Genetic and functional insights into the fractal structure of the heart.

The inner surfaces of the human heart are covered by a complex network of muscular strands that is thought to be a remnant of embryonic development1,2. The function of these trabeculae in adults and their genetic architecture are unknown. Here we performed a genome-wide association study to investigate image-derived phenotypes of trabeculae using the fractal analysis of trabecular morphology in 18,096 participants of the UK Biobank. We identified 16 significant loci that contain genes associated with haemodynamic phenotypes and regulation of cytoskeletal arborization3,4. Using biomechanical simulations and observational data from human participants, we demonstrate that trabecular morphology is an important determinant of cardiac performance. Through genetic association studies with cardiac disease phenotypes and Mendelian randomization, we find a causal relationship between trabecular morphology and risk of cardiovascular disease. These findings suggest a previously unknown role for myocardial trabeculae in the function of the adult heart, identify conserved pathways that regulate structural complexity and reveal the influence of the myocardial trabeculae on susceptibility to cardiovascular disease.

Repeat EUS-FNA of pancreatic masses after nondiagnostic or inconclusive results: systematic review and meta-analysis.

BACKGROUND AND AIMS: EUS-guided FNA (EUS-FNA) is the criterion standard for the diagnosis of solid pancreatic lesions. Several studies assessed the role of repeat EUS-FNA (rEUS-FNA) after an inconclusive examination. Our aim was to evaluate the pooled diagnostic accuracy of rEUS-FNA after a nondiagnostic result. METHODS: We conducted systematic research on electronic databases (Medline, PubMed, EMBASE) and a meta-analysis to obtain pooled sensitivity, specificity, positive and negative likelihood ratio, and diagnostic odds ratio. A summary receiver operating characteristic curve was used to calculate area under the curve. Subgroup analysis was used to assess the role of rapid on-site evaluation (ROSE). RESULTS: Twelve studies (505 patients) were included. Sensitivity was 77% (66%-86%), specificity 98% (78%-100%), and positive and negative predictive values 99% (98%-100%) and 61 (60%-63%), respectively. At 73% of disease prevalence (pretest probability), positive rEUS-FNA increased the disease probability to 99%, whereas a negative result decreased the disease probability to 39%. The sensitivity was 83% (64%-93%) and specificity 98% (80%-100%) when ROSE was available and 65% (57%-73%) and 94% (31%-100%) when not available. The number needed to diagnose was 1.2 (1.1-2.3) and 1.7 (1.4-8.3) in ROSE-positive and ROSE-negative cases, respectively. The number of correctly diagnosed cases increased from 6 (1-7) to 8 (4-9) of 10 patients without and with ROSE, respectively. CONCLUSIONS: This study objectively substantiated the added value of rEUS-FNA for the diagnosis of solid pancreatic masses in cases of a previous nondiagnostic or inconclusive result. Moreover, our data suggested that ROSE may be beneficial in this setting, because it increased the proportion of definitive diagnoses.

A bio-inspired microstructure induced by slow injection moulding of cylindrical block copolymers.

It is well known that block copolymers with cylindrical morphology show alignment with shear, resulting in anisotropic mechanical properties. Here we show that well-ordered bi-directional orientation can be achieved in such materials by slow injection moulding. This results in a microstructure, and anisotropic mechanical properties, similar to many natural tissues, making this method attractive for engineering prosthetic fibrous tissues. An application of particular interest to us is prosthetic polymeric heart valve leaflets, mimicking the shape, microstructure and hence performance of the native valve. Anisotropic layers have been observed for cylinder-forming block copolymers centrally injected into thin circular discs. The skin layers exhibit orientation parallel to the flow direction, whilst the core layer shows perpendicularly oriented domains; the balance of skin to core layers can be controlled by processing parameters such as temperature and injection rate. Heart valve leaflets with a similar layered structure have been prepared by injection moulding. Numerical modelling demonstrates that such complex orientation can be explained and predicted by the balance of shear and extensional flow.

Correction: Design, development, testing at ISO standards and in vivo feasibility study of a novel polymeric heart valve prosthesis.

Correction for 'Design, development, testing at ISO standards and in vivo feasibility study of a novel polymeric heart valve prosthesis' by Joanna R. Stasiak et al., Biomater. Sci., 2020, DOI: .

Design, development, testing at ISO standards and in vivo feasibility study of a novel polymeric heart valve prosthesis.

