Jacobs Journal of Materials Science

JACOBS PUBLISHERS

Jacobs Journal of Materials Science

Research Article

OPEN ACCESS

Permanent Percutaneous/Permucosal Portals: Osseointegrated Devices Robert E. Baier1* Oral Diagnostic Sciences, the State University of New York at Buffalo

1

*Corresponding author: Dr. Robert E. Baier, Oral Diagnostic Sciences, the State University of New York at Buffalo; Email: [email protected] Received:

08-05-2016

Accepted: 10-20-2016 Published: 11-07-2016 Copyright: © 2016 Robert E. Baier Abstract Unmet needs for safe, hygienic permanent “through-the-skin” ports for catheters, power and fluid conduits and cranial electrodes—as well as other applications—can now be confidently fulfilled by the use of osseointegrated devices using materials and principles underlying the half-century success of dental implants. Choice of unique commercially pure titanium screwlike fixtures that avoid fibrous encapsulation to allow biomechanically secure and infection-resistant bone bonding now favors placement of implants in diverse body zones, based on this record of craniomaxillofacial success internationally. Significant clinical experience with FDA-approved implants retaining facial prostheses encourages an expansion of such portals to brain electrodes and to shunts employed to regulate adult normal pressure hydrocephalus (NPH), prior to exploration of neonatal use. Keywords: Titanium; Osseointegration; Percutaneous; Permucosal; Catheters; Shunts; Electrodes Abbreviations cpTi : Commercially Pure Titanium; Ti6Al4V = titanium, 6-aluminum, 4-vanadium alloy; CST = Critical Surface Tension; NPH = Normal Pressure Hydrocephalus; UV-A = ultraviolet A light

Introduction

In Texas in 1981, founding president of the Society For Biomaterials [1], C. William Hall, MD of the Southwest Research Institute in San Antonio described for the world many significant unmet challenges of safely penetrating the body’s integuments [2]. A simultaneous review of the numerous applications waiting, and the disabling failure modes of all then-known artificial percutaneous devices was provided by a leading investigator of these devices [3]. Entering the Year 2000, these special concerns were still being reported [4], but with the indication that the emerging international success of permanent dental implants—especially those comprising commercially pure titanium (cpTi) implants introduced by P-I Branemark of Sweden in 1970 [5]-- held promise for numerous extra-oral applications, as well.

This had been preceded by a London –based Workshop of international experts, calling for the employment of osseointegration in orthopedics and other diverse specialties to little avail [6]. Important gains were made, however, in Branemark-influenced specialty rehabilitation clinics [7] and the dental community began to recognize the potentially universal value of the osseointegration principle, once properly understood [8]. Reported here is that “the correct algorithm (has been) attained that will make [a] permanent percutaneous implant[s] possible”[2].

Materials and Methods (Research)

The material exclusively utilized for these true trans-mucosal and skin-crossing implants, into bone, was required to be cpTi. The mechanism for the Osseointegration process has

Cite this article: Robert E. Baier. Permanent Percutaneous/Permucosal Portals: Osseointegrated Devices. J J Materl Sci. 2016. 1(1): 002.

Jacobs Publishers been speculatively described as involving cpTi’s scavenging of wound-healing-released free radicals into the cpTi’s superficial oxide layer, in a process called “catalytic reduction”[9]. This is basically the dark reaction that is the reverse of photocatalytic oxidation by cpTi’s release of free radicals in UV-A light. It was important that the cpTi’s surfaces be scrupulously free from contamination, as indicated by having an appropriately high Critical Surface Tension [10].

2 non-physiologic materials from all biological adjacent phases. This means, of course, that the universally encountered “foreign body reaction” to deliberately or accidentally implanted materials is not---in fact—universal, and that a new principle of material accommodation into biological tissues has been discovered!

After 40 years of dental experience, in the biologically and chemically hostile (to biomaterials) environment of the mouth, about 8,000,000 dental implants will be placed this year worldwide. The reliable expectation is that their interphases with bone and overlying tissue will sustain their infection-resistant and mechanical integrity despite constant variation of temperature, mechanical load, and chemical constituents in a permanently moist environment for the life of each patient. Given the excellent results obtained in the mouth, and the concurrent results reported for maxillofacial implants of the same qualities, the prospects for realizing diverse true long-term percutaneous and permucosal implants have been reached. Nonetheless, confirmations of these findings are still arriving from both in vitro and in vivo models to evaluate these interfaces [15, 16].

