Konstantinos Natsis
Aristotle University of Thessaloniki
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Featured researches published by Konstantinos Natsis.
European Journal of Endocrinology | 2011
George Noussios; Panagiotis Anagnostis; Dimitrios G. Goulis; Dimitrios Lappas; Konstantinos Natsis
Ectopic thyroid tissue is a rare entity resulting from developmental defects at early stages of thyroid gland embryogenesis, during its passage from the floor of the primitive foregut to its final pre-tracheal position. It is frequently found around the course of the thyroglossal duct or laterally in the neck, as well as in distant places such as the mediastinum and the subdiaphragmatic organs. Although most cases are asymptomatic, symptoms related to tumor size and its relationship with surrounding tissues may also appear. Any disease affecting the thyroid gland may also involve the ectopic thyroid, including malignancy. The clinician must distinguish between ectopic thyroid and metastatic deposits emerging from an orthotopic gland, as well as other benign or malignant masses. Thyroid scintigraphy plays the most important role in diagnosing ectopy, but ultrasonography contributes as well. In cases of symptomatic disease, surgery is the treatment of choice, followed by radioiodine ablation and levothyroxine suppression therapy in more refractory cases. This review provides current understanding about the wide clinical spectrum of this rare condition, also referring to optimal diagnostic approach, differential diagnosis, and management strategies.
Surgical and Radiologic Anatomy | 2009
Konstantinos Natsis; Ioannis Tsitouridis; Matthaios Didagelos; Andis A. Fillipidis; Konstantinos Vlasis; P. Tsikaras
BackgroundThe variations of vessels arising from the aortic arch are numerous. The purpose of the present study is the description of the aortic arch branches’ variations, in order to offer useful data to anatomists, radiologists, vascular, neck and thorax surgeons. In addition, literature has been reviewed so as to enable a comparison of our results with those of other studies and an analysis of the variations’ clinical implications is possible.Materials and methodsA total of 633 digital subtraction angiographies of Caucasian Greek patients were examined. No computed tomography or magnetic resonance angiographies were included.ResultsEight types of the aortic arch were found. The classification from I to VIII was made according to the incidences recorded, with type I being the most and type VIII being the least frequent. Type I, brachiocephalic trunk (BT), left common carotid artery (LCC), left subclavian artery (LS), 527 (83%); type II, BT with LCC and LS, 96 (15%); type III, BT, LCC, left vertebral artery (LV), LS, 5 (0.79%); type IV, right subclavian artery (RS), carotids in common, LS, 1 (0.16%); type V, carotids in common-LS, RS, 1 (0.16%); type VI, carotids and subclavians in common, 1 (0.16%); type VII, RS, right common carotid artery (RCC), LCC, LS, 1 (0.16%); type VIII, BT, thyroidea ima, LCC, LS, 1 (0.16%).ConclusionsDespite the fact that the variations in question are usually asymptomatic, they may cause dyspnea, dysphagia, intermittent claudication, misinterpretation of radiological examinations and complications during neck and thorax surgery. Furthermore, these variations may be accompanied by other congenital abnormalities.
Journal of Biomechanics | 2009
Eleftherios Kellis; Nikiforos Galanis; Konstantinos Natsis; George A. Kapetanos
The purpose of this study was to compare the architectural parameters of the long head of biceps femoris (BFlh) and semitendinosus (ST) muscles by comparing measurements from ultrasound (US) with those obtained from direct dissection. The BFlh and ST architectures were examined bilaterally in 6 legs from 3 male cadavers. The fascicle length, pennation angle, muscle thickness and muscle and tendon length were obtained from direct measurement and US scans along each muscle. Intraclass correlation coefficients between the two methods ranged from 0.905 to 0.913 for the BFlh variables and from 0.774 to 0.974 for the ST parameters. Compared with the direct measurements, the US method showed a mean typical error of 0.09-0.14 cm for muscle thickness, 1.01-1.31 degrees for the pennation angle, 0.92-1.71 cm for fascicle length and muscle-tendon length measurements. The US method is a valid alternative tool for assessing basic architectural parameters of ST and BFlh components of the hamstring muscles.
