PRP: Assessing Its Safety and Efficacy

What is the safety and efficacy of platelet-rich plasma (PRP) in adults pertaining to wound healing and aesthetic rejuvenation? As use of PRP expands, a growing number of physicians and patients seek to answer this question. Barring large-scale clinical trials, a systematic literature review offers the best chance of answering this question. Per the Cochrane collaboration, a systematic review evaluates and compiles the findings of multiple clinical trials and provides best evidence to address the chosen research question. Conclusions can then be made and future recommendations suggested.

Search Strategy

A comprehensive search of the current literature was undertaken using three databases—Cochrane Library, Medline via the Pubmed interface, and Google scholar—for an extensive review. The search parameters were limited to all English Language articles from 2006 to 2016, excluding animal studies, in vitro studies, and articles with no measureable endpoint.

The search strategy was designed to select all relevant articles via Mesh terms combined with key text terms to address our research question. Different constructs of search terms were formed by the implementation of truncation of the following terms: PRP wound healing, PRP facial rejuvenation, PRP, platelet-rich plasma, platelet preparations, PRFM platelet-rich fibrin matrix, growth factors, platelet therapy, platelet facial platelet wound healing, platelet plastic surgery AND facial rejuvenation or aesthetic rejuvenation or wound healing

Search Outcome

Initial search yielded 552 publications from Pubmed, nine from Cochrane Library, and 1,470 from Google Scholar. The search term was refined further to identify relevant articles, adhering to the steps of Prisma 2009. A review of the title and abstract of these papers was undertaken to determine their relevance to our research question, and this then yielded 23 potentially relevant papers. Scanning the references of these papers yielded further studies. Next, an in-depth analysis of these papers was carried out to ascertain the level of evidence, quality, and whether they met all of our inclusion and exclusion criteria. Six systematic reviews and one critical review were eventually extracted.

Conclusion

Efficacy. Of the six systematic reviews and one critical review, five evaluated various types of wound healing from post-surgical ulcers, sports related, and two evaluated aesthetic rejuvenation. Studies varied in design, size, and power, hence this lack of uniformity results in complexity in comparison, and poor validity and reproducibility of findings. Reports varied in outcome measures.

In wound healing, common parameters used were complete wound healing, wound area reduction, wound depth, healing rate, time to heal, complications, example wound infection, quality of life, and pain reduction. As wounds cover a wide spectrum, from medical to post surgical, and consist of a wide degree of variation, the studies unfortunately did not indicate a detailed description of the type of wounds investigated to correct for inter wound variability.

In aesthetic rejuvenation, common parameters used were subjective doctor and patient evaluation, photo reviews, and objective skin biopsy, trichoscan hair measurements, etc. Noting the above variation in outcome measures, findings tend to lack statistical power. Several studies lacked controls and split-face comparisons. Studies were often small scale, with few subjects.

There is a high likelihood of publication bias favoring positive results with the use of PRP in both cases, which demonstrated positive effects on cellular changes, wound healing and aesthetic rejuvenation. Many of the studies demonstrated results that were difficult to quantify objectively. PRP treatment protocol lacked standardization for extraction, injection, dosing, and volume. Lack of studies evaluating different forms of PRP and variation in the PRP collection process, which leads to difficulty in comparing studies.

Safety. On the aspect of safety, PRP is superior to filler agents, with self-limiting minor side effects of swelling, erythema and bruising as per QMUL module 8 coursework. The above studies have not reported any long-term or permanent side effects.

Clinical application. With reference to the research question, our findings show that although results are encouraging, high level evidence and high quality RCTs are still lacking. That said, the evidence for wound healing appears to be more substantial than for aesthetic rejuvenation as seen by the quality, design, and number of RCTs.

There is still a wide variation in the types and uses of platelet preparation, with no universal standard. Combination of PRP with other modalities is a big scope for future evaluation, specifically the choice, dosing, sequencing, interval, and frequency.

Large robust RCTs are needed, however a suitable split-face intervention as a control to PRP has yet to be established. Another challenge would be the fact that pharmaceutical companies would hesitate to fund a trial with no intellectual property rights.

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