Morphometric assessment of important landmarks on skull intended for Vidian nerve surgery.

PURPOSE: The aim of our study was to determine guide parameters for clinicians by morphometric assessment of important landmarks on cranium intended for Vidian nerve surgery. METHODS: For the study, 23 half-skull bases, 40 skull bases and 40 skulls were obtained from the Department of Anatomy, Ege University Medicine Faculty. The vertical distances were measured using a digital caliper to the nearest 0.01 mm. RESULTS: The anterior opening of the Vidian canal (pterygoid canal) was observed as oval shaped on 57 specimens (31.1%), funnel shaped on 58 specimens (31.7%), round shaped on 64 specimens (35%) and septated on 4 specimens (2.2%). Vidian canal was embedded into the body of sphenoid on 55 specimens (52.4%) (embedded type) and protruded to sphenoidal sinus on 50 specimens (47.6%) (protruded type). 21 specimens of 50 were partial and 29 specimens were total. There were dehiscences on 21 specimens of 50 protruded type on the base of sphenoidal sinus (20%). Anterior opening of the Vidian canal was assessed according to medial lamina of pterygoid process. It was located medially in 169 of the specimens (92.3%) and laterally in 14 specimens (7.7%). CONCLUSION: Vidian canal and Vidian nerve are deeply located structures on skull. Vidian canal and surrounding structures are important landmarks for microsurgery and endoscopic approaches to Vidian nerve. We consider that knowledge of anatomical features of Vidian canal and preoperative imaging by CT (computed tomography) will be supportive when choosing and planning a safe surgical approach.

Anatomic characteristics of left atrium and openings of pulmonary veins.

OBJECTIVE: Left atrium (LA) and left atrial pulmonary venous anatomy have clinical importance for atrial fibrillation (AF) and cardiac tumor surgery. A detailed anatomic knowledge of these structures may faciliate clinical evaluations. The aim of this study was to assess LA size and to demonstrate other anatomic features of LA with pulmonary vein openings in normal population. METHODS: This descriptive laboratory study was performed in 56 hearts of adult formalin fixed cadavers. The number of pulmonary vein openings into LA was recorded. Different patterns of pulmonary vein openings were described such as common ostium and additional vein. RESULTS: The roof of LA was determined as flat (75%), convex (14.3%) or concave (10.7%) in specimens. A roof pouch was present in 8.9% of specimens. The diameter of LA roof, the anteroposterior LA diameter and the LA diameter between septum and lateral wall were recorded. Thin areas on the atrial wall were observed in front of a light source around left atrial appendage orifice. Septal band was found in 7.1% of specimens. Five different patterns of pulmonary vein openings were recorded: The common arrangement, the unilateral common ostium, the unilateral additional vein, the additional vein on both side and the complex type were observed respectively in 41 specimens (73.2%), 10 specimens (17.9%), three specimens (5.4%), one specimen (1.8%) and one specimen (1.8%). CONCLUSION: It is expected that the data from present study will be a guide to the clinicians during the surgical approaches or radiologic examinations of LA and pulmonary vein openings into LA.

Human left atrial appendage anatomy and overview of its clinical significance.

OBJECTIVE: The left atrial appendage (LAA) is an important anatomic region since it is a source of thromboembolism in patients with atrial fibrillation. Although this anatomic and clinical relation it has received little attention until recent years. METHODS: This descriptive laboratory study was performed in 56 hearts of adult formalin fixed cadavers. The morphological characteristics of LAA were recorded. The distances between the orifices of left superior pulmonary veins (LSPV), circumflex artery, left anterior descending (LAD) artery, mitral valve and LAA were also measured in this study. RESULTS: The morphological appearance of the LAA was classified into two different ways. There were two types according to the first classification: slender like a crooked finger (in 73.2%) and stump-like (in 26.8%). The lobe number of LAA was two in 64.3% specimens and three in 35.7%. The types of LAA were Cactus (24%), Chicken Wing (12%), Windsock (38%) and Cauliflower (26%) according to the second classification. The LAA orifice was oval-shaped in 37.5% and round-shaped in 62.5%. The bridge on the orifice was determined in one specimen. The longest diameter of LAA orifice was 16.5±4 mm. The presence of accessory left atrial appendage was observed in one specimen. The distance between LAA orifice and oval fossa was 27.5±5.5 mm. CONCLUSION: We highlighted the anatomic features of LAA and LAA orifice. LAA diameters, shape and the relation between neighboring structures in relation to atrial fibrillation and surgical approaches were discussed.

Anatomic variations of popliteal artery that may be a reason for entrapment.

