Endoscopic Endonasal Reconstruction of Anterior Skull Base Defects: What Factors Really Affect the Outcomes?

Tissue Sealant Impact on Skull Base Reconstruction Outcomes: A Systematic Review and Meta-Analysis

OBJECTIVE

Despite significant advances in understanding of skull base reconstruction principles, the role of tissue sealants in modifying postoperative cerebrospinal fluid (CSF) leak outcomes remains controversial. We evaluate postoperative CSF leak incidence associated with tissue sealant use in skull base defect repair during endoscopic skull base surgery (ESBS).

DATA SOURCES

Web of Science, PubMed/MEDLINE, Scopus, and Cochrane Library.

REVIEW METHODS

Systematic review and meta-analysis of risk differences (RD). A search strategy identified original studies reporting CSF leakage following ESBS with disaggregation by tissue sealant use and/or type.

RESULTS

27 non-randomized studies (n = 2,403) were included for qualitative and meta-analysis. Reconstruction with a tissue sealant did not significantly reduce postoperative CSF leak risk compared with reconstruction without sealant (RD[95% CI] = 0.02[-0.01, 0.05]). Sub-analyses of dural sealant (-0.02[-0.11, 0.07]) and fibrin glue (0.00[-0.07, 0.07]) compared with no sealant were similarly unremarkable. Postoperative CSF leakage was not significantly modulated in further sub-analyses of DuraSeal (0.02[-0.02, 0.05]), Adherus (-0.03[-0.08, 0.03]), or Bioglue (-0.06[-0.23, 0.12]) versus no dural sealant use, or Tisseel/Tissucol versus fibrin glue nonuse (0.00[-0.05, 0.05]). No significant association was seen comparing dural sealant use versus fibrin glue use on pairwise (0.01[-0.03, 0.05]) or network meta-analysis (-0.01[-0.05, 0.04]). Limitations in source literature prevented sub-analyses stratified by leak characteristics, defect size and location, and accompanying reconstruction materials.

CONCLUSION

Tissue sealant use did not appear to impact postoperative CSF leak incidence when compared with nonuse. Higher quality studies are warranted to thoroughly elucidate the clinical value of adjunct sealant use in endoscopic skull base reconstruction.

LEVEL OF EVIDENCE

N/A Laryngoscope, 134:3425-3436, 2024.

Endoscopic Endonasal Reconstruction of Intraoperative Cerebrospinal Fluid Leak in Different Skull Base Regions: Outcomes, Meningitis, and Risk Factors

OBJECTIVES

Various nonvascularized or vascularized techniques have been adopted in endoscopic endonasal surgery (EES) for repairing intraoperative cerebrospinal fluid (CSF) leaks after tumor resection. Vascularized nasoseptal flaps, free nasoseptal grafts, free turbinate grafts, and fascia lata and mashed muscle are frequently used. Outcomes of those grafts applied in the defects of different regions need to be clarified.

METHODS

The data from a series of 162 patients with skull base tumor who underwent EES that had intraoperative CSF leak between Jan 2012 and Jan 2021 were retrospectively analyzed. The regions included anterior skull base, sellar region, clivus and infratemporal fossa. Repair failure rate (RFR), meningitis rate, and associated risk factors were assessed.

RESULTS

In total, 172 reconstructions were performed in 162 patients for the 4 sites of the skull base. There were 7 cases (4.3%) that had postoperative CSF leaks, which required second repair. The RFR for anterior skull base, sellar region, clivus, and infratemporal fossawas 2.6%, 2.2%, 16.7%, and 0%, respectively. The clivus defect was an independent risk factor for repair failure (P < 0.01). The postoperative meningitis rate was 5.6%. Repair failure was an independent risk factor for meningitis (P < 0.01).

CONCLUSIONS

Vascularized nasoseptal flap, free nasoseptal graft, free turbinate graft, and fascia lata and mashed muscle are reliable autologous materials for repairing the dural defects in different regions during EES. Clivus reconstruction remains a great challenge, which had a higher RFR and meningitis rate. Repair failure is significantly associated with postoperative meningitis.

Endoscopic transsphenoidal surgery reconstruction using the fibrin sealant patch Tachosil®

INTRODUCTION

The incidence of CSF leak following endoscopic transsphenoidal surgery remains the most important measure in the success of any repair. The nasoseptal flap (NSF) has played a pivotal role in reconstructing defects. However, morbidity associated with the NSF includes bleeding, septal injury, altered smell and crusting. Tachosil® is an absorbable fibrin sealant patch that promotes haemostasis and wound healing. The purpose of this study was to evaluate the effectiveness of Tachosil® to repair intraoperative defects during an endoscopic transsphenoidal approach.

MATERIALS AND METHODS

All patients who underwent an endoscopic transsphenoidal approach with the use of Tachosil® at the Queen Elizabeth Hospital Birmingham, between January 2013 and June 2020 were retrospectively analysed. Tachosil® was used as an overlay patch over of the bony defect, in a multi-layered repair depending on the defect and grade of CSF leak. The primary outcome measure was post-operative CSF leak.

RESULTS

A total of 52 primary procedures where Tachosil® was used as the overlay were analysed. There were 23 (44.2%) intraoperative CSF leaks. The overall post-operative CSF leak rate was 7.8% (n = 4), with all cases having had a Tachosil® overlay reconstruction with no NSF. A formal NSF was harvested in only five cases alongside the Tachosil® patch, where a grade 2 or more leak was identified at the time of the primary procedure, none of which developed a post-operative leak. No patient had any post-operative adverse outcomes that were attributed to Tachosil®.

