Agreement between computed tomography and ultrasound on abdominal aortic aneurysms and implications on clinical decisions.

OBJECTIVES: The United Kingdom abdominal aortic aneurysm (AAA) screening programme refers aneurysms with ultrasound (US) diameters of ≥5.5 cm to vascular services for consideration of computed tomography (CT) and intervention. We investigated the discrepancy between US and CT, implications on clinical decisions and question at which stage CT be used. DESIGN/METHODS: AAA USs over 5 years were retrospectively analysed. Patients included had aneurysms measuring ≥5 cm on US with subsequent CT within 2 months (n = 123). Based on maximum US diameters, 44 patients had aneurysms between 5 and 5.4 cm (group I) and 79 patients ≥5.5 cm (group II). Results were cross-referenced. Correlation and limits of agreement were calculated. Two radiologists re-measured 44 pairs of CT/US scans and the inter-observer bias in determining discrepancies between imaging modalities calculated. RESULTS: Mean difference between imaging modalities was 0.21 cm (±0.39 cm, p < 0.001). Limits of agreement were -0.55 to 0.96 cm, exceeding clinical acceptability. Mean difference was higher and significant in group I (0.39 cm, p < 0.001) compared to group II (0.10 cm, p > 0.05). Seventy-percent of group I patients had CT scans revealing diameters of ≥5.5 cm. Inter-observer bias was not significant. CONCLUSION: Significant differences between imaging modalities, more in US diameters of below 5.5 cm, exist. We recommend AAAs measuring ≥5 cm on US should undergo earlier referral to a vascular service and CT.

Long term follow-up of transcatheter coil embolotherapy for major colonic haemorrhage.

AIM: Therapeutic angiography with embolization is fast becoming the preferred treatment modality for major bleeding in the lower gastrointestinal (LGI) tract. The aim of this study was to determine the long term outcome and complications of percutaneous coil embolization (PCE) and its efficacy as definitive therapy in patients with major LGI bleeding. METHODS: All patients presenting to our institution with a haemodynamically significant LGI tract bleed between 1995 and 2001 that were unresponsive to conservative measures were considered for emergency angiography and coil embolization where appropriate. The outcome of these individuals was determined by case note review and telephone interview. RESULTS: There were 20 patients (11 females) with a mean follow-up period 72 months, mean age was 67 years. All underwent PCE following positive angiogram. The most common site of bleeding was the right colon (40%); haemostasis was successfully achieved in 16 (80%) patients. Five of the 20 patients died within 30 days of the intervention, three following PCE and two following surgery. None of the mortality following PCE was considered procedure related. On long term follow-up four patients required readmission to hospital for further LGI bleeds at 1, 2, 12 and 16 months respectively. Ischaemic complications occurred in 23%. CONCLUSION: Superselective embolization as the primary technique for the treatment of haemodynamically significant LGI bleeding is an effective, feasible and safe technique. Long term follow-up in our series up to 72 months has shown that it should be considered as both a primary and potentially definitive treatment for life threatening LGI bleeds.

Audit of the use of IVC filters in the UK: experience from three centres over 12 years.

AIM: To audit the use of inferior vena cava (IVC) filter insertions at three UK centres over 12 years to assess whether trends in filter use in the UK mirrored those seen elsewhere. MATERIALS AND METHODS: Radiology department databases were interrogated for IVC filter insertions and removals between 1994 and 2006. Reports for these interventions, along with prior and subsequent imaging reports, were analysed. Follow-up data were obtained when available. RESULTS: Five hundred and sixteen filters were placed with a significant year-on-year trend towards increasing use. Fifty-seven percent of filters placed were for absolute indications and 37% for relative indications. The filters were used for prophylaxis in 6% of patients in the absence of proven pulmonary embolism (PE) or deep vein thrombosis (DVT). A retrievable filter was used in 74% of cases with retrieval attempted in 40% of these and no evidence of an increasing rate of retrieval over time. A significant complication related to insertion or retrieval was encountered in 0.4 and 1% of procedures, respectively. Mean 24 h and 30 day mortalities were 1 and 8%, respectively. There was an absence of organized follow-up at all three centres. CONCLUSION: IVC filter use in the UK is increasing. The use of retrievable filters has not resulted in increased filter retrieval. Filter insertion and retrieval is associated with a low risk of significant complication, but lack of systematic follow-up limits conclusions regarding safety and efficacy.

