A comprehensive algorithm for anterior skull base reconstruction after oncological resections

Free temporalis muscle fascia graft in dural reconstruction following surgical resection of intermediate and malignant skull base tumors: A 10-year experience from a single center

BACKGROUND

Data from patients with post-ablative dural defects reconstructed using a free temporalis muscle fascia graft (FTFG) after resection of anterior or central skull base tumors were retrospectively analyzed.

METHODS

The primary predictor and outcome variables were the reconstructive methods for dural repair and postoperative cerebrospinal fluid (CSF) leakage rate, respectively.

RESULTS

Eighty patients were included, and 94 postoperative dural reconstructions were performed using FTFG. The postoperative CSF leakage rate was 3.19%. The postoperative CSF leakage rates did not significantly differ between open and endonasal endoscopic surgeries (1.92% vs. 4.88%; p > 0.05). In cases completed using the endonasal endoscopic approach, the postoperative CSF leakage rate was significantly associated with the intraoperative CSF leak flow (p < 0.05).

CONCLUSIONS

Post-ablative dural defect reconstruction using FTFG resulted in low postoperative CSF leakage and complication rates comparable to those of free fascia lata graft from available literature.

Skull Base Reconstruction by Subsite after Sinonasal Malignancy Resection

Reconstruction after the resection of sinonasal malignancies is complex and primarily dependent on the defect size and location. While the reconstructive paradigm for sellar mass resection is well delineated, the challenges associated with reconstruction after sinonasal malignancy resection are less well described. This narrative review will address the goals of reconstruction after both endonasal endoscopic and open sinonasal malignancy resection and reconstructive options specific to these subsites. The goals of reconstruction include repairing cerebrospinal fluid leaks, restoring sinonasal function, providing a nasal airway, and optimizing the patient's quality of life. These goals are often complicated by the anatomic nuances of each involved sinus. In this review, we will discuss the methods of reconstruction specific to each sinonasal subsite and describe the factors that guide choosing the optimal reconstructive technique.

Use of Temporalis Muscle and Temporoparietal Fasciocutaneous Flap (TPPF) for Orbital Exentration Defects: Our Experience of 10 Cases

Orbital defects represent difficulties in head and neck reconstruction owing to 3-dimensional complexity of the socket with aim to restore form and function. Recommended methods of reconstruction include mucosal and skin grafts free microvascular myofascial or fasciocutaneous flaps. However, most frequently, reconstruction of orbital defects calls for measures somewhere in between. The temporoparietal fascia flap (TPFF) fits well as it provides thin, pliable coverage of defects with dependable blood supply, tolerance for a large degree of rotation and minimal donor site morbidity. We hereby present our experience and results of 10 cases using TPPF and temporalis muscle post orbital exentration defects.Ten patients (7 male and 3 females) age ranging from 25 to 64 years underwent reconstruction of orbital exenteration defects using TPPF and temporalis muscle from June 2019 to June 2020 in our department. The primary disease was squamous cell carcinoma (SCC) of orbital structures (anterior compartment) in all 10 patients. All cases were clinically N0 and M0.All patients had successful transfer of TPFF grafts and temporalis muscle transfer without flap compromise. TPPF was used in all 10 patients while Temporalis muscle flap was used to fill orbital socket in our 9 patients. Temporoparietal fascial flap showed viable option for subtle orbital and malar contour defect. All patients had intact dura with residual orbital cavity after resection reconstructed with TPPF and temporalis muscle without any additional flap usage. No frontal paralysis or orbital fistula was seen but local recurrence occurred in one patient in follow up and managed with RT. The TPFF is one of the most reliable and versatile regional flaps in the head and neck for orbital reconstruction.

Anterior Skull Base Reconstruction

Anterior skull base reconstruction requires careful preoperative planning to use the most effective technique for the expected defect. Adherence to the principles of skull base reconstruction is imperative to minimize complications and improve patient outcomes.

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.

Endoscopic Reconstruction of the Anterior Skull Base Following Tumor Resection: Application of a Novel Bioabsorbable Plate

OBJECTIVE

Endoscopic repair of skull base defects is required following resection of intracranial pathology via the endoscopic endonasal approach (EEA). Many closure techniques have been described, but choosing between techniques remains controversial. We report outcomes of 560 EEA procedures of skull base reconstruction performed on 508 patients over a 15-year-period. Halfway through this period, we adopted the use of a rigid, bioabsorbable extrasellar plate for reconstruction, enabling a comparison between this technique and those used previously.

METHODS

All patients undergoing EEA from 2005 to 2019 at our institution were retrospectively reviewed. Demographic information, surgical pathology, tumor dimensions and radiographic features, reconstructive technique, and patient-related outcomes were collected and analyzed with univariate and multivariate statistical modeling.

RESULTS

Five-hundred sixty procedures were performed on 508 patients. The series complication rate was 8.2%. Overall, cerebrospinal fluid (CSF) leak rate was 5.0% but varied significantly across closure techniques (p < 0.001). Critically, the CSF leak rate in the 272 cases prior to our 2013 adoption of the Resorb-X Plate (RXP) was 8.5%, whereas leak rate in the subsequent 288 cases was 1.7%. RXP was protective against CSF leak (p = 0.001), whereas gross total resection (GTR) correlated with increased leak rate (p = 0.001). Patient BMI was significantly associated with risk of leak (p = 0.047). Other variables did not impact leak risk.

CONCLUSION

Reconstructive technique, extent of resection, and patient BMI significantly contributed to CSF leak rate. GTR was associated with increased leak risk while the RXP was protective. The bioabsorbable RXP is an effective option for rigid skull base repair with comparatively few complications.

LEVEL OF EVIDENCE

3 Laryngoscope, 133:1092-1098, 2023.

Anatomic Considerations of Microvascular Free Tissue Transfer in Endoscopic Endonasal Skull Base Surgery

Objective Though microvascular free tissue transfer is well established for open skull base reconstruction, normative data regarding flap design and inset after endoscopic endonasal skull base surgery (ESBS) is lacking. We aim to describe anatomical considerations of endoscopic endonasal inset of free tissue transfer of transclival (TC) and anterior cranial base resection (ACBR) defects.

Design and Setting Radial forearm free tissue transfer (RFFTT) model.

Participants Six cadaveric specimens.

Main Outcome Measures Pedicle orientation, pedicle length, and recipient vessel intraluminal diameter.

Results TC and ACBR defects averaged 17.2 and 11.7 cm2, respectively. Anterior and lateral maxillotomies and endoscopic medial maxillectomies were prepared as corridors for flap and pedicle passage. Premasseteric space tunnels were created for pedicle tunneling to recipient facial vessels. For TC defects, the RFFTT pedicle was oriented cranially with the flap placed against the clival defect (mean pedicle length 13.1 ± 0.6 cm). For ACBR defects, the RFFTT pedicle was examined in three orientations with respect to anterior–posterior axis of the RFFTT: anteriorly, posteriorly, and laterally. Lateral orientation offered the shortest average pedicle length required for anastomosis in the neck (11.6 ± 1.29 cm), followed by posterior (13.4 ± 0.7cm) and anterior orientations (14.4 ± 1.1cm) (p < 0.00001, analysis of variance).

