114 results on '"Jensen T. C."'
Search Results
2. A longitudinal study of supportive care needs among Chinese patients awaiting colorectal cancer surgery
- Author
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Lam, Wendy W. T., Law, Wai-Lun, Poon, Jensen T. C., Fong, Daniel, Girgis, Afaf, and Fielding, Richard
- Published
- 2016
- Full Text
- View/download PDF
3. A comparison of surgeon’s postural muscle activity during robotic-assisted and laparoscopic rectal surgery
- Author
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Szeto, Grace P. Y., Poon, Jensen T. C., and Law, Wai-Lun
- Published
- 2013
- Full Text
- View/download PDF
4. Single-incision versus conventional laparoscopic colectomy for colonic neoplasm: a randomized, controlled trial
- Author
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Poon, Jensen T. C., Cheung, Chi-Wai, Fan, Joe K. M., Lo, Oswen S. H., and Law, Wai-Lun
- Published
- 2012
- Full Text
- View/download PDF
5. Survival following laparoscopic versus open resection for colorectal cancer
- Author
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Law, Wai Lun, Poon, Jensen T. C., Fan, Joe K. M., and Lo, Oswens S. H.
- Published
- 2012
- Full Text
- View/download PDF
6. Outcome of Laparoscopic Resection for Colorectal Cancer in Patients with High Operative Risk
- Author
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Poon, Jensen T. C., Law, Wai-Lun, Chow, Lorraine C. Y., Fan, Joe K. M., and Lo, Siu-Hung
- Published
- 2011
- Full Text
- View/download PDF
7. Enhanced recovery program in laparoscopic colectomy for cancer
- Author
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Poon, Jensen T. C., Fan, Joe K. M., Lo, Oswens S. H., and Law, Wai Lun
- Published
- 2011
- Full Text
- View/download PDF
8. Laparoscopic Resection for Rectal Cancer: A Review
- Author
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Poon, Jensen T. C. and Law, Wai Lun
- Published
- 2009
- Full Text
- View/download PDF
9. Impact of the Standardized Medial-to-Lateral Approach on Outcome of Laparoscopic Colorectal Resection
- Author
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Poon, Jensen T. C., Law, Wai-Lun, Fan, Joe K. M., and Lo, Oswen S. H.
- Published
- 2009
- Full Text
- View/download PDF
10. Work-related Musculoskeletal Symptoms in Surgeons
- Author
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Szeto, Grace P. Y., Ho, Pei, Ting, Albert C. W., Poon, Jensen T. C., Cheng, Stephen W. K., and Tsang, Raymond C. C.
- Published
- 2009
- Full Text
- View/download PDF
11. Comparison of Outcome of Open and Laparoscopic Resection for Stage II and Stage III Rectal Cancer
- Author
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Law, Wai Lun, Poon, Jensen T. C., Fan, Joe K. M., and Lo, Siu Hung
- Published
- 2009
- Full Text
- View/download PDF
12. Impact of conversion on the long-term outcome in laparoscopic resection of colorectal cancer
- Author
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Chan, Albert C. Y., Poon, Jensen T. C., Fan, Joe K. M., Lo, Siu Hung, and Law, Wai Lun
- Published
- 2008
- Full Text
- View/download PDF
13. Laparoscopic Bowel Resection in the Setting of Metastatic Colorectal Cancer
- Author
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Lun Law, Wai, Fan, Joe K. M., Poon, Jensen T. C., Kwok Choi, Hok, and Lo, Oswens S. H.
- Published
- 2008
- Full Text
- View/download PDF
14. Clinical correlates of health preference and generic health-related quality of life in patients with colorectal neoplasms.
- Author
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Carlos K H Wong, Cindy L K Lam, Jensen T C Poon, and Dora L W Kwong
- Subjects
Medicine ,Science - Abstract
BACKGROUND: The aims of the study were to assess the health preference and health-related quality of life (HRQOL) in patients with colorectal neoplasms (CRN), and to determine the clinical correlates that significantly influence the HRQOL of patients. METHODS: Five hundred and fifty-four CRN patients, inclusive of colorectal polyp or cancer, who attended the colorectal specialist outpatient clinic at Queen Mary Hospital in Hong Kong between October 2009 and July 2010, were included. Patients were interviewed with questionnaires on socio-demographic characteristics, and generic and health preference measures of HRQOL using the SF-12 and SF-6D Health Surveys, respectively. Clinical information on stage of disease at diagnosis, time since diagnosis, primary tumour site was extracted from electronic case record. Mean HRQOL and health preference scores of CRN patients were compared with age-sex matched controls from the Chinese general population using independent t-test. Multiple linear regression analyses were conducted to explore the associations of clinical characteristics with HRQOL measures with the adjustment of socio-demographic characteristics. RESULTS: Cross-sectional data of 515 eligible patients responded to the whole questionnaires were included in outcome analysis. In comparison with age-sex matched normative values, CRN patients reported comparable physical-related HRQOL but better mental-related HRQOL. Amongst CRN patients, time since diagnosis was positively associated with health preference score whilst patients with rectal neoplasms had lower health preference and physical-related HRQOL scores than those with sigmoid neoplasms. Health preference and HRQOL scores were significantly lower in patients with stage IV colorectal cancer than those with other less severe stages, indicating that progressive decline from low-risk polyp to stage IV colorectal cancer was observed in HRQOL scores. CONCLUSION: In CRN patients, a more advanced stage of disease was associated with worse HRQOL scores. Despite potentially adverse effect of disease on physical-related HRQOL, the mental-related HRQOL of CRN patients were better than that of Chinese general population.
- Published
- 2013
- Full Text
- View/download PDF
15. Evaluation of P-POSSUM in Surgery for Obstructing Colorectal Cancer and Correlation of the Predicted Mortality With Different Surgical Options
- Author
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Poon, Jensen T. C., Chan, Bosco, and Law, Wai Lun
- Published
- 2005
- Full Text
- View/download PDF
16. Small bowel obstruction following low anterior resection: the impact of diversion ileostomy
- Author
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Poon, Jensen T. C., Law, Wai-Lun, and Chu, Kin-Wah
- Published
- 2004
- Full Text
- View/download PDF
17. Validity and reliability study on traditional Chinese FACT-C in Chinese patients with colorectal neoplasm
- Author
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Wong, Carlos K. H., Lam, Cindy L. K., Law, Wai-Lun, Poon, Jensen T. C., Chan, Pierre, Kwong, Dora L. W., and Tsang, Janice
- Published
- 2012
- Full Text
- View/download PDF
18. Direct medical costs of care for Chinese patients with colorectal neoplasia: a health care service provider perspective
- Author
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Wong, Carlos K. H., Lam, Cindy L. K., Poon, Jensen T. C., McGhee, Sarah M., Law, Wai-Lun, Kwong, Dora L. W., Tsang, Janice, and Chan, Pierre
- Published
- 2012
- Full Text
- View/download PDF
19. Prevalence of abdominal aortic aneurysm in Chinese patients with severe coronary artery disease
- Author
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Poon, Jensen T. C., Cheng, Stephen W. K., Wong, Joyce S. W., and Ting, Albert C. W.
- Published
- 2010
- Full Text
- View/download PDF
20. Reduction in deep vein reflux after concomitant subfascial endoscopic perforating vein surgery and superficial vein ablation in advanced primary chronic venous insufficiency
- Author
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Ting, Albert CW, Cheng, Stephen W. K., Ho, Pei, Poon, Jensen T. C., Wu, Lisa L. H., and Cheung, Grace C. Y.