CONCLUSIONS

We believe this to be the largest case series evaluating the endoscopic use of Tachosil® in skull base reconstruction. Our data show that in endoscopic transsphenoidal approach, Tachosil® may be used safely in a multi-layered approach as an effective alternative to the NSF in low flow CSF leak cases, or alongside a NSF in higher flow leaks.

Fat enhanced leukocyte-platelet-rich fibrin versus fascia lata in endoscopic reconstruction of CSF leaks

PURPOSE

The aim of this study was to use a new biological active fat enhanced leukocyte-platelet-rich fibrin membrane (L-PRF) for skull base defect reconstruction and compare its validity and reliability with the time-honored fascia lata.

METHODS

This prospective study was conducted on 48 patients with spontaneous CSF leaks who were divided into 2 matched groups by stratified randomization, 24 patients in each group. In group A we performed multilayer repair using fat enhanced L-PRF membrane. In group B we used fascia lata for the multilayer repair. In both groups we enforced the repair with mucosal grafts/flaps.

RESULTS

The two groups were statistically matched for age, sex, intracranial pressure, and site and size of the skull base defect. There was no statistically significant difference between the two groups regarding the outcome of the repair or recurrence of CSF leak during the first postoperative year. Meningitis occurred in one patient in group B and was successfully treated. Another patient in group B developed thigh hematoma which resolved spontaneously.

CONCLUSION

The fat enhanced L-PRF membrane is a valid reliable option in repair of CSF leaks. The membrane is autologous, readily available, easily prepared, and has the advange of including stromal fat, stromal vascular fraction (SVF), and leukocyte-platelet-rich fibrin (L-PRF). The present study showed that fat enhanced L-PRF membrane is stable, non-absorbable, not liable to shrink or become necrotic, and can establish good seal of the skull base defect and further enhance the healing process. The use of the membrane also has the advantage of avoiding thigh incision and possible hematoma formation.

Management of recurrent cerebrospinal fluid leak, current practices and open challenges. A systematic literature review

Cerebrospinal fluid leak (CSFL) is a rare pathological condition which requires prompt and adequate management due to the high rate of associated major complications. At present, CSFL can be successfully treated through endoscopic endonasal approaches with success rates higher than 90%. Despite this, CSFL recurrence may occur, and its management is critical and still represents a matter of debate. A systematic review of the literature on the management of recurrent CSFL was conducted. It included a cohort of 1,083 cases of CSFL treated with surgical or conservative approaches; 112 cases of recurrence were reported for an overall recurrence rate of 10.3%. Most of the leaks were localised in the anterior skull base (68.3%) and identification of recurrent CSFL may be troublesome. Therefore, the entire skull base must be meticulously examined and long-term follow-up is mandatory. The risk for CSFL recurrence is higher in patients affected by idiopathic intracranial hypertension (IIH), but its role in CSFL recurrence is yet to be understood. Recurrent CSFL must be repaired as soon as possible in order to reduce the risk of intracranial complications. The use of early post-operative CSF diversion by lumbar drain (LD) is currently a matter of debate even in case of CSFL recurrences.

Endonasal endoscopic management of spontaneous cerebrospinal fluid rhinorrhoea: The Birmingham UK experience

BACKGROUND

Spontaneous cerebrospinal fluid (CSF) leaks (SCSFL) occur in the absence of trauma, surgery, or underlying intracranial pathology. They represent a significant healthcare burden on patients with complications such as meningitis. We present our experience of SCSFL repair via the endonasal endoscopic approach.

METHODS

All patients who underwent CSF fistula repair at a tertiary UK hospital, between 1st January 2012 to 31st December 2019, were identified and had their case notes analyzed retrospectively.

RESULTS

There were 33 patients included consisting of 27 (81.8%) females, with age range from 31 to 81 years (mean 55.2). Mean body mass index (BMI) was 35.2 kg/m² , with 32 (97.0%) patients overweight (BMI >25). All patients presented with intermittent watery rhinorrhoea and had a positive biochemical analysis. Computed tomography (CT) and/or magnetic resonance imaging (MRI) identified leak sites in 29 patients (87.9%). The most common intraoperative defect site was the cribriform plate (42.4%). A variety of closing techniques were used including onlay grafts (72.7%), tissue glue (87.9%), nasoseptal flaps (63.6%), mucosal free grafts (21.2%), fat grafts (21.2%), and additional support materials (87.9%). Nasal packing was used in all patients. The average length of stay was 1.6 days. Postoperative complications occurred in two patients (6.1%) (meningitis, epistaxis). Overall, there was a successful primary repair in 32 (97.0%) patients with most cases employing a multilayered reconstruction method (78.8%).

CONCLUSION

Our results demonstrate excellent success rates with the endoscopic endonasal approach to SCSFL. This adds to the literature by demonstrating a detailed analysis of the experience in SCSFL management in one of the largest UK centres.

Reconstructive Outcomes of Multilayered Closure of Large Skull Base Dural Defects Following Open Anterior Craniofacial Resection

Introduction Standardized reconstruction protocols for large open anterior skull base defects with dural resection are not well described. Here we report the outcomes and technique of a multilayered reconstructive algorithm utilizing local tissue, dural graft matrix, and microvascular free tissue transfer (MVFTT) for reconstruction of these deformities.

