The Underestimated Complication Rate of Decompressive Craniectomy in Pediatric Traumatic Brain Injury^[*]

Decompressive Craniectomy after Severe Traumatic Brain Injury in Children: Complications and Outcome

Decompressive craniectomy for the treatment of refractory increased intracranial pressure (ICP) in pediatric traumatic brain injury is a common surgical procedure. It has been described already in the early years of neurosurgery and became popular in the 1970s. The enthusiasm subsided due to concerns with regard to clinical outcome. Since the 1990s, decompressive craniectomy experienced a renaissance, and numerous case series have been published mainly for the adult population.

Several studies have now focused not only on outcome but also on the complication rate of decompressive craniectomy in pediatric traumatic brain injury.[1] In comparison with adult patients, children exhibit some delicate characteristics, which may have an impact on further treatment decisions. In infants (up to the age of 1.5 years), the skull is still pliable and allows to expand to some extent due to the open cranial sutures. Thus, brain swelling may occur to a certain degree without significant elevation of the ICP. In contrast, in older children, the brain is more voluminous and has less compensatory reserve to tolerate increased ICP. With regard to brain maturation, myelinization will not be complete before the age of 18 to 24 months, thus making the brain of an infant more vulnerable and susceptible for significant damage after trauma. There is common agreement that children may benefit even more from decompressive craniectomy compared with adult patients especially with regard to long-term clinical outcome.[2] [3]

On the other hand, decompressive craniectomy with duroplasty is a highly invasive procedure. Further surgical interventions may become necessary. Not only the reimplantation of the bone flap has to be considered, but occasionally a ventriculo-peritoneal shunt for posttraumatic hydrocephalus or a drainage of subdural hygroma or hematoma become necessary. Other surgical complications include bone flap resorption and infection.

In this issue, Pechmann et al report a cohort of 12 children who received decompressive craniectomies after traumatic brain injuries.[4] The incidence of postoperative complications (up to 83%) is surprisingly high, but other reports support these findings. Bowers et al reported of a 50% rate of postimplantation bone flap resorption and described young age (<2.5 years), hydrocephalus, underlying contusion (as opposed to hemispheric acute subdural hematoma), and a comminuted skull fracture as independent risk factors.[5] In the study of Piedra et al on 61 children, early cranioplasty (within 6 weeks) could reduce the risk of bone flap resorption without influencing the risk for other surgical complications.[6] Also the size of the bone flap seems to matter. According to results from the study of Grant et al, the incidence of bone flap failure correlated significantly with larger skull defects.[7] The method of bone flap storage has also been addressed in many papers, but the conclusions are weak. The risk of bone flap resorption and infection may be lower for frozen bone compared with flaps kept at room temperature.[5] [6] No data are available for the pediatric population with subcutaneous bone flap storage.[8] Finally, the material used for cranioplasty and the mode of fixation may influence the risk of resorption, infection, or other postoperative complications. Rocque et al in their review summarized the data from several available studies and did not come to a final conclusion because of the inconsistent inclusion criteria (decompressive craniectomy for different clinical pathologies) and small sample size when looking at cranioplasty with fresh autograft bone such as ribs or titanium as opposed to methylmethacrylate or stored autologous bone.[8] Nonresorbable sutures for bone flap fixation seem to carry a higher risk of osteolysis as compared with titanium clamps or screw fixation, but the result of Martin et al[3] did not reach statistical significance, probably due to the low number of cases. In our experience, titanium clamps or screws should not been used in children younger than 7 years, and we prefer resorbable plates and screws instead of sutures in this age group.

Decompressive craniectomy is a life-saving procedure in children with severe traumatic brain injury. Nevertheless, further surgical complications have to be taken into account when it comes to cranioplasty. This is highlighted by the current study and other recent series in the literature. Definitive recommendations are difficult to obtain due to small sample size or different inclusion criteria. It would be highly desirable to prospectively review risk factors for cranioplasty in children on a larger cohort to reduce the high incidence of complications accompanied with cranioplasty after decompressive craniectomy.

^* This editorial is a commentary on the article by Pechmann A, Anastasopoulos C, Korinthenberg R, van Velthoven-Wurster V, Kirschner J. Decompressive craniectomy after severe traumatic brain injury in children: complications and outcome. Neuropediatrics 2015;46(1):5–12

• References

• 1 Frassanito P, Massimi L, Caldarelli M, Tamburrini G, Di Rocco C. Complications of delayed cranial repair after decompressive craniectomy in children less than 1  year old. Acta Neurochir (Wien) 2012; 154 (5) 927-933
• 2 Güresir E, Schuss P, Seifert V, Vatter H. Decompressive craniectomy in children: single-center series and systematic review. Neurosurgery 2012; 70 (4) 881-888 , discussion 888–889
• 3 Martin KD, Franz B, Kirsch M , et al. Autologous bone flap cranioplasty following decompressive craniectomy is combined with a high complication rate in pediatric traumatic brain injury patients. Acta Neurochir (Wien) 2014; 156 (4) 813-824
• 4 Pechmann A, Anastasopoulos C, Korinthenberg R, van Velthoven-Wurster V, Kirschner J. Decompressive craniectomy after severe traumatic brain injury in children: complications and outcome. Neuropediatrics 2015; 46 (1) 5-12
• 5 Bowers CA, Riva-Cambrin J, Hertzler II DA, Walker ML. Risk factors and rates of bone flap resorption in pediatric patients after decompressive craniectomy for traumatic brain injury. J Neurosurg Pediatr 2013; 11 (5) 526-532
• 6 Piedra MP, Thompson EM, Selden NR, Ragel BT, Guillaume DJ. Optimal timing of autologous cranioplasty after decompressive craniectomy in children. J Neurosurg Pediatr 2012; 10 (4) 268-272
• 7 Grant GA, Jolley M, Ellenbogen RG, Roberts TS, Gruss JR, Loeser JD. Failure of autologous bone-assisted cranioplasty following decompressive craniectomy in children and adolescents. J Neurosurg 2004; 100 (2) (Suppl Pediatrics): 163-168
• 8 Rocque BG, Amancherla K, Lew SM, Lam S. Outcomes of cranioplasty following decompressive craniectomy in the pediatric population. J Neurosurg Pediatr 2013; 12 (2) 120-125