- Published
- 2006
21. Five decades of terrestrial and freshwater research at Ny-Ålesund, Svalbard.
- Author
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Pedersen, Å. Ø., Convey, P., Newsham, K. K., Mosbacher, J. B., Fuglei, E., Ravolainen, V., Hansen, B. B., Jensen, T. C., Augusti, A., Biersma, E. M., Cooper, E. J., Coulson, S. J., Gabrielsen, G. W., Gallet, J. C., Karsten, U., Kristiansen, S. M., Svenning, M. M., Tveit, A. T., Uchida, M., and Baneschi, I.
- Subjects
FRESHWATER biodiversity ,BIOGEOCHEMICAL cycles ,INVERTEBRATE communities ,FRESH water ,TROPHIC cascades ,FRESHWATER invertebrates ,ATMOSPHERE - Abstract
For more than five decades, research has been conducted at Ny-Ålesund, in Svalbard, Norway, to understand the structure and functioning of High-Arctic ecosystems and the profound impacts on them of environmental change. Terrestrial, freshwater, glacial and marine ecosystems are accessible year-round from Ny-Ålesund, providing unique opportunities for interdisciplinary observational and experimental studies along physical, chemical, hydrological and climatic gradients. Here, we synthesize terrestrial and freshwater research at Ny-Ålesund and review current knowledge of biodiversity patterns, species population dynamics and interactions, ecosystem processes, biogeochemical cycles and anthropogenic impacts. There is now strong evidence of past and ongoing biotic changes caused by climate change, including negative effects on populations of many taxa and impacts of rain-on-snow events across multiple trophic levels. While species-level characteristics and responses are well understood for macro-organisms, major knowledge gaps exist for microbes, invertebrates and ecosystem-level processes. In order to fill current knowledge gaps, we recommend (1) maintaining monitoring efforts, while establishing a longterm ecosystem-based monitoring programme; (2) gaining a mechanistic understanding of environmental change impacts on processes and linkages in food webs; (3) identifying trophic interactions and cascades across ecosystems; and (4) integrating long-term data on microbial, invertebrate and freshwater communities, along with measurements of carbon and nutrient fluxes among soils, atmosphere, freshwaters and the marine environment. The synthesis here shows that the Ny-Ålesund study system has the characteristics needed to fill these gaps in knowledge, thereby enhancing our understanding of High-Arctic ecosystems and their responses to environmental variability and change. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
22. Improvement of Mortality of Ruptured Abdominal Aortic Aneurysm Patients over 12 Years and Its Relationship with Tracheostomy
- Author
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Ho, Pei, Cheng, Stephen W. K., Ting, Albert C. W., and Poon, Jensen T. C.
- Published
- 2006
- Full Text
- View/download PDF
23. Long‐term resilience in microcrustacean communities despite environmental changes.
- Author
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Eie, M., Jensen, T. C., Walseng, B., Eie, A. J., and Hessen, D. O.
- Subjects
GROWING season ,COMMUNITIES ,ACIDIFICATION ,WATER chemistry - Abstract
The ability of communities to withstand stress or maintain their species composition over extended periods of environmental changes is a matter of major concern. Here, we utilize a dataset where microcrustacean communities were related to water chemistry in 82 boreal‐alpine lakes over a 50‐yr time span (1968 and 2016), with the same person involved in sampling both times ensuring identical sites and sampling protocols. Over this time span, there has been a 1–2°C increase in mean annual temperatures and prolonged growing seasons. Also, the strong changes in SO4 deposition and acidification, peaking in the early 1980s, followed by a recovery period, have caused not only an increase in pH but also a pronounced browning (elevated DOC) and reduced levels of Ca over the past three decades. Despite this, the microcrustacean diversity and community composition have remained remarkably stable, and this holds both for the species‐rich larger, boreal sites and the species‐poor alpine sites. While likely there are interannual fluctuations in species abundance, and perhaps species may also be missing for certain periods, a combination of local refugia, resting egg seed‐banks and a regional recolonization that may occur at the meta‐population level, aims at maintaining a strong stability in community composition. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
24. Reply: The Impact of the Standardized Medial-to-lateral Approach on Outcome of Laparoscopic Colorectal Resection
- Author
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Poon, Jensen T. C. and Law, Wai Lun
- Published
- 2010
- Full Text
- View/download PDF
25. Freshwater harpacticoids (Crustacea: Copepoda: Harpacticoida) in Norway – a comprehensive contribution from G.O. Sars, and a provisional checklist.
- Author
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Dimante-Deimantovica, I., Jensen, T. C., and Walseng, B.
- Subjects
- *
HARPACTICOIDA , *CRUSTACEA , *COPEPODA , *FRESHWATER animals , *ANIMAL species - Abstract
Since the pioneering works of the Norwegian biologist G.O. Sars, little attention has been given to the freshwater harpacticoids in Norway. The prime purpose of this paper is to present the state of current knowledge about the Norwegian freshwater harpacticoid fauna based on all known published and unpublished literature and archive material. We highlight the contribution of G.O. Sars to the knowledge of this group by presenting his remaining unpublished archive material. We present two Norwegian species checklists – one for freshwater harpacticoids (16 species) and another for freshwater-associated/brackish-water harpacticoids (nine species). Four of the freshwater harpacticoid species are described by G.O. Sars. Original unpublished plates with drawings of those species are included in the paper. In addition, an overview of species distributions throughout the country is given. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
26. Preclinical analysis of the anti-tumor and anti-metastatic effects of Raf265 on colon cancer cells and CD26+ cancer stem cells in colorectal carcinoma.
- Author
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Chow, Ariel K. M., Cheng, Nathan S. M., Lam, Colin S. C., Ng, Lui, Wong, Sunny K. M., Wan, Timothy M. H., Man, Johnny H. W., Cheung, Alvin H. K., Yau, Thomas C. C., Poon, Jensen T. C., Wai-Lun Law, and Pang, Roberta W. C.
- Subjects
COLON cancer ,CD26 antigen ,CANCER stem cells ,METASTASIS ,CELL proliferation - Abstract
Background: In colorectal carcinoma (CRC), activation of the Raf/MEK/ERK signaling pathway is commonly observed. In addition, the commonly used 5FU-based chemotherapy in patients with metastatic CRC was found to enrich a subpopulation of CD26
+ cancer stem cells (CSCs). As activation of the Raf/MEK/ERK signaling pathway was also found in the CD26+ CSCs and therefore, we hypothesized that an ATP-competitive pan-Raf inhibitor, Raf265, is effective in eliminating the cancer cells and the CD26+ CSCs in CRC patients. Methods: HT29 and HCT116 cells were treated with various concentrations of Raf265 to study the anti-proliferative and apoptotic effects of Raf265. Anti-tumor effect was also demonstrated using a xenograft model. Cells were also treated with Raf265 in combination with 5FU to demonstrate the anti-migratory and invasive effects by targeting on the CD26+ CSCs and the anti-metastatic effect of the combined treatment was shown in an orthotopic CRC model. Results: Raf265 was found to be highly effective in inhibiting cell proliferation and tumor growth through the inhibition of the RAF/MEK/ERK signaling pathway. In addition, anti-migratory and invasive effect was found with Raf265 treatment in combination with 5FU by targeting on the CD26+ cells. Finally, the anti-tumor and anti-metastatic effect of Raf265 in combination with 5FU was also demonstrated. Conclusions: This preclinical study demonstrates the anti-tumor and anti-metastatic activity of Raf265 in CRC, providing the basis for exploiting its potential use and combination therapy with 5FU in the clinical treatment of CRC. [ABSTRACT FROM AUTHOR]- Published
- 2015
- Full Text
- View/download PDF
27. High-energy x-ray diffractometer for nondestructive strain depth profile measurement.
- Author
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Al-Shorman, M. Y., Jensen, T. C., and Gray, J. N.
