Search Results (53)

Introduction: Prosthesis-patient mismatch (PPM) in surgical aortic valve replacement (SAVR) is known to be a poor prognostic factor. However, the parameters for preventing postoperative PPM in SAVR have not been established. Materials and Methods: Two hundred and five patients (mean age 72.5 ± 7.4 years, 129 males) who underwent SAVR were analyzed. Preoperatively, we determined the recommended prosthesis valve size from the mean aortic valve (AV) diameter derived from the AV annulus area by preoperative three-dimensional transesophageal echocardiography (3D-TEE). We investigated the association between pre- and postoperative changes in annulus diameter and the occurrence of PPM. Results: PPM was present in 6 patients (2.9%). Pre- and postoperative AV annulus diameter change ratio was greater in the group with PPM than in that without PPM (10.4 ± 3.6% vs. 3.0 ± 5.6%, p = 0.002). The use of prosthetic valve rings smaller than the recommended size was higher in the group with PPM than in that without PPM. (83.3% vs. 20.6%, p = 0.002). On multivariate logistic regression analysis, use of a valve smaller than the recommended size was an independent predictor of PPM (odds ratio 19.3, 95% confidence interval 2.14–174.5, p = 0.008). Conclusions: The recommended prosthetic AV size based on preoperative 3D-TEE is useful for determining the optimal prosthetic AV size to prevent PPM after SAVR. Full article

This study investigates, for the first time, using finite element analysis (FEA), the differential impact of middle ear prosthesis diameter on hearing gain in two distinct surgical techniques: stapedotomy and partial stapedectomy. The model represented the cochlea as two fluid-filled straight channels separated by the basilar membrane and considered pistons of 0.4 mm and 0.6 mm diameters. The results demonstrated that in stapedotomy, a 0.6 mm diameter piston yielded a significantly better reduction in ABG (8.31 dB) compared to the 0.4 mm piston (10.67 dB), indicating improved hearing gain. Conversely, in partial stapedectomy, the smaller 0.4 mm piston was more effective, reducing ABG to 11.2 dB versus 12.12 dB with the larger piston. These findings highlight that the optimal prosthesis diameter varies according to surgical technique, emphasizing the need for tailored prosthesis selection. Full article

Background and Objectives: Prosthesis–patient mismatch (PPM) after surgical aortic valve replacement (SAVR) is associated with worse clinical outcomes and worse valve durability. The aim of this retrospective single-center study was to evaluate the consistency between predicted PPM (PPMp) and measured PPM (PPMm) after SAVR with three different bioprostheses. Materials and Methods: We analyzed data of all consecutive patients who underwent surgical aortic valve replacement with Magna Ease, Intuity, and Inspiris Resilia bioprostheses (Edwards Lifesciences, Irvine, CA, USA) at our institution. PPM was defined if EOAi ≤ 0.85 cm²/m². PPMm was determined by institutional echo lab-measured EOAi on discharge-day echocardiogram. PPMp was assessed using reference values for each valve model and size indexed to BSA based on height, weight, prosthesis type, and size. For the overall population and for the three valve types we evaluated the sensitivity, specificity, positive predicted value, negative predicted value, and accuracy of PPMp. Furthermore, the consistency between PPMm and PPMp were evaluated according to prosthesis type, size, stent internal diameter (ID), and true ID. Results: A total of 1323 patients underwent SAVR; complete hemodynamic data were available for 872 patients, who represent the population of our study. Magna Ease, Intuity, and Inspiris Resilia were implanted in 446 (51.1%), 341 (39.1%), and 85 (9.7%) patients, respectively. In 635 out of 872 cases (72.8%), PPMp was consistent with PPMm (Magna Ease: 321/446, 72%; Inspiris Resilia: 58/85, 68.2%; Intuity: 256/341, 75%). Overall, the sensitivity, specificity, positive predicted value, negative predicted value, and accuracy of PPMp were 0.26, 0.83, 0.24, 0.84, and 0.73, respectively (Magna Ease: 0.21, 0.82, 0.3, 0.8, and 0.72; Inspiris Resilia: 0.11, 0.82, 0.14, 0.79, and 0.68; Intuity: 0.45, 0.78, 0.19, 0.93, and 0.75). Conclusions: The consistency between PPMp and PPMm was suboptimal. We did not observe differences between PPMp and PPMm among different valve types. Discordance between PPMp and PPMm was more evident in smaller valve sizes. When implanting small valves, the evaluation of PPMp should be used with caution to avoid unexpected PPMm. Full article

