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Contents: Computers and eHealth: Procedures and Instruments

Three-Dimensional–Printed Uterine Model for Surgical Planning of a Cesarean Delivery Complicated by Multiple Myomas

Mackey, Amy MD; Ng, Joshua I. BSE; Core, Jason BS; Nguyen, Linh MS; Cross, Devon BS, BA; Lim, Philip MD; Woodfield, Courtney MD; Pugliese, Robert PharmD; Ku, Bon MD, MPP

Author Information
doi: 10.1097/AOG.0000000000003107

Myomas encountered at the time of cesarean delivery increase the risk of hemorrhage, blood transfusion, and fetal malpresentation and the need for myomectomy or hysterectomy.1 Surgical planning in these cases may help to maximize patient outcomes and reduce complications. Consideration must be given to the location of both the abdominal and uterine incisions. Knowledge of the internal architecture of the uterine cavity can also assist with fetal extraction from the myomatous uterus. A well-placed uterine incision can reduce the need for myomectomy at the time of uterine closure.

Applications of three-dimensional printing in medicine have been growing, in part owing to the increasing availability of lower cost, consumer-grade, desktop three-dimensional printers.2 A recent internet-based search for three-dimensional printers found printer costs as low as $158.49; the Ultimaker 3 three-dimensional printer, used for this model, was listed for $3,495.00. Historically, high printer costs and limited three-dimensional technical expertise in the medical community have been barriers to the widespread adoption of this emerging technology.2

Three-dimensional–printed models have been used in various fields of surgery to generate patient-specific organ models for hands-on operative planning and surgical training.3 These models offer the benefit of tactile feedback while retaining relevant anatomic accuracy.4 We hypothesized that a three-dimensional–printed model was feasible and beneficial for surgical planning for a patient with multiple anterior uterine myomas who was undergoing a planned cesarean delivery.

METHOD

Images of the patient's gravid uterus, placenta, and myomas were obtained from a magnetic resonance imaging (MRI) examination performed on a 1.5 Tesla magnet and exported into Digital Imaging and Communication in Medicine data sets. Segmentation of the MRIs was performed using open-source software (3DSlicer). Figure 1 shows the images created by computer-aided design software, which was used to refine the anatomic images of the uterus, placenta, and myomas. The digital model was exported as a stereolithography file for fabrication on a desktop three-dimensional printer (Ultimaker 3 Extended). The three-dimensional printable anatomic model was made with polylactic acid filament. Figure 2 and Video 1 (Video 1 is available online at http://links.lww.com/AOG/B290) show the final model used by the clinical team for surgical planning. Separating the uterus into a bivalve form further allowed for internal cavity visualization and better delineation of the penetrating myomas and the placenta. For the final printed three-dimensional model, the estimated materials cost was $35 and the time of three-dimensional printing was 49.5 hours.

Fig. 1.
Fig. 1.:
Three-dimensional slicer workspace view (A, C, and D) showing different colored segmentations of the uterus (I), placenta (I), and leiomyomas. B. The three-dimensional–generated model from the magnetic resonance imaging segmentation.Mackey. Three-Dimensional Gravid Myomatous Uterine Model. Obstet Gynecol 2019.
Fig. 2.
Fig. 2.:
Myometrium (white) and leiomyomas (red) are seen on the anterior (A) and posterior (C) surfaces of the uterus. The bivalved uterus is held together by magnets, with a large disc-shaped placenta (red) and rounded leiomyomas (red) projecting into the uterine cavity (B and D).Mackey. Three-Dimensional Gravid Myomatous Uterine Model. Obstet Gynecol 2019.
Video 1.
Video 1.:
This video shows the final three-dimensional-printed uterine model, with myomas shown in red. The model is bivalved, and myomas impinging on the internal cavity can be seen on the inner surface of the model. The placenta is also shown in red. Videographers: Philip Lim, MD, and Robert Pugliese, PharmD.

EXPERIENCE

A 33-year-old woman, gravida 1, with a history of myomectomy presented for prenatal care. A first-trimester ultrasound examination revealed at least 10 myomas of varying sizes up to 5 cm. The patient's case was discussed in a multidisciplinary team meeting for obstetric patients with surgically complicated cases. After this meeting, MRI was performed at 28 weeks of gestation to better delineate the number, size, and location of the patient's myomas. Magnetic resonance imaging revealed multiple myomas, many of which were anterior and 2–6 cm in size. Owing to the patient's previous myomectomy, a cesarean delivery was planned at 37 weeks. On further review of the MRI, it was believed that a three-dimensional model of the myomatous uterus would be beneficial for cesarean incision planning.

The patient underwent a primary cesarean delivery at 37 5/7 weeks of gestation. A vertical skin incision was made, and a J-shaped incision was made on the uterus after identifying the location of the patient's myomas by comparing the actual anatomy to the three-dimensional–printed model that was available in the operating room. The individual myomas were palpated, and the corresponding model myomas were located as illustrated in Figure 3. A 6-pound 14-ounce male neonate was delivered, with Apgar scores of 9 at 1 minute and 9 at 5 minutes. The quantitative blood loss for the surgery, estimated by the California Collaborative–recommended method, was 600 mL. The uterine incision was closed without difficulty, and the remainder of the surgery was uneventful. The patient and neonate were discharged on the third postoperative day.

