Biomedical subjects

Jern-Lin Leong

Publications and source records attributed to Jern-Lin Leong.

7 recordsLinked to original sources

PubMed2006

Endoscopic pituitary surgery.

Endoscopic pituitary surgery has definite advantages over the traditional method using the operating microscope. Improved visualization, angled view, and a wider panoramic perspective of the important anatomic relationships of the sphenoid and the sella turcica were the obvious advantages. The direct endonasal transsphenoidal approach is the most minimally invasive. Its advantages include wider access, avoidance of a septoplasty, and the ability for two surgeons to work together enabling better instrumentation and more complete and rapid removal of the tumor.

Endoscopy↗

PubMed2006

CT-MR image fusion for the management of skull base lesions.

OBJECTIVE: Image fusion software creates composite images from computed tomography (CT) and magnetic resonance (MR) images. STUDY DESIGN AND SETTING: CT-MR fusion studies between August 2004 to July 2005 were reviewed. CT scan images (1-mm axial) were obtained on a multi-detector CT scanner. MR images (1-mm axial) were obtained with a T1-weighted, volume acquisition technique. CT-MR fusion images were created on the Instatrak 3500 Plus or CBYON Suite. RESULTS: A total of 25 patients had 27 CT-MR image fusion studies. CT-MR fusion accuracy was 2 mm or better. During preoperative planning and intraoperative navigation, CT-MR fusion facilitated the delineation of the anatomic relationships between the lesion and the skull base. CONCLUSIONS: CT-MR image fusion yields composite images that combine features of each component imaging modality. Image fusion, when combined with surgical navigation, further enhances potential skull base applications for minimally invasive endoscopic surgery.

Adult↗

PubMed2005

Three-dimensional computed tomography angiography of the internal carotid artery for preoperative evaluation of sinonasal lesions and intraoperative surgical navigation.

INTRODUCTION: Three-dimensional computed tomographic angiography (3DCTA) demonstrates the spatial relationships of the internal carotid artery (ICA) and adjacent skull base. This imaging modality may be incorporated into intraoperative surgical navigation during endoscopic skull base surgery. METHODS: The charts of patients who had undergone 3DCTA imaging between July 2002 and February 2005 were reviewed. For 3DCTA, 1 mm axial computed tomography (CT) scan images were obtained with simultaneous intravenous contrast bolus on a multidetector CT scanner (Somatom Sensation 16, Siemens, Munich, Germany). The CBYON Suite version 2.6 to 2.8 (Med-Surgical Services, Mountain View, CA) was also used for creating CTA images through its volume-rendering protocols. RESULTS: A total of 22 3DCTA studies were performed for diagnostic evaluation or preoperative planning. In 18 instances, the 3DCTA images were used during intraoperative surgical navigation. The specific indications for obtaining the 3DCTA study included neoplasm (11 cases), cerebrospinal fluid leak (3 cases), fibro-osseous lesion (2 cases), mucocele (2 cases), and other (4 cases). Images generated by 3DCTA facilitated the definition of the anatomic relationships between the ICA and skull base lesion. During intraoperative surgical navigation, the 3DCTA provided critical information about the ICA location and adjacent skull base anatomy in the operative field. CONCLUSIONS: 3DCTA is a useful means for assessing the ICA and its relationship to skull base lesions. Incorporation of 3DCTA into intraoperative surgical navigation facilitates the comprehension of operative field anatomy in the ICA region. As a result, this imaging technique, especially when combined with intraoperative surgical navigation, may extend the applications of minimally invasive endoscopic approaches to the skull base.

Adolescent↗

PubMed2004

Insular carcinoma of the thyroid with jugular vein invasion.

