Device parameter to evaluate exciton energy transfer in organic whispering-gallery-mode microresonators and its dependence on the amplified spontaneous emission threshold.

Exciton energy transfer in organic whispering-gallery-mode (WGM) resonators and its effect on the amplified spontaneous emission (ASE) threshold have been investigated using the stilbene-based energy donor 4,4'-bis[(N-carbazole)styryl]biphenyl (BSB-Cz) and the coumarin-based energy acceptor 2,3,6,7-tetrahydro-1,1,7,7,-tetramethyl-1H,5H,11H-10-(2-benzothiazolyl)quinolizino[9,9a,1gh]coumarin (C545T). Using the stacked-layer structure of BSB-Cz/C545T/BSB-Cz, we fabricated bowl-shaped microresonators on silica microspheres with a total thickness of 250 nm fixing the thickness of the C545T layer to 1 nm. The ASE threshold depended on the thicknesses of the top and bottom BSB-Cz layers, which affect the magnitude of the energy transfer. To assess the relationship between the ASE threshold and energy transfer, we developed a device parameter to evaluate the magnitude of the energy transfer by formulating the rate equations. We found that ASE easily occurs under the condition that the C545T molecules become unable to accept energy from the BSB-Cz excitons owing to the high exciton density of C545T, and that the ASE threshold decreases with decreasing device parameter. The device parameter is useful for optimizing microresonator structures in multi-component organic WGM resonators that utilize energy transfer.

Suppression of the plasmon-quenching effect on light amplification in 20-µm-diameter plasmonic whispering gallery mode resonators fabricated from bowl-shaped organic/metal thin films.

Bowl-shaped plasmonic whispering gallery mode (WGM) resonators were fabricated from a 10-nm-thick metal (Al, Ag, or Au) plasmonic layer that was covered with a 100-nm-thick 4,4'-bis(N-carbazolyl)-1,1'-biphenyl spacer layer and a 250-nm-thick 2,7-bis[9,9-di(4-methylphenyl)-fluoren-2-yl]-9,9-di(4-methylphenyl)fluorene light-emitting layer; the layer structure was grown on a 20-µm-diameter silica microsphere. When compared with a reference structure without the plasmonic layer, the resonators, which included either Al or Ag, showed almost the same threshold excitation intensities for generation of amplified spontaneous emission (ASE). This result indicates that the ease of light amplification in the plasmonic resonators was comparable to that in the reference structure. Excitons that exist in the vicinity of metal thin films are generally easy to quench because propagating surface plasmon polaritons (SPPs) absorb the exciton energy. Therefore, the observed comparability demonstrates that the plasmonic WGM resonators overcome this quenching effect on ASE via localization of the SPPs in the vicinity of the excitons.

3-Fr steerable microcatheter system via the upper limb artery in RADPLAT for right maxillary cancer.

BACKGROUND: To evaluate the efficacy of a catheter system using a 3-Fr sheath with a steerable microcatheter through right upper limb artery access for superselective intra-arterial cisplatin infusion and concomitant radiotherapy (RADPLAT) to treat right maxillary sinus squamous cell carcinoma (MS-SCC). MATERIAL AND METHODS: We retrospectively studied 46 sessions in eight patients treated between November 2020 and February 2023 using the catheter system briefly described below. A 3-Fr sheath was inserted into the distal radial, conventional radial, or brachial arteries. A coaxial catheter system with a 2.9-Fr steerable microcatheter and a 1.9-Fr microcatheter was advanced into the brachiocephalic artery. The right common carotid artery was selected by bending the tip of the steerable microcatheter. Coil embolization and intra-arterial cisplatin infusion after selecting each external carotid artery branch were achieved using this catheter system. RESULTS: Cisplatin infusion and coil embolization were successful in all sessions. Arterial occlusion at the sheath insertion sites was found in 29.4% (5/17) of the distal radial arteries and 33.3% (3/9) of the conventional radial arteries. No other major complications were observed during the procedure. CONCLUSION: Using a 3-Fr catheter system with a steerable microcatheter through right upper limb artery access is a feasible method for RADPLAT in treating right MS-SCC.

