Untreated Stenosis Research Articles

Usefulness of optical coherence tomography with angiographic coregistration in the guidance of coronary stent implantation.

Optical coherence tomography (OCT)-angiography coregistration during stent implantation may be useful to avoid geographical mismatch and incomplete lesion coverage. Untreated lipid-rich plaque at stent edge is associated with subsequent stent edge restenosis. The present study sought to compare the frequency of untreated lipid-rich plaque at the stent edge between OCT-guided percutaneous coronary intervention (PCI) with and without OCT-angiography coregistration. We investigated 398 patients who underwent OCT-guided stent implantation (n = 198 in the coregistration group, and n = 200 in the no coregistration group). In OCT after PCI, untreated lipid-lich plaque was identified by the maximum lipid arc > 180˚ in the 5-mm stent edge segment. The PCI-targeted lesion characteristics and stent length were not different between the coregistration group and the no coregistration group. The frequency of untreated lipid-rich plaque in either proximal or distal stent edge segment was significantly lower in the coregistration group than in the no coregistration group (16% vs. 26%, P = 0.015). The frequency of stent-edge dissection (5% vs. 6%, P = 0.516) and untreated stenosis (2% vs. 3%, P = 0.724) was low and without significant differences between the two groups. In OCT-guided PCI, the use of OCT-angiography coregistration was associated with a reduced frequency of untreated lipid-rich plaque at stent edges. OCT-angiography coregistration has a positive impact on PCI results.

Safety of intermediate left main stenosis revascularization deferral based on fractional flow reserve and intravascular ultrasound: A systematic review and meta-regression including 908 deferred left main stenosis from 12 studies

BackgroundCurrent guidelines recommend intravascular ultrasound (IVUS) or fractional flow reserve (FFR) to decide upon ambiguous left main (LM) disease. However, no study has compared the safety of LM revascularization deferral based on FFR or IVUS. MethodsMEDLINE/PubMed was systematically screened for studies reporting on deferred treatment of angiographically ambiguous LM based upon FFR or IVUS evaluation. Baseline, angiographic and outcome data were appraised and pooled separately for each strategy according to random-effect models with inverse-variance weighting. ResultsA total of 908 LM stenoses from 7 FFR and 5 IVUS studies were included with median follow-up of 29.0 and 31.5 months respectively. Per year of follow-up occurrence of overall MACE were 5.1% in FFR group and 6.4% in IVUS group while death, myocardial infarction, LM revascularization were respectively 2.6%, 1.5% and 1.8% vs. 3.0%, 0.5% and 2.2%. Meta-regression analysis suggested the influence of a distal LM stenosis on MACE in FFR group (β = 0.06, p = 0.01) and age in IVUS group (β = 0.4, p = 0.001). In individual studies several independent predictors of MACE were identified including use of lower doses of intracoronary adenosine (OR 1.39, p = 0.04) in FFR group and plaque burden (OR 1.34, p = 0.025), number of other diseased vessels (OR 1.39, p = 0.04) and any untreated stenosis (OR 3.80; p = 0.037) in IVUS- studies. ConclusionsDeferring LM intermediate stenosis on the basis of FFR or IVUS showed an acceptable and similar risk of events in a mid-term follow-up. Conversely, several different variables related to each technique showed an interaction on outcome.

Abstract 13847: Impact of the Unzipping Technique on Pulmonary Artery Structure and Growth

Introduction: With the unzipping technique, small diameter stents are implanted to relieve pulmonary artery (PA) stenosis, subsequently dilated, fractured and re-stented with large stents dilatable to adult PA diameters. The unzipping technique is utilized in clinical practice with undefined long term results. This study assessed the impact of unzipping on PA structure and growth. Methods: Twelve piglets with left PA (LPA) stenosis underwent the unzipping sequence at 6, 10 and 18 weeks of age and were compared to normal controls and controls with untreated LPA stenosis. 2D and 3D rotational angiography pre/post interventions and PA histology was performed on all animals. Results: Eleven of twelve animals completed the three catheterizations. One stent (4 mm implant diameter) could not be crossed at the second procedure. Following the interventions, the diameter of the unzipped LPA was similar to the proximal LPA of normal controls (14 mm ± 1.2 vs 14.7 mm ± 1, p = 0.19). The diameter of the distal LPA was larger in normal controls, compared to interventions and controls with untreated LPA stenosis (14.6 mm ± 0.9 vs 11.6 mm ± 1.9, vs 10 mm ± 1.2, p < .01). Diameters of six 1 st order LPA branches were similar between normal controls and interventions, and larger than the branch diameters in the stenosis controls. Right PA (RPA) dimensions were larger in controls with untreated stenosis, compared to normal controls and interventions (17.8 mm ± 1.2 vs 16.2 mm ± .9 vs 16 ± 1.7 mm p<0.05). RPA 1 st order branching diameters were similar for normal controls and interventions. RPA 1 st order branch diameters in stenosis controls were larger for 3 of 6 branches compared to normal controls and 1 of 6 compared to interventions. Histologically, the distal LPA displayed uniform fibrointimal proliferation and smooth muscle hypertrophy in pigs with both interventions and untreated stenosis. Focal RPA fibrointimal proliferation was noted in stenosis and intervention animals. Conclusion: PA growth distal to the unzipped segment is partially compromised, yet 1 st order branch diameters are normal and significantly larger, compared to untreated stenosis. Histological vascular abnormalities are noted bilaterally in stenosis animals which do not normalize following the unzipping technique.

Lytic therapy in the treatment of axillary and subclavian vein thrombosis

The importance of individualized treatment of patients with primary and secondary axillary-subclavian vein thrombosis is described with special emphasis on the use of thrombolytic therapy. Nine patients were treated with streptokinase or urokinase. Balloon dilatation of the axillary or subclavian vein and first rib resection were also selectively used. Of the five patients with primary axillary-subclavian thrombosis, three did not have symptoms after the thrombus was lysed. Two had successful lysis of the thrombus but later suffered a rethrombosis, one of which most likely resulted from an untreated stenosis. All four of the patients with secondary thrombosis had successful thrombolysis. Patients with primary axillary-subclavian thrombosis are usually young and as many as 40% continue to have intermittent upper extremity edema or pain. For this reason we believe aggressive attempts to reestablish normal venous return through the axillary and subclavian veins are warranted. Patients with secondary axillary-subclavian thrombosis usually require prolonged venous catheterization for chemotherapy or total parenteral nutrition. Since patency of major upper extremity veins is extremely important in these patients with secondary thrombosis, we believe that vigorous attempts to restore these venous access routes are indicated and appropriate.