Classification of the patterns of the emerging branches of the superficial cervical plexus / Clasificación de los patrones de las ramas emergentes del plexo cervical superficial

SUMMARY: The cutaneous branches of the superficial cervical plexus (SCP) emerge at variable points, from beneath the posterior margin of the sternocleidomastoid muscle and from this point radiate like "spokes of a wheel" antero-inferiorly and postero-superiorly. This study aimed to classify the emerging points of the branches of the superficial cervical plexus in relation to their location on the sternocleidomastoid muscle. In order to classify the emerging points of the superficial cervical plexus, the sternocleidomastoid muscle was first measured from mastoid process to clavicle; subsequently each branch of the superficial cervical plexus was measured from the mastoid process to their exit points. The emerging points of the superficial cervical plexus branches were classified according to Kim et al. (2002) seven categories: Type I (32 %); Type II (13 %); Type III (35 %); Type IV (13 %); Type V, VI, VII (2 %). The order in which the superficial cervical plexus branches emerged from the posterior margin of the sternocleidomastoid muscle remained constant, i.e. lesser occipital, great auricular, transverse cervical and supraclavicular nerves. Knowledge of emerging points may assist in the effective anaesthesia to all branches of the superficial cervical plexus during surgical procedures of the neck, viz. carotid endarterectomy and thyroid surgery.

RESUMEN: Las ramas cutáneas del plexo cervical superficial (SCP) emergen en puntos variables, desde el margen pos- terior del músculo esternocleidomastoideo y desde este punto inferior irradian como "radios de rueda" anteroinferior y postero-superior. Este estudio tuvo como objetivo clasificar los puntos emergentes de las ramas del plexo cervical superficial en relación a su ubicación en el músculo esternocleidomastoideo. Para clasificar los puntos emergentes del plexo cervical superficial, primero se midió el músculo esternocleidomastoideo desde el proceso mastoides hasta la clavícula; posteriormente se midió cada rama del plexo cervical superficial desde el proceso mastoideo hasta sus puntos de salida. Los puntos emergentes de las ramas del plexo cervical superficial se clasificaron según Kim et al. (2002) en siete categorías: Tipo I (32 %); Tipo II (13 %); Tipo III (35 %); Tipo IV (13 %); Tipo V, VI, VII (2 %). El orden en el que las ramas del plexo cervical superficial emergían del margen posterior del músculo esternocleidomastoideo se mantuvo constante, es decir, los nervios occipital menor, auricular magno, cervical transverso y supraclavicular. El conocimiento de los puntos emergentes puede ayudar a la anestesia eficaz de todas las ramas del plexo cervical superficial durante los procedimientos quirúrgicos del cuello, a saber, endarterectomía carotídea y cirugía de tiroides.

Anatomic Variations In The Middle Cerebral Artery In Human Cadavers

Introduction: Middle cereal artery (MCAis the largest anch among all the anches of internal carotid artery,abnormal development of which in the emyonic period can lead to developmental anomalies of the cereal arteries. The present study was aimed to describe the anatomical variations in the MCA in the formalin preserved ains of human cadavers. Methodology: This study was conducted in the Department of Anatomy, Mahatama Gandhi Mission Medical College, Aurangabad in which 50 formalin preserved specimens of ain were dissected. We carefully dissected the MCA on either side from its origin to its termination and its course was traced through the lateral cereal fissure. We carefully and delicately separated the arterial networks of the Circle of Willis along with the MCA of both sides and using a verniercaliper the dimensions of the MCA were measured. Results:In all specimens, MCA originated from the internal carotid artery, and it ran towards the posterior end of the lateral sulcus of the cereal hemispheres lateral to the optic chiasma. The length ranged from 11.3 to 26.2 mm, with mean length being 18.9 and 17.6 mm in the right and left side respectively. Diameter of the MCA ranged from 2.5 cm to 4.8 cm, with mean diameter being 3.12 and 3.24 cm in the right and left side respectively. Symmetric anching of MCA was seen in 22 specimens and rest had asymmetric anching. Conclusions: Awareness about the anatomical variations in the morphometric measurements and anching patterns of MCA are essential from the clinical viewpoint. Since these variations are rare, multi-centric studies with larger sample size are required in future.

Morphologic relationship between the coronary arteries during fetal development / Relación morfológica entre las arterias coronarias durante el desarrollo fetal

SUMMARY: A detailed understanding of the coronary arteries is of paramount importance in the management of coronary arterial diseases. The arterial supply to the heart originates from right (RCA) and left (LCA) coronary arteries which form an oblique inverted crown within the atrioventricular groove. This study aimed to document the embryologic relationship between the RCA and the LCA including their lengths, diameters, branching patterns and arterial dominance in fetuses. Forty-one human fetal heart specimens with an age range of 13.13 to 26.95 weeks were dissected at the Department of Clinical Anatomy, University of Kwazulu-Natal, Durban, South Africa. The RCA arose from the right aortic sinus and was dominant in all the specimens. The LCA was classified into types according to their branching pattern. The bifurcation, trifurcation and quadrifurcation of the LCA occurred in 68.3 %, 29.3 % and 2.4 % of hearts, respectively. The mean lengths of the RCA and LCA were 0.98±0.54 mm and 1.83±0.77 mm, respectively. The mean external diameters of the RCA and LCA were 0.38±0.12 mm and 0.49±0.17 mm, respectively. There was a significant correlation between the RCA and LCA length and the fetal age which is indicative of significant changes in the coronary vasculature with fetal growth.

