Biomedical subjects

I Tekdemir

Publications and source records attributed to I Tekdemir.

At least 37 records · Page 2Linked to original sources

PubMed2001

Thoracic pedicle: surgical anatomic evaluation and relations.

This anatomic study investigated the thoracic pedicle and its relations. The objective was to emphasize the importance of the thoracic pedicle for transpedicular screw fixation to avoid complications during surgery. Twenty cadavers were used to observe the cervical pedicle and its relations. The isthmus of the pedicle was exposed after removal of whole-posterior bony elements, including spinous processes, laminas, lateral masses, and the inferior and superior facets. The pedicle width and height, interpedicular distance, pedicle-inferior nerve root distance, pedicle-superior nerve root distance, pedicle-dural sac distance, root exit angle, and nerve root diameter were measured. There was no distance between the pedicle and dural sac in eight specimens. There was, however, a short distance in 12 remaining specimens in the upper and lower thoracic regions. The distances between the thoracic pedicle and the adjacent nerve roots ranged from 1.5 to 6.7 mm and 0.8 to 6.0 mm superiorly and inferiorly at all levels. The mean pedicle height and width at T1-T12 ranged from 2.9 to 11.4 mm and 6.2 to 21.3 mm, respectively. The interpedicular distance decreased gradually from T1 to T5 and then increased gradually to T12. The mean root exit angle decreased consistently from 104 degrees to 60 degrees. The nerve root diameter was between 2.3 and 2.5 mm at the T1-T5 level and then increased consistently from 2.5 to 3.7 mm. All significant differences were noted at p < 0.05 and p < 0.01. The following suggestions are made based on these results. 1) More care should be taken when a transpedicular screw is placed in the horizontal plane. 2) Improper medial placement of the pedicle screw, especially in the middle thoracic spine, should be avoided, and the anatomic variations between individuals should be considered. 3) Because of substantial variations in the size of thoracic pedicles, utmost attention should be given to the findings of a computed tomographic evaluation before thoracic transpedicular fixation is begun.

Adult↗

PubMed2001

Certain anatomical relations and the precise morphometry of the infraorbital foramen--canal and groove: an anatomical and cephalometric study.

OBJECTIVES: To determine and to standardize the certain anatomical relations, and the precise size, course, and location of the infraorbital foramen, canal, and groove for facilitating surgical and invasive procedures. STUDY DESIGN: This anatomical study consisted of two main steps, namely, the examination of skulls and the cephalometric analysis of the skulls. Measurements of the skulls and of the radiograms were performed. METHODS: Thirty-five adult bony heads (70 sides) were studied regarding the localization and dimensions of the infraorbital groove (IOG), infraorbital canal (IOC), and infraorbital foramen (IOF) as well as their relationships with different anatomical landmarks. The cephalometric analysis of the skulls was measured for evaluating the relationships of certain anatomical points and the distances of the skulls in the cephalometric analysis. For this purpose, 13 different distances and two angles were measured on anteroposterior and lateral craniographies. Differences between data of skull and cephalogram measurements were analyzed by the Student t test. The Pearson correlation test was used in the statistical analysis of the 15 values in the cephalogram. RESULTS: Examination of the 70 sides of the 35 bony heads revealed that the shape of the IOF was oval in 34.3%, round in 38.6%, and semilunar in 27.1% of all skulls. The IOF was single in 94.3% and double in 5.7% of the cases. The average distance from the IOF to the infraorbital margin and to the lateral process of the canine tooth in vertical direction and to the lateral nasal border in horizontal direction were 7.19 +/- 1.39 mm, 33.94 +/- 3.15, and 17.23 +/- 2.64 mm, respectively. In cephalometric analysis, when S-N (the distance between the center of the sella turcica and the nasion) and N-ANS (the distance between the nasion and the anterior nasal spine) distances were used as independent parameters for the linear analysis, the correlation of the three values for both independent parameters were statistically significant. CONCLUSION: While the IOF has no statistically significant changes with regard to the size of the skull, expressive changes take place in the course and the length of the IOG and IOC. Meticulous preoperative evaluation of the IOF and the route of the infraorbital nerve are necessary in patients who are candidates for maxillofacial surgery and regional block anesthesia. 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.

