Open and Endoscopic Open-Assisted Repair of Anterior Skull Base Defects.

Introduction Skull base lesions in children and adolescents are rare, and comprise only 5.6% of all skull base surgery. Anterior skull base lesions dominate, averaging slightly more than 50% of the cases. Until recently, surgery of the anterior skull base was dominated by open procedures and endoscopic skull base surgery was reserved for benign pathologies. Endoscopic skull base surgery is gradually gaining popularity. In spite of that, open skull base surgery is still considered the "gold standard" for the treatment of anterior skull base lesions, and it is the preferred approach in selected cases. Objective This article reviews current concepts and open approaches to the anterior skull base in children in the era of endoscopic surgery. Materials and Methods Comprehensive literature review. Results Extensive intracranial-intradural invasion, extensive orbital invasion, encasement of the optic nerve or the internal carotid artery, lateral supraorbital dural involvement and involvement of the anterior table of the frontal sinus or lateral portion of the frontal sinus precludes endoscopic surgery, and mandates open skull base surgery. The open approaches which are used most frequently for surgical resection of anterior skull base tumors are the transfacial/transmaxillary, subcranial, and subfrontal approaches. Reconstruction of anterior skull base defects is discussed in a separate article in this supplement. Discussion Although endoscopic skull base surgery in children is gaining popularity in developed countries, in many cases open surgery is still required. In addition, in developing countries, which accounts for more than 80% of the world's population, limited access to expensive equipment precludes the use of endoscopic surgery. Several open surgical approaches are still employed to resect anterior skull base lesions in the pediatric population. With this large armamentarium of surgical approaches, tailoring the most suitable approach to a specific lesion in regard to its nature, location, and extent is of utmost importance.

Endoscopic repair of small- to medium-sized anterior skull base (ASB) defects using bone, cartilage, fascia, fibrin glue, lipolized dura, and, more recently, acellular dermal allograft have all been described with equal efficacy. The purpose of this study was to review our experience with the use of acellular dermis as the sole graft material in endoscopic reconstruction of large ASB defects. A retrospective chart review of all patients who underwent endoscopic repair of ASB defects at the University of Miami between the years of 2001 and 2006 was conducted. Fifty-six patients were identified who met these criteria. All repairs were performed by a transnasal, endoscopic approach. Outcome measures included success of graft take and incidence of major and minor complications. Dural defect size was defined as small (<0.4 cm), intermediate (0.4-2.0 cm), and large (>2.0 cm). AlloDerm (AlloDerm. LifeCell Corp. Woodlands, TX) was used as the primary graft material in 30/55 (55%) cases; 16/55 (29%) of the repaired defects were classified as large. Graft success was 97% in the AlloDerm group and 92% in the non-AlloDerm group. The incidence of major and minor complications in the AlloDerm group was 0 and 3.3%, respectively. In the non-AlloDerm group, the incidence of major and minor complications was 4 and 12%, respectively. There were no statistical differences in the complication rates based on the type of repair or defect size. Alloderm can be used successfully to repair ASB defects, including large defects that are >2 cm in size with little or no morbidity.