Conclusions In ACBR reconstruction using RFFTT, our data suggests lateral pedicle orientation shortens the length required to safely anastomose facial vessels and protects the frontal sinus outflow anteriorly while limiting pedicle exposure through a maxillary corridor within the nasal cavity. With greater understanding of anatomical factors related to successful preoperative flap planning, free tissue transfer may be added to the ESBS reconstruction ladder.

Anterior skull base reconstruction using an anterolateral thigh free flap

Background

Galeal or temporalis muscle flaps have been traditionally used to reconstruct skull base defects after tumor removal. Unfortunately, these flaps do not provide sufficient vascularized tissue for a dural seal in extensive defects. This study describes the successful coverage of large skull base defects using anterolateral thigh (ALT) free flaps.

Methods

This retrospective study included five patients who underwent skull base surgery between June 2018 and June 2021. Reconstruction was performed using an ALT free flap to cover defects that included the intracranial space and extended to the frontal sinus and cribriform plate.

Results

There were no major complications, such as ascending infections or cerebrospinal leakage. Postoperative magnetic resonance imaging showed that the flaps were well-maintained in all patients.

Conclusion

Successful reconstruction was performed using ALT free flaps for large anterior skull base defects. In conclusion, the ALT free flap is an effective option for preventing communication between the nasal cavity and the intracranial space.

When is a multidisciplinary surgical approach required in sinonasal tumours with cranial involvement?

The term “sinonasal tumours” includes a large spectrum of diseases, which are characterized by heterogeneous biological behavior and prognosis, and located in a critical anatomic area. Diagnosis and treatment of sinonasal tumours require the contribution of different disciplines. A narrative review was performed to highlight the role of surgeons in contributing to a multidisciplinary approach to sinonasal tumours. Diagnosis and staging of sinonasal tumours is challenging and requires collaboration between surgeons, radiologists, and pathologists. The identification and management of critical extensions (orbital or intracranial encroachment, vascular abutment or encasement) is fundamental for successful treatment. Most cases of advanced sinonasal tumours can undergo surgical intervention by an adequately trained otorhinolaryngological team. The contribution of neurosurgeons and oculoplastic surgeons is required in selected scenarios. In rare circumstances, multidisciplinary reconstructive strategies can be indicated for complex tissue defects. Furthermore, a multidisciplinary approach is pivotal in the management of perioperative complications. While surgery remains the mainstay of treatment, the role of non-surgical adjuvant or even exclusive treatments is constantly expanding.

Free Flap Reconstruction of the Head and Neck Region: A Series of 127 Flaps Performed by Otolaryngologists

Objective:

To determine flap success rate and complications in patients who underwent microvascular free tissue reconstruction after major head and neck ablative surgery and to report the improvement in the results.

Methods:

Medical records of 124 patients who were operated on in 2012 to 2019 were retrospectively reviewed. Indications for different free flap types, success rates and re-exploration rates, donor site morbidities, and reasons for flap loss were analyzed. Patients were divided into two groups to identify the effects of the anticoagulant and the antiaggregant treatments on postoperative results.

Results:

There were 127 flaps in 124 patients, including two different free flaps each in three patients that were harvested and used in the same surgical session. Of the total 127 flaps, 82 (64.6%) were radial forearm flaps, 39 (30.7%) were fibula flaps, and 6 (4.7) were rectus abdominis flaps. Four patients were re-explored for flap perfusion problems, and 18 patients were re-explored for hematoma drainage (n=22/124, %17.3). The rate of hematoma and re-exploration was higher in patients who received anticoagulant and antiaggregant treatments synchronously (p=0.02). Three flaps were lost, and the overall success rate was 97.6%. Two patients died from perioperative complications. No major complications were observed at the donor site; minor complications were observed in 30 patients.

Conclusion:

The success rate for the 127 flaps in 124 patients were found comparable to those reported in the literature. These results show that successful outcomes can be achieved with experience and a head and neck team dedicated to improving the results in microsurgical reconstruction, and flap failure rarely occurs if perioperative care of the patients is given meticulously.

Reconstructive Management of Gunshot Wounds to the Frontal Sinus: An Urban Trauma Center's Perspective

INTRODUCTION

In the last decade, we have seen a steady increase in the incidence of frontal sinus trauma due to gunshot wounds and a decrease in motor vehicle trauma. Penetrating gunshot wounds to the frontal sinus present a unique challenge to the reconstructive surgeon because they require careful consideration of the management principles of plastic surgery. Despite previous reviews on frontal sinus trauma, there are no studies examining the management techniques of frontal sinus fractures due specifically to gunshot wounds. In this study, we aim to retrospectively evaluate the use of a variety of tissue flaps in intervention and associated outcomes.

METHODS

A retrospective chart review was completed on all patients with gunshot wound(s) to the frontal sinus from January 2010 to January 2018 at a single institution. The patients were classified based on the fracture pattern (anterior vs posterior table vs both), degree of displacement, presence of nasofrontal outflow tract injury, and evidence of cerebrospinal fluid leak. Patients were then stratified according to the type of reconstruction performed (cranialization, obliteration and need for free flap) and evaluated for major and minor complications after reconstruction.

RESULTS

In this study, we present outcome data from 28 cases of frontal sinus trauma due to gunshot wounds. There was a statistically significant difference (P = 0.049) in the type reconstructive strategy employed with each type of flap, with pericranial flaps primarily used in cranialization, temporal grafts were more likely to be used in obliteration, and free flaps were more likely to be used in cranialization. The overall major complication rate was 52% (P = 0.248), with the most common acute major complication was cerebrospinal fluid leak (39%) and major chronic was abscess (23.5%).

CONCLUSIONS

This report explores the management of frontal sinus trauma and presents short-term outcomes of treatment for penetrating gunshot wounds at a tertiary referral center.

The Transorbital Pericranial Flap

OBJECTIVE

The objective of the present study was to describe and evaluate the feasibility, mobility, and surface area provided by the simple and extended transorbital pericranial flap (TOPF). Furthermore, we compared this novel technique with the current practice of pericranial flap harvesting and insetting techniques. We also studied the adequacy of the TOPF in the reconstruction of postoperative anterior cranial fossa (ACF) defects.

METHODS

The TOPF was performed bilaterally in 5 alcohol-preserved, latex-injected human cadaveric specimens. The TOPF was harvested in 2 stages: the orbitonasal stage and the cranial stage. For the orbitonasal stage, a transorbital superior eyelid approach was used. We have described 2 harvesting techniques for creating 2 distinct TOPF types (simple and extended) according to the main vascular pedicle. The superficial flap areas offered by the simple and extended TOPF and the traditional bicoronal pericranial flap were calculated and compared. The distances from the supratrochlear and supraorbital arteries to specified anatomical landmarks were also measured. Additionally, the ACF defect area of relevant surgical cases performed using endoscopic transcribriform approaches were measured on immediate postoperative computed tomography head scans using radiological imaging software.

