Date: Fri, 16 Jun 2000 14:08:18 +1200

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From: USSW

Date: Monday, 27 July 1998 17:06

Subject: NOTES ON THE IOM PROCEEDINGS - PART 4

NATIONAL ACADEMY OF SCIENCES

INSTITUTE OF MEDICINE

COMMITTEE ON THE SAFETY OF SILICONE BREAST IMPLANTS

SCIENTIFIC WORKSHOP - JULY 22, 1988

NOTES ON THE PROCEEDINGS - PART 4

DONALD J. SCHAEZLER, PH.D., P.E., CIH

SURGERY, PATHOLOGY, RADIOLOGY

This session had four speakers, none of whom had a hidden agenda, and each of whom appeared open-minded.

Dr. Nancy Hardt of U. Of Florida reported on her results as part of a multi- disciplinary team of researchers investigating silicones. Her work involves the pathological examination of capsule tissue samples from SBI women. She uses FTIR (Fourier Transform Infrared), similar to the LRM method Young reported on but for different types of sample preparation. She found silicone, urethane (some samples), but no silica in samples. Specifically, she found:

1. Macrophages with vacuoles filled with silicone, surrounded by protein.

2. Amorphous protein, probably collagen, surrounding refractive material, probably silicone

3. Wall-to-wall histiocytes with fine silicone

4. Lymph nodes with vacuoles, probably with silicone

5. Blood vessels in the capsule with Macrophages and silicone 

She investigated whether the capsule could be considered a Bursa. A bursa is evidently surrounded by a synovium, a unique tissue without a barrier to migration. Apparently Macrophages and fibroblasts are important to this distinction, and Capsules and Bursae are very similar.

She reported on the use of very fine carbon particles as tracers for migration from the SBI/Capsular surface. Such particles aligned themselves at the surface and migrated to the capsule material and to lymph nodes. They also formed carbon granulomas deep in the capsular tissue. She surmised silicone and carbon might take the same route.

Laboratory analysis of body tissues of SBI patients demonstrated increased silicon, probably as silicone, in the brain, spleen, and other tissues; the increases were greater if the implant had ruptured.

COMMENT: The importance is apparently the association of protein,

Especially collagen, with Macrophages around migrating silicone. 

Dr. Lu-Jeann Feng of Case Western Reserve School of Medicine spoke about her research over 7 years on SBI ruptures.

She first explained the different generations of SBIs.

generation 1 61 - 72 thick shell

Generation 2 73 - 80 thin shell

Generation 3 81 - 88 thick, barrier coat, Silastic II, some with

polyurethane

Generation 4 after 88 textured

Of 1619 explanted SBIs, all by Dr. Feng, 94% reported problems, local or systemic. She identified 16 factors, such as time, contracture, pocket location, local symptoms, type SBI, mfr, etc. Her results indicated

1. 72 % rupture after 15-19 years

2. 76 % rupture if implanted 1974-1977

3. 62 % rupture if implanted 1961-1974, or approximately the Generation 1 implants.

4. The retro-pectoral position is somewhat protective

5. No relationship to systemic symptoms

6. Polyurethane and double lumen types were the most protective

COMMENT: This work confirms the high rupture rates reported by others but is for a referred group of women, which may bias the rupture rate upwards. Dr. Feng is very professional and her presentation was very well done. 

Dr. Michael Middleton of UCAL San Diego spoke about his experience with MRI analysis of Breast Implants. He analyzed about 800 implants, about 400 of which ruptured. His accuracy was defined by (numbers are approximate)

True Negatives (negative by MRI and by explant) 400 False Negatives (negative by MRI, ruptured according to explant) 100 True Positives (ruptured by MRI and according to explant) 300 False Positives (ruptured by MRI, negative by explant) 6 COMMENT: MRI, done correctly, is very accurate for diagnosing ruptured Breast Implants. It may underestimate the true rupture rate somewhat. 

Dr. Marilyn Lightfoote of FDA spoke on Immunological effects associates with silicone Breast Implants. She used a rat model analog for thyroiditis, an autoimmune disease. She found:

1. Autoantibodies to collagen produced in rats injected with silicone oil or silicone gel.

2. Anti-Nuclear Antibodies (ANAs) stimulated in rats injected with silicone oil or silicone gel.

3. Injected silicone migrated to distal sites after one year.

4. In swollen joints there was evidence of inflammatory process after two years.

Pilot human studies were also conducted on women with and without

Connective Tissue Disease (CTD) and with and without Silicone Breast Implants. The results indicated Autoantibodies and ANAs were detected in women with Silicone Breast Implants, with or without CTD.

COMMENT: This is potentially VERY important. It directly refutes claims, such as Mentors, that there no immune effects associated with silicone. It is very encouraging that FDA has already found these effects and is conducting further studies.