PURPOSE: The aim of this study was to demonstrate some anatomic variations of popliteal artery and its surrounding structures that may be important especially for popliteal artery entrapment (PAE) syndrome. METHODS: A cadaveric study in 46 lower limbs was performed to improve the understanding of anatomy of the popliteal artery and its relations with surrounding structures. RESULTS: The popliteal artery was lateral to the popliteal vein in four specimens (8.7%) and deep to popliteal vein in three specimens (6.5%). An aberrant accessory head of gastrocnemius was present in three specimens (6.5%). The popliteal artery and vein were tethered at the adductor magnus hiatus very tightly in one specimen (2.2%). An aberrant medial arterial course around normal medial head of gastrocnemius muscle was seen in one specimen (2.2%). CONCLUSIONS: Various anomalous anatomic relationships between muscle and arteries in the popliteal fossa results in arterial compression. We believe that a review of the anatomic variations of the popliteal artery and its surrounding structures will be beneficial for the surgical approaches in PAE.

The incidence and anatomical features of the McKenzie branch: a cadaver study.

AIM: The aim of this study was to demonstrate the morphological characteristics of the connections between the spinal accessory nerve and the anterior root of the first cervical nerve (C1) which is also called the McKenzie branch. MATERIAL AND METHODS: The cranial cervical regions of 49 specimens from 27 human cadavers were used for this study under an operating microscope. The topographical relationship of the accessory nerve to the anterior roots of C1 were studied. RESULTS: One cadaver had a connection branch (McKenzie branch) on both sides. CONCLUSION: The knowledge of the anatomy of these connections may help the clinician in determining treatments and surgical approaches in this anatomical area.

Connection types between the spinal root of the accessory nerve and the posterior roots of the C2-C6 spinal nerves.

PURPOSE: The aim of this study was to demonstrate the connection types and frequency between the accessory nerve and the posterior roots of the C2-C6 cervical nerves. METHODS: The cranial cervical regions of 49 specimens from 27 human cadavers were used for the present study under an operating microscope. RESULTS: Five different connection types between the accessory nerve and the posterior roots of the cervical nerves were recorded and photographed (types A-F). One of these types was not described previously in literature (type F). All connections between the posterior roots of the C2-C6 spinal nerves and the accessory nerve were at the level of the C2 segment. Type B was the most frequently seen type in our series. One of the rootlets of the cervical posterior root joined the accessory nerve without a connection to the spinal cord in type B. CONCLUSIONS: The clinical importance of these connections is especially noticed during the radical neck dissection as it may lead to the development of the shoulder-arm syndrome.

Branching patterns of the popliteal artery and its clinical importance.

PURPOSE: The aim of this study was to evaluate the popliteal artery branching patterns and related measurements. METHODS: A cadaveric study in forty lower limbs was performed to improve the understanding of anatomy of the popliteal artery and its main branches. RESULTS: Normal branching of the popliteal artery was present in 36 specimens (90%). High origin of the anterior tibial artery was seen in two specimens (5%). The bifurcation was at the level of proximal border of popliteus, but the posterior tibial artery originated directly from the popliteal artery in one specimen (2.5%). Trifurcation pattern with no trunk was observed in one specimen (2.5%). CONCLUSIONS: We believe that a review of the anatomic characteristics of the popliteal artery and its branches will be beneficial for the surgical approaches and the choice of suitable arterial graft sites.

Connections between the accessory nerve and the posterior root of the first cervical nerve.

The aim of this study was to demonstrate the incidence of absence of the posterior root of the first cervical nerve, and the relation between the accessory nerve and the posterior root of the first cervical nerve in Turkish population. Dissections of the accessory nerve and the posterior root of the first cervical nerve were performed in 49 specimens from 27 formalin fixed cadavers (25 male and 2 female). The type of the connections between the accessory nerve and the posterior root of the first cervical nerve was classified into four types. Type III was the most common type in present study (30.6%). There was a connection between the accessory nerve and the posterior root of the first cervical nerve in this type. The connections demonstrated in this study are important in the etiology and surgical treatment of the spasmodic torticollis.

A cadaver study on preserving peroneal nerves during ankle arthroscopy.