RESULTS

The harvest of both the simple and the extended TOPFs was efficient. As expected, the areas offered by simple and extended TOPFs were smaller than that offered by the traditional bicoronal flap. However, the surface area offered by either the simple or extended TOPF provides sufficient coverage for most ACF defects. A high spatial distribution was observed between the vascular pedicles and their respective foramen or notch.

CONCLUSIONS

The TOPF represents a novel harvesting, tunneling, and insetting technique that offers a large, versatile, pedicled flap for coverage of most standard ACF defects after endoscopic surgery.

Multi-Layer Onlay Graft Using Hydroxyapatite Cement Placement without Cerebrospinal Fluid Diversion for Endoscopic Skull Base Reconstruction

Objective

The skull base reconstruction step, which prevents cerebrospinal fluid (CSF) leakage, is one of the most challenging steps in endoscopic skull base surgery (ESS). The purpose of this study was to assess the outcomes and complications of a reconstruction technique for immediate CSF leakage repair using multiple onlay grafts following ESS.

Methods

A total of 230 consecutive patients who underwent skull base reconstruction using multiple onlay grafts with fibrin sealant patch (FSP), hydroxyapatite cement (HAC), and pedicled nasoseptal flap (PNF) for high-flow CSF leakage following ESS at three institutions were enrolled. We retrospectively reviewed the medical and radiological records to analyze the preoperative features and postoperative results.

Results

The diagnoses included craniopharyngioma (46.8%), meningioma (34.0%), pituitary adenoma (5.3%), chordoma (1.6%), Rathke’s cleft cyst (1.1%) and others (n=21, 11.2%). The trans-planum/tuberculum approach (94.3%) was the most commonly adapted surgical method, followed by the trans-sellar and transclival approaches. The third ventricle was opened in 78 patients (41.5%). Lumbar CSF drainage was not performed postoperatively in any of the patients. Postoperative CSF leakage occurred in four patients (1.7%) due to technical mistakes and were repaired with the same technique. However, postoperative meningitis occurred in 13.5% (n=31) of the patients, but no microorganisms were identified. The median latency to the diagnosis of meningitis was 8 days (range, 2–38). CSF leakage was the unique risk factor for postoperative meningitis (p<0.001).

Conclusion

The use of multiple onlay grafts with FSP, HAC, and PNF is a reliable reconstruction technique that provides immediate and complete CSF leakage repair and mucosal grafting on the skull base without the need to harvest autologous tissue or perform postoperative CSF diversion. However, postoperative meningitis should be monitored carefully.

The transbasal approach to the anterior skull base: surgical outcome of a single-centre case series

A variety of sinonasal tumours, meningiomas or other lesions of the anterior skull base involve the paranasal sinuses and the periorbital area. The transbasal approach (TBA) has turned out to be a feasible technique to reach those lesions. A retrospective review at a neurosurgical university department between November 2007 and January 2020 with adult patients who underwent resection of oncologic pathologies through TBA. Surgical technique, extent of resection (EOR), clinical outcome and postoperative complications were analysed. 18 TBAs between November 2007 and January 2020 were performed. Median age was 62 (range 25–83), 7 female and 11 male patients. Gross total resection rate was 85.8% throughout all entities. Four (22.2%) patients suffered from WHO°I meningiomas and 14 (77.7%) from other extra-axial lesions. Preoperative Karnofsky Performance Status Scale (KPSS) was 80% (range 40–90), postoperative KPSS 80% (range 20–100). Rate of postoperative complications requiring intervention was 16.7%. Median follow-up was 9.8 (range 1.2–71.8) months. Modifications and extensions of the classic TBA are not mandatory. Complete resection can be performed under functional and cosmetic-preserving aspects. Second-step procedures such as transnasal approaches may be performed to avoid high morbidity of more aggressive TBAs, if necessary. Surgical considerations should be kept simple and straightforward.

Primary Repair of Posteriorly Located Anterior Skull Base Dural Defects Using Nonpenetrating Titanium Clips in Cranial Trauma

Objective Primary repair of posteriorly located anterior skull base (ASB) dural defects following cranial trauma is made difficult by narrow operative corridors and adherent dura mater. Inadequate closure may result in continued cerebrospinal fluid (CSF) leak and infectious sequelae. Here, we report surgical outcomes following the use of nonpenetrating titanium microclips as an adjunctive repair technique in traumatic anterior skull base dural defects extending from the olfactory groove to the tuberculum sellae.

Methods All trauma patients who underwent a bifrontal craniotomy from January 2013 to October 2019 were retrospectively reviewed. Patients with ASB defects located at posterior to the olfactory groove were analyzed. Patients with isolated frontal sinus fractures were excluded. All patients presented with CSF leak or radiographic signs of dural compromise. Patients were divided according to posterior extent of injury. Patient characteristics, imaging, surgical technique, and outcomes are reported.

Results A total of 19 patients who underwent a bifrontal craniotomy for repair of posteriorly located ASB dural defects using nonpenetrating titanium microclips were included. Defects were divided by location: olfactory groove (10/19), planum sphenoidale (6/19), and tuberculum sellae (3/19). No patients demonstrated a postoperative CSF leak. No complications related to the microclip technique was observed. Clip artifact did not compromise postoperative imaging interpretation.

Conclusion Primary repair of posteriorly located ASB dural defects is challenging due to narrow working angles and thin dura mater. Use of nonpenetrating titanium microclips for primary repair of posteriorly located dural defects is a reasonable adjunctive repair technique and was associated with no postoperative CSF leaks in this cohort.

The interhemispheric fissure-surgical outcome of interhemispheric approaches

Exposure of the anterior skull base is challenging due to strategic structures. The interhemispheric approach (IHA) has turned out to be a feasible technique. We report our experience with IHAs in patients with extraaxial lesions (EAL). We performed a retrospective chart review at a tertiary neurosurgical center between April 2009 and March 2020. We included patients with resection of EAL through IHAs concentrating on surgical technique, complete resection rate, postoperative outcome, and complications. Seventy-four patients resected by an IHA were included: 49 (66.2%) frontal (FIA), nine (12.1%) parietooccipital (PIA), and 16 (21.6%) frontobasal IHAs (FBIAs). Median age at time of surgery was 59 years (range 16–88 years), 47 (63.5%) female and 27 (36.5%) male. Complete resection rate was 83.8% (FIA 89.8%, PIA 55.6%, FBIA 81.3%). Rate of new minor deficits was 17.6%, rate of major deficits 5.4%, total rate 23.0%. 51 (68.9%) WHO°I meningiomas, ten (13.5%) WHO°II meningiomas, two (2.7%) WHO°III meningiomas, nine (12.2%) metastases, one (1.4%) sarcoma, and one (1.4%) local adenocarcinoma were resected. Total complication rate was 27.0%. Rate of major complications requiring intervention was 9.6%. Mean follow-up was 34.2 (± 33.2) months. In patients with lesions of the interhemispheric fissure, overall morbidity and complications are comparatively high. Extensions of IHAs with potential even higher morbidity are not necessary though; we support the use of standardized IHAs. Our findings suggest regular usage of relatively feasible IHAs for a satisfying outcome. Invasive, complicated, or contralateral trajectories were not needed.

