System For Closure Research Articles

Same-day discharge after percutaneous closure of persistent foramen ovale using intracardiac echocardiography and the Gore Septal Occluder.

Periprocedural and postinterventional care of patients undergoing closure of patent foramen ovale (PFO) varies significantly across care providers. Same-day discharge (SDD) after transcatheter interventions is an evolving concept. This study aimed to assess the same-day discharge rate and incidence of complications in patients undergoing PFO closure with intracardiac echocardiography (ICE) using the Gore®Cardioform Septal Occluder (GSO) device. The secondary aim was to analyse the efficacy of femoral vein closure with Perclose ProGlide. Patients who underwent PFO closure with the GSO device at a university hospital in Stockholm, Sweden, were retrospectively included between March 1, 2017, and June 30, 2020, all with cryptogenic stroke as the indication for the procedure. All patients underwent PFO closure with conscious sedation and local anaesthesia. The indication for all patients was a cryptogenic stroke. Periprocedural imaging was performed using ICE and fluoroscopy in all patients. Patient characteristics and periprocedural data were collected from patient charts. Patients were kept on bed rest for 4-6 h post-intervention. Transthoracic echocardiography and clinical examination, including groin status, were performed before discharge. No clinical routine follow-up was performed the day following the intervention. Clinical follow-up was done by phone call two weeks after the procedure, and echocardiographic follow-up was done after 12 months. Data were analysed using linear and logistic regression models. In total, 262 patients were included, of which 246 (94%) had SDD. 166 patients (63%) received the ProGlide™ system for femoral vein access closure. Post-procedural arrhythmias occurred in 17 (6%) patients, and vascular complications in 9 patients (3%). The overall closure rate at follow-up was 98.5%. 25 out of 264 patients (9.5%) had to be readmitted within the first eight weeks after PFO closure, 16 due to atrial fibrillation warranting electric cardioversion, one due to an arteriovenous fistula that was operated, four due to chest pain/pain at the access site, and four patients developed fever. There was no difference in SDD among patients who received ProGlide™ vs. patients who did not receive ProGlide™. SDD appears safe after transcatheter PFO closure with the GSO device with high procedural success rates. Low rates of complications and readmissions make the intervention suitable for this patient-friendly and cost-effective concept.

Endoscopic outcomes using a novel through-the-scope tack and suture system for gastrointestinal defect closure: a systematic review and meta-analysis.

Closure of gastrointestinal defects can reduce postprocedural adverse events. Over-the-scope clips and an over-the-scope suturing system are widely available, yet their use may be limited by defect size, location, operator skill level, and need to reinsert the endoscope with the device attached. The introduction of a through-the-scope helix tack suture system (TTSS) allows for closure of large irregular defects using a gastroscope or colonoscope, without the need for endoscope withdrawal. Since its approval 3 years ago, only a handful of studies have explored outcomes using this novel device. Multiple databases were searched for studies looking at TTSS closure from inception until August 2023. The primary outcomes were the success of TTSS alone and TTSS with clips for complete defect closure. Secondary outcomes included complete closure based on procedure type (endoscopic mucosal resection [EMR], endoscopic submucosal dissection [ESD]) and adverse events. Eight studies met the inclusion criteria (449 patients, mean defect size 34.3 mm). Complete defect closure rates for TTSS alone and TTSS with adjunctive clips were 77.2% (95%CI 66.4-85.3; I2=79%) and 95.2% (95%CI 90.3-97.7; I2=42.5%), respectively. Complete defect closure rates for EMR and ESD were 99.2% (95%CI 94.3-99.9; I2 = 0%) and 92.1% (95%CI 85-96; I2=0%), respectively. The adverse event rate was 5.4% (95%CI 2.7-10.3; I2=55%). TTSS is a novel device for closure of postprocedural defects, with relatively high technical and clinical success rates. Comparative studies of closure devices are needed.

Predictive Scoring System for Spontaneous Closure of Infant Ventricular Septal Defect: The P-VSD Score.