ObjectiveEndoscopic repair of large anterior skull base (ASB) defects has excellent results when using multilayered repairs with a nasoseptal flap. However, in extensive intranasal tumors, a nasoseptal flap may not always be available. One alternative option is a flexible single‐layer ASB repair. Initial studies indicate low cerebrospinal fluid leak rates with a single‐layer repair. However, the level of frontal lobe support, particularly the propensity for a significant inferior displacement of the frontal lobe, is not known. The goal of this study is to determine the frontal lobe position after single‐layer acellular dermal allograft repair in large ASB defects.Study DesignRetrospective cohort study.SettingTertiary care medical center.Subjects and MethodsThis cohort study compares the frontal lobe position in adults who underwent endoscopic endonasal ASB tumor resection and single‐layer cadaveric dermal matrix repair (ASB cohort) with control subjects without intracranial abnormalities (control cohort). The ASB cohort includes subjects with an ASB defect of ≥5 cm anterior/posterior and ≥1.5 cm wide and who had imaging at least 2 months after surgery. The frontal lobe position is measured on sagittal CT/MRI using a reference line from the base of the sella to the nasion. A value of zero indicates that the inferior‐most aspect of the frontal lobe is at the level of the nasion−sellar line. A positive value indicates that the frontal lobe is inferior to the nasion−sellar line. The ASB cohort frontal lobe position is compared with the control cohort using the Mann−Whitney U test. A priori we set an absolute difference of 5 mm as a clinically significant difference.ResultsThe ASB cohort includes 47 subjects who are 57% male with an average age of 60 years (range: 31−89 years). The most common ASB pathology is esthesioneuroblastoma (n = 21) and 81% of the ASB cohort had postoperative radiation. The control cohort includes 20 subjects who are 60% male, with a mean age of 45 years (range: 19−74 years). The majority of controls underwent imaging for head trauma (n = 13). The ASB mean frontal lobe position is −0.2 mm superior to the nasion−sellar line (range: −9.2 to 10.4 mm), while the control's mean frontal lobe position is 1.1 mm inferior to the nasion−sellar line. This difference is not statistically significant (P = 0.13) and does not reach our a priori definition of clinical significance. The frontal lobe position of ASB subjects who had radiation is closer to the nasion−sellar line as compared with those who did not undergo radiation.ConclusionsSingle‐layer acellular dermal graft repair maintains frontal lobe support and position in large ASB defects.

Foetal surgery and cleft lip and palate: current status and new perspectives

Successful reconstruction of large anterior skull base (ASB) defects after craniofacial resection of malignant skull base tumors is paramount for preventing cerebrospinal fluid (CSF) fistulas. The vascularized pedicled pericranial flap (PCF) has been the gold standard for repairing ASB defects after transbasal transcranial approaches. However, flap necrosis and delayed CSF leaks can occur after adjuvant radiation therapy. We describe a "double flap" reconstruction technique in which the PCF is augmented inferiorly by a secondary vascularized pedicled nasoseptal flap (NSF) that is harvested and rotated using an endoscopic endonasal approach. This technique is illustrated in 2 patients who underwent a combined cranionasal (transbasal and endoscopic endonasal) approach for large sinonasal malignancies with significant intracranial extension (1 esthesioneuroblastoma, 1 sinonasal teratocarcinosarcoma). After tumor removal via a combined cranionasal approach, primary repair of the ASB dural defect was performed with a free patch graft. The ASB defect was then repaired using the double flap technique with a vascularized PCF from above and augmented with a vascularized NSF from below. Postoperatively, there were no complications of CSF leakage, meningitis, or tension pneumocephalus in both patients. After subsequent radiation therapy, the double flap repair remained intact at 2 years postoperatively in both patients. The double flap skull base reconstruction technique provides an additional barrier of vascularized tissue to prevent CSF leakage, meningitis, tension pneumocephalus, and postradiation necrosis. This technique is a viable option if a combined transcranial and transnasal endoscopic tumor resection is performed and postoperative radiation is anticipated.

Measure the dimensions of the nasoseptal (NS) flap and the anterior skull base (ASB) defect. Verify whether the flap is sufficient to cover the defect. Study the anatomy of the septal artery (SA). Anatomical and radiological study. After endoscopic craniofacial resection, sufficiency of the flap to cover the ASB defect was assessed. The SA was dissected. The number of branches in the pedicle and the distance between the artery and the sphenoid ostium were noted. Radiologic study analyzing CT scans of 30 patients for comparison among measurements of the NS flap and the ASB defect was performed. In all cases the flap was sufficient to cover the ASB. Two branches of the SA were found in the pedicle in 71.4%. The distance between the SA and the sphenoid ostium was 9.3 mm. The reconstruction area of the flap (17.12 cm(2) ) was larger than the defect area (8.64 cm(2) ) (P < .001). The difference between the superior length of the flap and the anterior-posterior distance of the defect was ≤ 5 mm in 26.7%. Comparison between the anterior flap width and the anterior defect width revealed that in 33% the difference was ≤ 5 mm. The dimensions of NS flap are sufficient to cover completely the ASB defect. The anterior edge of the defect presents increased risk for failure in coverage. Additional width adding the nasal floor mucosa to the flap is important to decrease the risk of gap in the anterior orbit-orbit defect. It is more common to find two branches of the SA in the pedicle.

