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Biomedical subjects

K S Koh

Publications and source records attributed to K S Koh.

At least 19 recordsLinked to original sources
PubMed2006

Anatomical and radiological study of the superior and inferior gluteal arteries in the gluteus maximus muscle for musculocutaneous flap in Koreans.

The position, distribution pattern, and perforating branch of the superior gluteal artery (SGA) and the inferior gluteal artery (IGA) in the gluteus maximus muscle (GMM) were investigated through fine dissection and the radiological method. The SGA was located at about the upper one-third of the posterior superior iliac spine (PSIS)-greater trochanter of the femur (GT) line and medially at about 1cm from the line. The IGA was located at around the middle point of the PSIS-ischial tuberosity (IT) line. The perforating branches passed through the muscle to the subcutaneous tissue and were distributed to the GMM that divided the upper and lower parts; the SGA supplied to the upper two-fifths of the GMM; and the IGA supplied to the rest of the muscle. The course of the SGA and the IGA in the GMM were classified into four types according to their distribution patterns, and the most common type was the typical type whereby the IGA supplied an area larger than the SGA. These results were somewhat different from previous studies, but these differences must be considered for a safe and effective flap procedure.

Angiography↗
PubMed2005

Branching patterns of the arterial branches supplying the middle vascular pedicle of the sternocleidomastoid muscle: a topographic anatomical study with surgical applications for the use of pedicles osteomuscular flaps.

When making a sternocleidomastoid (SCM) osteomuscular flap to include the clavicle and determining the rotation arc of the osteomuscular flap, it is very important to know the location and the origin of the superior thyroid artery and the distribution pattern of the SCM branch. Accordingly, in this study, the 50 SCM muscles and their arteries were dissected in 26 Korean cadavers, and the results were analyzed. The average distances from the origin of the superior thyroid artery to the clavicular and sternal heads of the SCM muscle were 87.6 mm (57.7-123.8 mm) and 131.2 mm (99.7-166.8 mm), respectively. The average distance from the origin of the superior thyroid artery to the SCM branch entering the SCM muscle was 30.1 mm (16.0-37.7 mm). After entering the SCM muscle, the SCM branches of the superior thyroid artery bifurcated into the clavicular and sternal branches at a point located an average of 58.8 mm (28.4-130.4 mm) above the clavicle. The distribution patterns of the superior thyroid artery were classified into six types based on the branching order and the dual supplies to the SCM muscle. Among them, type I in which the laryngeal branch first divided from the superior thyroid artery was the most common case (36%).

Adolescent↗
PubMed2005

Biofilm formation and sloughing in Serratia marcescens are controlled by quorum sensing and nutrient cues.

We describe here a role for quorum sensing in the detachment, or sloughing, of Serratia marcescens filamentous biofilms, and we show that nutrient conditions affect the biofilm morphotype. Under reduced carbon or nitrogen conditions, S. marcescens formed a classical biofilm consisting of microcolonies. The filamentous biofilm could be converted to a microcolony-type biofilm by switching the medium after establishment of the biofilm. Similarly, when initially grown as a microcolony biofilm, S. marcescens could be converted back to a filamentous biofilm by increasing the nutrient composition. Under high-nutrient conditions, an N-acyl homoserine lactone quorum-sensing mutant formed biofilms that were indistinguishable from the wild-type biofilms. Similarly, other quorum-sensing-dependent behaviors, such as swarming motility, could be rendered quorum sensing independent by manipulating the growth medium. Quorum sensing was also found to be involved in the sloughing of the filamentous biofilm. The biofilm formed by the bacterium consistently sloughed from the substratum after approximately 75 to 80 h of development. The quorum-sensing mutant, when supplemented with exogenous signal, formed a wild-type filamentous biofilm and sloughed at the same time as the wild type, and this was independent of surfactant production. When we removed the signal from the quorum-sensing mutant prior to the time of sloughing, the biofilm did not undergo significant detachment. Together, the data suggest that biofilm formation by S. marcescens is a dynamic process that is controlled by both nutrient cues and the quorum-sensing system.

Biofilms↗
PubMed2004

Branching patterns of the facial nerve and its communication with the auriculotemporal nerve.

