Adding Safety Rules to Surgeon-Authored Virtual Reality Training.

INTRODUCTION: The Toolkit for Illustration of Procedures in Surgery (TIPS) is an open source virtual reality (VR) laparoscopic simulation-based training environment with force feedback. The TIPS-author is a content creation interface that allows a surgeon educator (SE) to assemble new laparoscopic training modules. New technology enables safety rules to be specified by the SE, automatically tracks specified safety errors, and summarizes and communicates achievements and errors to the surgical trainee. METHODS: The TIPS-author combines and initializes building blocks of anatomy with their physical properties, as selected by the SE from a database. The SE can add any safety rule that can be tested in terms of location, proximity, separation, clip count, and force. Errors are then automatically monitored during simulation and recorded as visual snapshots for feedback to the trainee. The TIPS was field tested at 2 surgical conferences, one before and one after adding the error snapshot feature. RESULTS: Sixty-four respondents at 2 surgical conferences assessed the utility of TIPS on a Likert scale. While other ratings remained unchanged for an overall score of 5.24 of 7 (7 = very useful), the rating of the statement "The TIPS interface helps learners understand the force necessary to explore the anatomy" improved from 5.04 to 5.35 of 7 after the snapshot mechanism was added. CONCLUSIONS: The ratings indicate the viability of the TIPS open source SE-authored surgical training units with safety rules. Presenting SE-determined procedural missteps via the snapshot mechanism at the end of the training increases perceived utility.

Stability of renal parenchymal volume and function during active surveillance of renal oncocytoma patients.

INTRODUCTION AND OBJECTIVE: To evaluate whether significant loss in ipsilateral renal parenchymal volume (IRPV) and renal function occurs during active surveillance (AS) of renal oncocytoma (RO) patients. METHODS: Renal function (estimated glomerular filtration rate, eGFR) dynamics were retrospectively analyzed in 32 consecutive biopsy-diagnosed RO patients managed with AS at a National Comprehensive Cancer Network institute. Three-dimensional kidney and tumor reconstructions were generated and IRPV was calculated using volumetry software (Myrian®) for all patients with manually estimated RO growth >+10 cm3. GFR and IRPV were compared at AS initiation vs. the last follow-up using 2-sided paired t-tests. The correlation between change in IRPV and change in RO size or GFR was tested using a Spearman coefficient. RESULTS: With median follow-up of 37 months, there was no significant change between initial vs. last eGFR (median 71.0 vs. 70.5 ml/min/1.73 m2, P = 0.50; median change -3.0 ml/min/1.73 m2). Among patients (n = 17) with RO growth >+10 cm3 during AS (median growth +28.6 cm3, IQR +16.9- + 46.5 cm3), IRPV generally remained stable (median change +0.5%, IQR -1.2%- + 1.2%), with only 2 cases surpassing 5% loss. No IRPV loss was detected among any patient within the top tertile of RO growth magnitude. RO growth magnitude did not correlate with loss of either IRPV (ρ = -0.30, P = 0.24) or eGFR (ρ = -0.16, P = 0.40), including among patient subsets with lower initial eGFR. Study limitations include a lack of long-term follow-up. CONCLUSIONS: Volumetry is a promising novel tool to measure kidney and tumor tissue changes during AS. Our study using volumetry indicates that clinically significant loss of IRPV or eGFR is uncommon and unrelated to tumor growth among untreated RO patients with intermediate follow-up. These findings support that AS is in general functionally safe for RO patients, however longer study is needed to determine safety durability, particularly among uncommon ≥cT2 RO variants.

First-In-Human Computer-Optimized Endobronchial Ultrasound-Guided Interstitial Photodynamic Therapy for Patients With Extrabronchial or Endobronchial Obstructing Malignancies.

