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The cystic vein, a portion of biliary anatomy whose insignificance in open gallbladder surgery led to its being relegated to mythology, has been rediscovered by the magnified view of laparoscopic surgery. Its presence is an important anatomic feature that helps distinguish between cystic duct and common hepatic duct, thus diminishing the risk of inadvertent bile duct injury during laparoscopic cholecystectomy.
The canal of the posterior ampullar nerve is located between the inferior part of the internal acoustic meatus and ampulla of the posterior semicircular canal. It permits a more accurate localisation of the underlying labyrinth in inner-ear surgery. An anatomical and radiological study was undertaken to determine the importance the relationship between the canal and the labyrinth. Ten dry and 10 cadaveric temporal bone dissections, together with 20 high resolution CT scans of the same temporal bones were studied in an attempt to describe the anatomy of the canal of the posterior ampullar nerve. The length of the canal of the posterior ampullar nerve, the length of internal acoustic meatus, and distances from porus acusticus to the singular foramen and the transverse crest, and from the singular foramen to the vestibule and transverse crest, and from operculum to the sigmoid sinus and to the porus acusticus were measured. During the transmeatal posterior cranial fossa approach using the canal of the posterior ampullar nerve as a landmark enables more bone to be safely removed from the internal acoustic meatus thus preserving hearing.
This investigation describes the variability in location of functionally important persylvian landmarks and of the calcarine sulcus within the Talairach stereotaxic grid, a system frequently used for cortical localization in functional images. Twenty healthy volunteers (40 hemispheres) had MR imaging under stereotaxic conditions. Outlines of the following structures were directly identified on sagittal 5-mm MR sections and marked on individual proportional grid overlays: inferior central sulcus, inferior precentral sulcus, inferior postcentral sulcus, anterior ascending ramus and posterior rami of the sylvian fissure, superior temporal sulcus, and calcarine sulcus. Maximal variation zones for these landmarks were defined by superimposition of the standardized individual data on a standard stereotaxic grid. The sulcal variation zones measured 1.5-2.0 cm. The findings indicate that macroanatomic individuality in the cerebral surface cannot be accounted for adequately by proportional coordinates, and that this method does not allow precise definition of anatomically based regions of interest for functional imaging. Instead, MR mapping of the individual sulcus pattern should be used to generate brain templates.
OBJECTIVE: Conventional cephalometry is an inexpensive and well-established method for evaluating patients with dentofacial deformities. However, patients with major deformities, and in particular asymmetric cases are difficult to evaluate by conventional cephalometry. Both two- and three-dimensional computed tomography (CT) have been proposed to alleviate some of these difficulties. Only a few studies using metallic markers have indicated 3-D CT to be a useful diagnostic method, whereas no studies have evaluated the reliability of the anatomic cephalometric points used in 3-D CT. The aim of our study therefore was to compare the reliability of anatomic cephalometric points from conventional cephalograms and 3-D CT. METHODS: Nine human dry skulls were CT scanned. In addition standard lateral and frontal cephalograms were obtained. The CT scans were 3-D image reconstructed, and the cephalometric points were recorded as x, y, and z co-ordinates by two investigators. Computerized cephalometrics were performed-on the lateral and frontal cephalograms. Intra- and interindividual variations were calculated for each method and tested for statistical significance. RESULTS: Lateral cephalogram measures were more reliable than 3-D CT, with interobserver variations less than 1 mm for most points compared to about 2 mm for 3-D CT. Lateral cephalometrics also showed significantly less interobserver variation for six variables. This was, however, less obvious when 3-D CT was compared to frontal cephalograms. Frontal cephalometrics showed significantly less interobserver variation for three of the investigated variables. CONCLUSIONS: For standard lateral and frontal cephalometric points, there is no evidence that 3-D CT is more reliable than the conventional cephalometric methods in normal skull, and the benefit of 3-D CT cephalometric is indicated to be in the severe asymmetric craniofacial syndrome patients, as conventional cephalometrics is known to be inferior in these cases.
