TISSUE EXPANDERS

- A Valuable Adjunct

By

Dr.T.Roger Paul

2nd yr PG

GDC&H, VJA.

Reconstructive Maxillofacial Surgery is a highly dynamic

discipline of Oral and Maxillofacial Surgery that relies on

traditional surgical skills as well as surgical innovations in order

to cope with the challenging management of congenital, acquired

defects and residual deformities of Maxillofacial region.

The observation that living tissues respond in dynamic fashion

to mechanical forces placed upon them has been applied to the

clinical problem of surgical defects; the technique of tissue

expansion, has provided great advantages to the surgeon and

patient.

This technique has improved the ability of the surgeon to

replace lost or surgically excised tissue with neighboring tissue of

similar color, texture, sensation, and thickness.

Introduction

Soft tissue expansion before vertical ridge augmentation.

INDICATIONS

CLEFT LIP & PALATE REPAIR.

Correction of post traumatic or postoperative alopecia

Treatment of male pattern baldness

Expansion of forehead skin prior to forehead flap total

nasal reconstruction

Expansion of postauricular skin prior to reconstruction

of the external ear

Expansion of cheek or neck skin to allow scar

revision, burn excision.

Breast reconstruction.

Alternative to reconstructive methods

Difficult decubitus ulcers

Contraindications

Active infection anywhere in the body.

Clinically persistent or recurrent cancer.

Poor vascularization of tissue in the area where the

implant is to be used

History of compromised wound healing.

Compromised immune system.

History of sensitivity to foreign materials

How does the tissue expansion yield extra tissue?

Tissue expansion technique exploits the adaptability

quality and induces a controlled in situ skin growth.

Stretches beyond the skin’s physiological limit, invoke

several Mechano-transduction pathways, which increase

mitotic activity and collagen synthesis, ultimately resulting

in a net gain in skin surface area

Tissue expansion involves a combination of

Creep

Biological stretch.

In “Creep”, when a constant force is applied to stretch the

skin, it continues to extend.

In “Biological stretch”, the skin or any other tissue

enlarges whenever a force is applied.

In tissue expansion, the tissue is stretched without

affecting the quality of the original tissue.

Biological effects of tissue expansion

Thickening of epidermis

Thinning of dermis

Alignment of collagen fibrils

Shorter telogen phase of scalp hair

Improved vascularity

Bone deformation

Periosteal reaction

Lengthening of the skeletal muscle fibres

Atrophy of muscle fibres in long-standing expansion

Lengthening of peripheral nerves

Molecular changes

Cytokines (VEGF)

Hormones

Adhesion molecules

Cytoskeleton

Signal transduction protein

A device consists of a

silicone elastomer

inflatable expander with a

remote injection dome.

The expander and remote

injection dome are for

temporary subcutaneous or

submuscular implantation

and is not intended for use

beyond six months.

Parts of a Silicone Tissue Expander

Expanders are available in round, rectangular,

elliptical and crescent shape with a smooth

elastomer shell.

Expander selection

Selection of shape of the expander – Area to be

reconstructed should be cosidered

Covering a large defect in Head & Neck region –

Rectangular expander is preferred

Round defects – Crescent shape is preferred

Expander base should be 2.3 to 3 times the surface area

of the defect to be closed

Technique

Tissue expanders are implanted using L.A or G.A.

Preoperative planning of incision site and orientation of

implanted expander are important.

Incision is made in an area adjacent to the area to be

reconstructed

The Expander is placed beneath the subcutaneous layer of

skin on muscle or bone.

For Scalp expansion the Expander is placed in subgaleal

pocket leaving pericranium intact.

The injection port of the tissue expander is placed in a

separate subcutaneous tissue pocket in the same incision.

The port should be easily palpated & accessible for

saline injections.

The access incision after implanting the tissue expander

is closed in layers.

After closure of incision the Expander may be injected

with saline to obliterate the remaining dead space.

To allow for sufficient healing, inflation of expander is

commenced 2 weeks after implantation.

“Rule of 10” for filling of the tissue expander

10% filling is performed intra-operatively,

Postoperative filling is started at the 10th postoperative day,

1/10th of the total capacity is filled in each filling session,

The entire filling process is completed over 10 weeks,

10% overfilling beyond the prescribed capacity is routinely

performed

Complications

Hematoma

Seroma

Deflation of the expander, either spontaneously or iatrogenic

ally during inflation (treated by replacement of the expander).

