Vascularized Flaps for Anterior Skull Base Defects.

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Middle turbinate (MT) flap, based on the branches of sphenopalatine artery is one of the commonest mucosal flaps used in endoscopic skull base surgery. The objective of this study is to analyze the outcomes of the MT flap in the reconstruction of non-tumorous ventral skull base defects. A retrospective review of patients was done from 2010-19. Patients who underwent reconstruction for non-tumorous ventral skull base defects using middle turbinate (MT) flap were included in the study. The parameters assessed include patient demography, primary etiology, site of the defect, size of the defect, graft materials used, outcomes and postoperative complications. A total of 13 patients who met the study criteria were included. Three (23.07%) of the patients had meningo-encephalocele, while the remaining 10 (76.93%) had CSF fistula. Isolated foveal defect (53.8%) was the most common site involved, followed by isolated cribriform, combined cribriform-foveal and combined foveal-planar defects. Graft materials used were fascia lata, fat and septal cartilage. MT flap was successfully harvested in 11 (84.6%) patients, with successful outcome in 10/11 patients. Hypoplastic MT was present in two patients, who subsequently required Hadad flap for defect closure. No major complications were reported in the postoperative period. The MT flap is effective in the reconstruction of selective skull base defects. Appropriate surgical technique and expertise are required for successful harvest. Further studies are required to analyze its outcomes in various skull base defects.

ObjectiveTechniques for reconstruction of skull base defects have advanced greatly since the introduction of the vascular pedicled nasoseptal flap in 2006. The objective of this review is to assess the current state of the field by examining both intranasal and extranasal techniques of vascular pedicled skull base defect repair, their indications and success rates, and novel techniques that are currently under investigation.MethodsA review of the literature describing the use of vascular pedicled flaps in skull base defect reconstruction was conducted using PubMed and Google Scholar.ResultsThe nasoseptal flap remains the most widely used vascular pedicled flap for endoscopic repair of skull base defects. Its ease of harvest, wide arch of rotation, and high success rates make it a popular choice among surgeons. Several variations including a “rescue” nasopseptal flap have been developed. Other less commonly used pedicled intranasal flaps include the middle turbinate flap and the posterior pedicled inferior turbinate flap. Additionally, several novel vascular pedicled flaps have been developed and tested in small cohorts of patients. Extranasal flaps such as the pericranial flap and the temporoparietal fascia flap are used less frequently than intranasal flaps. However, they remain valuable options for reconstruction in certain situations.ConclusionAdvancements continue to be made in the field of skull base defect reconstruction using vascular pedicled flaps. Though the nasoseptal flap remains the most widely utilized option, additional intranasal techniques continue to be developed and tested to optimize surgical outcomes and patient care.Level of EvidenceNA

Increasing indications for endoscopic endonasal approaches have led neurosurgeons to develop new reconstruction techniques for larger skull base defects. Vascularized grafts have been a great adjunction to reduce the rate of cerebrospinal fluid leak and can also be used to cover exposed critical structures such as the internal carotid artery. The nasoseptal flap and the inferior or middle turbinate flap are thus widely used in endoscopic skull base surgery, but may be insufficient for very large defects. To present a new mucosal flap used to cover large skull base defects in which the mucosa of the inferior turbinate, inferior meatus, nasal floor, and nasal septum is harvested in 1 piece keeping both vascular pedicles intact (inferior turbinate and septal arteries). We describe a surgical technique to harvest a combined inferior turbinate-nasoseptal flap. Technical pearls and surgical pitfalls are described through 2 clinical cases in which the nasoseptal mucosa was partially damaged during a previous surgery, rendering the nasoseptal flap insufficient by itself. The flap is harvested thanks to 2 mucosal cuts: a first circular cut around the choanal arch and the junction between the hard and the soft palate, and a second one combining classical cuts of the nasoseptal flap and the inferior turbinate flap. The inferior turbinate-nasoseptal flap can be a useful alternative in patients whose septal mucosa was partially damaged and/or with very large postoperative skull base defects.

