Original Article

Faisham WI, Zulmi W, Halim AS, Biswal BM, Mutum SS, Ezane AM
Correspondence: Dr WI Faisham, faisham@kb.usm.my

ABSTRACT
Introduction The surgical treatment of Stage III or aggressive giant cell tumour of the bone, whether to perform intralesional or en-bloc resection, remains controversial. The aim of this study is to identify the effectiveness of en-bloc resection for local control and final oncological outcome of the disease.
Methods The data of 20 consecutive patients with Stage III giant cell tumour were retrospectively reviewed to determine the local control and oncological outcome after treatment with wide resection.
Results The majority of the patients presented late with mean duration of symptoms of 24 months, and four patients presented with recurrences. All patients were treated with wide resection except for two patients who underwent ablative surgery due to major neurovascular involvement. Ten patients required free vascularised tissue transfer to cover massive soft tissue defect. Local recurrence occurred in one patient who was again treated with wide resection and vascularised flap. Six patients had pulmonary metastases. Two patients with resectable disease were treated with thoracoscopic surgery and they remained disease-free 36 months after surgery. Two patients with multiple lung metastases were treated with chemotherapy and the disease remained non-progressive. The remaining two patients who refused chemotherapy showed radiological progression, and one succumbed to the disease with massive haemoptysis.
Conclusion Aggressive giant cell tumour of bone should be treated with wide resection for better local control, and treatment of pulmonary metastases is mandatory for overall prognosis.

Keywords: aggressive giant cell tumour, bone tumours, giant cell tumour, wide resection
Singapore Med J 2006; 47(8): 679-683

Parmar KA, Rao S, Abu-Zidan FM
Correspondence: Dr Fikri M Abu-Zidan, fabuzidan@uaeu.ac.ae

ABSTRACT
Introduction The objective of this study was to study the clinical course and outcome of warfarinised patients who were hospitalised because of head trauma.
Methods 13 patients (ten males and three females; median age 69 years) who presented to the Royal Perth Hospital, Australia and who had suffered a head injury between July 1994 and June 2000 while concurrently taking warfarin, were studied.
Results Confusion was the commonest presenting symptom (four patients). Five patients presented after more than 24 hours of the injury. Eight patients were anticoagulated for thromboembolic disease and five for atrial fibrillation. The patients had a median injury severity score of 25 (range 1-43). The median international normalised ratio was 2.4 (range 1.8-10) on admission and 1.8 (range 1.0-10) on discharge. 11 of the 13 patients had computed tomography of the head. Intracerebral bleeding was the commonest injury (nine patients). The median length of hospital stay was six days (range 3-30). Five patients died (38.5%).
Conclusion Warfarinised patients who sustain minor head trauma should be hospitalised for close neurological observation and should have a low threshold for performing computed tomography.

Keywords: computed tomography, head trauma, intracerebral haemorrhage, warfarin
Singapore Med J 2006; 47(8): 676-678

Kaleem M, Asif M, Ahmed QU, Bano B
Correspondence: Dr Bilqees Bano, kaleem_biochem@yahoo.com

ABSTRACT
Introduction The aim of the study is to analyse the antioxidant effect of oral administration of aqueous extract of Annona squamosa (A. squamosa) leaf on blood glucose, haemoglobin, glycosylated haemoglobin, plasma insulin, antioxidant enzymes and lipid peroxidation in liver and kidney to streptozotocin (STZ)-induced diabetic rats.
Methods Aqueous extract of A. squamosa on blood glucose, haemoglobin, glycosylated haemoglobin, plasma insulin, serum lipid and the levels of lipid peroxides and antioxidant enzymes, such as catalase, superoxide dismutase, glutathione peroxidase and reduced glutathione, were examined in the liver and kidney tissues of control and experimental groups.
Results Oral administration of A. squamosa aqueous extract to diabetic rats for 30 days significantly reduced the levels of blood glucose, lipids and lipid peroxidation, but increased the activities of plasma insulin and antioxidant enzymes, like catalase, superoxide dismutase, reduced glutathione and glutathione peroxidase.
Conclusion The A. squamosa aqueous extract supplementation is useful in controlling the blood glucose level, improves the plasma insulin, lipid metabolism and is beneficial in preventing diabetic complications from lipid peroxidation and antioxidant systems in experimental diabetic rats; therefore, it could be useful for prevention or early treatment of diabetes mellitus.