- Subjects
- *
X-ray diffraction , *POLYCRYSTALS , *TUNGSTEN , *ALUMINUM , *TITANIUM - Abstract
We describe a lab-based high-energy x-ray diffraction system and a new approach to nondestructively measuring strain profiles in polycrystalline samples. This technique utilizes the tungsten Kα1 characteristic radiation from a standard industrial x-ray tube. We introduce a simulation model that is used to determine strain values from data collected with this system. Examples of depth profiling are shown for shot peened aluminum and titanium samples. Profiles to 1 mm depth in aluminum and 300 μm depth in titanium with a depth resolution of 20 μm are presented. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
28. Clinical Correlates of Health Preference and Generic Health-Related Quality of Life in Patients with Colorectal Neoplasms.
- Author
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Wong, Carlos K. H., Lam, Cindy L. K., Poon, Jensen T. C., and Kwong, Dora L. W.
- Subjects
COLON cancer patients ,QUALITY of life ,OUTPATIENT medical care ,EPIDEMIOLOGY ,HEALTH policy ,MEDICAL quality control ,CLINICAL trials ,PUBLIC health - Abstract
Background: The aims of the study were to assess the health preference and health-related quality of life (HRQOL) in patients with colorectal neoplasms (CRN), and to determine the clinical correlates that significantly influence the HRQOL of patients. Methods: Five hundred and fifty-four CRN patients, inclusive of colorectal polyp or cancer, who attended the colorectal specialist outpatient clinic at Queen Mary Hospital in Hong Kong between October 2009 and July 2010, were included. Patients were interviewed with questionnaires on socio-demographic characteristics, and generic and health preference measures of HRQOL using the SF-12 and SF-6D Health Surveys, respectively. Clinical information on stage of disease at diagnosis, time since diagnosis, primary tumour site was extracted from electronic case record. Mean HRQOL and health preference scores of CRN patients were compared with age-sex matched controls from the Chinese general population using independent t-test. Multiple linear regression analyses were conducted to explore the associations of clinical characteristics with HRQOL measures with the adjustment of socio-demographic characteristics. Results: Cross-sectional data of 515 eligible patients responded to the whole questionnaires were included in outcome analysis. In comparison with age-sex matched normative values, CRN patients reported comparable physical-related HRQOL but better mental-related HRQOL. Amongst CRN patients, time since diagnosis was positively associated with health preference score whilst patients with rectal neoplasms had lower health preference and physical-related HRQOL scores than those with sigmoid neoplasms. Health preference and HRQOL scores were significantly lower in patients with stage IV colorectal cancer than those with other less severe stages, indicating that progressive decline from low-risk polyp to stage IV colorectal cancer was observed in HRQOL scores. Conclusion: In CRN patients, a more advanced stage of disease was associated with worse HRQOL scores. Despite potentially adverse effect of disease on physical-related HRQOL, the mental-related HRQOL of CRN patients were better than that of Chinese general population. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
29. Colorectal resection after stent insertion for obstructing cancer: comparison between open and laparoscopic approaches.
- Author
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Law, Wai L, Poon, Jensen T C, Fan, Joe K M, and Lo, Oswens S H
- Published
- 2013
- Full Text
- View/download PDF
30. Prevalence of abdominal aortic aneurysm in Chinese patients with severe coronary artery disease.
- Author
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Jensen T. C. Poon, Stephen W. K. Cheng, Joyce S. W. Wong, and Albert C. W. Ting
- Subjects
- *
AORTIC aneurysms , *CORONARY disease , *ABDOMINAL aorta , *MEDICAL screening , *CORONARY artery bypass , *MEDICAL imaging systems , *PATIENTS - Abstract
Background: The Asian population is believed to have lower incidence of abdominal aortic aneurysm (AAA), and hence, the benefit of screening is uncertain. The size of native aorta in Asians, which shall affect the definition of AAA, has also never been reported. Our study investigated the prevalence of AAA and the infra-renal aortic diameter (AD) in Chinese patients with severe coronary artery disease. Methods: This is a prospective observational study of infra-renal aortic size for patients who had coronary artery bypass surgery by ultrasound. The patients' demographics, important co-morbidities and maximum AD were recorded. Results: The study included 624 consecutive Chinese patients (mean age = 63.2 years). The mean maximum infra-renal AD was 17.5 mm for men and 14.8 mm for women. The presence of AAA was defined as maximum AD greater than 30 mm. The result was also compared with an alternate definition that defines AAA as maximum AD of greater than 1.5 times of the group's mean. Eleven patients had an AD greater than 30 mm, and the prevalence of AAA was only 1.8%. With AAA defined as maximum AD of 1.5 times greater than the group's mean, 19 patients had AAA. The prevalence of AAA in this high-risk group would become 3% overall. Conclusion: The prevalence of AAA in Chinese patients was low, and the result did not support routine screening. The smaller mean infra-renal AD in Chinese merits validation by large-scale study and consideration when deciding threshold for small AAA repair in our locality. [ABSTRACT FROM AUTHOR]
- Published
- 2010
- Full Text
- View/download PDF
31. Single-Incision Laparoscopic Colectomy: Early Experience.
- Author
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Law, Wai-Lun, Fan, Joe K. M., and Poon, Jensen T. C.
- Published
- 2010
- Full Text
- View/download PDF
32. Impact of neoadjuvant treatment on total mesorectal excision for ultra-low rectal cancers.
- Author
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Yon Kuei Lim, Wai Lun Law, Rico Liu, Poon, Jensen T. C., Fan, Joe F. M., and Lo, Oswens S. H.
- Subjects
RECTAL cancer ,CANCER radiotherapy complications ,CHEMOTHERAPY complications ,ADJUVANT treatment of cancer ,SURGICAL excision ,ONCOLOGIC surgery ,POSTOPERATIVE care ,SURGICAL anastomosis ,CANCER patients - Abstract
Background: This study reviewed the impact of pre-operative chemoradiotherapy or post-operative chemotherapy and/or radiotherapy on total mesorectal excision (TME) for ultralow rectal cancers that required either low anterior resection with peranal coloanal anastomosis or abdomino-perineal resection (APR). We examined surgical complications, local recurrence and survival. Methods: Of the 1270 patients who underwent radical resection for rectal cancer from 1994 till 2007, 180 with tumors within 4 cm with either peranal coloanal anastomosis or APR were analyzed. Patients were compared in groups that had surgery only (Group A), pre-operative chemoradiotherapy (Group B), and post-operative therapy (Group C). Results: There were 115 males and the mean age was 65.43 years (range 30-89). APR was performed in 134 patients while 46 had a sphincter-preserving resection with peranal coloanal anastomosis. The mean follow-up period was 52.98 months (range: 0.57 to 178.9). There were 69, 58 and 53 patients in Groups A, B, and C, respectively. Nine patients in Group B could go on to have sphincter-saving rectal resection. The overall perioperative complication rate was 43.4% in Group A vs. 29.3% in Group B vs. 39.6% in Group C, respectively. The local recurrence rate was significantly lower in Group B (8.6.9% vs. 21.7% in Group A vs. 33.9% in Group C) p < 0.05. The 5-year cancer-specific survival rates for Group A was 49.3%, Group B was 69.9% and Group C was 38.8% (p = 0.14). Conclusion: Pre-operative chemoradiation in low rectal cancer is not associated with a higher incidence of perioperative complications and its benefits may include reduction local recurrence. [ABSTRACT FROM AUTHOR]
- Published
- 2010
- Full Text
- View/download PDF
33. The optimal number of lymph nodes examined instage II colorectal cancer and its impact of onoutcomes.
- Author
-
Hok Kwok Choi, Wai Lun Law, and Poon, Jensen T. C.
