Vessel Closure Research Articles

Total clipless laparoscopic nephrectomy carried out with the LigaSure device: Preliminary experience.

Total laparoscopic nephrectomy has become the standard method for the removal of diseased kidneys. The purpose of this study was to evaluate the feasibility of the LigaSure vessel closure system during laparoscopic nephrectomy. From January 2018 to June 2018, the LigaSure device was used in 5 patients undergoing laparoscopic nephrectomy for non functional kidney. Nephrectomy was carried out without the use of clips or sutures for vessel closure. We report intraoperative findings, conversion rates, blood loss, operative time, morbidity, and postoperative outcomes. Median operative time was 45minutes (range 25 to 60min). Median blood loss was 30mL (range 10 to 50mL). No conversions to open surgery were necessary. No patients experienced major bleeding intraoperatively or postoperatively. All patients left the hospital one day after the procedure. Histopathological examination of the removed kidneys was in favor of chronic non specific pyelonephritis. For the treatment of the renal pedicle during total laparoscopic nephrectomy of a destroyed kidney, the LigaSure device appears to be feasible and effective. Our experience is the first to demonstrate the advantages of LigaSure® in laparoscopic nephrectomy: reduction in operating time, blood loss, transfusions and length of stay in hospital.

Balloon-Uncrossable Lesions: Significant Higher Recanalization-Success with Metallic-Tip Catheters 5-year Follow-Up Data from XableCath-Study

Background: The metallic tip interventional recanalization catheter XableCath showed encouraging results (95.8percentage success rate) in crossing occluding atheroma in balloon uncrossable lesions after successful passage of a guide wire. Because successful crossing of balloon-uncrossable, mostly calcified atheromatous lesions may be associated with a higher complication rate, we investigated the long-term follow-up of all twenty-two patients (24 separate lesions), who have been included into the XableCath study. Patients and Methods: We investigated the long-term outcome (5-year follow-up) of 20 lesions in 18 patients, who had successfully been treated with the XableCath metallic tip interventional recanalization catheter (XableCath Inc., Salt Lake City, Utah) for balloon-uncrossable lesions (18 femoro-popliteal (90.0 percentage), 1 below-the-knee (5.0 %), 1 common iliac (5.0 percentage), 12 total occlusions (66.7 percentage). The primary study endpoint was the rate of target lesion patency resp. target lesion complications (e.a. perforation, aneurysms, dissections, or vessel closure) achieved by duplex-sonography. Secondary endpoints were the abscence of lesion associated major adverse events (MAE) as defined as limb amputations and/or cardiovascular death during the follow-up period of 5 years. Results: Follow-up informations after 5 years (incl. duplex-sonography) could have been achieved in 18 successfully treated patients (20 lesions). 3 patients (14.3percentage) died due to not-target lesion associated cardiovascular reasons. The primary endpoint (patency rate) was 85.0 percentage, target lesion associated complications (e.a. aneurysms, perforations or dissections) were not documented in any patient (0percentage), secondary endpoint (target lesion associated major adverse cardiovascular events) did not occur in any patient (0percentage). Conclusion: The metallic-tip interventional crossing catheter XableCath is a feasible, easy to use, time and money-saving option for successful angioplasty of balloon-uncrossable PAD-lesions without a higher rate of target lesion failure or target lesion-associated adverse events during a follow-up period of 5 years after successful recanalization of a balloon uncrossable lesion.

Complications of PCI and its Management

Contemporary percutaneous coronary intervention (PCI) has few complications and enhanced safety on one hand and on the other hand, available modern tools have enabled interventional cardiologists to venture into more complex patient subsets and fresh challenges in tackling the ensuing newer complications. Individual operators may take several years of experience before being exposed to the complications and hence, it is important to learn from the collective experience on the detection and management of these complications and better equipped to handle them when the need arises. The complications of PCI can be access related or coronary intervention related. The common acute coronary complications include abrupt vessel closure, thrombus, slow flow, dissection, perforation, stent dislodgement, and guidewire fracture and embolization. The chronic complications include late stent thrombosis, in-stent restenosis, and aneurysm formation. The use of imaging, physiology, and plaque modification tools are associated with specific complications which need to be kept in mind while using them. The successful management of complications needs prompt recognition, involving help from others and continued team effort and vigilance.