Over 10% of patients undergoing aortic endograft implantation experience endoleaks within a few years. In the case of type 1a endoleaks, a crack forms between the aorta and the prosthesis collar, allowing blood to pass. This blood fills the aneurysmal sac and can lead to its rupture. None of the strategies, such as prostheses with barbs and hooks or ad hoc pharmacological therapies, can prevent the phenomenon. An alternative approach is to reduce diameter oscillations due to pulsating pressure to improve the endoprosthesis adhesion to the internal vessel walls during the initial post-implantation phases. To reach this objective, we propose to use a passive intra-aortic balloon pump (PIABP) inserted and then maintained inside the vessel immediately after the surgical procedure. We tested our hypothesis in a mechanical mock of the cardiovascular system. A silicon aorta with physiological behavior was created for this purpose. The PIABP was inflated to increasing pressures between systolic and diastolic values (120/80 mmHg). For each aorta and each condition, the variations in aortic diameter between systole and diastole, and the pressure variations, were measured. For the normal aorta, with a PIABP pressure of 110 mmHg, the variations in diameter were reduced by 38%. Assuming an endoprosthesis with a diameter of 30 mm (oversized by 5% compared to the diastolic diameter), the time the oscillations are higher than 30 mm is also reduced by 36%. The results are positive and suggest the usefulness of a biomechanical approach to the problem of type 1a endoleaks. Further in silico and clinical trials are necessary to validate the method. Full article

In different applied load scenarios, this study evaluates the distribution of stress in the implant and bone exerted by zirconia, lithium disilicate, and cobalt chromium alloy. A 3D virtual model of a mandibular three-unit implant-supported prosthesis was created using SolidWorks 2022. The model featured two 12-mm Straumann Ti-Zr (Roxolid) implants with diameters of 4.5 mm and 4 mm. Zirconia, lithium disilicate, and cobalt chromium alloy were used as superstructure materials. Vertical loads of 100 N and 200 N were applied to the central fossa of the implant-supported prosthesis. The finite element analysis demonstrated that doubling the applied load leads to a proportional increase in von Mises stress on both the implant and bone in a mandibular posterior three-unit implant-supported prosthesis model. Zirconia and chromium cobalt as superstructure materials result in similar stress levels due to their closely matched elastic moduli of 200 GPa and 218 GPa, respectively. In contrast, lithium disilicate leads to the highest stress levels, which is attributed to its lower elastic modulus of 95 GPa. These findings highlight the critical role of superstructure material properties in stress distribution. Zirconia emerges as the preferred material for implant-supported prosthetics due to its favorable stress distribution. Full article

Objective: This randomized controlled split-mouth trial compared the performance of 5.5 mm length implants (test group; TG) splinted within the same fixed prosthesis as longer implants (≥6.5 mm; control group; CG) in posterior regions. Methods: The primary hypothesis was that implant length does not affect marginal bone loss (MBL) one year post-implantation, while the secondary hypotheses included implant survival, peri-implant clinical variables, and prosthetic complications. Fifteen patients (eight males, seven females) with a mean age of 67 ± 9 years were included. Results: No significant difference in the implant position between groups (p = 0.808) was observed. Implant diameters ranged from 3.00 to 4.25 mm, and the most common bone type was type I (67%). Bone density (p = 0.574) and implant insertion torque (p = 0.888) were similar between groups. Mesial MBL (mean: −0.1; range: −1.19 to 0.24 for TG, and −0.03; −1.75 to 0.45 for CG; p = 0.955) and distal MBL (mean: −0.05; range: −1.41 to 0.27 for TG, and 0.08; −1.45 to 0.72 for CG; p = 0.118) did not show statistical differences. There were no implant failures or technical complications. Conclusions: These findings suggest that 5.5 mm length implants could be a viable option for use in posterior regions, providing similar clinical outcomes to longer implants one year post-implantation. Full article

