Giorgio Gimelli

Intravascular ultrasound criteria for the assessment of the functional significance of intermediate coronary artery stenoses and comparison with fractional flow reserve.

The functional significance of coronary artery stenoses of intermediate severity is important in determining strategy in patient care. Intravascular ultrasound (IVUS) is often used to evaluate coronary stenosis severity. However, at present, few data are available about the role IVUS in the assessment of functional significance of intermediate lesions. Myocardial fractional flow reserve (FFR) <0.75 is a reliable index of a functionally severe coronary stenosis. In 53 lesions we assessed (1) by pressure wire: FFR (index of functional significance), and (2) by IVUS: minimal lumen cross-sectional area (MLA, square millimeters), minimal lumen diameter (MLD, millimeters), lesion length (millimeters), and percent area stenosis at the lesion site. By regression analysis, percent area stenosis and lesion length had a significant inverse correlation with FFR (r = -0.58, p <0.001, r = -0.41, p <0.004, respectively). MLD and MLA showed a significant positive relation with FFR (r = 0.51, p <0.001, r = 0.41, p <0.004, respectively). By using a receiver operating characteristic (ROC) curve, we identified a percent area stenosis > 70% (sensitivity 100%, specificity 68%), a MLD < or = 1.8 mm (sensitivity 100%, specificity 66%), a MLA < or =4.0 mm2 (sensitivity 92%, specificity 56%), and a lesion length of >10 mm (sensitivity 41%, specificity 80%) to be the best cut-off values to fit with a FFR <0.75. The combined evaluation of both percent area stenosis and MLD made the IVUS examination more specific (sensitivity 100%, specificity 76%). In 53 intermediate coronary lesions found by angiography, IVUS area stenosis >70%, MLD < or =1.8 mm, MLA < or =4.0 mm2, and lesion length > 10 mm reliably identified functionally critical intermediate coronary stenoses.

Immediate and Long-Term Clinical and Angiographic Results from Wiktor Stent Treatment for True Bifurcation Narrowings

From January 1996 to December 1998, 90 consecutive patients with true bifurcation lesions underwent percutaneous coronary angioplasty with Wiktor stent implantation in our centers. In 1 group (group I, n = 45), a simple approach (main vessel stenting and balloon angioplasty of the side branch) was pursued. In the other group (group II, n = 45), both the main vessel and the side branch were stented (T technique). There was no significant difference in clinical and angiographic characteristics between the 2 groups. Angiographic and procedural successes were 100% and 95.6%, respectively, in both groups. Angiographic results for the side branch were better in group II than in group I. In-hospital and long-term (12 month) major cardiac events were similar in the 2 groups. Target lesion revascularization was 15.5% in group I and 35.5% in group II (p = 0.12). In the main vessel, restenosis rate was 12.5% in group I and 25% in group II (p = 0.15). In the side branch, restenosis rate was 37.5% in group II and 12.5% in group I (p = <0.05; odds ratio 2.42; 95% confidence interval 1.05 to 6.26). Event-free probability at 12 months was 61% in group II and 80% in group I (p = 0.10). When dealing with true bifurcation lesions, a simple strategy is associated with a lower risk of restenosis in the side branch. In contrast, a complex approach does not appear to give any benefit in terms of early or long-term outcome or restenosis rate.

Carotid artery stenting in the first 100 consecutive patients: results and follow up

Background: Carotid artery stenting is now used as an alternative to surgical endarterectomy. The availability of cerebral protection systems has expanded the area of application of this procedure. Objective: To assess the feasibility, safety, and immediate and late clinical outcome in patients undergoing percutaneous carotid interventions. Methods: Between January 1999 and December 2000, 100 consecutive patients with 102 carotid artery stenoses were treated (71 men, 29 women, mean (SD) age 67 (8) years): 49 had coronary artery disease, 28 had previous stroke or transient ischaemic attack (TIA). On the basis of the Mayo Clinic carotid endarterectomy risk scale, 73 patients were grade III–IV and 13 grade VI. Results: Baseline diameter stenosis was 78.8 (10)%, with a mean lesion length of 12.6 (5.8) mm. Angiographic success was obtained in 99 lesions (97.0%) with a final diameter stenosis of 2.4 (3.5)%. Procedural success was obtained in 96 patients (96%). Selective cannulation of three carotid arteries was impossible owing to severe vessel tortuosity. Carotid stenting was performed in 97 of the treated lesions, and protection devices were used in 67 lesions. In-hospital complications occurred in seven patients (six TIA, one (category 1) minor stroke). No major stroke or death occurred. All patients were discharged from the hospital after an average of 2.5 days. At 12 (6.2) months of follow up restenosis occurred in three patients (3.4%) (one patient with carotid occlusion had TIA). Six patients had died: two from cerebrovascular events (5 and 11 months after the procedure) and four from cardiovascular causes. Conclusions: Carotid stenting appears feasible and safe, with few major complications. Long term follow up is affected by a high incidence of cardiovascular mortality.

Arterial interventions in arteriovenous access and chronic kidney disease: a role for interventional nephrologists.

