Endoscopic Transnasal Management of Meningoceles and Encephaloceles in Children: A Systematic Review

OBJECTIVE

To review surgical techniques used in the endoscopic transnasal repair of pediatric basal meningoencephaloceles and compare perioperative outcomes in children <2 and ≥2 years old.

DATA SOURCES

MEDLINE, EMBASE, and CENTRAL.

REVIEW METHODS

Data sources were searched from inception to August 22, 2022, using search terms relevant to endoscopic transnasal meningoencephalocele repair in children. Reviews and Meta-analyses were excluded. Primary outcomes were the incidence of intraoperative and postoperative complications, including cerebrospinal fluid leak, recurrence, and reintervention. Quality assessments were performed using Newcastle-Ottawa Scale, ROBIN-I, and NIH.

RESULTS

Overall, 217 patients across 61 studies were identified. The median age at surgery was 4 years (0-18 years). Fifty percent were female; 31% were <2 years. Most defects were meningoencephaloceles (56%), located transethmoidal (80%), and of congenital origin (83%). Seventy-five percent of repairs were multilayered. Children ≥2 years underwent multilayer repairs more frequently than those <2 years (P = 0.004). Children <2 years more frequently experienced postoperative cerebrospinal fluid leaks (P = 0.02), meningoencephalocele recurrence (P < 0.0001), and surgical reintervention (P = 0.005). Following multilayer repair, children <2 years were more likely to experience recurrence (P = 0.0001) and reintervention (P = 0.006).

CONCLUSION

Younger children with basal meningoencephaloceles appear to be at greater risk of postoperative complications following endoscopic endonasal repair, although the quality of available evidence is weakened by incomplete reporting. In the absence of preoperative cerebrospinal fluid leak or meningitis, it may be preferable to delay surgery as access is more conducive to successful repair in older children.

Sphenoid Meningoencephalocele Correction Through a Transpterygoid Approach

Sphenoid meningoencephaloceles are rare, and their treatment is challenging. In this report, we describe two clinical cases of sphenoid meningoencephalocele, in which one patient presented with a cerebrospinal fluid leak after repeated head trauma, while in the other, sphenoid meningoencephalocele was detected during the study of memory impairment as the patient was otherwise asymptomatic. The CT scans showed bony dehiscence on the lateral wall of the sphenoid sinus filled with soft tissue that was confirmed by MRI as being herniated brain tissue. A transpterygoid endoscopic endonasal approach was performed with a multilayer reconstruction of the defect with success in both cases without perioperative complications. Imaging techniques are fundamental for diagnosis and surgical planning. Treatment using an endoscopic endonasal approach is efficient with very low morbidity.

Prolactinoma extension as a contributing factor in dopamine agonist-induced CSF rhinorrhea: a systematic review of the literature

BACKGROUND

Dopamine agonist-induced cerebrospinal fluid (CSF) rhinorrhea is an uncommon treatment-related complication arising in 6.1% of prolactinoma patients treated with dopamine agonists. Locally invasive prolactinomas may create CSF fistulae through formation of dural and osseous skull base defects. Tumor shrinkage secondary to dopamine agonist therapy unmasks skull base defects, thus inducing CSF rhinorrhea. In these cases, repair of the leak may be achieved through collaborative surgical intervention by rhinologists and neurosurgeons. Multiple variables have been investigated as potential contributors to the risk of CSF rhinorrhea development in medically treated prolactinoma patients, with little consensus.

OBJECTIVE

The primary aim of our study was the characterization of risk factors for CSF rhinorrhea development following dopamine agonist treatment.

METHODS

A systematic review of the literature was conducted to identify cases of CSF rhinorrhea following dopamine agonist treatment of prolactinoma. The clinical history, radiographic findings and treatment outcomes are discussed.

RESULTS

Fifty-four patients with dopamine agonist-induced CSF rhinorrhea were identified across 23 articles published from 1979 to 2019. Description of diagnostic imaging [computed tomography (CT)/magnetic resonance imaging (MRI)] was not provided for 18/54 subjects. For the 36 cases that described prolactinoma appearance on CT or MRI, invasion of the cavernous sinuses was reported in 13 (36.1%) and invasion of the sphenoid sinus was reported in 18 (50%).

