Allografts and the risks of infection and disease transmission

Here is some valuable information on the risks associated with implantation of allografts [i.e. cadaver grafts in nose surgery]

 AAOS 2004: All About Allografts -- Select Highlights of the 71st Annual Meeting of the American Academy of Orthopaedic Surgeons

 Controlling Infection is Crucial

In limiting infection during allograft procedures, it is important to determine whether the tissue bank that you or your hospital is using is a member of the American Association of Tissue Banks (AATB). This organization requires that its members perform full screening that meets US Food and Drug Administration requirements; however, secondary sterilization of the grafts is still optional. Not all tissue banks are members of AATB, and not all tissue banks are inspected. The review by Vangsness and colleagues^[2] describes the process of procurement, processing, and storage, and should be required reading for anyone who is using allograft tissue. Be sure that you know your tissue bank and its procedures.
Infection of tissue can be controlled by screening the tissue donor and through secondary sterilization of the tissue. At this time, we can screen for both hepatitis B and C, which should prevent infection by these entities. There have only been 2 cases of HIV infection through allograft tissue, and both of these incidents occurred in the 1980s. These reported infections occurred with frozen bone as the vector, but none of the freeze dried grafts from the same donor transmitted the disease. The AATB has formulated guidelines for their members; these guidelines recommend donor screening.

There are a number of methods and federal guidelines for storing tissue after procurement. The methods of storing the tissue are: fresh frozen, deep frozen, freeze dried, demineralized, and proprietary treatments, such as CryoLife (CryoLife Inc., Kennesaw, Georgia

Factoring Relative Risk
The risk of hepatitis B after blood transfusion is 1/63,000. The risk of hepatitis C is 1/100,000, and the risk of HIV is 1/1,000,000. The risk of HIV after bone transplantation is 1/1,500,000. The risk of HIV after soft tissue transplantation is 1/1,600,000 with secondary sterilization.
To put this in the proper perspective, one should remember that the risk of death due to pregnancy is 1/10,000, the risk of death from administration of penicillin is 1/30,000, and the risk of death with oral contraceptives is 1/50,000. In fact, it may be more dangerous driving to the hospital than receiving a bone graft at the hospital.
In summary, allografts are a valuable treatment option for today's orthopaedic practice. The academy believes allografts to be safe if used within the guidelines, when they are supplied by an accredited tissue bank, and if the appropriate surgical techniques are employed.

How safe are soft-tissue allografts?

By C. Thomas Vangsness Jr., MD

 Although several cases of viral infection—specifically human immunodeficiency virus (HIV), viral hepatitis, and human T-lymphotropic virus (HTLV)—have been reported, these transmissions occurred before the guidelines for donor screening for viruses and bacteria were implemented and before the availability of currently validated serologic tests.

Sterility is expressed as a mathematic probability of relative risk. According to the FDA, a sterility assurance level (SAL) of 10-3 means there is a 1 in 1,000 chance that a nonviral viable microbe exists in or on the implanted material. The Association for the Advancement of Medical Instrumentation (AAMI) states that an SAL of 10-6 (one in a million chance) in organisms is more desirable. The American Association of Tissue Banks (AATB) requires an SAL of 10-6 for tissue bank allografts.

Contamination of the graft can also occur during the final handling and packaging of tissue. Gamma irradiation is commonly used to terminally sterilize allograft tissue with lower doses of radiation.

Freeze drying (lyophilization) is a preservation process that allows tissues to be stored at room temperature. Lyophilization freezes the tissue and reduces the water content to less than 6 percent of initial weight through a primary drying process (sublimation) and a secondary drying process (desorption). Although freeze-dried allografts (lyophilized grafts) are not commonly used for sports medicine applications in the United States, this process is commonly used with soft-tissue patches.

With improved donor screening techniques, such as nucleic acid testing (NAT), the current risk of transplanting tissue from an HIV-infected donor is reported to be between 1 in 1 million and 4 in 1 million.

