Biomedical subjects

A Elhan

Publications and source records attributed to A Elhan.

At least 19 recordsLinked to original sources

PubMed2005

Microsurgical anatomy of the dorsal cervical rootlets and dorsal root entry zones.

BACKGROUND: Detailed anatomical knowledge of the dorsal cervical rootlets and dorsal root entry zones (DREZ) is important for the diagnosis and treatment of cervical myeloradiculopathy and surgical management of pain. There are far fewer micro-anatomical studies of this area than gross anatomical studies. This study presents several anatomical points regarding the dorsal cervical rootlets and dorsal root entry zones. METHOD: Fifteen adult formalin-fixed cadaveric spines from C1 to T1 were used to observe the posterior structures. They were studied under the surgical microscope following en bloc laminectomy and foraminotomy. The morphological features of the dorsal root entry zones and dorsal rootlets were determined. The distance from the midline to the DREZ, the longitudinal length of the DREZ in the spinal canal, the length of the dorsal rootlets, the number of dorsal rootlets and the intersegmental anastomoses between the dorsal rootlets were measured. FINDINGS: The distance from the midline to the DREZ ranged from 1.1 to 4.7 mm. Longitudinal length of the dorsal rootlets ranged 4.3-17.7 mm. The shortest length of the dorsal rootlets ranged between 5-28 mm, and longest lengths of the dorsal rootlets ranged 6.8-30.3 mm. The number of dorsal rootlets ranged from 2-13. Between the C2-T1 dorsal rootlets, 142 connections out of 30 intersegments were noted. CONCLUSIONS: The distance from the midline to the DREZ decreased in the lower cervical spine. The longest longitudinal length of the DREZ was at the C5 level. The length of the dorsal rootlets was increased in the lower cervical spine. The average number of dorsal rootlets tended to increase in the lower cervical spine. Anastomoses were most often found between C6-7 and C5-6 dorsal rootlets. Knowledge of the anatomical features of dorsal cervical rootlets and dorsal root entry zones is essential for a surgeon to avoid injuring the neural structures. This knowledge is a must not only to avoid complications but also for the success, safety and effectiveness of microsurgical operations of the pathological conditions like posterior myeloradiculopathy and pain treatment such as DREZ operations.

Adult↗

PubMed2004

Internal anal sphincter: an anatomic study.

The anatomy of the internal anal sphincter and surrounding structures was investigated in 24 cadavers using a surgical microscope (6-25 x magnification). An understanding of the anatomy of the internal anal sphincter is helpful in avoiding complications during surgical procedures in the anorectal region. The external anal sphincter was composed of three ellipsoid rings of skeletal muscle (subcutaneous, superficial, and deep) that encircle the anal canal; in contrast, we found that the internal anal sphincter was composed of flat rings of smooth muscle bundles stacked one on top of the other, like the slats of a Venetian blind. In each anal canal, the average number of ring-like slats observed was 26.33 +/- 2.93 (range = 20-30) and each was covered by its own fascia. The smooth muscle fibers and fascia coalesced at three equidistant points around the anal canal to form three columns that extended distally into the lumen and differed in form from the other anal columns. When viewed from an anterior position, the columns were located anteriorly at the observer's right (5 o'clock position), posteriorly at the right (1 o'clock position), and laterally at the left (9 o'clock position). This heretofore unreported anatomy of the internal anal sphincter may play an important role in closing off the lumen of the anal canal and maintaining bowel continence.

Anal Canal↗

PubMed2004

Fossa navicularis: anatomic variation at the skull base.