The Immediate Management of the Patient with Rupture: Open Versus Endovascular repair (IMPROVE) aneurysm trial--ISRCTN 48334791 IMPROVE trialists.

BACKGROUND: Systematic reviews have suggested a survival advantage for patients with ruptured abdominal aortic aneurysm (AAA), who are managed by endovascular repair. These reviews are based on single centre experiences of selected patients. OBJECTIVE: To determine whether a policy of endovascular repair improves the survival of all patients with ruptured AAA. METHODS: A randomized controlled trial, IMPROVE (ISRCTN 48334791) will randomize patients with a clinical diagnosis of rAAA, made in hospital, either to immediate CT scan and endovascular repair whenever anatomically suitable (endovascular first), or to open repair, with CT scan being optional (normal care), The trial is set on a background of guidelines for emergency care, CT scanning and anaesthesia, which incorporate the protocol of permissive hypotension. Recruitment started in October 2009 and 600 patients are required to show a 14% survival benefit at 30 days (primary outcome) for the endovascular first policy. Recruitment will be from the UK and Europe. Secondary outcomes include 24h, in-hospital and 1 year survival, complications, major morbidities, costs and quality of life. DISCUSSION: This is a "real life" trial that will answer the fundamental relevant clinical dilemma, namely, do patients who present with ruptured AAA derive benefit from treatment in a system, which offers a preferential strategy of endovascular repair? The trial addresses whether the anticipated reduced mortality and morbidity associated with endovascular repair is offset by the relatively greater ease of access and speed to conventional surgery. This issue is pivotal to future patient care and provision of services.

Strategies for the management of SVC stent migration into the right atrium.

PURPOSE: Stent migration into the right atrium is a potentially fatal complication of stenting in the venous system and is most likely to occur during the treatment of superior vena cava obstruction. Endovascular approaches that can salvage this hazardous situation are described and the keys to successful treatment are highlighted. MATERIALS AND METHODS: Four different strategies are reviewed: (1) snaring the stent directly, (2) angioplasty balloon-assisted snaring of the stent, (3) guide wire-assisted snaring of the stent, and (4) superior vena cava-to-inferior vena cava bridging stent. RESULTS: These techniques have been employed in the successful management of four cases. No short- or long-term complications as a result of these maneuvers have been identified. Additional treatment of the underlying disease was possible at the same time in each case. CONCLUSION: We conclude that prompt management of right atrial stent migration is essential and can be successfully achieved by a variety of "bale-out" techniques which are within the technical range of most interventional radiologists.

Cryoplasty for arterial restenosis.

OBJECTIVE: A prospective follow-up study of patients with arterial restenosis undergoing cryoplasty. MATERIALS & METHODS: Between May 2004 and June 2005, 10 patients with restenosis following ilio-femoral endovascular treatment underwent twelve cryoplasty procedures. All patients had had at least one previous episode of stenosis treated by conventional endovascular methods and had suffered further restenosis. The indications for treatment were grafts at risk (n=5) and symptomatic in-stent restenosis (n=5). Two patients underwent re-cryoplasty. Cryoplasty was performed in accordance with manufacturer's instructions using 6-8mm balloons. All patients had Doppler ultrasound evaluation at 1, 3, 6 and 12 months. RESULTS: All procedures had angiographically successful immediate outcome with <30% residual stenosis. Non flow limiting dissection was evident in two cases. In six procedures (50%), restenosis was evident within 6 months post-procedure, whilst in the other six, there was progressive restenosis appearing between 6-12 months. Five cryoplasty procedures have needed endovascular re-intervention due to symptomatic high-grade restenosis and a sixth is awaiting surgery. CONCLUSION: Cryoplasty is of no value in patients with restenosis in the iliofemoral segment with half the procedures failing within six months and all of them within the first year. Evidence to support the use of cryoplasty in the peripheral arterial restenotic lesions is lacking.

