What is the success rate of a fasciectomy or a fasciotomy for chronic exertional compartment syndrome?

Fasc. done for acute: Fasciotomy done for acute cmpt. syndr. when muscle viability at risk and cmpt pressure > 20 mmHg. For mild "Shin Splints" rest, elevation and icing is sufficient. Remember fasciotomy caries about 25% decr. leg strength post-op

Not sure: If what you mean by exertional compartment syndrome is what is colloquially known as 'shin splints' then you may experience that after massage. True compartment 'syndrome' would necessitate a surgical treatment known as fasciotomy which is unlikely caused by massage.