S S C Chung

The Chinese University of Hong Kong, Hong Kong, Hong Kong

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Publications (20)87.89 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Safe entrance into the peritoneal cavity through the gastric wall is paramount for the successful clinical introduction of natural orifice transluminal endoscopic surgery (NOTES). The aim of the study was to develop alternative safe transgastric access to the peritoneal cavity. We performed 11 survival experiments on 50-kg pigs. In sterile conditions, the abdominal wall was punctured with a Veress needle. The peritoneal cavity was insufflated with 2 L carbon dioxide (CO (2)). A sterile endoscope was introduced into the stomach through a sterile overtube; the gastric wall was punctured with a needle-knife; after balloon dilation of the puncture site, the endoscope was advanced into the peritoneal cavity. Peritoneoscopy with biopsies from abdominal wall, liver and omentum, was performed. The endoscope was withdrawn into the stomach. The animals were kept alive for 2 weeks and repeat endoscopy was followed by necropsy. The pneumoperitoneum, easily created with the Veress needle, lifted the abdominal wall and made a CO (2)-filled space between the stomach and adjacent organs, facilitating gastric wall puncture and advancement of the endoscope into the peritoneal cavity. There were no hemodynamic changes or immediate or delayed complications related to pneumoperitoneum, transgastric access, or intraperitoneal manipulations. Follow-up endoscopy and necropsy revealed no problems or complications inside the stomach or peritoneal cavity. Creation of a preliminary pneumoperitoneum with a Veress needle facilitates gastric wall puncture and entrance into the peritoneal cavity without injury to adjacent organs, and can improve the safety of NOTES.
    Endoscopy 11/2007; 39(10):849-53. DOI:10.1055/s-2007-966844 · 5.05 Impact Factor
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    ABSTRACT: Multiple studies have demonstrated the feasibility of peroral transgastric endoscopic procedures in animal models. The aim of the study was to evaluate the feasibility of a peroral transgastric endoscopic approach to repair abdominal wall hernias. We performed acute experiments under general anesthesia with endotracheal intubation using 50-kg pigs. Following peroral intubation an incision of the gastric wall was made and the endoscope was advanced into the peritoneal cavity. An internal anterior abdominal wall incision was performed with a needle knife to create an animal model of a ventral hernia. After hernia creation an endoscopic suturing device was used for primary repair of the hernia. After completion of the hernia repair the endoscope was withdrawn into the stomach and the gastric wall incision was closed with endoscopic clips. Then the animals were killed for necropsy. Two acute experiments were performed. Incision of the gastric wall was easily achieved with a needle knife and a pull-type sphincterotome. A large (3 x 2 cm) defect of the abdominal wall (ventral hernia model) was closed with five or six sutures using the endoscopic suturing device. Postmortem examination revealed complete closure of the hernia without any complications. Transgastric endoscopic primary repair of ventral hernias in a porcine model is feasible and may be technically simpler than laparoscopic surgery.
    Endoscopy 06/2007; 39(5):390-3. DOI:10.1055/s-2007-966426 · 5.05 Impact Factor
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    ABSTRACT: We have previously reported the feasibility of diagnostic and therapeutic peritoneoscopy including liver biopsy, gastrojejunostomy, and tubal ligation by an oral transgastric approach. We present results of per-oral transgastric splenectomy in a porcine model. The goal of this study was to determine the technical feasibility of per-oral transgastric splenectomy using a flexible endoscope. We performed acute experiments on 50-kg pigs. All animals were fed liquids for 3 days prior to procedure. The procedures were performed under general anesthesia with endotracheal intubation. The flexible endoscope was passed per orally into the stomach and puncture of the gastric wall was performed with a needle knife. The puncture was extended to create a 1.5-cm incision using a pull-type sphincterotome, and a double-channel endoscope was advanced into the peritoneal cavity. The peritoneal cavity was insufflated with air through the endoscope. The spleen was visualized. The splenic vessels were ligated with endoscopic loops and clips, and then mesentery was dissected using electrocautery. Endoscopic splenectomy was performed on six pigs. There were no complications during gastric incision and entrance into the peritoneal cavity. Visualization of the spleen and other intraperitoneal organs was very good. Ligation of the splenic vessels and mobilization of the spleen were achieved using commercially available devices and endoscopic accessories. Transgastric endoscopic splenectomy in a porcine model appears technically feasible. Additional long-term survival experiments are planned.
    Surgical Endoscopy 04/2006; 20(3):522-5. DOI:10.1007/s00464-005-0263-x · 3.26 Impact Factor