Averting Delayed Complications of Open Anterior Skull Base Surgery

Objectives Despite its technical feasibility, anterior skull base surgery still carries the risk of severe postoperative complications, morbidity, and mortality. The reported rate of complications has diminished over the past two decades, but they continue to pose various challenges. This study aims to report late complications in a relatively large series of patients who underwent open anterior skull base surgery, and to propose methods for averting such complications.

Methods Retrospective chart review of all patients who underwent anterior open skull base surgery between 2000 and 2016 in a university-affiliated tertiary referral cancer center.

Results There were 301 operations, of which 198 (65.8%) were for benign disease and 103 (34.2%) were for malignant tumors. The male-to-female ratio was 1.4:1, and the mean age was 44.8 years. Delayed complications occurred in 85 patients (28.2%): 31 (10.3%) involved wounds, 18 (13.9%) involved the central nervous system, and 14 (4.6%) involved the orbit. Multivariate analysis found malignant pathology, intracranial extension, and previous radiochemotherapy as predictors for the development of a delayed complication. The patients who were operated in the later study period (after 2007) had lower rates of all three types of complications compared with the earlier study period.

Conclusion Delayed complications following skull base surgery are in decline. This is mainly due to the advancement in imaging studies, surgical techniques, development of sophisticated reconstructive procedures, and the cooperation of multidisciplinary teams. We attribute the reduction in our department to our revised treatment protocol which is presented herein, with emphasis on averting the occurrence of these complications.

Level of Evidence The level of evidence is 4.

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.

Free tissue reconstruction of the anterior skull base: A review

Objective

There has been a significant shift from open craniofacial resection of the anterior skull base to endoscopic approaches that accomplish the same outcomes in tumor ablation. However, when open resection is required, free flap reconstruction is often necessary to provide sufficient well-vascularized tissue for optimal wound healing as well as providing adequate tissue bulk for cosmesis. This articleaims to providea focused review of free flaps most commonly used in anterior skull base reconstruction.

Methods

This is a state-of-the-art review based on expert opinion and previously published reviews and journal articles, queried using PubMed and Google Scholar.

Results & conclusion

Anterior skull base reconstruction via free tissue transfer is imperative in limiting complications and promoting healing, particularly with large defects, post-radiation, and in at-risk patients. The type of free flap utilized for a particular anterior skull base reconstruction should be tailored to the patient and nature of the disease. This review offers insight into the numerous reconstructive options for the free flap surgeon.

Clinical study of endoscopic treatment of a sellar pituitary adenomas with sellar diaphragm defect

Background

Invasive growth of pituitary macroadenomas to the suprasellar region occurs commonly. Pituitary adenomas show varying growth patterns when the sellar diaphragm is absent, and they are often confused with other common tumors in the sellar region. This article explores the clinical features of suprasellar pituitary adenomas with defects of the sellar diaphragm (SPADSD) and evaluates the efficacy of the endoscopic endonasal approach (EEA) for treatment of such tumors.

Methods

We performed a detailed examination of records from 19 patients collected prior to surgery. After relevant diseases were excluded, the tumor properties were evaluated according to imaging characteristics. Diagnoses were verified using EEA surgery. The concept of SPADSD was put forward. Postoperative recovery was followed to determine whether EEA is suitable for the treatment of such tumors.

Results

In the 19 patients with SPADSD, we found that the tumors were less stressed on the pituitary, and tumors in the suprasellar region often had irregular shapes. During surgery, we took extended supra-saddle approaches and confirmed that unrestricted growth of the tumor was caused by defects in the diaphragm of the sella turcica to the suprasellar region. Recovery was good after surgery, confirming the efficacy of EEA for treatment of these tumors.

Conclusion

SPADSD has different clinical features from those of other pituitary tumors and requires careful screening prior to surgery. Endoscopic surgery is the preferred procedure for this type of tumor.

Efficacy of simultaneous pericranial and nasoseptal "double flap" reconstruction of anterior skull base defects after combined transbasal and endoscopic endonasal approaches

BACKGROUND

The "double flap" reconstruction technique, comprised of a simultaneous vascularized pedicled pericranial flap (PCF) and pedicled nasoseptal flap (NSF), can be used to repair anterior skull base defects after a combined cranionasal or transbasal-endoscopic endonasal approach (EEA) has been performed to remove malignant anterior skull base tumors. The use of two vascularized flaps may potentially decrease the incidence of post-radiation flap necrosis and postoperative cerebrospinal fluid (CSF) leaks after radiation therapy.

METHODS

We conducted a retrospective review of a prospective skull base database on patients who underwent the double flap reconstruction technique after a combined transbasal-EEA approach. Data collected for each patient included demographics, method of tumor resection and repair, complications, tumor recurrence, and follow-up.

RESULTS

Nine patients who underwent a combined transbasal-EEA approach for resection of anterior skull base tumors with significant intracranial extension followed by reconstruction of the cranial base using the double flap technique. Four were men and five were women, with a mean age of 49 years (range, 15-68 years). There was no postoperative CSF leakage detected or complications of infection, meningitis, mucocele, or tension pneumocephalus after a mean follow-up of 35.7 months (range, 4.5-98 months). Seven of the nine patients underwent adjuvant radiation without flap necrosis. Local tumor recurrence was not observed in any of the patients at last follow-up; however, one patient developed distant brain metastasis.

CONCLUSION

The simultaneous PCF and NSF double flap reconstruction is an effective technique in preventing postoperative CSF leakage and post-radiation necrosis when repairing anterior skull base defects after combined transbasal-EEA approaches. This technique may be useful in patients anticipated to undergo postoperative radiation therapy.

