Nationwide Analysis of Persistent Type II Endoleak and Late Outcomes of Endovascular Abdominal Aortic Aneurysm Repair in Japan: A Propensity-Matched Analysis.

BACKGROUND: We reviewed the results of endovascular aneurysm repair in patients from the Japanese Committee for Stentgraft Management registry to determine the significance of persistent type II endoleak (p-T2EL) and the risk of late adverse events, including aneurysm sac enlargement. METHODS: The prospectively captured medical records of 17 099 patients <75 years of age who underwent endovascular aneurysm repair for abdominal aortic aneurysm from 2006 to 2015 were reviewed. Patients were divided into 2 groups (with or without p-T2EL) and compared to examine the correlation between p-T2EL and the occurrence of aneurysm sac enlargement after endovascular aneurysm repair. RESULTS: Of the patients, 4957 (29.0%) had p-T2EL and 12 142 (71.0%) had no p-T2EL (non-T2EL). Mean age was significantly higher (P<0.001), and there were fewer men (P<0.001) in the p-T2EL group. Among comorbidities, hypertension (P=0.019) and chronic kidney disease (P=0.040) were more prevalent and respiratory disorders were less prevalent (P<0.001) in the p-T2EL group. From each group, 4957 patients were matched according to propensity score to adjust for differences in patient characteristics. The cumulative incidence rates of abdominal aortic aneurysm-related mortality (p-T2EL: 52 of 4957 [1.0%] versus non-T2EL: 21 of 12 142 [0.2%]), rupture (p-T2EL: 38 of 4957 [0.8%] versus non-T2EL: 13 of 12 142 [0.1%]), sac enlargement (≥5 mm; p-T2EL: 1359 of 4957 [27.4%] versus non-T2EL: 332 of 12 142 [2.7%]), and reintervention (p-T2EL: 739 of 4957 [14.9%] versus non-T2EL: 91 of 12 142 [0.7%]) were significantly higher in the p-T2EL than the nonpT2EL group (P<0.001). Propensity score matching yielded higher estimated incremental risk, including abdominal aortic aneurysm-related mortality, rupture, sac enlargement (≥5 mm), and reintervention for p-T2EL (P<0.001). Cox regression analysis revealed older age (P=0.010), proximal neck diameter (P=0.003), and chronic kidney disease (P<0.001) as independent positive predictors and male sex as an independent negative predictor (P=0.015) of sac enlargement. CONCLUSIONS: The Japanese Committee for Stentgraft Management registry data show a correlation between p-T2EL and late adverse events, including aneurysm sac enlargement, reintervention, rupture, and abdominal aortic aneurysm-related mortality after endovascular aneurysm repair. Besides p-T2EL, older age, female sex, chronic kidney disease, and dilated proximal neck were associated with sac enlargement.

Effect of the urgency and landing zone on rates of in-hospital death, stroke, and paraplegia after thoracic endovascular aortic repair in Japan.

OBJECTIVE: The present study used data from the Japanese Committee for Stentgraft Management's national registry, which contains unique surgical data, including surgical timing, anatomic factors, and pathologic factors, to determine the generalized community experience with thoracic endovascular abdominal aortic repair (TEVAR). METHODS: The medical background and short-term outcomes were reviewed for patients who had undergone TEVAR for a thoracic aortic aneurysm (TAA; 14,235 cases) or aortic dissection (AD; 990 type A and 4259 type B) from 2008 to 2015. TEVAR for AD was separated from that for TAAs; only the background and short-term outcomes were evaluated. The technical outcomes of TEVAR for TAA were also evaluated. All the cases were categorized as follows: elective, urgent (within 24 hours after admission), or emergent (immediately after admission). The outcomes included in-hospital mortality and persistent stroke and paraplegia diagnosed at discharge. The number of debranching bypasses, proximal landing zone (0, 1, 2, ≥3), and zone length were included in the logistic regression analysis. RESULTS: The mortality, stroke, and paraplegia rates in the TAA and AD groups were 4.4%, 4.6%, and 3.7% and 4.0%, 2.9%, and 2.8%, respectively. After analyzing the TAA cohort, we found that urgent and emergent cases were associated with all adverse outcomes. The rate of paraplegia increased drastically in the patients with stent graft coverage that extended for six or more zones. Massive atheroma was associated with stroke and paraplegia. The cumulative survival rate of the TAA group was stratified by the urgency (ie, elective, urgent, emergent; P < .001). We found that the more proximal (0, 1, and 2) the landing zone, the greater the risk of stroke. Likewise, the longer (six or more zones) the coverage, the greater the risk of paraplegia. CONCLUSIONS: Urgency was strongly associated with mortality, stroke, and paraplegia, and the classification of urgent and emergent, according to the surgical timing after admission, successfully stratified the population in the long-term overall survival analysis. A proximal landing zone involving the aortic arch and debranching bypasses were associated with the occurrence of stroke, and the length of stent graft coverage for six or more zones was associated with paraplegia. Identifying these risk factors will help operators of TEVAR develop appropriate operative strategies to mitigate patient risk.

