Cardiology ; organization & administration ; Cardiovascular System ; Cooperative Behavior ; Coronary Artery Disease ; diagnosis ; Humans ; Patient Care Team ; Singapore ; Tomography, Emission-Computed ; instrumentation

Global Health ; Humans ; Singapore

INTRODUCTIONC-arm Cone Beam CT (CBCT) is a technology that is being integrated into many of the newer angiography systems in the interventional suite. Due to its ability to provide cross sectional imaging, it has opened a myriad of opportunities for creating new clinical applications. We review the technical aspects, current reported clinical applications and potential benefits of this technology.

MATERIALS AND METHODSSearches were made via PubMed using the string "CBCT", "Cone Beam CT", "Cone Beam Computed Tomography" and "C-arm Cone Beam Computed Tomography". All relevant articles in the results were reviewed.

RESULTSCBCT clinical applications have been reported in both vascular and non-vascular interventions. They encompass many aspects of a procedure including preprocedural planning, intraprocedural guidance and postprocedural assessment. As a result, they have allowed the interventionalist to be safer and more accurate in performing image guided procedures. There are however several technical limitations. The quality of images produced is not comparable to conventional computed tomography (CT). Radiation doses are also difficult to quantify when compared to CT and fluoroscopy.

CONCLUSIONCBCT technology in the interventional suite has contributed significant benefits to the patient despite its current limitations. It is a tool that will evolve and potentially become an integral part of imaging guidance for intervention.

Angiography ; Arm ; Cone-Beam Computed Tomography ; Humans ; Imaging, Three-Dimensional ; Tomography, X-Ray Computed

INTRODUCTIONThis study aims to analyse the results of carotid stenting in a tertiary referral centre in Singapore.

MATERIALS AND METHODSRetrospective analysis of all carotid artery stenting (CAS) cases in a single centre from March 1997 to December 2008 was performed. Sixty successful procedures were performed in 61 patients, with bilateral stenting in 1 patient, and 2 failed procedures. The majority were Chinese (78.7%) and males (77.0%), with a high proportion having hypertension (82.0%) and hypercholesterolaemia (78.7%). The majority (91.8%) of patients were high surgical risk candidates, primarily due to cardiac risk factors. Ten patients (16.4%) had prior neck irradiation for nasopharyngeal carcinoma, and 3 patients each (4.9%) had previous endarterectomy and contralateral occlusion. A distal embolic protection device was used in 71.7% of cases.

RESULTSTechnical success was 96.8%. The 30-day stroke and death rate was 13.8%, comparable to reported results for this high surgical risk population.

CONCLUSIONCAS is a technically feasible and a relatively safe alternative to endarterectomy to treat extracranial carotid stenosis, especially in patients who are inoperable or at high surgical risk.

Aged ; Aged, 80 and over ; Angioplasty ; methods ; Angioplasty, Balloon, Coronary ; methods ; Carotid Artery Diseases ; surgery ; Female ; Hospitals, General ; Humans ; Male ; Middle Aged ; Outcome Assessment (Health Care) ; Retrospective Studies ; Risk ; Singapore ; Stents

INTRODUCTIONAn arteriovenous fistula (AVF) is the preferred method for haemodialysis in patients with end-stage renal failure. Previous studies have shown value in attempting percutaneous transluminal angioplasty (PTA) to salvage AVFs that fail to mature, but they are relatively small in size and mainly reported in Western populations. We reviewed our data of PTA in non-maturing AVFs to establish whether this technique is translatable to our local multiethnic population.

MATERIALS AND METHODSWe retrospectively reviewed the medical records and procedural images of 105 patients who had PTA for non-maturing AVFs performed at our department from January 2008 to January 2011. Technical success was defined as ≤30% residual stenosis after angioplasty. Clinical success was defined as at least 1 successful haemodialysis session within 4 weeks after PTA.

RESULTSAll 105 patients underwent angioplasty for at least 1 haemodynamically significant stenosis. Six (5.7%) had additional embolisation of accessory veins. Technical success was achieved in 95.2% of cases. The clinical success rate was 76.2%. Primary patency rates at 3, 6 and 12 months were 83%, 45% and 28%, respectively. Secondary patency rates at 3, 6 and 12 months were 90%, 79% and 70%, respectively. The minor complication rate was 18.1%. No major complications were encountered. An average of 1.7 interventions per access-year was required to maintain AVF patency. Patients with a preoperative vein size >2.0 mm and age <55 years were more likely to achieve clinical success, although not statistically significant.

CONCLUSIONPTA is a viable option to help salvage non-maturing AVFs in a multiethnic Asian population.

