Date Published: April 12, 2018
Publisher: Springer International Publishing
Author(s): Abel De La Peña, Javier De La Peña-Brambila, Juan Pérez-De La Torre, Miguel Ochoa, Guillermo J. Gallardo.
Cranial defects usually occur after trauma, neurosurgical procedures like decompressive craniotomy, tumour resections, infection and congenital defects. The purpose of cranial vault repair is to protect the underlying brain tissue, to reduce any localized pain and patient anxiety, and improve cranial aesthetics. Cranioplasty is a frequent neurosurgical procedure achieved with the aid of cranial prosthesis made from materials such as: titanium, autologous bone, ceramics and polymers. Prosthesis production is often costly and requires complex intraoperative processes. Implant customized manufacturing for craniopathies allows for a precise and anatomical reconstruction in a shorter operating time compared to other conventional techniques. We present a simple, low-cost method for prosthesis manufacturing that ensures surgical success.
Two patients with cranial defects are presented to describe the three-dimensional (3D) printing technique for cranial reconstruction. A digital prosthesis model is designed and manufactured with the aid of a 3D computed tomography. Both the data of large sized cranial defects and the prosthesis are transferred to a 3D printer to obtain a physical model in poly-lactic acid which is then used in a laboratory to cast the final customised prosthesis in polymethyl methacrylate (PMMA).
A precise compliance of the prosthesis to the osseous defect was achieved. At the 6 month postoperative follow-up no complications were observed i.e. rejection, toxicity, local or systemic infection, and the aesthetic change was very significant and satisfactory. Customized 3D PMMA prosthesis offers cost advantages, a great aesthetic result, reduced operating time and good biocompatibility.
Loss of a body part has significant repercussions for any individual. The absence of a body part has a great influence in a person’s physical state and state of mind, and causes social interaction difficulty; which frequently limits their hope of recovery . Lack of continuity of the cranial vault bones is usually secondary to severe head injury, but can also be secondary to neurosurgical procedures e.g. decompressive craniotomy or tumor resection. Infections, especially osteomyelitis and congenital anomalies or iatrogenic disorders can cause these type of defects .
Two patients, both with large cranial defects (> 100 cm2) underwent a cranioplasty with individually customized prefabricated molds generated from a 3D printed template. A description of some main characteristics of the cranial prostheses can be seen in Table 1.Table 1Description of cranial prostheses characteristicsAnalysisCase 1Case 2Intraoperative adjustment time8 min16 minPrecision to cranial defectExactExactIntraoperative exothermic reactionNoneNoneCranial symmetryExactExactCostLowLowThe left-hand column specifies the parameters that were evaluated on each prosthesis. This type of cranial vault reconstruction requires little trans-operative adjustment time, since most adjustments are done pre-operatively, and the prosthesis adapts precisely to the defect (this was measured by tracing the prosthesis and its adjustments on to a millimeter paper), restoring cranial symmetry to perfection (a comparison of the intact side against the side with the defect) without the burden of an exothermic reaction on brain tissue, and minimal production cost
Hand-manufacturing of a prosthetic implant can only be carried out if the original cranial bone fragment is available. Since the cases treated at our Hospital presented with fragmented cranial fractures, bone preservation was implausible.
For years, prefabricated customized cranial prostheses using 3D printers have demonstrated their use and advantage when compared to other techniques. In the Hospital Civil de Guadalajara Fray Antonio Alcalde, a group comprised of researchers and surgeons work together to obtain low-cost customized implants since titanium and PEEK (polyetheretherketone) prosthesis are too expensive for the type of population we treat.