FIVE-L Classification of Bone Flap Handling in Decompressive Craniectomy

Decompressive craniectomy (DC) is a well-recognized intervention for the management of elevated intracranial pressure following severe traumatic brain injury, stroke, or other causes of malignant cerebral edema.[1] [2] [3] An important intraoperative consideration is how to handle the bone flap after removal.[4] Current strategies vary widely based on institutional resources, surgeon preference, and patient-specific factors.[5] [6] A novel classification system FIVE-L to standardize bone flap handling strategies, improve intraoperative decision-making, and support surgical education can help in following the patients. The FIVE-L classification has five grades (L1 to L5) and each one represents specific strategy of bone handling ([Fig. 1], [Table 1]).

Table 1 FIVE-L classification: bone flap handling strategies

Grade	Strategy	Notes
L1	Leave in situ	Rarely used; associated with higher infection risk if skin integrity is compromised. May be used in selected cases where swelling is minimal
L2	Lock in abdomen	Subcutaneous abdominal storage; low-cost, biologically safe; risk of resorption or infection at storage site. Common in resource-limited settings
L3	Laboratory freeze	Cryopreservation in sterile bone bank; reduces infection risk but requires specialized infrastructure. Often preferred in high-income settings
L4	Lose (discard)	Reserved for contaminated or necrotic bone. Followed by delayed cranioplasty with synthetic material
L5	Load implant	Immediate synthetic cranioplasty using PEEK, PMMA, or titanium. Avoids second surgery but increases cost and operative time

Abbreviations: PEEK, polyetheretherketone; PMMA, polymethylmethacrylate.

Fig. 1 FIVE-L classification: bone flap handling.

This classification can be implemented intraoperatively as a decision-making guide and retrospectively to categorize DC procedures for research, auditing, or quality improvement purposes. The FIVE-L classification provides a practical approach to bone flap management in DC. In addition, it allows neurosurgeons to select an appropriate strategy based on patient condition, infection risk, infrastructure, and available materials. It also facilitates retrospective research, surgical audit, and the development of institutional protocols.

In other words, each strategy has advantages and limitations. For example, while laboratory freezing (L3) offers excellent sterility, it is not always feasible in low-resource settings, where locking the flap in the abdomen (L2) may be more appropriate. Furthermore, an immediate implantation with synthetic materials (L5) is optimal in select cases but requires careful patient selection and additional resources. We believe that implementing the FIVE-L classification is a practical tool for intraoperative decision-making and postoperative planning in DC. It supports safer, evidence-based, and globally adaptable neurosurgical practice.

 

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Conflict of Interest

None declared.

• References

• 1 Alvis-Miranda H, Castellar-Leones SM, Moscote-Salazar LR. Decompressive craniectomy and traumatic brain injury: a review. Bull Emerg Trauma 2013; 1 (02) 60-68
• 2 Janjua T, Narvaez AR, Florez-Perdomo WA, Guevara-Moriones N, Moscote-Salazar LR. A review on decompressive craniectomy for traumatic brain injury: the mainstay method for neurotrauma patients. Egypt J Neurosurg 2023; 38 (01) 75
• 3 Moscote-Salazar LR, M Rubiano A, Alvis-Miranda HR. et al. Severe cranioencephalic trauma: prehospital care, surgical management and multimodal monitoring. Bull Emerg Trauma 2016; 4 (01) 8-23
• 4 Nobre MC, Veloso AT, Santiago CFG. et al. bone flap conservation in the scalp after decompressive craniectomy. World Neurosurg 2018; 120: e269-e273
• 5 Al-Salihi MM, Ayyad A, Al-Jebur MS. et al. Subcutaneous preservation versus cryopreservation of autologous bone grafts for cranioplasty: a systematic review and meta-analysis. J Clin Neurosci 2024; 122: 1-9
• 6 Ernst G, Qeadan F, Carlson AP. Subcutaneous bone flap storage after emergency craniectomy: cost-effectiveness and rate of resorption. J Neurosurg 2018; 129 (06) 1604-1610

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Artikel online veröffentlicht:
22. September 2025