Objective: Patients with inoperable extrabronchial or endobronchial tumors who are not candidates for curative radiotherapy have dire prognoses with no effective long-term treatment options. To reveal that our computer-optimized interstitial photodynamic therapy (I-PDT) is safe and potentially effective in the treatment of patients with inoperable extra or endobronchial malignancies inducing central airway obstructions. Methods: High-spatial resolution computer simulations were used to personalize the light dose rate and dose for each tumor. Endobronchial ultrasound with a transbronchial needle was used to place the optical fibers within the tumor according to an individualized plan. The primary and secondary end points were safety and overall survival, respectively. An exploratory end point evaluated changes in immune markers. Results: Eight patients received I-PDT with planning, and five of these received additional external beam PDT. Two additional patients received external beam PDT. The treatment was declared safe. Three of 10 patients are alive at 26.3, 12, and 8.3 months, respectively, after I-PDT. The treatments were able to deliver a prescribed light dose rate and dose to 87% to 100% and 18% to 92% of the tumor volumes, respectively. A marked increase in the proportion of monocytic myeloid-derived suppressor cells expressing programmed death-ligand 1 was measured in four of seven patients. Conclusions: Image-guided light dosimetry for I-PDT with linear endobronchial ultrasound transbronchial needle is safe and potentially beneficial in increasing overall survival of patients. I-PDT has a positive effect on the immune response including an increase in the proportion of programmed death-ligand 1-expressing monocytic myeloid-derived suppressor cells.

Preoperative survival calculator for resectable hepatocellular carcinoma.

BACKGROUND: Estimation of preoperative overall survival (OS) of hepatocellular carcinoma (HCC) may guide surgical decision-making. METHODS: OS was analyzed using the National Cancer Data Base from 1998-2012. Patients with HCC who underwent wedge resection, lobectomy or extended lobectomy were selected. Patients who had metastatic disease or previous treatment prior to surgery were excluded. Data was randomly allocated to model building (nb =4,364) and validation cohorts (nv =1,091). Multivariable regression analyses of the nb were used to construct prediction models and optimized using nv. RESULTS: HCC patients (n=5,455) who underwent curative resection had a median OS of 36 months (95% CI, 34-38 months) with 1- and 3-year OS of 73% (95% CI, 72-74%) and 50% (95% CI, 49-51%), respectively. The patient median age was 65, 66% of patients were male, median tumor size was 60 mm; clinical stage 1 =25%, stage 2 =30% and stage 3 =45%. Alpha fetoprotein (AFP) was elevated in 63% of patients. Factors significant in the prediction model included degree of resection, age, race, tumor size, grade, and histologic subtype. CONCLUSIONS: A preoperative OS calculator was developed to assist in the treatment evaluation and OS prediction of HCC patients.

Surgeon-Authored Virtual Laparoscopic Adrenalectomy Module Is Judged Effective and Preferred Over Traditional Teaching Tools.

OBJECTIVE: The study assesses user acceptance and effectiveness of a surgeon-authored virtual reality (VR) training module authored by surgeons using the Toolkit for Illustration of Procedures in Surgery (TIPS). METHODS: Laparoscopic adrenalectomy was selected to test the TIPS framework on an unusual and complex procedure. No commercial simulation module exists to teach this procedure. A specialist surgeon authored the module, including force-feedback interactive simulation, and designed a quiz to test knowledge of the key procedural steps. Five practicing surgeons, with 15 to 24 years of experience, peer reviewed and tested the module. In all, 14 residents and 9 fellows trained with the module and answered the quiz, preuse and postuse. Participants received an overview during Surgical Grand Rounds session and a 20-minute one-on-one tutorial followed by 30 minutes of instruction in addition to a force-feedback interactive simulation session. Additionally, in answering questionnaires, the trainees reflected on their learning experience and their experience with the TIPS framework. RESULTS: Correct quiz response rates on procedural steps improved significantly postuse over preuse. In the questionnaire, 96% of the respondents stated that the TIPS module prepares them well or very well for the adrenalectomy, and 87% indicated that the module successfully teaches the steps of the procedure. All participants indicated that they preferred the module compared to training using purely physical props, one-on-one teaching, medical atlases, and video recordings. CONCLUSIONS: Improved quiz scores and endorsement by the participants of the TIPS adrenalectomy module establish the viability of surgeons authoring VR training.

Three-dimensional printing to facilitate anatomic study, device development, simulation, and planning in thoracic surgery.

