Impaired Cerebrovascular Reactivity Predicts Recurrent Symptoms in Patients with Carotid Artery Occlusion: A Hypercapnia BOLD fMRI Study.

BACKGROUND AND PURPOSE: A key factor in predicting recurrent ischemic episodes in patients with carotid artery occlusion is the presence of hemodynamic impairment. There is, however, no consensus on how to best assess this risk in terms of imaging modalities or thresholds used. Here we investigated whether a predefined threshold of hemispheric asymmetry in hypercapnia fMRI predicts recurrent symptoms in patients with carotid artery occlusion. MATERIALS AND METHODS: We studied 23 patients (2 women) with a mean age of 67.5 ± 9 years. Patients were assessed for recurrent ischemic events until lost to follow-up, study end, death, or recurrent ischemic event. Hypercapnia fMRI was used to assess the cerebrovascular reserve and quantify the percentage signal change in GM in the MCA territory and the hemispheric asymmetry index. Kaplan-Meier survival analysis and log-rank tests were performed to assess differences between patients with normal or abnormal hemispheric indices. RESULTS: The median follow-up was 20 months. During this period, 8 patients experienced recurrent events, and 15 did not. The percentage signal change in GM in the MCA territory was significantly decreased in those patients with recurrent events compared with those without (2.39 ± 0.22 versus 2.70 ± 0.42, P = .032). The normal hemispheric index predicted event-free survival during follow-up (median, 20 months) for both the combined outcome (recurrent events and/or death, log-rank, P = .034) and recurrent retinal or ipsilateral ischemic events only (log-rank, P = .012). CONCLUSIONS: The hemispheric asymmetry index derived from hypercapnia fMRI showed hemodynamic impairment in more than half of the studied patients with carotid occlusion, and those patients showed a higher risk of recurrent ischemic symptoms.

Stenting of the Cystic Duct in Benign Disease: A Definitive Treatment for the Elderly and Unwell.

PURPOSE: There have been few case reports describing cystic duct stent insertion in the management of acute cholecystitis secondary to benign disease with no case series published to date. We present our series demonstrating the role of cystic duct stents in managing benign gallbladder disease in those patients unfit for surgery. MATERIALS AND METHODS: Thirty three patients unfit for surgery in our institution underwent cystic duct stent insertion for the management of acute cholecystitis in the period June 2008 to June 2013. Patients underwent a mixture of transperitoneal and transhepatic gallbladder puncture. The cystic duct was cannulated with a hydrophilic guidewire which was subsequently passed through the common bile duct and into the duodenum. An 8Fr 12-cm double-pigtail stent was placed with the distal end lying within the duodenum and the proximal end within the gallbladder. RESULTS: Ten patients presented with gallbladder perforation, 21 patients with acute cholecystitis, 1 with acute cholangitis and 1 with necrotising pancreatitis. The technical success rate was 91%. We experienced a 13% complication rate with 3% mortality rate at 30 days. CONCLUSION: Cystic duct stent insertion can be successfully used to manage acute cholecystitis, gallbladder empyema or gallbladder perforations in those unfit for surgery and should be considered alongside external gallbladder drainage as a definitive mid-term treatment option.

Randomized clinical trial of stents versus angioplasty for the treatment of iliac artery occlusions (STAG trial).

BACKGROUND: The management of total iliac artery occlusion is now undertaken routinely using percutaneous techniques but there are no controlled data to indicate whether either balloon angioplasty or stent placement is preferable. This was a multicentre randomized trial to assess whether stents confer any safety or efficacy advantage over balloon angioplasty for complete iliac artery occlusion. METHODS: Six participating centres recruited patients with symptoms of lower limb peripheral arterial disease due to iliac artery occlusion 8 cm or less in length. Patients were assigned randomly to either percutaneous transluminal angioplasty (PTA group) or primary stent placement (stent group) alone after the lesion had been traversed with a guidewire. RESULTS: There were 118 patients recruited to the study; six were excluded from the analysis owing to major protocol violations, leaving a total of 112 patients for analysis. Some 55 patients had PTA and 57 had a primary iliac stent. Technical success was achieved in 46 patients (84 per cent) in the PTA group and 56 (98 per cent) in the stent group (P = 0.007). There were 11 (20 per cent) major procedural complications after PTA compared with three (5 per cent) after primary stenting (P = 0.010). There were no significant differences in primary or secondary patency between the groups after 1 and 2 years. CONCLUSION: Primary stent placement for iliac artery occlusion increased technical success and reduced major procedural complications (predominantly distal embolization) compared with balloon angioplasty. REGISTRATION NUMBER: ISRCTN 48145465 (http://www.controlled-trials.com).

