Mario Alerci

Effects of Percutaneous Transluminal Angioplasty and Endovascular Brachytherapy on Vascular Remodeling of Human Femoropopliteal Artery by Noninvasive Magnetic Resonance Imaging

Background—Percutaneous transluminal angioplasty (PTA) of severely stenotic peripheral vascular lesions is hampered by a higher restenosis rate. The effects of PTA on vascular wall as well as the effects of the antirestenotic properties of endovascular brachytherapy (EVBT) remain unclear. MRI allows in vivo noninvasive assessment of the vascular effects of such treatment strategies. We sought to elucidate the vascular effect of PTA and PTA+EVBT by serial MRI. Methods and Results—Twenty symptomatic patients with severe stenosis of the femoropopliteal artery were randomly assigned to PTA (n=10) or PTA+EVBT (n=10; 14 Gy by &ggr;-irradiation source) and imaged by high-resolution MRI before and 24 hours and 3 months after intervention. An independent observer blinded to the procedure analyzed the MRI data. At 24 hours, cross-sectional MRI revealed that lumen area (86% and 67%) and total vessel area (47% and 34%) increased similarly in the PTA and PTA+EVBT groups, respectively. All patients showed severe splitting of the atherosclerotic plaque, resulting in an irregularly shaped lumen. At 3 months, MRI revealed a significant difference in lumen area change between the PTA and PTA+EVBT groups (40% and 106%, respectively; P=0.026) and in the total vessel area (14% and 39%, respectively; P=0.018). At 3 months, plaque disruption was still present in 50% of the patients treated with PTA+EVBT. Conclusions—After PTA, there is deep disruption of the atherosclerotic plaques and an extensive remodeling process of the arterial wall. Luminal loss after PTA is partially due to inward vessel remodeling. Brachytherapy prevents inward remodeling and induces an increase in lumen area but partially prevents healing of disrupted vessel surface.

Stenting of a Spontaneous Dissection of the Superior Mesenteric Artery: A New Therapeutic Approach?

Spontaneous dissection of the superior mesenteric artery (SMA) is rare and has been reported only sporadically. Therapeutic options are either a surgical approach, which is the more frequently adopted, or a simple observation. We report a case of spontaneous dissection of the SMA with a review of the literature and present a new therapeutic approach.

Preoperative embolization of collateral side branches: a valid means to reduce type II endoleaks after endovascular AAA repair.

Purpose: To report the results of preprocedural embolization of collateral branches arising from abdominal aortic aneurysms (AAA) scheduled for endovascular repair. Methods: Twenty-three consecutive AAA patients (all men; mean age 73 years, range 56–82) had coil embolization of patent lumbar and inferior mesenteric arteries (IMA) in a staged procedure prior to endovascular repair. Embolization with microcoils was attempted in 37 of the 52 identified lumbar arteries and 14 of 15 inferior mesenteric arteries. Follow-up included biplanar abdominal radiography, spiral computed tomography, and duplex ultrasonography at 1, 30, 90, and 180 days after the stent-graft procedure and at 6-month intervals thereafter. Results: Successful embolization was obtained in 24 (65%) of lumbar arteries, while all 14 (100%) IMAs were occluded with coils. No complication was associated with embolotherapy. Over a mean 17-month follow-up of 22 patients (1 intraoperative death), there was only 1 (4.5%) type II endoleak from a patent lumbar artery, with no sac expansion after 2 years. There were 4 (18%) type I and 1 (4.5%) type III endoleaks. Conclusions: The embolization of side branches arising from an infrarenal aortic aneurysm before endovascular repair is feasible, with a high success rate; this maneuver may play a relevant role in reducing the rate of type II endoleak, improving long-term outcome.

