The value of medical 3D printing : hope versus hype

3D printing has been growing fast in the medical field. While preliminary clinical results have been reported in the literature, it’s health economic value has not been analyzed yet. Medical 3D printing has found its main applications in surgery; especially orthopedics and reconstructive surgery. Its applications rage from anatomic models to surgical guides and implants. All of these can be seen as consecutive levels of integration. While papers often report improved clinical results, a great accuracy and an acceptable price, few of these are backed with numbers. We performed 3 health economic analyses using Markov models using a payer perspective on each of these 3 levels of integration. As a first level, we analyzed the impact of using anatomic models as a tool for surgical planning in congenital heart diseases for 9 different procedures. Results varied from not being cost effective for atrial septum defects, to being highly cost-effective in highly complex procedures such as a Norwood repair. Second, we analyzed the already well integrated use of surgical guides for primary total knee arthroplasty using Belgian registry data. The database approach showed an significantly reduced revision rate in the group using custom guides compared to the conventional approach. The Markov models showed the technology to be cost-effective if CT-based guides are used. At last, we analyzed the use of custom 3D printed acetabular implants for revision surgery in patients with acetabular defects compared to non-3D printed custom implants. The 3D printed implants showed to be cost effective, especially in younger patients. The final chapter gives an overview of the pitfalls encountered during these preliminary analyses and gives a glance at possible solutions to allow better analysis and faster adoption of medical innovations

3D-printing techniques in a medical setting : a systematic literature review

Background: Three-dimensional (3D) printing has numerous applications and has gained much interest in the medical world. The constantly improving quality of 3D-printing applications has contributed to their increased use on patients. This paper summarizes the literature on surgical 3D-printing applications used on patients, with a focus on reported clinical and economic outcomes. Methods: Three major literature databases were screened for case series (more than three cases described in the same study) and trials of surgical applications of 3D printing in humans. Results: 227 surgical papers were analyzed and summarized using an evidence table. The papers described the use of 3D printing for surgical guides, anatomical models, and custom implants. 3D printing is used in multiple surgical domains, such as orthopedics, maxillofacial surgery, cranial surgery, and spinal surgery. In general, the advantages of 3D-printed parts are said to include reduced surgical time, improved medical outcome, and decreased radiation exposure. The costs of printing and additional scans generally increase the overall cost of the procedure. Conclusion: 3D printing is well integrated in surgical practice and research. Applications vary from anatomical models mainly intended for surgical planning to surgical guides and implants. Our research suggests that there are several advantages to 3D- printed applications, but that further research is needed to determine whether the increased intervention costs can be balanced with the observable advantages of this new technology. There is a need for a formal cost-effectiveness analysis

An early health technology assessment of 3D anatomic models in pediatric congenital heart surgery : potential cost-effectiveness and decision uncertainty

Background: Three-dimensional anatomic models have been used for surgical planning and simulation in pediatric congenital heart surgery. This research is the first to evaluate the potential cost-effectiveness of 3D anatomic models with the intent to guide surgeons and decision makers on its use. Method: A decision tree and subsequent Markov model with a 15-year time horizon was constructed and analyzed for nine cardiovascular surgeries. Epidemiological, clinical, and economic data were derived from databases. Literature and experts were consulted to close data gaps. Scenario, one-way, threshold, and probabilistic sensitivity analysis captured methodological and parameter uncertainty. Results: Incremental costs of using anatomical models ranged from -366euro (95% credibility interval: -2595euro; 1049euro) in the Norwood operation to 1485euro (95% CI: 1206euro; 1792euro) in atrial septal defect repair. Incremental health-benefits ranged from negligible in atrial septal defect repair to 0.54 Quality Adjusted Life Years (95% CI: 0.06; 1.43) in truncus arteriosus repair. Variability in the results was mainly caused by a temporary postoperative quality-adjusted life years gain. Conclusion: For complex operations, the implementation of anatomic models is likely to be cost-effective on a 15 year time horizon. For the right indication, these models thus provide a clinical advantage at an acceptable cost

Bi-Objective Search with Bi-Directional A*

Bi-objective search is a well-known algorithmic problem, concerned with finding a set of optimal solutions in a two-dimensional domain. This problem has a wide variety of applications such as planning in transport systems or optimal control in energy systems. Recently, bi-objective A*-based search (BOA*) has shown state-of-the-art performance in large networks. This paper develops a bi-directional and parallel variant of BOA*, enriched with several speed-up heuristics. Our experimental results on 1,000 benchmark cases show that our bi-directional A* algorithm for bi-objective search (BOBA*) can optimally solve all of the benchmark cases within the time limit, outperforming the state of the art BOA*, bi-objective Dijkstra and bi-directional bi-objective Dijkstra by an average runtime improvement of a factor of five over all of the benchmark instances

Vehicle Dynamics in Pickup-And-Delivery Problems Using Electric Vehicles

Electric Vehicles (EVs) are set to replace vehicles based on internal combustion engines. Path planning and vehicle routing for EVs need to take their specific characteristics into account, such as reduced range, long charging times, and energy recuperation. This paper investigates the importance of vehicle dynamics parameters in energy models for EV routing, particularly in the Pickup-and-Delivery Problem (PDP). We use Constraint Programming (CP) technology to develop a complete PDP model with different charger technologies. We adapt realistic instances that consider vehicle dynamics parameters such as vehicle mass, road gradient and driving speed to varying degrees. The results of our experiments show that neglecting such fundamental vehicle dynamics parameters can affect the feasibility of planned routes for EVs, and fewer/shorter charging visits will be planned if we use energy-efficient paths instead of conventional shortest paths in the underlying system model

Practical implementation of the comprehensive geriatric assessment to optimise care for older adults with cancer

Whilst cancer remains a very serious health problem at any stage, cancer combined with increasing age creates an even more challenging situation for health care providers [...

