Design and Physical Properties of 3-Dimensional Printed Models Used for Neurointervention: A Systematic Review of the Literature.

BACKGROUND: Three-dimensional (3D) printing has revolutionized training, education, and device testing. Understanding the design and physical properties of 3D-printed models is important. OBJECTIVE: To systematically review the design, physical properties, accuracy, and experimental outcomes of 3D-printed vascular models used in neurointervention. METHODS: We conducted a systematic review of the literature between January 1, 2000 and September 30, 2018. Public/Publisher MEDLINE (PubMed), Web of Science, Compendex, Cochrane, and Inspec databases were searched using Medical Subject Heading terms for design and physical attributes of 3D-printed models for neurointervention. Information on design and physical properties like compliance, lubricity, flow system, accuracy, and outcome measures were collected. RESULTS: A total of 23 articles were included. Nine studies described 3D-printed models for stroke intervention. Tango Plus (Stratasys) was the most common material used to develop these models. Four studies described a population-representative geometry model. All other studies reported patient-specific vascular geometry. Eight studies reported complete reconstruction of the circle of Willis, anterior, and posterior circulation. Four studies reported a model with extracranial vasculature. One prototype study reported compliance and lubricity. Reported circulation systems included manual flushing, programmable pistons, peristaltic, and pulsatile pumps. Outcomes included thrombolysis in cerebral infarction, post-thrombectomy flow restoration, surgical performance, and qualitative feedback. CONCLUSION: Variations exist in the material, design, and extent of reconstruction of vasculature of 3D-printed models. There is a need for objective characterization of 3D-printed vascular models. We propose the development of population representative 3D-printed models for skill improvement or device testing.

Initial experience with a 3D printed model for preoperative simulation of the Nuss procedure for pectus excavatum.

The incidence of pectus excavatum has been estimated to be between 0.1% and 0.8% though a large autopsy series reports. After publication of the Nuss procedure for pectus excavatum, it became widely accepted. However, there are still some complications, such as over-correction and recurrence. To reduce differences in the procedure due to surgeons' experience level, preoperative simulation may be useful. Thus, we performed simulated surgery using a specific patient's three-dimensional (3D) chest wall model made by a 3D printer before operation. A 13-year-old male patient with a severe deformity of the chest underwent the Nuss procedure. As in the simulation, bars were inserted into the 5th and 7th intercostal spaces (ICS), leading to improvement of the chest wall. This simulation can increase surgeons' confidence to improve the deformity by determination of the number and insertion sites of bars.

Three-dimensional (3D) bronchial tree model for bronchial resection with pulmonary segmentectomy.

There has been an increase in pulmonary segmentectomy procedures because of increased numbers of individuals with small lung cancer. However, it is difficult to identify the correct bronchus during surgery even with pre-operative three-dimensional (3D) computed tomography. We investigated using a 3D-printed model of the bronchi to prepare for bronchus resection during pulmonary segmentectomy. The model was useful to determine pre-operatively which bronchus should be transected, and being composed of a soft material it could be mobilized similarly to the actual bronchus during surgery. This simulation can increase surgeons' confidence to identify the correct bronchus during pulmonary segmentectomy.