Intra-Arterial Injection of Temporary Embolic Material Through a Needle Inserted into the Radial or Ulnar Artery for Distal and Proximal Interphalangeal Joint Osteoarthritis: A Retrospective Study of 92 Patients.

PURPOSE: To assess the efficacy and safety of intra-arterial injection of imipenem/cilastatin sodium (IPM/CS) via a needle placed into the radial artery or ulnar artery (RA/UA) for distal interphalangeal and proximal interphalangeal joint osteoarthritis (DIP/PIP-OA). MATERIALS AND METHODS: This is a retrospective single-arm cohort study. Ninety-two patients [92% women, mean (SD) age 55(8.3) years] with a primary DIP/PIP-OA meet the American College of Rheumatology criteria for hand osteoarthritis with pain ≥ 4 on the 0-10 numeric rating scale (NRS) were enrolled. All procedures were performed by injecting IPM/CS through a 24-gauge needle percutaneously inserted into the RA/UA. Two procedures were planned; the second procedure was scheduled 1-2 months after the first. NRS, Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH) score, Patient Global Impression of Change (PGIC) scale, and procedure-related adverse events were evaluated. RESULTS: Technical success, defined as injection of IPM/CS into the RA/UA, was achieved in all patients. Clinical success, defined as a reduction of 2 points or more in the NRS at 12 months, was 77% (95% confidence interval 68-85%). The NRS improved from the baseline to 3, 6, and 12 months (7.8 ± 1.6 vs. 3.8 ± 2.6, 3.9 ± 2.7, and 4.0 ± 2.8, respectively, all p < 0.001). The QuickDASH score improved from the baseline to 12 months (27 ± 15 vs. 19 ± 17, p < 0.001) respectively. No major adverse events were observed. CONCLUSIONS: Intra-arterial injection of IPM/CS is a feasible treatment option for DIP/PIP-OA.

Two-year outcomes comparing Embosphere® microspheres versus Imipenem Cilastatin for genicular artery embolization in patients with moderate to severe knee osteoarthritis.

BACKGROUND: Genicular artery embolization (GAE) is a novel technique and has the potential to provide midterm relief of pain for patients with mild-to-moderate knee osteoarthritis resistant to conservative management. This study compares the efficacy and safety of trisacryl gelatin microspheres to Imipenem/Cilastatin particles for GAE with 2 years of clinical follow-up. METHODS: In this retrospective study, eight patients with knee osteoarthritis (11 knees) who underwent GAE with 100-300 µm trisacryl gelatin microspheres particles were compared with six patients (nine knees) who underwent GAE with Imipenem/Cilastatin particles. Clinical outcomes were evaluated at 3-month and 24-month follow-ups and compared to baseline using the WOMAC questionnaire. RESULTS: The median follow-up was 796 days (range: 736-808). There were no significant differences in clinical outcome measures at the 3-month or 24-month follow-up. Both embolic materials resulted in a decrease in Pain WOMAC and Total WOMAC scores at 3 months (p < 0.05), and the effect of treatment on Pain WOMAC and Total WOMAC score reduction was sustained until the 24-month follow-up (p < 0.05). Minor events (Clavien-Dindo classification grade I) included transient cutaneous color change (n = 3) and transient leg numbness (n = 1) after embolization with trisacryl gelatin microspheres particles (p = 0.08). All minor adverse events resolved spontaneously. There were no major adverse events. CONCLUSION: One hundred to three hundred µm trisacryl gelatin microspheres particles can be considered for genicular artery embolization and is comparable to Imipenem/Cilastatin particles in pain reduction of moderate to severe knee osteoarthritis. A sustained effect is observed for up to 2 years of follow-up.

Transcatheter arterial embolization of abnormal neovessels in a swine model of knee arthritis.