This study examines the anatomic relationships and variability of the facial nerve trunk and its branches, with emphasis on the intraparotid connections between the divisions. Microdissections were performed on 30 Korean half-heads, and the facial nerve trunks and branches were exposed. The average depth of the stylomastoid foramen from the skin surface was 21.0 +/- 3.1 mm, and the distance between the stylomastoid foramen and the bifurcation of the temporofacial (upper) and cervicofacial (lower) divisions was 13.0 +/- 2.8 mm. In 26 of 30 dissections (86.7%), the facial nerve trunk bifurcated into two main divisions, and a trifurcation pattern was seen in the other four cases (13.3%). According to the origin of the buccal branches, we classified the branching patterns of the facial nerve into four categories. In type I (13.8% of cases), the buccal branches arose from the two main divisions of the trunk but not from other branches of the facial nerve. In type II (44.8% of cases), the buccal branches arising from the two main divisions were interconnected with the zygomatic branch. In type III (17.3% of cases), the marginal mandibular branch sent nerve twigs to the buccal branch, which originated from the upper and lower divisions. In type IV (17.3% of cases), the nerve twigs from the zygomatic and marginal mandibular branches merged to the buccal branch arising from the two main divisions. Communications between the facial and auriculotemporal nerve branches, which are known as "communicating auriculotemporal nerves," were observed in 28 of the 30 cases (93.3%). Familiarity with these common variations in the facial anatomy provides useful information for the surgeon in careful dissection, preservation of the facial nerve, and complete removal of the tumors in parotidectomies.

Adult↗
PubMed2004

Topographic anatomy of the inferior wall of the maxillary sinus in Koreans.

Knowledge of the relationship between the root apex and the inferior wall of the maxillary sinus are crucial for diagnosing and treating a sinus pathosis as well as in assisting in dental implantation. Therefore, identifying the proximity between the root apex and the inferior wall of the sinus and clarifying the cortical thickness of the inferior wall of the sinus is essential for determining the topography of a spreading dental infection into the maxillary sinus. Accordingly, knowledge of the topography between the root apex and the inferior wall of maxillary sinus is important for diagnosing and planning dental implantation, endodontic procedures, and orthodontic treatment. This study was undertaken to clarify the morphological and clinical characteristics of the maxillary sinus, particularly the inferior wall of the sinus in Koreans, and to identify the relationship between the inferior wall of the maxillary sinus and the roots of the maxillary teeth. Twenty-four sides of the maxillae of hemi-sectioned Korean heads were used in this study. All specimens were decalcificated and sectioned coronally. On the sectioned specimens, 21 items were measured using an image analyzing system. The distances between the each root apex and the inferior wall of the maxillary sinus were measured. The distance from the root apex to the inferior wall of the sinus was the shortest in the second molar area and the longest in the first premolar area. The thickness of the cortical plate of the inferior wall of the maxillary sinus was thinnest in the first premolar area but it was thickest in the second premolar area. The vertical relationship between the inferior wall and the roots of the maxillary molars was classified into five types. Type I (the inferior wall of the sinus located above the level connecting the buccal and lingual root apices) dominated (54.5% in the first molar area, 52.4% in the second molar area). The horizontal relationship between the inferior wall of the sinus and the root apex was classified into three types. Type 2 (the alveolar recess of the inferior wall of the sinus was located between the buccal and lingual roots) was most common (80% in the first and second molar area). Overall, this study demonstrated the many anatomical characteristics and determined the relationships between the maxillary sinus and their surrounding structures. These findings may have an impact on the clinical management of patients.

Anatomy, Cross-Sectional↗
PubMed2003

Branching patterns and symmetry of the course of the facial artery in Koreans.

The topography and the course of the facial artery were investigated in 47 Korean cadavers. The final branch of the facial artery was the lateral nasal branch in 44.0% whereas it was the angular branch in 36.3% of the cases. In 54.5% of the cases, the facial artery ended symmetrically. According to previous studies, variations in the distribution pattern of the facial artery have been regarded as racial difference. However, in this study we showed that the diverse pattern of the facial artery distribution demonstrates individual variation rather than racial difference. The superior and inferior labial arteries on the right side were more dominant than those on the left. The average distance between the branching points for the inferior alar branch and for the lateral nasal branch was 15.9 mm, and it was 25.2 mm between the points for the superior labial branch and for the inferior alar branch. The branching point of the inferior labial branch was 30.9 mm apart on average from that of the superior labial branch. The courses of the facial arteries showed no significant differences based on either laterality or gender.

Adolescent↗
PubMed2003

Topographic anatomy of the mandibular nerve branches distributed on the two heads of the lateral pterygoid.

