higher in an ambulatory setting than in the hospital. The comfort of the patient is higher, the costs can be reduced. The present review discusses the different conditions for ambulatory treatment of deep venous thrombosis. The question will be addressed which patients will probably be considered for outpatient treatment of deep vein thrombosis.

Ambulatory Care↗