Sources and sites used for constructing nasal grafts: Generally accepted principles

Decision Tree (algorithm) for revision rhinoplasty [4]

The subject of which is the  best material to improve or rebuild the support structures and./or improve cosmetic look of the nose (assuming deficiency of septal cartilage for replacement which is the gold standard) is one that is controversial amongst nose surgeons. It's also too vague a question since certain area's of the nose tolerate different specific type of material grafts or from different loci sites better then other area's of the nose. For example "in a study with leprosy patients [1] autogenous costal cartilage shield grafts underwent more resorption (55%) than auricular grafts (23%). Auricular cartilage is probably more resistant to resorption caused by micro-trauma and stresses from the overlying soft tissue envelope in the nasal tip area than Irradiated homologous rib grafts (IHRG) and autogenous costal cartilage." Costal cartilage however is excellent source for major dorsal augmentation, or spreader grafts, when prepared properly to avoid warping. IHRG is also shown to work better (less resorption) when used for dorsal augmentation where it's virtually static then in other more mobile parts of the nose ie. Lateral wall. Even with silicone implant, facial plastic surgeons [2] claim that silicone dorsal graft (l shaped ) is safer then silicone L strut in rebuilding the nasal profile. Some studies suggest Gortex is superior overall when compared to other synthetic implants, while some surgeons like medpore in limited use for dorsal augmentation.Some surgeons use K-wire to avoid warping in costal cartilage and when used for columellar strut graft  the surgeon drill's a hole into your upper jaw (premaxillary) to attach the K-wire for added stability. However most nose surgeons who harvest costal cartilage prefer to not use K-wire, and instead carve the cartilage from the center to avoid warping. Carving is performed in a symmetric fashion using the central core of the rib (as opposed to the peripheral area) to minimize warping. Allowing the rib to soak in saline in regular intervals during the carving stage allows it to warp and thus the carving may be tailored. Another issue to note with costal cartilage is that the cartilage becomes calcified and harder to carve as we age. There's no set age when this happens, as it varies from person to person, but generally after the age of 45 some calcification will be present. Upside to this is if it can still be utilized then the chances of warping is decreased. Even ear cartilage can become more brittle and difficult to shape as we age. Some surgeons like to dice the rib cartilage and then wrap it in Deep temporal fascia or use Tasman method. Those methods work very well for dorsal augmentation.

*** NOTE: DICED RIB CARTILAGE IS NOT MEANT FOR STRUCTURAL SUPPORT. ie. spreader, lateral crura strut or batten graft. FOR THAT YOU NEED SOMETHING STRONGER LIKE SOLID PIECE OF SEPTAL, OR RIB CARTILAGE FOR THOSE NEEDING STRONG SUPPORT. EAR CARTILAGE IS USED MORE IN THE LOWER THIRD OF THE NOSE AND FOR CASES THAT DON'T REQUIRE STRONG SUPPORT. THIS IS VERY SUBJECTIVE AND WHERE SURGEONS HAVE VARYING OPINIONS ABOUT LOCATION OF HARVESTING THE GRAFT.

So as you can see our own personal circumstance also weighs in quite heavily when the surgeon decides which grafts will be used and which won't. Another major factor as to what a surgeon will prescribe for grafting depends on his/her level of expertise and training. Some nose surgeons were never trained to harvest autologous body grafts therefore prefer to restrict their use to synthetic implants or cadaver (homologous grafts) , some have no experience with synthetic grafts and limit their practice to auto and allografts, some only septal and ear, and very few will have experience with many different types of autologous grafts and will eventually specialize in using some of the following; septal, ear, rib, calvarial bone, Iliac crest grafts, diced with fascia, crushed cartilage, composite grafts, and soft tissue grafts. Not only is there differing opinions about the material composition of the graft to use, but as well as to the actual TYPE of graft to use. ie. In case of increasing Lateral support to correct Nasal Valve Collapse, some will recommend Lateral crural strut graft, some prefer Alar or Sub-Alar batten graft, some like Butterfly graft, or may recommend a Spanning Alar graft.  Specific indicators after thorough examination of the overall nose & being cognizant of what the desired goals are, the surgeon will determine which type of graft would be most appropriate. With experience surgeons will become more proficient  and favor certain methods over others, some even modifying &/or developing new procedures. For those that are younger and have never had septal cartilage removed, you are in superior position (assuming all is equal) for revision nose surgery, compared to someone who is over middle age and no septal cartilage to work with. 