Ventricular septal defect (VSD) is a common congenital heart disease. However, consensus on the utility of echocardiography in predicting spontaneous closure (SC) of VSD remains lacking. This study aimed to identify and validate significant predictors of SC through a predictive scoring system. This retrospective study included medical records of 712 echocardiography instances performed on 304 patients diagnosed with VSD from 2016 to 2020 in their first year of life. A novel scoring system for predicting the SC of VSD was developed and validated using another dataset from different hospitals. Of the 304 patients, 215 (70.7%) had perimembranous (PM) VSDs and 89 had muscular (29.3%) VSDs. The median follow-up periods were 36.2 (interquartile range [IQR], 13-59) months and 13.7 9 (IQR, 5-37.4) days for PM and muscular VSDs, respectively. The overall SC rate during follow-up was 29.3%. Pulmonary hypertension (HTN), concomitant left ventricle (LV)-right atrium (RA) shunt, VSD size to aortic valve (AV) annulus size ratio, and left ventricular end-diastolic dimension (LVEDD) z-score were significant risk factors affecting SC of VSD. The "P-VSD" score, a new scoring system, demonstrated an area under the curve for predictability of 0.769. Pulmonary HTN, concomitant LV-RA shunt, LVEDD z-score, and VSD size-to-AV annulus size ratio at diagnosis were significantly associated with non-SC VSD after infancy. The P-VSD score can predict the SC of VSD in clinical settings and simplify the identification and appropriate management of high-risk patients.

Surgical and Clinical Outcomes Associated With the Use of Barbed Sutures and Self-Adhering Mesh System and Polymeric Glue for Wound Closure in Multilevel or Revision Spinal Surgery: A Matched Cohort Comparative Study With Conventional Wound Closure Procedure.

Multilevel or revisional posterior spinal surgery is prone to infection and delayed wound healing, related with the wound closure time and suture strength. Knotless barbed suture is an innovative self-locking, multianchor suture. This study aims to evaluate the safety and efficacy of the knotless barbed suture and self-adhering mesh with polymeric glue in multilevel or revisional posterior spinal surgery. This is a single-center retrospective matched cohort study. Patients were divided into 2 groups based on the wound closure method: barbed suture group with novel wound closure, and conventional suture group with conventional wound closure, 1:1 matched by the level of surgery and sex, resulting in 120 subjects each. Total operation time and wound closure time were measured intraoperatively, and perioperative clinical outcome parameters including postoperative wound complication were investigated for the first 3 months postoperatively. The distribution of continuous variables was assessed for normality by Shapiro-Wilk test, then parametric or nonparametric tests were applied accordingly (paired t-test or Wilcoxon signed-rank test). Wound closure time was significantly shorter with the novel barbed suture than with conventional suture in all subgroups divided by the level of spinal surgery: 3-5, 6-9, ≥ 10 levels (p < 0.001). The 2 groups showed no significant differences in surgical complications (p = 1.000). Specially, total operation time and wound-closing time were significantly shorter in revisional subgroup. Absorbable knotless barbed suture and self-adhering mesh with polymeric glue can shorten spinal wound closure time with noninferiority in complications for multilevel or revisional spinal surgery.

OTSC Proctology clip as appropriate treatment for complicated anorectal fistula.

Evaluation of the effectiveness and tolerability of the application of an OTSC (Ovesco Endoscopy AG Tuebingen, Germany) Proctology clip as an innovative strategy of anorectal fistulae closure when established treatment strategies had already failed or were not feasible. Retrospective single-center study including consecutive patients treated between March 2014 and March 2016 with the OTSC Proctology system for anorectal fistula closure, including one rectovaginal and one rectourethral fistula. The primary outcome was the healing rate with a minimum follow up of 6 months. Healing was defined as closure of the internal fistula ostium and absence of secretion or local inflammation during follow up. A total of 66 fistula closures by the OTSC Proctology clip were investigated, including cryptoglandular fistulas (45/66 patients, 68%), fistulas associated with CED (19/66 patients, 29%), and other non-cryptoglandular fistulas (2/66 patients, 4%). 47% (31/66 patients) had a failed previous therapy. In that selected collective, a successful fistula closure was achieved in 29/66 cases (44%) after a median follow up time of 40 months (6-61 months). Suprasphincteric and high transsphincteric fistulas showed healing in 63% and 42% in CD associated fistulas. Fistula closure by the OTSC Proctology clip is an innovative, sphincter protecting treatment strategy in anorectal fistulas that can achieve long-term cure in complex anorecta.