"Whatever happened to the class of 2000?" An outcome survey of potential interventional radiologists.

OBJECTIVES: To find out what final career choices were made by trainee doctors who had indicated a strong interest in pursuing a career in interventional radiology and to establish the reasons behind their final career choice. METHODS: Eighty-eight doctors who attended a meeting in 2000 designed to promote interventional radiology as a career were questioned as to whether the meeting influenced their potential career choices and then further surveyed via postal questionnaire 5 years later to find out their eventual career choices. Of the 88 doctors who attended, 56 were radiology trainees and 32 were training in either medical or surgical specialties. There were 25 women and 63 men. RESULTS: Five years after the meeting, six are now interventional radiologists (6.8%) though four of these are still in a 6th year interventional radiology fellowship. A further 12 (13.6%) are systems based, predominantly diagnostic radiologists with an interest in intervention. Thirty-two (43.2%) are diagnostic radiologists who undertake little or no therapeutic intervention. Of the 32 non-radiologists who attended the meeting only three entered radiology and are still in training. CONCLUSIONS: Interventional radiology is a popular initial career choice amongst trainee doctors. However, only a small number eventually pursue the specialty. If the manpower shortage of interventional radiologists is to be addressed, there needs to be improvements in training, accreditation, career opportunities and working conditions.

Endovascular embolization of visceral artery aneurysms with ethylene-vinyl alcohol (Onyx): a case series.

We report the application of the liquid embolic agent ethylene-vinyl alcohol (Onyx; MicroTherapeutics, Irvine, CA, USA) in the management of visceral artery aneurysms. The technique and indications for using Onyx are discussed with emphasis on the management of wide-necked aneurysms and maintenance of patency of the parent vessel. None of the cases was considered suitable for stent-grafting or embolization with conventional agents. Two aneurysms of the renal artery bifurcation and one aneurysm of the inferior pancreaticoduodenal artery were treated. Following treatment there was complete exclusion of all aneurysms. There was no evidence of end-organ infarction. Follow-up with intervals up to 6 months has shown sustained aneurysm exclusion. Onyx is known to be effective in the management of intracranial aneurysms. Our experience demonstrates the efficacy and applicability of the use of Onyx in the treatment of complex visceral artery aneurysms.

Percutaneous thrombin injection for the treatment of a post-pancreatitis pseudoaneurysm.

Visceral artery pseudoaneurysms are often treated surgically or by transcatheter embolisation. We report a case of a pseudoaneurysm in a patient with chronic pancreatitis, which was successfully occluded by percutaneous injection of thrombin into the pseudoaneurysmal sac as a first-line management.

Symptomatic malignant gastroesophageal anastomotic leak: management with covered metallic esophageal stents.

