Alvaro Zaccaria

Contrast-Enhanced Ultrasound Imaging for Aortic Stent-Graft Surveillance

Purpose: To compare unenhanced and enhanced ultrasound imaging to computed tomographic angiography (CTA) or magnetic resonance angiography (MRA) for surveillance of aortic endografts. Methods: Thirty consecutive patients (29 men; mean age 69 years, range 50–82) who underwent endovascular aortic aneurysm repair agreed to participate in a follow-up program. Patients underwent CTA (26/30) or MRA (4/30), plain abdominal radiography, and unenhanced and enhanced ultrasound examinations at 3, 12, and 24 months to evaluate aneurysm diameter, endoleaks, and graft patency. The accuracy of ultrasound was compared with CTA or MRA as the reference standards. Results: Twenty-six patients reached the 24-month assessment (mean follow-up 30 months, range 6–60). All endoleaks detected by CTA or MRA were confirmed by enhanced ultrasound; the aneurysm diameter in these patients remained unchanged or increased. In patients without endoleaks on any imaging method, the sac diameter remained unchanged or decreased. Endoleaks disclosed by enhanced ultrasound alone, all type II, numbered 16 at 3 months, 6 at 12 months, and 3 at 24 months. In this group, the aneurysm diameter remained unchanged or increased. Enhanced ultrasound yielded 100% sensitivity in detecting endoleaks, but compared with CTA and MRA, all endoleaks detected by enhanced ultrasound alone were false positives (mean specificity 65%). Nevertheless, because changes in the postoperative aneurysm diameter were similar in patients with endoleaks detectable on CTA/MRA and on enhanced ultrasound (“true positives”) and in those with endoleaks detectable only on enhanced ultrasound (“false positives”), some endoleaks were possibly “true positive” results. Conclusions: Enhanced ultrasound is a useful method in the long-term surveillance of endovascular aortic aneurysm repairs, possibly in association with CTA or MRA. Enhanced ultrasound also seems able to identify endoleaks missed by other imaging techniques, but this conclusion awaits further investigation.

Atherosclerotic ischemic renal disease. Diagnosis and prevalence in an hypertensive and/or uremic elderly population

BackgroundAtherosclerotic ischemic renal disease is a frequent cause of end-stage renal failure leading to dialysis among the elderly; Its prevalence is inferred from autopsy or retrospective arteriographic studies. This study has been conducted on 269 subjects over 50 with hypertension and/or CRF, unrelated to other known causes of renal disease.MethodsAll 269 patients were studied either by color-flow duplex sonography (n = 238) or by renal scintigraphy (n = 224), and 199 of the 269 patients were evaluated using both of these techniques. 40 patients, found to have renal artery stenosis (RAS), were subjected to 3D-contrast enhancement Magnetic Resonance Angiography (MRA) and/or Selective Angiography (SA). An additional 23 cases, negative both to scintigraphy and to ultrasound study, underwent renal angiography (MRA and/or SA).ResultsColor-duplex sonography, carried out in 238 patients, revealed 49 cases of RAS. MR or SA was carried out in 35 of these 49 patients, and confirmed the diagnosis in 33. Color-duplex sonography showed a PPV value of 94.3% and NPV of 87.0% while renal scintigraphy, carried out in 224 patients, had a PPV of 72.2% and a NPV of 29.4%. Patients with RAS showed a higher degree of renal insufficiency compared to non stenotic patients while there were no differences in proteinuria. RAS, based on color-duplex sonography studies, was present in 11% of patients in the age group 50–59, 18% in the 60–69 and 23% at age 70 and above.ConclusionsA relatively large percentage of the elderly population with renal insufficiency and/or hypertension is affected by RAS and is at risk of developing end-stage renal failure. Color-duplex ultrasonography is a valid routine method of investigation of population at risk for renal artery stenosis.

Atherosclerotic renal artery stenosis: one year outcome of total and separate kidney function following stenting.

