Tracheal Replacement Devices

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Seminar by Ashmita Poddar

Roll no. 25



Introduction

Requirements for tracheal replacement

Various approaches

Artificial trachea

Literature survey

Conclusion/summary

References



TRACHEA: The Trachea or the wind pipe is a part of the respiratorysystem through which the air passes in organisms.

As the ability to reconstruct parts of the body has increased, so has

the potential for complications associated with the replacement

devices used to do so. Some of the most significant complicationsassociated with replacement devices are caused by infections at

the implantation site.

As the trachea is located facing the ´external environment,µ

these prostheses are exposed to a high risk of infections and severecomplications.

Hence developing a compatible tracheal replacement device is a

challenge ahead of the biomedical engineers.



Laterally rigidbut longitudinally

flexible tube

Surface ciliated

respiratoryepithelium

Requirements

for a trachealreplacement

device



Material used should have following properties:

1.Biocompatible

2.Non toxic

3. Non carcinogenic

4.Must not dislocate or erode over time5.Ideally should provide or facilitate epithelial

resurfacing

6.Should avoid stenosis7.Should resist bacterial colonization



Tissue engineering of needed components

such as cartilage

Transplantation of allografts with and

without immunosuppressive therapy,preservation, and vascularization procedures.

Trials of a host of foreign materials with

many technical modifications to avoid

complications of implantation Implantation of nonviable tissues

Reconstruction with artificial material .



Artificialtrachea

NONPOROUS

TYPE

MESHTYPE



Comprises a silicone tube with two suture rings

(Dacron)attached to each of its ends.

Used it on a total of 62 patients from 1970 to

1988.

Late complications, such as migration of the

artificial trachea and granular tissue formation

at anastomosis

Not used for patients with benign tracheal

disease.



Courtesy: the Biomedical Engineering Handbook by Joseph D. Bronzino (Editor-in-Chief)



T shaped as the name suggests

Courtesy: The Biomedical Engineering handbook by Joseph D. Bronzino(Editior-in-Chief)



Major advantage of such nonporous

tubular prostheses is that airway

patency can be ensured.T

herefore,for patients for whom end-to-end

anastomosis is impossible,

nonporous prostheses may be used

as the last resort to avoidthreatened suffocation

(asphyxiation).



Courtesy: the biomedical engineering handbook by Joseph D. Bronzino



Non elastic

Suture rings poses a problem when used for

long term

Problems at the anastomosis



1950s: Several trials of tracheal

reconstruction using metallic meshes made

of tantalum and stainless steel were

conducted . 1960s: Heavy Marlex mesh (trademark

name for high density polyethylene and

crystalline polypropylene ) was used

clinically for tracheal reconstruction, andgood short-term results were reported.



The optimal pore size for tracheal

replacement mesh is 200 ~ 300 m. Fine

Marlex mesh is made of polypropylene with a

pore size 200- 300 m.





air-tight

Good tissue regeneration is achieved .

The grafted collagen has excellent biocompatibility

and promotes connective tissue infiltration into the

mesh.

However, the fine mesh alone was too soft to keep

the tube open, so a tracheal prosthesis was made of

collagen-grafted fine Marlex mesh reinforced with a

continuous polypropylene spiral



This research was carried out by H. H.

Schauwecker*, J. Gerlach* ,H. Planck**

and E. S. Bücherl* in west Germany

(*Chirurgische Universitatsklinik undPoliklinik Klinikum Charlotte burg, Freie

Universität Berlin, West-Germany, **Institut

für Textil-und Verfahrenstechnik,

Denkendorf, F.R.G. Correspondenceto Chirurgische Klinik und Poliklinik,

Klinikum Charlotte burg, FU Berlin,

Spandauer Damm 130, D-1000 Berlin 19,

F.G.R ) in 1989.



Porous polyurethane (nonwoven) was used for thedevelopment of tracheal prosthesis, which-in aspecial testing design-was adapted to shape andimitate the biomechanic properties of the naturalorgan. This prosthesis was implanted into 19 beagledogs using end-to-end anastomosis. Insufficiency ofthe anastomosis or infection was observed in theend-to-end anastomosis, whereas the invertedanastomosis showed complete incorporation into

surrounding tissue of the porous prosthesis but wascomplicated by airway obstruction due toanastomosis granuloma.



There has been a flood of tracheal

transplantation experiments in recent years.

With the present limitations that the

biomedical engineers face, the prospects forjustifiable tracheal replacement device as a

solution for extended tracheal resection still

remains remote. Tracheal transplantation

has a long way to go and extensive researchis being carried out to find a device that

aims at increased life quality of the

patients.



1. A Textbook of Biology, Volume II M. Sudhakar Rao

2. Scherer M.A., Ascherl R., Geissdorfer K., et al. Experimentalbiosynthetic reconstruction of the trachea. Arch Otorhinolarynol1986;243:215-223. (Referred by Hermes C. Grillo)

3. Tracheal replacement: a critical review

Hermes C. Grillo, MD*a,b

a Division of General Thoracic Surgery, Massachusetts General Hospital,Boston, Massachusetts, USAb Department of Surgery, Harvard Medical School, Boston, Massachusetts,USA

4. Rob C.G., Bateman G.H. Reconstruction of the trachea and cervicaloesophagus. Br J Surg 1949;37:202-205. (Referred by Hermes C. Grillo)

5. Belsey R. Resection and reconstruction of the intrathoracic trachea.Br J Surg 1950;38:200- 205.[Medline] (Referred by Hermes c. Grillo).

6. The Biomedical Engineering Handbook, second edition, Volume 1, byJoseph D. Bronzino (Editor- in- chief).

7. Jackson T.L., O·Brien E.J., Tuttle W., Meyer J. The experimental use ofhomogenous tracheal transplants in the restoration of continuity of thetracheobronchial tree. J Thorac Surg 1950;20:598-612. ( Referred byHermes C. Grillo)



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Tracheal Replacement Devices