Late acute thrombotic occlusion after endovascular brachytherapy and stenting of femoropopliteal arteries

OBJECTIVES The aim of this article is to underline the importance of this complication after endovascular brachytherapy (EVBT) and intravascular stenting of the femoropopliteal arteries occurring in a running randomized trial. BACKGROUND Endovascular brachytherapy has been proposed as a promising treatment modality to reduce restenosis after angioplasty. However, the phenomenon of late acute thrombotic occlusion (LATO) in patients receiving EVBT after stenting is of major concern. METHODS In an ongoing prospective multicenter trial, patients were randomized to undergo EVBT (iridium 192; 14 Gy at a depth of the radius of the vessel +2 mm) after percutaneous recanalization of femoropopliteal obstructions. Of the 204 patients who completed the six months follow-up, 94 were randomized to EVBT. RESULTS Late acute thrombotic occlusion occurred exclusively in 6 of 22 patients (27%) receiving EVBT after intravascular stenting and always in concomitance with reduction of antithrombotic drug prevention (clopidogrel). Conversely, none of the 13 patients with stents and without EVBT (0%; p < 0.05) and none of the 72 patients (0%; p < 0.01) undergoing EVBT after simple balloon angioplasty presented LATO. CONCLUSIONS Late thrombotic occlusion occurs not only in patients undergoing EVBT after percutaneous coronary recanalization but also after stenting of the femoropopliteal arteries and may compromise the benefits of endovascular radiation. The fact that all our cases with LATO occurred concomitantly with stopping clopidogrel may indicate a possible rebound mechanism. An intensive and prolonged antithrombotic prevention is probably indicated in these patients.

Spiral Computed Tomography A Novel Diagnostic Approach for Investigation of the Extracranial Cerebral Arteries and Its Complementary Role in Duplex Ultrasonography

BACKGROUND For the detection of atherosclerotic lesions of the extracranial cerebral arteries, duplex ultrasonography (US) is an established operator-dependent method, whereas arteriography is associated with the not-insignificant risk of embolic complications. Spiral CT is a promising novel diagnostic tool that allows noninvasive, operator-independent diagnosis of obstruction of extracranial cerebral arteries. The aim of our prospective study was to evaluate in a clinical setting the complementary role of duplex US and spiral CT. METHODS AND RESULTS We compared the results obtained independently by spiral CT and duplex US in 59 consecutive patients with clinical suspicion of an obstructive lesion affecting the carotid arteries. We analyzed a total of 354 segments from the extracranial carotid arteries, including the common, internal, and external carotid arteries. A total of 4 complete occlusions, 38 severe stenoses (70% to 99%), and 32 moderate stenoses (30% to 69%) were concordantly identified by means of duplex US and spiral CT. In 5 cases in which duplex US did not allow sufficient evaluation of the carotid artery because of a poor US window or severe calcification, spiral CT allowed identification and correct measurement of the stenotic lesion. The comparison of the percentage of stenosis with both methods was good (r=0.91, P=0.024). CONCLUSIONS Our results indicate that spiral CT of the extracranial cerebral arteries is a promising noninvasive complementary and non-operator-dependent examination. Its application is particularly attractive in cases in which duplex US is not reliable (ie, severe kinking, severe calcification, short neck, and high bifurcation) and particularly when an overall view of the vascular field is required.

Effects of probucol versus aspirin and versus brachytherapy on restenosis after femoropopliteal angioplasty: the PAB randomized multicenter trial.

