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FP1: Moyamoya Disease in Hong Kong: natural history and surgical revascularization outcome.
Anderson Chun On TSANG1 , Wai Man LUI1 , Yin Chung PO2 , Hok Ming CHIU3
1 Department of Neurosurgery, Queen Mary Hospital, Hong Kong, 2 Department of Neurosurgery, Princess Margaret Hospital, Hong Kong, 3 Department of Neurosurgery, Queen Elizabeth Hospital, Hong Kong
Objective: Moya-moya disease (MMD) is an occlusive cerebral vasculopathy associated with high risk of recurrent ischemic and hemorrhagic events. Surgical revascularization had proven benefits in ischemic MMD but the role in hemorrhagic presentations is less clear. We studied the natural history of symptomatic MMD patients in Hong Kong and compared the long term outcome of revascularized patients with those treated conservatively.
Methods: Patients with MMD managed in three high volume neurosurgical centers from 1997–2015 in Hong Kong were identified from the Hospital Authority's clinical data analysis and reporting system. The demographic and clinical characteristics, surgical outcome, and follow-up information were retrospectively reviewed. The primary outcome was recurrent hemorrhagic and ischemic stroke. The annual stroke risk and functional status of patients treated surgically and conservatively was compared.
Results: Our cohort included 101 patients with a mean follow-up of 80.2 months. Female-to-male ratio was 1.8:1. 85.1% of patients had bilateral disease. The mean age of symptom onset was 42.6 years, with a bimodal distribution. 54.5% presented with intracranial hemorrhage and 39% with cerebral ischemic symptoms.
64 patients were treated conservatively, 15 underwent direct vascular bypass and 22 had indirect revascularization. 20 of the 64 (31.3%) patients treated conservatively had rebleeding, compared with 5 of 32 (15.6%) of surgically revascularized patients. The overall annual stroke risk per patient was significantly lower in revascularized than conservatively managed patients (4.6%/year vs 8.3%/year (p = .015). 2 (5.4%) patients in the surgical group and 12 (18.8%) in the conservative group died of MMD during the follow up period. Surgically treated patients were more likely to have good functional outcome (mRS 0–2) at last follow up. (86.1% vs 62.5%, p = .024)
Conclusion: Our results confirmed the devastating natural history with high recurrent stroke risk in amongst Hong Kong MMD patients treated conservatively. Surgical revascularization conferred significant risk reduction for recurrent adverse neurological events, in particular that of hemorrhagic stroke. This translated to favourable survival and functional outcome compared with conservatively managed patients
FP2: Outcome of Endovascular Treatment versus Neurosurgical Clipping: A Single Center Retrospective Study
Natalie MW Ko1, Alain KS Wong1, KY Chan1, S Lam2, S Lau2, John CK Kwok1
1Department of Neurosurgery, Kwong Wah Hospital, 2Department of Radiology, Kwong Wah Hospital, Hong Kong
Background: The International Subarachnoid Aneurysm Trial (ISAT) was a landmark paper published in 2002, which revolutionized the approach of treating ruptured intracranial aneurysms1. It demonstrated that the disability-free survival rate at one year was significantly better for patients with endovascular therapy.
Objectives: We primarily aim to compare functional outcomes in terms of the modified Rankin Score (mRS) of patients undergoing endovascular treatment and neurosurgical clipping at three, six and twelve months. Furthermore, we aim to ascertain rebleeding rates and successfulness of complete aneurysm obliteration of these treatment modalities.
Methodology: This was a single-center retrospective study. Consecutive patients with an intracranial aneurysm, ruptured and unruptured, treated at this institution from 1st January 2012 to 30th April 2015 were recruited. All patients were evaluated by our endovascular team for their feasibility to undergo either endovascular therapy or neurosurgical clipping, and were allocated endovascular intervention as the preferred treatment modality. Good outcome was classified as having a mRS of 0–2. Poor outcome was defined as a mRS of 3–6.
Results: To be released in the meeting.
Conclusions: To be discussed in the meeting.
References
1AJ Molyneux., et al. International Subarachnoid Aneurysm Trial (ISAT) of neurosurgical clipping versus endovascular coiling in 2143 patients with ruptured intracranial aneurysms: a randomised trial. The Lancet. Oct 2002. Volume 360, No. 9342. P1267 – 1274.
FP3: Prospective trial of monitoring clopidogrel response and dosage patterns in patients undergoing neurovascular stenting
Joanna WK Ho, Alain KS Wong, KY Chan, JCK Kwok
Department of Neurosurgery, Kwong Wah Hospital, Hong Kong
Background and aims: Variability in response to clopidogrel therapy is increasingly recognized as a factor affecting thromboembolic and hemorrhagic outcomes in neurointervention. While it has been reported that the CYP2C19 loss-of-function allele is common in Asians, which is believed to be associated with high on-clopidogrel treatment platelet reactivity (HTPR), further evidence is limited. We hope to revise the current clopidogrel regimen and monitoring of the P2Y12 reaction units (PRU) by VerifyNow® platelet function testing to obtain information regarding the drug response in our local population, aiming to identify factors that may affect clopidogrel response pattern, and/or to establish an appropriate an appropriate regime for drug dosage titration and PRU monitoring.
Methods: We conducted a prospective single center cohort from June 2013 to April 2015, recruiting consecutive patients undergoing neurovascular stenting for intracranial aneurysms/ intracranial arterial stenosis/ extracranial arterial stenosis and requiring antiplatelet therapy. VerifyNow® testing was conducted at regular intervals throughout the perioperative period, and clopidogrel dosage was titrated accordingly using a standardized protocol. Data regarding the antiplatelet regimes, platelet function assay results, procedural details, complications and outcomes were collected and studied.
Results: 32 female and 11 male patients were recruited from the study period. Only 3 patients (6.97%) demonstrated hyporesponse to clopidogrel while the PRU of only 4 patients (9.31%) remained within range throughout the entire surveillance programme with the ‘standard’ dosage of 75 mg daily. The majority of patients (30 out of 43, 69.77%) displayed a phenomenon of delayed hyper-response that has only been reported in one case series, but these did not result in clinically significant hemorrhagic events.
