Accurate course and relationships of the intraorbital part of the ophthalmic artery in the sagittal plane.

INTRODUCTION: Knowledge of variations in the course and distribution of the intraorbital part of ophthalmic artery (OA) is necessary for the diagnosis and treatment of anterior cranial and orbital disorders. MATERIAL: 38 human cadaver dissections to demonstrate the microsurgical anatomy of the intraorbital part of the OA were studied in three stages, considering its neighbourhood with the optic nerve in the sagittal plane. RESULTS: The first part of the OA was located on the inferolateral aspect of the optic nerve in 89.47%. The diameter and the length of the first part of the OA were 1.69+/-0.34 mm and 7.58+/-0.89 mm. 73.68% of the cases crossed the optic nerve superiorly, and 26.31% inferiorly. The diameter and length of the second part of the OA were as 1.52+/-0.29 mm and 4.12+/-0.85 mm. The diameter and length of the third part of the OA were 1.07+/-0.18 mm and 4.12+/-0.85 mm. The first branch of the intraorbital part of the OA was the central retinal artery in 26.31% of the specimens. CONCLUSION: A better understanding of the vascular anatomy of the orbit should allow for the modification of surgical techniques to reduce bleeding during biopsy or excision of orbital structures.

A morphometric study on the superficial palmar arch of the hand.

The vascular anatomy of the hand is a complex and challenging area and has been the subject of many studies. Knowledge of the vascular patterns and diameters of the hand gained more importance with improvements in microsurgical techniques in reconstructive hand surgery. We evaluated 50 hands (26 left, 24 right) of 26 formalin preserved cadavers to determine the superficial palmar arch, its branches and contributing vessels with special attention to the diameters. The symmetry of the types was also evaluated in detail for the first time in the literature. Measurements were made with the help of a digital caliper. The diameters of the ulnar, radial and median arteries were taken at the level of the wrist while the common palmar digital arteries, hypothenar branches and the superficial palmar branch of the radial artery were measured at their origin. Two types of superficial palmar arch were found and defined as complete (43/50 hands) and incomplete arches (7/50 hands). The complete arches were divided into four subgroups and incomplete arches into three subgroups. Most cases were found at the complete AI group (17 hands). Comparison of the arterial diameters showed the ulnar artery was the dominant vessel of the palm. The diameters of the common palmar digital arteries were not different with regard to complete or incomplete arches and between both sides. It looks safe to sacrifice one of the radial or ulnar arteries in some arterial interventions including radial artery cannulation, radial forearm flap and radial or ulnar artery harvesting for bypass grafting if the arch is complete. But we still recommend the noninvasive tests like modified Allen test or Doppler ultrasonography, before performing an invasive arterial intervention. We propose the radiologists to incorporate the median artery into the Doppler dynamic test in particular the existence or the absence of anastomoses between radial and ulnar arteries.

Distal variations of the neurovascular pedicle of the serratus anterior muscle as a flap.

The serratus anterior muscle has recently been suggested as a versatile and reliable flap for reconstruction of complex craniofacial and neck lesions, extremity and sacroiliac region injuries, as well as intrathoracic and extrathoracic reconstruction procedures. The muscle has been used as a microvascular flap or a pedicled transfer and has been transferred in combination with other muscles, bones, and skin. We performed 15 dissections of adult axilla regions that were examined under x3.5 loupe magnification to collect anatomic data regarding the neurovascular pedicle of the serratus anterior muscle. The serratus muscle and fascia were found to have a dual blood supply, with the upper part supplied by the lateral thoracic artery and the lower part by terminal branches of the thoracodorsal artery. The lateral thoracic artery was noted to supply the upper four slips but it extended into the lower serratus anterior muscle in two cases. Seven branching patterns were found in the lower serratus anterior muscle. In type I, the only branch of serrati proceeded over the long thoracic nerve. Type II had the only branch of serrati proceeding under the long thoracic nerve. In type III, double branches of serrati proceeded over the long thoracic nerve; while in type IV branches of serrati ran with a double branch under the long thoracic nerve. In type V, three serrati branches proceeded over the long thoracic nerve. Type VI serrati branches were branches of thoracodorsalis, which was hypoplastic, and the supply was maintained from the lateral thoracic artery. In type VII, one serrati branch ran over the long thoracic nerve. There was no connection between the branches of serrati and the branches of the lateral thoracic artery. The length of the long thoracic nerve, the number of motor axons and the vascular network in anatomic proximity to this nerve make it an expendable but powerful source of reconstructions of head, neck, chest wall and extremity defects. Results of this study provide an anatomic framework to improve current reconstructive or aesthetic procedures on the serratus anterior neurovascular structures.

