Anterior skull base reconstruction using nasoseptal flap: cadaveric feasibility study and clinical implication [SevEN-001]

Skull base reconstruction using hydroxyapatite and nasoseptal flap versus nasoseptal flap alone: meta-analysis and systematic review

Endoscopic endonasal surgery (EES) is widely employed for interventions in skull base. Despite advancements in surgical techniques, cerebrospinal fluid (CSF) leakage remains a significant concern. The introduction of nasoseptal flap (NSF) dramatically reduced the CSF leakage rates, yet reconstruction techniques continue to vary among institutions and lack standardization. Recently, injectable hydroxyapatite (HA), traditionally used in open skull base reconstruction, has been adapted for use in EES. This study compares the effectiveness of HA and NSF reconstruction with the standard multilayer NSF reconstruction alone. We searched for eligible studies in PubMed, Embase, and Cochrane Library. CSF leakage rates and reconstruction-associated complication rates were thoroughly evaluated. We initially reviewed 3650 records, narrowing down to 13 articles for full-text examination. Of these, 3 retrospective cohort studies met our inclusion criteria, comparing outcomes of HA combined with NSF to NSF alone. The HA plus NSF group tended to exhibit lower rates of CSF leakage compared to the NSF alone group. Similarly, the rate of reconstruction-associated complication was also lower in the HA plus NSF group than in the control group. Skull base reconstruction using HA and NSF can be an effective way to minimize CSF leakage without major complications.

Cadaveric and Computed Tomography Analysis of the Anterior Ethmoidal Artery Flap

BACKGROUND

The anterior ethmoidal artery (AEA) flap has been successful in repairing anterior nasal septal perforations and has been presumed to be axially based on AEA branches coursing through or around the cribriform plate (CP). However, limited evidence supports the flap's axial supply. The purposes of this cadaveric and computed tomography (CT) study were to assess the arterial anatomy from the CP to the septum, and to determine AEA flap length to predict ideal flap base width.

METHODS

Ten fresh latex-injected cadavers were utilized for endoscopic dissection to identify arteries traversing the CPs on each side. First, arterial trajectories along the dorsal septum were recorded. Measurements were then made bilaterally along the septum from the middle turbinate (MT) axilla to the nasal branch of the AEA (NBAEA) traversing the CP. Additionally, 100 sinus CTs were reviewed to measure AEA flap lengths bilaterally.

RESULTS

From 10 cadavers, 20 sides were utilized for measurements. In all cadavers, the AEA septal branches coursed diagonally or horizontally along the dorsal septum, and never directly vertically. The mean distance from the MT axilla to the NBAEA was 1.24 ± 1.93 cm (range = 1-1.5 cm). Based on CTs, the mean AEA flap length was 6.40 ± 0.60 cm.

CONCLUSIONS

Based on the non-vertical courses of AEA septal branches, the AEA flap is more likely a random transposition flap than an axial flap. Average AEA flap length ranged from 6.0 to 7.0 cm. Assuming 3:1 length:width ratios, AEA flap base widths should be about 2.0-2.3 cm.

LEVEL OF EVIDENCE

NA Laryngoscope, 134:2100-2104, 2024.

Reconstruction of the Anterior Skull Base Using the Nasoseptal Flap: A Review

The nasoseptal flap is a workhorse reconstructive option for anterior skull base defects during endonasal surgery. This paper highlights the versatility of the nasoseptal flap. After providing a brief historical perspective, this review will focus on the relevant primary literature published in the last ten years. We will touch upon new applications of the flap, how the flap has been modified to expand its reach and robustness, and some of the current limitations. We will conclude by discussing what the future holds for improving upon the design and use of the nasoseptal flap in anterior skull base reconstruction.