토끼에서 흡입후 자가이식된 지방조직의 생존 및 조직학적 변화

Abstract

[한글]

지방조직의 유리 자가이식은 여러분야에서 미용 및 재건 목적으로 사용되어 왔다. 지방조직의 이식은 지방절편이나 진피지방이 주로 사용되어 왔으며 최근에는 지방 흡입기 및 주사기를 이용하여 지방을 흡입한 후 이식하는 방법들이 보고되고 있다.

자가이식 된 지방조직의 생존과 조직학적 변화에 관하여 과거에는 많은 연구와 보고가 있었으나 근래에는 무관심 내지는 무시되고 있는 분야의 하나이다. 또한 최근에 시행하고 있는 지방 흡입기 및 주사기를 이용한 지방조직 자가이식의 경우, 기존의 지방조직 자가

이식들과 조직학적 변화나 생존도가 차이가 있는지, 흡입 및 주입 후 정상세포율이 얼마나 되는지 등 기초적인 자료가 거의 없는 실정이다.

자가이식 된 지방조직의 생존에 관하여 이식된 모든 지방세포가 셍존하지 못하며 파괴된 지방세포로부터 유리된 지방질을 조직구가 흡수하여 다른 조직으로 대체된다는 숙주 대체설(host replacement theory)과 이식된 지방세포의 일부는 파괴되어 조직구에 의해서

제거되지만 일부는 이식된 그대로 생존하여 지속된다는 세포 생존설(cell survival theory)이 있는데 현재까지 이러한 세포 생존설이 정설로 받아들여져 왔다. 그러나 최근까지도 지방조직 자가이식 후 섬유아세포와 섬유조직만 관찰되며 생존하는 지방세포를 발견할 수 없다고 새포 생존설을 부정하는 주장이 계속되고 있다.

본 연구에서는 이식된 지방조직의 조직학적 변화를 시기별로 관찰하고 주입된 지방세포가 생존하는지 여부를 확인하기 위하여 New Zealand 백색토끼의 서혜부에서 가는 흡입관을 사용하여 지방조직을 흡입한 후 0.5ml씩 복직근에 16 gauge 주사침으로 자가이식하였

다. 이식 후 1, 2, 4, 6, 8,12주에 이식된 지방조직을 채취하여 Hematoxylin-Eosin 염색과 Oil red 0-Hematoxylin 염색을 시행하여 검경하였으며 부가적으로 흡입된 지방과 16 gauge 주사침으로 주입한 지방 및 절편지방의 정상세포율을 구분구적법으로 측정하여 다음과 같은 결과를 얻었다.

1. 이식 후 1, 2주 지방조직에서는 조직구, 거대세포, 호중구, 호산구등의 침윤이 보이고 이식 후 4, 6, 8주 지방조직에서는 다양한 크기의 낭포성 지방종( oil cyst )이 증가하고 생존 지방 세포 주위로 섬유화가 진행되었으며 조직구, 거대세포 및 파괴된 지방 세포에서 유리된 지방질을 포식한 공포성 세포질의 거대세포(foamy giant cell)도 증가하였다. 이식 후 12주 지방조직에서는 호중구와 호산구가 소수 관찰되며 조직구 및 거대세포의 수도 감소하였으며 주변 섬유화는 더욱 진행되었다.

2. 정도의 차이는 있으나 이식된 지방세포가 이식 후 12주까지 생존하였으며 근육에 접한 부위 등 주변부에서 생존율이 더 높았다.

3. 흡입된 지방과 주입되는 지방의 정상 세포율은 각각 89-91%, 89-9O%로 절편지방의 정상세포율 99-100%에 비해 10% 정도 저하되었으며 광학현미경 소견에서 지방세포의 모양과 크기등은 차이점을 발견할 수 없었으나 세포 간격이 다소 넓어보이고 불규칙한 세포막을 보이는 파괴된 지방세포가 일부 보이며 정상 절편지방에서는 발견되지 않은 소수의 림프구가 관찰되었다.

이상의 결과를 종합하여 볼 때 흡입기를 이용하여 지방을 흡입한 후 주사기로 주입 이식한 지방조직은 일부는 괴사되어 조직구에 의해 포식되고 섬유화되나 일부는 생존이 지속된다고 생각된다. 아울러 흡입 및 주입되는 지방은 절편지방에 비해 정상 세포율이 10 % 정도 낮으므로 정재제 후 이식하는 것이 바람직 할 것이다.

The survival and histologic change of aspirated fat after reimplantation in rabbit

Young Joong Hwang

Department of Medical science The Graduate school, Yonsei University

( Directed by Prefessor Keuk Shun Shin )

Autogenous fat graft in human has been widly used for various plastic and

reconstructive purposes. Conventional fat grafting has been performed most commonly

in the form of dermofat or excised fat. In recent years, adipocytes obtained by

suction-assisted lipectomy or aspirated with syringe have been used for

implantation by injection methods. But there are no definite informations about

normal cell ratio in aspirated or sucked fat and histologic changes of this graft.