Introduction: Endoscopic surgery of the frontal recess and sinus proves to be a challenge due to the large anatomical variability of this area, the proximity of the olfactory groove and the orbit. These difficulties are often compounded by exacerbation of inflammation or intraoperative bleeding. Possible complications of endoscopic frontal sinus surgeries are cerebrospinal fluid leakage, orbital damage, bleeding from the anterior ethmoid artery, frontal recess disease postoperative obstruction of the drainage pathway of the frontal sinus. For this reason, detailed knowledge of anatomy, a thorough preoperative radiological evaluation and appropriate surgical skills are crucial in performing this type of procedure. Aim: The aim of the study was to develop a checklist of elements that ought to be considered before endoscopic surgery of the frontal sinus. Methods: The study presents a review of the latest literature including 40 publications about radioanatomy of the frontal recess and sinus, complications of endoscopic surgery in this area and methods of their prevention. Results: The elements that ought to be assessed in computed tomography before frontal sinus endo-scopic surgery are the frontoethmoidal cells, the insertion of the uncinate process, the measurement of the angulation of the posterior wall of the frontal sinus and its dimensions, the anatomy of the olfactory groove, the location of the anterior ethmoid artery, the possible sinus aplasia. Conclusions: Proper use of the multiplanar computed tomography reconstruction technique enables the recognition of anatomical variabilities, the prediction of intraoperative difficulties and the selection of appropriate tools, which improve the surgical process and its safety.

Nasopharyngeal tumors (NPTs) are primarily treated with nonsurgical therapy. Recent studies have demonstrated endoscopic salvage surgery for NPT recurrences may improve survival relative to reirradiation. However, there are very limited data on open compared with endoscopic approaches for NPTs. We investigated whether endoscopic and open surgical approaches to the nasopharynx improve overall survival for all histologic subtypes of NPTs. We performed a retrospective cohort study using the National Cancer Database (NCDB). All adult patients with NPTs from 2004 to 2016 without distant metastasis who underwent treatment with curative intent were included. We extracted clinical and treatment variables to assess our primary outcome of overall survival. On univariate analysis, patients undergoing endoscopic surgery, but not open surgery, had significantly improved overall survival relative to those undergoing nonsurgical treatment. Post hoc analysis demonstrated significantly improved overall survival for surgery in patients with minor salivary gland histology, but not squamous cell carcinoma (SCC) histology or by T or N classification. A Cox proportional hazards model was used for multivariate regression. After adjusting for covariates, both endoscopic and open approaches were associated with improved overall survival relative to nonsurgical treatment for all tumor types. A multivariate regression of SCC found that open surgery, but not endoscopic surgery, was significantly associated with improved overall survival. Both endoscopic and open surgical approaches are associated with improved overall survival of patients with NPT. These findings highlight important oncologic validity as endoscopic and robotic platforms to the nasopharynx become more widely adopted.