Figure 1. A typical clinically placed implant of commercially pure titanium, which permanently Osseointegrates with skeletal bone and maintains an infection-free seal via epithelial normal hygiene. Courtesy of R. Duthie, BUD Industries, manufacturer

Demonstrating the percutaneous long-term security of the cpTi interfaces to the bone and overlying tissue was a series of clinical cases [11] utilizing the illustrated BUD Implant (Figure 1) fabricated and inserted as described in an Implant System Patent of 1990 [12]. A series of FDA approvals for these medical devices was obtained [13].

Success criteria for the Osseointegrated skin-penetrating cpTi fixtures were as described in concurrent publications by international teams [14]. The most important observation has been that, unlike the surrounding tissue of natural teeth, clearly infected peri-implant, like periodontal, sulcus regions do not cause breakdown of the secure bone-to-implant attachments. Simple hygienic measures are sufficient to achieve long-term function and security of these portals.

Results and Discussion

The proper definition of the term “Osseointegration” is that no capsular fibrous tissue intervenes between the implanted material and living host bone, excepting a universal 100-200 Angstrom thick “conditioning film” of glycoprotein separating all

The challenge has now shifted from the once-judged-impossible permanent tissue-to-port interface to the interiors of those ports where synthetic material-to-material passage must be obtained, often in a tissue-growth-agile manner [17]. One such immediate trial site for these permanent portals is recommended to be in the adult skull where catheter-based shunting is applied to overcome normal pressure hydrocephalus effects that simulate Alzheimer’s syndrome [18]. It is not yet known if similar applications in neonatal or growing skull bones will be geometrically sustainable [19]. Chronically implanted neural electrodes, which fail due to tissue reaction and loosening at the skull, should immediately benefit [20], however.

It is obvious, of course, that this dependence on osseointegration presumes the presence of nearby “Osseo” tissue, limiting potential soft tissue applications because of the usual fibrous scar capsule response [21]. Good news is that proper modulation of the surface properties of a variety of biomaterials, inducing different degrees of tissue response by control of their Critical Surface Tensions, may lead to interfaces of similarly high integrity away from bony sites [22]. Implementation

Consultation with experts in craniomaxillofacial intervention has encouraged further exploration of this concept and engaged bioengineering/biomaterials students have noted the specific need for safer, less expensive intervention in children and older adults with revised hydrocephalus shunts (estimated 40,000/year in the US). Current surgical costs for revising these, unfortunately, frequent shunt failures (by infection and


Jacobs Publishers occlusion) are estimated at $35,000 per case, reducible to approximately $10,000 per case with titanium portals osseointegrated into skulls, with expected lower pain and suffering for patients. Prior work of Schaaf [11] and Duthie [12, 13] has demonstrated that both the anticipated surgical and regulatory difficulties for these implant procedures have already been overcome, and discussions with Oral and Maxillofacial Surgeons suggest their readiness to cooperate with neurosurgical specialists in placing such implants, as they are already placing about 8,000,000 osseointegrating dental implants in patients around the world in 2016. The neurosurgeons could then, more swiftly, safely, and effectively perform shunt replacements through the fixed portals when the need arises. A current commercialization plan is being developed around University at Buffalo’s New Technology Disclosure of specific portal designs and fabrication steps [23].

Conclusion

The intimate bonding of cpTi to living bone, with only an intervening molecular “conditioning layer” of glycoprotein, provides a long-term sustainable interface between the interior and exterior of the living body. Thereby, long-sought permanent portals for power and fluidic transfer across percutaneous and permucosal regions can emulate the excellent results of dental implants, and provide for a host of new therapeutic and diagnostic implements with higher-than-previously realized security and integrity.

Future research should continue to seek this same security for the bonds of soft tissues to biomaterials. Attention to proper implant surface preparation will be critical to these forecast discoveries [24].

Acknowledgement

The basic findings of these studies were developed with the support and enthusiasm of Dr. J. R. Natiella, under his Grant No. DE-04226, from the National Institute of Dental Research, in 1981.

References

1. Society For Biomaterials,

3 lor & Francis Publishers, Philadelphia, PA (Andreas F. von Recum, editor). 1999: 721-725.