OBJECTIVE: Gastroesophageal anastomotic leak after cancer resection has a mortality rate of up to 60% and significant morbidity, whatever the mode of treatment. We assessed the efficacy of esophageal stenting as a therapeutic option to reduce the mortality and morbidity associated with symptomatic intrathoracic anastomotic leakage. SUBJECTS AND METHODS: During a 52-month period, 14 patients had placement of stents for clinically significant postoperative leaks: 10 patients had an esophagogastrectomy and four patients had a total gastrectomy with esophagojejunal anastomosis. Thirteen of 14 patients had tumors that were histologically staged as T3 N1 M0 or worse. Significant anastomotic leaks were revealed by a contrast-enhanced study at 3-28 days after surgery. Stents were inserted in patients in whom the leakage was debilitating or initial conservative treatment had failed. Stenting outcome in terms of clinical and radiologic healing, hospital stay, survival, and complications was assessed. RESULTS: No procedural morbidity or 30-day mortality occurred. Immediate postprocedural leak occlusion was obtained in all patients. Clinical healing of the leak occurred in 13 (92.8%) of 14 patients, with a median healing time of 6 days. Of the 13 patients, healing occurred within 10 days in 10 patients (76.9%). Eight of these 10 early closures received a knitted nitinol stent (p = 0.02). One patient (7%) died as a consequence of leakage at 135 days. Median survival for all 14 patients was 11 months (Kaplan-Meier method). Complications included five episodes of food blockages in three patients, which required endoscopic clearance, and one case of stent-related upper gastrointestinal hemorrhage. No patients developed anastomotic stricture or occlusive epithelial hyperplasia. CONCLUSION: Covered esophageal stenting appears to reduce the mortality and morbidity of symptomatic anastomotic leakage after surgery for gastroesophageal cancer. Knitted nitinol stents may be best suited to this purpose.

Recurrent superior vena caval obstruction due to invasion by malignant thymoma: treatment using a stent-graft.

A stent-graft was used to palliate superior vena caval obstruction in a 50-year-old patient with histologically proven ingrowth of malignant thymoma through three previously inserted non-covered stents. The stent-graft is still patent 12 months later. This is the first report of such a procedure where histological evidence of tumour ingrowth is available and long-term patency is verified.

Long-term follow-Up of percutaneous balloon angioplasty in adult aortic coarctation.

PURPOSE: To assess long-term outcomes following percutaneous transluminal angioplasty (PTA) of congenital aortic coarctation in adults. METHODS: Seventeen patients underwent PTA for symptomatic adult coarctation of the aorta. Sixteen patients, with a mean age of 28 years (range 15-60 years), were reviewed at a mean interval after angioplasty of 7.3 years (range 1.5-11 years). Assessment included magnetic resonance imaging (MRI), Doppler echocardiography, and clinical examination. Current clinical measurements were compared with pre- and immediate post-angioplasty measurements. RESULTS: At follow-up 16 patients were alive and well. The patient not included in follow-up had undergone surgical repair and excision of the coarctation segment following PTA. Mean brachial systolic blood pressure for the group decreased from 174 mmHg before angioplasty to 130 mmHg at follow-up (p = 0.0001). The mean gradient had fallen significantly from 50.9 to 17.8 at follow-up (p = 0.001). The average number of antihypertensive drugs required per patient decreased from 0.56 to 0.31 (p = 0.234). No significant residual stenoses or restenoses were seen at MRI. Small but clinically insignificant residual pressure gradients were recorded in all patients using Doppler echocardiography. Complications included one transient ischemic attack at 5 days, one external iliac dissection requiring stent insertion, and a further patient who developed a false aneurysm close to the coarctation site at 12 months which subsequently required surgical excision. CONCLUSION: PTA of adult coarctation is safe and effective in the long term. Although primary stenting has recently been advocated in the treatment of this condition, our results suggest that PTA remains the treatment of choice.

Vascular imaging and intervention in peripheral arteries in the diabetic patient.

Diabetic patients are four times more likely to develop peripheral vascular disease than the general population. This disease is likely to be more aggressive, with five times more patients developing critical limb ischaemia. Early diagnosis and treatment allows up to 80% of these patients to have some form of surgical or endovascular re-vascularisation. The primary imaging modalities to be used should be duplex ultrasound followed by angiography. Magnetic resonance angiography, however, holds out promise for the future as being a good method of non-invasive imaging. Endovascular (interventional radiological) procedures have a major role to play in treatment of vascular stenoses and occlusions. Thrombolytic agents can be used to dissolve thrombus within occluded vessels and so restore patency. Percutaneous transluminal angioplasty is of value in dilating the stenotic lesions within the vessels and so restoring normal blood flow. Endovascular stents may be inserted to ensure longer term patency. There is indirect evidence to suggest that the outcomes of endovascular procedures in the diabetic patient are less good than those in the general population, but nevertheless such procedures may save the diabetic patient from primary amputation and allow healing of ischaemic ulcers.

