Development and State of the Art

History of Auricular Reconstruction

Ear reconstruction was first referred to in the Susruta Samhita [5], where a cheek flap was suggested for repairing the earlobe. As early as 1597, the Italian surgeon Tagliacozzi described and illustrated repair of both upper and lower ear deformities with skin flaps from behind the auricular region [102]. In Germany in 1845, Dieffenbach described repair of the ear's middle third with an advancement skin flap [41]. This may occasionally still have application today.

This early work focused mainly on traumatic deformities. However, by the end of the 19th century, surgeons began to address congenital defects, particularly prominent ears [43].

The origin of microtia repair had its significant beginnings in 1920, when Gillies buried carved homograft rib cartilage under mastoid skin, then separated it from the head with a flap of neck skin [49]. Pierce (1930) modified this method by lining the new ear's posterior surface with a skin graft and building the helix with a flap of rolled up skin [82]. Gillies (1937) repaired more than 30 microtic ears using ear cartilage from the patient's mother [50]; these were found to progressively resorb and disappear [32].

Young [108] and Peer [81] (1948) turned to autogenous rib cartilage, which they ingeniously diced and placed in a vitallium ear-shaped mold beneath the abdominal skin. After five months they retrieved the banked mold, opened it, and harvested the framework of cartilage chips, which had united by scar tissue that had grown through the mold's fenestrations. Although this framework's matricial scar contracted and the shape withered, this technique led to a wave of ear enthusiasm which again turned to homograft cartilage. Experiencing the same frustration of others [42, 63, 83], Steffensen (1952) used preserved rib cartilage to produce excellent results [92], but three years later reported progressive resorption of the same cartilage frameworks [93].

A major breakthrough came in 1959, when Tanzer rekindled using autogenous rib cartilage, which he carved in a solid block [96]. His excellent results have persisted during the years (see Fig. 10).

In an effort to circumvent the significant operation to harvest rib cartilage, Cronin (1966) introduced silicone ear frameworks [36], but found that, like other inorganic implants (e.g., polyethylene, nylon mesh, Marlex, polyester net, and Teflon), they suffered a high incidence of extrusion [69, 99]. Initially, Cronin minimized this problem by covering the framework's rim with extra tissue grafts and flaps [37], but later when he found that the alloplastic frames still extruded he discontinued this practice and stopped using them altogether.

To this date, autogenous cartilage remains the most reliable material that produces results with the least complications [13, 14, 20, 47, 46, 96, 97, 98]. Although various donor sites (including the knee!) [75] have been used for harvesting the cartilage, only rib cartilage provides a substantial source for fabricating a total ear framework. Even contralateral ear cartilage (from the conchal "bowl") has been used for this purpose [38, 51], but I feel it is best to reserve auricular cartilage for repairing small partial ear defects, for which considerably less tissue bulk is needed [9, 12, 22].

Although Tanzer began his pioneering work in ear reconstruction somewhat late in his career and therefore only operated on 43 microtia patients, his results were excellent. Building upon Tanzer's sound principles, I continue refining and evolving the use of rib cartilage and have created frameworks for more than 1,700 patients during the years [23, 27]. Other dedicated proponents of rib cartilage from various parts of the globe include Firmin [47], Osorno [80], Nagata [78]; Weerda and Siegert [105].

Six-year-old patient and his uncle. I repaired the boy's microtia exactly 30 years after his uncle's microtia was repaired by my mentor and friend, Dr. Radford Tanzer.

Ear Framework "Pre-Fabrication:" Is this the future?

For many years there has been considerable interest in creating a "pre-fabricated" framework from autogenous cartilage in order to circumvent the necessity to fabricate an ear framework during a prolonged reconstructive procedure, and to attempt to eliminate the variability of the surgeon's artistic ability to create a realistic ear framework from rib cartilage. As briefly mentioned in the history of ear reconstruction above, Young [108] and Peer [81] first conceived the idea of "framework pre-fabrication" prior to the actual auricular reconstruction way back in the 1940s. This innovative technique was accomplished by means of "diced" pieces of autogenous rib cartilage that were placed in a two-piece, ear-shaped metal mold that, in turn, was "banked" in the patient's abdominal wall. After several months they retrieved the banked mold, opened it, and harvested the framework of cartilage chips, which had united by scar tissue that had grown through the mold's openings. However, the results were not consistent, perhaps because contraction of the fibrous tissue surrounding the multiple cartilage islands distorted the resultant framework.

Recently, interest in this "pre-fabrication" concept has been rekindled via modern "tissue engineering" techniques in which cartilage cells are grown in the laboratory and seeded upon a synthetic ear form which is then implanted beneath the skin of a mouse [29]. The early results are interesting, but one should note that the trial work is not being carried out under the same conditions as in a human ear reconstruction; the researchers' frameworks are being placed under the very loose skin of an animal's back, whereas in human ear repair, the new framework must be placed underneath snug skin just in front of the hairline in the ear region. Unlike the loose skin of an animal's back, that skin is very tight and will flatten out any framework that consists of flimsy material.

Although these new laboratory studies are intriguing, unless a very solid, substantial three-dimensional framework can be produced from autogenous tissues, it will likely suffer the same consequences I observed for frameworks created by Peer's method, i.e., flattening out under the restrictive, two-dimensional skin envelope under which the framework must be placed to complete the ear reconstruction. The other obvious limitation of "pre-fabricated" ear frameworks is the difficulty of accommodating the great variation in size and shape that must be produced to match the opposite, normal ear. When sculpting directly from rib cartilage, these limitations do not exist because the surgeon creates the required specific size and shape each time.

However, I am intrigued with the concept of creating a living "prefabricated" ear framework, and I have collaborated with researchers to explore the possibilities of bioengineering firm, autogenous cartilage frameworks, to see if some of the above-mentioned limitations can be overcome.[27a]