Adult↗

PubMed2000

Radiological anatomy of the intratemporal course of facial nerve.

Preoperative evaluation of the facial nerve (FN) anatomy within the temporal bone by high-resolution computed tomography (HRCT) helps in minimizing surgical trauma to the nerve. In order to demonstrate the radiological correlation of the intratemporal FN, eight adult, formalin-preserved cadavers were studied by comparing the transaxial and coronal sections of HRCT with anatomic microdissection findings. It was possible to visualize all segments of the FN canal in its intratemporal course. The most difficult part of the FN to demonstrate was the pyramidal section. Anatomic microdissection findings were consistent with the HRCT images. It was concluded that adequate information on the FN anatomy could be obtained from standard HRCT scans.

Aged↗

PubMed2000

Anatomical study of the lateral wall of the cavernous sinus, emphasizing dural construction and neural relations.

This study aims to determine the microscopic anatomy of the layers of the lateral wall of the cavernous sinus (CS) and, in particular, intends to examine the location and relations of the dural openings on the deep layer. Forty sides of 20 formalin-fixed and fresh cadavers were dissected and their CS examined. In 12 cases we found an opening on the deep dural layer; however, in four of them the inferolateral trunk of the internal carotid artery (ICA) was identified through these dural openings. We noticed the trochlear nerve making a curve (5% of cases) or lying close to the ophthalmic nerve (12.5%) on the lateral wall. In one case, the triangular area described by Parkinson could not be exposed surgically. Our findings indicate the importance of the heterogeneous courses of the cranial nerves lying on the lateral wall and point to the significance of the dural openings, which can influence the etiology of neoplastic invasions originating from the CS.

Cavernous Sinus↗

PubMed2000

A radiologico-anatomical comparative study of the cochlear aqueduct.

AIM: A comparative radiologico-anatomical study of the cochlear aqueduct (CA) was performed. MATERIALS AND METHODS: Eight cadavers and 23 dry temporal bones were studied. High-resolution computed tomography (HRCT) was carried out on each cadaver before microdissection. Microdissection was carried out in a plane parallel to the HRCT sections. RESULTS: The CA was found to be located an average of 7 mm inferior to the internal acoustic meatus and at the superior edge of the jugular foramen. The external aperture of the CA was triangular in shape in 18 bones (78.3%). The petrosal fossa was located just inferior to the external aperture and housed the glossopharyngeal nerve, which had an incomplete bony canal in four bones (17.4%) and a complete bony canal in three bones (13%). It was possible to demonstrate the petrosal portion of the CA on both coronal and axial HRCT. The otic capsule segment of the CA was impossible to demonstrate on coronal sections. CONCLUSION: The CA cannot be visualized in only one section of the plane in HRCT. Both the otic capsule and petrosal segments can be demonstrated on axial HRCT.

Aged↗

PubMed2000

Anatomy of the anterior sacroiliac joint with reference to lumbosacral nerves.

There are no detailed descriptions of the neural structures that may be seen during surgical interventions of the pelvis. Anatomic dissections were performed to see which nerves are endangered in approaches to the anterior sacroiliac joint for plate fixations. Sixty cadavers were dissected bilaterally. Fifty-one were male and nine were female. L4 and L5 nerve roots were followed along the sacroiliac joint from the intervertebral foramen to the entrance into the lesser pelvis. Measurements were made between the nerves and sacroiliac joint from the proximal end of the joint to the pelvic brim. The L4 nerve root and the lumbosacral trunk (and not the L5 nerve root) were the nerves most susceptible to injury because of their course and proximity to the sacroiliac joint. As a result, during the anterior approach and fixation of the sacroiliac joint with plates, extreme care should be taken to identify the L4 nerve root or lumbosacral trunk or both at the anteroinferior third of the joint because the distance between the nerve and the joint is less than 1 cm.

Adult↗

PubMed2000

Surgical anatomic evaluation of the cervical pedicle and adjacent neural structures.