Outcomes of Endovascular Repair for Abdominal Aortic Aneurysms: A Nationwide Survey in Japan.

OBJECTIVE: To analyze data on patients treated with a bifurcated stent graft for abdominal aortic aneurysm (AAA). BACKGROUND: The Japan Committee for Stentgraft Management (JACSM) was established in 2007 to manage the safety of endovascular aortic aneurysm repair (EVAR) in Japan. The JACSM registry includes detailed anatomical and clinical data of all patients who undergo stent graft insertion in Japan. METHODS: Among 51,380 patients treated with bifurcated stent graft for AAA, we identified 38,008 eligible patients (excluding those with rupture or insufficient data). The analyzed factors included age, sex, comorbidities, AAA pathology and etiology, aneurysm and neck diameters, 7 anti-instructions for use (IFU) factors, and endoleaks at hospital discharge. The endpoints were death, adverse events, sac dilatation (≥5 mm), and reintervention. RESULTS: The rates of intraoperative and in-hospital mortality were 0.08% and 1.07%, respectively. Infectious aneurysm and pseudo-aneurysm were associated with overall survival and reintervention. Older age, large aneurysm diameter, and all types of persistent endoleaks were strong predictors of adverse events, sac dilatation, and reintervention. Comorbid cerebrovascular disease, renal dysfunction, and respiratory disorders were also risk factors. In total, 47.6% of patients violated the IFU; among the anti-IFU factors assessed, poor access and severe neck calcification were strong risk factors for mortality, reintervention, and adverse events. The sac dilatation rate at 5 years was 23.3%. CONCLUSIONS: Although the analysis included EVAR with poor anatomy, the perioperative mortality rate was acceptable compared with that in previous large population studies.

Anomalous enhancement of proton conductivity for water molecular clusters stabilized in interstitial spaces of porous molecular crystals.

In an investigation into the proton conductivity of crystallized water clusters confined within low-dimensional nanoporous materials, we have found that water-stable nanoporous crystals are formed by complementary hydrogen bonding between [Co(III) (H2 bim)3 ](3+) (H2 bim: 2,2'-biimidazole) and TATC(3-) (1,3,5- tricarboxyl-2,4,6-triazinate); the O atoms in the -COO(-) groups of TATC(3-) in the porous outer wall are strongly hydrogen bonded with H2 O, forming two types of WMCs (water molecular clusters): a spirocyclic tetramer chain (SCTC) that forms infinite open 1D channels, and an isolated cyclic tetramer (ICT) present in the void space. The ICT is constructed from four H2 O molecules as a novel C2 -type WMC, which are hydrogen bonded with four-, three-, and two-coordination spheres, respectively. The largest structural fluctuation is observed at elevated temperatures from the two-coordinated H2 O molecules, which begin to rapidly and isotropically fluctuate on heating. This behavior can be rationalized by a simple model for the elucidation of pre-melting phenomena, similar to those in ice surfaces as the temperature increases. Moreover, high proton conductivity of SCTCs (ca. 10(-5) S cm(-1) at 300 K with an activation energy of 0.30 eV) through a proton-hole mechanism was observed for pellet samples using the alternating impedance method. The proton conductivity exhibits a slight enhancement of about 0.1×10(-5) S cm(-1) at 274 K due to a structural transition upon approaching this temperature that elongates the unit cell along the b-axis. The proton-transfer route can be predicted in WMCs, as O(4) of an H2 O molecule at the center of an SCTC shows a motion that rotates the dipole in the b-axis direction, but not the c-axis; the thermal ellipsoids of O(4) based on anisotropic temperature factors obtained by X-ray crystallography reflect a structural fluctuation along the b-axis direction induced by [Co(III) (H2 bim)3 ](3+) .

Description of a new species of Sternomoera (Crustacea: Amphipoda: Pontogeneiidae) from Japan, with an analysis of the phylogenetic relationships among the Japanese species based on the 28S rRNA gene.