Design This study is a retrospective review.

Results Eleven patients (82% males) met inclusion criteria, with five (45%) having concurrent orbital exenteration and eight (73%) requiring maxillectomy. All patients required dural resection with or without intracranial tumor resection, with the average dural defect being 36.0 ± 25.9 cm2. Dural graft matrices and pericranial flaps were used for primary reconstruction of the dural defects, which were then reinforced with free fascia or muscle overlay by means of MVFTT. Eight (73%) patients underwent anterolateral thigh MVFTT, with the radial forearm, fibula, and vastus lateralis comprising the remainder. Average total surgical time of tumor resection and reconstruction was 14.9 ± 3.8 hours, with median length of hospitalization being 10 days (IQR: 9.5, 14). Continuous cerebrospinal fluid drainage through a lumber drain was utilized in 10 (91%) patients perioperatively, with an average length of indwelling drain of 5 days. Postoperative complications occurred in two (18%) patients who developed asymptomatic pneumocephalus that resolved with high-flow oxygen therapy.

Conclusion A standardized multilayered closure technique of dural graft matrix, pericranial flap, and MVFTT overlay in the reconstruction of large open anterior craniofacial dural defects can assist the reconstructive team in approaching these complex deformities and may help prevent postoperative complications.

Effects of cruciate embedding fascia-bone flap technique on grade II-III cerebral spinal fluid leak in endoscopic endonasal surgery

Background

Cerebral spinal fluid (CSF) leak remains an important issue in endoscopic endonasal surgery (EES). A standard protocol for skull base closure has not yet been established, and the application of rigid buttress has not been given sufficient attention. To emphasize the functions of support and fixation from rigid buttress in reconstruction, we introduced the cruciate embedding fascia-bone flap (CEFB) technique using autologous bone graft to buttress the fascia lata attachment to the partially sutured skull base dural defect and evaluated its efficacy in a consecutive case series of grade II–III CSF leaks in EES.

Methods

Data from consecutive patients diagnosed with sellar region lesions with grade II–III CSF leaks during EES were collected from May 2015 to May 2020. Skull base reconstructions were performed with the CEFB or the conventional pedicle vascularized nasoseptal flap (PNSF). Related clinical data were analysed. The combined use of the CEFB and PNSF was applied to an additional supplemental case series of patients with grade III leak and multiple high-risk factors.

Results

There were 110 and 65 patients included in the CEFB and PNSF groups, respectively. The CEFB demonstrated similar effects on the incidence of postoperative CSF leak (2.7%), intracranial infection (4.5%), and lumbar drainage (LD) placement (5.5%) as PNSF (3.1%, 3.1%, and 6.2%), but with less epistaxis (CEFB: 0%, PNSF: 6.2%) and nasal discomforts (CEFB: 0%, PNSF: 7.7%). The LD duration (CEFB: 6.67 ± 2.16 days, PNSF: 10.50 ± 2.38 days), bed-stay time (CEFB: 5.74 ± 1.58 days, PNSF: 8.83 ± 3.78 days) and hospitalization time (CEFB: 10.49 ± 5.51 days, PNSF: 13.58 ± 5.50 days) were shortened in the CEFB group. The combined use of CEFB and PNSF resulted in 0 postoperative CSF leaks in the supplemental case series of 23 highly susceptible patients.

Conclusion

This study suggested that the new CEFB technique has the potential to prevent postoperative CSF leak in EES. The results indicated that it can be used effectively without PNSF in suitable cases or applied in addition to a PNSF with high compatibility when necessary. Its effectiveness should be further verified with a larger cohort and better design in the next step.

Trial Registration Current Controlled Trials ChiCTR2100044764 (Chinese Clinical Trial Registry); date of registration: 27 March 2020. Retrospectively registered

Optimal Multiple-Layered Anterior Skull Base Reconstruction Using a 360° Suturing Technique

BACKGROUND

Advances in technique and instrumentation have improved outcomes after resection of anterior skull base tumors. However, cerebrospinal fluid (CSF) leak occurs in 4%-20% of patients. To reduce the risk of CSF leak, we have developed a novel reconstruction technique that consists of a 4-layered graft with patchwork suturing and hard material.

OBJECTIVE

To evaluate the effectiveness of this reconstruction technique when used for resection of anterior skull base tumors.

METHODS

This case series included 59 patients with anterior skull base tumors in whom the 4-layered closure technique was used. The main outcome measures were complications, including CSF leak, meningitis, postoperative bleeding, and infection.

RESULTS

There were no CSF leak cases or serious complications after closure of the anterior skull base using the 4-layered technique.

CONCLUSION

Closure of the anterior skull base in 4 layers prevented CSF leak and was not associated with any serious complications. However, further studies in larger numbers of patients are needed to confirm our outcomes using this closure method.

Ectopic Primary Olfactory Neuroblastoma: Case Series and Literature Review

OBJECTIVE

Olfactory neuroblastoma (ONB) is a rare malignant tumor arising in the upper nasal cleft. Rarely, ONB may originate in ectopic sites and the impact of this on prognosis and treatment strategies continues to be debated.

