Using a bio-scanner and 3D printing to create an innovative custom made approach for the management of complex entero-atmospheric fistulas

1 Vol.:(0123456789) Scientific Reports | (2020) 10:19862 | https://doi.org/10.1038/s41598-020-74213-7 www.nature.com/scientificreports Using a bio‑scanner and 3D printing to create an innovative custom made approach for the management of complex entero‑atmospheric fistulas Virginia Durán Muñoz‑Cruzado1, Francisco José Calero Castro1, Andrés Padillo Eguía2, Luis Tallón Aguilar1, José Tinoco González1, Juan Carlos Puyana3, Felipe Pareja Ciuró1* & Javier Padillo‑Ruiz1 Enteroatmospheric fistulae are challenging clinical conditions that require surgical expertise and that can result in chronic debilitating conditions placing the patient in a vicious cycle characterized by non healing wounds and malnutrition. They are a complex entity that presents great variability depending on the number, shape, and size of the fistulous orifices, their debit, and the dimensions of the wound. This means that, at present, there is no device that adapts to the anatomical characteristics of each patient and manages to control the spillage of intestinal effluvium from the wound. The aim of this study is to describe the manufacturing technique and to assess the preliminary results of a custom device designed through bioscanner imaging and manufactured using 3D printing for use with negative pressure wound therapy (NPWT) in the management of enteroatmospheric fistula. A proof of concept is given, and the design of the device is presented for the first time. After obtaining images of each fistula with a bioscanner, a personalised device was designed for each patient by 3D printing shape of a prism and a hollow base, taking into account the dimensions of the fistulous area in order to perform a floating ostomy to isolate the wound from the debit enteric. The polycaprolactone (PCL) device was placed including inside the fistulous surface and surrounding it with the NPWT system in order to accelerate wound healing. Enteroatmospheric fistula is defined as the communication between the intestinal lumen and the surface of an open abdominal wound1–6. It occurs in 10% of patients who have an open abdomen due to treatment for peritonitis or compartment symdrome5 causing 40% mortality4. The main challenge presented by this pathology is the local control of the fistula, that is, to ensure that the intestinal content that is poured through the fistula does not come into contact with the wound, since the chemical burn and the contamination produced by the Intestinal material prevents effective granulation an adequate healing of the surrounding tissue. The local control of the fistula presents a wound care challenge due to the enormous variability of this entity: the size of the wound, the position and number of fistulous orifices, intestinal segments involved, and the volumen of intestinal output, etc. These many factors result in complex management challenges and currently, due to the great anatomical variability of these fistulae there is not a unique device or solution that can be used to ensure adequate local control in this very heterogenous complication. typical of complex enteroatmospheric fistulae. The ideal treatment is resection of the intestinal segment involved and an anastomosis with the reconstruction of the abdominal wall1,2,4. This treatment is not feasible at the time of diagnosis due to the peritoneal adhesions presented by the patients and the inflammation of the surrounding tissues; therefore, there is bridge therapy that is used for externalisation of intestinal fluids to avoid continuous contact with the wound, thus favouring the correct healing and granulation of the wound until definitive surgery can be performed1,2,4. OPEN 1Division of General Surgery, Virgen del Rocío University Hospital, Av Manuel Siurot S/N, 41013 Seville, Spain. 2University of Seville, Seville, Spain. 3Division of Surgery, Critical Care Medicine and Clinical Translational Science, University of Pittsburgh, Pittsburgh, USA. *email: [email protected] 2 Vol:.(1234567890) Scientific Reports | (2020) 10:19862 | https://doi.org/10.1038/s41598-020-74213-7 www.nature.com/scientificreports/ One of the alternatives of bridge therapy is negative pressure wound therapy (NPWT), which is applied to the wound surface to promote granulation. However, this therapy must be accompanied by a device that is capable of isolating the fistulous orifice of the NPWT, since if negative pressure is produced on the fistula, it would have untoward consequences and therefore perpetuating and even enlarge the fistulous surface. Thus, different techniques have been described to isolate the wound from the faecal material and to provide correct granulation of the wound by combining NPWT with various devices that help establish a “floating stoma”4. These therapies include artisanal and commercial devices intended to isolate the fistula. However, the clinical variability and the various presentations of this pathology make the currently designed devices not valid for all types of fistulas, making personalised treatment of these fistulas necessary. Given the special characteristics of the enteroatmospheric fistula that make personalised treatment necessary, we proposed the creation of a customised adapter, made of polycaprolactone (PCL) by 3D printing, for each patient and for each evolutionary moment based on the characteristics of the patient. Materials and methods Patient selection. From June 2017 to September 2019, all patients at our centre or derived from other centres that were over 18years of age and diagnosed with enteroatmospheric fistula were prospectively preselected for the study. Exclusion criteria included the following: shapes or dimensions of the wound that did not allow for application of the device (for example, a fistula very close to the edge of the wound), clinical conditions of the patient that prevented placement of the device (hemodynamic instability or need for urgent surgery), and not signing the informed consent. This study has been approved by the ethics committee (Research Ethics Committee of Seville). All experiments were performed inaccordance with relevant named guidelines and regulations. Informed consent was obtained from all participants and/or their legal guardians, even to publish the information and images in an online open-access publication. In this period, five patients were shortlisted. Of these, four were included in the study; one patient was excluded because they did not sign the informed consent. The clinical characteristics of the selected patients and the evolutionary changes of the fistula are described in Table1. Description of the intervention applied. Device design. The design of the adapter was personalised for each patient, taking into account the dimensions of the exposed intestinal surface of the enteroatmospheric fistula and the dimensions of the wound, and images of each patient were obtained through the bioscanner (Einscan pro+, 3D shining, China) (Fig.1A,B). Once the precise dimensions of the fistulous surface were known, the device was designed using FreeCAD 0.16. software (FreeCAD Juergen Riegel, Werner Mayer, Yorik van Havre). The design of the device was based on a prism with different shapes and a hollow interior. The intestinal surface that forms the fistula was inside the prism, and the abdominal wall wound was isolated from the intestinal contents, generating a floating ostomy when applying the NPWT system around the device. In order to correctly adapt to the NPWT system, protrusions were created at both ends of the device, which were exteriorised at the top, in contact with the adhesive plastics of the NPWT system, and at the bottom, in contact with the wound. Each of these are personalised devices, and the characteristics of each design are described in Table2. For patient 3 and 4, two different devices were designed due to the evolutionary changes that the wound had presented. Once the device was tailored to the fistulous surface with FreeCAD 0.16 software, it was exported in stl format. The scanned surface was imported into the Meshmixer software (Autodesk, San Rafael, EEUU) next to the device. The fistulous wound was selected and extruded in order to perform a Boolean operation in with intestinal surface is subtracted through the hole in the device. Finally, the ring-shaped device was placed on the image of the wound to verify the customisation and placement (Fig.1C–E). Through the virtual simulation of the coupling of the prosthesis on the surface of the patient’s wound, we can generate the tolerance margin so that the fistulous tissue is not pressed by the prosthesis and thus avoiding erosions around it. Manufacturing. Once the designs were made, they were exported in an .stl file, which was read by Regemat 3D designer software, and .gcode files were created and sent to the 3D printer (Regemat 3D, Granada, Spain). The impression was made with clinical grade PCL (99 filament 750g 1.75mm, 3D4makers, Haarlem, The Netherlands) with a solid fill pattern and a layer height of 0.35mm. The head speed was 20mm/s for the filling, and for the perimeter it was 10mm/s. The printing flow was 1.8mm/s at a temperature of 80°C (Fig.1F). After printing the device, a refinement phase is undertaken. This is done in order to create the best possible fitting between the device and the tissues surrounding the fistula. Due to the complex trajectory that the bioprinter must follow, it is sometimes difficult to obtain a perfectly smooth device that adapts to all edges of the wound. The total time to carry out the complete process of generating the device is an average of 4 ± 0.45h. Prior to application in patients, each device was sterilised according to the standards of the centre for sterilisation of biomaterials. Two devices of each design were manufactured. In the case of patient 3 and 4, due to the evolutionary changes that are characteristic of this pathology, two different devices were designed according to the needs of the patient and the evolutionary moment (device 3a, 3b, 4a and, 4b from Table2). Device placement. For application of the NPWT system, the abdominal wound was washed with physiological serum to eliminate possible remains of the intestinal discharge (Fig.2A). A sponge was moulded to the shape of 3 Vol.:(0123456789) Scientific Reports | (2020) 10:19862 | https://doi.org/10.1038/s41598-020-74213-7 www.nature.com/scientificreports/ Patient Age (years) Initial cause Time of evolution (days) Intestinal segment Daily debit (cc/24h) Diameters of the wound transverse/ length/depth (cm) Fistulous surface (cm2)Number of fistulous holes Fistula scheme 1 56 Septic complication of abdominal amputation due to anal canal epidermoid tumor (6 surgical interventions) 150 Yeyuno 800 (high) 14/12/2 42.41 4 2 45 Acute Diverticulitis WSES IV (7 surgical interventions) 10 Terminal ileon 500 (medium) 13/16/6 18.28 3 Continued 4 Vol:.