Autonomous System for Vaginal Cuff Closure via Model-Based Planning and Markerless Tracking Techniques

Autonomous robotic suturing has the potential to improve surgical outcomes compared to manual operations due to better accuracy and consistency of suture placement. In this paper, we develop an autonomous system with model-based planning and markerless tissue tracking techniques for autonomous vaginal cuff closure. The proposed planning method constructs an optimal suture plan that minimizes tissue collisions with the robotic suturing tool. Moreover, DeepLabCut is utilized for autonomous markerless soft-tissue tracking in robotic vaginal cuff closure. Furthermore, an instruction-based autonomous surgery interface (ASI) is designed to automate the complex suturing workflow. The proposed planning method is evaluated via a robotics simulator and real-world suture-placement tests. End-to-end vaginal cuff closure via Smart Tissue Autonomous Robot (STAR) on synthetic tissues was carried out and compared to the suturing results via conventional laparoscopic and robot-assisted approaches performed by experienced surgeons. The comparison results indicate that by using the proposed planning pipeline, STAR outperforms conventional laparoscopic and robotic-assisted methods with better accuracy and consistency, thus achieving a higher success rate of autonomous suture placement.

Prospective study on the efficacy of endoscopic through-the-scope tack and suture system for gastric peroral endoscopic myotomy mucosal incision site closure.

Background and study aims Mucosal closure after gastric per-oral endoscopic myotomy (G-POEM) can be difficult due to the thick gastric mucosa. We evaluated the use of a novel through-the-scope (TTS) suture system for G-POEM mucosotomy closure. Patients and methods This was a single-center prospective study on consecutive patients who underwent G-POEM with TTS suture closure between February 2022 and August 2022. Technical success was defined as complete mucosotomy closure with TTS suture alone. On subgroup analysis, we compared performance on TTS suturing between the advanced endoscopist and the advanced endoscopy fellow (AEF) under supervision. Results Thirty-six consecutive patients (median age 60 years, interquartile range [IQR] 48.5-67], 72 % women) underwent G-POEM with TTS suture of the mucosotomy. Median mucosal incision length was 2 cm (IQR: 2-2.5). Mean mucosal closure and total procedure time were 17.5 ± 10.8 and 48.4 ± 16.8 minutes, respectively. Technical success was achieved in 24 patients (66.7 %) and 100 % of the cases were adequately closed with a combination of TTS suture and clips. When compared to the advanced endoscopist, the AEF required > 1 TTS suture system for complete closure significantly more frequently (66.7 % vs. 8.3 %, P = 0.009) and more time for mucosal closure (20.4 ± 12.1 vs. 11.9 ± 4.9 minutes, P = 0.03). Conclusions TTS suturing is effective and safe for G-POEM mucosal incision closure. With experience, technical success is high, and most closures may be achieved using a single TTS suture system alone, which has important cost and time implications. Additional comparative trials with other closure devices are need1ed.

Through-the-scope suture closure of peroral endoscopic myotomy mucosal incision sites.

BACKGROUND : Peroral endoscopic myotomy (POEM) is now widely used for esophageal motility disorders including achalasia. Closure of the mucosal incision site is a critical step of the procedure. We evaluated the use of a novel through-the-scope (TTS) suture system for closure of POEM mucosal incision sites. METHODS : We retrospectively reviewed consecutive patients who underwent POEM with TTS suture closure at our institution between February and July 2021. Technical success was defined as complete mucosal incision site closure using TTS suturing, without the need for adjunctive devices. Continuous variables are presented as median (interquartile range [IQR]) or mean (SD). RESULTS : 35 consecutive patients (median age 58 years [IQR 46.5-72]; 54.3 % female) underwent POEM with attempted mucosal closure by TTS suturing. Technical success was achieved in 32 patients (91.4 %) with a mean closure time of 12.4 (SD 6.9) minutes. The median mucosal incision length at time of closure was 2.5 cm (IQR 2-2.5). Overall, 17 patients (53.1 %) required ≥ 2 TTS suture systems and 3 patients (8.6 %) required additional TTS clips to achieve secure mucosal closure. No adverse events were encountered. CONCLUSIONS : TTS suturing was effective and safe for POEM mucosotomy closure. However, prospective comparative trials and cost-effectiveness analyses are warranted before routine adoption.

Follow-up outcomes of mucosal defect closures after endoscopic resection using a helix tacking system and endoclips.