METHODS

A retrospective analysis was undertaken of patients with ectopic ONB treated between 2000 and 2020 in a tertiary-care referral center for skull base tumors. Three patients were included in this analysis: a 37-year-old woman with ONB arising from the bulla ethmoidalis; a 28-year-old man with inappropriate secretion of antidiuretic hormone caused by a maxillary sinus ONB; and a 41-year-old man with lacrimal sac ONB. Preoperative workup, surgical approach, adjuvant treatments and postoperative surveillance were analyzed. Relevant literature published between 2000 and January 2021 was fully reviewed to investigate oncologic outcomes and delineate the standard of care for such rare tumors.

RESULTS

All patients were treated via endoscopic endonasal resection with radical intent, followed by adjuvant treatments when required. No recurrences of disease were observed after a mean follow-up time of 32 months (range, 12-60 months). Data emerging from the literature suggest that a multidisciplinary treatment approach, including free-margins surgical resection followed by adjuvant radiotherapy or radiochemotherapy, is recommended. Olfactory bulb and dura preservation should be attempted whenever feasible.

CONCLUSIONS

Endoscopic endonasal surgery should be preferred, when possible, to achieve complete excision to minimize patients' morbidity. The ectopic site of origin affects prognosis and should be considered when selecting the appropriate multimodal treatment strategy.

The Role of Endonasal Endoscopic Skull Base Repair in Posttraumatic Tension Pneumocephalus

OBJECTIVES

Information about the endonasal endoscopic approach (EEA) for the management of posttraumatic tension pneumocephalus (PTTP) remains scarce. Concomitant rhinoliquorrhea and posttraumatic hydrocephalus (PTH) can complicate the clinical course.

METHODS

The authors systematically reviewed pertinent articles published between 1961 and December 2020 and identified 6 patients with PTTP treated by EEA in 5 reports. Additionally, the authors share their institutional experience including a seventh patient, where an EEA resolved a recurrent PTTP without rhinoliquorrhea.

RESULTS

Seven PTTP cases in which EEA was used as part of the treatment regime were included in this review. All cases presented with a defect in the anterior skull base, and 3 of them had concomitant rhinoliquorrhea. A transcranial approach was performed in 6/7 cases before EEA was considered to treat PTTP. In 4/7 cases, the PTTP resolved after the first intent; in 2/7 cases a second repair was necessary because of recurrent PTTP, 1 with and 1 without rhinoliquorrhea, and 1/7 case because of recurrent rhinoliquorrhea only. Overall, PTTP treated by EEA resolved with a mean radiological resolution time of 69 days (range 23-150 days), with no late recurrences. Only 1 patient developed a cerebrospinal fluid diversion infection probably related to a first incomplete EEA skull base defects repair. A permanent cerebrospinal fluid diversion was necessary in 3/7 cases.

CONCLUSIONS

Endonasal endoscopic approach repair of air conduits is a safe and efficacious second-line approach after failed transcranial approaches for symptomatic PTTP. However, the strength of recommendation for EEA remains low until further evidence is presented.

Anterior Skull Base Surgery via Endoscopic Endonasal Approach: Outcomes and Analysis

BACKGROUND

This study was retrospectively conducted to evaluate the postoperative surgical results of our patients with anterior skull base mass, defect, and/or cerebrospinal fluid rhinorrhea who underwent reconstruction via endoscopic endonasal approach and to share our experiences.

METHODS

Sociodemographic features of patients who had undergone endoscopic surgery in our clinic due to anterior skull base mass, defect, or rhinorrhea were evaluated in terms of etiological factors, surgical method, pathology, postoperative complications, need for revision surgery and comorbid disease.

RESULTS

A total of 131 patients were included; 76 were male and mean age was 36.2 years. Endoscopic endonasal surgery was performed for nasal mass (70.2%) in 92 cases, rhinorrhea (17.6%) in 23 cases, chronic sinusitis (7.6%) in 10 cases, and gunshot injury (4.6%) in 6 cases. After surgery, benign mass pathology was detected in 75 patients and malignant mass pathology was detected in 23 patients. Osteoma was the most common among benign formations, and squamous cell carcinoma was the most common among malignant formations. The most common cause of surgical revision was nasal masses (25 cases, 77.4%).

CONCLUSION

Endoscopic intracranial interventions and increased anterior skull base surgery are garnering increased interest of physicians as endoscopic approaches are gaining popularity in recent years. Successful results are achieved through appropriate diagnostic methods and endoscopic approaches. Success rates will be further increased due to developing technology and imaging methods, while the risk of complications and revision surgery will be further reduced.

Intraoperative Indocyanine Green Angiography for Assessing Flap Perfusion in Skull Base Reconstruction: A Systematic Review

Objective This study was aimed to study the current use of intraoperative indocyanine green (ICG) angiography during skull base reconstruction and understand its efficacy in predicting postoperative magnetic resonance imaging (MRI) enhancement and flap.

Study Design The Embase, the Cochrane Central Register of Controlled Trials (CENTRAL), Web of Science, and Google Scholar databases were searched from the date of inception until August 2020 for studies of ICG flap perfusion assessment during skull base reconstruction. The primary outcome of interest was the development of cerebrospinal fluid (CSF) leak after skull base reconstruction. Secondary outcomes of interest included postoperative meningitis, flap MRI enhancement, flap necrosis, flap perfusion measurements, and total complications.

Results Search results yielded 189 studies, from which seven studies with a total of 104 patients were included in the final analysis. There were 44 nasoseptal flaps (NSF), two lateral nasal wall flaps (LNWF), 14 pericranial flaps (PCF), and 44 microvascular free flaps. The rates of CSF leak and postoperative MRI enhancement were 11 and 94%, respectively. There was one case of postoperative meningitis. Pooled analysis of the available data showed that intraoperative ICG flap perfusion was associated with flap enhancement on postoperative MRI (p = 0.008) and CSF leak (p = 0.315) by Fisher's exact test.