A Comparison of Outcomes Based on Vessel Type (Native Artery vs. Bypass Graft) and Artery Location (Below-Knee Artery vs. Non-Below-Knee Artery) Using a Combination of Multiple Endovascular Techniques for Acute Lower Limb Ischemia.

BACKGROUND: To evaluate outcomes of endovascular treatment (EVT) using a combination of multiple endovascular techniques for acute lower limb ischemia (ALLI) and to compare outcomes based on vessel type and artery location. METHODS: A total of 95 consecutive patients with ALLI (mean age, 72.0 years; 65 males; 104 lower limbs) who received emergency EVT using a combination of multiple endovascular techniques including thrombolysis, aspiration thrombectomy, stenting, and balloon angioplasty with or without surgical thromboembolectomy, between January 2005 and December 2017 were included. Vessel type was classified into native artery occlusion (native occlusion) and bypass graft occlusion (graft occlusion), including prosthetic and vein graft. Additionally, native arteries were categorized into below-knee occlusion and non-below-knee occlusion. Technical success, perioperative death (POD), ALLI-related death, amputation, amputation-free survival (AFS), and complications were compared according to vessel type (native occlusion vs. graft occlusion) and artery location (below-knee occlusion vs. non-below-knee occlusion). RESULTS: Of all patients with ALLI, 16.8% underwent a single endovascular technique, whereas 83.2% underwent a combination of multiple endovascular techniques. The technicalsuccess, POD, and ALLI-related death rates in the total number of patients were 94.7%, 11.6%, and 4.2%, respectively. A total of 67 patients (75 limbs) and 28 patients (29 limbs) were classified as having native occlusion and graft occlusion (prosthetic, 24 limbs; vein, 5 limbs), respectively. No significant differences in technical success (native occlusion: 92.5% vs. graft occlusion: 100%), POD (14.9% vs. 3.6%), and ALLI-related death (6.0% vs. 0%) were noted between native occlusion and graft occlusion. However, the 30-day AFS rate of native occlusion was significantly lower than that of graft occlusion (75.2% vs. 96.3%, P=0.01). The amputation rate (P=0.03) and AFS rate (P=0.03) of below-knee occlusion were significantly worse for below-knee occlusion patients than for non-below-knee occlusion patients. CONCLUSIONS: EVT using multiple endovascular techniques for ALLI is effective and safe. A combination of multiple endovascular techniques is crucial for successful treatment. However, native occlusion may have a lower AFS rate than graft occlusion, and below-knee occlusion may have a higher risk of amputation than non-below-knee occlusion.

Ferrocene on Insulator: Silane Coupling to a SiO2 Surface and Influence on Electrical Transport at a Buried Interface with an Organic Semiconductor Layer.

A silane coupling-based procedure for decoration of an insulator surface containing abundant hydroxy groups by constructing redox-active self-assembled monolayers (SAMs) is described. A newly synthesized ferrocene (Fc) derivative containing a triethoxysilyl group designated FcSi was immobilized on SiO2/Si by a simple operation that involved immersing the substrate in a toluene solution of the Fc silane coupling reagent and then rinsing the resulting substrate. X-ray photoelectron spectroscopy (XPS) measurements confirmed that the Fc group was immobilized on SiO2/Si in the Fe(II) state. Cyclic voltammetry measurements showed that the Fc groups were electrically insulated from the Si electrode by the SiO2 layer. The FcSi on SiO2/Si structures were found to serve as a good scaffold for formation of organic semiconductor thin films by vacuum thermal evaporation of C8-BTBT (2,7-dioctyl[1]benzothieno[3,2-b][1]benzothiophene), which is well-known as an organic field-effect transistor (OFET) material. The X-ray diffraction profile indicated that the conventional standing-up conformation of the C8-BTBT molecules perpendicular to the substrates was maintained in the thin films formed on FcSi@SiO2/Si. Further vacuum thermal evaporation of Au provided an FcSi-based OFET structure with good transfer characteristics. The FcSi-based OFET showed pronounced source-drain current hysteresis between the forward and backward scans. The degree of this hysteresis was varied reversibly via gate bias manipulation, which was presumably accompanied by trapping and detrapping of hole carriers at the Fc-decorated SiO2 surface. These findings provide new insights into application of redox-active SAMs to nonvolatile OFET memories while also creating new interfaces through junctions with functional thin films, in which the underlying redox-active SAMs play supporting roles.