The purpose of this study was to evaluate the topography of the nerve distribution on the two heads of the lateral pterygoid and to clarify their morphological-functional correlations. The nerve distribution on the lateral pterygoid was studied in 24 hemi-sectioned heads. Both heads of the lateral pterygoid were innervated from the mandibular nerve branches, but with various nerve distribution patterns. The nerves innervating the superior head of the lateral pterygoid originated from the buccal nerve only in 45.8% of cases. In contrast, the nerves innervating the inferior head of the lateral pterygoid originated from both the buccal and mandibular nerve trunk in 58.3% of cases. In the seven distribution categories of the mandibular nerve branches, both the superior and inferior heads of the lateral pterygoid had a common source of nerve innervation in only 20.8% of cases, the buccal nerve. In contrast, in 45.9% of cases, additional nerve twigs from the mandibular nerve trunk were distributed on the inferior head of the lateral pterygoid. In summary, besides the buccal nerve described in anatomy textbooks, the nerve branches that originated directly from the mandibular nerve trunk innervated the lateral pterygoid.

Aged↗
PubMed2002

Adult-to-adult living donor liver transplantation at the Asan Medical Center, Korea.

Between February 1997 and December 2001, 311 adult-to-adult living donor liver transplants (A-A LDLTs) were performed at the Asan Medical Center for patients above 20 years of age. Indications for A-A LDLT were: chronic hepatitis B (203), chronic hepatitis C (5), hepatocellular carcinoma (64), alcoholic cirrhosis (9), cryptogenic cirrhosis (4), secondary biliary cirrhosis (5), primary biliary cirrhosis (1), Wilson' s disease (2), autoimmune hepatitis (1), hepatic tuberculosis (1), cholangiocarcinoma (1), fulminant hepatic failure (14) and primary non-function of cadaveric liver graft (1). Of 311 A-A LDLTs, 36 were of medical high urgency, 20 were for acute and subacute hepatic failure, 15 were for hepato-renal syndrome and 1 was for primary non-function. Recipient age ranged from 27 to 64 years. Donor age ranged from 16 to 62 years. There was no donor mortality. Implanted liver grafts were categorized into seven types: 175 modified right lobe (MRL), 70 left lobe, 32 right lobe, 20 dual grafts, 10 left lobe plus caudate lobe, three extended right lobe and one posterior segment. In MRL, the tributaries of the middle hepatic vein were reconstructed by interpositioning a vein graft. Indication for dual graft implantation was the same as single graft A-A LDLT, and four of 20 were emergency cases. Of 20 dual grafts, 14 received two left lobes, four received a left lobe and a lateral segment, one received a right lobe and a left lobe and one received a lateral segment and a posterior segment. Graft volume ranged from 28% to 83% of the standard liver volume of the recipients. There were 33 (10.6%) in-hospital mortalities (< 4 months) among the 310 patients after 311 A-A LDLTs. Of the 36 patients receiving emergency transplants, 31 survived. These encouraging results justify the expansion of A-A LDLT in coping with increasing demands, even in urgent situations. We have aimed to introduce the establishment of the efficacy of A-A LDLT in various end-stage chronic and acute liver diseases, as well as new technical advances to overcome small graft-size syndrome by using dual-graft implantation and MRL, both of which were first developed in our department.

Adult↗
PubMed2002

Hypoglossal-facial crossover in facial-nerve palsy: pure end-to-sideanastomosis technique.

Hypoglossal-facial crossover is the most popular method of reconstructing the facial nerve in facial palsy resulting from proximal facial-nerve injury near the brainstem. Conventional hypoglossal-facial crossover involves performing a partial hypoglossal-nerve section or incision and an interpositional nerve graft to bridge the gap between the two nerves, which sometimes results in hemiglossal atrophy and its sequelae. Furthermore, the nerve graft may delay recovery and make facial reanimation weak. To solve these problems, we attempted to perform 'pure end-to-side anastomosis' (without section of the hypoglossal nerve) between the hypoglossal and facial nerves in four patients with facial palsy. In two patients (group I) a sural-nerve graft was used to bridge the gap between the two nerves. In the other two patients (group II) the intratemporal facial nerve was mobilised to the neck and one tension-free end-to-side anastomosis was performed. Facial symmetry and tone at rest were restored in all cases. Facial reanimation was achieved in group II after 8 months. Despite the small number of cases, we believe that the technique of hypoglossal-facial crossover with 'pure end-to-side anastomosis' and mobilisation of the intratemporal facial nerve can decrease donor-nerve morbidity in facial-nerve rehabilitation.