Intraplaque wiring enables drug-coated balloons to be utilized for percutaneous recanalization of chronically occluded coronary arteries.

This study aimed to determine whether drug-coated balloon (DCB) angioplasty following intraplaque wiring and the use of modified balloons is safe and effective in the percutaneous treatment of coronary chronic total occlusions (CTOs). DCB is an alternative therapeutic option without the limitations of permanent vascular implants. However, its efficacy in CTOs has yet to be confirmed. The combination of modified balloons and DCB can be effectively applied when the intraplaque passage of the guidewire is achieved in CTOs. Data from 124 consecutive CTO lesions (105 patients) treated at our hospital between February 2016 and December 2020 were screened for inclusion and retrospectively analyzed. Among the 118 lesions successfully recanalized, intraplaque wiring was achieved in 108, and 85 were treated by the DCB-only approach following cutting/scoring balloon dilatation. Follow-up data were available for 82 lesions (71 patients). The median occlusion length was 18.5 mm, and the J-CTO score was 1.7 ± 0.9. No in-hospital major adverse cardiac events occurred, including abrupt vessel closure. During the median 29-month follow-up period, target lesion revascularization was performed for 10 lesions. Follow-up coronary angiography (8.7 ± 3.9 months after the index procedure) was performed for 64 lesions, demonstrating late lumen loss of -0.15 mm (interquartile range -0.4 to 0.23 mm), binary restenosis (diameter stenosis ≥50%) in 12 lesions (18.8%), and late lumen enlargement in 37 (57.8%). The DCB-only approach following the use of modified balloons is a promising strategy for coronary CTOs when intraplaque wiring is achieved.

Multicentre International Registry of Open Surgical Versus Percutaneous Upper Extremity Access During Endovascular Aortic Procedures

To investigate access failure (AF) and stroke rates of aortic procedures performed with upper extremity access (UEA), and compare results of open surgical vs. percutaneous UEA techniques with closure devices. A physician initiated, multicentre, ambispective, observational registry (SUPERAXA - NCT04589962) was carried out of patients undergoing aortic procedures requiring UEA, including transcatheter aortic valve replacement, aortic arch, and thoraco-abdominal aortic endovascular repair, pararenal parallel grafts, renovisceral and iliac vessels repair. Only vascular procedures performed with an open surgical or percutaneous (with a suture mediated vessel closure device) UEA were analysed. Risk factors and endpoints were classified according to the Society for Vascular Surgery and VARC-3 (Valve Academic Research Consortium) reporting standards. A logistic regression model was used to identify AF and stroke risk predictors, and propensity matching was employed to compare the UEA closure techniques. Sixteen centres registered 1 098 patients (806 men [73.4%]; median age 74 years, interquartile range 69 - 79 years) undergoing vascular procedures using open surgical (76%) or percutaneous (24%) UEA. Overall AF and stroke rates were 6.8% and 3.0%, respectively. Independent predictors of AF by multivariable analysis included pacemaker ipsilateral to the access (odds ratio [OR] 3.8, 95% confidence interval [CI] 1.2 - 12.1; p = .026), branched/fenestrated procedure (OR 3.4, 95% CI 1.2 - 9.6; p = .019) and introducer internal diameter ≥ 14 F (OR 6.6, 95% CI 2.1 - 20.7; p = .001). Stroke was associated with female sex (OR 3.4, 95% CI 1.3 - 9.0; p = .013), vessel diameter > 7 mm (OR 3.9, 95% CI 1.1 - 13.8; p = .037), and aortic arch procedure (OR 7.3, 95% CI 1.7 - 31.1; p = .007). After 1:1 propensity matching, there was no difference between open surgical and percutaneous cohorts. However, a statistically significantly higher number of endovascular adjunctive procedures were recorded in the percutaneous cohort (p < .001). AF and stroke rates during complex aortic procedures employing UEA are non-negligible. Therefore, selective use of UEA is warranted. Percutaneous access with vessel closure devices is associated with similar complication rates, but more adjunctive endovascular procedures are required to avoid surgical exposure.

