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Marios Loukas

Publications and source records attributed to Marios Loukas.

At least 19 recordsLinked to original sources
PubMed2007

Observations at the craniocervical junction with simultaneous caudal traction of the spinal cord.

INTRODUCTION: Some have opined that caudal traction of the spinal cord may result in caudal descent of the hindbrain. MATERIALS AND METHODS: In fresh adult cadavers (n = 12; less than 6 h postmortem) with no CIM, distal tension (75 N) was applied to the conus medullaris with simultaneous observation of the cervical spinal cord, brainstem, and hindbrain and their relationship to the foramen magnum per occipital craniectomy and removal of the posterior arch of C1. RESULTS: After lumbar laminectomy in cadavers, caudal tension on the cord (conus medullaris) demonstrated negligible movement (less than 1 mm) of the caudal brain stem and cervical spinal cord. No movement of the cerebellar tonsils was identified. Moreover, after transection of the lumbar dural cul-de-sac and lumbar spinal dural nerve sleeves, distal traction produced only 2 to 3 mm of caudal descent of the brain stem and cervical spinal cord. Again, no movement of the cerebellar tonsils was visualized. CONCLUSIONS: Our findings in a fresh cadaveric model suggest that it is unlikely that caudal fixation of the distal spinal cord results in inferior displacement of the cerebellar tonsils, and a resultant Chiari I malformation or that transection of the filum terminale may reverse tonsillar ectopia. In vivo animal studies are now necessary to verify our findings.

Aged↗
PubMed2007

False tendons: an endoscopic cadaveric approach.

False tendons (FTs) have been extensively described and recognized by gross anatomic studies. However, in the clinical setting the recognition of FTs is limited to the use of echocardiography. We examined 200 formalin fixed adult hearts, with gross dissections. In addition, 90 of these specimens were also examined with ultrasonographic and endoscopic techniques. Gross examination was able to identify FTs in 128 (62%) specimens. The total number of FTs observed, was 248 and was classified into five types according to their location. In Type I (92, 37.1%) the FT was located between the posteromedial papillary muscle and the ventricular septum. In Type II (55, 22.1%) the FT was located between the two papillary muscles. Type III (41, 16.5%) was classified as an FT between the anterolateral papillary muscle and the ventricular septum. The FT in Type IV (31, 12.5%) was observed to connect between the ventricular septum and the free wall and lastly in Type V (29, 11.6%) the FTs were found to be weblike with three or more points of insertion. When using all three techniques (n = 90), gross dissection and endoscopy were able to identify FTs in 62.2% of specimens while echocardiographic imaging was only able to identify FTs in 27.7% of specimens. Of the 114 FTs detected grossly and endoscopically, echocardiography was only able to identify 46 (40.3%). Therefore, the overall sensitivity of echocardiography for detecting left ventricular FTs was only 40.3%, compared to 100% for endoscopy. Based upon the ability or lack thereof of echocardiography to detect certain topographical patterns, we have created a small series of subtypes for the FTs. Histologically, in 30% of the FTs, conduction tissue fiber was observed to be present, which may implicate them in the appearance of arrhythmias.

Adult↗
PubMed2007

Wilhelm Erb and Erb's point.

Wilhelm Erb is well known for his early contributions to the field of neurology and was an eminent physician of his time. One area described by him and that still bears his name is Erb's point. This point located just superior to the clavicle was used by Erb to transcutaneously elicit contractions of various proximal arm muscles with electrical stimulation. Many have mistakenly interchanged the terms "Erb's point" and "nerve point" when describing the point of emergence of the cutaneous branches of the cervical plexus near the posterior border of the sternocleidomastoid muscle. We present a brief history of Erb's adult life and review his original description of his supraclavicular point and contrast this to the so called nerve point of the posterior cervical triangle. Clinicians and anatomists should be aware of the discrepancy often found in the literature between these two terms.

Anatomy↗
PubMed2007

Branches of the petrous and cavernous segments of the internal carotid artery.

