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.

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.

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 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.

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.

Unilateral high origin of radial artery from axillary artery

Variations in the vascular system of upper limbs are relatively common, with considerable significance towards the clinical and surgical point of view. The major arterial variations reported are of high origins of radial and ulnar arteries. During routine dissection of an upper extremity in the Department of Anatomy, Medical University of the Americas, Nevis, West Indies, a variation in the origin of the radial artery from the axillary artery was observed in the right upper limb of a 55-year-old female cadaver. The normal and variant origin of the radial artery has pragmatic importance for surgeons and radiologists. Also, the superficial position of an artery makes it vulnerable to injury during cannulation, which may lead to pseudoaneurysm.