UNLABELLED: The site for needle insertion in femoral nerve block varies significantly among various descriptions of the technique. To determine the site with the highest likelihood of needle-femoral nerve contact, femoral nerve block was simulated in a human cadaver model (17 femoral triangles from 9 adult cadavers). Four 20-gauge 50-mm-long styletted catheters were inserted at four frequently suggested insertion sites for femoral nerve block. At the levels of inguinal ligament and the inguinal crease, the catheters were inserted adjacent to the lateral border of the femoral artery and 2 cm lateral to the femoral artery. During anatomical dissection, we studied the number of catheter-nerve contacts for each of the four insertion sites, and relationships between the femoral nerve and other anatomical structures of relevance to femoral nerve block. Insertion of the needle at the level of the inguinal crease, next to the lateral border of the femoral artery resulted in the highest frequency of needle-femoral nerve contacts (71%). Of note, the femoral nerve was significantly wider (14.0 vs 9.8 mm) and closer to the fascia lata (6.8 vs 26.4 mm) at the inguinal crease than at the inguinal ligament level. We conclude that needle insertion at the inguinal crease level immediately adjacent to the femoral artery produced the highest rate of needle-femoral nerve contacts. The main factors influencing this result include the greater width of the femoral nerve and the more predictable femoral artery-femoral nerve relationship at the inguinal crease level, compared with the inguinal ligament level. IMPLICATIONS: Insertion of a needle at the inguinal crease level and immediately adjacent to the lateral border of the femoral artery results in a high rate of needle-femoral nerve contact.
Activation sequence in the atria was investigated in 35 dogs. The atria were studied as four regions, and activation sequence in one region was determined in each experiment. In each region 60 electrograms were recorded simultaneously from bipolar electrodes. The maximal first derivative of the electrograms was taken as activation time. Dried atrial specimens, which permitted identification of pectinate muscles, crista terminalis, and the axis of fiber direction, were prepared. Nonuniform activation was demonstrated with more rapid conduction over the long axis of fiber direction and in Bachmann's bundle, crista terminalis, and pectinate muscles. These regions of rapid conduction were the same during sinus rhythm and ectopic and retrograde activation. Findings confirm the presence of paths with relatively rapid conduction in the atria and demonstrate that these are related to gross anatomic features. Findings also demonstrate that the paths are accessible to activation from multiple sites rather than insulated conduction paths with limited sites for entry and exit of activation.
The aim of this study was to examine the relationships of the surgical landmarks on the lateral surface of the mastoid bone with the landmarks in a deeper location. Simple mastoidectomy was carried out without drilling over the linea temporalis inferior (LTI) on 20 adult temporal bones. The suprameatal spine, i.e., Henle spine (HS), variants were noted. Morphometric measurements were performed between these surgical landmarks, and their variations with pneumatization or HS types were evaluated. Three types of HS were identified: triangular, crest, absent. The HS-lateral semicircular canal distance was 15 mm on average and longer in bones with a triangular HS than a crest type HS (16.4 vs. 14.3 mm). The LTI was found to be located on average 4.7 mm inferior to the middle fossa dural plate (MFD). The LTI-MFD distance had a tendency to be longer in bones without an HS than with a crest type of HS (5.9 vs. 3.9 mm). Chorda tympani emerged from the facial nerve at the stylomastoid foramen in five specimens (25%). This anatomical organization was not correlated with the type of HS. Korner's septum (KS) was identified in nine bones (45%). It was present in eight of 16 (50%) bones with good pneumatization. No tendency for the existence of KS was found for any specific type of HS. This study confirms that the mastoid antrum is located 15 mm deep to the lateral surface of the mastoid bone. It should be expected to be longer in bones with a triangular HS. In addition, the MFD is located on average 5 mm above the LTI, which could be useful information for beginners or inexperienced surgeons. The ear surgeon should anticipate that the MFD might be longer in bones without an HS.
