Publications by authors named "Andreas G Tsantes"

37 Publications

Thromboelastometry: studying hemostatic profile in small for gestational age neonates-a pilot observational study.

Eur J Pediatr 2019 Apr 1;178(4):551-557. Epub 2019 Feb 1.

Laboratory of Haematology and Blood Bank Unit, "Attiko" Hospital, School of Medicine, National and Kapodistrian University of Athens, Athens, Greece.

Scarce data exists about the hemostatic status of small for gestational age (SGA) neonates. We aimed at evaluating the hemostatic profile of SGA neonates, using thromboelastometry (TEM). This is an observational study performed in a Greek tertiary General Hospital during an 18-month period. Ninety-three neonates were included in the study: 48 appropriate for gestational age weight (AGA) neonates and 45 SGA neonates Extrinsically activated TEM (ex-TEM) parameters, such as clotting time, clot formation time, amplitude recorded at 5 and 10 min, a angle, maximum clot firmness, lysis index at 60 min, and also platelet count, were used for the evaluation of the hemostatic profile in all neonates. No statistically significant differences were noticed regarding all ex-TEM parameters between AGA and SGA neonates, while no event of hemorrhage or thrombosis was noticed in the study population.Conclusions: The coagulation system of SGA neonates seems to be fully functional, with no evident tendency toward coagulopathy or thrombosis, when compared with AGA neonates. TEM seems to provide a promising and valid assessment of coagulation and fibrinolysis systems and may be used as a valuable biomarker, in the future. Further studies, with large samples, are necessary to confirm our results. What is Known: • SGA neonates may present coagulation disorders mainly due to hepatic dysfunction, polycythemia, and thrombocytopenia owing to long-term intrauterine hypoxia. • In the literature, despite the statistically significant differences in laboratory results between SGA and AGA neonates, no clinical manifestations of significantly altered hemostasis were recorded. Data of TEM interpretation of hemostasis in SGA neonates are not available. What is New: • TEM seems to interpret coagulation mechanism of preterm and full-term SGA neonates and confirm previous relevant literature findings regarding hemostasis in these neonates.
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http://dx.doi.org/10.1007/s00431-019-03331-wDOI Listing
April 2019

Secondary procedures for restoration of upper limb function in late cases of neonatal brachial plexus palsy.

Eur J Orthop Surg Traumatol 2019 Feb 8;29(2):329-336. Epub 2019 Jan 8.

Department of Οrthopedics, University Hospital of Ioannina, Stavros Niarchos Avenue, 45500, Ioannina, Greece.

Neonatal brachial plexus palsy is a devastating complication after a difficult delivery. The incidence of this injury has not significantly decreased over the past decades, despite all the advances in perinatal care. Although primary repair of the nerves with microsurgical techniques is the common treatment strategy nowadays, there are late cases in which secondary procedures in tendons or bones are necessary. Moreover, secondary procedures may be needed to improve the results of primary repair. A careful preoperative assessment of all the residual defects and deformities in upper limbs of these patients is essential. The aim of these procedures is usually to restore the deficient shoulder abduction and external rotation, release of any elbow flexion contracture or to correct a weak elbow flexion. More distally a supination or pronation deformity is usually apparent, and available options include tendon transfers or radial osteotomy. The wrist of these patients may be ulnarly deviated or may has absent extension, so tendon transfers or free muscle transfers can also be used for correction of these deformities. In severe cases, wrist fusion is an alternative option. The clinical presentation of the hand is highly variable due to complex deformities including thumb adduction deformity, metacarpophalangeal joints drop, and weak finger flexion or extension depending on the level of the injury. Each of these deformities can be restored with a combination of soft tissue procedures like local or free muscle transfer and bony procedures like arthrodesis.
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http://dx.doi.org/10.1007/s00590-019-02362-1DOI Listing
February 2019

Idiopathic hip chondrolysis: a case report of a Caucasian HLA-B27 positive adolescent with a history of long walking.

Rheumatol Int 2019 04 5;39(4):751-755. Epub 2019 Jan 5.

Department of Οrthopedics, University Hospital of Ioannina, Stavros Niarchos Avenue 1, Karaoli kai Dimitriou 5, Ioannina, 45332, Greece.

