Caudal Branch Research Articles

Assessment of the biliary branching pattern of the caudate lobe in perihilar cholangiocarcinoma using ENBD-CT cholangiography.

Preoperative recognition of the anatomy of caudate biliary branches is important for the safe and complete resection of perihilar cholangiocarcinoma (PHC). In the present study, we identified these branches using an endoscopic nasobiliary drainage tube (ENBD). Between January 2012 and October 2022, 89 patients with suspected PHC underwent computed tomographic (CT) cholangiography through ENBD and caudate biliary branching patterns were examined. Multidetector raw CT (MDCT) scans on 85 patients with PHC without biliary drainage were also investigated. The caudate biliary branches detected by each modality were evaluated. ENBD-CT cholangiography detected 206 caudate branches (2.44 branches/patient), while MDCT identified 62 branches (0.78 branches/patient). ENBD-CT cholangiography showed that 89 caudate branches drained into the left hepatic duct (LHD), 87 into the posterior hepatic duct (Bpost), and 30 into the right hepatic duct. LHD and Bpost were the common roots of the caudate branches. Some branches (20%) joined the contralateral hepatic duct across the left-right border, but not the anterior hepatic duct or infraportal-type Bpost. ENBD-CT cholangiography clearly showed the caudate biliary branches in patients with PHC after biliary drainage.

Association between the paracaval branches of the caudate lobe and the three major hepatic veins in liver casts: Locating the cranial boundary of the caudate lobe.

According to Couinaud's definition, the cranial boundary of the caudate lobe is delineated by the three major hepatic veins. However, many branches of the caudate lobe go through the ceiling that is composed of these hepatic veins. The cranial boundary of the caudate lobe should be determined by employing the portal segmentation. We conducted a study based on the dissection of 37 colored resin liver casts to reveal the caudate branches of the liver. The paracaval portal vein branches (PCPvs) were defined as cranial portal branches from the main trunk or first-order branch of the portal vein distributed in front of the inferior vena cava, according to Kumon's classification. The PCVs were traced to reveal the cranial boundary of the caudate lobe. Results showed that in 18 cases (49%), the PCPvs reached the liver surface through the gap between the right and middle hepatic veins (type RM, n = 11), between the tiny branches of the middle hepatic vein (type M, n = 4), and between the middle and left hepatic veins (type ML, n = 3). The PCPvs did not reach the liver surface in 19 cases (type 0). No PCPvs reached the hepatic surface behind the right hepatic vein. Half of the PCPvs in the liver reached the hepatic surface beyond the boundary composed of the three major hepatic veins. Recognition of the PCPvs in the liver is indispensable to perform anatomically precise liver resections involving the major hepatic veins.

Multicentre Experience with Novel Bidirectional Double Cuffed Inner Branches for Complex Endovascular Aortic Repair

This study aimed to report the initial experience with a novel bidirectional double cuff inner branch design for incorporation of renal and mesenteric arteries in patients undergoing fenestrated and branched endovascular aortic repair (F/BEVAR). A retrospective review was undertaken of the experience of F/BEVAR with grafts integrating at least one bidirectional double cuffed inner branch implanted at three tertiary aortic centres between March 2022 and June 2023. All consecutive patients were included. Baseline characteristics, operative data, and follow up data were collected. Results were presented as number or median (interquartile range) unless otherwise stated. Thirteen patients (10 male; median age 72 [68, 77] years) had F/BEVAR using a total of 15 bidirectional double cuffed inner branches (30 cuffs). Indications for bidirectional doubled cuffed inner branches included cranial vessel orientation or double renal arteries in four patients each, common coeliomesenteric trunk in three patients, and early renal artery bifurcation, renal artery origin from a false lumen requiring a flexible route for catheterisation, and surplus configuration in one patient each. Twenty three of the 30 cuffs were used, whereas the remaining seven cuffs were intentionally occluded with vascular plugs. Target vessel incorporation was successful in all bidirectional branches. There was one technical failure related to unsuccessful catheterisation of a left renal artery targeted through a unidirectional caudal inner branch. During a median follow up of seven months there were no instances of target vessel instability or re-interventions and two patients died of causes unrelated to the bidirectional branches. The results of the use of bidirectional double cuff inner branches are promising, with high technical success and no short term branch related complications in this preliminary experience. This could potentially expand the applicability of branch endografting of complex endovascular aortic repairs, but long term results are still missing.

