Transgastric surgery, or natural orifice translumenal endosurgery (NOTES), as it is officially known, involves passing flexible surgical tools and a camera in through the patient’s mouth to reach the abdominal cavity via an incision made in the stomach lining. Once the operation is over, the surgeon draws any removed tissue back out through the patient’s mouth and stitches up the hole in the stomach. To some it may sound disgusting, to others the prospect of scar-free surgery may sound too good to be true. Either way it’s coming. In the past couple of weeks three separate surgical teams say they have carried out NOTES procedures on humans – surgical firsts for both Europe and the US. And doctors in India say they have performed appendectomies through the mouth.
At the Ohio State University Medical Center, in Columbus, US, 10 patients were diagnosed for possible pancreatic cancer using procedures that entered their bodies via their mouths, while two women, one in New York, the other in Strasbourg, France, had their gall bladders removed by surgeons using a variation in the technique – they reached the abdominal cavity through an incision in the vagina. Like all surgery, NOTES is not without risk – including the possibility of internal bleeding, or post-operative pain caused by inflating the abdominal cavity with carbon dioxide to make it easier to work in. However, the success of the operations may now open the floodgates for large numbers of surgeons who are desperate to try NOTES, making it easier for them to gain ethical approval to try the technique.
In many ways, transgastric surgery is a natural extension of keyhole surgery, in which slim surgical tools are inserted into the abdomen via small incisions in the skin, avoiding a large cut in the belly. It has now become routine for procedures such as gall bladder removal. Transgastric surgery promises to go one better. Much of the discomfort and recovery time after conventional surgery – even keyhole surgery – is due to the incisions made in the abdominal wall. However, because transgastric surgeons reach the abdominal cavity through the mouth, there is no need for an incision, so patients should be back up on their feet much faster, says Jürgen Hochberger at St Bernward Hospital in Hildesheim, Germany. Although an incision is still made in the stomach lining, this is relatively painless, because the stomach has fewer nerve fibres that register pain than our skin.
“Even with keyhole surgery, patients stay off work for several days,” says Lee Swanstrom, director of the Oregon Clinic in Portland, US, which specialises in gastrointestinal and keyhole surgery. “With NOTES they could go back to work the same day.” The reduced pain also makes it possible for the procedure to be carried out under mild sedation, rather than general anaesthetic.
Consequently, elderly or infirm patients who would not be fit enough to receive a general anaesthetic, could still be treated. Going in through the stomach may also reduce the risk of post-operative infections with, say, the drug-resistant superbug MRSA, which often lives on the skin. “If you don’t have skin incisions then you don’t get MRSA,” says Paul Swain, an endosurgeon at Imperial College, London, UK, who is leading UK research into NOTES. And while there is a risk of infecting the abdominal cavity with bacteria from the gastrointestinal tract, animal studies suggest that risk is small. “Stomach acid is pretty cleansing. Not many bugs can stand it,” Swain says.
At least that’s the theory. “At this stage it’s all assumption,” says Per-Ola Park who has been leading NOTES research at Sahlgrenska University Hospital in Gothenburg, Sweden. While highly complex procedures have been successfully demonstrated in pigs, it is difficult to gauge details like levels of pain in animal tests, Park says. Until the evidence is in, there is a danger that NOTES will become over-hyped, with patients becoming blind to the risks, warns Ara Darzi head of surgery at Imperial College London who helped pioneer keyhole surgery in the UK. However, Swain thinks that if surgery can ultimately be made pain-free, convalescence-free and scar-free, whilst reducing the risk of complications and infections then it is something to be greatly encouraged. “Given the choice patients are obviously going to vote to have no scars and are right to do so,” he says.
May 15, 2007
Original web page at New Scientist