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

Nasal Valve Collapse: Causes, Diagnosis, & External Valve Stenosis

 If you have a functional problem such as Nasal Valve Collapse caused by a previous surgeon (iatrogenic) this may be  due to over re-sectioning of bone &/or cartilage or due to weak or medially displaced lateral crura in the lower lateral cartilage. The Lower lateral cartilage is also referred to as the greater (major) alar cartilage. The Lower cartilage (The crura and lateral components together) have been perceived in different ways by surgeons from its frontal and basal views. The left and right lower cartilage can be viewed together as tripod or the M golden arches of McDonalds Corporation.. Modification of the M arch can in many ways modify the shape of the nasal tip. I believe there can never be enough diagrams so I will include some more illustrations here for better understanding.

Click on pictures for larger view

Causes of Valve Collapse

According to Dr. Gary Bennett, aging weakens the nasal sidewalls and causes the tip of the nose to sag. These changes can obstruct airflow inside the nose. Weak cartilage or cartilage turned inward can also predispose patients to nasal valve obstruction. The primary cause of nasal valve obstruction requiring surgery is previous nasal surgery. Taking down a large bump or decreasing a large tip can weaken support in the rest of the nose. Dividing the cartilage from the septum can cause scarring in the internal valve area that is very difficult to correct. Cosmetically, the nose may look great, but your breathing is still problematic. This can be avoided by choosing a surgeon trained to avoid and correct this deformity.
http://nycfacemd.com/nasal-valve-collapse-and-treatment/

Rhinoplasty, Postrhinoplasty Nasal Obstruction

Author: Thomas Romo III, MD, FACS
Coauthor(s): James M Pearson, MD,Paul Presti, MD, Haresh Yalamanchili, MD

External nasal valve collapse is due to collapse of the nostril margin at the opening of the nose (alar collapse) with moderate-to-deep inspiration through the nose. This phenomenon is usually observed in patients with narrow slitlike nostrils, a projecting nasal tip, and thin alar sidewalls.

This article focuses on only postrhinoplasty-related external valvular collapse. Constantian and Clardy reviewed 160 patients treated for external nasal valve incompetence. Surgical reconstruction was performed with septal cartilage or with composite conchal cartilage-skin grafts. Using rhinomanometry, Constantian and Clardy found that correction of external valvular incompetence increased total nasal airflow during quiet ventilation by more than 2-fold over preoperative values. Thus, the external nasal valve may play a crucial role as the cause of nasal airway obstruction in some patients.

Kern and Wang divide the etiologies of nasal valve dysfunction into mucocutaneous and skeletal/structural disorders. The mucocutaneous component refers to the mucosal swelling (secondary to allergic, vasomotor, or infectious rhinitis) that can significantly decrease the cross-sectional area of the nasal valve and thus reduce nasal airway patency. The skeletal/structural component refers to any abnormalities in the structures that contribute to the nasal valve area. This includes the nasal septum, upper and lower lateral cartilage, fibroareolar lateral tissue, piriform aperture, head of the inferior turbinate, and floor of the nose.
Skeletal deformity

Deformities that affect the external nasal valve

• Static deformity
  • Tip ptosis
  • Cicatricial stenosis
• Dynamic deformity
  • Collapsed lower lateral cartilage secondary to excessive excision
  • Nasal muscle deficiency

Physical examination

Identification of patients with nasal valve dysfunction can be difficult. Other more common causes of nasal airway obstruction should always be evaluated and treated as well. The classic maneuver in the evaluation of nasal valve collapse is the standard Cottle maneuver, which is used to assess nasal valve incompetence by judging improvement in nasal breathing with lateral distraction of the ipsilateral cheek. The problem with the standard Cottle maneuver is the results can be nonspecific. A straightforward narrowing of the nasal airway produced by septal deviation or turbinate hypertrophy is improved by the Cottle maneuver. Anterior rhinoscopy is also a poor means of accurately evaluating subtle changes in nasal valve anatomy; the dysfunctional nasal valve can be missed due to distortion from the nasal speculum.

External nasal valve collapse can be diagnosed based on observation of the nostril margin to determine if the alae collapse with moderate-to-deep nasal inspiration. One nostril can be occluded to facilitate this maneuver. Next, a modified Cottle maneuver can be performed with a cerumen curette placed intranasally to support the internal or external nasal valve to determine specifically if improvement in nasal airflow results. Minimal distraction of a collapsed internal valve or stabilization of the external valve during inspiration can dramatically increase airflow on the affected side and confirm the diagnosis. The patient can usually appreciate an immediate improvement in airflow when a flaccid or collapsible valve is supported during inspiration.

More recently, Hilberg et al introduced acoustic rhinometry as a noninvasive and reliable objective method for determining the cross-sectional area of the nasal cavity. Acoustic rhinomanometry is based on the analysis of sound waves reflected from the nasal cavities. Also, analysis can be done before and after topical decongestants are applied, allowing discrimination of mucocutaneous versus structural blockage. Standards for age, race, ethnicity and sex have been recently published.

http://emedicine.medscape.com/article/841574-overview#Classificationofnasalvalvedysfunction

External Valve Stenosis

Author:Alicia R Sanderson, MD

Co-Authors:Craig Cupp, MD, Peter A Weisskopf, MD

Etiology

Nasal valve collapse or obstruction has many potential etiologies. Some of the more frequent causes include the following:

• Deficiency of the lateral crus of the lower lateral cartilage secondary to previous surgery with overaggressive resection of cartilage
• Congenital deficiency of cartilage or cephalad rotation of lower lateral cartilage
• Trauma that leads to loss of tissue
• Full-thickness surgical resection of the alar with insufficient reconstruction
• Aggressive narrowing of the nasal tip during rhinoplasty (see the eMedicine article Rhinoplasty, Postrhinoplasty Nasal Obstruction)
• Caudal septal deflection that narrows the valve and causes increased velocity of airflow with a larger transalar pressure differential
• Facial nerve palsy that leads to loss of nasal dilators
• Sequelae of aging that leads to loss of nasal alar stiffness
• Overprojection of nasal tip that leads to slitlike nares with increased velocity of airflow

Pathophysiology

Any process, condition, or trauma that weakens the lower lateral cartilage or alar walls or that narrows the entrance to the nose can lead to collapse of the external valve. Upon inspiration, the increase in transmural pressure across the nasal ala leads to collapse of the external valve.

Indications
Any airway compromise caused by obstruction of the external nasal valve is an indication of external valve stenosis. The most absolute indication is the symptomatic collapse of the alar upon inspiration.
http://emedicine.medscape.com/article/877600-overview