Non-enhanced MR angiography of renal arteries: comparison with contrast-enhanced MR angiography.

BACKGROUND: The main causes of renal artery stenosis (RAS) are atherosclerosis and fibromuscular dysplasia. Despite contrast-enhanced magnetic resonance angiography (CE-MRA) being a safe and reliable method for diagnosis of RAS especially in young individuals, recently it has been possible to adopt innovative technologies that do not require paramagnetic contrast agents. PURPOSE: To assess the accuracy of steady-state free-precession (SSFP) non-contrast-enhanced magnetic resonance angiography (NC-MRA) by using a 1.5 T MR scanner for the detection of renal artery stenosis, in comparison with breath-hold CE-MRA as the reference standard. MATERIAL AND METHODS: Sixty-three patients (33 men, 30 women) with suspected renovascular hypertension (RVHT) were examined by a 1.5T MR scanner; NC-MRA with an electrocardiography (ECG)-gated SSFP sequence was performed in 58.7% (37/63) of patients; in 41.3% (26/63) of patients a respiratory trigger was used in addition to cardiac gating. CE-MRA, with a three-dimensional gradient echo (3D-GRE) T1-weighted sequence, was performed in all patients within the same session. Maximum intensity projection (MIP) image quality, number of renal arteries, and the presence of stenosis were assessed by two observers (independently for NC-MRA and together for CE-MRA). The agreement between NC-MRA and CE-MRA as well as the inter-observer reproducibility were calculated with Bland-Altman plots. RESULTS: MIP image quality was considered better for NC-MRA. NC-MRA identified 143 of 144 (99.3%) arteries detected by CE-MRA (an accessory artery was not identified). Fourteen stenoses were detected by CE-MRA (11 atherosclerotic, 3 dysplastic) with four of 14 (28.5%) significant stenosis. Bland-Altman plot demonstrated an excellent concordance between NC-MRA and CE-MRA; particularly, the reader A evaluated correctly all investigated arteries, while over-estimation of two stenoses occurred for reader B. Regarding NC-MRA, inter-observer agreement was excellent. CONCLUSION: NC-MRA is a valid alternative to CE-MRA for the assessment of renal arteries.

Removable vena cava filter: single-centre experience with a single device.

PURPOSE: The aim of our study was to evaluate the safety of retrieving both short- and long-term permanent/ retrievable ALN vena cava filters (VCF). MATERIALS AND METHODS: From 2002 to 2010, 201 permanent/retrievable VCF were percutaneously placed in 201 patients (age range, 18-80 years). Sixty-seven were placed through the jugular vein, 61 through the brachial vein and 63 through the femoral vein. In 109 patients, the VCF was placed for absolute indications, in 77 for relative indications, and in 15 for temporary filtration. Follow-up was carried out with colour Doppler ultrasound (CDUS) and abdominal X-ray at 3 and 12 months, then annually. Indications for removal included: lack of contraindications to anticoagulant therapy, absence of pulmonary embolism and iliocaval venous patency. All candidates for VCF removal underwent computed tomography angiography (CTA). RESULTS: VCF placement with correct position (tilting up to 15°) was achieved in 99.01% of cases. In two (0.99%) cases, tilting >15° was present. Haematomas, which resolved spontaneously, occurred in only eight jugular access sites. A total of 26 of 201 VCF were removed, with 96.16% technical success. The removal procedure failed in one case only. In seven cases, a double approach through the right jugular and femoral veins was necessary. VCF was removed 6 months after deployment in 11 patients, 12 months in eight, 24 months in four after 36 months in three (range, 180-1,155 days.) There were no periprocedural complications. Of the 26 removed VCF, 21 were infrarenal and five suprarenal. Of the 15 VCF placed for temporary use, 12 were removed; the remaining three not removed owing to persistence of the neoplastic thrombus after nephrectomy for kidney cancer. Of the 186 VCF placed for permanent use, with absolute and relative indications, 14 were removed (4/109 and 10/77, respectively). Only one showed thrombi occluding the cranial end. CONCLUSIONS: VCF removal is certainly more difficult than placement. Technical failure of the removal procedure is directly proportional to the VCF tilt, and the VCF is as yet unable to ensure absolute removal safety, with the result that failure may occasionally occur. The morphological and structural features of permanent/retrievable VCF allow for unlimited time from placement to removal, documented to be up to 3 years after placement.

Volumetric analysis of the aneurysmal sac with computed tomography in the follow-up of abdominal aortic aneurysms after endovascular treatment.

