2.Atypical enhancement pattern of hepatocellular carcinoma with portal vein thrombosis on multiphasic CT.
Yee Liang THIAN ; Albert S C LOW ; Pierce K H CHOW ; London L OOI ; Alexander Y F CHUNG ; Shoen C S LOW ; Wanying XIE ; Choon Hua THNG
Annals of the Academy of Medicine, Singapore 2011;40(10):454-459
INTRODUCTIONThe 2005 American Association for Study of Liver Diseases (AASLD) diagnostic criteria allow non-invasive diagnosis of hepatocellular carcinoma (HCC) based on their enhancement pattern but we have observed a high incidence of atypical enhancement characteristics in HCC associated with portal vein thrombosis. This study seeks to examine the radiological features of this particular subgroup.
MATERIALS AND METHODSPatients with HCC and portal vein thrombosis who underwent pre-treatment multiphasic CT imaging were drawn from a surgical database. The arterial, portal venous and delayed phase images were assessed qualitatively and quantitatively (with region of interest [ROI] analysis) for lesion hypervascularity and washout. The background enhancement of the left and right lobes of the liver was also quantifi ed by ROI analysis.
RESULTSTwenty-fi ve lesions in 25 patients were selected for analysis. Qualitative analysis showed that 10/25 (40%) lesions demonstrated arterial hypervascularity while 16/25 (64%) lesions showed washout. Ten out of 25 (40%) lesions demonstrated both arterial hypervascularity and washout. Quantitative analysis showed that the average absolute lesion enhancement from precontrast to arterial phases was 49.1 (± 17.1) HU for hypervascular lesions compared to 23.8 (± 16.6) HU for non-hypervascular lesions (P <0.01). The mean absolute enhancement of the background liver parenchyma in the arterial phase was 13.79 (± 7.9) HU for hypervascular lesions compared to 36.6 (± 30.6) HU for non-hypervascular lesions (P = 0.03).
CONCLUSIONA large proportion of HCC with portal vein thrombosis lack characteristic arterial hypervascularity, which may be secondary to compensatory increased arterial supply to the background liver. This is a potential pitfall when applying imaging criteria for diagnosis of HCC.
Adult ; Aged ; Aged, 80 and over ; Carcinoma, Hepatocellular ; complications ; diagnostic imaging ; Female ; Humans ; Liver Neoplasms ; complications ; diagnostic imaging ; Male ; Middle Aged ; Pattern Recognition, Automated ; Portal Vein ; diagnostic imaging ; physiopathology ; Retrospective Studies ; Tomography, X-Ray Computed ; methods ; Venous Thrombosis ; diagnostic imaging ; etiology
3.A clinicopathologic study of uterine smooth muscle tumours of uncertain malignant potential (STUMP).
Joseph S Y NG ; Aaron HAN ; Sung Hock CHEW ; Jeffrey LOW
Annals of the Academy of Medicine, Singapore 2010;39(8):625-628
INTRODUCTIONThe clinical management of Smooth Muscle Tumours of Uncertain Malignant Potential (STUMPs) remains controversial because little is known about the natural history of these tumours and pathological classifications do not correlate well with clinical outcomes and therefore cannot direct management. The objective of this study was to review a single institution's experience with STUMP and recommend a rational clinical approach to the management of patients with this histological diagnosis.
MATERIALS AND METHODSA systematic review of all diagnoses of STUMP and leiomyosarcoma from the gynaecologic oncology and pathology databases between January 1970 and February 2006.
RESULTSA total of 18 diagnoses of STUMP and 72 diagnoses of Ieiomyosarcoma were made during the study period. None of these 72 cases of leiomyosarcoma had a prior diagnosis of STUMP. There were no recurrences in the 18 cases of STUMP with all 18 cases being registered as disease-free after 5 years.
CONCLUSIONSWe recommend that patients with a diagnosis of STUMP be expectantly managed given the low likelihood of leiomyosarcomatous transformation, the lack of any evidence that adjuvant treatments result in better long-term outcomes and that recurrences are amenable to surgical resection with good outcomes.
