Vinicio Napoli

Endovascular Repair of Abdominal Aortic Aneurysms: Analysis of Aneurysm Volumetric Changes at Mid-Term Follow-Up

PurposeTo evaluate the volumetric changes in abdominal aortic aneurysms (AAA) after endovascular AAA repair (EVAR) in 24 months of follow-up.MethodsWe evaluated the volume modifications in 63 consecutive patients after EVAR. All patients underwent strict duplex ultrasound and computed tomography angiography (CTA) follow-up; when complications were suspected, digital subtraction angiography was also performed. CTA datasets at 1, 6, 12, and 24 months were post-processed through semiautomatic segmentation, to isolate the aneurysmal sac and calculate its volume. Maximum transverse diameters (Dmax) were also obtained in the true axial plane, Presence and type of endoleak (EL) were recorded. A statistical analysis was performed to assess the degree of volume change, correlation with diameter modifications, and significance of the volume increase with respect to ELs.ResultsMean reconstruction time was 7 min. Mean volume reduction rates were 6.5%, 8%, and 9.6% at 6, 12, and 24 months follow-up, respectively. Mean Dmax reduction rates were 4.2%, 6.7%, and 12%; correlation with volumes was poor (r = 0.73–0.81). ELs were found in 19 patients and were more frequent (p = 0.04) in patients with higher preprocedural Dmax, The accuracies of volume changes in predicting ELs ranged between 74.6% and 84.1% and were higher than those of Dmax modifications. The strongest independent predictor of EL was a volume change at 6 months ≤0.3% (p = 0.005), although 6 of 19 (32%) patients with EL showed no significant AAA enlargement, whereas in 6 of 44 (14%) patients without EL the aneurysm enlarged.ConclusionThe lack of volume decrease in the aneurysm of at least 0.3% at 6 months follow-up indicates the need for closer surveillance, and has a higher predictive accuracy for an endoleak than Dmax.

Predictive Factors of In-Stent Restenosis in Renal Artery Stenting: A Retrospective Analysis

PurposeTo retrospectively evaluate the role of clinical and procedural factors in predicting in-stent restenosis in patients with renovascular disease treated by renal artery stenting.MethodsFrom 1995 to 2002, 147 patients underwent renal artery stenting for the treatment of significant ostial atherosclerotic stenosis. Patients underwent strict clinical and color-coded duplex ultrasound follow-up. Ninety-nine patients (111 stents), with over 6 months of continuous follow-up (mean 22±12 months, range 6–60 months), were selected and classified according to the presence (group A, 30 patients, 32 lesions) or absence (group B, 69 patients, 79 lesions) of significant in-stent restenosis. A statistical analysis was performed to identify possible preprocedural and procedural predictors of restenosis considering the following data: sex, age, smoking habit, diabetes mellitus, hypertension, serum creatinine, cholesterol and triglyceride levels, renal artery stenosis grade, and stent type, length and diameter.ResultsComparing group A and B patients (χ2 test), a statistically significant relation was demonstrated between stent diameter and length and restenosis: the risk of in-stent restenosis decreased when the stent was ≥6 mm in diameter and between 15 and 20 mm in length. This finding was confirmed by multiple logistic regression analysis. Stent diameter and length were proved to be significantly related to in-stent restenosis also when evaluating only patients treated by Palmaz stent (71 stents).ConclusionAlthough it is based on a retrospective analysis, the present study confirms the importance of correct stent selection in increasing long-term patency, using stents of at least 6 mm in diameter and with a length of approximately 15–20 mm.

Ultrasonographic Surveillance with Selective CTA after Endovascular Repair of Abdominal Aortic Aneurysm

Purpose: To evaluate the agreement between color-coded duplex ultrasound (US) and computed tomographic angiography (CTA) in monitoring aneurysm diameter and detecting endoleaks after endovascular aneurysm repair (EVAR). Methods: From November 1998 to January 2007, 196 patients (191 men; mean age 72.4 years, range 52–88) underwent EVAR and were followed by CTA and US over a mean 3.9±2.4 years (range 0––8.9, median 3.4). Annual paired CTA and US examinations were reviewed to assess agreement in measuring maximum aneurysm transverse diameter and to evaluate diagnostic accuracy of US in detecting endoleak. Results: The 5-year cumulative endoleak incidence was 43.8% (72 patients). At first diagnosis, US detected 55/72 (76.4%) endoleaks; of the remaining 17, only 3 (4.3%) were clinically significant in terms of aneurysm enlargement. Pairing 709 annual CTA and US examinations from 184 patients showed a high agreement (k=0.96) between examinations in measuring maximum transverse diameter, with a mean difference between US and CTA of −2.5 mm. Conclusion: After the first year of follow-up, EVAR surveillance costs can be reduced by performing annual US examinations only. Keeping in mind that US underestimates diameter measurements, CTA can be reserved for patients with increasing or persistently stable aneurysm diameters.