The literature presents insufficient data evaluating the displacement and micromotion effects resulting from the combined use of tooth-implant connections in fixed partial dentures. Analyzing the biomechanical behavior of tooth-implant fixed partial denture (FPD) prothesis is vital for achieving an optimum design and successful clinical implementation. The objective of this study was to determine the relative significance of connector design on the displacement and micromotion of tooth-implant-supported fixed dental prostheses under occlusal vertical loading. A unilateral Kennedy class I mandibular model was created using a 3D reconstruction from CT scan data. Eight simulated designs of tooth-implant fixed partial dentures (FPDs) were split into two groups: Group A with rigid connectors and Group B with non-rigid connectors. The models were subjected to a uniform vertical load of 100 N. Displacement, strain, and stress were computed using finite element analysis. The materials were defined as isotropic, homogeneous, and exhibiting linear elastic properties. This study focused on assessing the maximum displacement in various components, including the bridge, mandible, dentin, cementum, periodontal ligament (PDL), and implant. Displacement values were predominantly higher in Group B (non-rigid) compared to Group A (rigid) in all measured components of the tooth-implant FPDs. Accordingly, a statistically significant difference was observed between the two groups at the FPD bridge (p value = 0.021 *), mandible (p value = 0.021 *), dentin (p value = 0.043 *), cementum (p value = 0.043 *), and PDL (p value = 0.043 *). Meanwhile, there was an insignificant increase in displacement values recorded in the distal implant (p value = 0.083). This study highlighted the importance of connector design in the overall stability and performance of the prosthesis. Notably, the 4.7 mm × 10 mm implant in Group B showed a displacement nearly 92 times higher than its rigid counterpart in Group A. Overall, the 5.7 mm × 10 mm combination of implant length and diameter showcased the best performance in both groups. The findings demonstrate that wider implants with a proportional length offer greater resistance to displacement forces. In addition, the use of rigid connection design provides superior biomechanical performance in tooth-implant fixed partial dentures and reduces the risk of micromotion with its associated complications such as ligament overstretching and implant overload, achieving predictable prognosis and enhancing the stability of the protheses. Full article

Background: The timing of treatment for chronic aortic valve regurgitation (AR), especially in asymptomatic patients, is gaining attention since less invasive strategies have become available. The aim of the present study was to evaluate left ventricular reverse remodeling after aortic valve replacement (AVR) for severe AR. Methods: Patients (n = 25) who underwent surgical AVR for severe AR with left ventricular ejection fraction (LVEF) less than 55% were included in this study. Preprocedural and follow-up clinical and echocardiographic measurements of LVEF and left ventricular (LV) diameters were retrospectively analyzed. Results: Mean LVEF increased significantly following surgical AVR (p < 0.0001). LV diameters showed a clear regression (p = 0.0088). Younger patients and those receiving a mechanical valve tended to have less improved LVEF on follow-up than patients over 60 years or the ones who were implanted with a biological prosthesis (p = 0.0239 and p = 0.069, respectively). Gender had no effect on the degree of LVEF improvement (p = 0.4908). Conclusions: We demonstrated significant LV reverse remodeling following AVR for AR. However, more data are needed on LV functional and geometrical improvement comparing the different types of valve prostheses to provide an optimal treatment strategy. Full article

Dental implant fractures pose a significant challenge to long-term treatment success. This systematic review aims to comprehensively examine the clinical factors influencing dental implant fractures (IFs). Furthermore, strategies to choose the right type of implant and prevent this complication are addressed. A systematic search was conducted across PubMed, Scopus, and Web of Science databases. Eligible studies included retrospective case–control, prospective cohort studies, and clinical trials. The initial search yielded 361 articles, of which 312 were excluded being these reviews, case reports, irrelevant, or written in languages other than English. This left 49 articles, with only 6 meeting the eligibility criteria for an in-depth review. These studies, all retrospective case–control, examine implant characteristics, patient demographics, surgical and prosthetic variables, biomechanical and functional factors, clinical and procedural variables, complications and maintenance issues. The risk of bias was assessed as low using the ROBINS-I tool. Key findings suggest a correlation between implant diameter and structural resistance, with wider implants demonstrating reduced fracture risk. Additionally, posterior regions, especially molars and premolars, exhibit higher susceptibility to IFs due to increased masticatory forces. Implant design and material may considerably influence fracture risk, with conical implants and screw-retained prostheses showing higher vulnerability. Biomechanical overload, particularly in patients with bruxism, emerges as a primary contributing factor to IFs. Prosthesis type significantly influences fracture incidence, with cantilever prostheses posing a higher risk due to increased stress. Peri-implant bone loss is strongly associated with IFs, emphasizing the need for meticulous preoperative assessments and individualized management strategies. Future research should prioritize larger and heterogeneous populations with long-term follow-up and standardized methodologies to enhance the generalizability and comparability of findings. Randomized controlled trials and biomechanical studies under controlled conditions are also essential to elucidate the complex interactions contributing to IFs and developing effective prevention strategies. Additionally, integrating patient-reported outcomes may offer a comprehensive understanding of the impact of IFs on quality of life. Full article

