Hepatic portal vein branching patterns according to different liver assessment methods and classifications of branching type.

BACKGROUND: It is known that there are varying frequencies of hepatic portal vein branching patterns found in the literature. Studies use different methods and classifications to evaluate the anatomy of the portal vein, which limits accurate comparison between studies and the determination of true frequency of branching patterns in different populations. The aim of the present study was to investigate the intrahepatic branching of the portal vein in corrosive samples using different methods - somatoscopic and computed tomography (CT) and compare with similar studies as well as compare the reclassified data according to the most popular classifications used in the literature. METHODS: A total of 105 liver corrosion specimens from the 1960-1980 period (51 male and 54 female individuals; min-max age variation - 21-90 y., M=59,46 y.) were investigated. The branching patterns of the hepatic portal vein (HPV), left (HPV-LB) and right branch of hepatic portal vein (HPV-RB), and their segmental branches were examined and scanned by CT. Standard HPV ramification was considered, when HPV divided into HPV-LB and HPV-RB, HPV-RB bifurcated to the anterior and posterior branches, and further segmental ramification into the superior and inferior branches was considered standard. We compared the HPV main branch length and diameter measurements between manual and CT method. A review of the literature was performed on portal vein branching variations. RESULTS: The standard HPV ramification pattern was detected in 85.7% of the cases in both somatoscopic and CT evaluation. Variations related to the main branches were HPV trifurcation - 7.6%, posterior branch of right branch of hepatic portal vein from HPV - 4.8% and 5.7%, HPV quadrifurcation 1.9% and 1% respectively, in somatoscopic and CT evaluation. There was a significant difference between HPV-LB length and diameter in CT and manual measurements. According to the literature, more variations are seen using the CT method versus somatoscopic corrosion cast evaluation. The varying frequency in studies may be explained by a lack of one unanimous classification of branching patterns (some authors do not consider segmental variations as standard HPV ramification) and different evaluation methods. CONCLUSION: Somatoscopic evaluation of the branching patterns of the hepatic portal vein in corroded specimens and their CT reconstructions did not differ significantly (which allows relatively accurate comparison of old specimens with newer data). However, the ability to evaluate the reconstructed 3D images of the specimens allowed a more accurate assessment of segmental branching and measurements of lengths and diameters. Standard HPV branching (according to a self-developed classification) in this study was 85.7%. Depending on the classification, the rate of standard branching in the same corrosive samples varied from 63.8% to 84.8% of all cases, indicating that the lack of a unified and stable classification makes it difficult to compare the results of different studies. Deviations from standard branching are very important in surgical procedures and liver transplantation.

Morphology of the aortic arch branching pattern in raccoon dogs (Nyctereutes procyonoides, Gray, 1834).

BACKGROUND: Aortic arch (AA) branching patterns vary among different mammalian species. Most previous studies have focused on dogs, whereas those on raccoon dogs remain unexplored. OBJECTIVES: The objective of this study was to describe the AA branching pattern in raccoon dogs and compare their morphological features with those of other carnivores. METHODS: We prepared silicone cast specimens from a total of 36 raccoon dog carcasses via retrograde injection through the abdominal aorta. The brachiocephalic trunk (BCT) branching patterns were classified based on the relationship between the left and right common carotid arteries. The subclavian artery (SB) branching pattern was examined based on the order of the four major branches: the vertebral artery (VT), costocervical trunk (CCT), superficial cervical artery (SC), and internal thoracic artery (IT). RESULTS: In most cases (88.6%), the BCT branched off from the left common carotid artery and terminated in the right common carotid and right subclavian arteries. In the remaining cases (11.4%), the BCT formed a bicarotid trunk. The SB exhibited various branching patterns, with 26 observed types. Based on the branching order of the four major branches, we identified the main branching pattern, in which the VT branched first (98.6%), the CCT branched second (81.9%), the SC branched third (62.5%), and the IT branched fourth (52.8%). CONCLUSIONS: The AA branching pattern in raccoon dogs exhibited various branching patterns with both similarities and differences compared to other carnivores.

Clinical anatomy of the lateral antebrachial cutaneous nerve: Is there any safe zone for interventional approach?

