Underlying data set.

Background
Standardized guidelines for optimal tunnel length in tunneled peripherally inserted central catheters (PICCs) are lacking.
Objectives
The objective of this study was to evaluate the real-world impact of tunnel length on clinical outcomes.
Methods
This retrospective cohort study included 207 cancer patients who received tunneled PICCs, categorized into a control group (tunnel length > 4 cm, n = 134) and an observation group (tunnel length ≤ 4 cm, n = 73). Propensity score matching (PSM) was used to address baseline heterogeneity. Cox regression analyses were used to assess the risk of complication during a 120-day follow-up.
Results
Compared to the control group (tunnel length > 4 cm), the observation group (tunnel length ≤ 4 cm) had a significantly higher adjusted overall complication risk (HR = 2.92, 95% CI: 1.07–7.94, P = 0.036) and unplanned catheter removal rate (4.4% vs. 0.0%, P = 0.027), confirming the safety of longer tunnels despite comparable comfort levels between groups. After PSM, Cox regression analysis showed results consistent with those from the unmatched cohort. Subgroup analyses revealed a reduced risk of complications with longer tunnels in patients with BMI ≤ 25 kg/m² (HR = 0.29, 95% CI: 0.11–0.82), without hypertension (HR = 0.36, 95% CI: 0.13–1.00), without diabetes (HR = 0.38, 95% CI: 0.15–0.97), and with solid tumors (HR = 0.31, 95% CI: 0.11–0.85).
Conclusion
The results show that tunnel lengths > 4 cm reduce overall complications and prolong catheter retention, supporting the implementation of standardized protocols while advocating for personalized adjustments based on BMI, comorbidities, and cancer type.