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    S K H Wong · W Y So · P Y P Yau · A K L Chan · S Lee · P N Chan · F C C Chow · S S C Chung ·
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    ABSTRACT: To evaluate the efficacy of laparoscopic adjustable gastric banding in the management of morbid obesity in a cohort of Chinese patients. DESIGN. Cohort study. University teaching hospital, Hong Kong. From August 2002 to September 2003, 10 patients (6 male, 4 female) with a median age of 34 years (range, 23-48 years) underwent laparoscopic adjustable gastric banding to treat morbid obesity. Considerable co-existing diseases were present in 90% of the cases. We instituted a team approach that allowed every patient to see our dietitian, physician, psychiatrist (if necessary), and surgeon prior to deciding on the procedure to be used. Excessive body weight loss, quality-of-life score (SF36), and co-morbidities improvement. The 10 patients had a median weight of 127 kg (range, 115-196 kg) and median body mass index of 47 kg/m(2) (range, 38-67 kg/m(2)). The operation was successful in all patients with a median operating time of 110 minutes (range, 75-240 minutes). The median hospital stay was 3 days (range, 3-4 days) and three of the patients required overnight observation in the intensive care unit because of severe sleep apnoea and asthma. The median follow-up period was 12 months (range, 1-18 months). The mean weight loss at 6, 12, and 18 months was 19.3, 22.4, and 25.9 kg, respectively. Mean percentage of excessive weight loss at 6, 12, and 18 months was 34.9%, 36.5%, and 40.5%, respectively. Unsatisfactory weight loss (<20 kg) occurred in three patients because of poor dietary compliance and non-follow-up. Surgery also considerably improved the patients' co-morbidities (hypertension, diabetes, and obstructive sleep apnoea) and the quality of life. In the short term, laparoscopic adjustable gastric banding is certainly an effective procedure for morbid obesity, which results in a substantial weight loss and improvement of co-existing morbidities. Longer follow-up will show whether this weight loss is maintainable.
    Hong Kong medical journal = Xianggang yi xue za zhi / Hong Kong Academy of Medicine 02/2005; 11(1):20-9. · 0.87 Impact Factor
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    ABSTRACT: The pathophysiology of severe acute respiratory syndrome (SARS) is at present poorly understood, but advanced age and serum total lactate dehydrogenase (LD) activity >300 U L(-1) have been associated with adverse clinical outcomes. Blood leucocytes and lymphocyte subsets were reported to decrease, respectively, in 47% and up to 100% of 38 patients in Beijing. However, their prognostic implications have not been thoroughly investigated. To investigate serum total LD, LD isoenzymes, and other parameters including blood lymphocyte subsets as prognostic indicators in SARS patients for adverse clinical outcomes in terms of admission to intensive care unit (ICU) and death. Retrospective analysis. A total of 109 patients with a clinical diagnosis of SARS according to the modified World Health Organization case definition of SARS were recruited from two major acute hospitals in Hong Kong. They were either involved in the initial outbreak of SARS, or cases from the community outbreak of Amoy Gardens between 10 March and 5 May 2003. The clinical diagnosis was subsequently confirmed by serological test and/or molecular analysis. Serum total LD and LD isoenzyme activities, complete blood picture with total leucocyte count and differential counts, absolute counts of CD3+, CD4+, CD8+, natural killer cells and B lymphocytes were measured daily upon admission. Receiver operating characteristic curve analysis was used to determine and compare different cut-offs for various biochemical and immunological parameters at peak serum total LD concentration in predicting adverse clinical outcomes. Of a total of 109 patients, 41 were admitted to ICU and 42 died. Of 42 fatal patients, 24 died in ICU and 18 died in general medical wards. Age was found to be an independent prognostic indicator for death with an area under curve (AUC) of 0.96 [95% confidence interval (CI) = 0.90-0.99] but not for admission to ICU [AUC = 0.61 (CI = 0.51-0.70)]. Whilst serum total LD could only achieve AUC of 0.68 (CI = 0.59-0.77) for predicting death, LD1 isoenzyme was found to be the best biochemical prognostic indicator with AUC of 0.84 (CI = 0.75-0.90), sensitivity of 62% (CI = 46-76%), specificity of 93% (CI = 83-98%) at cut-off activity of > or =80 U L(-1). CD3+, CD4+, CD8+ and natural killer cell counts were promising immunological prognostic indicators for predicting admission to ICU with AUC of 0.94 (CI = 0.86-0.98), 0.91 (CI = 0.81-0.96), 0.93 (CI = 0.85-0.98), and 0.87 (CI = 0.76-0.94), respectively. Apart from age, serum LD1 activity was the best prognostic indicator for predicting death in patients with SARS compared with serum total LD activity, haemoglobin concentration, leucocyte and lymphocyte counts. Its release could possibly be from blood erythrocytes and body tissues other than the myocardium. Blood CD3+, CD4+, CD8+ and natural killer cell counts were found to be good prognostic indicators for predicting admission to ICU in patients with SARS compared with age, leucocyte count and LD isoenzymes. The suppressed CD3+, CD4+, CD8+, and natural killer cell counts were also implicated in the pathophysiology of SARS. Patients with increased serum LD1 should be closely monitored to ensure prompt management, and preparation for admission to ICU could be planned ahead for patients with suppressed lymphocyte subsets.
    Journal of Internal Medicine 04/2004; 255(4):512-8. DOI:10.1111/j.1365-2796.2004.01323.x · 6.06 Impact Factor
  • W H Ng · Y L Chan · J Y Sung · Y T Lee · S F Lee · S S C Chung ·
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    ABSTRACT: Azygos venous blood flow as an index of blood flow through the gastroesophageal collaterals and varices is of value in the prediction of gastrointestinal bleeding. Measurement of azygos venous blood flow has been achieved by non breath-hold (NBH) cine phase-contrast magnetic resonance imaging. The objective of this study was to compare the faster breath-hold (BH) phase-contrast technique with the standard (NBH) cine phase-contrast technique in the measurement of azygos blood flow. Thirty-two cirrhotic patients with esophageal varices were examined by magnetic resonance imaging using a BH technique and a NBH cine phase-contrast technique to measure the flow velocity, flow volume and calibre of the azygos vein at the mid-right atrial level. The flow values were obtained on the velocity image of the phase-contrast study. Values obtained from the two methods were evaluated statistically for the strength and significance of correlation by the Pearson test. Measurement by the BH method performed at full-inspiration as well as end-expiration was also obtained in 15 healthy volunteers. The breath-hold phase-contrast method has significant but weak correlation with non BH cine phase-contrast method in the measurement of azygos venous blood flow volume (r = 0.55, p < 0.01) and flow velocity (r = 0.43, p = 0.01). However, the calibre of the azygos vein gave a strong correlation in these two methods (0.82). In the subgroup of patients whose azygos blood flow velocity was greater than 7.4 cm/s, the correlation of azygos blood flow volume is strong (r = 0.80, p < 0.01). The azygos vein calibre remains highly correlated between the BH and NBH method, in both high flow velocity (r = 0.73) and low flow velocity (r = 0.83) groups. Breath-hold sequence leads to higher values for flow velocity and flow volume in the cirrhotic patients and also the control group. In patients with portal hypertension, BH 2D phase-contrast (PC) magnetic resonance angiography (MRA) could give a comparable estimation of the calibre of the azygos vein as the NBH 2D cine PC MRA but not for azygos flow volume. In patients with high azygos flow velocity, the strong correlation in flow volume between the BH and NBH method suggests that the BH method may be a time-saving alternative to the NBH method.
    MAGMA Magnetic Resonance Materials in Physics Biology and Medicine 04/2004; 16(5):211-7. DOI:10.1007/s10334-003-0026-4 · 2.87 Impact Factor
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    ABSTRACT: Severe acute respiratory syndrome (SARS) is a recently emerged infectious disease caused by a novel coronavirus, but its immunopathological mechanisms have not yet been fully elucidated. We investigated changes in plasma T helper (Th) cell cytokines, inflammatory cytokines and chemokines in 20 patients diagnosed with SARS. Cytokine profile of SARS patients showed marked elevation of Th1 cytokine interferon (IFN)-gamma, inflammatory cytokines interleukin (IL)-1, IL-6 and IL-12 for at least 2 weeks after disease onset, but there was no significant elevation of inflammatory cytokine tumour necrosis factor (TNF)-alpha, anti-inflammatory cytokine IL-10, Th1 cytokine IL-2 and Th2 cytokine IL-4. The chemokine profile demonstrated significant elevation of neutrophil chemokine IL-8, monocyte chemoattractant protein-1 (MCP-1), and Th1 chemokine IFN-gamma-inducible protein-10 (IP-10). Corticosteroid reduced significantly IL-8, MCP-1 and IP-10 concentrations from 5 to 8 days after treatment (all P < 0.001). Together, the elevation of Th1 cytokine IFN-gamma, inflammatory cytokines IL-1, IL-6 and IL-12 and chemokines IL-8, MCP-1 and IP-10 confirmed the activation of Th1 cell-mediated immunity and hyperinnate inflammatory response in SARS through the accumulation of monocytes/macrophages and neutrophils.
    Clinical & Experimental Immunology 04/2004; 136(1):95-103. DOI:10.1111/j.1365-2249.2004.02415.x · 3.04 Impact Factor
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    ABSTRACT: Severe acute respiratory syndrome (SARS) is a highly infectious disease caused by a novel coronavirus, and has become pandemic within a short period of time. Imaging plays an important role in the diagnosis, management and follow-up of patients with SARS. The current status of imaging in SARS is presented in this review.
    Clinical Radiology 12/2003; 58(11):825-32. DOI:10.1016/S0009-9260(03)00308-8 · 1.76 Impact Factor
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    F H Y Yap · J Y W Lau · G M Joynt · P T Chui · A C W Chan · S S C Chung ·
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    ABSTRACT: To assess patient outcome following transthoracic (Ivor-Lewis) oesophagectomy and the effects of epidural analgesia and early extubation compared with overnight sedation and ventilation. Retrospective study. University teaching hospital, Hong Kong. A retrospective review of patients undergoing oesophagectomy during two periods, 1990 to 1994 (n=65) and 1995 to 1998 (n=83), was completed. In the latter period, factors associated with early extubation were also evaluated. Between 1990 and 1994, only three (4.6%) of 65 patients were extubated early compared with 34 (41.0%) of 83 patients between 1995 and 1998 (P<0.001). Comparing these two periods, there were no differences in respiratory complications or hospital mortality. In the period 1995 to 1998, more patients who were extubated early had received epidural analgesia (85% versus 41%, P<0.001). There were no differences between the early and late extubation groups in terms of respiratory complications and hospital mortality. Patients extubated early had shorter stays in the intensive care unit (1 versus 2 days, P=0.005). Epidural analgesia was an independent factor associated with early extubation (odds ratio=9.4; 95% confidence interval, 2.8-31.2). After transthoracic oesophagectomy, early extubation is safe and can lead to a shorter stay in the intensive care unit. Epidural analgesia appears to facilitate early extubation.
    Hong Kong medical journal = Xianggang yi xue za zhi / Hong Kong Academy of Medicine 05/2003; 9(2):98-102. · 0.87 Impact Factor
  • T K W Ling · W K Leung · C C Lee · E K W Ng · MY Yung · S S C Chung · J J Y Sung · A F B Cheng ·

