Robot-Assisted Extraperitoneal Ventral Hernia Repair-Experience From the First 160 Consecutive Operations With Lateral eTEP and eTAR Techniques.

Introduction: There is a growing consensus on the benefits of retro-muscular (RM) mesh positioning, highlighted by its recommendation in the latest edition of EHS guidelines. The eTEP method has facilitated minimally invasive hernia repairs with retro-muscular mesh placement. With the increasing availability of robotic systems, there has been a corresponding increase in robotic adaptations of minimally invasive techniques involving retro-muscular mesh placement.

Evaluation of design parameters on the outcome of intrastromal ring surgery using biomechanical simulations.

Background: The cornea plays a role in the refractive power of the eye, and when its natural curvature and thickness are compromised by diseases such as keratoconus or high myopia, this results in loss of visual acuity. Intracorneal rings (ICRs) were developed as a treatment option to restore the natural corneal curvature by implanting rings into tunnels cut within the corneal stroma. However, selecting and placing the appropriate ring can be difficult, and predicting refractive outcomes is challenging.

Robotic-assisted surgery for lateral ventral hernias - experience of robot-assisted methods for retromuscular and preperitoneal abdominal wall reconstruction.

Background: Due to the proximity to bony structures and the complex anatomy of the three-layered lateral abdominal wall, the surgical treatment of lateral ventral hernias is technically demanding. With this study we would like to demonstrate how lateral abdominal wall hernias can be treated using new robotic surgical techniques with extraperitoneal mesh placement.

Objectives: The purpose of this study is to demonstrate that the application of the robot in minimally invasive treatment of lateral abdominal wall hernias is safe and efficient.

Dynamic evaluation of corneal cross-linking and osmotic diffusion effects using optical coherence elastography.

Dynamic deformation events induced by osmosis or photochemical stiffening substantially influence geometrical and mechanical assessments in post-mortem corneas, therefore need to be carefully monitored in experimental settings. In this study, we employed optical coherence elastography (OCE) to quantify dynamic deformation processes at high resolution in freshly enucleated porcine corneas. Osmotic effects were studied by immerging n = 9 eyes in preservation media of three different tonicities.

Automatic quantification of scapular and glenoid morphology from CT scans using deep learning.

Objectives: To develop and validate an open-source deep learning model for automatically quantifying scapular and glenoid morphology using CT images of normal subjects and patients with glenohumeral osteoarthritis.

Materials And Methods: First, we used deep learning to segment the scapula from CT images and then to identify the location of 13 landmarks on the scapula, 9 of them to establish a coordinate system unaffected by osteoarthritis-related changes, and the remaining 4 landmarks on the glenoid cavity to determine the glenoid size and orientation in this scapular coordinate system. The glenoid version, glenoid inclination, critical shoulder angle, glenopolar angle, glenoid height, and glenoid width were subsequently measured in this coordinate system.

A Multidisciplinary Hyper-Modeling Scheme in Personalized In Silico Oncology: Coupling Cell Kinetics with Metabolism, Signaling Networks, and Biomechanics as Plug-In Component Models of a Cancer Digital Twin.

The massive amount of human biological, imaging, and clinical data produced by multiple and diverse sources necessitates integrative modeling approaches able to summarize all this information into answers to specific clinical questions. In this paper, we present a hypermodeling scheme able to combine models of diverse cancer aspects regardless of their underlying method or scale. Describing tissue-scale cancer cell proliferation, biomechanical tumor growth, nutrient transport, genomic-scale aberrant cancer cell metabolism, and cell-signaling pathways that regulate the cellular response to therapy, the hypermodel integrates mutation, miRNA expression, imaging, and clinical data.

Impact of Tissue Damage and Hemodynamics on Restenosis Following Percutaneous Transluminal Angioplasty: A Patient-Specific Multiscale Model.

Multiscale agent-based modeling frameworks have recently emerged as promising mechanobiological models to capture the interplay between biomechanical forces, cellular behavior, and molecular pathways underlying restenosis following percutaneous transluminal angioplasty (PTA). However, their applications are mainly limited to idealized scenarios. Herein, a multiscale agent-based modeling framework for investigating restenosis following PTA in a patient-specific superficial femoral artery (SFA) is proposed.

Glenohumeral joint force prediction with deep learning.

