Singapore Health Services Pte, National University Hospital Singapore and National University of Singapore | Date: 2015-01-30
Defining proximal as toward the heart and distal as away from the heart, a sheath includes a proximal opening and multiple fenestrations maintainable in position slightly beyond a site or point of sheath entry into a vessel by way of an anchoring assembly having a set of radially displaceable anchoring elements configured for abutting a superficial vessel wall. The fenestrations and/or anchoring element(s) are arranged obliquely or non-obliquely around peripheral portions of the sheath. The sheath can receive blood from a pumping source at a proximal opening, and channel the blood toward, to, and through the fenestrations. The fenestrations, in combination with the proximal opening, enable the perfusion of blood into the cannulated vessel in a set of distal directions for perfusing a distal tissue or organ. Flow of blood out of fenestrations directs blood distally towards the limb, head, or other distal region, mitigating the risk of or preventing ischemia.
Singapore Health Services Pte Ltd, National University Hospital Singapore and National University of Singapore | Date: 2015-01-30
A cannula includes a first segment configured to reside entirely within a vessel. The first segment includes a proximal exit opening disposed nearer to the heart, and multiple fenestrations disposed distally away from the proximal exit opening near a cannulation site. The fenestrations in combination with the proximal exit opening enable simultaneous perfusion of blood into the cannulated vessel along proximal and distal directions. During a medical procedure, blood introduced into a vessel (e.g., the femoral artery) by way of the cannula can exit the cannula in a manner that provides concurrent blood flow in a first set of directions proximally towards the heart and a second set of directions distally away from the heart. Radially displaceable anchoring elements positionable adjacent to the vessels superficial wall aid retention of the first segment in the vessel. The fenestrations and/or anchoring elements can be arranged obliquely around portions of the cannulas circumference.
National University of Singapore and National University Hospital Singapore | Date: 2015-02-24
Aspects of the present disclosure are directed to an ocular drainage device that includes a stability system. The stability system includes a plate, and can further include a material comprising collagen covering at least a portion of a top surface of the plate, and/or a viscoelastic substance covering at least a portion of the plates top surface. The plate is formed of a flexible material and includes a tube retaining structure integrally formed therewith, wherein the tube retaining structure is configured to hold a tube that is at least partially surrounded by the tube retaining structure to the plate when the tube is moved. The tube retaining structure can include a low profile ridge, and/or a channel having an undercut or horseshoe shape. The plate has at least one plate channel, including a plate channel configured for carrying the tube. The plate can further include a reservoir.
IRIDEX Corporation, National University Hospital Singapore and National University of Singapore | Date: 2015-06-25
Systems, devices, and methods for treating a glaucomatous eye are provided. Embodiments may provide a treatment probe for treating an eye of a patient. The treatment probe may have an elongate body with a contact surface at a distal end of the elongate body. A treatment fiber or light source may be housed in the treatment probe and may be configured to direct treatment energy from the contact surface. The contact surface may be configured to couple to a surface of the eye to deliver the energy into the target area. In many embodiments the contact surface may have a convex configuration with a rounded outer shape and edge that facilitates the sweeping of the probe surface across the eye during treatment delivery. In some embodiments the probe may be swept in arc motions while delivering treatment energy to the eye.
Agency For Science and National University Hospital Singapore | Date: 2014-06-11
A method for surgical resection planning of a mass is disclosed, the method comprises the steps of modelling the mass based on a plurality of physical dimensions, determining a plurality of safety margins around a plurality of features within the mass, simulating a resection surface on the mass comprising a plurality of triangles, optimizing local area and position of a first of the plurality of triangles on the resection surface based on a triangle-based algorithm, updating the simulation of the resection surface, and repeating the steps of optimizing and updating for each of the plurality of triangles on the resection surface.
Tang J.W.,University of Alberta |
Loh T.P.,National University Hospital Singapore
Reviews in Medical Virology | Year: 2014
SUMMARY: Respiratory syncytial virus is the most common respiratory virus infection in early childhood, causing a wide range of illness from mild colds to life-threatening croup, bronchiolitis and pneumonia that may require intensive care. Exactly which parameters contribute to the seasonality of RSV (and other respiratory viruses, such as influenza) and their comparative significance are the subject of ongoing intensive debate. This review article summarises the specific contributions and correlations between the incidence of RSV and various climate parameters. This systematic review of the literature specifically focuses on these climate associations and have been stratified by study site latitudes: tropical (0-23.5°N or S), subtropical (23.5-40°N or S) and temperate latitudes (>40°N or S). Correlations between RSV incidence and temperature and relative humidity are particularly variable and inconsistent amongst the tropical regions. In subtropical and temperate regions, RSV incidence is more consistently positively correlated with lower temperatures and higher relative humidity. Although there is some variation with the diagnostic methods used in these studies, most used immunofluorescent viral antigen testing to diagnose RSV infection. Statistically, most studies used some form of regression analysis, which assumes no dependence between data taken at different time points. A few used the autoregressive integrated moving average approach, which may be more realistic for an infectious agent as the total number of cases usually evolves in a time-dependent manner during a typical seasonal epidemic. © 2013 John Wiley & Sons, Ltd.