Angioplasty ; methods ; Arteriovenous Shunt, Surgical ; Constriction, Pathologic ; therapy ; Embolization, Therapeutic ; Female ; Humans ; Kidney Failure, Chronic ; therapy ; Male ; Middle Aged ; Renal Dialysis ; Reoperation ; Retrospective Studies ; Singapore ; Veins

INTRODUCTIONCone beam computed tomography (CBCT) is a relatively new technological innovation that utilises fl at-panel detector technology to obtain CT-like images. The key strength of a CBCT system is that cross-sectional imaging can be obtained using the angiographic fl at panel unit without having to move the patient, allowing the radiologist to obtain soft tissue imaging during the procedure. This allows treatment planning, guidance, and assessment of outcome to be performed in one interventional suite.

MATERIALS AND METHODSFrom December 2008 to June 2009, 24 CBCT scans were performed during vascular interventional procedures on our department's newly installed multi-axis fl at panel angiographic unit.

RESULTSTen cases were performed for hepatic trans-arterial chemoembolisation, 9 cases for hepatic arterial Yttrium-90 infusion, while 5 cases were for other indications. CBCT was found to be useful in 20 of the 24 cases.

CONCLUSIONOur early experience showed that CBCT was useful in impacting decisions during selected vascular interventional procedures. As CBCT technology improves, we can foresee wider applications of this technology.

Aged ; Angiography ; Cone-Beam Computed Tomography ; standards ; Embolization, Therapeutic ; Female ; Humans ; Male ; Medical Audit ; Middle Aged ; Radiology, Interventional ; methods ; Retrospective Studies

UNLABELLEDThe aim of this paper was to study the efficacy, side effects and complications of radiofrequency (RF) ablation of primary and metastatic liver malignancies.

MATERIALS AND METHODSWe retrospectively reviewed 57 patients (39 men, 18 women; mean age, 63 years; age range, 44 to 83 years) who underwent RF ablation for liver malignancies from January 2002 to December 2004. A total of 87 tumours were ablated - 71 (81.6%) hepatocellular carcinomas and 16 (18.4%) metastases (from primaries in the colon, stomach and pancreas). RF ablation was performed either percutaneously (n = 71) under conscious sedation or intraoperatively (n = 16) under general anaesthesia. Follow-up ranged from 1 month to 41 months (mean, 15.2) and included computed tomography (CT) 1 day, 1 month and 3 months after ablation, and half-yearly thereafter. Patients were observed for local tumour progression and for the emergence of new tumours.

RESULTSFour patients with a total of 5 tumours were lost to follow-up. Of the remaining 82 tumours treated, complete ablation was attained in 66 tumours after a single procedure, giving a primary effectiveness rate of 80.5%. Seven (8.5%) required 2 procedures to achieve complete ablation, giving a secondary effectiveness rate of 89% after 2 ablations. One tumour (1.2%) required 3 procedures to achieve complete ablation. One tumour required 4 procedures to date, with the latest follow-up CT still demonstrating incomplete ablation. Two tumours (2.4%) had an initial RF ablation and subsequent transarterial chemoembolisation (TACE). One tumour had an initial RF ablation followed by 32Phosphorus-biosilicon (BrachySil) injection, the latter as part of a Phase IIA trial. One tumour required 2 RF ablations and a subsequent TACE. Lastly, 3 tumours received initial RF ablation but subsequent local tumour progression was not treated as the patients were deemed unfit for repeat ablation. No procedure-related deaths or major complications were encountered. Minor complications were reported in 2 patients (3.8%) - subcapsular haematoma and thermal injury to the adjacent gastric antrum, both not necessitating surgical intervention.

CONCLUSIONSRF ablation is an effective, safe and relatively simple procedure for the treatment of unresectable liver malignancies.

Adult ; Aged ; Aged, 80 and over ; Carcinoma, Hepatocellular ; mortality ; secondary ; surgery ; therapy ; Catheter Ablation ; Chemoembolization, Therapeutic ; Combined Modality Therapy ; Female ; Hospitals, General ; Humans ; Liver Neoplasms ; mortality ; secondary ; surgery ; therapy ; Male ; Middle Aged ; Retreatment ; Retrospective Studies ; Singapore ; Surgery, Computer-Assisted

Adult ; Arteriovenous Malformations ; therapy ; Embolization, Therapeutic ; methods ; Enbucrilate ; therapeutic use ; Female ; Humans ; Kidney ; blood supply ; Male ; Middle Aged

Enteral Nutrition ; instrumentation ; methods ; Female ; Fluoroscopy ; methods ; Gastrostomy ; adverse effects ; instrumentation ; methods ; Humans ; Male ; Middle Aged ; Outcome and Process Assessment (Health Care) ; Postoperative Complications ; classification ; diagnosis ; therapy ; Reproducibility of Results ; Retrospective Studies ; Singapore ; Surgery, Computer-Assisted ; methods ; Treatment Outcome