Immobilizing a π-Conjugated Catecholato Framework on Surfaces of SiO2 Insulator Films via a One-Atom Anchor of a Platinum Metal Center to Modulate Organic Transistor Performance.

Chemical modification of insulating material surfaces is an important methodology to improve the performance of organic field-effect transistors (OFETs). However, few redox-active self-assembled monolayers (SAMs) have been constructed on gate insulator film surfaces, in contrast to the numerous SAMs formed on many types of conducting electrodes. In this study, we report a new approach to introduce a π-conjugated organic fragment in close proximity to an insulating material surface via a transition metal center acting as a one-atom anchor. On the basis of the reported coordination chemistry of a catecholato complex of Pt(II) in solution, we demonstrate that ligand exchange can occur on an insulating material surface, affording SAMs on the SiO2 surface derived from a newly synthesized Pt(II) complex containing a benzothienobenzothiophene (BTBT) framework in the catecholato ligand. The resultant SAMs were characterized in detail by water contact angle measurements, X-ray photoelectron spectroscopy, atomic force microscopy, and cyclic voltammetry. The SAMs served as good scaffolds of π-conjugated pillars for forming thin films of a well-known organic semiconductor C8-BTBT (2,7-dioctyl[1]benzothieno[3,2-b][1]benzothiophene), accompanied by the engagements of the C8-BTBT molecules with the SAMs containing the common BTBT framework at the first layer on SiO2. OFETs containing the SAMs displayed improved performance in terms of hole mobility and onset voltage, presumably because of the unique interfacial structure between the organic semiconducting and inorganic insulating layers. These findings provide important insight into creating new elaborate interfaces through installing coordination chemistry in solution to solid surfaces, as well as OFET design by considering the compatibility between SAMs and organic semiconductors.

An Extremely Rare Complication: Abdominal Aortic Aneurysm Rupture Caused by Migration of a Zenith Main Body Years After Repair of the Suprarenal Stent Separation.

PURPOSE: To report an unusual case of an abdominal aortic aneurysm (AAA) rupture caused by migration of a Zenith stent-graft main body years after its separation from the suprarenal stent. CASE REPORT: A 72-year-old man underwent endovascular aneurysm repair with a Zenith stent-graft for an infrarenal AAA in year 2000. At that time, a femorofemoral bypass was performed because the left external iliac and common femoral arteries were dissected during treatment. In 2013, follow-up computed tomography (CT) showed disconnection of the uncovered proximal stent, which led to a type Ia endoleak. An additional Zenith main body and Large Palmaz XL balloon-expandable stent were deployed; the endoleak disappeared. In 2016, the patient had abdominal pain, and emergency CT showed AAA rupture caused by migration of the first main body deployed in 2000 under the distal edge of the contralateral (left) leg of the additional main body from 2013, which led to a type IIIa endoleak between the 2 main bodies. A converter and iliac legs were deployed to successfully seal the type IIIa endoleak. The patient remains well 18 months after the second repair; CT scans document stable stent-grafts and no endoleak. CONCLUSION: Physicians should be aware of the potential risk for AAA rupture caused by late main body migration after treatment for suprarenal stent separation from a Zenith stent-graft.

Orexigenic action of oral zinc: metabolomic analysis in the rat hypothalamus.