Clinically available prosthetic heart valves are life-saving, but imperfect: mechanical valves requiring anticoagulation therapy, whilst bioprosthetic valves have limited durability. Polymer valves offer the prospect of good durability without the need for anticoagulation. We report the design and development of a polymeric heart valve, its bench-testing at ISO standards, and preliminary extra-vivo and in vivo short-term feasibility. Prototypes were manufactured by injection moulding of styrenic block copolymers to achieve anisotropic mechanical properties. Design was by finite element stress-strain modelling, which has been reported previously, combined with feedback from bench and surgery-based testing using various combinations of materials, valve geometry and processing conditions. Bench testing was according to ISO 5840:2015 standards using an in vitro cardiovascular hydrodynamic testing system and an accelerated fatigue tester. Bench comparisons were made with a best-in-class bio-prosthesis. Preliminary clinical feasibility evaluations included extra-vivo and short-term (1-24 hours) in vivo testing in a sheep model. The optimised final prototype met the requirements of ISO standards with hydrodynamic performance equivalent to the best-in-class bioprosthesis. Bench durability of greater than 1.2 billion cycles (30 years equivalent) was achieved (still ongoing). Extra-vivo sequential testing (n = 8) allowed refinement of external diameter, 3D shape, a low profile, flexibility, suturability, and testing of compatibility to magnetic resonance imaging and clinical sterilisation. In vivo short-term (1-24 hours) feasibility (n = 3) confirmed good suturability, no mechanical failure, no trans-valvular regurgitation, competitive trans-valvular gradients, and good biocompatibility at histopathology. We have developed and tested at ISO standards a novel prosthetic heart valve featuring competitive bench-based hydrodynamics and durability, well beyond the ISO requirements and comparable to a best-in-class bioprosthesis. In vivo short-term feasibility testing confirmed preliminary safety, functionality and biocompatibility, supporting progression to a long-term efficacy trial.

Evaluation of a new slim radial echoendoscope: A better option for an aging population.

BACKGROUND AND OBJECTIVES: The radial echoendoscope is still widely used for the investigation of abnormalities in the gastrointestinal wall and for stone detection in the extrahepatic biliary tree. Due to aging patient population, EUS is frequently performed in fragile and elderly individuals. We aimed to compare the maneuverability and image quality of a new thin radial echoendoscope to the current one. PATIENTS AND METHODS: This evaluation was conducted at a referral academic EUS center. The new radial echoendoscope has a thinner shaft and distal tube and a shorter bending section compared to the previous one. Patients referred for diagnostic EUS with a radial echoendoscope were enrolled. Indications included pancreaticobiliary disease, esophagogastric abnormalities, and neoplasms and rectal cancer staging. RESULTS: We enrolled 177 patients (122 pancreaticobiliary, 48 esophagogastric, and 7 rectal cases). Overall, the new echoendoscope performed better than the previous model in terms of maneuverability during esophageal intubation and transition from the duodenal bulb to the second portion. On the other hand, pylorus traversing was comparable to the current radial echoendoscope. No loss in image quality was appreciated at predefined stations (esophagus, stomach, and duodenum) compared to the current model. On the other hand, image penetration depth in tissue harmonic mode was significantly improved with the new echoendoscope. CONCLUSIONS: A new thinner radial echoendoscope showed improved maneuverability compared to the existing version. Image quality was also improved thanks to increased penetration depth in the tissue harmonic mode. We speculate that this new echoendoscope may allow for safer and faster EUS examination, which may prove useful in an aging patient population.

CO 2 vs. air insufflation in endoscopic ultrasonography: a prospective study.

Background and study aims Carbon dioxide (CO 2 ) is being increasingly used for insufflation during endoscopy for safety and better tolerance. The role of CO 2 during endoscopic ultrasonography (EUS) has not been studied yet. Our main aim was to compare the effects of CO 2 vs. air insufflation on abdominal discomfort in patients undergoing EUS. Our secondary outcomes were to ascertain the effects of CO 2 insufflation on image quality/visual artifacts and on the amount of sedation. Patients and methods This was a prospective, controlled, single-blind, observational study. Abdominal discomfort was assessed before diagnostic EUS, and 1 and 3 hours post-procedure and recorded as a visual analogue scale. Image quality was also recorded as a 4-point scale from optimal to poor at four different scanning sites (esophagus, stomach, duodenal bulb and second portion). Results A total of 198 patients were enrolled. We observed that CO 2 resulted in less abdominal discomfort than air insufflation that was statistically significant at 3 hours ( P  = 0.048) but not at 1 hour after EUS ( P  = 0.112), probably due to the ongoing effects of sedation at the latter stage. On the other hand, no differences were found in the dose of sedation administered in the two groups. Image quality was significantly better in the CO 2 group compared to the air group at all four different scanning sites ( P  < 0.01). Similarly, CO 2 correlated with less visual artifacts and need of suction ( P  < 0.01). Conclusions Similarly to previous findings with other endoscopic procedures, EUS was associated with improved scores for abdominal discomfort with CO 2 rather than air insufflation. Moreover, overall EUS image quality was improved using CO 2 insufflation. Future studies are warranted to ascertain whether CO 2 insufflation should be regarded as the standard of care for diagnostic EUS.