BACKGROUND: In recent years, transcatheter arterial embolization (TAE) using imipenem/cilastatin (IPM/CS) has attracted attention as a treatment for relieving osteoarthritis (OA) pain. However, IPM/CS is not approved by Japanese medical insurance for use as an embolic material. Therefore, it is necessary to develop new embolic materials for TAE to relieve OA pain. The purpose of this study was to develop a swine model of knee arthritis and embolize abnormal neovessels (ANs) using two different embolic materials. We compared the embolic effects and tissue damage in knees. METHODS: Knee arthritis was induced by intra-articular injection of papain into 12 knees in six female swine. The swine were divided into two groups of three swine each (six knees per group) for embolization of ANs in the knees with either IPM/CS or soluble gelatin sponge particles (SGSs). Three days after embolization, we compared the embolic effects using angiography and the tissue damage histopathologically. RESULTS: ANs were observed in all 12 knees at 42 days after papain injection. The ANs disappeared and the patent arteries were recanalized 3 days after TAE in all 12 knees. Histopathological evaluation revealed synovitis changes, such as synovial thickening and inflammatory cell infiltration, in all 12 knees. There was no evidence of skin or muscle necrosis in either group. The appearance of ANs, recanalization of the parent arteries, and histopathological outcomes were not significantly different between the two groups. CONCLUSION: SGSs were as safe as IPM/CS for TAE of ANs in this swine model of knee arthritis.

Transcatheter Arterial Embolization Using Imipenem/Cilastatin Sodium for Chronic Low Back Pain Resistant to Conservative Treatment: A Pilot Study with 2-Year Follow-Up.

PURPOSE: To evaluate the safety and 2-year follow-up clinical outcomes of transcatheter arterial embolization (TAE) using imipenem/cilastatin sodium for chronic low back pain resistant to conservative treatment. MATERIALS AND METHODS: A retrospective review identified 14 patients who underwent TAE for chronic low back pain between October 2017 and August 2018. Patients with low back pain related to the facet or sacroiliac joint, lasting ≥ 6 months, refractory to ≥ 3 months of conservative treatment were eligible for TAE. Each patient received embolization of feeding arteries of painful regions. The changes in brief pain inventory (BPI) scores, adverse events, and the Oswestry Disability Index (ODI) were evaluated at baseline and 1, 3, and 24 months after TAE. Clinical success was defined as BPI maximum pain intensity decrease of ≥ 2 and ODI decrease of ≥ 10 points from baseline. RESULTS: Follow-up data were available in 13 and 11 patients, at 3 and 24 months after embolization, respectively. Intention-to-treat clinical success was obtained in 11/14 (79%) of patients at 3 months and 8/14 (57%) of patients at 24 months after TAE. Mean BPI maximum pain intensity and ODI scores decreased significantly from baseline to 1, 3, and 24 months after treatment (7.6 vs.. 4.3, 3.4, and 4.1; 40.8 vs 21.5, 20.0, and 23.8, respectively; all P < 0.01). No major adverse events were associated with the procedures. CONCLUSION: TAE is one possible treatment option for patients with chronic low back pain refractory to conservative treatment.

Intra-arterial Infusion of Temporary Embolic Material in a Patient with Plantar Fasciitis: A Case Report.

This case report concerns a 51-year-old woman with a 6-month history of severe right heel pain diagnosed as plantar fasciitis (PF) treated with intra-arterial infusion of imipenem/cilastatin (IPM/CS) through a 24G indwelling needle directly inserted into the posterior tibial artery (PTA). Angiography of the indwelling needle immediately before the infusion of IPM/CS demonstrated an increased number of abnormal vessels at the calcaneal attachment of the plantar fascia. Two procedures were planned: The first procedure was performed, and the second was performed 1 month after the first. A week after the first treatment, her pain gradually decreased. Three months after the first treatment, she no longer had difficulties with activities of daily living. Intra-arterial infusion of IPM/CS directly through an indwelling needle into the PTA represents a minimally invasive embolic treatment option for PF.

Mechanisms of gradual pressure drop in angiographically normal left anterior descending and right coronary artery: Insights from wave intensity analysis.

