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PubMed1984

The nerve loops crossing below the subclavian artery and their anatomical variations.

60 dissections analysed the variability of three types of nerve loops crossing beneath the subclavian artery : Vieussens' annulus, the anastomotic ansa between the lower laryngeal nerve and the cervical sympathetic, and the anastomotic ansa between the phrenic nerve and the stellate ganglion. The classic disposition of these loops, situated below the artery and present simultaneously, was found in only 10% of the cases. Though Vieussens' annulus was present in most of the dissections, the anastomotic ansa between the cervical sympathetic and both the lower laryngeal nerve and the phrenic nerve corresponds more rarely to the conventional pattern.

Adult↗
PubMed2004

Anatomic variations due to radical prostatectomy. Impact on target volume definition and dose-volume parameters of rectum and bladder.

BACKGROUND AND PURPOSE: A quantitative estimate of the impact of prostatectomy on pelvic anatomy is unavailable, even if it would be an important prerequisite for a precise definition of clinical target volume (CTV) in post-prostatectomy radiotherapy. The purpose of this study was to investigate the impact of prostatectomy on the definition of CTV, on the position of bladder and rectum and their implications for three-dimensional conformal radiotherapy (3-D CRT). PATIENTS AND METHODS: Six patients eligible for radical retropubic prostatectomy were considered. Each patient underwent a planning CT between 1 week and 1 month before surgery (CTpre), and then CT was repeated in the same positioning 1-2 months after surgery (CTpost). For each patient the CT(pre/post) scans were matched; rectum, bladder and CTV were contoured on both CT scans for each patient by one observer. Two different CTVs were contoured: CTV1: prostate + seminal vesicles in CTpre; prostate + seminal vesicles surgical bed in CTpost; CTV2: prostate in CTpre; prostate surgical bed in CT(post). After image registration, the contours of rectum, bladder and CTV1/2 drawn on CTpost were transferred on CTpre. The corresponding planning target volumes (PTVs) were generated, and for each PTV, a conformal four field technique using 18-MV X-rays was planned. The volumes of CTV1, CTV2, PTV1, PTV2, rectum and bladder pre- and post-surgery were compared. Differences in 3-D position of these structures before and after surgery were analyzed by beam's eye view (BEV) images. Pre- and post-surgery dose-volume histograms (DVHs) of rectum and bladder were compared together with the fraction of rectum/bladder receiving at least 95% of the ICRU dose (V95), the treated volume (TV, body included in the 95% isodose) and the irradiated volume (IV, body included in the 50% isodose). RESULTS: For both CTV1 and CTV2, the volumes were significantly reduced after prostatectomy (average reduction around 30 cm3 for both; range 0-60 cm3). This reduction was mainly due to a more caudal definition of the cranial edge of CTV after prostatectomy (average difference for CTV2: 1.5 cm; range 0-2.5 cm). Concerning the bladder, a systematic posterior shift of the bladder base (average: 1.5 cm) was found and was correlated with a significant reduction of V95 for bladder (around 10 cm3; p = 0.03). V95 of the rectum, TV and IV also resulted to be significantly lower after surgery. The average reduction of V95 for the rectum was relatively small (2.5 cm3 of rectal wall). CONCLUSION: The impact of prostatectomy on CTV definition is high. A significant reduction of CTV, PTV, TV and IV may be expected after surgery with a consequent reduction of the portions of rectum/bladder irradiated with adjuvant radiotherapy.

Aged↗
PubMed2006

Anatomic variations of the shape of the menisci: a neonatal cadaver study.

Meniscal injuries in children and adolescents are being seen with increased frequency. The menisci are two crescentic lamellae whose functions are to deepen the articular surfaces of the tibial plateu for reception of the condyles of the femur. In our study, our aim is to determine the variations of the shapes and attachments of the menisci in newborns. This study was performed on 11 neonatal cadavers, 22 knee joints that were obtained from the anatomy laboratory. The variations of the shape of the menisci were noted. We found that 77% of the lateral menisci were discoid. This percent is higher than the previously reported percents of the lateral discoid menisci. The different shapes of the menisci were determined as horse shoe, sickle, sided U, sided V and C shaped. We did not determine any discoid medial menisci. We believe that our study will provide support to the neonatal anatomy of the knee, concerning with the surgical procedures and arthroscopy of the knee joint.

Cadaver↗
PubMed2003

A very rare anatomic variation of the left brachiocephalic vein: left retro-aortic brachiocephalic vein with tetralogy of Fallot.

An anomalous course of the left brachiocephalic vein behind the aortic arch was identified in a patient with tetralogy of Fallot. A 6-year-old male patient had been admitted to the hospital with a diagnosis of tetralogy of Fallot and patent foramen ovale. At the beginning of the operation the left brachiocephalic vein could not be found. The pericardium was opened longitudinally and there was no persistent left superior vena cava. After careful examination, the left brachiocephalic vein was found behind the aorta. Especially during open heart surgery this pathology is very important. We conclude that when the left brachiocephalic vein can not be found, the possibility of persistent left superior vena cava and retro-aortic left brachiocephalic vein should be borne in mind.

Aorta, Thoracic↗
PubMed2004

Anatomical variations of occipital bone impressions for dural venous sinuses around the torcular Herophili, with special reference to the consideration of clinical significance.

