The latest bit of gee whizz technology, laparoscopic cholecystectomy (gallbladder removal), has been given US official "gold standard" treatment approval for gallstones, even though questions persist about the safety and efficacy of the procedure.

The operation is performed by distending the abdominal cavity of the patient with carbon dioxide and then making a 1 cm incision in the abdomen through which the laparoscopic imaging equipment and surgical instruments are introduced. Guided by the image of the gallbladder and surrounding structures on a video screen, the surgeon needs meticulous skill to isolate the gallbladder ducts and arteries, detach the diseased organ and pull it through the tiny incision.

The American National Institutes of Health recently put together a Consensus Development Panel which convened last September to define who is eligible for the operation and, indeed, when gallbladder removal is warranted.

Because the procedure results in relatively little pain and half the hospital stay and convalescence of the old open operation for gallbladder removal, some 80 per cent of all gallbladder operations are performed with laparoscopes, whether or not the surgeons have been fully trained.

The consensus panel concluded that most patients with symptoms of gallstones are candidates for the laparoscopic procedure, (other than women in the last stages of pregnancy or those with diseased organs near the gallbladder), even though there has never been a large, randomized trial to compare it with open gallbladder surgery.

The consensus also concluded that although complications of this operation are "infrequent", the evidence indicates that the "incidence of bile duct injuries is increased" compared with open surgery.

While the US has sanctioned the new operation, even allowing surgical trainees in Washington DC to try their hands at it, several surgeons from St George's Hospital in Sydney, Australia, sounded a warning about the risk of thromboembolism (potentially fatal blood clots) in patients undergoing this operation.

Out of 400 plus patients, three developed thrombosis, two in the lungs from which one patient died.