The focus of Dr. Hijjawi's plastic surgery practice is the reconstructive and aesthetic surgery of the breast. He began this practice in 2005 and has now performed over 1600 primary breast reconstruction procedures in addition to secondary breast reconstructions and cosmetic breast procedures. His training includes a residency and fellowships at Northwestern University in Chicago and the Mayo Clinic in Rochester, Minnesota. In 2006, Dr. Hijjawi won the prestigious Stephen Kroll Fellowship at the University of Gent in Gent, Belgium, where he trained in microvascular breast reconstruction, including performing the DIEP Flap procedure under Dr. Phillip Blondeel, one of the pioneers in breast reconstruction.

Dr. Hijjawi served as the Reconstructive Microsurgery Fellowship Program Director at the Medical College of Wisconsin for 6 years before coming to Intermountain Medical Center in Salt Lake City, Utah. He also serves as the Chief Editor of the American Society of Plastic Surgeons online educational tool, the Plastic Surgery Education Network. Dr. Hijjawi performs many types of breast reconstruction, including the DIEP Flap, the SIEA Flap, the SGAP Flap, AlloDerm breast reconstruction, the Latissimus Flap, and the TUG Flap as well as fat-grafting procedures. Dr. Hijjawi has made over 50 national presentations to other plastic surgeons focusing on breast reconstruction with breast implants, breast reconstruction with the DIEP Flap, and the use of fat grafting in breast reconstruction.