BACKGROUND: The development and deployment of new technologies in additive 3-dimensional (3D) printing (ie, rapid prototyping and additive manufacturing) in conjunction with medical imaging techniques allow the creation of anatomic models based on patient data. OBJECTIVE: To explore this rapidly evolving technology for possible use in care and research for patients undergoing thoracic surgery. METHODS: Because of an active research project at our institution on regional lung chemotherapy, human pulmonary arteries (PAs) were chosen for this rapid prototyping project. Computed tomography (CT) and CT angiography in combination with segmentation techniques from 2 software packages were used for rapid generation and adjustment of the 3D polygon mesh and models reconstruction of the PAs. The reconstructed models were exported as stereolithographic data sets and further processed by trimming, smoothing, and wall extrusion. RESULTS: Flexible 3D printed replicas of 10 patient PAs were created successfully with no print failures; however, 1 initial test print with a 1 mm mural thickness was too fragile so the whole group was printed with a 1.5 mm wall. The design process took 8 hours for each model (CT image to stereolithographic) and printing required 97 hours in aggregate. Useful differences in anatomy were defined by this method, such as the expected greater number of proximal branches on the left versus right (2.5 ± 1.1 vs 1.0 ± 0.0; P = .001). CONCLUSIONS: Reconstructed models of pulmonary arteries using 3D rapid prototyping allow replication of sophisticated anatomical structures that can be used to facilitate anatomic study, surgical planning, and device development.

A simple master-slave control mapping setup to learn robot-assisted surgery manipulation.

A simple, but yet effective application for learning and testing instrument manipulation of available (and future) master-slave control robot-assisted surgical systems has been created. As an example, the paper describes a simple mapping of da Vinci surgical system master-slave control with two haptic devices acts as the master control.

A simulation framework for wound closure by suture for the endo stitch suturing instrument.

Our simulation framework for wound closure by suture is designed for education and training purposes. Currently, it is designed specifically to support a simulation of the Endo StitchTM suturing instrument by Covidien, and could be extended for other surgical instruments designed for intracorporeal suturing. The framework allows the user to perform a virtual wound closure by suture with real surgical instrument handles customized to fit on haptic devices. The wound simulation is based on a triangular surface mesh embedded in a linear hexahedral finite element mesh, whereas the suture simulation is based on a simplified Cosserat theory of elastic rods. The simulation utilizes a combination of physically-based and control-based simulations.

Simplified Cosserat rod for interactive suture modeling.

This paper presents a real-time simulation of a virtual surgical suture, which is a physically-based model adapted from the Cosserat theory of elastic rods. The focus is on achieving a physically plausible simulation of the suture that can be simulated in real time. With simulation parameters adjustment, the virtual surgical suture can be accustomed to exhibit bending and twisting similar to a real suture. It is simple to implement and easy to extend for collision detections and interactions with other virtual objects. Its simulation is similar to a simulation of a composition of two mass-spring chains--for positions and orientations. Test results show that the virtual surgical suture can be used to tie knots in real time.

Game-based mass casualty burn training.

An interactive, video game-based training module, Burn Center, was developed to simulate the real-life emergency events of a mass casualty disaster scenario, involving in 40 victims.The game contains two components - triage and resuscitation. The goal of the triage game is to correctly stabilize, sort, tag and transport burn victims during a mass casualty event at a busy theme park. After complete the triage component, the player will then take on the role of a burn care provider, balancing the clinical needs of multiple burn patients through a 36-hour resuscitation period, using familiar computer-simulated hospital devices. Once complete, players of Burn Center will come away with applicable skills and knowledge of burn care, for both field triage and initial resuscitation of the burn patients.

Development and initial validation of a virtual reality haptically augmented surgical knot-tying trainer for the Autosuture ENDOSTITCH instrument.

The Autosuture Endostitch device (Covidien, CT) is difficult to learn. In particular, the handle requires the use of a toggle which is unique in this instrument. We have developed a virtual reality trainer for the device that offers the use of the actual instrument handle while creating a visible virtual instrument tip complete with virtual needle and suture on a monitor. This report represents the development and initial validation experiments for the device.

Interactive peritoneum in a haptic surgery illustration environment.

We describe a fully interactive, low-overhead and robust peritoneum representation allowing for probing and cutting. The peritoneum implementation has been tested within a surgical illustration environment.

Fatty tissue in a haptic illustration environment.

