Feasibility and efficacy of an ultra-short side branch-dedicated balloon in coronary bifurcation stenting

BACKGROUND

Side branch (SB) dilation with an ultra-short balloon after main vessel (MV) stenting may minimise stent failure in coronary bifurcation lesions.

AIMS

We sought to investigate the feasibility and efficacy of the Glider balloon (GB), a side branch (SB)-dedicated balloon 4 mm in length, in coronary bifurcation stenting.

METHODS

In bench testing, stent configuration was examined with micro-focus computed tomography after crossover stenting followed by GB dilation or kissing balloon inflation (KBI). In the clinical study we performed GB dilatation after MV stenting for 207 lesions in 194 patients. Failure of the GB dilation and additional procedures due to inducible stent failure were investigated as well as adverse cardiac events at 1-year follow-up.

RESULTS

In bench testing GB dilation maintained cross-sectional stent area without significant deformation and presented effective jailed strut removal in a high-angled bifurcation model. In the clinical study the cohort included left main, true bifurcation lesion, and two-stent treatment in 42.0%, 45.9%, and 14.0%, respectively. The proximal optimisation technique (POT) or POT-like inflation was performed in 82.1%. GB crossing failure, SB stenting due to dissection, and stent deformation requiring correction by KBI or MV dilation occurred in 8.7%, 1.4%, and 5.8%, respectively. Finally, simple GB dilation without KBI was completed in 91.8% for SB dilation. At one-year follow-up, target lesion revascularisation, cardiac death, myocardial infarction, and stent thrombosis were found in 7.2%, 2.1%, 2.1%, and 1.0%, respectively.

CONCLUSIONS

Simple GB dilation after adequate expansion of the proximal MV stent provided acceptable acute and long-term results as an alternative to KBI.

Coronary perforation during insertion of a long stent in a severely calcified lesion

We reported a case that the insertion of a 48-mm-long stent in a calcified coronary lesion after rotational atherectomy led to stent stacking and S-shaped flection, resulting in longitudinal coronary perforation without stent inflation. Its flexibility and length pose a possible risk of deformation inside the vessel during stent insertion.

A case of very late stent thrombosis on the protruded struts at the left main coronary bifurcation

A previous autopsy study has revealed that malapposed or protruded struts in the coronary bifurcation were a risk factor for very late stent thrombosis (VLST); however, a live clinical case has not yet been reported due to difficulty in observation at the VLST site. In this case, a 56-year-old male patient underwent a zotarolimus-eluting stent implantation in the proximal left anterior descending artery for acute myocardial infarction 3 years previously and had been treated with dual antiplatelet therapy. The patient experienced chest pain and suddenly collapsed due to acute coronary syndrome caused by a huge thrombus in the left main coronary bifurcation. After insertion of the intra-aortic balloon pump, kissing balloon inflation improved coronary flow and hemodynamics. Two weeks later, a 3-dimensional optical frequency domain imaging (3-D OFDI) revealed uncovered protruded struts on the ostium of the left circumflex artery (LCX). We removed the protruded struts using a double lumen catheter, for which the second wire was advanced to more distal cell along with the first wire located in the same LCX branch. 3-D OFDI clearly demonstrated that uncovered protruded struts at the LCX ostium were the cause of VLST and navigated optimal wiring with a double lumen catheter. Learning objective: Existence of protruded struts at the coronary bifurcated branch ostium is a risk factor for very late stent thrombosis. Three-dimensional optical frequency domain imaging clearly demonstrates the protruded strut configuration at the side branch of ostium and facilitates optimal guide wire re-crossing for kissing balloon inflation. Usage of double lumen catheter increases the possibility of optimal side branch wiring.

