Slobodan Vlajković

Trigeminal artery: a review of normal and pathological features

ObjectsCarotid–vertebrobasilar anastomoses—the trigeminal, otic, hypoglossal, and proatlantal intersegmental arteries—serve as transitory channels between primitive internal carotid arteries and bilateral longitudinal neural arterial plexus, which is the precursor of future basilar artery, when the human embryo reaches about 4-mm length.Material and methodsNormal and/or abnormal morphofunctional aspects of the prenatal and postnatal forms of the trigeminal artery are described according to personal and literature data. Many arteries of similar origin and course are also noted in the differential diagnosis of the trigeminal artery.ConclusionsThe persistent primitive trigeminal artery, as the most commonly carotid–vertebrobasilar anastomosis, has a reported incidence of 0.03–2.2% in the literature. There is female sex predilection, and it may be discovered in patients of any age, on either side, and in association with many vascular variants. Although the significance of persistent primitive trigeminal artery regarding the development of an aneurysm or association with another pathological condition may not be clear, its (ab)normal morphology is the inspiration for anatomists, especially for neurosurgeons, before planning diagnostic and therapeutic procedures.

Morphological and biomechanical features of the temporomandibular joint disc: an overview of recent findings.

The temporomandibular joint is a type of synovial joint with unique structure and function. Between the mandibular condyle and the mandibular fossa there is a dense fibrocartilaginous oval articular disc, temporomandibular joint disc. This disc serves as a nonossified bone, thus permitting the complex movements of the joint, and plays a major role in jaw function by providing stress distribution and lubrication in the temporomandibular joint. Pathological mechanical loads are one of the principal causes of temporomandibular joint disc displacement. There is a high frequency of temporomandibular joint disc disorders and treatment options are very limited. For this reason, it is necessary to examine possible alternatives to current treatment options like physiotherapy, drugs, splints or surgical techniques. Recent discoveries in the field of structure and functions of temporomandibular joint disc have created the need for their particular systematization, all in order to create an implant that would be used to replace the damaged disc and be more similar to the natural one. There is a need to more fully meet the morphology and biomechanical properties of the temporomandibular joint disc, and using tissue engineering, make a substitute for it, as faithful as possible, in a case where the natural TMJ disc is damaged so much that the normal function of the joint can be preserved only through implanted disc. Therefore, the aim of this paper was to describe morphology and structure, as well as biomechanical properties of the TMJ disc, in light of the possible applications of this knowledge for the purposes of tissue engineering.

Possible therapeutic use of spermatogonial stem cells in the treatment of male infertility: a brief overview.

Development of germ cells is a process starting in fetus and completed only in puberty. Spermatogonial stem cells maintain spermatogenesis throughout the reproductive life of mammals. They are undifferentiated cells defined by their ability to both self-renew and differentiate into mature spermatozoa. This self-renewal and differentiation in turn is tightly regulated by a combination of intrinsic gene expression as well as the extrinsic gene signals from the local tissue microenvironment. The human testis is prone to damage, either for therapeutic reasons or because of toxic agents from the environment. For preservation of fertility, patients who will undergo radiotherapy and/or chemotherapy have an attractive possibility to keep in store and afterwards make a transfer of spermatogonial stem cells. Germ cell transplantation is not yet ready for the human fertility clinic, but it may be reasonable for young cancer patients, with no other options to preserve their fertility. Whereas this technique has become an important research tool in rodents, a clinical application must still be regarded as experimental, and many aspects of the procedure need to be optimized prior to a clinical application in men. In future, a range of options for the preservation of male fertility will get a new significance.

Age-Related Changes of the Human Fetal Kidney Size

Early prenatal diagnostics and the importance of genetic counseling are of great interest for echosonographic evaluation of normal fetus anatomy. Development of the human fetal kidney runs through a series of continual and mutually dependent changes during which the kidney obtains its morphological and functional maturity. This study was created to estimate the changes in kidney size during gestation in fetuses from the 4th to the 10th lunar month, to evaluate the dynamics of their growth, as well as to establish the validity of the volume calculated from these dimensions. Serial measurements of kidney dimensions (length, width, thickness) were performed in 110 fetuses. Photomicrographs of kidneys from the 4th, 6th, 8th and 10th lunar months are also presented. On the basis of the results obtained by our examination, we concluded that the period from the 14th to 16th week of intrauterine life is the fastest period of kidney growth during fetal development. Using the ellipsoid formula for calculating the fetal renal volume offers an underestimation of about 32–33% on average. The importance of this study lies in determining the average fetal kidney dimensions, which could be used as standard values in obstetrics.