The fossa navicularis is a relatively rare anatomic variation of the skull base. Awareness of its existence will avoid misinterpretations of radiological images and unnecessary investigations. This study describes the appearance of the fossa navicularis, and investigates its incidence and whether it is related to pathology at the basiocciput. We studied 492 dry human skulls and 525 computer tomography (CT) images of patients. Dry skulls showing a fossa navicularis were investigated by CT scan, whereas patients identified as having a fossa navicularis were further examined with magnetic resonance imaging (MRI). To document the position of the fossa more precisely, measurements were made between the fossa navicularis and certain anatomic landmarks such as the foramen ovale, the pharyngeal tubercle, the posterior border of the vomer, the foramen lacerum, the carotid canal, and the occipital condyle. Upon examination, 26 of 492 skulls (5.3%) were found to have a fossa navicularis. Twelve were <2 mm in depth and the other 14 had a depth of >/=2 mm. Of the 525 patients, 16 (3.0%) were identified as having a fossa navicularis in CT images. Evaluation of MRIs showed no soft tissue lesions in any of these patients. Comprehensive anatomic details of the fossa navicularis have not been reported in the literature. The results of this study may be useful to radiologists, anatomists, and surgeons interested in the skull base.

Bone Cysts↗

PubMed2004

Evaluation of the anterior and posterior ethmoidal canal by computed tomography.

AIM: To examine the anatomy, length and angulation of the anterior and posterior ethmoidal canals (AECs and PECs) using computed tomography (CT), and to determine the anatomical landmarks in which the canals are expected to be seen in transverse and coronal planes. MATERIALS AND METHODS: CT images of 150 patients were analysed. One, 2, and 3 mm thick sections were obtained separately in axial and coronal images. The frequency of visualization of the AECs and PECs, and if present, a third canal, was noted. The course and the angulation of the AEC and the PEC in transverse and coronal planes were recorded. On axial sections the distance between the AEC and PEC and the previously defined landmarks were measured. On coronal images, the distances were calculated from the thickness of the cross-section and the number of sections between the various structures. RESULTS: The AEC was identified as a separate canal in 84% of patients, and was embedded in the ethmoid roof in 16%. The PEC was seen as a separate canal in 8% and was present in the ethmoid roof in 92%. On the 1 mm thick coronal and transverse sections, a third canal was identified at the junction of the middle and posterior third of the AEC-PEC distance in both of the images. The average lengths of these canals were 4-12 mm (mean 8.2 mm) for the AEC, and 2-13 mm (mean 7.6 mm) for the PEC. CONCLUSIONS: To avoid the complications that can develop during endoscopic sinus surgery; the course, length and the angulations of the anterior and posterior ethmoidal arteries and their canals can be identified by CT in standard positions if a sufficiently thin section thickness is used. The present study has shown the exact CT localization of the AECs and PECS, which are frequently overlooked when evaluating para-nasal sinuses.

Adult↗

PubMed2004

Accurate course and relationships of the transverse facial artery in human cadavers.

Both the course and localization of the transverse facial artery are described, based upon the bilateral dissection of heads from 20 human cadavers. Its anatomical relationships with the mandibular fossa, the articular tubercle, the zygomatic arch, the parotid duct and the maxillary artery are studied and morphometric features are calculated. Furthermore, the transverse facial territory was examined. This territory was supplied by a single perforating branch in 28 cases, by two perforating branches in 10 and by three perforating branches in 2. Knowledge of the course and relationships of the transverse facial artery should help to protect this artery from the risk for transection. However, the variable course of the transverse facial artery must always be taken into consideration by the clinicians during surgical procedures.

Adult↗

PubMed2003

A clinical case and anatomical study of the innervation supply of the vastus medialis muscle.

The innervation supply to the vastus medialis (VM) muscle, a component of quadriceps femoris (QF), is provided by a branch of the femoral nerve (FN) running along the muscle. The course of the nerve from lumbar roots to the muscle has been described by many researchers. It is known to ride along the femoral vein, artery and saphenous nerve and enter the adductor canal (Hunter's canal), and then to divide into branches that supply vastus medialis and the knee joint. Femoral mononeuropathy is uncommon, and is usually due to compression in the spinal level. Hematoma in the psoas and iliacus muscles, drug abuse, lithotomy position and limb lengthening are the other associated reasons for a mononeuropathy of the femoral nerve. Isolated vastus lateralis (VL) atrophies have been reported by a few authors, suggesting that compression of the nerve and direct violation of the nerve with injections might be the reason for mononeuropathy. Isolated VM atrophy has not been previously reported. The purpose of the study was to identify the anatomical structures around the FN branch which innervates the VM muscle.

