Our Team - Crozer-Keystone Health System - PA

Our Team


Our multidisciplinary team includes a nationally-renowned surgeon who is also our director, a board-certified surgeon experienced in all aspects of weight-loss surgery, a physician assistant, a case management nurse, a program coordinator, and registered dietitian.

Our Surgeons and Staff

Aley Tohamy, M.D. - Surgeon and Medical Director

Sergey Zhitnikov, M.D. - Surgeon

Harry Guarino, PA-C - Physician Assistant

Kathleen Nee, R.N., Bariatric Program Administrator

Kaitlin Masciantonio, MA, R.D., L.D.N. - Bariatric Dietitian

Cheryl Stabulis, R.N. – Case Management Nurse

How the Program Works

  • To get started, attend our FREE educational seminar – there’s no obligation, but it’s required as the first step in joining our program.
  • If you decide to pursue surgery, we’ll provide you with all the information, prescriptions and requests for specialty clearances so you can proceed with your pre-operative workup.
  • Our Team will help track and monitor your progress, including obtaining authorization from your insurance company and scheduling your surgery.
    • After surgery, your surgeon and case management nurse will follow up with you at one week, one month, three months, six months, one year and yearly thereafter.
    • Your dietitian will follow up with you at two weeks, 6 weeks, and 4 months. Further follow-up is strongly suggested to stay on track.
  • Monthly support group attendance will help keep you motivated and allow you to share your success with others.