The past decade has witnessed an evolution of the specialty of Nephrology in the United States to an interventional discipline. Traditionally, Interventional Nephrologists have focused on the venous side of an arteriovenous access. However, these specialists are beginning to include arterial disease related to renal patients under the purview of this specialty. Recent data have emphasized that inflow stenosis of an arteriovenous access frequently results in vascular access dysfunction. Peripheral vascular disease, resulting in distal hypoperfusion ischemia syndrome of the hand bearing the access, is similarly being recognized and managed more frequently by these experts. Two distinct entities, subclavian artery and renal artery stenosis, are also being addressed by interventional nephrologists. This article focuses on arterial interventions performed by interventional nephrologists and describes the epidemiology, techniques, and outcomes of arterial intervention as they relate to the care of patients with hemodialysis access and chronic kidney disease.

How I do it: preferential use of the right external jugular vein for tunneled catheter placement.

We describe a case in which the right external jugular vein (REJ) was preferentially used to place a tunneled catheter, even though the left internal jugular vein (LIJ) was widely patent. The possible advantage of placing REJ catheters over LIJ is that doing so may function to preserve better the left‐sided vasculature in general, and, in particular, when future left‐sided access is planned. Contrast venography was required. While REJ is a viable option for catheter insertion, the effect of REJ vs. LIJ catheter placement on long‐term vessel patency as well as catheter function must be more rigorously defined to conclusively establish the superiority of one over the other.

Treatment of an Angio-Seal™-related vascular complication using the SilverHawk™ plaque excision system: A case report

The Angio‐Seal™ is a user‐friendly and safe arterial closure device increasingly used after percutaneous diagnostic and interventional procedures. Although it achieves rapid hemostasis and facilitates early patient mobilization, its use can be associated with vascular complications. A specific problem related to the device is protrusion of the collagen plug into the artery, causing either acute occlusion or symptomatic stenosis. When this occurs, treatment with balloon angioplasty alone is usually suboptimal, while stenting of the common femoral artery may be undesirable. In this report we describe a novel application of the SiverHawk™ plaque excision system to treat a highly eccentric stenosis at the site of a previously deployed Angio‐Seal. Since the device allows preferential cutting in the direction of the lesion and collagen plug debulking, it may be ideally suited to treat this complication without the need for stenting of the common femoral artery.

Chronic Total Occlusion and Successful Drug-Eluting Stent Placement in Takayasu Arteritis–Induced Renal Artery Stenosis

Takayasu arteritis-induced renal artery stenosis (TARAS) is a condition rarely described in the literature. Although percutaneous transluminal angioplasty and stenting has been well-described in the treatment of atherosclerotic renal artery stenosis, its role has not been established in non-atherosclerotic TARAS. We report a case of a female, age 17 years, with Takayasu arteritis who presented to the hospital with seizures and hypertensive crisis. A renal angiogram showed chronic total occlusion (CTO) of the left renal artery. Renal angioplasty and stenting was successfully performed after multiple attempts to deliver a wire distal to the CTO. After sequential balloon predilation, a drug-eluting stent was deployed, resulting in full reperfusion of the kidney. The patient’s blood pressure improved dramatically, and patency of the stent was demonstrated with magnetic resonance angiography over 9 months after the procedure.

Percutaneous closure of a large PDA in a 35-year-old man with elevated pulmonary vascular resistance.

The presence of a large patent ductus arteriosus (PDA) may result in significant pulmonary hypertension, which may not be reversible. We present the case of a 35-year-old man with pulmonary hypertension who had successful percutaneous closure of a large PDA with an Amplatzer muscular ventricular septal defect occluder and resolution of his pulmonary hypertension. The use of prior balloon test occlusion of the PDA suggested that the procedure would be successful, despite the lack of an immediate fall in the pulmonary artery pressure.

ASDIN Original Investigations: How I Do It: Directional Atherectomy for In-Stent Restenosis of a PTFE Arteriovenous Graft

We describe the use of directional atherectomy (DA) to restore patency of a thrombosed polytetrafluoroethylene arteriovenous graft with an in‐stent restenosis at the venous anastomosis. Technically, the procedure described is not an atherectomy per se, but rather the removal of fibrosis and intimal hyperplasia with sharp endoluminal dissection. Certainly, the operator must be cautious when performing DA directly adjacent to a previously deployed stent. Nevertheless, our report suggests that there may be a role for DA in the treatment of severe, resistant in‐stent stenosis. Further investigation is necessary to evaluate the safety and efficacy of the described technique.

How I do it: directional atherectomy for in-stent restenosis of a PTFE arteriovenous graft.

We describe the use of directional atherectomy (DA) to restore patency of a thrombosed polytetrafluoroethylene arteriovenous graft with an in‐stent restenosis at the venous anastomosis. Technically, the procedure described is not an atherectomy per se, but rather the removal of fibrosis and intimal hyperplasia with sharp endoluminal dissection. Certainly, the operator must be cautious when performing DA directly adjacent to a previously deployed stent. Nevertheless, our report suggests that there may be a role for DA in the treatment of severe, resistant in‐stent stenosis. Further investigation is necessary to evaluate the safety and efficacy of the described technique.