Conclusion The available literature suggests intraoperative ICG enhancement is associated with postoperative MRI enhancement. Given the small sample sizes in the literature and the rarity of complications associated with skull base reconstruction, intraoperative ICG enhancement has not been predictive of flap necrosis or postoperative complications such as CSF leak or meningitis.

Level of Evidence This study presents level 3 evidence as a systematic review of case studies, case reports, and retrospective and prospective trials with no blinding, controls, and inconsistently applied reference standards.

Failure of anterior skull base reconstruction for sinonasal carcinoma: consequence on the postoperative follow up. A multicentre evaluation of management

BACKGROUND

Numerous techniques for closure of the anterior skull base in cancer patients have a high success rate but management of failure is poorly documented.

OBJECTIVES

To standardize the post-operative follow-up after reconstruction surgery of the anterior skull base after removal for sinonasal carcinoma.

MATERIALS AND METHODS

Retrospective review of failure of anterior skull base reconstruction between 2005 and 2018 in a multicenter setting.

RESULTS

Twenty four patients were included. Reconstruction failure was detected by a cerebrospinal (CSF) leak in 79.2%, by an infectious complication without CSF leak (i.e. meningitis) in 12.5%, and in 8.3% by extensive pneumocephalus. Failure was observed during the first week after surgery in 75% of patients, in the second week in 21%, and in 4% after day 15. The delay in discovery of the failure was associated with multilayer reconstruction (p=.03). Failure was treated surgically in 54% of the patients and medically in 46%, with a similar success rate (85 vs. 100%).

CONCLUSION AND SIGNIFICANCE

After carcinologic resection of the anterior skull base, monitoring should be systematic during the first postoperative week. Surgical management of failure is not always necessary.

The Effectiveness and Safety of Intrathecal Fluorescein in the Management of Cerebrospinal Fluid Leaks

BACKGROUND

Cerebrospinal fluid (CSF) leaks can be associated with significant morbidity such as meningitis. Surgical management has proven effective, with endoscopic approaches having become the gold standard due to success rates >90%. Inability to localise the leak site prior to surgery is associated with surgical failure. The use of intrathecal fluorescein (IF) to localise CSF fistulae sites was first demonstrated in 1960. Despite this, its use in this context is unlicensed.

OBJECTIVE

Evaluate the safety and efficacy of IF use in the management of CSF leak repairs in our centre.

METHODS

All patients who underwent endoscopic repair of CSF fistula by a single surgeon where IF was used between January 2010 - September 2019 at a single-centre (tertiary skull base referral unit in the United Kingdom) were retrospectively analysed. Primary outcome measures were localisation of CSF fistula with IF (efficacy) and peri-operative complications likely to be attributable to IF (safety).

RESULTS

There were 55 patients included (60 procedures) with a positive localisation rate of 90.0% with IF. The overall peri-operative complication rate was 8.3% (n = 5). It is likely that none were related to IF use. However, three complications may be linked giving a complication rate potentially related to IF of 5.0%. There were no peri-operative mortalities.

CONCLUSION

Many studies have demonstrated IF to be safe at low doses (<50mg) with a high sensitivity, specificity and positive predicative value. Our results demonstrate that the use of IF in our centre is safe and effective at identifying CSF fistulae. While we have reported some complications in our cohort, these were unlikely to be directly attributable IF use. We have described no serious complications such as seizures, limb weakness or death. We believe this study adds to the growing body of evidence that IF use in the management CSF fistula repairs is safe and effective.

Risk factor for cerebrospinal fluid leak after endoscopic endonasal skull base surgery: a single-center experience

BACKGROUND

One of the major complications in endoscopic endonasal skull base surgery (EESBS) is postoperative cerebrospinal fluid (CSF) leaks. Recently, EESBS has been applied to various skull base diseases as well as more complicated cases influenced by previous treatment with or without various comorbidities.

AIMS/OBJECTIVES

This study aimed to assess the factors that influence the results of postoperative CSF leak after EESBS with mixed patient backgrounds.

MATERIALS AND METHODS

We conducted a retrospective analysis of the clinical records of patients undergoing EESBS in our institution from 2012 to 2017.

RESULTS

Out of a total of 230 cases of EESBS, 11 (4.8%) suffered from postoperative CSF leakage. The rate of CSF leakage for pituitary adenoma, Rathke's cleft cyst, chordoma, and meningioma was 3.5%, 0%, 3.6% and 8.0%, respectively. Multiple variate analysis revealed that repeated surgery (p = .008) and intraoperative CSF leak (p = .044) were significant risk factors for postoperative CSF leakage.

CONCLUSIONS AND SIGNIFICANCE

The rate of postoperative CSF leakage in this study was comparable to previous reports, and repeated surgery may increase postoperative CSF leakage. The surgical strategy for tumor removal as well as skull base reconstruction should be given careful consideration according to tumor pathology and the patient's condition.

Skull base reconstruction: A question of flow? A critical analysis of 521 endoscopic endonasal surgeries

INTRODUCTION

Post-operative CSF leak still represents the main drawback of Endoscopic Endonasal Approach (EEA), and different reconstructive strategies have been proposed in order to decrease its rate.