Contrast-enhanced endoscopic ultrasound for the differential diagnosis between benign and malignant lymph nodes: a meta-analysis.

Background The differential diagnosis between benign and malignant lymph nodes (LNs) is crucial for patient management and clinical outcome. The use of contrast-enhanced endoscopic ultrasound (EUS) has been evaluated in several studies with diverse results. The aim of this meta-analysis was to evaluate the pooled diagnostic accuracy of contrast-enhanced EUS (CE-EUS) and contrast-enhanced harmonic EUS (CH-EUS) in this setting. Methods A systematic electronic search was performed, including all original papers dealing with assessment of the nature of the LNs using CE-EUS or CH-EUS. A meta-analysis was performed to obtain pooled sensitivity, specificity, positive and negative likelihood ratio, and diagnostic odds ratio. The Summary Receiver Operating Characteristic (ROC) Curve method was used to calculate the area under the curve. Statistical analysis was carried out using Meta-Disc V.1.4, Stata V.12.0 and Review Manager V.5.2. Results Among 210 pertinent studies, four (336 patients) were included in the analysis. The pooled sensitivity was 82.1 % (75.1 - 87.7 %) and pooled specificity was 90.7 % (85.9 - 94.3 %) with significant heterogeneity found in sensitivity; the positive-likelihood ratio (LR) was 7.77 (5.09 - 11.85) and the negative-LR was 0.15 (0.05 - 0.46); the pooled diagnostic odds ratio (DOR) was 54 (15 - 190). Subgroup analysis including studies performed using CH-EUS (two studies, 177 LNs) showed a pooled sensitivity of 87.7 % (77.0 - 93.9 %) and a pooled specificity of 91.8 % (84.5 % - 96.4 %) with no significant heterogeneity; the pooled positive-LR was 9.51 (4.95 - 18.28) and the pooled negative-LR was 0.14 (0.06 - 0.35); pooled DOR was 68.42 (15.5 - 301.4). Conclusions From these data, CE-EUS is not recommended due to inadequate sensitivity. On the other hand, CH-EUS studies showed optimal accuracy (pooled sensitivity 87.7 % and specificity 91.8 %), comparable to elastography and even EUS-guided fine needle aspiration (EUS-FNA), suggesting a role in the diagnostic algorithm.

EUS liver assessment using contrast agents and elastography.

Transabdominal-US is the first-line imaging modality used to assess the whole liver parenchyma and vascularization; EUS assessment of the liver is incomplete and is not sufficient to rule out the presence of focal liver lesions. On the other hand, due the high diagnostic yield in detecting very small (< 1 cm) lesions, EUS is considered complementary to radiological imaging techniques for the investigation of liver parenchyma. Scarce data are available regarding the investigation of liver parenchyma using both EUS-elastography (EUS-E) and CH-EUS. The aim of this review is to evaluate the clinical role of image enhancement techniques, namely EUS-E and contrast harmonic-EUS (CH-EUS), for the evaluation liver diseases. Despite a potential interest for the application of EUS-E in the assessment of liver diseases, available evidence relegates this technique only to research areas, such as the differential diagnosis between benign and malignant focal liver lesions and the quantification of liver fibrosis in diffuse parenchymal diseases. With the future introduction of EUS shear-wave elastography, interesting data can be obtained for the assessment of liver fibrosis during real-time EUS evaluation. The usefulness of CH-EUS for the evaluation of liver disease is limited by the intrinsic EUS ability to explore only the left lobe and a small part of the right lobe. CH-EUS could be used to increase the diagnostic ability of EUS for the detection and characterization of small lesions and for guiding tissue sampling. Targeting EUS-guided treatments with either EUS-E or CH-EUS might represent potential future applications.

Basics in Endoscopic Ultrasound Part 2: EUS-guided Sampling and Therapeutic Applications.

