Argenine suppletie om de reperfusie schade te verminderen en doorbloeding te verbeteren na vrije weefsel transplantaties.

Partial flap loss due to microvascular failure is first initiated by the incapability of the vascular pedicle to provide sufficient microvascular perfusion in distal segments of the flap. In addition, in free flap surgery the entire flap is affected by ischemia reperfusion injury. The distal segments in free flap surgery are particular vulnerable for ischemia reperfusion injury, and are thus primarily affected by ischemia reperfusion injury which may lead to distal partial flap loss.
Nitric oxide (NO) has been the focus in an extensively amount of studies regarding its use in reducing the IR-injury. It is widely accepted that the L-Arginine-Nitric Oxide pathway plays a pivotal role in the pathophysiology of IR-injury. L-Arginine, the sole precursor of NO, can be metabolized in NO and citruline by a family of tree isoforms of NO synthase (NOS). Endothelial NOS (eNOS) and neuronal NOS (nNOS), these are mainly constitutively expressed by respectively endothelial cells and neuronal cells. Expression of inducible NOS (iNOS) is induced by inflammatory mediators and is mainly expressed in leucocytes. L-Arginine has shown to scavenge free radicals which are expressed during reperfusion. Its end product NO is an important and potent vasodilatator and prevents aggregation and activation of neutrophils and platelets. Furthermore NO concentrations are reduced during ischemia and production remains low after reperfusion. Therefore increasing NO production by stimulating the L-Arginine-NO pathway may lessen the severity of IR-injury. In experimental studies intravenous L-Arginine substantially reduces ischemia-reperfusion injury in cutaneous and musculocutaneous flaps. The purpose of this translational study was to establish the possible protective effect of L-arginine on microvascular perfusion and clinical outcome in free flap surgery.

L-arginine, a precursor of NO, reduces ischemia-reperfusion injury and increases microcirculatory bloodflow. This will lead to a reduction of complications in free flap surgery.

1. After flap dissection;

2. ischemia;

3. reperfusion;

4. 1,2,3,4,5 hours after reperfusion;

5. 1 week outpatient clinic;

6. 6 week outpatient clinic.

Patients received intravenously one liter of either L-arginine (verum group, 30 g L-arginine-HCl / 1L 0.9% NaCl) or an Alanine (placebo group, 25.2 g Alanine / 1L 0.9% NaCl) during a 24 hour period.