Described are: 1. Length and width values of the rhomboid fossa. 2. Number and development of the transverse and oblique striae in the bottom area of the fourth ventricle. 3. The course of the facial nerve inside the pons and the medulla oblongata. 4. Some fiber tracts and nuclei in the tegmentum pontis and the medulla oblongata. 5. A very thick arcuato-cerebellar tract. 6. The results of our investigations are compared with descriptions of other researchers.
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.
PURPOSE: Approximately 50 percent of all patients with resected colorectal carcinoma have tumors with pT3 status; however, no subclassifications of the penetration depth have been proposed. The purpose of this study is to evaluate the significance of histologic invasion beyond subserosal elastic lamina by colorectal carcinoma for postoperative recurrence and long-term survival after resection. METHODS: pT3 colorectal carcinomas located above the peritoneal reflection were retrospectively classified into two depth grades (subserosal elastic lamina classification). Namely, "pT3-shallow" is defined as tumors those are confined above the subserosal elastic lamina, and "pT3-deep" is defined as tumors those penetrate beyond it. Based on subserosal elastic lamina classification, the 325 consecutive patients who underwent resections were divided into two groups, and then the clinicopathologic features, incidence of postoperative recurrence, and survival rates were compared between the two groups. RESULTS: The overall postoperative recurrence rate in the pT3-deep group (35.2 percent) was higher than that in the pT3-shallow group (20.8 percent). In detail, liver and peritoneal recurrence rates in the pT3-deep group (19.7 percent, 7.7 percent, respectively) were higher than those in the pT3-shallow group (9.4 percent, 2.0 percent, respectively). There was a strong difference ( P < 0.0001) in overall survival rate between the pT3-deep group (5-year survival of 57.0 percent) and the pT3-shallow group (5-year survival of 78.6 percent). Multivariate analysis revealed that synchronous hematogenous metastasis ( P < 0.0001), lymph node metastasis ( P < 0.05), venous invasion ( P < 0.01), and subserosal elastic lamina classification ( P < 0.05) were the independent prognostic factors for postoperative survival. CONCLUSIONS: The newly proposed subserosal elastic lamina classification is a useful subclassification to predict the prognosis of patients with resected pT3 colorectal carcinomas.
A vein is described that allows easy identification of the fifth thoracic vertebra of the rat. Leading from the dorsal hibernating gland to the azygos vein, the vessel was present in each of 135 rats.
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We investigated age-related spatial relations of the osseous epipharynx--the region between the vomer and the anterior border of the great occipital foramen (basion) on 60 skulls of both sexes: 16 adult (age range 21-59 years), 19 aged (age range 60-86 years), and macerated occipital bones, sphenoid bones, and vomers in 25 specimens of children disarticulated skulls aged 1-15 years. We measured the distances basion-tuberculum pharyngeum, tuberculum pharyngeum-ala vomeris, tuberculum pharyngeum-crista choanalis vomeris, basion-crista choanalis vomeris, width of the pars basilaris at the level of the tuberculum pharyngeum, narrowest width of the pars basilaris, width at the level of pyramidal apexes; and width at the level of laminae mediates processus pterygoidei of the sphenoid bone. We found a statistically significant increase in the frontal and sagittal measurements of the osseous epipharynx increasing from childhood to adulthood, without further significant changes into old age. In the aged adult and skulls, the distance from the tuberculum pharyngeum to the basion was half the distance to the vomer, whereas in children the ratio of these distances was 1:3. The major difference in the bony landmarks of the osseous epipharynx between children and adults were the attachments of muscles, m. longus capitis and m. rectus capitis anterior. Whereas the most common morphological feature of the m. longus capitis attachment was a bony fossa lateral to the tuberculum pharyngeum, the muscle attached to a prominent crest in children. These previously unreported findings illustrate the role of muscle activity in the formation of osseous landmarks of the epipharynx.