Migration of the expander.

Infection, necessitating removal of the expander.

Wound dehiscence.

Necrosis over the fill port or over the expander.

Implant exposure or extrusion .

Scar widening with growth of the individual.

Contraction of the flap with distortion of the

appearance.

Pain that may necessitate expander removal.

Neurapraxia that may necessitate expander removal.

Erosion or deformation of underlying bone.

Case Report -1

Case Report -2

Self-inflating tissue expanders

The adoption of biocompatible osmotically active

hydrogels was a major advance in the evolution of self-

inflating devices.

Surgeons will be able to accurately and predictably control

the direction, the timing, and rate of the material’s expansion

in the body.

Oxtex device

The Use of Self-Inflating Soft Tissue Expanders Prior to Bone Augmentation of

Atrophied Alveolar Ridges Mertens C, et al. Journal Clin Implant Dent Relat Res.

2013 May 28. doi: 10.1111/cid.12093

The Oxtex device typically displays a

triphasic swelling profile in vivo.

Phase I biodegradable ‘time switch’ which delays the onset of swelling

following implantation for a period of typically

two weeks.

Phase II

is carefully controlled either by an integral polymer

scaffold or an external

semipermeablemembrane.

The final degree of swelling achieved at Phase III can be precisely controlled (up to 1500% if necessary)

Advantages

• Removes the need for injection ports.

• Delayed action device is available whereby swelling

commences after a predetermined time period .

• A precisely controlled expansion rate (ranging from six

weeks to six months).

• A choice of isotropic and anisotropic expansion profiles.

ENDOSCOPIC TISSUE EXPANSION

Endoscopically assisted tissue expander placement was

first described by Serra et al in 1997

The endoscopic approach allows placement of tissue

expanders through smaller, remote incisions.

Specialized endoscopic instruments allow improved

visualization of the tissue expander pocket through

smaller incisions.

Endoscopic Approach for Tissue Expansion for Different Cosmetic Lesions in

Pediatric Age.,. Annals of Pediatric Surgery Vol. 6, No 1, January 2010, PP 27-33

Advantages

Incision can be placed at a distance from the tissue to

be expanded.

Fewer incisions, reduced operative time, reduced

complication rates, less time to full expansion

Decreased rate of wound dehiscence, a decreased

rate of tissue expander extrusion.

More tissue expanders can be placed through a single

incision because of the improved visualization.

CONCLUSION

Knowledge of tissue regeneration in tissue expansion is important for its clinical

application. Ultimately, one is able to achieve increased surface area of the tissue

by mechanical creep and biological stretch, which is used for resurfacing of the

defect. It improves the quality and quantity of soft tissue and facilitates primary

wound closure & reduces the incidence of wound dehiscence and exposure of

bone grafts. Tissue expansion has certainly earned the status of being an

indispensable adjunct for reconstructive procedures in Maxillofacial Surgery.

References Tissue expanders in facial reconstructive surgery International Journal of Oral

& Maxillofacial Surgery Volume 36, Issue 11 , Page 1058, November 2007.

Tissue Expansion: A Valuable Adjunct to Reconstructive Surgery Ann. Pak. Inst.

Med. Sci. 2013; 9(3): 103-104

The effect of tissue expanders on the growing craniofacial skeleton, Indian J

Plast Surg January-June 2006 Vol 39 Issue 1

KanerD,Friedmann A.Soft tissue expansion withself filling osmotic tissue

expanders before vertical ridge augmentation J.ClinPeriodontol 2010;

Tissue regeneration during tissue expansion and choosing an expander Indian

Journal of Plastic Surgery January-April 2012 Vol 45 Issue 1

The Use of Self-Inflating Soft Tissue Expanders Prior to Bone Augmentation of

Atrophied Alveolar Ridges Mertens C, et al. Journal Clin Implant Dent Relat Res.

2013 May 28. doi: 10.1111/cid.12093

Local Flaps in Facial Reconstruction,2nd Edition.,Shan.R.Baker.

GRABB AND SMITH’S PLASTIC SURGERY, 6th edition ,Charles .H.Thorne.

Acknowledgements

Dr.K.Surekha MDS.,

Professor & Head

Dr.G.Sudhakar MDS.,

Reader