Luke Jenkins died of brain damage after Bristol Children's Hospital op
A boy who died after heart surgery in Bristol suffered brain damage caused by cardiac arrest, an inquest has heard.
Luke Jenkins, seven, from Cardiff, was expected to make a full recovery after the operation at Bristol Children's Hospital in March 2012.
Avon coroner Maria Voisin recorded a narrative verdict saying she had heard "no evidence of gross failure" in the care he received in hospital.
Luke's mother said she still believed his death had been preventable.
Faye Valentine, 28, said she could not rule out legal action and that the family still had many concerns.
'Panic and disorganisation'
The coroner said Luke, who was born with a congenital heart defect, died as a result of brain damage caused by a heart attack.
This followed a catastrophic bleed in his chest a week after heart surgery on 30 March 2012.
Ms Voisin said she was happy with the steps the hospital had taken following the incident and she had no further recommendations to make.
A health trust report released in September revealed a series of errors that contributed to Luke's death, including staff shortages and staff not knowing where to find resuscitation equipment after he suffered cardiac arrest.
Luke's father, Stephen Jenkins, had described a situation of "panic and disorganisation" among hospital staff on Ward 32 when his son suffered a cardiac arrest.
He told the inquest in a written statement that while his son was on that ward, he and his partner had concerns that Luke was not receiving the appropriate level of care.
He said they requested that he be returned to the paediatric intensive care unit but "our request was denied and Luke remained on Ward 32".
The boy's parents also had concerns that the ward "seemed short-staffed" and that "throughout those first two days, there were sporadic observation checks".
Mr Jenkins said his son complained of pain in his abdomen on 2 April and the next day seemed very "withdrawn and quiet".
The court heard that on 6 April Luke began complaining of severe chest pains.
Before the cause could be investigated, he suffered a cardiac arrest.
On 9 April his parents took the decision to switch off their son's life support machine.
A report by an investigative team at University Hospitals Bristol NHS Foundation Trust said "the workload and patient dependency is recognised as being significant" in Luke's death.
However, the coroner heard evidence of changes made by the trust since Luke's death.
Miss Valentine said she regarded the changes as an admission by the trust that mistakes had been made over his care.
"We still have a lot of concerns and some more from hearing the evidence," she said.
"We understand the coroner is not there to establish blame.
"Maybe that's something for later on. But they [the trust] played a big part in what happened to Luke and again that's probably part of our questions that weren't answered."