Objectives: The aim of this retrospective study was to evaluate the results of complementary TEVAR following the frozen elephant trunk (FET) procedure for patients with residual type A aortic dissection (rTAAD) in terms of technical feasibility, safety and mid-term outcomes. Methods: This was a retrospective single-centre analysis of patients who received TEVAR after FET for rTAAD from January 2012 up to December 2021. The primary endpoint was technical success. Safety parameters included 30-day/in-hospital morbidity and mortality. Furthermore, mid-term clinical and morphological outcomes were evaluated. Results: Among 587 TEVAR procedures, 60 patients (11 with connective tissue disorders) who received TEVAR after FET for rTAAD were identified. The median interval between FET and TEVAR was 28.5 months. Indications for TEVAR after FET were true lumen collapse distal to FET prosthesis (n = 7), dSINE (n = 2), planned completion (n = 13) and aortic diameter progression (n = 38). In forty-seven patients, TEVAR was performed in an elective setting; eight and six patients were operated on in an urgent or emergency setting, respectively. All TEVAR procedures were successfully completed. The 30-day mortality and spinal cord ischemia rates were 1.7%. During a median follow-up of 37 months, two further patients died. Nine patients had to undergo a further aortic intervention: fenestrated stent-graft (n = 3) or open repair of the infrarenal abdominal aorta (n = 6). Conclusions: Complementary TEVAR following FET for rTAAD showed excellent technical success and low perioperative risk, supporting the feasibility and safety of this strategy. Despite the favourable mid-term survival, certain patients might require a further aortic procedure. Full article

The objective of this study is to assess the ability of an Artificial Circulatory Phantom (ACP) to verify its accuracy in simulating the movement of artificial vessels vs. real vessels under changing cardiovascular parameters such as heartbeat, ejection fraction, and total peripheral resistance. The experiments were conducted with blood-like fluid that flows through two types of vessels: iliac arteries and different types of ePTFE vascular prostheses. Parameters such as diameter and tortuosity were measured and analyzed. The flow characteristics included a pulsating pattern with a frequency of 60–120 min⁻¹ and ejection volumes ranging from 70 to 115 mL. The results showed a predominantly positive correlation between wall displacement (W_d) and tortuosity index (T_i) for the iliac artery (R² = 0.981), as well as between Wd and mean tortuosity index (MT_i) (R² = 0.994). Similarly, positive correlations between Wd and T_i (R² = 0.942) and Wd and MT_i (R² = 0.922) were computed for the ePTFE vascular prosthesis. The ACP introduced in this study is a valuable tool for evaluating various vessel types and the spatial configurations of vascular prostheses under diverse hemodynamic conditions. These findings are promising for the advancement of novel approaches to the testing and design of vascular grafts, ultimately enhancing their patency rates in future applications. Full article

Narrow-diameter implants (NDI) serve as a solution for treating limited bone volume in the anterior mandible. This study aimed to evaluate the one-year clinical outcomes of various NDIs in the mandibular incisor area after immediate loading in partially edentulous patients. This single-center, prospective, single-blinded, randomized controlled trial study included 21 patients, with 7 patients in each of the following groups: control (BLT NC SLActive^®; Straumann), experimental group 1 (CMI IS-III Active^® S-Narrow; Neobiotech), and experimental group 2 (CMI IS-III Active^® Narrow; Neobiotech). Using full digital flow, two fixtures were placed in each patient and immediately provisionalized on the day of surgery. Evaluations encompassed periapical radiographs, implant stability quotient (ISQ), implant stability test (IST) readings, per-implant soft tissue health, patient satisfaction surveys, and esthetic score assessments. Definitive prostheses were delivered twelve weeks post-surgery (CRiS, number: KCT0007300). Following exclusions due to low stability values (n = 2), fixture failure (n = 5), and voluntary withdrawal (n = 1), the implant success rate for patients completing all clinical protocols stood at 100%. The resulting patient failure rates in the control, experimental group 1, and experimental group 2 were 50.0%, 42.9%, and 14.3%, respectively. There were no significant differences between the groups in terms of marginal bone loss, soft tissue health, patient satisfaction, and esthetic scores. Narrow implants showed superior clinical outcomes, followed by S-Narrow and Straumann implants. Calculated one-year survival rates at the implant level were 66.7% for the control group, 85.7% for experimental group 1, and 100% for experimental group 2. All three types of NDIs showed acceptable clinical and radiographic results during the year-long observation period. Full article

