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

Inclusion Criteria: 1. Age 50-80 years, male or female. 2. Diagnosed with AD according to NIA-AA criteria. 3. Moderate-to-severe AD dementia, defined as Clinical Dementia Rating Scale Global Score (CDR-GS) ≥1. 4. Mini-Mental State Examination (MMSE) score 10-20. 5. The course of AD more than 6 months. 6. 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. 7. 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. 8. Signed informed consent (from the participant or their relative, and the caregiver). Exclusion Criteria: 1. 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. 2. Other causes of dementia, including vascular dementia, hereditary cerebral small vessel disease, vitamin deficiency, or any other etiology leading to dementia. 3. Previous evidence of severe stenosis (≥70%) in the middle cerebral artery and/or internal carotid artery. 4. Presence of primary psychiatric disorders (such as schizophrenia, schizoaffective disorder, major depressive disorder, or bipolar disorder) rather than psychiatric symptoms caused by AD. 5. 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. 6. History of drug or alcohol abuse or dependence. 7. History of malignant tumors or prior radiotherapy or surgery involving the head and neck. 8. Major surgical procedures or severe head or body trauma within the past 30 days. 9. Presence of other life-threatening conditions with an expected survival time of less than 2 years. 10. Contraindications to head MRI (including cardiac pacemakers/defibrillators, ferromagnetic metal implants, etc.). 11. 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. 12. 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. 13. Requirement for long-term use of antithrombotic medications, with inability to discontinue them before surgery or potential risks associated with discontinuation. 14. Uncontrolled persistent hypertension (systolic blood pressure \>160 mmHg or diastolic blood pressure \>95 mmHg). 15. Co-infection with HIV or Treponema pallidum, or any uncontrolled infectious disease. 16. Use of other investigational drugs or devices within 30 days prior to obtaining informed consent, or current participation in other interventional clinical studies. 17. Pregnancy, lactation, potential for pregnancy, or plans for pregnancy during the study period. 18. 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.