BackgroundRenal artery stenosis (RAS) is a known cause of hypertension and ischemic nephropathy. Stenting of the artery is a valid approach, in spite of cases of unexpected adverse evolution of renal function.MethodsIn this study, 27 patients with unilateral RAS were subjected to stenting and followed for a period of one year, while 19 patients were observed while on medical treatment only. The group of 27 patients, 67.33 ± 6.8 years of age, creatinine of 2.15 ± 0.9 mg/dl, following stenting, were followed at intervals with biochemical tests, renal scintigraphy and doppler ultrasonography. The control group (70.0 ± 6.1 years, creatinine 1.99 ± 0.7 mg/dl) was also followed for one year.ResultOne year after stenting mean creatinine clearance (Ccr) increased from 36.07 ± 17.2 to 40.4 ± 21.6 ml/min (NS). Arterial BP, decreased after 1,3,6, and 12 months (p < 0.05). The number of antihypertensive drugs also decreased (p < 0.05). A significant increase in proteinuria was also observed. In the control group both Ccr, BP and proteinuria did not show significant changes. Based on renal scintigraphy and Ccr at subsequent times, it was possibile to evaluate the timecourse of renal function in both kidneys of the stented patients. In the stented kidneys Ccr increased significantly. On the controlateral kidney a decrease of renal function (p < 0.05) was observed. Resistance index appeared to be a risk factor of the functional outcome.ConclusionsStenting of RAS due to atherosclerosis is followed by stabilization or improvement of Ccr, mainly at the stented kidney, while contralateral renal function showed a decrease.

Revascularization versus medical therapy for renal artery stenosis: antihypertensive drugs and renal outcome.

Endovascular procedures may play a role in renal artery stenosis (RAS) treatment in attempt to preserve renal function and improve hypertension control. We determined renal outcome and the incidence of restenosis in patients with RAS treated with renal percutaneous transluminal angioplasty and stenting (RPTAs) and medical therapy versus patients with RAS treated only with medical therapy. We performed an observational study based on 93 patients with RAS. In all, 53 patients underwent RPTAs in association with medical therapy and 40 patients were only treated pharmacologically. In patients receiving RPTAs, a better renal outcome, a decrease of restenosis rate, and systolic—diastolic blood pressure were associated with angiotensin receptor blockers (ARBs) + angiotensin-converting enzyme inhibitors (ACE-is) therapy. In patients treated with medical therapy alone, renal improvement was related to ARBs in association with BBs (β-blockers; P < .0001). This study suggests that medical therapy may exert beneficial effects in patients with RAS.

Minor asymptomatic carotid stenosis contralateral to carotid endarterectomy (CEA): Our experience

The authors report their experience from 1985 to 1988 with 75 consecutive patients affected by bilateral carotid artery stenosis in whom only one side was surgically treated and the other had a minor (15-45%) asymptomatic carotid stenosis. These patients have been followed for a period ranging from 10 to 50 months (mean follow-up 21 months) by clinical examinations and non-invasive investigations (Doppler CW, Duplex scanner). The non-invasive evaluation included assessment of haemodynamic data and characterisation of plaque morphology (regular vs. irregular or ulcerated surface, homogeneous vs. heterogeneous plaque). During follow-up eight patients died: two (2.6%) from acute myocardial infarction, four from stroke (5.3%), and two (2.6%) from other causes. Twenty-five patients (33.3%) had neurological symptoms related to the unoperated side: and four suffered stroke (5.3%). Twenty-one patients had TIAs (28%) related to the observed side. During follow-up five out of 29 (17.2%) homogeneous and 20 out of 46 (43.4%) heterogeneous plaques progressed (p less than 0.01). With regard to the surface characteristics, nine out of 25 regular plaques progressed and only three patients (12%) had neurological events; 19 out of 34 (55.9%) irregular plaques showed a progression and 14 caused neurological symptoms. Fourteen ulcerated plaques (87.5%) progressed (p less than 0.01). Our experience suggests that the basic trend in the follow-up of patients with bilateral carotid artery disease, is that the contralateral unoperated lesion may evolve and become symptomatic. These symptoms are generally TIAs but five patients (4.3%) suffered from strokes related to the unoperated side, all without warning TIAs.

