Foramen of Vesalius: Prevalence, Morphology, Embryological Basis and Clinical Implications

The objectives of the present study were to find the prevalence of foramen of Vesalius and to discuss its morphology. The embryological basis of this foramen and its surgical highlights are emphasized. The study comprised 78 human adult dried skulls, which were obtained from the anatomy laboratory of our institution. The greater wing of the sphenoid bone was macroscopically observed for the presence of foramen of Vesalius. It was observed that the foramen was present in 29 skulls (37.2%). It was seen bilaterally in 13 (16.7%) skulls and unilaterally in 16 (20.5%) specimens.Anatomical literature has explained the variation of this foramen by the developmental considerations. We believe that the details of this foramen are known to have significant implications for the medical and surgical literature. The details are also enlightening to the clinical anatomists and other broad specialties of medicine.This sphenoidal emissary foramen contains a bridging vein, which connects the pterygoid venous plexus with the cavernous sinus. This communication is clinically important, since an extra cranial infection may sometimes reach the cavernous sinus through this foramen, which may lead to cavernous sinus thrombosis. Foramen of Vesalius can get injured during the trigeminal nerve block technique performed for the trigeminal neuralgia. In this procedure, the foramen can get hurt by a displaced instrument, which would end up in intracranial bleeding, which can spread the extracranal infection into the cavernous sinus. This may lead to serious disorders like Tolosa Hunt and Gradenigo syndromes. Keywords: Foramen ovale, middle cranial fossa, morphology, skull base, sphenoid bone

An anomalous left external jugular vein draining into right subclavian vein: a case report

Knowledge of the varying drainage patterns of superficial veins of head & neck, in particular, jugular veins are not only important for anatomists but also for the surgeons operating at this level and to clinicians in general. The variations are important for interventional radiologists too who perform transjugular procedures, such as port implantations and the transjugular intrahepatic portosystemic shunt or selective venous samplings. Results of recent studies report that the superficial veins, especially the external jugular vein (EJV), is been increasingly utilized for cannulation to conduct diagnostic and therapeutic procedures. We report a very unusual presentation of external jugular vein on left side of an embalmed male cadáver. Embryological evaluations of the anomaly was done and compared with available literature which showed that the observed variation is rare.

El conocimiento de los diferentes patrones de drenaje de las venas superficiales de la cabeza y cuello, en particular, las venas yugulares no sólo son importantes para anatomistas, sino también para los cirujanos que operan a este nivel y para los médicos en general. Las variaciones son importantes también para los radiólogos intervencionistas, quienes realizan procedimientos transyugulares, así como implantaciones portales y portosistémicas transyugulares intrahepáticas o derivación venosa selectiva. Resultados de estudios recientes informan que la venas superficiales, especialmente la vena yugular externa, es cada vez más utilizada para la canulación en diagnósticos y procedimientos terapéuticos. Se reporta una muy inusual variación anatómica de la vena yugular externa del lado izquierdo, presente en un cadáver embalsamado de sexo masculino. Fueron realizadas evaluaciones embriológicas de la anomalía y se compararon con la literatura mostrando que se trata de una variación rara.

Relationship between the deep peroneal nerve and dorsalis pedis artery in the foot: a cadaveric study.

The aim of our work was to study the relationship between deep peroneal nerve (DPN) and dorsalis pedis artery (DPA) so that the frequency of these variations can be kept in mind by the angiographers and surgeons to ensure safe surgical approach during flap surgery. Ninety-two legs in 46 cadavers were dissected to study the relationship between DPN and DPA on the dorsum of the foot. The relationship of neurovascular bundle of the dorsum of the foot was classified into four types. Type I: division of the DPN distal to the midpoint between the two malleoli (observed in 26 limbs). In Type II, the division of the DPN was midway between the two malleoli (seen in 20 limbs). Both Type I and II are further divided into two subtypes (a and b) depending upon the crossing pattern of terminal branches of the DPN over DPA. In Type III, multiple branches of DPN were noted in two limbs. In Type IV, the looping pattern of DPN around the DPA was considered and was seen in eight limbs. Awareness of possible variations in the relationship of the DPA to DPN on the dorsum of the foot is important for vascular and reconstructive surgeons. Because it might help in decreasing confusion when considering treatment options like microvascular anastomosis in reconstruction of the leg.

Incidence of extensor digitorum brevis manus muscle.

