Melanie R D'Souza

Absence of retromandibular vein associated with atypical formation of external jugular vein in the parotid region.

Veins of the head and neck exhibiting anatomical variations or malformations are clinically significant. Anatomical variation in the external jugular vein is very common. However, anatomical variation in the retromandibular vein is rare. In this paper, we report a rare case of complete absence of the retromandibular vein. In the absence of the retromandibular vein, the maxillary vein divided into anterior and posterior divisions. The posterior division joined the superficial temporal vein to form an atypical external jugular vein, and the anterior division joined the facial vein to form an anonymous vein. In clinical practice, radiologists and surgeons use the retromandibular vein as a guide to expose the branches of the facial nerve during superficial parotidectomy. Therefore, absence of the retromandibular vein is a hurdle during this procedure and may affect the venous drainage pattern from the head and neck.

Bifurcated Bicipital Aponeurosis Giving Origin to Flexor and Extensor Muscles of the Forearm – A Case Report

Bicipital aponeurosis is usually attached to the antebrachial fascia on the medial side of forearm and to posterior border of ulna assisting in the supination of the forearm along with biceps brachii muscle. Variations in the bicipital aponeurosis may lead to neurovascular compression as reported earlier. In the present case, the bicipital aponeurosis had two slips i.e. medial and lateral. Medial slip gave origin to some fibers of pronator teres and flexor carpi radialis and the lateral slip gave origin to some fibers of brachioradialis. Such unusual slips of bicipital aponeurosis may distribute the stress concentration and may work in different directions affecting the supination of forearm by biceps brachii muscle and bicipital aponeurosis.

A unique variation of azygos system of veins

Knowledge of variations of azygos and hemiazygos veins is of importance to cardiothoracic surgeons and radiologists during various surgical, radiological, and echography techniques. We report some unique variations of azygos system of veins observed during dissection classes for undergraduate medical students. The azygos vein was formed as usual by the union of right subcostal and ascending lumbar veins. The vein ascended upward and to the left to reach the midline at the level of the 9 th thoracic vertebra. After ascending till 5 th thoracic vertebra, it gradually inclined to the right of midline and terminated by opening into the superior vena cava at the level of the 3 rd thoracic vertebra. There was no major variation in the tributaries of the azygos vein on the right side, except that the right superior intercostal vein crossed behind the azygos vein from right to left and opened into the left side of the azygos vein. Further, two anastomotic veins connected the 10 th , 11 th and 12 th posterior intercostal veins with each other to form two anastomotic circles on the right side of 10 th to 12 th thoracic vertebrae. The hemiazygos vein bifurcated on the left side of the 10 th thoracic vertebra and the two ends opened into the azygos vein at the level of 9 th and 10 th thoracic vertebrae forming a venous circle in front of the 10 th thoracic vertebra. The course of accessory hemiazygos vein was noteworthy. Instead of its classic descending course, the vein ascended upward from the left side of the 8 th thoracic vertebra till the 6 th thoracic vertebra before opening into the azygos vein.

A Rare Case of Persistent Jugulocephalic Vein and its Clinical Implication

Persistence of jugulocephalic vein is one of the extremely rare variations of the cephalic vein. Knowledge of such a variation is of utmost importance to orthopedic surgeons while treating the fractures of the clavicle, head and neck surgeons, during surgery of the lower part of neck, for cardiothoracic surgeons and radiologists during catheterization and cardiac device placement. We report the persistent jugulocephalic vein in an adult male cadaver, observed during the routine dissection classes. The right cephalic vein ascended upwards, superficial to the lateral part of the clavicle and terminated into the external jugular vein. It also gave a communicating branch to the axillary vein below the clavicle. We discuss the embryological and clinical importance of this rare variation.

Anomalous origin of dorsalis pedis artery and its clinical significance

Arterial variations of the lower limb have been reported in the past. However, we report in here a very unusual variation. During routine dissections, an anomalous origin of the dorsalis pedis artery (DPA) was noted on the right foot of an adult male cadaver. In here, the arteries of the crural region arose from the popliteal artery, as usual. However, the anterior tibial artery (ATA) was very slender. The peroneal artery (PA) was larger than usual and reached the anterior compartment of the leg by piercing the interosseous membrane at its lower part. In the foot, the ATA joined with the PA to form the DPA. Knowledge of such type of variations in the anatomy of DPA is important for angiographers, vascular surgeons and reconstructive surgeons who operate upon these regions.

Presence of an accessory spleen in the gastrosplenic ligament: Its histological observation and clinical consequences

Accessory or supernumerary spleens are congenital in occurrence. Its presence may result in differential diagnosis or exhibit continued symptoms after therapeutic splenectomy. We report here a case of accessory spleen (AS), which was remarkably larger in size was found within the gastro-splenic ligament, adherent to its anterior layer. It received an independent vascular supply from splenic vessels supplying the main spleen (MS). Its histological architecture was in close resemblance to that of MS, but with the deficiency of white pulp. Failure to remove AS during main splenectomy done for pathological conditions may result in failure of resolving the condition due to which the pathological condition persists. Occurrence of ASs may also be confused for enlarged lymph nodes or neoplastic growth in the tail of pancreas, gastrointestinal tract and adrenal glands.

Origin of Medial and Lateral Pectoral Nerves from the Supraclavicular Part of Brachial Plexus and its Clinical Importance – A Case Report

Knowledge of normal and anomalous formation of brachial plexus and its branches is of utmost importance to anatomists, clinicians, anesthesiologists and surgeons. Possibility of variations in the origin, course and distribution of branches of brachial plexus must be kept in mind during anesthetizing the brachial plexus, mastectomy and plastic surgery procedures. In the current case, the medial pectoral nerve arose directly from the middle trunk of the brachial plexus and the lateral pectoral nerve arose from the anterior division of the upper trunk of the brachial plexus. The lateral pectoral nerve supplied the pectoralis major and the medial pectoral nerve supplied pectoralis major and pectoralis minor muscles through two separate branches.

Unusual morphology of the superior belly of omohyoid muscle

Though anomalies of the superior belly of the omohyoid have been described in medical literature, absence of superior belly of omohyoid is rarely reported. Herein, we report a rare case of unilateral absence of muscular part of superior belly of omohyoid. During laboratory dissections for medical undergraduate students, unusual morphology of the superior belly of the omohyoid muscle has been observed in formalin embalmed male cadaver of South Indian origin. The muscular part of the superior belly of the omohyoid was completely absent. The inferior belly originated normally from the upper border of scapula, and continued with a fibrous tendon which ran vertically lateral to sternohyoid muscle and finally attached to the lower border of the body of hyoid bone. The fibrous tendon was about 1 mm thick and received a nerve supply form the superior root of the ansa cervicalis. As omohyoid mucle is used to achieve the reconstruction of the laryngeal muscles and bowed vocal folds, the knowledge of the possible anomalies of the omohyoid muscle is important during neck surgeries.