Introduction: Implant placement in the maxillary anterior area requires sufficient quantity and quality of both soft and hard tissue. In cases where soft and hard tissues are insufficient, additional regeneration using biomaterials is recommended. Treatment using bovine-derived xenograft and acellular dermal matrix (ADM) may increase bone volume and soft tissue thickness. Case and management: A 65-year-old woman sought help for discomfort and aesthetic issues with her denture, reporting missing teeth (11, 12, 13, 14, and 21) and bone volume shrinkage due to disuse atrophy. Intraoral examination revealed 1 mm gingival thickness. CBCT showed labio-palatal bone thickness of 6.0 mm, 5.8 mm, and 4.7 mm for teeth 21, 12 and 14, respectively. Implant planning and surgical guide fabrication were carried out before the surgery. Surgery included the placement of implants 3.3 mm in diameter and 12 mm in length, with the use of xenograft and ADM. Three months post-op, improvements in soft and hard tissues were observed, with a final prosthesis being a long-span implant-supported bridge. Conclusions: Disuse alveolar atrophy causes soft and hard tissue deficiency. The use of xenograft and ADM show favourable results even on a geriatric patient. Full article

Diabetes Mellitus (DM) is identified as an important condition that leads to implant complications, and the apico-coronal position and the prosthetic abutment seem to interfere with peri-implant tissue behavior This study aimed at assessing the effect on peri-implant parameters after implant loading of two different methodologies in type two diabetics patients (T2DM) who received implant muco-retained overdentures. Twenty-two mandibular edentulous T2DM received two implants: Test group: prosthetic abutment of a diameter smaller than the platform of the implant and a morse taper subcrestal implant level; Control group: prosthetic abutment of diameter identical to the platform and hexagonal external implant placed at crestal bone level. Clinical, inflammatory, and tomographic evaluations were performed at baseline (after prosthesis installation), and twelve and twenty-four months after implant loading. Test implants presented inferior probing depth and clinical attachment level compared to control at baseline and 12 months (p < 0.05). Test implants presented reduced levels of pro-inflammatory cytokines at 24 months compared to the control implants (p < 0.05). The control group had more changes in bone parameters from baseline to the first and second years (p < 0.05). The test group resulted in reduced bone remodeling and better clinical conditions and positively modulated peri-implant immunoinflammatory molecules. Trial identification UTN code: U1111-1239-3638. Full article

Transcatheter aortic valve implantation (TAVI) is a procedure to treat severe aortic stenosis. There are several clinical concerns related to potential complications after the procedure, which demand the analysis of computerized tomography (CT) scans after TAVI to assess the implant’s result. This work introduces a novel, fully automatic method for the analysis of post-TAVI 4D-CT scans to characterize the prosthesis and its relationship with the patient’s anatomy. The method enables measurement extraction, including prosthesis volume, center of mass, cross-sectional area (CSA) along the prosthesis axis, and CSA difference between the aortic root and prosthesis, all the variables studied throughout the cardiac cycle. The method has been implemented and evaluated with a cohort of 13 patients with five different prosthesis models, successfully extracting all the measurements from each patient in an automatic way. For Allegra patients, the mean of the obtained inner volume values ranged from 10,798.20 mm³ to 18,172.35 mm³, and CSA in the maximum diameter plane varied from 396.35 mm² to 485.34 mm². The implantation of this new method could provide information of the important clinical value that would contribute to the improvement of TAVI, significantly reducing the time and effort invested by clinicians in the image interpretation process. Full article