We previously reported an orexigenic action of oral zinc administration in male Sprague-Dawley (SD) rats during an early stage of feeding with a zinc-deficient diet, without decreased zinc concentrations in tissues. The overall conclusion was that orally but not intraperitoneally administered zinc stimulates food intake in short-term zinc-deficient-diet fed rats. We here investigate the mechanism of the orexigenic action of zinc using GC-MS/MS-targeted metabolomic analysis in the rat hypothalamus. Four-week-old, male SD/Slc rats were used, and after 2 days of feeding with a zinc-deficient diet, 3 mg of ZnSO4 in 5 mL saline solution were administered to each rat either orally or intraperitoneally. Three hours after administration, the rats were sacrificed and the hypothalamus were excised and analyzed. We found that the oral administration group showed increased concentrations of 3-aminopropanoic acid (ß-alanine), hypotaurine, dopamine, and biotin. In light of metabolomic analysis of these results, we indicate directions for further research.

Gapless quantum spin liquid in an organic spin-1/2 triangular-lattice κ-H3(Cat-EDT-TTF)2.

We report the results of SQUID and torque magnetometry of an organic spin-1/2 triangular-lattice κ-H(3)(Cat-EDT-TTF)(2). Despite antiferromagnetic exchange coupling at 80-100 K, we observed no sign of antiferromagnetic order down to 50 mK owing to spin frustration on the triangular lattice. In addition, we found nearly temperature-independent susceptibility below 3 K associated with Pauli paramagnetism. These observations suggest the development of gapless quantum spin liquid as the ground state. On the basis of a comparative discussion, we point out that the gapless quantum spin liquid states in organic systems share a possible mechanism, namely the formation of a band with a Fermi surface possibly attributed to spinons.

Negative-balance isolated pelvic perfusion in patients with incurable symptomatic rectal cancer: results and drug dose correlation to adverse events.

BACKGROUND: Drug leakage and lack of a drug-removal system have prevented clinical application of isolated pelvic perfusion (IPP). These barriers were overcome with negative-balance IPP (NIPP) in experimental pig models. Here, a phase 1 clinical study of NIPP was performed in patients with incurable symptomatic rectal cancer. PURPOSE: To establish a safe regimen of high-dose regional chemotherapy with NIPP using cisplatin in patients with incurable rectal cancer. MATERIAL AND METHODS: Between June 2004 and January 2007, NIPP therapy was performed for 23 patients (11 women, 12 men; mean age, 58 years). NIPP was routinely performed twice over a 4-week interval. Dose-limiting toxicities (DLTs) were defined using a 5 + 3 design, and cisplatin doses were escalated from 170 mg/m(2), with a fixed 5-fluorouracil dose of 1000 mg/m(2). The grade of adverse events (AEs) at the first and second sessions of NIPP therapy, pharmacokinetics, and antitumor response were evaluated. RESULTS: No DLTs were observed during the first session of NIPP. However, at the second session, two patients experienced the DLT of neuropathy after administration of 200 mg/m(2) cisplatin. Therefore, 190 mg/m(2) cisplatin was indicated as the maximum tolerated dose (MTD). The plasma pelvic-to-systemic exposure ratio was 18.4 based on the maximum concentration and 19.0 based on the concentration-time curve. Solid tumor responses included complete response in two patients, partial response in five patients, stable disease in 15 patients, and progressive disease in one patient. CONCLUSION: NIPP may offer the safe delivery of high-dose regional chemotherapy (MTD of 190 mg/m(2) cisplatin) with negligible AEs and effective control of tumor growth in patients with incurable rectal cancer.

Mechanism of enhanced optical second-harmonic generation in the conducting pyrochlore-type Pb2Ir2O7-x oxide compound.

The structural, electronic, and optical properties of pyrochlore-type Pb(2)Ir(2)O(6)O(0.55)('), which is a metal without spatial inversion symmetry at room temperature, were investigated. Structural analysis revealed that the structural distortion relevant to the breakdown of the inversion symmetry is dominated by the Pb-O' network but is very small in the Ir-O network. At the same time, gigantic second-harmonic generation signals were observed, which can only occur if the local environment of the Ir 5d electrons features broken inversion symmetry. First-principles electronic structure calculations reveal that the underlying mechanism for this phenomenon is the induction of the noncentrosymmetricity in the Ir 5d bands by the strong hybridization with O' 2p orbitals. Our results stimulate theoretical study of inversion-broken iridates, where exotic quantum states such as a topological insulator and Dirac semimetal are anticipated.