Some patients online have claimed that when they had costal cartilage in the columellar there smile was negatively affected. That however could be due to improper placement or size of the graft,  being too wide or long. If too large of a solid graft  is used in tip area, there will be increase risk of extrusion and/or skin necrosis.

Some surgeons also seem more proficient with sutures while others are more adept at grafting. ex.. An alternative for alar batten grafts is the Lateral crus pull-up. It is a suture technique in which the lateral crus is pulled up laterally and upward to the bony pyramid. The effect is twofold widening of the valve area and strengthening of the lateral wall [3]. In some cases instead of using a Lateral crura strut graft, the cephalic lateral crus can be reorientated to give support and correct aesthetic defects. Gruber et al ^[5]created an “island” of cephalic lateral crus that was slipped under the main body of the lateral crus to stiffen and straighten it. They suggest that the cephalic part of the lateral crus can act as a lateral crural strut to maintain the ala in a more caudal position  Tongue in groove is another popular suture technique used to aid in correction of columellar show, a deviated caudal septum, and various tip rotation and projection problems. It is typically used in combination with other septorhinoplasty maneuve. Many surgeons utilize both grafting and complicated suture techniques during surgery for optimal cosmetic and structural results.

It can be very daunting task to figure all this out and getting opinions online like on realself.com which is a great site, demonstrates how widely surgeons opinions and approaches vary, sometimes even contradicting each other. As in the example in dorsal augmentation there are many choices (autografts; bone, solid or diced cartilage, soft tissue, homografts, alloplasts,)  available to choose from  as I mentioned earlier. Beware though, that in some cases the surgeons are not simply contradicting each other, but suggesting a better alternative to correct  specific problem(s) for specific type of individuals. Some surgeons will  use whats called superficial muscular aponeurotic system. (SMAS) graft.(more applicable and useful for those with THICK SKIN) which is an autologous soft tissue filler onlay graft,  while others may use crushed cartilage for onlay graft. Some nose surgeons recommend Fascia Lata  over bone grafts in dorsal augmentation because it's a heavier fascia which is better to conceal the rigidity of a bone graft. Some may suggest Lateral crural strut graft because it corrects few problems at once, like narrowing a bulbous tip, and strengthening a  weakened nasal valve.  A competent revision nose surgeon will be knowledgeable and able to perform many types of grafts, sutures, flaps, and other septorhinoplasty modifying techniques [I.E. Lateral crural steal (LCS) & Lateral crural overlay (LCO)/Medial crural overlay (MCO)]and know which alternative method to apply according to  each individual's specific case. What they discover esp. in revision rhinoplasty during surgery may justifiably cause them to alter or add/subtract to their pre-surgical plans. A good surgeon should be prepared for worse then expected scenarios. ie. during surgery the surgeon discovers that the patient's  lower cartilages need to be reshaped, repositioned, or totally replaced with new cartilage.

