Mehmet Asim Ozer

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.

Anatomical variations of the frontal and supraorbital transcranial passages.

In this study, 500 frontal and supraorbital transcranial passages were studied in 50 cadavers and 200 crania of 500 samples. One hundred six specimens had a frontal foramen (notch), and all the samples had a supraorbital foramen (notch). The frontal passage was a foramen in 7 samples and a notch in 99 samples. As for the supraorbital passage, it was found as a foramen in 133 of specimens and as a notch in 358 of specimens. In 9 of the specimens, there were double notches or foramina. The distances from the foramina (notches) to angulus oculi medialis were measured in the cadavers. The average distance from the angulus oculi medialis to the frontal foramen (notch) was 4.50 mm, and the average distance to the supraorbital foramen (notch) was 9.87 mm. The distances from the foramina (notches) to the midline were measured in the crania. The average distances from the midline to the frontal foramen (notch) and the supraorbital foramen (notch) were 20.24 mm and 25.23 mm, respectively. The average distance between the frontal foramen (notch) and supraorbital foramen (notch) was 5.37 mm in cadavers and 4.99 mm in crania. In 200 crania, the distances of the frontal and supraorbital transcranial passages to the midline were measured. Types of these passages were also evaluated, and frequencies were calculated. Measurements were made using a digital compass, and the student t test was used in the statistical evaluation of results.

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.

A morphometric study of the inferior orbital fissure using three-dimensional anatomical landmarks: Application to orbital surgery

The inferior orbital fissure (IOF) is an important structure during orbital surgery, however, neither its anatomical features nor the procedures necessary to expose the IOF have been examined in detail. A morphometric analysis of the IOF was performed on 232 orbits using computer software. The longest and shortest borders of the IOF were 18.2 ± 4.9 and 1.9 ± 1.3 mm, respectively. The outer and the inner angles were 138.9 ± 32.7° and 38.4 ± 24.7°, respectively. The perimeter of the IOF was 50.6 ± 13.5 mm and its area was 61.3 ± 39.1 mm2. Eight types of IOF were observed. Type 1 IOF was observed in 42.2% and the Type 2 IOF was identified in 15.9%. A statistically significant relation was found between the longest edge and area and the widest edge and area of the IOF. The findings of our study suggest that the removal of the lateral wall should begin inferiorly, just lateral to the IOF and extended superolaterally. These data may be useful during surgical approaches to the orbit. Clin. Anat. 22:649–654, 2009.

Orbital restoration surgery in the zygomaticotemporal and zygomaticofacial nerves and important anatomic landmarks.

A variety of etiologies may result in functional and aesthetic deficiencies requiring orbital reconstruction. Fractures of the zygomaticomaxillary complex in the acute stage are frequently accompanied by sensory disturbances of the zygomatic nerve (ZN). The purpose of the current study was to describe the anatomic and topographic landmarks of the ZN in 18 adult human cadavers regarding the localization and dimensions in the orbit. The zygomaticotemporal (ZTN) and zygomaticofacial nerves (ZFN) along the lateral wall of the orbit passed through the zygomaticotemporal and zygomaticofacial foramens, respectively. The angle between the ZTN and the ZFN within the orbit was approximately 42.21 degrees. The mean (SD) distance between the orbital opening of the ZTN and the meeting point of the ZTN was measured as 9.21 (5.18) mm. The mean (SD) distance between the orbital opening of the ZFN and the meeting point of the ZTN was calculated as 11.22 (4.25) mm. The mean (SD) distance between the orbital opening of the ZFN and the infraorbital margin of the orbit was 13.04. (3.21) mm. A detailed knowledge of the ZNs passage in the orbit is necessary for a surgeon while performing maxillofacial surgery. If these measurements are taken into account, there will be little surgical risk, and this will be helpful in identifying the extent of the operative field.

Three-dimensional anatomic landmarks of the foramen magnum for the craniovertebral junction.

The foramen magnum (FM) has a vital importance to have a direct view of the vertebral artery, lower cranial nerves, and the brainstem. The morphologic analysis of the FM was studied in 352 occipital bones of adult human skulls by 3D-Doctor V 3.5.050402 Demo version. The perimeter and area of the FM were calculated as 115.6 (SD, 9.9) mm and 829 (SD, 137.7) mm2, respectively. The FM index was found as 84.02%, and the majority (38.4%) of holes were observed to have a narrow index. The FM was observed to 8 different types. The most frequently observed types were the tetragonal type in 25.66%, and the one formed by the combination of 2 semicircles in 23.28%. The large anterior margin of the FM type, such as types 1, 4, 5, and 6, can be easily performed partially. In the cases of types 2, 3, and 8, the anterior margin was determined as narrow, the resection procedure is completed with more difficulty. In Pearson correlation analysis, it is significant that a statistically strong relation was found between the area and perimeter, and the area and length of FM. This findings suggest that the resection should be started at the anterior margin, just lateral and then extended superolaterally.