Conclusion: This is the first prospective local study to investigate into the clopidogrel response pattern in the local population; when compared to the western population, the differences in drug dosage and PRU trends that our locality demonstrated calls for further exploration and modifications to our current practices in order to optimize the post-intervention care for local patients.
FP4: Endovascular coiling versus neurosurgical clipping of aneurysm: 5 years historical comparison.
Yeung KT, Cheung WH, Chan KT, Po YC
Department of Neurosurgery, Princess Margaret Hospital, Hong Kong
The International Subarachnoid Aneurysm Trial (ISAT) cohort have reported on the risks of recurrent subarachnoid haemorrhage and death or dependency after treatment of a ruptured intracranial aneurysm with either neurosurgical clipping or endovascular coiling. At 1 year there was a 7% absolute and a 24% relative risk reduction of death and dependency in the coiling group compared with the clipping group.
In year 2013 treatment of aneurysmal SAH shifted from neurosurgical clipping to endovascular coiling in our center. We retrospectively reported the early results of the two groups of patients.
Methods: We reviewed 139 patients presented with aneurysmal subarachnoid haemorrhage to our department treated either by neurosurgical clipping or endovascular coiling during the period July 2010 – June 2015. Data regarding patients’ demographics, aneurysm location and size, clinical and radiological presentation, outcome and mortality rates in 6 months were collected and analysed.
Results: Results will be presented in the upcoming Annual Scientific Meeting.
FP5: Haemorrhagic Complications Associated with EVD Placement: A Two-centre Retrospective Study
Alberto CH Chu1, PYM Woo1, HT Wong1, HM Chiu2, KY Chan1
1 Department of Neurosurgery, Kwong Wah Hospital, 2 Department of Neurosurgery, Queen Elizabeth Hospital, Hong Kong
Introduction: External ventricular drain (EVD) placement is one of the commonest operations performed in neurosurgery. It is useful as a diagnostic and therapeutic procedure in a variety of neurosurgical conditions such as traumatic brain injury, acute subarachnoid haemorrhage and hydrocephalus. In spite of its broad indications and use, recent studies have observed that there is a significant risk of haemorrhage from 7% to 41% per EVD placement1–2.
Objectives: To determine the frequency of haemorrhagic complications after the primary placement of EVD and to identify its associated risk factors.
Methodology: This is retrospective two-center study. Consecutive patients who underwent EVD placement in two regional hospitals from 1st January 2013 to 31st December 2014 were reviewed. Clinical and radiological data were collected from the Hospital Authority electronic patient record system. The primary endpoint was EVD associated intracranial haemorrhage detected on postoperative computed tomography scans.
Results: To be presented in the meeting.
Conclusions: To be presented in the meeting.
References
1. Bauer DF1, Razdan SN, Bartolucci AA, et al. Meta-analysis of hemorrhagic complications from ventriculostomy placement by neurosurgeons. Neurosurgery. 2011 Aug;69(2):255–60.
2. Gardner PA, Engh J, Atteberry D, et al. Hemorrhage rates after external ventricular drain placement. J Neurosurg. 2009 May;110(5):1021–5.
FP6: Stroke and incidental unruptured aneurysm
TF Zhuang, KC Wong
Division of Neurosurgery, Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong
Background: The incidence, morphology of incidental intracranial aneurysm in acute ischemic stroke in Hong Kong Population has yet to be studied. The outcome and mortality of patients having incidental unruptured aneurysm with stroke will also be studied.
Methods: 970 Patients with acute ischemic stroke were identified from Stroke Registry of Prince of Wales Hospital in 2010. Among them, MRI was performed in 304 of these patients. Patient's demographics, risk factors, stroke subtypes, antithrombotic use and outcome at 1 year and 5 year after stroke were studied.
Results: Incidental intracranial aneurysms were found in 2% of stroke patients. 45% were female patients and 55% were male. Mean age is 68. The average size, location of the incidental aneurysm will be studied.
The aneurysms are mainly located in anterior circulation. The outcome of patients with aneurysm and without aneurysm is compared. Their mortality and modified Rankin Scale were compared. Recurrence of stroke in aneurysm and non-aneurysm patient were compared.
Conclusion: Incidence, risks factors of incidental aneurysms in ischemic stroke were studied. Outcome including mortality and modified Rankin Scale of patients with aneurysms and without was compared.
FP7: Experience with long term intrathecal baclofen therapy for spasticity in a university neurosurgical centre
CHAN SK, SUN TF, POON WS
Prince of Wales Hospital, Hong Kong
Objective: To report the experience in intrathecal baclofen (ITB) therapy for spastic patients being followed up in Prince of Wales Hospital.
Methods: Retrospective review of all patients on ITB therapy ever followed up in Prince of Wales Hospital
Results: A total of 8 patients were included, with ITB therapy started at the age from 11 to 52. Compared with pre-operative status, for spasticity, there was a mean reduction of 1.75 point in the modified Ashworth score (p < 0.01). Pain improvement was shown in some patients as evidenced by a mean reduction of 1.25 points in the numerical rating scale. One patient developed episodes of mild baclofen withdrawal syndrome due to premature end of life of battery and kinking of connection. Two patients suffered from local infection near the pump; one was successfully treated with 1 week of intravenous antibiotics, while one required surgical revision. On average, patients on ITB therapy wound have 14.8% chance of receiving a procedure annually to deal with complication or to change the hardware due to end of life of battery.
Conclusion: Intrathecal baclofen is an effective therapy for control of spasticity in carefully selected patients.
FP8: Use of local temporalis fascia graft for the repair of cerebrospinal fluid leak in patients with skull base surgery involving the cavernous sinus
JSW Chow, WM Lui
Queen Mary Hospital, Hong Kong
Objectives: Cerebrospinal fluid (CSF) leaks are common after extensive skull base surgery. We aim to provide a novel method for reconstruction of the skull base for repair of CSF fistula in this study.