- Subjects
LYMPH nodes ,COLON cancer ,PATIENTS ,MULTIVARIATE analysis ,DIAGNOSIS - Abstract
Background: Lymph node status is the most important prognostic factor for colorectal cancer. The number of lymph nodes that should be histologically examined has been controversial. The aims of this study were to assess the impact of the number of lymph nodes examined on survival of patients with stage II colorectal cancer and to determine the optimal number of lymph nodes that should be examined. Methods: The study included 664 patients who underwent resection for stage II colorectal cancer. The clinical and histopathologic data of the patients were prospectively collected and analyzed. Results: The median number of lymph nodes examined was 12 (range: 1 to 58). The 5-year disease free survival rate was significantly higher for patients with 12 or more lymph nodes examined compared to those with less than 12 lymph nodes examined. The significant difference in 5-year disease free survival persisted if the dividing number increased progressively from 12 to 23. However, the difference in survival was most significant (lowest p value and highest hazard ratio) for the number 21. The 5-year disease free survival of patients with 21 or more lymph nodes examined was 80% whereas that of patients with less than 21 lymph nodes examined was 60% (p = 0.001, hazard ratio 2.08). Multivariate analysis showed that 21 or more lymph nodes examined was a factor that independently influenced survival. The 5-year disease free survival also increased progressively with the number of lymph node examined up to the number 21. After the number 21, the survival rate did not increase further. It was likely that 21 was the optimal number, at and above which the chance of lymph node metastasis was minimal. Conclusions: The number of lymph nodes examined in colorectal cancer specimen significantly influences survival. It is recommended that at least 21 lymph nodes should be examined for accurate diagnosis of stage II colorectal cancer. [ABSTRACT FROM AUTHOR]
- Published
- 2010
- Full Text
- View/download PDF
34. RNA responses to N- and P-limitation; reciprocal regulation of stoichiometry and growth rate in Brachionus.
- Author
-
HESSEN, D. O., JENSEN, T. C., KYLE, M., and ELSER, J. J.
- Subjects
- *
ROTIFERA , *STOICHIOMETRY , *PHYSICAL & theoretical chemistry , *RNA , *NUCLEIC acids , *ORGANISMS , *LIFE (Biology) , *ECOLOGY , *BIOLOGY - Abstract
1. In this study we address how growth rate in consumers may be regulated by nitrogen (N)- and phosphorus (P)- limitation of ribonucleic acid (RNA), using the rotifer Brachionus calyciflorus as the model organism. 2. Growth rate, RNA and weight-specific concentrations of carbon (C), N and P were analyzed in B. calyciflorus fed algae with different C : N, C : P and N : P ratios. 3. Growth rate correlated negatively with food C : N, but not with C : P or N : P, strongly suggesting N-limited growth. Growth rate also strongly correlated with tissue concentrations of RNA and P, in support of the growth rate hypothesis which states that specific P-content of organisms reflects their RNA-content and thus capacity for protein synthesis. 4. Food C : N rather than C : P regulated the growth, RNA and P in this consumer under the food conditions applied. This suggests that availability of N can also be an important regulator of cellular acquisition of P and build-up of ribosomes in that animals released from N-limitation have an increased demand for the P-rich cellular machinery for protein synthesis. 5. The data suggest a strong reciprocal regulation of consumer demands and their C : N : P stoichiometry via the intimate connections between ribosome allocation and protein synthesis and also lend support to the view that reduced protein synthesis efficiency under high growth rates may affect stoichiometry of the consumer. [ABSTRACT FROM AUTHOR]
- Published
- 2007
- Full Text
- View/download PDF
35. How realistic is cutaneous gene therapy?
- Author
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Hengge, U. R., Taichman, L. B., Kaur, P., Rogers, G., Jensen, T. C., Goldsmith, L. A., Rees, J. L., and Christiano, A. M.
- Subjects
GENE therapy ,GENE expression ,GENETIC engineering ,STEM cells ,GENETICS ,GENETIC regulation - Abstract
Recent progress with innovative, experimental gene therapy approaches in animals, and recent improvements in our understanding and manipulation of stem cells, gene expression and gene delivery systems, have raised plenty of hopes in essentially all branches of clinical medicine that hitherto untreatable or poorly manageable diseases will soon become amenable to treatment. Few other organ systems have received such enthusiastic reviews in recent years as to the chances and prospects of gene therapy as the skin, with its excellent accessibility and its pools of--seemingly--readily manipulated epithelial stem cells (cf. Cotsarelis et al., Exp Dermatol 1999: 8: 80-88). However, as in other sectors of clinical medicine, the actual implementation of general gene therapy strategies in clinical practice has been faced with a range of serious difficulties (cf. Smith, Lancet 1999: 354 (suppl 1): 1-4; Lattime & Gerson (eds.), Gene Therapy of Cancer, Academic Press, San Diego, 1999). Thus, it is critically important to carefully distinguish unfounded hype from justified hope in this embryonal area of dermatologic therapy, to discuss in detail what can be realistically expected from cutaneous gene therapy approaches in the next few years, and importantly, what kind of promises should not be made to our patients at this time. [ABSTRACT FROM AUTHOR]
- Published
- 1999
- Full Text
- View/download PDF
36. Preclinical analysis of the anti-tumor and anti-metastatic effects of Raf265 on colon cancer cells and CD26(+) cancer stem cells in colorectal carcinoma.
- Author
-
Chow AK, Cheng NS, Lam CS, Ng L, Wong SK, Wan TM, Man JH, Cheung AH, Yau TC, Poon JT, Law WL, and Pang RW
- Subjects
- Animals, Apoptosis drug effects, Cell Line, Tumor, Cell Movement drug effects, Cell Proliferation drug effects, Cell Self Renewal, Colorectal Neoplasms pathology, Drug Evaluation, Preclinical, Extracellular Signal-Regulated MAP Kinases metabolism, Fluorouracil pharmacology, HCT116 Cells, HT29 Cells, Humans, Mice, Mitogen-Activated Protein Kinases metabolism, Proto-Oncogene Proteins B-raf metabolism, Signal Transduction drug effects, Antineoplastic Agents pharmacology, Colorectal Neoplasms metabolism, Imidazoles pharmacology, Neoplastic Stem Cells drug effects, Neoplastic Stem Cells metabolism, Pyridines pharmacology
- Abstract
Background: In colorectal carcinoma (CRC), activation of the Raf/MEK/ERK signaling pathway is commonly observed. In addition, the commonly used 5FU-based chemotherapy in patients with metastatic CRC was found to enrich a subpopulation of CD26(+) cancer stem cells (CSCs). As activation of the Raf/MEK/ERK signaling pathway was also found in the CD26(+) CSCs and therefore, we hypothesized that an ATP-competitive pan-Raf inhibitor, Raf265, is effective in eliminating the cancer cells and the CD26(+) CSCs in CRC patients., Methods: HT29 and HCT116 cells were treated with various concentrations of Raf265 to study the anti-proliferative and apoptotic effects of Raf265. Anti-tumor effect was also demonstrated using a xenograft model. Cells were also treated with Raf265 in combination with 5FU to demonstrate the anti-migratory and invasive effects by targeting on the CD26(+) CSCs and the anti-metastatic effect of the combined treatment was shown in an orthotopic CRC model., Results: Raf265 was found to be highly effective in inhibiting cell proliferation and tumor growth through the inhibition of the RAF/MEK/ERK signaling pathway. In addition, anti-migratory and invasive effect was found with Raf265 treatment in combination with 5FU by targeting on the CD26(+) cells. Finally, the anti-tumor and anti-metastatic effect of Raf265 in combination with 5FU was also demonstrated., Conclusions: This preclinical study demonstrates the anti-tumor and anti-metastatic activity of Raf265 in CRC, providing the basis for exploiting its potential use and combination therapy with 5FU in the clinical treatment of CRC.