Venous blood flow through the cerebral dural sinus is variable and clinically significant. It has been investigated by cadaver dissection or radiology; however, we thought that osteology might be informative. A total of 160 dried skulls were macroscopically examined for impressions on the inner surface of the occipital bone in order to interpret the sinus flow around the torcular Herophili. The continuity between the grooves for the superior sagittal sinus (SSS) and the transverse sinuses was categorized into four types. Confluence type was noted in 56 specimens (35%), in which SSS drained into a common pool of venous sinuses. Bifurcation type was noted in 22 cases (14%), in which SSS was divided to drain into the bilateral transverse sinuses. Right dominant type was the most frequent one with 66 cases (41%), in which SSS drained only into the right transverse sinus. Left dominant type was the least frequent one with 16 cases (10%), in which SSS drained to the left, in a mirror image to the right dominant type. Clinical significance is discussed with our preliminary trial for the optimization of the inner skull surface and venous flow using computed tomography and magnetic resonance imaging, and demonstration of cerebrovascular disease.

Adult↗
PubMed2004

A very rare anatomic variation of the right ventricular branch: right ventricular descending branch from the anterior interventricular branch.

The anterior interventricular branch of the left coronary artery has the most constant distribution in the human heart and rarely gives off right ventricular branches. Here we report a case with a right ventricular branch which diverged from the anterior interventricular branch and descended on the anterior right ventricular wall parallel to the anterior interventricular sulcus; we termed it the "right ventricular descending branch." This artery gave a collateral artery to the occluded anterior interventricular branch at the apex, and had prevented anterior myocardial infarction. The right ventricular descending branch should be precisely identified in order to perform successful myocardial revascularization procedures such as coronary artery bypass grafting and percutaneous coronary intervention, especially in a patient with anterior interventricular branch occlusion.

Aged↗
PubMed2006

Mental foramen in Thais: an anatomical variation related to gender and side.

Sixty-nine adult mandibles (45 male, 24 female) of Thai dry skulls were assessed to determine the size, the orientation and the location of the mental foramen (MF) related to gender and side. The results showed that the usual direction of exit of the MF was in a posterosuperior direction. The most common location of the MF was bilaterally symmetrical and located on the same vertical line with the long axis of the lower second premolar. The mean distances from the MF to the symphysis menti (A), to the posterior border of the mandibular ramus (P), to the lower border of the mandible (mb) and to the buccal cusp tip of the second premolar (cm) were 28.83, 68.85, 14.88 and 24.27 mm, respectively. The mean distances from the alveolar bone crest across the MF to the lower border of the mandible (ab) was 29.97 mm. The mean distance from the buccal cusp tip of the second premolar through the long axis of the clinical crown to the lower border of the mandible (cb) was 39.18 mm. No measurements varied according to the sides (P > 0.05). In contrast, gender differences were significant in all measurements with the longer distances in males (P < 0.05). The mean ratios of A/(A + P), mb/ab and cm/cb in all subjects were 0.30, 0.50 and 0.62, respectively. The values of the three ratios were nearly equal in males and females. Our results may assist surgeons to localize important maxillofacial neurovascular bundles passing through the MF in avoiding complication from local anesthetic, surgical and other invasive procedures.

Adult↗
PubMed1999

Mandibular neuralgia due to anatomical variations.

In our large collection of macerated human adult skulls and disarticulated skulls of young individuals we found cases with an extremely large lateral lamina of the pterygoid process. The medial wall of the infratemporal fossa was defined as its formation by the lateral lamina of the pterygoid process and the medial pterygoid muscle. The muscular part formed two-thirds and the lateral lamina one-third of this wall. In cases of a very large lateral lamina in our specimens nearly the whole medial wall was osseous. The third portion of the trigeminal nerve gives off the lingual nerve and alveolar mandibular nerve in the region of the infratemporal fossa. These two nerves generally passed between the lateral and medial pterygoid muscles to their terminal sites. In cases of extremely large lateral laminae the nerves had to make a curve in their course, following the shape of the enlarged lamina. During contraction of the pterygoid muscles both nerves can be compressed. Since the lingual nerve runs between muscular elements, tension and compression is probably avoided. In contrast, the mandibular nerve fixed between the oval and mandibular foramina cannot avoid tension and compression. The result is possible pain, especially during chewing, and may finally create a trigeminal neuralgia. Similar symptoms could be provoked by a foramen pterygospinale or ovalis canal replacing the foramen ovale.

Adolescent↗
PubMed1990

A multivariate morphometric analysis of hippocampal anatomical variation in C57BL/6 in equilibrium BALB/c chimeric mice.

We investigated hippocampal anatomy in artificially-produced chimeras derived by the aggregation of embryos from two widely-studied inbred mouse strains, C57BL/6J and BALB/cJ. Contrary to expectations, the chimeras were not always intermediate between the parental strains. For a number of characters, the chimeras exceeded qualitatively as well as quantitatively the phenotypical range displayed by both inbred parental strains. These findings imply that if only one parent is available for comparison, for instance, in studies involving a normally inviable genotype, separating effects of this genotype from idiosyncratic effects inherent to the chimeric model will be very difficult, if not impossible.

Animals↗