Biomedical subjects

Matthew K-H Hong

Publications and source records attributed to Matthew K-H Hong.

3 recordsLinked to original sources

PubMed2006

Angiosome territories of the nerves of the upper limbs.

BACKGROUND: The use of free vascularized nerve grafts requires intimate knowledge of the blood supply of peripheral nerves. The authors aimed to demonstrate radiographically the topography of the upper limb nerves with their blood supply, and to examine them as an application of the angiosome concept. An angiosome is a three-dimensional block of composite tissue supplied by a single source artery. METHODS: This anatomical study involved the meticulous dissection of four fresh upper limb specimens injected intraarterially with a gelatin-lead oxide mixture. The nerves were tagged circumferentially with copper wire and radiographs were taken of the nerves with their arterial blood supply. The median, ulnar, radial, musculocutaneous, and axillary nerves were examined. RESULTS: The authors showed that the nerves of the upper limb were supplied segmentally by source vessels, which reinforced the angiosome concept. The suitability of each nerve for harvest in free vascularized nerve transfer was assessed according to its pattern of blood supply. CONCLUSIONS: The authors' work has a wide range of clinical applications and provides an anatomical basis for neurovascular and neurocutaneous flaps and free vascularized nerve grafting.

Arm↗

PubMed2005

Is the testis intraperitoneal?

The relationship of the testis to the peritoneal cavity, and hence its position as an intraperitoneal or extraperitoneal organ, remains controversial. Adult anatomy texts favour an extraperitoneal position during and after testicular descent, whereas journal articles favour an intraperitoneal position. Interestingly, there is no similar debate around the position of the ovary despite the common origin of each as indifferent gonads. Through direct observation and the literature review, we aimed to determine whether the testis should be considered an intraperitoneal or an extraperitoneal organ. The anatomical and embryological literature relevant to human and animal models was reviewed. Direct dissections were made in rats (n=8) during foetal development, postnatally, and in mature animals, allowing comparison of foetus with adult and male with female. The position of the human testis was also recorded in various pathological states. Direct dissection in rats reveals an intraperitoneal testis on a mesorchium during both foetal and postnatal life. Intraperitoneal testes are demonstrated in humans in cases of gastroschisis (where the testis may protrude through the periumbilical defect with the bowel), testicular torsion (where the testis is mobile within the peritoneum), and bell clapper testis (where the testes are identifiable as intraperitoneal). We conclude that the foetal testis is an intraperitoneal organ. In the adult rat the testis remains intraperitoneal. The postnatal human testis is intraperitoneal. The adult human testis is intraperitoneal but may appear extraperitoneal. The apparent discrepancy between the adult testis being intraperitoneal or extraperitoneal is likely to result from differences in the relative size of the tunica vaginalis between infant boys and elderly men.

Animals↗

PubMed2004

The broad ligament: a review of its anatomy and development in different species and hormonal environments.

The broad ligament is a double fold of peritoneum forming a mesentery for the human female genital tract. We investigated the anatomy of the broad ligament in different species and its hormonal regulation to determine if it had a role in gonadal positioning. The medical and veterinary literature was reviewed for descriptions of broad ligament anatomy and development. In addition, four adult female rats were dissected to compare the macroscopic anatomy of the broad ligament with any homologous structures in the male (n = 2). Detailed review was made of human males with persistent Müllerian duct syndrome (PMDS) and of bovine freemartin calves to determine the effect of abnormal hormonal environments on broad ligament development. Human and veterinary texts show variable broad ligament development between species, most being consistent with the size and shape of the uterus and uterine tubes. The broad ligament in adult female rats is a simple peritoneal fold and is homologous with the mesentery of the testis and vas deferens in males. Patients with PMDS and bovine freemartins have a broad ligament with intermediate anatomy. In PMDS the broad ligament is elongated and narrow, and not attached to the pelvic wall. The broad ligament is the mesentery of the genital ducts, and its anatomy varies with the degree of Müllerian duct fusion. The absence of a human male homologue is unusual, as the genital mesentery persists in male rodents. Apparent lack of a male homologue in the human may relate to obliteration of the processus vaginalis. The variable development of the broad ligament in pathological conditions is consistent with a role for steroid hormones in its development.

Adult↗