BACKGROUND: Ankle arthroscopy is an important diagnostic and therapeutic procedure, but neurovascular injury remains a disadvantage. By understanding the anatomy of the superficial peroneal nerve (SPN) and deep peroneal nerve (DPN) the risk of nerve injury can be minimized. METHODS: Thirty-four lower limbs from 17 cadavers were dissected to find the safest anatomical points easily during arthroscopy. RESULTS: There was a single branch of the SPN in eight of 34 specimens (23.5%); type 1), two branches in 18 (52.9%; type 2), three branches in six (17.7%; type 3) and four branches in two specimens (5.9%; type 5) at the level of the talocrural (TC) joint. The closest SPN branch to lateral border of the TC joint was 14 +/- 8.4 mm. There was no branch of the SPN or DPN medial to the extensor hallucis longus tendon in any specimen. The DPN bifurcation was 6.5 mm proximal to the TC joint in a single specimen (2.9%) and 14.5 +/- 5.5 mm distal to TC joint in 26 specimens (76.5%). In four specimens (11.8%), the DPN bifurcation was at the same level with the TC joint. In three specimens (8.8%), there was no bifurcation of the DPN. CONCLUSIONS: From this study the anatomic landmarks defining the medial midline portal are safely away from the SPN and DPN and their respective branches. Clinical studies are needed to define its safety during ankle arthroscopy. CLINICAL RELEVANCE: This study proves that the medial midline portal is the best portal for the anterior arthroscopic procedures.

The clinical importance of the relationship between the deep peroneal nerve and the dorsalis pedis artery on the dorsum of the foot.

BACKGROUND: The aim of this study was to describe the relationship between the deep peroneal nerve and the dorsalis pedis artery to help ensure a safer surgical approach in flap surgery. METHODS: The dissection of 36 cadaver lower limbs was undertaken to describe the relationship of the deep peroneal nerve to the dorsalis pedis artery in the anterior tarsal tunnel and on the dorsum of the foot. RESULTS: Four distinct relationships of the deep peroneal nerve to the dorsalis pedis artery were determined. In type 1 (36.1 percent), the artery was medial to the deep peroneal nerve in the tunnel and medial to the medial terminal branch below the tunnel on the dorsum of the foot. In type 2 (25.0 percent), the artery was medial to the deep peroneal nerve in the tunnel and lateral to the medial terminal branch below the tunnel on the dorsum of the foot. In type 3 (30.6 percent), the deep peroneal nerve and the artery were crossing over each other at multiple levels. In type 4 (8.3 percent), no medial terminal branch was observed. The artery was medial to the lateral terminal branch. CONCLUSIONS: The dorsalis pedis neurovascular island flap contains both the dorsalis pedis artery and the deep peroneal nerve. Because the design of a neurovascular free flap requires detailed knowledge of the nerve and vascular supply, the data presented here will help surgeons during the surgical approaches to the foot and ankle.

Dimensions of the anterior tarsal tunnel and features of the deep peroneal nerve in relation to clinical application.

BACKGROUND: The aim of this study was to demonstrate anatomical features of the anterior tarsal tunnel and the deep peroneal nerve and to discuss the importance of these structures for the anterior tarsal tunnel syndrome and some other surgical approaches to minimize the injury risk. METHODS: Lower limbs of 18 formalin fixed cadavers were examined. The limbs showed no evidence of pathology or trauma. RESULTS: The lateral length of the tunnel was 21.7 +/- 4.3 mm and the medial length of the tunnel was 55.0 +/- 9.0 mm. The width of the tunnel at the inferior border between the extensor hallucis longus and extensor digitorum longus tendons was 12.6 +/- 2.1 mm. The location of the deep peroneal nerve bifurcation was in the anterior tarsal tunnel in 31 specimens (86.1%) and distal to the tunnel in two specimens (5.6%). In three specimens (8.3%) there was no bifurcation because of the absence of the medial terminal branch of the deep peroneal nerve. In these three specimens, the superficial peroneal nerve distributed to the adjacent sides of the great and second toes. Bifurcation above the tunnel was not observed in our specimens. There was connection between the deep peroneal nerve and the superficial peroneal nerve in 10 specimens (27.8%) in the first interdigital space. During the observations, the presence of a fibrous band over the nerve and vessel was noted in 22 specimens (61.1%). CONCLUSIONS: We believe that a detailed anatomic knowledge of the anterior tarsal tunnel and the deep peroneal nerve will be of help during surgical approaches to this area and the diagnosis of the problems related to the peripheral nerves on the dorsum of the foot.

Localization of the marginal mandibular branch of the facial nerve.

The aim of this study was to observe the course of the marginal mandibular branch of the facial nerve (MMBFN) in relation to the inferior border of the mandible and parotid gland and its relevance to surgical procedures such as rhytidectomy and parotid gland surgery. In this study, 50 specimens were dissected. The relationships between the MMBFN and the inferior border of the mandible were recorded and analyzed. We found that posterior to the facial artery, the MMBFN ran above the inferior border of the mandible in 37 (74%) of the specimens. In 11 (22%) specimens, below the inferior border of the mandible it was divided into two branches at the crossing point with the facial artery. In 2 (4%) specimens the MMBFN divided into two branches at the point of emergence from the parotid gland. There were no statistical differences between the left and right sides, and both sexes. The MMBFN is one of the most vulnerable branches to surgical injury because of its location. For this reason, the surgeons who are willing to operate on this area, especially for the rhytidectomies, should have a true knowledge about the anatomy of this branch.

