Revisiting the transorbital approach for emergency external ventricular drainage: an anatomical study of relevant parameters and their effect on the effectiveness of using Tubbs' point.

The transorbital approach (TOA) can provide immediate access to the lateral ventricles by piercing the roof of the orbit (ROO) with a spinal needle and without the need of a drill. Reliable external landmarks for the TOA ventriculostomy have been described, however, the necessary spinal needle gauge and other relevant parameters such as the thickness of the ROO have not been evaluated. Nineteen formalin-fixed adult cadaveric heads underwent the TOA. Spinal needles of different gauges were consecutively used in each specimen beginning with the smallest gauge until the ROO was successfully pierced. The thickness of the ROO at the puncture site and around its margins was measured. Other parameters were also measured. The TOA was successfully performed in 14 cases (73.68%), where the most suitable needle gauge was 13 (47.37%), followed by a 10-gauge needle (36.84%). The mean thickness of the ROO at the puncture site, and the mean length of the needle to the puncture site were 1.7 mm (range 0.2-3.4 mm) and 15.5 mm (range 9.2-23.4 mm), respectively. A ROO thickness of greater than 2.0 mm required a 10-gauge needle in seven cases, and in five cases, a 10-gauge needle was not sufficient for piercing the ROO. The presence of hyperostosis frontalis interna (HFI) (21.05%) was related to the failure of this procedure (80%; p < 0.00). Using a 13/10-gauge spinal needle at Tubbs' point for TOA ventriculostomy allowed for external ventricular access in most adult specimens. The presence of HFI can hinder this procedure. These findings are important when TOA ventriculostomy is considered.

The superior vesical artery: A review of conflicting definitions and how these could affect invasive procedures.

Since the superior umbilical artery is the only functioning branch of the patent umbilical artery, some anatomical and surgical books/atlases fail to clarify that it is a branch of the umbilical artery and not a direct branch of the anterior division of the internal iliac artery and so specifically state that it is a direct branch of the internal iliac artery. This discrepancy in nomenclature can obviously affect invasive procedures and communication between physicians. Therefore, the present review is intended to highlight this issue. The term "superior vesical artery" was searched using standard search engines, for example, PubMed and Google Scholar. Several standard and specialized anatomy textbooks were also examined to ascertain how the superior vesical artery was described. Thirty-two articles were identified that used the terms "superior vesical artery" or "superior vesical arteries." After applying exclusion criteria, in 28 papers, the definition of the superior vesical artery was undetermined in eight, described as a direct branch of the internal iliac artery in 13, described as a branch of the umbilical artery in six, and defined as being equivalent to the umbilical artery in one. Of the sampled textbooks, some defined the superior vesicle artery as a branch of the umbilical artery, some as a direct branch of the internal iliac artery and some as both. Taken all together, most define the superior vesical artery as a branch of the umbilical artery. As the superior vesical artery is described as a branch of the umbilical artery in the internationally accepted terminology (Terminologia Anatomica), we recommend that this definition be used by anatomists and physicians alike so that communication is clear.

Novel Muscle in Infraspinous Fossa.

The infraspinatus muscle (IS) makes a minor contribution to lateral rotation of the arm but mainly serves to stabilize the glenohumeral (GH) joint as part of the rotator cuff. Although reports of variations in the rotator cuff muscles have been documented previously, specific discussions of IS variants are lacking. In this report, we present a novel case of an accessory muscle in the infraspinous fossa and its relationship to the IS, which was normally located. We describe the observed physical features of the muscles and their innervation patterns.

A Three-Headed Piriformis Muscle With Splitting of the Common Fibular Nerve.

Although the division of the piriformis muscle by the sciatic nerve or its branches is fairly common, other anatomical variations of this muscle are relatively uncommon. Here, we present a cadaveric case found to have an atypical composition of the piriformis muscle. During the routine dissection of the right gluteal region in an adult male cadaver, an unusual finding of the piriformis muscle was observed. Three distinct heads of the muscle were identified. In addition, one of these heads split the common fibular nerve. The anatomy and relationships of this case are presented here. Any variation in neurovasculature and musculature can be relevant for diagnosing or surgically intervening in the gluteal region. The present case is apparently unique and of archival value.

The sphenopalatine vein: anatomical study of a rarely described structure.

Although in counterpart, the sphenopalatine artery (SPA), has been well described in the medical literature, the sphenopalatine vein (SPV) has received scant attention. Therefore, the present anatomical study was performed. Additionally, we discuss the variations, embryology, and clinical significance of the SPV. Adult cadaveric specimens underwent dissection of the SPV. In addition, some specimens were submitted for histological analysis of this structure. The SPV was found to drain from the sphenoidal sinus and nasal septum. Small tributaries traveled through the nasal septum with the posterior septal branches of the SPA and nasopalatine nerve. The SPA and SPV were found to travel through the sphenopalatine foramen and another tributary was found to perforate the medial plate of the pterygoid process and to connect to the pterygoid venous plexus which traveled lateral to the medial plate of the pterygoid process. The vein traveled through the posterior part of the lateral wall of the nasal cavity with the posterior lateral nasal branches of the SPA and the lateral superior posterior nasal branches of the maxillary nerve. To our knowledge, this is the first anatomical study on the SPV in humans. Data on the SPV provides an improved anatomical understanding of the vascular network of the nasal cavity. Developing a more complete picture of the nasal cavity and its venous supply might help surgeons and clinicians better manage clinical entities such as posterior epistaxis, cavernous sinus infections, and perform endoscopic surgery with fewer complications.

Anatomical Study of the Atrioventricular Nodal Branch of the Heart.