Purpose: To evaluate the effect of probucol and/or of endovascular brachytherapy (EVBT) on restenosis after percutaneous transluminal angioplasty (PTA) of femoropopliteal arteries. Methods: A total of 335 patients (206 men; mean age 72±9 years) with intermittent claudication were randomized according to a 2×2 factorial design to 1 of the 4 groups: probucol, placebo, EVBT, and EVBT+probucol. Probucol (1 g/d) or placebo were given in double-blinded fashion 1 month before and for 6 months after PTA. Gamma irradiation (192Iridium, 14 Gy, 5-mm reference depth) was randomly applied in an unblinded manner from a noncentered endoluminal catheter. All patients received aspirin (100 mg/d). Primary endpoint was restenosis (>50% diameter reduction) detected by duplex ultrasound 6 months after PTA. Secondary endpoints included clinical and hemodynamic assessment. Results: Restenosis in patients undergoing EVBT was 17% (23/133) versus 35% (50/142) in patients without EVBT (p<0.001); in patients treated with probucol versus placebo, the rates were 23% (31/135) and 30% (43/140, p<0.001). Three quarters (77%, 102/133) of patients were free of claudication after EVBT therapy versus 61% (87/142) without EVBT (p<0.05). Need for target vessel revascularization was 6% (8/133) with EVBT versus 14% (20/142) without EVBT (p<0.01). Late thrombotic occlusions occurred in 4% (6/133), exclusively in patients treated with EVBT after stent implantation. Conclusions: Endovascular brachytherapy significantly reduces restenosis, improves symptoms, and reduces reinterventions after PTA of femoropopliteal arteries. Probucol reduces restenosis but has no additive effect when combined with brachytherapy.

Telementoring during endovascular treatment of abdominal aortic aneurysms: a prospective study.

Purpose: To explore the use of telementoring for distant teaching and training in endovascular aortic aneurysm repair (EVAR). Methods: According to a prospectively designed study protocol, 48 patients underwent EVAR: the first 12 patients (group A) were treated at a secondary care center by an experienced interventionist, who was training the local team; a further 12 patients (group B) were operated by the local team at their secondary center with telementoring by the experienced operator from an adjacent suite; and the last 24 patients (group C) were operated by the local team with remote telementoring support from the experienced interventionist at a tertiary care center. Telementoring was performed using 3 video sources; images were transmitted using 4 ISDN lines. EVAR was performed using intravascular ultrasound and simultaneous fluoroscopy to obtain road mapping of the abdominal aorta and its branches, as well as for identifying the origins of the renal arteries, assessing the aortic neck, and monitoring the attachment of the stent-graft proximally and distally. Results: Average duration of telementoring was 2.1 hours during the first 12 patients (group B) and 1.2 hours for the remaining 24 patients (group C). There was no difference in procedural duration (127±59 minutes in group A, 120±4 minutes in group B, and 119±39 minutes in group C; p=0.94) or the mean time spent in the ICU (26±15 hours in group A, 22±2 hours in group B, and 22±11 hours for group C; p=0.95). The length of hospital stay (11±4 days in group A, 9±4 days in group B, and 7±1 days in group C; p=0.002) was significantly different only for group C versus A (p=0.002). Only 1 (8.3%) patient (in group A: EVAR performed by the experienced operator) required conversion to open surgery because of iliac artery rupture. This was the only conversion (and the only death) in the entire study group (1/12 in group A versus 0/36 in groups B + C, p=0.31). Conclusions: Telementoring for EVAR is feasible and shows promising results. It may serve as a model for development of similar projects for teaching other invasive procedures in cardiovascular medicine.

Endovascular abdominal aneurysm repair and impact of systematic preoperative embolization of collateral arteries: endoleak analysis and long-term follow-up.

Purpose To report our results of endovascular aneurysm repair (EVAR) over a 10-year period using systematic preoperative collateral artery embolization. Methods From 1999 until 2009, 124 patients (117 men; mean age 70.8 years) with abdominal aortic aneurysm (AAA) underwent embolization of patent lumbar and/or inferior mesenteric arteries prior to elective EVAR procedures. Embolization was systematically attempted and, whenever possible, performed using microcoils and a coaxial technique. Follow-up included computed tomography and/or magnetic resonance imaging and abdominal radiography. Results The technical success for EVAR was 96% (119/124), with 4 patients dying within 30 days (3.2% perioperative mortality) and 1 type III endoleak accounting for the failures. Collateral arteries were occluded spontaneously or by embolization in 60 (48%) of 124 patients. The endoleak rate was 50.9% (74 in 61 patients), most of which were type II (19%). Over a mean clinical follow-up of 60.5±34.1 months (range 1–144), aneurysm sac dimensions decreased in 66 patients, increased in 19 patients, and were stable in 35. The endoleak rate was significantly higher in the patients with increasing sac diameter (p<0.001). Among the patients with patent collateral arteries, 38/64 (59.3%) developed 46 leaks, while 28 leaks appeared in 23 (41%) of 56 patients with collateral artery occlusion (p=0.069). The type II endoleak rate significantly differed between these two groups (47.8% vs. 3.6%, p<0.001). Conclusion Preoperative collateral embolization seems to be a valid method of reducing the incidence of type II endoleak, improving the long-term outcome.