According to a recent AATB survey covering data from 2003 to 2004, the current risk of an allograft infection to the average patient appears to be much less than the risk of infections surrounding the surgery itself. According to the report, there were 192 reports of suspected allograft-related infections in 2003-2004; 42 percent involved soft-tissue grafts and 37 percent involved bone grafts, with an overall incidence of 0.014 percent. Currently, better reporting of infections is actively under investigation to improve the accuracy of these numbers.

Do not do routine culturing of allograft tissue in the operating room immediately prior to implantation. These cultures are documented to be inaccurate and may reflect the native airborne or backtable contamination.

Musculoskeletal tissue regeneration: biological materials and methods  By William S. Pietrzak, Charles A. Vacanti

Although the risk is low, bacteria, hepatitis, HIV, and syphilis can be transmitted from donor to recipient. There is also the theoretical possibility of transmitting slow viruses (prions) with allograft use.
Irradiation of the soft tissue allografts with high dose (>3Mrad) radiation can sterilize allograft tissue, destroying bacteria and viruses including HIV and hepatitis. Bone plug allografts may still be capable of transmitting hepatitis despite treatment with 3 Mrad irradiation. Although, allograft irradiation will reduce the risk of disease transmission, it does so at the expense of diminishing the biomechanical properties of the tissue. Newer screening tests such as polymerase chain reaction (PCR) and nucleic acid testing (NAT) improve the detection of viral and bacterial DNA and RNA, and many increase the accuracy of identifying infected donor tissue and minimizing false-negatives. By improving the sensitivity and specificity of infected donor  tissue identification, the risk of bacterial and viral disease transmission should be less, thereby increasing the safety of allograft use. These newer techniques could potentially decrease the need for graft irradiation and other sterilization techniques that many affect allograft properties.

Surgeons can minimize complications associated with infected allograft tissue by only using tissue processed from a tissue bank accredited by the American Association of Tissue Banks (AATB). It is imperative that surgeons know the source of their allograft tissue, particularly if they rely on the hospital or a surgery center to obtain the allograft tissue for their patients.

http://www.aaos.org/news/bulletin/aug07/clinical1.asp

http://www.medscape.com/viewarticle/491618

http://books.google.ca/books?id=2qq56LYomagC&pg=PA397&lpg=PA397&dq=RISK+OF+TRANSMITTED+DISEASE+WITH+ALLOGRAFTS&source=bl&ots=cU9MnbRoBB&sig=KSY91n5fKiD2lVksKSU6A8vG204&hl=en&ei=iqHuTMmwAcnFnAf0u5jwCg&sa=X&oi=book_result&ct=result&resnum=10&ved=0CFIQ6AEwCTge#v=onepage&q=RISK%20OF%20TRANSMITTED%20DISEASE%20WITH%20ALLOGRAFTS&f=false

Using freeze dried bone grafts for Nasal Dorsal Augmentation

Recently in a PRSjournal a study was conducted and reported by Dr.Richard Clark called Nasal Dorsal Augmentation with Freeze dried allograft bone. Non irradiated freeze dried bone typically comes from tibia and femur shafts (more specifically cortical shafts).

Here's some general background information on bone grafts.

Type of Grafts:

Per definition there are four types of grafts, i.e. autografts, allografts, alloplasts and xenografts:

Autografts refers to tissue transplanted from one site to another
within the same individual.
Allografts are obtained from cadavers or living individuals from the same species. In human medicine they can be obtained from tissue banks (KÜBLER 1997).
Alloplasts are synthetic materials consisting of biological inert substances.
Xenografts are composed of tissue taken from another species (i.e. from an animal source, usually bovine). In case the organic material is removed from xenogenic bone, it may be considered as an alloplast (GARG 1999).
The term 'composite grafts' refers to grafts that are composed of materials from different origins, usually autogenous bone mixed with other materials (HABAL1991).