Adult ; Female ; Humans ; Leiomyoma ; diagnosis ; pathology ; surgery ; Retrospective Studies ; Smooth Muscle Tumor ; diagnosis ; pathology ; surgery ; Uterine Neoplasms ; diagnosis ; pathology ; surgery ; Uterus ; pathology ; surgery
4.Use of the Fix and Flap Approach to Complex Open Elbow Injury: The Role of the Free Anterolateral Thigh Flap.
Christopher Hoe Kong CHUI ; Chin Ho WONG ; Winston Y CHEW ; Mun Hon LOW ; Bien Keem TAN
Archives of Plastic Surgery 2012;39(2):130-136
BACKGROUND: Complex elbow injuries with associated nerve, muscle, or joint injury commonly develop post-inury stiffness. In order to preserve function, joint congruency, elbow stability and durable wound coverage must be achieved in a timely manner. METHODS: A retrospective review of patients who underwent orthopaedic fixation followed by free anterolateral thigh (ALT) flap soft tissue coverage was performed. Five patients were identified and included in this study. RESULTS: We present a series of 5 cases managed with this principle. Soft tissue defects ranged in size from 4x9 cm (36 cm2) to 15x30 cm (450 cm2) and were located either posteriorly (n=4) or anteriorly (n=1). Associated injuries included open fractures (n=3) and motor nerve transection (n=2). Wound coverage was achieved in a mean duration of 18.8 days (range, 11 to 42 day). There were no flap failures and no major complications. The mean postoperative active elbow motion was 102degrees (range, 45degrees to 140degrees). CONCLUSIONS: In our small series we have highlighted the safety and utility of using the free ALT flap in complex elbow injuries. The ALT flap has many advantages which include abundant skin and subcutaneous tissue; vascularised vastus lateralis muscle that was used in our series to obliterate dead space, provide a vascular bed for nerve grafts and combat infection; and, access to fascia lata grafts for reconstruction of the triceps tendon.
Elbow
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Elbow Joint
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Fascia Lata
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Fractures, Open
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Free Tissue Flaps
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Humans
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Joints
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Muscles
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Quadriceps Muscle
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Reconstructive Surgical Procedures
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Retrospective Studies
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Skin
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Tendons
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Thigh
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Transplants
5.Swallowed foreign bodies in children: report of four unusual cases.
T R Sai PRASAD ; Y LOW ; C E TAN ; A S JACOBSEN
Annals of the Academy of Medicine, Singapore 2006;35(1):49-53
INTRODUCTIONAlthough a majority of ingested foreign bodies (FBs) pass down the gastrointestinal tract spontaneously, those that are sharp, pointed or large in size need removal to avert serious complications. We highlight the urgent need and utility of endoscopic accessories and technical artistry in safe retrieval of FBs in children.
CLINICAL PICTUREFour children had accidentally swallowed a nail, metallic dumbbell, open safety pin and a cushion pin respectively. They were symptom-free and the abdominal plain radiographs revealed foreign body in the stomach in all the cases.
TREATMENTOesophago-gastro-duodenoscopy (OGD) was done in all the patients and could retrieve the nail, metallic dumbbell and open safety pin successfully using a Dormia basket, a polypectomy snare and a pair of rat-tooth forceps respectively. The cushion pin had migrated to the duodeno-jejunal junction within 4 hours of ingestion and necessitated open duodenotomy and retrieval.
OUTCOMEAll patients did well after the procedure with no complications.
CONCLUSIONSSwallowed FBs with pointed or sharp ends or large enough to cross the pylorus and duodenal sweep need removal and in the majority of the cases they can be retrieved by OGD. Sharp or pointed FBs that have crossed the second part of the duodenum necessitate urgent laparotomy for retrieval to prevent complications.
Adolescent ; Child ; Child, Preschool ; Deglutition ; Endoscopy, Gastrointestinal ; Female ; Foreign Bodies ; diagnosis ; etiology ; Humans ; Infant ; Male
6.Use of percussion as a screening tool in the diagnosis of occult hip fractures.
