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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