Morphologic characterisation of the posterior inferior cerebellar artery. A direct anatomic study.

BACKGROUND: The number of studies on the cerebellar arteries has increased. The purpose of this study was to determine the morphological expression of posterior inferior cerebellar artery in a sample of Colombian population. MATERIALS AND METHODS: One hundred eighty-six posterior inferior cerebellar arteries of fresh cadavers were studied. In each specimen, vertebral arteries were injected with 100 mL of semi-synthetic resin, dyed with mineral red. RESULTS: In the 93 blocks of brainstem and cerebellum evaluated, 174 (93.5%) posterior inferior cerebellar arteries were found. Also, there were 12 (6.5%) ageneses. There was single posterior inferior cerebellar artery in 159 (91.4%) samples and duplicate in 10 (5.7%), while 5 (2.9%) specimens showed hypoplasia. The posterior inferior cerebellar artery originated from the vertebral artery in 121 (69.5%) samples and from the basilar artery in 42 (24.1%) samples; while in 11 (6.4%) it originated in a common trunk with the anterior inferior cerebellar artery. In 101 (83.5%) cases, the posterior inferior cerebellar artery originated from the intracranial segment of the vertebral artery, while 20 (16.5%) samples originated from the extracranial segment. The calibres of posterior inferior cerebellar artery in its proximal and distal segments were 1.45 ± 0.37 mm and 1.33 ± 0.31 mm, respectively. CONCLUSIONS: This study, carried out in cadaveric material, provides relevant qualitative and morphometric information of the posterior inferior cerebellar artery, useful for the diagnosis and clinical management, as well as for the surgical approaches that may compromise this structure.

Morphometric analysis of cardiac conduction fibers in horses and dogs, a comparative histological and immunohistochemical study with findings in human hearts.

The principal function of the ventricular conduction system is rapid electrical activation of the ventricles. The aim of this study is to conduct a morphometric study to pinpoint the morphological parameters that define cardiac conduction cells, allowing us to distinguish them from other cells. Five male horse hearts and five male dog hearts were used in the study. The hearts were fixed in a 5% formaldehyde solution. Histological sections of 5 µm thickness were acquired and stained with hematoxylin-eosin and Masson's trichrome and cardiac conduction cells and their junctions were identified by desmin, connexin 40 and a PAS method. We found statistically significant differences in cardiac conduction fibers density and thickness, which was much higher in horses than in dogs (p = 0.000 for both values). By comparing the measured parameters of the cells in both species, we determined that cardiac conduction cells area and diameters were greater in horses than in dogs (p = 0.000 for all values). In dogs there are more junctions (30.8%) than in horses (26.1%), a statistically significant difference (p = 0.041). Our findings regarding the cardiac conduction fibers distribution in the animal species studied becomes new knowledge that contributes to the morphological study of this component of the cardiac conduction system and also makes it possible to locate exactly the site with the highest density of cardiac conduction fibers as a contribution to the cardiological study of these structures that lead to the prevention of ventricular arrhythmias and the identification of their treatment site.

Morphologic characterization of the anterior inferior cerebellar artery: a direct anatomic study.

OBJECTIVE: An adequate knowledge of the anterior inferior cerebellar artery (AICA) is oriented to the morphological sciences, clinical management and surgical planning of the posterior fossa. We aimed to determine the morphology of AICA in a sample from Colombian population. METHOD: We studied 92 AICA from fresh cadavers. For each specimen, the vertebral arteries were injected with 100 cc of semi-synthetic resin (a mixture of Palatal E210® BASF 80 cc and Styrene 20 cc) dyed with mineral red. The biometrics and morphological variables of AICA were registered. RESULTS: AICA originated at 9.9 ± 3.2 mm from the vertebrobasilar junction. In 12 samples (8.1%), we observed a common trunk between AICA and posterior inferior cerebellar artery, which presented a caliber of 1.56 ± 0.23 mm and a length of 11.3  ± 3. 53 mm. In 80 (51.3%) specimens, AICA was originated from the proximal segment of basilar artery, while in 76 (48.7%) of them emerged from the medium segment. The AICA bifurcation distance from its origin was less than 20 mm in 20.5% of cases; between 20 and 40 mm in 62.3%. In its trajectory, AICA passed ventral to the facial nerve in 85 samples (53.2%), dorsal to the facial nerve in 68 samples (43.6%) and between the roots in 5 samples (3.2%). CONCLUSIONS: The origin of the AICA from the proximal segment of the basilar artery is confirmed in this study, which disagrees with reports that point out its origin in the middle segment.

Anatomical study of the renal excretory system in pigs. A review of its characteristics as compared to its human counterpart.

BACKGROUND: Despite the importance of the pyelocalyceal system in the pig as an experimental model, there is little information about this particular anatomical subject. We determined the morphological characteristics of the renal excretory system in pigs. MATERIALS AND METHODS: This descriptive cross-sectional study evaluated 130 pairs of kidneys of pigs destined to slaughter. The pyelocalyceal system was subjected to injection technique - corrosion by infusion of polyester resin (85% Palatal and 15% Styrene) and subsequent infusion in potassium hydroxide (KOH) for 10 days. The significance level used was p < 0.05. RESULTS: The renal excretory system is characterised by the presence of type A major cranial and caudal calyxes seen in 34.3% of the kidneys (type A1 in 30% and type A2 in 4.3%). type B calyxes, corresponding to minor calyxes draining directly into the renal pelvis, were present in 65.7% of the specimens (type B1 59.2%; type B2 6.5% of the cases). The number of minor calyxes in the collector system was 7.9 ± 2.27 with statistically significant differences in side (p = 0.0047). CONCLUSIONS: The morphometric characteristics of the kidneys in this study are slightly smaller than reported in humans. Similarly, the incidence of type A renal excretory system distribution is highest in humans and lowest in pigs. Due to its few morphological differences, the pig kidney is an excellent model for teaching- -learning processes, for research purposes, and for training of urologic applications.

Variaciones vasculares en cavidad abdominal y de vías urinarias: presentación de caso / Vascular variations in urinary tract and abdominal cavity: case report

Se presenta un raro caso de múltiples variaciones en la cavidad abdominal de un espécimen cadavérico de 50 años de género masculino, del laboratorio de anatomía de la Universidad Industrial de Santander (Bucaramanga-Colombia). Se observó variaciones arteriales (arteria renal adicional derecha y origen de la rama hepática derecha desde la arteria mesentérica superior), venosa (vena renal derecha adicional) y de vía urinaria (doble uréter en el lado derecho). Estas diversas variantes anatómicas además de suscitar interés académico, deben ser consideradas y descritas correctamente por los clínicos durante la realización de procedimientos quirúrgicos, radiológicos y de imágenes diagnósticas en la cavidad abdominal.

Here we present a rare case of multiple abdominal cavity variations in a 50-year-old male cadaveric specimen of the anatomy laboratory of the Universidad Industrial de Santander (Bucaramanga, Colombia). The anatomical dissection revealed arterial variations (right additional renal artery and origin of the right hepatic branch from the superior mesenteric artery), venous (right additional renal vein) and urinary tract (duplicated ureter on the right side). These multiple anatomic variations in addition to raising academic interest, should be considered and described correctly by clinicians while performing surgical, radiological and imaging procedures in the abdominal cavity.