Real Surgery Research Articles

Dynamic Pressure Measurements During Vitrectomy in a Model of the Eye.

PurposeTo accurately evaluate pressure changes during vitrectomy in a rigid model of the vitreous chamber and to test the efficiency of the EVA phacovitrectomy system (Dutch Ophthalmic Research Center) in terms of compensation of intraocular pressure variations.MethodsWe tested 23-, 25-, and 27-gauge double-blade vitreous cutters in both vented global pressure control and automatic infusion compensation (AIC) modes in a vitreous chamber model, mimicking the real surgical procedure. Balanced salt solution and artificial vitreous, similar to the real vitreous body, were used. We tested both standard-flow (SF) and high-flow (HF) infusion systems, varying the infusion pressure between 20 and 40 mm Hg. In each experiment, flow rate was also measured.ResultsPressure drop was rapidly and efficiently compensated when 23- and 25-gauge cutters were used in AIC mode, with infusion pressures ranging between 30 and 55 mm Hg. The 27-gauge cutter was less efficient in compensating pressure variations. Pressure fluctuations related to the high-frequency motion of the cutter blade were small compared to the overall pressure variations. The use of the HF infusion system resulted in larger flow rates and lower pressure changes compared to the SF infusion system.ConclusionsDespite the rigid material of the model, the present pressure measurements are in line with previous studies performed on porcine eye. The use of AIC mode compensates intraoperative pressure drops efficiently, with both 23- and 25-gauge cutters. The HF infusion system is more efficient than the SF infusion system.Translational RelevanceThe AIC infusion mode efficiently compensates intraoperative pressure drops, in both 23- and 25-gauge experimental vitrectomy. The HF infusion system resulted in larger flow rate and lower pressure changes.

Scene-graph-driven semantic feature matching for monocular digestive endoscopy

Background and objectiveRegistration of the preoperative 3D model with the video of the digestive tract is the key task in endoscopy surgical navigation. Accurate 3D reconstruction of soft tissue surfaces is essential to complete registration. However, existing feature matching methods still fall short of desirable performance, due to the soft tissue deformation and smooth but less-textured surface. MethodsIn this paper, we present a new semantic description based on the scene graph to integrate contour features and SIFT features. Firstly, we construct the semantic feature descriptor using the SIFT features and dense points in the contour regions to obtain more dense point feature matching. Secondly, we design a clustering algorithm based on the proposed semantic feature descriptor. Finally, we apply the semantic description to the structure from motion (SfM) reconstruction framework. ResultsOur techniques are validated by the phantom tests and real surgery videos. We compare our approaches with other typical methods in contour extraction, feature matching, and SfM reconstruction. On average, the feature matching accuracy reaches 75.6% and improves 16.6% in pose estimation. In addition, 39.8% of sparse points are increased in SfM results, and 35.31% more valid points are obtained for the DenseDescriptorNet training in 3D reconstruction. ConclusionsThe new semantic feature description has the potential to reveal more accurate and dense feature correspondence and provides local semantic information in feature matching. Our experiments on the clinical dataset demonstrate the effectiveness and robustness of the novel approach.

Personalized virtual reality simulation training system for percutaneous needle insertion and comparison of zSpace and vive

PurposeIn this research, we present a personalized simulation training system for percutaneous needle insertion based on virtual reality (VR). Within this system, surgeons can become more familiar with real surgical procedures, thereby reducing errors that may occur in real surgery. Additionally, different VR technologies, i.e., zSpace and Vive, were compared to provide surgeons with a better surgical training environment. Methodsand Methods A VR system combined with the treatment planning system was developed to create personalized patient training environment. An evaluation study recruiting twenty novices was performed to demonstrate the system. Each participant performed six independent needle placements using the VR system. Placement time was recorded. Placement error was defined as the distance from the needle tip to the target center. The participants completed a seven-point Likert scale questionnaire after the simulation. ResultsCompared with Vive, using zspace reduces the placement time (from 90.32 s to 68.94 s). The placement error using zSpace and Vive was similar (1.27 ± 0.68 mm, 1.56 ± 0.81 mm, respectively). The questionnaire survey results show that most participants are highly satisfied with the training effect of the VR system. Participants prefer the operation mode and convenience of zSpace but think that the immersion of Vive is better. ConclusionsThe personalized virtual reality surgical training system was effective as a training system for percutaneous needle insertion. The system based on zSpace had a shorter placement time while maintaining placement accuracy compared to the system based on Vive. The system based on zSpace achieved higher satisfaction in most aspects except for immersion.

