Ear Reconstruction Simulation: From Handcrafting to 3D Printing

Abstract

Microtia is a congenital malformation affecting one in 5000 individuals and is characterized by physical deformity or absence of the outer ear. Nowadays, surgical reconstruction with autologous tissue is the most common clinical practice. The procedure requires a high level of manual and artistic techniques of a surgeon in carving and sculpting of harvested costal cartilage of the patient to recreate an auricular framework to insert within a skin pocket obtained at the malformed ear region. The aesthetic outcomes of the surgery are highly dependent on the experience of the surgeon performing the surgery. For this reason, surgeons need simulators to acquire adequate technical skills out of the surgery room without compromising the aesthetic appearance of the patient. The current paper aims to describe and analyze the different materials and methods adopted during the history of autologous ear reconstruction (AER) simulation to train surgeons by practice on geometrically and mechanically accurate physical replicas. Recent advances in 3D modelling software and manufacturing technologies to increase the effectiveness of AER simulators are particularly described to provide more recent outcomes.

Using 3D Printing Technology to Teach Cartilage Framework Carving for Ear Reconstruction

“…The interest initially appeared to favor material carvability above other mechanical properties, with readily accessible materials such as wood, apple, wax, and soap dominating early efforts (4,8,25). Though carvable, these materials are notoriously brittle and inelastic, failing to replicate the carvable nature of cartilage, and moreover lacking the necessary flexibility.…”

“…Whilst these materials offer a greater degree of flexibility, they suffer from key limitations. Rubber fails to replicate the geometry of costal cartilage and is unable to hold sutures, whilst dental silicone is expensive and difficult to carve ( 4 , 7 ). One of the greatest potential strengths of synthetic materials is the ability to cast into specific shapes and sizes using 3D printed molds, offering the potential for specific models based on patient data.…”

“…The complexity and variability of autologous auricular reconstruction means outcomes rely heavily on the experience of the operating surgeon. As such, there has been significant interest in developing models to facilitate the planning, teaching, and training of autologous auricular reconstruction (4). The use of simulation as a training tool is crucial to improving skills, increasing precision while ensuring effectiveness and safety of patient care (5).…”

“…In 2016, Berens et al ( 7 ) devised a low-cost, flexible and carvable composite material comprised of cornstarch and silicone sealant that was felt to closely resemble the desired properties of costal cartilage, such as firmness, carvability and bend required for surgical simulation. Previously explored options have included plant matter such as apples, potatoes and rubber ( 8 , 9 ); animal ( 10 , 11 ) and human cadaveric cartilage tissue ( 4 ) and synthetic materials such as polyurethane and silicone ( 7 , 12 , 13 ). There are limitations that hinder the use of many of these materials, including cost, inadequate replication of the mechanical properties and ethical considerations.…”

An analytical study of neocartilage from microtia and otoplasty surgical remnants: A possible application for BMP7 in microtia development and regeneration

“…Current ear reconstruction implements the use of autologous costal cartilage, Medpor or other prostheses for the auricular framework [6][7]. The surgical process requires advanced training because of its complex and challenging multiple stages [8][9][10][11][12]. Even though many innovations have improved these surgeries, complications and disadvantages for each type of current ear reconstruction still remain [13][14][15].…”