PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Anatomic Variation”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 379 records · Page 21Linked to original sources
PubMed2000

Anatomical variations in the pattern of the right hepatic veins: possibilities for type classification.

A morphological study of the right hepatic veins (RHVv) was conducted based on the shape and the confluence pattern of the superior right hepatic vein (SRHV) and the presence of accessory right hepatic veins. The study was performed in 110 undamaged, randomly selected, cadaveric human livers prepared using the corrosion cast methodology. The principles for classifying the RHVv into types were as follows: the length of the vein trunk, the confluence of 2 or 3 main tributaries that form a trunk, and the accessory right hepatic veins that modify the venous drainage of the right side of the liver. Four types of SRHV were identified. Type 1 (20 %), type 2 (40 %) and type 3 (25 %) were the most common, while type 4 (15 %) was linked to the accessory right hepatic veins in cases where they drain a surgically important part of the liver. Accessory right hepatic veins were found in a total of 31 casts (28 %). The hepatocaval confluence was studied and the tributary-free part of the SRHV trunk before it entered the inferior vena cava was measured. The tributary-free part of the SRHV was longer than 1 cm in 77 % of the casts. Anastomoses between the terminal tributaries of the veins involved in the drainage of the right side of the liver were also investigated.

Corrosion Casting↗
PubMed2001

Development of the arterial pattern in the upper limb of staged human embryos: normal development and anatomic variations.

A total of 112 human embryos (224 upper limbs) between stages 12 and 23 of development were examined. It was observed that formation of the arterial system in the upper limb takes place as a dual process. An initial capillary plexus appears from the dorsal aorta during stage 12 and develops at the same rate as the limb. At stage 13, the capillary plexus begins a maturation process involving the enlargement and differentiation of selected parts. This remodelling process starts in the aorta and continues in a proximal to distal sequence. By stage 15 the differentiation has reached the subclavian and axillary arteries, by stage 17 it has reached the brachial artery as far as the elbow, by stage 18 it has reached the forearm arteries except for the distal part of the radial, and finally by stage 21 the whole arterial pattern is present in its definitive morphology. This differentiation process parallels the development of the skeletal system chronologically. A number of arterial variations were observed, and classified as follows: superficial brachial (7.7%), accessory brachial (0.6%). brachioradial (14%), superficial brachioulnar (4.7%), superficial brachioulnoradial (0.7%), palmar pattern of the median (18.7%) and superficial brachiomedian (0.7%) arteries. They were observed in embryos belonging to stages 17-23 and were not related to a specific stage of development. Statistical comparison with the rates of variations reported in adults did not show significant differences. It is suggested that the variations arise through the persistence, enlargement and differentiation of parts of the initial network which would normally remain as capillaries or even regress.

Aorta↗
PubMed2002

Unusual anatomic variation of palmar sensory branches of the ulnar nerve: a case report.

Variant sensory branches of the ulnar nerve were encountered during a routine dissection of the palmar aspects of a cadaver hand. The variant branches were distributed to the ulnar half of the index, ulnar half of the middle, and radial half of the ring fingers. The communicating branch between the superficial ulnar branch and the third common digital branch of the median nerve was absent. Distribution of the median nerve sensory branches was normal. The clinical significance of this variation is discussed.

Dissection↗
PubMed2003

Anatomic variations in the levator ani muscle, endopelvic fascia, and urethra in nulliparas evaluated by magnetic resonance imaging.

OBJECTIVE: The purpose of this study was to develop a system to quantify interindividual variation in the appearance of continence system structures in normal continent nulliparous women. STUDY DESIGN: Magnetic resonance imaging (1.5 T) was performed in 20 healthy continent nulliparous women (mean age, 30.1 +/- 5.1 years) with normal pelvic organ support and urodynamics. Morphometric measurements of the levator ani muscle, endopelvic fascia, and urethra were performed. RESULTS: The ratio of the maximum-to-minimum measured values shows that 2- to 3-fold differences occur in distance, area, or volume measures of continence system morphologic features. The mean urogenital hiatus area was 15.2 +/- 2.9 cm(2) in women without a visible connection of the levator ani muscle to the pubic bone (4/20 women) and 12.3 +/- 2.4 cm(2) in women with an levator ani muscle-pubic bone connection (16/20 women, P =.05). CONCLUSION: Considerable variation that was not attributable to limitations of the measuring technique that was used occurs in the size and configuration of the urethral support structures in nulliparous asymptomatic women.

Adult↗
PubMed2002

Anatomical variations of the arterial pattern in the left hemiliver.

The arterial supply to the left hemiliver was studied in 70 liver casts. The arteries were divided into 15 groups according to their origin and branching pattern. The left hemiliver was supplied by one artery in 53% of cases, by two arteries in 40% and by three arteries in 7%. The left hepatic artery, which originated from the proper hepatic artery, supplied all three left segments in 39% of specimens. The replacing left hepatic artery, which originated from the left gastric artery, supplied the whole left hemiliver in 3% of cases. The incomplete, replacing left hepatic artery supplied segments 2, 3 and a part of segment 4 in 6% of cases, and only segments 2 and 3 in 11%. There was one segmental artery for segment 2 in 86%, and two in 14%. Segment 3 was supplied by one artery in 87%, and by two in 13%. Segment 4 was supplied by one artery in 39% of cases, by two arteries in 43%, by three in 14% and by four arteries in 4%.

