Seismic response of a mid-story isolated structure considering SSI in mountainous areas under long-period earthquakes

At present,there is not much research on mid-story isolated structures in mountainous areas.In this study,a model of a mid-story isolated structure considering soil-structure interaction(SSI)in mountainous areas is established along with a model that does not consider SSI.Eight long-period earthquake waves and two ordinary earthquake waves are selected as inputs for the dynamic time history analysis of the structure.The results show that the seismic response of a mid-story isolated structure considering SSI in mountainous areas can be amplified when compared with a structure that does not consider SSI.The structure response under long-period earthquakes is larger than that of ordinary earthquakes.The structure response under far-field harmonic-like earthquakes is larger than that of near-fault pulse-type earthquakes.The structure response under near-fault pulse-type earthquakes is larger than that of far-field non-harmonic earthquakes.When subjected to long-period earthquakes,the displacement of the isolated bearings exceeded the limit value,which led to instability and overturning of the structure.The structure with dampers in the isolated story could adequately control the nonlinear response of the structure,effectively reduce the displacement of the isolated bearings,and provide a convenient,efficient and economic method not only for new construction but also to retrofit existing structures.

Sedimentary build-ups of pre-salt isolated carbonate platforms and formation of deep-water giant oil fields in Santos Basin,Brazil

In response to the problems of unclear distribution of deep-water pre-salt carbonate reservoirs and formation conditions of large oil fields in the Santos passive continental margin basin,based on comprehensive utilization of geological,seismic,and core data,and reconstruction of Early Cretaceous prototype basin and lithofacies paleogeography,it is proposed for the first time that the construction of pre-salt carbonate build-ups was controlled by two types of isolated platforms:inter-depression fault-uplift and intra-depression fault-high.The inter-depression fault-uplift isolated platforms are distributed on the present-day pre-salt uplifted zones between depressions,and are built on half-and fault-horst blocks that were inherited and developed in the early intra-continental and inter-continental rift stages.The late intra-continental rift coquinas of the ITP Formation and the early inter-continental rift microbial limestones of the BVE Formation are continuously constructed;intra-depression fault-high isolated platforms are distributed in the current pre-salt depression zones,built on the uplifted zones formed by volcanic rock build-ups in the early prototype stage of intra-continental rifts,and only the BVE microbial limestones are developed.Both types of limestones formed into mound-shoal bodies,that have the characteristics of large reservoir thickness and good physical properties.Based on the dissection of large pre-salt oil fields discovered in the Santos Basin,it has been found that both types of platforms could form large-scale combined structural-stratigraphic traps,surrounded by high-quality lacustrine and lagoon source rocks at the periphery,and efficiently sealed by thick high-quality evaporite rocks above,forming the optimal combination of source,reservoir and cap in the form of“lower generation,middle storage,and upper cap”,with a high degree of oil and gas enrichment.It has been found that the large oil fields are all bottom water massive oil fields with a unified pressure system,and they are all filled to the spill-point.The future exploration is recommended to focus on the inter-depression fault-uplift isolated platforms in the western uplift zone and the southern section of eastern uplift zones,as well as intra-depression fault-high isolated platforms in the central depression zone.The result not only provides an important basis for the advanced selection of potential play fairways,bidding of new blocks,and deployment of awarded exploration blocks in the Santos Basin,but also provides a reference for the global selection of deep-water exploration blocks in passive continental margin basins.

Large isolated fibrous tumors in the upper esophagus: A case report

BACKGROUND Solitary fibrous tumors(SFT)are rare spindle cell tumors that are usually benign.A total of 10 cases of SFTs in the upper esophagus have ever been reported.Here,we report the anesthetic management of a patient with a large isolated fibrous tumor of the upper esophagus compressing the tracheal membrane.We also provide a literature review of the current research.CASE SUMMARY We report the case of a 49 year old male with“cough aggravation and wheezing after exercise”,who underwent esophagectomy for a large isolated fibrous tumor compressing the tracheal membrane in the upper esophagus.We advise the use of a single-lumen tube with a blocker in patients with difficult airways to reduce the incidence of airway injury and fibrinoscopy at all stages of the perioperative period to guide airway management.This case study is the first report of the anesthetic management of a large,isolated fibrous tumor compressing the tracheal membrane in the upper esophagus.CONCLUSION This rare case emphasizes the importance of perioperative management of anesthesia in patients with large isolated fibrous tumors of the upper esophagus that compress the tracheal membrane.The use of blocker reduce the incidence of airway injury and fibrinoscopy at the perioperative period to guide airway mana-gement.