CONCLUSION

Based on our systematic review, we propose that CT findings of osseous erosion of the sella or the anterior skull base may predict dopamine agonist-induced CSF rhinorrhea. We recommend obtaining a thin-slice CT of the sinuses in cases with MRI evidence of sphenoid involvement.

Case report: regression of aspiration pneumonitis after nasal endoscopic repair of traumatic cerebrospinal fluid nasal leak

Aspiration pneumonitis is an inflammatory lung disease caused by the inhalation of oropharyngeal secretions colonized by pathogenic bacteria. Accurate diagnosis of aspiration pneumonitis can be challenging, and cerebrospinal fluid (CSF) rhinorrhea is often overlooked as a rare cause of aspiration. In this case report, we present the case of a 48-year-old male patient who experienced right-sided nasal flow of clear watery secretions for 6 months, accompanied by a dry cough as the major symptom. Through comprehensive assessment of clinical symptoms, sinus imaging, nasal endoscopy, and relevant laboratory testing, a presumptive diagnosis of traumatic cribriform plate fracture with CSF rhinorrhea was made. Chest imaging revealed flocculent ground glass shadows in the bilateral lungs. After ruling out viral pneumonia, nasal endoscopic repair of the skull base defect was performed. The patient's dry cough and rhinorrhea symptoms resolved within 1 week after surgery, and the pneumonia showed significant improvement and complete resolution within 2 weeks postoperatively. Despite the absence of characteristic symptoms and evident inhalation factors, chronic CSF rhinorrhea caused by the cribriform plate fracture was ultimately identified as the primary etiology of the patient's aspiration pneumonitis. This rare case highlights the importance of considering traumatic CSF rhinorrhea as an uncommon cause of aspiration, which can enhance physicians' awareness and focus on the less-common etiologies of aspiration. Such awareness can contribute to more accurate diagnosis and early operative intervention, particularly in the context of the coronavirus disease 2019 pandemic.

Formal Closure of Endoscopic Endonasal Skull Base Defects With a "Bow Tie" Tri-Layer Graft

OBJECTIVE

Risk factors for a postoperative cerebrospinal fluid leak (CSF) after surgery include an intraoperative high flow of CSF, elevated body mass index, defect size, and defect site. In our prior series, a high postoperative CSF leak rate for tumors of the central skull base (planum, sella, and clivus) appeared to be due to graft migration. We changed our closure technique from a single layer of collagen +/- fat graft to a novel graft, termed a "Bow tie" (a tri-layer fat graft with two pieces of collagen matrix), and report our results in this study.

METHODS

Retrospective temporal epoch study of a single otolaryngologist's experience of closing skull base defects in our skull base center from 2005 to 2017.

RESULTS

One hundred and forty-nine patients met inclusion criteria in two time periods, pre- and post-introduction of the Bow tie technique. In epoch I, from 2005 to 2013, 79 patients had reconstruction with a single layer of dural graft (25 had additional free fat graft). In epoch II, from 2014 to 2017, 70 patients had reconstruction with the Bow tie.

RESULTS

CSF leak rates were 8.7% overall: 15.2% in epoch I and 1.4% in epoch II (p = 0.01). After controlling the procedure, defects with a size greater than 2 cm had a 5.7 greater likelihood of failure. Epoch II had a lower incidence of major complications.

CONCLUSION

Using a single surgeon's experience, the multilayer Bow tie has a significant reduction in postoperative CSF leak and associated major complications for defects of the central skull base.

LEVEL OF EVIDENCE

3 Laryngoscope, 133:1568-1575, 2023.

Diagnosis and Localization of Cerebrospinal Fluid Rhinorrhea: A Systematic Review

Background

Cerebrospinal fluid (CSF) rhinorrhea results from abnormal communications between the subarachnoid and sinonasal spaces. Accurate preoperative diagnosis and localization are vital for positive clinical outcomes. However, the diagnosis and localization of CSF rhinorrhea remain suboptimal due to a lack of accurate understanding of test characteristics.

