Endovascular treatment of ruptured internal carotid artery pseudoaneurysms after irradiation for nasopharyngeal carcinoma patients.

OBJECTIVES. To evaluate the efficacy and complications of endovascular treatment for ruptured internal carotid artery pseudoaneurysms following irradiation of nasopharyngeal carcinoma. DESIGN. Retrospective case series. SETTING. Tertiary neurosurgical referral unit of a Hong Kong public hospital. PATIENTS. Patients with ruptured radiation-induced internal carotid artery pseudoaneurysms that were treated endovascularly from October 1999 to October 2011 at Queen Elizabeth Hospital were reviewed. Hospital records, imaging, and angiographic data were studied. RESULTS. During the study period, 15 such nasopharyngeal carcinoma patients were treated by endovascular means at Queen Elizabeth Hospital. Ten presented with epistaxis, three with otorrhagia (bleeding from the ear), and two with both. Therapeutic occlusion of the affected internal carotid artery was performed in four patients, and stenting of the artery (with or without coil obliteration of the pseudoaneurysm) was performed in 11. Immediate haemostasis was achieved in all cases. One (7%) of the 15 patients endured symptomatic recurrence of the pseudoaneurysm, and in another an asymptomatic residual pseudoaneurysm was noted in the follow-up angiogram. Three patients suffered clinically significant procedure-related complications, including cerebral infarction (n=2) and brain abscess (n=1). In the angiograms obtained after a mean post-treatment interval of 13 (range, 0.7-60) months, the stent patency rate was 67%. All three patients with occluded stents were asymptomatic. CONCLUSIONS. Ruptured internal carotid artery pseudoaneurysms following radiotherapy is a rare but life-threatening condition. Endovascular treatment by occlusion or reconstruction of the internal carotid artery with stents provides immediate haemostasis and obliteration of the pseudoaneurysms, with a low recurrence rate. Long-term follow-up is necessary to look out for delayed post-treatment complications.

Angioplasty and stenting for intracranial atherosclerotic stenosis: position statement of the Hong Kong Society of Interventional and Therapeutic Neuroradiology.

As a means of preventing secondary ischaemic stroke, angioplasty and stenting are considered potentially beneficial for patients with severe intracranial atherosclerotic stenosis. However, the role of stenting has been challenged since the publication of the first randomised controlled trial on Stenting versus Aggressive Medical Management for Preventing Recurrent stroke in Intracranial arterial Stenosis (SAMMPRIS). This indicated that aggressive medical management was superior to stenting using Wingspan to prevent recurrent stroke, because stenting has a high peri-procedural stroke and death rate. In this paper, we review the management of intracranial atherosclerosis, revisit the skepticism on stenting, and state our position on the topic in the form of recommendations. These are based on the prevalence of the disease in Hong Kong, the high risk of recurrent stroke despite medical therapy in the presence of haemodynamic intracranial stenosis without sufficient collaterals, an analysis of the weak points of SAMMPRIS, and results of clinical studies in Hong Kong.

Transarterial embolisation with Guglielmi detachable coils in an infant with a vein of Galen aneurysmal malformation.

Vein of Galen aneurysmal malformation is a rare entity in the paediatric population. However, it is being recognised with increasing frequency due to better diagnostic techniques. Neonates usually present with congestive heart failure, while in older infants and children it tends to manifest with seizures, hydrocephalus, intracerebral or subarachnoid haemorrhages. We present a case of ruptured vein of Galen aneurysmal malformation in a 3-month-old baby boy treated by transarterial embolisation using Guglielmi detachable coils.

Minimization of the mean square velocity response of dynamic structures using an active-passive dynamic vibration absorber.

An optimal design of a hybrid vibration absorber (HVA) with a displacement and a velocity feedback for minimizing the velocity response of the structure based on the H(2) optimization criterion is proposed. The objective of the optimal design is to reduce the total vibration energy of the vibrating structure under wideband excitation, i.e., the total area under the velocity response spectrum is minimized in this criterion. One of the inherent limitations of the traditional passive vibration absorber is that its vibration suppression is low if the mass ratio between the absorber mass and the mass of the primary structure is low. The active element of the proposed HVA helps further reduce the vibration of the controlled structure, and it can provide very good vibration absorption performance even at a low mass ratio. Both the passive and active elements are optimized together for the minimization of the mean square velocity of the primary system as well as the active force required in the HVA. The proposed HVA was tested on single degree-of-freedom (SDOF) and continuous vibrating structures and compared to the traditional passive vibration absorber.

