Characteristics of participants
The cohort comprised 187 consecutive PD catheter insertions from January 1, 2015 to December 31, 2016, while 178 eligible cases were included in the analysis. The baseline characteristics are shown in Table 1. The mean age of group P was significantly higher than that of group S (48.07±16.84 years vs. 43.22±13.13 years, P=0.04). There were no significant differences in mean weight or mean BMI. Sex ratio of group P was similar to that of group S, 62.65% (52 cases) and 66.32% (63 cases) of male, respectively, P=0.61. There was a higher incidence of carotid atherosclerosis in group P than in group S, 72.29% (60 cases) vs. 37.89% (36 cases), P<0.001. Respiratory disease was more commonly observed in group P (13.25%, 11 cases) than in group S (none), P<0.001. There was no significant difference in other comorbidities, such as diabetes, hypertension, coronary heart disease or cerebrovascular disease.
Non-infectious complications
Non-infectious complications of the two groups are shown in Table 2. In the present study, none of the patients had insertion failure, visceral injury, leakage, severe bleeding, or hernia development during the early period. Late stage hernia development was observed more commonly in group S (4.21%, 4 cases) than in group P (none), though of no statistical significance. Early mechanical catheter dysfunction rates were similar between the two groups (9.64% and 9.47% for group P and S respectively, P=0.97). Late mechanical dysfunction rates were as well similar (2.41% and 3.16% for group P and S respectively, P=1.00). Total non-infectious complication rates were similar between the two groups (12.05% and 16.84% for group P and S respectively, P=0.37). The results of subgroup analysis (shown in Table 3) were similar to the above.
Infectious complications
Infectious complications of the two groups are shown in Table 2. Early stage catheter related infections were not observed in group P or S. Late stage catheter related infections were similar between group P (none) and group S (1.05%), P=1.00. There were no significant differences in peritonitis rate between the two groups (1.20% vs. 3.16% with P=0.71 in early stage, and 4.82% vs. 11.58% with P=0.11 in late stage). Total infectious complication rate was lower in group P (6.02%) than in group S (15.79%), P=0.04.
The results of subgroup analysis are shown in Table 3. Between different subgroups, only the total infectious complication distribution was significantly different (P=0.02). This difference was driven mainly by subgroup A in which the total infectious complication rate of group P (4.55%) was lower than that of group S (22.73%). Both the early and the late infectious complication distributions showed no difference between subgroup A and B.
One-year catheter survival
The one-year dysfunction-free catheter survivals were similar between the two groups, 71.08% (59 cases) and 74.74% (71 cases) for group P and S, respectively, P=0.58. The one-year infection-free catheter survivals were also similar between the two groups, 75.90% (63 cases) and 68.42% (65 cases) for group P and S, respectively, P=0.27. Similarly, the one-year dysfunction-and-infection-free catheter survivals showed no significance between the two groups, 65.06% (54 cases) and 63.16% (60 cases) for group P and S respectively, P=0.79. The overall catheter survival was also similar between the two groups, 81.93% (68 cases) and 81.05% (77 cases) for group P and S, respectively, P=0.88. The one-year infection-free catheter survival demonstrated the largest gap between the two groups (group P 75.90% vs. group S 68.42%), though not of statistical significance. However, a significant difference appeared in Kaplan-Meier analysis for one-year infection-free catheter survival between group P and S (by log-rank test P=0.04, Figure 2).
The results of subgroup analysis are shown in Table 4. Between different subgroups, the one-year infection-free catheter survival distribution was significantly different. Further, we discovered that in subgroup A the survival of group P (40.91%) was higher than that of group S (22.73%). The one-year dysfunction-free catheter survival, one-year dysfunction-and-infection-free catheter survival, and overall catheter survival distributions were similar between all subgroups. Kaplan-Meier survival analysis confirmed that the one-year infection-free catheter survival of group P was significantly higher than that of group S in subgroup A (by log-rank test P=0.03, Figure 3).