American Journal of Sports Medicine | 2006
Ioannis Terzidis; Anastasios Christodoulou; Avraam Ploumis; Panagiotis Givissis; Konstantinos Natsis; Miltiadis Koimtzis
Background There has been great interest in the literature regarding meniscal tears in unstable knees, but there is not as much information available on stable knees. Purpose To report the characteristics of isolated meniscal tears (type and location) in athletes with intact cruciate ligaments. Study Design Case series; Level of evidence, 4. Methods Arthroscopic surgery was performed on 314 (83.1%) knees in the acute phase (<6 weeks) of injury and on 64 (16.9%) knees more than 6 weeks after injury for a total of 364 athletes (378 knees). Coopers classification was used to classify the meniscal tears according to the type and location. Results Overall, 262 of 378 tears (69.3%) were located in the medial meniscus and 116 (30.7%) in the lateral meniscus. Vertical tears (77.5%) were significantly more frequent than were horizontal tears (22.5%; ϰ2 test, P < .001). A total of 23.2% of tears involved the peripheral zones (zone 0 or 1), and tears that extended into the posterior horn accounted for 75.7%. Regarding the tear shape between male and female athletes, on both sides there were no statistically significant differences in the percentage of horizontal, bucket-handle, longitudinal, or radial tears. Conclusion The characteristics of isolated meniscal tears differ with regard to the sport, sex, and tear location and type from those seen in unstable knees. This knowledge is useful in knee injury management.
Surgical and Radiologic Anatomy | 2014
Konstantinos Natsis; Maria Piagkou; Antonia Skotsimara; Vassilis Protogerou; Ioannis Tsitouridis; Panagiotis Skandalakis
Horseshoe kidney (HSK) is the most common renal fusion, which is characterized by three anatomic anomalies: ectopia, malrotation and vascular changes. Patients with HSK are prone to a variety of complications, genitourinary and non-genitourinary. In this paper, the anatomy of HSK is delineated with a great emphasis on its blood supply. After reviewing the literature, the arterial supply patterns found by each author were categorized according to the classification system proposed by Graves. The majority of HSKs were found to be supplied by renal arteries derived from the abdominal aorta below the isthmus or by vessels originating from the common iliac arteries. In addition, the abnormalities associated with HSK are highlighted and classified in anatomical variations, congenital anomalies as well as in pathologic conditions related to HSK.
Experimental and Clinical Endocrinology & Diabetes | 2012
George Noussios; Panagiotis Anagnostis; Konstantinos Natsis
Ectopic parathyroid glands result from aberrant migration during early stages of development and lack of successful identification may lead to lack of success in parathyroid surgery. They constitute a common etiology of persistent or recurrent hyperparathyroidism, when they are missed at initial diagnosis. Their prevalence is about 2-43% in anatomical series and up to 16% and 14% in patients with primary and secondary hyperparathyroidism, respectively. Ectopic inferior parathyroids are most frequently found in the anterior mediastinum, in association with the thymus or the thyroid gland, while the most common position for ectopic superior parathyroids is the tracheoesophageal groove and retroesophageal region. Neck ultrasound and 99mTc Sestamibi scan are first-line imaging modalities, although with low sensitivity and specificity. However, their combination with modern techniques, such as single photon emission computed tomography (SPECT) alone or in combination with CT (SPECT/CT) increases their diagnostic accuracy. Fine needle-aspiration cytology of a lesion suspicious for parathyroid tissue and measurement of parathyroid hormone (PTH) in the aspired material further assist to the successful preoperative localization of ectopic glands. Common sites for surgical investigation are the upper thyroid pole and the upper vascular thyroid stalk behind the hypopharynx and cervical esophagus for the superior parathyroids, and the carotid artery bifurcation and the thymic tongue, for the inferior parathyroids. Radioguided minimally invasive parathyroidectomy after successful localization, assisted by rapid PTH measurement postoperatively, significantly improves surgical outcomes in patients with ectopic parathyroid adenomas.