True posterior tibial artery aneurysm in a young patient: surgical or endovascular treatment?

Aneurysms of tibial arteries are extremely rare. Here we report a case of a true posterior tibial artery aneurysm in a young patient without any associated pathology and discuss surgical and endovascular treatment. A young Caucasian male was admitted to our department for painful and pulsatile swelling of the right calf. Colour Doppler ultrasound scan visualised an aneurysmal dilation of the posterior tibial artery. The patient had no trauma to the area and denied other history of vascular disease. Angio-CT and angio-magnetic resonance imaging showed a larger aneurysm compared to ultrasound scan. We performed an embolisation of the aneurysm because of the risk of rupture, as distal collateral circulation ensured foot vascularisation. Endovascular treatment of aneurysms of small arteries seems to be a safe therapeutic and non-invasive choice, particularly in young patients in whom the presence of collaterals guarantees distal vascularisation.

In-Stent Restenosis of the Renal Artery in a Single Kidney Patient: The Role of ACEI in the Therapeutic Choice

Renal artery stenosis (RAS) caused by atherosclerotic changes of the renal arteries has become a concern as a cause of end-stage renal failure. Percutaneous balloon angioplasty with or without endovascular stenting is an increasingly accepted procedure at the expense of classical approaches such as aortorenal bypass and other types of surgery. Renal percutaneous transluminal angioplasty and stenting (RPTAS) represent the first therapeutic choice; however, there is doubt regarding the satisfactory long-term outcome for primary RPTAS. Currently, there is no clear evidence whether or not RPTAS prevents further progressive renal function decline because comparisons between interventional randomized studies and medical therapy are still lacking. Despite the fact that the use of angiotensin-converting enzyme inhibitors (ACEIs) may be a potential cause of acute renal failure, clinical data suggest that ACEI therapy is associated with better survival in patient with RAS. In our case, the use of ACEIs has been fundamental for the indirect evaluation of restenosis degree and RPTAS.

Multiple steno-obstructive vascular lesions and femoral superficial artery dissection in a young Caucasian male with antiphospholipid syndrome

A young Caucasian male was admitted for claudication intermittens, hyposphygmia on the right lower limb, high blood pressure and deterioration of renal function. Instrumental investigations documented right renal artery stenosis, multiple steno-obstructive manifestations of the splanchnic artery system, occlusion of the right external iliac artery and dissection of the left superficial femoral artery. The patient had not been previously diagnosed with antiphospholipid syndrome. Subsequently, the vascular lesions, because of his thrombophilic state, needed endovascular treatment and anticoagulant therapy.

Color Doppler Ultrasound Guidance during Renal Angioplasty and Stenting

PURPOSE To investigate whether an imaging technique combining color Doppler ultrasonography and selective renal artery digital subtraction angiography reduces contrast requirements in patients with progressive renal insufficiency undergoing renal artery angioplasty and stenting. METHODS Eight patients (5 men; mean age 58 years) with renal artery stenosis and renal insufficiency underwent percutaneous transluminal angioplasty and stenting under color Doppler ultrasound guidance. RESULTS Color Doppler ultrasound imaging yielded the information necessary for verifying catheter position, stent placement and expansion, and hemodynamics after revascularization. The combined imaging technique considerably reduced contrast requirements to only 10 mL in each case. No worsening of renal function was seen in any patient. CONCLUSIONS The combined imaging procedure uses low doses of contrast agent and is especially suited to patients with renal dysfunction undergoing percutaneous renal revascularization.

Management of diseases of the renal, celiac and mesenteric arteries

Renovascular occlusive disease has two important clinical manifestations: renovascular hypertension, i.e. hypertension caused by renal artery disease, which can potentially be cured or improved with renal revascularization or nephrectomy; and renovascular renal insufficiency which can be defined as a renal insufficiency caused by a reduction of renal blood flow.