Deep learning models (DLM) are efficient replacements for computationally intensive optimization techniques. Musculoskeletal models (MSM) typically involve resource-intensive optimization processes for determining joint and muscle forces. Consequently, DLM could predict MSM results and reduce computational costs.

Predicted vs. measured paraspinal muscle activity in adolescent idiopathic scoliosis patients: EMG validation of optimization-based musculoskeletal simulations.

Musculoskeletal (MSK) models offer great potential for predicting the muscle forces required to inform more detailed simulations of vertebral endplate loading in adolescent idiopathic scoliosis (AIS). In this work, simulations based on static optimization were compared with in vivo measurements in two AIS patients to determine whether computational approaches alone are sufficient for accurate prediction of paraspinal muscle activity during functional activities. We used biplanar radiographs and marker-based motion capture, ground reaction force, and electromyography (EMG) data from two patients with mild and moderate thoracolumbar AIS (Cobb angles: 21° and 45°, respectively) during standing while holding two weights in front (reference position), walking, running, and object lifting.

[Roboticassisted incisional hernia surgery-Retromuscular techniques].

The trend to minimally invasive surgery has also made its way into the surgical treatment of incisional hernias. Unlike other areas of visceral surgery, recent years have seen a resurgence of open sublay repair in incisional hernia procedures, primarily due to the recognition of the retromuscular layer as the optimal mesh placement site. Additionally, with the growing availability of robotic systems in visceral surgery, these procedures are increasingly being offered in the form of minimally invasive procedures.

Optomechanical assessment of photorefractive corneal cross-linking via optical coherence elastography.

Corneal cross-linking (CXL) has recently been used with promising results to positively affect corneal refractive power in the treatment of hyperopia and mild myopia. However, understanding and predicting the optomechanical changes induced by this procedure are challenging. We applied ambient pressure modulation based optical coherence elastography (OCE) to quantify the refractive and mechanical effects of patterned CXL and their relationship to energy delivered during the treatment on porcine corneas.

Depth-dependent mechanical properties of the human cornea by uniaxial extension.

The purpose of this study was to investigate the depth-dependent biomechanical properties of the human corneal stroma under uniaxial tensile loading. Human stroma samples were obtained after the removal of Descemet's membrane in the course of Descemet's membrane endothelial keratoplasty (DMEK) transplantation. Uniaxial tensile tests were performed at three different depths: anterior, central, and posterior on 2 × 6 × 0.

Patient-specific finite element analysis of human corneal lenticules: An experimental and numerical study.

The number of elective refractive surgeries is constantly increasing due to the drastic increase in myopia prevalence. Since corneal biomechanics are critical to human vision, accurate modeling is essential to improve surgical planning and optimize the results of laser vision correction. In this study, we present a numerical model of the anterior cornea of young patients who are candidates for laser vision correction.

Analysis of Biomechanical Response After Corneal Crosslinking with Different Fluence Levels in Porcine Corneas.

Purpose: To evaluate corneal stiffening of porcine corneas induced by corneal crosslinking (CXL) with constant irradiance as a function of total fluence.

Methods: Ninety corneas from freshly enucleated porcine eyes were divided into five groups of 18 eyes. Groups 1-4 underwent epi-off CXL using a dextran-based riboflavin solution and an irradiance of 18 mW/cm, group 5 served as the control group.

Establishment of minimally invasive ventral hernia repair with extraperitoneal mesh placement in a primary care hospital using the robotic platform.

Background: The progressive availability of robotic surgical systems opens new perspectives in abdominal wall surgery due to excellent visibility and dexterity of instruments. While complex hernias until today were treated primarily through an open access, we evaluated if this promising technology is suitable for treating the entire spectrum of a hernia center, including complex hernias.

Material/methods: In 2017, minimally invasive hernia surgery with extraperitoneal mesh placement was started in Kempten hospital.

Traditional T1-S1 Measurement of the Spinal Length on X-ray Images Does Not Correlate With the True Length of the Spine.

Background: The T1-S1 distance to evaluate spinal length is traditionally measured as a straight line on an anteroposterior radiograph. However, this method may not reflect the true 3-dimensional (3D) spinal length. The objective of the study was to evaluate the difference between the traditional T1-S1 measurement and a 3D reconstruction from standard x-ray imaging.

[Robot-assisted extraperitoneal ventral hernia repair-Experience from the first 61 consecutive operations with eTEP and eTAR techniques].