Precise Intraoral Condylectomy With the Guide of Three-Dimensional Printed Template in a Mandibular Condylar Hyperplasia Patient.

This study aimed to introduce an innovative method for mandibular condylectomy. A customized three-dimensional (3D) printed template is used to perform precise condylectomy in an intraoral approach. Condylectomy combined with orthognathic surgery was used for the treatment of facial asymmetry secondary to unilateral condylar hyperplasia. The customized 3D printed osteotomy guide was placed with an intraoral approach under endoscopy, in order to perform a precise condylectomy. With the customized 3D printed template, the condylectomy was performed more precisely, and the conventional extraoral incision was avoided. The osteotomy line was accurately transferred from the virtual surgical plan to the real surgery, which assured the precise resection. The intraoral approach combined with a 3D printed template provides a novel solution to perform the condylectomy precisely.

Surgical training in ophthalmology: Role of EyeSi in the era of simulation-based learning.

Recent advancements in surgical training methods have escalated the need for simulators. The EyeSi simulation has played a major role in Ophthalmology training by providing opportunity to the novice residents to grasp the surgical steps of the procedure and master the skill by repeated attempts. Participants were assessed on single level of cataract module and their consecutive scores were assessed with each attempt. It was found that repetitive practice on simulator can help develop proficiency in the desired steps that can ultimately prepare the surgical trainees for real life surgery.

A Solution Approach to Distributionally Robust Joint-Chance-Constrained Assignment Problems

We study the assignment problem with chance constraints (CAP) and its distributionally robust counterpart DR-CAP. We present a technique for estimating big-M in such a formulation that takes advantage of the ambiguity set. We consider a 0-1 bilinear knapsack set to develop valid inequalities for CAP and DR-CAP. This is generalized to the joint chance constraint problem. A probability cut framework is also developed to solve DR-CAP. A computational study on problem instances obtained from using real hospital surgery data shows that the developed techniques allow us to solve certain model instances and reduce the computational time for others. The use of Wasserstein ambiguity set in the DR-CAP model improves the out-of-sample performance of satisfying the chance constraints more significantly than the one possible by increasing the sample size in the sample average approximation technique. The solution time for DR-CAP model instances is of the same order as that for solving the CAP instances. This finding is important because chance constrained optimization models are very difficult to solve when the coefficients in the constraints are random.

Continuous Monitoring of Mental Load During Virtual Simulator Training for Laparoscopic Surgery Reflects Laparoscopic Dexterity: A Comparative Study Using a Novel Wireless Device.

IntroductionCognitive Load Theory (CLT) relates to the efficiency with which individuals manipulate the limited capacity of working memory load. Repeated training generally results in individual performance increase and cognitive load decrease, as measured by both behavioral and neuroimaging methods. One of the known biomarkers for cognitive load is frontal theta band, measured by an EEG. Simulation-based training is an effective tool for acquiring practical skills, specifically to train new surgeons in a controlled and hazard-free environment. Measuring the cognitive load of young surgeons undergoing such training can help to determine whether they are ready to take part in a real surgery. In this study, we measured the performance of medical students and interns in a surgery simulator, while their brain activity was monitored by a single-channel EEG.MethodsA total of 38 medical students and interns were divided into three groups and underwent three experiments examining their behavioral performances. The participants were performing a task while being monitored by the Simbionix LAP MENTOR™. Their brain activity was simultaneously measured using a single-channel EEG with novel signal processing (Aurora by Neurosteer®). Each experiment included three trials of a simulator task performed with laparoscopic hands. The time retention between the tasks was different in each experiment, in order to examine changes in performance and cognitive load biomarkers that occurred during the task or as a result of nighttime sleep consolidation.ResultsThe participants’ behavioral performance improved with trial repetition in all three experiments. In Experiments 1 and 2, delta band and the novel VC9 biomarker (previously shown to correlate with cognitive load) exhibited a significant decrease in activity with trial repetition. Additionally, delta, VC9, and, to some extent, theta activity decreased with better individual performance.DiscussionIn correspondence with previous research, EEG markers delta, VC9, and theta (partially) decreased with lower cognitive load and higher performance; the novel biomarker, VC9, showed higher sensitivity to lower cognitive load levels. Together, these measurements may be used for the neuroimaging assessment of cognitive load while performing simulator laparoscopic tasks. This can potentially be expanded to evaluate the efficacy of different medical simulations to provide more efficient training to medical staff and measure cognitive and mental loads in real laparoscopic surgeries.