Methods: Clinical data was reviewed from Apr 2004- July 2015 in a regional neurosurgery center in Hong Kong. Those with extensive skull base surgery involving the cavernous sinus and complicated by cerebrospinal fluid leak were included. All pathologies were included, but posterior fossa and endoscopic surgeries were excluded in our study.
Results: 16 patients met our inclusion criteria for cerebrospinal fluid leaks after extensive skull base surgery. The mean age was 52yo with a mean follow-up time of 36.1 months. Surgeries were done via different skull base approaches, and most of the dura defects were located at the lateral sphenoid sinus wall. 12 patients (75%) eventually required surgical repair. 7 of which (43.8%) required > =2 surgeries for repair, all of these patients had >1 surgeries done before and 5 (71.4%) had previous radiotherapy done. 4 patients had local temporalis fascia flap done for their initial surgery and only 1 had immediate CSF leak. Of the patients with multiple repairs done, 2 were finally repaired by local temporalis fascia flap.
Conclusion: Local temporalis fascia flap at the anteromedial triangle of the middle cranial fossa is an effective method for dural repair after extensive skull base surgery.
FP9: Treatment of ruptured small wide neck cerebral aneurysms with flow diverters alone
NLA Chan, KTT Chan, YC Po
Princess Margaret Hospital, Hong Kong
Background: Ruptured small wide neck cerebral aneurysms remain a clinically challenge as they are difficult to clip or tackle with conventional coiling procedure.
Objective: To report our initial experience on using flow diverters alone for treatment of ruptured small wide neck cerebral aneurysms
Patients and methods: We reviewed our database of patients who have undergone endovascular treatment for ruptured cerebral aneurysms in our unit. Since 2013, six patients received flow diverters alone for treatment of ruptured cerebral aneurysms. Four of them had ICA aneurysms and two of them had vertebrobasilar aneurysms.
Results:Flow diverters were successfully deployed in all cases. There was one case of mortality due to acute pulmonary edema shortly after the procedure. All patients were put on anti-platelets after the procedure with monitoring with the VerifyNow assay. After a median follow up of six months, there was no case of re-bleeding.
Conclusion: Flow diverters alone treatment appears to be feasible for acute management of ruptured small wide neck cerebral aneurysms. The optimal timing to perform the procedure and the antiplatelet regime remain controversial.
FP10: Does vessel wall MRI help to distinguish stable from unstable intracranial aneurysms? Literature review and pilot results
LY Ho, KC Wong and J Abrigo
Prince of Wales Hospital, Hong Kong
Intracranial aneurysms are common cerebrovascular lesions. About 12% of patients die before receiving medical attention, 40% die within 1 month after the event. Among those who survive, almost 30% will develop major neurological deficits. Morbidity and mortality remained high in rupture cases despite advances in endovascular and microsurgical interventions. Histopathologic evidence from human and animal studies has lent support to the concept that inflammation plays a major role in aneurysm rupture. Vessel wall MRI is a noninvasive assessment of cerebral aneurysms possibly, may differentiate "unstable" lesions that require early intervention from "stable" lesions that can be safely observed.
Among the CT cerebral angiogram performed from 1/1/2007 to 30/4/2014 in Prince of Wales Hospital, we identified 84 patients with unrupture cerebral aneurysms. We included 10 patients for the high resolution MR vessel wall imaging. Circumferential aneurysm wall enhancement (CAWE) which was believed as indirect marker of aneurysmal wall inflammation, was also determined. CAWE, size, location, multiplicity of aneurysms, angioarchitecture were analyzed to assess if any factor suggestive of unstable status
FP11: Prognosis of patients with internal carotid or middle cerebral artery stenosis showing hemodynamic compromise in computed tomography perfusion scan with acetazolamide
WN Ho, Kevin Yu, ST Wong, KY Yam.
Department of Neurosurgery, Tuen Mun Hospital, Hong Kong
Background: Compromised cerebral hemodynamic is shown to be related with increase stroke risk. There is increasing evidence for using acetazolamide (Diamox) to assess the cerebral vascular reserve. Ipsilateral stroke is known to occur within few months in severe compromised patients. However, the detection method currently focuses on Single-photon emission computed tomography (SPECT) and prognosis correlation has not been clearly defined. The purpose of this study was to retrospectively investigate the outcome of patients with computed tomography (CT) perfusion scan performed in our centre in recent years.
Methods: Patients with CT perfusion scan performed from Aug 2012 to Jun 2015 were identified in electronic database of Radiology department. Patients with report concluded impaired cerebrovascular reserve were included. Patients with followed up less than 3 months were excluded. CT perfusion scan was performed more than 4 weeks from latest ischemic infract episode. Outcomes were measured by stroke risk and modified Rankin Scale (mRS). Data was analysed using Microsoft Excel and IBM SPSS.
Results: 70 patients (mean age, 62 yr; 70% male) were included. 69% had internal carotid stenosis/occlusion, 43% had middle cerebral artery stenosis/occlusion. 47% had history of stroke.
Severe impaired reserve cerebral blood flow (rCBF) was defined as <20 ml/100 g/min post Diamox. Severe impaired cerebral vascular reserve (CVR) was defined as mean of −5%. Patients were classified into 4 groups, Group1: mild to moderate decrease in rCBF and CVR only; Group 2: only CVR severe impaired; Group 3: both rCBF and CVR severe impaired; Group 4: only rCBF severe impaired.
For patients who received intervention, there were 15, 8, 2, 2 patients in group 1 to 4 respectively. For patients medically treated, there were 18, 16, 4, 5 patients in group 1 to 4 respectively. There was no statistically significant difference in 2 groups (p = 0.0598, paired t-test)
For operative treatment, 9 patients received carotid stenting, 5 patients received carotid endarterectomy, 14 patients received EC-IC bypass. For medical treatment, 90% of patients were taking aspirin and 11% of patients were taking long-term Plavix. Patients received medical treatment were only due to multiple Intracranial stenosis (12%), poor premorbid status (24%), clinically asymptomatic (29%) and reluctant for operation (35%).
