1.Intracranial aneurysm detection with 3T magnetic resonance angiography.
Phua-Hwee TANG ; Francis HUI ; Yih-Yian SITOH
Annals of the Academy of Medicine, Singapore 2007;36(6):388-393
INTRODUCTIONThe new 3 Tesla (T) magnetic resonance (MR) scanners yield improved signal-to-noise ratio and spatial resolution with superior background suppression compared to lower field strength systems. This is advantageous for MR angiograms. The purpose of our study was to compare unenhanced three-dimensional time-of-flight magnetic resonance angiography (3D TOF MRA) at 3T with catheter digital subtraction angiography (DSA) in detecting unruptured intracranial aneurysms.
MATERIALS AND METHODSOut of 1375 consecutive patients who underwent unenhanced 3D TOF MRA at 3T, 15 patients with unruptured intracranial aneurysms were retrospectively identified. Nine of these 15 patients had DSA as the reference standard for comparison. Aneurysm size, location and morphology were independently assessed on both MRA and DSA by 2 radiologists.
RESULTSSeventeen aneurysms ranging in size from 1 mm to 24 mm were identified in 15 patients on MRA. DSA confirmed the aneurysms in 9 patients with good anatomical correlation compared with the MRA findings.
CONCLUSIONS3D TOF MRA at 3T has good correlation with DSA and aneurysms as small as 1 mm in size can be detected. This can be a promising, non-invasive method for aneurysm surveillance.
Adult ; Aged ; Angiography, Digital Subtraction ; Female ; Humans ; Image Processing, Computer-Assisted ; methods ; Intracranial Aneurysm ; diagnosis ; Magnetic Resonance Angiography ; methods ; Male ; Middle Aged ; Retrospective Studies ; Singapore
4.Multi-detector computer tomography angiography in the initial assessment of patients acutely suspected of having intracranial aneurysm rupture.
Suyash MOHAN ; Wickly LEE ; Jau Tsair TAN ; Liang Kwee WEE ; Francis K H HUI ; Yih-Yian SITOH
Annals of the Academy of Medicine, Singapore 2009;38(9):769-773
INTRODUCTIONMulti-detector computer tomography angiography (CTA) provides a fast non-invasive assessment of the cerebral vessels, is readily available in an acute setting and can potentially replace invasive digital subtraction angiography (DSA) for the diagnosis of intracranial vascular lesions in an emergency setting. We report our experience in the use of emergent cerebral CTA versus DSA in the assessment of patients presenting acutely with symptoms suspicious of brain aneurysm rupture.
MATERIALS AND METHODSThirty-seven consecutive patients presenting acutely with clinical suspicion of brain aneurysm rupture were evaluated over a 4-month period from January to April 2008. CTA with peripheral intravenous contrast injection was performed on a 32 slice helical scanner. DSA was performed within 48 hours for all cases when CTA was the initial assessment. Studies were assessed via radiology reports using DSA or surgery as the gold standard.
RESULTSAll except for 3 patients had CTA as the initial study. There were 26 cerebral aneurysms detected by CTA in these 37 patients, with 9 negative studies. There were 2 patients with arteriovenous malformations (AVM), 1 with AV fistula (AVF), 1 tumoral bleed, 2 vertebral dissections, and 1 missed sagittal sinus thrombosis (CVT) on CTA. Based solely on CTA assessment, 3 patients had direct surgical clipping of the aneurysm, while 4 proceeded to direct endovascular coiling.
CONCLUSIONEmergent CTA is a non-invasive, reliable and viable alternative to emergent DSA for the assessment of the cerebral vessels in the acute assessment of patients presenting with symptoms suspicious of brain aneurysm rupture. Where positive, it can serve as a guide to therapeutic decisions. Review of CTA source data is essential, especially for small lesions and for post-clipping assessment.
Adolescent ; Adult ; Aged ; Aneurysm, Ruptured ; diagnosis ; Angiography, Digital Subtraction ; methods ; Cerebral Angiography ; instrumentation ; methods ; Female ; Humans ; Intracranial Aneurysm ; pathology ; Male ; Middle Aged ; Tomography, X-Ray Computed ; methods ; Young Adult
5.The MERCI Retrieval System for the management of acute ischaemic stroke--the NNI Singapore experience.
Wickly LEE ; Yih-Yian SITOH ; C C Tchoyoson LIM ; Winston E H LIM ; Francis K H HUI
Annals of the Academy of Medicine, Singapore 2009;38(9):749-755
INTRODUCTIONSystemic and local intra-arterial thrombolysis in patients with large vessel ischaemic stroke is hampered by poor re-canalisation rates and risk of haemorrhage. The Merci Retrieval System is an endovascular device for removal of acute intracranial thrombus. We present our initial experience using this device in conjunction with existing thrombolytic therapy already in place in our institute.