5. Lewin T., Per-Ingvar Branemark, Dental Innovator, Dies at 85, The New York Times. 2014.(DECEMBER)

6. Baier R E, Glantz P-O, Heinegard D, Branemark R, Branemark P-I et al. Osseointegration in Orthopedics, J. Adhesion. 1997. 60: 95-97.

7. Branemark R, Branemark P-I, Rydevik B, Myers, RR. Osseointegration in skeletal reconstruction and rehabilitation: A review. Journal of Rehabilitation Research and Development. 2001, 38(2): 175-181. 8. Taylor TD. Dental Implant Research—Are We Focusing Too Much on the Dental? The International Journal of Oral & Maxillofacial Implants. 1994, 9(5): 493-494. 9. Baier R. Catalytic Reduction Aids Titanium Biocompatibility. Proceedings 24th Annual Meeting, Adhesion Society (John A. Emerson, Editor) ISSN 1086-9506, 2001: 442-444.

10. Baier RE. Surface behavior of biomaterials: The theta surface for biocompatibility. J Mater Sci Mater Med. 2006. 17(11): 1057-1052. 11. Gitto CA, Plata WG, Schaaf, NG. Evaluation of the Peri-Implant Epithelial Tissue of Percutaneous Implants Abutments Supporting Maxillofacial Prostheses. The International Journal of Oral & Maxillofacial Implants. 1994, 9(2): 197-206.

12. Duthie RE: Implant System. US Patent Number 4976739. 1990: 10. 13. Office of Device Evaluation, Food and Drug Administration, Section 510(k) notifications of market approval for BUD Implant Systems K902331, K912521, K913688, 1991-1995.

14. Jacobsson M, Tjellstrom A, Fine L, Andersson H. A. Retrospective Study of Osseointegrated Skin-Penetrating Titanium Fixtures Used for Retaining Facial Prostheses, The International Journal of Oral & Maxillofacial Implants. 1992, 7(4): 523528 .

2. Von Recum AF, Hall CW. Preface- The Percutaneous Devices Workshop. Journal of Biomedical Materials Research. 1984, 18: 321-322.

15. Fukano Y, Knowles NG, Usui ML, Underwood RA, Hauch KD et al. Characterization of an in vitro model for evaluating the interface between skin and percutaneous biomaterials, Wound Rep Reg. 2006, 14 (4): 484-491.

4. Jansen JA. Special Aspects of the Permucosal Interface in Handbook of Biomaterials Evaluation, Scientific, Technical, and Clinical Testing of Implant Materials, Second Edition. Tay-

17. Baier R E. Catheter for Long-Term Emplacement. US Patent 4266999 A. 1981.

3. Von Recum AF. Applications and failure modes of percutaneous devices: A review. Journal of Biomedical Materials Research. 1984. 18(4): 323-326.

16. Isenhath SN, Fukano Y, Usui ML, Underwood RA, Irvin CA et al. A mouse model to evaluated the interface between skin and a percutaneous device, J Biomed Mater Res, 2007, 83(4): 915-922.


Jacobs Publishers 18. Normal pressure hydrocephalus (NPH) Signs, Symptoms, 2016.([email protected])

19. Oesterle LJ, Cronin Jr RJ, Ranly DM. Maxillary Implants and the Growing Patient, The International Journal of Oral & Maxillofacial Implants, 1993, 8(4): 377-387. 20. Polikov V S, Tresco P A, Reichert W M. Tissue reactions to chronically implanted neural electrodes. Journal of Neuroscience Methods. 2005, 148(1): 1-18.

21. Budd TW, Nagahara K, Bielat KL, Meenaghan MA, Schaaf NG. Visualization and Initial Characterization of the Titanium Boundary of the Bone-Implant Interface of Osseointegrated Implants, The International Journal of Oral & Maxillofacial Implants. 1992, 7(2): 151-160.

4 22. Carter JM, Natiella JR, Baier RE, Natiella RR. Fibroblastic Activities Post Implantation of Cobalt Chromium Alloy and Pure Germanium in Rabbits. Artificial Organs. 1984, 8(1): 102-104. 23. The State University of New York at Buffalo, STOR New Technology Disclosure #R7043. “Secure Through-the-Skin Portals”, 01 December 2015.

24. Baier RE, Meyer AE. Implant Surface Preparation, The International Journal of Oral & Maxillofacial Implants, 1988, 3(1): 9-20.