The median follow up period was 29 months (3–107). There was 1 patient loss of follow up. Progress CT perfusion scan was performed for post-operative assessment and for identifying spontaneous cerebrovascular improvement in medically treated patients.
In the studied period, only 3 patients had recurrent stroke, all were ipsilateral. 1 patient was due to stent thrombosis, 1 patient received stenting and bypass had hemorrrhgic stroke, 1 patient was medically treated but had poor drug compliance.
Annual stroke risk was 2.5% for operative group, and 0.78% for medical treatment group (chi-square, p = 0.33). For 65 stroke-free patients, 85% had favourable functional outcome (mRs < =2) at time of last follow-up.
Conclusions: In selected patients with high surgical risk, best medical treatment is an acceptable management with relative low stroke risk. Further investigation and longer follow-up is needed to better understand the use of CT perfusion scan in predicting stroke prognosis and guidance to offer surgical treatment.
FP12: Carotid In-Stent Restenosis in Irradiated Head & Neck Cancer Patients and the Common Presentations
KY Cheng, PH Wong, SM Lo, WL Poon, KF Fok, HM Chiu
Queen Elizabeth Hospital Department of Neurosurgery and Department of Radiology, Hong Kong
Objective: To investigate whether in patients with radiation-induced carotid stenosis with stenting done in particular those with history of nasopharyngeal carcinoma (NPC), has a higher chance of developing symptomatic restenosis and the common presentations of such patients.
Methods: The data of all patients undergoing carotid stenting from January 2010 up to December 2014 were collected. Their demographics, medical history including risk factors such as hypertension/hyperlipidemia/diabetes mellitus/ischemic heart disease/cerebrovascular accident/head and neck cancer with radiotherapy/NPC with radiotherapy, diagnosis, procedure performed, presence or absence of restenosis, interval to restenosis, presentation of symptomatic restenosis and mortality status of patient were highlighted. All diagnosis and procedures were performed by an experienced team of neurosurgeons and neuroradiologists. Patients were followed up at outpatient department with standardized clinical assessments and ultrasound imaging.
Results: 63 patients with irradiated head & neck cancer out of the 147 patients with carotid stenosis collected were identified. The majority of the head & neck cancer patients had nasopharyngeal carcinoma 57 (90%) patients. Other head & neck cancers included larynx, thyroid, hypopharynx and tonsil. 13 patients died and were unable to follow up. 9 (14%) patients with in-stent restenosis with irradiated head & neck cancers within this recruitment period were identified which is comparable to the rate of in-stent restenosis in those without history of irradiated head & neck cancers (10%). 3 (95% symptom-free in-stent restenosis) patients with symptomatic restenosis with head & neck cancers were identified which is similar to those without history of irradiated head & neck cancers (96% symptomatic in-stent restenosis-free). The interval time to in-stent restenosis were 1.5, 1.5, 3.75 years, with an average of 2.25 years which is slightly longer than the interval time to restenosis in patients without history of irradiated head and neck cancers (mean = 0.25 years). The commonest presentation of symptomatic in-stent restenosis is transient ischemic attack.
Conclusion: This study has shown that carotid angioplasty and stenting is a feasible and sustainable treatment for carotid stenosis in patients with irradiated head & neck cancers. The rates of symptomatic in-stent restenosis in such patients are very satisfactory. The commonest presentation of patients with symptomatic in-stent restenosis is transient ischemic attack. The outcomes of patients receiving carotid stenting were not affected by any history of irradiated head & neck cancers and a slightly longer time interval to symptomatic restenosis is observed in those with history of irradiated head & neck cancers.
FP13: Angiographic patency of regional side branches after treatment of supraclinoid aneurysm with pipeline flow diverters: a single centre experience
Remy SL Hung1, Alain KS Wong1, KM Leung1, S Lau2, HY Cho2, KY Chan1, JCK Kwok1
1Department of Neurosurgery, Kwong Wah Hospital, 2Department of Radiology, Kwong Wah Hospital, Hong Kong
Background and purpose: Pipeline embolization device (PED) has been gaining its popularity in the treatment of intracranial aneurysms. The patency of covered side branches and its effect has been a concern. This study aims to evaluate the patency of covered side branches in patient receiving PED treatment for supraclinoid aneurysms.
Methods: Retrospective review of immediate and follow-up angiographies and clinical data of 91 patients with supraclinoid aneurysms treated with PED in Kwong Wah Hospital from January 2008 to March 2015.
Result: 60 patients (66%) had ophthalmic segment aneurysms, 27 patients (30%) had communicating segment aneurysm and 4 patients (4%) had clinoidal segment aneurysms. 17 patients had more than one supraclinoid aneurysms. 19 patients had more than one pipeline stent deployed. 29 patients (32%) had received previous coiling of their aneurysms; 2 patient had his aneurysm clipped before and 2 patient had received prior pipeline stenting. 3 patient presented with acute rupture with emergency stenting performed while the rest were performed as elective procedures.
Complete obliteration of aneurysms was achieved in 74 (81%) patients. Numbers of regional side branches covered by PED ranges from 1–4 (median = 2.00). Followup angiogram was available in 68 patient. 14 patients was followed up with CT angiogram and 3 patient with MR angiogram only. 5 patients had one or more covered regional side branches occluded radiographically upon followup imaging. Another 8 patients had all side branches patent but with obvious diminished flow angiographically.
Conclusion: Risk of occlusion of covered side branches in patient receiving PED treatment for supraclinoid aneurysm is small.
