Biomedical subjects

Gen Murakami

Publications and source records attributed to Gen Murakami.

79 records · Page 5Linked to original sources

PubMed2002

Variation in insertion of the abductor digiti minimi: an anatomic study.

We dissected 70 cadaver hands to examine the anatomy of the insertion of the abductor digiti minimi (ADM). The insertion had 2 forms. In 58 hands the insertion of the ADM was divided into 2 tendinous portions: one attached the base of the proximal phalanx (bone insertion) and the other attached the extensor aponeurosis (extensor insertion). In 12 hands the bone insertion existed solely. The mean length and width of the bone insertion were 10.6 +/- 3.1 and 4.0 +/- 0.9 mm and those of the extensor insertion were 18.5 +/- 4.0 and 2.1 +/- 1.1 mm, respectively. The mean proportion of the width of the extensor insertion to that of whole tendon was 31% (range, 0% to 50%). These observations show greater variation in the insertional anatomy of the ADM than reported previously.

Aged↗

PubMed2002

Anatomy of the tonsillar bed: topographical relationship between the palatine tonsil and the lingual branch of the glossopharyngeal nerve.

Taste disturbance may result from injury to the lingual branch of the glossopharyngeal nerve (LBGN) during tonsillectomy. Because an understanding of the anatomy of this nerve is required in order to avoid injuring it, a gross, histologic anatomic study was undertaken of the topographical relationship between the LBGN and the muscle layer of the palatine tonsillar bed. Evaluation of 107 sides of 83 Japanese adult cadavers (aged 27-88 years) confirmed that the muscular composition and lamination of the tonsillar bed do not change with age or pathological conditions such as inflammation. In about a quarter (23.4%) of cases, the LBGN traveled inferior to the styloglossus muscle and lateral to the superior constrictor pharyngeal muscle over its whole course to the base of the tongue, so that the palatine tonsil was clearly separated from the LBGN. In 55.1% of cases, however, the muscle lining of the tonsillar bed was discontinuous and thin muscle bundles, derived from the stylopharyngeus, palatopharyngeus or superior constrictor pharyngeal muscle, partially covered the tonsillar capsule externally. Moreover, in 21.5% of cases the LBGN was firmly adherent to the tonsillar capsule, due to the complete absence of muscles lining the tonsillar bed. In these cases, and also probably in a similar percentage of patients undergoing tonsillectomy, taste disturbance may occur on removal of the hypertrophic tonsillar capsule. Therefore, minimal disturbance of the tonsillar bed is recommended in all cases of tonsillectomy.

Adult↗

PubMed2002

Investigation of the localization of nerves in the uterosacral ligament: determination of the optimal site for uterosacral nerve ablation.

We select surgical treatment for cases for which severe dysmenorrhea persists following medical treatment. Many reports have described the use of neurectomies by cutting off pain conducting nerve pathways using laparoscopic surgery. Laparoscopic uterosacral nerve ablation (LUNA) has been associated with a high success rate for pain control, but there are few reports of anatomical studies in the uterosacral ligament. Using an immunohistochemical method, we examined the number and types of nerve fiber bundles in the uterosacral ligaments and its surrounding tissue in cadavers. The greatest number of nerve fiber bundles was found at a distance of 16.5-33 mm and at a depth of 3-15 mm distal to the site of attachment of the uterosacral ligament to the uterine cervix. Furthermore, there were many more sympathetic and parasympathetic nerve fiber bundles than sensory ones in the uterosacral ligament and its surrounding tissue. These results show the appropriate site of transection of uterosacral ligaments when performing LUNA.

Calcitonin Gene-Related Peptide↗

PubMed2002

Morphometrical study of the joint surface and capsule of the lumbar zygapophysial joint with special reference to their laterality.

Using 26 osteoligamentous lumbar vertebral columns (260 facets), we morphometrically investigated the cartilagenous joint surface, inner capsular surface and capsular thickness. We also examined whether the subcapsular pocket was present and, if present, how far it extended along the joint margin. The proportion of the inner capsular area in the total joint surface area in a facet (the capsular-joint surface ratio) was hypothesized to correspond to the potential looseness (or tightness) of the facet. The absolute data themselves seemed to be useful for better understanding of the joint morphology. However, further evaluations of the differences between segments, left/right differences, individual segmental fluctuation patterns and correlations between parameters provided a novel classification of specimens according to the hypothetical progress of joint degeneration. Criteria for the classification existed in 1) the laterality in parameters defined as more than 100% larger or smaller than the contralateral facet and 2) the drastic segmental difference in parameters over 50% larger or smaller than the adjacent segment. Consequently, three types were identified: 1) outside of the criteria in both area and thickness (-/- type, 9 of 26); 2) the criteria did not fit the area parameters but did fit the thickness parameters (-/+ type, 8); the criteria were filled in both categories of parameters (+/+ type, 9). Notably, in the +/+ types, the capsular thickness and capsular-joint surface ratio correlated significantly (p < 0.01), i.e., the hypothetical loose joint had a thick capsule. We speculated that early joint degeneration starts from the -/- type and advances via the -/+ type to the +/+ type. Considerating these results, we recommended using MR imaging for detailed identification of laterality in the capsular thickness for low-back pain patients to discriminate candidates for future severe degenerative changes of the articular cartilage in the lumbar spine.

