This study employed a multicenter, randomized controlled trial (RCT) design to evaluate the efficacy and safety of deep cervical lymphatic/lymph node-venous anastomosis combined with oral donepezil compared to donepezil monotherapy in patients with Alzheimer's disease and moderate dementia. Participants were randomized using a central randomization system with stratified block design, with the study center and age group (50-64 years, 65-80 years) as stratification factors. While study participants and surgical investigators could not be blinded due to the nature of the intervention, efficacy assessors and imaging specialists remained blinded to ensure the objectivity and reliability of the findings. The intervention group received deep cervical lymphatic/lymph node-venous anastomosis (detailed surgical procedure is specified in the protocol) in combination with oral donepezil (5-10 mg/day), while the control group received oral donepezil alone. The total treatment and follow-up period was 18 months, with assessments conducted at baseline, 1 week, 1, 3, 6, 12, and 18 months post-operation. These included neuropsychological evaluations (MMSE, MoCA, CDR, BADL, IADL, NPI, AES), neuroimaging (MRI, PET, ultrasound), fluid biomarker analyses (CSF and blood levels of Aβ, Tau, neuroinflammatory factors, etc.), and safety monitoring. The primary efficacy endpoint was the change in CDR-SB score at 12 months post-treatment. Secondary endpoints included changes in multiple cognitive scales, neuroimaging metrics, and biomarkers at 18 months. Safety indicators encompassed adverse event recording, vital signs, and laboratory tests.