Arteries↗
PubMed2003

Anatomical variations of the cystic artery.

Thorough knowledge about the origin of the cystic artery is surgically important, especially when intraoperative or post-operative bleeding occurs in the gallbladder fossa. The arterial supply of the gallbladder was studied in 81 livers. The gallbladder was supplied by one cystic artery in 86% and by two arteries in 14% of cases. When a single artery was present, it originated from the right hepatic artery in 53% of livers. Other origins included the anterior or the posterior sectional hepatic artery, the replacing right hepatic artery, and in 5% of cases, segmental arteries for segments 4, 5, 6 and 8. When two cystic arteries supplied the gallbladder, both most commonly originated from the right hepatic artery (7% incidence). In 1% of cases, a subsegmental branch for segment 6 and a subsegmental branch for segment 5 respectively, originated from the cystic artery.

Arteries↗
PubMed1999

Anatomic variations of the infraorbital foramen.

The aims of this study were to locate the infraorbital foramen and to determine the frequency and location of any accessory foramen, which may be troublesome during anesthetization of this region. In 45 cadavers, the infraorbital foramen was dissected according to classic principles for location. The line between the angulus oculi medialis and the angulus oculi lateralis was divided into three equal pieces, and a second line was drawn downward, perpendicular to the point uniting the internal and medial thirds. The position of the infraorbital foramen was determined in relation to that line and the infraorbital margin. For the right and left sides, the infraorbital foramen was found to be on that line in 75.6% and 68.9% of the specimens, respectively. The infraorbital foramen was 10.9 mm and 8.3 mm under the infraorbital margin in men and women, respectively. Regarding accessory foramen, 119 crania and 229 maxilla were observed (a total of 467 infraorbital foramen), and it was found that single accessory foramen were present in 11.5% of specimens and double accessory foramen were present in 1.28% of specimens. In 79.6% of specimens with single accessory foramen, the accessory foramen was superior and medial to the main opening. These results are helpful in decreasing anesthetic complications.

Anesthesia↗
PubMed2003

Anatomical variations of the frontal and supraorbital transcranial passages.

In this study, 500 frontal and supraorbital transcranial passages were studied in 50 cadavers and 200 crania of 500 samples. One hundred six specimens had a frontal foramen (notch), and all the samples had a supraorbital foramen (notch). The frontal passage was a foramen in 7 samples and a notch in 99 samples. As for the supraorbital passage, it was found as a foramen in 133 of specimens and as a notch in 358 of specimens. In 9 of the specimens, there were double notches or foramina. The distances from the foramina (notches) to angulus oculi medialis were measured in the cadavers. The average distance from the angulus oculi medialis to the frontal foramen (notch) was 4.50 mm, and the average distance to the supraorbital foramen (notch) was 9.87 mm. The distances from the foramina (notches) to the midline were measured in the crania. The average distances from the midline to the frontal foramen (notch) and the supraorbital foramen (notch) were 20.24 mm and 25.23 mm, respectively. The average distance between the frontal foramen (notch) and supraorbital foramen (notch) was 5.37 mm in cadavers and 4.99 mm in crania. In 200 crania, the distances of the frontal and supraorbital transcranial passages to the midline were measured. Types of these passages were also evaluated, and frequencies were calculated. Measurements were made using a digital compass, and the student t test was used in the statistical evaluation of results.

Cadaver↗
PubMedDate not supplied

Anatomic variations of the coronary arteries supplying the anterolateral aspect of the left ventricle: possible explanation for the "Unexplained" anterior aneurysm.

Coronary arteriograms of 418 adult patients were studied to ascertain the frequency of variations in blood supply of the anterolateral free wall of the left ventricle; 92.6% had from one to three ramus medianus or diagonal branches supplying this area. Complete absence of any ramus medianus or diagonal branches was exceedingly rare (only 0.5% in this series), and when this occurs the angiographer should suspect complete occlusion of one or more such branches immediately at their origins. Failure to detect ostial occlusion of a ramus medianus or diagonal branch may be a cause of significant misinterpretation of coronary arteriograms.

Adult↗
PubMed1979

Avoiding facial nerve injuries in rhytidectomy. Anatomical variations and pitfalls.

Injury to the facial nerve in rhytidectomy has been occurring in less than one percent of the cases, and a spontaneous return of function in more than 80 percent of these injuries has resulted within 6 months. With the introduction of the newer and more aggressive techniques of platysmal and subplatysmal flaps and SMAS dissections, the risk of injury to facial nerve branches is obviously increased. Though there has not yet been an increase in the facial nerve injuries reported, these techniques are still relatively recent additions to the face-lift operation-and usually they have been done by more experienced surgeons, taking more time and working under direct vision with a more careful dissection. More care is needed to prevent injuries. We discuss here the detailed anatomy of the muscular branches of the facial nerve, how to prevent injuries to them during rhytidectomy, and how to manage injuries when they do occur.

Face↗