Percutaneous coronary intervention with drug-coated balloon-only strategy combined with single antiplatelet treatment in patients at high bleeding risk:Single center experience of a novel concept.

At least 1 month of dual antiplatelet therapy is required after coronary stenting. The aim of this all-comers retrospective registry study was to assess the efficacy and safety of percutaneous coronary intervention (PCI) using drug-coated balloon (DCB) with single antiplatelet treatment (SAPT). Between 2011 and 2020, 232 PCIs were performed in 172 patients using the DCB-only strategy and discharged with SAPT. The mean age of the patients was 75 ± 11 years and 59% were male. The clinical presentation was stable coronary artery disease (CAD) in 42% of the patients and acute coronary syndrome (ACS) in 58%. The lesions were mainly de novo (96%). The majority (58%) of treated lesions were in large coronary arteries (≥3.0 mm). Most (87%) of the patients were at high bleeding risk (HBR) with at least one major or two minor Academic Research Consortium (ARC) risk factors for bleeding. Periprocedural DAPT was used in 49% of the patients. The 12-month major adverse cardiac events (MACE, the composition of cardiovascular death, nonfatal myocardial infarction, and target-lesion revascularization) rate was 1.4% in stable CAD and 7.1% in ACS. The 12-month all-cause mortality after DBC only + SAPT strategy was 4.1% in stable CAD and 12.1% in ACS. The rate of ischemia-driven target lesion revascularisation (TLR) was 0% in stable CAD and 3.0% in ACS at 12 months. The 12-month rate of significant bleeding (BARC type 2-5) was 10.5%. There were no acute or subacute vessel closures. Despite the aged patient population with comorbidities, the TLR, MACE, and bleeding rates were low with DCB-only PCI combined with SAPT. This novel approach could reduce the post-PCI bleeding risk in patients with CAD and HBR compared to stenting.

Acute Vessel Closure or Major Adverse Cardiac Events of Drug-Coated Balloons and Stents: A Systematic Review and Meta-Analysis

While the use of drug-eluting stents (DES) has become the first-line strategy for treating coronary artery disease, there are still drawbacks with their use. As our understanding of coronary artery anatomy and physiology evolves, growing evidence supports the use of drug-coated balloons (DCB) not only in the treatment of in-stent restenosis but also in de novo lesions. The aim of this systematic review and meta-analysis is to determine if there is a difference in outcomes when DCBs are used versus when stents are used. PubMed, Cochrane and Web of Science databases were systematically searched. The primary outcome of the meta-analysis was acute vessel closure and the secondary outcomes were stent complications including major adverse cardiovascular events (MACE) and all-cause mortality. Eleven studies with a total of 2349 patients were included. No significant difference was found in terms of acute vessel closure between DCBs and all stents (2.6% vs. 1.0%, OR: 2.13 (0.74–6.44), I2: 4%, p = 0.16). Furthermore, there was no difference in MACE (6.8% vs. 10.1%, OR: 0.53 (0.27–1.04), I2: 48%, p = 0.06), all-cause mortality and target lesion revascularisation. This meta-analysis suggests that the use of DCBs is a safe alternative to stents when treating coronary artery disease.

Metal free percutaneous coronary interventions in all-comers: First experience with a novel sirolimus-coated balloon.

