Direct comparison of bioabsorbable and biodurable polymer everolimus-eluting stent in neointimal stent coverage and in-stent thrombus using high-resolution angioscope

Background/Introduction

Although second-generation drug eluting stent (DES) employing biodurable polymer drastically shortened the duration of dual antiplatelet therapy (DAPT), previous reports raised concerns that switching from DAPT to single antiplatelet therapy increased rates of subsequent stent thrombosis with time. Third-generation DES employing bioabsorbable polymer has been introduced so as not to hinder the healing process of the vessel wall, however, at present, both DES with bioabsorbable polymer and those with biodurable polymer are used in parallel. It means there is no conclusive evidence regarding pros and cons of these two types of polymers.

Purpose

This study aims to clarify how bioabsorbable polymer and biodurable polymer act on the human coronary artery by observing neointimal stent coverage (NIC) and in-stent thrombus by comparing the third-generation DES with bioabsorbable-polymer cobalt-platinum everolimus-eluting stent (BP CoPt-EES), and the second-generation DES with biodurable-polymer cobalt-chromium everolimus-eluting stent (DP CoCr-EES).

Methods

This is a multicenter observational study including 11 hospitals. We investigated 70 stents (BP CoPt-EES: 40, DP CoCr-EES: 30) of 60 cases, who underwent stent implantation followed by simultaneous observation by coronary angiography, IVUS and angioscopy within 6 to 12 months. For angioscopy, we used a recently available, high-resolution angioscope with a pixel count of 9,000 which realized both stent coverage analysis and planar thrombus detection precisely. Neointimal stent coverage was graded from G0: non coverage to G3: full coverage, and heterogeneity value of neointima was measured as the difference between maximum and minimum NIC grade.

Results

A strong relationship was observed between NIC grade and in-stent thrombus in all stents (p=0.0011), and between the heterogeneity value and stent thrombus (p=0.012). There was no statistical difference in NIC grade between BP CoPt-EES vs. DP CoCr-EES; grade 0: 0 (0.0%) vs. 2 (6.7%), grade 1: 13 (32.5%) vs. 11 (36.7%), grade 2: 6 (15.0%) vs. 6 (20.0%), grade 3: 21 (52.5%) vs. 11 (36.7%), p=0.17) and neither in the heterogeneity value of neointima (p=0.49). The ratio of stent thrombus did not reach statistical difference; 16 (40.0%) in BP CoPt-EES vs. 17 (56.7%) in DP CoCr-EES (p=0.23).

Conclusion

The existence of stent thrombus was associated with the neointimal stent coverage. There was no significant difference both in neointimal stent coverage and stent thrombus between bioabsorbable polymer cobalt-platinum EES and biodurable polymer cobalt-chromium EES after 6 to 12 months following stent deployment.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Boston Scientific JapanOvalis ltd

P4704The efficacy of intravascular ultrasound for patients with peripheral artery diseases presenting aorto-iliac artery disease

Background

The use of intravascular ultrasound (IVUS) promotes better clinical outcomes for intervention in complex lesions. However, the data demonstrating whether use of IVUS improves primary patency following stenting for aorto-iliac lesions in patients with peripheral artery disease (PAD) are limited.

Purpose

The purpose of the current study was to investigate the impact of IVUS use on primary patency 12 months after stent implantation for aorto-iliac lesions.

Methods

We analyzed a clinical database of the OMOTENASHI registry (Observational prospective Multicenter registry study on Outcomes of peripheral arTErial disease patieNts treated by AngioplaSty tHerapy in aortoIliac artery), registering symptomatic PAD patients (Rutherford category 2, 3, or 4) undergoing endovascular therapy for aorto-iliac lesions between January 2014 and April 2016 in Japan. The current study analyzed 803 patients who underwent self-expandable stent implantation at 61 centers with the institutional volume known. The primary endpoint was 12-month restenosis, defined as ≥50% stenosis on computed tomography or angiography, or a peak systolic velocity ratio ≥2.5 on duplex ultrasound. When treatment strategies, endovascular procedures and clinical outcomes were compared between the patients treated with IVUS use and those treated without IVUS use, the propensity score matching was performed to minimize the inter-group difference in baseline characteristics.

Results

A total of 545 patients (67.9%) underwent IVUS-supported stent implantation. Patients treated with IVUS use had a lower prevalence of regular dialysis, whereas they had a higher prevalence of TASC II class D and chronic total occlusion. In patients treated with IVUS use, carbon dioxide contrast agent were more often used, and 0.035-inch guidewire was less frequently selected. Implanted stents in these patients were longer and smaller in diameter. The propensity score matching extracted 138 pairs, with no remarkable intergroup difference in baseline characteristics. Procedure time ≤1 hour was less frequent in patients treated with IVUS use; their radiation time was longer. Endovascular strategies, as well as postoperative medication were not significantly different between patients with and without IVUS use. The 12-month restenosis risk was not significantly different between patients with and without IVUS use (10.2% [6.9 to 14.9%] versus 10.3% [5.4 to 18.6%], P=0.99).