    Helicobacter 11/2002; 7(5):327-8. DOI:10.1046/j.1523-5378.2002.00101_1.x · 4.11 Impact Factor
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    Y L Chan · W T Yang · J.J.Y. Sung · Y T Lee · S.S.C. Chung ·
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    ABSTRACT: A prospective study to compare the diagnostic performance of ultrasonography with magnetic resonance imaging using gradient-recalled echo technique in cases of siderosis of spleen was conducted in 53 cirrhotic patients with endoscopic proof of gastroesophageal varices. Of the 34 patients with splenic siderosis on MR imaging, punctate hyperechoic foci were detected in the spleen on ultrasonography in 24 patients. Using MR imaging as the reference standard for the diagnosis of splenic siderosis, the sensitivity of ultrasonography is 70.6%; specificity is 78.9%; positive predictive value is 85.7%; and negative predictive value is 40%. We conclude that ultrasonography is a fairly accurate technique in the diagnosis of splenic siderosis.
    Journal of ultrasound in medicine: official journal of the American Institute of Ultrasound in Medicine 09/2000; 19(8):543-7. · 1.54 Impact Factor
  • T.M.K. Fung · S.K.H. Wong · A.C.W. Chan · E.K.W. Ng · J.C.Y. Wu · D.W.H. Lee · S.S.C. Chung ·