Limus-eluting stents have become the mainstay for percutaneous coronary intervention (PCI). However, even with the latest generation drug-eluting stent, in-stent restenosis and very late stent thrombosis remain a concern. The Selution SLR™ drug-coated balloon (DCB) is a novel sirolimus-coated balloon that provides a controlled release of the antiproliferative drug. Herein we evaluated its performance in a real-world patient cohort with complex coronary artery lesions. Patients undergoing PCI using the Selution SLR™ DCB were analyzed from the prospective SIROOP registry. We evaluated procedural success and clinical outcomes, including major adverse cardiovascular event (MACE), cardiac death, target vessel myocardial infarction and target lesion revascularization. From September 2020 to April 2021, we enrolled 78 patients (87 lesions) treated using a "DCB only" strategy. The mean age was 66.7 ± 10.4 years and 28 (36%) presented with an acute coronary syndrome. Almost all lesions were type B2/C 86 (99%) and 49 (63%) had moderate to severe calcifications. Procedural success was 100%. After a median follow-up of 11.2 months (interquartile range: 10.0-12.6), MACE occurred in 5 (6.8%) patients. No acute vessel closure was observed. In complex coronary lesions, a "DCB only" strategy using the Selution SLR™ DCB is not just safe and feasible, but also seems to be associated with a low rate of MACE at 1-year follow-up. Our promising results warrant further evaluation in a dedicated comparative trial.

Different Risk Profiles for Progression of Nonproliferative Diabetic Retinopathy: A 2-Year Study.

Characterization of 2-year progression of different risk phenotypes in eyes with mild and moderate nonproliferative diabetic retinopathy (NPDR) in type 2 diabetes (T2D). A 2-year prospective longitudinal cohort study (CORDIS, NCT03696810) was conducted. Ophthalmological examinations were performed including best corrected visual acuity, color fundus photography and optical coherence tomography (OCT and OCTA). OCT metrics, central retinal thickness and ganglion cell layer + inner plexiform layer (GCL + IPL) thickness were analyzed. OCTA metrics, vessel density (VD), perfusion density (PD) and area of intercapillary spaces (AIS) were obtained from superficial and deep capillary plexus (SCP, DCP). Only phenotype C identified by decreased VD ≥ 2 SD of healthy controls and phenotype B identified by subclinical macular edema with decreased VD < 2 SD of healthy controls were included. One hundred twenty-two eyes from T2D individuals were included in study; 65 eyes (53%) were classified as phenotype B and 57 eyes (47%) as phenotype C. For phenotype B, progression was associated with thinning of the GCL + IPL (ETDRS 35, 1 year p = 0.013, 2 year p < 0.001; ETDRS 43-47, 2 year p = 0.003) and vessel closure involving mainly the DCP for both ETDRS grades (ETDRS 35, 1 year p = 0.025, 2 year p = 0.034; ETDRS 43-47, 1 year p = 0.011). For phenotype C there was also progressive thinning of the GCL + IPL (ETDRS 35, in both years p ≤ 0.001; ETDRS 43-47, 1 year p = 0.002, 2 year p = 0.001), with vessel closure involving mainly SCP (ETDRS 35, 1 year p = 0.012, 2 year p = 0.023 in full-retina), which appeared to stabilize at maximal values in ETDRS grade 43-47 at the end of 2 years. ETDRS severity changes at the end of the 2-year period showed that worsening was associated with phenotype C with changes involving predominantly the SCP (VD, p = 0.005; PD, p = 0.008; AIS, p = 0.005). Association between ETDRS classification of NPDR severity and identification of different risk phenotypes offers new perspective to predict disease progression in T2D individuals with NPDR.