RESUMEN: Una comprensión detallada de las arterias coronarias es de suma importancia en el manejo de las enfermedades en estas arterias. El suministro arterial al corazón se origina de las arterias coronarias derecha (ACD) e izquierda (ACI) que forman una "corona oblicua invertida" dentro del surco atrioventricular. Este estudio tuvo por objetivo documentar la relación embriológica entre la ACD y la ACI, incluyendo sus longitudes, diámetros, patrones de ramificación y dominio arterial en fetos. Se disecaron 41 corazones de fetos humanos con un rango de edad de 13,13 a 26,95 semanas, en el Departamento de Anatomía Clínica, Universidad de Kwazulu-Natal, Durban, Sudáfrica. La ACD surgió del seno aórtico derecho y fue dominante en todos los especímenes. La ACI se clasificó en distintos tipos según su patrón de ramificación. La bifurcación, trifurcación y cuadrifurcación de la ACI ocurrieron en 68,3 %, 29,3 % y 2,4 % de los corazones, respectivamente. Las longitudes medias de la ACD y ACI fueron 0,98 ± 0,54 mm y 1,83 ± 0,77 mm, respectivamente. Los diámetros externos medios de la ACD y ACI fueron 0,38 ± 0,12 mm y 0,49 ± 0,17 mm, respectivamente. Hubo una correlación significativa entre la longitud de la ACD y la ACI y la edad fetal, que es indicativa de cambios significativos en la vasculatura coronaria con crecimiento fetal.

Anomalous branching patterns of the axillary artery / Patrones de ramificación anómalos de la arteria axilar

Arterial variations in the upper limbs can cause iatrogenic injury during invasive procedures. During educational dissection of countered uncommon branching patterns of the axillary artery which have not yet been reported yet, to our knowledge. First, the second part of the axillary artery was divided into three trunks. The lateral trunk ran downward as a superficial brachioradial artery. The medial trunk raised the lateral thoracic artery, and was divided into the subscapular artery and the posterior circumflex humeral artery. The intermediate trunk branched off the anterior circumflex humeral artery as expected for an axillary artery. Second, in the other cadaver, we found a common trunk containing the thoracoacromial artery and a bulk artery dividing into three branches, the subscapular, posterior circumflex humeral, and lateral thoracic arteries. Taken together, we discuss the clinical implications and possible developmental origins of variations in the axillary artery branching and course.

Las variaciones arteriales en los miembros superiores pueden causar lesiones iatrogénicas al realizarse procedimientos invasivos. Durante una disección de rutina de los patrones de ramificación de la arteria axilar, se encontró una disposición aún no informada. En primer lugar, la segunda porción de la arteria axilar se presentó dividida en tres troncos. El tronco lateral se desplazó hacia abajo como una arteria braquiorradial superficial (arteria radial originándose de la arteria axilar). El tronco medial dio origen a la arteria torácica lateral, y se dividió en arteria subescapular y arteria circunfleja humeral posterior. El tronco intermedio dio origen a la arteria circunfleja humeral anterior como se espera para una arteria axilar. En un segundo cadáver, encontramos un tronco común entre la arteria toracoacromial y una arteria de mayor tamaño que se dividió en tres arterias: subescapular, circunfleja humeral posterior y torácica lateral. Consideradas estas variaciones arteriales en conjunto, se discuten las implicaciones clínicas y posibles orígenes del desarrollo de las variaciones en la ramificación de la arteria axilar y su trayecto.

Anatomy of the facial nerve branching patterns, the marginal mandibular branch and its extraparotid ramification in relation to the lateral palpebral line.

Background: Surgery of face and parotid gland may cause injury to branches of the facial nerve, which results in paralysis of muscles of facial expression. Knowledge of branching patterns of the facial nerve and reliable landmarks of the surrounding structures are essential to avoid this complication. Objective: Determine the facial nerve branching patterns, the course of the marginal mandibular branch (MMB), and the extraparotid ramification in relation to the lateral palpebral line (LPL). Materials and methods: One hundred cadaveric half-heads were dissected for determining the facial nerve branching patterns according to the presence of anastomosis between branches. The course of the MMB was followed until it entered the depressor anguli oris in 49 specimens. The vertical distance from the mandibular angle to this branch was measured. The horizontal distance from the LPL to the otobasion superious (LPL-OBS) and the apex of the parotid gland (LPL-AP) were measured in 52 specimens. Results: The branching patterns of the facial nerve were categorized into six types. The least common (1%) was type I (absent of anastomosis), while type V, the complex pattern was the most common (29%). Symmetrical branching pattern occurred in 30% of cases. The MMB was coursing below the lower border of the mandible in 57% of cases. The mean vertical distance was 0.91±0.22 cm. The mean horizontal distances of LPL-OBS and LPLAP were 7.24±0.6 cm and 3.95±0.96 cm, respectively. The LPL-AP length was 54.5±11.4% of LPL-OBS. Conclusion: More complex branching pattern of the facial nerve was found in this population and symmetrical branching pattern occurred less of ten. The MMB coursed below the lower border of the angle of mandible with a mean vertical distance of one centimeter. The extraparotid ramification of the facial nerve was located in the area between the apex of the parotid gland and the LPL.