Effects of Local Administration of Platelet Rich Plasma on Functional Recovery after Bridging Sciatic Nerve Defect Using Silicone Rubber Chamber; An Experimental Study

Abstract

Objective: To determine the effects of local administration of platelet rich plasma (PRP) on peripheral nerve regeneration in rat sciatic nerve transection model.

Methods: Forty-five male white Wistar rats were randomized into three experimental groups (n=15): Normal control group (NC), silicon group (SIL), PRP treated group (SIL/PRP). In NC group left sciatic nerve was exposed through a gluteal muscle incision and after homeostasis muscle was sutured. In SIL group left sciatic nerve was exposed the same way and transected proximal to tibio-peroneal bifurcation leaving a 10-mm gap. Proximal and distal stumps were each inserted into a silicone conduit and filled with 10 µL phosphate buffered solution. In SIL/PRP group silicon conduit was filled with 20 µL PRP. Each group was subdivided into three subgroups of five animals each and were studied 4, 8, 12 weeks after surgery.

Results: The animals were comparable regarding the baseline characteristics. Behavioral testing, sciatic nerve functional study and gastrocnemius muscle mass showed earlier regeneration of axons in SIL/PRP than in SIL group.

Conclusion: Local administration of PRP combined with silicon grafting could accelerate functional recovery of peripheral nerve. Easily available growth factors and bioactive proteins present in PRP may have clinical implications for the surgical management of patients after nerve transection.

Keywords: Functional recovery; Local administration; Peripheral nerve repair; Platelet rich plasma (PRP); Sciatic.

Fig. 1

Pawprints in rats 2 weeks after surgery with for designated measurments: PRP-treated (A) and normal rats (B), toe spread (TS), print length (PL), intermediate toe spresd (IT). E: experimental, N: Normal. Note the elongation of the PL and narrowing of TS and IT in operated limb

Fig. 2

Gastrocnemius muscles dissected and harvested from injured sides. Note to the lesser mass of gastrocnemius muscle of SIL (A) group compared to those of SIL/PRP (B) and NC group (C) 12 weeks after surgery

Fig. 3

BBB score for all experimental groups. Local administration of PRP with silicon grafting gave better scores than in SIL group. Standard error at each data point is shown with bars. *P=0.001 vs SIL group. Data are presented as mean ± SD

Fig. 4

Effects on the sciatic nerve function index (SFI) in each experimental group during the study period.  Statistically significant improvement (P=0.001) was observed in functional recovery of sciatic nerve in PRP treated animals at the end of the study period. *P=0.001 vs SIL group. Data are presented as mean ± SD

Fig. 5

Measurement of gastrocnemius muscle mass. The gastrocnemius muscles of both sides (operated left and unoperated right) are excised and weighed in the experimental groups at 12 weeks after surgery, *P=0.001 vs SIL group. Data are presented as mean ± SD