Anatomical study of the morphometry of portal caudate veins

The caudate lobe is a relatively unknown part of the liver due to its location and many variations. The caudate lobe is a separate entity that is located behind the trunk of the portal vein.It constitutes the hepatic dorsal area that comprises of only segment I. Thus, this lobe can be vascularized by caudate veins (CV) born either from the right branch of the portal vein (PV),from the left branch or from both. Therefore, the work allows us to study the morphometry of caudate veins. Based on the exploitation of vascular mussels of the inferior vena cava and the portal vein after injection-corrosion of the liver, the study conducted from April 2018 to March 2019 involved 41 livers of which 30 were exploited for caudate veins. These were from fresh adult subjects, both sexes free of any hepatobilio-pancreatic pathology or trauma. The injection-corrosion parts of his vascular mussels included the hepatobasement junction and the hepatic pedicle. The PV and its right and left branches provided accessory caudate branches for the caudate lobe at the level of the hepatic hilum. Thus, for all livers, we found 102 branches cauded by accessories. The accessory caudate veins were born either from the left branch of the PV in 28 livers out of 30 (93.37% ), by 1 to 4 vessels with an average distance between its branches and the portal bifurcation being 17 mm with extremes ranging from 7 to 39 mm; either from the right branch of the PV in 23 livers out of 30(76.6%), by 1 to 3 vessels with an average distance of 12.9 mm between its branches and the portal bifurcation, with extremes ranging from 9 to 18 mm. The stem of the portal vein gave branches to the caudate lobe in 11 livers on 30(36.6%),by 1 to 2 vessels whose diameter varied from 1 mm to 3 mm. We studied on 30 liver samples the anatomical variations related to CV. This is a contribution to the fundamental foundations of liver removal surgery because too little work (and often radiological) exists in Africa on the subject. However, this lack of comparative anthropometric data confirms the diversity of anatomical variations in caudate veins. On the therapeutic level these anatomical data contribute to the peri-operative safety of liver surgery.

Composition of encephalic arteries and origin of the basilar artery are different between vertebrates.

Intracranial arterial anatomy is lacking for most mammalian and non-mammalian model species, especially concerning the origin of the basilar artery (BA). Enhancing the knowledge of this anatomy can improve animal models and help understanding anatomical variations in humans. We have studied encephalic arteries in three different species of birds and eight different species of mammals using formalin-fixed brains injected with arterial red latex. Our results and literature analysis indicate that, for all vertebrates, the internal carotid artery (ICA) supplies the brain and divides into two branches: a cranial and a caudal branch. The difference between vertebrates lies in the caudal branch of the ICA. For non-mammalian, the caudal branch is the origin of the BA, and the vertebral artery (VA) is not involved in brain supply. For mammals, the VA supplies encephalic arteries in two different ways. In the first type of organization, mostly found in ungulates, the carotid rete mirabile supplies the encephalic arteries, the caudal branch is the origin of the BA, and the VA is indirectly involved in carotid rete mirabile blood supply. The second type of encephalic artery organization for mammals is the same as in humans. The caudal branch of the ICA serves as the posterior communicating artery, and the BA originates from both VAs. We believe that knowledge of comparative anatomy of encephalic arteries contributes to a better understanding of animal models applicable to surgical or radiological techniques. It improves the understanding of rare encephalic variations that may be present in humans.