(1234567890) Scientific Reports | (2020) 10:19862 | https://doi.org/10.1038/s41598-020-74213-7 www.nature.com/scientificreports/ Patient Age (years) Initial cause Time of evolution (days) Intestinal segment Daily debit (cc/24h) Diameters of the wound transverse/ length/depth (cm) Fistulous surface (cm2)Number of fistulous holes Fistula scheme 3 69 Duodenal perforation (2 surgical interventions) 7 Duodenum 100 (low) 3.a. Initial moment: 4/20/2 3.b. Change during therapy: 3/19/1 3.a. Initial moment: 0.78 3.b. Change during therapy: 0.75 1 Continued 5 Vol.:(0123456789) Scientific Reports | (2020) 10:19862 | https://doi.org/10.1038/s41598-020-74213-7 www.nature.com/scientificreports/ Patient Age (years) Initial cause Time of evolution (days) Intestinal segment Daily debit (cc/24h) Diameters of the wound transverse/ length/depth (cm) Fistulous surface (cm2)Number of fistulous holes Fistula scheme 4 62 Late evisceration after intestinal obstruction due to bezoar (1 surgical intervention) 2 Yeyuno 300 (medium) 4.a. Initial moment: 9/15/2 4.b Change during therapy: 9/15/2 4.a. Initial moment: 1.1 4.b Change during therapy: 13.74 1 Table 1. Baseline characteristics of the patient. WSES World Society of Emergency Surgery. 6 Vol:.(1234567890) Scientific Reports | (2020) 10:19862 | https://doi.org/10.1038/s41598-020-74213-7 www.nature.com/scientificreports/ the abdominal wound of each patient, and inside it an opening the size of the device was made. In this opening, the custom adapter was placed, and the rest of the abdominal wound was covered with the sponge, leaving the intestinal surface inside the adapter (Fig.2B). To facilitate the adhesion of the NPWT adhesive film, we lined the device with transparent polyurethane adhesive dressings (Opsite, Smith and Nephew). Adhesive films were used to completely cover the wound and the sponge, and, subsequently, a hole was made in the adhesive film on the internal part of the prosthesis that allowed the intestinal material to escape (Fig.2C,D). The sponge was subsequently connected to the NPWT device at a pressure of − 125mmHg. For correct sealing of the system, which maintains the vacuum, the angle formed between the internal walls of the adapter and the surface of the fistulous area was covered with sealing paste (Stomahesive, ConvaTec) (Fig.2E). In this way, a floating ostomy was performed, where the intestinal surface of the fistula protrudes through the interior of the tailor-made adapter, leaving the abdominal wound completely separated from the intestinal discharge (Fig.2F). Finally, an ostomy bag was placed in the system to collect the intestinal contents (Fig.2G). The procedure was the same for each replacement and for each patient. Figure1. Process of using of bioscanning and 3D printing. (A) Process of taking pictures with the bioscanner. (B) Images obtained with the bioscanner. (C) Measurement of the exposed intestinal surface dimensions for device design. (D) Verification of the suitability of the prosthesis by extrusion of the fistulous surface. (E) Placement of the device on the image of the bioscanned wound to determine the correct adaptation to the patient. (F) 3D printing of the bioprosthesis. 7 Vol.:(0123456789) Scientific Reports | (2020) 10:19862 | https://doi.org/10.1038/s41598-020-74213-7 www.nature.com/scientificreports/ Device Shape Device dimensions (cm) Centre hole size (cm2)Device height (cm) Top output size (cm) Lower output size (cm) Bioscanner design 3D printed device 1 Oval Major radius: 4.5 Minor radius: 3 42.41 2 1.5 1 2Rectangular base with two semicircles at the ends Device base: 8 Major end radius: 1 Minor end radius: 1.5 18.28 2 1.5 1 3.a Circular Radius: 0.941 2.78 1 0.3 0.3 3.b Oval Major end radius: 3.394 Minor end radius: 2.555 2.2 1.5 1 1 8 Vol:.(1234567890) Scientific Reports | (2020) 10:19862 | https://doi.org/10.1038/s41598-020-74213-7 www.nature.com/scientificreports/ Device Shape Device dimensions (cm) Centre hole size (cm2)Device height (cm) Top output size (cm) Lower output size (cm) Bioscanner design 3D printed device 4.a Circular Radius: 0.643 0.566 1.5 0.3 0.2 4.b Triangular Length: 6.330 Width:4.486 14.903 1.5 0.7 0.5 Table 2. Characteristics of each device. 9 Vol.:(0123456789) Scientific Reports | (2020) 10:19862 | https://doi.org/10.1038/s41598-020-74213-7 www.nature.com/scientificreports/ Figure2. Device placement in combination with negative pressure therapy. (A) Initial status of patient 4. (B) Insertion of the prosthesis in the polyurethane sponge and placement on the wound. (C) Application of a plastic sheet to cover the device and the sponge. (D) Hole in the internal part of the prosthesis that allows the intestinal material to escape. (E) Application of the vacuum system and application of stoma paste to preserve the vacuum. (F) Placement of an ostomy bag. (G) Implanted device with observed outflow of enteric material through the central hole of the prosthesis, with collects the ostomy bag. Vacuum therapy maintained in the upper part of the wound without enteric content. (H) Final outcome of patient 4.