Discussion

The debate over the optimal choice between PICC and MC for intravenous therapy in oncology and critical care is ongoing. Both catheter types play essential roles in patient management, yet their associated complications and overall effectiveness require detailed evaluation to inform clinical decision-making. This study aims to address the controversy by systematically comparing the safety profiles of PICC and MC, focusing on complications, cost, and patient satisfaction. Our findings suggest that PICC generally have fewer complications (catheter-related thrombosis [DVT+SVT], catheter-related SVT, infiltrations, and leaks) but are associated with higher costs and greater patient dissatisfaction compared to MC.

Thrombosis is a primary concern with the use of vascular access devices. Our study showed that the rate of catheter-related thrombosis (DVT+SVT) was higher in the MC group, especially when evaluated per catheter days. These results are consistent with previous studies that reported a higher risk of thrombosis with MC, likely due to their shorter length and positioning in peripheral veins, which may predispose patients to venous irritation and subsequent clot formation. ^{Reference Tripathi, Kumar and Kaushik26} In contrast, PICCs extend into larger central veins, potentially providing better hemodilution of infused substances and a reduced risk of thrombosis. ^{Reference Lago, Tiozzo, Boccuzzo, Allegro and Zacchello27} The longer duration of PICC placement, averaging 30.49 days compared to 18.24 days for midlines, may also contribute to the higher rate of thrombosis observed in the PICC group. The prolonged catheter placement may cause mechanical irritation to the vessel wall, leading to endothelial damage and promoting thrombus formation. ^{Reference Siddiqui, Coughlin, Koenen, Al-Yaman, Bestgen and Regueiro28} Additionally, the extended exposure time allows for a greater accumulation of fibrin and other clotting factors around the catheter, which could increase the likelihood of developing DVT. ^{Reference Liu, He, Zeng, Yue, Wei and Zeng29} Moreover, the presence of the catheter over a longer period increases the risk of CRBSIs, which are known to contribute to a hypercoagulable state and further elevate the risk of thrombosis. ^{Reference Sánchez Cánovas, García Torralba, Blaya Boluda, Sánchez Saura, Puche Palao and Sánchez Fuentes30} However, it is important to note that PICCs are not without thrombotic complications, necessitating vigilant monitoring and management to mitigate these risks. ^{Reference Zochios, Umar, Simpson and Jones31}

Beyond thrombosis, other complications associated with these catheters are also critical. Our analysis revealed that MC had higher incidences of infiltrations and leaks, complications that can significantly affect patient comfort and safety. ^{Reference Sharp, Esterman, McCutcheon, Hearse and Cummings7} Conversely, PICCs were more frequently associated with CRBSIs, severe complications that require prompt medical intervention. ^{Reference Mai, Cui, Wang, Tan, Xian and Pai32} This discrepancy suggests that although MC may be preferable in scenarios where reducing the risk of CRBSIs is paramount, PICCs might be more suitable for longer-term use where infiltration and leakage are primary concerns. ^{Reference Seo, Altshuler, Dubrovskaya, Nunnally, Nunn and Ello5} Notably, the lower rates of catheter occlusion and phlebitis in PICCs suggest a more favorable profile for long-term use in stable patients. ^{Reference Meto, Cabout, Rosay, Espinasse, Lot and Hajjam33}

Cost and patient satisfaction are crucial factors influencing the choice of vascular access devices. Our study found that PICCs incur higher costs due to their more complex insertion and maintenance protocols, contributing to higher dissatisfaction rates reported among patients. ^{Reference Chen, Yue, Liao and Li34} The dissatisfaction associated with PICCs may be attributed to the frequent need for maintenance and the discomfort linked to long-term central venous access. On the other hand, MCs, despite their lower costs, often lead to higher complication rates, potentially increasing overall healthcare costs due to the additional treatments required to manage these complications. ^{Reference Lee, Ryu, Hong, Cho, Hong and Bae35} Balancing these factors is vital to optimizing patient outcomes and healthcare resource utilization. Additionally, the patient satisfaction aspect sheds light on the holistic patient care approach. The higher dissatisfaction rates in PICC users could be a result of the invasive nature of the procedure and the associated discomfort over extended periods. ^{Reference Buchanan, Burt, Moureau, Murray and Nizum36} In contrast, MCs, being less invasive, tend to offer better patient comfort despite their higher complication rates. This dichotomy suggests a nuanced approach to catheter selection where patient preferences and clinical indications must be harmonized.

The limitations of this meta-analysis should be considered when interpreting the results. First, the included studies vary in design, population characteristics, and clinical settings, introducing heterogeneity into the analysis. Second, the quality of evidence, as assessed by the GRADE approach, was generally low to very low, reflecting potential biases and limitations in the primary studies. Thirdly, none of the included studies specified whether thrombosis and other adverse events occurred during or after catheter placement, making it challenging to analyze the causes of these complications. Additionally, the reliance on published data may result in publication bias, as studies with negative results are less often published. Future research should include high-quality RCTs with standardized outcome measures to provide more robust evidence. Despite these limitations, our findings contribute valuable insights into the comparative safety profiles of PICC and MC. The higher thrombosis rates observed with MC highlight the need for careful consideration of patient-specific factors when selecting a vascular access device. For instance, patients with a higher risk of thrombotic events may benefit more from PICC, despite their higher costs and maintenance requirements. Conversely, in settings where the risk of infection is a primary concern, and short-term access is sufficient, MC might be the preferred choice.