Background and AimsThe X-Tack endoscopic HeliX tacking system (Apollo Endosurgery, Austin, Tex, USA) has recently been approved by the Food and Drug Administration and is slowly gaining popularity for the closure of large tissue defects. Despite its increasing use, outcome data of using the X-Tack system for mucosal defect closure after endoscopic resection (ER) are limited. Here, we report the follow-up outcomes of a series of cases that underwent ER and mucosal closure aided by the HeliX tacking system.MethodsWe identified a total of 5 cases in which the X-Tack system and endoclips were used for mucosal defect closure after ER. The cases involved ER of large and/or flat polyps in the duodenum and colon. The patients were followed up at 4, 6, and 9 months after ER.ResultsIn all cases, X-Tacks with endoclips achieved complete closure of the large mucosal defects. None of the patients experienced any adverse events, such as abdominal pain or bleeding. At follow-up, the X-Tacks either fell off or were seen grouped or situated as a single piece (tack) in the mucosa where initially placed. None of the endoclips were found during the follow-up endoscopic examinations.ConclusionsThe X-Tack system together with endoclips facilitated complete closure of large mucosal defects, especially for lesions located in difficult locations. At follow-up, several retained X-Tacks were found either in groups or as a single piece. The X-Tacks seen in groups will likely fall off with repetitive pulling forces with food or feces. However, the single tacks that were secured in the wall may stay indefinitely. The novel HeliX tacking system seems to be a promising aid for the effective closure of large mucosal defects; however, further studies are needed to assess the long-term outcome of this novel system.

Pre-clinical Evolution of a Novel Transcatheter Bioabsorbable ASD/PFO Occluder Device.

To date, there has been limited investigation of bioabsorbable atrial septal defect (ASD) or patent foramen ovale (PFO) closure devices using clinically relevant large animal models. The purpose of this study is to explore the function and safety of a bioabsorbable ASD occluder (BAO) system for PFO and/or secundum ASD transcatheter closure. Using a sheep model, the intra-atrial septum was evaluated by intracardiac echo (ICE). If a PFO was not present, atrial communication was created via transseptal puncture. Device implantation across the intra-atrial communication was performed with fluoroscopic and ICE guidance. Our 1st generation device consisted of a main structure of thin Poly(L-lactide-co-epsilon-caprolactone) (PLCL) fibers, and an internal Poly glycolic acid (PGA) fabric. Four procedures validated procedure feasibility. Subsequently, device design was modified for improved transcatheter delivery. The 2nd generation device has a two-layered structure and was implanted in six sheep. Results showed procedural success in 9/10 (90%) animals. With deployment, the 1st generation device did not reform into its original disk shape and did not conform nicely along the atrial septum. The 2nd generation device was implanted in six animals, 3 out of 6 survived out to 1year. At 1 year post implantation, ICE confirmed no residual shunting. By necropsy, biomaterials had partially degraded, and histology of explanted samples revealed significant device endothelialization and biomaterial replacement with a collagen layer. Our results demonstrate that our modified 2nd generation BAO can be deployed via minimally invasive percutaneous transcatheter techniques. The BAO partially degrades over 1 year and is replaced by host native tissues. Future studies are needed prior to clinical trials.

Hybrid endoscopic submucosal dissection with novel helix tacking system for defect closure.

Video 1Hybrid endoscopic submucosal dissection with novel helix tacking system for defect closure.

Video demonstration of the ColubrisMX ELS robotic system for local excision and suture closure in a preclinical model.

Video demonstration of the ColubrisMX ELS robotic system for local excision and suture closure in a preclinical model.

Demonstration of proof-of-concept of StrokeShield system for complete closure and occlusion of the left atrial appendage for non-valvular atrial fibrillation therapy.