BACKGROUND: This study evaluated the mechanism of decline in coronary pressure from the proximal to the distal part of the coronary arteries in the left anterior descending (LAD) versus the right coronary artery (RCA) from the insight of coronary hemodynamics using wave intensity analysis (WIA). METHODS: Twelve patients with angiographically normal LAD and RCA were prospectively enrolled. Distal coronary pressure, mean aortic pressure, and average peak velocity were measured at 4 different positions: 9, 6, 3, and 0 cm distal from each coronary ostium. RESULTS: The distal-to-proximal coronary pressure ratio during maximum hyperemia gradually decreased in proportion to the distance from the ostium (0.92±0.03 and 0.98±0.03 at 9 cm distal to the LAD and RCA ostium). WIA showed the dominant forward-traveling compression wave gradually decreased and the backward-traveling suction wave gradually decreased in proportion to the decrease in coronary pressure through the length of the non-diseased LAD but not the RCA. CONCLUSIONS: The pushing wave and suction wave intensities on WIA were diminished in proportion to the distance from the ostium of the LAD despite the wave intensity not changing across the length of the RCA, which may lead to gradual intracoronary pressure drop in the angiographically normal LAD.

Effects of Transcatheter Arterial Microembolization on Persistent Trapezius Myalgia Refractory to Conservative Treatment.

PURPOSE: To evaluate the safety and efficacy of transcatheter arterial microembolization for patients with trapezius myalgia. MATERIALS AND METHODS: We retrospectively evaluated the prospectively collected data of patients with trapezius myalgia for > 6 months who were refractory to conservative treatment and were treated by transcatheter arterial microembolization between October 2017 and January 2019. Transcatheter arterial microembolization was performed using imipenem/cilastatin on the vessels of the transverse cervical artery, suprascapular artery, and circumflex scapular artery according to the region of pain. RESULTS: Forty-two patients were treated by transcatheter arterial microembolization and followed up for 6 months. No major adverse events occurred related to the procedures. The brief pain inventory worst pain scores significantly improved at 1, 2, 3, and 6 months after transcatheter arterial microembolization (8.6 ± 1.3 (before procedure) vs. 5.1 ± 2.9, 4.4 ± 2.9, 4.1 ± 2.8, and 3.9 ± 2.9, respectively, P < 0.001). The brief pain inventory pain interference scores, including general activity, mood, walking ability, normal work, relations with others, sleep, and enjoyment of life, also significantly decreased at 1, 2, 3, and 6 months after transcatheter arterial microembolization compared to those at baseline (all P < 0.01). The clinical success rate at 6 months after transcatheter arterial microembolization was 71.4% (95% confidence interval, 55.4-84.3%). CONCLUSION: Transcatheter arterial microembolization is a safe and effective treatment for persistent trapezius myalgia. Further evaluation with a control group is needed to confirm the effects of transcatheter arterial microembolization. LEVEL OF EVIDENCE: Level 4, Case Series.

Randomized phase II trial of adjuvant chemotherapy with docetaxel plus cisplatin versus paclitaxel plus carboplatin in patients with completely resected non-small cell lung cancer: TORG 0503.

OBJECTIVE: Adjuvant chemotherapy is standard of care for patients with completely resected stage IB, II and IIIA NSCLC. However, optimum chemotherapy regimen has not been determined. TORG0503 was undertaken to select a preferred platinum-based 3rd generation regimen in this clinical setting. MATERIALS AND METHODS: Patients with completely resected stage IB, IIA, IIB or stage IIIA NSCLC were stratified by stage (IB/IIA vs. IIB/IIIA) and institutions, and randomized to receive 3 cycles of docetaxel (60 mg/m2) plus cisplatin (80 mg/m2) (arm A) or paclitaxel (200 mg/m2) plus carboplatin (AUC 6) (arm B) on day 1, every 3 weeks. The primary endpoint of the study was 2-year relapse free survival, and the key secondary endpoints included overall survival, feasibility and toxicity. RESULTS: 111 patients were randomized, 58 patients to arm A and 53 to arm B. Patient demographics were balanced between the two arms. 93 % (54/58) of patients on the arm A and 92 % (49/53) patients on the arm B completed the planned 3 cycles of chemotherapy. There was no treatment-related death in both arms. The 2 and 5 year relapse free survival was 74.5 % (95 %CI: 68.6-80.4) and 61.6 % in the arm A, and 72.0 % (95 %CI: 65.7-78.3) and 46.0 % in the arm B. The overall 2, 5-year survival was 89.7 %, 73.9 % in the arm A and 86.9 %, 67.5 % in the arm B. CONCLUSION: Both docetaxel plus cisplatin and paclitaxel plus carboplatin are safe and feasible regimens as adjuvant chemotherapy. We choose docetaxel plus cisplatin as the control regimen for the next clinical trial.