Adolescent↗

PubMed2003

Accessibility of calf perforating veins from the superficial posterior compartment: an anatomic dissection study.

OBJECTIVES: to determine the anatomic location of medial perforating veins (PVs) and their course within the compartments of the leg. MATERIALS AND METHODS: the lower extremity veins of 15 cadavers were filled with coloured latex solution. Medial PVs between the ankle and the knee were dissected out. RESULTS: in total 95 direct PVs (mean 6.3 per extremity, range 3-9) were identified and classifed as Cockett I, II, or III, proximal and distal paratibial and Boyd. Cockett PVs were present in more than half of the cases, of which the majority (except Cockett I) were located in the superficial posterior compartment. Whereas the vast majority of Cockett PVs originate from the posterior arch vein, the other perforators originate from the greater saphenous vein. CONCLUSIONS: only 62% of all PVs pass through the superficial posterior compartment. As a result, during subfascial endoscopic perforating vein surgery (SEPS), at least one third of patients require a paratibial fasciotomy in order to reach and ligate the PVs.

Chronic Disease↗

PubMed2002

Comparison of long-term quality of life after laparoscopic and open cholecystectomy.

BACKGROUND: Although many studies have compared open and laparoscopic procedures, showing many advantages in favor of the laparoscopic technique during the early postoperative period, only a limited number of reports in the literature compare the two techniques during the later follow-up period with regard to quality of life. This study aimed to compare the effects of these two cholecystectomy techniques on the quality of life and clinical outcome of the patients during long-term follow-up evaluation. METHODS: This study evaluated 200 patients who underwent cholecystectomy operations with either technique between 1993 and 1999 in our department. There were 100 patients in each group. Both groups were similar with respect to age, gender, body mass indexes, American Society of Anesthesiology (ASA) scores, and indications for surgery. The Medical Outcome Study Short Form 36 Health survey (SF-36), which includes 36 items, was used for evaluating the quality-of-life index. In addition to this, a system-specific instrument for gastrointestinal diseases was used to investigate clinical outcome. RESULTS: The mean administration time for the questionnaire was 46.8 +/- 18.7 months in the laparoscopic cholecystectomy (LC) group and 41.5 +/- 16 months in the open cholecystectomy (OC) group. Statistically significant differences were noted in the scores for all eight SF = 36 health status domains in favor of laparospopic surgery. No statistically significant difference was found for abdominal pain, location of the pain, referral to a doctor for the pain, accompanying symptoms, relieving factors for the pain, distention, and dyspeptic complaints, usage of antacid therapy, weight changes, changes in bowel habit, need for a special diet, or sexual functions between the two groups. CONCLUSIONS: The gastrointestinal clinical symptoms were similar in the two groups during the long-term follow-up evaluation, but laparoscopic cholecystectomy was found to be significantly superior to the open technique with respect to the quality of life over the long term.

Abdominal Pain↗

PubMed2002

Innervation pattern of the abductor digiti minimi muscle of the hand.

This cadaver study investigated the innervation patterns of the abductor digiti minimi in Guyon's canal. There was only one branch to the abductor digiti minimi in 22 of the 30 specimens. Two branches were found in three hands, and three branches in two. Three other variations were documented.

Adult↗

PubMed2001

Surface landmarks of brachial plexus: ultrasound and magnetic resonance imaging for supraclavicular approach with anatomical correlation.

