Deep Cervical Lymphatic Venous Anastomosis in the Treatment of Alzheimer's Disease (CLEAN-AD)

Inclusion criteria

• Age 50-80 years, male or female.
• Diagnosed with AD according to NIA-AA criteria.
• Moderate-to-severe AD dementia, defined as Clinical Dementia Rating Scale Global Score (CDR-GS) ≥1.
• Mini-Mental State Examination (MMSE) score 10-20.
• The course of AD more than 6 months.
• If receiving an approved AD treatment, must be on a stable drug dose for at least 3 months prior to Baseline. AD Treatment-naïve subjects can be entered into the study.
• Have an identified caregiver (defined as a person able to support the subject for the duration of the study and who spends at least 8 hours per week with the subject). The caregiver must accompany with the participant at all study follow-up visits.
• Signed informed consent (from the participant or their relative, and the caregiver).

Exclusion criteria

• Any neurological condition other than AD that may affect cognitive function, including stroke, Parkinson's disease, epilepsy, intracranial tumors or space-occupying lesions, traumatic brain injury, intracranial infections, metabolic encephalopathy, etc.
• Other causes of dementia, including vascular dementia, hereditary cerebral small vessel disease, vitamin deficiency, or any other etiology leading to dementia.
• Previous evidence of severe stenosis (≥70%) in the middle cerebral artery and/or internal carotid artery.
• Presence of primary psychiatric disorders (such as schizophrenia, schizoaffective disorder, major depressive disorder, or bipolar disorder) rather than psychiatric symptoms caused by AD.
• Severe neurological deficits in limb movement, language, vision, hearing, or consciousness, or any condition that the investigator determines may prevent the completion of cognitive function assessments.
• History of drug or alcohol abuse or dependence.
• History of malignant tumors or prior radiotherapy or surgery involving the head and neck.
• Major surgical procedures or severe head or body trauma within the past 30 days.
• Presence of other life-threatening conditions with an expected survival time of less than 2 years.
• Contraindications to head MRI (including cardiac pacemakers/defibrillators, ferromagnetic metal implants, etc.).
• Severe diseases or functional impairment of the heart, lungs, liver, kidneys, or other solid organs, making the patient unable to tolerate anesthesia or DC-LVA.
• Severe bleeding tendency (including but not limited to): platelet count \<100×10⁹/L; heparin therapy within the last 48 hours with APTT ≥35 seconds; ongoing warfarin use with INR \>1.7.
• Requirement for long-term use of antithrombotic medications, with inability to discontinue them before surgery or potential risks associated with discontinuation.
• Uncontrolled persistent hypertension (systolic blood pressure \>160 mmHg or diastolic blood pressure \>95 mmHg).
• Co-infection with HIV or Treponema pallidum, or any uncontrolled infectious disease.
• Use of other investigational drugs or devices within 30 days prior to obtaining informed consent, or current participation in other interventional clinical studies.
• Pregnancy, lactation, potential for pregnancy, or plans for pregnancy during the study period.
• Immediate family members of the investigator (spouse, parents, children, or siblings), staff of the research institution or third-party organizations, or any other individuals with potential conflicts of interest related to the study.