The head of the pediatric surgery department at McMaster Children's Hospital said that the deaths of two children following tonsil and adenoid surgeries at his hospital are "tragic" and "very rare".

Dr. Devin Peterson said in a video posted online on Friday - two days after Hamilton Health Sciences announced the children's deaths and its plans for an external review: "We are deeply saddened by their loss and extend our heartfelt condolences to their families."

A statement on the Hamilton Health Sciences website noted that one child died the day after surgery while the other died nine days after the procedure, indicating that the hospital has temporarily suspended all surgeries except for emergency tonsil and adenoid surgeries for children as of Tuesday.

Peterson stated that surgical operations will not resume until the external review is completed.

Addin' "McMaster Children's Hospital is a leading center for pediatrics, and we take this responsibility very seriously."

According to the Canadian Society of Otolaryngology, about five percent of patients experience bleeding after surgery and may need to return to the hospital as a result.

The society's website explained: "A tonsillectomy is considered a major surgical procedure. The main risk is bleeding, which can be serious."

"Most bleeding occurs seven to ten days after surgery, but rarely does bleeding occur after 17 days from the surgery."

Hamilton Health Sciences reported that McMaster Children's Hospital performed 584 tonsil and/or adenoid surgeries for children last year, with 5.8% of patients returning to the emergency department after being discharged from the hospital.

On Friday, the Hamilton Spectator reported that another child who underwent a tonsil and adenoid surgery at the hospital in May began vomiting blood the morning after the procedure.

The newspaper stated that the eight-year-old girl was released hours after the surgery. Her grandfather, Dr. Stephen List, told the Spectator that she became seriously ill and ended up in the intensive care unit, clarifying that she survived but has not fully recovered yet.

In response to a Canadian Press email, a spokesperson for Hamilton Health Sciences said that patient care decisions such as when they can be discharged from the hospital after surgery "are based on the clinical expertise of their care team, standard clinical guidelines, the appropriateness and safety of the patient, and family consent."

Lilian Badiuș, director of risk management and communications, stated in the email that clinical practice guidelines recommend keeping patients who are under three years old or those suffering from severe obstructive sleep apnea overnight for monitoring after undergoing tonsil and/or adenoid surgery.

But for most other children, it is an outpatient procedure.

Badiuș said: "Most children aged three and older who undergo tonsil and adenoid surgery go home the same day in accordance with clinical practice guidelines and after meeting safe discharge criteria."