Endoscopic endonasal skull base surgery defects require effective reconstruction. Although the nasoseptal flap (NSF) has become our institution's workhorse for large skull base defects with cerebrospinal fluid (CSF) leaks, situations where it is unavailable require secondary flaps. Clinical outcomes, pearls and pitfalls, and an algorithm will be presented for these secondary flaps. Clinical case series. Medical records of all endoscopic endonasal skull base surgeries at a tertiary care academic medical center were reviewed for skull base defect type, reconstruction method, CSF leak rate, and flap necrosis rate. Of 330 flaps for reconstructing endoscopic endonasal skull base defects, secondary flaps were used in 34 cases (10%). These included 16 endoscopic-assisted pericranial flaps, seven tunneled temporoparietal fascia flaps, three inferior turbinate flaps, two middle turbinate flaps, two anterior lateral nasal wall flaps, two palatal flaps, one occipital flap, and one facial artery buccinator flap. There were 19 anterior cranial fossa defects, 10 clival defects, three sellar defects, and one frontal and one lateral orbit/middle fossa defect. Twenty-five of the 34 cases (73.5%) had either prior or postoperative radiation therapy. The most common pathology was sinonasal cancer, with 16 cases (47.1%). The postoperative CSF leak rate was 3.6% due to one middle turbinate flap necrosis. Secondary flaps for skull base reconstruction can be harvested with minimally invasive techniques and demonstrate excellent success rates (97%) that are comparable to that of the NSF (>95%). Multiple flaps for complex skull base defects should be in the armamentarium of comprehensive skull base surgery centers. 4.

Introduction: The reconstruction of the skull base and nasal mucosa can be performed using different local flaps. The use of the nasoseptal flap is the most common method to reconstruct these areas, but sometimes, due to septal perforations, a history of previous surgeries that may have damaged its pedicle, or because its rotational arc is not ideal, other nasal flaps such as those from the inferior or middle turbinate with their various pedicles may need to be employed. Objectives: The aim of this study was to ascertain the success rate of reconstructions involving the nasal cavity and skull base utilizing inferior and middle turbinate flaps. Methods: Data collected prospectively were analyzed using an Excel spreadsheet for patients who underwent skull base and nasal cavity defect repairs employing turbinate flaps between May 2014 and August 2021. Results: Nine patients were treated and a total of ten reconstructions were performed. Five middle turbinate flaps were executed, two involving medial rotation to address defects situated on the ethmoid roof and three involving lateral rotation to repair a defect within the ethmoid fovea, with two of these flaps closing the frontal ostium. Furthermore, an inferior turbinate flap with a posterior pedicle was utilized to repair the defect resulting from the resection of a meningocele, which was located on the ethmoid roof. Four lateral wall flaps with an anterior pedicle were employed to reconstruct the mucosa of the nasal cavity and to address a defect in the anterior skull base. Conclusion: The reconstruction of anterior skull base defects using turbinate flaps was highly satisfactory, achieving a 100% success rate. The use of lateral wall flaps to repair defects produced by rhinectomies that included resection of the nasal mucosa was also successful and we did not have partial or total necrosis of the flaps. The excellent blood supply to the lateral nasal walls and the ability to dissect these flaps with different arterial pedicles and extend their surface, including the nasal floor, allows for various flap rotations and the reconstruction of defects of different sizes.

Cerebrospinal fluid (CSF) leaks most commonly arise during or after skull base surgery, although they occasionally present spontaneously. Recent advances in the repair of CSF leaks have enabled endoscopic endonasal surgery to become the preferred option for management of skull base pathology. Small defects (<1 cm) can be repaired by multilayered free grafts. For large defects (>3 cm), pedicled vascular flaps are the repair method of choice, resulting in much lower rates of postoperative CSF leaks. The pedicled nasoseptal flap (NSF) constitutes the primary reconstructive option for the vast majority of skull base defects. It has a large area of potential coverage and high rates of success. However, preoperative planning is required to avoid sacrificing the NSF during resection. In cases where the NSF is unavailable, often due to tumor involvement of the septum or previous resection removing or compromising the flap, other flaps may be considered. These flaps include intranasal options - inferior turbinate or middle turbinate flaps - as well as regional pedicled flaps: pericranial flap, temporoparietal fascial flap, or palatal flap. More recently, novel alternatives such as the pedicled facial buccinator flap and the pedicled occipital galeopericranial flap have been added to the arsenal of options for skull base reconstruction. Characteristics of and appropriate uses for each flap are described.

The success of expanded endoscopic endonasal approaches (EEAs) to the anterior skull base, sellar, and parasellar regions has been greatly aided by the advancement in reconstructive techniques. In particular, the pedicled vascularized flaps have been developed and effectively cover skull base defects of varying sizes with a significant reduction in postoperative CSF leaks. There are two aims to this review: (1) We will provide our current, simplified reconstruction algorithm. (2) We will describe, in detail, the relevant anatomy, indications/contraindications, and surgical technique, with a particular emphasis on the nasoseptal flap (NSF). The inferior turbinate flap (ITF), middle turbinate flap (MTF), pericranial flap (PCF), and temporoparietal fascial flap (TPFF) will also be described. The NSF should be the primary option for reconstruction of majority of skull base defects following endonasal endoscopic surgery. In general, for the planum, cribriform, and upper two-thirds of the clivus, the NSF is ideal. For the lower-third of the clivus, the NSF may not be adequate and may require additional reconstructive options. Although limited in reach or more technically challenging, these reconstructive flaps should still be considered and kept in the surgical algorithm.