INTRODUCTION: The lateral antebrachial cutaneous nerve (LACN) is a somatosensory nerve coursing in the lateral portion of the forearm. The nerve is located in a close proximity to the cephalic vein (CV) all along its course with a danger of being injured during venipuncture. The LACN also overlaps and communicates with the superficial branch of the radial nerve (SBRN) in the distal forearm and hand, making the awareness of their relationship of great importance in the treatment of neuroma. The aim of the study was to observe the relationship of the LACN to surrounding structures as well as its branching pattern and distribution. MATERIALS AND METHODS: Ninety-three cadaveric forearms embalmed in formaldehyde were dissected. The relationship of the LACN to surrounding structures was noted and photographed, and distances between the structures were measured with a digital caliper. The cross-sectional relationships of the LACN and SBRN to the CV were described using heatmaps. RESULTS: The emerging point of the LACN was found distally, proximally or at the level of the interepicondylar line (IEL). The LACN branched in 76 cases (81.7 %) into an anterior and posterior branch at mean distance of 47.8 ± 34.2 mm distal to the IEL. The sensory distribution was described according to the relationship of the LACN branches to the medial border of the brachioradialis muscle. The LACN supplying the dorsum of the hand was observed in 39.8 % of cases. The LACN and the SBRN intersected in 86 % of upper limbs with communications noticed in 71 % of forearms. The LACN was stated as the most frequent donor of the communicating branch resulting in neuroma located distal to the communication and being fed from the LACN. The relationship of the LACN and the CV showed that the IEL is the most appropriate place for the venipuncture due to maximal calibers of the CV and deep position of the LACN. The LACN was adjacent to the cubital perforating vein and the radial artery in all cases. The medial border of the brachioradialis muscle was observed less than 1.8 mm from the LACN. CONCLUSION: The study provides morphological data on the LACN distribution, branching pattern and relationship to surrounding structures in a context of clinical use in different spheres of medicine. The branching pattern of the LACN appears to be more constant compared to data provided by previous authors. We emphasized the meaning of cross-sectional relationship of the LACN to the CV to avoid venipuncture outside the cubital fossa if possible. The posterior branch of the LACN was predicted as appropriate donor of the graft for a digital nerve. The LACN appeared to be in a close proximity within the whole length of the brachioradialis muscle what the orthopedic surgeons must be concerned of. The meaning of the donor-nerve of the communicating branch in neuroma treatment was also introduced.

Classification and fascicular analysis of variant branching pattern of femoral nerve for microsurgical intervention: a series of thirteen cadavers / Clasificación y análisis fascicular de las variantes en el patrón de ramificación del nervio femoral en intervenciones microquirúrgicas: una serie de 13 cadáveres

Femoral neuropathy associated with lower limb is treated by surgical intervention through activation/regeneration/grafting of nerve fibers by a nerve cuff electrode implant or neuro-prosthesis. These procedures require detailed and precise knowledge of neuro-anatomical variants of the femoral nerve and its fascicular anatomy so that the nerve injury can be investigated and treated more efficiently. The aim of the study is to uncover the variations both in the femoral nerve and its branches, to classify them and to bring out corresponding fascicular anatomy using a hypothesis based on the principle of consistency, continuity and traceability of fascicles. The study was carried out in the Department of Anatomy AIIMS Rishikesh using 13 matched lower limbs (26 femoral nerves) from 13 cadavers. The femoral nerve was exposed in the femoral triangle and traced to the posterior abdominal wall. Variations in the shape, size and course of the femoral nerve and its branches were analyzed. The fascicular arrangement was also conceptualized based on the hypothesis. Seven classes, high division, trunk anomaly, semi-scattered, scattered branching pattern, pectocutaneous, lateral cutaneous nerve of thigh and nerve to sartorius anomalies were detected. The corresponding fascicular organizations were modeled. The seven classes along with corresponding fascicular pattern will be very useful for neurosurgeons, radiologists, anesthetists and anatomists in diagnosis and treatment of femoral neuropathy.

