Chapter 14.

Repair & Grafting of Dermis,  Fat & Fascia

DERMIS TRANSPLANTATION

History

Fate of Dermal Grafts

Surgical Technique

Complications

The Futures

FAT TRANSPLANTATION

History

Fate of Transplanted Fat cells

Clinical Applications

The Future

FASCIA TRANSPLANTATION

History

Physical Property

Harvesting of Fascia Lata Grafts

Vascularized Fascial transfers

* dermis, fat, fascia의 용도

1) soft tissue augmentation

2) coverage of vital structure

3) elimination of dead space

4) reconstruction

^ 기타	thenar m.의 soft tissue augmentation

replacement of articular disc

dura mater defect의 repair

DERMIS TRANSPLANTATION

* component of dermis graft

① deeper layer of papillary dermis

② entire reticular layer of dermis

③ minimal amount of adherent subcutaneous fat

④ indigenous subepidermal extensions of epithelial appendages

* reversed dermal graft가 보통 FTSG & STSG보다 vascularization이 더 잘됨

History

Fate of Dermal Grafts

□ 4일째 host vessel의 ingrowth & inosculation 관찰 - surface of epidermis의 제거로 촉진

1) Epithelial component :

① epi. wall - keratinous epi. debris의 lumen내 축적으로 extended & necrotic

--> fibrosis

② sweat gland - normal, function 계속 지속

* active한 증거 : 자극에 반응하여

ⓐ succinic dehydrogenase가 나타남 - 포유류세포의 vital process에 필수적

ⓑ glycogen depletion

③ sebaceous gland - 2주 후 소실

④ hair follicle - 2개월 후 소실

□ 2주 째 microscopic epidermoid cyst가 형성되며 이는 주로 hair follicle에 의함

2) Dermal component - no abnormal change or mesodermal metaplasia

□ mesodermal metaplasia : functional stimulus에 반응하여 dermal component가 transformation

① tension - tendon-like structure

② pressure - cartilage-like structure

Surgical Technique

1. Dermal graft를 위한 basic pre-requisites

① inconspicuous donor site

② favorable recipient bed, free of infection and scar tissue

③ meticulous hemostasis

④ adequate immobilization

2.. dermal graft donor site

① groin	② gluteal fold

③ lateral gluteal region	④ submammary region in female

⑤ lower abdomen

□	contraction이 되므로 원하는 surface area 보다 25% 크게 harvest

step-off appearance를 최소화하기 위해 graft margin울 bevelling

Complications

① hematoma & wound infection : most common

② clinical cyst formation

③ necrosis

④ persistent draining sinuses <-- re-epithelized dermal graft

The Future

dermal papilla - can induce hair growth when implanted in the follicles and can interact with skin epidermis to develop new hair follicles

FAT TRANSPLANTATION

□ autogenous fat transplantation의 방법

① free transplantation

② dermis-fat graft

③ microvascular free tissue transfer

History

Fate of Transplanted Fat Cells ( □ transplanted fat cell의 운명(fig 14-4) )

□ 이식 후 4일째 circulation시작

1. host cell replacement theory : fat cell이 죽은 후 host histiocyte가 lipid를 탐식한 후 새로운 adipose cell로 됨

2. cell survival theory(정설) : 이식된 fat cell의 일부가 계속 생존

□ 1955, Peer에 의하면 histiocyte는 scavenger의 역할을 할뿐이다.

□ 증거

ⓐ 이식된 fat이 donor 특성을 갖는다.

ⓑ crushing 적을수록 부피감소가 작다

Clinical Applications

1. Free grafts

① obliteration of the denuded frontal sinus

- revascularization이 안되면 fibrous tissue 또는 osteoneogenesis로 채워진다

② resurface denuded dura mater during lumbar spine op.

2. Dermofat grafts

⑴ Ix

① enuncleated orbits 후의 dead space를 채울 때

② correct soft tissue deficit

ⓐ retromandibular depression

ⓑ secondary to either postradical parotid resection

ⓒ cong. facial asymmetry

⑵	basic technique in dermis-fat grafting

① 눈에 띄지 않는 공여부

② preparation of graft, including de-epithelization

③ gentle handling of the graft

④ secure placement of graft into the recipient site

⑤ meticulous hemostasis

⑥ absence of infection

⑦ moderate overcorrection : 50%가 1년 내 소실

□ 20% 정도만 overcorrection - 환자의 cosmetic tolerance 때문

⑶ dermis-fat의 ideal donor site

① groin	② lateral gluteal area

③ gluteal fold

⑷ vascularized omental transfer

① 장점

ⓐ predictable ultimate volume retention

ⓑ decrease number of procedures required for reconstruction

ⓒ malleability

② 용도

ⓐ facial soft tissue reconstruction

- hemifacial microsomia, craniofacial microsomia

ⓑ to tailor a skin flap

The Future

SAL(suction assisted lipectomy) 후의 aspirated fat injection

① 문제점

ⓐ traumatized fat cell이 생존할 것인가?

ⓑ 생존한다면 예견되는 atrophy는 어느 정도인가?

② depend on

ⓐ proper injection pressure

ⓑ needle of appropriate diameter

FASCIA TRANSPLANTATION

History

Physical Property ( fascia lata )

① SG : 1.31

② tensile strength : 7000 lbs/square inch

③ average strength : 10.73 lbs - when meshed in 1/4 inch strips

Harvesting of Fascia Lata Grafts

: 10-15mm width로 얻을 때 muscle hernia 없이 즉 donor morbidity 없이 가능

□ clinical use of fascial graft

① correction of facial palsy

② repair of urethral fistulas

③ closure of nasal septal defects

④ coverage of exposed implant

⑤ Robin sequence에서 tongue stabilizer

⑥ TM joint ankylosis시 ostectomy후 interposition material

Vascularized Fascial Transfer : temporalis fascia free flap

1. 장점

① ultra-thin

② leaves a minimal donor site defect

2. application

ⓐ external ear reconstruction

ⓑ avulsed scalp resurfacing

ⓒ reconstitution of soft tissues

ⓓ replacement of soft tissue deficits of hand