BACKGROUND AND OBJECTIVES:Endoscopic sinus surgery (ESS), markedly improved with the introduction of new preoperative imaging techniques, intraoperative visualization tools, and the use of surgical navigation systems. In this retrospective study we evaluated the usefulness of CT-guided endscopic sinus surgery and studied its advantages over conventional endscopic sinus surgery.METHODS:We retrospectively reviewed the records of 60 randomly chosen patients with chronic rhinosinusitis (CRS) and moderate-to-severe sinonasal polyposis, undergoing endoscopic sinus surgery with surgical navigation (n=30) and without navigation (n=30). Data on the operative note, time of surgery, complications, and recurrence rate were collected and analyzed.RESULTS:Of the 60 patients, 40 (66.7%) were diagnosed with CRS and 20 (33.3%) had allergic fungal sinusitis. Primary surgery was performed in 37 (61.7%) and revision surgery was performed in 23 (38.3%) cases. The computer-aided surgery (CAS) group included 28 (93.3%) patients with extensive disease and 12 (40%) with bone erosions, with intraorbital or extradural extension, while the non-CAS group included 24 (80%) patients with extensive disease and seven (23.3%) with bone erosions, with intraorbital or extradural extension. The average operative time was approximately 13 minutes greater in the navigation group, with significant improvement in the recurrence rate (n=11, 36.7% in the non-CAS group; n=5, 16.7% in the CAS group), and intraoperative complications were fewer in the CAS group (two exposures of orbital fat in the non-CAS group; no complications in the CAS group).CONCLUSION:Computer navigational systems appear to serve as a valuable adjunct in preoperative planning and safe intraoperative dissection.

The skull base inventory (SBI) was developed to better assess health-related quality of life (HR-QOL) in patients with anterior and central skull base neoplasms treated by endoscopic and open approaches. The primary objective of this study was to prospectively assess the psychometric properties of the SBI. This study is part of a multi-center study of patients undergoing endoscopic and open procedures completed between 2012 and 2018. Participants were eligible if they were over 18years of age; had benign or malignant anterior, antero-lateral, or central skull base tumors; and required either an open or endoscopic skull base surgical approach. In order to assess the psychometric properties of the SBI, patients completed the instrument at six time points (preoperative, 2weeks, 3months, 6months, 12months postoperative). Patients also completed the Anterior Skull Base (ASB) questionnaire and the Sinonasal Outcome Test (SNOT-22) to allow comparison to the SBI. One hundred and eighty-seven patients were included across five centers, with 121 having an endoscopic procedure. Internal consistency (Cronbach's alpha = 0.95) and test-retest at 12 months and 12 months plus 2weeks (intraclass correlation > 0.90) were excellent. Concurrent validity was demonstrated by very strong correlation between total SBI scores and ASB scores (r = 0.810 to 0.869, p < 0.001) and moderate correlation between nasal domain SBI scores and SNOT-22 scores (r = -0.616 to -0.738, p < 0.001). Convergent validity was demonstrated by moderate correlation between change in SBI scores and global QOL change (rs = 0.4942, p < 0.001). The minimally important clinical difference (global HR-QOL change of "a little better" or "a little worse") was 6.0. The SBI questionnaire is reliable and valid for patients treated by both endoscopic and open approaches and can be used for assessment of HR-QOL in these settings.

BackgroundThe targets of minimally invasive surgery (MIVA) could be summarised by: achievement of the same results as those obtained with traditional surgery, less trauma, better post-operative course, early discharge from hospital and improved cosmetic results. The minimally invasive techniques in thyroid surgery can be described as either endoscopic "pure" approach (completely closed approach with or without CO2 insufflation), or "open approach" with central neck mini-incision or "open video-assisted approach". Traditionally, open thyroidectomy requires a 6 to 8 cm, or bigger, transverse wound on the lower neck. The minimally invasive approach wound is much shorter (1.5 cm for small nodules, up to 2–3 cm for the largest ones, in respect of the exclusion criteria) upon the suprasternal notch.Patients also experience much less pain after MIVA surgery than after conventional thyroidectomy. This is due to less dissection and destruction of tissues.Pathologies treated are mainly nodular goiter; the only kind of thyroid cancer which may be approached with endoscopic surgery is a small differentiated carcinoma without lymph node involvement.The patients were considered eligible for MIVA hemithyroidectomy and thyroidectomy on the basis of some criteria, such as gland volume and the kind of disease. In our experience we have chosen the minimally invasive open video-assisted approach of Miccoli et al. (2002). The aim of this work was to verify the suitability of the technique and the applicability in clinical practice.MethodsA completely gasless procedure was carried out through a 15–30 mm central incision about 20 mm above the sternal notch. Dissection was mainly performed under endoscopic vision using conventional endoscopic instruments. The video aided group included 11 patients. All patients were women with a average age of 54.ResultsWe performed thyroidectomy in 8 cases and hemithyroidectomy in 3 cases. The operative average time has been 170 minutes.ConclusionNowadays this minimally invasive surgery, in selected patients, clearly demonstrates excellent results regarding patient cure rate and comfort, with shorter hospital stay, reduced postoperative pain and most attractive cosmetic results.