A new species of amphipod, Sternomoera morinoi Tomikawa and Ishimaru, is described from subterranean aquatic habitats in Shiga Prefecture, Japan. In addition, Relictomoera tsushimana (Uéno, 1971) from a well on the island of Tsushima in Japan is transferred to Sternomoera and redescribed based on the holotype. Sternomoera morinoi sp. nov. is most similar to S. tsushimana (Uéno, 1971) comb, nov., but is distinguished by having many fine setae on the body, a shorter antenna 1, fewer C-setae on mandibular palp article 3, a shorter mandibular palp article 3, sparsely setose anterior margins of coxae 1-4, a different armature of the palmar margins of gnathopods 1 and 2, and no long setae on the posterior margin of the basis in gnathopod 2 and pereopods 3 and 4. The phylogenetic relationships among the Japanese species of Sternomoera are also estimated, based on partial DNA sequences of the nuclear 28S rRNA gene.

Structures and phase transition of multi-layered water nanotube confined to nanochannels.

We placed nanometer-scale water-tube clusters with phase transition within a porous crystal formed from molecular blocks specifically designed to investigate the molecular dynamics of confined water molecules.

Evaluation of thrombogenicity by indium-111 platelet scintigraphy in endografting for abdominal aortic aneurysms.

Obstruction of the endograft limb by thrombosis has often been reported and may cause fatal complications such as leg necrosis or myonephropathic metabolic syndrome. The purpose of this study was to evaluate endograft antithrombogenicity by indium-111 platelet scintigraphy. Seventeen patients with abdominal aortic aneurysms were treated by endografting. Thirteen patients were treated with conventional open surgery using an artificial graft. The endograft was constructed from a self-expanding Z-shaped stent and woven polyester fabric. Autologous platelets labeled with indium-111 were injected at 2 weeks postoperatively. At 24 hours and 72 hours postinjection, the ratio of scintillation count of the endograft or graft to that of the native artery was calculated to assess platelet deposition. The normalization ratio was calculated as follows: (scintillation count per pixel of endograft or graft/circumference)/(scintillation count per pixel of the native femoral artery). Platelet factor 4 and beta-thromboglobulin were measured to evaluate the systemic platelets activity at 2 weeks postoperatively. There was no significant difference in platelet counts or labeling efficiency between the groups. The ratio was significantly higher in the endografting group than in the open surgery group at 72 hours postinjection (2.5-0.7 vs 3.9-1.1, P<.001). There was no significant difference in platelet factor 4 and beta-thromboglobulin between the groups. Although there was no difference in systemic platelet activity, endografting was associated with lower antithrombogenicity. It remains unclear whether lower antithrombogenicity causes thromboembolism as a complication of the procedure. The authors recommend the administration of antiplatelet drugs to prevent endograft obstruction in patients with very narrow iliac arteries.

[Endovascular stent-graft repair for thoracic aortic aneurysm].

Endovascular stent-grafting holds great potential as a minimally invasive alternative to open surgery for thoracic aortic aneurysm. Although there have been several commercially available stent graft systems applied to abdominal aortic aneurysm in the United States, Gore TAG is the only device that is approved by Food and Drug Association (FDA) for thoracic aortic aneurysm repair. Experience of endovascular aneurysm repair by our homemade system and TAG device which is crafted particularly for the thoracic aorta is reported. TAG was successfully delivered to the target region in 137 patients (98%). The aneurysm was successfully excluded by our homemade system in 258 patients (94%). The mortality rates of TAG and our homemade device groups were 2.1 and 3.6% respectively. Postoperative stroke incidence was 1.8% and was more frequent in patients with stent-graft deployed in the region between the landing zone map of Z3 and Z4. The rate of paraplegia/paraparesis with delayed onset was 2.8% in TAG group, and was almost similar in the homemade group (2.6%). The event-free rate of patients treated with stent-graft was low as compared to that of open surgery in 1 and 3 year follow-up period. Endovascular stent-grafting is feasible as one treatment option for thoracic aortic aneurysm. Selection of proper indications, development of the better device and technical improvement are keys to successful stent-grafting.

Molecular dynamics and residual entropy in the soft crystal, SmE phase, of 4-butyl-4'-isothiocyano-1,1'-biphenyl.

Molecular dynamics and resulting disorder in the soft crystal, smectic E (SmE) phase, were studied in detail for the title compound, 4-butyl-4'-isothiocyano-1,1'-biphenyl (4TCB), by (1)H NMR spectroscopy and adiabatic calorimetry. The ordered crystal phase of 4TCB was realized for the first time under ambient pressure after long two-step annealing and used as the reference state in the analysis of the experimental results. Four motional modes were identified in the SmE phase through the analysis of the (1)H NMR T(1). The residual entropy was determined as ca. 6 J K(-1) mol(-1). This magnitude implies that most of the disorder in the SmE phase at high temperatures is removed on cooling except for the head-to-tail disorder of the rod-shaped 4TCB molecule. Standard thermodynamic functions are tabulated below 375 K.