Intracranial aneurysms in twins: case report and review of the literature.

Intracranial aneurysm in twins is a rare clinical disease entity. Only 15 cases have been described in the literature. We report on a pair of identical twins with intracranial aneurysms. One presented with subarachnoid haemorrhage; digital subtraction angiography showed a left posterior communicating artery aneurysm, which was treated by coiling. The patient's twin sister was called for screening, whereupon digital subtraction angiography revealed a right ophthalmic internal carotid artery aneurysm that was treated conservatively.

A venographic operational classification for transvenous embolization of dural carotid-cavernous fistula.

INTRODUCTION: It is hypothesized that a venographic-based operational classification of dural carotid-cavernous fistula (DCCF) will facilitate early selection of the optimal venous route and enhance the efficacy of transvenous catheterization and embolization of the cavernous sinus. METHODS: This was a retrospective study on 97 patients who presented with symptomatic DCCF. Definition of classification type 1: both the anterior and posterior compartments of the cavernous sinus were opacified, type 2: only the anterior compartment was opacified, type 3: only the posterior compartment was opacified. Subtype a: the facial vein (FV) draining the superior ophthalmic vein (SOV) was opacified, subtype b: only the inferior petrosal sinus (IPS) was opacified, subtype c: neither the FV nor the IPS were opacified, subtype d: both the FV and the IPS were opacified. The SOV route was recommended for subtype 1a and type 2. The IPS route was recommended for subtype 1b, 1c, 1d, and type 3. Success rates of catheterization by the recommended routes and non-recommended routes were calculated. RESULTS: Number of DCCF lesions were 20 (1a), 28 (1b), 23 (1c), 26 (1d), 16 (2a), 10 (2c), 2 (3b). Of 145 attempted catheterization, 91 and 54 were performed with a recommended route and un-recommended route, respectively. Success rate for catheterization and embolization performed with the recommended route and un-recommended route was 71/91 (78%) and 20/54 (37%), respectively (Chi-Square test P = 0.0024). CONCLUSIONS: Venographic operational classification is useful for guiding the selection of optimal venous route which enhances the efficacy of transvenous embolization of the DCCF.

Triple coaxial catheter technique for transfacial superior ophthalmic vein approach for embolization of dural carotid-cavernous fistula.

We report a triple coaxial catheter technique to facilitate the venous access to the superior ophthalmic vein during transvenous embolization of dural carotid-cavernous fistula (DCCF) via the transfacial venous route. Two patients with transvenous embolization of DCCFs by coils were treated with transfacial superior ophthalmic vein (SOV) approach by the triple coaxial catheter technique. The triple coaxial catheter system consisted of a 6F guiding catheter as the outer catheter and a 4F guiding catheter as the middle catheter and a microcatheter as the inner catheter to help navigation and manipulation. The DCCFs were completely obliterated in both cases. There were no complications associated with the procedure. The ophthalmic symptoms of the patients had totally resolved at two-month follow-up. The triple coaxial catheter technique can be used with the transfacial SOV approach in embolization of DCCF. This technique has two advantages over the double coaxial catheter technique because it offers additional length and support for the distal navigation of microcatheter into the SOV.

Size, location, and multiplicity of ruptured intracranial aneurysms in the Hong Kong Chinese population with subarachnoid haemorrhage.

OBJECTIVE: To review the pattern of ruptured intracranial aneurysms in terms of size, location, and the prevalence of multiple aneurysms in the Hong Kong Chinese population with subarachnoid haemorrhage. DESIGN: Retrospective study. SETTING: Three public hospitals in Hong Kong. PATIENTS: A total of 267 Chinese patients with subarachnoid haemorrhage from ruptured intracranial aneurysms between July 1998 and June 2002 were reviewed retrospectively. RESULTS: The patients had a mean age of 59 (range, 13-96) years, with a female-to-male ratio of 2:1. Concerning the age at presentation, males presented with ruptured intracranial aneurysms at a younger age (P=0.001) than females. Ruptured aneurysms were more commonly located in the anterior than posterior circulation (84% vs 16%). The posterior communicating artery (26%) and anterior communicating artery (22%) were the most common sites of rupture. As a whole, 64% of the aneurysms had a size of 5 mm or less. The anterior communicating artery had a higher proportion with a size of 5 mm or less compared to other locations (P<0.05). In this cohort, the prevalence of multiple aneurysms was 17%. There was no significant difference in the prevalence of multiple aneurysms between men and women (P=0.30). In patients with multiple aneurysms, the sizes of ruptured aneurysms were greater than those of the largest unruptured aneurysms (P<0.001). When compared with the group with single aneurysms, patients with multiple aneurysms had a smaller proportion of small aneurysms, sized 5 mm or less (P<0.05). CONCLUSIONS: The pattern of ruptured intracranial aneurysms in the Hong Kong Chinese population was different from western and Japanese populations. Although the distribution of locations for ruptured aneurysms was similar, Hong Kong Chinese had a larger proportion of small aneurysms sized 5 mm or less. The prevalence of multiple aneurysms in Hong Kong is comparable to that in the Japanese population, but lower than that in the western populations.