Keywords: Annona squamosa, antioxidant, blood glucose, diabetes mellitus, free radicals, oxidative stress
Singapore Med J 2006; 47(8): 670-675

Ganesh R, Leese T, Rao AD, Baladas HG
Correspondence: Dr Trevor Leese, tbleese54@hotmail.com

ABSTRACT
Introduction Severe obesity is an increasing problem in Singapore. Laparoscopic adjustable gastric banding (LAGB) was introduced at our hospital in 2001 as part of a comprehensive weight management programme. To assess the effectiveness of this procedure, our results to date have been reviewed.
Methods A prospective database was kept of all patients undergoing LAGB and this was used to retrieve the information.
Results 256 consecutive patients underwent LAGB from January 2001 up to December 2005. There were 163 females and 93 males, with a median age of 36 years (range 18-63 years). Median preoperative weight was 112.7 kg (range 71.5-204 kg) and median body mass index (BMI) was 41.9 (range 32-73). Three patients were converted from laparoscopic to open laparotomy (1.2 percent). 91 percent of patients were discharged home on the first postoperative day. There were seven hospital morbidities (2.7 percent) with one mortality (0.4 percent). During follow-up, 20 patients (7.8 percent) developed late complications requiring revision surgery. Ten were band complications, requiring revision or removal of the band. The other ten were minor access port or tubing complications. Median weight loss at one year was 27.6 kg (range 5.6-71.2 kg) and median excess weight loss, using a BMI of 23 as a baseline, was 51.7 percent (range 9-117.5 percent). Easily measurable comorbidities such as diabetes mellitus and hypertension improved or resolved in 85.4 percent of patients.
Conclusion There is a clear demand for LAGB in Singapore. This has increased since the BMI thresholds for severe obesity were reduced in Asian patients. The surgery provides effective, lasting weight loss with improvement or resolution of comorbidity for most patients. LAGB has the advantages of allowing controlled weight loss and life-long treatment while being easily reversible. When compared to other bariatric surgical procedures, low hospital morbidity has to be offset against the closer follow-up required and the need for secondary surgical procedures in some patients.

Keywords: bariatric surgery, gastric band, laparoscopic adjustable gastric banding, laparoscopy, obesity
Singapore Med J 2006; 47(8): 661-669

Tan TY, Ng SY
Correspondence: Dr Tan Thean Yen, thean_yen_tan@cgh.com.sg

ABSTRACT
Introduction Colistin is a polypeptide antibiotic belonging to the polymyxins, and has been increasingly used for the treatment of multiresistant gram-negative infections. There is little current available data on the susceptibility of gram-negative bacilli to colistin, in part because susceptibility testing for colistin remains problematic, and also because the use of colistin is not widespread. This study tested clinical isolates of gram-negative bacilli for susceptibility to colistin using the reference susceptibility testing method of agar dilution.
Methods 102 strains of gram-negative bacilli were collected over a one-year period. Antibiotic susceptibility profiles were derived from disc susceptibility testing, and organisms were identified by standard microbiological methods. Isolates were selected for inclusion in the study using susceptibility profiles and epidemiological data. Minimum inhibitory concentrations to colistin were obtained by performing agar dilution according to a standardised method.
Results 30 percent of tested isolates were resistant to colistin. All Acinetobacter spp. and Escherichia coli were susceptible to colistin. Colistin resistance was detected predominantly in Stenotrophomonas maltophilia and Pseudomonas aeruginosa, but was also present in Enterobacter spp. and Klebsiella spp.
Conclusion Colistin resistance is uncommon in the Enterobacteriaceae, but present in a significant proportion of S. maltophilia and P. aeruginosa isolates. From the results of this study, we recommend that susceptibility testing be performed whenever the clinical use of the polymyxins is considered.