Adult↗
PubMed2002

Emerging patterns of the cervical cutaneous nerves in Asians.

Numerous reports exist upon clinical viewpoints of the four cervical cutaneous nerves. Unfortunately, a detailed description of the cervical cutaneous nerves has not yet been published. For this reason, administering effective anaesthesia to a particular nerve branch is difficult. The aim of this study was to clarify the anatomical knowledge about the emerging patterns of the cervical cutaneous nerves in the superficial neck using 35 Korean cadavers (22 male, 13 female). Four cervical cutaneous nerve branches penetrating the fascia of the posterior border of the sternocleidomastoid muscle (SCM) were classified into seven types based on the locations of their nerve emergence. Among these, the separated type (L-G-T-S) was the most frequent (50%). followed by the L-G x T-S type (20.3%), in which the great auricular nerve (G) and the transverse cervical nerve (T) emerged at the same level on the posterior SCM border.

Asian People↗
PubMed2001

Intradural anastomoses between the accessory nerve and the posterior roots of cervical nerves: their clinical significance.

This study was performed to identify the anastomoses between the accessory nerve and the posterior roots of cervical nerves below the level of C1 segment, and to evaluate their clinical significance. One hundred spinal cord sides of Koreans were studied under the surgical microscope. In order to trace the posterior root of a cervical nerve after anastomosis with the accessory nerve, or the bridging fibers between the accessory nerve and the cervical posterior roots, the accessory nerves with the posterior roots and the bridging fibers were stained with osmium tetroxide. The anastomosis was classified into five types, according to whether the accessory nerve and the cervical posterior root crossed each other, and also according to the site of the bridging fiber between them. The bridging fibers in the most common type of anastomoses were observed to connect the posterior roots of a cervical nerve with the spinal rootlet of the accessory nerve. The possibility that the motor fibers of accessory nerve from the spinal cord may innervate the trapezius muscle through the cervical nerve, was discussed.

Accessory Nerve↗
PubMed2001

Topographical anatomy of the fibula and peroneal artery in Koreans.

Vascularized fibula flaps have many advantages in the restoration of the contour and function of the mandible. Potential disadvantages include, unreliable skin paddle and the limited volume of the fibula. This study was designed, to clarify the anatomy of the peroneal artery to the fibula and lateral leg skin, and to measure the dimensions of the fibula available for dental implant placement in Korean. Through the dissection of 63 legs of Korean cadavers, we demonstrated that in most cases the musculoperiosteal (mp) and septocutaneous (sc) branches of the peroneal artery were distributed at the middle and lower thirds of the fibula. There were double the number of mp perforators to the skin compared to sc branches. This indicates the inclusion of a generous > 1 cm cuff of Peroneous longus and flexor hallucis longus (FHL) in the distal and middle third of the fibula. The location of the nutrient foramen was just proximal to the midpoint. Thus, a 15-20 cm length of the fibula is available in Koreans and an 8 12 mm length of implant can be placed to the fibula, which provides sufficient bone to reconstruct a large mandibular defect.

Adolescent↗
PubMed2000

Anatomical study of the accessory head of the flexor pollicis longus and the anterior interosseous nerve in Asians.

Anterior interosseous nerve palsy is known to occur uncommonly due to the compression of the nerve by the accessory head of flexor pollicis longus (AHFPL). This study was conducted to investigate the prevalence and origin of the AHFPL and the topographical relationship between the AHFPL and the anterior interosseous nerve in Asians. The AHFPL was present in 48 of 72 arms examined (66.7%), a majority of which originated from the coronoid process. The anterior interosseous nerve was observed to arise from both the medial and posterior aspects of the median nerve. The topographical relationship between the anterior interosseous nerve and the AHFPL was classified into three types depending on if the anterior interosseous nerve crossed the muscular part, or the tendinous part of the AHFPL, or coursed lateral to the AHFPL. The case in which the anterior interosseous nerve crossed the muscular part of the AHFPL occurred most frequently in the current study. The types in which the anterior interosseous nerve may be compressed were also discussed.

Adult↗
PubMed2000

Fontanelle and uncinate process in the lateral wall of the human nasal cavity.