The cranio-orbital foramen, the groove on the lateral wall of the human orbit, and the orbital branch of the middle meningeal artery.

The cranio-orbital foramen, a foramen in the lateral wall of the orbit, contains an anastomosis between the anterior branch of the middle meningeal artery and the lacrimal artery. Previous workers have speculated that the groove starting either from the cranio-orbital foramen or the lateral extremity of the superior orbital fissure contains the anastomotic artery. We investigated the cranio-orbital foramen and the groove on the lateral wall of the orbit in a series of 170 dried adult human skulls, and the course of the orbital branch of the middle meningeal artery in 74 specimens from 37 cadavers. We observed the cranio-orbital foramen in 141 skulls (82.9%). It was unilateral in 55 (32.4%) and bilateral in 86 (50.6%) skulls. The groove on the lateral wall of the human orbit was observed in 122 skulls (71.8%). It was unilateral in 40 (23.5%) and bilateral in 82 (48.2%). The groove on the lateral wall of the orbit started from the cranio-orbital foramen in 20 skulls (11.8%). The orbital branch of the middle meningeal artery was found in 48 cadaveric specimens (64.9%): 32 (43.2%) passed through the cranio-orbital foramen and 12 (16.2%) passed through the superior orbital fissure. In four specimens (5.4%), orbital branches of the middle meningeal artery passed through both the superior orbital fissure and the cranio-orbital foramen. The anatomy of the cranio-orbital foramen and the course of the orbital branch should be well known by surgeons reconstructing the anterior base of the skull, the orbit after orbital base surgery, and during excision of meningiomas.

Surgical implications of anatomical landmarks on the lateral surface of the mastoid bone.

The aim of this study was to examine the relationships of the surgical landmarks on the lateral surface of the mastoid bone with the landmarks in a deeper location. Simple mastoidectomy was carried out without drilling over the linea temporalis inferior (LTI) on 20 adult temporal bones. The suprameatal spine, i.e., Henle spine (HS), variants were noted. Morphometric measurements were performed between these surgical landmarks, and their variations with pneumatization or HS types were evaluated. Three types of HS were identified: triangular, crest, absent. The HS-lateral semicircular canal distance was 15 mm on average and longer in bones with a triangular HS than a crest type HS (16.4 vs. 14.3 mm). The LTI was found to be located on average 4.7 mm inferior to the middle fossa dural plate (MFD). The LTI-MFD distance had a tendency to be longer in bones without an HS than with a crest type of HS (5.9 vs. 3.9 mm). Chorda tympani emerged from the facial nerve at the stylomastoid foramen in five specimens (25%). This anatomical organization was not correlated with the type of HS. Korner's septum (KS) was identified in nine bones (45%). It was present in eight of 16 (50%) bones with good pneumatization. No tendency for the existence of KS was found for any specific type of HS. This study confirms that the mastoid antrum is located 15 mm deep to the lateral surface of the mastoid bone. It should be expected to be longer in bones with a triangular HS. In addition, the MFD is located on average 5 mm above the LTI, which could be useful information for beginners or inexperienced surgeons. The ear surgeon should anticipate that the MFD might be longer in bones without an HS.

Nasal cavity and paranasal sinus bony variations: a computed tomographic study.

Variations of the nasal cavity are very important for the otolaryngologist in functional endoscopic sinus surgery. To provide data on bony variations of this region, we performed high resolution computed tomography images of paranasal sinuses on 82 adult patients without sinus pathology and on 90 adult patients with sinus disease. We observed paradoxical curvature of the middle concha in 11 (12.22%) sinus patients and 6 (7.31%) in non-sinus patients. Concha bullosa was observed in 26 sinus patients (28.88%) and 22 (26.83%) in non-sinus patients, deviated nasal septum in 20 (22.22%) sinus and 10 (12%) non-sinus, Haller's cell in 5 (5.55%) sinus and in 3 (3.65%) non-sinus, agger nasi cell in 7 (7.77%) sinus and 4 (4.88%) non-sinus patients. Pneumatisation of cristae galli was observed in 8 (8.88%) sinus and 2 (2.44%) non-sinus, of the anterior clinoid process in 5 (5.55%) sinus and 1 (1.22%) non-sinus patients, pneumatisation of the nasal septum in 7 (7.77%) and of the pterygoid recess in 12 (13.33%) sinus patients. We did not find any correlation between age intervals and paranasal sinus variations, and also no statistically significant difference was observed between males and females. These data provide very important information to guide the otolaryngologist and/or radiologist in the evaluation of patients with coronal CT which guides functional endoscopic sinus surgery.

