Intravascular brachytherapy: indications and management of adverse events.

Intravascular brachytherapy has become the standard of care for the treatment of coronary in-stent restenosis after repeat angioplasty. More than 5000 patients have been treated as part of various clinical trials. Based on the results of the GAMMA I trial, the START ((90)Sr Treatment of Angiographic Restenosis Trial), and the INHIBIT (INtimal Hyperplasia Inhibition with Beta In-stent restenosis Trial), the Checkmate system using (192)Ir, the Betacath system using (90)Sr/Y, and the Galileo system using (32)P, have been approved for the treatment of in-stent restenosis.

Prevention of restenosis after coronary angioplasty.

Purpose Of Review: Despite numerous advances in coronary interventional techniques, the frequent occurrence of restenosis continues to plague interventional cardiology. With the widespread use of drug-eluting stents, there is a need to reexamine critically the roles of the various interventional techniques currently available.

Recent Findings: Drug-eluting stents have dramatically reduced the rates of restenosis and target vessel revascularization in a wide spectrum of patients with varying lesion morphologies.

New approaches to preventing restenosis.

For over a quarter of a century percutaneous coronary interventions have been used to treat patients with coronary artery disease, yet restenosis continues to be a problem. This review discusses the advances being made to overcome restenosis, particularly the development of drug eluting stents

Five-year clinical and angiographic follow-up after intracoronary iridium-192 radiation therapy.

Background: Ionizing gamma radiation has been shown to reduce neointimal formation and the incidence of restenosis after balloon angioplasty and stenting in clinical trials. However, the long-term effects of this therapy are unknown. The first cohort of patients to receive intracoronary gamma radiation after balloon angioplasty for the prevention of restenosis have completed a 5-year angiographic and clinical follow-up.

Safety and efficacy of manual stepping and overlapping of beta-emitter for diffuse in-stent restenosis lesions.

Background: The effects of overlapping beta-emitter sources on the treatment of in-stent restenosis (ISR) lesions as a result of manual stepping are unknown.

Methods And Results: In the BETA WRIST (Beta Washington Radiation for In-stent Restenosis Trial), 17 out of the 50 patients who received radiation treatment had diffuse ISR in native coronaries that required manual stepping of the beta-emitter (90Y) source in order to cover the lesion and the edges. Fourteen of those patients received radiation with an overlap of up to 3 mm in the middle of the stented segment.

Intramural coronary delivery of advanced antisense oligonucleotides reduces neointimal formation in the porcine stent restenosis model.

Objectives: We evaluated the long-term influence of intramural delivery of advanced c-myc neutrally charged antisense oligonucleotides (Resten-NG) on neointimal hyperplasia after stenting in a pig model.

Background: Neointimal hyperplasia after percutaneous coronary interventions is one of the key components of the restenotic process. The c-myc is a critical cell division cycle protein involved in the formation of neointima.

Clinical outcomes of compromised side branch (stent jail) after coronary stenting with the NIR stent.

Acute side-branch (SB) compromise or occlusion stent jail after native coronary stenting is a matter of concern. Attempts at maintaining SB patency can be a technical challenge. The purpose of this study was to determine the clinical impact of SB compromise or occlusion in patients undergoing stenting of parent vessel lesions.

Decreased adventitial neovascularization after intracoronary irradiation in swine: a time course study.

Background: Intracoronary radiation (IR) suppresses the formation of neointima after arterial injury in swine, through mechanisms incompletely understood. Neointimal development appears related to expansion of adventitial microvessels; we therefore examined the hypothesis that IR inhibits neointima formation through an anti-angiogenic effect.

Methods And Results: Juvenile swine were treated with either 0 or 15 Gy (192)Ir (gamma-source) and euthanized 3, 7, or 14 days later or treated with 18 Gy (90)Y (beta-source) and euthanized after 14 days.

A novel 32P deployable balloon system inhibits formation of neointima in porcine coronary arteries after balloon-overstretching injury.

Background: Intracoronary radiation has shown the potential to reduce formation of neointima in porcine models of restenosis.

Objective: To investigate the feasibility, safety, and efficacy of a new 'deployable-balloon' device with radioisotope 32P integrated into the balloon material.