Keywords: anti-bacterial agents, antibiotic resistance, bacterial drug resistance, colistin, gram-negative infection
Singapore Med J 2006; 47(7): 621-624

Chuah CT, Lim MCC, Seah LL, Ling Y, Chee SP
Correspondence: Dr C T Chuah, chintekchuah@yahoo.com

ABSTRACT
Introduction Retinoblastomas of the eye are a cause of childhood blindness and have a high rate of mortality, as well as a hereditary mode of transmission. Other conditions that mimic retinoblastomas are known as pseudoretinoblastomas, and are managed differently. Although pseudoretinoblastoma and the accuracy of retinoblastoma diagnosis have been reviewed in Caucasian patients, published studies in Asian patients are lacking. The purpose of this article is to report our experience with pseudoretinoblastomas in two major ophthalmological centres in Asia.
Methods A case series of 28 enucleations carried out for suspected retinoblastoma at the Singapore National Eye Centre and KK Women's and Children's Hospital, Singapore, between January 1991 and December 2002, is reported. All cases were subjected to a detailed history from parents, followed by external ocular examination, slit-lamp biomicroscopy and binocular indirect ophthalmoscopy. Ancillary studies, such as B-scan ultrasonography and computed tomography, were employed as necessary to confirm the diagnosis. Histology was obtained on all cases.
Results Of the 28 cases, 25 (89 percent) were found on histological analysis to be retinoblastomas. Three (11 percent) were pseudoretinoblastomas. There were two cases of Coat's disease and a case of presumed ocular toxocariasis. These three cases were described in detail.
Conclusion Although our sample size is small, the percentage of confirmed retinoblastomas was found to be only slightly higher than that found in western countries. Our findings are consistent with their findings that Coat's disease and presumed ocular toxocariasis are the more common causes of pseudoretinoblastoma.

Keywords: Coat’s disease, eye enucleation, retinoblastoma, toxocariasis
Singapore Med J 2006; 47(7): 617-620

Kang WL, Balakrishnan A
Correspondence: Dr Wee Lee Kang, kangweelee@yahoo.com.sg

ABSTRACT
Introduction The KK Women's and Children's Hospital (KKWCH) is Singapore's only tertiary institution dedicated wholly to the provision of healthcare for women and children. Since its opening in 1997, the clinical caseloads and the complexity of medical conditions managed by the various departments has increased considerably. This review aims to analyse the operative caseloads in the Department of Otolaryngology over five years from 2000 to 2004.
Methods This is a retrospective review of the KKWCH Department of Otolaryngology operative records from year 2000 to 2004. The data on the type of operation and their frequency were collated, and the data are presented in a descriptive format.
Results There was an increase in the number of operations performed from 656 in year 2000 to 1,148 in 2004, an increase of 75 percent. The increase in the staffing and operating clinical hours (in 2003 and 2004) plus the significant demand for paediatric otolaryngology service probably contributed to this increase. Tonsillectomy, with or without adenoidectomy, continues to be the most common procedure being performed in children, with myringotomy and tympanostomy tube insertion being the second commonest. Together, the ten most common operative procedures constitute 78.2 percent of all paediatric otolaryngological operative workload in the department over a five-year period.
Conclusion The data provided a review of the current pattern of otolaryngological surgical disease in the Singapore paediatric population, which may require operative intervention. Understanding and monitoring of this trend is important, as it allows the proper allocation of appropriate resources for the prevention and treatment of common paediatric surgical otolaryngological conditions.

Keywords: children, operative workload, otolaryngology, tonsillectomy
Singapore Med J 2006; 47(7): 614-616

How SH, Chin SP, Zal AR, Liam CK
Correspondence: Dr How Soon Hin, how_sh@yahoo.com

ABSTRACT
Introduction Previous studies have reported high rates of undetermined causes of pleural effusions. We aimed to find out the proportion of pleural effusions in which the aetiology is uncertain despite commonly available investigations.
Methods A prospective study was carried out at the University of Malaya Medical Centre from May 2001 to January 2002. All patients with pleural effusion admitted to the medical wards and non-medical wards during that period were included in the study.
Results Of 111 patients with pleural effusion, malignancy was the commonest cause of pleural effusion (34.2 percent), followed by tuberculosis (22.5 percent) and parapneumonic effusions (18.9 percent). There were only two patients (1.8 percent) with undetermined cause despite extensive investigations. Carcinoma of the lung was the commonest cause of malignant effusions and bronchoscopic biopsy gave the highest yield of histological diagnosis (66 percent), followed by pleural fluid cytology (59 percent) and pleural biopsy (50 percent). The combination of these three procedures increased the diagnostic yield to 96 percent. In tuberculous pleural effusion, pleural fluid staining for acid-fast bacilli was negative in all cases but mycobacterial culture was positive in 24 percent of cases while pleural biopsy gave a better yield of 68.8 percent. Examination of sputum and bronchoalveolar lavage specimens confirmed the diagnosis of tuberculosis in 40 percent of cases. A combination of these investigations yielded the diagnosis in 92 percent of patients with tuberculous effusion.
Conclusion Malignancy is the commonest cause of pleural effusion, followed by tuberculosis and pneumonia, in patients treated in a teaching hospital in Malaysia. The number of undetermined causes could be minimised with a combination of readily-available and established investigations.