OBJECTIVE: Estimate the relevance of the Tuffier line, which connects both iliac crests, in analyzing the location of the puncture point for spinal anaesthesia for pregnant women. STUDY DESIGN: Prospective. PATIENTS AND METHODS: The age, weight, height, body mass index (BMI) and uterine height, (HU) of 121 patients admitted in the delivery room in July 2005, were recorded. The intersection point of the Tuffier line with the rachis was recorded in seating and sleeping positions. The corresponding vertebral level was verified by counting spiny apophyses from C7. RESULTS: The Tuffier line crossed the spine at the expected level for 29.7% of the patients. The intersection point was below the expected in 6.6% of the cases and above in 63.7% of the cases. Only the weight and the BMI were significantly connected with stronger probability of error (p=0.001). CONCLUSION: The error level with this method is important and comparable to error level in the series published in patients who are not pregnant woman. The main risk is the spinal injury, since the level of ending of the spinal cord is variable. It seems safe to use another method of location, especially with patients experiencing excessive weight.
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The authors calculated axial length measurements in 185 consecutive patients undergoing strabismus surgery and found a mean measurement of 21.98 +/- 1.59 mm (range, 18.75-25.37 mm). Although significant correlation between axial length, refractive error, and age was found, wide variation was present, which indicates that age and refractive error could not accurately predict axial length. Based on a formula derived from a geometric model to determine the equator-limbus distance, given the axial length, the authors found that the equator had a mean distance from the limbus of 11.56 +/- 1.75 mm (range, 9.10-13.76 mm). Based on the variability found at surgery for the insertion-limbus distance, the number of millimeters of recession of the medial rectus from the insertion that would have been necessary to place it at the equator ranged between 3.5 and 8.5 mm in this series, and for the lateral rectus, 3.5 mm to 7.0 mm. The number of millimeters necessary to recess the lateral rectus to its point of tangency with the globe ranged between 9.5 and 14.4 mm.
OBJECTIVE: To determine the effect of error in the location of the anterior superior iliac spine, and the centres of the patella and tibial tuberosity, on the measured value of the quadriceps angle. BACKGROUND: The quadriceps angle is said to be relevant in the etiology and management of patello-femoral pain. However, the issues around measurement accuracy have not been reported. METHODS: Errors between 1 and 5 mm were introduced to the medial/lateral and vertical co-ordinate data describing the position of the anterior superior iliac spine, the centre of the patella and the centre of the tibial tuberosity, and the effect on the quadriceps angle determined. RESULTS: Errors between 1 and 5 mm in the medial/lateral location of the centre of the patella produced changes in the quadriceps angle between 1.13 degrees and 5.53 degrees. Errors between 1 and 5 mm in the medial/lateral location of the tibial tuberosity produced changes in the quadriceps angle between 1.02 degrees and 5.18 degrees. CONCLUSIONS: The quadriceps angle is highly sensitive to error in the definition of the centre of the patella and tibial tuberosity. As an approximation, these centres need to be defined with an accuracy of less than 2 mm if the error in the quadriceps angle is to remain below 5 degrees. RELEVANCE: Until a clinical technique for measuring the quadriceps angle with a high level of accuracy is developed, the clinical use of the quadriceps angle is questionable.
PURPOSE: To identify thoracic structures that exhibit little internal motion during irradiation and to determine setup variations in patients with lung cancer. METHODS AND MATERIALS: Intrafractional images were generated with an electronic portal-imaging device from the AP fields of 10 patients, during several fractions. To determine the intrafractional mobility of thoracic structures, visible structures were contoured in every image and matched with a reference image by means of a cross-correlation algorithm. Setup variations were determined by comparing portal images with the digitized simulator films using the stable structures as landmarks. RESULTS: Mobility was limited in the lateral direction for the trachea, thoracic wall, paraspinal line, and aortic notch, and in the craniocaudal direction for the clavicle, aortic notch, and thoracic.wall. Analysis of patient setup revealed random deviations of 2.0 mm (1 SD) in the lateral direction and 2.8 mm in the craniocaudal direction, while the systematic deviations were 2.5 and 2.0 mm (1 SD) respectively. CONCLUSIONS: We have identified thoracic structures that exhibit little internal motion in the frontal plane, and recommend that these structures be used for verifying patient setup during radiotherapy. The daily variation in the setup of lung cancer patients at our center appears to be acceptable.