Analysis and Comparison of Electromagnetic Microrobotic Platforms for Biomedical Applications

Magnetic microrobotics is a promising technology for improving minimally invasive surgery (MIS) with the ambition of enhancing patient care and comfort. The potential benefits include limited incisions, less hemorrhaging and postoperative pain, and faster recovery time. To achieve this, a key issue relies on the design of a proper electromagnetic actuation (EMA) setup which is based on the use of magnetic sources. The magnetic field and its gradient generated by the EMA platform is then used to induce magnetic torque and force for microrobot manipulations inside the human body. Like any control systems, the EMA system must be adapted to the given controlled microrobot and customized for the application. With great research efforts on magnetic manipulating of microrobots, the EMA systems are approaching commercial applications, and their configurations are becoming more suitable to be employed in real medical surgeries. However, most of the proposed designs have not followed any specific rule allowing to take into account the biomedical applications constraints. Through reviewing the different proposed EMA systems in the literature, their various specifications and configurations are comprehensively discussed and analyzed. This study focus on EMA platforms that use electromagnets. From this review and based on the biomedical application specifications, the appropriate EMA system can be determined efficiently.

Xray Exposure Time in Dedicated Academic Simulation Programs Is Realistic of Patient Procedures

ObjectiveTo ascertain whether simulated endovascular procedures are comparable to real life operating room (OR) procedures, particularly with regard to irradiation time.MethodsThis was a retrospective study comparing simulation with clinical data. Fluoroscopy time and overall operation time were compared between simulated abdominal aortic endovascular repair (EVAR) and iliac procedures that were performed, respectively, from 2016 to 2019 and from 2015 to 2019, and clinical EVAR and iliac procedures performed in the OR between January 2018 and November 2021.ResultsWithin the defined periods, 171 simulated procedures (91 EVAR, 80 iliac) and 199 clinical procedures (111 EVAR, 88 iliac) were performed. For both EVAR and iliac procedures, median total procedure time was much longer during real surgery (p < .001). However, median total fluoroscopy time remained the same, whether the procedure was real surgery or performed on the simulator, for iliac procedures (8.47 minutes in the OR, 8.35 minutes on the simulator, p = .61) and for EVAR procedures (14.80 minutes in the OR, 15.00 minutes on the simulator p = .474).ConclusionSimulated endovascular procedures are comparable with real life OR procedures, particularly with regard to irradiation time when integrated in a dedicated curriculum.

Do room air temperature and human activity affect the particle concentration under real surgical procedures in operating rooms with mixing ventilation? - An experimental study at St. Olavs hospital

The objective of this study is to explore the effects of different room temperatures and different types of activities on the indoor air quality in the operating room during surgery. Three mock-up surgeries were performed at 21 °C, 23 °C, and 25 °C at St. Olavs hospital in Norway. The effects of the surgeon’s activity and nurse's movement on the concentration of particulate matter at the surgical site and instrument table were compared. The results show that the concentrations of particles at both the surgical site and the instrument table are the lowest at room temperature of 23 °C. The activity of the surgeon was the main factor leading to the increase in the concentration of particulate matter with the size 0.3-0.5 μm at the surgical site, while the nurse movement led to the increase in the concentration of particulate matter with the larger size. At all room temperatures, the movement of the distribution nurse had a greater effect than the activity of the surgeon on the increase of the concentration of particles at the instrument table. In addition, the intensity of the particulate source may be factors affecting the concentration of particulate matter. Therefore, it is recommended that distribution nurses should avoid unnecessary activities during the operation.

The use of 3D printed models for the pre-operative planning of surgical correction of pediatric hip deformities: a case series and concise review of the literature.