Mohan TIRU ; S H GOH ; B Y LOW
Singapore medical journal 2002;43(9):467-469
Traumatic hip pain is a common clinical problem in the emergency department. There is significant morbidity in discharging a patient with an undiagnosed undisplaced hip fracture. The auscultatory percussion technique is a useful method to risk stratify patients who present with traumatic hip pain and with normal radiographs. We sought to study the sensitivity and specificity of the auscultatory percussion technique in a prospective study.
Aged
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Aged, 80 and over
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Auscultation
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methods
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Confidence Intervals
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Female
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Hip Fractures
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diagnosis
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diagnostic imaging
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Humans
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Injury Severity Score
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Male
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Middle Aged
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Percussion
;
methods
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Physical Examination
;
methods
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Predictive Value of Tests
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Prospective Studies
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Reference Values
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Sampling Studies
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Sensitivity and Specificity
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Singapore
;
Single-Blind Method
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Tomography, X-Ray Computed
;
methods
7.Orthogonal test analysis of compressive strength of porous hydroxylapatite prepared by gel-casting process.
Yanjun HAN ; Musen LI ; Yupeng LÜ ; Yunjing SONG ; Y CHEN ; H LOW
Journal of Biomedical Engineering 2004;21(5):704-707
Porous hydroxylapatite (HA) has excellent osseous inductive ability. It has been prepared by gel-casting process, which is feasible and can make complex ceramic material. According to the result of orthogonal test based on the compressive strength, the order and the level of the factors, including monomer HA, initiator MBAM, catalyst APS and water, were dealt with. The effects of drying and sintering technique on the properties of porous hydroxylapatite were also researched. The results showed that the order of every factor in the gel-casting process is as follows, AM-APS, MBAM, H2O. Based on the determined level of each factor, the suitable slurry constituents and drying and sintering technologies were selected, and the porous hydroxylapatite with compressive strength of 6-7 MPa was produced.
Biocompatible Materials
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chemistry
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Bone Substitutes
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chemistry
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Compressive Strength
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Durapatite
;
chemical synthesis
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chemistry
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Gels
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Humans
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Materials Testing
;
methods
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Porosity
;
Surface Properties
8.Capillary blood flow with dynamical change of tissue pressure caused by exterior force.
Yufeng LIU ; Shixiong XU ; Juntao YAN ; Guoquan SHEN ; Wuquan SUN ; Y CHEW ; H LOW ; Jun XU
Journal of Biomedical Engineering 2004;21(5):699-703
A hemodynamic model of capillary and tissue, in which tissue pressure changed with swing manipulation of Traditional Chinese Medical Massage (TCMM), is presented in this paper to explain the hemodynamic mechanism of swing manipulation. Blood flowed in capillary with low Reynolds number. Plasma exuded through capillary according to the Starling's Law. Tissue pressure changed linearly with the massage force measured. Blood apparent viscosity, plasma protein concentration and red cell's hematocrit were taken into account. Capillary flow rate, blood apparent viscosity, filtration rate and filtration fraction with dynamical change of tissue pressure were calculated numerically, and were compared with those in static tissue pressure condition. Results showed that, dynamical change of tissue pressure led to the increase of capillary flow rate and the decrease of blood apparent viscosity, which qualitatively explained the hemodynamic mechanism of "promoting blood circulation and removing blood stasis" in swing manipulation of TCMM.
Biomechanical Phenomena
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Blood Flow Velocity
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Blood Viscosity
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Capillaries
;
physiology
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Hematocrit
;
Hemodynamics
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Humans
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Massage
;
Models, Cardiovascular
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Pressure
;
Regional Blood Flow
9.Long-term Outcomes of Medical Therapy Versus Coronary Revascularisation in Patients with Intermediate Stenoses Guided by Pressure Wire.
Hongyu SHI ; Chi Hang LEE ; Mark Y Y CHAN ; Adrian F LOW ; Swee Guan TEO ; Koo Hui CHAN ; Rishi SETHI ; Arthur Mark RICHARDS ; Huay Cheem TAN
Annals of the Academy of Medicine, Singapore 2015;44(5):157-163
INTRODUCTIONThis study aimed to examine the long-term clinical outcomes of coronary fractional flow reserve (FFR)-guided percutaneous coronary intervention (PCI) in a real-world population in an Asian tertiary centre.