- Published
- 2015
- Full Text
- View/download PDF
37. Evolving standards in preoperative staging and treatment of rectal cancer.
- Author
-
Poon JT
- Subjects
- Female, Humans, Male, Radiography, Adipose Tissue diagnostic imaging, Magnetic Resonance Imaging standards, Rectal Neoplasms diagnostic imaging
- Published
- 2014
- Full Text
- View/download PDF
38. Use of biologics for inflammatory bowel disease in Hong Kong: consensus statement.
- Author
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Leung WK, Ng SC, Chow DK, Lao WC, Leung VK, Li MK, Hui YT, Ng SS, Hui AJ, Lai ST, Lam JT, Poon JT, Chan AO, Yuen H, and Wu JC
- Subjects
- Delphi Technique, Drug Monitoring methods, Hong Kong, Humans, Immunologic Factors administration & dosage, Immunologic Factors adverse effects, Inflammatory Bowel Diseases physiopathology, Immunologic Factors therapeutic use, Inflammatory Bowel Diseases drug therapy, Practice Patterns, Physicians'
- Abstract
Unlabelled: OBJECTIVE; With the increasing use of biologics in patients with inflammatory bowel disease, the Hong Kong IBD Society developed a set of consensus statements intended to serve as local recommendations for clinicians about the appropriate use of biologics for treating inflammatory bowel disease., Participants: The consensus meeting was held on 9 July 2011 in Hong Kong. Draft consensus statements were developed by core members of the Hong Kong IBD Society, including local gastroenterologists and colorectal surgeons experienced in managing patients with inflammatory bowel disease., Evidence: Published literature and conference proceedings on the use of biologics in management of inflammatory bowel disease, and guidelines and consensus issued by different international and regional societies on recommendations for biologics in inflammatory bowel disease patients were reviewed., Consensus Process: Four core members of the consensus group drafted 19 consensus statements through the modified Delphi process. The statements were first circulated among a clinical expert panel of 15 members for review and comments, and were finalised at the consensus meeting through a voting session. A consensus statement was accepted if at least 80% of the participants voted "accepted completely or "accepted with some reservation"., Conclusions: Nineteen consensus statements about inflammatory bowel disease were generated by the clinical expert panel meeting. The statements were divided into four parts which covered: (1) epidemiology of the disease in Hong Kong; (2) treatment of the disease with biologics; (3) screening and contra-indications pertaining to biologics; and (4) patient monitoring after use of biologics. The current statements are the first to describe the appropriate use of biologics in the management of inflammatory bowel disease in Hong Kong, with an aim to provide guidance for local clinical practice.
- Published
- 2013
39. Mapping the Functional Assessment of Cancer Therapy-general or -Colorectal to SF-6D in Chinese patients with colorectal neoplasm.
- Author
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Wong CK, Lam CL, Rowen D, McGhee SM, Ma KP, Law WL, Poon JT, Chan P, Kwong DL, and Tsang J
- Subjects
- Aged, China ethnology, Colorectal Neoplasms ethnology, Female, Hong Kong, Humans, Male, Middle Aged, Quality of Life psychology, Self Report, Colorectal Neoplasms classification, Health Surveys instrumentation, Patient Preference
- Abstract
Objectives: To map Functional Assessment of Cancer Therapy-General (FACT-G) and Functional Assessment of Cancer Therapy-Colorectal (FACT-C) subscale scores onto six-dimensional health state short form (derived from short form 36 health survey) (SF-6D) preference-based values in patients with colorectal neoplasm, with and without adjustment for clinical and demographic characteristics. These results can then be applied to studies that have used FACT-G or FACT-C to predict SF-6D utility values to inform economic evaluation., Methods: Ordinary least square regressions were estimated mapping FACT-G and FACT-C onto SF-6D by using cross-sectional data of 537 Chinese subjects with different stages of colorectal neoplasm. Mapping functions for SF-6D preference-based values were developed separately for FACT-G and FACT-C in four sequential models for addition of variables: 1) main-effect terms, 2) squared terms, 3) interaction terms, and 4) clinical and demographic variables. Predictive performance in each model was assessed by the R(2), adjusted R(2), predicted R(2), information criteria (Akaike information criteria and Bayesian information criteria), the root mean square error, the mean absolute error, and the proportions of absolute error within the threshold of 0.05 and 0.10., Results: Models including FACT variables and clinical and demographic variables had the best predictive performance measured by using R(2) (FACT-G: 59.98%; FACT-C: 60.43%), root mean square error (FACT-G: 0.086; FACT-C: 0.084), and mean absolute error (FACT-G: 0.065; FACT-C: 0.065). The FACT-C-based mapping function had better predictive ability than did the FACT-G-based mapping function., Conclusions: Models mapping FACT-G and FACT-C onto SF-6D reached an acceptable degree of precision. Mapping from the condition-specific measure (FACT-C) had better performance than did mapping from the general cancer measure (FACT-G). These mapping functions can be applied to FACT-G or FACT-C data sets to estimate SF-6D utility values for economic evaluation of medical interventions for patients with colorectal neoplasm. Further research assessing model performance in independent data sets and non-Chinese populations are encouraged., (Copyright © 2012 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.)
- Published
- 2012
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40. Surgeons' static posture and movement repetitions in open and laparoscopic surgery.
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Szeto GP, Cheng SW, Poon JT, Ting AC, Tsang RC, and Ho P
- Subjects
- Adult, Biomechanical Phenomena, Electromyography, Female, Humans, Male, Musculoskeletal Diseases epidemiology, Risk Factors, Digestive System Surgical Procedures, Laparoscopy, Movement physiology, Physicians, Posture physiology
- Abstract
Background: There is increasing concern about the surgeon maintaining a static posture during laparoscopic surgery, which can contribute to musculoskeletal disorders. A series of studies are being conducted in Hong Kong examining the surgeons' real-time movements and electromyography in the operating theater during different operations. The present paper examines the postures and movements of surgeons during real-time open and laparoscopic procedures., Materials and Methods: Fourteen surgeons participated in the study (12 men, 2 women). Cervical spine movements were measured using a biaxial inclinometer attached to the surgeon's head via a headband. Biaxial electrogoniometers were attached to the surgeon's bilateral shoulder joints. Real-time joint movements in sagittal and coronal planes were recorded during open and laparoscopic surgeries for periods ranging from 30 to 80 min., Results: Surgeons generally maintained a flexed neck posture during open surgery and a more extended neck posture during laparoscopic procedures. There were statistically significant differences in mean neck posture and mean left shoulder abduction posture between the two types of surgery. Laparoscopic procedures showed a trend for longer duration in static posture in the neck, while open procedures showed trends for higher frequencies of movements., Conclusions: This study presented a novel approach to quantify the physical workload of surgeons using biomechanical parameters to describe duration of static posture and repetitiveness of movements. Results showed that long durations of static postures in laparoscopic surgery were closely associated with low-level muscle tension, which may contribute to an increased risk of surgeons developing musculoskeletal disorders., (Copyright © 2012 Elsevier Inc. All rights reserved.)
