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Dive into the research topics where Alex Mortimer is active.

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Featured researches published by Alex Mortimer.


Journal of Clinical Neuroscience | 2016

Meta-analysis of stent-assisted coiling versus coiling-only for the treatment of intracranial aneurysms

Kevin Phan; Ya R. Huo; Fangzhi Jia; Steven Phan; Prashanth J. Rao; Ralph J. Mobbs; Alex Mortimer

Endovascular coil embolization is a widely accepted and useful treatment modality for intracranial aneurysms. However, the principal limitation of this technique is the high aneurysm recurrence. The adjunct use of stents for coil embolization procedures has revolutionized the field of endovascular aneurysm management, however its safety and efficacy remains unclear. Two independent reviewers searched six databases from inception to July 2015 for trials that reported outcomes according to those who received stent-assisted coiling versus coiling-only (no stent-assistance). There were 14 observational studies involving 2698 stent-assisted coiling and 29,388 coiling-only patients. The pooled immediate occlusion rate for stent-assisted coiling was 57.7% (range: 20.2%-89.2%) and 48.7% (range: 31.7%-89.2%) for coiling-only, with no significant difference between the two (odds ratio [OR}=1.01; 95% confidence intervals [CI}: 0.68-1.49). However, progressive thrombosis was significantly more likely in stent-assisted coiling (29.9%) compared to coiling-only (17.5%) (OR=2.71; 95% CI: 1.95-3.75). Aneurysm recurrence was significantly lower in stent-assisted coiling (12.7%) compared to coiling-only (27.9%) (OR=0.43; 95% CI: 0.28-0.66). In terms of complications, there was no significant difference between the two techniques for all-complications, permanent complications or thrombotic complications. Mortality was significantly higher in the stent-assisted group 1.4% (range: 0%-27.5%) compared to the coiling-only group 0.2% (range: 0%-19.7%) (OR=2.16; 95% CI: 1.33-3.52). Based on limited evidence, stent-assisted coiling shows similar immediate occlusion rates, improved progressive thrombosis and decreased aneurysm recurrence compared to coiling-only, but is associated with a higher mortality rate. Future randomized controlled trials are warranted to clarify the safety of stent-associated coiling.


Journal of NeuroInterventional Surgery | 2016

Outcomes of endovascular treatment of basilar artery occlusion in the stent retriever era: a systematic review and meta-analysis

Kevin Phan; Steven Phan; Ya Ruth Huo; Fangzhi Jia; Alex Mortimer

Background Stent retriever thrombectomy has recently been found to be effective for anterior circulation strokes, but its efficacy for basilar artery occlusion (BAO) is unclear. Objective To carry out a systematic review and meta-analysis to analyze the available evidence for the use of stent retrievers for BAO. Methods Two independent reviewers searched six databases for studies reporting outcomes following endovascular treatment for BAO. Results A total of 17 articles (6 prospective and 11 retrospective) were included. The weighted mean age of patients was 67 years (range 59–82) and 59% were male. Thrombolytic drugs were administered intravenously and intra-arterially in 46% (range 0–88%) and 38% (range 0–90%) of patients, respectively. Weighted pooled estimates of successful recanalization (TICI 2b–3) and good outcome (modified Rankin Scale ≤2) were 80.0% (95% CI 70.7% to 88.0%; I2=80.28%; p<0.001) and 42.8% (95% CI 34.0% to 51.8%; I2=61.83%; p=0.002), respectively. Pooled mortality was 29.4% (95% CI 23.9% to 35.3%; I2=37.01%; p=0.087). Incidence of procedure-related complications and symptomatic hemorrhage was 10.0% (95% CI 3.7% to 18.3%; I2=61.05%; p=0.017) and 6.8% (95% CI 3.5% to 10.8%; I2=37.99%; p=0.08), respectively. Conclusions Stent retriever thrombectomy achieves a high rate of recanalization and functional independence while being relatively safe for patients with BAO. Future prospective studies with long-term follow-up are warranted.