Distribution of pressure gradients along the left anterior descending artery in patients with angiographically normal arteries.

OBJECTIVES: This study tested the hypothesis that there is no decline of coronary pressure from the proximal to the distal left anterior descending coronary artery (LAD) of humans and swine. BACKGROUND: In the daily clinical practice, the fractional flow reserve (FFR) in the LAD is frequently lower than that in the other arteries in the presence of a similar degree of stenosis. METHODS: Twenty-six patients with angiographically normal LAD were prospectively enrolled. The coronary pressure ratio (mean distal/proximal coronary pressures at hyperemia) was measured at five different positions: 12, 10, 7, and 5 cm distal from the LAD ostium, and at the ostium of the LAD. The coronary pressure measurement was further investigated in a swine model without atherosclerosis. RESULTS: The coronary pressure ratio during maximum hyperemia gradually decreased in proportion to the distance from the ostium (average: 0.85 ± 0.06 at 12 cm distal to the ostium). This finding was confirmed in swine model. The degree of the coronary pressure decrease during maximum hyperemia was similar in patients with and without evidence of minor plaque on intravascular ultrasound, however it was strongly associated with the amount of myocardium mass in the territory of the LAD. CONCLUSIONS: Intracoronary pressure gradually decreases in proportion to the distance from the ostium in the LAD of humans and swine, regardless of the presence of minor atherosclerotic plaques. The degradation degree of the coronary pressure ratio during maximum hyperemia is enlarged in the presence of larger amount of myocardium mass in the territory of the LAD.

Multicenter study of zoledronic acid administration in non-small-cell lung cancer patients with bone metastasis: Thoracic Oncology Research Group (TORG) 1017.

Skeletal-related events (SREs) may occur at the time of first diagnosis in 20-30% of lung cancer patients with bone metastases. Several clinical trials have shown that zoledronic acid (ZA) is effective for decreasing SREs. The main objective of the present study was to discuss clinical data of ZA and compare the frequency of SREs with previous reports. All patients with non-small-cell lung cancer (NSCLC) with metastatic bone disease who were administered ZA at least twice between January 2008 and December 2009 were eligible for inclusion in the study. In total, 198 consecutive patients were identified. The median duration of ZA administration was 106 days [95% confidence interval (CI), 92-133 days], and the median number of ZA administrations was 4 (range, 2-41). The median time to first SRE in patients who experienced SRE following ZA treatment was 202 days (95% CI, 156-264 days). Among the 78 patients who had already experienced SRE prior to ZA treatment, 35 (45%) experienced SRE subsequently after starting ZA treatment. On the other hand, among the 120 patients without a history of SRE before starting ZA treatment, 42 (35%) experienced SRE after the start of ZA administration (P=0.16). No osteonecrosis of the jaw (ONJ) was reported in any of the patients. The present study revealed that ZA had a certain level of efficacy regardless of the presence or absence of prior SREs. However, the duration of ZA therapy was short in this study; further accumulation of data on the long-term prognosis and incidence rates of ONJ and other late complications of ZA therapy seems to be particularly important.

Impact of low tissue backscattering by optical coherence tomography on endothelial function after drug-eluting stent implantation.

This study evaluated the impact of optical coherence tomography (OCT)-derived low-backscattered tissue on mid-term coronary endothelial function after drug-eluting stent (DES) implantation. Although OCT enables detailed in vivo evaluation of neointimal tissue characterization after DES implantation, its association with physiological vascular healing response is unclear. Thirty-three stable angina pectoris patients underwent OCT examination and endothelial function testing with intracoronary infusion of incremental doses of acetylcholine 8-month after DES implantation in a single lesion of the left anterior descending artery. Neointimal tissue was classified into two patterns based on the predominant OCT light backscatter: high backscatter and low backscatter. Although the presence of uncovered or malapposed stent strut was not associated with the degree of vasoconstriction, the degree of vasoconstriction was significantly greater in the DES with low-backscattered neointima than in the DES without low-backscattered neointima (- 32.1 ± 25.7 vs. - 4.1 ± 20.1%, p = 0.003). Moreover, there was an inverse linear relationship between low backscatter tissue index and degree of vasoconstriction after acetylcholine infusion (r = 0.50 and p = 0.003). The endothelium-dependent vasomotor response after 8-month of DES was impaired in patients with low neointimal tissue backscatter on OCT imaging. OCT assessment of low-backscattered tissue may be used as surrogate markers for impairment of endothelial function after DES.