The expanded endonasal approaches to the skull base are modular approaches that arise from the sphenoidal sinus. The reconstructive techniques in these approaches are key to avoid postoperative complications. Available flaps for reconstruction include the pedicled nasoseptal flap, the transpterygoid temporoparietal fascia flap, and the posterior pedicle inferior turbinate flap (PPITF), among others. Recently, the middle turbinate flap has been described in a cadaveric study. We report our preliminary experience in the use of this middle turbinate vascularized flap for skull base reconstruction after expanded endonasal approaches. Ten patients underwent reconstructive procedures with the mucoperiostial vascularized middle turbinate flap. Capability to cover the defect, closure success, operative time and complications related to the procedure are retrospectively analyzed. A satisfactory closure was obtained in all procedures, and there were no complications related to the technique. Required operative time was similar to the time employed for the nasoseptal flap. The vascularized middle turbinate flap is a reliable reconstructive technique for the reconstruction of moderate-sized skull base defects. It can be considered either as the first choice of closure or as an alternative to the nasoseptal flap when this is not available. Different flap combinations may facilitate skull base defect reconstruction.

To introduce a method and the clinical effects of repairing skull base defects and dural defects using vascular pedicled nasoseptal mucoperiosteal flaps through an endoscopic endonasal approach. The clinical and follow-up data for 8 patients who underwent endoscopic endonasal reconstruction of skull base defects and cerebrospinal fluid rhinorrhea with a vascular pedicled nasoseptal mucoperiosteal flap between July 2008 and March 2010 were retrospectively reviewed. All patients were male. The age of these patients ranged from 28 to 60 years (average 41 years). The diagnosis for these patients included one hemangiopericytoma of the anterior skull base one olfactory neuroblastoma (type of Kadish C), one ethmoid sinus cancer, three local recurrent cancers of the nasopharynx after radiotherapy, one carcinoid of skull base and one traumatic cerebrospinal fluid rhinorrhea with recurrent intracranial infection. There were six anterior skull base defects and two middle cranial fossa defects. An endoscopic endonasal surgical approach was used for the repair. A pedicled flap using the nasal septal mucoperiosteum based on the posterior nasal artery was harvested from the ipsilateral side. The tissue flap was used to cover the dural defects. The margin was covered with gelatin sponge and fixed with fibrin glue. The nasal cavity was packed with iodoform gauze, a Foley catheter balloon and Merocel in this sequence to secure the flap in place. Nasal packing was removed 5 to 7 days postoperatively. Partial septal flap necrosis was found in one case, but the flaps in the other 7 cases survived. A postoperative cerebrospinal fluid leak occurred in one case 7 days after surgery. This was re-explored and successfully repaired with abdominal fat. All cases healed well, with no delayed cerebrospinal fluid leaks or intracranial infections during the 6 to 24 months follow-up period. The vascular pedicled nasoseptal mucoperiosteal flap is a reliable choice for endoscopic endonasal skull base reconstruction.

Pericranial flap for endoscopic reconstruction of skull base defects ("money box approach"): Experience at our center and literature review.

EnAbstract Introduction The repair of skull base defects after skull base surgeries is a major problem. Postoperative cerebrospinal fluid leak in reconstruction of the anterior skull base defect using a nasal septal flap was minimal when compared with other techniques. The nasal septal flap should be considered as the first line of treatment after transnasal endoscopic skull base surgery. Objectives Evaluation of the usefulness and reliability of endoscopic endonasal skull base reconstruction using a nasal septal flap. Patients and methods This study was carried out on 10 paediatric patients with skull base defects because of different pathologies. These patients were admitted in El-Kasr El-Ainy Hospital, Otorhinolaryngology Department. These patients included one patient with a germ cell tumour, five patients with a congenital encephalocele and four patients with skull base defects because of trauma to the skull base. Results and conclusion Various endoscopic techniques have been described to separate the cranial cavity from the sinonasal cavity to prevent infection, pneumocephalus and cerebrospinal fluid leak. Different techniques were used to close the anterior skull base defects such as multilayer free graft, suturing the dural defect combined with free graft and reconstruction based on a vascularized graft. The nasal septal flap should be considered as the first line of treatment after transnasal endoscopic skull base resections.