FP14: Long term outcome of endovascular treatment for intracranial aneurysms: single centre experience and risk factor analysis for recanalization
MH Yuen, PH Wong, KF Fok, HM Chiu
Department of Neurosurgery, Queen Elizabeth Hospital, Hong Kong
The need for routine angiographical studies beyond 6 months is questioned by some authors. We performed a retrospective study to evaluate the recanalization rate of our centre. 258 patients with 265 intracranial aneurysms received endovascular treatment in our centre between 1/6/2009 and 31/5/2014. Patient data were retrieved via electronic patient record system. In this study, we reviewed the frequency of recanalization and regrowth of intracranial aneurysms after at least 1.5 year of follow up. The overall rate of recanalization that required reintervention was 16.5%. We also performed risk factor analysis to identify any significant risk factors that can be served as a guide on the plan of follow up angiographic studies.
FP15: External Ventricular Drain Infection: A Territory-wide Hospital Authority Clinical Audit from 2012 to 2014
PYM Woo, HT Wong, JKS Pu, YW Wong, WK Wong, MWY Lee, KY Yam, WM Lui, WS Poon
Working Group on Neurosurgical Outcomes Monitoring, Hong Kong
Introduction: External ventricular drainage (EVD) is the commonest of procedures performed in daily neurosurgical practice. In spite of this, the operation may entail certain devastating complications. The most challenging of which is ventriculostomy associated infection (VAI) that can occur in 1% to 9.5% of cases [1]. The aim of this study is to determine the frequency of VAI among EVDs performed in Hospital Authority (HA) neurosurgical centers and identify risk factors for this complication.
Methodology: This was a retrospective multi-center study. Electonic patient record data from all seven HA neurosurgical centers were collected. Consecutive patients that underwent EVD insertion from 1st January 2012 to the 31st December 2014 were included. Patients that had EVDs placed before 2012 or at a non-HA center during this period were excluded from the study. The primary endpoint was VAI. Secondary endpoints include the total number of neurosurgical procedures, length of hospital stay and mortality.
Results: To be released at the meeting.
Conclusions: To be discussed at the meeting.
References
[1]. Ramanan J., Lipman J., Schorr A, Shankar, A. A meta-analysis of ventriculostomy-associated cerebrospinal fluid infections. BMC Infect Dis 2015 15:3 1–12
FP16: Surgery for Neural Tube Defects for Chinese Baby Orphans: A Decade of Experience
CP Yu, WY Fan, LK Lam. Private, Hong Kong
Northern China has the highest incidence of neural tube defects(NTD) in the world. Many such newborns and infants are abandoned. Foster homes, such as Hope Foundation, Starfish and Baobai Foundations, take the initiative to request treatment of these unfortunate babies, usually via email to the senior author. Operations are then performed by the authors, mostly at Suzhou University Children Hospital, occasionally in Hong Kong and rarely in other Chinese hospitals. Suzhou provides manpower and facilities via the newly founded Combined Suzhou-Hong Kong Spina Bifida Clinic. Between Oct 2005 and July 2015, the senior author had taken more than 50 trips to China, operating and assessing more than 200 babies suffering from myelomeningoceles, lipo-myelomeningocele, encephaloceles, split cord syndrome, and hydrocephalus, the latter occurring in > 50% of patients suffering NTD. Pathology of NTD is extremely diversified. Successful repair is facilitated by micro techniques, neuro-monitoring, sectioning of filum, restoring dorsal pia surface, expansile duroplasty and water tight layered closure. Patients were sent back to the referring foster homes when they are fit for discharge. An online follow up program ensures adequate long term care. There was no operative mortality. One large encephalocele baby died of respiratory complications on the way back to referring foster home. One infant with split cord syndrome suffered from reversible multi-organ dysfunction syndrome. Infection rate is extremely low (<2%) after introduction of anti-infection protocol. About 40% of the operated babies are adopted into normal families, both locally and abroad. A decade of such experience is demanding on time, personal commitment, and resources, but humbling and rewarding for all parties involved.
FP17: Impact of Prothrombin complex concentrates on warfarin associated traumatic brain injury – A local experience
CF Ng, JK Sham, CHK Mak, FC Cheung, HM Chiu
Department of Neurosurgery, Queen Elizabeth Hospital, Hong Kong
Background: Warfarin was known to have a negative impact on survival in patients who suffered from traumatic brain injury. Prothrombin complex concentrates (PCCs) offer rapid reversal of warfarin, especially for those with significant intracranial hemorrhage. However, evidence on clinical outcome is lacking. This study aims to look into the effectiveness of PCCs on warfarin associated traumatic brain injury.
Methods: We retrospectively reviewed patient data from the Traumatic Brain Injury registry of Queen Elizabeth Hospital from 2006 to 2013. The outcome of patients who suffered from traumatic brain injury and were taking warfarin at the time of head injury was analyzed, including 30-day mortality, Glasgow Outcome Score (GOS) at 6 weeks and 6 months. Satisfactory outcome was classified as GOS 3 to 5. Prothrombinex, a 3-factor PCCs, was introduced since 1 January 2011 for warfarin reversal, and was adopted as cutoff for analysis.
Results: We identified 34 patients who were taking warfarin at the time of head injury. 16 (47%) of them were admitted before implementation of Prothrombinex protocol while 18 patients were admitted after implementation of Prothrombinex protocol. Baseline characteristics were similar. Patients in the Prothrombinex group enjoyed significantly better outcome at both 6 weeks (OR = 4.4, p = 0.043) and 6 months (OR = 6.5, p = 0.017).
Conclusion: Use of PCCs was associated with better clinical outcome in warfarin associated traumatic brain injury.
FP18: Surgical outcome of traumatic acute subdural hematoma in adult patients with significant head injury
JK Sham, CF Ng, CHK Mak, FC Cheung, HM Chiu
Department of Neurosurgery, Queen Elizabeth Hospital, Hong Kong
Background: Acute subdural hematoma (ASDH) is common in patients with traumatic brain injury. Our previous study showed that surgical evacuation of isolated traumatic ASDH is beneficial in elderly patients with moderate and severe head injury. In this study, we aim to evaluate the outcome of surgical evacuation of traumatic ASDH in adult patients who suffered from significant head injury and had impaired consciousness upon presentation. The outcome of patients with associated cerebral contusion and traumatic subarachnoid hemorrhage (SAH) is also analyzed.