Effect of Transcatheter Arterial Microembolization on Phantom Limb Pain Persisting for 17 Years.

Phantom limb pain is a frequent consequence of the amputation; currently available treatments are far from satisfactory. The present report describes a case in which transcatheter arterial microembolization had a remarkable curative effect on phantom limb pain persisting for 17 years. The patient began feeling phantom limb sensations and brief intermittent pain following lower limb amputation above the knee in 2001. The frequency, intensity, and duration of the pain increased over time, and it was resistant to conservative treatments. Following transcatheter arterial microembolization in 2018, patient immediately experienced marked improvement. The pain has been infrequent, much less intense, and did not interfere with daily life 6 months posttreatment. Transcatheter arterial microembolization could be an alternative treatment option for phantom limb pain. LEVEL OF EVIDENCE: IV, Case Report.

Atherosclerotic Component of the Yellow Segment After Drug-Eluting Stent Implantation on Coronary Angioscopy　- An Ex-Vivo Validation Study.

BACKGROUND: Coronary angioscopy (CAS) is used to comprehensively evaluate vascular responses after drug-eluting stent (DES) implantation. This study sought to evaluate the capability of CAS for evaluating DES strut coverage grade and color grade of the intima compared with histological images in coronary autopsy specimens. Methods and Results: A total of 23 DES extracted from 11 autopsy hearts were imaged by CAS. All stent segments were graded as white or yellow according to the luminal surface color, and thrombus was evaluated according to a previous report. Neointimal coverage over the DES was graded as 0 (stent struts fully visible) to grade 3 (stent struts fully embedded and invisible). Of 76 segments, neointimal coverage was graded as 0 in 35 (46%), 1 in 22 (29%), 2 in 8 (11%), and 3 in 11 (14%). The neointimal thickness increased significantly with increasing neointimal coverage grade on angioscopy. Neointimal color was graded as white in 40 (53%) and yellow in 36 segments (47%). Histological analysis revealed that yellow neointima contained fibroatheroma, foam cells accumulation or superficial calcium deposition. A thrombus was identified in 13 segments. Thrombi adherent around the stent strut were partly intimal erythrocyte accumulation around the strut. CONCLUSIONS: In-stent yellow segment had atherosclerotic components. CAS could evaluate vascular status comprehensively after DES implantation.

Impact of bioresorbable versus permanent polymer on longterm vessel wall inflammation and healing: a comparative drug-eluting stent experimental study.

AIMS: Drug-eluting stents (DES) have evolved to using bioresorbable polymers as a method of drug delivery. The impact of bioresorbable polymer on long-term neointimal formation, inflammation, and healing has not been fully characterised. This study aimed to evaluate the biological effect of polymer resorption on vascular healing and inflammation. METHODS AND RESULTS: A comparative DES study was performed in the familial hypercholesterolaemic swine model of coronary stenosis. Permanent polymer DES (zotarolimus-eluting [ZES] or everolimus-eluting [EES]) were compared to bioresorbable polymer everolimus-eluting stents (BP-EES) and BMS. Post implantation in 29 swine, stents were explanted and analysed up to 180 days. Area stenosis was reduced in all DES compared to BMS at 30 days. At 180 days, BP-EES had significantly lower area stenosis than EES or ZES. Severe inflammatory activity persisted in permanent polymer DES at 180 days compared to BP-EES or BMS. Qualitative para-strut inflammation areas (graded as none to severe) were elevated but similar in all groups at 30 days, peaked at 90 days in DES compared to BMS (p<0.05) and, at 180 days, were similar between BMS and BP-EES but were significantly greater in DES. CONCLUSIONS: BP-EES resulted in a lower net long-term reduction in neointimal formation and inflammation compared to permanent polymer DES in an animal model. Further study of the long-term neointima formation deserves study in human clinical trials.