In the US, the most significant morbidity and mortality associated with non-valvular atrial fibrillation (NVAF) is embolic stroke, with 90% of thrombus originating from the left atrial appendage (LAA). Anticoagulation is the preferred treatment for the prevention of stroke in NVAF patients, but clinical studies have demonstrated high levels of non-compliance and increased risk of bleeding or ineligibility for anticoagulation therapy, especially in the elderly population where the incidence of NVAF is highest. Alternatively, stroke may be preventing using clinically approved surgical and catheter-based devices to exclude or occlude the LAA, but these devices continue to be plagued by peri-device leaks and thrombus formation because of residual volume. To overcome these limitations, Cor Habere (Louisville, KY) and the University of Louisville are developing a LAA closure device (StrokeShield) that completely occludes and collapses the LAA to minimize the risk of stroke. The StrokeShield device is a collapsible occluder (nitinol reinforced membrane) that completely covers the LAA orifice with an expandable conical coil anchor that attaches to the myocardium. The device is designed for catheter-based delivery and expands to completely occlude the LAA orifice and collapse the LAA. The primary advantages of the StrokeShield system are a completely sealed LAA (no peri-device flow or residual space) and smooth endothelialized connection to the left atrial wall with minimal risk of cardiac bleeding and tamponade. We tested proof-of-concept of a prototype StrokeShield device in acute (n = 2) and chronic 60-day (n = 2) healthy canine models. Acute results demonstrated that the conical coil securely attached to the myocardium (5N pull-out force) and the Nitinol umbrella fully deployed and covered the LAA ostium. Results from the chronic implants demonstrated long-term feasibility of device placement with no procedural or device-related intra- or post-operative complications, secure placement and correct positioning of the device with no device migration. The device successfully occluded the LAA ostium and collapsed the LAA with no interference with the mitral valve, circumflex coronary artery, or pulmonary veins. Necropsy demonstrated no gross signs of thrombus or end-organ damage and the device was encapsulated in the LAA. Histology demonstrated mature neointima covering the device with expected foreign body inflammatory response. These early positive results will help to guide the iterative design process for the continued development of the StrokeShield system.

Design Optimization of a Novel Multifiring Clip Applicator System for Endoscopic Closure of Large Perforations

AbstractEndoscopic closure has become the first choice for closing iatrogenic perforations. Previously, we reported a self-developed endoscopic multifiring clip applicator (EMFCA) system. In this paper, a new EMFCA system for endoscopic closure of large perforations with a redesigned clip, the less traumatic grasper, and a highly efficient driving system was presented, and its efficacy was evaluated. The behaviors of the new clip and grasper were verified through finite element analysis (FEA). The capability of pushing transmission for the EMFCA system was identified by the proposed model and the validation experiment. Ex-vivo studies were conducted on porcine stomachs to compare the outcomes of the closures. The FEA results showed that the deformation of the clip was safe and smoother, with a maximum stress of 640.0 MPa. The less traumatic grasper could increase the grasping force and avoid trauma by exerting uniform stress along the axis. The capability of pushing transmission was enhanced by the double-nested tendon-sheath actuation system with an efficiency of 0.45–0.48. The mechanical strength, the leakage pressure, and the operating time for the closures with the new EMFCA system and the previous EMFCA system were 6.1 N ± 0.8 N, 37.1 mmHg ± 6.8 mmHg, 7.3 min ± 0.4 min and 5.1 N ± 1.0 N, 27.4 mmHg ± 6.4 mmHg, 11.4 min ±0.8 min, respectively. The new EMFCA system can realize a superior, reliable, and high-efficiency endoscopic closure of large perforations.

Combination plate and band fixation for primary closure in bilateral lung transplantation.

Sternal complications are common following transverse thoracosternotomy in patients undergoing bilateral lung transplantation. We present a single-institution experience using a next generation rigid fixation system for primary sternal closure following transverse sternotomy for bilateral lung transplantation. Retrospective review was performed on all patients who had bilateral sequential lung transplants utilizing a transverse thoracosternotomy from 2016 to 2020. Demographics, baseline characteristics, peri-operative data, and outcomes were collected, reviewed and summarized. Two groups of patients were identified: wire cerclage (Group A), combination plate-and-band rigid fixation (Group B). The primary outcome was sternal complications, which were divided into mechanical and non-mechanical. Twenty-two patients met inclusion criteria. Three patients (13.6%) were in Group A, nineteen patients (86.4%) in Group B. Two patients in each Group A (66.6%) and Group B (10.5%) experienced a sternal complication. Sternal complications included sternal dehiscence (2), sternal malunion (1), and surgical site infection (1). One patient with plate-and-band fixation (5.2%) had a mechanical sternal complication. Three patients required reoperation secondary to sternal complication. The utilization of a combination plate-and-band rigid fixation system for primary closure is safe and may be an effective method to reduce sternal complications following transverse thoracosternotomy for lung transplantation.