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PubMed2002

The lateral collateral ligament complex and related muscles act as a dynamic stabilizer as well as a static supporting structure at the elbow joint: an anatomical and experimental study.

Among 71 osteoligamentous elbow joint specimens from Japanese subjects, 66% of the lateral ulnar collateral ligaments (LUCLs) were in an incomplete form, such as a fibrous intermuscular septum lying between the anconeus, supinator and extensors, and terminated on the annular ligament. The 'typical' complete ligament, extending from the lateral epicondyle and over the radial collateral ligament (RCL) to the crista spinatoris, appeared in only 20% of the elbows examined. This observation suggests that, in Japanese subjects, the LUCL is not usually a simple ligamentous static stabilizer, but acts as a dynamic stabilizer, together with its related muscles. In addition, when the elbow was flexed by more than 90 degrees, the distance between the lateral epicondyle and the radial head became almost 1.5 mm larger than the distance from the epicondyle to the annular ligament. We therefore consider that, in the overflexed position, the radial head moves slightly distal while the length of the RCL remains almost constant. This morphometrical observation suggests that the annular ligament needs to be supported by the LUCL-muscle complex from the distal side, as well as by the RCL from the proximal side. This extended definition of the lateral collateral ligament complex and its associated muscular function is discussed.

Aged↗

PubMedDate not supplied

Surgical anatomy of the inferior vena cava ligament.

BACKGROUND/AIMS: The inferior vena cava ligament is a fibrous membrane located around the inferior vena cava. Few reports exist on the ligament's location, attachment to the liver, or the inferior vena cava. METHODOLOGY: We obtained 16 specimens of human liver and inferior vena cava from cadavers. The inferior vena cava ligament was photographed and then dissected for histological examination. Relationships among the ligament, inferior vena cava, and liver were examined microscopically. The numbers and diameters of veins, arteries, and lymph vessels at least 1 mm in diameter were recorded. RESULTS: The cranial margin of the inferior vena cava ligament was ended in a blind loop. The cranial portion above the mid-portion of the Spiegel lobe was thicker than the caudal portion. The ligament was attached to the right and left hepatic veins. The mean length of the right side of the inferior vena cava ligament was 37.0 mm and the mean width 15.6 mm. The inferior vena cava ligament had a mean thickness of 0.8 mm (thin end) and 2.5 mm (thick end). Although the inferior vena cava ligament was usually tightly continuous with the liver capsule, microscopically the attachment between the ligament and the inferior vena cava was loose. The mean number and diameter of veins in the inferior vena cava ligament was 1.0 and 1.4 mm, respectively. The mean number and diameter of arteries was 0.2 and 2.4 mm, respectively. The mean number and diameter of lymphatic vessels was 2.8 and 1.7 mm, respectively. CONCLUSIONS: After dissection of the inferior vena cava ligament, major hepatic veins can be dissected extrahepatically. Because the ligament is wider caudally, the forceps should be inserted caudocranially during separation. Since both the number and diameters of lymphatic vessels in the ligament are large, the ligament should be ligated and cut.

Aged↗

PubMedDate not supplied

Surgical anatomy of arteries running transversely in the pancreas, with special reference to the superior transverse pancreatic artery.

BACKGROUND/AIMS: In pancreatic surgery, the pancreas is usually divided over the portal vein. Knowledge of transversely oriented arterial systems within the pancreas that would need to be ligated in most forms of pancreatic surgery is clinically important. We studied the anatomy of arteries running transversely in the pancreas. METHODOLOGY: Thirty-eight cadavers donated for education and research were examined. The parenchyma of the pancreas was removed gradually from both the ventral and dorsal sides to reveal these arteries. Arteries at least 0.5 mm in diameter were sketched and counted. RESULTS: The mean number of divided arteries over the portal vein at least 0.5 mm in diameter per specimen was 2.5 +/- 1.1 (range 1 to 5). The divided arteries were mainly transverse pancreatic (TP), superior TP, and dorsal pancreatic (DP) arteries. The superior TP artery was observed in 24/38 specimens (63.2%) and ran along the superior ventral side of the head of the pancreas in 79.2% of specimens. The superior TP artery was formed between the gastroduodenal (GD) and DP arteries in 15/38 specimens (39.5%). In pancreatic surgery, surgeons need to be aware of the anatomy of the superior TP artery. The TP artery usually originated from the GD artery and its branches. The TP artery joined with the DP artery in 61.3% of specimens and ran along the inferior surface of the body and tail of the pancreas. The TP artery frequently anastomosed with the great pancreatic artery. Arterial catheters for continuous delivery of protease inhibitors in acute necrotizing pancreatitis should be placed into the GD artery, because this will achieve perfusion of the entire pancreatic parenchyma. CONCLUSIONS: We termed the artery originating from the GD or DP arteries, located at the cranial side of the head of the pancreas, the superior TP artery. Surgeons should pay close attention to the anatomy of the superior TP artery during pancreatic surgery.

Arteries↗