Structural Optimization, Fabrication, and Corrosion Behaviors of Biodegradable Mg-Nd-Zn-Zr Alloy Hemostatic Clip

In this study, the process of ligating blood vessels via biodegradable Mg alloy hemostatic clips with toothless, transverse teeth, and embedded teeth was simulated through finite element analysis (FEA). The results showed that the transverse tooth clip caused the minimum stress (0.81489 MPa) to blood vessels. Furthermore, the effects of clips with transverse teeth of different parameters, including lower tooth length, tooth height, and tooth pitch, on clamped blood vessels were studied. The numerical simulation results showed that the three optimal parameters for clips with transverse teeth were 0.2, 0.1, and 0.1 mm, respectively. Then, the optimally designed clip based on the Mg–Nd–Zn–Zr alloy was manufactured and evaluated using immersion tests. Results from the corrosion behavior study showed that closed clips (0.118 ± 0.041 mg·cm−2·day−1) corroded slightly faster than open clips (0.094 ± 0.041 mg·cm−2·day−1). Moreover, micromorphological observations showed that no cracks appeared on the closed clips, indicating that the Mg alloy had excellent performance and avoided stress corrosion cracking (SCC). Thus, the new type of Mg alloy clip kept good blood vessel closure during FEA and exhibited no corrosion cracking during the degradation process, making it a promising candidate for applications with biodegradable hemostatic clips.

Buckling behaviour of auxetic domes under external pressure

In view of ongoing great interest in novel materials exhibiting Negative Poisson Ratio (NPR), the current study examines its influence on buckling behaviour of externally pressurized​ torispherical pressure vessel closures. Failure pressures are computed for the range of Poisson’s ratio: −1.0 ≤ν < 0.5. The following wall constructions are considered: (i) single auxetic layer, (ii) outer metallic skin supported on inside by an auxetic layer, and (iii) sandwich with auxetic core. Both metallic and auxetic layers are assumed to be isotropic, and exhibit elastic, perfectly plastic behaviour.Results of this numerical study show that the inclusion of auxetic can lead to 89% gain in failure pressures above auxetic-free configuration of the wall. The range of analysed diameter-to-wall thickness ratio varied between 666 and 2000. Two layer wall construction (metallic skin supported by auxetic layer), was found to exhibit better performance than the equivalent sandwich configuration.

Technical success, clinical efficacy, and insight into the causes of restenosis after the percutaneous coronary intervention of de novo coronary artery lesions using a paclitaxel-coated balloon with citrate ester excipient.

The aim of this all-comers registry study was to investigate the technical success, clinical efficacy, and safety of a drug-coated balloon (DCB) with paclitaxel combined with citrate ester excipient (CEE) in percutaneous coronary intervention (PCI) of de novo coronary lesions in an all-comers population. A total of 338 consecutive PCIs using the DCB (CEE)-only approach comprising 406 de novo lesions were included in the study. Technical success was determined by the successful delivery of the device and no need for bailout stenting. The mean follow-up time was 25 ± 12 months. The mean age of patients was 71 ± 11 years, and 48% had the acute coronary syndrome. A total of 55% of the patients were at risk of factor bleeding. The delivery of DCB was successful in 98% of cases. The overall technical success rate was 83%. Bailout stenting was used in 9% of lesions. Rotational atherectomy was used in 11% of cases before the DCB-only approach. The mean diameter of the DCBs used was 2.7 ± 0.5 mm and 38% of DCBs were large (≥3.0 mm). The 12-month MACE rates were 5.4 ± 1.7 and 18.3 ± 3.1% in stable CAD and in ACS, respectively. The respective target lesion revascularization (TLR) rates were 3.0 ± 1.3 and 8.5 ± 2.3%. Unacceptable acute recoil (>30%) was found in 74% of cases that needed repeat revascularization. No acute vessel closures occurred after DCB treatment. The DCB-only strategy using a paclitaxel-coated (CEE) device was technically feasible, safe, and effective in an all-comers population. Acute recoil was found as a significant cause of restenosis after the DCB-only strategy.