Extended Inferior Turbinate Flap for Skull Base Defects

&lt;p class="abstract"&gt;&lt;strong&gt;Background:&lt;/strong&gt; &lt;span lang="EN-IN"&gt;To study the clinical outcomes of Hadad-Bassagasteguy flap (HBF) in endonasal reconstruction of anterior skull base defects. &lt;/span&gt;&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Methods:&lt;/strong&gt; &lt;span lang="EN-IN"&gt;We prospectively analyzed the demographic data &amp;amp; the outcome results particularly Post-operative CSF leak in 53 patients who underwent HBF in our hospital from February 2013 to June 2014. The early harvested flap was used to reconstruct anterior skull base defects among patients with high-flow on-table CSF leak. Post-operatively the patients were analyzed for CSF leak and bleeding. &lt;/span&gt;&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Results:&lt;/strong&gt; &lt;span lang="EN-IN"&gt;Most of the study subjects were between21-50 years of age (73.6%). The mean age of the study subjects was 41.8±13.8 years. Male/female ratio of the study sample was 1.2 with 29 males and 24 females. Of the total 53 patients 46 (86.8%) has macro defects while 7 (13.2%) had micro defects. Non-secretary lesions were present in 60.4% (32/53) patients while secretary were present in 39.6% (21/53) patients. Cerebrospinal fluid leak was present in all the patients undergoing surgery and majority of them were put on lumbar drain, while bleeding was present in 49.1% patients. Of the total 53 patients only 2 had post-operative cerebrospinal fluid leak (2/53; 3.8%). &lt;/span&gt;&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Conclusions:&lt;/strong&gt; &lt;span lang="EN-IN"&gt;Use of HB posterior nasal septal flap for reconstruction of anterior skull base among patients with high-flow intra-operative CSF leak has a remarkable impact in preventing post-operative CSF leak. Its applicability to wide patient-profiles with respect to age, size of defect, diagnosis is making it a versatile choice of reconstruction after endonasal anterior skull base surgeries.&lt;/span&gt;&lt;/p&gt;