Background and aim:Three-dimensional (3D) printing is prevailing in surgical planning of complex cases. The aim of this study is to describe the use of 3D printed models during the surgical planning for the treatment of four pediatric hip deformity cases. Moreover, pediatric pelvic deformities analyzed by 3D printed models have been object of a concise review.Methods:All treated patients were females, with an average age of 5 years old. Patients’ dysplastic pelvises were 3D-printed in real scale using processed files from Computed Tomography (CT) or Magnetic Resonance Imaging (MRI). Data about 3D printing, surgery time, blood loss and fluoroscopy have been recorded.Results:The Zanoli-Pemberton or Ganz-Paley osteotomies were performed on the four 3D printed models, then the real surgery was performed in the operating room. Time and costs to produce 3D printed models were respectively on average 17:26 h and 34.66 €. The surgical duration took about 87.5 min while the blood loss average was 1.9 ml/dl. Fluoroscopy time was 21 sec. MRI model resulted inaccurate and more difficult to produce. 10 papers have been selected for the concise literature review.Conclusions:3D printed models have proved themselves useful in the reduction of surgery time, blood loss and ionizing radiation, as well as they have improved surgical outcomes. 3D printed model is a valid tool to deepen the complex anatomy and orientate surgical choices by allowing surgeons to carefully plan the surgery. (www.actabiomedica.it)

Construction and application of a low-cost laparoscopy training simulator as a teaching tool through motor coordination and two-dimensional vision practices.

to describe the construction of a low-cost laparoscopy training simulator and evaluate its level of acceptance, impact on learning, and skill development in medical students. we built a video training simulator using low-cost materials. We then carried out a cross-sectional study, with the use of an applied questionnaire to medical students. 51 medical students participated in the research, of whom 76.47% gained confidence in relation to laparoscopic surgery, 100% stated that the model successfully trained the skills of motor coordination and two-dimensional visual-spatial field, in addition to enabling a greater understanding of laparoscopy. All agreed that the simulator should be used before a real laparoscopic surgery scenario. the construction of the described laparoscopic surgery training simulator proved to be feasible and effective as an educational resource. It was well accepted by medical students, with easy handling, and promoted the development of motor and visual skills in video surgery.

The Resistance Force of the Anterior Cruciate Ligament during Pull Probing Is Related to the Mechanical Property.

There are various methods for reconstructing the anterior cruciate ligament (ACL) from other muscles or tendons. Initial tension of the reconstructed ACL is one of the key elements affecting postoperative outcomes. However, tension cannot be measured after graft fixation. The only intraoperative assessment is pull probing, which is performed by pulling joint soft tissues with the arthroscopic probe and can be measured quantitatively. Therefore, its value might be used as an alternative value for the mechanical property of the ACL. Using a probing device one author developed to measure the resistance force of soft tissues quantitatively while probing, we measured the resistance force of dissected ACLs and used tensile testing to investigate the correlation between the resistance force and the mechanical property of the ligaments. According to the results, when a certain amount of tension (strain; 16.6%) was applied, its mechanical properties were moderately correlated (r = 0.56 [p = 0.045]) with the probing force. Therefore, the tension of the reconstructed ACL after fixation under real ACL reconstruction surgery can be derived from the value of the probing device.

Automated tool detection with deep learning for monitoring kinematics and eye-hand coordination in microsurgery

In microsurgical procedures, surgeons use micro-instruments under high magnifications to handle delicate tissues. These procedures require highly skilled attentional and motor control for planning and implementing eye-hand coordination strategies. Eye-hand coordination in surgery has mostly been studied in open, laparoscopic, and robot-assisted surgeries, as there are no available tools to perform automatic tool detection in microsurgery. We introduce and investigate a method for simultaneous detection and processing of micro-instruments and gaze during microsurgery. We train and evaluate a convolutional neural network for detecting 17 microsurgical tools with a dataset of 7500 frames from 20 videos of simulated and real surgical procedures. Model evaluations result in mean average precision at the 0.5 threshold of 89.5–91.4% for validation and 69.7–73.2% for testing over partially unseen surgical settings, and the average inference time of 39.90 ± 1.2 frames/second. While prior research has mostly evaluated surgical tool detection on homogeneous datasets with limited number of tools, we demonstrate the feasibility of transfer learning, and conclude that detectors that generalize reliably to new settings require data from several different surgical procedures. In a case study, we apply the detector with a microscope eye tracker to investigate tool use and eye-hand coordination during an intracranial vessel dissection task. The results show that tool kinematics differentiate microsurgical actions. The gaze-to-microscissors distances are also smaller during dissection than other actions when the surgeon has more space to maneuver. The presented detection pipeline provides the clinical and research communities with a valuable resource for automatic content extraction and objective skill assessment in various microsurgical environments.