Effect of procedure volume on outcomes after iliac artery angioplasty and stenting.

BACKGROUND: Service reorganization to concentrate complex vascular services in hospitals with high caseload volume aims to reduce mortality and complication rates. The present study assessed the relationship between caseload volume and outcome for iliac artery angioplasty and stenting in England using a routinely available national data set (Hospital Episode Statistics, HES). METHODS: Routine administrative data for iliac artery angioplasty and stent procedures performed in England between 2007 and 2011 were analysed. Associations between centre volume and outcomes (death, complications and duration of hospital stay) were tested and compared for two methods of stratification (quartiles and quintiles) and two statistical tests (odds ratios and the Cochran-Armitage test for trend). Multivariable analysis was also performed. RESULTS: There were 23,308 episodes of care recorded in HES with Office of Population Censuses and Surveys Classification of Surgical Operations and Procedures, fourth revision, codes L54.1 or L54.4 corresponding to iliac artery intervention. There was a gradual increase year by year in number of procedures performed. Univariable and multivariable analysis showed no association between centre volume and either death or complications (multivariable odds ratio, OR 1.00, 95 per cent confidence interval 1.00 to 1.00) for elective and non-elective procedures. Age was associated with higher mortality and complication rates in elective procedures, and with mortality in non-elective procedures. The risk of death after elective iliac angioplasty or stenting was significantly higher in women (multivariable OR 4.98, 2.09 to 13.26). CONCLUSION: There was no association between the outcomes of endovascular iliac artery intervention and centre volume, but outcomes were significantly worse with increasing age and female sex.

United Kingdom carotid artery stent registry: short- and long-term outcomes.

BACKGROUND: Carotid artery stenting (CAS) has evolved to treat carotid artery disease with the intention of prevent stroke. The British Society of Interventional Radiologists developed a voluntary registry to monitor the practice of this novel procedure. We present the data from the United Kingdom (UK) CAS registry for short and long-term outcomes for symptomatic and asymptomatic carotid disease. METHODS: The UK CAS registry collected data from 1998 to 2010 from 31 hospitals across the UK for 1,154 patients. All interventions were enrolled in the registry for both asymptomatic and symptomatic patients. Initial entry forms were completed for each patient entered with data including indications, demographic data, CAS data (including stents and protection device details) and 30-day outcomes. Complications were documented. Follow-up data were collected at yearly intervals. RESULTS: Nine hundred fifty-three (83 %) symptomatic and 201 (17 %) asymptomatic patients were enrolled into the registry. The 30-day all stroke and death rates for symptomatic patients were 5.5 and 2.2 % for those with asymptomatic disease. The 30-day mortality rate was 1.7 % for symptomatic and 0.6 % for asymptomatic patients. For symptomatic patients undergoing CAS, the 7-year all-cause mortality rate was 22.2 % and for asymptomatic patients 18.1 %. The 7-year all-cause mortality and disabling stroke rates were 25.3 and 19.4 %, respectively. CONCLUSION: These data indicate that outside of the tight constraints of a randomised trial, CAS provides effective prophylaxis against stroke and death.

Laser and radiofrequency ablation study (LARA study): a randomised study comparing radiofrequency ablation and endovenous laser ablation (810 nm).