Nonequilibrium noise as a probe of pair-tunneling transport in the BCS-BEC crossover.

The detection of elementary carriers in transport phenomena is one of the most important keys to understand nontrivial properties of strongly correlated quantum matter. Here, we propose a method to identify the tunneling current carrier in strongly interacting fermions from nonequilibrium noise in the Bardeen-Cooper-Schrieffer to Bose-Einstein condensate crossover. The noise-to-current ratio, the Fano factor, can be a crucial probe for the current carrier. Bringing strongly correlated fermions into contact with a dilute reservoir produces a tunneling current in between. The associated Fano factor increases from one to two as the interaction becomes stronger, reflecting the fact that the dominant conduction channel changes from the quasiparticle tunneling to the pair tunneling.

Glue embolization for endoscopically unmanageable gastrointestinal haemorrhage.

BACKGROUND/AIMS: To evaluate the clinical feasibility of embolization with n-butyl cyanoacrylate (NBCA) for endoscopically unmanageable non-variceal gastrointestinal hemorrhage (GIH). METHODOLOGY: Between June 2004 and May 2009, 61 patients with confirmed acute upper and/or lower GIH underwent emergency embolization for haemorrhage control; NBCA was used in 28 of these patients, all of whom were in shock despite receiving blood transfusions. The results were studied retrospectively. Clinical parameters and embolization data were assessed for technical success, clinical success and outcome. RESULTS: Technical success was achieved in all patients. Clinical success was achieved in 19 (68%) of the 28 patients. The mortality rate was 25% (7 patients). The cause of death was disseminated intravascular coagulation (DIC) in 6 patients and heart failure in 1. The presence of coagulopathy or DIC significantly decreased the degree of clinical success (p=0.015, p=0.001, respectively) and increased the mortality rate (p=0.013, p<0.001, respectively). Unfortunately, 86% patients who had DIC before embolization, died. CONCLUSIONS: NBCA embolization is technically feasible and is effective for the control of haemorrhage in endoscopically unmanageable GIH. However, the presence of coagulopathy or DIC significantly decreases the clinical success and increases the mortality rate.

Massive pulmonary embolism requiring extracorporeal life support treated with catheter-based interventions.

When pulmonary embolism (PE) develops, circulatory collapse and hypoxia are caused at the same time. The rapid and proper use of extracorporeal life support (ECLS) can improve the mortality rate of patients with collapsed massive PE. No study has examined the influence of treatment that involved adding catheter based-intervention to ECLS with massive collapsed PE. Thirty-five patients with massive PE were examined, and 10 of these patients were placed on ECLS. Eight of the 10 patients placed on ECLS for massive PE were female, and the median age was 61 years. Seven patients had in-hospital onset PE and 3 patients out-of-hospital onset PE. Their underlying conditions were a cerebral infarction (3 patients), coronary artery disease (5 patients), collagen disease (one patient), postoperative state (3 patients), and lung disease (2 patients). Pulmonary angiographic findings showed that a filling defect or complete occlusion was observed in all 10 patients in the proximal lobular arteries, 6 of which had large thrombi stretching to the main pulmonary arteries. All patients underwent thrombolysis. Percutaneous catheter embolus fragmentation and/or thrombectomy were undertaken in 7 patients. All patients required red blood cell transfusion for cannulation site bleeding. The mean duration of ECLS bypass was 48 ± 44 hours. The 30 day mortality rate was 30%. The current study clarified the characteristics of patients with massive PE requiring ECLS. These patients have extensive pulmonary thromboemboli, thus, the aggressive use of catheter-based intervention appears to have beneficial effects for massive PE requiring ECLS.

Elective Endovascular Stent-Graft Implantation for External Iliac Artery Injury after Blunt Pelvic Trauma.