OBJECTIVE: Although several clinical applications of transpedicular screw fixation in the cervical spine have been documented recently, few anatomic studies concerning the cervical pedicle are available. This study was designed to evaluate the anatomy and adjacent neural relationships of the middle and lower cervical pedicle (C3-C7). The main objective is to provide accurate information for transpedicular screw fixation in the cervical region and to minimize complications by providing a three-dimensional orientation. METHODS: Twenty cadavers were used to observe the cervical pedicle and its relationships. After removal of the posterior bony elements, including spinous processes, laminae, lateral masses, and inferior and superior facets, the isthmus of the pedicle was exposed. Pedicle width, pedicle height, interpedicular distance, pedicle-inferior nerve root distance, pedicle-superior nerve root distance, pedicle-dural sac distance, medial pedicle-dural sac distance, mean angle of the pedicle, root exit angle, and nerve root diameter were measured. RESULTS: The results indicate that there was no distance between the pedicle and the superior nerve root and between the pedicle and the dural sac in 16 specimens, whereas there was a slight distance in the lower cervical region in the 4 other specimens. The mean distance between the pedicle and the inferior nerve root for all specimens ranged from 1.0 to 2.5 mm. The mean distance between the medial pedicle and the dural sac increased consistently from 2.4 to 3.1 mm. At C3-C7, the mean pedicle height ranged from 5.2 to 8.5 mm, and the mean pedicle width ranged from 3.7 to 6.5 mm. Interpedicular distance ranged from 21.2 to 23.2 mm. The mean root exit angle ranged from 69 to 104 degrees, with the largest angle at C3 and the smallest at C6. The mean angle of the pedicle ranged from 38 to 48 degrees. The nerve root diameter increased consistently from 2.7 mm at C3 to 3.8 mm at C6 and then decreased to 3.7 mm at the C7 level. Differences in measurements were considered statistically significant at levels ranging from P < 0.05 to P < 0.01. CONCLUSION: This study indicates that improper placement of the pedicle screw medially and superiorly in the middle and lower cervical spine should be avoided and that the anatomic variations between individuals should be established by measurement.

Adult↗

PubMed2000

Temporoparietal fascia: an anatomic and histologic reinvestigation with new potential clinical applications.

Temporoparietal fascia constitutes a very important structural unit from both an aesthetic and a reconstructive surgical point of view. A histologically supported anatomic study was conducted for the reappraisal of the anatomic relationships and clinical application potentials of the data obtained. Anatomy of the temporoparietal fascia was investigated on 20 sides from 10 cadavers. After dissections, necropsies were obtained to demonstrate histologic features of the temporoparietal fascia. The outer part of the temporoparietal fascia is continuous with the superficial musculoaponeurotic system (SMAS) in the inferior border and with orbicularis oculi and frontalis muscles in the anterior border. Therefore, plication of the temporoparietal fascia can increase tightness of the SMAS, orbicularis oculi, and frontalis muscle in rhytidectomy. The frontal branches of facial nerve were noted to course parallel to the frontal branch of the superficial temporal artery, lying deeper to the temporoparietal fascia within the innominate fascia. In the view of these findings, conventional subfascial dissection, which is performed to protect frontal branches of the facial nerve, is not reasonable during the temporal part of rhytidectomy. Careful subcutaneous dissection just under the hair follicles is more appropriate to avoid nerve injury and also provides excellent exposure of the temporoparietal fascia for plication in rhytidectomy with protection of the auriculotemporal nerve and the superficial temporal vessels. Furthermore, two layered structures of the temporoparietal fascia are very suitable to insert a framework into the temporoparietal fascia for ear reconstruction to eliminate some of the shortcomings of Brent's technique. A thin muscle layer was also noted within the outer part of the temporoparietal fascia below the temporal line; the term "temporoparietal myofascial flap" would, therefore, be more accurate than "temporoparietal fascial flap." Finally, the innominate fascia and the deep temporal fascia can be elevated with the two layers of the temporoparietal myofascial flap to obtain a well-vascularized, four-layered myofascial flap based on the superficial temporal vessels. This multilayered flap can be used to reconstruct all defects when fine, pliable, thin, multilayered flaps are required.

Adult↗

PubMed2000

Anatomical projection of the cervical uncinate process in ventral, ventrolateral, and posterior decompressive surgery.