Methods: We retrospectively reviewed patient data from the Traumatic Brain Injury registry of Queen Elizabeth Hospital from January 2006 to June 2014. Adult patients of traumatic ASDH, with motor score in Glasgow Coma Scale (GCS) of not more than 5 on admission, are included.
Results: There were 1589 adult patients admitted for traumatic intracranial hemorrhage from January 2006 to June 2014. 330 patients suffered from traumatic ASDH, of which 57 patients had isolated ASDH. Sixteen patients (28.1%) with isolated ASDH had clot evacuation performed. The mean thickness of ASDH of the operated and non-operated group was 19.5 mm and 13.7 mm respectively (p = 0.016). Other baseline characteristics of the operated and non-operated patients were similar. Mortality rate of the operated group was lower (p = 0.008). Surgical evacuation of ASDH was associated with delayed improvement of Glasgow Outcome Score at 6 months from 6 weeks (p = 0.005) and also appeared to be associated with good outcome (Glasgow Outcome Score 4–5) at 6 months (p = 0.05).
For patients with ASDH together with cerebral contusion and traumatic SAH, 69 patients (27.5%) underwent surgical clot evacuation via craniotomy or craniectomy. Mortality rate of the operated and conservative group is 49.3% and 61.5% respectively (p = 0.054).
Conclusion: Surgical evacuation of isolated traumatic ASDH is beneficial for adult patients with significant head injury and impaired consciousness.
FP19: A Prospective Pilot Study on the Efficacy of Atorvastatin on Chronic Subdural Haematoma
David YC Chan, David TF Sun, Danny TM Chan, George KC Wong, Stephanie CP Ng, Wai S Poon
Division of Neurosurgery, Department of Surgery, Prince of Wales Hospital, Hong Kong
Chronic subdural haematoma (CSDH) is a common neurosurgical condition. The prevalence was up to 58.1 per 100,000 persons per year above the age of 65. Burr hole for drainage is an effective standard treatment. However recurrence can be up to 8 to 32%. One of the underlying pathogenesis was postulated to be aberrant vessel formation and localized inflammation. Statin, or HMA CoA reductase inhibitor, is a class of lipid lowering drug. It also has property of promoting neovascularization and modulation of inflammation. In animal study and preliminary clinical trial, Atorvastatin has been shown to be effective in treatment of chronic subdural haematoma. Our study aim to investigate the efficacy and safety of Atorvastatin on CSDH. During the period January to December 2014, we have recruited 24 patients with CSDH. They were either judged by the oncall Neurosurgeon to have low risk of immediate brain herniation or patients and/or relatives declined operation. Informed consent was obtained. 12 were prescribed with
Atorvastatin while the other 12 were recruited as control with observation. By 3 months follow up, 9 out of 12 in the Statin group improved (with 8 resolving CSDH and 1 resolved CSDH at the 3 months CT scan). 1 remained static. 2 deteriorated requiring burr hole operation. By 6 months FU and CT, 7 improved (4 resolving CSDH and 3 resolved CSDH). 1 remained static in size. 1 defaulted follow up and 1 dead.
For the control group, 5 out of 12 had resolving CSDH by 3 months FU. 7 deteriorated requiring burr hole operation. By 6 months, 2 were revolving, 2 had resolved CSDH and 1 defaulted follow up.
In summary, improvement rate at 3 months was 75% for the Atorvastatin group, versus 42% for the Control group (p value = 0.214).
With Type 1 error of 0.05 and power of 80%, we can generate a sample size of 80 patients. Allowing 25% lost to follow up, we can generate a sample size of 110 patients.
In conclusion, this prospective pilot study has shown that Atorvastatin is effective in the treatment of CSDH with higher resolution rate and lower rate deterioration requiring operation. It was clinically significant though statistically insignificant. This initial promising result prompt further large scale randomized controlled trial, in which our data from this pilot study also generated a potential sample size of 110 patients.
FP20: Brain metastasis in targeted therapy era
Jason MK Ho
Tuen Mun Hospital, Hong Kong
According to the latest Cancer registry of Hong Kong, not only is lung cancer the commonest cancer but also the cancer causing the highest mortality among other malignancies. About 20% of lung cancer patient also present with brain metastasis. 5 year suvival of lung cancer with brain metastasis can be as low as 2%. Most of these patients are treated with multiple modalities including surgery, radiotherapy, nonselective systemic chemotherapy and targeted therapy. Since the evidence of targeted therapy efficacy after surgical resection is still limited, this study aims to explore the role of targeted therapy in post resected brain metastasis of lung cancer
FP21: Pattern of Recurrence in Glioblastoma in Chinese Patients
Hsieh Yi Pin Sonia, Chan Tat Ming Danny
Prince of Wales Hospital, Hong Kong
Background: Glioblastoma is an aggressive and currently incurable disease. Despite given maximum treatments (surgery, irradiation and chemotherapy), GBM still recur for all patients. Several studies showed that recurrence remained local, accompanied with an increasing tendency of non-local spread.
Purpose: To evaluate pattern of recurrence in GBM in Chinese patients and factors which affect the distribution of recurrence.
Methods: Medical records of patients with confirmed disease recurrence were reviewed. Local recurrence was defined as tumour regrowth contiguous to the preoperative abnormal signals on magnetic resonance images T2 sequence.
New recurrence was a new lesion away from the preoperative T2 abnormal signals. Those with contact to cerebrospinal fluid pathways was further registered as new CSF dissemination. Time to progress and time to death were calculated and compared using Kaplan-Meier survival curves. Potential risk factors for new CSF dissemination were assessed, using univariate and followed by multivariate analysis.