Objective

This systematic review aims to assess the diagnostic accuracy of various tests and imaging modalities for diagnosing and localizing CSF rhinorrhea.

Methods

A systematic review of the MEDLINE and EMBASE databases was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.

Results

Our search identified 4039 articles—53 cohort studies and 24 case series describing 1622 patients were included. The studies were heterogeneous and had a wide range of sensitivities and specificities. Many specificities were incalculable due to a lack of true negative and false positive results, thus precluding a meta-analysis. Median sensitivities and specificities were calculated for cohort studies of the following investigations: high-resolution computed tomography (HRCT) 0.93/0.50 (sensitivity/specificity), magnetic resonance cisternography (MRC) 0.94/0.77, computed tomography cisternography (CTC) 0.95/1.00, radionuclide cisternography (RNC) 0.90/0.50, and contrast-enhanced magnetic resonance cisternography (CEMRC) 0.99/1.00, endoscopy 0.58/1.00, topical intranasal fluorescein (TIF) 1.00/incalculable, intrathecal fluorescein (ITF) 0.96/1.00. Case series were reviewed separately. Etiology and site-specific data were also analyzed.

Conclusion

MR cisternography is more accurate than high-resolution CT at diagnosing and localizing CSF rhinorrhea. CT cisternography, contrast-enhanced MR cisternography, and radionuclide cisternography have good diagnostic characteristics but are invasive. Intrathecal fluorescein shows promising data but has not been widely adopted for purely diagnostic use. Office endoscopy has limited data but does not sufficiently diagnose CSF rhinorrhea independently. These findings confirm with current guidelines and evidence.

[Multiple skull base defects: features of pathogenesis, diagnosis and treatment]

OBJECTIVE

To determine the risk factors of multiple skull base defects, as well as features of diagnosis and treatment of this pathology.

MATERIAL AND METHODS

A retrospective analysis included 39 patients who underwent surgery for nasal CSF leakage at the Burdenko Neurosurgical Center in 2000-2019. The study recruited patients with multiple simultant skull base defects.

RESULTS

Traumatic defects were observed in 23 (59%) patients, spontaneous defects - in 16 (41%) cases. All patients underwent endoscopic endonasal closure of skull base defects with autografts.

CONCLUSION

Multiple defects are more common in severe traumatic brain injury. The main risk factors of multiple spontaneous defects are female sex and overweight. Adequate diagnosis implies high-resolution CT (slice width 0.5-1 mm), as well as intraoperative control of all suspicious and «weak» areas. Endoscopic endonasal technique is effective and safe for multiple skull base defects (efficiency 97%).

Dural Contact to the Malleus Head in Patients with Superior Semicircular Canal Dehiscence (SSCD): Case Series and Review of SSCD and Tegmen Defects

OBJECTIVE

Report a series of cases in which patients have concomitant superior semicircular canal dehiscence (SSCD) and a dehiscent tegmen tympani with Dural contact to the malleus head (DCMH).

METHODS

An analysis of radiologic and audiologic data in 4 patients who presented with SSCD and DCMH at a tertiary care institution. A pertinent literature review was performed.

RESULTS

Four patients (5 ears) had SSCD and DCMH. In 3 patients with unilateral DCMH, the mean maximum air-bone gap was 15 dB in the ear with DCMH compared to 50 dB in the ear without DCMH. Of the 5 ears with DCMH, the mean air conduction threshold at 250 Hz was 17 dB compared to 42 dB in the 3 ears without DCMH.

CONCLUSIONS

We report the findings of DCMH in a series of 4 patients with bilateral SSCD. This limited series suggests that ears with SSCD and DCMH have less of an air-bone gap than would be expected, as 1 would expect an additive effect of DCMH and SSCD on the air-bone gap.