OBJECT: The cervical uncinate processes (UPs), their variations, and the relationships between the neurovascular structures and surrounding bone were investigated in this anatomical study. The object of this study was to highlight the important surgery-related considerations associated with ventral, ventrolateral, and posterior decompressive surgery. METHODS: Forty-nine adult C3-7 dry bone samples were used, and 10 measurements were obtained for each vertebra. The anterior measurements involved the cervical uncinate process (UP): height, width, length, distance between its tip and vertebral foramina, interuncinate process distance, sagittal angle with the superior margin of the vertebral body (VB), VB anteroposterior diameter, and VB width. Posterior measurements involved the vertical distance between the superior border of the lamina at the lamina-facet joint and the tip of the UP, as well as the horizontal distance between the medial-most border of the superior facet and the tip of the UP. All symmetrical structures were measured bilaterally. There were no statistically significant differences between right- and left-sided measurements in this series. The height of the UP increased gradually at each segmental level between C-3 and C-7. The width of the UP did not change with segmental level (5.0 mm at C-3 compared with 5.3 mm at C-7). On average, the length of the UP was relatively constant. The distance from the tip of the UP to vertebral foramina averaged 1 mm at the C2-3 level and 1.5 mm at the C5-6 level. Interuncinate distance and VB width gradually increased and were highly variable, which appeared to be related with osteophyte formation. There was a slight gradual increase from C-3 to lower segments, and it paralleled with the midline anteroposterior diameter of the same VB. The angle between the UP and the superior margin of the VB exhibited great variety. The posterior measurements decreased gradually from C-3 to C-7. CONCLUSIONS: Based on the data obtained in this study, a surgeon is provided with a three-dimensional orientation as well as anatomical knowledge. This knowledge also allows for a more effective neurovascular decompression by minimizing the surgery-related complications.

Adult↗

PubMed1999

Surgical exposure in translabyrinthine approaches--an anatomical study.

OBJECTIVE: Translabyrinthine approach (TLA) is a procedure of choice for the removal of vestibular schwannomas in cases of profound hearing loss. There is a lack of anatomic studies reviewing the surgical anatomy of the cerebellopontine angle (CPA) as seen in the classical and enlarged TLAs. METHODS: Seven formalin-preserved cadavers were dissected. Structures, visualized in the CPA through the TLA, were scored according to the degree of their exposure (1, structure not seen; 2, partial exposure; 3, full exposure). RESULTS: The acousticofacial bundle, anterior inferior cerebellar artery and flocculus had the highest scores in both types of surgery. However. the fifth, ninth, and tenth cranial nerves, prepontine cistern, pons, superior cerebellar artery, and posterior inferior cerebellar artery had higher scores, i.e. better exposure, in the enlarged TLA than in the classical TLA. CONCLUSION: These findings suggest that the enlarged TLA be preferred in cases of larger tumors extending to either jugular foramen or middle fossa whereas the indications of the classical TLA should be limited to vestibular neurectomy and removal of smaller tumors.

Brain Mapping↗

PubMed1999

The subarcuate canaliculus and its artery--a radioanatomical study.

The anatomy of the subarcuate canaliculus (SAC), subarcuate fossa (SAF) and subarcuate artery (SAA) was studied in 12 cadavers and 35 dry temporal bones. Each cadaver was scanned with high resolution CT (HRCT) prior to microdissection. The SAC was always found to be a single canal located between the two arcs of the anterior semicircular canal in both microdissections and HRCT scans and the internal acoustic meatus was observed to be located just inferior to the SAC. The SAC was on average of 9.2 mm in length and 1 mm in width. The SAF was situated at a distance of 4.2 mm from the internal acoustic meatus, 3.5 mm from the groove for the superior petrosal sinus, 6.7 mm from the opening of the vestibular canaliculus and 11.5 mm from the most superior part of the jugular foramen. The SAA was found to originate from the anterior inferior cerebellar artery in 9 cadavers and from the internal auditory artery in 3 cadavers. The SAA always emerged from the main artery outside the internal acoustic meatus. It ran through the SAC as a single artery. This study investigated CT correlated anatomical aspects of the subarcuate canaliculus and its artery which is claimed to be responsible for the blood supply of the mastoid antrum, facial canal and bony labyrinth.