PURPOSE: Our aim was to assess the usefulness of volumetric analysis for the follow-up of abdominal aortic aneurysms after endovascular repair (EVAR) and operator independence of the method. MATERIALS AND METHODS: We retrospectively evaluated 99 computed tomography (CT) exams of 33 patients. Two blinded operators assessed the volume before treatment and after EVAR at 1-3 and 12-24 months. Friedman's statistical test was used to assess the reproducibility of the method. The time required for postprocessing by the two operators was compared. RESULTS: One patient was excluded. Twenty-one patients showed no endoleak: 12/21 showed a volume reduction at both follow-up scans (9.7% and 19.5%, respectively); 8/21 showed an early volume increase (9.8%) with a late reduction (10.5%); 1/21 patient showed a volume increase at both follow-up scans (endotension). Eleven patients had an endoleak (one type I, nine type II and one type III); 4/9 type II endoleaks showed a volume reduction at both post-EVAR scans (8.5% and 19.5%). All other cases showed a volume increase after EVAR (type II 15.4%/16.8%, type I 24.1%/9.1%, type III 8%/10.7%). The Friedman statistical test assessed operator independence with p < 0.001. Mean difference between the two operators was 0.9% (0-4.3%). CONCLUSIONS: CT volume analysis is an accurate and reproducible modality for the follow-up of abdominal aortic aneurysms after EVAR. At early follow-up, contrast-enhanced CT remains mandatory to identify small endoleaks. For later follow-up, volumetric analysis would eliminate the need for contrast material in asymptomatic patients with stable or decreasing aneurysm volume.

Recanalisation of thrombotic arterial occlusions with rotational thrombectomy.

PURPOSE: This study sought to assess the effectiveness of rotational thrombectomy (RT) with the Rotarex device in the treatment of thrombotic occlusions in native arteries, by-pass grafts, stents and stent-grafts. MATERIALS AND METHODS: Over the last 4 years, 22 patients (14 men and 8 women; mean age 62.6 years) affected by 5 acute (<14 days) thrombotic occlusions of the native arteries (4 plaque thromboses in the common iliac artery and one on a dissection intimal flap of the external iliac artery), 17 subacute and chronic thromboses affecting 4 femoro-popliteal by-pass grafts, 10 stents (7 in the common iliac artery and 3 in the superficial femoral artery) and 3 stents-grafts were studied. Acute thromboses of native arteries were follow-up with colour-Doppler ultrasound (US) examination at 1 and 3 months. Subacute and chronic thrombotic occlusions were follow-up with colour-Doppler US examination at 1, 3, 6 and 12 months and yearly thereafter. RESULTS: Immediate technical success was achieved without any need for additional procedures in all acute occlusions of native arteries (4/22 cases). In the subacute and chronic occlusions, the procedure was completed with percutaneous transluminal angioplasty (PTA) (8/22), cutting balloon (6/22) and stenting (5/22). The complication rate was 4.8% (1 rupture of the external iliac artery repaired with a stent-graft). CONCLUSIONS: Arterial recanalisation with RT is the treatment of choice for acute thrombosis of healthy native arteries (4-7 mm); the treatment of thrombosis complicating calcified plaques or dissection intimal flaps may cause rupture of the arterial wall. In subacute and chronic occlusions of by-pass grafts, stents and stent grafts, additional procedures are necessary to achieve complete recanalisation.

"Full metal jacket" with direct stenting of complete chronic occlusions of the superficial femoral artery.

PURPOSE: This study evaluated the short- and midterm patency of complete total occlusions of the superficial femoral artery (SFA) treated with direct stenting. MATERIALS AND METHODS: Fifty-two consecutive patients (36 men and 16 women; mean age 73.6 years; range 58-85) with chronic complete SFA occlusion and good distal run-off (two or three patent vessels) underwent endovascular recanalisation by direct stenting. All patients were symptomatic (severe claudication or critical ischaemia). Recanalisation was achieved by using a contralateral approach in 44 patients and an ipsilateral antegrade access in eight patients. A total of 152 nitinol stents were used: three stents in 32 cases, four stents in eight cases and two stents in 12 cases. Follow-up consisted of clinical evaluation and colour Doppler ultrasound at 6, 12, 18 and 24 months. RESULTS: The immediate technical success rate was 100%, with complete SFA recanalisation documented on postprocedural angiography. Four cases of distal embolism occurred, which were treated successfully with intra-arterial thrombolysis. During the follow-up, 12 reocclusions were observed: eight were treated with mechanical thrombectomy and in-stent angioplasty, and four were converted into femoropopliteal bypasses. The primary patency rates at 6, 12, 18 and 24 months were 92.3%, 76.9%, 69.2% and 69.2%, respectively. The secondary patency rates at 6, 12, 18 and 24 months were 100%, 100%, 92.3% and 92.3%. CONCLUSIONS: The percutaneous treatment of chronic complete SFA occlusions yielded good primary and secondary patency rates in the short and medium term, with few periprocedural complications. Reocclusions were treated using the percutaneous technique, which guarantees a good secondary patency rate.