Morphology of the cerebral arterial circle in the prenatal and postnatal period of Serbian population

BackgroundIn the literature, there are descriptions of morphological types of the cerebral arterial circle (CAC) of different human populations around the world, but not the Serbian population. This additionally inspired the authors to present the results of previous and current researches of CAC’s configuration in the prenatal, as well as in the postnatal period.MethodThe study was performed on CACs of 190 human fetuses and 143 adult cadavers. The caliber and configuration of fetal vessels were examined under the operating microscope, while the same of adults were studied using the ImageJ. Statistical analysis of CACs vessels’ calibers was performed. Classification into one of CAC morphological types was based on the presence of hypoplasia of corresponding vessel(s).ResultsThere was not only significant difference of the three communicating arteries calibers before and beyond the 16th week of gestation. Calibers of the right pre-communicating part of the posterior cerebral artery and right cerebral part of the internal carotid artery were significantly higher in male than in female adults. There were 13 morphological types of CACs from the prenatal to the postnatal period. Most frequent CAC types were the type I (normal CAC) prenatally and type IV (unilateral hypoplasia of the posterior communicating artery) in the postnatal period. There were not relationships between the cerebral cause of death and a presence of aneurysm.ConclusionResults of this study will be the basis for future investigation of CACs according to the same or different ages and causes of disease and/or death.

Types and Subtypes of the Posterior Part of the Cerebral arterial Circle in Human Adult Cadavers

The main cerebral distribution center of 15-20% blood flow from the cardiac output is the cerebral arterial circle or circle of Willis, a nonagon of collateral vessels on the human brain base. At about 4 mm stage of the embryo, the primitive internal carotid arteries, which develop as cranial extensions of the paired dorsal aorta, are formed. Paired longitudinal neural arteries appear along the hindbrain and coalesce to form the basilar trunk at the 7to 12-mm stage. The caudal division of the primitive internal carotid artery anastomoses with ipsilateral neural artery and becomes the posterior communicating artery. At the 40-mm stage the posterior cerebral arteries are as extensions of the posterior communicating arteries. The vertebrobasilar system develops and thus participates in the supply of the posterior cerebral artery through the segment between the basilar artery and the post-communicating part of the posterior cerebral artery. In that phase, the component vessels of the circle of Willis all have the same caliber (Silver & Wilkins, 1991). The posterior cerebral artery originates from the basilar bifurcation within the interpeduncular cistern. From its origin the artery curves superior to the corresponding oculomotor nerve in relation to the antero-medial portion of the cerebral peduncle and joins ipsilateral posterior communicating artery (Yasargil, 1984). The posterior communicating artery takes origin from the infero-lateral wall of the cerebral part of the internal carotid artery. It is encased in a sleeve of arachnoid along the course from the carotid cistern to the piercing of the interpeduncular cistern and junction with posterior cerebral artery (Yasargil, 1984). Topographically, the circle of Willis is divided on anterior and posterior parts. The anterior part composes five vascular components – bilateral cerebral parts of internal carotid arteries (communicating and choroid subparts) and the pre-communicating part of anterior cerebral arteries interconnected by the anterior communicating artery; the posterior part composes

Hemodialysis Treatment in Patients with Balkan Endemic Nephropathy: An Epidemiological Study

Aim. To analyze hemodialysis (HD) treatment of patients with Balkan endemic nephropathy (BEN) from five endemic villages in the South Morava Region of Serbia. Analyses of patterns of incidence may generate hypotheses about the underlying causes of BEN, and prevalence data provide information on the current and likely future burden on health services for managing BEN. Methods. A total of 143 end-stage kidney disease patients (ESKD) with BEN were admitted to the renal replacement program from 1974 to 2004: 121 to HD, 15 peritoneal dialysis, and 7 kidney transplantation. As a control group, 117 patients with other kidney disease (chronic pyelonephritis, glomerulonephritis, and ischemic nephropathy) admitted to HD at the time of BEN patients and matched by age and gender were studied. Results. Most of the BEN patients (93.4%) treated by HD were born from 1917 to 1941. The majority of patients (79.3%) started HD from 1977 to 1991 (period of 15 years). The mean age of BEN patients starting HD treatment was 49.1 years in the period from 1974 to 1978, and increased steadily in the following years, being 72.5 years in the last period of study (2004–2006) The mean survival time of BEN males was 4.70 (95% CI 3.66–5.75) and for females was 5.02 (95% CI 1.47–4.53). Difference between males and females was not statistically significant (log rank 0.14, p = 0.7, P > 0.5). Mean survival times of 4.84 (95% CI 3.97–5.70) in BEN patients and 3.1 (95% CI 2.78–3.84) in other kidney disease patients were found. Difference between BEN patients and controls was statistically significant (log rank 8.38, p = 0.0038, P < 0.01). Conclusion. The population of endemic villages around the South Morava River admitted to HD treatment after 1974 was exposed to environmental toxicant(s) from 1917 to 1941. The most intense effect of environmental exposure was in that period, with ESKD in patients in their forties. The exposure to environmental toxicants has diminished, so ESKD of BEN has become less frequent and manifested in the older age, mean 72.5 in the period from 2004 to 2006. Different type of exposure was registered in some other endemic regions in Serbia and abroad.