    Surgical Practice 05/2000; 4(2). DOI:10.1046/j.1442-2034.2000.058.5.x · 0.17 Impact Factor
  • S. K. H. Wong · S. C. H. Yu · YH Lam · S. S. C. Chung ·
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    ABSTRACT: Percutaneous cholecystostomy is a valuable alternative temporary measure for acute cholecystitis in elderly patients with severe underlying cardiopulmonary disease, but the subsequent management of gallbladder calculi is still controversial. Eleven patients treated with percutaneous endoscopic cholecystolithotripsy after percutaneous cholecystostomy were evaluated retrospectively. All patients showed clinical improvement after percutaneous cholecystostomy. Tract dilation succeeded in 9 patients. Complete stone clearance was achieved in seven patients over one to four sessions (average, two sessions). Stone extraction could not be completed in two patients because gallbladder access was lost in one patient, and the other refused further procedure. There were three complications, with two biliary fistulas and one major bile leakage leading to emergency cholecystectomy. The duration of the entire procedure ranged from 30 to 126 days (mean, 58 days). During the follow-up (mean 17.2 months), one patient had recurrent cholangitis and the others remained asymptomatic. Percutaneous cholecystolithotripsy after percutaneous cholecystostomy is a safe alternative in the management of high-risk elderly patients with acute cholecystitis.
    Surgical Endoscopy 02/1999; 13(1):48-52. DOI:10.1007/s004649900896 · 3.26 Impact Factor
  • C. K. Yeung · H. N. Chiu · J. J. Y. Sung · S. S. C. Chung ·