Modeling soft tissue for surgery simulation is a challenging task due to the complex way that the tissue can deform and interact with virtual surgical tools manipulated by user. One soft tissue that is ubiquitous but often not modeled, is fatty tissue. Here we present a novel fatty tissue model based on the mass-spring system on the Graphics Processing Unit (GPU) as part of our Toolkit for Illustration of Procedures in Surgery (TIPS). The user can interact with the fatty tissue in real time via a handheld haptic stylus that represents a virtual surgical tool in TIPS environment. The currently available interactions are palpation, grasp, and cut.

Ectopic expression of Wnt10b decreases adiposity and improves glucose homeostasis in obese rats.

The Wnt family of secreted glycoproteins had previously been shown to regulate diverse processes during early development. Wnt signaling also plays a key role in the homeostasis of adult tissues maintaining stem cell pluripotency and determining differentiating cell fate. The age-related decrease in Wnt signaling may contribute to increased muscle adiposity and diminished bone strength. In the current study, we investigated the long-term metabolic consequences of the upregulated Wnt/beta-catenin signaling in skeletal muscles of adult diet-induced obese (DIO) rats. To this end, we generated a recombinant adeno-associated virus (rAAV) vector encoding murine Wnt10b cDNA. The long-term expression of rAAV1-Wnt10b was tested after intramuscular injection in the female DIO rat. Animals fed high-fat diet and treated with rAAV1-Wnt10b showed a sustained reduction in body weight compared with controls, and expression of Wnt10b was accompanied by a reduction in hyperinsulinemia and triglyceride plasma levels as well as improved glucose homeostasis. Nuclear magnetic resonance methods revealed that ectopic expression of Wnt10b resulted in a decrease in both global and muscular fat deposits in DIO rats. The long-range effect of locally expressed Wnt10b was also manifested through the increased bone mineral density. The detailed analysis of molecular markers revealed fibroblast growth factor-4 and vascular endothelial growth factor as possible mediators of the systemic effect of Wnt10b transgene expression. Our data demonstrate that altering Wnt/beta-catenin signaling in the skeletal muscle of an adult animal invokes moderate responses with favorable metabolic profile, bringing the notion of alternative therapeutic modality in the treatment of obesity, diabetes, and osteoporosis.

A haptic-enabled toolkit for illustration of procedures in surgery (TIPS).

Good surgical training depends greatly on case experiences that have been difficult to model in software since current training technology does not provide the flexibility to teach and practice uncommon procedures, or to adjust a training scenario on the fly. The TIPS kit aims to overcome these limitations. To the expert, it presents visual and haptic tools that make illustrating procedures easy and can model unusual anatomic variations. For a non-specialist, it provides a locally customized learning environment and repeated practice in a safe environment. We used the toolkit to illustrate removal of the adrenal gland.

Developing a multimedia environment for customized teaching of an adrenalectomy.

We have developed a computer based simulation process which allows a surgical expert to create a customized operative environment. This virtual environment, the Toolkit for Illustration of Procedures in Surgery (3D TIPS), is deployed on a low-cost computer system and requires minimal training for the programmer. The learner can be engaged in training immediately and the educator can modify the system and annotate the procedure to highlight specific points using video clips, operative images, and the like. A laparoscopic adrenalectomy is presented as a proof of concept in the accompanying article.

Exploiting graphics hardware for haptic authoring.

Real-time, plausible visual and haptic feedback of deformable objects without shape artifacts is important in surgical simulation environments to avoid distracting the user. We propose to leverage highly parallel stream processing, available on the newest generation graphics cards, to increase the level of both visual and haptic fidelity. We implemented this as part of the University of Florida's haptic surgical authoring kit.

Simulation for training with the Autosuture Endo Stitch device.

The rapid development and deployment of novel laparoscopic instruments present the surgical educator and trainee with a significant challenge. Several useful instruments have been particularly difficult to teach the novice. We have developed a platform that allows the combination of the actual instrument handle with a virtual re-creation of the instrument tip. We chose the Autosuture Endo Stitch device as the prototypical instrument because it satisfies our subjective experience of "useful, but hard to teach." A software package was developed to support the re-creation of the needle and suture that accompany the device. The apparatus has haptic capabilities and collision detection so that the needle driver is "aware" of suture and instrument contact. The developed virtual environment allows re-creation of the necessary motion to simulate the instrument, the trainee can use the actual instrument handle, and the system can be altered to accommodate other instruments.