A external investigation has been launched into Alder Hey Children's Hospital after seven so-called "never events" in two years.
Never events are incidents classified by NHS managers as so serious they should never happen, and reviews are carried out every time one occurs.
The children's hospital says no patients came to harm as a result of the incidents and says the investigation shows it has a "transparent and learning culture."
The never events include a teenage boy, 15, who had the wrong tooth removed, an operation on the wrong eye, a swab being left inside a patient and an incorrect implant being inserted into a patient.
Now the Association for Perioperative Practitioners, a body set up to improve safety and quality in operating theatres, has been commissioned to review the incidents.
A report by Liverpool Clinical Commissioning Group in July said: "The trust has had a series of seven Never Events and there is a plan to undertake an external review that has been delayed due to the pandemic response.
"The Trust have approached the Association for Perioperative Practitioners and have agreed the process for the independent review however, as stated, this is delayed.
"The Trust also plan to work with Imperial College London on a peer review and bespoke human factors training to include simulation training and coaching.
"The Trust also plan to produce an overarching action plan to bring together the themes and learning from the seven Never Events. This work is still underway and NHSE/I and CCG had requested a copy of this plan."
A spokesman for Alder Hey said: "These incidents stretch back to 2018. We would wish to make it absolutely clear that although classified as 'Never Events', not a single one resulted in harm to any patient.
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"Alder Hey’s top priority is the safe care of every single child we treat.
"In line with best practice, these incidents were all immediately reported to our regulator and commissioner as soon as they arose and were subject to detailed independent internal investigations and in some cases further review by Imperial.
"The findings from these investigations have all been shared with every family and with all members of staff in Alder Hey. "