Comparison of ankle-brachial pressure index and pulse wave velocity as markers of the presence of coronary artery disease in subjects with a high risk of atherosclerotic cardiovascular disease.

Recently, a measurement device that can simultaneously measure the ankle-brachial pressure index (ABI) and brachial-ankle pulse wave velocity (PWV) has become available. The present study compares the applicability of ABI and PWV as markers for predicting the prevalence of coronary artery disease (CAD) in subjects with a high risk of atherosclerotic cardiovascular disease. The ABI and brachial-ankle PWV were measured in 472 consecutive subjects who subsequently underwent coronary angiography for diagnosis or exclusion of CAD. The prevalence of CAD in the lowest ABI quartile was higher than those in the other 3 ABI quartiles, whereas the prevalence in the lowest brachial-ankle PWV quartile was lower than those in the other 3 brachial-ankle PWV quartiles. A multivariate logistic regression analysis demonstrated that the lowest ABI quartile was a significant independent variable for the prevalence of CAD and that the lowest brachial-ankle PWV quartile was a significant independent variable for the absence of CAD in a population. Thus, a low ABI is an independent marker for an additive risk of CAD, whereas a low brachial-ankle PWV may be used as an independent marker for excluding the risk of CAD among subjects with a high risk of atherosclerotic cardiovascular disease.

Preoperative risk stratification for endovascular surgery using pharmacologic stress myocardial imaging.

To stratify perioperative cardiac risk for endovascular surgery, pharmacologic stress single-photon emission computed tomography (SPECT) was performed in 206 patients. Of 8 patients who had cardiac events, 7 occurred in 67 patients with positive SPECT results, whereas only 1 occurred in 139 patients with negative SPECT results (7 of 67 vs 1 of 139, p <0.002). Furthermore, a scintigraphic marker of a summed stress score >/=14 was the most important factor identifying patients who subsequently had cardiac events by multivariate analysis.

Endovascular stent grafting of the descending thoracic aorta after arch repair in acute type A dissection.

An endovascular stent graft was successfully deployed to the primary entry site in the proximal descending thoracic aorta after total aortic arch replacement using the "elephant trunk" technique in acute type A aortic dissection. The residual false lumen of the descending aorta was thrombosed completely after stent grafting. The elephant trunk was feasible for a proximal landing zone for stent grafting of the descending aorta. Stent grafting in combination with aortic arch replacement was a safe and effective procedure, and may be an alternative choice in carefully selected patients with type A aortic dissection.

Implications of carotid arteriomegaly in patients with aortic aneurysm.

The pathophysiology of aortic aneurysm is complex and it has remained unclear how frequently arteriomegaly, a diffuse dilatation of the artery, is associated with aneurysm. Therefore, ultrasonic study of the carotid artery was conducted to clarify this issue in a large number of subjects. Carotid ultrasonography was performed in 1,108 Japanese men aged 50 or older, and the results of 379 patients with arteriosclerotic aortic aneurysm (AA) were compared with those of 211 patients with peripheral arterial disease, 65 patients with aortic dissection, 232 hypertensive subjects, and 221 normotensive subjects. The carotid diameter was measured bilaterally at two points on the common carotid artery, and we defined carotid arteriomegaly as an arterial diameter in the 95th percentile or above that in the normotensive control group according to the relevant age subgroups. The incidence of carotid arteriomegaly in the AA group (25.9%) was significantly higher than in the other groups (p < 0.01) even when adjusted for body height and blood pressure. In the arteriomegaly subgroup, hypertension and cigarette smoking was significantly more frequent than in the non-dilated artery subgroup. This study demonstrates that one fourth of patients with aortic aneurysm have arteriomegaly as a generalized systemic abnormality in the arterial wall.

Arterial conduit shear stress following bypass grafting for intermediate coronary artery stenosis: a comparative study with saphenous vein grafts.