MATERIALS AND METHODSProspective data in all patients presenting with large vessel ischaemic stroke treated using the Merci Retrieval System from July 2007 to March 2009 were analysed. Selection criteria for patients were similar to the multi- Merci trial of 2008. We compared re-canalisation rate, National Institutes of Health Stroke Score (NIHSS) and modified Rankin score (mRS) outcomes to the published trial results.
RESULTSSeventeen patients were reviewed; none suffered immediate post-procedural complications. Fifteen underwent successful thrombus retrieval but in 2 cases the device failed due to technical considerations. Sites of vascular occlusion included: ICA/ICA-'T' junctions 27%, middle cerebral artery 13% and vertebrobasilar artery 60%. Of the 15 patients treated by MERCI with or without adjuvant thrombolytic therapy, complete re-canalisation was achieved in 60%, partial re-canalisation in 20%, partial re-canalisation with persistent distal vessel occlusion in 6% and failure of re-canalisation in 14%. Asymptomatic haemorrhage occurred in 33% and there was 1 death (6%) from symptomatic haemorrhage. Pre-treatment median NIHSS was 17.88 and 9.5 immediately post-treatment. Median mRS at 30 days was 2.6 for patients who achieved complete re-canalisation and 4.5 in failure or partial re-canalisation with or without persistent distal vessel occlusion.
CONCLUSIONRe-canalisation rates using the Merci Retrieval System was comparable to the multi-Merci trial. Haemorrhagic complications and safety were also found to be satisfactory. Importantly, treatment success with eventual good clinical outcome hinges strongly on the ability of the device to achieve complete re-canalisation.
Acute Disease ; Aged ; Cerebral Arteries ; diagnostic imaging ; physiopathology ; Cerebral Revascularization ; Female ; Humans ; Intracranial Thrombosis ; radiotherapy ; Male ; Middle Aged ; Outcome Assessment (Health Care) ; Prospective Studies ; Radiography ; Singapore ; Stroke ; pathology ; radiotherapy ; Thrombectomy ; instrumentation
7.Evaluation of the Neurological Safety of Epidural Milnacipran in Rats.
Seung Mo LIM ; Mee Ran SHIN ; Kyung Ho KANG ; Hyun KANG ; Francis Sahngun NAHM ; Baek Hui KIM ; Hwa Yong SHIN ; Young Jin LIM ; Sang Chul LEE
The Korean Journal of Pain 2012;25(4):228-237
BACKGROUND: Milnacipran is a balanced serotonin norepinephrine reuptake inhibitor with minimal side effects and broad safety margin. It acts primarily on the descending inhibitory pain pathway in brain and spinal cord. In many animal studies, intrathecal administration of milnacipran is effective in neuropathic pain management. However, there is no study for the neurological safety of milnacipran when it is administered neuraxially. This study examined the neurotoxicity of epidural milnacipran by observing behavioral and sensory-motor changes with histopathological examinations of spinal cords in rats. METHODS: Sixty rats were divided into 3 groups, with each group receiving epidural administration of either 0.3 ml (3 mg) of milnacipran (group M, n = 20), 0.3 ml of 40% alcohol (group A, n = 20), or 0.3 ml of normal saline (group S, n = 20). RESULTS: There were no abnormal changes in the behavioral, sensory-motor, or histopathological findings in all rats of groups M and S over a 3-week observation period, whereas all rats in group A had abnormal changes. CONCLUSIONS: Based on these findings, the direct epidural administration of milnacipran in rats did not present any evidence of neurotoxicity in behavioral, sensory-motor and histopathological evaluations.
Animals
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Brain
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Cyclopropanes
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Injections, Epidural
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Neuralgia
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Norepinephrine
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Rats
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Serotonin
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Spinal Cord
8.Acute unilateral submandibular gland swelling associated with the laryngeal mask airway.
Thangavelautham SUHITHARAN ; Sathyendran SEEVANAYAGAM ; Francis Christopher PARKER ; Wendy Hui Ling TEOH
Singapore medical journal 2013;54(12):e236-9
We describe a rare complication of acute unilateral submandibular gland swelling following the use of laryngeal mask airway (LMA) in two patients with otherwise uneventful perioperative airway management. This is likely to be a consequence of the pressure exerted by the airway cuff on the tissues within the submandibular triangle. As this complication is rarely reported, its true incidence may in fact be higher, suggesting a need for greater attention on LMA cuff pressures and degree of cuff inflation. We discuss the presenting clinical features, pathophysiology and utilisation of ultrasonographic confirmation of sialadenopathy, and review the current anaesthetic literature to raise awareness of this unusual and under-reported complication of LMA. This complication can be mitigated by incorporating routine manometric checks and limiting intracuff pressures to < 60 cmH2O, potentially avoiding LMA insertions in patients with sialolithiasis and avoiding the use of nitrous oxide.
Adult
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Anesthetics
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therapeutic use
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Female
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Humans
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Laryngeal Masks
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adverse effects
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Male
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Pressure
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Submandibular Gland
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diagnostic imaging
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pathology
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Ultrasonography