Idiopathic hip chondrolysis is a rare disorder, the pathophysiology of which has not been fully elucidated. Several theories have been proposed regarding the cause of the disease with some of them involving autoimmune-mediated cartilage destruction. There are several similar features between idiopathic hip chondrolysis and rheumatologic diseases such as juvenile idiopathic arthritis, so whether these two disorders are different or not is still debatable. This case report aims to help comprehending this complex disorder by presenting a case of idiopathic hip chondrolysis with apparent risk factors, such as repetitive microtrauma and presence of HLA-B27 antigens. A 15-year-old HLA-B27 positive male presented with idiopathic hip chondrolysis after excessive walking. Initial treatment consisted of medications including corticosteroids, protected weight bearing and surgical soft tissue release. After failure of all these modalities in restoring the decreased range of motion of the hip, a course of a TNF-inhibitor, etanercept was tried. Alleviation of pain achieved early in the treatment period, but range of motion remained mainly unchanged. Although there was a brief improvement of stiffness for a short period after surgery which lasted for about 3 months, stiffness came back afterwards. Administration of a TNF inhibitor in the following period significantly improved his range of motion. The presence of laboratory findings indicating an autoimmune tendency in this patient supports the hypothesis of susceptibility of these patients to autoimmune reactions, while excessive walking was an apparent trigger factor. In future, traditional treatments may be abandoned in favor of novel medications targeting immunologic pathways.
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http://dx.doi.org/10.1007/s00296-018-04239-8DOI Listing
April 2019

Antithrombotic efficacy of direct oral anticoagulants on patency rate following microsurgical anastomosis in crushed rat arteries.

J Orthop Sci 2019 May 2;24(3):552-557. Epub 2018 Nov 2.

Department of Orthopaedic Surgery, University Hospital of Ioannina, Stavros Niarchos Avenue 1, Ioannina, Greece.

Background: During the last decade direct oral anticoagulants (DOAC) have been established in various fields of medicine.Their use in microsurgery has not been evaluated yet though. This study aims to evaluate their efficacy in microsurgery and additionally compare them with a well established antithrombotic agent.

Materials And Methods: The right femoral artery of 101 rats divided into 4 groups, was crushed and anastomosed. Group A (20 rats) received placebo therapy (1 ml NaCl 0.9%, orally), while Group B (27 rats), Group C (27 rats) and Group D (27 rats) received rivaroxaban (3 mg/kg, orally), dabigatran (30 mg/kg, orally) and enoxaparin (30 mg/kg, subcutaneously) respectively. All drugs were administered 3 h preoperatively and once daily for the following postoperative days until the sacrifice of the animals. Patency was evaluated at 1st, 7th and 20th postoperative day. Following patency evaluation the rats were sacrificed and the vessels were harvested for histological examination.

Results: None of the rats died postoperatively. Patency rates of rivaroxaban group (78%), dabigatran group (70%) and enoxaparin group (63%) were statistically similar, but significantly higher than the placebo-treated control group (p < 0.05). Cells with morphologic features of endothelial cells were evident 7 days after the injury.

Conclusion: The results of this study demonstrate the following: (1) rivaroxaban and dabigatran through inhibition of thrombus formation significantly enhanced the patency rate compared to placebo treatment (2) the antithrombotic efficacy of rivaroxaban and dabigatran in compromised microvessels was similar to that of enoxaparin, the most widely used antithrombotic agent.
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http://dx.doi.org/10.1016/j.jos.2018.10.011DOI Listing
May 2019

Laboratory Assessment of the Anticoagulant Activity of Apixaban in Patients With Nonvalvular Atrial Fibrillation.

Clin Appl Thromb Hemost 2018 Dec 1;24(9_suppl):194S-201S. Epub 2018 Oct 1.

Laboratory of Haematology & Blood Bank Unit, "Attiko" University Hospital, School of Medicine, National and Kapodistrian University of Athens, Athens, Greece.