La neuropatía femoral asociada con el miembro inferior es tratada por intervención quirúrgica a través de activación, regeneración e injerto de fibras nerviosas mediante un implante de electrodo de manguito de nervios o neuro-prótesis. Estos procedimientos requieren un conocimiento detallado y preciso de las variantes neuro-anatómicas del nervio femoral y su anatomía fascicular de modo que la lesión del nervio pueda ser investigada y tratada de manera más eficiente. El objetivo del estudio fue descubrir las variaciones tanto en el nervio femoral y sus ramas y clasificarlos a partir de la anatomía fascicular utilizando una hipótesis basada en el principio de la continuidad y trazabilidad de los fascículos correspondientes. El estudio se llevó a cabo en el Departamento de Anatomía AIIMS Rishikesh utilizando 13 miembros inferiores pareados (26 nervios femorales) de 13 cadáveres. El nervio femoral se expuso en el triángulo femoral y fue trazado en la pared abdominal posterior. Se analizaron las variaciones en la forma, tamaño y trayecto del nervio femoral y sus ramas. El patrón fascicular fue conceptulizado de acuerdo a la hipótesis planteada. Se detectaron anomalías clasificadas en: siete clases, división alta, anomalías de tronco, semi-dispersos, patrón de ramificación dispersa, pectocutáneo, nervio cutáneo lateral y nervio del músculo sartorio. Las clasificaciones junto con el patrón fascicular correspondientes serán de gran utilidad para los neurocirujanos, radiólogos, anestesistas y anatomistas en el diagnóstico y tratamiento de la neuropatía femoral.

The great auricular nerve in fetuses / El nervio auricular mayor en fetos

The great auricular nerve (GAN) is the largest branch of the superficial cervical plexus that winds around the posterior border of the sternocleidomastoid muscle, accompanied by the external jugular vein. Forty fetuses (right side: 40/80; left: 40/80) with gestational ages between 15 to 28 weeks were microdissected to document the anatomy of the GAN. The results obtained were classified as: i) Incidence and morphometry: GAN was present in 100 percent of the fetal specimens with average length on the right and left sides recorded as 12.65 +/- 2.14 mm and 12.55 +/- 2.82 mm respectively. ii) Course: GAN was located parallel to the transverse cervical nerve and the external jugular vein. Duplicate external jugular veins were observed in 5 percent (4/80) with GAN located anterior to one of the tributaries; iii) Branching Pattern: 16 percent (13/80) of specimens depicted a single branch. Duplicate branches in 67 percent (54/80) (referred to as Type I: anterior and posterior branches and 33 percent (26/80) referred to as Type II: anterior and posterior branches; iv) Variation: the transverse cervical nerve formed a communication with GAN, inferior to the parotid gland in 1 percent. The anatomical knowledge of the course, bifurcation pattern and variations of GAN may prevent complications during surgical procedures such as parotidectomies.

El nervio auricular mayor (NAM) es el ramo más grande del plexo cervical superficial que gira alrededor del margen posterior del músculo esternocleidomastoideo, acompañado de la vena yugular externa. Cuarenta fetos (lado derecho: 40/80; izquierdo: 40/80), con edades gestacionales de 15 a 28 semanas fueron microdisecados para describir la anatomía del NAM. Los resultados obtenidos se clasificaron en: i) Incidencia y morfometría: NAM estaba presente en el 100 por ciento de las muestras fetales con una longitud media de los lados derecho e izquierdo de 12,65+/-2,14mm y 12,55+/-2,82mm, respectivamente. ii) Curso: NAM se encuentra paralelo al nervio cervical transverso y la vena yugular externa. Duplicación de las venas yugulares externas se observaron en el 5 por ciento (4/80) con el NAM situado por delante de uno de los afluentes, iii) Patrón de ramificación: 16 por ciento (13/80) de las muestras presentaba una solo ramo. Ramos duplicados en el 67 por ciento (54/80) de Tipo I, ramos anterior y posterior y, el 33 por ciento (26/80) Tipo II, ramos anterior y posterior, y iv) Variación: el nervio cervical transverso formando una comunicación con NAM, inferior a la glándula parótida en el 1 por ciento. El conocimiento anatómico del curso, patrón de bifurcación y variaciones del NAM pueden prevenir las complicaciones durante los procedimientos quirúrgicos como la parotidectomía.

Variations in the branching pattern of the aortic arch in three Trinidadians / Variaciones en los Patrones de Ramificación Del arco Aórtico en Tres Tinitenses

In routine anatomical dissections for the purpose of preparation of teaching and museum specimens, it was observed that three cadavers of elderly Trinidadian males (of African descent) showed uncommon origin and variations in the number of branches of the aortic arch.

En disecciones de rutina con el propósito de preparar la enseñanza así como especímenes de museo, se observó que tres cadáveres de hombres mayores trinitenses (de descendencia africana) mostraban un origen poco común y variaciones en el número de ramas del arco aórtico.