    Gastroenterology 04/1998; 114(4). DOI:10.1016/S0016-5085(98)81382-6 · 16.72 Impact Factor
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    ABSTRACT: To compare endoscopic adrenaline injection alone and adrenaline injection plus heat probe for the treatment of actively bleeding peptic ulcers. Randomised prospective study of patients admitted with actively bleeding peptic ulcers. One university hospital. 276 patients with actively bleeding ulcers detected by endoscopy within 24 hours of admission: 136 patients were randomised to endoscopic adrenaline injection alone and 140 to adrenaline injection plus heat probe treatment. Initial endoscopic haemostasis; clinical rebleeding; requirement for operation; requirement for blood transfusion; hospital stay, ulcer healing at four weeks; and mortality in hospital. Initial haemostasis was achieved in 131/134 patients (98%) who received adrenaline injection alone and 135/136 patients (99%) who received additional heat probe treatment (P = 0.33). Outcome as measured by clinical rebleeding (12 v 5), requirement for emergency operation (14 v 8), blood transfusion (2 v 3 units), hospital stay (4 v 4 days), ulcer healing at four weeks (79.1% v 74%), and in hospital mortality (7 v 8) were not significantly different in the two groups. In the subgroup of patients with spurting haemorrhage 8/27 (29.6%; 14.5% to 50.3%) patients from the adrenaline injection alone group and 2/31 (6.5%; 1.1% to 22.9%) patients from the dual treatment group required operative intervention. The relative risk of this was lower in the dual treatment group (0.17; 0.03 to 0.87). Hospital stay was significantly shorter in the dual treatment group than the adrenaline injection alone group (4 v 6 days, P = 0.01). The addition of heat probe treatment after endoscopic adrenaline injection confers an advantage in ulcers with spurting haemorrhage.
    BMJ Clinical Research 06/1997; 314(7090):1307-11. DOI:10.1136/bmj.314.7090.1307 · 14.09 Impact Factor
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    ABSTRACT: To prospectively compare magnetic resonance (MR) cholangiography with endoscopic retrograde cholangiography (ERC) in the diagnosis of choledocholithiasis. Forty-seven patients with suspected choledocholithiasis underwent non-breath-hold, heavily T2-weighted, respiratory-triggered turbo spin-echo MR cholangiography. They then underwent ERC within 5 hours. The results of the two procedures were compared in 45 patients. The absence of ductal dilatation was shown in 16 patients at MR cholangiography and at ERC. MR cholangiography showed common duct dilatation in 28 of the 29 patients with dilatation shown at ERC. MR cholangiography helped correctly identify 18 of the 19 patients with choledocholithiasis and 22 of the 26 patients without choledocholithiasis. Sensitivity with MR cholangiography was 95%, specificity was 85%, positive predictive value was 82%, and negative predictive value was 96%. Two of the false-positive findings were due to pneumobilia. Non-breath-hold MR cholangiography is as accurate for the evaluation of choledocholithiasis as ERC.
    Radiology 08/1996; 200(1):85-9. DOI:10.1148/radiology.200.1.8657949 · 6.87 Impact Factor