Anatomical variations of artery of angular gyrus

Context: Angular gyrus is an anatomical structure of the brain located in the parietal lobe, taking part in writing and reading, language-use, memory and attention and spatial recognition. It is supplied by the angular gyrus artery, which is one of the caudal branches of the middle cerebral artery. One of the clinical pathologies of the angular gyrus artery is the ischemic stroke of the angular gyrus in the dominant hemisphere, responsible for the presence of Gerstmann Syndrome: left-right disorientation, agraphia, alexia, acalculia and finger agnosia. This systematic review aims to present the variety of anomalies of the main cerebral artery and the angular gyrus artery.
 Objective: Preparing a systematic review of papers describing the course anomalies of the angular gyrus artery.
 Materials and methods: PubMed and Google Scholar electronic databases was searched for phrases: ‘Angular gyrus artery’, ‘Artery of angular gyrus’, ‘Middle cerebral artery branches’, ‘Branches of middle cerebral artery’, ‘Gerstmann Syndrome’ published between years 2015 and 2023. Also 3 papers published before 2000 were used. From the selected 30 papers, 6 were used to prepare this analysis.
 Results: The middle cerebral artery, from which arises the angular gyrus artery, is marked by a significant variety of its division, mainly the number of the dividing trunks of the artery. Depending on the type of the division, the angular gyrus artery can arise from the upper, middle or lower trunk and vary in sizes. It can also appear as a singular or two separate branches. Instances of the anomaly of both the angular gyrus artery and posterior parietal artery are rare, but reported.
 Conclusions: The angular gyrus artery is characterised by a number of anomalies in its course, separation from the middle cerebral artery, diameter and branching.

Evaluation of Canine Shoulder Arthroscopy for Anatomical and Safety Considerations.

Arthroscopy is a well-established diagnostic modality for various orthopaedic conditions in veterinary medicine. The aim of this study was to describe the relationship of canine shoulder arthroscopy portals to major muscular, ligamentous, and neurovascular structures for anatomical and safety considerations. Arthroscopic exploration of 20 adult canine cadaver shoulders was performed. Each shoulder region was dissected layer by layer to the level of the joint. Musculotendinous, ligamentous, and cartilaginous lesions were documented. The distance was measured from each portal to neurovascular structures encountered. Muscular lesions included the deltoideus, cleidobrachialis, omotransversarius, supraspinatus, infraspinatus, and teres minor muscles. The neurovascular structures identified were the omobrachial vein, the caudal circumflex humeral artery, axillobrachial vein, and branches of the axillary nerve. Lesions to the lateral glenohumeral ligament were noted from the caudal instrument portal and the middle arthroscope portal. Iatrogenic articular cartilage injuries were identified on the caudal humeral head and the glenoid. This study supports the safety of lateral shoulder arthroscopy in dogs. Most local neurovascular structures are unaffected with traditional scope portal positions. Musculotendinous lesions are unavoidable due to the extensive muscling surrounding the shoulder but are unlikely to cause severe complications postoperatively.

Macro-anatomical Investigations on the Plexus Lumbosacralis of the Aksaray Malakli Dog

Background: In this study, cadavers of 5 adult Aksaray Malakli breed dogs were used to examine the structure of the lumbosacral plexus, which provides innervation of the hindlimb and pelvic region. Objectives: This study aimed to determine the nerve root composition of the lumbosacral plexus, determine the branching patterns, map the nerve directions macro-anatomically, and collect data for future comparisons with similar breeds. Methods: The corpses were kept in a formaldehyde pool (10%) for 14 days. After this period, the anatomical area was dissected using appropriate techniques to identify the lumbosacral plexus nerves and roots. The course and origin of the nerves forming the plexus were identified and photographed. Results: In all 5 cadavers, the lumbosacral plexus originated from the L4-S3 nerves. The plexus comprised n. ischiadicus, n. tibialis, n. obturatorius, n. femoralis, n. saphenous, n. pelvini, n. pudendus, n. cutaneus femoris caudalis, n. peroneus communis, and n. gluteus caudalis. Conclusion: It was determined that n. femoralis was formed from the ventral branches of the L4 and L5 nerves and the cranial branch of the L6 nerve. N. obturatorius originated from the caudal branch of L5 and the ventral branch of L6. It was determined that n. ischiadicus originated from the L6 caudal, L7 and ventral branch of S1 nerves. The femur branched into n. tibialis and n. peroneus communis (n. fibularis) at the level of extremitas distalis.

Laparoscopic partial pancreatectomy of the left limb using a harmonic scalpel in nine cats.