MATERIALS AND METHODSAll patients who underwent FFR measurement for intermediate coronary lesions in our centre from June 2002 to December 2009 were enrolled. A threshold of FFR ≤0.75 was used for revascularisation. All the patients were prospectively followed-up for major adverse cardiac events (MACE) of death, myocardial infarction (MI), target vessel revascularisation (TVR) and stent thrombosis.
RESULTSBased on FFR measurement, 368 (57%) patients were treated medically while 278 (43%) underwent revascularisation. At a mean follow-up duration of 29.7 ± 16 months, 53 (14.4%) patients in the medical therapy group and 32 (11.5%) patients in the revascularised group experienced MACE (P = 0.282). There were no statistical differences in all the clinical endpoints between the 2 groups.
CONCLUSIONMedical therapy based on FFR measurement is associated with low incidences of MACE at long-term follow-up.
Adult ; Aged ; Aspirin ; therapeutic use ; Coronary Stenosis ; complications ; diagnosis ; therapy ; Drug Therapy, Combination ; Female ; Follow-Up Studies ; Humans ; Male ; Middle Aged ; Percutaneous Coronary Intervention ; methods ; Platelet Aggregation Inhibitors ; therapeutic use ; Retrospective Studies ; Ticlopidine ; analogs & derivatives ; therapeutic use ; Treatment Outcome
10.Reperfusion strategy and mortality in ST-elevation myocardial infarction among patients with and without impaired renal function.
Mark Y CHAN ; Richard C BECKER ; Ling-Ling SIM ; Virlynn TAN ; Chi-Hang LEE ; Adrian F H LOW ; Swee-Guan TEO ; Kheng-Siang NG ; Huay-Cheem TAN ; Tiong-Cheng YEO
Annals of the Academy of Medicine, Singapore 2010;39(3):179-184
INTRODUCTIONSeveral randomised controlled trials have demonstrated better outcomes with primary percutaneous coronary intervention (PCI) over fibrinolytic therapy in the treatment of patients with ST-segment elevation myocardial infarction (STEMI) and normal renal function. Whether this benefit extends to patients with impaired renal function is uncertain.
MATERIALS AND METHODSWe studied 1672 patients with STEMI within 12 hours of symptom onset who were admitted to 2 major public hospitals in Singapore from 2000 to 2002. All patients received either upfront fibrinolytic or PCI as determined by the attending cardiologist. Serum creatinine was measured on admission and the glomerular filtration rate (GFR) was determined using the Modification of Diet in Renal Disease equation. The impact of reperfusion strategy on 30-ay mortality was then determined for patients with GFR > or =60 mL min-(1) 1.73 m-(2) and GFR <60 mL min-(1) 1.73 m-(2).
RESULTSThe mean age was 56 +/- 12 years (85% male) and mean GFR was 81 +/- 30 mL min-(1) 1.73 m-(2). Unadjusted 30-day mortality rates for fibrinolytic-treated vs primary PCI-treated patients were 29.4% vs 17.9%, P <0.05, in the impaired renal function group and 5.4% vs 3.1%, P <0.05, in the normal renal function group. After adjusting for covariates, primary PCI was associated with a significantly lower mortality in the normal renal function group [odds ratio (OR), 0.41; 95% confidence interval (CI), 0.19-0.89] but not in the impaired renal function group [OR, 0.70; 95% CI, 0.31-1.60].
CONCLUSIONSPrimary PCI was associated with improved 30-day survival among patients with normal renal function but not among those with impaired renal function. Randomised trials are needed to study the relative efficacy of both reperfusion strategies in patients with impaired renal function.
Adult ; Angioplasty, Balloon, Coronary ; Antifibrinolytic Agents ; therapeutic use ; Electrocardiography ; Female ; Glomerular Filtration Rate ; Humans ; Male ; Middle Aged ; Myocardial Infarction ; complications ; drug therapy ; surgery ; Registries ; Renal Insufficiency, Chronic ; complications ; Retrospective Studies ; Survival Analysis