OBJECTIVES: There have been few randomised studies comparing Radiofrequency Ablation(RFA) with other endovenous techniques. The primary aim of this study was to determine whether RFA of the great saphenous vein (GSV) was associated with less pain and bruising than endovenous laser ablation (EVLA). MATERIALS AND METHODS: This trial had two cohorts--patients with bilateral GSV incompetence causing varicose veins (VV) and those with unilateral GSV VVs. In total 87 legs were treated in this study. Limbs in the bilateral group were treated with RFA in one leg and EVLA in the other. In the unilateral group limbs were randomised to RFA or EVLA. RFA was performed using the Celon RFiTT system (Teltow, Germany). EVLA was performed using an 810nm Laser (Biolitec AG, Germany). Phlebectomies were performed as required. Primary endpoints were patient assessed pain and bruising measured by visual analogue scale (VAS). Secondary endpoints were patency assessed by duplex ultrasound at 6 weeks and 6 months. RESULTS: In the bilateral group, RFA resulted in significantly less pain than EVLA on days 2-11 postoperatively. RFA also resulted in significantly less bruising than EVLA on days 3-9. There were no significant differences in mean post operative pain, bruising and activity scores in the unilateral group. Both RFA and EVLA resulted in occlusion rates of 95% at 10 days postoperatively. CONCLUSIONS: RFA was less painful for patients than EVLA and produced less bruising in the postoperative period with comparable success rates but there was no difference in the unilateral group.

Carotid endarterectomy improves cerebrovascular reserve capacity preferentially in patients with preoperative impairment as indicated by asymmetric BOLD response to hypercapnia.

PURPOSE: In patients with symptomatic carotid artery disease the predominant mechanism causing ischaemic injury is considered to be thromboembolic, however compromise of cerebral haemodynamics is considered to be a significant factor. Removal of the embolic source is accepted as the major benefit from carotid endarterectomy (CEA), however improvement in cerebral haemodynamics may be another beneficial outcome as suggested by transcranial doppler (TCD). Blood oxygen level-dependent (BOLD) hypercapnia functional magnetic resonance imaging (fMRI) can be used to map the cerebrovascular reserve (CVR). The aim of this study was to assess the effects of carotid surgery on cerebral haemodynamics in patients with carotid artery disease using a hypercapnia BOLD fMRI and assessment of hemispheric asymmetry. MATERIALS AND METHODS: Seventeen patients with symptomatic internal carotid artery stenosis were scanned using a clinical 1.5T MR scanner. Scanning was done immediately prior to and between 4 and 8 weeks after CEA. 10% carbon dioxide was administered to achieve transient episodes of hypercapnia. The data was analyzed using FMRIB Software Library (FSL) software to derive percentage signal change (PSC) for the grey matter of the middle cerebral artery (MCA-GM) territory for both hemispheres. MCA-GM PSC was furthermore normalized to the contralateral hemisphere to derive an Hemispheric Asymmetry Index (hAI) for all patients pre- and postoperatively. RESULTS: Ipsilateral GM CVR improved significantly following CEA (2.47% preoperatively vs. 2.73% postoperatively, p=0.038). There was no change in CVR in the contralateral grey and white matter MCA territories (p=0.27, p=0.1). Also, the hAI was significantly more shifted to the ipsilateral hemisphere after CEA (preoperative hAI -0.56, vs. -3.90 postoperatively, p=0.02). Patients with an impaired hAI preoperatively were found to show the greatest improvement in PSC and hAI following CEA (p=0.007). CONCLUSIONS: CEA resulted in improved CVR in patients with carotid artery disease as shown by the absolute and hemispheric asymmetry of BOLD response to hypercapnia.. These findings show that benefits from recanalisation may go beyond removal of the embolic source, by improving the cerebrovascular reserve. Moreover, hypercapnia BOLD fMRI may be a useful clinical tool in predicting this therapeutic potential in patients with severe carotid artery disease.

The importance of anatomical suitability and fitness for the outcome of endovascular repair of ruptured abdominal aortic aneurysm.