Persistent Primitive Olfactory Artery in Serbian Population

The continuation of the cranial branch of the primitive internal carotid artery is called the primitive olfactory artery (POℓA). It takes this name according to the fact that it is mainly concerned with supplying the developing nasal region. We reported two new cases of the persistent POℓA (PPOℓA) in Serbian population after retrospective analysis of digital images of 200 fetal and 269 adult cases. This PPOℓA originated from the precommunicating part (A1) of the right anterior cerebral artery, coursed along the olfactory tract, and turned on the medial cerebral hemisphere in both male adults. Some vascular variations (fenestration of the A1 and the median artery of the corpus callosum) were associated with this persistent vessel. According to the fact that we did not find aneurysm in our previous and two recent cases, we are of the opinion that PPOℓA is usually asymptomatic in Serbian population.

Infundibular dilatation of the posterior communicating artery in a defined population

Unusual widening of the posterior communicating artery (PCoA) at its beginning from the cerebral portion of the internal carotid artery (ICA) was described as its infundibular dilatation (ID). A possibility of ID rupture or progression to aneurysm was the reason for an investigation of its frequency and morphologic features in specimens of the Serbian population. Cerebral arteries on the brain base of 267 adult cadavers of both genders and varying age and causes of death were dissected. The images of the PCoA in 190 fetuses were also reviewed. ID of the PCoA was defined as a funnel shaped beginning of different width from ICA, wherein PCoA continues from ID apex to the posterior cerebral artery. There were no cases of ID in fetuses. ID and aneurysms of the PCoA were found in 6/267 or 2.2% and 3/267 or 1.12% of adults, respectively. Unilaterally, they existed on the left side and, frequently, in male cases aging 70 years and older, that had died without cerebral cause. Bilaterally, ID was found in 2/6 cases. There was only one case of ID and aneurysm of the PCoA, but from the ID. We are of the opinion that ID of the PCoA only develops postnatally and probably is due to the influence of hemodynamic factors or hypertension.

Fenestrations and Various Duplications of the Posterior Communicating Artery in the Prenatal and Postnatal Periods

BACKGROUND The 2 paired arteries-the posterior communicating arteries (PCoAs) and the precommunicating parts of the posterior cerebral arteries-form the so-called posterior segment of the cerebral arterial circle on the base of the brain. A number of (ab)normal morphologic features were described in the literature (e.g., unusual kinking, or extreme elongations, hypoplasia, duplications, fenestrations, the infundibular widening, or aplasia of the PCoA in the prenatal and/or postnatal periods). The aim of this study was to analyze an incidence of various fenestrations and duplications of the PCoA, and describe their general features and their association with other vascular abnormalities. METHODS The research was performed on the brains of 200 human fetuses and 377 adult cadavers of both genders and different ages using microdissection and macrodissection methods. RESULTS There were 0.34% cases with PCoA fenestrations and 3.12% cases with various PCoA duplications. Their morphologic features were described and compared with the similar PCoA abnormalities recorded in the scientific literature. There was no association between the PCoA and either duplication or aneurysm in adult cases. CONCLUSIONS After thorough examination, the fenestrations and duplications of the PCoA are distinguished as 2 special forms of vascular abnormalities, and the PCoA duplications are characterized as partial and total. Furthermore, whereas the low incidence of a fenestration of the PCoA suggests it to be a sufficiently rare phenomenon, the duplications of the PCoA trunk are fairly frequent, especially concerning its terminal segment.