Study protocol for a multicenter randomized controlled pilot study on decompressive laparotomy vs. decompressive craniectomy for intractable intracranial pressure after traumatic brain injury: The SCALPEL study.

Introduction: Decompressive craniectomy (DC) is the ultimate intervention to lower intracranial pressure (ICP) following severe traumatic brain injury (TBI). However, this intervention is associated with considerable adverse events and a higher proportion of survivors with poor functional outcomes. Research question: In a multicompartment system ICP is associated with intraabdominal pressure (IAP) due to cerebral venous outflow from the brain. This is the rationale for decompressive laparotomy (DL) to control ICP after TBI as reported by experimental and retrospective clinical data. The safety profile of DL is superior to DC. This study aims to randomly assign patients with intractable high ICP after severe TBI to DL or DC. Material and methods: Among other inclusion criteria, ICP must be above 20 mmHg (1-12 h) despite sedation and all other measures according to current guidelines. The primary outcome is the Extended Glasgow Outcome Scale assessed after twelve months. Further secondary outcome measures are compartmental pressure values, complications, etc. After 20 initial patients, results will be reviewed by the ethics committees and safety monitoring board to decide on the enrolment of 80 additional patients. Results: The study is designed to provide not only high-quality prospective data for the first time on this treatment approach, its two-stage design (20 + 80 pts) also provides maximum patient safety. This protocol conforms with the SPIRIT 2013 Statement. Ethics approval was granted by our but also 5 other university ethics committees (registration 473/18S). Conclusion: Registration was performed prior to study initiation in November 2021 (registration number NCT05115929).