OBJECTIVES: Although a complete anatomic knowledge of the fontanelle is a prerequisite to perform a surgical antrostomy opening, little is known about the boundary, shape, and size of the fontanelle. The purpose of this paper is to determine the best site for maintaining the patency of a surgical antrostomy opening by defining the anatomic boundaries, shape, and size of the fontanelle as well as its histological structure. MATERIALS AND METHODS: One hundred sagittally divided heads were utilized. Mucosa overlying the lateral nasal wall was carefully removed with an operating microscope under 6x magnification. In some cases, a double mucous membrane, including the posteroinferior portion of the uncinate process, was cut as a whole and embedded in paraffin. The sections were stained with H&E. RESULTS: The boundary of the fontanelle and the location of the natural ostium were described in detail. Eight patterns of the posteroinferior portion of the uncinate process were observed. There were three major fontanelle shapes when observed from the medial aspect to the lateral: triangular, pencil-like, and oval. The triangular type was the most common. The anterior portion of the fontanelle was shorter than the posterior when observed medially and was wider than the posterior portion when observed inferiorly. CONCLUSIONS: The anterior portion of the fontanelle is more prone to stenosis than the posterior portion. An antrostomy in the posterior fontanelle may be more ideal for a middle meatal antrostomy of the maxillary sinus.

Adult↗
PubMed2000

Arterial supply of the nasal tip in Asians.

OBJECTIVES: The blood supply to the nasal tip and columella was examined to determine whether it could be damaged as a result of transcolumellar incision during an external rhinoplasty approach in Asians. METHODS: The blood vessels that supply the nasal tip were examined by dissecting 51 cadavers, and their corresponding 102 nasal sections were injected with red latex before dissection. The size and distribution of the vessels were measured with the unaided eye and the primary supply vessels were determined. The subdermal layer in which the vessels lie and the course of the vessels were also investigated. RESULTS: The main blood supply source of the nasal tip proved to be the lateral nasal artery in 78% (80/102) of the cases examined, while the remaining cases (22%) received their blood supply via the dorsal nasal artery. Columellar branches were narrow in diameter and varied in size and appearance, and were therefore appeared insufficient as a main blood supply. These arteries passed through the musculoaponeurotic layer, but they were also in close proximity to the main surgical plane in the dome of the lower lateral cartilage. CONCLUSIONS: The authors speculate that the nasal tip blood supply in Asians is primarily derived from the lateral nasal or dorsal nasal arteries, with a variable contribution from the columella arteries. Therefore, it is important to correctly determine the surgical plane below the musculoaponeurotic layer in order to prevent skin flap necrosis or nasal tip deformity that may occur from damage to the main vessel during an external rhinoplasty approach.

Adult↗
PubMed1999

Asymmetric incision for open rhinoplasty in cleft lip nasal deformity.

One of the problems in the correction of the unilateral cleft lip nasal deformity is the alar web deformity on the mediosuperior side of the nostril. A number of methods for the correction of the alar web deformity have been introduced, but no single procedure has been identified as the standard. In this report, the incision line of the open rhinoplasty was modified and the alar web deformity was corrected by using an incision and closure. Open rhinoplasty with the asymmetric incision was performed on 18 patients with unilateral cleft lip nasal deformity. The incision line used in the normal side was the usual intranasal rim incision line and that used for the columella was the transcolumella incision line. For the cleft side, an intranasal rim incision line was plotted after the rim was lifted upward with forceps to achieve symmetry of the nasal tip. After removal of the forceps, the incision line of the cleft side was displaced outside the nostril. After such an incision, the alar cartilage mobilization and suspension were performed with or without the conchal cartilage graft. All patients used nasal retainers for 6 months after the procedures. So far, satisfactory results have been obtained with the modification of the incision line for open rhinoplasty. This method is unique in designing the incision line, and its procedure is rather simple. The postoperative follow-up period has been 12 to 26 months. A long-term follow-up is still needed, especially in growing children.

Adolescent↗
PubMed1999

Extramammary Paget's disease with aggressive behavior: a report of two cases.

Extramammary Paget's disease (EMPD) is an intraepithelial neoplastic disorder which is included as a rare malignant condition. However, it sometimes shows aggressive behavior of local recurrence and coexisting malignancy. We had experienced nine cases of EMPD involving the scrotum for seven years. Two cases of them presented metastasis. The first case presented extensive inguinal lymph node metastasis with underlying adnexal adenocarcinoma one year after wide local excision. The second case initially presented multiple metastasis to the liver and in the lymph node. The latter, showing fulminant progression with liver metastasis, may be only the second case reported in English literature. EMPD is considered as a malignant neoplasm with aggressive behavior from initial presentation. Because wide local excision of the lesion alone may be occasionally insufficient, a careful follow-up must be done to detect recurrence or internal malignancy.

Aged↗