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Anterior Skull Base Defect

Successful resection of complex tumors involving the skull base (SB) depends on the ability to reconstruct the resulting defects.

Endoscopic surgery is safe and effective for ASB reconstruction. Refinements in surgical technique and increasing experience have contributed to improving success rates over the years 1).

Case series


Data from patients who underwent endoscopic endonasal ASB reconstruction in a single Institution between 1998 and 2017 were collected. Patients were stratified according to selected risk factors: sex, age, previous surgery, disease treated (cerebro-spinal fluid leaks, benign tumors, malignant tumors), single or multiple defects, defect dimension (<1cm2, 1-2cm2, 2-6 cm2, >6 cm2) and site (olfactory cleft, ethmoidal roof, planum sphenoidalis, posterior wall of frontal sinus), reconstruction technique (overlay graft, multilayer grafts, pedicled flap) and materials used, post-operative radiotherapy, and year of surgery. Statistical significance was assessed using Fisher's exact tests. A univariate logistic regression was implemented to analyze the association between risk factors and failures.

513 cases met the inclusion criteria with a median follow-up of 96 months (range,12-257). There was a 95%(487/513) success rate for initial repair, with 100% for secondary closure after revision surgery. Failures were not significantly related to sex(p=.54), reconstruction technique(p=.28), location of the defect(p=.65), dimension(p=.69), disease(p=.83), and post-operative radiotherapy(p=.83). The year of surgery, considered as a continuous variable, was associated with a statistically significant reduction of failures (Odd-Ratio= 0.89,p.005).

Endoscopic surgery is safe and effective for ASB reconstruction. Refinements in surgical technique and increasing experience have contributed to improving success rates over the years 2).


From 1995 to 2010 a retrospective review of cases was undertaken. Demographics, histology, surgical management, complications, locoregional control, and survival were analyzed. Results We performed 62 flaps in 57 patients. There was a preponderance of sinonasal malignancies (45%), and most lesions involved the anterior SB (81%). A total of 94% of patients underwent radiotherapy. Reconstruction was undertaken mainly with anterolateral thigh (37%) or radial forearm (34%) flaps. Complications occurred in 17% of patients, and the flap's success rate was 94%.

Free flaps are versatile and highly reliable for reconstructing defects resulting from resections of the SB. They should be considered for SB reconstruction of large three-dimensional defects as well as defects involving an irradiated field. Successful reconstruction of the SB can be performed using a small number of highly dependable flaps 3).

Holzer et al. report the first case of an intracranial and intradural nasal polyposis occurring in a close topographical relation to a previous, iatrogenic anterior skull base defect. The tumour was resected and the skull base defect was closed transnasally by an interdisciplinary team. The histopathological report confirmed recurrent polyposis 4).

1) , 2)
Turri-Zanoni M, Zocchi J, Lambertoni A, Giovannardi M, Karligkiotis A, Battaglia P, Locatelli D, Castelnuovo P. Endoscopic Endonasal Reconstruction of Anterior Skull Base Defects: What Factors Really Affect the Outcomes? World Neurosurg. 2018 May 9. pii: S1878-8750(18)30946-X. doi: 10.1016/j.wneu.2018.04.225. [Epub ahead of print] PubMed PMID: 29753077.
Llorente JL, Lopez F, Camporro D, Fueyo A, Rial JC, de Leon RF, Suarez C. Outcomes following Microvascular Free Tissue Transfer in Reconstructing Skull Base Defects. J Neurol Surg B Skull Base. 2013 Oct;74(5):324-30. doi: 10.1055/s-0033-1353364. Epub 2013 Aug 14. PubMed PMID: 24436932.
Holzer M, Thon N, Stelter K, Rachinger W, Betz CS. Intracranial and intradural nasal polyposis after iatrogenic skull base defect: A case report. Br J Neurosurg. 2016 Jan 13:1-3. [Epub ahead of print] PubMed PMID: 26761416.
anterior_skull_base_defect.txt · Last modified: 2018/05/13 12:14 by administrador