Journal of Clinical Neuroscience | 2016

Endovascular therapy including thrombectomy for acute ischemic stroke: A systematic review and meta-analysis with trial sequential analysis

Kevin Phan; Dong Fang Zhao; Steven Phan; Ya Ruth Huo; Ralph J. Mobbs; Prashanth J. Rao; Alex Mortimer

One of the primary strategies for the management of acute ischemic stroke is intravenous (IV) thrombolysis with tissue plasminogen activator (t-PA). Over the past decade, endovascular therapies such as the use of stent retrievers to perform mechanical thrombectomy have been found to improve functional outcomes compared to t-PA alone. We aimed to reassess the functional outcomes and complications of IV thrombolysis with and without endovascular treatment for acute ischemic stroke using conventional meta-analysis and trial sequential analysis. Pooled relative risks (RR) and 95% confidence intervals (CI) were calculated for the effect of IV thrombolysis with and without endovascular therapy on functional outcome, mortality and symptomatic intracranial hemorrhage (SICH). Trial sequential analysis was done to strengthen the meta-analysis. We analyzed six randomized controlled trials involving 1943 patients. Patients who received IV thrombolysis with endovascular treatment showed significantly higher rates of excellent functional outcomes (modified Rankin Scale [mRS] 0-1) (RR, 1.75 [95% CI, 1.29-2.39]) compared to those who received IV thrombolysis alone. A similar association was seen for good functional outcomes (mRS 0-2) (RR, 1.56 [95% CI, 1.24-1.96]). Trial sequential analysis demonstrated endovascular treatment increased the RR of a good functional outcome by at least 30% compared to IV thrombolysis alone. There was no significant difference in all-cause mortality for mechanical thrombectomy compared to IV thrombolysis alone or the incidence of SICH at 3month follow-up. Endovascular treatment is more likely to result in a better functional outcome for patients compared to IV thrombolysis alone for acute ischemic stroke.


Journal of Radiology Case Reports | 2009

Delayed presentation of a vertebral arterio-venous fistula secondary to penetrating cervical trauma: endovascular management using coil embolisation - a case report

Alex Mortimer; Euan Stubbs; Daniel Cookson; Raymond Dawson; Mustafa Fleet

Vertebro-vertebral arteriovenous fistulae occur infrequently. We report on such a case with delayed presentation following penetrating neck injury. This was successfully treated via coil embolisation. A 40-year-old woman presented with a subjective tinnitus that was abolished by turning her head to the right. She had sustained penetrating neck trauma 6 months earlier. Doppler Ultrasound and magnetic resonance angiogram confirmed the presence of a vertebral arterio-venous fistula. Using a trans-femoral arterial approach, the left vertebral artery was embolised by deployment of multiple coils. The patient had no return of symptoms at 3 months follow up. Radiological diagnosis and endovascular management of this condition is discussed.


Interventional Neuroradiology | 2013

Endovascular Therapy in Hyperacute Ischaemic Stroke: History and Current Status

Alex Mortimer; Marcus D Bradley; Shelley Renowden

This is a literature review on to the use of endovascular therapy in hyperacute ischaemic stroke secondary to large vessel occlusion (LVO). The prognosis for LVO is generally poor and the efficacy of intravenous tissue plasminogen activator (IV TPA) in the treatment of this subtype of stroke is questionable. It is well documented that recanalisation is associated with improved outcomes but IV TPA has limited efficacy in LVO recanalisation and the complication rates are higher for IV TPA in this stroke subset. Improved recanalisation rates have been demonstrated with intra-arterial TPA and first and second generation mechanical techniques but the rate of favourable outcome has not overtly mirrored this improvement. Several controversial trials using these early techniques have recently been published but fail to reflect modern practice which centres on the use of stent-retriever technology. This has been proven to be superior to older techniques. Not only are recanalisation rates higher, but the speed of recanalisation is greater and clinical results are improved. Multiple observational studies demonstrate consistently high rates of LVO recanalisation; TICI 2b/3 in the order of 65–95% and, rates of favourable outcome (mRS 0–2) in the order of 55% (42.5–77%) in clinically moderate to severe stroke with complicating symptomatic haemorrhage in the order of 1.5–15%. A major factor determining outcome is time to treatment but success has been demonstrated using these devices with bridging therapy, after IV TPA failure or as a stand-alone treatment.


Neurointervention | 2017

A Meta-Analysis of Observational Evidence for the Use of Endovascular Thrombectomy in Proximal Occlusive Stroke Beyond 6 Hours in Patients with Limited Core Infarct