The Endonasal Endoscopic Management of Cerebrospinal Fluid Rhinorrhea

Introduction

Cerebrospinal fluid (CSF) rhinorrhea is the result of a bony defect at the skull base with disruption of the arachnoid, dura mater, and sinonasal mucosa that leads to an active CSF leak and flow of clear fluid from the nose. The endoscopic repair of CSF leaks and skull defects have been used by an increasing number of surgeons and is the standard of care for repairing CSF leaks.

Materials and methods

We conducted a retrospective study of all cases of CSF leaks managed via the endonasal endoscopic approach from 2010 to 2020 at a tertiary referral hospital of King Fahad Specialist Hospital, Dammam (KFSH-D).

Results

Over 10 years, 61 procedures were performed on a total of 56 patients (average age, 39.9 years) with 26 spontaneous CSF leaks and 30 traumatic CSF leaks. The leak sites were frontal bone in 14% of the cases, the roof of the ethmoid in 25%, the cribriform plate of ethmoid in 39%, and the walls of sphenoid sinus in 21%; multiple site defects were found in eight patients. The defect was localized by high-resolution computed tomography (CT) of the paranasal sinuses and skull base and magnetic resonance imaging (MRI) in all patients. CT cisternography, intrathecal fluorescein injection, and topical application of fluorescein dye were used in patients as required. A combination of free grafts and flaps materials were used in most patients. A middle and inferior turbinate graft was used in 12 patients, a septal cartilage graft in 18 patients, and a pedicled nasoseptal flap in 12 patients. The success rate was 92% after the first closure attempt. A recurrence of CSF leaks was observed in four patients. The mean hospitalization time was 6.5 days. The postoperative follow-up period ranged from one year to 10 years with a mean postoperative follow-up time of three years.

Conclusions

The endonasal endoscopic approach is the current standard of care for repairing most CSF leaks and skull base defects. We have had an excellent experience with endonasal endoscopic CSF leak repair, with high success rates and low morbidity. Our results support the effectiveness and safety of this technique and should encourage otolaryngologists to apply the procedure in cases of CSF leak.

Endoscopic Reconstruction of Skull Base Defects Using Tutoplast

BACKGROUND

Various graft materials that are classified as autografts, xenografts, and allografts based on their origin have been used to endoscopically repair skull base defects. Tutoplast® (Tutogen Medical GmbH), an allogeneic natural collagen matrix, is processed through chemical sterilization that preserves tissue biocompatibility and structural integrity.

OBJECTIVE

To study the safety and efficacy of Tutoplast Fascia Lata and Tutoplast Temporalis Fascia® as primary graft materials in the endoscopic reconstruction of skull base defects of different sizes and etiologies and to compare the outcomes with those of other traditional graft materials based on our experience.

METHODS

This is a multi-center retrospective chart review of patients who underwent cerebrospinal fluid leak (CSF) endoscopic reconstruction with Tutoplast Fascia Lata or Tutoplast Temporalis Fascia as either a stand-alone reconstruction material or a part of a multilayer reconstruction depending on the defect at Prince Sultan Military Medical City and King Faisal Specialist Hospital and Research Center in Riyadh, Saudi Arabia, between 2017 and 2020. Our inclusion criteria were CSF leak repair with Tutoplast and a transnasal endoscopic approach. We reviewed demographic data, intraoperative and postoperative complications, repair materials, repair failure, defect size and location.

RESULTS

Tutoplast® was used as the primary graft material in 33 cases. Our main outcome was repair success with lack of post operative CSF leak, observed in 30 cases (90.9%). There was no significant association between postoperative CSF leaks and factors including different defect sizes, defect sites, demographic data, hospitalization duration, or postoperative radiation in oncological cases.

CONCLUSION

Tutoplast alone or in combination with other materials can be used safely and effectively for skull base defects repair.