Skull Base Reconstruction with Multilayered Fascia Lata: A Single-Center 17 Years Experience

Objective  Reconstruction after open surgery of anterior skull base lesions is challenging. The fascia lata graft is our workhorse for achieving dural sealing and preventing cerebrospinal fluid leak and meningitis. This study seeks to analyze the donor and recipient site complication rates after fascia lata reconstruction. Methods  This is a retrospective review of all open anterior skull base operations in which a double-layer fascia lata graft was used for the reconstruction of the defect from 2000 to 2016 at the Tel-Aviv Sourasky Medical Center, a tertiary referral center in Israel. Results  Of the 369 patients operated for skull base lesions, 119 underwent open anterior skull base surgery and were reconstructed with a fascia lata graft. The patients' mean age was 47.1 years, and 68 (57.1%) were males. The overall postoperative early and late donor site complication rates were 6.7% ( n  = 8) and 5.9% ( n  = 7), respectively. Multivariate analysis found minor comorbidities and persistent/recurrent disease as being predictors for early-term complications. The overall postoperative early central nervous system (CNS) complication rate was 21.8% ( n  = 26), while 12.6% ( n  = 15) of the patients had late postoperative CNS complications. Conclusion  Reconstruction of open anterior skull base lesions with fascia lata grafting is a safe procedure with acceptable complication and donor site morbidity rates.

Endoscopic Paramedian Forehead Flap Reconstruction of the Anterior Skull Base for Recalcitrant Cerebrospinal Fluid Leaks: Minimally Invasive Adaptation of Ancient Flap

BACKGROUND

The anterior skull base (ASB) remains one of the greatest challenges for reconstructive surgeons. The current armamentarium includes endoscopic placement of free grafts, endonasal vascularized pedicled flaps, regional flaps, and microvascular free flaps. As the defect size increases, reconstruction complexity increases along with potential complications. Here, we report an endoscopic-assisted paramedian forehead flap, a novel adaptation of an age-old technique, for ASB reconstruction.

CASE DESCRIPTION

A 66-year-old male underwent a dual bifrontal and transnasal endoscopic approach for the resection of a T4N0M0 sinonasal squamous cell carcinoma. The resulting ASB defect was repaired using simultaneous pericranial and nasoseptal flaps. Adjuvant radiation therapy resulted in delayed radiation necrosis in the right frontal lobe 3 years later requiring debridement via a supraorbital approach. Recovery from this operation was complicated by an ASB defect and cerebrospinal fluid (CSF) leak. The defect remained despite multiple attempts at endoscopic repairs. Due to multiple medical comorbidities, the patient was not a candidate for microvascular reconstruction. Prior surgeries had disrupted the traditional regional flaps (i.e., pericranial, nasoseptal, and temporoparietal fascia flaps) bilaterally. Therefore the novel endoscopic-assisted paramedian forehead flap was used to successfully repair the ASB defect. Postoperatively, the patient has done well with no recurrences in the CSF leak.

CONCLUSIONS

The endoscopic-assisted paramedian forehead flap is a robust regional flap whose advantages include the utilization of muscle, low donor morbidity, and endoscopic placement with avoidance of craniotomies. Therefore it should be considered an important option for ASB reconstruction of recalcitrant CSF leaks when all other options are unavailable.

Extended temporalis flap for skull base reconstruction

Traditionally, a galeal flap has been used for skull base reconstruction. In addition to the galeal flap, several other flaps, such as the temporalis muscle flap or the free vascularized flap, can be options for skull base reconstruction, and each option has advantages and disadvantages. Certain cases, however, can be challengeable in the application of these flaps. We successfully managed to cover a skull base defect using an extended temporalis flap. Herein, we present the case and introduce this novel method.

Pericranial Flap Anterior Skull Base Reconstruction With Gelfoam Intradural Compression

Anterior cranial base reconstruction is occasionally necessary following severe trauma. Several methods for reconstruction have been described and some authors have described their experiences regarding the use of a pericranial flap for anterior skull base reconstruction after trauma. A 26-year-old woman was admitted to our department with multiple facial bone fractures identified using facial bone computed tomography. Plastic surgeons performed surgery under general anesthesia for the patient's nasal bone fractures. On the seventh day after admission, the patient's brain computed tomography showed an abscess in the frontal lobe. Antibiotic treatment was started, but the lesion deteriorated. Anterior skull base reconstruction was then performed using a pericranial flap with gelfoam compression. No complications, including leakage of cerebrospinal fluid, cerebral hemorrhage, necrosis of the pericranial flap, or frontal lobe herniation, were observed 1 year following surgery. In our case, the authors performed a simple and effective treatment with reconstruction using pericranial flap and gelfoam compression without complications. This technique is useful for reconstructing defects in the base of the frontal bone resulting from various causes, as well as for fracture of the anterior skull base following trauma.

Anterior skull base reconstruction after tumour resection using the posterior wall of the frontal sinus

INTRODUCTION

The authors describe their experience of surgical closure of the anterior skull base after tumour resection, using the posterior wall of the frontal sinus.

MATERIAL AND METHOD

The authors describe their anterior skull base closure technique performed in three patients after tumour resection. Tumour resection via a transglabellar approach resulted in an anterior skull base defect. Reconstruction consisted of direct implantation of the posterior wall of the frontal sinus without using a bone substitute (except when nasofrontal duct obstruction is required).

RESULTS

Three patients were operated by this surgical procedure with complete tumour resection in every case and no infectious complications. This technique was easy to perform, despite one case of persistent CSF leak. Follow-up imaging showed no displacement of the onlay bone graft.

CONCLUSION

Anterior skull base reconstruction after tumour resection using autologous frontal sinus bone graft is easy to perform with a low complication rate.

Side-Door Temporoparietal Fascia Flap: A Novel Strategy for Anterior Skull Base Reconstruction

BACKGROUND

The armamentarium for anterior skull base (ASB) reconstruction includes a variegate spectrum of grafts, endonasal pedicled flaps, regional pedicled flaps, and free flaps, which are selected to face specific scenarios. The use of a vascularized flap in case of large ABS defects ensures an adequate blood supply. The aim of this study was to evaluate the possible role of temporoparietal fascia flap (TPFF) in ASB reconstruction.

METHODS

Eight fresh-frozen head specimens were dissected to evaluate the adequacy of TPFF and pericranial flap (PF) for the reconstruction of ASB defects. The percentage of coverage of the ASB was calculated for TPFF and PF. An anatomic-radiologic analysis was performed to provide useful practical information for flap harvesting and positioning.

RESULTS

The TPFF was easily transposed to the ABS defect through an epidural corridor; the edges of the TPFF were successfully placed in the intradural space, in the epidural space, or on the extracranial surface of the ABS defect. The PF was particularly adequate for median defects, and the TPFF was shown to be useful also in cases with paramedian-supraorbital extension. The median percentage of coverage of the ASB was significantly higher for TPFF (85.1%) than PF (65.7%) (P = 0.018).

CONCLUSIONS

The supraorbital epidural corridor is a possible novel pathway for transposition of the TPFF for ASB reconstruction. Side-door TPFF was shown to be an ideal choice for large ASB defect with lateral supraorbital extension and could be useful in the scenario of salvage reconstruction for recurrent ABS cerebrospinal fluid leak.

