What are the success rate of carpal tunnel syndrome release after having it for 9 months??

Varies: Some patients don't get full relief of symptoms. Associated joint pathology and chronic tendonitis can interfere with complete symptom relief of preoperative symptoms. Also open technique may get somewhat better results than endoscopic technique. However 90% success rate appears to be expected.

Pretty Bad: According to NIOSH, immediate failure rates ranges from 3% to 25%. Only 23% of patients return to work doing the same job. Within 2 years, there is 57% of all patients with return of symptoms when working the same job. If your doctor recommends a second surgery, they almost all FAIL. Doctors and facilities make make $billions each year for such a bad outcome. Why listen to them?