Depending on where the bone graft is needed, a different doctor may be requested to do the surgery. Doctors that do bone graft procedures are commonly orthopedic surgeons, otolaryngology head and neck surgeons, neurosurgeons, craniofacial surgeons, oral and maxillofacial surgeons, and periodontists.^[9]
There are three types of bone allograft available:

1. Fresh or fresh-frozen bone
2. Freeze-dried bone allograft (FDBA)
3. Demineralized freeze-dried bone allograft (DFDBA)

Freeze dried bone describes the method used to process the bone, not the source, and there is freeze dried bone available that comes from cadavers.

The most commonly used allograft is demineralized and freeze-dried bone.
The latter is used for minimising the antigenicity (BLOCK and POSER 1995), resulting in a demineralized bone matrix (DFDBA).

Freeze-drying and gamma irradiation are the techniques widely use in tissue banking for preservation and sterilization of tissue grafts respectively.
Frozen allografts are stored at temperatures below −60°C,
which decreases enzyme degradation and host immune response.
Freeze-drying involves removal of water from the tissue
with subsequent vacuum packing and storage at room temperature.

Some medical terminology:
➤Osteoinduction is a process that supports the mitogenesis of undifferentiated mesenchymal cells, leading to the formation of osteoprogenitor cells that form new bone.
➤ The human skeleton has the ability to regenerate itself as part of the repair process.
➤ Recombinant bone morphogenetic protein has osteoinductive properties, the effectiveness of which is supported by Level-I evidence from current literature sources.
➤ Osteoconduction is a property of a matrix that supports the attachment of bone-forming cells for subsequent bone formation.
➤ Osteogenic property is a relatively new term that can be defined as the generation of bone from boneforming cells.

For more info on bone grafts:
http://www.master-biomed.ethz.ch/education/bio_courses/Mechanobiology/DeLong_et_al_2007.pdf

http://dare.ubn.kun.nl/bitstream/2066/18869/1/18869_autoboanb.pdf

Related articles: 

Does Type of Bone Graft Used in Spinal Fusion Increase Risk of Infection?
http://activemotionphysio.ca/Injuries-Conditions/Lower-Back/Research-Articles/Does-Type-of-Bone-Graft-Used-in-Spinal-Fusion-Increase-Risk-of-Infection/a~2442/article.html 

Effect of freeze-drying and gamma irradiation on the mechanical properties of human cancellous bone 
http://www.ncbi.nlm.nih.gov/pubmed/10937629 

Bone graft substitutes
http://books.google.ca/books?id=QnCbGDbl-UwC&pg=PA46&lpg=PA46&dq=freeze+dried+bone+non+irradiated&source=bl&ots=nwVtoPS1vS&sig=DyEXoQ0s_QHAzC042e3ltfQMdyo&hl=en&ei=R6TtTLa3MIvDnAeAoZyRAg&sa=X&oi=book_result&ct=result&resnum=8&ved=0CFYQ6AEwBw#v=onepage&q=freeze%20dried%20bone%20non%20irradiated&f=false

According to Dr.Clarks site; 

Dr. Clark has currently published pilot study using freeze dried and frozen bone to augment and straighten the nasal dorsum (bridge). Dr. Clark uses American Bone Bank approved treated bone which has an excellent history of use in orthopedic surgery for over 10 years without transmission of any disease or rejection of implants. (For details of the extensive evaluation of bone donors and cleansing of the bone, please contact Dr. Clark.) The first patient receiving a dorsal implant with a frozen bone was in June, 2004. That patient's bone graft remains in perfect position and has maintained it's size and remains thus far to be a success. This bone graft has revascularized and become live healthy bone. We are following over 10 patients with excellent results, and time will tell as to whether this will be an answer to the quandary of dorsal augmentation, and we remain very hopeful.

 http://www.ncbi.nlm.nih.gov/pubmed/19935318

Techniques used to lessen the degree of rib (costal) graft warping in nose surgery

Rib carving is a tedious procedure, says Dr. Paul Nassif in this video. He soaks the rib graft in normal saline solution to soften it up and gives you the curve of where the cartilage is going to go.  The inner cortex of rib has less chance of warping, so its left intact. For rim grafts you need to carve the cartilage which is very delicate process, since you have to make sure the graft doesn't end up splintering.