Anterior Median Skull Base Reconstruction Using a Vascularized Free Flap: Rationale, Patient Selection and Outcome

Objectives  To present our method of median anterior skull base (ASB) reconstruction using a subcranial approach with a free flap in cases of naso-fronto-orbital (NFO) bony segment failure and in patients at high risk for future failure of the bony frontal segment. Design  This study presents as a retrospective case series. Setting  Tertiary university-affiliated medical center. Participants  Adult and pediatric patients who underwent median ASB resection via the subcranial approach with a free flap reconstruction were participated in this study. Main Outcome Measures  Pathologic outcome and postoperative quality of life (QoL) as assessed by a validated Hebrew version of the "Anterior Skull Base Quality-of-Life Questionnaire." Results  The departmental database yielded 13 suitable patients aged between 15 and 70 years. The main indication ( n  = 7) for ASB surgery was osteoradionecrosis (ORN) of the NFO bony segment which was first detected at an average of 3.6 years (range: 2-32 years) postradiation therapy. High-risk patients for future ORN of the NFO segment ( n  = 3) were primarily reconstructed using a vascularized free flap. Nine patients had malignant disease, and four of them were alive without evidence of disease during the follow-up period (average, 48 months). Their QoL was comparable to that of patients who had undergone subcranial ASB resection without free flap reconstruction. Conclusions  The ASB median free flap method of reconstruction is a safe and reliable in cases of large complex median ASB defects without orbital resection or maxillectomy. This approach is suitable for patients who had undergone previous surgery, radiotherapy and/or those who present with osteoradionecrosis, as well as for patients with high risk of NFO segment ORN.

Impact of Dural Resection on Sinonasal Malignancies with Skull Base Encroachment or Erosion

Objectives  (1) To determine the occult rate of dural invasion in patients with tumors extending to and/or eroding the bony anterior skull base but without evidence of dural invasion on preoperative imaging. (2) To determine the impact of dural resection and of skull base erosion on survival outcomes in this group of patients (without evidence of dural invasion upon preoperative imaging). Study Design  Retrospective study. Setting  Tertiary care academic center. Participants  Patients with sinonasal malignancies with anterior skull base encroachment/erosion without dural invasion on preoperative imaging treated surgically. Main Outcome Measures  (1) Histopathologic disease in the dura in patients who had dural resection and (2) Oncologic outcomes (5-year local recurrence, dural recurrence, disease-specific survival, and overall survival) in patients with and without dural resection, and patients with and without skull base erosion. Results  Thirty-seven patients were included. The occult rate of dural invasion was 54%. Patients with dural resection had improved margin control versus those without dural resection (90% vs 56%, p  = 0.02). Dural resection improved 5-year overall survival only in patients with esthesioneuroblastoma compared with bony skull base resection alone (100% vs 75%, p  = 0.03). Patients with skull base erosion had reduced local control versus those without erosion (63% vs 93%, p  = 0.047). Conclusion  This study suggests a substantial rate of occult dural invasion despite no overt imaging findings. Dural resection may be associated with improved margin control, but no oncologic benefit except for esthesioneuroblastomas, although treatment heterogeneity and small sample size may limit conclusions.

Biomechanical Comparison of the Temporalis Muscle Fascia, the Fascia Lata, and the Dura Mater

The purpose of our research is to prove that elastic biomechanical characteristics of the temporalis muscle fascia are comparable to those of the fascia lata, which makes the temporalis muscle fascia adequate material for dural reconstruction in the region of the anterior cranial fossa. Fifteen fresh human cadavers, with age range from 33 to 83 years (median age: 64 years; mean age: 64.28 years), were included in the biomechanical study. Biomechanical stretching test with the comparison of elasticity among the tissues of the temporalis muscle fascia, the fascia lata, and the dura was performed. The samples were stretched up to the value of 6% of the total sample length and subsequently were further stretched to the maximum value of force. The value of extension at its elastic limit for the each sample was extrapolated from the force-extension curve and was 6.3% of the total sample length for the fascia lata (stress value of 14.61 MPa), 7.4% for the dura (stress value of 6.91 MPa), and 8% for the temporalis muscle fascia (stress value of 2.09 MPa). The dura and temporalis muscle fascia shared the same biomechanical behavior pattern up to the value of their elastic limit, just opposite to that of the fascia lata, which proved to be the stiffest among the three investigated tissues. There was a statistically significant difference in the extension of the samples at the value of the elastic limit for the fascia lata in comparison to the temporalis muscle fascia and the dura ( p  = 0.002; Kruskal-Wallis test). Beyond the value of elastic limit, the temporalis muscle fascia proved to be by far the most elastic tissue in comparison to the fascia lata and the dura. The value of extension at its maximum value of force for the each sample was extrapolated from the force-extension curve and was 9.9% of the sample's total length for the dura (stress value of 10.02 MPa), 11.2% for the fascia lata (stress value of 23.03 MPa), and 18.5% (stress value of 3.88 MPa) for the temporalis muscle fascia. There was a statistically significant difference in stress values at the maximum value of force between the dura and the temporalis muscle fascia ( p  = 0.001; Mann-Whitney U test) and between the dura and the fascia lata ( p  < 0.001; Mann-Whitney U test). Because of its elasticity and similarity in its mechanical behavior to the dura, the temporalis muscle fascia can be considered the most suitable tissue for dural reconstruction.

[Tactics of reconstructive closure of basal defects after resection of midline tumors of the anterior skull base (a literature review)]

The purpose of this review is to analyze the techniques used to reconstruct midline defects in the anterior skull base after transcranial and endoscopic endonasal resection of skull base tumors. We provide brief information on the technique for preparing various flaps, indications and contraindications, and advantages and disadvantages. We analyze the international experience in the use of vascularized and non-vascularized flaps as well as the existing algorithms for reconstruction of complex defects of the midline structures of the skull base. The literature data demonstrate the absence of a conventional tactics of reconstructive closure of the discussed defects. To resolve this issue, a meta-analysis in combination with an original prospective study is required.

Combined Endoscopic Transorbital and Endonasal Repair of High Flow Orbital Apex/Middle Fossa Cerebrospinal Fluid Leak with a Nasoseptal Flap

BACKGROUND AND IMPORTANCE

High flow orbital apex or middle fossa cerebrospinal fluid (CSF) leaks can be life threatening and complex to repair. These leaks associated with large dural defects are most commonly repaired with an open temporalis muscle patch or free flaps, but these flaps do not always stop the leak.

CLINICAL PRESENTATION

A 65-year-old patient presented two years after orbital exenteration and radiation for squamous cell carcinoma. He developed multi-organism meningitis and pneumocephalus secondary to a large high-flow orbital apex/middle fossa CSF leak. To repair the leak, a combined endoscopic transorbital/endonasal approach with pedicled nasospetal flap and dermis fat graft was used. We describe the unique endoscopic technique that was used to treat the life threatening high flow orbital apex/middle fossa CSF leak. The technique allowed the use of the transposed pedicled flap, which is an alternative to the free flap in controlling CSF leak. Cisternogram post-operatively and clinical exam confirmed resolution of CSF leak. Although a critically ill patient at admission with a modified Rankin scale (MRS) of 5, he was discharged home on continued IV antibiotic therapy with a MRS of 3. Endoscopic evaluation at three months after treatment showed the effectiveness of the flap and he continued to improve clinically.