Design of a non-traditional dynamic vibration absorber.

A non-traditional dynamic vibration absorber is proposed for the minimization of maximum vibration velocity response of a vibrating structure. Unlike the traditional damped absorber configuration, the proposed absorber has a linear viscous damper connecting the absorber mass directly to the ground instead of the main mass. Optimum parameters of the proposed absorber are derived based on the fixed-point theory for minimizing the maximum vibration velocity response of a single-degree-of-freedom system under harmonic excitation. The extent of reduction in maximum vibration velocity response of the primary system when using the traditional dynamic absorber is compared with that using the proposed one. Under the optimum tuning condition of the absorbers, it is proved analytically that the proposed absorber provides a greater reduction in maximum vibration velocity response of the primary system than the traditional absorber.

Persistent sciatic artery complicated by aneurysm formation and thrombosis.

A persistent sciatic artery is a rare embryological anomaly. We report a case of a persistent sciatic artery with aneurysm formation and thrombosis in a patient with rheumatoid arthritis/systemic lupus erythematosus overlap syndrome and Raynaud's phenomenon. The diagnosis and complete, accurate evaluation of the arterial anatomy of the lower limb were achieved using computed tomographic angiography.

A treatable case of dementia--intracranial dural arteriovenous fistula.

Dementia is a common medical problem that affects elderly patients. We report on a 77-year-old man with an intracranial dural arteriovenous fistula who presented with dementia that was initially thought to be irreversible and degenerative. Subsequent neuroendovascular intervention resulted in significant functional and cognitive improvement.

Transvenous embolisation of dural carotid-cavernous fistulas by multiple venous routes: a series of 27 cases.

BACKGROUND: Transvenous embolisation is an effective option in the treatment of dural carotid-cavernous fistulas (DCCFs). This can be achieved via a number of venous routes. METHOD: From 1997 to 2001, 27 patients with DCCFs (15 unilateral and 12 bilateral) were treated by transvenous embolisation with Guglielmi detachable coils and fibered platinum coils. The transvenous embolisation routes included inferior petrosal sinus (IPS) alone (18 patients), IPS and inter-cavernous sinus (6 patients), IPS and clival plexus (1 patient), superior ophthalmic vein (SOV) via facial vein (1 patient) and SOV via superficial temporal vein (1 patient). One patient required further transarterial embolisation with polyvinyl alcohol particles. FINDINGS: The follow-up period ranged from 4 to 57 months (average 26 months). Two patients had transient ophthalmoplegia and 2 patients had symptomatic recurrence of the DCCF during the follow-up. There was no permanent procedure-related morbidity. Clinical cure was achieved in 26 patients (96%) and complete angiographic obliteration was documented in 24 patients (89%). INTERPRETATION: DCCFs can be successfully treated by transvenous embolisation via different venous routes.

Endovascular treatment of radiation-induced petrous internal carotid artery aneurysm presenting with acute haemorrhage. A report of two cases.

Haemorrhage from rupture of petrous ICA aneurysm can be life threatening and emergency treatment is required. We report 2 cases of radiation-induced petrous internal carotid artery (ICA) aneurysm presenting with acute haemorrhage (epistaxis and otorrhagia) after radiotherapy (RT) for nasopharyngeal carcinoma (NPC). Both patients had a history of RT treatment for NPC. The first patient, a 54-year-old man, presented with sudden severe epistaxis and haemorrhagic shock. The second patient, a 35-year-old man, presented with episodes of severe otorrhagia. The first patient was immediately resuscitated. Obliteration of the aneurysm was performed by endovascular occlusion of the ICA with Guglielmi detachable coils and fibered platinum coils. For the second patient, the aneurysm was treated by deploying a self-expandable stent across the aneurysm neck. In an emergency situation, ruptured petrous ICA aneurysm can be treated with endovascular occlusion of the ICA with microcoils if there is a good collateral blood flow. Alternatively, the aneurysm can be treated by deployment of a stent, which can induce stasis and eventual thrombosis of the aneurysm.