P1912Incidence of silent cerebral thromboembolism in catheter ablation for atrial fibrillation under the use of DOAC: Comparison of cryoballoon versus radiofrequency ablation system

Background

Silent cerebral thromboembolism (CE) in catheter ablation for atrial fibrillation (AF) is not rare. Prior our study has reported lower incidence of silent CE in AF radiofrequency (RF) ablation using irrigated-tip catheter than conventional 4 or 8mm-tip catheter. In addition, the incidence of silent CE in AF ablation under direct oral anticoagulant (DOAC) was equivalent to continuous therapeutic warfarin. Recently pulmonary vein isolation (PVI) using cryoballoon (CB) has emerged as an alternative technique to RF ablation because some studies suggested that the efficacy for PVI by CB was equivalent to RF. However, incidence of silent CE in CB ablation under the use of DOAC is unknown.

Objective

We aimed to evaluate the incidence new silent CE in AF ablation using CB system compared with irrigated RF system under the use of DOAC.

Methods

322 consecutive patients with paroxysmal or persistent AF (155 using CB system, 167 using RF system) who underwent the first AF ablation were taking DOAC more than one month prior to the procedure. Throughout AF ablation procedure, heparin was administered to maintain activated clotting time (ACT) between 300 and 400 seconds. Head MRI was performed in all patients within 24 hours after the procedure.

Results

In 14 (9.0%) patients using CB and in 20 (12.0%) patients using RF, head MRI showed new embolic lesions without neurological symptom (P=0.469). Although the amount of heparin during the procedure in group CB was significantly less than in group RF (16134±3125 U vs. 18689±5222 U; P<0.0001), amount of heparin per hour in group CB was more than in group RF (8335±1955 U/h vs. 6143±1918 U/h; P<0.0001) because procedure time in group CB was shorter than in group RF (121.3±34.1 min vs. 189.5±47.4 min; P<0.0001). Mean ACT in both groups was maintained high level (3367±25.3 sec. vs. 338.6±23.5 sec.; P=0.479). In univariate analysis, minimum ACT during procedure, as before puncture of interatrial septum, were significantly correlated with the incidence of silent CE (P=0.027).

Conclusions

The incidence of silent CE in AF ablation using CB system was lower than RF system, although it was not a significant difference between different ablation techniques for AF. In AF ablation, the use of CB may be preferred rather than RF as ablation system in regard to risk reduction of thromboembolic complications.

Probing the Entropic Effect in Molecular Noncovalent Interactions between Resin-Bound Polybrominated Arenes and Small Substrates

The associative interaction between resin-bound polybrominated arenes and small molecules was analyzed by using various spectroscopic techniques as well as a synthetic molecular model to establish the thermodynamics. The binding in acetonitrile was three orders of magnitude stronger than that in methanol, partly owing to the tertiary conformational gating of the resin that controls the entropic terms. By using the entropic superiority, the associative binding of up to 3×10⁴  m^-1 is achieved with the non-biological system. A modified Hill plot for the quantitative analysis of bindings was also devised, which enabled the interactions at the molecular level to be elucidated.

Development of a Hybrid Artificial Liver using a Polyurethane Foam/Hepatocyte-Spheroid Packed-Bed Module

Primary dog hepatocytes spontaneously formed spheroids in the pores of polyurethane foam (PUF) within 1–2 days of stationary culture. The spheroids, about 100–150 μm in diameter, partly attached to the surface and immobilized inside these pores.

The lidocaine disappearance rate decreased to about 4 μg/105 viable cells/day for 10 days, while in the PUF/spheroid culture the rate was maintained at almost the initial level of 8 μg/105 viable cells/day for 10 days. Then, two scales of PUF packed-bed modules were designed. A small module (PUF volume; 14.5 cm3) was used for in vitro culture to investigate optimum culture conditions, and a large module (PUF volume; 300 cm3) was designed for dog experiments. Hepatocytes inoculated in these modules also formed spheroids and maintained almost the same activity of albumin secretion rate (111 μg/cm3 PUF/day in the small module and 87.7 μg/cm3 PUF/day in the large module). These results indicate that the PUF packed-bed module containing hepatocyte-spheroids is promising as a hybrid artificial liver

Conditions Required for a Hybrid Artificial Liver Support System using a PUF/Hepatocyte-Spheroid Packed-Bed Module and it's use in Dogs with Liver Failure

We studied the effects of a hybrid artificial liver support system we developed on dogs with hepatic failure. The system consisted of a multi-channel polyurethane foam packed-bed culture module, including primary dog hepatocyte spheroids.