The cavernous sinus: topographic morphometry of its contents.

The microsurgical anatomy of the cavernous sinus of 54 Turkish adult cadaveric heads (108 specimens) was examined to provide data for major topographic aspects and morphometry of the region, which is of special clinical importance for neurosurgeons. Significant findings were: 1) the abducent nerve in the cavernous sinus was observed as one rootlet in most of the specimens (78%), two rootlets in 14%, three in 5% and four in 3% of the specimens; 2) the anterior inferior venous space was dominant in 58%, the posterior superior venous space in 16%, and an intermediate type in 29% of the specimens; 3) the artery of the inferior cavernous sinus originated from the internal carotid artery (ICA) in 74% of the cases, and 4) the dorsal meningeal artery originated from the ICA in 6 (5.5%) of the specimens.

Relationship between nicotinamide adenine dinucleotide phosphate-diaphorase-reactive neurons and blood vessels in basal ganglia.

The relationship between nicotinamide adenine dinucleotide phosphate-diaphorase-positive neurons and blood vessels was investigated within the rat basal ganglia. Nicotinamide adenine dinucleotide phosphate-diaphorase-positive cell bodies, dendrites or axon-like processes surrounding many but not all blood vessels were observed in the caudate-putamen, ventral pallidum, medial part of the globus pallidus, substantia nigra and subthalamic nucleus. It is concluded that this close relationship contributes to the local vasodilator effect of nitric oxide in the regulation of blood flow in cerebral blood vessels.

The superior orbital fissure and its contents.

Topographic landmarks for the superior orbital fissure are useful for general orientation and approach to the middle fossa, cavernous sinus and orbit. In this study, the microsurgical anatomy and morphometry of the superior orbital fissure and its related structures were examined in 57 disarticulated sphenoid bones, 102 skull bases and 58 adult cadaveric heads. The superior orbital fissure was observed in nine different shapes based on the classification of Sharma et al. (1988), and the most frequently observed was Type VI. The distance from the superomedial to the superolateral edge was measured as 17.3 +/- 3.4 mm on the right side and 16.9 +/- 2.9 mm on the left side, and from the superolateral to the inferior edge as 20.8 +/- 3.9 mm on the right side and 20.1 +/- 3.8 mm on the left side. The distance from the superomedial to the inferior edge of the fissure was measured as 9.5 +/- 2.2 mm on the right side and 9 +/- 2.4 mm on the left side. No right-left differences were observed for these measurements. Measurements regarding the relationship of the oculomotor, trochlear and abducent nerves, the ophthalmic branch of the trigeminal nerve and the superior orbital vein were performed and topographic aspects of the superior orbital fissure region were described.

Neuro-arterial relations in the region of the optic canal.

In this paper, we present the results of our investigations on the neuro-arterial relations in the region of the optic canal. A thorough knowledge of the microanatomic features of the ophthalmic artery, optic canal and optic nerve is very important for surgeons approaching lesions of this area. We aimed to extend our present knowledge of the origin of the ophthalmic artery and microsurgical anatomy of the optic canal with exposure of the optic nerve. The optic canal walls and width and height of the orbital and cranial apertures, and thickness of the bony roof of the optic canal were measured on the right and left sides of 57 sphenoid bones, 102 skull bases and 58 fixed adult cadaver heads. The ophthalmic artery originated from the rostromedial circumference of the internal carotid artery in 51.8%, from the medial circumference in 26.2% and the laterobasal circumference in 22% of the specimens. The outer diameter of the ophthalmic artery at its origin was 1.81 +/- 0.36 mm on the right and 1.75 +/- 0.37 mm on the left side.

Anatomical guidelines for intranasal surgery of the lacrimal drainage system.

