New surgical procedure shown to improve symptoms of moderate Alzheimer’s disease

SINGAPORE – A new surgical procedure has been shown to improve the behavioural and psychological symptoms associated with mild to moderate Alzheimer’s disease – a neurodegenerative disease that progressively affects cognitive function.

In 2025, Changi General Hospital (CGH) began trialling what is known as the cervical lymphatico-venous bypass for Alzheimer’s disease (CLyVeB-AD-1).

The procedure repurposes lymphatic bypass surgery.

The latter is performed to connect blocked lymphatic vessels to nearby veins, allowing lymph fluid to drain more efficiently, and is typically used to treat lymphoedema, a chronic condition that causes fluid accumulation and painful swelling of the limbs.

CLyVeB-AD-1 connects lymph nodes in the patient’s neck to adjacent veins, which helps to clear amyloid and tau – proteins whose build-up is thought to interfere with the communication between brain cells – via the glymphatic and meningeal lymphatic systems, pathways which act as the brain’s waste removal network.

“This procedure was an opportunity to apply our expertise in lymphatic microsurgery to help patients with Alzheimer’s disease who had limited medical treatment options,” said Clinical Assistant Professor Vincent Tay, a consultant with the plastic, reconstructive and aesthetic surgery service at CGH’s surgery department.

The surgery could not only slow the disease progression in patients, but could also potentially improve their quality of life and ease the caregiving journey for their families, said Prof Tay, the principal investigator for the trial.

“The surgical principles are similar – creating bypass pathways for fluid drainage – but the target is different,” said Clinical Assistant Professor Jeremy Sun, the trial’s co-investigator.

“By connecting neck lymphatic structures to veins to enhance the brain’s natural waste clearance system, we can potentially help clear the toxic proteins that accumulate in Alzheimer’s disease,” said Prof Sun, who heads CGH’s plastic, reconstructive and aesthetic surgery service.

This comes as some 100,000 people are living with dementia in Singapore, about 70 per cent of whom have Alzheimer’s disease.

The CGH trial is believed to be the first South-east Asian clinical trial of the procedure, which was first performed in Hangzhou, China, in 2024.

In 2025, the trial received approval from an institutional review board under the Health Sciences Authority, and was also prospectively registered on clinicaltrials.gov, a website run by the US National Library of Medicine.

Four patients – all women, aged between 61 and 73, with mild to moderate Alzheimer’s – have undergone the procedure here as part of the trial.

In the six months following the procedure, scans showed reductions in toxic protein biomarkers – which are related to Alzheimer’s – in the cerebrospinal fluid of the patients.

The patients showed improved performance on the Mini-Mental State Examination and the Montreal Cognitive Assessment, two tests used to assess for cognitive impairment.

Adjunct Associate Professor Lim Si Ching, also the trial’s co-investigator, noted that one patient with longstanding depression and anxiety seemed to be less anxious after the surgery, while another who had challenges with language became more sociable and communicated better.

Said a family member of one of the patients, who declined to be named: “One noticeable change immediately post-surgery was how she brought up stories from long ago, some that none of us remembered. We observed her disposition becoming more cheerful and her ability to recall things has seen gradual improvements.”

“These changes, while preliminary, represent hope for families who previously had limited medical treatment options for their loved ones with Alzheimer’s disease,” said Prof Lim, who is also a senior consultant with CGH’s geriatric medicine department.

The four patients will undergo further clinical neuropsychological evaluation, MRI and PET (positron emission tomography) scans, as well as blood biomarker analysis within the two-year follow-up period.

The researchers hope to recruit an additional six patients this year as part of the trial’s next phase, said Prof Tay. In the longer term, they hope to recruit 60 more patients as the trial expands to include other institutions, he added.

Should the CLyVeB-AD-1 procedure become part of normal clinical care, there needs to be a rethink of how Alzheimer’s patients are managed, said Prof Tay.

“We really have to see how they change and how we can support them in terms of being sure that they get the most out of the surgery,” he said.

This comes amid other developments such as the creation of monoclonal antibodies – lab-produced proteins that mimic natural antibodies – like lecanemab and donanemab, which target and remove amyloids, thus slowing the progression of Alzheimer’s.

In 2025, lecanemab and donanemab were approved for use in Singapore.

Separately, scientists from Monash University in Melbourne, Australia, and the Yale School of Medicine in the US are developing non-invasive devices that gently stimulate the neck to boost the brain’s lymphatic drainage pathways, which could be used to treat stroke as well as other conditions such as Alzheimer’s.

The CGH team is watching such developments closely as it looks for new ways to support Alzheimer’s patients, said Prof Tay.