External iliac artery (EIA) injuries caused by blunt trauma are rare. Here, we describe a blunt EIA injury after a motorbike accident suffered by a 16-year-old male. Despite conservative treatment, intermittent claudication persisted. He was successfully treated by elective endovascular stent-graft implantation on day 59 after the injury. Ankle-brachial index (ABI) improved, as did his symptoms. A contrast-enhanced computed tomography scan on postoperative day 90 showed no residual stenosis and favorable peripheral blood flow. This report suggests that elective endovascular stent-graft implantation might be a viable treatment option for blunt EIA injuries.

Endovascular treatment with Viabahn stent-grafts for arterial injury and bleeding at the visceral arteries: initial and midterm results.

PURPOSE: The purpose of the study is to evaluate the initial and midterm efficacy and safety of endovascular treatment (EVT) using Viabahn stent-graft (SG) for arterial injury and bleeding (AIB) at the visceral arteries. MATERIALS AND METHODS: Consecutive patients with visceral AIB who underwent EVT using Viabahn between January 2017 and February 2021 were retrospectively reviewed. Technical success, clinical success, peripheral organ ischemia, peri-procedural complications, bleeding-related mortality, 30-day mortality, neck length, re-bleeding, endoleaks, and patency of the SGs at 1, 3, 6, and 12 months were evaluated. RESULTS: EVT using Viabahn was performed in 14 patients (mean age: 68.6 years; 12 males) and 15 arteries. The technical and clinical success rates were 100%. The rates of peripheral organ ischemia, peri-procedural complications, bleeding-related mortality, and 30-day mortality were all 0%. The mean neck length was 9.9 mm. No endoleaks or re-bleeding occurred during the follow-up (mean: 732 days). The SG patency was confirmed after 1, 3, 6, and 12 months in 78.6%, 78.6%, 78.6%, and 56.1% of the patients, respectively. CONCLUSION: EVT using Viabahn for AIB at the visceral arteries was safe and effective. SG occlusions without ischemia often occurred after 12 months.

Impact of Cytoreductive Nephrectomy Following Nivolumab Plus Ipilimumab Therapy for Patients With Advanced Renal Cell Carcinoma.

BACKGROUND/AIM: CheckMate 214 study revealed that nivolumab plus ipilimumab combination therapy showed a strong and durable effect compared to sunitinib for patients with advanced renal cell carcinoma (aRCC). Most of the patients underwent previous nephrectomy before systemic treatment. We retrospectively investigated the clinical outcomes of Japanese patients treated with cytoreductive nephrectomy following nivolumab plus ipilimumab for aRCC. PATIENTS AND METHODS: Seventy-nine patients were treated with systemic therapy for aRCC between October 2018 and August 2021 at the Saitama Medical University International Medical Center. Ten of 61 patients treated with nivolumab plus ipilimumab underwent cytoreductive nephrectomy after the combined immunotherapy. RESULTS: The median overall survival and progression-free survival were 24.3 and 15.9 months, respectively. The objective response rate was 50.8%; 9.8% of patients had a complete response, and the median time to objective response was 3.2 (range=1.3-19.7) months. The estimated percentage of patients who sustained an objective response at 30 months was 73.0%. Twenty-three patients (74%) in the complete or partial response (CR/PR) group, 11 patients (52%) in the stable disease (SD) group, and two patients (22%) in the progressive disease (PD) group had immune-related adverse events of grade 3 or higher, respectively. For all 10 patients, cytoreductive nephrectomy following nivolumab plus ipilimumab treatment were completed safely. Three patients achieved a pathological complete response without viable cancer cells. Only two patients had residual lesions on images after deferred cytoreductive nephrectomy; the remaining patients achieved radiological CR. CONCLUSION: Cytoreductive nephrectomy after nivolumab plus ipilimumab treatment could be useful in a limited number of cases, possibly resulting in curative nephrectomy due to the durable therapeutic effect of immunotherapy.

Traumatic renal artery occlusion treated with an endovascular stent--the limitations of surgical revascularization: report of a case.