Recurrence of intracardiac large B-cell non-Hodgkin's lymphoma (NHL) encasing and nearly obliterating the right coronary artery: a case report.

Among malignant tumors of the heart, primary malignant lymphomas are unusual and they are typically non-Hodgkin's B-cell cancers. A 73-year-old man affected by non-Hodgkin lymphoma (NHL) treated with four cycle of chemotherapy and radiotherapy was admitted to the Emergency Department for chest pain. Echocardiography showed a mass inside the right ventricle obstructing blood outflow in the pulmonary artery. The ECG-gated angio-multidetector computed tomography (MDCT) examination confirmed a solid mass in the right ventricle encasing the proximal-middle tract of the right coronary artery (RCA); RCA stenosis was confirmed by coronary angiography. After trans-thoracic CT-guided biopsy the mass was characterized as a recurrence of NHL and the patient started a new cycle of chemotherapy. After 15 days a MDCT exam showed both mass reduction and absence of RCA significant stenosis. MDCT imaging allows an accurate assessment of tumour extension and it represents an useful guide during biopsy procedures, necessary for a precise histological characterization of neoplasms.

Hybrid treatment of isolated aortic arch aneurysms.

PURPOSE: This study sought to assess the feasibility and effectiveness of hybrid treatment of isolated aortic arch aneurysms. MATERIALS AND METHODS: Between December 2000 and December 2006, we selected 14 patients affected by 14 isolated aortic arch aneurysms. All patients had involvement of the left subclavian artery, four of the innominate artery and four of the left carotid artery. All patients underwent intentional exclusion of the left subclavian artery and placement of a straight graft; four patients underwent supra-aortic vessel transposition and four underwent carotid-carotid bypass in one case combined with carotid-subclavian bypass. The procedures were planned with multislice computed tomography (MSCT), in some cases associated with virtual endoscopy. The follow-up was performed with MSCT angiography at 1, 3, 6 and 12 months and yearly thereafter. RESULTS: Immediate technical success was achieved in 100% of cases. There were four ischaemic attacks (three transient ischaemic attacks and one stroke). During follow-up (range 12-48, average 21 months), we observed two type-I endoleaks that were treated by endograft extension, in one case associated with supra-aortic vessel transposition, and two type-II endoleaks that were treated with embolisation. CONCLUSIONS: Hybrid treatment for aortic arch aneurysms is feasible and provides good short-term results, although it requires accurate planning. Further studies are needed to verify the long-term results.

MDCT evaluation of the cardiac venous system.

PURPOSE: This study was undertaken to evaluate the usefulness of electrocardiographically (ECG)-gated multidetector-row computed tomography (MDCT) for the assessment of the coronary venous system and detection of its anatomical variants, in order to identify those suitable for lead placement in cardiac resynchronisation therapy (CRT). MATERIALS AND METHODS: We retrospectively examined the coronary MDCT studies of 89 patients (73 males, 16 females, average age 62.5 years, range 31-79) referred for suspected coronary artery disease. The cardiac venous system was assessed in all patients using three-dimensional (3D) postprocessing on a dedicated Vitrea workstation (five patients were excluded from the analysis). RESULTS: The coronary sinus, the great cardiac vein, the anterior interventricular vein and the middle cardiac vein were visualised in all cases. The lateral cardiac vein was visualised in 56/84 patients (67%) and the posterior cardiac vein in 63/84 patients (75%), never both missing. Along the postero-lateral wall of the left ventricle, only one branch was present in 44 cases, two branches in 21 cases and three or more branches in 19/84 cases (22%). Evaluation of the maximum diameter revealed that the lateral vein was dominant over the posterior vein in 20/40 cases. The small cardiac vein was visualised in 11/84 cases. CONCLUSIONS: MDCT provides good depiction of the cardiac venous system, enabling the study of the vessel course and the identification of anatomical variants. Hence, this imaging technique could be proposed for the preoperative planning of CRT in selected patients.

Indications for the use of the Amplatzer vascular plug in interventional radiology.