Spontaneous Cerebral Spinal Fluid Rhinorrhea with Meningocele Secondary to Congenital Foramen Rotundum Defect: A Case Report and Review of Literature

Spontaneous cerebrospinal fluid (CSF) rhinorrhea is a rare occurrence. We present a case of spontaneous CSF rhinorrhea in a 57-year-old patient secondary to a sphenoid osseous defect involving the foramen rotundum and maxillary nerve with an associated arachnoid cyst and meningocele compressing the maxillary nerve. The location of the defect made correction amenable to an open skull-based approach. To the best of our knowledge, this is the first reported case of a spontaneous meningocele herniating into the sphenoid osseous defect through the medial aspect of the foramen rotundum. Early detection of these defects, open or endoscopic approaches and definitive treatment by closing the defect can result in excellent outcomes.

[Skull base defects multilayer plasty in patients with spontaneous cerebrospinal fluid leak: our experience]

Spontaneous cerebrospinal fluid (CSF) leak is one of the types of non-traumatic CSF leaks in which the etiologic factor is unknown. Skull base defects transnasal endoscopic plasty is the initial method of surgical repair of spontaneous cerebrospinal fluid leaks. METHODS: Forty-five patients with spontaneous CSF leaks were managed using multilayer transplant technique. The basic choice criteria of endoscopic transnasal surgical approach and materials to reconstruction of skull base defects were the size of defect and its localization. In all cases pediculated flaps in combination with free graft were used. RESULTS: In 43 (96%) cases CSF leaks was successfully managed in primary surgery, which indicates high efficiency of the described surgical interventions.

A Primary Clival Defect: Endoscopic Binostril Approach With Nasal Septal Flap Closure and Preservation of Septal Integrity

Primary spontaneous cerebrospinal fluid (CSF) rhinorrhea is an unusual phenomenon that may occur anywhere along the skull base. However, CSF leaks originating from clival defects are rarely reported in the literature. The majority of reported cases were managed with microscopic techniques, using free grafts. The present study discusses a case of spontaneous CSF rhinorrhea from a clival defect closed with our transnasal operative approach using endoscopic techniques. The skull base defect was successfully managed with an endoscopic binostril approach to create a nasal septal flap pedicled at the sphenopalatine artery, while also preserving the integrity of the nasal septum.

[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.

The Surgical Treatment of Posttraumatic Skull Base Defects with Cerebrospinal Fluid Leak

Objectives  The objective was to explore further the surgical treatment of posttraumatic skull base defects with cerebrospinal fluid (CSF) leak and to identify the most common factors affecting the surgical treatment of posttraumatic skull base defect with CSF leak retrospectively. Materials and Methods  This study included 144 patients with head trauma having skull base defect with CSF leak who had been surgically treated at Sun Yat-Sen Memorial Hospital of Sun Yat-Sen University from 1998 to June 2016. There were 113 (78.5%) males and 31 (21.5%) females, with age ranging from 1 to 78 years and mean age of 26.58 ± 14.95 years. We explored the surgical approaches for the treatment of the skull base defect and the graft materials used and also measured the association among surgical approaches; location, size, and type of skull base defects; presence or absence of associated intracranial pathologies; postoperative complications; outcome; age; Glasgow outcome score (GOS) at discharge; and days of hospital stay. Results  The location, size, and types of skull base defect and the presence of associated intracranial pathologies were the common factors identified not only for choosing the appropriate surgical approach but also for choosing the materials for defect repair, timing of the surgery, and the method used for the defect as well as leak repair. The statistically significant correlation with p  < 0.001 was found in this study. Conclusion  From this study, we could conclude that size, location, and types of the defect and the presence of associated intracranial injuries were the common factors that affected the surgical treatment of posttraumatic skull base defect with CSF leak. Hence, the importance of careful evaluation of these factors is essential for proper selection of the surgical approach and for avoiding unnecessary hassles.