OBJECTIVE

To critically analyze the effectiveness of different adopted reconstruction strategies in patients that underwent EEA.

MATERIALS AND METHODS

Adult patients with skull base tumor surgically treated with EEA were retrospectively analyzed. Data recorded for each case concerned patient demographics, type of surgical approach, histotype, anatomical site of surgical approach, intra-operative CSF leak grade (no leak (INL), low flow (ILFL), high flow (IHFL)), reconstructive adopted strategy, Lumbar Drain positioning, post-operative CSF leak rate and intra/post-operative complications.

RESULTS

A total number of 521 patients (January 2012-December 2019) was included. Intra-operative CSF leak grade showed to be associated with post-operative CSF leak rate. In particular, the risk to observe a post-operative CSF leak was higher when IHFL was encountered (25,5%; Exp(B) 16.25). In particular, vascularized multilayered reconstruction and fat use showed to be effective in lowering post-operative CSF leaks in IHFL (p 0.02). No differences were found considering INL and ILFL groups. Yearly post-operative CSF leak rate analysis showed a significative decreasing trend.

CONCLUSION

Intra-operative CSF leak grade strongly affected post-operative CSF leak rate. Multilayer reconstruction with fat and naso-septal flap could reduce the rate of CSF leak in high risk patients. Reconstructive strategies should be tailored according also to the type and the anatomical site of the approach.

Reconstruction after extended endonasal approaches to the anterior cranial base: surgical techniques and current results

The development of extended endoscopic endonasal approaches (EEA) to the anterior skull base has allowed successful resection of selected extradural and intradural skull base tumors through an endonasal corridor, minimizing brain and cranial nerve manipulation. However, as the complexity of the approaches has increased, so has the need for more robust and reliable reconstructive options to minimize morbidity. Reconstructive decision-making after extended EEA for anterior skull base tumors must take into consideration multiple factors including patient characteristics (Body Mass Index, previous surgeries, and radiation), location and the size of the skull base defect. A multilayered reconstruction which includes a combination of free grafts and a vascularized flap is the standard approach to anterior skull base defects after EEA and should be applied in a stepwise manner tailored to each patient. The techniques and materials used to accomplish skull base repair are discussed, the outcomes in the literature are reviewed, and our reconstructive paradigm presented.

Congenital Anterior Skull Base Encephaloceles: Long-Term Outcomes After Transnasal Endoscopic Reconstruction

BACKGROUND

Congenital intranasal encephaloceles (ECs) are rare malformations of the pediatric age, complex to diagnose and treat, above all if associated with genetic syndromes or concomitant dysmorphisms. The aims of the study were to report our experience in managing nasal ECS in children, to evaluate the efficacy and safety of the transnasal endoscopic repair, and to analyze in an overall way the surgical long-term outcomes. Moreover, we sought to contribute to the debate on pathogenesis of ECs, investigating possible related risk factors described in the literature.

METHODS

A retrospective analysis was performed of pediatric nasal ECs managed with a transnasal endoscopic approach at a tertiary referral center through clinical follow-up and telephone survey.

RESULTS

Twenty-three patients with nasal ECs fitted the criteria of the study. Mean age at surgery was 5 years (69 months) and the mean follow-up was 59 months. The clinical presentation is described in detail, with particular emphasis on syndromic cases. Of 23 patients, 17 had an isolated EC, and in 4 patients, a malformation syndrome was associated. EC recurred in 2/23 patients (8.7%) after surgical correction, necessitating a revision procedure. No perioperative complications or long-term sequelae were noted in the entire population.

CONCLUSIONS

Endonasal endoscopic management of congenital ECs is feasible in children, although regular long-term follow-up is essential. Furthermore, the surgical approach does not seem to affect patients' development and quality of life, although more studies and validated questionnaires are needed. No recurrent risk factors were observed able to justify a certain etiologic relation.

Extended endonasal endoscopic approach for anterior midline skull base lesions

AIM

In recent years, extended endoscopic endonasal approach (EEEA) has been used as an alternative to transcranial approaches in the treatment of anterior midline skull base lesions. We retrospectively reviewed our cases operated using this technique and compared the results with current literature.

METHOD

The data of 24 patients who were operated using EEEA in our department between 2010-2018 were retrospectively analyzed. The lesions were located in the midline between the posterior wall of the frontal sinus and tuberculum sella. Tumor locations, histopathological diagnoses, surgical techniques, outcomes and complications were documented.

RESULTS

Eleven patients were female and 13 were male. Their ages ranged between 18-75 years (mean 40.5 years). Considering their locations; 12 were in the anterior fossa (50 %), 7 were in the tuberculum sella (29.1 %), and 5 were in both anatomic sites (20.8 %). Histopathologically, our series consisted of 15 meningiomas, 6 osteomas, 2 dermoid tumors and 1 metastatic carcinoma. We achieved gross total resection in 75 % of our patients. Ten patients presented with visual complaints and 7 of them improved postoperatively. Postoperative cerebrospinal fluid leakage (CSF) was observed in 3 patients and one of them developed meningitis and subsequently died of sepsis.

CONCLUSION

Although the number of cases is low, EEEA seems like a safe, effective and well-tolerated treatment modality for anterior midline skull base lesions. But strict preventive measures should be taken for a possible CSF leak.