The extensor digitorum brevis manus, a supernumerary muscle in the fourth extensor compartment of the dorsum of the wrist, is a relatively rare anomalous muscle. Extensor digitorum brevis should be included in the differential diagnosis of soft tissue masses on the dorsal aspect of the hand as it may mimic cystic, neoplastic, inflammatory, and infectious masses arising in the dorsum of the wrist. Seventy-two upper limbs of male and female cadavers were dissected and examined to study the pattern of extensor tendons of the index finger. In the present study, we observed three cases (4.2%) of the extensor digitorum brevis manus on the left side. In one cadaver (0.72%), there was an additional tendon arising from the extensor indices which was inserted to the radial side of the dorsal digital expansion of the index finger. The extensor digitorum brevis manus muscle (EDBM), an anatomic variant of the extensor muscle of the dorsum of the hand, is found in approximately 2% to 3% of the population. This variation is, therefore, clinically and surgically relevant because the EDBM may be the only muscle responsible for the independent extension of the second digit. The aim of the present study is to report the incidences of this muscle thereby creating awareness of its existence and of its characteristic appearance to surgeons.

The scalenus accessorious muscle / El músculo escaleno accesorio

Many of the anatomical variations that are inadequately described or quantified are actually more clinically and surgically significant than being just anatomical curiosities. We report about such a variation where an aberrant slip existed in the scalene group, in a 56 year old embalmed female cadaver. This kind of variation may affect the size of the scalene triangle, and thus, may potentially result in varied signs and symptoms in patients vulnerable to thoracic outlet syndrome (TOS). Proximity of the scalene muscles to the brachial plexus, subclavian artery and vein, coexisting with aberrant slips or bundles may also predispose to compression syndromes.

Muchas de las variaciones anatómicas no están suficientemente descritas o cuantificadas y son actualmente clínica y quirúrgicamente significativas más que curiosidades anatómicas. Reportamos una variación anatómica en el grupo de los músculos escalenos, presente en un cadáver de una mujer de 56 años. Este tipo de variación puede afectar el tamaño del triángulo escalénico y por lo tanto, puede potencialmente resultar en variados signos y síntomas en pacientes vulnerables al síndrome de salida torácica. La proximidad de los músculos escalenos con el plexo braquial, arteria y vena suclavias, coexistiendo con fascículos aberrantes pueden predisponer a síndromes de compresión.

Unilateral pectoralis minimus muscle: a case report / Músculo pectoralis minimus unilateral: reporte de caso

Presence of additional muscles in the pectoral region has often been reported. We report about the presence of Pectoralis Minimus muscle, in a male cadaver. It was present deep to the pectoralis major muscle and superomedial to the pectoralis minor muscle. The variant was closely related to the branches of thoracoacromial vessels where one of the branches was passing between the pectoralis minor muscle and the variant muscle. Hyperabduction of the arm may compress these vessels giving rise to certain vascular symptoms. Also these variations should be borne in mind during certain surgical procedures in the pectoral region

Presencia de músculos supernumerarios en la región pectoral han sido reportados. En un cadáver de un hombre se describe la presencia de un músculo Pectoralis Minimus. El músculo se localizaba profundo al músculo pectoral mayor y superomedial al músculo pectoral menor. La variación se relacionaba con las ramas de los vasos toracoacromiales donde una de las ramas pasaba entre el músculo pectoral menor y la variación muscular. La hiperabducción del brazo puede comprimir estos vasos provocando síntomas vasculares. Estas variaciones se deben tener en cuenta durante los procedimientos quirúrgicos en la región pectoral

Clinically-relevant variations of the carotid arterial system.

INTRODUCTION: Developmental anomalies in the origin and branching pattern of the external carotid artery are not common. The level of the bifurcation of the common carotid artery and also the variations in the origin/branching pattern of the external carotid artery are well known and documented. METHODS: The variations in the level of bifurcation of the common carotid artery and the branching pattern of the external carotid artery were studied on 95 cadavers (52 male and 43 female). The common, external and internal carotid arteries were dissected on both sides. The level of carotid bifurcation was determined by comparison with the cervical vertebrae. Branching patterns of the carotid arteries were examined. RESULTS: Apart from the textbook description of the arteries, we came across several interesting variations. The bifurcation level of the common carotid artery was determined to be 50 percent at the C3 level, 40 percent at the C4 level and ten percent at the C2 level on the right side, and 55 percent at the C3 level, 35 percent at the C4 level, one percent at the C5 level and nine percent at the C2 level on the left side. CONCLUSION: Anatomical knowledge of the origin, course, and branching pattern of the external carotid artery, as well as the level of bifurcation of the common carotid artery, will be useful to surgeons when ligating the vessels in the head and neck regions during surgery and to avoid unnecessary complications during carotid endarterectomy.