Biomedical subjects

Wei-Keat Cheah

Publications and source records attributed to Wei-Keat Cheah.

8 recordsLinked to original sources

PubMed2006

Contrast CT in localization of acute lower gastrointestinal bleeding.

Localization of the source of acute lower gastrointestinal bleeding is of paramount importance in its management as it allows for planned segmental resection rather than a "blind" abdominal total colectomy. Various methods of localization with radionuclide scan, mesenteric angiography and colonoscopy have been utilized, but none has been shown to be superior to others. The recent use of contrast-enhanced multislice computed tomography (MSCT) has generated much interest as it is rapid, noninvasive and readily accessible, and allows for excellent reformation on different planes. These are clear advantages in an emergency setting for accurate localization prior to surgery. We report a case where the use of MSCT resulted in prompt and accurate localization in a patient who presented acutely with massive lower gastrointestinal bleed. We believe that contrast-enhanced MSCT has the potential of accurately localizing the source of bleeding in an emergency setting, and should be part of the algorithm in the management of acute lower gastrointestinal bleeding.

Aged↗

PubMed2006

A hyperthyroid patient with measurable thyroid-stimulating hormone concentration - a trap for the unwary.

INTRODUCTION: In a patient with hyperthyroidism, the detection of elevated thyroid hormone concentration with measurable thyroid-stimulating hormone (TSH) value poses considerable diagnostic difficulties. CLINICAL PICTURE: This 38-year-old lady presented with clinical features of thyrotoxicosis. Her serum free thyroxine concentrations were unequivocally elevated [45 to 82 pmol/L (reference interval, 10 to 20 pmol/L)] but the serum TSH values were persistently within the reference interval [0.49 to 2.48 mIU/L (reference interval, 0.45 to 4.5 mIU/L)]. TREATMENT: Investigations excluded a TSH-secreting pituitary adenoma and a thyroid hormone resistance state and confirmed false elevation in serum TSH concentration due to assay interference from heterophile antibodies. The patient was treated with carbimazole for 18 months. OUTCOME: The heterophile antibody-mediated assay interference disappeared 10 months following the initiation of treatment with carbimazole, but returned when the patient relapsed. It disappeared again 2 months after the initiation of treatment. CONCLUSIONS: Clinicians should be aware of the potential for interference in immunoassays, and suspect it whenever the test results seem inappropriate to the patient's clinical state. Misinterpretation of test values, arising as a result of assay interference, may lead to misdiagnosis, unnecessary and at times expensive investigations, delay in initiation of treatment and worst of all, the initiation of inappropriate treatment.

Adenoma↗

PubMed2005

Improvements in health care for patients undergoing thyroidectomy.

OBJECTIVE: In this study, we evaluated the effect on cost and clinical outcome of the implementation of departmental subspecialization and a clinical care pathway for patients undergoing thyroidectomy. METHODS: Subspecialization and a clinical thyroidectomy pathway were implemented in 2001 at the Department of Surgery, National University Hospital, Singapore. A total of 150 patients (Group A) who served as controls were compared with 143 patients who were managed after implementation of subspecialization and the clinical thyroidectomy pathway (Group B). Length of stay, postoperative complications and cost per patient were compared between the two groups. RESULTS: The mean age was 46 years and females comprised 77% of all patients. The mean length of hospital stay was shorter in Group B (1.9 days) compared with Group A (3.3 days; p < 0.001). The mean hospital charges also fell significantly after implementation, at 3,524 dollars per patient in Group B compared with 3,929 dollars in Group A (p = 0.003). There was no difference in morbidity between the two groups (2.0% and 1.4% in Groups A and B, respectively). CONCLUSION: This study confirms that length of hospital stay and hospital costs are effectively reduced through the combination of subspecialization and a clinical pathway for patients undergoing thyroidectomy. Subspecialty units and pathways reduce variation in patient care. This effectively leads to better-quality outcomes, more efficient discharge planning and improved cost-effectiveness of clinical services.

Cost-Benefit Analysis↗

PubMed2005

Laparoscopic-assisted management of small bowel obstruction due to phytobezoar.

Laparoscopy is gaining increasing acceptance for diagnosis and treatment of selected cases of small bowel obstruction. We describe a laparoscopic-assisted procedure used for the treatment of small bowel obstruction caused by a bezoar. A 51-year-old man presented with acute small intestinal obstruction. He had no history of previous abdominal surgery. Diagnostic laparoscopy confirmed a distal ileal obstruction due to an enterolith (bezoar). A limited abdominal incision allowed enterotomy and removal of the obstructing bezoar. Gastroscopy performed a month later showed gastric bezoars which could not be removed endoscopically. Instead, cellulase, a hydrolytic enzyme, was used successfully to treat the condition.