PURPOSE: This study was undertaken to assess the indications and effectiveness of the Amplatzer vascular plug (AVP) system in interventional radiology. MATERIALS AND METHODS: Over the past year, we selected 12 patients (seven men and five women; mean age 65.8 years, range 45-82) for the occlusion of five internal iliac arteries (in three aortoiliac aneurysms, one internal iliac aneurysm and one isolated common iliac artery aneurysm), two common iliac arteries (in two ruptured abdominal aortic aneurysms), two subclavian arteries (in aortic arch aneurysms) and three splenic artery aneurysms. We used 15 AVPs (splenic artery aneurysms were excluded, with one AVP in the feeding vessel and one in the draining vessel). RESULTS: We achieved immediate technical success in 12/12 cases. No rupture or dissection of the treated arteries occurred. During the follow-up (mean 4.6 months, range 3-6) computed tomography (CT) angiography and/or contrast-enhanced ultrasound demonstrated complete artery occlusion and aneurysm exclusion. CONCLUSIONS: Ease and speed of use combined with precise, controlled delivery justify the growing use of the AVP in interventional radiology. No doubt, the system's versatility will extend its indications, and larger studies with longer follow-up periods will validate the results achieved so far.

Imaging-guided percutaneous radiofrequency ablation of adrenal metastases: preliminary results at a single institution with a single device.

The aim of this study was to show the feasibility, safety, imaging appearance, and short-term efficacy of image-guided percutaneous radiofrequency ablation (RFA) of adrenal metastases (AM). Seven imaging-guided percutaneous RFA treatments were performed in six patients (two men and four women; mean age, 67.2 years; range, 55-74 years) with six AM who were referred to our institution from 2003 to 2006. One patient was treated twice for recurrence after first treatment. The average diameter of the treated AM was 29 mm (range, 15-40 mm). In all patients, the diagnosis was obtained with CT current protocols in use at our institution and confirmed by pathology with an image-guided biopsy. No major complications occurred. In one patient shortly after initiation of the procedure, severe hypertension was noted; another patient developed post-RFA syndrome. In five of six lesions, there was no residual enhancement of the treated tumor. In one patient CT examination showed areas of residual enhancement of the tumor after treatment. Our preliminary results suggest that imaging-guided percutaneous RFA is effective for local control of AM, without major complications and with a low morbidity rate related to the procedure. Long-term follow-up will need to be performed and appropriate patient selection criteria will need to be determined in future randomized trials.

Hepatic radiofrequency under CT-fluoroscopy guidance.

PURPOSE: This study was done to assess the effectiveness and advantages of computed tomography (CT) fluoroscopy as a guide for locating and treating lesions that are not amenable to ultrasound (US) guidance, and to evaluate the CT signs of immediate technical success and the short-term results. MATERIALS AND METHODS: Over the past year, we selected 14 patients (four women and ten men; mean age 73, range 61-83 years) out of 103 candidates for hepatic radiofrequency ablation (RFA). The 14 lesions comprised seven residual tumours after combined embolisation and US-guided RFA of a large hepatocellular carcinoma (HCC), which were indistinguishable from necrosis or surrounding healthy parenchyma; two HCC nodules in locations that were inaccessible by US; five metastases (two from renal carcinoma, two from colorectal adenocarcinoma and one from lung carcinoma), of which one could not be distinguished from the surrounding healthy parenchyma on US and four were inaccessible by US. Lesion diameters were between 1.4 and 3.5 cm. The procedures were performed in the CT room with anaesthesiological assistance using a coaxial LeVeen needle electrode (14 gauge, 2-to 4-cm array diameter). Immediate technical success was evaluated by multidetector CT (MDCT), and follow-up was carried out with MDCT at 3 and 6 months and yearly thereafter. RESULTS: Immediate technical success was obtained in 13/14 patients; one case required further placement of the electrode due to incomplete ablation of a hypervascular lesion. In 2/3 metastatic lesions with portal vein supply, there were no recurrences at 3 and 6 months; in 1/3, we observed disease progression, with the appearance of additional nodules at 6 months. The two metastases with arterial supply showed no signs of recurrence at 3 months; one case developed a recurrence along the ablation margin, with the appearance of satellite nodules at 6 months. In two HCC nodules, there was immediate technical success and no recurrence at 3 and 6 months. Of the seven residual tumours of HCC, all treated with immediate technical success, we observed disease progression, with the appearance of satellite nodules at 3 months in one case, at 6 months in another and at 12 months in another; 3/7 patients were free of disease at 12-month follow-up; 1/7 died 5 months later due to causes unrelated to the procedure. CONCLUSIONS: CT fluoroscopy is overcoming the limitations of CT in locating and treating lesions with different hepatic vascularisation and those unamenable to US; furthermore, it reduces the length of the procedure, thanks to the faster and more accurate placement of the needle electrode. MDCT proved to be a reliable method in the assessment of immediate and short-term results of RFA.

Fluoroscopically guided retrograde replacement of ureteral stents.