Pediatric meningoencephaloceles and nasal obstruction: A case for endoscopic repair

Endoscopic endonasal transsphenoidal surgery (ETSS) is an effective, minimally invasive approach for the resection of anterior skull base tumors. Cerebrospinal leakage is a common complication, and repair of the anterior skull base defect with alloplastic materials has been used to minimize the risk of postoperative CSF rhinorrhea and meningitis. Injectable cements, such as low-viscosity polymethylmethacrylate (PMMA), are useful for cranial base reconstruction because they are easy to shape to the contour of the defect. These low-viscosity materials, however, are more susceptible to leakage into the nasal cavity prohibiting their use and are prone to cracking upon hardening. Cement extravasation not only obstructs the operator's view during placement, but it is also associated with significant local and systemic complications. High-viscosity (HV) PMMA-based cement and its specialized delivery system have recently been shown to be safe and effective in human applications. Moreover, its constant high viscosity significantly reduces cement leakage and its associated complications. The authors hypothesized that this type of cement would therefore be ideal for ETSS to repair anterior skull base defects. The authors report their experience using HV-PMMA to reconstruct the anterior skull base in 12 patients following ETSS. The unique puttylike consistency of this material is easy to work, malleable, does not leak into the nasal cavity, does not aspirate into suction tubing, and hardens without cracks in less than 10 minutes. None of the 12 patients suffered postoperative CSF leaks or infections more than 8 months, on average, after surgery. Although not necessary in all cases of ETSS, the authors conclude that HV-PMMA, if needed, may be an excellent choice for reconstructing the anterior skull base after ETSS. Further studies are needed to better assess the long-term outcomes of HV-PMMA cement and its use in repairing skull base defects after extended ETSS.

Promising clinical results were reported in watertight closure of anterior skull base defects (ASBDs) with bisphenol-a-glycidyl-dimethacrylate (bis-GMA)-based materials to prevent the cerebrospinal fluid leaks. However, interrelation of these materials with surrounding bones in histologic level, referred to as the osteointegration, has not been reported in the anterior skull base. In addition, an illustrative case with an ASBD that was repaired using a bis-GMA composite has been presented. Twenty New Zealand rabbits were divided into 4 groups: control and sham groups consisted of 2 and 6 rabbits, respectively. The "skull base defect" group (n = 6) underwent a unifrontal craniectomy and an iatrogenic ASBD followed by creating a dural defect to obtain a cerebrospinal fluid leak. Similar bony and dural defects were acquired in the "repair with bis-GMA based allograft" group (n = 6), but the bony defect was closed with bis-GMA-based allograft. All animals in the "skull base defect" group died in 3 weeks after surgery. There were no animal losses in the "repair with bis-GMA based allograft" group at the sixth month. Histologic evaluation revealed complete osteointegration of bis-GMA composite with surrounding bones. bis-GMA based allograft achieved a watertight repair of the ASBD. Histologic findings of this study showed that bis-GMA composite is a reliable material to be used in the closure of anterior skull base bony defects.

Open and endoscopic fetal myelomeningocele surgeries display similar in-hospital safety profiles in a large, multi-institutional database