Asterion as a surgical landmark for lateral cranial base approaches.

INTRODUCTION: When approaching the posterior fossa and posterolateral cranial base, surface landmarks are helpful in locating the junction of the transverse and the sigmoid sinus. MATERIAL AND METHODS: On 100 skull halves a 2mm drill bit was externally placed over the asterion and was drilled through the bone perpendicular to the skull surface. Various positions of the asterion and its distance from the root of the zygomatic process of the temporal bone, from the suprameatal crest and the mastoid tip were investigated. RESULTS: The position of the asterion has been found to be located superficial to the transverse-sigmoid sinus junction in 87% of all samples, inferior to the transverse-sigmoid sinus junction in 11% and superior to the transverse-sigmoid sinus junction in 2%. The distance from the asterion to the root of the zygoma has been determined to be 54.6+/-5.5mm. The distance between asterion and Henle's spine was 45.2+/-5.2, and from asterion to Frankfurt Horizontal Plane 15+/-7.5mm. CONCLUSION: Asterion varies regarding its cephalocaudal position. The findings of this study might have direct consequences for transmastoid and retrosigmoid approaches for microvascular trigeminal root decompression and combined petrosal approaches.

Anatomic landmarks of the buccal branches of the facial nerve.

The aim of this study was to classify the buccal branches of the facial nerve in relation to the parotid duct and its relevance to surgical procedures such as rhytidectomy and parotid gland surgery. In this study, 30 cadaver heads (60 specimens) were dissected. The vertical and horizontal relationships between the buccal branches of the facial nerve and tragus, and parotid duct were recorded and analyzed. The buccal branches of the facial nerve were classified into four types: Type I: a single buccal branch of the facial nerve at the point of emergence from the parotid gland and inferior to the parotid duct. Type II: a single buccal branch of the facial nerve at the point of emergence from the parotid gland and superior to the parotid duct. Type III: buccal and other branches of the facial nerve formed a plexus. Type IV: two branches of buccal branch; one superior and one inferior to the duct at the point of emergence from the parotid gland. The buccal branches of the facial nerve are very vulnerable to surgical injury because of its location in the midface. For this reason, the surgeons who are willing to operate on this area should have a true knowledge about the anatomy of these branches.

The distribution of the superficial peroneal nerve on the dorsum of the foot and its clinical importance in flap surgery.

BACKGROUND: The superficial peroneal nerve (SPN) and its branches are at risk during surgical exposures. Our study aimed to demonstrate the distribution of the SPN on the dorsum of the foot to aid in surgical procedures close to this nerve. METHODS: The SPN was dissected in 30 cadaver lower limbs (13 male and two female). RESULTS: The variations in the distribution of the nerve were classified into seven types. CONCLUSION: A detailed knowledge of the branching patterns of the SPN may help to decrease iatrogenic injury to this nerve.

Multiplicity of the variations in ventral branches of abdominal aorta.

Numerous variations of the ventral branches of the abdominal aorta were observed during routine dissection of the abdominal region in a 63-year-old male cadaver in the Department of Anatomy at Ege University Medicine Faculty. The branches of the celiac trunk were arising from two different trunks as the upper and below ones. The trunk at the upper was gastrophrenic trunk and the trunk at the below was hepatosplenic trunk. The superior mesenteric artery arose from the front of the abdominal aorta just below the hepatosplenic trunk. The relations of the right testicular artery was also unusual. Although the variations of the abdominal aorta branches are common the present case is interesting because of the multiplicity of the variations. The knowledge of these variations could be useful for clinicians for recognition and protection.

Reduced hippocampal volume in drug-free depressed patients.