BACKGROUND: Endoscopic ultrasound (EUS) has been used in the clinical arena for almost 35 years and it is now well-integrated in everyday hospital practice. METHOD: We conducted a systematic review of the available English-language articles. OBJECTIVE: The purpose of this review is to summarize the relevant applications of operative EUS. RESULTS: More than 5000 scientific papers published in the literature have demonstrated its high accuracy for the diagnosis and staging of a variety of benign and malignant conditions. The main indications of operative EUS, both diagnostic and therapeutic, are related to its ability to combine ultrasound imaging and safe and effective needle insertion into lesions originating from the gut wall and from organs nearby. In addition, technologic advancements of echoendoscopes with a therapeutic working-channel have allowed to perform several EUS-guided interventions, i.e. celiac plexus neurolysis, drainage of fluid collections, drainage of dilated biliary and pancreatic ducts, and vascular interventions.

Basics in Endoscopic Ultrasound Part 1: Diagnostic Indications and Tissue Sampling.

BACKGROUND: Endoscopic Ultrasound has been used in the clinical arena for almost 35 years and it is now well-integrated in everyday hospital practice. METHOD: We conducted a systematic review of the available English-language articles. OBJECTIVE: The purpose of this review is to summarize all the relevant indications to endoscopic ultrasound and analyze its relevant data in terms of accuracy and clinical outcomes. RESULTS: More than 5000 scientific papers published in the literature have demonstrated its high accuracy for the diagnosis and staging of a variety of benign and malignant conditions. Staging indications include gastroesophageal and rectal cancers. Diagnostic, staging and therapeutic indications include diseases of the pancreaticobiliary area. Finally, differential diagnosis of submucosal tumors represents another important indication to this technique.

Role of contrast harmonic-endoscopic ultrasound in pancreatic cystic lesions.

Incidental pancreatic cysts (PCs) are frequently encountered in the general population often in asymptomatic patients who undergo imaging tests to investigate unrelated conditions. The detection of a PC poses a significant clinical dilemma, as the differential diagnosis is quite broad ranging from benign to malignant conditions. Endoscopic ultrasound (EUS) with fine-needle aspiration (FNA) has been reported to be an accurate tool in the differential diagnosis; however, its sensitivity is suboptimal and false negative results do occur. Contrast harmonic EUS (CH-EUS) was demonstrated to be a useful tool to investigate pancreatic solid lesions to differentiate between benign and malignant ones. In the setting of PCs, CH-EUS could help identify areas of malignant growth inside the cystic cavities. Several studies have reported promising results showing malignant areas in PCs as hyperenhanced lesions. Confirmation of malignancy can then be obtained by FNA, which should be precisely targeted according to the findings of the contrast harmonic study.

Quantifying the Shift Toward Transcatheter Aortic Valve Replacement in Low-Risk Patients: A Meta-Analysis.

BACKGROUND: In recent years, use of transcatheter aortic valve replacement has expanded to include patients at intermediate- and low-risk cohorts. We sought to determine disease prevalence and treatment distribution including transcatheter aortic valve replacement eligibility in low-risk patients across 37 advanced economies. METHODS AND RESULTS: Four systematic searches were conducted across MEDLINE, EMBASE, and the Cochrane database for studies evaluating disease prevalence, severity, decision making, and survival in patients with aortic stenosis. Estimates of disease prevalence and treatment eligibility were calculated using stochastic simulation and population data for the 37 countries comprising the International Monetary Fund's advanced economies index. Fifty-six studies comprising 42 965 patients were included across 5 domains: prevalence, severity, symptom status, treatment modality, and outcome. The pooled prevalence in the general population aged 60 to 74 years and >75 years was 2.8% (95% confidence interval [CI], 1.4%-4.1%) and 13.1% (95% CI, 8.2%-17.9%), respectively-corresponding to an estimated 16.1 million (95% CI, 12.2-20.3) people in 37 advanced economies. Of these, an estimated 3.2 million (95% CI, 2.2-4.4) patients have severe aortic stenosis with 1.9 million (95% CI, 1.3-2.6) eligible for surgical aortic valve replacement. There are ≈485 230 (95% CI, 284 550-66 7350) high-risk/inoperable patients, 152 690 (95% CI, 73 410-263 000) intermediate-risk patients, and 378 890 (95% CI, 205 130-610 210) low-risk patients eligible for transcatheter aortic valve replacement. CONCLUSIONS: With a prevalence of 4.5%, an estimated 16.1 million people aged ≥60 years across 37 advanced economies have aortic stenosis. Of these, there are ≈1.9 million patients eligible for surgical aortic valve replacement and 1.0 million patients eligible for transcatheter aortic valve replacement.