PURPOSE: We assessed the feasibility of fluoroscopically guided transurethral replacement of ureteral stents as an alternative to cystoscopy. MATERIALS AND METHODS: Over the last year, we replaced 27 double-J ureteral stents in 20 patients (10 men and 10 women; mean age 67.7 years, range 43-83); 15/20 patients had a native kidney, 3/20 had a transplanted kidney and 2/20 had a ureteroileal conduit. The procedures were performed in the angiography suite with the patient under sedation. All stents were grasped with a gooseneck snare under fluoroscopic control, and the distal end was withdrawn just outside the urethra; then a wire was advanced through the stent lumen and positioned in the renal pelvis. The stent was then removed and replaced with a new double-J stent. RESULTS: The procedures were successful in 26/27 cases. We observed 7 cases of mild haematuria that resolved spontaneously. During follow-up (1-16 months, mean 6.7), stent obstruction occurred in 4 cases, requiring an additional retrograde replacement. CONCLUSIONS: Transurethral fluoroscopically guided retrograde replacement of dysfunctioning ureteral stents is an effective and safe alternative to cystoscopy.

Endovascular treatment of steno-occlusions of the infrarenal abdominal aorta.

PURPOSE: Our aim is to report our experience in the endovascular treatment of steno-occlusions of the infrarenal abdominal aorta. MATERIALS AND METHODS: We selected 19 patients (mean age 66.3 years, range 45-80): five with complete occlusion of the infrarenal aorta and both common iliac arteries (CIAs), four of which were associated with occlusion of the external iliac arteries (EIAs); three with complete occlusion and three with severe stenosis of the distal aorta with occlusion or stenosis of the CIAs and EIAs; and eight with focal severe stenosis of the infrarenal aorta. All patients were treated with direct stenting. RESULTS: Immediate technical success was 94.7% (18/19 cases). We observed two cases of distal embolism treated with thrombolysis, one case of mild renal failure and one case of transient angina abdominis. During the follow-up (mean 19.6 months; range 6-48), 2/18 (11.1%) occlusions of an iliac stent occurred 1 and 3 months after the procedure (treated with local intra-arterial thrombolysis). The primary patency rate was 88.8% and the secondary patency rate was 100%. CONCLUSIONS: Direct stenting is a feasible and safe option for the treatment of infrarenal abdominal aortic steno-occlusions, especially in patients at high surgical risk, with good early and late clinical results.

Complications of percutaneous nephrostomy in the treatment of malignant ureteral obstructions: single-centre review.

PURPOSE: The purpose of this study was to evaluate the incidence and type of complications connected with percutaneous nephrostomy (PCN) deployment by comparing two different techniques. MATERIALS AND METHODS: In the last 3 years, 299 procedures of nephrostomy were performed on 201 patients (93 women, 108 men; mean age 65.7 years, range 32-102 years) at our Institute; all patients were affected by malignancy. In 44 cases (14.72%), patients presented grade IV hydronephrosis and in 255 cases (85.28%) grade II-III hydronephrosis. In 68 patients (23.07%), the procedure was carried out under emergency conditions because of the rapid worsening of renal function. All procedures were carried out in the angiography room, with the patient lying in a prone or prone-oblique position, under ultrasound and fluoroscopic guidance. Access to the pyelocalyceal system (intermediate or lower calices) was performed by using a Seldinger technique in 255/299 cases, or a one-step technique (OST) in 44 procedures when grade 4 hydronephrosis was present. Statistical analysis of results was performed using bilateral tests on proportions as well as chi2 test of independence for contingency tables. RESULTS: We observed no major complications. All in all, the rate of minor complications was 3.01% (9/299 cases): 8/255 (3.13%) cases with the Seldinger technique; 1/44 (2.27%) with OST. We observed 43/299 (14.4%) dislodgements: 32/255 (10.70%) with the Seldinger technique and 11/44 (3,68%) with OST. In 4/299 (1.33%), rupture of the catheter occurred, and in 2/299 (0.67%), kinking occurred (in all cases with OST). From the statistical analysis, we conclude that the examination technique modifies the percentage of complications; in particular, it significantly (p<0.05) influences complications connected with the catheter but not minor complications. In addition, the system of fixing does not affect the percentage of dislodgements. CONCLUSIONS: PCN is a method with a high percentage of technical success with low rate of complications thanks to combined use of sonographic and fluoroscopic guidance for the procedure. The OST technique is indicated for a highly remarkable hydronephrosis and in cases where the catheter is only placed for a short period. The Seldinger technique is carried out in patients with grades II and III hydronephrosis and if the disease is predicted to have a long duration.