There are two theories concerning the fate of grafted autogenous fat. One is the

host replacement theory proposing that histiocyte would take up lipid materials

released from destructed adipocytes of graft and eventually replaced all adipose

tissue of graft which failed to survive and the other is the cell survival theory

in which some of adipocytes were destructed and phagocyted by histiocytes but

remaining adipocytes are survive for a long tome. Now cell survival theory is

thought more reasonable but there are some arguments against the cell survival

theory still now.

In this study, adipocytes obtained by aspiration from inguinal area of New

Zealand White rabbits are reimplanted to rectus muscle by using 16 gauge needle and

then survival and histoloaic changes are evaluated at 1, 2, 4, 6, 8, 12 weeks after

implantation. Normal adipocyte ratio of aspirated, reimplanted and excised fat

tissue are also estimated.

The results are as follows:

1. In 1 and 2 weeks after implantation, there are some infiltration of

histiocytes, lymphocytes, giant cells, neutrophils and eosinophils and in 4, 6 and

8 weeks, various sized oil cysts and fibrosis are seen around surviving adipocytes.

In 12 weeks, neutrophils and eosinophils are rarely seen and histiocytes and giant

cells are also decreased. Fibrotic changes become more evident at this stage.

2. There are normal surviving adipocytes even in 12 weeks after implantation and

survival of grafted fat seems to be increased highly towards the periphery.

3. The normal adipocyte ratio of aspirated and reimplanted fat are 89-9l% and

89-90%. This is 10% less than that of excised fat which is 99-lOO% and there is no

significant histologic difference between them except somewhat wide intercellular

distance and being lymphocytes in aspirated and reimplanted fat in light

microscopic examination.

After reviewing all of above results, it is concluded that adipocytes grafted

autogenously using aspiration survive for long time regardless of fibrosis and

phagocytosis by histiocyte and also the normal adipocyte ratio of aspirated and

reimplanted fat are 89-9l% and 89-90%, respectively. This is 10% less than that of

excised fat which is 99-100% and so it is advisable reimplantation after

purification in aspirated fat graft

[영문]

Autogenous fat graft in human has been widly used for various plastic and reconstructive purposes. Conventional fat grafting has been performed most commonly in the form of dermofat or excised fat. In recent years, adipocytes obtained by suction-assisted lipectomy or aspirated with syringe have been used for

implantation by injection methods. But there are no definite informations about normal cell ratio in aspirated or sucked fat and histologic changes of this graft.

There are two theories concerning the fate of grafted autogenous fat. One is the host replacement theory proposing that histiocyte would take up lipid materials released from destructed adipocytes of graft and eventually replaced all adipose tissue of graft which failed to survive and the other is the cell survival theory in which some of adipocytes were destructed and phagocyted by histiocytes but remaining adipocytes are survive for a long tome. Now cell survival theory is thought more reasonable but there are some arguments against the cell survival theory still now.

In this study, adipocytes obtained by aspiration from inguinal area of New Zealand White rabbits are reimplanted to rectus muscle by using 16 gauge needle and then survival and histoloaic changes are evaluated at 1, 2, 4, 6, 8, 12 weeks after implantation. Normal adipocyte ratio of aspirated, reimplanted and excised fat tissue are also estimated.

The results are as follows:

1. In 1 and 2 weeks after implantation, there are some infiltration of histiocytes, lymphocytes, giant cells, neutrophils and eosinophils and in 4, 6 and 8 weeks, various sized oil cysts and fibrosis are seen around surviving adipocytes.

In 12 weeks, neutrophils and eosinophils are rarely seen and histiocytes and giant cells are also decreased. Fibrotic changes become more evident at this stage.

2. There are normal surviving adipocytes even in 12 weeks after implantation and survival of grafted fat seems to be increased highly towards the periphery.

3. The normal adipocyte ratio of aspirated and reimplanted fat are 89-9l% and 89-90%. This is 10% less than that of excised fat which is 99-lOO% and there is no significant histologic difference between them except somewhat wide intercellular distance and being lymphocytes in aspirated and reimplanted fat in light microscopic examination.

After reviewing all of above results, it is concluded that adipocytes grafted autogenously using aspiration survive for long time regardless of fibrosis and phagocytosis by histiocyte and also the normal adipocyte ratio of aspirated and reimplanted fat are 89-9l% and 89-90%, respectively. This is 10% less than that of excised fat which is 99-100% and so it is advisable reimplantation after purification in aspirated fat graft