A surgical procedure designed to improve the brain's waste-clearing system gained popularity across hundreds of Chinese hospitals before regulators halted it in July 2025, citing insufficient evidence of safety and effectiveness. The procedure, called deep cervical lymphatic-venous anastomosis, connects the brain's lymphatic vessels to neck veins to enhance the removal of toxic proteins linked to Alzheimer's disease. While the scientific rationale sounds plausible, experts emphasize that human evidence remains limited, and the rapid adoption outpaced rigorous clinical testing.

Why Did This Surgery Spread So Quickly Without Proof?

The appeal is understandable. Current Alzheimer's treatments like Leqembi and Kisunla require expensive intravenous infusions, regular MRI monitoring for side effects, and are only available to people in the earliest disease stages. A one-time surgical procedure lasting two to three hours sounds far more convenient by comparison. In 2020, Chinese plastic surgeon Qinping Xi performed the first surgery in an Alzheimer's patient and promoted it online with the slogan "Stop Progressing, Start Recovering." Other Chinese scientists published studies detailing individual cases from single surgical centers, but without control groups for comparison.

The procedure is based on a compelling idea: the brain's lymphatic and glymphatic systems remove toxic proteins like amyloid and tau, which accumulate in Alzheimer's disease. If waste clearance is impaired with aging or disease, improving drainage might help prevent cognitive decline. However, most evidence supporting this mechanism comes from animal studies, not human trials.

"The existing evidence is largely based on experimental data from animal research, and the evidence in humans is limited," said Dr. Per Kristian Eide, a neurosurgeon and professor at Oslo University Hospital.

Dr. Per Kristian Eide, Neurosurgeon and Professor, Oslo University Hospital

What's the Problem With Animal Models?

Mice and rats don't naturally develop Alzheimer's disease, so researchers insert human genetic mutations into these animals to study the condition. This approach has limitations. "Mice and rats are not like humans in all respects, not least when it comes to lymphatic function," Eide cautioned. Additionally, scientists lack standardized measures to confirm whether the surgery actually improves waste clearance in human brains.

Even when researchers can measure changes, the connection between those measurements and actual clinical benefit remains unclear. PET scans can show reduced amyloid levels after anti-amyloid drug treatment, yet under a microscope, some amyloid remains deep in the brain. This gap between what biomarkers show and what's actually happening in brain tissue underscores the challenge of translating laboratory findings into effective treatments.

What Are the Real Risks of This Surgery?

Any invasive procedure carries risks, especially for older, vulnerable patients with cognitive decline. Potential complications include infection, bleeding, nerve injury, and delirium. Additionally, invasive procedures can produce placebo effects, making it difficult to interpret whether reported improvements in cognition are real or psychological.

Patient selection, concomitant treatments, and outcome measures varied widely across the published case reports from China, making it impossible to draw reliable conclusions about the surgery's true effectiveness. Without large, well-controlled, independently monitored studies, the overall complication rate and long-term safety profile remain undefined.

How to Evaluate Emerging Dementia Treatments Responsibly

• Demand Rigorous Trials: Any new treatment should undergo large, randomized controlled trials with blinded participants whenever possible, independent monitoring, and standardized outcome measures before widespread adoption.
• Verify the Mechanism: Proof that a treatment works in animals or in test tubes is not proof it works in humans. Look for evidence that the proposed mechanism actually occurs in human brains, not just in laboratory models.
• Compare to Existing Options: New treatments should be evaluated against current standard care, not just against doing nothing. Consider both efficacy and safety profiles when weighing alternatives.
• Check for Conflicts of Interest: Be cautious when a treatment is promoted primarily by its developer or in media campaigns before peer-reviewed evidence is published in independent journals.

The Chinese government's decision to ban the procedure pending further research reflects this principle. Two large trials are now planned in China: the CLEAN-AD study will follow people with moderate to severe Alzheimer's for one year after surgery, while another trial will track participants for two years. Neither study is blinded, meaning participants will know whether they receive the surgery, which can introduce bias.

In the United States, Dr. Bohdan Pomahac, the Yale plastic surgeon who performed the first face transplant in the country, is planning a safety study of the procedure in five patients in collaboration with Yale's Alzheimer's Disease Research Center. If that succeeds, the procedure will be tested in 15 more individuals. This Yale trial is designed as a prevention study for people who are amyloid-positive, aiming to clear plaques before cognitive decline begins.

"Reported improvements in cognition or symptoms are hard to interpret because invasive procedures can produce placebo effects, and because patient selection, concomitant treatments, and outcome measures vary widely," said Dr. Per Kristian Eide.

Dr. Per Kristian Eide, Neurosurgeon and Professor, Oslo University Hospital

While the rationale behind the surgery is scientifically plausible, its effectiveness remains uncertain. Converging evidence showing effectiveness, proof of the mechanism, and demonstrated safety are needed to transition this procedure from experimental to clinical practice. Until then, deep cervical lymphatic-venous anastomosis remains an intriguing but unproven idea for treating Alzheimer's, a cautionary tale about the importance of patience and rigor in dementia research.