Cartilage very often needs to be harvested in rhinoplasty and ear reconstructive surgeries. Even in elective aesthetic rhinoplasty, the use of cartilage grafting is quite frequent. While the septum is often the best source of cartilage graft harvest, it may be depleted from prior surgeries or may simply not have enough graft volume. This then entails going to the ear or even the rib with the tradeoff of some additional scar and discomfort.
In the April 2014 issue of Lancet, an article was published entitled ‘Engineered Autologous Cartilage for Nasal Reconstruction after Tumour Resection: An Observational First-In-Human Trial’. In this reported clinical study in humans, five patients underwent nasal reconstruction after excision of non-melanoma skin cancer that took more than 50% of the alar lobule. Chondrocytes were initially harvested from the patients’ nasal septum (at time of tumor biopsy) and grown in culture over a four week period. This created engineered cartilage grafts of a size of 25mm x 25mm and 2mms thick. These grafts were then used under local flap reconstruction of nasal defects. During subsequent flap revisions, biopsies and one year assessment of the implanted cartilage grafts were done. The results showed that the histology and reconstructive stability of the cartilage grafts were adequate and comparable to an autogenously harvested cartilage graft.
Growing tissues in cell culture has long been and continues to be a lofty surgical ambition. To be able to make the tissues or organ needed for reconstruction would spare the need for a donor site harvest. Cartilage has been grown in cell culture for decades and its theoretical benefits have been touted numerous times with the most famous example of an ear being grown on a mouse’s back. But the jump as not yet been made to its use in humans. This paper is the first to do so and to demonstrate the use of engineered cartilage.
While the size of the nasal cartilage defects in this paper could have been done just as easily with septal cartilage harvested at the time of surgery, the use of relatively small nasal defects is a safe start on which to build future efforts.
The biggest challenge for engineered cartilage would be in subtotal or complete ear reconstruction. This is the single greatest cartilage graft done in humans and always involves the harvest of ribs for the ear reconstruction. Making a whole ear framework for implantation is a great cartilage engineering challenge but would be a supreme test of the technology.
Dr. Barry Eppley
Indianapolis, Indiana