Symmetric carving of the costal cartilage graft will minimize the chance of the graft warping over time.

Here's an interesting study on comparison of  warping after using different techniques of carving.  Concentric grafts warped less than Eccentric grafts.

David W. Kim, MD; Anil R. Shah, MD; Dean M. Toriumi, MD

  http://www.shahfacialplastics.com/carvedcostal.html

Dr.Jack Gunter, has devised a technique in which the larger grafts, the dorsal onlay graft and the columellar strut, are reinforced with a centrally placed Kirschner (K)- wire to decrease warping and provide a more stable and predictable result.
"Graft warping can occur in autogenous rib cartilage and lead to long-term postoperative distortions of nasal shape. The use of stabilizing K-wires placed through the center of these grafts has been a successful technique to counterbalance the tendency of the grafts to warp. To avoid warping of smaller grafts, we follow the principle of carving balanced cross-sections originally described by Gibson and later substantiated by Kim et al"
 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2884866/

 http://journals.lww.com/plasreconsurg/Abstract/1997/07000/Internal_Stabilization_of_Autogenous_Rib_Cartilage.26.aspx

Control of grafted rib cartilage warping using K wire by Dr. A. Nakamura
http://www.springerlink.com/content/t33w777gk6668438/

More info regarding techniques to avoid warping of costal grafts:

Controversies in Otolaryngology: By Myles L Pensak
http://books.google.ca/books?id=xJNDV-KxYjcC&pg=PA176&lpg=PA176&dq=how+to+avoid+rib+warping+k+wire&source=bl&ots=yqnbTNt4GH&sig=M50C2vLAynJ_zlsAvkUBkhIlY90&hl=en&ei=_Z_TTLW5KIzCnAfTwLyOBg&sa=X&oi=book_result&ct=result&resnum=3&ved=0CCIQ6AEwAg#v=onepage&q=how%20to%20avoid%20rib%20warping%20k%20wire&f=false

Revision Rhinoplasty: By Daniel G. Becker, Stephen S. Park
http://books.google.ca/books?id=vwHmwB8qSeAC&pg=PA112&lpg=PA112&dq=how+to+avoid+rib+warping+k+wire&source=bl&ots=wJ4csX9UTT&sig=AY6roDDVffKe5bniZhAz3neSmAM&hl=en&ei=_Z_TTLW5KIzCnAfTwLyOBg&sa=X&oi=book_result&ct=result&resnum=6&ved=0CC4Q6AEwBQ#v=onepage&q=how%20to%20avoid%20rib%20warping%20k%20wire&f=false

Non surgical, non-medical treatment for collapsed nostrils (nasal valve collapse)

Image via Wikipedia

One, if not the most difficult thing to do is find a non medical device that will help you breath, especially when you have a nostril that is collapsed or weakened (nasal valve collapse-internal or external), or septum which deviates to one of the sides. It for me, especially has become a challenge when i become congested on my worse side which is often, and probably a secondary condition to my nasal collapse. My collapsed side is very narrow more so in middle section with a septum that already deviates towards it, which then doesn't allow enough space to breath properly especially when the turbinates start to swell creating blocked up congestion leading to post nasal drip. One factor that I realize that aggravates this problem is salt. After eating a meal high in salt, my collapsed side gets worse. Another factor is humidity. I've noticed after a shower, i can become congested as well, but not as bad now since my turbinates were partially removed. Cold weather can be another factor. Over the nearly 30 years of suffering with my nose, i have tried different treatments and have had surgery's along the way, which changes the way your nose will respond to treatments as well. Other factors could be allergic reaction to dust, strong scents, a pet, etc etc... I have been on non steroidal sprays which don't work for me as effectively as it once did since my last surgery but still works at times. I also use to take anti inflammatory medication which seemed to give a little relief. When all else fails i would take my over the counter (otc) decongestant nose spray. Problem with that spray however is after taking it for few days straight it causes rebound congestion, making my problem much worse for days. I also use a ocean spray nasal mist every day to hydrate my nose, which is important if you've had nose surgery and experience some degree of dryness. Problem again is all these liquid sprays can and for me does cause post nasal drip. Occasionally instead of the otc decongestant spray i will take otc decongestant pill in its place. This can be better option at times, however the pill form can still cause rebound congestion if taken too often and has other side effects which affect your blood pressure, and even you heart rate.