Bezoars↗

PubMed2005

Laparoscopic management of acute small bowel obstruction.

BACKGROUND: Conventional surgical management of acute small bowel obstruction involves laparotomy. The laparoscopic approach has not been favoured due to the presumed increased risk of bowel injury. METHODS: A retrospective review of our experience of laparoscopic management of acute small bowel obstruction was undertaken. Nine patients were identified from 1997 to 2003. The aetiology of obstruction was identified laparoscopically in all cases. Eight cases were caused by bands or local adhesions and one patient had a bezoar. RESULTS: Laparoscopic treatment was successful in 78% of patients including one laparoscopy-assisted procedure. Conversion to laparotomy was performed in two patients, one due to difficult adhesiolysis and one due to iatrogenic bowel injury during adhesiolysis. The mean operating time was 74 minutes. There were no postoperative complications and the mean length of hospital stay was 4.3 days. CONCLUSION: This small series demonstrates that laparoscopy can serve as a good diagnostic tool as well as treatment of acute small bowel obstruction. In an appropriately selected patient, laparoscopic management of small bowel obstruction is a feasible therapeutic approach and appears to convey the benefits of a short postoperative hospital stay, reduced postoperative complications and possibly reduced subsequent adhesion formation.

Abdomen, Acute↗

PubMed2004

Loss of parafibromin immunoreactivity is a distinguishing feature of parathyroid carcinoma.

PURPOSE: A reliable method for diagnosing parathyroid carcinoma has remained elusive over the years, resulting in its under-recognition and suboptimal therapy. Obtaining an accurate diagnosis has become an even more pressing matter with recent evidence that germline HRPT2 gene mutations are found in patients with apparently sporadic parathyroid carcinoma. There is a high prevalence of HRPT2 gene mutations and biallelic inactivation in parathyroid carcinoma. We hypothesize that loss of parafibromin, the protein product of the HRPT2 gene, would distinguish carcinoma from benign tissue. EXPERIMENTAL DESIGN: We generated a novel antiparafibromin monoclonal antibody and performed immunostaining on 52 definite carcinoma specimens, 6 equivocal carcinoma specimens, 88 benign specimens, and 9 hyperparathyroidism-jaw tumor (HPT-JT) syndrome-related adenomas from patients with primary hyperparathyroidism from nine worldwide centers and one national database. RESULTS: We report that the loss of parafibromin nuclear immunoreactivity has 96% sensitivity [95% confidence interval (CI), 85-99%] and 99% specificity (95% CI, 92-100%) in diagnosing definite carcinoma. Inter-observer agreement for evaluation of parafibromin loss was excellent, with unweighted kappa of 0.89 (95% CI, 0.79-0.98). Two equivocal carcinomas misclassified as adenomas were highlighted by parafibromin immunostaining. One of these tumors has since recurred, satisfying criteria for a definite carcinoma. Similarly, eight of nine HPT-JT syndrome-related adenomas showed absent nuclear immunoreactivity. CONCLUSIONS: Parafibromin is a promising molecular marker for diagnosing parathyroid carcinoma. The similar loss of parafibromin immunoreactivity in HPT-JT syndrome-related adenomas suggests that this is a pivotal step in parathyroid tumorigenesis.

Antibodies, Monoclonal↗

PubMed2004

Posterior mediastinal goiter.

Most mediastinal goiters are retrosternally situated in the anterior mediastinal compartment. Posterior mediastinal goiters, either retrotracheal or retroesophageal, are rare. We herein describe a case involving a retrotracheal goiter in the right posterior mediastinum, which was excised using a combined cervico-partial sternotomy and right thoracotomy approach.

Cough↗

PubMed2002

Laparoscopic appendectomy for perforated appendicitis.

Although laparoscopic appendectomy for uncomplicated appendicitis is feasible and safe, its application to perforated appendicitis is uncertain. A retrospective study of all patients with perforated appendicitis from 1992 to 1999 in a university hospital was performed. A series of 231 patients were diagnosed as having perforated appendicitis. Of these patients, 85 underwent laparoscopy (LA), among whom 40 (47%) required conversion to an open procedure. An open appendectomy (OA) was performed in 146 patients. The operating time was similar for the two groups. Return of fluid and solid diet intake were faster in LA than OA patients (p < 0.01). Postoperative infections including wound infections and abdominal abscesses occurred in 14% of patients in the laparoscopy group and in 26% of those with OA (p < 0.05). The surgeon's experience correlated with the conversion rate. Laparoscopic appendectomy is associated with a high conversion rate for perforated appendicitis. If successful, it offers patients faster recovery and less risk of infectious complications.

Adolescent↗