A pilot study on the effect of progressive muscle relaxation training of patients after stoma surgery.

Eighteen patients who had undergone stoma surgery were assessed with respect to their anxiety level and self-reported quality of life (QoL) on three occasions; namely, immediately after surgery, 5 weeks after surgery, and 10 weeks after surgery. The patients were randomised into a control group (n = 10) and an experimental group (n = 8). A 20-min set of audiotaped instructions on progressive muscle relaxation training (PMRT) was given to the patients in the experimental group for home practice. Assessment instructions included the Chinese State-Trait Anxiety Inventory (C-STAI), the Quality of Life Index for Colostomy (QoL-Colostomy) and the Hong Kong Chinese version of the World Health Organisation Quality of Life Scale (WHOQoL). Results indicated that there was a significant decrease in both the C-STAI score (F = 4.66, P < 0.05) and the WHOQoL score (F = 4.74, P < 0.05) in the experimental group. Among the domains of WHOQoL, a significant difference was shown in physical health/independence and general perception of QoL, with the experimental group demonstrating better functioning. For the QoL-Colostomy, however, there was no significant difference between the control and experimental groups. The results suggest that the use of PMRT could enhance quality of life and decrease state anxiety in patients after stoma surgery.

Brain abscess formation in radiation necrosis of the temporal lobe following radiation therapy for nasopharyngeal carcinoma.

BACKGROUND: Radiation necrosis is a known complication following radiation therapy for extracranial as well as intracranial tumours. However, brain abscess formation in radiation necrosis has not been reported in the literature. We report the clinical data of 6 patients suffering from this condition. METHOD: Twenty-eight patients with radiation necrosis of the temporal lobe following radiotherapy for nasopharyngeal carcinoma were treated surgically at the Department of Neurosurgery, Queen Elizabeth Hospital, Hong Kong between January 1992 and July 1999. Of these, 6 cases were complicated by brain abscess formation. The clinical data of these 6 patients are retrospectively reviewed. FINDINGS: The patients were 5 males and 1 female, ranging in age from 41 to 67 years. Three patients had previous treatment with steroids for the symptomatic radiation necrosis. A history of nasal infection or otitis media was recognised in all 6 patients. All patients were treated surgically by temporal lobectomy and excision of the necrotic tissue together with the abscess cavity. Intra-operatively, a bony defect was observed between the middle cranial fossa and the sphenoid sinus in 3 patients and the bony defect was repaired with a temporalis muscle flap. The species of organisms could only be identified in 3 patients. In 3 patients, the pus smear was positive but the culture was negative. Subsequently, 4 patients recovered and 2 patients died. INTERPRETATION: Cerebral radiation necrosis is a predisposing cause of brain abscess formation. Surgical excision is recommended as the treatment of choice in this group of patients.

Brain MRI of hippocampal volumetry in patients with refractory temporal lobe epilepsy.

OBJECTIVE: To detect for hippocampal sclerosis presurgically in a group of patients with refractory temporal lobe epilepsy. METHODS: Eighty-four consecutive patients with refractory temporal lobe epilepsy were subjected to brain MRI of hippocampal volumetry. A ratio of smaller to larger hippocampal volume was determined and unilateral hippocampal atrophy (HA) was diagnosed if the ratio is less than 0.91. RESULTS: Unilateral HA was diagnosed in 42 patients (50%) and bilateral HA in 1 patient. Other MRI abnormalities were detected in 18 patients with or without coexisting HA. CONCLUSIONS: Hippocampal sclerosis can be detected presurgically in many patients by brain MRI. Additional abnormalities not detected by brain CT can also be demonstrated.

Differential expression of CYP1A1, CYP1A2, CYP1B1 in human kidney tumours.