The clinical utility of spiral CT cholangiography.

Spiral CT cholangiography has received little attention, yet in a single breath-hold spiral and with limited manipulation at the workstation it can yield high resolution images of the biliary tract. In addition it can clearly demonstrate periampullary detail and contribute some dynamic information regarding biliary excretion. The clinical utility of this technique is illustrated and discussed. Breen, D. J., Nicholson, A. A. (2000). Clinical Radiology55, 733-739.

Mechanical properties of metallic stents: how do these properties influence the choice of stent for specific lesions?

PURPOSE: To assess selected balloon-expandable and self-expanding stents for radial force, flexibility, radio-opacity, and trackability, and to relate these physical characteristics to potential indications for placement. METHODS: Force-strain curves were plotted for each stent and the force required to produce 50% luminal narrowing was recorded. The ability of the stent to show elastic recoil following deformation was also noted. Flexibility was measured by bending the stents against a force transducer and recording the force required per degree of flexion. Radio-opacity was measured by comparing each stent against a standard aluminum step wedge. Trackability was measured by testing the ability of the stent on its delivery system to track over angles of 90 degrees and 60 degrees. RESULTS: The balloon-expandable stents showed greater radial strength and radio-opacity but, apart from the AVE Iliac Bridge stent, showed poorer flexibility and trackability. The self-expanding stents showed less radial force but were able to re-expand following deformity. They were generally more flexible and had better trackability but lower radio-opacity. CONCLUSION: There is no stent which exhibits all the ideal properties required and therefore the interventionist will need to keep a range of stents available if all lesions are to be addressed.

Long-term follow-up of the Bird's Nest IVC Filter.

AIM: This study is a long-term clinical follow-up of the Bird's Nest Filter which addresses issues such as caval patency, filter integrity, morbidity and mortality. MATERIALS AND METHODS: 78 consecutive patients with Bird's Nest Filters inserted between 1989 and 1994 were recalled for clinical assessment and imaging follow-up. Pre- and post-filter medical histories were obtained from the patients and their medical records. They were examined for clinical signs of inferior vena cava occlusion. Imaging follow-up was by plain abdominal radiography, colour duplex ultrasound and computed tomography. RESULTS: 52 patients were alive and well at 4-6 years. Thirty-day mortality was 5.1%. Three-year mortality was 19.2%. Recurrent pulmonary embolus occurred in 1.3%. IVC occlusion was demonstrated in 4.7%. No evidence of filter migration was seen. Wire prolapse occurred in 70% on abdominal X-ray and asymptomatic performation of the caval wall in 85.3% on CT. Morbidity and mortality were the same whether the patient was anticoagulated or not. CONCLUSION: The Bird's Nest Filter is safe and effective in both the short and long term.

Treatment of rectal hemorrhage by coil embolization.

Four patients, aged 54-84 years, presenting with life-threatening rectal bleeding from the superior hemorrhoidal artery, underwent percutaneous fibered platinum coil embolization via coaxial catheters. Pre-procedure sigmoidoscopy had failed to identify the source of hemorrhage, because the rectum was filled with fresh blood. Embolization was technically and clinically successful in all four patients. Subsequent sigmoidoscopy confirmed the diagnoses in three patients as a solitary rectal ulcer, iatrogenic traumatic ulceration following manual evacuation, and a rectal Dieulafoy's lesion. The other case was angiographically seen to be due to a rectal angiodysplasia. Embolization is an effective procedure in life-threatening superior hemorrhoidal arterial bleeding when endoscopic treatment fails, and should be preferred to rectosigmoid resection.