To facilitate identification of the nasolacrimal duct during intranasal surgery, we have determined the distances between the lacrimal drainage system and certain anatomical structures on the lateral wall of the nasal cavity. A total of 15 adult cadaver skulls were bisected mid-sagittally and evaluated morphometrically. In our specimens, the average distance from the natural ostium of the maxillary sinus to the nasolacrimal duct (NLD) was only 5.5 mm. This rather small distance should be taken into consideration, in order to prevent trauma of the NLD during surgical enlargement of the ostium of the maxillary sinus. The distances from NLD to the anterior surface of the bulla ethmoidalis, the free edge of the uncinate process and the attachment point of the middle turbinate on the lateral nasal wall were found to be 10.2 mm, 8.8 mm and 5.4 mm, respectively. Taking these distances into account, easy identification of the NLD during endonasal dacryocystorhinostomy surgery will be possible.

The variational anatomy of the external aperture of the human vestibular aqueduct.

A study was undertaken to demonstrate the variational anatomy of the external aperture of the vestibular aqueduct in 90 human temporal bones obtained from 58 cadavers. Topographic landmarks of the posterior surface of the petrous bone are useful for general orientation and include the external aperture of the vestibular aqueduct, internal auditory meatus, sigmoid sinus, subarcuate fossa, superior petrosal sinus and cochlear canaliculus. We determined the mean distances from the external aperture of vestibular aqueduct to the above structures to be 10.98, 11.21, 9.42, 10.27 and 13.90 mm, respectively. Furthermore, the length of the external aperture of the vestibular aqueduct revealed significant differences between the right and left sides. The distances between the EAVA and certain anatomical structures on the posterior surface of the temporal bone should be taken into consideration during surgery. Knowing the variability of the position of the external aperture of the vestibular aqueduct may help surgeons avoid traumatizing, and thus producing inadvertent lesions to the hearing mechanism.

An anatomical study of the sigmoid sulcus and related structures.

Variations in the shape and size of the sigmoid sulcus were investigated in 561 temporal bones (438 isolated temporal bones, 49 skull bases and 25 half skull bases) and measurements of related structures were made. Right-left differences were analysed. The sigmoid sulcus was significantly wider (12 mm) and longer (38 mm) in the skull bases, while no differences were observed in the isolated temporal bones. The distance from the most prominent point of the mastoid process to the Frankfort horizontal plane (FHP) was 33 mm; no right-left difference was found. The distance from the genu of the sigmoid sulcus to the external acoustic meatus was 24.06 mm on the right side and 24.74 mm on the left side and this difference is significant, being considerably longer on the left side. The jugular foramen diameter was 7.8 mm; no right-left difference was observed. The relationship of the mastoid air cells to the sulcus was analysed and air cells were found just behind the sulcus in 66% and behind and posterior to the sulcus in 5% of temporal bones.

Origin of the anterior spinal artery.

This investigation was designed to extend our present knowledge of the origin of the anterior spinal a. and is based on 80 brains of human cadavers. The anterior spinal a. is usually formed rostrally by the union of the anterior spinal branches from the intracranial segments of the vertebral aa. In this study, we observed three different locations of the origin of the anterior spinal a. Each type has different characteristics. A bilateral origin (type I) was present in 60 specimens (75%). This type could be further subdivided according to the caliber of the arteries, into the following subtypes: "balanced" (type Ia 42.5%), right-dominated (type Ib 17.5%), and left-dominated (type Ic 15%). A unilateral origin (type II) was found in 9 specimens (11.3%), and an origin in an intervertebral transverse anastomosis was demonstrated in 11 (13.8%). In all cases, the anterior spinal a. had an average caliber of 1.145 +/- 0.12 mm.

Assessment of normal clivus related to age with magnetic resonance imaging.

The signal intensity pattern cf normal clivus bone marrow related to age was studied on T1-weighted sagittal plain magnetic resonance images. Bone marrow in the clivus had a uniformly low signal intensity (grade 1) in 100% of the patients at 0-5 years and 96% of patients in the first decade (0-9 years). In the second decade there was a sharp decrease in the number of patients (43%) showing grade 1 clivus. Patients having mixed clivus signal intensity (grade 2) were mostly seen in the second decade (28.5%). Uniform high signal intensity (grade 3) was not observed under the age of 10. Grade 3 clivus pattern increased with age from the second decade, while grades 1 and 2 clivus bone marrow showed a marked decrease.