Effect of Percutaneous Transluminal Angioplasty on Severely Stenotic Femoral Lesions In Vivo Demonstration by Noninvasive Magnetic Resonance Imaging

The angiogram of a 68-year-old woman with severe claudication (Rutherford clinical class 3) of the right leg revealed a chronic high-grade preocclusive stenosis of the distal superficial femoral artery, with multiple collateral vessels (Figure 1A). Post-percutaneous transluminal angioplasty (PTA) angiography demonstrated restoration of both lumen and antegrade flow (Figure 1B). Cross-sectional magnetic resonance (MR) imaging performed 24 hours after PTA at the level of the arterial occlusion (Figure 2) revealed severe disruption …

Localized hepatic ischemia after liver resection: a prospective evaluation.

Objective:To prospectively assess the frequency, severity, and extension of localized ischemia in the remaining liver parenchyma after hepatectomy. Background:Major blood loss and postoperative ischemia of the remnant liver are known factors contributing to morbidity after liver surgery. The segmental anatomy of the liver and the techniques of selective hilar or suprahilar clamping of the Glissonian sheaths permit identification of ischemia on the surface of the corresponding segments for precise section of the parenchyma. Incomplete resection of a segment, or compromised blood supply to the remaining liver, may result in ischemia of various extension and severity. Methods:Patients undergoing hepatectomy received enhanced computerized tomodensitometry with study of the arterial and venous phases within 48 hours after resection. We defined hepatic ischemia as reduced or absent contrast enhancement during the venous phase. We classified the severity of ischemia as hypoperfusion, nonperfusion, or necrosis. The extension of ischemia was identified as marginal, partial, or segmental. Factors that may influence postoperative ischemia were analyzed by univariate and multivariate analyses. Results:One hundred fifty consecutive patients (70 F, 80 M, mean age 62 ± 12 years) underwent 64 major and 81 minor hepatectomies and 5 wedge resections. We observed radiologic signs of ischemia in 38 patients (25.3%): 33 hypoperfusions (17 marginal, 12 partial, and 4 segmental), 3 nonperfusions (1 marginal, 1 partial, and 1 segmental), and 2 necroses (1 partial, 1 segmental). One patient with a segmental necrosis underwent an early reoperation. In all other cases, the evolution was spontaneously favorable. Postoperative peak levels of serum aspartate aminotransferase and alanine aminotransferase were significantly higher in patients with ischemia. Patients with ischemia had a significantly higher risk of developing a biliary leak (18.4% vs. 2.6%, P < 0.001). There was no correlation between liver ischemia and mortality (2%). None of the following factors were associated with ischemia after univariate and multivariate analysis: age, preoperative bilirubin level, liver fibrosis, malignant tumor, type of hepatectomy, surface of transection, weight of resected liver, Pringle maneuver, blood loss, and number of transfusions. Conclusions:Some form of localized ischemia after hepatectomy was detected in 1 of 4 of our patients. Its clinical expression was discreet in the large majority of cases, even if it might have been one of the underlying causes of postoperative biliary fistulas. Clinical observation is sufficient to detect the rare patient with suspected postoperative liver ischemia that will require active treatment.