Experience with 24 cases of reconstructive anterior skull base surgery: classification and evaluation of postoperative facial appearance

Reconstruction in open anterior skull base surgery: A review and algorithmic approach

PURPOSE

Defects resulting from open resection of anterior skull base neoplasms are difficult to reconstruct. Our objective was to review the literature and describe an evidence-based algorithm that can guide surgeons reconstructing anterior skull base defects.

METHODS

A research librarian designed database search strategies. Two investigators independently reviewed the resulting abstracts and full text articles. Studies on reconstruction after open anterior skull base resection were included. Studies of lateral and posterior skull base reconstruction, endoscopic endonasal surgery, traumatic and congenital reconstruction were excluded. Based on the review, a reconstructive algorithm was proposed.

RESULTS

The search strategy identified 603 unique abstracts. 53 articles were included. Adjacent subsites resected, defect size, radiotherapy history, and contraindications to free tissue transfer were identified as key factors influencing decision making and were used to develop the algorithm. Discussion of the reconstructive ladder as it applies to skull base reconstruction and consideration of patient specific factors are reviewed. Patients with a prior history of radiotherapy or with simultaneous resection of multiple anatomic subsites adjacent to the anterior skull base will likely benefit from free tissue transfer.

CONCLUSIONS

Reconstruction of anterior skull base defects requires knowledge of the available reconstructive techniques and consideration of defect-specific and patient-specific factors.

Vascular pedicled flaps for skull base defect reconstruction

OBJECTIVE

Techniques for reconstruction of skull base defects have advanced greatly since the introduction of the vascular pedicled nasoseptal flap in 2006. The objective of this review is to assess the current state of the field by examining both intranasal and extranasal techniques of vascular pedicled skull base defect repair, their indications and success rates, and novel techniques that are currently under investigation.

METHODS

A review of the literature describing the use of vascular pedicled flaps in skull base defect reconstruction was conducted using PubMed and Google Scholar.

RESULTS

The nasoseptal flap remains the most widely used vascular pedicled flap for endoscopic repair of skull base defects. Its ease of harvest, wide arch of rotation, and high success rates make it a popular choice among surgeons. Several variations including a "rescue" nasopseptal flap have been developed. Other less commonly used pedicled intranasal flaps include the middle turbinate flap and the posterior pedicled inferior turbinate flap. Additionally, several novel vascular pedicled flaps have been developed and tested in small cohorts of patients. Extranasal flaps such as the pericranial flap and the temporoparietal fascia flap are used less frequently than intranasal flaps. However, they remain valuable options for reconstruction in certain situations.

CONCLUSION

Advancements continue to be made in the field of skull base defect reconstruction using vascular pedicled flaps. Though the nasoseptal flap remains the most widely utilized option, additional intranasal techniques continue to be developed and tested to optimize surgical outcomes and patient care.

LEVEL OF EVIDENCE

NA.

A Systematic Review on Outcomes of Anterior Skull Base Reconstruction

INTRODUCTION

Anterior skull base resection often results in large defects that need to be reconstructed. This can be done using loco-regional, free flaps or both.

OBJECTIVE

The aim of this systematic review is to evaluate the surgical outcomes (mortality, complication rates and functional outcomes) for patients undergoing anterior skull base reconstruction.

METHODS

Electronic databases (MEDLINE, EMBASE and Scopus) were systematically searched for relevant articles from 1974 to March 2018. A total of 41 studies were included in this systematic review. No randomized controlled trials were identified; therefore, a meta-analysis was not performed.

RESULTS

Mortality from anterior skull base reconstruction were about 0-4% for loco-regional flaps while free flaps were around 0-7%. Overall complications ranged from 0% to 43% in loco-regional flaps, while rate of complications for free flaps ranged from 25% to 66.7%. Flap complications ranged from 0% to 14% for free flaps and 0% to 35% for local flaps. Quality-of-life measures did not differ significantly depending on surgical approach but were worse for patients with malignancies.

CONCLUSION

Due to varying standards of reporting of outcomes, lack of a standardized classification system for anterior skull base defects and absence of clinical trials, we were unable to perform a meta-analysis in this systematic review. Recommendations to guide future studies are proposed.

Outcomes following Microvascular Free Tissue Transfer in Reconstructing Skull Base Defects

Objective Successful resection of complex tumors involving the skull base (SB) depends on the ability to reconstruct the resulting defects. The objective of this study was to assess the outcomes of patients undergoing reconstruction after resection of SB tumors with free flaps. Methods 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%. Conclusion 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.

A new concept for classifying skull base defects for reconstructive surgery

To classify the defects of the skull base, we present a new concept that is intuitive, simple to use, and consistent with subsequent reconstructive procedures. The centers of defects are determined in the anterior (I) or middle (II) skull base. The defects are classified as localized in the defect's center (Ia, IIa) or extended horizontally (Ib, IIb) or vertically (Ic, IIc) from the defect's center. Accompanying defects of the orbital contents and skin are indicated by "O" and "S," respectively. An algorithm for selecting subsequent reconstructive procedures was based on the classification. Using the new system, we retrospectively reclassified 90 skull base defects and examined how the defect classifications were related to the reconstructive flaps used and postoperative complications. All defects were reclassified with the new system without difficulty or omission. The mean correlation rate was high (88%) between the flaps indicated by the new classification and the flaps that had actually been used. The rate of postoperative complications tended to be higher with Ia, Ic, and IIb defects and combined defects. Our new classification concept can be used to classify defects and to help select flaps used for subsequent reconstructive procedures.