Initial pathological responses of second-generation everolimus-eluting stents implantation in Japanese coronary arteries: Comparison with first-generation sirolimus-eluting stents.

BACKGROUND: The clinical benefit of second-generation drug-eluting stents (2nd DES) has been established, compared to first-generation drug-eluting stents (1st DES). However, pathological response after 2nd DES implantation remains unclear, particularly in the Japanese population. METHODS: Using specimens obtained by autopsy, we compared the histology between 2nd DES (41 sections) and 1st DES (38 sections) lesions within 1 year after stent implantation to evaluate early tissue reaction in Japanese patients. Stent segments were fixed with 10% buffered formalin and embedded in plastic, followed by hematoxylin-eosin and Masson's trichrome staining. Ratio of covered stent struts was calculated, and the area of fibrin deposition was morphometrically evaluated. The degree of inflammation around struts was examined semi-quantitatively (score 0-3). RESULTS: The ratio of covered struts and mean fibrin area of 2nd DES were 0.69±0.05 and 658.0±173.4µm2. Those of 1st DES were 0.44±0.12 and 3107.5±1405.9µm2. In the 2nd DES, there was significantly less fibrin deposition and a higher covered struts ratio. The inflammation score was significantly lower in 2nd DESs compared to 1st DESs (1.02±0.16 vs. 1.19±0.54, p<0.05). CONCLUSIONS: Histopathological analysis showed advanced healing process in 2nd DES compared with 1st DES lesions. These results are consistent with clinical beneficial outcome of 2nd DES implantation.

Potential of New-Generation Double-Layer Micromesh Stent for Carotid Artery Stenting in Patients with Unstable Plaque: A Preliminary Result Using OFDI Analysis.

BACKGROUND: One disadvantage of carotid artery stenting (CAS) is a high incidence of distal embolism (DE) during or after the procedure. Patients with unstable plaque are considered at high risk for DE and plaque protrusion (PP) after stent placement, which can cause postprocedural ischemic complications. This study was conducted to compare the rate and size of PP between the CASPER stent, a new-generation double-layer micromesh stent, and conventional stents as assessed by optical frequency domain imaging (OFDI), and also to evaluate the efficacy of CAS with the CASPER stent in cases with unstable plaque. METHODS: The study group comprised 46 consecutive patients with unstable plaque, identified on magnetic resonance imaging, undergoing CAS with OFDI image acquisition. Cross-sectional OFDI images within the stented segments were evaluated at 0.125-mm intervals, and the rate and size of PP were compared between the CASPER stent and conventional stents. RESULTS: The CASPER stent was used in 9 patients. No procedural complications occurred. On OFDI analysis, the presence of PP was apparently lower in CASPER stent group compared with the conventional stent group (44% vs. 88%; P = 0.022). In addition, mean PP area was significantly smaller in the CASPER stent group (mean PP area, 0.013 ± 0.034 mm2 vs. 0.057 ± 0.09 mm2; P = 0.006). CONCLUSIONS: On OFDI evaluation after CAS, the degree of PP was significantly smaller in the CASPER stent group compared with the conventional stent group. This result provides new insight into the use of CAS to treat carotid artery stenosis with unstable plaque.

The distribution of calcified nodule and plaque rupture in patients with peripheral artery disease: an intravascular ultrasound analysis.