The Pedicled Buccal Fat Pad: Anatomical Study of the New Flap for Skull Base Defect Reconstruction After Endoscopic Endonasal Transpterygoid Surgery

Objectives To evaluate the efficacy and safety of using a buccal fat pad for endoscopic skull base defect reconstruction. Design Descriptive anatomical study with an illustrative case presentation. Setting Anatomical study was performed on 12 fresh human cadaver specimens with injected arteries (24 sides). Internal carotid artery was exposed in the coronal plane via the endoscopic transpterygoid approach. The pedicled buccal fat pad was used for reconstruction. Participants: 12 human cadaver head specimens; one patient operated using the proposed technique. Main outcome measures: Proximity of the buccal fat pad flap to the defect, compliance of the flap, comfort and safety of harvesting procedure, and compatibility with the Hadad-Bassagasteguy nasoseptal flap. Results: Harvesting procedure was performed using anterior transmaxillary corridor. The pedicled buccal fat pad flap can be used to pack the sphenoid sinus or cover the internal carotid artery from cavernous to upper parapharyngeal segment. Conclusion The buccal fat pad can be safely harvested through the same approach without external incisions and is compliant enough to conform to the skull base defect. The proposed pedicled flap can replace free abdominal fat in central skull base reconstruction. The volume of the buccal fat pad allows obliteration of the sphenoid sinus or upper parapharyngeal space.

Anterior Skull Base Defects Reconstructed Using Three-Layer Method: 78 Consecutive Cases with Long-Term Follow-Up

Objectives Anterior skull base defects are potentially lethal and surgical treatment must be performed as soon as possible. The purpose of this study was to evaluate whether our technique is effective or not in long-term period. Design Retrospective chart review of all patients whose data were entered into the Hospital Registry System between 1995 and 2015. Setting/Participants This study was performed at the Gaziantep University School of Medicine, Gaziantep, Turkey, in 2015 and included 78 patients who in the past 20 years underwent three-layer reconstruction surgery for anterior skull base defects at the same university. Main Outcome Measures Among the patients, defects repaired by transcranial approach had the lowest recurrence rate. Overall, successful repair was achieved in 100% of the patients. Results Pure transbasal approach was used as a single procedure on 71 (91%) patients. Combined approaches were used in seven (9%) cases. The extended transbasal approach was combined with a transfacial approach in four patients and with a pterional approach in three patients. Conclusion We encourage the use of three-layer reconstruction and recommend free fascia lata grafts and galeal flaps with vascularized pedicle as sealing material of choice in all types of cases such as tumor and trauma.

Reconstruction of the Base of Skull Defect-Lessons Learned over 25 Combined Years

With an increased understanding of the pathological processes involved in perinerual spread, surgery has come to play a greater role in its management. As skull base techniques have been refined, the reconstructive surgeon has been presented with increasingly complex and voluminous defects requiring repair. To enable such surgery to have acceptable outcomes, attention to form and function is paramount. This article describes the methods of repair, which have evolved over the last 25 years of practice, and that we find to be both reliable and durable. Our accumulated experience is presented as a treatment algorithm, which will aid the skull base reconstructive surgeon to achieve success for the wide variety of defects encountered with these patients.

Intracranial and intradural nasal polyposis after iatrogenic skull base defect: A case report

We 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.

Reconstruction Using Locoregional Flaps for Large Skull Base Defects

We present a modified locoregional flap for the reconstruction of large anterior skull base defects that should be reconstructed with a free flap according to Yano's algorithm. No classification of skull base defects had been proposed for a long time. Yano et al suggested a new classification in 2012. The lb defect of Yano's classification extends horizontally from the cribriform plate to the orbital roof. According to Yano's algorithm for subsequent skull base reconstructive procedures, a lb defect should be reconstructed with a free flap such as an anterolateral thigh free flap or rectus abdominis myocutaneous free flap. However, our modified locoregional flap has also enabled reconstruction of lb defects. In this case series, we used a locoregional flap for lb defects. No major postoperative complications occurred. We present our modified locoregional flap that enables reconstruction of lb defects.

Immediate complications associated with high-flow cerebrospinal fluid egress during endoscopic endonasal skull base surgery

Endoscopic expanded endonasal approaches (EEAs) to the skull base are increasingly being used to address a variety of skull base pathologies. Postoperative CSF leakage from the large skull base defects has been well described as one of the most common complications of EEAs. There are reports of associated formation of delayed subdural hematoma and tension pneumocephalus from approximately 1 week to 3 months postoperatively. However, there have been no reports of immediate complications of high-volume CSF leakage from EEA skull base surgery. The authors describe two cases of EEAs in which complications related to rapid, large-volume CSF egress through the skull base surgical defect were detected in the immediate postoperative period. Preventive measures to reduce the likelihood of these immediate complications are presented.

