Doctors in Southampton use pioneering 'string test' to help treat swallowing disease

Doctors at University Hospital Southampton (UHS) are using a pioneering ‘string test’ to help monitor and manage a condition which can cause difficulty in swallowing and eating.

Known as the Coiled oEsophageal String Test (CEST), it involves swallowing a thin piece of specially designed coiled string which is secured to the cheek with tape and unravels when it is washed down with water and enters the stomach.

After 30 minutes the string is removed by gently pulling it out of the mouth and then sent for analysis.

The string collects fluid and proteins from the oesophagus and measures a specific molecule called Eosinophilic Cationic Protein (ECP), which gives a good indication of the degree of inflammation and provides clinicians with an accurate reading of the effectiveness of treatment.

It has been designed to monitor and treat Eosinophilic Oesophagitis (EOE), an emerging chronic inflammatory condition of the oesophagus (the tube connecting the mouth to the stomach) which affects one in 1,000 people.

Symptoms can include reflux, sickness and discomfort while swallowing with food occasionally becoming stuck, known as food bolus obstruction.

Food is a recognised trigger for EOE, with milk and wheat the most common, so changes to patients’ diets are required to exclude possible causes.

Although a high proportion of patients with EOE also suffer with allergies, testing for allergies through blood or skin allergy tests cannot identify the cause of EOE.

Therefore, the only way to determine the impact of dietary changes until now has been through regular endoscopies with biopsies proving invasive for patients as well as costly.

The new non-invasive string procedure, developed by Dr Efrem Eren, a consultant immunologist at UHS, gives a quicker and more cost-effective alternative.

It is a simple way of monitoring patients with EOE and its unique design is safe, comfortable and easy to swallow – even for children as young as six and those who cannot swallow tablets.

Dr Eren said: “Before this test patients would sometimes have to endure numerous invasive endoscopy procedures a year which, especially for children, can be quite traumatic and disruptive.

“The simplicity and ease of this test means they are in and out of hospital within an hour without needing an anaesthetic.

“What really struck me was how relieved parents are knowing that their children will no longer have to undergo regular endoscopies.”

Dr Nadeem Afzal, consultant paediatric gastroenterologist at UHS, said: "Biomarker measurement is a new proven revolutionary method to assess inflammation and reduce the need for repeat endoscopies in chronic conditions like Crohn’s Disease and Colitis.

“Now, for the first time in the UK, we can now offer a string test to children with EOE – another chronic condition – which is a simple to perform during a short 30-minute clinic visit, reducing the stress and anxiety for children and their families and the need for repeat endoscopies.”

Patient Eli Rana, 13, from Southampton, was diagnosed with food allergies (egg and dairy) when he was six months old. Last year he developed difficulties in swallowing, had to cut his food up into small pieces and suffered from severe reflux when eating.

After seeking advice from the allergy clinic at UHS he was referred on to gastroenterology where he was diagnosed with EOE.

He said: “The endoscopy hurts for days after and I have to have time off school, but this is really easy and you hardly feel a thing – I much prefer having it done this way.”

Eli’s mum, Lisa Bolton, said: “We are so grateful to be able to have the string test, it is literally life changing for us. It's such a simple and effective procedure that Eli can have during a school day and return to school straight after.

“The alternative is an invasive and painful procedure, where he would have to miss at least two days off school each time.

She added: “We know a few parents in different parts of the country whose children are needing to have regular endoscopies and they are desperate for the string test to be used near them. We are very lucky to have this at Southampton.”

At present University Hospital Southampton is the only NHS trust in the UK using this test as part of routine practice in adults and children, with more hospitals hoping to adopt the method in the future.