Objective:To explore the effectiveness and complications of non-incision removal of tunneled cuffed catheter (TCC).Methods:The clinical characteristics, surgical plans and complications of patients with TCC removal in the Renal Division of Peking University First Hospital from January 1, 2015 to December 31, 2020 were collected and analyzed retrospectively. The patients were divided into non-incision removal group and traditional incision removal group. The clinical characteristics, procedure success rate, procedural duration and complications were compared between the two groups.Results:A total of 349 patients were included in this study, for whom 368 catheter removal procedures were performed, including 286 procedures in the non-incision removal group, 75 procedures in the traditional incision removal group, and 7 procedures without records of surgical plans. There was no significant difference in age, sex, basic kidney diseases and catheter remaining time and location between the two groups (all P>0.05). Two procedures in the non-incision removal group and 1 procedure in the traditional incision removal group failed respectively, and there was no significant difference in the procedure success rate between the two groups (99.3% vs 98.7%, χ2=0.290, P=0.590). The procedural duration in the non-incision removal group was lower than that in the traditional incision removal group [(5.36±1.70) min vs (17.55±3.28) min, t=44.198, P<0.001]. Among the patients who needed TCC exchange, there was no significant difference in the selection of new catheter position between the two groups ( P=0.330). In terms of complications, there were 2 procedures of local hematoma in the non-incision removal group and 1 procedure of infection in the traditional incision removal group, and there was no severe complication in both groups. Conclusions:There was no significant difference in the procedural success rate and complications between non-incision removal group and traditional incision removal group, and non-incision procedure may be superior in reducing the procedure duration and harm less to the patients. Non-incision procedure is a safe and effective method to remove TCC.

Objective:To explore the association of access blood flow measured by ultrasound dilution and color Doppler ultrasound with patency loss of arteriovenous fistula (AVF).Methods:This was a bidirectional cohort study. The adult patients who underwent maintenance hemodialysis (MHD) with AVF in Peking University First Hospital from January 1, 2018 to July 31, 2020 were enrolled. AVF blood flow was measured by ultrasonic dilution method (Qa), and color Doppler ultrasound in cephalic vein and brachial artery. Patients were divided into low Qa (<500 ml/min), normal Qa (500-1 500 ml/min) and high Qa (>1 500 ml/min) groups according to baseline AVF blood flow measured by ultrasonic dilution method. Qa was monitored every 3 months within the first year. The endpoint events of follow-up were defined as AVF patency loss or death. The deadline of the follow-up was July 31, 2022. Linear regression analysis was used to assess the change trend of Qa. Fine and Gray competitive risk model was used to evaluate the cumulative incidence of AVF patency loss. The Cox proportional hazards regression model was used to evaluate the association between access AVF blood flow and patency loss.Results:A total of 163 patients were enrolled, with age of (57.0±13.7) years old and 110 males (67.5%). The median follow-up time was 45(22, 53) months. Forty-four patients (27.0%) had AVF failure, and 29 patients (17.8%) died. The cumulative incidence rates of AVF patency loss in patients with low Qa, low blood flow of brachial artery and cephalic vein (<500 ml/min), and in those with a downward trend of Qa were higher than those in patients with normal or high blood flow, and in those with a upward trend of Qa (Gray′s test, all P<0.05). After adjusted for age, sex, age of fistula, diabetes and vascular stenosis, multivariable Cox regression analysis results showed that baseline Qa<500 ml/min ( HR=3.508, 95% CI 1.382-8.905, P=0.008), baseline brachial artery flow<500 ml/min ( HR=2.413, 95% CI 1.058-5.503, P=0.036) and a downward trend of Qa ( HR=2.498, 95% CI 1.241-5.027, P=0.010) were independently associated with AVF patency loss. Conclusions:Patients with low baseline value or downward trend of AVF blood flow are at significantly higher risk of patency loss. The brachial artery measurement of AVF blood flow is the preference location for color Doppler ultrasonic.