Background The atrioventricular (AV) node is a relay station for electrical signals passing between the atria and ventricles. The artery supplying the AV node is functionally important, and its anatomical topography is relevant during invasive procedures. Therefore, the aim of this study was to identify and understand the variations of the origin of the AV nodal branch (AVNb) and its variations. Materials and methods We dissected 31 adult human hearts to evaluate their AVNb and its variations. A classification scheme was used to detail the morphology found for each of these arteries. Results We identified five distinct origins of the AVNb: AVNb originating from the right coronary artery (RCA) proximal to the inferior interventricular branch (IVb) (type I, 3.2%), AVNb originating from the junction of the RCA and IVb (type II, 19.4%), AVNb originating from the RCA distal to the IVb (type III, 64.5%), AVNb originating from the IVb (type IV, 6.5%), and AVNb originating from the circumflex branch of the left coronary artery (LCA) (type V, 6.5%). Conclusions Our study provides data on the morphology and variations of the AVNb. Such information can assist in better diagnoses based on imaging, better guide invasive procedures, and provide the cardiac surgeon with an improved method of classifying the AVNb and its branches during procedures of the coronary arteries and their branches.

A Case of a Previously Unreported Drainage of the Maxillary Vein.

Due to the importance of venous drainage of the head and neck in various pathological conditions, knowledge of anatomical variations is important to the clinician. Here we report a case of an unusual drainage pattern of the maxillary vein. A tributary of the left maxillary vein was found in a female cadaver (72 years old at the time of death) to travel through the medial aspect of the ramus of the mandible via an accessory mandibular foramen, which drains into the ipsilateral facial vein slightly proximal to the point where the anterior branch of the retromandibular and facial veins merged to form the left common facial vein. The diameter of the variant vein at the junction with the maxillary vein and at the junction with the facial vein was 1.0 mm and 1.1 mm, respectively. We report a previously unreported variant of the maxillary vein bypassing the retromandibular vein and draining directly into the facial vein. Knowledge of such a variant might help explain various complications such as hemorrhage and might prevent iatrogenic injury of the blood vessels during surgery in this region.

A study of the anatomical variations in the position of the greater palatine foramen in adult human skulls and its clinical significance / Variaciones anatómicas en la posición del foramen palatino mayor en cráneos humanos adultos y su significación clínica

Pain is a common distressing symptom in dental practice. Depending upon the cases, different techniques are used to relieve pain. One of these is peripheral trigeminal nerve block. Peripheral trigeminal nerve block anaesthesia has proved to be an effective and convenient way to anaesthetise large regions of oral and maxillofacial complex. This block can be intraoral or extra oral. The intraoral route is through the greater palatine foramen in which the dental surgeons enter into the pterygopalatine fossa, where the maxillary nerve is situated. The morphological variations in the position of greater palatine foramen may be of clinical importance in the administration of local anaesthesia and in palatal surgery. In the present study, the distance of greater palatine foramen from the median palatine suture, and from the posterior border of hard palate have been noted, and the position of greater palatine foramen relative to the maxillary molars, as well as the direction of the foramen have been examined.

El dolor es un síntoma común y preocupante en la práctica dental. Dependiendo de los casos, diferentes técnicas se utilizan para aliviar el dolor. Una de ellas es el bloqueo periférico del nervio trigémino. Esta, ha demostrado ser una forma eficaz y conveniente para anestesiar grandes regiones del complejo oral y maxilofacial. Este bloqueo puede ser intraoral o extraoral. La vía intraoral es a través del foramen palatino mayor en la cual se ingresa en la fosa pterigopalatina, donde se encuentra el nervio maxilar. Las variaciones morfológicas en la posición del foramen palatino mayor puede ser de importancia clínica en la administración de anestesia local y en la cirugía del paladar. En el presente estudio, se examinó la distancia del foramen palatino mayor desde la sutura palatina mediana y el margen posterior del paladar duro, y su posición relativa a los molares superiores, así como la dirección del foramen palatino mayor.

Unilateral third/accessory head of the gastrocnemius muscle: a case report / Tercera cabeza unilateral del músculo gastrocnemio: reporte de un caso

The superficial muscle group of the posterior compartment of leg forms a powerful muscular mass in the calf. The two-headed gastrocnemius is the most superficial muscle of this group, and forms the proximal, most prominent part of the calf. Gastrocnemius muscle exhibits numerous variations in the origin and/or insertion. The present report describes the incidental occurrence of the third/accessory head of gastrocnemius muscle in the left lower limb. During routine educational dissection of a 54-year old American female cadaver in the Anatomy lab of the Medical University of the Americas, Nevis, West Indies, we found an unusual 10.8 cm long muscle in the left popliteal region, attached proximally to the lateral aspect of the popliteal surface of femur, and distally terminated as a tendon which was attached at the junction of the medial and lateral heads of gastrocnemius muscle. No such variation was found on the right side. This is described as a case of third / accessory head of gastrocnemius muscle...

El grupo muscular superficial del compartimento posterior de la pierna forma una poderosa masa muscular. El músculo gastrocnemio de dos cabezas es el más superficial de este grupo y forma la parte proximal, más prominente de la pantorrilla. El músculo gastrocnemio presenta numerosas variaciones en el origen y/o inserción. El informe describe la presencia de una tercera/accesoria cabeza del músculo gastrocnemio, encontrada. durante una disección de rutina en un cadáver de una mujer americana de 54 años, en el Laboratorio de Anatomía de la Medical University of the Americas, Nevis, West Indies. La variación muscular inusual medía 10,8 cm de longitud y se originaba en la región poplítea izquierda, proximalmente en la cara lateral de la superficie poplítea del fémur, y se insertaba en un tendón que se adhería a la unión de las cabezas medial y lateral del músculo gastrocnemio. La variación no se encontró en el lado derecho. Este hallazgo se describe como un caso de tercera/accesoria cabeza del músculo gastrocnemio...