Renal Artery Stenting in Patients with a Solitary Functioning Kidney

AbstractPurpose: To retrospectively evaluate the results of renal artery stenting in patients with renovascular disease and a solitary functioning kidney. Methods: Palmaz stents were placed in 16 patients with a solitary functioning kidney, renal artery stenosis, hypertension and renal failure. Stenoses were evaluated with color Doppler ultrasound, MR angiography and digital subtraction angiography (DSA). Indications for stenting were: recoil after percutaneous transluminal renal angioplasty (PTRA) (63%), arterial dissection after PTRA (13%) and primary stenting (25%). Immediate results were evaluated by DSA. On follow-up (6-36 months), patients underwent periodical evaluation of clinical conditions (blood pressure and serum creatinine level) and stent patency, by means of color Doppler ultrasound. Results: Stent placement was successful in all patients (100%). Cumulative primary patency rate was: 100% at 1 day, 93.75% at 6 months, 81.25% at 12 months and 75% at 24 months. A significant reduction in diastolic blood pressure occurred (mean ± SD 104 ± 6 vs 92 ± 3; p < 0.05); renal function improved or stabilized in over 80% of patients. However, there was no significant difference in the creatinine values before and after treatment (mean ± SD 200 ± 142 mmol/l vs 197 ± 182 mmol/l; p > 0.05). Conclusion: Renal artery stenting, both after PTRA and as primary stenting, represents a safe procedure, able to preserve renal function in patients with a solitary functioning kidney.

Peripheral ischemic occlusive arterial disease : Comparison of color Doppler sonography and angiography

We examined 334 legs in 167 consecutive patients with advanced peripheral ischemic disease using color Doppler sonography and angiography. Angiography revealed 714 lesions (369 nonsignificant stenoses, 297 significant stenoses, and 48 occlusions) in the 334 legs examined. Overall, color Doppler sonography revealed diagnostic agreement with angiography in 668 of 714 lesions (93.5%), including 343 of 369 (92.9%) nonsignificant stenoses, 279 of 297 (93.9%) significant stenoses, and 46 of 48 (95.8%) occlusions. Overestimation occurred in 26 of 369 (7%) nonsignificant stenoses and 3 of 297 (1%) significant stenoses. Underestimation was observed in 15 of 297 (5%) significant stenoses and in 2 of 48 (4.2%) occlusions. Peak systolic velocity ratio correlated better (P < 0.01) than peak systolic velocity with diameter reduction percentage as assessed at angiography. Color Doppler sonography is an accurate noninvasive method for evaluating patients with peripheral ischemic disease.

Noninvasive assessment of renal artery stenosis: current imaging protocols and future directions in ultrasonography

Doppler ultrasound is one of many modalities that have been evaluated for the detection of renal artery stenosis. The lack of standardization in examination protocols and diagnostic criteria, as well as the wide differences in reported accuracy among different laboratories have, however, prevented universal acceptance of this technique as a reliable screening test for renal artery stenosis. The recent introduction of ultrasound contrast agents has substantially expanded the potential of color Doppler ultrasound. The use of microbubble echoenhancers in combination with harmonic Doppler imaging has been shown to improve diagnostic confidence by improving the operators ability to visualize the renal arteries, and to significantly reduce the number of equivocal examinations. Moreover, contrast-enhanced Doppler ultrasound can provide functional information through analysis of renal time-intensity wash in/wash out curves. State-of-the-art contrast-enhanced Doppler ultrasound seems to have the potential to become a useful screening test for patients at risk from renovascular hypertension.

Thrombosis of Kommerell’s diverticulum with subclavian steal phenomenon in a patient with non-small cell lung carcinoma under chemotherapy

Kommerell’s diverticulum (KD) is defined as a bulbous dilatation of the origin of an aberrant subclavian artery due to a remnant of the left fourth aortic arch. We report the case of an asymptomatic woman in whom progressive thrombosis of the KD extending to the prevertebral tract of an aberrant right subclavian artery was detected at multidetector computed tomography imaging for lung cancer staging performed before and after the beginning of chemotherapy. Reversed blood flow in the ipsilateral vertebral artery due to subclavian steal phenomenon was also observed by color Doppler ultrasound examination.