John Cousins used a 3D print-out of his kidney to aid his operation at Southampton General Hospital

Dad-of-two John Cousins, 46, started up his own 3D printing business 18 months ago and began branching out into printing bones for the NHS.

But when he was giving a presentation at his company's headquarters last October to surgeons about the future of 3D Printing in the NHS, he collapsed.

Mr Cousins was taken to hospital and it emerged he had appendicitis - and that night doctors removed his appendix to relieve the pain.

However, scans on his kidney also revealed he had kidney stones which needed to be operated on at a later date.

On a visit to the clinic to speak with the lead stone surgeon at Southampton General Hospital, Mr Cousins sprang the idea of printing his own kidney to help the operation.

He said: "I had my appendix removed at the hospital but then I was talking with a consultant about removing the kidney stones.

"Whilst I was lying in bed I thought, hang on, we could use the technology we have to reconstruct the kidney to assist the surgeon in his operation."

Mr Cousins can use dicom data or CT scans to recreate a 3D image and, because of that, he can then recreate a 3D model using a printer.

Surgeon Bhaskar Somani, a leading researcher in kidney stone operations and who operated on Mr Cousins, sent him his CT scan.

After receiving images from the CT scan, which revealed a kidney stone around 3.5cm by 2.5cm, he used them to print a model used in the operation.

Mr Cousins, from Southampton, then had his two-hour operation on Monday and is expecting to be discharged today.

He said: "It's gone really well and I'm feeling no pain. When it first happened it was like I was weeing razorblades but now I'm feeling great.

"The issue people ask us is why do we do this?

"We've been doing 3D printing for 18 months with a variety of new materials at our organisation.

"It costs just £123 to make that model which took five hours to print and the benefits are huge.

"It's giving patients a greater engagement in understanding what the consultant has found, it's fantastic for visuals, it can be used for training and educating staff too.

"It can be used to plan the accuracy of operations and even reduce operation time.

"In the long run it saves money - for £123 the benefits are amazing and I believe the NHS needs to go down this route sooner rather than later.

"It's funny how it's all come about as I suppose I was in the right place at the right time. We provided both the patient and the technology."

Currently, doctors look at 2D screens to operate on kidneys but 3D scans are used on high-end operations, such as hip replacement surgery.

Mr Somani, 39, said the technology actually helped him plan the accuracy of the operation, which he carried out with radiologist Tim Bryant.

The surgeon of 12 years, who in his three years at Southampton General Hospital has written 40 papers on the latest technology for kidney operations, hopes to carry out a trial with 20 other patients using Tim's firm Isodo3d, where he is the managing director.

He said: "Having a 3D model helps you plan the operation a lot better and the main thing about kidney stone surgery is that that precision is so important.

"To reconstruct a kidney for this purpose is something I don't think anyone has done before.

"When he came into my clinic he said to me 'do you want me to reconstruct this for you?'

"The 3D model of the kidney actually shows where the stone lies inside so when we went in from the outside with the needle the accuracy was slightly better."

Mr Somani, also a urologist for ten years, added: "Clearly he knew what he was talking about once I started to imagine what he could do. It was very impressive.

"We are hoping to work together to get more 3D models in trials for 20 other patients."