In addition to plaque rupture (PR), calcified nodule (CN) may also have the potential to develop into arterial thrombus in the peripheral arteries. This study evaluated the distribution of plaque ruptures and calcified nodules in the peripheral arteries and their impact on the outcome of endovascular therapy (EVT). Consecutive 159 patients who underwent EVT with intravascular ultrasound guidance were enrolled. The position of CNs and PRs were assigned to any of common iliac artery, external iliac artery, common femoral artery, and superficial femoral artery. Forty-six (29%) patients had calcified nodule and twenty-eight (18%) patients had plaque rupture somewhere in the lower limb arteries. Although calcified nodules were evenly distributed throughout the length of the arteries plaque ruptures were predominantly located in the proximal segment of the iliofemoral arteries. Stent expansion ratio was significantly smaller in the target arteries with calcified nodules than in those with plaque rupture. Multivariate logistic regression analysis identified hemodialysis as an independent clinical predictor of calcified nodule (odds ratio 8.15, 95% confidence interval 1.73-38.3; P = 0.008). CN definitely affects incomplete stent deployment in the peripheral artery contributing to adverse events, on the other hand, PR has more acceptable outcomes after stent implantation. In the clinical setting, it is important that we realize the features of peripheral artery disease and its patient characteristics which having CNs and PRs to make a strategy for revascularization.

Preclinical in vivo long-term evaluation of the novel Mitra-Spacer technology: experimental validation in the ovine model.

AIMS: The Mitra-Spacer (Cardiosolutions, Bridgewater, MA, USA) is designed to treat mitral regurgitation by introducing a dynamic spacer that constantly adapts to the changing haemodynamic conditions during the cardiac cycle. We aimed to evaluate the performance and safety of this device in the chronic ovine model. METHODS AND RESULTS: Eight sheep were enrolled in this study. Through a left thoracotomy, the Mitra-Spacer was inserted via the transapical approach and advanced into the left atrium (LA) under imaging guidance. Device performance and safety were evaluated up to 90 days using fluoroscopy, echocardiography and histopathology. The volume within the balloon spacer shifted during the cardiac cycle in all cases. Seven animals survived up to 90 days for terminal imaging and tissue harvest. Echocardiography showed no change in left ventricle (LV) ejection fraction from baseline to 90 days. There were no observations of changes in LV diastolic function, pulmonary vein inflow, or tricuspid valve function. Histological analysis demonstrated no significant injury to the mitral apparatus. CONCLUSIONS: In the healthy ovine model, Mitra-Spacer implantation was feasible and safe. At 90 days, no evidence of structural damage to the mitral apparatus or deterioration of cardiac performance was demonstrated.

Impact of stent diameter on vascular response after self-expanding paclitaxel-eluting stent implantation in the superficial femoral artery.

BACKGROUND: The optimal sizing of self-expanding paclitaxel-eluting stents (PES) in the treatment for superficial femoral artery (SFA) lesions is unclear. This study sought to investigate the influence of PES diameter on stent patency in SFA lesions using optical frequency domain imaging (OFDI). METHODS: A total of 20 de novo SFA lesions were randomized 1:1 to receive either self-expanding PES with a nominal diameter of 6mm or 8mm. Follow-up angiography and OFDI was scheduled six months after stent implantation, and volumetric OFDI analysis was performed to evaluate vascular response to the stents. Volume index (VI) was defined as the volume divided by the stent length. The primary end point was lumen VI at the 6-month follow-up. Secondary end point was minimum lumen diameter (MLD) by quantitative vascular angiography (QVA) at the follow-up. RESULTS: Stent length was 78.0±23.9mm in the 6-mm group and 70.0±23.6mm in the 8-mm group (p=0.46). Baseline QVA data were also similar between the two groups. MLD immediately after stent implantation was similar between the two groups (4.2±0.5mm in the 6-mm group and 3.9±0.5mm in the 8-mm group, p=NS). At the 6-month follow-up, MLD was greater in the 8-mm group compared to the 6-mm group (4.0±1.0mm vs. 3.2±0.4mm, p<0.05). Stent VI was larger in the 8-mm group (28.4±6.7mm3/mm vs. 22.2±1.2mm3/mm, p=0.01). Neointimal VI was similar between the two groups (5.8±2.9mm3/mm vs. 5.2±2.6mm3/mm, p=0.68). Lumen VI was greater in the 8-mm group (23.2±7.6mm3/mm vs. 17.3±2.6mm3/mm, p=0.04). CONCLUSIONS: Chronic stent enlargement resulted in greater lumen area after implantation of self-expanding PES with a large diameter at the mid-term follow-up. Stent diameter might be important for stent patency in procedure with PES for SFA lesions.