Surgical technique for repair of complex anterior skull base defects

Background:

Modern microsurgical techniques enable en bloc resection of complex skull base tumors. Anterior cranial base surgery, particularly, has been associated with a high rate of postoperative cerebrospinal fluid (CSF) leak, meningitis, intracranial abscess, and pneumocephalus. We introduce simple modifications to already existing surgical strategies designed to minimize the incidence of postoperative CSF leak and associated morbidity and mortality.

Methods:

Medical records from 1995 to 2013 were reviewed in accordance with the Institutional Review Board. We identified 21 patients who underwent operations for repair of large anterior skull base defects following removal of sinonasal or intracranial pathology using standard craniofacial procedures. Patient charts were screened for CSF leak, meningitis, or intracranial abscess formation.

Results:

A total of 15 male and 6 female patients with an age range of 26–89 years were included. All patients were managed with the same operative technique for reconstruction of the frontal dura and skull base defect. Spinal drainage was used intraoperatively in all cases but the lumbar drain was removed at the end of each case in all patients. Only one patient required re-operation for repair of persistent CSF leak. None of the patients developed meningitis or intracranial abscess. There were no perioperative mortalities. Median follow-up was 10 months.

Conclusion:

The layered reconstruction of large anterior cranial fossa defects resulted in postoperative CSF leak in only 5% of the patients and represents a simple and effective closure option for skull base surgeons.

An empirical approach to the diagnosis and treatment of cerebrospinal fluid rhinorrhoea: an optimised method for developing countries

BACKGROUND

We aimed to test a new approach for repairing cerebrospinal fluid (CSF) leaks and to determine the demographic, diagnostic, and treatment factors associated with the successful management of intracranial complication. Owing to the high frequency of endoscopic surgeries and the low cost of medical care in Iran, we decided to report our experience of reconstruction after CSF leaks.

METHODS

We retrospectively reviewed our experience in the diagnosis and management of CSF rhinorrhoea in Iran between 2005 and 2012. The locations of all pre-repair leaks were identified using simple, readily available methods. The follow-up time ranged from 2 to 72 months.

RESULTS

Of the 37 participants, 59.5% were men and the mean age was 33 years. The success rate was 86.1%, and the most common aetiological factor was trauma (57%). The most common location was the ethmoidal fovea (45.9%), followed by the sphenoid sinus (24.3%), the cribriform plate (13.5%), and the posterior table of the frontal sinus (5.4%).

CONCLUSION

Medical care in Iran has considerable budget restrictions. This study advocates a practical method of treatment for patients in similar circumstances, with a success rate of 86.1% when compared to the 90.6% achieved with other techniques.

KEYWORDS

cerebrospinal fluid leak, endoscopic, intracranial pressure ICP.

The endoscopic hemi-transseptal approach to the sella turcica: operative technique and case-control study

Background The hemi-transeptal (Hemi-T) approach was developed to facilitate a binasal two-surgeon endoscopic approach for sellar tumors, with preservation of the nasoseptal flap and selective mobilization for reconstruction. Methods A retrospective case-control study was performed comparing the Hemi-T approach with previously used methods of sellar exposure and reconstruction. Outcome measures included operative time and postoperative nasal morbidity. Results A total of 23 patients underwent the Hemi-T approach versus 42 in whom traditional exposure was performed. Operative time was significantly shorter using the Hemi-T technique (152.6 ± 56.8 versus 205.2 ± 61.3 minutes; p = 0.001), as was the length of hospital stay (3.3 ± 1.9 versus 5.4 ± 3.6 days; p = 0.004). There was no difference in the rates of intraoperative or postoperative cerebrospinal fluid leak, cartilage necrosis, septal perforation, or mucosal adhesions. Conclusion The Hemi-T approach facilitates binasal two-surgeon access to the sella without compromise of the pedicle during the extended sphenoidotomies and tumor removal. Operative time and nasal morbidity is not increased, and iatrogenic injury to the nasal cavity is minimized when a flap is not required.