OV03 TEP IN COLORS: ANATOMICAL VIEW USING ARTICULATED FORCEPS

Abstract Aim Present through an illustrative and educational video, an anatomical and colorful vision of the totally extraperitoneal laparoscopic approach (TEP) of inguinofemoral hernias, with the aim of favoring the learning process of this technique, facilitating the identification of the main anatomical structures, ensuring a safe and effective approach. Material and Methods In this video we show the laparoscopic approach to inguinofemoral hernias via TEP, highlighting the most important anatomical structures with different colors. Additionally, the surgical technique of this approach using articulated forceps is shown, which we consider to be a good resource for dissection in a space as small as the preperitoneal one. Results The anatomical study of the inguinofemoral area constitutes the basis of a correct preperitoneal approach, especially in PET, where the most difficult is probably the space location and the identification of the structures. Conclusions The preperitoneal PET route is a relatively novel approach for inguinofemoral hernia repair. Its benefits are based on the ability to identify all the anatomical structures of the myopectineal orifice from a preperitoneal view without the need to access the peritoneal cavity. The knowledge of preperitoneal anatomy is the cornerstone for learning the TEP approach, and we consider that anatomical videos of real surgeries are good strategies to shorten the learning curve. Mastering the preperitoneal anatomy ensures obtaining the benefits inherent to the TEP approach, such as bilateral exploration of the myopectineal orifice, direct visualization of the pain and doom triangles, tension-free repair with mesh of all possible defects and faster postoperative recovery.

A Customized Knee Antibiotic-Loaded PMMA Spacer: A Preliminary Design Analysis.

A preliminary design of customized antibiotic-loaded poly-methyl-methacrylate (ALPMMA) spacer characterized by an appropriate footprint according to the specific patient’s anatomy and a reliable mechanical response to severe functional loads (i.e., level walking and 45° bent knee) is reported. The targeted virtual prototyping process takes origin from a novel patented 3D geometrical conceptualization characterized by added customization features and it is validated by a preliminary FEM-based analysis. Mechanical and thermomechanical properties of the antibiotic-doped orthopedic PMMA cement, which will be used for the future prototype manufacturing, were measured experimentally by testing samples taken during a real day-running orthopedic surgery and manufactured according to the surgeon protocol. FEM analysis results indicate that small area is subjected to intensive stresses, validating the proposed geometry from the mechanical point of view, under the two loading scenarios, moreover the value of safety margins results positive, and this is representative of the lower stress magnitude compared to the critical material limits. The experimental data confirm that the presence of antibiotic will last during the surgeon period moreover, the temperature dependent modulus of the bone cement is slightly affected by the body range temperature whereas it will drastically drop for higher temperature out the range of interest. A complete customization, according to a patient anatomy, and the corresponding real prototype spacer will be manufactured by 3D printing techniques, and it will be validated by destructive testing during the second stage of this activity before commercialization.

Can clothing systems and human activity in operating rooms with mixed flow ventilation systems help achieve the ultraclean air requirement (≤10 CFU/m3) during orthopaedic surgeries?

The level of airborne microbial contamination in operating rooms (ORs) is an important indicator of indoor air quality and ensures a clean surgical environment. The main objective of this study was to clarify the possibility of achieving the requirement for an ultraclean operating room (≤ 10 CFU/m3) with mixed flow ventilation based on clothing and human activity. Experimental measurements during mock surgeries were conducted in an actual OR with mixed flow ventilation in the Emergency, Heart and Lung Centre at St. Olavs Hospital in Trondheim. The bacterial concentration close to the surgical site was measured during five mock-up surgeries. All five mock-up surgeries followed real surgical procedures which could represent similar conditions in the OR. The experiment results verified that the average CFU/m3 of three of the five mock-up surgeries was 8.5, which was below or equal to the ultraclean requirement, while the other two mock-up surgeries did not meet the ultraclean requirement. Surgical activity together with the type of clothing worn by surgical staff in ORs seem to be the most significant reason for the high CFU level during surgery. It is possible to achieve the ultraclean air requirement (≤ 10 CFU/m3) during a surgical process with proper clothing and low surgical activity in ORs. This study clarifies the effect of clothing and human activity on the CFU level in the surgical micro-environment in ORs, and contributes to developing new products for the surgical team.