Single versus double use of a suture-based closure device for transfemoral aortic valve implantation

BackgroundThe most common method of percutaneous closure in transfemoral transcatheter aortic valve implantation (TAVI) employs two obtusely oriented ProGlide devices. The aim of this study was to assess the feasibility and safety of using a single ProGlide system for primary access site closure in comparison with the double ProGlide approach in an all-comers TAVI population. MethodsBetween March 2016 and December 2018, a total of 1105 patients underwent transfemoral TAVI for severe aortic stenosis at our center. Application of two ProGlide systems was standard until April 2017 (n = 432), whereas thereafter a single ProGlide system was used (n = 663). A 1:1 propensity score matching was performed to adjust for baseline differences between the two groups, resulting in 327 matched cases. Primary outcomes of interest were main access site-related vascular complications. ResultsThe mean number of ProGlide devices used per patient was 1.03 (SD 0.2) in the single-ProGlide group versus 2.01 (SD 0.14) in the double-ProGlide group. An additional vascular closure device was required to obtain full hemostasis in 23.2% versus 9.5% of patients (p < 0.001) in the two groups, respectively. Technical success of ProGlide usage was similar (94.3% versus 92.1%, p = 0.163). In the matched cohorts, the rates of main access site-related major vascular complications were similar (4.0% vs. 6.4%, p = 0.217). ConclusionThe single-ProGlide technique is feasible, with rates of technical success similar to those of the double-ProGlide technique. Use of this method did not lead to more frequent access site-related complications but was more cost effective than the double-ProGlide approach.

SHAPE MEMORY POLYMER HYDROGEL FOAMS FOR FISTULA CLOSURE

Abstract Introduction Crohn’s disease can lead to fistula formation between portions of the urinary, reproductive, and digestive systems. The abnormal connections caused by these tunneling sores cause severe pain, infections, and abscess formation. Currently, 83% of Crohn’s patients with fistula formation undergo surgical intervention to either drain or bypass the fistula openings, and ~23% of these patients ultimately require bowel resections. To address this clinical need, we propose to synthesize a shape memory polymer (SMP) hydrogel foam system for fistula closure and healing. SMP foams are porous materials that can be heated and compressed into a low-profile geometry that is retained after cooling. This shape enables minimally invasive delivery (i.e. via catheter) to a fistula site. Once the foams are heated to body temperature, they expand back to their original shape to conform to the implantation site geometry. Here, we present a degradable SMP hydrogel foam with antimicrobial and antioxidant phenolic acids for potential use as a fistula closure scaffold. Methods Foams were synthesized with 3-arm and linear poly(ethylene glycol) (PEG), amylopectin/pullulan, and phenolic acids in combination with hexamethylene diisocyanate in the presence of surfactants, catalysts, and foam blowing agents to form a hydrophilic, chemically crosslinked foam. Resulting foams were characterized in terms of swelling ratios, pore sizes, glass transition temperatures, and shape recovery. Degradation profiles were characterized in glucoamylase. Antimicrobial efficacy against E. coli was measured by quantifying colony forming units of bacteria following exposure to SMP hydrogels. Antioxidant properties were assessed in the presence of hydrogen peroxide. Results SMP hydrogel swelling ratio, stiffness, shape memory properties are tuned by altering monomer ratios and lengths and foaming conditions. In preliminary degradation studies in glucoamylase, degradation rates are dependent upon starch content; increased degradation is observe with increase pullalan content, Figure 1. Phenolic acid-containing SMP foams exhibit antimicrobial efficacy against E. coli and antioxidant properties in hydrogen peroxide. Conclusions Current studies include full material characterization of the library of synthesized hydrogels and longer-term degradation analysis. This system can be further built upon in future studies to include a drug-delivery component. Overall, SMP hydrogel foams present a highly tunable platform material that can be modified with required functionalities to promote fistula closure.

Relevant correlation of Galectin-3 with a novel morphological classification system for LAA closure – the end of echocardiographic follow up after occluder implantation?