Evaluation of an aortic valve prosthesis: Fluid-structure interaction or structural simulation?

Bio-inspired polymeric heart valves (PHVs) are excellent candidates to mimic the structural and the fluid dynamic features of the native valve. PHVs can be implanted as prosthetic alternative to currently clinically used mechanical and biological valves or as potential candidate for a minimally invasive treatment, like the transcatheter aortic valve implantation. Nevertheless, PHVs are not currently used for clinical applications due to their lack of reliability. In order to investigate the main features of this new class of prostheses, pulsatile tests in an in-house pulse duplicator were carried out and reproduced in silico with both structural Finite-Element (FE) and Fluid-Structure interaction (FSI) analyses. Valve kinematics and geometric orifice area (GOA) were evaluated to compare the in vitro and the in silico tests. Numerical results showed better similarity with experiments for the FSI than for the FE simulations. The maximum difference between experimental and FSI GOA at maximum opening time was only 5%, as compared to the 46.5% between experimental and structural FE GOA. The stress distribution on the valve leaflets clearly reflected the difference in valve kinematics. Higher stress values were found in the FSI simulations with respect to those obtained in the FE simulation. This study demonstrates that FSI simulations are more appropriate than FE simulations to describe the actual behaviour of PHVs as they can replicate the valve-fluid interaction while providing realistic fluid dynamic results.

Contrast enhancement and elastography in endoscopic ultrasound: an update of clinical applications in pancreatic diseases.

It is well established that endoscopic ultrasound (EUS) is fundamental in the characterization of many diseases concerning different organs, i.e. pancreaticobiliary diseases, gastrointestinal pathologic conditions, and lymph nodes of unknown origin. It is also well known that many factors can hamper the accuracy of EUS, i.e. biliary stents, chronic pancreatitis, poor operator's expertise. These factors can also lead to suboptimal accuracy when cytological confirmation through EUS-fine needle aspiration (EUS-FNA) is indicated. In recent years, new technological tools have rapidly increased their clinical impact improving the diagnostic power of EUS and EUS-FNA. Among these new tools, the most investigated and useful ones are represented by contrast harmonic-EUS (CH-EUS) and EUS-elastography (EUS-E). The purpose of this paper is to provide, through a review of the literature, an update of the applications of CH-EUS and EUS-E in the routine clinical practice in pancreatic diseases. We discussed the first reports and applications of these techniques in our previous review published in Minerva Medica. The applications of CH-EUS and EUS-E to the study of pancreatic diseases appear feasible and safe. The use of both techniques is very simple and does not require any relevant additional workload for the endoscopic personnel. CH-EUS is now considered an important and accurate tool in the diagnosis of solid pancreatic masses and in the differential diagnosis of pancreatic cystic lesions. CH-EUS targeted FNA is an active field of research. However the available studies show that CH-EUS increases FNA accuracy by a little extent, without statistical significance; moreover, CH-EUS FNA showed a trend toward being more efficient vs. simple EUS FNA (less needle passes and more abundance in cytological material) but this trend did not reach statistical significance. On the other hand, the clinical impact of EUS-E in terms of differential diagnosis of pancreatic masses is still under investigation. Chronic pancreatitis evaluation represents the most recent field of application of EUS-E that shows promising results.

Contrast Harmonic-Endoscopic Ultrasound Is Useful to Identify Neoplastic Features of Pancreatic Cysts (With Videos).

OBJECTIVES: To evaluate the potential role of contrast harmonic endoscopic ultrasound (CH-EUS) in the differential diagnosis of pancreatic cysts and detection of malignancy. METHODS: Patients who underwent CH-EUS for evaluation of cyst wall, septae, and solid components of pancreatic cysts were included. The findings were compared to fine needle aspiration and surgery. RESULTS: Seventy-six patients were included. Serous and mucinous cysts were both hyperenhanced (86% and 89%, respectively; P = ns), whereas pseudocysts were hypoenhanced in 90% of the cases (P = 0.000004 vs serous cysts and P = 0.000005 vs mucinous cysts). Patients showing hyperenhanced solid components were finally diagnosed with malignancy (2 malignant intraductal papillary mucinous neoplasms, 2 cystic neuroendocrine tumors), in contrast to the patients with nonenhanced solid components who resulted to have either benign cysts with internal mucus clots (n = 10) or pseudocysts with internal debris (n = 8). CONCLUSIONS: CH-EUS allowed differentiation between pseudocysts and other pancreatic cysts but not mucinous versus serous cysts. Malignant vegetations inside pancreatic cystic lesions were clearly shown by CH-EUS as solid components with features of hyperenhancement, directing EUS-fine needle aspiration of potential neoplastic areas and avoiding puncture of debris and mucus plugs.