Cadaver↗

PubMed1999

Relation of the radial nerve with the sulcus nervi radialis: a morphometric study.

The radial nerve's course from the axillary region, branch patterns and the relation of the nerve to fixed anatomical landmarks in the arm region were studied in 27 embalmed intact cadavers. The radial nerve and its relation with the sulcus nervus radialis (SNR) was analyzed. The direct contact of the nerve with humerus in SNR was observed during the dissections. The following measurements were made: the total length of the humerus (the palpable uppermost point of the tuberculum majus and the lateral epicondyle); proximal safe zone (the tuberculum majus and the proximal beginning of the SNR); distal safe zone (the intercondylar axis and the middle of SNR); lateral safe zone (the lateral epicondyle and the distal end of SNR). In conclusion, it was aimed to correlate the osseus palpable landmarks of humerus with the course of the radial nerve for a safe surgery as the sulcus nervi radialis region is one of the main risky areas for the radial nerve palsies.

Anatomy, Artistic↗

PubMed1998

The jugular foramen: a comparative radioanatomic study.

BACKGROUND: Advances in microsurgical techniques made possible the removal of advanced jugular foramen (JF) lesions, which once had been accepted as unoperable. However, successful surgery requires detailed knowledge of the JF anatomy. METHODS: Sixteen jugular foramina in eight formalin-preserved adult cadavers were scanned with axial and coronal high resolution computed tomography (HRCT) prior to dissection. After craniectomy and removal of brain tissue, the relationships of the neurovascular structures in the JF were determined by drilling the temporal bones from superior to inferior on planes parallel to the skull base. RESULTS: No bony partition of the JF was observed. A dural band consistently divided the JF into two parts. Anterior to it was the glossopharyngeal nerve (IX) while the vagus (X) and accessory (XI) nerves were located posteriorly. There was a notch in which the IX nerve entered the JF. It was also identified on the CT scans and defined as the glossopharyngeal recess. The IX nerve made a genu within the JF in all specimens. Then, it ran inferiorly through a bony canal in three specimens (18.75%), and through an incomplete bony canal in two (12.5%), which were also defined on the CT images. The inferior petrosal sinus ran through a sulcus anteromedial to the glossopharyngeal recess. The posterior meningeal artery was found to be located between the X and XI nerves within the JF. CONCLUSIONS: This study revealed a complex and highly variable pattern of the relationships of the neurovascular structures in the JF, and their HRCT images correlated well with the anatomic microdissections.

Aged↗

PubMed1998

Branches of the intracavernous internal carotid artery and the blood supply of the intracavernous cranial nerves.

With the increasing frequency of surgical operations to the cavernous sinus greater knowledge of the microanatomy of the cavernous sinus has become necessary. The most frequently seen complications during cavernous sinus surgery involve impairment of cranial nerves. This can occur due to direct damage or ischemia. For these reasons, it is important to know the arterial supplies to the cranial nerves in the cavernous sinus and the anatomy of these branches as well. 15 formaline fixed adult cadavers were used in this study. Before the dissections, the internal carotid artery and vertebral artery were filled with coloured latex on both sides. In this report, the intracavernous branches of internal carotid artery (I.I.C.A.) were identified based on the principles of Nomina Anatomica (1989) and compared with others. In our study we found that the segment of the abducens nerve which lies in Dorello's channel was supplied by the meningeal branch; from the point at which it pierces the cerebellar tentorium, the trochlear nerve is supplied by the tentorial cerebellar artery; the posterior cerebellar artery supplies the proximal segment of the oculomotor nerve that proceeds to the oculomotor triangle. Except for these, all the cranial nerves that were located on the lateral wall of the sinus cavernosus are supplied by the tentorial marginal branch and the branches of the lateral trunk.

Adult↗

PubMed1998

An anatomical study of the tympanic branch of the glossopharyngeal nerve (nerve of Jacobson).

