A 34 year old female has presented to you at a GP surgery with complaining that the digits on her left hand tend to change colour during cold weather. She complains that she is experiencing more pain now than she has done in the past. She has tried your recent advice on exercising, quitting smoking and avoiding sudden temperature changes but she complains that these symptoms are having a significant negative impact on her quality of life. What is the next most appropriate step in her treatment?