A number of studies have used magnetic resonance imaging to examine the volumetric differences in temporal lobe structures especially the hippocampus in patients suffering from major depressive disorder (MDD). Although some studies reported lower hippocampal volume, others did not. It is proposed that the inconsistency among studies may be due to the heterogeneity of patients and antidepressant treatment during scanning. In this study, we aimed to evaluate the hippocampus in drug-free patients. Twenty-four patients (6 males and 18 females) diagnosed as having MDD according to the DSM-IV criteria and 24 healthy controls (6 males and 18 females) were included in the study. Eleven of the patients had their first mood episode and were drug-naïve. Other patients were drug-free for at least 4 weeks. The Hamilton depression rating scale (HAM-D) assessed the severity of depression. Magnetic resonance imaging was performed on a 1.5-T MR unit. The Cavalieri method of modern design stereology in conjunction with point counting was used to estimate hippocampal volume. The data were evaluated by a repeated measure of ANOVA and the intracranial volume was taken as a covariate. A significant hippocampal volume difference was observed between the patients and healthy controls (F=4.43, df=1.45, P<0.05); however, laterality had no effect on the volumes (F=0.03, df=1.45, P>0.05). The left hippocampus of patients was significantly lower than those of controls (t=1.98, df=46, P<0.05). Correlation analysis showed a correlation between HAM-D scores and the right hippocampal volume. The results of this study indicate that hippocampus volume is reduced in depressed patients especially in the left side. This finding in the drug-free depressed outpatients without a history of alcohol dependence supports previous studies that have reported lower hippocampal volume.

Anatomic guides to precisely localize the zygomatic branches of the facial nerve.

UNLABELLED: Descriptions of superficial anatomic landmarks for the identification of the zygomatic branches of the facial nerve, and their relevance for plastic surgery, are lacking in the literature. This paper provides such a description and discusses its relevance to facial surgery. MATERIALS AND METHODS: Sixty-six specimens, including the parotid region, from 33 adult cadavers were dissected and studied. All specimens were fixed in formaldehyde, and the superficial tissues were removed and the zygomatic branches of the facial nerve, the parotid gland, the tragus and the lateral palpebral commissure were identified. The vertical and horizontal relationships were recorded and analyzed. RESULTS AND CONCLUSIONS: A total of 69.7% of the cadavers had two branches, 25.8% had three branches, and 4.5% had a single zygomatic branch. The mean horizontal distance of the zygomatic branch (the most upper one) as it emerged from the anterior border of the parotid gland and the tragus was 30.71 mm, whereas the mean vertical distance of the zygomatic branch from the midpoint between the tragus and the lateral palpebral commissure was 19.29 mm. The branching patterns with the buccal branches were reported. There were no statistical differences between the left and right sides or between the sexes. The zygomatic branches of the facial nerve were always under the oblique line between the tragus and the lateral palpebral commissure and have a close relationship with the buccal branches of the facial nerve under this anatomic landmark. Application of the results in facial surgery is discussed.

The Distribution of the Superficial Peroneal Nerve on the Dorsum of the Foot and its Clinical Importance in Flap Surgery.

BACKGROUND: The superficial peroneal nerve (SPN) and its branches are at risk during surgical exposures. Our study aimed to demonstrate the distribution of the SPN on the dorsum of the foot to aid in surgical procedures close to this nerve. METHODS: The SPN was dissected in 30 cadaver lower limbs (13 male and two female). RESULTS: The variations in the distribution of the nerve were classified into seven types. CONCLUSION: A detailed knowledge of the branching patterns of the SPN may help to decrease iatrogenic injury to this nerve.

The anatomic barriers in the coronary sinus: implications for clinical procedures.

BACKGROUND: Coronary sinus (CS) catheterization is often used in cardiac resynchronization therapy. Failure to enter the CS is the most common reason for LV pacing lead implant failure. METHODS: We evaluated the anatomic barriers, Thebesian and Vieussens valves, the CS and its tributaries in 52 adult human cadaver hearts. RESULTS: The average diameter of CS ostiums was 9.47 mm. In 20 of the hearts heavier than 300 g, the average CS os diameter was 10.76 mm, whereas in the remaining hearts was 8.72 mm (p<0.005). The Thebesian valves were observed in 35(67%) of the hearts. In 39(75%) of the hearts Vieussens valves were observed and noted that 6(11%) of them were qualitatively well developed and 33(63%) diminutive. Twenty cases (38%) had 3 vein branches, 19(37%) had 4 branches, 6(11%) had 5 branches, 6(11%) had 2 branches and 1(2%) had 6 branches between great and middle cardiac veins. The anatomic barriers in coronary sinus i.e., Thebesian and Vieussens valves and their branchings were evaluated and found optimal, suboptimal and worst for catheterization in 33, 15 and 4 Thebesian valves; 40, 8, 4 Vieussens valves, respectively. The coronary sinus tributaries between great and middle cardiac veins were found to be optimal, suboptimal and worst for catheterization in 88, 60 and 38 veins, respectively. CONCLUSIONS: Careful evaluation of anatomic barriers is important for treatment success. Thus, knowledge of these functional anatomic features and barriers allows for better utilization of the human coronary sinus for diagnostic and therapeutic purposes.