Microsurgical approaches to the skull base require a thorough knowledge of the microvasculature of this region. Interestingly, most standard texts of anatomy do not mention the branches of the internal carotid artery as it travels through the temporal bone and cavernous sinus. Although small and with often conflicting descriptions, these arterial branches may be of significance when contributing to the vascular supply of such pathological entities as meningiomas and vascular malformations. Furthermore, multiple anastomoses exist between these branches and branches of the external carotid artery, thus providing a potentially important collateral circulation between these two systems and thus retrograde flow needed to maintain the patency of the distal internal carotid artery (ICA) when this vessel is obstructed proximally. We review the literature regarding these branches of the internal carotid artery and their clinical significance.

Carotid Artery, Internal↗
PubMed2007

Benign fibrous histiocytoma of the skull base. Case report.

The authors report the case of benign fibrous histiocytoma (BFH) of the skull base in an 11-month-old girl. During draining for a middle ear infection, the child was noted to have an anomalous mass in the skull base. On magnetic resonance imaging studies a soft-tissue mass of the skull base primarily involving the regions of the temporal and occipital bones was discovered. Results of a surgical biopsy were consistent with BFH. At the most recent follow-up examination--18 months postoperatively--the child was noted to be asymptomatic with no gross increase in tumor size.

Biomarkers, Tumor↗
PubMed2007

Foramen arcuale: anatomical study and review of the literature.

OBJECT: The neurosurgical literature is lacking information on the so-called foramen arcuale. When this foramen is present, the vertebral artery (VA) travels through it after exiting the transverse foramen of the atlas and prior to entering the cranium. METHODS: The authors performed a study in 60 cadavers to determine the incidence of the foramen arcuale and ascertain morphometric information on its anatomy. In specimens in which the foramen arcuale was observed, the authors studied the relationship between it and the VA. The authors identified a foramen arcuale in 5% of specimens. The mean length and thickness of the osseous struts that converted the groove for the VA into the foramen arcuale were 7.0 and 2.0 mm, respectively. The mean area of the identified foramina was 14.2 mm2. The mean area of the ipsilateral C-1 transverse foramina was 18 mm2 in specimens with a foramen arcuale. The mean measurements of the proximal, intraforaminal (foramen arcuale), and distal diameter of the V3 segment of the VA at the level of the foramen arcuale were 6, 4, and 5 mm, respectively. In all specimens the authors noted that the intraforaminal part of the V3 segment was grossly compressed. CONCLUSIONS: The authors found that the foramen arcuale may compress the V3 segment of the VA. Based on their postmortem study, however, they cannot conclude that compression at this location results in symptomatic VA insufficiency. Based on their review of the literature, it seems that symptomatic compression of the VA at this location may be alleviated in some patients with decompressive procedures.

Cadaver↗
PubMed2006

Superior phrenic artery: an anatomic study.

The majority of anatomical textbooks offer very little information concerning the anatomy and distribution of the superior phrenic artery (SPA). However, in the last decade, a number of reports have appeared with reference to the transcatheter arterial chemoembolization of the collateral arterial supply of hepatic carcinoma (HC). Considering the potential role of the SPA as a source of collateral blood supply to HC, the aim of this study was to identify the origin and distribution of the SPA. One hundred formalin-fixed adult cadavers with no evidence of significant gross diaphragmatic pathology were examined. The right SPA originated from the aorta (R1) in 42%, as a branch of the proximal segment of the 10th intercostal artery (R2) in 33%, and as a branch of the distal segment of the 10th intercostal artery (R3) in 25%, of the specimens. The left SPA originated from the aorta (L1) in 51%, from proximal segment of the left 10th intercostal artery (L2) in 40%, and from the distal segment of the left 10th intercostal artery (L3) in 9%, of the specimens. In types R1, R2, L1 and L2 the SPA terminated, after a short course, within the medial and posterosuperior surfaces of the thoracic diaphragm and diaphragmatic crura. Conversely, in types R3 and L3 the lateral origin of the SPAs confined the ultimate distribution of the vessels to the posterior surface of the diaphragm. These findings could provide a better understanding of the anatomy and distribution of the arterial supply of the diaphragm and the potential involvement of the right SPA as an extrahepatic collateral artery developed in HC.

Aged↗
PubMed2006

Multiple variations of the hepatobiliary vasculature including double cystic arteries, accessory left hepatic artery and hepatosplenic trunk: a case report.

