A randomized, single blind, parallel controlled, multicenter clinical study was performed in which patients who had undergone a cerebrospinal fluid to peritoneal shunt that met the criteria were divided into two groups (test and control) in a 1:1 ratio, with the test group applied disinfection by the "three-step sterilization method" and completed the procedure, and the control group underwent the same surgical procedure according to the routine aseptic disinfection procedure, relevant literatures were reviewed and the previous ones in our hospital were summarized, it is intended to conduct a one-year clinical observation of the two groups, to compare the perioperative and long-term infection incidence of the two groups and evaluate them comprehensively, to evaluate whether the "three-step sterilization method" disinfected patients have reduced perioperative and long term infection risk after surgery compared with previous surgery with routine disinfection procedure, and to evaluate their effectiveness.

Data Collection:

Preoperative symptoms and signs, medical records, imaging data, preoperative functional scores (Glasgow score, ADL score, jnphgsr score) were collected.

Data Security Monitoring:

1. Follow-up after surgery according to the study scheme, and comprehensive collection of safety data, for key patient researchers should focus on, in order to comprehensively and early detection of all kinds of adverse events.
2. All adverse events are well documented, properly handled and tracked until they are properly resolved or stable, and serious and unexpected events are reported to the ethics committee, competent authorities, applicants and pharmaceutical supervisory and administrative departments in a timely manner as required;
3. Major investigators regularly conduct cumulative reviews of all adverse events and, if necessary, hold researcher meetings to assess the risks and benefits of the study;

Data Preservation:

The experimental data is stored in Access database and stored locally after entering electronic data. This clinical trial uses the subject's Research Medical Record as the original data source. Researchers need to record the subject's data in the Case Report Form according to the Research Medical Record. The sponsors will verify the integrity, accuracy and authenticity of the data in Case Report Form.After completing the enrollment, complete Case Report Form is required and the first Case Report Form copy is withdrawn by the sponsor.At the end of the study, the original data, informed consent and remaining Case Report Form data will be kept at the various research centers as required.The retention period was 10 years after the end of the clinical trial.

Statistical analysis was performed by double-sided test, with P < 0.05 being statistically significant except for those specified in particular; measurements were described by means, medians, standard deviations, maximum and minimum values; counts or ranks were expressed by frequency and frequency.

Statistical Processing:

Homogeneity between groups was compared by t test, chi-square test or rank sum test.

Efficacy evaluation: Continuous corrected chi-2 test was used to compare the intracranial infection rates within 365 days after surgery. The unilateral 95% confidence interval of difference between the two groups was calculated. If the lower limit of the confidence interval was greater than -10%, the superiority was established, that is, the experimental group was superior to the control group.

Sample Size and Research Plan:

Statistical analysis uses Statistical Product and Service Solutions(SPSS) 26.0 software, the analysis process is all programmed.

The trial was designed for superiority and inferiority according to "Chow, S.C., Shao, J., and Wang, H. 2008. Sample Size Calculations in Clinical Research, Second Edition. Chapman &amp; Hall/CRC. Boca Raton,Florida. "The main efficacy indicators were the intracranial infection rate in one year after operation. The estimated infection rate was 2.8% in the experimental group and 9.5% [18] in the control group. The other relevant parameters were set as follows: Class I error alpha=0.05 (unilateral), test efficiency 1-beta=0.8, and the number of cases in the experimental group and the control group was designed as 1:1.Comparing sample size calculation formulas based on two sample rates:

To calculate the sample size, 156 cases in the experimental group and 156 cases in the control group were obtained. Considering the dropout rate of no more than 15%, 180 cases in the experimental group and 180 cases in the control group were planned to be enrolled. The total number of cases in the two groups was 360.This study requires at least 360 patients to have sufficient test intensity to avoid false negative. In the design of the study, 600 patients were initially recruited, of whom 200 were from our center and 400 were from other centers.

Inclusion Criteria:

1. Age ≥ 18, regardless of gender.
2. Patients with hydrocephalus of high, normal and low pressure caused by various reasons need V-P shunt and meet the operation indications.
3. Before the start of the trial, a written informed consent signed by the subject himself or his legal representative must be obtained.

Exclusion Criteria:

1. Patients who had participated in clinical trials of other drugs or medical devices within 6 months.
2. Patients with abnormal coagulation mechanisms or who had received treatment with thrombolytic agents, anticoagulants, or inhibitors of platelet coagulation within 2 weeks, and patients with hemophilia.
3. Patients with severe diseases of other systems, such as severe diseases of the hematological, respiratory, digestive, and urinary systems, were combined.
4. Patients with co-existing infectious diseases.
5. Pregnant, lactating female patient.
6. Physicians judged other situations in which they could not participate in the trial.
7. The subjects themselves or their legal surrogates refused to participate in the clinical trial.