CONCLUSION

This is the first case to describe a combined endoscopic transorbital and endonasal repair of high flow orbital apex/middle fossa CSF leak with a pedicled nasoseptal flap. These techniques can be utilized during initial reconstruction after orbital exenteration or as a salvage flap.

Nasoseptal Flap for Skull Base Reconstruction in Children

Objective  The endoscopic endonasal approach is being increasingly used for the resection and reconstruction of anterior skull base (ASB) lesions. Vascularized nasoseptal flaps (NSF) have become the workhorse for the reconstruction of ASB defects, resulting in a significant decrease in the incidence of cerebrospinal fluid (CSF) leaks. The objective of this study was to investigate the efficacy and safety of NSF in children. Methods  This is a retrospective analysis of the medical records of all patients under the age of 18 years who underwent endoscopic repair of ASB lesions with the use of NSF at our tertiary medical center between 1/2011 and 8/2016. Results  Twelve children underwent ASB defect repair for both benign and malignant neoplasms using the endoscopic endonasal NSF technique. Four children had previously undergone ASB surgery. The male-to-female ratio was 1:1, the average age was 12.3 years, the average hospitalization time was 8.3 days, and the maximum follow-up period was 24 months, during which craniofacial growth appeared to be unimpaired. A lumbar drain was used postoperatively in six cases. Crust formation and synechia were observed in two cases. There was one case of a major long-term complication (a CSF leak followed by meningitis). Conclusions  Endoscopic endonasal NSF was both an effective and a safe technique for ASB defect reconstruction in 12 children for both benign and malignant neoplasms. It had a high success rate and a low complication rate. No apparent negative influence on craniofacial growth was observed in our series.

Surgical Interventions for Advanced Parameningeal Rhabdomyosarcoma of Children and Adolescents

Owing to its rarity, rhabdomyosarcoma of the head and neck (HNRMS) has seldom been discussed in the literature. As most of the data is based only on the retrospective experiences of tertiary healthcare centers, there are difficulties in formulating a standard treatment protocol. Moreover, the disease is poorly understood at its pathological, genetic, and molecular levels. For instance, 20% of all histological assessment is inaccurate; even an experienced pathologist can confuse rhabdomyosarcoma (RMS) with neuroblastoma, Ewing’s sarcoma, and lymphoma. RMS can occur sporadically or in association with genetic syndromes associated with predisposition to other cancers such as Li-Fraumeni syndrome and neurofibromatosis type 1 (von Recklinghausen disease). Such associations have a potential role in future gene therapies but are yet to be fully confirmed. Currently, chemotherapies are ineffective in advanced or metastatic disease and there is lack of targeted chemotherapy or biological therapy against RMS. Also, reported uses of chemotherapy for RMS have not produced reasonable responses in all cases. Despite numerous molecular and biological studies during the past three decades, the chemotherapeutic regimen remains unchanged. This vincristine, actinomycin, cyclophosphamide (VAC) regime, described in Kilman, et al. (1973) and Koop, et al. (1963), has achieved limited success in controlling the progression of RMS. Thus, the pathogenesis of RMS remains poorly understood despite extensive modern trials and more than 30 years of studies exploring the chemotherapeutic options. This suggests a need to explore surgical options for managing the disease. Surgery is the single most critical therapy for pediatric HNRMS. However, very few studies have explored the surgical management of pediatric HNRMS and there is no standard surgical protocol. The aim of this review is to explore and address such issues in the hope of maximizing the number of options available for young patients with HNRMS.

Skull Base Reconstruction in the Pediatric Patient

Introduction  Pediatric skull base and craniofacial reconstruction presents a unique challenge since the potential benefits of therapy must be balanced against the cumulative impact of multimodality treatment on craniofacial growth, donor-site morbidity, and the potential for serious psychosocial issues. Objectives  To suggest an algorithm for skull base reconstruction in children and adolescents after tumor resection. Materials and Methods  Comprehensive literature review and summary of our experience. Results  We advocate soft-tissue reconstruction as the primary technique, reserving bony flaps for definitive procedures in survivors who have reached skeletal maturity. Free soft-tissue transfer in microvascular technique is the mainstay for reconstruction of large, three-dimensional defects, involving more than one anatomic region of the skull base, as well as defects involving an irradiated field. However, to reduce total operative time, intraoperative blood loss, postoperative hospital stay, and donor-site morbidity, locoregional flaps are better be considered the flap of first choice for skull base reconstruction in children and adolescents, as long as the flap is large enough to cover the defect. Our "workhorse" for dural reconstruction is the double-layer fascia lata. Advances in endoscopic surgery, image guidance, alloplastic grafts, and biomaterials have increased the armamentarium for reconstruction of small and mid-sized defects. Conclusions  Skull base reconstruction using locoregional flaps or free flaps may be safely performed in pediatrics. Although the general principles of skull base reconstruction are applicable to nearly all patients, the unique demands of skull base surgery in pediatrics merit special attention. Multidisciplinary care in experienced centers is of utmost importance.

Indication for and Limitation of the Facial Dismasking Flap Approach for Skull Base Surgery to Achieve the Best Esthetical and Functional Results

BACKGROUND

The facial dismasking flap (FDF) approach to operations on the deep skull base region consists of a coronal incision and a circumpalpebral incision. This approach provides a wide surgical field for extirpation of deep extended craniofacial tumors without leaving any undesirable scars on the face. Therefore, the FDF approach can provide satisfactory esthetical and functional results. Meanwhile, in some cases, especially in patients with a history of skull base surgery or orbital extension, patients are not fully satisfied even when the FDF approach is used. In this study, we evaluated the indication for and limitation of the FDF approach.

METHODS

We reviewed 26 patients who underwent the FDF approach for skull base surgery. The patients were 16 men and 10 women, and average age was 37 years. Of these patients, 21 were treated using a hemi-FDF approach, and the remaining 5 were subjected to a bilateral FDF approach. Patients were divided into 2 groups in this study: group A (11 patients), patients with no history of skull base surgery and orbital extension; and group B (15 patients), patients with a history of skull base surgery and/or orbital extension.

RESULTS

There was no FDF loss or facial palsy in either group A or group B. In group A, there was no lagophthalmos or scar contracture of the eyelid. In group B, there were 5 cases (33%) of ectropion and lagophthalmos and 7 of eyelid scar contracture (46%). As for esthetical evaluation, group B showed a significantly higher rate of facial asymmetry than group A. Moreover, in group A, the total ratings for above average reached 90.9%, whereas in group B, nearly half of the patients (48.9%) gave ratings of fair and poor.