The present study is able to describe a certain line, under which brachial plexus (BP) lies underneath in the supraclavicular region. A line drawn between midpoint of the sternocleidomastoid muscle to the midpoint of the clavicle was considered for BP. Surface landmarks were evaluated by applying ultrasound (US) on 30 volunteers (15 female, 15 male). Axial and sagittal views of BP were taken and distances between skin and BP were measured. Coronal magnetic resonance (MR) sections were taken from 7 volunteers according to the second line after applying two fat capsules on each line. The sonographic views were seen at the same line. Mean distances from skin were found as 16.5+/-0.7 mm for male and 14.5+/-0.5 mm for female volunteers. MR images were obtained bilaterally, which were parallel and posterior from sonographic lines. Surface landmarks, as presented in this study, are simple to accomplish and are not dependent on structural variations as external jugular vein.

Adult↗

PubMed2001

Comprehensive microsurgical anatomy of the jugular foramen and review of terminology.

The microsurgical anatomy of the jugular foramen was studied in 12 formalin preserved cadavers (24 foramina) and 40 dry-skulls (80 foramina). The jugular foramen was exposed by microsurgical dissection with drilling from a superior to inferior direction. Observations regarding dural architecture of the jugular foramen and relationships between neurovascular structures passing through the foramen were noted in cadavers. Normal bony construction of the foramen and its variational anatomy were examined in dry-skull specimens. Using photographs and drawings, the anatomy of the jugular foramen is presented and related terminology is discussed in the light of a literature review.

Cadaver↗

PubMed2001

Rehabilitation of stroke patients: clinical profile and functional outcome.

OBJECTIVE: To describe the nature of functional recovery of 67 Turkish survivors of first-episode stroke who were referred for inpatient rehabilitation and to identify the variables that best predict discharge functional status of these patients. DESIGN: A retrospective, descriptive study of the demographic and clinical profile and the functional status of patients with first-episode stroke. RESULTS: The mean age was 60 (11.8, SD) yr, and 35.8% were men. The mean onset-admission interval and length of stay were 62.9 and 97.1 days, respectively. The mean functional status score, as measured by the FIM instrument, at the time of admission was 75 compared with 86.7 at the time of discharge, showing a mean improvement of 11.7. Although rehabilitation gains were similar for the right- and left-side involved groups, patients with right-side paresis had lower FIM scores at the time of admission than did the left-side involved group. Significant predictors of functional status at the time of discharge were admission functional status score and onset-admission interval. CONCLUSION: Knowledge of these predictors can contribute to more appropriate treatment and discharge planning.

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

Hierarchical cluster analysis as an approach for systematic grouping of diet constituents on basis of fatty acid, energy and cholesterol content: application on consumable lamb products.

The role of dietary fat in the etiology of chronic diseases is both a qualitative and a quantitative issue. The dietary fat intake is largely influenced by behavioral and social influences on food choice. Ongoing scientific research has led to dietary recommendations with main concerns being the percentage of saturated, essential fatty acids and cholesterol with respect to total energy intake. However, the compositional complexity of food choice constituting the diet is a critical concept complicating the interpretation of epidemiologic, clinical and laboratory evidence to define the role of dietary fat in the etiology of diseases. This study was conducted on the observation of the need to better systematically classify consumable food based on complex composition and lamb meat is randomly selected as a non-specific subset for application of hierarchical cluster analysis method to obtain the dendogram using average linkage. Data on fat composition of consumable lamb prepared by different methods was obtained from USDA Nutrient Database for Standart Reference. Using agglomerative hierarchical cluster analysis lamb meat was grouped into two main clusters among which one divided into two families of which each was subdivided into two subfamilies based on fatty acids, cholesterol and energy composition. Present work may be considered as a leading study to systematically classify larger food sets. As high fat foods are rich in flavor and overall palatability, the outcome of this study may lead to behaviorally more acceptable but healthier dietary replacements. Besides future use of the results obtained may reveal the effect of complex compositional dietary influences on health and disease and may have superiority to studies questioning individual dietary items. Furthermore, hieararchial cluster analysis may be used to cluster food including other compositional data in food items like amino acids, vitamins, carbohydrates, as well.

Animals↗

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

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↗