Performance of the forward-view echoendoscope for pancreaticobiliary examination in patients with status post-upper gastrointestinal surgery.

BACKGROUND AND OBJECTIVES: Failures of endoscopic ultrasound (EUS) imaging of the head of the pancreas (HOP) and the common bile duct (CBD) have been reported in up to 50% of patients with status postsurgery (e.g., Billroth II and Roux-en-Y). This is attributable to inability to intubate the afferent limb or the duodenum. Recently, a forward-view (FV) echoendoscope has become available. The frontal endoscopic and ultrasound field of view theoretically allow easier manipulation throughout the gastrointestinal tract compared to the traditional echoendoscopes. The aim of our study was to evaluate the safety and performance of the FV echoendoscope for the investigation of the biliary tree and the pancreas, including fine-needle aspiration (FNA), in patients with surgically altered upper gastrointestinal anatomy. PATIENTS AND METHODS: This was a retrospective evaluation of a prospectively maintained database. All EUS procedures were performed at our institution by one experienced endosonographer from March to September 2009 under conscious sedation. The FV echoendoscope was used for all procedures. RESULTS: Twenty-five (25) out of 37 presented status post-Billroth II and 12 out of 37 with status post-Roux-en-Y surgery. Overall, HOP and CBD were adequately visualized in 28 out of 37 (75.7%). All the failures occurred in the Roux-en-Y patients. EUS-FNA was successfully performed in 16 patients. No adverse events were observed. CONCLUSIONS: The FV echoendoscope proved to be safe and effective in reaching the periampullary area in patients with previous Billroth II, allowing complete exploration of the HOP and the CBD and performance of EUS-FNA. However, FV EUS was unsuccessful in the majority of patients with Roux-en-Y, which still remains a challenging condition.

A Newly Developed Tri-Leaflet Polymeric Heart Valve Prosthesis.

The potential of polymeric heart valves (PHV) prostheses is to combine the hemodynamic performances of biological valves with the durability of mechanical valves. The aim of this work is to design and develop a new tri-leaflet prosthetic heart valve (HV) made from styrenic block copolymers. A computational finite element model was implemented to optimize the thickness of the leaflets, to improve PHV mechanical and hydrodynamic performances. Based on the model outcomes, 8 prototypes of the designed valve were produced and tested in vitro under continuous and pulsatile flow conditions, as prescribed by ISO 5840 Standard. A specially designed pulse duplicator allowed testing the PHVs at different flow rates and frequency conditions. All the PHVs met the requirements specified in ISO 5840 Standard in terms of both regurgitation and effective orifice area (EOA), demonstrating their potential as HV prostheses.

Fluid dynamic characterization of a polymeric heart valve prototype (Poli-Valve) tested under continuous and pulsatile flow conditions.

PURPOSE: Only mechanical and biological heart valve prostheses are currently commercially available. The former show longer durability but require anticoagulant therapy; the latter display better fluid dynamic behavior but do not have adequate durability. New Polymeric Heart Valves (PHVs) could potentially combine the hemodynamic properties of biological valves with the durability of mechanical valves. This work presents a hydrodynamic evaluation of 2 groups of newly developed supra-annular, trileaflet prosthetic heart valves made from styrenic block copolymers (SBC): Poli-Valves. METHODS: 2 types of Poli-Valves made of SBC and differing in polystyrene fraction content were tested under continuous and pulsatile flow conditions as prescribed by ISO 5840 Standard. A pulse duplicator designed ad hoc allowed the valve prototypes to be tested at different flow rates and frequencies. Pressure and flow were recorded; pressure drops, effective orifice area (EOA), and regurgitant volume were computed to assess the behavior of the valve. RESULTS: Both types of Poli-Valves met the minimum requirements in terms of regurgitation and EOA as specified by the ISO 5840 Standard. Results were compared with 5 mechanical heart valves (MHVs) and 5 tissue heart valves (THVs), currently available on the market. CONCLUSIONS: Based on these results, PHVs based on styrenic block copolymers, as are Poli-Valves, can be considered a promising alternative for heart valve replacement in the near future.