Keywords: bronchoscopy, malignant pleural effusion, pleural biopsy, tuberculosis
Singapore Med J 2006; 47(7): 609-613

Sutedja DS, Wai CT, Teoh KF, Lee YM, Diddapur RK, Isaac J, Mak K, Da Costa M, Lee KH, Prabhakaran K, Tan KC, Lim SG
Correspondence: Dr Seng-Gee Lim, mdclimsg@nus.edu.sg

ABSTRACT
Introduction Patients who survive the initial post-liver transplantation period face the development of chronic diseases in the long run. We studied two important complications of liver transplantation, namely: renal impairment and diabetes mellitus.
Methods We analysed adult patients followed-up for more than one year using data from our liver transplant clinical records. Long-term post-transplant renal impairment (RI) was defined as glomerular filtration rate (GFR) less than 60 ml/min/1.73 square metres and long-term post-transplant diabetes mellitus (DM) was defined as fasting blood glucose more than 7.8 mmol/L, that existed at least one year after liver transplantation. Pre- and post-transplant factors that could be associated with these conditions were examined.
Results Altogether, 35 patients were evaluated. Mean age at transplant was 50 years. Mean duration of follow-up was 58.4 months. There was 11.4 percent of pre-transplant RI and 17.0 percent of pre-transplant DM. Prevalence of post-transplant RI was 43.5 percent at one year and 45.0 percent at four years. Long-term post-transplant RI was associated with renal impairment at six months post-transplant (p-value is 0.033). Prevalence of severe post-transplant RI (GFR is less than 30 ml/min/1.73 square metres) at four years was 5.7 percent. Prevalence of post-transplant DM was 45.5 percent at two years but declined to 5.3 percent at four years.
Conclusion Post-transplant renal impairment appears to be a potential long-term problem while post-transplant diabetes mellitus appears to improve with time.

Keywords: diabetes mellitus, glomerular filtration rate, liver transplant, liver transplant complications, renal impairment
Singapore Med J 2006; 47(7): 604-608

Lim SG, Wai CT, Da Costa M, Sutedja DS, Lee YM, Lee KH, Tan CK, Aw MM, Quak SH, Prabhakaran K, Tan KC, Isaac J
Correspondence: Dr Seng-Gee Lim, mdclimsg@nus.edu.sg

ABSTRACT
Introduction Referral patterns, waiting times, waiting list, and mortality provide information on how effectively a transplant programme deals with referred patients. This paper aims to review these parameters in the Singapore National Liver Transplant Programme.
Methods Data of all patients referred to the Singapore National Liver Transplant Programme since its inception were captured and outcomes were retrieved and described.
Results 562 patients were referred for liver transplant evaluation from 1990-2004, consisting of 457 adults and 105 children. The main indications for referral were hepatitis B liver disease and hepatocellular carcinoma in adults, and biliary atresia in children. Most patients were of United Network of Organ Sharing (UNOS) status 3 or 4 at the time of referral. 114 (20.28 percent) patients had transplants, consisting of 66 adults (14.44 percent) and 48 (45.71 percent) children. 138 adults and ten children were rejected for transplant, mainly for the reason of being "too early". The median waiting time for adults who had transplants was 3.3 months while adults still on the waiting list had been waiting for 16.2 months. The overall waiting list mortality was 44.3 percent, being 52.5 percent in adults and 23.2 percent in children.
Conclusion The overall transplantation rate is low and the waiting list mortality is high as a result of low availability of organs, particularly in adults. Paediatric liver transplant appears to have been better at dealing with referred patients but this is probably due to availability of living-related liver transplant. Improvement in these may result from the Human Organ Transplant Act.

Keywords: liver transplantation, organ availability, patient referral patterns, waiting lists
Singapore Med J 2006; 47(7): 599-603