Risk factors for cerebrospinal leak after endoscopic skull base reconstruction with nasoseptal flap

OBJECTIVE

The use of expanded endonasal surgery (EES) in the treatment of skull base neoplasms has increased significantly in recent years. Since 2006, the nasoseptal flap (NSF) has become the workhorse for the closure of skull base defects involving the anterior and central skull base. We hypothesized that defect site impacts the rate of cerebrospinal fluid (CSF) leak following EES.

STUDY DESIGN

Retrospective cohort study.

SETTING/SUBJECTS/METHODS

Patients who underwent skull base defect repair using a NSF at the University of California at San Francisco (UCSF) minimally invasive skull base center were retrospectively reviewed. Patient demographics, disease, and defect location and size were recorded along with the presence of a postoperative CSF leak. Data were analyzed using Fisher's exact test.

RESULTS

One hundred and twenty-one patients met inclusion criteria. Ten patients had a NSF failure with CSF leakage, 2 in the anterior skull base (frontal sinus, ethmoid, cribriform, planum), and 8 in the central skull base (sella, clivus) (P = .047). Dural defect size ≥2.0 cm(2) in the central skull base strongly correlated with the risk of flap failure (P = .034).

CONCLUSIONS

This study of endoscopic closure of skull base defects using a NSF demonstrates there is an association between both surgical site and dural defect size with NSF failure. Expanded defects of the sella and clivus have an increased risk of failure and may warrant augmented techniques.

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.

Skull base defect in a patient with ozena undergoing dacryocystorhinostomy

Ozena, which is often used interchangeably with atrophic rhinitis or empty nose syndrome, is a progressive and chronically debilitating nasal disease that results in atrophy of the nasal mucosa, nasal crusting, fetor, and destruction of submucosal structures. Although the etiology is not completely understood, infection with Klebsiella ozaenae is widely believed to contribute to the destructive changes. We present a case of a patient with ozena secondary to K. ozaenae with extensive destruction of bony structures of the nasal cavity undergoing elective dacryocystorhinostomy. An extensively thinned skull base secondary to the disease process resulted in an unforeseen complication in which the skull base was entered leading to a cerebrospinal fluid leak. Patients with known history of ozena or atrophic rhinitis often have extensive destruction of the lateral nasal wall and skull base secondary to progression of disease. Submucosal destruction of these bony structures mandates the need for extreme caution when planning on performing endoscopic intervention at or near the skull base. If physical examination or nasal endoscopy is suspicious for atrophic rhinitis or a patient has a known history of infection with K. ozaenae, we recommend preoperative imaging for surgical planning with careful attention to skull base anatomy.

The transnasal approach to the skull base. From sinus surgery to skull base surgery

The indications for endonasal endoscopic approaches to diseases of the skull base and its adjacent structures have expanded considerably during the last decades. This is not only due to improved technical possibilities such as intraoperative navigation, the development of specialized instruments, and the compilation of anatomical studies from the endoscopic perspective but also related to the accumulating experience with endoscopic procedures of the skull base by multidisciplinary centers. Endoscopic endonasal operations permit new approaches to deeply seated lesions and are characterized by a reduced manipulation of neurovascular structures and brain parenchyma while at the same time providing improved visualization. They reduce the trauma caused by the approach, avoid skin incisions and minimize the surgical morbidity. Transnasal endoscopic procedures for the closure of small and large skull base defects have proven to be reliable and more successful than operations with craniotomies. The development of new local and regional vascularized flaps like the Hadad-flap have contributed to this. These reconstructive techniques are furthermore effectively utilized in tumor surgery in this region. This review delineates the classification of expanded endonasal approaches in detail. They provide access to lesions of the anterior, middle and partly also to the posterior cranial fossa. Successful management of these complex procedures requires a close interdisciplinary collaboration as well as continuous education and training of all team members.