When renal artery occlusion occurs secondary to blunt trauma, the recovery rate of renal function after open revascularization is varied and far from satisfactory. Although the optimal treatment for this type of injury has not been established, percutaneous revascularization by endovascular stenting has recently been advocated for patients with unilateral renal artery occlusion. We herein report a case of blunt renal artery occlusion treated with an endovascular stent. After the placement of the stent, renal arteriography showed multiple nonflow-limiting contrast defects in the distal renal arteries, suggesting peripheral thrombosis. Although the duration of warm renal ischemia appears to be the crucial determinant of renal function, multiple thrombi in the distal renal arteries, which would be undetectable during open surgery, could also affect the functional outcome. The presence of these thrombi may explain the limited success of surgical revascularization in such cases.

Late clinical outcomes of manual aspiration thrombectomy for a massive acute pulmonary thromboembolism.

PURPOSE: We investigated the late outcomes of patients who underwent manual aspiration thrombectomy for acute massive pulmonary thromboembolism. MATERIALS AND METHODS: Fifteen patients underwent manual aspiration thrombectomy between December 1995 and June 2002. All patients were discharged after the procedure. Patients' statuses were checked by medical record examinations and telephone interviews. The median follow-up was 162 months (116-208 months). RESULTS: Five patients died during follow-up; two for malignancy, one for septic shock, one for cerebral infarction, and in one patient the cause of death was unknown. There were no pulmonary thromboembolism-related deaths during the period and no recurrence. The 1-year survival rate was 100%, the 5-year survival rate was 75.0 ± 12.5%, and the 10-year survival rate was 75.0 ± 12.5%. CONCLUSION: Patients who undergo manual aspiration thrombectomy for acute massive pulmonary thromboembolism show acceptable outcomes.

Emergency endovascular treatment using a Viabahn stent graft for upper and lower extremity arterial bleeding: a retrospective study.

BACKGROUND: A Viabahn stent graft (SG) is a heparin-coated self-expandable SG for lower extremity arterial disease that exhibits high flexibility and accuracy in the delivery system. This study aimed to evaluate the short-term efficacy and safety of emergency endovascular treatment (EVT) using a Viabahn SG for upper and lower extremity arterial bleeding (ULEAB). METHODS: Consecutive patients with ULEAB who underwent emergency EVT using the Viabahn SG between January 2017 and August 2021 were retrospectively reviewed. The indications for EVT, location of artery, technical success, clinical success, limb ischemia, periprocedural complications, bleeding-related mortality, 30-day mortality, diameter of the target artery, diameter of the SG, neck length, rebleeding, endoleaks, and patency of the SGs at 1, 3, 6, and 12 months were evaluated. RESULTS: EVT using the Viabahn SG was performed in 22 patients (mean age, 72.0 ± 13.0 years; 11 men) and 23 arteries (upper, 6; lower, 17). The indications for EVT were pseudoaneurysm (n = 13, 59.1%), extravasation (n = 9, 39.1%), and inadvertent arterial cannulation (n = 1, 4.3%). The anatomical locations of the 23 ULEAB injuries were the brachiocephalic (1 [4.3%]), subclavian (3 [13.0%]), axillary (1 [4.3%]), brachial (1 [4.3%]), common iliac (4 [17.4%]), external iliac (8 [34.8%]), common femoral (2 [8.7%]), superficial femoral (2 [8.7%]), and popliteal (1 [4.3%]) arteries. The technical and clinical success rates were 100%. The rates of limb ischemia, periprocedural complications, and bleeding-related mortality were 0%, whereas the 30-day mortality rate was 22.7%. The mean diameters of the arteries and SGs were 7.7 ± 2.2 and 8.9 ± 2.3 mm, respectively. The mean neck length was 20.4 ± 11.3 mm. No endoleaks or rebleeding occurred during the follow-up period (mean, 169 ± 177 days). Two SG occlusions without limb ischemia occurred in the external iliac and brachial arteries after 1 and 4 months, respectively. Subsequently, cumulative SG patency was confirmed after 1, 3, 6, and 12 months in 91.7%, 91.7%, 81.5%, and 81.5% of patients, respectively. CONCLUSIONS: Emergency EVT using the Viabahn SG for ULEAB was effective and safe according to short-term outcomes. Appropriate size selection and neck length are important for successful treatment. SG patency was good after 1, 3, 6, and 12 months.