Study on the Influence of Aspect Ratio on the Seismic Response and Overturning Resistance of a New Staggered Story Isolated Structure

The aspect ratio of the structure has a significant impact on the overall stability of the ultra high-rise building. A large aspect ratio of the structure increases the risk of overturning and reduces the lateral stiffness of the structure, leading to significant tensile and compressive stresses in the isolated bearings. To study the effect of aspect ratio on the seismic response and overturning resistance of a new staggered story isolated structure, three models with different aspect ratios were established. Nonlinear time-history analysis of the three models was conducted using ETABS finite element software. The results indicate that the overturning moment and overturning resistance moment of the superstructure in the new staggered story isolated structure increase with an increasing aspect ratio. However, the increase in the overturning moment of the superstructure is much greater than the increase in the overturning resistance moment, resulting in a decrease in the overturning resistance ratio of the superstructure with an increasing aspect ratio. The overturning moment and overturning resistance moment of the substructure in the new staggered story isolated structure decrease with an increasing aspect ratio. However, the decrease in the overturning moment of the substructure is greater than the decrease in the overturning resistance moment, leading to an increase in the overturning resistance ratio of the substructure with an increasing aspect ratio. The decrease in the overturning resistance ratio of the superstructure in the new staggered story isolated structure is much greater than the increase in the overturning resistance ratio of the substructure. Therefore, as the aspect ratio of the overall structure increases, the overturning resistance ratio of the superstructure and the entire structure decreases.

Endoscopic ultrasound-guided treatment of isolated gastric varices entwined with arteries:A case report

BACKGROUND Interventional endoscopic ultrasound is clinically used for the treatment of isolated gastric varices(IGVs)owing to its precise visualization.CASE SUMMARY A 39-year-old man was diagnosed with a large IGV during a routine physical examination.Endoscopic ultrasonography showed gastric varices entwined with an artery,which greatly increased the difficulty of treatment.We successfully treated the patient with endoscopic ultrasonography-guided coil embolization combined with cyanoacrylate injection.CONCLUSION Endoscopic ultrasonography-guided coil embolization combined with cyanoacrylate injection was safe and effective for the treatment of an IGV entwined with an artery.

Seismic Response of Adjacent Structure to Inter-Story Isolated Structure

Currently, land resources are becoming more and more constrained and structures are getting closer to each other. To investigate the seismic response of inter-story isolated structure to adjacent structure, models considering no soil-structure interaction (SSI), considering soil-structure interaction (SSI), and considering structure-soil-structure interaction (SSSI) were established. Nonlinear seismic response comparative analysis was conducted by varying the spacing between adjacent structure and inter-story isolated structure, as well as the weight of adjacent structure, under different earthquake inputs, in order to obtain the structural response characteristics. The results indicate that the inter-story drift and inter-story shear of the inter-story isolated structure without considering SSI are smaller than those considering SSI and SSSI. The inter-story drift and inter-story shear of the inter-story isolated structure considering SSSI are further affected compared to that of the inter-story isolated structure considering only SSI. As the spacing between adjacent structure and inter-story isolated structure increases, the influence of adjacent structure on inter-story isolated structure decreases. The variation in the spacing between the two structures has a negligible effect on the isolation layer of the inter-story isolated structure. With the increase in the weight of adjacent structure, the influence of adjacent structure on inter-story isolated structure becomes more significant. The increasing weight of adjacent structure has an increasing effect on the Isolation layer of the inter-story isolated structure.

Progressive Collapse Resistance of a New Staggered Story Isolated System

A new staggered isolated system developed from the mid-story isolated system is the new staggered story isolated system. There are not many studies on this structure currently. In this study, an 18-story new staggered story isolated system model is established using SAP2000. The dynamic nonlinear dynamic alternate method is used to analyze the structure against progressive collapse. Results show that the structure has good resistance to progressive collapse, and there is no progressive collapse under each working condition. The progressive collapse does not occur for the case of removing only one vertical structural member of the new staggered of isolated system. The side column has big influence on this isolated structures’ progressive collapse;the removal of vertical structural member of the isolation layer has less impact on the structure than the removal of the bottom vertical structural member. After the removing of the member, the internal force of the structure will be redistributed, and the axial force of the adjacent columns will change obviously, showing a trend of “near large and far small”.