To describe a laparoscopic technique and outcome for partial pancreatectomy in cats. Prospective cohort study. Nine cats. Laparoscopic pancreatectomy was performed using a single incision laparoscopic surgery port and an additional 5.5 mm port. The left pancreatic limb was dissected, sealed and divided at the level of the splenic vein insertion to the portal vein using a harmonic device. Surgical time and complications were recorded. The weight and length of the resected pancreatic limb was recorded. Pre- and postoperative trypsin-like immunoreactivity (TLI), pancreatic lipase immunoreactivity (PLI), and hemoglobin A1C were documented. Laparoscopic partial pancreatectomy was performed successfully in all cats. One grade 1 intraoperative complication occurred (1/9; 11%) resulting in minor hemorrhage from a caudal splenic vein branch. A grade 2 postoperative complication occurred within 3 days after surgery in one cat (1/9; 11%), involving localized, sterile peritonitis in the region of the pancreatic angle. Signs resolved with conservative management. No cats exhibited signs of pancreatitis postoperatively. Long-term, mean TLI decreased by 37% ± 38% (p = .03) following partial pancreatectomy, while PLI and A1C were unchanged. All cats were alive and clinically well at last follow-up 250 to 446 days following surgery. Laparoscopic partial pancreatectomy using a harmonic device is effective in cats, and offers a minimally-invasive alternative to open surgical pancreatectomy techniques. Laparoscopic pancreatectomy of the left limb results in adequate exocrine and endocrine function in the long-term.

The course and branching of the extraorgan veins of the organs of urination in the arctic fox

When keeping fur-bearing animals, it is necessary to take into account that these animals have increased motor activity when they are in natural biogeocinosis. Due to the fact that these representatives of fur-bearing animals are kept in conditions of inactivity, this can inevitably lead to changes in the structure of the cardiovascular system. The purpose of the study is to study the features of the course and branching of extraorgan veins of the organs of urination in Arctic foxes, to determine the morphometric data of these vessels. The objects for this study were the corpses of female arctic foxes of two age groups: newborns and three to four months, five in each group. To achieve this task, a set of traditional anatomical research methods was used. According to the results of the study, it was found that the course and branching of the extraorgan vessels of the organs of urination in female arctic foxes is different. The main outflow of blood from the kidneys are the right and left renal veins; from the ureter – the cranial and caudal branches of the ureter; from the tip of the bladder – the cranial cystic vein; from the body and the bottom of the bladder is the caudal cystic vein. It is also necessary to note the close relationship of the organs of urination with the reproductive system, since the left renal vein communicates with the ovarian. In addition, we have established the presence of rare valves in the veins of the ureters and bladder, and the absence of such in the vessels of the kidneys. Thus, based on linear parameters, it can be concluded that the diameter of the veins gradually increases with the growth of the animal, especially by the period of maturation and intensification of organs.

Transverse Canal Foramen and Pericarotid Venous Network in Metatheria and Other Mammals

Transverse Canal Foramen and Pericarotid Venous Network in Metatheria and Other Mammals

Comparison of the Rostral Epidural Rete Mirabile and the Patterns of Its Blood Supply in Selected Suiformes and Hippopotamuses.

The rostral epidural rete mirabile (rete mirabile epidurale rostrale) is built of considerable small arterial vessels that anastomose with each other. This structure is formed as a result of the division of a large arterial vessel into many small arteries. Furthermore, on the other side of the rete mirabile, these small arteries are joined together to form one large artery, through which blood flows out of the rete mirabile. This system participates in decreasing the temperature of the brain and thus protects the body from thermal stress. Moreover, it influences body-water balance and has a crucial role in the retrograde transfer of neuropeptides. The goal of this study was to describe the rostral epidural rete mirabile and pathways that provide blood to this structure as well as compare it in selected Suiformes and hippopotamuses. The study was performed on desert warthogs (Phacochoerus aethiopicus), Eurasian wild boars (Sus scrofa), collared peccaries (Pecari tajacu), pygmy hippopotamuses (Choeropsis liberiensis), and common hippopotamuses (Hippopotamus amphibius). Preparations were made using the latex method and corrosion cast. An elongated shape characterizes its anatomy with a much wider rostral part than caudal part in the Eurasian wild boars, desert warthogs, and collared peccaries. The main source of blood was the branch to the rostral epidural rete mirabile branched off from the internal carotid artery. Moreover, blood enters the rete by the caudal branch and rostral branch to the rostral epidural rete mirabile. In hippopotamuses, the major source of blood was the rostral branches to the rostral epidural rete mirabile.