- Published
- 2012
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41. The optimal number of lymph nodes examined in stage II colorectal cancer and its impact of on outcomes.
- Author
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Choi HK, Law WL, and Poon JT
- Subjects
- Adult, Aged, Aged, 80 and over, Biopsy, Chemotherapy, Adjuvant, Colectomy, Colorectal Neoplasms mortality, Colorectal Neoplasms secondary, Colorectal Neoplasms surgery, Disease-Free Survival, Female, Humans, Kaplan-Meier Estimate, Lymph Node Excision, Lymph Nodes surgery, Lymphatic Metastasis, Male, Middle Aged, Neoplasm Staging, Proportional Hazards Models, Retrospective Studies, Risk Assessment, Risk Factors, Time Factors, Treatment Outcome, Colorectal Neoplasms pathology, Lymph Nodes pathology
- Abstract
Background: Lymph node status is the most important prognostic factor for colorectal cancer. The number of lymph nodes that should be histologically examined has been controversial. The aims of this study were to assess the impact of the number of lymph nodes examined on survival of patients with stage II colorectal cancer and to determine the optimal number of lymph nodes that should be examined., Methods: The study included 664 patients who underwent resection for stage II colorectal cancer. The clinical and histopathologic data of the patients were prospectively collected and analyzed., Results: The median number of lymph nodes examined was 12 (range: 1 to 58). The 5-year disease free survival rate was significantly higher for patients with 12 or more lymph nodes examined compared to those with less than 12 lymph nodes examined. The significant difference in 5-year disease free survival persisted if the dividing number increased progressively from 12 to 23. However, the difference in survival was most significant (lowest p value and highest hazard ratio) for the number 21. The 5-year disease free survival of patients with 21 or more lymph nodes examined was 80% whereas that of patients with less than 21 lymph nodes examined was 60% (p = 0.001, hazard ratio 2.08). Multivariate analysis showed that 21 or more lymph nodes examined was a factor that independently influenced survival. The 5-year disease free survival also increased progressively with the number of lymph node examined up to the number 21. After the number 21, the survival rate did not increase further. It was likely that 21 was the optimal number, at and above which the chance of lymph node metastasis was minimal., Conclusions: The number of lymph nodes examined in colorectal cancer specimen significantly influences survival. It is recommended that at least 21 lymph nodes should be examined for accurate diagnosis of stage II colorectal cancer.
- Published
- 2010
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42. Impact of neoadjuvant treatment on total mesorectal excision for ultra-low rectal cancers.
- Author
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Lim YK, Law WL, Liu R, Poon JT, Fan JF, and Lo OS
- Subjects
- Adenocarcinoma drug therapy, Adenocarcinoma pathology, Adenocarcinoma radiotherapy, Adult, Aged, Aged, 80 and over, Combined Modality Therapy, Female, Humans, Male, Middle Aged, Radiotherapy Dosage, Rectal Neoplasms drug therapy, Rectal Neoplasms pathology, Rectal Neoplasms radiotherapy, Survival Rate, Treatment Outcome, Adenocarcinoma therapy, Antimetabolites, Antineoplastic therapeutic use, Digestive System Surgical Procedures, Fluorouracil therapeutic use, Neoadjuvant Therapy, Rectal Neoplasms therapy
- Abstract
Background: This study reviewed the impact of pre-operative chemoradiotherapy or post-operative chemotherapy and/or radiotherapy on total mesorectal excision (TME) for ultralow rectal cancers that required either low anterior resection with peranal coloanal anastomosis or abdomino-perineal resection (APR). We examined surgical complications, local recurrence and survival., Methods: Of the 1270 patients who underwent radical resection for rectal cancer from 1994 till 2007, 180 with tumors within 4 cm with either peranal coloanal anastomosis or APR were analyzed. Patients were compared in groups that had surgery only (Group A), pre-operative chemoradiotherapy (Group B), and post-operative therapy (Group C)., Results: There were 115 males and the mean age was 65.43 years (range 30-89). APR was performed in 134 patients while 46 had a sphincter-preserving resection with peranal coloanal anastomosis. The mean follow-up period was 52.98 months (range: 0.57 to 178.9). There were 69, 58 and 53 patients in Groups A, B, and C, respectively. Nine patients in Group B could go on to have sphincter-saving rectal resection. The overall peri-operative complication rate was 43.4% in Group A vs. 29.3% in Group B vs. 39.6% in Group C, respectively. The local recurrence rate was significantly lower in Group B (8.6.9% vs. 21.7% in Group A vs. 33.9% in Group C) p < 0.05. The 5-year cancer-specific survival rates for Group A was 49.3%, Group B was 69.9% and Group C was 38.8% (p = 0.14)., Conclusion: Pre-operative chemoradiation in low rectal cancer is not associated with a higher incidence of peri-operative complications and its benefits may include reduction local recurrence.
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- 2010
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43. Multimodality minimally invasive autopsy--a feasible and accurate approach to post-mortem examination.
- Author
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Fan JK, Tong DK, Poon JT, Lo OS, Beh PS, Patil NG, and Law WL
- Subjects
- Adult, Aged, Aged, 80 and over, Arteries pathology, Biopsy methods, Feasibility Studies, Female, Forensic Pathology methods, Humans, Lung pathology, Male, Middle Aged, Stomach pathology, Autopsy methods, Endoscopy
- Abstract
Background: Autopsy examination has been the bedrock of western medicine. With the decline in the autopsy rate secondary to the negative psychological impact to the deceased's relatives, the benefits of autopsy have been undermined. Minimally invasive autopsy has been introduced but has not been widely adopted as an alternative to the 'traditional' open approach. This technique not only provides information on the cause of death abut also minimizes the disfigurement induced to the deceased. Our study aims to explore the feasibility and evaluate the accuracy of this technique., Methods: A series of coroner cases ordered for autopsy were examined by a group including an experienced forensic pathologist and two experienced laparoscopic surgeons using thoracoscopic, laparoscopic, endoluminal or endovascular approaches. The procedure was video-recorded and the provisional diagnoses and causes of death were made based on the findings. These findings were subsequently correlated with the full autopsy examination. A few limited clinical post-mortem examinations were also performed with consent from relatives., Results: A total of 22 cases of minimally invasive autopsies were performed from November 2007 to March 2008. The median duration of the procedures was 78.3+/-20.7 min. Thoracoscopies and laparoscopies were performed in 18 patients while additional arterioscopic examination with endoscope was performed in two patients with suspected aortic diseases. Four consented limited clinical autopsies were also performed: two of them involved thoracoscopic biopsies of lung tissues, one was a para-mortem upper endoscopy for the investigation of pathology of the stomach and the other one was laparoscopy for a patient, who died of unexplained acidosis. Comparison with full autopsies showed that the accuracy of the diagnosis was 94.4%, the sensitivity was 90%, the specificity was 100%, the positive predictive value was 100% and the negative predictive value was 88.9%., Conclusion: Minimally invasive autopsy is a feasible approach, yielding accurate findings when compared with conventional autopsies. The former can be a valuable tool for obtaining more valuable information in situations when the next-of-kin of the deceased does not consent to a conventional autopsy., (2009 Elsevier Ireland Ltd. All rights reserved.)
