ABSTRACT
El músculo axilopectoral (MAP) es una estructura fibromuscular accesoria de la región axilar, que se relaciona con el plexo braquial, vasos y linfonodos axilares, y es reportado en los diferentes grupos poblacionales con incidencia variable. Se evaluaron un total de 106 axilas correspondientes a 53 cadáveres frescos que fueron sometidos a autopsia. El MAP se presentó en 5 regiones axilares (4,7 %), con tres casos unilaterales (2,8 %) y uno bilateral (0,9 %). La longitud total del MAP estuvo en un rango de 81,6-119,7 mm, mientras que su segmento tendinoso midió 13,3-28,1 mm. El espesor de su vientre muscular fue de 7,1-52 mm y del tendinoso 6,920,1 mm. En todos los casos, el MAP se originó del músculo latísimo del dorso y se insertó en el labio lateral del surco intertubercular del húmero, adyacente a la inserción del músculo pectoral mayor. Los MAP evaluados fueron inervados por el nervio toracodorsal. En dos casos, el vientre muscular del MAP cursó con trayectoria antero medial a las fibras infraclaviculares del plexo braquial, mientras que en los tres restantes, los segmentos fibrosos de inserción del MAP estuvieron relacionados con el plexo. La incidencia del MAP encontrada en el presente estudio es similar a los reportes previos realizados en cadáveres y considerablemente mayor a los reportes anatomoquirúrgicos. La importancia del MAP radica en su implicación con el síndrome de salida torácica, trombosis profunda del miembro superior y en las complicaciones en la linfadenectomía axilar.
The axillary pectoral muscle (APM) is an accessory fibromuscular structure of the axillary region. It is related to the brachial plexus, axillary vessels and lymph nodes, and is reported with variable incidence in different population groups. A total of 106 axilla were evaluated corresponding to 53 fresh cadavers. The APM was presented in 5 axillary regions (4.7 %), with three unilateral cases (2.8 %) and one bilateral (0.9 %). The total length of the APM ranged from 81.6-119.7 mm, while its tendinous segment measured 13.3-28.1 mm. Muscular belly thickness was 7.1-52 mm and the tendinous segment measured 6.9-20.1 mm. In all cases, the APM originated from the latissimus dorsi muscle and inserted into the lateral lip of humerus intertubercular sulcus, adjacent to the pectoralis major muscle insertion. The evaluated APMs were innervated by the thoracodorsal nerve. In two cases, the APM muscular belly had an anterior medial trajectory to brachial plexus fibers, while in the remaining samples, long fibrous segments of APM insertion were related to the plexus. The incidence of the APM found in the present study is similar to previous reports carried out in cadavers; it was considerably higher than previous anatomy-surgical reports. The importance of APM relies on its involvement with thoracic outlet syndrome, deep thrombosis of the upper limb and complications in axillary lymphadenectomy.
Subject(s)
Humans , Pectoralis Muscles/anatomy & histology , Axilla/anatomy & histology , Cadaver , Cross-Sectional Studies , ColombiaABSTRACT
Objective To establish a submental tumorigenesis model by injecting human hypopharyngeal carcinoma cells to nude mice, and to compare the model with traditional axillary tumorigenesis model. Methods Five-week-old male nude mice were selected and divided into submental tumorigenesis model group (submental group) and axillary tumorigenesis model group (axillary group). Each group was divided into two subgroups by injecting human hypopharyngeal carcinoma cells FADU or HN31, namely sub-FADU, sub-HN31, ax-FADU, and ax-HN31 groups, with 12 nude mice in each group. The nude mice in the submental group were injected with tumor cells in the left side of submental area, and those in the axillary group were injected with tumor cells in the right side of axillary area. The time of tumor formation, tumor volume and body mass of nude mice were measured. The death of nude mice was recorded. After eight weeks, the local tumor growth, infiltration, and organ metastasis such as liver, spleen and kidney of the survival nude mice were examined by ultrasound, and the tumor metastasis was observed by routine H-E staining and immunohistochemical staining. Results On the 7th and 9th days after injection, the tumors were observed in the submental group and the axillary group. On the 33rd day after injection, the tumor volume in the ax-FADU and ax-HN31 groups was significantly bigger than those in the sub-FADU and sub-HN31 groups (P<0.05, P<0.01). The body mass of nude mice in each group reached peak on the 17th to 19th days after injection, and thereafter the body mass in the submental group was gradually decreased and that in the axillary group was still increased. On the 33rd day after injection, the body mass in the ax-FADU and ax-HN31 groups were significantly higher than those in the sub-FADU and sub-HN31 groups, respectively (P<0.01). After eight weeks, there were eight deaths in the sub-FADU group and 10 in the sub-HN31 group, with six mice alive in the submental group; there were six deaths in the ax-FADU group and six in the ax-HN31 group, with 12 alive in the axillary group. There was no significant difference in mortality of nude mice between the four subgroups. Ultrasound and pathological examination showed that four survived nude mice were found with cervical lymph node and liver metastases in the submental group, and only one was found with liver metastases in the axillary group; and the difference between the two groups was statistically significant (P<0.05). There were two pulmonary metastases in the submental group, and one in the axillary group; there was one spleen metastases in the submental group and no spleen metastases in the submental group; and there were no significant differences between the two groups. Conclusion Submental tumorigenesis model and axillary tumorigenesis model have their own characteristics. The submental tumorigenesis model has shorter tumorigenesis time, higher local invasion and higher distant metastasis rate, and is suitable for studying the invasiveness and metastasis of tumor in vivo. The axillary tumorigenesis model has larger volume of tumor, less injury to the adjacent organs and tissues, longer survival time and lower distant metastasis rate, and is suitable for the study of the characteristics of tumor cells.
ABSTRACT
Las comunicaciones entre los ramos terminales de plexo braquial son frecuentes y tienen importancia en la evaluación de traumatismos y procedimientos quirúrgicos de las regiones axilar y braquial. En este artículo presentamos un caso en el que durante la disección de rutina del miembro superior, se observó la presencia de comunicaciones bilaterales entre los nervios musculocutáneo y mediano. Los ramos comunicantes fueron descritos en su trayecto, relaciones y morfometría y se discutió acerca de la prevalencia e importancia clínica de estas comunicaciones.
Communication of the musculocutaneous and median nerves of the brachial plexus is common and is important in the evaluation of trauma and surgical procedures in axillary and brachial regions. This paper presents a case in which during a routine dissection of upper limb the presence of bilateral communication between musculocutaneous and medium nerves was observed. Trajectory of communicating branches was described, relation and morphometry was discussed with regard to prevalence and clinical significance of these communications.