Blood ammonia was well metabolized by 20 g hepatocytes, but the other functions such as glucose concentration, total bile acid concentration, and survival time required 30 g hepatocytes to improve conditions. We found that we should use a culture substratum that easily forms spheroids, and that an artificial liver module should be used as soon as possible after spheroid formation by hepatocytes in the module.

DNA synthesis and intracellular calcium elevation in porcine cerebral arterial smooth muscle cells by cerebrospinal fluid from patients with subarachnoid haemorrhage

To understand the molecular mechanism of the pathogenesis of cerebral vasospasm following subarachnoid haemorrhage, we analysed the effect of cerebrospinal fluid from patients with subarachnoid haemorrhage on DNA synthesis and cytosolic-free calcium elevation in cultured porcine cerebral smooth muscle cells. Cerebrospinal fluid from patients on day 2 after subarachnoid haemorrhage induced transient elevation in cytosolic-free calcium levels. In contrast, the maximal elevation of cytosolic-free calcium levels induced by cerebrospinal fluid from control patients (without subarachnoid haemorrhage) was significantly lower than that induced by cerebrospinal fluid from patients with subarachnoid haemorrhage. In cultured porcine cerebral arterial smooth muscle cells, cerebrospinal fluid from patients with subarachnoid haemorrhage promoted levels of [3H]-thymidine incorporation (DNA synthesis) more than 2.5-fold higher than that promoted by cerebrospinal fluid from control patients without subarachnoid haemorrhage. However, in cultured aortic smooth muscle cells, there was no significant difference in [3H]-thymidine incorporation between cerebrospinal fluid from patients with subarachnoid haemorrhage and that by control cerebrospinal fluid. From these results in cerebral arterial smooth muscle cells, cerebrospinal fluid from patients following subarachnoid haemorrhage may play not only constrictive functions, evidenced by cytosolic-free calcium elevations, but also proliferative functions, demonstrated by promotion of [3H]-thymidine incorporation. The relevance of these factors to vasospasm will be discussed.

Superconducting pairing and the pseudogap in the nematic dynamical stripe phase of La2-xSrxCuO4

Fully absorption coefficient corrected Raman spectra were obtained in La2-xSrxCuO4. The B1g spectra have a Fleury-Loudon type two-magnon peak (resonant term) whose energy decreases from 3180 cm(-1) (394 meV) to 440 cm(-1) (55 meV) on increasing the carrier density from x = 0 to 0.25, while the B2g spectra have a 1000-3500 cm(-1) (124-434 meV) hump (hill) whose lower-edge energy increases from x = 0 to 0.115 and then stays constant to x = 0.25. The B2g hump is assigned to the electronic scattering (non-resonant term) of the spectral function with magnetic self-energy. The completely different carrier density dependence arises from anisotropic magnetic excitations of spin-charge stripes. The B1g spectra were assigned to the sum of k ∥  and k⊥ stripe excitations and the B2g spectra to k⊥ stripe excitations according to the calculation by Seibold and Lorenzana (2006 Phys. Rev. B 73 144515). The k ∥  and k⊥ stripe excitations in fluctuating spin-charge stripes were separately detected for the first time. The appearance of only k⊥ stripe excitations in the electronic scattering arises from the charge hopping perpendicular to the stripe. This is the same direction as the Burgers vector of the edge dislocation in metal. The successive charge hopping in the Burgers vector direction across the charge stripes may cause Cooper pairs as predicted by Zaanen et al (2004 Ann. Phys. 310 181). Indeed, this is supported by the experimental fact that the superconducting coherent length coincides with the inter-charge stripe distance in the wide carrier density range. The one-directional charge hopping perpendicular to the stripe causes the flat Fermi surface and the pseudogap near (π,0) and (0,π), but the states around (π/2,π/2) cannot be produced. The low-energy Raman scattering disclosed that the electronic states at the Fermi arc around (π/2,π/2) are coupled to the A1g soft phonon of the tetragonal-orthorhombic phase transition. This suggests that the Fermi arc is produced by the electron-phonon interaction. All the present Raman data suggest that Cooper pairs are formed at moving edge dislocations of dynamical charge stripes.