Shah S.M.,National University Hospital Singapore
The journal of knee surgery | Year: 2013
Severe medio-patellofemoral osteoarthritis (MPFOA) is often managed with a total knee arthroplasty (TKA). Bicompartmental knee arthroplasty (BKA), as compared with TKA can offer a bone and ligament preserving solution for MPFOA. We aimed to compare the early clinical and functional outcomes of modular BKA (n = 16) with TKA (n = 20) in MPFOA. Knee Society Score (KSS-clinical and function scores) and Knee injury & Osteoarthritis Outcome Score (KOOS-pain, symptoms, stiffness, and function scores) were recorded at 6, 12 and 24 months postoperatively and compared between the two groups. Pre- and postoperative radiographs were evaluated for alignment and radiolucencies. We found that none of the outcome scores were significantly different (p ≥ 0.137) between the two groups at any point in time. Postoperative knee range of motion (ROM) was significantly greater in the BKA group at all points in time (p ≤ 0.007). None of the patients in either group were revised or pending revision at the end of 24 months. To conclude, modular BKA resulted in better knee ROM but similar clinical and functional scores than TKA in MPFOA at short term. Modular BKA is a viable option for MPFOA but may not necessarily result in significant superior functional outcomes than with TKA. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.
Karlsson B.,National University Hospital Singapore
Journal of neurosurgery | Year: 2012
The optimal management of central neurocytoma (CN) remnants and recurrences is still not clear. To date no large series of patients treated with Gamma Knife surgery (GKS) for CNs has been published. For that reason the authors decided to combine data from 5 different centers so that they could analyze the largest population of patients treated with GKS for CN currently available. Data obtained in 42 patients who were treated for CN with GKS before July 1, 2010, were retrospectively collected and analyzed. The median prescribed dose was 13 Gy (range 11-25 Gy). The follow-up time in these patients ranged from 0.5 to 14.7 years (mean 6.1 years, median 4.9 years). Eleven patients were followed up for 5-10 years and 9 patients for more than 10 years. All patients were alive and well at the closing of the study except 1 patient, who died of injuries sustained in a traffic accident. Two cases of local tumor progression and 2 cases of distant tumor recurrence occurred among the patient population, yielding 5- and 10-year tumor control rates of 91% and 81%, respectively. No permanent complications occurred. The findings were in line with results reported in earlier publications. Despite the high tumor control rate, enlargement of part of or the whole ventricular system was seen in 45% of patients. The high tumor control rate and the low complication rate following GKS indicate that GKS is the preferred treatment for CN tumor remnants or recurrences following microsurgery. However, data from longer follow-up times in more patients are needed before this conclusion can be validated. The patients need to be closely monitored and potential hydrocephalus managed despite tumor control.
Farouk R.,National University Hospital Singapore
Annals of Coloproctology | Year: 2014
Purpose: To estimate the risk of recurrent fissure in ano after sphincter preserving treatments. Methods: A retrospective case note review, combined with a telephone survey was conducted for all patients treated for a chronic anal fissure between 1998 and 2008. Results: Six hundred and twelve patients (303 women: mean age, 39 years; range, 16-86 years) were treated for chronic anal fissure between 1998 and 2008. Topical diltiazem 2% was initially prescribed for 8 weeks. The fissure did not heal in 141 patients. These patients (61 women: mean age, 30 years; range, 15-86 years) were treated with 100 IU botulinum A toxin (Botox) injection combined with a fissurectomy under general anaesthesia. Thirty eight patients suffered a recurrence of their fissure within two years. Thirty-four healed with further medical or sphincter conserving surgical therapy while four required a lateral internal sphincterotomy. Conclusion: The vast majority of patients with chronic anal fissure can be treated with sphincter conserving treatments. This may require several interventions before healing can be achieved. Assessment for recurrence after 'conservative' treatments requires a minimum of two-year follow-up. © 2014 The Korean Society of Coloproctology.
Wee A.,National University Hospital Singapore
Cytopathology | Year: 2011
The role of fine needle aspiration (FNA) biopsy of the liver has evolved. Advances in imaging modalities have obviated the need for tissue confirmation in clinically classic hepatocellular carcinoma (HCC). The risks of needle tract seeding and haematogenous dissemination have been actively debated. Nowadays, cytopathologists are confronted by smaller and smaller nodules, detected due to increased surveillance of high-risk cirrhotic patients. Tissue characterization of small well-differentiated hepatocellular nodular lesions (size less than and equal to 2cm) is extremely challenging and has therapeutic implications. Major issues in the cytodiagnosis of HCC include: (i) distinguishing benign hepatocellular nodular lesions, namely, large regenerative nodules, dysplastic nodules, focal nodular hyperplasia and hepatocellular adenoma from reactive hepatocytes; (ii) distinguishing well-differentiated HCC from benign hepatocellular nodular lesions; (iii) distinguishing poorly differentiated HCC from intrahepatic cholangiocarcinoma and metastatic carcinomas; (iv) determining the histogenesis of a malignant tumour; and (v) determining the site of origin of a malignant tumour. An overview of the biological evolution and histopathological aspects of dysplastic nodules, small HCCs and 'nodule-in-nodule' lesions is presented in tandem with clinically relevant nomenclature. An algorithmic approach to FNA diagnosis of HCC and hepatocellular nodular lesions is outlined. Optimal results depend on (i) a dedicated radiologist-cytopathologist team; (ii) an on-site cytology service, (iii) a combined cytohistological approach, (iv) immunohistochemistry, and (v) clinicopathological correlation. As we move towards personalized medicine, it is envisaged that hepatic FNA is likely to become a point of care in the management protocol as it takes on the additional role of procurement of tumour and peritumoural tissues for genomic and proteomic profiling to enable targeted molecular therapy. © 2011 Blackwell Publishing Ltd.