Duplicated superior cerebellar arteries, one of which was supplied by a persistent trigeminal artery variant diagnosed by magnetic resonance angiography.

The purpose of the study was to describe a case of duplicated superior cerebellar arteries (SCAs), whose caudal branch was supplied by a persistent trigeminal artery (PTA) variant, diagnosed by magnetic resonance (MR) angiography. A 74-year-old woman with a history of cerebral infarction underwent cranial MR imaging and MR angiography. MR imaging revealed chronic-stage left cerebellar and right basal ganglionic infarctions. MR angiography showed no steno-occlusive lesions in the intracranial arteries; however, duplicated left SCAs were observed and the caudal branch arose from the precavernous segment of the left internal carotid artery, which is indicative of a PTA variant. Variations of the SCA (e.g., duplication, early bifurcation, and common trunk of the posterior cerebral artery and SCA) are frequently seen. A cerebellar artery arising from the precavernous segment of the internal carotid artery without connection to the basilar artery is regarded as a PTA variant. According to a meta-analysis, the prevalence is reported to be 0.2%. The majority of PTA variants are classified as the anterior inferior cerebellar artery type. PTA and PTA variants are frequently associated with other cerebral variations. A case of duplicated posterior inferior cerebellar artery, in which one of the branches was supplied by a PTA variant, was reported previously. However, the combination of duplicated SCA and PTA variants has not been reported. Using MR angiography, the author diagnosed a case of duplicated SCA, whose caudal branch was supplied by a PTA variant. No similar case has been reported in the relevant English-language literature.

Endocranial anatomy of the Guercy 1 early Neanderthal from Baume Moula-Guercy (Soyons, Ardèche, France).

We provide the first comparative description of the endocranium of the Guercy 1 Early Neanderthal and examine its affinities to Preneanderthals, Neanderthals, and Homo sapiens. The Guercy 1 cranium derives from deposits chronostratigraphically and biostratigraphically dated to the Eemian Interglacial (MIS 5e). For comparative purposes, we compiled a sample of European and Southwest Asian subadult and adult Middle-to-Late Pleistocene hominins (≈MIS 12-MIS 1; N=65). We sampled both a Preneanderthal-Neanderthal group and a Homo sapiens group. The Preneanderthal-Neanderthal group was further divided into three time-successive subgroups defined by associated MIS stages. Metric and morphological observations were made on original fossils and physical and virtual endocranial reconstructions. Guercy 1 and other Early Neanderthals, differ from Preneanderthals by increased development of the prefrontal cortex, precentral and postcentral gyri, inferior parietal lobule, and frontoparietal operculum. Early Neanderthal differ, in general, from Late Neanderthals by exhibiting less development in most of the latter brain structures. The late group additionally differentiates itself from the early group by a greater development of the rostral superior parietal lobule, angular gyrus, superior and middle temporal gyri, and caudal branches of the superior temporal gyrus. Endocranial morphology assessed along the Preneanderthal-Neanderthal sequence show that brain structures prominent in Preneanderthals are accentuated in Early-to-Late Neanderthals. However, both the Early and Late groups differentiate themselves by also showing regionally specific changes in brain development. This pattern of morphological change is consistent with a mosaic pattern of neural evolution in these Middle-to-Late Pleistocene hominins.

Anatomical variations of the canine adrenal vessels.