Building 3D anatomical model of coiling of the internal carotid artery derived from CT angiographic data

The purpose of this study is to recreate live patient arterial anomalies using new recent application of three-dimensional (3D) printed anatomical models. Another purpose of building such models is to evaluate the effectiveness of angiographic data. With the help of the DICOM files from computed tomographic angiography (CT-A), we were able to build a printed model of variant course of the internal carotid artery (ICA). Images of coiling of the ICA taken by CT-A, were then converted into 3D images using Google SketchUp free software, and the images were saved in stereolithography format. Imaging helped us conduct the examination in details with reference to geometrical features of ICA, degree of curve, its extension, location and presence of loop. Challenging vascular anatomy was exposed with models of adverse curve of carotid anatomy, including highly angulated necks, conical necks, short necks, tortuous carotid arteries, and narrowed carotid lumens. It assisted us to comprehend spatial anatomy configuration of life-like models. 3D model can be very effective in cases when anatomical difficulties are detected through the CT-A, and therefore, a tactile approach is demanded preoperatively. 3D life-like models serve as an essential office-based tool in vascular surgery as they assist surgeons in preoperative planning, develop intraoperative guidance, teach both the patients and the surgical trainees, and simulate to show patient-specific procedures in medical field.

Development of Life-Size Patient-Specific 3D-Printed Dural Venous Models for Preoperative Planning

BACKGROUND Despite significant improvement in clinical care, operative strategies, and technology, neurosurgery is still risky, and optimal preoperative planning and anatomical assessment are necessary to minimize the risks of serious complications. Our purpose was to document the dural venous sinuses (DVS) and their variations identified during routine 3-dimensional (3D) venography created through 3D models for the teaching of complex cerebral anatomy. METHODS 3D models of the DVS networks were printed. Compared with the controls, cases with cortical venous thrombosis have altered venous anatomy, which has not been previously compared. RESULTS Geometrical changes between the neighboring DVS could be easily manipulated and explored from different angles. Modeling helped to conduct the examination in detail with reference to geometrical features of DVS, degree of asymmetry, its extension, location, and presence of hypoplasia/atresia channels. Challenging DVS anatomy was exposed with models of adverse anatomical variations of the DVS network, including highly angulated, asymmetrical view, narrowed lumens, and hypoplasia and atresia structures. It assisted us in comprehending spatial anatomy configuration of life-like models. CONCLUSIONS Patient-specific models of DVS geometry could provide an improved understanding of the complex brain anatomy and better navigation in difficult areas and allow surgeons to anticipate anatomical issues that might arise during the operation. Such models offer opportunities to accelerate the development of expertise with respect to new and novel procedures as well as new surgical approaches and innovations, thus allowing novice neurosurgeons to gain valuable experience in surgical techniques without exposing patients to risk of harm.

Morphometry of the anterior third ventricle region as a guide for the subfrontal (translaminaterminalis) approach

The anterior third ventricle region acquires clinical significance in benign and malignant tumors and cyst formations, of which craniopharyngiomas and gliomas are the most common. The subfrontal approach is one of the most preferred approaches for removing these tumors. In this study, the microsurgical anatomy of 81 Turkish, adult cadaveric hemispheres was examined to provide morphometric data of the region. These measurements from the anterior third ventricle region serve as a guide for neurosurgeons during surgical approach for removing anterior third ventricle tumors.

Creating vascular models by postprocessing computed tomography angiography images: a guide for anatomical education

BackgroundA new application of teaching anatomy includes the use of computed tomography angiography (CTA) images to create clinically relevant three-dimensional (3D) printed models. The purpose of this article is to review recent innovations on the process and the application of 3D printed models as a tool for using under and post-graduate medical education.MethodsImages of aortic arch pattern received by CTA were converted into 3D images using the Google SketchUp free software and were saved in stereolithography format. Using a 3D printer (Makerbot), a model mode polylactic acid material was printed.ResultsA two-vessel left aortic arch was identified consisting of the brachiocephalic trunk and left subclavian artery. The life-like 3D models were rotated 360° in all axes in hand.ConclusionsThe early adopters in education and clinical practices have embraced the medical imaging-guided 3D printed anatomical models for their ability to provide tactile feedback and a superior appreciation of visuospatial relationship between the anatomical structures. Printed vascular models are used to assist in preoperative planning, develop intraoperative guidance tools, and to teach patients surgical trainees in surgical practice.