Our aim is to determine the most appropriate laboratory tests, besides anti-factor Xa (anti-FXa) chromogenic assays, to estimate the degree of anticoagulation with apixaban and compare it with that of rivaroxaban in real-world patients. Twenty patients with nonvalvular atrial fibrillation treated with apixaban 5 mg twice daily and 20 patients on rivaroxaban 20 mg once daily were studied. Conventional coagulation tests, thrombin generation assay (TGA), and thromboelastometry (nonactivated TEM [NATEM] assay) were performed in the 40 patients and 20 controls. The anti-FXa chromogenic assays were used to measure apixaban and rivaroxaban plasma levels. The NATEM measurements showed no significant difference between the 2 groups of patients. Concerning TGA, endogenous thrombin potential (ETP) was significantly decreased in patients on rivaroxaban as compared to those treated with apixaban ( < .003). A statistically significant, strong inverse correlation between apixaban plasma concentrations and ETP ( < .001) was observed. Apixaban significantly reduces ETP compared to controls, but to a lesser extent than rivaroxaban. Thrombin generation assay might provide additional information on apixaban exposure, which is required in order to individualize treatment especially for patients with a high bleeding risk. Our findings have to be further investigated in studies with larger sample sizes, in the entire range of apixaban exposure, with other direct oral anticoagulants, and in relation to clinical outcomes.
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http://dx.doi.org/10.1177/1076029618802364DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6714834PMC
December 2018

Spinal motion preservation surgery: indications and applications.

Eur J Orthop Surg Traumatol 2018 Apr 6;28(3):335-342. Epub 2017 Oct 6.

Department of Οrthopedics, University Hospital of Ioannina, Stavros Niarchos Avenue, 45500, Ioannina, Greece.

Fusion is one of the most commonly performed spinal procedures, indicated for a wide range of spinal problems. Elimination of motion though results in accelerated degeneration of the adjacent level, known as adjacent level disease. Motion preservation surgical methods were developed in order to overcome this complication. These methods include total disc replacement, laminoplasty, interspinous implants and dynamic posterior stabilization systems. The initial enthusiasm about these methods was followed by certain concerns about their clinical usefulness and their results. The main indications for total disc replacement are degenerative disc disease, but the numerous contraindications for this method make it difficult to find the right candidate. Application of interspinous implants has shown good results in patients with spinal stenosis, but a more precise definition is needed regarding the severity of spinal stenosis up to which these implants can be used. Laminoplasty has several advantages and less complications compared to fusion and laminectomy in patients with cervical myelopathy/radiculopathy. Dynamic posterior stabilization could replace conventional fusion in certain cases, but also in this case the results are successful only in mild to moderate cases.
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http://dx.doi.org/10.1007/s00590-017-2052-3DOI Listing
April 2018

The role of new oral anticoagulants in orthopaedics: an update of recent evidence.

Eur J Orthop Surg Traumatol 2017 Jul 17;27(5):573-582. Epub 2017 Mar 17.

Department of Οrthopedics, University Hospital of Ioannina, Stavros Niarchos Avenue, 45500, Ioannina, Greece.

Rivaroxaban, dabigatran, apixaban and edoxaban are the four available new oral anticoagulants (NOAC) which are currently approved for venous thromboembolism prophylaxis after total hip and knee replacement. Large phase 3 and phase 4 studies comparing NOAC with low molecular weight heparins have shown similar results regarding the efficacy and safety of these two categories of anticoagulants. Management of bleeding complications is a matter of great significance. Three reversal agents have been developed: idarucizumab, andexanet alfa and ciraparantag. Idarucizumab is now commercially available. Regarding the perioperative management of NOAC, two main scientific groups have published their own recommendations. The European Heart Rhythm Association recommends 48-h period of stoppage preoperatively for factor Xa inhibitors and at least 3 or 4 days for dabigatran, while the French Study Group on Thrombosis and Haemostasis recommends 5-day discontinuation for all NOAC. Conventional clot tests can only be used as rough indicators for laboratory assessment of the activity of NOAC. Specific laboratory tests have been developed for more accurate measurements of NOAC blood levels, including a dilute thrombin time test (Hemoclot test) and the ecarin clot test for dabigatran and chromogenic anti-factor Xa assays for direct factor Xa inhibitors. Due to the beneficial properties of NOAC, these drugs are gaining ground in daily orthopaedic practice, and many studies are being conducted in order to extend the indications of these anticoagulants agents.
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http://dx.doi.org/10.1007/s00590-017-1940-xDOI Listing
July 2017
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