James Wareham; Kevin Phan; Shelley Renowden; Alex Mortimer

Purpose The safety and efficacy of endovascular thrombectomy (EVT) for patients with proximal occlusive stroke presenting beyond 6 hours and selected on the basis of favorable neuroimaging remains unclear. Materials and Methods A systematic search was performed from four electronic databases from their inception to Jan 2017. A meta-analysis of outcomes from studies with patients treated beyond 6 hours was compared to those treated within the established 6 hour therapeutic window in randomized trials, selected using conventional imaging methods with CT/CT angiography. Results A total of 8 articles met inclusion criteria for the study population (a prospective single-center study, 5 retrospective single-center studies and 2 retrospective multicenter studies). These were compared to the results of three prospective trials of patients treated within 6 hours selected using CT/CT angiography. For patients treated >6 hours and <6 hours respectively, the weighted mean age was 64.7 vs. 67.0 years; the presenting NIHSS was 15.7 vs. 17.1 and the time from symptom onset to puncture was 4.0 hours vs. 15.1 hours. Weighted pooled estimates of successful recanalization (TIMI 2/3 or TICI 2b/3) and favorable outcome (mRS ≤2) were similar between both groups, 70.1% vs. 70.6%, P=0.75 and 38.9% vs. 38.4%, P=0.88 respectively. Pooled mortality measured at 3 months was 22.8% for those treated >6 hours and 12.5% for <6 hours, P<0.0001. Symptomatic intracranial hemorrhage was not significantly different (10.0% vs. 7.7%, P=0.33). Conclusion When compared to established methods of patient selection, EVT employed beyond 6 hours in those selected with imaging to exclude large core infarcts achieves similar rates of recanalization, and functional outcome but there is a significant increase in mortality despite no increase in symptomatic intracranial hemorrhage.


BMJ | 2012

Managing hyperacute ischaemic stroke with interventional neuroradiology

Alex Mortimer; Marcus D Bradley; Shelley Renowden

Provides effective vessel recanalisation but well designed trials are needed to establish the full spectrum of patients who could benefit


Journal of Radiology Case Reports | 2008

Jejunal diverticulitis: an unusual cause of an intra- abdominal abscess - coronal Computed Tomography reconstruction can aid the diagnosis

Alex Mortimer; James Harding; Huw Roach; Mark Callaway; Jim Virjee

Jejunal diverticulitis is a rare condition that can present with an acute abdomen and be referred for imaging. We present the case of an elderly patient who at CT was diagnosed with an intra-abdominal abscess involving both jejunum and transverse colon. However, the underlying eitiology was not initially clear until small bowel barium follow-through.Pertinent points regarding CT findings in jejunal diverticulitis are discussed, and practical recommendations in small bowel diverticulum recognition and diagnosis are made.


CardioVascular and Interventional Radiology | 2010

Interval Biliary Stent Placement Via Percutaneous Ultrasound Guided Cholecystostomy: Another Approach to Palliative Treatment in Malignant Biliary Tract Obstruction

James Harding; Alex Mortimer; Michael D. Kelly; Eric Loveday

Percutaneous cholecystostomy is a minimally invasive procedure for providing gallbladder decompression, often in critically ill patients. It can be used in malignant biliary obstruction following failed endoscopic retrograde cholangiopancreatography when the intrahepatic ducts are not dilated or when stent insertion is not possible via the bile ducts. In properly selected patients, percutaneous cholecystostomy in obstructive jaundice is a simple, safe, and rapid option for biliary decompression, thus avoiding the morbidity and mortality involved with percutaneous transhepatic biliary stenting. Subsequent use of a percutaneous cholecystostomy for definitive biliary stent placement is an attractive concept and leaves patients with no external drain. To the best of our knowledge, it has only been described on three previous occasions in the published literature, on each occasion forced by surgical or technical considerations. Traditionally, anatomic/technical considerations and the risk of bile leak have precluded such an approach, but improvements in catheter design and manufacture may now make it more feasible. We report a case of successful interval metal stent placement via percutaneous cholecystostomy which was preplanned and achieved excellent palliation for the patient. The pros and cons of the procedure and approach are discussed.


Journal of Radiology Case Reports | 2012

A rare cause of neural foraminal widening

Jonathan Carl Luis Rodrigues; Alex Mortimer; Seth Love; Shelley Renowden

The differential diagnosis for lesions causing neural foraminal widening is vast. The majority are solitary benign peripheral nerve sheath tumours, such as neurofibromas or schwannomas. We present a case of a rare cause of neural foraminal expansion secondary to a posterior thoracic extradural angiolipoma. We describe the presence of chemical shift artefact on post gadolinium T1-weighted imaging as indirect evidence of a fatty component. This potentially important diagnostic sign may raise the suspicion of angiolipoma, especially in an isointense or hypointense dumbbell lesion on T1-weighted imaging, and has not been described previously in this context. Accurate radiological diagnosis of an angiolipoma is important to reduce unexpected haemorrhagic complications from biopsy or resection of the lesion.

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Kevin Phan

University of New South Wales

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Ya Ruth Huo

University of New South Wales

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Prashanth J. Rao

University of New South Wales

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