Spontaneous CSF Leaks and IIH: A Flawless Connection? An Experience With 167 Patients

OBJECTIVES

Spontaneous cerebrospinal fluid (CSF) leaks are a rare but insidious clinical entity. In the recent literature, their pathogenesis has been linked with idiopathic intracranial hypertension (IIH). Considering a worse surgical outcome compared to traumatic leaks, a medical treatment of the underlying IIH has been suggested in order to prevent relapses. Nevertheless, some aspects of this rare pathology remain unclear. We report our long experience in the management of spontaneous CSF leaks.

METHODS

A retrospective evaluation of all patients with spontaneous CSF leaks treated from 1998 to 2018 in a tertiary referral center was carried out. All patients received surgery without any adjuvant routine medical treatment. Epidemiological and clinical data were reviewed. A telephone survey was conducted to investigate IIH-related symptoms in this population.

RESULTS

One hundred sixty-seven patients and 195 procedures were included in the study. The total rate of failure after surgical treatment was 9%. Eight patients suffered a relapse in the same site (4%, 8 of 195), whereas seven patients experienced a relapse in a different site (4%, 7 of 167). Twenty-nine percent of the population interviewed referred at least one IIH-related symptom.

CONCLUSION

Spontaneous CSF leaks represent a complex pathology that need a multidisciplinary evaluation. Surgical treatment seems to guarantee favorable results in most of the patients. Despite this, a not negligible percentage of patients experienced a relapse during a long-term follow-up. Further studies are needed to reach a deeper understanding of the presentation and course of this particular condition.

LEVEL OF EVIDENCE

4 Laryngoscope, 131:E401-E407, 2021.

Pediatric sinonasal and skull base lesions

Pediatric skull base lesions are complex and challenging disorders. Safe and comprehensive management of this diverse group of disorders requires the expertise of an experienced multidisciplinary skull base team. Adult endoscopic skull base surgery has evolved due to technologic and surgical advancements, multidisciplinary team approaches, and continued innovation. Similar principles continue to advance the care delivered to the pediatric population. The approach and management of these lesions varies considerably based on tumor anatomy, pathology, and surgical goals. An understanding of the nuances of skull base reconstruction unique to the pediatric population is critical for successful outcomes.

The expanded endonasal approach in pediatric skull base surgery: A review

OBJECTIVE

Surgery of the pediatric skull base has multiple unique challenges and has seen recent rapid advances. The objective of this review is to assess key issues in pediatric skull base surgery (SBS), including anatomic limitations, surgical approaches, reconstruction techniques, postoperative care, complications, and outcomes.

DATA SOURCES

PubMed literature review.

REVIEW METHODS

A review of the literature was conducted to assess the challenges, recent advances, and reported outcomes in pediatric SBS.

RESULTS

The pediatric skull base presents multiple anatomic challenges, including variable patterns of pneumatization, narrow piriform aperture width, and narrow intercarotid distance at the level of the cavernous sinus but not the superior clivus. These issues may be particularly challenging in patients less than 2 years of age. Endoscopic endonasal approaches in the sagittal and coronal plane have been applied to the pediatric skull base while open approaches may still be necessary in the setting of extensive intracranial or orbital disease, as well as disease lateral to critical neurovascular structures. While the nasoseptal flap was initially called into question for pediatric cases, it has been shown through multiple reports to be a feasible and robust reconstructive option. Complications and outcomes often depend upon the pathology. In children, response to noxious stimuli, ability to avoid Valsalva, and adherence to nasal precautions is variable. The use of lumbar drains is more common in pediatric than adult patients.

CONCLUSION

While the pediatric skull base presents unique challenges, outcomes data support that endoscopic endonasal approaches are a pertinent surgical technique in appropriately selected patients.

LEVEL OF EVIDENCE

3a.

Perioperative Considerations in Endoscopic Skull Base Surgery

Purpose of the Review

Present an overview of perioperative considerations specific to endoscopic skull base surgery necessary to maximize successful outcomes.

Recent Findings

The majority of perioperative considerations for endoscopic skull base surgery lack strong supporting evidence and frequently have varied use or implementation amongst institutions. A notable exception comes from a recent randomized controlled trial demonstrating the benefit of lumbar drainage in high-risk cerebrospinal fluid leaks.

Summary

Skull base surgeons must consider a multitude of perioperative factors. While many components of perioperative management are extrapolated from related fields such as endoscopic sinus surgery or open cranial base surgery, additional high-quality studies are needed to delineate best practices specific to endoscopic skull base surgery.

The role of a post therapeutic surveillance program for sinonasal malignancies: Analysis of 417 patients

BACKGROUND

Post therapeutic surveillance of head and neck neoplasms is a still debated issue in the current literature: although different works tried to establish frequency, modality, and efficacy of a routine follow-up, little evidence has been produced, in particular considering only sinonasal malignancies.

METHODS

A retrospective review of patients treated for sinonasal malignancies in a single tertiary center and followed through a regular program of follow-up was carried out. Rate of recurrence, location, timing, diagnosis, and salvage treatment were the main data analyzed.

RESULTS

Of note, 417 patients were included in the study and 117 experienced at least one relapse. Staging, histological type, and previous treatment represent the main clinical factors to be considered to stratify patient's risk of recurrence.

CONCLUSION

A regular post therapeutic surveillance can provide an early recurrence detection for patients treated for sinonasal malignancies, offering opportunity for salvage treatment in a high percentage of patients.