Our study was aimed to examine the anatomic relationships of the tympanic branch of the glossopharyngeal nerve (GPN), namely the Jacobson's nerve (JN). The JN is the first branch of the GPN after having passed the jugular foramen. It contributes to the tympanic plexus on the promontory. It transmits secretory innervation to the parotid gland. Its possible role in the regulation of the middle ear pressure has also been hypothesized in terms of animal studies. Using microdissection techniques and high-resolution computed tomography (HRCT) scanning, the anatomic relationships and course of the JN were examined in eight formalin-preserved cadavers (16 sides). A morphometric analysis related to the JN was also performed both in the 16 cadavers and 40 dry-skull specimens. The JN emerged from the inferior ganglion of the GPN in all specimens. The mean distance between the ganglion and the genu of the GPN was 11.3 mm. The inferior 2/3 of the tympanic canal (TC) followed a vertical course, and then it ran anteromedially with an angle of 160 degrees to 170 degrees. The mean length of the TC was 9.5 mm. The TC was well-defined in all axial HRCT scans. In 2 cases the JN was entirely encased in a bony canal in the middle ear. A double JN was observed in one case. This study gives an additional information regarding the anatomy of the JN.

Aged↗

PubMed1998

Island V-Y tensor fasciae latae fasciocutaneous flap for coverage of trochanteric pressure sores.

The distal fasciocutaneous portion of the lateral thigh is supplied by the direct cutaneous branch of the lateral descending branch of the lateral circumflex femoral artery and the third perforating artery of the deep femoral artery. This consistent vascular anatomy allows raising a distal skin island based on both arteries on the lateral thigh, and this flap can be advanced into a trochanteric defect according to the V-Y technique. Based on anatomic and clinical study, a new design has been developed of the tensor fasciae latae fasciocutaneous flap, which is supplied by two pedicles. Seven island V-Y tensor fasciae latae fasciocutaneous flaps have been used for the coverage of trochanteric pressure sores in six patients. It is believed that the island V-Y tensor fasciae latae fasciocutaneous flap could overcome the traditional drawbacks of the conventional tensor fasciae latae flap and its modifications, and this is an ideal flap for covering trochanteric pressure sores without any donor site deformity and morbidity, which greatly improves the aesthetic result.

Adult↗

PubMed1998

A clinico-anatomic study of the auricular branch of the vagus nerve and Arnold's ear-cough reflex.

The results of a clinico-anatomic study of the auricular branch of the vagus nerve (ABVN) and Arnold's ear-cough reflex are presented. The frequency of the ear-cough reflex was found to be 2.3% (12 out of 514 patients). It was bilateral in 3 cases (0.6%). The reflex was elicited by palpation of the postero-inferior wall of the external acoustic meatus (EAM) in 11 patients, and by palpation of the antero-inferior wall in one patient (0.2%). The reflex was frequently noticed to occur after a short latent period. The course of the ABVN inside the jugular foramen (JF), and distribution of the terminal branches of the ABVN in the external acoustic meatus were determined in 8 male cadavers (16 sides). In addition, the length of the mastoid canaliculus (MC) and the relationships of the ABVN with the facial nerve and stylomastoid foramen (SMF) were studied in both cadavers and 25 dry skulls (50 sides). High-resolution computed tomography (HRCT) scanning was also performed in all cadavers prior to microdissections. The ABVN emerged from the superior ganglion of the vagus nerve in all the cadavers. It ran between the internal jugular vein (IJV) and the bony wall of the jugular foramen. The ABVN was encased in a partial bony canal during its course from the jugular foramen to mastoid canaliculus in 18% of all specimens. The average length of the mastoid canaliculus was 5.6 mm (4.2-6.5), and it ran transversely towards the tympanomastoid suture 4.5 mm (4-5.1) above the stylomastoid foramen. The mastoid canaliculus was well demonstrated in all the HRCT scans.

Adult↗

PubMed1994

Morphometric evaluation of paranasal sinuses for endoscopic sinus surgery.

Endoscopic surgical treatment of paranasal sinus infections is currently being applied in many Otorhinolaryngology Clinics. Although high rates of success are reported with this treatment method, life threatening complications sometimes do occur due to disorientation, especially when angled telescopes are used. In order to avoid such complications, we evaluated the distances from the anterior nasal spine to various important anatomic structures encountered during endoscopic surgery. The measurements obtained by a morphometric anatomic study of cadavers are presented in this study. We believe that if surgery is carried beyond the measured distances, serious complications may ensue during endoscopic surgery.

Aged↗