Radiation dose management in thoracic CT: an international survey

PURPOSEWe aimed to examine current practice patterns of international thoracic radiologists regarding radiation dose management in adult thoracic computed tomography (CT) examinations. MATERIALS AND METHODSAn electronic questionnaire was sent to 800 members of five thoracic radiology societies in North America, Europe, Asia, and Latin America addressing radiation dose training and education, standard kVp and mAs settings for thoracic CT, dose reduction practices, clinical scenarios, and demographics. RESULTSOf the 800 radiologists, 146 responded to our survey. Nearly half (66/146, 45% [95% confidence interval, 37%–53%]) had no formal training in dose reduction, with “self-study of the literature” being the most common form of training (54/146, 37% [29%–45%]). One hundred and seventeen (80% [74%–87%]) had automatic exposure control, and 76 (65% [56%–74%]) used it in all patients. Notably, most respondents (89% [84%–94%]) used a 120 to 125 kVp standard setting, whereas none used 140 kVp. The most common average dose-length-product (DLP) value was 150 to 249 mGy.cm (75/146, 51% [43%–59%]), and 59% (51%–67%) delivered less than 250 mGy.cm in a 70 kg patient. There was a tendency towards higher DLP values with multidetector-row CT. Age, gender, and pregnancy were associated more with dose reduction than weight and clinical indication. CONCLUSIONEfforts for reducing patient radiation dose are highly prevalent among thoracic radiologists. Areas for improvement include reduction of default tube current settings, reduction of anatomical scan coverage, greater use of automatic exposure control, and eventually, reduction of current reference dose values. Our study emphasizes the need for international guidelines to foster greater conformity in dose reduction by thoracic radiologists

Manometric demonstration of duodenal/jejunal motor function consistent with the duodenal brake mechanism

© 2020 John Wiley & Sons Ltd Background: High-resolution manometric studies below the stomach are rare due to technical limitations of traditional manometry catheters. Consequently, specific motor patterns and their impact on gastric and small bowel function are not well understood. High-resolution manometry was used to record fed-state motor patterns in the antro-jejunal segment and relate these to fasting motor function. Methods: Antro-jejunal pressures were monitored in 15 healthy females using fiber-optic manometry (72 sensors at 1cm intervals) before and after a high-nutrient drink. Key Results: Postprandial motility showed a previously unreported transition point 18.8cm (range 13-28cm) beyond the antro-pyloric junction. Distal to the transition, a zone of non-propagating, repetitive pressure events (11.5±0.5cpm) were dominant in the fed state. We have named this activity, the duodeno-jejunal complex (DJC). Continuous DJC activity predominated, but nine subjects also exhibited intermittent clusters of DJC activity, 7.4±4.9/h, lasting 1.4±0.55minutes, and 3.8±1.2minutes apart. DJC activity was less prevalent during fasting (3.6±3.3/h; P=.04). 78% of fed and fasting state propagating antro-duodenal pressure events terminated proximally or at the transition point and were closely associated with DJC clusters. Conclusions and Inferences: High-resolution duodeno-jejunal manometry revealed a previously unrecognized transition point and associated motor pattern extending into the jejunum, consistent with the duodenal brake previously identified fluoroscopically. Timing suggests DJC activity is driven by chyme stimulating duodenal mucosal chemosensors. These findings indicate that the duodenum and proximal jejunum consists of two major functional motor regions

Oncologic Home-Hospitalization Delivers a High-Quality and Patient-Centered Alternative to Standard Ambulatory Care: Results of a Randomized-Controlled Equivalence Trial

PURPOSE- Given the increasing burden of cancer on patients, health care providers, and payers, the shift of certain outpatient procedures to the patients' homes (further indicated as oncologic home-hospitalization [OHH]) might be a high-quality, patient-centered, and cost-effective alternative to standard ambulatory cancer care (SOC). METHODS- A randomized-controlled trial was conducted to evaluate the quality of a locally implemented model for OHH (n = 74) compared with SOC (n = 74). The model for OHH consisted of home administration of certain subcutaneous cancer drugs (full OHH) and home nursing assessments before ambulatory systemic cancer therapy (partial OHH). Quality was evaluated based on patient-reported quality of life (QoL) and related end points; service use and cost data; safety data; patient-reported satisfaction and preferences; and model efficiency. An equivalence design was used for primary end point analysis. Participants were followed during 12 weeks of systemic cancer treatment. RESULTS- This trial demonstrated equivalence of both models (OHH v SOC) in terms of patient-reported QoL (95% CI not exceeding the equivalence margin of 10%). Full OHH resulted in significantly less hospital visits (mean of 5.6 ± 3.0 v 13.2 ± 4.6; P = .011). Partial OHH reduced waiting times for therapy administration at the day care unit with 45% per visit (2 hours 36 minutes ± 1 hour 4 minutes v 4 hours ± 1 hour 4 minutes; P < .001). No safety issues were detected. Of the intervention group, 88% reported to be highly satisfied with the OHH model, and 77% reported a positive impact on their QoL. At study end, 60% of both study arms preferred OHH above SOC. CONCLUSION- The shift of particular procedures from the outpatient clinic to the patients' homes offers a high-quality and patient-centered alternative for a large proportion of patients with cancer. Further research is needed to evaluate potential cost-efficiency