Surgeons at Andover Surgical Associates


Paul J. Gemis, MD, FACS
  • Undergraduate Education– University of Liege, Belgium
  • Medical School– University of Leige, Belgium
  • Post Graduate Medical Training– University of Massachusetts Medical Center, Worcester, MA
  • Fellowship– Surgical Endoscopy, University of Massachusetts Medical Center, Worcester, MA
  • Clinical Instructor– Tufts University School of Medicine
  • Certified by the American Board of Surgery
  • Fellow of the American College of Surgeons
Nancy Cho Landay, MD, FACS

A graduate of Yale University and Washington University School of Medicine in St. Louis, Dr. Landay completed her residency in General Surgery at Beth Israel Hospital (now Beth Israel Deaconess Medical Center) in Boston. She then completed a one-year position as Surgical Coordinator for Beth Israel’s Department of Surgery as a staff surgeon and Instructor of Surgery at Harvard Medical School.

Dr. Landay joined Andover Surgical Associates in 1995, practicing all aspects of general surgery but with a special interest in breast surgery. Since September 2017, she has focused exclusively on breast care and evaluation and surgical management of breast cancer and other breast disease, using minimally invasive techniques and oncoplastic surgical techniques including breast conservation, skin-sparing and nipple-sparing mastectomy. A member of the American Society of Breast Surgeons (ASBS), Dr. Landay is certified in breast ultrasound, ultrasound-guided breast biopsies and stereotactic breast biopsies with the ASBS. She is also certified in Hidden Scar Breast Surgery techniques by Invuity and offers Biozorb marker placement for breast cancer surgery. She is certified by the American Board of Surgery.

A longtime Andover resident, Dr. Landay is a Yoga Alliance-registered yoga teacher (RYT 200) and enjoys singing with local choruses.

Earl R. Gonzales, MD, FACS

Dr. Gonzales was born in Manila and is a graduate of the University of the Philippines with a Bachelor of Science in Zoology. He obtained his medical degree at the University of the East with top honors. He finished his first General Surgery Residency in the Philippine General Hospital.

He moved to Maryland in 2004 and did a Research Fellowship in Trauma at the Uniformed Services University in Bethesda. He then completed his second General Surgery Residency at the University of Massachusetts in Worcester.

Dr. Gonzales has over 15 years of experience in General Surgery. He is one of the rare breed of surgeons who are well-trained in both open cases as well as minimally invasive surgery. He has special interests in laparoscopic colorectal, complex hernia surgery, acute care and trauma.

He is currently the Trauma Medical Director of the Lawrence General Hospital. He is Certified by the American Board of Surgery and Fellow of the American College of Surgeons. He is also an Advanced Trauma Life Support instructor.

He lives in Andover with his wife and three children. On his spare time, Dr. Gonzales enjoys hiking, cooking and even singing. He is an avid fan of the New England Patriots and Boston Celtics.

Victor Victor Villarreal, MD, FACS

Dr. Villarreal graduated from MIT in 1978 with a degree in Chemical Engineering. He then went on to get his Medical Degree from Harvard Medical school having completed the combined Harvard/MIT Health Sciences and Technology MD program.

Dr. Villarreal got his early surgical training at Johns Hopkins Hospital and then completed his formal surgical training at UMass Medical Center in Worcester. During this time, Dr. Villarreal accepted a commission in the United States Air force Reserve and served 4 years of active duty and 4 as a reservist. He became board certified in 1988 and a Fellow of the American College of Surgeons soon after.

Dr. Villarreal then went into solo practice at United Hospital Center, a large rural referral hospital in Harrison County, West Virginia. There he grew a surgical practice that included advanced laparoscopic surgery, GI endoscopy and trauma. Working at a large rural hospital exposed Dr. Villarreal to a great variety of surgical illness, allowing his surgical skills to grow. Time passed on, Dr. Villarreal’s children left West Virginia to develop their careers and he found himself an empty nester with a bit of wanderlust.

Feeling a call to return to New England, Dr. Villarreal reconnected with his classmate from UMass, Dr. Paul Gemis. He then joined Andover Surgical Associates and relocated to Haverhill in March 2012.

Dr. Villlareal performs laparoscopic gastric bypass as well as sleeve gastrectomy. He is skilled in all aspects of laparoscopic surgery including colon resection, hernia repair, and cholecystectomy. Acute care and trauma continue to be a part of his practice.

When not working, Dr. Villarreal can be found working in his basement shop, scratch building wooden sailing ship models. He likes to keep fit, working out and enjoys road bicycling along the beach on Rt 1a in NH. He and his wife Pat enjoy riding a tandem bike. They are also both amateur foodies. They enjoy exploring the many eateries in the region or trying out a new recipe at home with friends.

Brian Kwitkin, MD
A board-certified general surgeon, Dr. Brian Kwitkin recently completed a Mastery in General Surgery fellowship through the University of Florida/St. Vincent’s Hospital following completion of his surgical training at Cooper University Hospital in New Jersey. Dr. Kwitkin specializes in advanced laparoscopic and minimally invasive procedures, including anti-reflux procedures, small bowel/colon resections, hernia repair, and peritoneal dialysis access.

Before receiving his M.D. from Ross University School of Medicine, Dr. Kwitkin completed his B.S. in Materials Science and Engineering at the University of Florida followed by a M.S. in Biomedical Engineering at the University of Miami. Prior to medical school, his work and research as a biomedical engineer in both the US and Europe led to numerous patents focusing on endovascular stent grafts.

As a father of three, Dr. Kwitkin enjoys spending his free time with his family traveling, attending sporting events, and being outdoors as much as possible.

Seungwhan Pee, MD

Dr. Pee earned his fellowship in Trauma/Surgical Critical Care at Westchester Medical Center. He graduated from Chungnam National University Medical School and completed his residency at Westchester Medical Center.

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