Correlation between Raman sum and optical conductivity sum in La(2-x)Sr(x)CuO4

In a strongly correlated electron system, the single-particle spectral function changes into a coherent peak and incoherent humps which extend over 1 eV. The incoherent parts lose the symmetry and k dependence, so that the Raman spectra with different symmetries become identical and they are expressed by the optical conductivity. We found that the B1g and B2g spectra in La(2-x)Sr(x)CuO4 become identical above 2000 cm(-1) in the underdoped phase, if Fleury-Loudon type B1g two-magnon scattering is removed. The first Raman susceptibility moment correlates with the generalized optical conductivity moment. The good correlation arises from the incoherent states of a hump from 1000 to 4000 cm(-1). The hump is the only structure of the incoherent electronic states in the mid-infrared absorption spectra below 1.4 eV at low carrier densities. The energy is twice the separated dispersion segments of the spin wave in the k(perpendicular) stripe direction. The incoherent state is formed by the magnetic excitations created by the hole hopping in the antiferromagnetic spin stripes in the real space picture.

Gender differences in factors influencing electrocardiographic findings of left ventricular hypertrophy in severe aortic stenosis

We investigated gender differences in factors influencing the electrocardiographic (ECG) findings of left ventricular hypertrophy (LVH) in patients with severe aortic stenosis (AS). The functional and geometric responses of the left ventricle to chronic pressure overload, such as hypertension and AS, have been reported to be different between men and women. However, gender differences in the factors influencing the ECG findings of LVH in pressure overload remain unknown. We conducted a retrospective observational study in consecutive patients with severe AS (aortic valve area (AVA) assessed by cardiac catheterization <1.0 cm(2)) without concomitant significant aortic regurgitation, mitral stenosis and/or regurgitation, conduction disturbance, or myocardial infarction (n = 35 males, 68 females). The ECG criteria were classified into three categories: (1) high voltage by the Sokolow-Lyon index associated with ST-T wave changes (with no digitalis therapy); (2) high voltage alone; and (3) normal. Groups 1 and 2 were defined as LVH on ECG. We compared the ECG findings in relation to the AS severity between genders. Women were older, but there were no significant differences in the prevalence of hypertension, AVA index (AVAI), mean pressure gradient or peak velocity across the AV, LV mass index (LVMI) derived from echocardiography or the distribution of ECG categories between genders. A multiple logistic regression analysis including age, gender, hypertension, AVAI, mean pressure gradient, and LVMI revealed that the LVMI (P = 0.001) and AVAI (P = 0.0434) were significantly related to the distribution of ECG categories. LVMI significantly predicted LVH on ECG in both genders, but AVAI was a predictive factor in only women. ECG LVH in patients with severe AS may be mainly reflected by LVMI in men and by both LVMI and AVAI in women. Factors other than AVA, such as end-stage disease and/or complicating factors such as hypertension, may underlie the observed differences in ECG findings of LVH between men and women.