Results: 36 patients were proven to have recurrence. 22 developed local recurrence and 14 new recurrence. 11/14 had new CSF dissemination. Median time to progress for local, new parenchymal recurrence and new CSF dissemination were 5.5 months, 9.9 months and 12.1 months, whereas median overall survival were 12.8 months, 21.7 months and 18.5 months respectively. Ventricular entry during surgery, completion of Stupp's Regimen were associated with new CSF dissemination. Patients with MGMT methylation, progression-free for more than 9 and 12 months showed a higher proportion of CSF dissemination.
Conclusions: Our study suggested that the incidence for non-local recurrence was higher than previous beliefs. Combined chemoradiotherapy lengthens survival duration and is associated with disseminated disease via CSF. Ventricular entry should be avoided during excision for GBM. Whole neuro-axis MRI surveillance is considerable for patients with progression free for 9 months or more. Novel researches and therapies oriented to underlying mechanism should be designed, in order to tackle the upcoming difficulty.
FP22: Use of Pipeline Embolization Device for treatment of cerebral aneurysm: favourable long-term outcome of vascular status
Yu SCH 1 , Lee KT1 , Lau T1 , Wong GKC2 , Pang VKY3 , Chan KY4
1Department of Radiology and 2Division of Neurosurgery, The Chinese University of Hong Kong, 3Pamela Youde Nethersole Eastern Hospital, 4Kwong Wah Hospital, Hong Kong
Purpose: Pipeline embolization device (PED) has been found to be a safe and effective treatment for unruptured cerebral aneurysms. We aimed to assess the status of the aneurysm and parent artery following long-term PED implantation.
Materials and Method: This was an on-going prospective study approved by Institutional-Review-Board. Consecutive and consented patients with intracranial aneurysms treated with PED were included. Between September 2008 and December 2011, 178 cerebral aneurysms in 143 patients were treated with PED. Patients with modified Rankin scale score 3 or below were invited to follow up imaging after a median time interval of 56.6 months (interquartile range 42.9 to 62.4 months) from PED implantation. Cone-beam CT angiography with intravenous contrast enhancement (IVCBCTA) performed with the patient fully conscious, utilizing C-arm CT with flat-panel detector, was used for the imaging, because it is a non-invasive investigation with high spatial resolution and without metal artifacts.
Results: There were 31 patients and 34 vascular segments. In all 34 cases, contrast effect and image quality was good and not substantially different from that of intraarterial CBCTA. Metal artifact occurred in all 14 cases with coil mass, PED was obscured in 3 cases. In all 31 cases, there was no residual aneurysm, no vascular occlusion, one vascular stenosis (50%), good PED apposition to vessel, and no PED-induced calcification. All 28 PED-covered side branches were patent.
Conclusion: PED for intracranial aneurysms is probably safe and promising for long-term placement, with favorable morphological outcome and without delayed complications. IVCBCTA is potentially promising and useful for effective evaluation of the vascular status following intracranial flow-diverters.
FP23: The initial experience of Flow Re-direction Endoluminal device (FRED) in Hong Kong
Samuel SK Lam1, N Mahboobani, CB Tan2
1Department of Neurosurgery, Tuen Mun Hospital, 2Department of Radiology, Tuen Mun Hospital, Hong Kong
Background: The FRED (Microvention, Inc.) is a braided self-expandable flow diverting stent with a stent in stent design. It maintains its internal diameter and cylindrical shape without kinking around the carotid siphon. This makes FRED more advantageous in treating those large, wide neck and fusiform aneurysms. We aim to report our initial experience on the use of FRED system in Hong Kong.
Methods: Retrospective review of clinical parameters, aneurysm characteristics, technical aspects, immediate and post-procedural outcomes of patients in which the FRED system was used in a single institution.
Results: 6 aneurysms were treated in 6 patients. In 5 cases the system was used as the primary means of treatment. In 1 case it was used to treat an enlarging residual neck of a previously coiled aneurysm. For the 5 cases with primary treatment, all aneurysms had wide neck, 4 were paraclinoid in location with 1 in posterior circulation. There were 4 small (range 4-11 mm) and 1 large (21 mm) aneurysms. There was no immediate or peri-procedural complication.
6 month post-procedure follow up DSA is available in 4 patients thus far. In 2 cases the aneurysm has been occluded. In 2 cases there is minimal residual filling of aneurysm, which is further reduced when compared to immediate post-procedure DSA. Arteries covered by the flow diverter remained patent. There was no in-stent thrombosis or stent migration.
Conclusion: FRED is a next generation flow diverter. It is easy to use and has technological advantages over previous generations of flow diverters. It has shown good angiographic results in our case series with no immediate or peri-procedural complication.
FP24: Time is Brain – Only Part of the Story: Role of CT perfusion in Workup for Mechanical Thrombectomy in Acute Stroke
A.C.S. Lam 1, C.P. Tsang 2, K.K. Wong 1, W.M. Lui 2, R. Lee 1
1Department of Radiology, Queen Mary Hospital, 2Department of Neurosurgery, Queen Mary hospital, Hong Kong
Purpose: Recent randomized controlled studies have shown favorable results for endovascular treatment of acute ischemic stroke, which signifies a new era in stroke management. Mechanical thrombectomy, in addition to intravenous thrombolysis, in treatment of acute stroke with large artery occlusion in the anterior circulation up to 6 hours after symptom onset is now level 1a evidence. However, there is no well-established universal consensus regarding the imaging workup protocol for acute stroke patients, which differ amongst these trials.
We believe computed tomographic (CT) perfusion imaging, with its ability to identify irreversibly damaged infarcted core and potentially salvageable ischemic penumbra, can help in patient selection and improve patient outcome. We will review our recent experience in this group of patients.
Methods: Retrospective review from January 2014 to September 2015 yielded 24 patients with acute stroke eligible for consideration of mechanical thrombectomy presenting within a time window of less than 6 hours. CT perfusion was performed for 12 of the 24 patients with Toshiba Aquilion One machine and CT perfusion images were generated by Vitrea Fx software version 6.5.1 and reviewed by two reviewers.