Cerebrospinal fluid (CSF) rhinorrhea is a consequence of a breakdown of the layers of the arachnoid membrane, dura matter, the bony skull base and periosteum, and the nasal mucosa.1 In the past few years, several endoscopic techniques have been described to close ventral skull base CSF leaks. These include local pedicled flaps (e.g., nasoseptal flap,2 turbinates3), regional pedicled flaps (e.g., pericranium,4 fascia temporalis5), free grafts (e.g., abdominal fat,6 fascia lata7), microanastomosed free flaps,8 as well as synthetic grafts.8 Nowadays, most authors use multiple-layer reconstruction by combining these techniques to improve the success rate of endoscopic skull base reconstruction. The choice of skull base reconstruction technique depends on the location and the size of the defect, as well as intracranial pressure. The graft can be placed in the extracranial or extradural spaces that are often used, or in the intradural space, which is technically more demanding. In cases of small-size CSF leaks, we propose a new surgical technique, with a good success rate, that allows centering the intradural graft adequately on the defect. This “parachute” placement can be used with both autologous free grafts and synthetic materials. A retrospective chart review was performed to identify patients who had undergone endoscopic-guided transnasal duraplasty for small low-flow CSF leaks (<2 cm) of the ventral skull base in the Lariboisière University Hospital in Paris, France. Leaks that were reconstructed with other techniques were excluded. We report on the surgical technique, graft materials, and outcomes. All patients were imaged preoperatively with skull base computed tomography and magnetic resonance imaging. The procedure (Supporting Video S1) is done under general anesthesia. The patient is positioned supine, with the patient's head in a neutral position. An anterior and posterior ethmoidectomy is performed, associated most often with a middle turbinate removal. Then, the CSF leak site is identified endoscopically and measured. Site preparation begins by removal of the overlying mucosa. Abrasion of the adjacent and involved bone is generally advocated to stimulate osteoneogenesis. If needed, the bone defect is enlarged to see the limits of the dura defect. Then, an intradural and extradural circular dissection is performed with angled elevators to allow an underlay and overlay placement of the graft. The parachute technique allows the use of both fascia lata and synthetic materials. We present here a skull base reconstruction of a 1.5-cm defect of the planum sphenoidale (Fig. 1). A Biodesign duraplasty graft (Cook Biotech, West Lafayette, IN) in a size that was approximatively 30% larger was designed. A nonabsorbable polypropylene suture (3/0) is passed through the graft near the center in a U shape (Fig. 2). The two strands must be long enough to easily exit the nose. Then, the graft is placed in the subdural space using classic microsurgical instruments (angled endonasal blunt hook and seeker, spoon curettes, blunt angled elevators). A slight tension on the strands allows centering the graft on the defect, and then it is applied against the dura without any pucker (Fig. 3), hence the name parachute technique. It should be noted that the role of the suture is not to anchor the graft but to center it on the defect. The graft is then covered with fibrin glue to seal the reconstruction and the suture is removed, with back pressure being maintained on the graft with a blunt instrument to avoid displacement (Fig. 4). Fibrin glue sealing should be used sparingly between the two reconstruction layers to avoid dead space during resorption. Then, a second graft designed like the first graft is placed in the extradural space, as a “sandwich” to maintain the dura between two graft layers. At the end of the procedure, fibrin glue sealant is applied (Fig. 5). With this parachute closure technique, it is possible to associate a multilayer reconstruction using a mucosal graft or mucosal flaps to cover the graft and surrounding bone. We did not use any nasal packing or postoperative antibiotics. Patients must follow common postoperative advice such as avoiding Valsalva-like maneuvers and do not strain. Acetazolamide was prescribed only in case of suspicion of intracranial hypertension. We did not use any lumbar drain. Sixteen patients were included in the study from 2005 to the present. All patients were operated on by the same surgeon (p.h.). The main results are summarized in Table 1. Iatrogenic CSF leaks were addressed by other centers and then closed during another surgical procedure. The mean postoperative follow-up was 24 months (range = 1–101 months). We did not notice any leak recurrence. It was difficult to find in our database all of the patients who were treated with the parachute technique, and we probably missed some. In addition, only 25% of the population described here had a spontaneous CSF leak, which is at higher risk of recurrence. However, in our mind, we did not notice any recurrence after this type of reconstruction, which is used for small defects of the ventral skull base, regardless of the medical history. Small CSF leaks are not so easy to close. Dot-shaped leaks are accessible through a simple bipolar cauterization of the dura mater and a common fibrin glue sealing. Then, a graft or flap can be used extracranially to secure the repair. If the dura defect is greater than a few millimeters, this technique may not be enough to achieve a watertight closure.9 Many techniques have been proposed with good results.10 Among them, we can cite the “bath-plug” reconstruction,11 which consists in introducing a fat plug intracranially, secured with a Vicryl suture into the intradural space, and placing traction to seal the defect. This is a unique layer transdural technique with some disadvantages. The amount of intracranial fat is difficult to quantify, the reconstruction is not anatomical as it does not reproduce the dura mater layer, and the Vicryl suture remains in the fat plug until its absorption. The sandwich technique12 requires the placement of a layer of fascia lata in the epidural space (first layer), then a layer of cartilage or bone fitted to close the bony defect (second layer), and finally another piece of fascia lata extracranially. In a comparison of these two techniques, the parachute closure allows an anatomical reconstruction of the dura mater and a guided healing of the dura defect between two layers of reconstruction material, with a complete removal of the suture at the end of the procedure. A third layer can also be placed (mucosal graft or mucosal flap) extracranially but is not mandatory. The gasket seal technique13 can also be used. It consists in an autologous fascia lata or synthetic graft used to create a gasket seal around a bone buttress, gently applying a countersunk on the bone graft into the defect. If the bone graft is not perfectly sized up, it can lead to a lack of support of the fascia lata (if too small) or in excessive force applied on the defect (too large). If the margins of leak are not surrounded by bone, this technique is not easy to achieve. Again, it is transdural and does not reproduce the anatomical layers. Furthermore, in cases of small defects, the gasket seal technique may require an enlargement of the primary defect so as to place the reconstruction. The parachute technique may also be used in second-intention surgeries in failures of skull base reconstruction, even after chemoradiotherapy (two patients in our experience). We believe that this technique can be part of a surgical arsenal for small CSF leaks closure, and that is complementary to the techniques already described. The surgical technique described here can be a suitable alternative to other closure techniques for small, first-intention CSF leaks of the ventral skull base and is a minimally invasive option for small CSF leak recurrences after oncologic resection. It allows a multilayer reconstruction in the intradural and extradural space to guide the healing of the dura mater. The authors gratefully acknowledge the technical support of Mr. Clément Jourdaine from the Otorhinolaryngology Department–Skull Base Center of Lariboisière Hospital, and Mrs. Pamela Combastet for the English-language editing. Video S1. Skull base reconstruction of a 1.5-cm defect of the planum sphenoidale using the “parachute” technique. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.