Compromised Grafts and Flaps
Certain situations where there is a higher risk that the flap or graft might not take.
It is extremely rare for plastic surgery procedures where either skin grafts or skin and muscle grafts have been placed to be unsuccessful. However there are some instances when this mght occur.
For instance, if a person is having surgery on part of their body previously exposed to radiotherapy, the blood supply within the flap or on the area where it is being placed, might have been affected by the radiotherapy. The flap might not be receiving enough oxygen to survive and may become dusky before eventually becoming necrotic (dying) and failing.
HBO is most useful early when a problem with flap viability has been identified and where the problem does not need further surgery to address it properly. HBO can provide higher levels of oxygen to a flap, helping meet the energy needs of the tissue.
HBO is not effective when a flap or graft has died (necrosis) so prompt referral is needed when a problem is suspected.
Hyperbaric oxygen is only indicated according to the UHMS in skin grafts or flaps which are showing signs of compromise. This may be due to radiation damage, areas of decreased perfusion or hypoxia. It is not a necessary adjunct in routine cases or for normally healing tissue.
Increasing oxygen tension in the tissue at risk leads to
- Reduction in hypoxic insult to tissue through reactive oxygen species
- Reduction in oedema by restoring cell membrane active transport
- Closure of AV shunts around areas of poor perfusion
- Improved microcirculation within capillaries• Enhanced fibroblast function and collagen synthesis
- Neovascularisation
There are multiple animal studies which have shown improved outcomes in flaps on rats.
In particular, Qirinia and Viidik conducted research on the outcomes of incisional and ischaemic flaps in young and old rats and the impact of additional HBO. They showed that in older rats flaps had higher levels of ischaemia. The use of HBO reversed this finding. The greatest difference in healing was seen in the old rats, but there was also enhanced healing seen in the younger rats.
Perrins et al completed an RCT in 1967 on 48 patients with split skin grafts. The 24 patients that received HBO saw a significant increase in graft survival (64%) vs controls (17%).
It must be borne in mind that HBO is best used as an adjunct to best standard clinical care.
Treatment entails up to 40 sessions of HBO over an 8 week period subject to response to treatment. If surgery is planned then this may be split into pre and post operative treatment.
Information on Referral & Funding ca be found here.
References
The Royal College of Surgeons of Edinburgh
Diploma in Remote and Offshore Medicine
Qirinia(1996)
Qirinia A, Vlidik A “The impact of ischemia on wound healing is increased in old age but can be countered by hyperbaric oxygen therapy.” Mech Ageing Dev. 1996 Oct 25; 91(2):131-44.
Perrins(1967)
Perrins DJ “Influence of hyperbaric oxygen on the survival of split skin grafts.” Lancet 1967 Apr 22; 1(7495):868-71