Abstract Introduction Echocardiographic detection of residual peri-device leakage (PDL) after percutaneous left atrial appendage closure (LAAC) remains crucial. Significance of PDL and cardiac tissue remodeling after LAAC are still poorly understood but might have diagnostic implications. This study aims to characterize and verify if a novel echocardiographic classification system to asses the success of LAAC in combination with quantifiable biomarkers of cardiovascular tissue remodeling can help in the prediction of PDL. Methods Patients eligible for LAAC were included. Serum levels of the cardiac remodeling marker Galectin-3 were determined before device implantation (baseline), 45 days (45d) and 6 months (6M) after LAAC using ELISAs. Transesophageal echocardiography (TEE) was carried out to assess success of the LAAC procedure. All echo images were retrospectively evaluated by two independent investigators. Based on the amount of echodensity and luceny inside the devices after LAAC, three types can be distinguished that grade the degree of closure of the LAA. Type A has complete homogenous echodensity in 0, 45, 90 and 135°, indicating completely thrombosed device. Type B shows inhomogeneous echo-lucencies (&amp;lt;50% of device). Type C describes a partially thrombosed device with echo-lucencies &amp;gt;50%. Novel classification according to Hamadanchi, Jena, Germany (Fig. 1). Results We included 44 patients (characteristics listed in Table 1). Complete LAAC (without any residual flow) was achieved in 64% (28 patients) after 45 days and in 80% (35 patients) after 6 months. Mean PDL diameter was 3.5±1.5mm. Type A showed the lowest rate of PDL after 45d (Type A: 22% vs. Type B: 33% vs. Type C: 88%; p=0.007) and after 6M (Type A: 12% vs. Type B: 28% vs. Type C: 100%; p=0.002). Galectin-3 levels did not show a relevant difference regarding the type of AF at baseline (paroxysmal AF: 11.7±5.4 ng/ml vs. permanent AF: 12.1±6.3 ng/ml; p=0.45). We observed a significant increase and distribution of serum levels of Galectin-3 [ng/ml] after 45 days among the three types (Baseline: 13.1±5.8; 45d: 16.3±7.2 (Type A) vs. 19.2±8.6 (Type B) vs. 25.8±9.4 (Type C); p=0.031) followed after 6 months by a drop of Galectin-3 for type A and B toward and below baseline levels (6M: 8.9±3.1 (Type A) vs. 12.4±5.5 (Type B)) whereas type C persisted in showing elevated Galectin-3 levels compared to all other types (6M: 17.5±4.5 (Type C); p&amp;lt;0.001), Fig. 2. Correlation analysis shows a significant negative correlation trend between Galectin-3 and mean PDL diameter (−0.51; p=0.016) after 45 days and a relevant positive correlation after 6 months (0.58; p=0.017). Conclusion After LAAC, Galectin-3 levels are elevated, as a marker of myocardial fibrosis in the LAA. Depending on the degree of closure of the LAA, Galectin-3 decreases to the baseline level or stays elevated in case of relevant PDL and could therefore be considered as a new biomarker for closure success. Funding Acknowledgement Type of funding source: None

Hydro-chemo-mechanical modelling of long-term evolution of bentonite swelling

The swelling properties of compacted bentonite have typically been studied by means of hydro-mechanical models. The question of how these properties are affected by changes in its chemical composition has been given much less attention. However, cation exchange reactions in montmorillonite interlayer or changes in salinity are known to affect the swelling properties of bentonite. In this paper, a hydro-chemo-mechanical (HCM) model is proposed to study the effects of reactive transport processes on the long-term evolution of swelling pressure of compacted bentonite under confined and partially saturated conditions. The HCM model is implemented in iCP, an interface between Comsol Multiphysics and PHREEQC and is calibrated using available experimental data. At the constitutive level, the hydro-mechanical Barcelona Basic model is extended to include the effects of cation exchange reactions between interlayer and bulk water, changes in salinity, and montmorillonite dissolution in highly alkaline environments. The geochemistry of bentonite is based on an advanced reactive transport model that couples solute transport by diffusion and advection with chemical reactions. An application case is presented to demonstrate the main HCM model features and its ability to predict long-term changes in bentonite swelling pressure. The performance of the sealing system for closure of the repository for radioactive waste in France is simulated under unsaturated and isothermal conditions over a period of 50,000 years. The HCM interactions of MX-80 bentonite with other near-field materials such as concrete and claystone are simulated to predict the evolution of the swelling pressure of the seal. The results show the potential of the proposed model for the performance assessment of repository components. Overall, the model predicts limited impact of geochemical alteration on the swelling pressure of the bentonite seals, which is mainly driven by cation exchange reactions between the Na-rich bentonite, the Ca-rich claystone, and the calcium and alkalis from concrete porewater.

NOVEL EPICARDIAL-ONLY APPROACH TO LAA LIGATION

Atrial fibrillation is the leading cause of stroke, and the left atrial appendage (LAA) is the most common source of thrombus. A percutaneous suture delivery system (LARIAT) for LAA closure has emerged, however it requires simultaneous endo-epicardial access. We describe a new epicardial-only