Update on anterior skull base reconstruction

PURPOSE OF REVIEW

Anterior skull base reconstruction has rapidly evolved over the past few years as endoscopic approaches to resect tumors in this region have become more established. The present review evaluates the robust amount of new literature on this topic over the past year with particular attention to minimally invasive methods for reconstruction.

RECENT FINDINGS

Although vascularized local flaps remain the mainstay reconstructive choice when available for the anterior skull base, innovative techniques for all types of reconstruction, ranging from free grafts to free flaps continue to emerge.

SUMMARY

Because of the unique challenges and wide variety of options available to repair the anterior skull base with the goal to prevent or treat cerebrospinal fluid leaks, surgical expertise and experience in this field is of utmost importance.

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.

The Helmet-Visor Pericranial Flap as a Viable Option for Anterior Cranial Base Reconstruction in Complex Oncologic Cases

OBJECTIVE

To describe a novel bilaterally pedicled pericranial flap for anterior cranial base reconstruction after removal of complex frontobasal cancers extending to the frontal region, thus precluding the use of standard reconstructive techniques.

METHODS

In selected oncologic cranial base surgeries, the use of the standard galea frontalis pericranial flap for reconstructive purposes may be precluded by tumor infiltration. In such cases, dura mater reconstruction and exclusion of frontal sinuses from the intracranial space can be performed using a large superficial temporal artery bilaterally pedicled pericranial flap obtained from both temporoparietal regions. Surgical technique, indication, contraindication, complications, and degree of resection are recorded to evaluate the efficacy of this surgical method.

RESULTS

A 48-year-old man affected by a recurrence of frontobasal squamous cell carcinoma was surgically treated by combined transcranial and endoscopic endonasal resection. A large pericranial flap pedicled bilaterally on the parietal branches of the superficial temporal artery was obtained, transposed anteriorly, carefully watertight sutured to the dural defect, and used to exclude cranialized frontal sinuses as well. The reconstruction was successful, and the patient was discharged home on the tenth postoperative day without any complications and/or development of cerebrospinal fluid leak. Contrast-enhanced magnetic resonance imaging 3 months after surgery was clear from disease with consolidated surgical outcomes.

CONCLUSIONS

This novel pericranial flap seems to be easily obtained and effective for anterior cranial base reconstruction when the use of a traditional galea frontalis flap is precluded for oncologic reasons and there are concerns for the possible development of contaminations and cerebrospinal fluid leaks.

Medial Temporal Encephalocele and Medically Intractable Epilepsy: A Tailored Inferior Temporal Lobectomy and Case Report

BACKGROUND AND IMPORTANCE

Temporal lobe encephaloceles are increasingly recognized as a potential cause of medically refractory epilepsy and surgical treatment has proven effective. Resection of the encephalocele and associated cortex is often sufficient to provide seizure control. However, it is difficult to determine the extent of adjacent temporal lobe that should be resected. We present a case report and our technique of a tailored inferior temporal pole resection.

CLINICAL PRESENTATION

A 32-yr-old man with an 11-yr history of medically refractory epilepsy. Prolonged electroencephalography (EEG) revealed frequent left and rare right frontotemporal sharp waves. Numerous seizures were captured with EEG, all of which originated from the left temporal region. Statistical parametric mapping (SPM) subtraction ictal–interictal SPECT coregistered with magnetic resonance imaging (MRI) (SISCOM) demonstrated ictal hyperperfusion in the anterior left temporal lobe. MRI showed 2 encephaloceles in the left anterior temporal lobe with the accompanying bony defects in the floor of the middle cranial fossa apparent on the computed tomography scan. The patient underwent left temporal craniotomy with intraoperative electrocorticography, resection of the encephaloceles, and a tailored inferior temporal lobectomy (IFTL) and repair of the middle fossa defects. At 7 mo follow up he reported seizure-freedom since surgery.

CONCLUSION

Resection of temporal encephalocele and adjacent cortex is safe and effective procedure for select patients with medically refractory epilepsy. This video demonstrates our technique which provides a more standardized approach to the resection.

Septal Flip Flap for Anterior Skull Base Reconstruction After Endoscopic Transnasal Craniectomy: Long-Term Outcomes

BACKGROUND

Endoscopic endonasal anterior skull base malignant sinonasal tumor resection and reconstruction remains a challenge. We describe our septal flip flap (SFF) reconstruction, a new surgical technique for repairing anterior skull base defects and report our outcomes.

METHODS

We retrospectively reviewed the clinical data of 24 patients who underwent skull base reconstruction using a SFF following endoscopic resection with transnasal craniectomy. We raise the SFF from the contralateral nasal septum based on the septal branches of the anterior and posterior ethmoidal arteries; the SFF is then rotated laterally for anterior skull base reconstruction after transnasal resection with craniectomy.

RESULTS

The SFF was used for multiple tumor types including, most commonly, intestinal-type adenocarcinoma, followed by olfactory neuroblastoma, squamous cell carcinoma, sinonasal undifferentiated carcinoma, and other types. All of the cases had either preoperative or postoperative radiation therapy. All flaps remained viable postoperatively. Postoperatively, nasal crusting was significantly reduced with faster healing of the surgical cavity.

CONCLUSIONS

The SFF adds to the clinical armamentarium the opportunity to provide vascularized mucosal coverage extending from the frontal recess back to the planum sphenoidalis. The use of SFF requires careful consideration when dealing with paranasal sinus cancers so as not to infringe oncologic principles.