Combined strategy for large-bore arteriotomy closure after transcatheter aortic valve implantation

Abstract Background The access site vascular complications remain a relevant complication following transcatheter aortic valve implantation (TAVI). They are frequently associated with vascular closure device failure (VCD). Incidence of vascular complications depends on different factors such as patient's characteristics and clinical risk profile, femoral morphology, access sheath size or technical procedural experience. Their rate is reported between 4–19% [1]. Vascular complications negatively affect morbidity and mortality following TAVI [2]. VCDs that are most commonly used include the suture-based ProGlide and the plug-based MANTA. ProGlide was originally developed for small-bore vessel closure between 6–8F, but a combination of 2 or more devices is suitable for large-bore vessel closure &amp;gt;12F. The MANTA device is originally dedicated for large-bore vessel closure. The MANTA device was not superior to the use of 2 ProGlides in their direct comparison in terms of access site–related vascular complications or access site bleedings. Plug-based VCDs required fewer, but a different kind of bailout maneuvers [3,4]. The alternative and less frequently used strategy is intentional combination of one suture-based VCD – ProGlide with small-bore plug-based VCD AngioSeal. The data supporting this approach are very limited, but showing this concept as a safe, with lower risk of vascular or bleeding complications. Moreover, this strategy requires less additional endovascular interventions when compared with vascular closure using two suture-based VCDs [5]. Methods Retrospectively analysed single centre comparison of two different large-bore vessel closure strategies: two suture-based ProGlides (SB group) vs. intentional combination of one ProGlide with plug-based AngioSeal 8F (CB group). The primary endpoint was occurrence of access site–related vascular complications at 30-days. Results 71 consecutive patients treated between Aug/2020 and May/2021 (SB group) were compared with 68 consecutive patients treated between May/2021 and Jan/2022 (CB group). There wasn`t any significant difference in patient's characteristics between both groups: mean age 80 vs. 81 years, females 53,8% vs. 54,9%, STS score 3,46% vs. 3,47%. The only difference was higher proportion of the patients treated oral anticoagulation in SB group (46,4% vs. 38,5%). The lower rate of vascular complication was observed in CB group 2,9% vs. 7,1%. Moreover, we had to use additional VCD in 14 cases among patients from SB group to achieve haemostasis. Conclusion The intentional combination of one suture-based VCD with one plug-based VCD is effective and safe. This combined strategy was associated with lower rate of vascular complication compare the use of 2 suture-based VCDs in our patient's cohort following TAVI. Funding Acknowledgement Type of funding sources: None.

Prevalence and prognostic implications of the no-reflow phenomenon in patients undergoing primary percutaneous coronary intervention in a university center in a middle-income country

Abstract Background No-reflow (TIMI flow ≤2) during primary PCI for STEMI occurs in 7–25% of cases, indicates poor myocardial tissue perfusion, and is associated with a poor outcome. (1–3) The incidence in our hospital is unknow. Purpose To analyse the prevalence of no-reflow and the 30-day mortality in our hospital. Methods We analysed the database of a teaching hospital and identified 2463 patients who underwent primary PCI from January 2006 to December 2021. No-reflow was defined as post-PCI TIMI flow ≤2, in the absence of post-procedural significant (≥25%) residual stenosis, abrupt vessel closure, dissection, perforation, thrombus of the original target lesion, or epicardial spasm. The outcome measure was 30-day mortality. Results Of total of 2050 patients, no-reflow phenomenon was found in 413 (16.8%) patients, and it was associated with significantly higher 30-day mortality (16.7% vs. 4.29%; p = &amp;lt;0.001). Patients with no-reflow were older (60 [53–69.5] vs. 59 [51–66]; p=0.001), with a higher delay in onset of symptom to emergency department arrival (270 min vs. 247 min; p=0.001) but had similar door to balloon time (75 min vs. 80 min; p=0.434). No-reflow patients also had had fewer previous myocardial infarction (11.6 vs. 18.4; p=0.001), lower systolic blood pressure (128 mm Hg vs. 132 mm Hg; p = &amp;lt;0.001) and a Killip class &amp;gt;1 (37% vs. 26.4%; p = &amp;lt;0.001). No-reflow patients were more likely to have an anterior myocardial infarction (55.4% vs. 47.8; p=0.005), initial TIMI flow 0 (76% vs. 68%; p = &amp;lt;0.001) and TMP 0 (14.1% vs. 4.5%; p = &amp;lt;0.001). Conclusion No-reflow occurred in 16.8% of STEMI patients undergoing primary PCI and was more likely with older age, delayed presentation, anterior myocardial infarction and Killip class &amp;gt;1. No-reflow was associated with a higher mortality at 30-day follow-up. Funding Acknowledgement Type of funding sources: None.