Conclusion

IVUS use in aorto-iliac stenting for patients with PAD was not associated with primary patency at 12 months.

Acknowledgement/Funding

None

Bone-peg grafting for osteochondritis dissecans of the humeral capitellum

PURPOSE

To review the outcome of bone-peg grafting for osteochondritis dissecans (OCD) grade II lesions of the humeral capitellum.

METHODS

Records of 10 male adolescent baseball players aged 10 to 15 (mean, 12.3) years who underwent bone-peg grafting for OCD grade II lesions of the humeral capitellum of the dominant arm were reviewed. The mean time from symptom onset to presentation was 11 (range, 1-36) months. The mean duration of conservative treatment was 5 (range, 1-25) months. The mean time from symptom onset to surgery was 17 (range, 3-39) months; it was >6 months in 6 patients. The mean size of the lesions was 13x14 mm. Patients were assessed for elbow pain, range of elbow and forearm motion, Timmerman- Andrews elbow score, return to sports activity level, and radiographic evidence of healing, osteoarthritic changes, and radial head hypertrophy.

RESULTS

The mean follow-up period was 25 (range, 10-52) months. Postoperatively, elbow pain was absent in 6, mild in 2, and moderate in 2 patients. The mean range of elbow motion changed from 136º to 139° (p=0.80). The mean Timmerman-Andrews elbow score improved from 163 to 189 (p=0.014); it was excellent in 7, good in 2, and fair in one patient. The mean extent of lesion healing was 71% (range, 33-100%). Five patients achieved complete healing after a mean of 5.2 (range, 5-6) months and returned to sports at a competitive level. The other 5 achieved partial healing of 33 to 56% (mean, 41%) that occurred laterally but not medially. Two of them returned to sports at a competitive level: one changed the throwing side and another had radial head hypertrophy. The remaining 3 underwent arthroscopic debridement of the unhealed lesion at 5, 10, and 15 months. One patient developed secondary osteoarthritis and further underwent costal osteochondral autografting 10 months later. None of the 5 patients with partial healing versus 4 of the 5 patients with complete healing underwent surgery within 6 months of symptom onset. All 3 patients with a dot at the interface versus 2 of the 6 patients with a line at the interface between the fragment and the lesion on MRI had complete healing.

CONCLUSION

Bone-peg grafting is a viable option for OCD grade II lesions of the humeral capitellum when performed within 6 months of symptom onset and when the interface between the fragment and the lesion appears as a dot (rather than a line) on MRI.

Radiological features of long bones in synovitis, acne, pustulosis, hyperostosis, osteitis syndrome and their correlation with pathological findings

Abstract The purpose of this study was to demonstrate the radiological features of long bones in synovitis, acne, pustulosis, hyperostosis, osteitis (SAPHO) syndrome and to correlate these with the clinical findings. Eleven long bone lesions in seven cases of SAPHO syndrome were examined. The patients ranged in age from 6 to 63 years, with a mean of 47 years. In all seven cases, radiography, (99m)technetium bone scintigraphy, CT scan, and magnetic resonance imaging (MRI) were performed. In six of the cases, bone biopsy and bone culture were carried out for 7 long bones. Seven of the involved lesions were from the shaft of the femur, one each was from the neck and the shaft of the humerus, and one was from the proximal tibia. These lesions showed radiologically hyperostosis, osteolysis, and bone infarction-like lesion. Osteolysis was occasionally accompanied by sclerotic change. Hyperostosis usually showed diaphyseal involvement, presenting low signal intensity on T1- and T2-weighted MR images. Histologically, these findings corresponded to massive bone necrosis, new bone formation, fibrosis, or a mixture of these associated with mild inflammatory cell infiltration. Osteolysis involved dyaphysis, metaphysis, or epiphysis associated with arthritis, and presented low signal intensity on T1-weighted images, nonhomogeneous signal intensity lower than fat on T2-weighted images, and high signal intensity on fat suppression images. These findings corresponded to fibrosis, granulation, and inflammatory cell infiltration with lymphocyte aggregation. Bone infarction-like lesion was observed in the shaft or neck of the femur and the humerus and accompanied by calcification and cystic change. Bone cultures were negative in all cases in which bone biopsy was performed. Although hyperostosis is thought to be a characteristic bone lesion in SAPHO syndrome, the long bone lesion can occasionally show not only hyperostosis but also osteolytsis and bone infarction-like lesions.