Background: As in many other fields of surgery, robotically assisted surgical procedures have been established in the treatment of ventral hernias in recent years. The use of the robot can combine the demands of a minimally invasive approach and retromuscular mesh placement. In addition to a transabdominal approach, these procedures can also be performed using an extraperitoneal approach.

Orientation and depth dependent mechanical properties of the porcine cornea: Experiments and parameter identification.

The porcine cornea is a standard animal model in ophthalmic research, making its biomechanical characterization and modeling important to develop novel treatments such as crosslinking and refractive surgeries. In this study, we present a numerical model of the porcine cornea based on experimental measurements that captures both the depth dependence and orientation dependence of the mechanical response. The mechanical parameters of the established anisotropic hyperelastic material models of Gasser, Holzapfel and Ogden (HGO) and Markert were determined using tensile tests.

Age- and sex-specific normative values of bone mineral density in the adult glenoid.

The objective of this study was to determine the normative bone mineral density (BMD) of cortical and trabecular bone regions in the adult glenoid and its dependence on the subject's age and sex. We analyzed computed tomography (CT) scans of 441 shoulders (310 males, 18-69 years) without any signs of glenohumeral joint pathology. Glenoid BMD was automatically quantified in six volumes of interest (VOIs): cortical bone (CO), subchondral cortical plate (SC), subchondral trabecular bone (ST), and three adjacent layers of trabecular bone (T1, T2, and T3).

[Ventral Hernia Repair in Endoscopically Total Extrapertoneal Technique (eTEP) - Evaluation of Postoperative Outcome and One Year Follow-up].

Background: Several recent meta-analyses have identified the retromuscular plane as the preferred mesh position in ventral hernia repair. Open surgery used to be the standard technique for these procedures. However, new minimally invasive techniques with totally extraperitoneal access and mesh positioning in the retromuscular plane have evolved.

Towards a better understanding of the posttreatment hemodynamic behaviors in femoropopliteal arteries through personalized computational models based on OCT images.

The hemodynamic behavior following endovascular treatment of patients with peripheral arterial disease plays a significant role on the occurrence of restenosis in femoro-popliteal (FP) arteries. The atheroprone flow conditions that are generally accepted to promote restenosis can be calculated by computational fluid dynamics (CFD) analyses, and these results can be used to assess individualized treatment outcomes. However, the impact of endovascular therapy on the flow behaviors of FP arteries are still poorly understood, as the imaging modalities used in existing numerical works (X-ray angiography, computed tomography angiography) are unable to accurately represent the post-treatment arterial geometry due to their low resolutions.

Robotically assisted enhanced-view totally extraperitoneal repair (eTEP) of a recurrent umbilical hernia in a patient with peritoneal dialysis.

Abdominal wall hernias are frequent in patients with peritoneal dialysis. Guidelines recommend an open hernia repair with extraperitoneal mesh placement to avoid access to the abdominal cavity. We performed a lateral docking robotically assisted enhanced-view totally extraperitoneal repair (eTEP) of a recurrent umbilical hernia with diastasis recti in a patient with peritoneal dialysis due to polycystic kidney disease.

[Current robotic ventral hernia surgery exemplified by 50 consecutive patients].

Background: In recent years there has been a rise in robotic techniques and approaches regarding hernia repair with extraperitoneal mesh placement.

Methods: A retrospective analysis of the first 50 patients who underwent robotic ventral hernia repair between May 2019 and November 2020 at the department of general surgery of the Kempten Clinic was performed.

Results: This case series consisted of 36 incisional hernias, 12 primary hernias (8 umbilical and 3 epigastric hernias in combination with a diastasis recti abdominis as well as 1 Spigelian hernia) and 2 parastomal hernias.

Coaxial micro-extrusion of a calcium phosphate ink with aqueous solvents improves printing stability, structure fidelity and mechanical properties.

Micro-extrusion-based 3D printing of complex geometrical and porous calcium phosphate (CaP) can improve treatment of bone defects through the production of personalized bone substitutes. However, achieving printing and post-printing shape stabilities for the efficient fabrication and application of rapid hardening protocol are still challenging. In this work, the coaxial printing of a self-setting CaP cement with water and ethanol mixtures aiming to increase the ink yield stress upon extrusion and the stability of fabricated structures was explored.