Fig. 3.
Fig. 3.:
Surgical team mapping the myomas by comparing the palpable myomas with the three-dimensional model to determine the previously planned uterine incision site.Mackey. Three-Dimensional Gravid Myomatous Uterine Model. Obstet Gynecol 2019.

DISCUSSION

Myomas encountered at the time of cesarean delivery pose challenges for the obstetric surgeon. In this case, we were able to produce a patient-specific three-dimensional–printed model of the uterus from MRIs with minimal material cost. Because this was our first attempt at printing a uterine model, multiple iterations of the model were printed to generate the most clinically useful three-dimensional display. Video 2, available online at http://links.lww.com/AOG/B291, shows an earlier version of the three-dimensional–printed model.

Video 2.
Video 2.:
This video shows an earlier version of the three-dimensional–printed uterine model arranged in a stacked slice pattern. Myomas are seen in red. As the slices are moved, the internal cavity can be seen. The placenta in this model is not highlighted and is white like the surrounding myometrium. Videographers: Philip Lim, MD, and Robert Pugliese, PharmD.

At our institution, MRI of a gravid uterus is considered in addition to ultrasound imaging in cases of extensive uterine myomas. Magnetic resonance imaging can accurately assess the number, size, and location of uterine myomas with a large field of view. Our patient's MRI was performed at 28 weeks of gestation. Magnetic resonance imaging examination performed closer to the time of delivery likely would have provided the most accurate assessment of uterine myoma sizes and locations. However, we have found that, beyond 30 weeks of gestation, many patients cannot undergo MRI of the gravid uterus owing to either abdominal girth size limitations or difficulty lying supine or in a left lateral decubitus position for the length of the study (approximately 20–30 minutes).

The accuracy of the three-dimensional uterine model with respect to the number, location, and relative size of the myomas mapped on the uterus was evaluated and confirmed by both direct radiologist comparison of the three-dimensional model with the MRIs and by surgeon assessment of the uterus compared with the model at the time of surgery. Figure 4 shows the myomas in the uterine fundus postdelivery.

Fig. 4.
Fig. 4.:
Multiple myomas are seen at the fundus of the uterus after delivery of the neonate.Mackey. Three-Dimensional Gravid Myomatous Uterine Model. Obstet Gynecol 2019.

The cost and difficulty of printing the three-dimensional model at our institution was relatively low. Three-dimensional printers are already available in our health system's Health Design Lab, and we routinely perform MRI of the gravid uterus in obstetric patients with complex cases. For our purpose, a three-dimensional model of the uterus with highly detailed measurements and precision was not required for surgical planning. We were therefore able to use a relatively lower cost, commercially available three-dimensional printer for our model. However, other health care applications, such as custom implants and prostheses,5 where precision or full-size products are required, may have higher printer and material costs. The relatively low cost of printing a three-dimensional model also may not yet be realized in institutions where three-dimensional printers are not currently available and where there is limited experience with obstetric MRI. The time required to convert the MRIs to a printable form is an additional cost, and for us the most expensive component of this application. We expect the time expense to decrease with further experience and innovations of three-dimensional printing technology.

Three-dimensional printing could also be considered for other complex obstetric and gynecologic conditions, including surgical planning for placenta accreta, treatment planning for cervical and endometrial cancer, and surgery for müllerian anomalies.6 Patient-specific three-dimensional–printed models can also be useful in counseling patients regarding the unique aspects of their surgeries, including surgical steps and surgical risks and challenges. Further studies on the application of three-dimensional–printed patient-specific models in obstetrics and gynecology are needed to elucidate the true value and patient safety benefits from this emerging technology.

REFERENCES

1. Coronado GD, Marshall LM, Schwartz SM. Complications in pregnancy, labor and delivery with uterine leiomyomas: a population-based study. Obstet Gynecol 2000;95:764–9.
2. Hammad M, Darwood A, Shaunak S, Kulatilake P, El-Hilly A, Mulki O, et al. Three-dimensional printing in surgery: a review of current surgical applications. J Surg Res 2015;199:512–22.
3. Ganguli A, Pagan-Diaz G, Grant L, Cvetkovic C, Bramlet M, Vozenilek J, et al. 3D printing for preoperative planning and surgical training: a review. Biomed Microdevices 2018;20:65.
4. Marconi S, Pugliese L, Botti M, Peri A, Cavazzi E, Latteri S, et al. Value of 3D printing for the comprehension of surgical anatomy. Surg Endosc 2017;31:4102–10.
5. Lal H, Patralekh MK. 3D printing and its applications in orthopaedic trauma: a technological marvel. J Clin Orthop Trauma 2018;9:260–8.
6. Baek MH, Kim DY, Kim N, Thim CC, Kim JH, Nam JH. Incorporating a 3-dimensional printer into the management of early-stage cervical cancer. J Surg Oncol 2016;114:150–2.

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© 2019 by the American College of Obstetricians and Gynecologists. Published by Wolters Kluwer Health, Inc. All rights reserved.