The presence of mRNA of individual members of the CYP1 gene family in normal and neoplastic kidney has been investigated by RTPCR. CYP1B1 mRNA was consistently expressed in both normal and neoplastic kidney while CYP1A1 was present in the majority of normal and neoplastic whereas CYP1A2 was infrequently expressed. Expression of the Ah receptor and Arnt which are involved in the transcriptional activation of the CYP1 genes was also studied. The Ah receptor mRNA and Arnt mRNA were consistently expressed both in kidney tumours and normal kidney. These results indicate differential expression of individual members of the CYP1 gene family in normal and neoplastic kidney and suggest that several mechanisms including the Ah receptor complex could be involved in their regulation.

Jasmine green tea epicatechins are hypolipidemic in hamsters (Mesocricetus auratus) fed a high fat diet.

These studies were designed to test the hypolipidemic activity of green tea epicatechins (GTE) isolated from jasmine green tea. In Experiment 1, three groups of hamsters were given a semisynthetic diet containing 200 g lard/kg and 1 g cholesterol/kg for 4 wk. The control group received distilled water, and the other two groups received either 15 g/L green tea water extract (GTWE) or 5.0 g/L GTE solution. Both the GTWE and GTE groups had lower concentrations of serum total cholesterol (TC) and triacylglycerols (TG) than the controls (P < 0.05). In Experiment 2, four groups of hamsters received tap water as the drinking fluid, but they were given the same high fat and cholesterol diet supplemented with 0 (control), 1.1, 3.4 or 5.7 g GTE/kg diet. The hypolipidemic effect of jasmine GTE was dose dependent. In Experiment 3, the time-course of changes in serum TC and TG was monitored in hamsters given the high fat diet supplemented with 5.7 g GTE/kg in comparison with that of controls. The hypolipidemic effects of dietary GTE were evident after feeding for 2 wk. Dietary supplementation of GTE did not affect liver fatty acid synthase. However, GTE-supplemented hamsters had higher fecal excretions of total fatty acids, neutral sterols and acidic sterols compared with the control group. In Experiment 4, hamsters were fed nonpurified diet; the control group drank distilled water, and the GTE group drank distilled water containing 5.0 g GTE/L. No differences in activities of 3-hydroxy-3-methyl glutaryl coenzyme A reductase and intestinal acyl CoA:cholesterol acyltransferase were observed. This study suggests that the hypolipidemic activity of GTE is not due to inhibition of synthesis of cholesterol or fatty acid but is most likely mediated by its influence on absorption of dietary fat and cholesterol.

Cytochrome P450 CYP3A in human renal cell cancer.

Renal cell cancer is the main malignant tumour of the kidney and has an increasing incidence. This type of tumour has a poor prognosis and shows intrinsic resistance to several anti-cancer drugs. The CYP3A P450 family, which consists of three closely related forms, is involved in the oxidative activation and deactivation of a variety of carcinogens and several anti-cancer drugs. In this study the presence and cellular localization of CYP3A has been investigated using a combination of immunohistochemistry, immunoblotting and reverse transcriptase polymerase chain reaction (RT-PCR) in renal cell cancer and corresponding normal kidney. CYP3A was consistently expressed in both renal call cancer and in normal kidney. In renal cell cancer, CYP3A was localized to tumour cells and in normal kidney the predominant cellular localization of CYP3A was to proximal tubular epithelial cells. RT-PCR showed that both CYP3A5 mRNA and CYP3A7 mRNA were consistently present in both tumour and normal samples, while CYP3A4 mRNA was present in 65% of tumours and 90% of normal samples. This study indicates that individual members of the CYP3A family are expressed in renal cell cancer. The presence of CYP3A in renal cell cancer might be important in the metabolic potentiation as well as the detoxification of chemotherapeutic agents used to renal cancer.

Ophthalmologic outcome of transvenous embolization of spontaneous carotid-cavernous fistulas: a preliminary report.

We give a preliminary report of the ophthalmologic outcome of four patients with transvenous embolization studied for their spontaneous carotid-cavernous fistulas. One of them is a direct type while three of them are indirect dural shunts. In indirect dural shunts, traditional transarterial embolization rarely achieves a complete clinical cure in a short period of time. All cases had an ophthalmologic disturbance justified for endovascular intervention. We performed catheterization, and subsequently embolization with Guglielmi Detachable coils, to the cavernous sinus via the femoral vein and inferior petrosal sinus/superior ophthalmic vein. All four patients achieved clinical and angiographic improvement with a follow-up period range from two to sixteen months except for one patient who had residual bilateral sixth nerve palsy. The transvenous approach offers an effective and safe alternative for the management of spontaneous carotid-cavernous fistula.