Isolated left ventricular apical hypoplasia:Systematic review and analysis of the 37 cases reported so far

BACKGROUND Isolated left ventricular apical hypoplasia(ILVAH),also known as truncated left ventricle(LV),is a very unusual cardiomyopathy.It is characterised by a truncated,spherical,and non-apex forming LV.The true apex is occupied by the right ventricle.Due to the rarity of the disease,just a few case reports and limited case series have been published in the field.AIM To analysing the so far 37 reported ILVAH cases worldwide.METHODS The electronic databases PubMed and Scopus were investigated from their establishment up to December 13,2022.RESULTS The majority of cases reported occurred in males(52.7%).Mean age at diagnosis was 26.1±19.6 years.More than a third of the patients were asymptomatic(35.1%).The most usual clinical presentation was breathlessness(40.5%).The most commonly detected electrocardiogram changes were T wave abnormalities(29.7%)and right axis deviation with poor R wave progression(24.3%).Atrial fibrillation/flutter was detected in 24.3%.Echocardiography was performed in 97.3%of cases and cardiac MRI in 91.9%of cases.Ejection fraction was reduced in more than a half of patients(56.7%).An associated congenital heart disease was found in 16.2%.Heart failure therapy was administered in 35.1%of patients.The outcome was favorable in the vast majority of patients,with just one death.CONCLUSION ILVAH is a multifaceted entity with a so far unpredictable course,ranging from benign until the elderly to sudden death during adolescence.

Activity of the Mechanically Isolated Hybrid Stromal Vascular Fraction on Osteoarthritis

Background: Regenerative medicine holds promise for treating degenerative and inflammatory conditions like osteoarthritis (OA). However, the complex molecular mechanisms of OA and the limitations of current therapies remain challenges. Adipose-derived stem cells (ADSC) and stromal vascular fraction (SVF) are gaining attention for OA treatment due to their abundance in adipose tissue. The literature delineates two primary techniques for SVF extraction from adipose tissue: enzymatic digestion and mechanical methods. The Lipocube Hybrid SVF presents a straightforward and secure mechanical isolation method for SVF, enhancing its regenerative potential for various applications. Purpose: This study aims to provide valuable insights into the potential of Lipocube Hybrid SVF as a regenerative therapy for OA, contributing to the broader understanding of its applicability in addressing this debilitating condition. Method: To assess the effectiveness and safety of the Lipocube Hybrid SVF, we have designed a comparative study that evaluates cellular activity and viability, phenotypic characterization, and differentiation potential. The in vitro activity of mechanically isolated SVF is compared to the established gold standard enzymatic digestion method. After in vitro studies, Lipocube Hybrid mechanical isolation method was used to isolate SVF and applied in 42 knee and 7 hip joints of 28 patients with Grade II, Grade III, and Grade IV OA. Results: The Lipocube Hybrid group had slightly lower viable cell numbers but higher cell viability. Flow cytometry analysis showed the Lipocube Hybrid group exhibited more favorable markers for regenerative potential and reduced inflammatory response. Additionally, both groups demonstrated successful osteogenic differentiation, with the Lipocube Hybrid group excelling in chondrogenic and adipogenic differentiation. The clinical application of the Lipocube Hybrid SVF in OA patients resulted in significant improvements in WOMAC and VAS scores across different OA grades. Conclusions: This comparative study was conducted to evaluate the effectiveness and safety of the Lipocube Hybrid SVF, which has shown promise in laboratory settings, for different stages of osteoarthritis. The study findings provide valuable insights into the potential of Lipocube Hybrid SVF as a regenerative therapy for OA, highlighting its suitability for addressing this debilitating condition.

Emulsifying property,antioxidant activity,and bitterness of soybean protein isolate hydrolysate obtained by Corolase PP under high hydrostatic pressure

Enzymatic hydrolysis of proteins can enhance their emulsifying properties and antioxidant activities.However,the problem related to the hydrolysis of proteins was the generation of the bitter taste.Recently,high hydrostatic pressure(HHP)treatment has attracted much interest and has been used in several studies on protein modification.Hence,the study aimed to investigate the effects of enzymatic hydrolysis by Corolase PP under different pressure treatments(0.1,100,200,and 300 MPa for 1-5 h at 50℃)on the emulsifying property,antioxidant activity,and bitterness of soybean protein isolate hydrolysate(SPIH).As observed,the hydrolysate obtained at 200 MPa for 4 h had the highest emulsifying activity index(47.49 m^(2)/g)and emulsifying stability index(92.98%),and it had higher antioxidant activities(44.77%DPPH free radical scavenging activity,31.12%superoxide anion radical scavenging activity,and 61.50%copper ion chelating activity).At the same time,the enhancement of emulsion stability was related to the increase of zeta potential and the decrease of mean particle size.In addition,the hydrolysate obtained at 200 MPa for 4 h had a lower bitterness value and showed better palatability.This study has a broad application prospect in developing food ingredients and healthy foods.