CONCLUSIONS

The FDF approach could be a good option for skull base surgery. In particular, patients without a history of skull base surgery and orbital extension could obtain satisfactory esthetical and functional outcomes. However, the procedure had limited effectiveness for patients with a history of skull base surgery or orbital extension because esthetical and functional outcomes inevitably became worse.

Updates in anterior skull base reconstruction

PURPOSE OF REVIEW

This article summarizes the indications and surgical techniques for the reconstructions of anterior skull base defects.

RECENT FINDINGS

There is increasing popularity of the vascularized pedicled flaps in endoscopic skull base surgery for the successful reconstruction of anterior skull base defects, compared with the use of free-tissue grafts. The location and size of the defect as well as the rate of cerebrospinal fluid (CSF) flow are important considerations for selection of the most appropriate reconstructive approach. Recent literature provides evidence suggesting that pedicled flaps may be more effective for clival defects and high-flow CSF leaks, potentially reducing the incidence of postoperative CSF leaks. Although the nasoseptal flap (NSF) continues to be the mainstay of endoscopic skull base reconstruction, alternative vascularized flaps exist when the NSF is impractical or unavailable, and new surgical approaches continue to evolve.

SUMMARY

Vascularized pedicled flaps, and especially the NSF, have greatly reduced complications associated with endoscopic skull base surgery. Multiple considerations should be taken into account during closure of skull base defects, and several options are available to accommodate different needs.

Multidisciplinary approach for reconstruction of cranial defect with polymethyl methacrylate resin reinforced with titanium mesh

Cranial defects occur most commonly as a sequelae to trauma, the incidence being as high as 70%. The successful management of a case of trauma in an emergency situation requires quick evacuation of the hematoma, repair of the dura, and the scalp but not necessarily the integrity of the calvarial segment as an immediate measure. So the reconstruction of the calvarial defect in these cases is mostly carried out as a secondary procedure. Various materials are used for reconstruction of cranial defects, polymethyl methacrylate (PMMA) resin being one of them. In this article, we report a case which was successfully treated by PMMA resin in combination with a titanium mesh for reconstruction of the cranial defect as a secondary procedure.

Tension Pneumocephalus Following Orbital Exenteration

Pneumocephalus is a known complication of skull base surgery, but is rarely seen by orbital surgeons. We report a case of postoperative mental status changes after exenteration due to tension pneumocephalus. After surgical and medical management, the patient's pneumocephalus resolved and she recovered fully. Risk factors for tension pneumocephalus, mechanism, clinical presentation, and management techniques are discussed.

Esthetic Craniofacial Bony and Skull Base Reconstruction Using Flap Wrapping Technique

For a safe and esthetic skull base reconstruction combined with repair of craniofacial bone defects, the authors introduce the flap wrapping technique in this study. This technique consists of skull base reconstruction using the vastus lateralis muscle of an anterolateral thigh (ALT) free flap, and structural craniofacial bony reconstruction using an autologous calvarial bone graft. The key to this technique is that all of the grafted autologous bone is wrapped with the vascularized fascia of the ALT free flap to protect the grafted bone from infection and exposure. Two anterior skull base tumors combined with craniofacial bony defects were included in this study. The subjects were a man and a woman, aged 18 and 64. Both patients had preoperative proton beam therapy. First, the skull base defect was filled with vastus lateralis muscle, and then structural reconstruction was performed with an autologous bone graft and a fabricated inner layer of calvarial bone, and then the grafted bone was completely wrapped in the vascularized fascia of the ALT free flap. By applying this technique, there was no intracranial infection or grafted bone exposure in these 2 patients postoperatively, even though both patients had preoperative proton beam therapy. Additionally, the vascularized fascia wrapped bone graft could provide a natural contour and prevent collapse of the craniofacial region, and this gives patients a better facial appearance even though they have had skull base surgery.

Brain Herniation After Endoscopic Transnasal Resection of Anterior Skull Base Malignancies

BACKGROUND

Endoscopic endonasal approaches, when appropriate, allow a less invasive method to remove anterior skull base cancer than traditional external transfacial/craniofacial approaches. The resultant skull base defect can be significantly large, potentially extending from the posterior table of the frontal sinus to the tuberculum sellae in the sagittal plane, and from one lamina papyracea to the other in the coronal plane. However, frontal lobe herniation after such expanded endoscopic resection has been considered more of a theoretical than a practical occurrence.

OBJECTIVE

To report the occurrence of frontal lobe herniation into the sinonasal cavity after expanded endonasal approaches, and to analyze causes and pathogenetic mechanisms of this unusual complication, proposing how it could have been prevented.

METHODS

Two cases have been observed in 2 different skull base referral centers in the United States and Italy. Surgical and perioperative complications, postoperative course, and need for revisions were analyzed.

RESULTS

Available data support the hypothesis that this complication is not attributable to the size of the anterior skull base defect, to the surgical technique, or to the materials used for the reconstruction. We found that 1 possible contributing factor may be the presence of increased intracranial pressure associated with obesity and obstructive sleep apnea, observed in both patients.

CONCLUSION

Frontal lobe herniation must be considered as a possible, albeit rare, complication of expanded endoscopic anterior skull base resection. Preoperative investigations concerning the presence of obstructive sleep symptoms as well as proper identification of neuroimaging signs of intracranial hypertension are recommended for such cases.

Single-staged resections and 3D reconstructions of the nasion, glabella, medial orbital wall, and frontal sinus and bone: Long-term outcome and review of the literature

BACKGROUND

Aesthetic facial appearance following neurosurgical ablation of frontal fossa tumors is a primary concern for patients and neurosurgeons alike. Craniofacial reconstruction procedures have drastically evolved since the development of three-dimensional computed tomography imaging and computer-assisted programming. Traditionally, two-stage approaches for resection and reconstruction were used; however, these two-stage approaches have many complications including cerebrospinal fluid leaks, necrosis, and pneumocephalus.

CASE DESCRIPTION

We present two successful cases of single-stage osteoma resection and craniofacial reconstruction in a 26-year-old female and 65-year-old male. The biopolymer implants were preselected and contoured based on imaging prior to surgery. The ideal selection of appropriate flaps for reconstruction was imperative. The flaps were well vascularized and included a pedicle for easy translocation. Using a titanium mesh biopolymer implant for reconstruction in conjunction with a forehead flap proved advantageous, and the benefits of single-stage approaches were apparent. The patients recovered quickly after the surgery with complete resection of the osteoma and good aesthetic appearance. The flap adhered to the biopolymer implant, and the cosmetic appearance years after surgery remained decent. The gap between the bone and implant was less than 2 mm. The patients are highly satisfied with the symmetrical appearance of the reconstruction.

CONCLUSIONS

Advances in technology are allowing neurosurgeons unprecedented opportunities to design complex yet feasible single-stage craniofacial reconstructions that improve a patient's quality of life by enhancing facial contours, aesthetics, and symmetry.