INTRODUCTION: Endovascular repair of aortic aneurysm (EVAR) has a lower mortality than open repair. The aim of this study was to assess mortality from EVAR for emergency AAA repair and the impact of fitness for operation and adverse anatomy. METHODS: One-hundred and forty two patients who had EVAR for a ruptured AAA (80, REVAR) or a symptomatic AAA (62, SEVAR) between 1994 and 2007 in a single specialist endovascular centre were reviewed. Fitness for surgery was assessed by Hardman's index (age>76, loss of consciousness, Hb<9.0, Cr>190, ischaemic ECG). CT scans were reviewed, compared with operative images and operation notes for adverse anatomy. Details of perioperative complications, and outcome were recorded. RESULTS: Overall mortality at 24-h, 30-days and one year were, respectively: 17%, 36%, 50% for REVAR and 5%, 8%, 23% for SEVAR. Overall adverse anatomy increased 30-day mortality. Hardman's index of three or more increased mortality HR=2.59 (1.24-5.41), p=0.01. On Cox regression Univariate analysis increasing Hardman's index score and adverse anatomy increased the overall mortality over time. In multivariate Cox regression analysis (controlled for the Hardman's index) adverse anatomy was associated with significant increase in graft related mortality. CONCLUSION: The use of EVAR is feasible in patients who present with a ruptured or acutely symptomatic AAA. Care must be taken not to extend anatomical or clinical guidelines.

Suitability of varicose veins for endovenous treatments.

The aim of the study was to assess the suitability of radiofrequency ablation (RFA), endovenous laser ablation (EVLA), and foam sclerotherapy (FS) for patients with symptomatic varicose veins (VVs). The study comprised 403 consecutive patients with symptomatic VVs. Data on 577 legs from 403 consecutive patients with symptomatic VVs were collected for the year 2006. Median patient age was 55 years (interquartile range 45-66), and 62% patients were women. A set of criteria based on duplex ultrasonography was used to select patients for each procedure. Great saphenous vein (GSV) reflux was present in 77% (446 of 577) of legs. Overall, 328 (73%) of the legs were suitable for at least one of the endovenous options. Of the 114 legs with recurrent GSV reflux disease, 83 (73%) were suitable to receive endovenous therapy. Patients with increasing age were less likely to be suitable for endovenous therapy (P = 0.03). Seventy-three percent of patients with VVs caused by GSV incompetence are suitable for endovenous therapy.

Precision of cerebrovascular reactivity assessment with use of different quantification methods for hypercapnia functional MR imaging.

BACKGROUND AND PURPOSE: Tools for noninvasive mapping of hemodynamic function including cerebrovascular reactivity are emerging and may become clinically useful to predict tissue at hemodynamic risk. One such technique assesses blood oxygen level-dependent (BOLD) MR imaging contrast in response to hypercapnia, but the reliability of its quantification is uncertain. The aim of this study was to prospectively investigate the intersubject and interhemispheric variability and short-term reproducibility of hypercapnia functional MR imaging (fMRI) in healthy volunteers and to assess the effects of different methods of quantification and normalization. MATERIALS AND METHODS: Sixteen healthy volunteers, (7 women and 9 men) underwent hypercapnia fMRI with a clinical 1.5T scanner; 8 underwent scanning twice. We determined BOLD amplitude changes using a visually defined block design or automated regression to end-tidal (ET) carbon dioxide (CO2). Absolute percent signal intensity changes (PSC) were extracted for whole-brain, gray matter, and middle cerebral artery territory, and also normalized to ETCO2 change. Intersubject and intrasubject (between hemispheres and sessions) coefficients of variation (COV) were derived. We assessed the effects of different quantification methods on reproducibility indices using the t test and U tests. RESULTS: The mean change in ETCO2 was 7.8 +/- 3.3 mm Hg. Averaged BOLD increases varied from 2.54% to 2.92%. Short-term reproducibility was good for absolute PSC (4.8% to 10%) but poor for normalized PSC (range, 24% to 27% COV). Intersubject reproducibility varied between 11% and 23% for absolute PSC and, again, was poorer for normalized data (32% to 39%). Interhemispheric reproducibility of absolute PSC was excellent ranging between 1.24 and 2.16% COV. CONCLUSIONS: In conclusion, quantification of cerebrovascular reactivity with use of hypercapnia fMRI was found to have good between-session and very good interhemispheric reproducibility. The technique holds promise as a diagnostic tool, especially for sensitive detection of unilateral disease.