The canine adrenal glands receive blood from the celiac artery, cranial mesenteric artery, caudal phrenic artery, cranial abdominal artery, phrenicoabdominal trunk, abdominal aorta, renal artery and lumbar artery. These are classified into three types: cranial, middle and caudal adrenal branches. It is also known that the adrenal vein flows into the phrenicoabdominal vein. However, individual differences in the branching pattern of adrenal vessels have not been systematically analysed. We evaluated adrenal vessels in dogs that underwent contrast-enhanced abdominal computed tomography (CT). There were 255 arteries travelling to the adrenal glands in 47 cases, with 1-6 arteries travelling per adrenal gland. The arteries included 67 caudal phrenic arteries, 62 aortic arteries, 60 cranial abdominal arteries, 39 renal arteries, 12 phrenicoabdominal trunks, 8 cranial mesenteric arteries, 6 celiac arteries and 1 lumbar artery. Most of the branches were from the aorta and caudal phrenic artery on the left side, and the cranial abdominal and caudal phrenic artery on the right side. A total of 110 adrenal veins were identified. Inflow into the phrenicoabdominal vein and into the right and left renal veins was observed, and we identified no inflow into other veins. This study demonstrated two points: laterality and individual differences in adrenal blood vessels. When evaluating adrenal blood vessels with abdominal contrast-enhanced CT, it is recommended to take images under general anaesthesia with breath-holding and observe them using multiplanar reconstruction.

Characterization of Endothelium-Dependent Relaxation in the Saphenous Artery and Its Caudal Branches in Young and Old Adult Sprague Dawley Rats.

Ageing is associated with reduced endothelium-derived nitric oxide (NO) production in the femoral artery of Sprague Dawley (SD) rats. In the current study, we examined endothelium-dependent relaxation (EDR) in the saphenous artery and its caudal branches. We used acetylcholine and the Proteinase-Activated receptor-2 (PAR2)-specific agonist (2fLIGRLO) with nitroarginine methylester (L-NAME) to assess EDR in two groups of male SD rats (age in weeks: young, 10–12; old, 27–29). Acetylcholine and 2fLIGRLO were potent NO-dependent relaxant agents in all arteries. For all arteries, EDR by acetylcholine decreased significantly in old compared to young SD rats. Interestingly, PAR2-induced EDR of proximal saphenous artery segments and caudal branches decreased significantly in old compared to young, but did not differ for the in-between middle and distal ends of the saphenous artery. L-NAME treatment increased subsequent contractions of proximal and middle segments of saphenous arteries by phenylephrine and U46619 in young, but not in old, SD rats. We conclude the SD saphenous artery and caudal branches exhibit regional characteristics that differ in response to specific EDR agonists, endothelial NO synthase inhibitor, and changes to endothelium function with increased age, which are, in part, attributed to decreased sensitivity of vascular smooth muscle to the gaseous transmitter NO.

Study on the portal ramification pattern of the right anterior sector of the liver and a unique medial branch (PV8c) of the right anterior portal vein.

AimThe concept of Couinaud segmentation is widely used in clinical practice. However, there were no definite anatomical landmarks between segments V and VIII. Therefore, segmentation of the right anterior sector is still controversial. We aimed to investigate the portal segmentation of the right anterior sector using 3D image analysis, and to reveal the existence of the medial branch (PV8c), a unique, characteristic branch of the right anterior portal vein.MethodsThe ramification form and pattern of the tertiary portal branch of the right anterior portal vein were retrospectively analyzed, and the frequency of PV8c was evaluated in 261 patients between January 2016 and June 2020.ResultsThe ramification pattern of tertiary portal branches of the right anterior portal vein was classified into four types: craniocaudal, 28.0% of patients; ventrodorsal, 21.8%; trifurcation, 39.5%; and quadfurcation, 5.7%, and each type was further subdivided into six patterns by focusing especially on the caudal branches. The ramification pattern in the remaining 5.0% of the livers did not belong to the above‐mentioned four types. The PV8c branch was identified in 140 of 261 livers (53.6%); the mean proportion of the feeding area of PV8c in the whole liver volume was 3.4%.ConclusionSince the ramification pattern of tertiary portal branches of the right anterior portal vein does not necessarily show a single pattern, it is important to confirm the portal vein branching in each case during hepatectomy. This is the first study of the details of PV8c by 3D computed tomography.