Novel System of Simulation Models for Aneurysm Clipping Training: Description of Models and Assessment of Face, Content, and Construct Validity.

Aneurysm clipping simulation models are needed to provide tactile feedback of biological vessels in a nonhazardous but surgically relevant environment. To describe a novel system of simulation models for aneurysm clipping training and assess its validity. Craniotomy models were fabricated to mimic actual tissues and movement restrictions experienced during actual surgery. Turkey wing vessels were used to create aneurysm models with patient-specific geometry. Three simulation models (middle cerebral artery aneurysm clipping via a pterional approach, anterior cerebral artery aneurysm clipping via an interhemispheric approach, and basilar artery aneurysm clipping via an orbitozygomatic pretemporal approach) were subjected to face, content, and construct validity assessments by experienced neurosurgeons (n=8) and neurosurgery trainees (n=8). Most participants scored the model as replicating actual aneurysm clipping well and scored the difficulty of clipping as being comparable to that of real surgery, confirming face validity. Most participants responded that the model could improve clip-applier-handling skills when working with patients, which confirms content validity. Experienced neurosurgeons performed significantly better than trainees on all 3 models based on subjective (P=.003) and objective (P<.01) ratings and on time to complete the task (P=.04), which confirms construct validity. Simulations were used to discuss clip application strategies and compare them to prototype clinical cases. This novel aneurysm clipping model can be used safely outside the wet laboratory; it has high face, content, and construct validity; and it can be an effective training tool for microneurosurgery training during aneurysm surgery courses.

Automatic landmark detection in distal femur from surgical video footage

ABSTRACT Total knee arthroplasty (TKA) is a surgical procedure that consists in replacing the entire knee joint by artificial knee implants. Computer-based navigation systems have been investigated and developed to improve the outcome of TKA procedures. These systems support the surgeon in planning the most adequate position for the implants and assist during the procedure in effectively following the defined surgical plan. This work tackles image-free TKA navigation, which requires the acquisition of particular anatomical landmarks intra-operatively. The accurate localisation of these anatomical landmarks in the distal femur bone is essential for the success of the surgery. However, the landmark identification process is often conducted manually, which is time-consuming, lacks accuracy and has high variability. This work presents an algorithm for automatic detection and localisation of bone landmarks from RGB images acquired during the surgery. It proposes new geometric algorithms for computing the anatomical landmarks in 3D models of the femur, which are used for annotating the images of the surgical footage. The annotated images are then used for training a deep learning-based model, which is able to infer anatomical landmarks from a single RGB image. The experimental results using real surgery data show encouraging performance, being able to generalise for unseen data and presenting reliable predictions.

Design and Evaluation of Personalized Percutaneous Coronary Intervention Surgery Simulation System.

In recent years, medical simulators have been widely applied to a broad range of surgery training tasks. However, most of the existing surgery simulators can only provide limited immersive environments with a few pre-processed organ models, while ignoring the instant modeling of various personalized clinical cases, which brings substantive differences between training experiences and real surgery situations. To this end, we present a virtual reality (VR) based surgery simulation system for personalized percutaneous coronary intervention (PCI). The simulation system can directly take patient-specific clinical data as input and generate virtual 3D intervention scenarios. Specially, we introduce a fiber-based patient-specific cardiac dynamic model to simulate the nonlinear deformation among the multiple layers of the cardiac structure, which can well respect and correlate the atriums, ventricles and vessels, and thus gives rise to more effective visualization and interaction. Meanwhile, we design a tracking and haptic feedback hardware, which can enable users to manipulate physical intervention instruments and interact with virtual scenarios. We conduct quantitative analysis on deformation precision and modeling efficiency, and evaluate the simulation system based on the user studies from 16 cardiologists and 20 intervention trainees, comparing it to traditional desktop intervention simulators. The results confirm that our simulation system can provide a better user experience, and is a suitable platform for PCI surgery training and rehearsal.