Breeding Biology of Isolated Captive Dalmatian Pelicans (Pelecanus crispus) at the Shanghai Zoo, China

The breeding biology of a captive, isolated population of Dalmatian Pelicans (Pelecanus crispus) at theShanghaiZoo,China, was studied from 2007 to 2019. The breeding age of the Dalmatian Pelicans was estimated at three to four years old, and they started breeding in late October or early November. The clutch size varied between one and two eggs per nest, and the eggs were 83.2 ±4.8 mmin length, 55.6 ±2.9 mmin breadth and 136.1 ±21.5 gin weight. The fertility fluctuated slightly, with an average rate of 38.7% ± 9.7%, but remained consistently low. The survival rate of chicks fluctuated substantially from 0% to 100%, with an average survival rate of 68.6% ± 27.6%. The averaged values of observed heterozygosity, expected heterozygosity and polymorphism information content were 0.468, 0.465 and 0.446, respectively. It indicated that the population had a low heterozygosity and genetic diversity. There was a significant change in the breeding index compared to that recorded 40 years ago, which indicates that inbreeding depression has occurred in this small, isolated, captive population of Dalmatian Pelicans. These results can be used to improve management of Dalmatian Pelicans in captivity.

Generation of quasi-chirp-free isolated attosecond pulses from atoms under the action of orthogonal two-color combined pulse of fundamental frequency and higher intensity second harmonic fields

The intrinsic chirp of high-order harmonic generation is an important factor limiting the production of ultrashort attosecond pulses.Based on numerically solving the time-dependent Schrodinger equation,the generation process of highorder harmonic from the He atom under the action of orthogonal two-color combined pulse of fundamental frequency and higher intensity second harmonic fields is studied.In this paper,we propose to achieve quasi-chirp-free isolated attosecond pulses by superimposing a higher second-harmonic field on the orthogonal direction of the fundamental frequency field.It is found that the high-energy part of its harmonic emission exhibits small chirp characteristics,which can be used to synthesize isolated attosecond pulses.Through the analysis of the wave packets evolution and the classical motion trajectories of the electron,it is demonstrated that the quasi-chirp-free harmonic can be attributed to the simultaneous return of electrons ionized at different times to the parent particle.The influence of the relative phase of the two pulses on the harmonics is further analyzed,and it is observed that this phenomenon is sensitive to the relative phase,but it can still generate isolated attosecond pulses within a certain phase.

Isolated Major Aortopulmonary Collateral Artery Causing Heart Failure: Transcatheter Occlusion of Mapcas Using Amplatzer Vascular Plugs and Amplatzer Piccolo Occluders

Major aortopulmonary collateral arteries (MAPCAs) are congenital vessels that arise from the aorta or its first-order branches and are distally connected to the pulmonary arterial vasculature, thereby providing pulmonary blood flow. MAPCAs are often associated with cyanotic congenital heart disease with decreased pulmonary blood flow. Isolated MAPCAs are rare in patients without congenital heart disease with structurally normal hearts. Sometimes, isolated congenital MAPCAs can occur without any lung disease. Isolated MAPCAs represent the occurrence of collaterals in the absence of underlying heart disease, which commonly presents as heart failure, recurrent respiratory tract infection, and pulmonary artery hypertension. We report a rare case of congestive heart failure in a 6-year-old patient with dual arterial supply to an otherwise normal right lung, with a normal bronchial tree, and a structurally normal heart. The patient was successfully managed by the closure of collaterals by Amplatzer vascular plugs II (AVPII) and Amplatzer Piccolo Occluders.

Isolated traumatic gallbladder injury: A case report

BACKGROUND Isolated gallbladder injury(GI)(IGI)directly induced by abdominal trauma is rare.Symptoms,indications,and imaging examinations of IGI are frequently non-specific,posing tremendous diagnostic challenges,which are simple to overlook and may have severe implications.Improving doctors'understanding of gallbladder injury(GI)facilitates early detection and decreases the likelihood of severe consequences,including death.CASE SUMMARY We report a case of IGI caused by blunt violence(after falling from three meters with the umbilicus as the stress point)and performed laparoscopic repair of the gallbladder rupture,which helps clinicians understand IGI and reduce the severe consequences of delayed diagnosis.Through extensive medical history and dynamic abdominal ultrasound evaluation,doctors can identify GI early and begin surgery,thereby decreasing the devastating repercussions of delayed diagnosis.CONCLUSION This article aims to improve clinicians'understanding of IGI and propose a method for the diagnosis and treatment of GI.

