Intracranial Hypotension Mechanism and Implant Retention Procedure for Patients With Titanium Mesh Exposure

Background and objectives: The study aimed to investigate the potential pathogenesis and present an implant retention procedure for patients with titanium mesh exposure after cranioplasty.

Methods: The clinical data were obtained from 26 consecutive cases with titanium mesh exposure who underwent surgical treatment between 2018 and 2023. These patients' medical records, scalp photographs, operative notes, and outcomes were retrospectively analyzed. In addition, a literature search was conducted for articles describing treatment strategies for titanium mesh exposure published within the past 10 years.

Results: A total of 26 patients (15 males; mean age [±SD] 52.3 ± 15.0 years) underwent surgical treatment for titanium mesh exposure. Among the subset of patients with a history of ventriculoperitoneal shunt implantation (n = 10), low-pressure hydrocephalus was observed in 90% of cases. The pathogenesis of titanium mesh exposure can be categorized into 4 stages: ischemic stage, depletion stage, defect stage, and infection stage, with a median onset time of 392 days (range from 40 to 5114 days). Based on this, we introduce a novel technique of using a pedicled galea aponeurotica-periosteal flap in titanium mesh retention surgery for treating various types of skin defects. Consequently, 15 patients (57.8%) underwent this procedure and exhibited favorable wound healing over a follow-up period averaging at 640.4 ± 397.2 days (range 117-1573 days).

Conclusion: Implant removal surgery is not the optimal choice for patients presenting with titanium mesh exposure after cranioplasty. The 4 stages of skin defect outlined in this study offer clinical guidance for managing cases of titanium mesh exposure, while highlighting intracranial hypotension as an underappreciated pathogenic factor. A pedicle galea aponeurotica-periosteal flap represents a valuable and versatile alternative for retaining the existing titanium mesh, as it ensures adequate blood supply and withstands pressure gradients.