Suture-based vs. pure plug-based vascular closure devices for VA-ECMO decannulation

Abstract Background VA-ECMO is a valuable treatment option for patients in cardiogenic shock, but complications during decannulation may worsen the overall outcome. To date, no larger study has ever compared suture-based to pure plug-based vessel closure devices for VA-ECMO decannulation. Purpose The aim of the study was to compare the efficacy and safety of suture-based to pure plug-based vascular closure devices for veno-arterial extracorporeal membrane oxygenation (VA-ECMO) decannulation for patients with cardiogenic shock. Methods In this retrospective study, the outcome of 33 patients with suture-based closure devices implanted between 02/2019 to 05/2020 were compared to 38 patients with plug-based closured device implanted between 06/2020 to 11/2021. Results Closure device success rate was 88% in the suture-based group versus 97% in the plug-based group (Figure 1, p=0.27). Median number of devices used was two for patients with suture-based closure device and 1 for patients with plug-based closure device (p&amp;lt;0.01). Severe bleeding was more frequent in the suture-based (21%) compared to the plug-based group (3%) (Figure 2, p=0.04). Ischemic complications occurred in 6% with suture-based and 5% with plug-based device (p=1.00). Pseudoaneurysm formation was detected in 3% in both groups (p=1.00). Application of the femoral compression system was required in 27% of patient with suture-based closure device and 11% of patients with plug-based closure device (p=0.13). No switch to open vascular surgery due to closure device failure occurred in both groups. Conclusions Based on our retrospective analysis, we propose that plug-based vascular closure should be the preferred option for VA-ECMO decannulation. This hypothesis should be further tested in a randomized trial. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Deutsche Forschungsgemeinschaft

Analysis of dismantling process and disposal cost of waste RVCH

During the operation of a nuclear power plant (NPP), the waste reactor vessel closure head (RVCH) that is replaced owing to design or manufacturing defects is buried in a designated area or temporarily stored in a radiation shielding facility within the NPP. In such cases, storing it for extended periods proves a challenge owing to space constraints in the power plant and a safety risk associated with radiation exposure; therefore, dismantling it quickly and safely is crucial. However, not much research has been done on the dismantling of the RVCH in an operational power plant.This study proposes a dismantling process based on the radioactive contamination level measured for the Kori #1 RVCH, which is currently being discarded and stored, and examines the decontamination and cutting according to this process. In addition, the amount of secondary waste and dismantling cost are evaluated, and the dismantling effect of the reactor closure head is analyzed.