This algorithm (above) reflects Dr.W.H..Beeson's preferences

Generally Accepted Principles for Nasal grafting:

1. Your own body is best source for grafts (bone,cartilage, soft tissue). Referred to as Autografts also known as Autogeneous, Autologous grafts. Best site within your body for nose grafts, is the septum. If there isn't enough septal cartilage, then other options are; Rib, Ear, or Calvarial as mentioned above.
2. Allografts/Homografts/Homologous-irradiated(cadaver grafts) are another good source for cartilage but work better in the immobile regions of nose.Alloderm (skin cadaver graft) has high absorption rate.
3. Synthetic implants (Alloplasts) Types: Silicone, Meshed, Porous, Porous high density polyethylene (PHDPE;Medpor),Expanded polytetraflouroethylene (e-PTFE ;GoreTex). Which is preferred is debatable amongst surgeons. GoreTex seems to be best of the choices, but some like Medpor. Silicone/Silastic implant which has been used extensively in Asian rhinoplasty is losing favor due to high rates of infections and extrusions. Meshed are also not favored due to infection rates. Medpor can be a problem when needed to be removed due to it's modest porosity. Higher porosity values means it integrates more with surrounding tissue therefore more difficult to remove without causing more damage or removal of surrounding tissue. This is why GoreTex may be preferred since it has a low porosity value. Silicone has no porosity so remains separated and unfixed. It however carry's significant risk of extrusion, higher in columellar area then dorsal area, and is not meant for structural support.
4. Xenografts is from another species mostly from bovine (cattle) or porcine (pigs). Eg. Enduragen is a tough but flexible biomaterial made up of cross-linked porcine dermal collagen and its constituent elastin fibers. Its use is indicated for tissue augmentation of the head and face, and it is commercially available in flat sheets.   Permacol is another type made by different manufacturer. There is risk of allergic reaction to such type of material. To my knowledge not commonly used in Nasal revision surgery.
5. Soft tissue filler is normally preferred from own body. ex. fascia grafts
6. Bone graft, like cartilage, can be used for augmentation and as a supportive structural framework for nasal tip and internal nasal valve support. Generally considered a second choice after autogenous cartilage.
 Note: In every case the Surgeon has to weight the pros/cons so their may be justifiable exceptions to the above list. Important that the surgeon & patient discuss all the options which relate to the patient's circumstances.

Open Approach to nose surgery has become more popular allowing clear visual inspection, ease of access to existing structures, & allowance for implanting larger sized grafts. This could lead however to more unnecessary over grafting of the nose. Closed Approach advantages are no scarring, less dissection which is important for those who have had prior nose surgery therefore less damage to soft tissue,vascular, & innervation system of the nose, and faster healing period. More conservative methods are being employed today compared to past, where a lot of reductive surgery was performed, without taking into account supporting structure of the nose.Today astute  nose surgeons are even placing grafts in some primary surgery's to avoid long term pitfalls.

Future: 

• Preserved cartilage for future surgery. Primary & Revision patients should request for their surgeons to preserve cartilage that may be removed and not re-used during the surgery. 

•  Tissue engineering

***Here's an excellent slideshow you should watch: ***

This slideshow called Grafts in Nasal Surgery by Dr. D.J.Menger What I really like about it, is how he mentions in some cases his preference of cartilage grafts. He doesn't mention synthetic material, so I gather that would be his last preference.
http://www.slideshare.net/therhinoplastycourse/grafts-in-nasal-surgery


 ©noserevisionsurgeryandsurgeons.blogspot.ca
Interesting site's to look at:

http://www.egms.de/static/en/journals/cto/2011-9/cto000065.shtml

http://www.shimmianmanila.com/side-effects-of-silicone-implant
References;
[1] Menger D.J., Fokkens W.J., Lohuis P.J., Ingels K.J., Nolst Trenité G.J. Reconstructive surgery of the leprosy nose: a new approach. J Plast Reconstr Aesthet Surg. 60(2):152-62, 2007
[2] http://www.realself.com/question/Best-material-nose-implant
[3] Grafts in Nasal Surgery p.77 D.J.Menger
[4] Chapter 30:  Revision Surgery in Otolaryngology by David Edelstein
[5] Gruber RP, Zhang AY, Mohebali K. Preventing alar retraction by preservation of the lateral crus.  Plast Reconstr Surg. 2010;126(2):581-5