The options for non medicated relief is limiting for those suffering with collapse&/or blocked nostril(s). Some find salt water or baking soda mixes or drops of solutions in water using a neti pot helpful for sinus issue's. Some will do steam treatments by draping a towel over their heads above a hot steaming bowl of water or mix. You may even try menthol or other topical ointment products. However if you have a collapsed nostril or over enlarged turbinate issues then those treatments won't be of much use. The only other non medicated treatment that may be of help are the nasal breath strips you place over the middle area of your outer nose, like a bandaid. For me this may work well for the first hour, but after that my nose becomes itchy from the adhesive and the strip starts to weaken over a few hours as well. It also may not open the area as much as you need or would like. So whats left??? Well there is one other option i discovered after seeing a well known nose surgeon named Dr.Dean Toriumi in Chicago a year ago. After one of my visits with him, he mentioned that i could try a plastic nose splint (plastic internal dilator) which he helped design. They go inside the nostrils and are much stronger then the otc nasal strips. Because only one side of my nose is very  hard to breath with i only use one splint . It takes time to notice its effect, but after a couple hours i find that it does help my congestion problem which then helps me breath better. I usually will try to sleep with it over night. It's not a cure, but it's the best non medicated treatment i have available, which  helps reduce the use of otc medications and therefore I strongly recommend it.

For more information contact Dr. Dean Toriumi's office.

***Update:  Dec.27 , 2010***

Here are some more new non-medicated options for nasal valve collapse utilizing internal nasal dilators such as: unseen nasal dilator, breathe with eez, nozovent & sinus cones. I will be doing another post soon on  minor surgical techniques for correcting nasal valve collapsing. But in the meantime do yourself a favor and check out the links down below. They discuss all kinds of breathing issue's with the nose and the many different options available to improve it.

http://www.feelbetterri.com/index.php?section=9&pid=90

http://www.selfgrowth.com/articles/what-you-can-do-about-your-stuffy-nose

Unusual but somewhat effective treatment for Nasal Valve Collapse
Muscle-building therapy in treatment of nasal valve collapse.
M Vaiman, E Eviatar, S Segal
 The present study was performed to investigate the best way to combine transcutaneous and intranasal surface electromyography (sEMG) biofeedback training of muscles involved in nasal valve function with a home exercise program and electric stimulation of nasal muscles. 

CONCLUSION: Relieve of nasal valve stenosis and collapse can be achieved with a complex muscle-building therapy as described. It helps a significant cohort of patients with symptoms of obstructed nasal breathing to avoid surgical intervention. Electric stimulation of the muscles does not contribute significantly in achieving of good results. http://www.camresearch.net/showabstract.php?pmid=15521668

The mystery of all the different types of nose grafts

Do you get confused by all the different types of  nose grafts that are mentioned? Wonder where do they go, and how do they work? I'm not referring to where the source of origin for harvesting  are, like ear, septal, costal, calvarial, in cases of autologous grafts,  but referring to the actual names of the grafts relative to its location in the nose. For example: Columellar strut is a hidden graft that strengthens and supports the nasal tip. Spreader graft is another hidden graft, which supports the middle part of the nose. A graft is simply a piece of cartilage or bone that is used for some purpose in rhinoplasty. Each graft has a specific purpose. There are also tip grafts, batten grafts, strut grafts, dorsal augmentation grafts, rim grafts, lateral crural grafts, plumping grafts, caudal extension grafts, radix grafts, onlay grafts, shield grafts, etc.  Enough to get anyone confused and left scratching their head. Well here are some links that will help unravel this mystery. Grafts go by many names relating to their shape, size &/or locality in the nose.  A shield graft relates to the shape of the graft in the nasal tip lobule.. An "alar" batten graft relates more specifically to locality, but batten grafts can be placed in different area's. The website links are from  Dr. Anil R. Shah , Dr. Daniel Becker (See Chapters 8-12) , Dr. Naderi and Dr. William Portuese.  Kudos to these Doctors for including this valuable information.

