Medical 3D Printing for Surgery: Anatomical Models and Surgical Guides

In this issue of “From Academia”, we included three recent publications focusing on medical 3D printing for surgical planning, either using 3D printed anatomical models or surgical guides. The first is a review article focusing on cost/benefit analysis of using 3D printing in orthopedic and maxillofacial surgery, primarily in terms of operating room time saved. This is very relevant to our guide focusing on 3D printing in hospitals. The second study focuses on a case study using an innovative patient-specific instrument guide (PSIG) for the safe removal of a skull bone tumor. The final article introduces a 2-in-1 patient-specific 3D printed laminectomy surgical guide with integrated pedial screw drill guides. “From Academia” features recent, relevant, close to commercialization academic publications. Subjects include but not limited to healthcare 3D printing, 3D bioprinting, and related emerging technologies.

Email: Rance Tino (tino.rance@gmail.com) if you want to share relevant academic publications with us.

Medical 3D Printing Cost-Savings in Orthopedic and Maxillofacial Surgery: Cost Analysis of Operating Room Time Saved with 3D Printed Anatomic Models and Surgical Guides

Authored by David H. Ballard, Patrick Mills, Richard Duszak Jr., Jeffery A. Weisman, Frank J. Rybicki, Pamela K. Woodward. Academic Radiology. August 2020

medical 3D printing
Cost-savings from operative room time saved plotted for the individual studies  including 3D printed anatomic models (a) and surgical guides (b) used in patients’ operative care compared to a control group. The $22, $62, and $133 USD/minute are collective data from the reference study reporting range of operating room time/minute in the United States . Note that standard deviation is not presented via error bars due to scale and overlap of the data points. Copyright. Academic Radiology

Abstract

Rationale and Objective:

Three-dimensional (3D) printed anatomic models and surgical guides have been shown to reduce operative time. The purpose of this study was to generate an economic analysis of the cost-saving potential of 3D printed anatomic models and surgical guides in orthopedic and maxillofacial surgical applications.

Materials and Methods:

A targeted literature search identified operating room cost-per-minute and studies that quantified time saved using 3D printed constructs. Studies that reported operative time differences due to 3D printed anatomic models or surgical guides were reviewed and cataloged. A mean of $62 per operating room minute (range of $22–$133 per minute) was used as the reference standard for operating room time cost. Different financial scenarios were modeled with the provided cost-per-minute of operating room time (using high, mean, and low values) and mean time saved using 3D printed constructs.

Results:

Seven studies using 3D printed anatomic models in surgical care demonstrated a mean 62 minutes ($3720/case saved from the reduced time) of time saved, and 25 studies of 3D printed surgical guides demonstrated a mean 23 minutes time saved ($1488/case saved from the reduced time). An estimated 63 models or guides per year (or 1.2/week) were predicted to be the minimum number to breakeven and account for annual fixed costs.

Conclusion:

Based on the literature-based financial analyses, medical 3D printing appears to reduce operating room costs secondary to shortening procedure times. While resource-intensive, 3D printed constructs used in patients’ operative care provides considerable downstream value to health systems.

medical 3D printing
Potential cost-savings per surgical case from the listed anatomic models and surgical guide studies paired with reference data of mean cost of operating room minutes. Potential cost savings are grouped according to the mean ($62/minute), minimum ($22/minute), and maximum ($133/minute) from the reference study that queried operating room time costs in the United States (15). These mean, minimum, and maximum values per minute of operating room time adjusted for 2019 inflation would increase to $83, $30, and $179 per minute, respectively. *Inflation from reference study published in 2005  adjusted for 2019 inflation using the U.S. Bureau of Labor Statistics Consumer Price Index Inflation Calculator. Copyright. Academic Radiology

Printing a patient-specific instrument guide for skull osteoma management

Authored by Authored by Tien-Hsiang Wang, Li-Ying Huang, Yu-Cheng Hung, Te-Han Wang, Wen-Chan, Fang-Yau Chiu, Shyh-Jen Wang, Wei-Ming Chen. Journal of the Chinese Medical Association, October 2020

medical 3D printing
The patient-specific instrument: A, computer model and B, printed with resin. Copyright Journal of the Chinese Medical Association

Abstract

Background:

To surgically remove osteoma and to keep an optimal cosmetic profile would be very challenging. To solve the difficulty, we utilized medical 3D printing technologies in generating a patient-specific instrument guide (PSIG) for the safe removal of a skull bone tumor.

Methods:

The preoperational brain computed tomography (CT) provided the digital imaging with thin slices, and then images were reconstructed into a 3D skull model. Based on the model, we designed a PSIG to make landmarks on the osteoma to avoid excessive removal of the skull bone. During the operation, the surgeons could remove the osteoma piece by piece by using the landmark as a reference point.

Results:

The PSIG was successfully applied to remove an osteoma that measured 60 × 48 × 40 mm3 over the left frontoparietal skull of a female patient. The 3D CT reconstruction taken both before and 4 months after surgery showed a significant change in the appearance of the osteoma.

Conclusion:

The PSIG was able to guide the surgeon in the safe removal of the skull osteoma, as well as in maintaining the cosmetic skull profile.

medical 3D printing
The surgical site and the SPI for drilling landmark holes. Copyright Journal of the Chinese Medical Association

The Development of Novel 2-in-1 Patient-Specific, 3D-Printed Laminectomy Guides with Integrated Pedicle Screw Drill Guides

Authored by Andrew Kanawati, Renan Jose Rodrigues Fernandes, Aaron Gee, Jennifer Urquhart, Fawaz Siddiqi, Kevin Gurr, Christopher S. Baley, Parham Rasoulinejad. World Neurosurgery. February 1 2021

medical 3D printing
 CAD model of the spinal guide..Copyright. World Neurosurgery

Abstract

Objective:

To determine if 2-in-1 patient-specific laminectomy and drill guides can be safely used to perform laminectomy and pedicle screw insertion.

Methods:

This was a cadaveric study designed to test novel 2-in-1 patient-specific laminectomy guides, with modular removable pedicle screw drill guides. Three-dimensional (3D) printing has not been applied to laminectomy. Computed tomography (CT) scans of 3 lumbar spines were imported into 3D Slicer. Spinal models and patient-specific guides were created and 3D printed. The bones were cleaned to visualize and record the undersurface of the lamina during laminectomy. Pedicle screws and laminectomies were performed with the aid of patient-specific guides. CT scans were performed to compare planned and actual screw and laminectomy positions.

Results:

Thirty screws were inserted in 15 lumbar vertebrae by using the integrated 2-in-1 patient-specific drill guides. There were no cortical breaches on direct examination, or on postoperative CT. Digital video analysis revealed the burr tip did not pass deep to the inner table margin of the lamina in any of the 30 laminectomy cuts. The average surgical time was 4 minutes and 46 seconds (standard deviation, 1 min 38 sec).

Conclusions:

This study has explored the development of novel 2-in-1 patient-specific, 3D-printed laminectomy guides with integrated pedicle screw drill guides, which are accurate and safe in the laboratory setting. These instruments have the potential to simplify complex surgical steps and improve accuracy, time, and cost.

medical 3D printing
3D printed surgical guide attached to a spine model.  Copyright. World Neurosurgery

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From Academia: 3D Printing for Neurosurgery Training, Vat Photopolymerization, soft robotic microsystem

From Academia: In Vivo & Robotic-assisted Minimally Invasive Bioprinting, 3DP for Liver Surgery

Smart Spine Surgery- From Planning to 3D Printed Templates

The Past and Present of 3D Printing in Maxillofacial Surgery

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