OBJECTIVES: Graft failure has been reported when the arterial conduit, such as the internal thoracic artery (ITA) or the right gastroepiploic artery (GEA), is grafted to a lower grade coronary artery stenosis. The shear stress as a significant factor affecting graft patency was compared between the arterial conduit and the saphenous vein graft (SVG) after surgery. METHODS: In 101 patients, 40 ITAs, 27 GEAs and 34 SVGs were examined using a Doppler-tipped guide wire during postoperative angiography. The graft flow volume and shear stress were calculated from velocity and diameter data. The study grafts were classified according to the grade of native coronary artery stenosis: group L had more than 50 up to 75% stenosis, and group H had more than 75% stenosis. Group H consisted of 25 ITAs, 17 GEAs and 21 SVGs, while group L consisted of 15 ITAs, 10 GEAs and 13 SVGs. RESULTS: In group H, graft flow volume did not significantly differ among the ITA (34+/-11 ml/min), GEA (36+/-16 ml/min) and SVG (41+/-15 ml/min), and graft shear stress significantly (ITA vs. GEA P<0.0001; GEA vs. SVG P<0.01) differed among the ITA (16.0+/-4.8dyn/cm(2)), GEA (9.1+/-3.2dyn/cm(2)) and SVG (4.8+/-1.6dyn/cm(2)). In group L, flow volume was lower (P<0.001) in the ITA (18+/-6 ml/min) and GEA (13+/-8 ml/min) than in the SVG (35+/-16 ml/min), and shear stress was significantly (P<0.001) greater in the ITA (13.7+/-4.9dyn/cm(2)) than the GEA (5.6+/-2.0dyn/cm(2)) or SVG (4.6+/-2.0dyn/cm(2)). CONCLUSIONS: These data suggest that shear stress of the ITA is superior and maintained despite the flow volume being reduced by flow competition. Lower shear stress of the GEA for intermediate stenosis may be associated with the development of conduit failure.

[Stent grafting for aortic aneurysms].

Endovascular stent grafting for aortic aneurysms/dissections using metallic stents covered with conventional vascular grafts has attracted attention as a minimally invasive alternative to open surgery. Since the first clinical experience of endovascular stent grafting for abdominal aortic aneurysm was reported in 1991, numerous clinical applications have been undertaken worldwide. Although several commercial bifurcated stent grafts for abdominal aortic aneurysm are available in various countries, including Europe, the USA, and Australia at present, none of the devices are approved for clinical use in Japan. Particularly for thoracic aortic aneurysms, hand-made devices are still used in individual institutions. Endovascular stent grafting is feasible for aneurysm repair within limited conditions. Although further investigation is necessary to clarify the indications, it is clear that aortic aneurysms could be successfully treated with precise stent-graft deployment and proper patient selection based on our 10-year follow-up results.

Endovascular stent graft repair for thoracic aortic aneurysms: the history and the present in Japan.

Stent-grafts for endovascular repair of thoracic aortic aneurysms have been commercially available for more than ten years in the West, whereas, in Japan, a manufactured stent-graft was not approved for the use until March 2008. Nevertheless, endovascular thoracic intervention began to be performed in Japan in the early 1990s, with homemade devices used in most cases. Many researchers have continued to develop their homemade devices. We have participated in joint design and assessment efforts with a stent-graft manufacturer, focusing primarily on fenestrated stent-grafts used in repairs at the distal arch, a site especially prone to aneurysm. In March 2008, TAG (W.L. Gore & Associates, Inc., Flagstaff, Arizona, USA) was approved as a stent graft for the thoracic area first in Japan, which was major turning point in treatment for thoracic aortic aneurysms. Subsequently, TALENT (Medtronic, Inc., Minneapolis, Minnesota, USA) was approved in May 2009, and TX2 (COOK MEDICAL Inc., Bloomington, Indiana, USA) in March 2011. Valiant as an improved version of TALENT was approved in November 2011, and TX2 Proform as an improved version of TX2 began to be supplied in October 2012. These stent grafts are excellent devices that showed good results in Western countries, and marked effectiveness can be expected by making the most of the characteristics of each device. A clinical trial in Japan on Najuta (tentative name) (Kawasumi Labo., Inc., Tokyo, Japan) as a line-up of fenestrated stent grafts that can be applied to distal arch aneurysms showing a high incidence, and allow maintenance of blood flow to the arch vessel was initiated. This trial was completed, and Najuta has just been approved in January of 2013 in Japan, and further development is expected. In the U.S., great efforts have recently been made to develop and manufacture excellent stent grafts for thoracic aneurysms, and rapid progress has been achieved. In particular, in the area of the aortic arch, in which we often experience aneurysmal change, but there are no commercially available devices which are urgently needed. Companies are competing keenly to develop devices. To our knowledge, more than 4 manufacturers are involved in the development of functionally new stent grafts in this area. The introduction of branched stent grafts may not be faraway.