Journal of Electromyography and Kinesiology | 2010
Eleftherios Kellis; Nikiforos Galanis; Konstantinos Natsis; George A. Kapetanos
The purpose of this study was to examine whether muscle architecture of the long head of biceps femoris (BF) and semitendinosus (ST) muscles varies along their length. The ST and BF muscles were dissected and removed from their origins in eight cadaveric specimens (age range 67.8-73.4 years). One-way analysis of variance designs were used to compare fascicle length (FL), pennation angle (PA) and muscle thickness (MT) between proximal, mid-belly and distal positions. Tendon and muscle length properties were also quantified. For the BF muscle, one-way analysis of variance tests showed a higher PA (23.96±3.82°) and FL (7.12±0.48 cm) proximally than distal positions (PA=17.78±1.95° and FL=6.35±0.89 cm, respectively). For the ST, there was a significantly (p<0.05) lower PA (8.81±1.22°) and FL (13.10±1.54 cm) proximally than distally (PA=14.69±1.09° and FL=15.49±2.30 cm, respectively). Muscle thickness significantly increased from distal to more proximal positions (p<0.05). These data suggest that the ST and BF architecture is not uniform and that measurement of these parameters largely depends on the measurement site. Modeling these muscles by assuming a uniform architecture along muscle length may yield less accurate representation of human hamstring muscle function.
Anatomical Science International | 2010
Konstantinos Natsis; Stylianos Apostolidis; George Noussios; Efthymia Papathanasiou; Aggela Kyriazidou; Vasilios Vyzas
A case of a duplicated inferior vena cava (IVC) along with other anatomical vessel variations in a 72-year-old male cadaver is presented. The anomalous vessels involved, besides the IVC, were the left testicular vein and artery, the left suprarenal artery and a superior accessory left renal artery. Based on the gross appearance of the preaortic anastomotic trunk between the left and right IVC as well as on the underlying embryological features, a classification is proposed: incomplete bilateral duplication of the IVC and complete bilateral duplication of the IVC. The latter can be further divided into three types: major, minor and asymmetric.
Journal of Electromyography and Kinesiology | 2012
Eleftherios Kellis; Nikiforos Galanis; George A. Kapetanos; Konstantinos Natsis
The purpose of this study was to understand the detailed architectural properties of the human hamstring muscles. The long (BFlh) and short (BFsh) head of biceps femoris, semimembranosus (SM) and semitendinosus (ST) muscles were dissected and removed from their origins in eight cadaveric specimens (age 67.8±4.3 years). Mean fiber length, sarcomere length, physiological cross-section area and pennation angle were measured. These data were then used to calculate a similarity index (δ) between pairs of muscles. The results indicated moderate similarity between BFlh and BFsh (δ=0.54) and between BFlh and SM (δ=0.35). In contrast, similarity was low between SM and ST (δ=0.98) and between BFlh and SM (δ=1.17). The fascicle length/muscle length ratio was higher for the ST (0.58) and BFsh (0.50) compared with the BFlh (0.27) and SM (0.22). There were, however, high inter-correlations between individual muscle architecture values, especially for muscle thickness and fascicle length data sets. Prediction of the whole hamstring architecture was achieved by combining data from all four muscles. These data show different designs of the hamstring muscles, especially between the SM and ST (medial) and BFlh and BFsh (lateral) muscles. Modeling the hamstrings as one muscle group by assuming uniform inter-muscular architecture yields less accurate representation of human hamstring muscle function.
Clinical Anatomy | 2011
Konstantinos Natsis; Athanasios Raikos; Ioannis Foundos; George Noussios; Nikolaos Lazaridis; Samouel N. Njau
Studies on the origin of the superior thyroid artery, define that it could originate either from the external carotid artery, (at the level of common carotid bifurcation), or from the common carotid artery. However, there is a classical anatomic knowledge that the superior thyroid artery is a branch of the external carotid artery. Variability in the anatomy of the superior thyroid artery was studied on 100 carotids. Moreover, a review about the origin of superior thyroid artery between recent and previous cadaveric, autopsy, and angiographic studies, on adults and fetuses, was carried out. The superior thyroid artery originated from the external carotid artery in 39% and at the level of carotid bifurcation and common carotid artery in 61% of cases. The anterior branches of the external carotid artery were separate in 76% of cases, while common trunks between the arteries were found in 24% of the specimens. A new classification proposal on the origin of the superior thyroid artery is also suggested. In this study, the origin of superior thyroid artery is considered at the level of the carotid bifurcation and not from the external carotid artery as stated in many classical anatomy textbooks. This has a great impact on the terminology when referring to the anterior branches of the external carotid artery, which could be termed as anterior branches of the cervical carotid artery. Head and neck surgeons must be familiar with anatomical variations of the superior thyroid artery in order to achieve a better surgical outcome. Clin. Anat. 24:699–705, 2011.