http://www.revisionrhinoplasty.com/RhinoplastyManual/index.html 

http://www.shahfacialplastics.com/grafts.html

http://www.seattlesinusdoctor.com/facial_procedures.html

http://www.rhinoplastyspecialistsurgeon.com/ethnic-rhinoplasty/grafts-sutures-in-rhinoplasty/

http://archfaci.ama-assn.org/content/5/4/291.full

http://www.glasgoldgroup.com/tipgrafts_theireffectsontipposition_contour-03.html

If any of the above links are broken, please don't hesitate to let me know. 

Alar Batten Graft (green area) and Different Shield grafts

FREQUENTLY USED GRAFTS IN RHINOPLASTY: NOMENCLATURE AND ANALYSIS

Author: Alan Landecker M.D. Co Authors: C.Spencer Cochran, Dr. Jack Gunter

Introduction Over the past several decades, numerous grafting techniques have been developed to sculpt the nasal framework in primary and secondary rhinoplasty. However, surgeons have been confused by the significant variability related to the nomenclature, exact anatomical position, and clinical indications of each graft. In this paper, the most commonly utilized grafts (a total of 24 grafts will be presented; below are 6 examples) in modern rhinoplasty are comprehensively analyzed according to the aforementioned factors.

http://www.hitechbrasil.com.br/sbcp/anais/42/paginas/285.htm#1355

The Butterfly Graft

The "Butterfly Graft" is a functional nasal procedure that Dr. J. Madison Clark has helped to develop and refine. Dr. Clark teaches the procedure to other nasal surgeons locally, regionally, and nationally. 

The simplest way to describe the procedure is as an internal "Breathe-Right" strip. The graft is taken from the ear but doesn't change the shape of the ear appreciably. It is usually intended that the graft not change the appearance of the nose, but it can be performed along with procedures that improve the aesthetic appearance of the nose (rhinoplasty).

The procedure is usually done under general anesthesia and takes about an hour to an hour and a half.

http://www.nc-faces.com/the-butterfly-graft/

Seagull Wing Graft

A technique for the replacement of the lower lateral cartilages

Fernando Pedroza, MD; Gustavo Coelho Anjos, MD; Lucas Gomes Patrocinio, MD; Jose M.Barreto, MD; Jorge Cortes, MD; Suad H. Quessep, MD

The seagull wing technique is indicated in cases in which there are severe signs of overresection of the lower lateral cartilages. 

We describe our 20-year experience with the seagull wing technique, which is designed to replace the lower lateral cartilages and to reconstruct the nasal tip. This technique has the advantages of almost completely rebuilding the structure of the nasal tip, restoring the function of the external nasal valve, and effectively correcting a great variety of aesthetic deformities. 

http://archfaci.ama-assn.org/content/8/6/396.full 

Structural Approach to Endonasal Rhinoplasty
Anil R. Shah, M.D. and Philip J. Miller, M.D.
Includes Information on Extended Tip graft and Columellar strut
Abstract
The marriage of endonasal rhinoplasty with structural grafting has resulted in more consistent rhinoplasty results. The nasal base can be stabilized by tongue-in-groove techniques, a columellar strut, or extended columellar strut. The middle vault can be addressed with spreader grafts or butterfly grafts. Lower lateral cartilage weakness can be supported with alar batten grafts or repositioning of the lower lateral cartilages.
http://www.drphilipmiller.com/Assets/Structuralapproach.pdf