Anatomical variations in the origins and branching patterns of the hepatobiliary arterial system may be encountered during both conventional surgical and laparoscopic cholecystectomy. We report a rare case of double cystic arteries arising from both the right hepatic artery and the proximal part of the posterior superior pancreaticoduodenal artery. Additional variations consisting of an accessory left hepatic artery arising from a left gastric which in turn arose from the descending aorta superior to the origin of the celiac trunk and a small left hepatic artery arising from the hepatic proper artery were also noted. The celiac trunk bifurcated into the splenic artery and the common hepatic artery forming a hepatosplenic or lienohepatic trunk. The possible clinical implications are discussed.

Cadaver↗
PubMed2006

Pseudoaneurysm of the membranous septum, case report and review of the literature.

Pseudoaneurysm (dissecting aneurysm) of the membranous septum is a rare occasion. Clinically, aneurysms and pseudoaneurysms not only have the potential to reduce ventricular size, but also can be further complicated by rupture of the aneurysm and by promoting tricuspid insufficiency, aortic valve prolapse, ventricular outflow tract obstruction, and bacterial endocarditis. We describe a case in which a pseudoaneurysm of the membranous septum was identified protruding into the left outflow tract.

Aged↗
PubMed2006

A detailed observation of variations of the facial artery, with emphasis on the superior labial artery.

The reconstruction of lip defects through the use of the Abbe flap and other lip flap procedures involves surgical manipulation of one of the major branches of the facial artery, specifically the superior labial artery (SLA). We examined 284 hemifaces derived from 142 formalin fixed cadavers. Observations regarding the distribution patterns of the facial artery were recognized and categorized into five Types, labeled "A" through "E". Type A (135, 47.5%): facial artery bifurcates into SLA and lateral nasal (the latter gives off inferior and superior alar and ends as angular); Type B (110, 38.7%): similar to Type A, except lateral nasal terminates as superior alar (angular artery is absent); Type C (24, 8.4%): facial artery terminates as SLA; Type D (11, 3.8%): angular artery arises directly from facial arterial trunk rather than as the termination of lateral nasal, with the facial artery ending as superior alar; Type E (4, 1.4%): facial artery terminates as a rudimentary twig without providing any significant branches. Furthermore, we were able to categorize variations within each Type. Sub-Type variations were examined in Types A through C (A: 1-7; B: 1-4; C: 1-3). Our aim was to equip both the anatomist and surgeon with a more thorough understanding of the vasculature of the face, as well as to enable plastic surgeons to have a more confident approach to reconstructive procedures in this region.

Adult↗
PubMed2006

Gross anatomical, CT and MRI analyses of the buccal fat pad with special emphasis on volumetric variations.

The use of the buccal fat pad (BFP) has increased in popularity in recent years because of its reliability, ease of harvest, and low complication rate during oral and maxillofacial procedures. The aim of this study was to evaluate the volumetric variations of the BFP with a CT and MRI, as well as the thickness, weight and volume with conventional methods. We have examined the BFP from 80 formalin fixed adult cadavers (mean age 59) derived from both males (45) and females (35). In addition, we also examined 20 cadaveric BFPs using MR and CT imaging. Digital image analysis software was used to measure the volumetric distribution and to characterize the morphology of BFP. The BFP can be divided into three lobes (anterior, intermediate, and posterior) and has four extensions (buccal, pterygoid, pterygopalatine, and temporal). The BFP is fixed by six ligaments, to the maxilla, posterior zygoma, inner and outer rim of infraorbital fissure, temporalis tendon, and buccinator membrane. The mean volume in males was 10.2 ml and ranged 7.8-11.2 ml, while in females the mean volume was 8.9 ml and ranged 7.2-10.8 ml. Additionally, the mean thickness was 6 mm, with a mean weight of 9.7 g. These facts may be important when considering the use of the BFP in reconstruction, particularly whether the correct volume has been removed from each side in aesthetic, oral, or maxillofacial procedures.

Adipose Tissue↗
PubMed2006

Anatomical and surgical considerations of the sacrotuberous ligament and its relevance in pudendal nerve entrapment syndrome.