- Published
- 2010
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44. Day surgery varicose vein treatment using endovenous laser.
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Ho P, Poon JT, Cho SY, Cheung G, Tam YF, Yuen WK, and Cheng SW
- Subjects
- Adult, Aged, Ambulatory Surgical Procedures instrumentation, Ambulatory Surgical Procedures methods, Anesthesia, Local, Female, Hong Kong, Humans, Laser Therapy instrumentation, Male, Middle Aged, Outpatient Clinics, Hospital, Pain Measurement, Prospective Studies, Saphenous Vein diagnostic imaging, Treatment Outcome, Ultrasonography, Doppler, Duplex, Varicose Veins diagnostic imaging, Laser Therapy methods, Saphenous Vein surgery, Varicose Veins surgery
- Abstract
Objective: To examine the safety and efficacy of endovenous laser obliteration to treat varicose vein in a day surgery setting, using sedation and local anaesthesia., Design: Prospective study., Setting: Day surgery centre in a regional hospital in Hong Kong., Patients: A total of 24 patients with duplex-confirmed long saphenous vein insufficiency underwent endovenous laser (940 nm) varicose vein treatment from July to November 2007 in a single day surgery centre. Adjuvant phlebectomy and injection sclerotherapy were performed in the same session if indicated. All patients had postprocedural venous duplex scan and clinic assessment on day 7 and day 10 respectively., Main Outcome Measures: Procedure success rate, unplanned hospital admissions and re-admissions, major complications, and long saphenous vein obliteration rate., Results: A total of 31 limbs of the 24 patients were treated with endovenous laser varicose vein treatment under local anaesthesia and sedation. The procedural success rate was 100%. All but two patients were admitted on the day of treatment and none were re-admitted. The patients' mean visual analogue pain score for the whole procedure was 2.3 (standard deviation, 1.5; range, 0-5). Post-procedural duplex scans showed 100% thrombosis of the treated long saphenous veins with no deep vein thrombosis. There were no skin burns or instances of thrombophlebitis. Induration of the treated long saphenous vein was relatively common (54%). The majority of the patients (54%) experienced mild discomfort in the early postoperative period., Conclusion: Endovenous laser varicose vein treatment performed under local anaesthesia and sedation in a day surgery setting is safe, and yields satisfactory clinical and duplex outcomes.
- Published
- 2009
45. Endovascular repair for thoracic aortic pathologies--early and midterm results.
- Author
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Ting AC, Cheng SW, Ho P, Chan YC, Poon JT, and Cheung GC
- Subjects
- Adult, Aged, Aged, 80 and over, Female, Follow-Up Studies, Humans, Male, Middle Aged, Time Factors, Treatment Outcome, Aneurysm, False surgery, Angioplasty, Aortic Aneurysm, Thoracic surgery, Aortic Rupture surgery, Blood Vessel Prosthesis Implantation, Stents
- Abstract
Objective: To assess the early and midterm results of endovascular stent graft repair in patients with thoracic aortic pathologies., Methods: Between March 2000 and December 2005, 44 consecutive patients undergoing endovascular repair for 45 thoracic aortic lesions were studied. Follow-up protocol includes regular clinical examination and computed tomographies., Results: There were 37 men and 7 women with a median age of 59 years at operation (range, 26-90). The pathologies consisted of 15 thoracic aortic aneurysms, nine pseudoaneurysms, 16 thoracic aortic dissections, and five thoracic aortic injuries. Successful deployment of the endovascular stent grafts with complete sealing of the pathology were achieved in all but one patient who had the procedure abandoned as a result of access difficulty, giving a technical success of 98%. The median hospital stay was 7 days (range, 3-196), with no hospital death nor paraplegia. The median follow-up was 25 months (range, 0-86). There were eight follow-up deaths, two of which were thoracic aortic pathology related (both patients had aortoesophageal fistulae). There were three other clinical failures: distal attachment endoleak in a patient with thoracic aortic aneurysm, one enlarging and one newly developed dissecting thoracic aortic aneurysm despite endografting. The cumulative freedom from clinical failure and failure free survival were 90% and 75% at 18 months respectively., Conclusion: Endovascular stent graft repair is a feasible option in thoracic aortic pathologies with promising early and midterm results.
- Published
- 2009
- Full Text
- View/download PDF
46. Endovascular repair for abdominal aortic aneurysms: the first hundred cases.
- Author
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Ting AC, Cheng SW, Ho P, Chan YC, Poon JT, Yiu WK, and Cheung GC
- Subjects
- Aged, Aged, 80 and over, Aneurysm, Ruptured epidemiology, Female, Follow-Up Studies, Humans, Length of Stay, Male, Middle Aged, Postoperative Complications, Prospective Studies, Retrospective Studies, Stents, Treatment Outcome, Aortic Aneurysm, Abdominal surgery, Blood Vessel Prosthesis Implantation
- Abstract
Objective: To evaluate the early and mid-term results of the first 100 elective endovascular repairs for abdominal aortic aneurysms., Design: Retrospective analysis of prospectively collected data., Setting: University teaching hospital, Hong Kong., Patients: The first 100 patients with infrarenal abdominal aortic aneurysms who underwent elective endovascular repair., Main Outcome Measures: Peri-operative data, mortality and morbidities as well as the follow-up details were recorded. Cumulative data on endoleaks, clinical failures, secondary procedures, and survival were evaluated with Kaplan-Meier analyses., Results: There were 85 men and 15 women, with a mean age of 75 (range, 50-90) years. Failed implantations due to access difficulty occurred in two patients during the same period, giving a technical success rate of 98%. The mean aneurysm diameter was 6.2 cm. Access site injury requiring repair occurred in four (4%) of the patients, while wound problems were the most common complications (11%). The median hospital stay was 6 days, and there were two hospital deaths, giving a hospital mortality rate of 2%. During a mean follow-up of 36 (standard deviation, 24) months, there were three aneurysmal ruptures and four elective open conversions, with only one aneurysm-related death after hospital discharge. At 3 years, the cumulative rates of freedom from any endoleak, freedom from primary failure, freedom from secondary failure, freedom from secondary procedures, and survival were 60%, 84%, 89%, 88%, and 78%, respectively., Conclusions: The early and mid-term results of elective endovascular repair for abdominal aortic aneurysms appear promising. The procedure is effective in preventing aneurysm-related death in the mid-term. Nevertheless, the importance of constant surveillance cannot be over-emphasised, as clinical failures and ruptures are still a concern.