  • British Journal of Surgery 07/1996; 83(7). DOI:10.1002/bjs.1800830742 · 5.54 Impact Factor
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    ABSTRACT: The relationship between upper gastrointestinal hemorrhage and drug use was studied in 251 Chinese patients (179 men, 72 women) admitted to the Prince of Wales Hospital, Hong Kong, and control subjects matched for age and sex. There was a highly significant difference between the cases and control subjects in the use of NSAIDs (odds ratio 14.0, p < 0.00001), ulcer healing drugs (odds ratio 12.5, p < 0.00001), and Chinese proprietary medicines (odds ratio 16.0, p < 0.00001). There was also a significant difference in the use of analgesics (odds ratio 14.0, p = 0.001), paracetamol (odds ratio 2.5, p = 0.01), antacids (odds ratio 2.7, p < 0.001) and unknown drugs (odds ratio 4.7, p < 0.001). Cases also differed from control subjects regarding the use of tobacco (odds ratio 2.3, p < 0.001) and alcohol (odds ratio 1.7, p = 0.02), and the presence of peptic ulcer symptoms (odds ratio 29.8, p < 0.00001). Significantly more control subjects than cases were receiving aspirin, cardiovascular drugs, bronchodilators, oral hypoglycemic drugs/lipid-lowering drugs, and anticonvulsants/hypnotics, due to the inevitable differences in disease pattern between the 2 groups. NSAID use was a major factor associated with upper gastrointestinal hemorrhage from primarily peptic ulcers. Differences in the use of other drugs may reflect variations in disease patterns between cases and controls, the common practice of self-medication in Hong Kong, and the concomitant use of NSAIDs and ulcer healing drugs/antacids.
    International journal of clinical pharmacology and therapeutics 07/1996; 34(7):304-8. · 1.22 Impact Factor
  • S. S. C. Chung · A. K. C. Li ·

    British Journal of Surgery 10/1989; 76(10). DOI:10.1002/bjs.1800761039 · 5.54 Impact Factor

Publication Stats

929 Citations
87.89 Total Impact Points


  • 1996-2007
    • The Chinese University of Hong Kong
      • Department of Surgery
      Hong Kong, Hong Kong
  • 2006
    • Johns Hopkins Medicine
      Baltimore, Maryland, United States
  • 1989-2004
    • Prince of Wales Hospital, Hong Kong
      Chiu-lung, Kowloon City, Hong Kong