In view of the paucity of literature, this study was undertaken to reappraise the gross anatomy of the sacrotuberous ligament (STL), with the objective of providing an accurate anatomical basis for clinical conditions involving the STL. We studied the gross anatomy of the STL in 50 formalin fixed cadavers (100 sides) during the period of 2004-2005. All specimens exhibited an STL with a ligamentous part and (87%) of specimens exhibited a membranous (falciform) segment, which extended towards the ischioanal fossa. The variations of the falciform extensions were classified into three types. In Type I (69%), the falciform process extended towards and along the ischial ramus to terminate at the obturator fascia. In Type II (108%), the falciform process extended along the ischial ramus, fused with the obturator fascia and continued towards the ischioanal fossa. In addition, the medial border of the falciform process descended to fuse with the anococcygeal ligament, forming a continuous membrane. Lastly, in Type III (13%), the falciform process of the STL was absent. The above mentioned data could have an important implication to the understanding of the relationship between the pudendal nerve and the sacrotuberous ligament and their relevance to pudendal nerve entrapment syndrome.

Aged↗
PubMed2006

The gross anatomy of the extrathoracic course of the intercostobrachial nerve.

Recent reports emphasize the importance of preserving the intercostobrachial nerve (ICBN) during surgical procedures (i.e., mastectomy, axillary clearance). However, a limited number of scientific reports explore the surgical anatomy of this nerve. We dissected 100 adult human formalin-fixed cadavers (200 axillae). In all the cadavers the ICBN was present with variant contributions from intercostal nerves T1, T2, T3, and T4. The arrangements of the ICBN were typed as I through VIII. The components of Type I (45% or 90 of our specimens) included a branch to the posterior antebrachial cutaneous nerve, a branch to the anterior and lateral parts of the axilla, a branch to the medial side of the arm, and a branch to the medial antebrachial cutaneous nerve. Type II (25%) describes the ICBN arising from T2 and giving off a branch to the brachial plexus. In Type III (10%), lateral cutaneous branches of T2 and T3 fuse as a common trunk and then split immediately after exiting the intercostal space to form an ICBN. In type IV (5%), T2 and T3 join distally to form an ICBN that ends as its terminal branches. Type V (5%): T3 joins T2 from the same intercostal space proximally, with Type VI (3%) showing a very proximal branching of the sensory terminal nerves. Type VII (5%) displayed a contribution from T3 and a branch to the brachial plexus with multiple terminating branches. A contribution from T3 and T4 and a branch to the brachial plexus with multiple branches of termination comprised Type VIII (2%).

Aged↗
PubMed2006

Anatomical examination of the recurrent artery of Heubner.

There is considerable inconsistency in the description of the origins, dimensions, and course of the recurrent artery of Heubner (RAH). The RAH frequently supplies parts of the basal ganglia and the anterior limb of the internal capsule and can be damaged with improper clip placement during repair of aneurysms near the anterior communicating artery. Thus, further elaboration of the anatomical descriptions of the RAH is necessary. The gross anatomy of the RAH was studied in 69 human brain hemispheres. RAH was found as a single vessel in 53 hemispheres (77%), as double arteries in 12 hemispheres (17%), and was absent in 4 hemispheres (6%). The origin of the RAH was from the junction of the anterior cerebral artery and anterior communicating artery in 48 (62.3%) hemispheres, from the proximal A2 segment of the anterior cerebral artery in 18 (23.3%) hemispheres and from the A1 segment in 11 (14.3%) hemispheres. The diameters of the artery ranged from 0.2 to 1.3 mm with a mean of 0.8 mm, while the length ranged from 0.9 to 3.8 cm with a mean of 2.4 cm. The above data may provide important information to neurosurgeons operating in this area, as well as to neuroanatomists teaching the vascular supply of the brain.

Anterior Cerebral Artery↗
PubMed2006

An unusual innervation of pectoralis minor and major muscles from a branch of the intercostobrachial nerve.

Variations of the branching pattern of the intercostobrachial nerve have been known to complicate dissection during mastectomy and other procedures involving the axilla. We present a unilateral case of a 73-year-old Caucasian female, in which the intercostobrachial nerve gives rise to an additional medial pectoral branch, which partially innervates the pectoralis minor muscle, as well as the abdominal head of pectoralis major muscle. Clinical consequences of such a variation may include motor losses, in addition to the commonly reported sensory losses, resulting from accidental or intentional dissection of the intercostobranchial nerve.

Aged↗