Results: Of the 12 patients with CT perfusion scan performed, 3 perfusion patterns were observed. 6 patients had matched defects, 5 patients had perfusion mismatch and 1 patient had lacunar infarct. All of the 5 patients with perfusion mismatch subsequently underwent mechanical thrombectomy. 1 patient with matched defect underwent mechanical thrombectomy in view of early presentation with short duration of symptom onset, unfortunately complicated by hemorrhagic transformation and poor outcome.
Conclusion: Duration after stroke onset is a very important factor in considering eligibility for mechanical thrombectomy, however it cannot account for varying physiology amongst different patients, such as cerebral collateral arterial supply and tissue resistance to ischemia. Advanced neuroimaging techniques are practical in clinical setting of acute stroke and can help triage patients for revascularization therapy.
FP25: Mechanical Thrombectomy in Tuen Mun Hospital: review of 5 year experience
Samuel SK Lam1, N Mahboobani, CB Tan2
1Department of Neurosurgery, Tuen Mun Hospital, 2Department of Radiology, Tuen Mun Hospital, Hong Kong
Background: Mechanical thrombectomy has become a recommended therapy in acute stroke patients with large vessel occlusion. There is very good evidence for early thrombectomy with stent retrievers. We aim to review our own results and look for potential factors that influence the clinical outcome.
Method: This is a retrospective analysis. We reviewed all our stroke patients who had undergone mechanical thrombectomy from 2010 to 2014. Demographic data, time to reperfusion, angiographic findings, early and late outcome were reviewed.
Results: There were 24 patients in our series. There were 17 males and 7 females. Age was ranged from 40 to 81 with the median age of 62. Majority of device used was Solitaire stent, followed by Trevo and Penumbra system. Complete recanalisation was achieved in 13 patients. In the remaining 11 patients , only partial recanalisation was achieved due to preexisting intracranial stenosis. There were 4 early mortalities in our series.
Conclusion: Mechanical thrombectomy is effective in acute stroke management. Angiographic recanalisation does not necessarily translate into good clinical outcome. To improve patient selection, protocol driven stroke assessment and advanced imaging technique such as perfusion scan are recommended.
FP26: EC-IC bypass service in NTEC – from salvage to prevention
SUN DTF, CHAN EKY, POON WS
Division of Neurosurgery, Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong
Cerebrovascular insufficiency either due to carotid stenosis or Moyamoya disease could lead to ischemic and hemorrhagic stroke. In the past, revascularization surgery by means of EC-IC bypass is done for salvage of impaired cerebrovascular reserve. However, recent evidence has shown that in the Moyamoya group of patients, early EC-IC bypass surgery could reduce the incidence of hemorrhagic stroke. We would like to review on the delivery of EC-IC bypass service in the NTEC over the past 20 years.
Methods: Patients who are followed up in NTEC Neurosurgery unit are included. Demographic data, etiology of cerebrovascular insufficiency, data on perfusion status, the relevant bypass surgery and the surgical outcome were evaluated.
Results: From year 1997 – 2015, there are 53 patients included. Mean age at diagnosis was 47.8 years. Mean follow up was 74.9 months post-op. Etiology of cerebrovascular insufficiencies include: 17 patients with atherosclerosis, 23 patients with Moyamoya disease, 7 patients with post-radiotherapy arteriopathy, 6 other patients had bypass surgeries for other causes. Total 53 surgeries were done for 44 patients; in which 11 of them are high-flow bypass and 42 of them are low-flow. Post-operative complication was 15% with the majority being aspirin related acute subdural hematoma in the atherosclerosis group. Complication rate was 5% in the Moyamoya group. Graft patency rate in STA-MCA bypass was 96%.
Conclusion: EC-IC bypass may be effective in prevention of both ischemic and hemorrhagic stroke in Moyamoya disease. It may also reduce the stroke incidence in patients with cerebrovascular insufficiency secondary to atherosclerosis or post-radiotherapy arteriopathy.
FP27: Symptomatic hyperperfusion after surgical revascularization for moyamoya disease: incidence, natural history and predictors
Tsang Chun Pong, Ho Wai Shing Wilson, Leung Ka Kit Gilberto, Lui Wai Man
Department of Neurosurgery, Queen Mary Hospital, Hong Kong
Aim: To study the incidence, natural history and predictors for post-revascularization symptomatic hyperperfusion in moyamoya patient.
Background: Moyamoya disease is an uncommon cerebrovascular disease. It refers to progressive stenosis of the internal carotid artery at supraclinoid level, resulted into cerebral ischemia. Direct and/or indirect revascularizations are well established procedures to improve cerebral perfusion and decrease the risk of future stroke in patients with moyamoya disease. Peri-operative ischemic stroke is one of the major complications. Transient neurological events may occur other than that.
Method: Patients with moyamoya disease undergone revascularization operation were included. All the medical records were studied retrospectively. Symptomatic hyperperfusion was defined as new neurological event with improved perfusion on perfusion scan.
Results: From January 2009 to February 2015, 16 patients with moyamoya disease had undergone 22 revascularization operations. The mean age was 38.9 years old. 15 of them presented with ischemic symptoms. The mean follow-up was 16 months. All grafts of direct revascularization were patent on post-operative computed tomographic angiogram. Two patients (9%) had persistent/ recurrent ischemic symptoms after the operation. 9 operated hemisphere (40%) were found to have symptomatic hyperperfusion. The mean onset interval from operation was 4 days. All were transient with complete resolution of symptoms. No significant predictor was identified, including the presence of pre-existing extracranial-intracranial anastomosis and the proximity of the recipient vessel.
Summary: New neurological event after revascularization operation for moyamoya disease could be ischemic or hyperperfusion related. Symptomatic hyperperfusion was not uncommon in our series. All patients improved with time.