BACKGROUND: Gross angioinvasion with intraluminal tumor thrombus is rarely seen in thyroid cancer, with few cases reported in the literature. METHODS: We report an insular carcinoma of the thyroid displaying this aggressive local invasion and angioinvasion of the internal jugular chain. Complete surgical removal of the intraluminal disease, regional metastasis, and primary tumor was carried out. RESULTS: Adjuvant external beam radiation therapy and iodine-131 were administered, and the patient died with pulmonary metastases 30 months after surgery. No locoregional recurrence was noted at last follow-up. CONCLUSIONS: Treatment of insular carcinoma of the thyroid with invasion of the internal jugular vein is amenable to surgical resection. Postoperative radioactive iodine and external beam radiotherapy can achieve locoregional disease control and prolonged survival.

Aged↗

PubMed2004

Epidermal growth factor receptor in undifferentiated carcinoma of the nasopharynx.

OBJECTIVES: To determine the expression levels of epidermal growth factor receptor (EGFR) and its prognostic value in undifferentiated carcinoma (UC) of the nasopharynx. STUDY DESIGN: A prospective study of 75 patients diagnosed with UC over a 4-year period in a tertiary care hospital. MATERIALS AND METHODS: Postnasal space biopsies were obtained and processed, and immunohistochemical staining was performed. The over-expression of EGFR was measured, and the expression levels were statistically analyzed with the clinical and pathologic variables. Disease-free and overall survival analyses were performed. RESULTS: There were 62 (82.7%) specimens that showed over-expression of EGFR levels. Over-expression of EGFR correlated significantly only with primary tumor size (P =.007). Age, sex, positive smoking and family history, presence of nodal metastasis, distant metastasis, and Epstein-Barr virus serology titers were not significantly correlated with over-expression of EGFR. Both 54-month disease-free and 56-month overall survivals were not associated with EGFR over-expression. CONCLUSION: The frequency of over-expression of EGFR in UC is similar to other squamous cell carcinoma (SCC) of the head and neck region. Only primary tumor size is independently correlated with over-expression of EGFR. EGFR over-expression does not affect disease-free and overall survival.

Carcinoma↗

PubMed2003

Hazardous foreign bodies: complications and management of button batteries in nose.

Miniature batteries are easily available in our domestic environment, powering many electronic devices and toys. Despite improvement in the safety standards, children are able to remove the batteries from these devices. These batteries pose a hazard to children, as they are small and easily inserted into the nose or ears or even swallowed. We describe 6 children who inserted button batteries into their noses. Four of these insertions resulted in septal perforations. The mechanisms and management of button battery injury are discussed. We emphasize the need for urgent removal of a battery from the nose to prevent long-term complications.

Child, Preschool↗

PubMedDate not supplied

Reconstruction of skull base defects after minimally invasive endoscopic resection of anterior skull base neoplasms.

BACKGROUND: The endoscopic resection of the cribriform plate during minimally invasive endoscopic resection (MIER) of the anterior skull base neoplasms may result in large anterior skull base defects. The objective of this study is to describe techniques for the management of skull base defects after MIER. METHODS: Retrospective analysis was performed on patients undergoing MIER and skull base reconstruction between April 2000 and August 2005. RESULTS: Fourteen patients underwent endoscopic resection of anterior skull base tumors and reconstruction during the study period. The mean age was 57.4 years (range, 26-84 years). The sex distribution was eight men and six women. The specific indications for resection included 11 malignant and 3 benign neoplasms. Ten patients received adjuvant therapy, and in two instances this occurred before surgery. In all instances, the dura was exposed; however, only 10 cerebrospinal fluid (CSF) leaks were encountered intraoperatively. Reconstruction of the skull base was successfully performed, most commonly in a multilayer fashion, using an array of materials including cartilage, fat, acellular dermal graft, and mucosal free grafts. Lumbar drain placement was used in seven cases for an average of 5.6 days. No postoperative CSF leaks occurred. The mean follow-up was 18.0 months (range, 1-56 months). CONCLUSION: This report describes methods for the reconstruction of the skull base after MIER. Reconstitution of the skull base barrier can be achieved through application of principles for surgical repair of CSF rhinorrhea.

Adult↗