Isolated lateral leg compartment syndrome:A case report

BACKGROUND Acute leg compartment syndrome is a well-known orthopedic emergency associated with potentially devastating consequences if not treated immediately.Multiple compartments are usually involved with a clear history of trauma and classic symptoms and signs.However,isolated lateral leg compartment syndrome is relatively rare and is often misdiagnosed due to the atypical presentation of no trauma and the lack of pathognomonic signs.CASE SUMMARY A 31-year-old male patient presented to our emergency room with excruciating left calf pain and inability to mobilize one-day after participating in a football match despite no clear history of preceding trauma.The patient went to another hospital before presenting to us where he was diagnosed to have a soft tissue injury and was discharged home on simple analgesics.On clinical examination,the left leg showed a tense lateral compartment with severe tenderness.The pain was aggravated by dorsiflexion and ankle inversion.Neurovascular examination of the limb was normal.We suspected a compartment syndrome but as the presentation was atypical and an magnetic resonance imaging(MRI)was readily available in our institution,we immediately performed an MRI and this confirmed a large hematoma in the lateral compartment with a possible partial proximal peroneus longus muscle tear.The patient was taken immediately for an emergency open fasciotomy.The patient is now 18 mo postoperatively having recovered completely and engages fully in sports with no restrictions.CONCLUSION Atypical presentation due to the lack of pathognomonic signs makes the diagnosis of isolated lateral leg compartment syndrome difficult.Pain on passive inversion and dorsiflexion and weak active eversion may be suggested as sensitive signs.

Left epigastric isolated tumor fed by the inferior phrenic artery diagnosed as ectopic hepatocellular carcinoma:A case report

BACKGROUND Hepatocellular carcinoma(HCC)is one of the most frequent cancers and the main cause of cancer-related death worldwide.Ectopic HCC,an extremely rare type of HCC,exhibits a wide range of clinical signs and radiographic features,making preoperative identification challenging.CASE SUMMARY A 47-year-old man underwent routine abdominal color ultrasonography,which identified an asymptomatic tumor in the left upper abdomen.The patient had no history of hepatitis,did not drink alcohol,and had no family history of cancer.Abdominal contrast-enhanced computed tomography(CT)revealed a heterogeneously enhanced lesion between the spleen and stomach that had invaded the diaphragm,with blood supplied by the left inferior phrenic artery.The patient underwent laparoscopic surgery,and HCC was identified by postoperative pathology.Additionally,specific immunohistochemical staining was performed to assess the molecular biological characteristics of the HCC.The patient underwent two rounds of hepatic arterial interventional chemotherapy after surgery.Abdominal plain and enhanced magnetic resonance imaging and lung CT 3 mo postoperatively revealed no signs of local recurrence or distant metastasis.CONCLUSION This asymptomatic ectopic HCC case described achieved an excellent result due to early detection,radical resection,and systematic surveillance.

Influence of Vertical Irregularity on the Seismic Behavior of Base Isolated RC Structures with Lead Rubber Bearings under Pulse-Like Earthquakes

Nowadays,an extensive number of studies related to the performance of base isolation systems implemented in regular reinforced concrete structures subjected to various types of earthquakes can be found in the literature.On the other hand,investigations regarding the irregular base-isolated reinforced concrete structures’performance when subjected to pulse-like earthquakes are very scarce.The severity of pulse-like earthquakes emerges from their ability to destabilize the base-isolated structure by remarkably increasing the displacement demands.Thus,this study is intended to investigate the effects of pulse-like earthquake characteristics on the behavior of low-rise irregular base-isolated reinforced concrete structures.Within the study scope,investigations related to the impact of the pulse-like earthquake characteristics,irregularity type,and isolator properties will be conducted.To do so,different values of damping ratios of the base isolation system were selected to investigate the efficiency of the lead rubber-bearing isolator.In general,the outcomes of the study have shown the significance of vertical irregularity on the performance of base-isolated structures and the considerable effect of pulse-like ground motions on the buildings’behavior.