Some anatomical studies on the kidney of goat (Capra hircus) with special reference to angioarchitecture, ultrasonography and Doppler

The present work was carried out on twenty-five goats to study the anatomy and sonar as well as Doppler vascular perfusion of kidney in the goat. The ultrasonographic scanning of goat's kidney appeared its cortex oriented as a homogenous hypoechoic area while the medullary pyramids are presented as hypoechoic-anechoic areas deeper than the cortex. The arterial supply of the kidneys of the goat was supplied by the right and the left renal arteries. The renal artery gives accessory renal artery then passing for dividing into the dorsal and the ventral renal branches. Both branches detache the caudal dorsal, caudal dorsal midzone, cranial dorsal midzone, cranial dorsal apical segmental arteries where each of segmental artery supplies the corresponding area of the kidney. The venous drainage of the goat?s kidney is oriented by right and left renal veins. The renal vein receives two dorsal and ventral renal tributaries. Both renal tributaries extend to drain by cranial and caudal renal branches. The cranial renal branch extends in the mid, cranial parts of the kidney to receive the cranial apical the cranial midzone segmental veins, while the caudal renal branch passes in the mid and caudal parts of the kidney to drain by caudal and caudal midzone segmental tributaries. The RI measurements of the right cranial segmental, caudal segmental interlobar and arcuate renal arteries had the lowest coefficient of variation (CV; 5.45, 5.08, 5.79, and 3.44, respectively) with pooled SD (0.03, 0.03, 0.03, and 0.04, respectively). The RI evaluations of the left main, cranial segmental, caudal segmental, interlobar and arcuate renal arteries had the lowest CV in form of (7.31, 6.66, 5.88, 4.34, and 5.94, respectively) with SD (0.03, 0.03, 0.03, 0.02, and 0.04, respectively). The results obtained were tabulated and discussed with the available literature in different animals and analyzed by ANOVA.

SOME TOPOGRAPHICAL AND HISTOLOGICAL STUDIES OF THYROID AND PARATHYROD GLANDS OF MOORHEN (Gallinula c. chloropus)

The thyroid gland of Moorhen has two separated lobes. These lobes were located in the throracic inlet and receive blood supply from the cranial, middle and caudal thyroid arteries.
 The histological organization of the thyroid gland in Moorhen is surrounded by a distinct connective tissue capsule and the parenchymal cells were arranged into colloid filled follicles enmeshed in the highly vascular interstitial connective tissue. The bilaterally paired, round to oval, parathyroid glands in Moorhen were located intrathoracically near or close to the caudal pole of the thyroid glands. They receive blood by short branches from caudal thyroid artery and small branch from the common carotid artery.
 The parathyroid glands in Moorhen have a thin connective tissue capsule. Its parenchymal cells were arranged into an irregular, anastomosing cords of chief cells. No oxyphil cells were found in the parathyroid glands of Moorhen.

Morphologic characterization of the superior cerebellar artery. A direct anatomic study

Aimto determine the morphological features of superior cerebellar artery and its branches in a Colombian population sample. Materials and methodsNinety-three superior cerebellar arteries from cadaveric donors were studied. In each sample, the vertebral arteries were injected with semi-synthetic resin. The biometric and morphological variables of superior cerebellar arteries were measured. Resultsall samples from the superior cerebellar arteries originated from the basilar artery at a distance of 27.22 ± 3.13 mm from the vertebrobasilar junction. A symmetric origin was identified in 40 samples (43%), asymmetric in 53 (57%), unilateral duplication in 41 samples (22,1%). The superior cerebellar artery bifurcated in rostral and caudal branches, mainly in the second segment in 66 samples (47.5%). This excluding cases with duplication and agenesis of SCA. The superior cerebellar artery caliber in the anterior segment (1.46 ± 0.20 mm) was significantly larger than in the lateral segment (1.37 ± 0.18 mm) (p = 0.001) and in the cerebellum-mesencephalic segment (1.25 ± 0.22 mm) (p < 0.001). In its course, the artery contacted the trigeminal nerve in 47 samples (25.9%) and the trochlear nerve passed between the rostral and caudal branches in 92 samples (51.1%). Conclusionthis study reported the highest incidence of early SCA bifurcation (40.8%) and a detailed morphometric characterization of its cortical branches. Knowledge that benefices the diagnostic imaging, clinical and surgical approach of the SCA.