Supplementary Material for: The cost of serial cerebrospinal fluid aspirations between ventricular access device (VAD) and ventriculosubgaleal shunt (VSGS) for treatment of post-hemorrhagic ventricular dilatation (PHVD) in premature infants

Introduction: Ventriculosubgaleal shunts (VSGS) require fewer cerebrospinal (CSF) aspirations than ventricular access devices (VAD) for temporization of post-hemorrhagic ventricular dilatation (PHVD) in preterm infants. Cost of postoperative CSF aspiration has not been quantified. Methods: We reviewed CSF aspiration and laboratory studies obtained in preterm infants with PHVD and VAD at our institution between 2009-2020. Cost per aspiration was calculated for materials, labs, and Medicare fee schedule for ventricular puncture through implanted reservoir. We searched PubMed, Cochrane Library, Embase, CINAHL, and Web of Science for meta-analysis of pooled mean number of CSF aspirations and proportion of patients requiring aspiration. Results: Thirty-five preterm infants with PHVD had VAD placed with 22.2±18.4 aspirations per patient. Labs were obtained after every aspiration per local protocol. Cost per aspiration at our institution was $935.51. Of 269 published studies, 77 reported on VAD, 29 VSGS, and 13 both. Five studies on VAD (including the current study) had a pooled mean of 25.8 aspirations per patient (95%CI:16.7-34.8). One study on VSGS reported a mean of 1.6±1.7 aspirations. 3 studies on VAD (including the current study) had a pooled proportion of 97.4% of patients requiring aspirations (95%CI: 87.9-99.5). Four studies on VSGS had a pooled proportion of 36.5% requiring aspirations (95%CI:26.9-47.2). Frequency of lab draws ranged from weekly to daily. Based on costs at our institution, mean number of aspirations, and proportion of patients requiring aspirations, cost difference ranged between $4,243 to $23,235 per patient and $500,903 to 2.36 million per 100 patients depending on frequency of taps and Medicare locality. Discussion/Conclusion: Lower number of CSF aspirations using VSGS can be associated with considerably lower cost compared to VAD.