Confused about what's the difference between Lateral crural strut grafts and alar strut grafts? Or rim grafts and Alar batten grafts?
Dr. Naderi explains in simple terms. Alar strut grafts and Lateral crural strut grafts are same.  But Alar batten grafts are not the same. A "rim graft" sits along the alar rim (right at the margin just like it sounds) whereas a "alar strut graft" site higher OVER the lateral aspect of the Lower Lateral Cartilage. The rim graft supports the soft tissue rim (nostril) while the strut graft supports the LLC laterally and thereby supports the entire nostril sidewall, not just the rim. An alar batten graft is a longer grafts that sits UNDER the lateral aspect of the Lower Lateral Cartilage and extends to the body pyriform apperture to prevent collapse of the nostrils during forceful inspiration.
Here's some other diagrams displaying nasal grafts. Click for larger view

Regenerative Medicine: Re-Growing Body Parts

This may seem futuristic, but it is happening today. Now imagine if we could apply this technology to those who suffer from empty nose syndrome, because of surgically removed turbinates, to burn victims, to cancer patients who are missing parts of their nose, if not most, to those like me suffering with nerve pain due to excessive removal of tissue in and around my nose tip and nostril area, even for those who need major reconstruction of the nose with grafts could benefit from this technology, since the surgeon wouldn't have to harvest the grafts from your own body which adds a lot of time to your surgery once shaped and put in place. You also wouldn't have to worry about warping, absorption, infection, or any of those downsides with grafting as performed today. It's an area that i hope some Plastic Surgeon or E.N.T. will explore. I think this is the future for nose reconstruction surgery/treatment as well as it is for all the other medical fields. One won't have to depend on donor body parts for transplants any longer. It's truly a transformational breakthrough.

More concerns when harvesting costal cartilage for use in nose surgery.

Image via Wikipedia

Two major concerns about, harvesting rib cartilage are: 1. the risk of  pneumothorax, a release of air from the lungs and 2. the concern about as we age rib cartilage tends to calcify therefore the cartilage becomes more like bone. 

According to Dr. Barry Eppley, a plastic surgeon in Indianapolis, his preference is the 7th, 8th, and free floater 9th rib for harvesting.  He claims it " is easier and provides plentiful options of shape and configurations. A small subcostal incision can be moved around to provide good visibiity and the underlying rectus muscle is split vertically for access rather than transecting it." See link below (exploreplasticsurgery).

He continues,  "One of the major concerns about rib harvesting is the risk of pneumothorax as the lung pleura  is close by underneath. But at the level of the 7^th ribs and lower, the lower apex of the lung is higher so this is not going to happen. In over 65 cases of rib harvest at this chest wall level, the pleura has never been violated. It becomes evident at the level of the 7^th and most certainly at the 6^th rib."  So for those seeking revision rhinoplasty and need rib grafts, don't forget to ask the surgeon at time of consult which rib he uses, how many has he done like that, and has he/she had any complications with it. 

Another nose revision surgeon , Dr. Anil Shah in Chicago prefers to use the 5th, and 6th rib. He says "either the 5th or 6th rib are most commonly used.  The 5th rib has the advantage of being straighter and not really connected to any of the other ribs.  The disadvantage is it tends to be smaller.  The 6th rib tends to be longer but more curved than the 5th rib.  In addition, it tends to connect to other ribs." See link below (shahfacial plastics).

How about calcification of the ribs as we age?

According to Dr. Shah,  "as we age, the cartilage portion of the rib cage becomes calcified and eventually actually turns to bone. This process is typically complete at age 55, but I operated on patients well over fifty who have had substantial cartilage remaining in their ribs".  When your over the age of 40 there is normally more calcification which makes the costal graft harder to shape, however the upside to this is there is less chance of warping over the years. 

Dr. Eppley mentions "one can always find enough cartilage to use. I have done rib grafts up to age 65 and adequate cartilage has always been found". 

http://exploreplasticsurgery.com/2010/04/10/rib-grafts-for-rhinoplasty 

http://www.shahfacialplastics.com/costal%20cartilage%20grafting.html