Methods: Ten swine were subjected to balloon-overstretching injury in 20 coronary arteries and were randomly allocated to receive a radiation dose of 0, 15, or 20Gy prescribed to 1 mm from the surface of the radioactive balloon material.

Delayed re-endothelialization and T-cell infiltration following intracoronary radiation therapy in the porcine model.

Purpose: To evaluate the late induction of apoptosis following intracoronary radiation (IR) and the effects of IR on inflammatory cells.

Methods And Materials: Porcine coronaries were injured by balloon overstretch followed by either 0 or 15 Gy of 192Ir prescribed to 2 mm from the center of the source. Swine were euthanized at 3, 7, and 14 days posttreatment, and arteries were stained for markers of smooth muscle cells (SMCs alpha-actin), T cells (CD3), macrophages, endothelial cells, and apoptotic nuclei (terminal uridine nick end labeling, TUNEL).

Differential remodeling after balloon overstretch injury and either beta- or gamma-intracoronary radiation of porcine coronary arteries.

Background: Restenosis is a consequence of both neointimal hyperplasia and vessel remodeling. Prior studies have shown that intracoronary radiation (IR) prevents neointima accumulation, but its contribution to vessel remodeling is unknown. The purpose of this study was to evaluate the effect of IR on differential vascular remodeling after balloon angioplasty in porcine coronary arteries.

Intracoronary radiation with gamma wire inhibits recurrent in-stent restenosis.

To study the safety and efficacy of intracoronary gamma radiation delivered via a new high-activity (192)Ir source wire for the treatment of in-stent restenosis. In-stent restenosis results from neointimal tissue proliferation especially in its diffused form and presents a therapeutic challenge. Gamma radiation has been shown to decrease neointima formation within stents in animal models and in initial clinical trials.

Edge stenosis and geographical miss following intracoronary gamma radiation therapy for in-stent restenosis.

Objectives: We sought to determine the relationship between geographical miss (GM) and edge restenosis (ERS) following intracoronary radiation therapy.

Background: Edge restenosis may be a limitation of intracoronary irradiation to prevent in-stent restenosis (ISR). Inadequate radiation source coverage of the injured segment (GM) has been proposed as a cause of ERS.

Supplemental oxygen does not synergize with intracoronary radiation for the prevention of restenosis in porcine coronary arteries.

Purpose: Recurrence of obstructive coronary arterial lesions (restenosis) after angioplasty remains a significant clinical problem. Ionizing radiation, at doses >10 Gy administered locally to the angioplasty site, has been shown to inhibit restenosis in porcine coronary arteries, but lower doses are ineffective. Methods that will allow delivery of lower doses of radiation while retaining the antirestenotic efficacy observed at the higher doses are desirable.

Yttrium-90 delivered via a centering catheter and afterloader, given both before and after stent implantation, inhibits neointima formation in porcine coronary arteries.

Background: Intracoronary radiation (IR) studies have shown reduction of neointima formation (NF). Extrapolation of animal studies with beta-radiation to clinical trials have shown variable results, which may be related to dosimetry, centering issues, and/or shielding of beta-rays by the stent metal. We examined the effect of yttrium-90 (90Y), a pure beta-emitter delivered via an automatic afterloader to a centering catheter, on the inhibition of NF in balloon-injured (BI) porcine coronary arteries as well as in arteries receiving 90Y either prior to or following stent implantation (SI).

Autonomic studies in hypertensive patient with unusual sexual dysfunction: response to reserpine.

The authors examined a 48-year-old man with a history of hypertension (6 years) and a history of erection and ejaculation during cold exposure and confrontation with fear (20 years). Exposing the foot to cold water induced ejaculation in 10 seconds. A variety of antihypertensive medications resulted in control of hypertension, without improvement in ejaculatory dysfunction.

Serial volumetric intravascular ultrasound analysis of the efficacy of beta irradiation in preventing recurrent in-stent restenosis.

We compared postintervention and follow-up intravascular ultrasound findings of 25 patients from the beta-Washington Radiation for InStent restenosis Trial (in which all patients received radiation) and 75 patients from the Washington Radiation for InStent restenosis Trial (in which patients were randomized to gamma irradiation). The decrease in lumen volume was similar for beta versus gamma and less in both gamma versus placebo and beta versus placebo; the increase in intimal hyperplasia volume was similar for beta versus gamma and greater in both beta versus placebo and gamma versus placebo.