- Published
- 2008
47. Laparoscopic bowel resection in the setting of metastatic colorectal cancer.
- Author
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Law WL, Fan JK, Poon JT, Choi H, and Lo OS
- Subjects
- Adult, Aged, Aged, 80 and over, Bone Neoplasms secondary, Colorectal Neoplasms pathology, Female, Humans, Length of Stay, Liver Neoplasms secondary, Lung Neoplasms secondary, Male, Middle Aged, Peritoneal Neoplasms secondary, Postoperative Complications, Prospective Studies, Survival Rate, Treatment Outcome, Bone Neoplasms surgery, Colorectal Neoplasms surgery, Laparoscopy, Liver Neoplasms surgery, Lung Neoplasms surgery, Peritoneal Neoplasms surgery
- Abstract
Background: This study aimed to review the outcomes of laparoscopic colorectal resection for patients with stage IV colorectal cancer., Methods: From the prospectively collected database for patients who underwent surgery for colorectal cancer in our institution, those with stage IV colorectal cancer who underwent elective resection of tumor during the period from January 2000 to June 2006 were included. The outcomes of those with laparoscopic resection were reviewed and comparison was made between patients with laparoscopic and open resection., Results: A total of 200 patients (127 men) with median age of 69 years (range: 25-91 years) were included, and 77 underwent laparoscopic resection. Conversion was required in ten patients (13.0%) and all except one conversion were due to fixed or bulky tumors. There was no operative mortality in the laparoscopic group. The complication rate was 14% and the median postoperative hospital stay was 7 days. When patients with laparoscopic resection were compared with those with open operations, there was no difference in age, gender, comorbidity, or tumor size between the two groups. However, the complication rate was significantly lower in those with laparoscopic resection (14% versus 32%, P = 0.007) and the median hospital stay was significantly shorter (7 days versus 8 days, P = 0.005). The operative mortalities and the survivals were similar in the two groups., Conclusions: Colorectal resection can be performed safely in patients with stage IV colorectal cancer. The operative outcomes in terms of complication rate and hospital stay compare favorably with patients with open resection.
- Published
- 2008
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48. Ionizing radiation absorption of vascular surgeons during endovascular procedures.
- Author
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Ho P, Cheng SW, Wu PM, Ting AC, Poon JT, Cheng CK, Mok JH, and Tsang MS
- Subjects
- Humans, Prospective Studies, Radiation Injuries prevention & control, Radiation Monitoring, Radiation Protection, Aortic Aneurysm surgery, Blood Vessel Prosthesis Implantation, Occupational Exposure, Radiography, Interventional, Vascular Surgical Procedures methods
- Abstract
Objective: Endovascular procedures have become an integral part of a vascular surgeon's practice. The exposure of surgeons to ionizing radiation and other safety issues have not been well studied. We investigated the radiation exposure of a team of vascular surgeons in an active endovascular unit and compared yearly dosages absorbed by various body parts among different surgeons. Patients' radiation exposure was also assessed., Methods: The radiation absorption of a team of vascular surgeons was prospectively monitored in a 12-month period. During each endovascular procedure, the effective body, eye, and hand radiation doses of all participating surgeons were measured by mini-thermoluminescent dosimeters (TLD) attached at the chest level under a lead apron, at the forehead at eye level, and at the hand. The type of procedure, fluoroscopy machine, fluoroscopy time, and personal and operating theatre radiation protection devices used in each procedure were also recorded. One TLD was attached to the patient's body near the operative site to measure the patient's dose. The yearly effective body, eye, and hand dose were compared with the safety limits of radiation for occupational exposure recommended by the International Commission on Radiation Protection (ICRP). The radiation absorption of various body parts per minute of fluoroscopy was compared among different surgeons., Results: A total of 149 consecutive endovascular procedures were performed, including 30 endovascular aortic repairs (EVAR), 58 arteriograms with and without embolization (AGM), and 61 percutaneous transluminal angioplasty and stent (PTA/S) procedures. The cumulative fluoroscopy time was 1132 minutes. The median yearly effective body, eye, and hand dose for the surgeons were 0.20 mSv (range, 0.13 to 0.27 mSv), 0.19 mSv (range, 0.10 to 0.33 mSv) and 0.99 mSv (0.29 to 1.84 mSv) respectively, which were well below the safety limits of the ICRP. The mean body, eye, and hand dose of the chief surgeon per procedure were highest for EVAR. A significant discrepancy was observed for the average hand dose per minute of fluoroscopy among different surgeons. The mean radiation absorption of patients who underwent EVAR, AGM, and PTA/S was 12.7 mSv, 13.6 mSv, and 3.4 mSv, respectively., Conclusion: With current radiation protection practice, the radiation absorbed by vascular surgeons with a high endovascular workload did not exceed the safety limits recommended by ICRP. Variations in practice, however, can result in significant discrepancy of radiation absorption between surgeons.
- Published
- 2007
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49. Hybrid endovascular operation for ruptured thoracic aortic aneurysm.
- Author
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Ho P, Cheng SW, Ting AC, Poon JT, and Liu LH
- Subjects
- Aged, Anastomosis, Surgical, Humans, Male, Polytetrafluoroethylene, Aortic Aneurysm, Thoracic surgery, Aortic Rupture surgery, Blood Vessel Prosthesis, Carotid Artery, Common surgery, Stents
- Abstract
The rupture of a thoracic aortic aneurysm is a life-threatening emergency. Conventional open surgical repair carries a high mortality and morbidity. We report an elderly patient who suffered from rupture of a proximal descending thoracic aortic aneurysm close to the aortic arch. A hybrid operation consisting of a right-to-left carotid bypass followed by endovascular repair of the descending thoracic aorta was carried out. The patient recovered uneventfully. A hybrid endovascular repair should be considered the treatment of choice for rupture of a thoracic aortic aneurysm near the arch.
- Published
- 2007
50. Endovascular stent graft repair for infected thoracic aortic pseudoaneurysms--a durable option?
- Author
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Ting AC, Cheng SW, Ho P, and Poon JT
- Subjects
- Adult, Aged, Aged, 80 and over, Aneurysm, False diagnostic imaging, Aneurysm, Infected diagnostic imaging, Aortic Aneurysm, Thoracic diagnostic imaging, Female, Follow-Up Studies, Humans, Male, Middle Aged, Prosthesis Design, Retrospective Studies, Tomography, X-Ray Computed, Treatment Outcome, Aneurysm, False surgery, Aneurysm, Infected surgery, Aortic Aneurysm, Thoracic surgery, Blood Vessel Prosthesis Implantation instrumentation, Stents
- Abstract
Objective: Open surgical repair for infected thoracic aortic pseudoaneurysms carries significant mortality and morbidity. Endovascular stent graft repair has been our preferred approach, although its role remains controversial because persistent infection is always a concern. We aimed to assess the efficacy and durability of endovascular stent graft repair in these patients., Methods: Between August 2000 and November 2005, seven consecutive patients with eight infected pseudoaneurysms of the thoracic aorta were treated with endovascular stent graft repair. Patients were diagnosed based on a typical appearance of an infected pseudoaneurysm on imaging together with a positive bacteriology culture or clinical evidence of sepsis. The follow-up protocol included regular clinical examination, hematologic tests, and computed tomography scans., Results: There were six men and one woman with a median age of 68 years at operation. Three patients presented with an aortoenteric fistula. The operations were performed in the operating room with the image guidance of a mobile C-arm. Endovascular stent grafts were deployed successfully in all patients, with complete exclusion of the pseudoaneurysms. Intravenous antibiotics were continued for 1 to 6 weeks and followed by lifelong maintenance oral antibiotics. The median hospital stay was 27 days, with no hospital deaths. No paraplegia or other major complications occurred. Two patients with aortoesophageal fistula where the fistula tracts were persistent died during follow-up. The other five patients remained well, with no evidence of graft infection at a median follow-up of 34 months. A significant reduction in the diameter of the pseudoaneurysm (>5 mm) was noted on computed tomography scans after 12 months., Conclusion: Endovascular stent graft repair is effective and may be a durable option for infected pseudoaneurysms of the thoracic aorta.
- Published
- 2006
- Full Text
- View/download PDF
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