Evaluating the association between histological manifestations of cord colitis syndrome with GVHD

Cord colitis syndrome (CCS) is a recently proposed clinical entity characterized by a persistent diarrheal illness after cord blood transplantation (CBT), which is not caused by GVHD or CMV colitis. CCS is histologically characterized by chronic active colitis with granulomatous inflammation and Paneth cell metaplasia suggesting chronicity. However, the specificity of these pathological features to CCS remains to be validated. We conducted a retrospective study of 49 patients who had diarrhea and underwent diagnostic colonoscopy with biopsy following allogeneic hematopoietic SCT. None of the patients met the clinical criteria for CCS. Chronic active colitis with granulomatous inflammation and Paneth cell metaplasia was present in 12/33 (36%) patients with biopsy-proven GVHD, 4/6 (67%) patients with CMV colitis and 2/15 (13%) patients with nonspecific colitis. In patients with GVHD and/or CMV colitis, these pathological features were present in 4/8 (50%) patients after CBT and in 11/26 (42%) patients undergoing BMT or PBSCT. These results demonstrate that chronic active colitis with granuloma and Paneth cell metaplasia is not only a specific feature of CCS but also is present in GVHD and CMV colitis, irrespective of stem cell source.

Formation of porcine hepatocyte spherical multicellular aggregates (spheroids) and analysis of drug metabolic functions

Porcine hepatocytes are used in the hybrid artificial liver support system that we are developing because of their high level of liver functions in vitro and because human hepatocytes can not be used in Japan for ethical reasons. Spherical multicellular aggregates or spheroids have been found to be effective in vitro for long-term maintenance of liver functions. Therefore, we formed spherical multicellular aggregates (spheroids) of primary porcine hepatocytes using a polyurethane foam (PUF) as a culture substratum and analyzed their drug metabolic functions in vitro. Primary porcine hepatocytes inoculated into the pores of a flat PUF plate (25 x 25 x 1 mm), spontaneously formed spheroids within the range of 100 to 150 mum in diameter 24 to 36 h after inoculation. The formed spheroids were attached to the bottom surface of the PUF pores, and their morphology and viability were maintained for more than 12 days. The P-450 activity in the spheroids of porcine hepatocytes was demonstrated by detecting production of monoethylglycinexylidide from lidocaine. In addition, the conjugation enzyme activity was demonstrated by detecting glucuronidation and sulfation of acetaminophen. These activities were maintained for 12 days at a level twice as high as in the monolayer culture. This result shows that the porcine hepatocyte spheroids formed by using PUF can maintain the drug metabolic functions important in a hybrid artificial liver device. Consequently, culturing porcine hepatocyte spheroids using PUF seems to be promising for development of a hybrid artificial liver.

[Lung cancer accompanied by active pulmonary tuberculosis]

We report 2 patients with lung cancer accompanied by active pulmonary tuberculosis. Case1 was a 82-year-old woman with stage I A bronchioloalveolar carcinoma and tuberculosis in right upper lobe. Right upper lobectomy was performed after the histological diagnosis of lung cancer by intraoperative frozen section. Case2 was a 69-year-old man with papillary adenocarcinoma in right lower lobe and tuberculosis in bilateral upper lobe. Partial resection in right lower lobe was performed for diagnosis of lung cancer. Smear-positive tuberculosis was diagnosed by sputum examination after the operation. Post-operative anti-tuberculosis chemotherapy was added in both patients.

Evidence for a correlated insulator to antiferromagnetic metal transition in CrN

We investigate the electronic structure of chromium nitride (CrN) across the first-order magnetostructural transition at T(N)∼286  K. Resonant photoemission spectroscopy (PES) shows a gap in the 3d partial density of states at the Fermi level and an on-site Coulomb energy U∼4.5  eV, indicating strong electron-electron correlations. Bulk-sensitive high-resolution (6 meV) laser PES reveals a clear Fermi edge indicating an antiferromagnetic metal below T(N). Hard x-ray Cr 2p core-level PES shows T-dependent changes across T(N) which originate from screening due to coherent states as substantiated by cluster model calculations using the experimentally observed U. Electrical resistivity confirms an insulator above T(N) (E(g)∼70  meV) becoming a disordered metal below T(N). Thus, CrN transforms from a correlated insulator to an antiferromagnetic metal, coupled to the magnetostructural transition.