Treatment of In-Stent Restenosis Using a Dedicated Super High-Pressure Balloon

BackgroundTreatment of in-stent restenosis (ISR) is challenging and treatment failure rate remains high. Correction of stent under-expansion and neointimal compression using the twin-layer OPN™ highly non-compliant balloon (NCB) at high pressure (>30 atm) may lead to increased luminal gain and thus better clinical outcomes. We evaluated periprocedural safety and clinical long-term outcomes after ISR treatment using the OPN™ NCB in a real-world population. MethodsFrom an ongoing registry, consecutive ISR patients treated with the OPN™ NCB at a tertiary cardiology center in Switzerland were analyzed. We evaluated procedural efficacy, periprocedural complications, target lesion/vessel failure (TLF/TVF), and major adverse cardiovascular events (MACE). ResultsTotally, 208 ISR lesions were treated in 188 patients (mean age 68 ± 13 years, 78 % males). Most lesions were moderately to heavily calcified (89 %), the majority (70.2 %) had complex lesion characteristics (AHA Type B2/C lesions) and 50.5 % were non-focal ISR lesions. After ISR treatment using high pressure pre- and post-dilatation (mean pressure 33 ± 6 atm) with the OPN™ NCB device, the rate of major complications was low (0.96 % coronary perforation, 4 % major dissections, 1.9 % no-reflow and 0.5 % acute vessel closure). At 1-year follow-up, MACE occurred in 19.7 %; 15.4 % patients had TVF; MI and stent thrombosis was found in 5.9 % and 2.1 % of all patients, respectively; and 5 patients died. ConclusionsFor ISR treatment, using the super non-compliant OPN™ balloon at very high pressures is safe. Moreover, its use might lead to a low rate of TLF/TVF during long-term follow-up, but this requires further evaluation in dedicated comparative trials.

Evolution of drug-eluting coronary stents: a back-and-forth journey from the bench to bedside.

Coronary stents have revolutionized the treatment of coronary artery disease. Compared with balloon angioplasty, bare-metal stents (BMSs) effectively prevented abrupt vessel closure but were limited by in-stent restenosis (ISR) due to smooth muscle cell proliferation and neointimal hyperplasia. The first-generation drug-eluting stent (DES), with its antiproliferative drug coating, offered substantial advantages over BMSs as it mitigated the risk of ISR. Nonetheless, they had several design limitations that increased the risk of late stent thrombosis. Significant advances in stent design, including thinner struts, enhanced polymers' formulation, and more potent antiproliferative agents, have led to the introduction of new-generation DES with a superior safety profile. Cardiologists have over 20 different DES types to choose from, each with its unique features and characteristics. This review highlights the evolution of stent design and summarizes the clinical data on the different stent types. We conclude by discussing the clinical implications of stent design in high-risk subsets of patients.

Information for Readers

The development of bare metal coronary stents revolutionized the treatment of coronary artery disease by reducing rates of acute vessel closure and restenosis associated with balloon angioplasty. However, bare metal stents (BMS) resulted in high rates of restenosis and led to the development of drug-eluting stents (DES). Those first-generation DES were followed by successive generations of DES that included improvements, such as biodegradable and more biocompatible polymers. Despite the superiority of the current DES compared to BMS, a subset of patients still receives BMS. The following paper reviews the literature comparing the safety and efficacy of newer generation DES to BMS in such patients and ultimately challenges the use of BMS in contemporary current DES era.

Manual Compression versus Suture-Mediated Closure Device Technique for VA-ECMO Decannulation.

Background The impact of devices for vessel closure on the safety and efficacy of cannula removal in VA-ECMO patients is unknown. Methods We retrospectively analyzed 180 consecutive patients weaned from VA-ECMO after cardiac arrest or cardiogenic shock from January 2012 to June 2020. In the first period (historical technique group), from January 2012 to December 2018, primary decannulation strategy was manual compression. In the second period (current technique group), from January 2019 to June 2020, decannulation was performed either by a conventional approach with manual compression or by a suture-mediated closure device technique. Results A femoral compression system was necessary in 71% of patients in the historical group compared to 39% in the current technique group (p < 0.01). Vascular surgery was performed in 12% in the historical cohort and 2% in the current technique cohort, which indicated a clear trend, albeit it did not reach significance (p = 0.07). Conclusion We illustrated that a suture-mediated closure device technique for VA-ECMO decannulation was feasible, safe, and may have reduced the need of surgical interventions compared to manual compression alone.