Two surgical pathways for isolated hip fractures:A comparative study

BACKGROUND Hip fractures(HF)are common among the aging population,and surgery within 48 h is recommended.Patients can be hospitalized for surgery through different pathways,either trauma or medicine admitting services.AIM To compare management and outcomes among patients admitted through the trauma pathway(TP)vs medical pathway(MP).METHODS This Institutional Review Board-approved retrospective study included 2094 patients with proximal femur fractures(AO/Orthopedic Trauma Association Type 31)who underwent surgery at a level 1 trauma center between 2016-2021.There were 69 patients admitted through the TP and 2025 admitted through the MP.To ensure comparability between groups,66 of the 2025 MP patients were propensity matched to 66 TP patients by age,sex,HF type,HF surgery,and American Society of Anesthesiology score.The statistical analyses included multivariable analysis,group characteristics,and bivariate correlation comparisons with theχ^(2)test and t-test.RESULTS After propensity matching,the mean age in both groups was 75-years-old,62%of both groups were females,the main HF type was intertrochanteric(TP 52%vs MP 62%),open reduction internal fixation was the most common surgery(TP 68%vs MP 71%),and the mean American Society of Anesthesiology score was 2.8 for TP and 2.7 for MP.The majority of patients in TP and MP(71%vs 74%)were geriatric(≥65-years-old).Falls were the main mechanism of injury in both groups(77%vs 97%,P=0.001).There were no significant differences in pre-surgery anticoagulation use(49%vs 41%),admission day of the week,or insurance status.The incidence of comorbidities was equal(94%for both)with cardiac comorbidities being dominant in both groups(71%vs 73%).The number of preoperative consultations was similar for TP and MP,with the most common consultation being cardiology in both(44%and 36%).HF displacement occurred more among TP patients(76%vs 39%,P=0.000).Time to surgery was not statistically different(23 h in both),but length of surgery was significantly longer for TP(59 min vs 41 min,P=0.000).Intensive care unit and hospital length of stay were not statistically different(5 d vs 8 d and 6 d for both).There were no statistical differences in discharge disposition and mortality(3%vs 0%).CONCLUSION There were no differences in outcomes of surgeries between admission through TP vs MP.The focus should be on the patient’s health condition and on prompt surgical intervention.

Baseline Isolated Printed Text Image Database for Pashto Script Recognition

The optical character recognition for the right to left and cursive languages such as Arabic is challenging and received little attention from researchers in the past compared to the other Latin languages.Moreover,the absence of a standard publicly available dataset for several low-resource lan-guages,including the Pashto language remained a hurdle in the advancement of language processing.Realizing that,a clean dataset is the fundamental and core requirement of character recognition,this research begins with dataset generation and aims at a system capable of complete language understanding.Keeping in view the complete and full autonomous recognition of the cursive Pashto script.The first achievement of this research is a clean and standard dataset for the isolated characters of the Pashto script.In this paper,a database of isolated Pashto characters for forty four alphabets using various font styles has been introduced.In order to overcome the font style shortage,the graphical software Inkscape has been used to generate sufficient image data samples for each character.The dataset has been pre-processed and reduced in dimensions to 32×32 pixels,and further converted into the binary format with a black background and white text so that it resembles the Modified National Institute of Standards and Technology(MNIST)database.The benchmark database is publicly available for further research on the standard GitHub and Kaggle database servers both in pixel and Comma Separated Values(CSV)formats.

Isolated Tricuspid Valve Repair and Right Atrial Plication Performed Using a Beating-Heart Technique for Atrial Functional Tricuspid Valve Regurgitation

Background: Isolated tricuspid valve disease remains a controversial indication for surgical intervention. Many patients referred for surgery already have a poor clinical condition and an advanced New York Heart Association functional class. There is no consensus on the optimal surgical technique for this condition, including on whether to perform the procedure on a beating or an arrested heart and whether to perform valve repair or replacement. Methods: We analyzed four case series between 2015 and 2022 in which patients with secondary tricuspid regurgitation (TR) underwent valve repair on a beating heart and right atrial plication for a dilated right atrium. The TRI-SCORE was calculated for each patient. Results: All patients experienced a favorable postoperative course with significant improvements in heart failure symptoms. TR was markedly reduced;however, in one patient with concomitant mitral regurgitation (MR) and a high TRI-SCORE, MR worsened postoperatively. This patient later died from unknown causes due to multiple comorbidities in the late phase. Conclusions: Tricuspid valve repair on a beating heart was effective for improving the cardiac function, and the TRI-SCORE proved useful as a preoperative risk assessment tool. The underlying mechanism by which TR exacerbates MR requires further investigation.