Anterior Skull Base Reconstruction Research Articles

Musculocutaneous Submental Flap for Anterior and Lateral Skull Base Reconstruction

Background: Reconstruction of the skull base commonly requires vascularized tissue. There are a variety of reconstructive options including the anterolateral thigh, rectus abdominis, latissimus dorsi and others. Many of these flaps have the significant disadvantage of excess bulk which may require multiple revision procedures to remove adipose tissue. Furthermore, all of these reconstructive options are a poor color match to the facial skin.

The Reverse-Flow Facial Artery Buccinator Flap for Skull Base Reconstruction: Key Anatomical and Technical Considerations.

Objective To highlight key anatomical and technical considerations for facial artery identification, and harvest and transposition of the facial artery buccinator (FAB) flap to facilitate its future use in anterior skull base reconstruction. Only a few studies have evaluated the reverse-flow FAB flap for skull base defects. Design Eight FAB flaps were raised in four cadaveric heads and divided into thirds; the facial artery's course at the superior and inferior borders of the flap was measured noting in which incisional third of the flap it laid. The flap's reach to the anterior cranial fossa, sella turcica, clival recess, and contralateral cribriform plate were studied. A clinical case and operative video are also presented. Results The facial artery had a near vertical course and stayed with the middle (⅝) or posterior third (⅜) of the flap in the inferior and superior incisions. Seven of eight flaps covered the sellar/planar regions. Only four of eight flaps covered the contralateral cribriform region. Lastly, none reached the middle third of the clivus. Conclusions The FAB flap requires an understanding of the facial artery's course, generally seen in the middle third of the flap, and is an appropriate alternative for sellar/planar and ipsilateral cribriform defects.

Relaxing Sphenoidal Slit Incision: A Simple Technique to Extend the Anterior and Posterior Reach of Pedicled Nasoseptal Flaps during Endoscopic Skull Base Reconstruction of Transcribriform Defects

Objective: Endoscopic endonasal skull base surgery via the transcribriform corridor has become an accepted approach for lesions of the cribriform plate such as olfactory groove meningiomas and esthesioneuroblastomas. Nevertheless, reconstruction of the large anterior skull base (ASB) defects after endoscopic endonasal transcribriform approaches remain a technical challenge despite the advent of the vascularized pedicled nasoseptal flap (PNSF). These defects often extend from orbit to orbit in the coronal plane and from the posterior table of the frontal sinus to the planum sphenoidale in the sagittal plane. In some cases, the PNSF may be under tension and not have enough anterior reach to cover the posterior table of the frontal sinus. In addition, tension across the sphenoidal portion of the PNSF prevents the flap from covering the posterior extent of transcribriform defects. We describe a relaxing slit incision that is made in the sphenoidal portion of the PNSF that extends the anterior reach as well as the posterior reach of the PNSF to maximize tensionless flap coverage of transcribriform ASB defects. We also present illustrative cases demonstrating the operative technique and nuances.

Utilization of Free Flaps for Endoscopic Anterior Skull Base Reconstruction

Objective: This study aims to discuss the utility of free flaps for the reconstruction of anterior skull base defects and describe a case of successful reconstruction using a radial forearm free flap for a large clival defect.

Three-dimensional evaluation of the danger zone of ethmoidal foramens on the frontoethmoidal suture line on the medial orbital wall.

It is clear that the importance of the ethmoidal foramen (EF) is based on its vascular contents. The frontoethmoidal suture (FS) line is recommended as more reliable navigational landmark for identifying the EF. The vertical orientation between the EF and the FS line was studied in 188 orbits using a computer software program. 146 anterior EFs (77.7 %) and 42 anterior EFs (22.3 %) were situated in the FS line as intrasutural and extrasutural, respectively. 146 posterior EFs (77.25 %) and 8 posterior EFs (4.25 %) were presented as intrasutural and extrasutural, respectively. Although accessory EFs were detected in 25.5 % specimen exhibited an extrasutural location. Majority of the EFs (1-4 EFs) were situated on the FS line. The mean distances from the FS and the anterior EF, the posterior EF and the accessory EF were measured as 2.1 ± 0.5, 2.0 ± 1.5 and 2.3 ± 1.2 mm, respectively. The range of the distances from the FS to the anterior EF, posterior EF and accessory EF were -1.2 to 3.32 , -1.02 to 5.76 and -1.1 to 3.65 mm, respectively. The ranges of EF changed within 1-6 mm. As the FS is not a single point, it is more suitable to make the incision 7 mm above the suture line. The data from this study to help the orbital surgeons explain and avoid unexpected hemorrhage during the orbital procedures such as posttraumatic orbital reconstruction, orbital tumor resections, anterior skull base reconstruction, and orbital decompression surgery.

Split‐calvarial osteopericranial flap for reconstruction following endoscopic anterior resection of cranial base

To conceive and critically evaluate an adaptation of the split calvarial osteopericranial flap for reconstruction following endoscopic endonasal resection of the anterior skull base. Cadaveric anatomic study. Five cadavers were embalmed with methanol, and vasculature was injected with latex. Endoscopic endonasal resection of the anterior skull base was performed, followed by reconstruction with a unilateral osteopericranial flap and a contralateral conventional pericranial flap. Rigid reconstruction was achieved in all specimens. Osteoplastic flap harvest was made more reliable by drilling the diploe below the graft with a curved bur. Dimensions of the bony flap were ideally shorter and wider than the defect, allowing for flap inset and rigid support by the orbits without compromise of the flap vascular supply. Endoscopic inset of the flap is feasible via nasion-frontal osteotomy and inlay technique. Rigid anterior skull base reconstruction via split calvarial osteopericranial flap is adaptable to current endoscopic techniques. This provides more anatomic reconstruction than current methods and may lead to decreased complication rates following anterior skull base resection.

Immediate Reconstruction of Midfacial Defects with Osteofascial and Osteocutaneous Free Flaps following Oncological Anterior Skull Base Surgery

Background: Free tissue transfer is commonly used in head and neck reconstruction to restore both form and function following tumor excision. Although, the use of vascularized bone is widely reported in mandibular reconstruction, there is a paucity of literature on the use of osteocutaneous or osteofascial free flaps in facial reconstruction. Free tissue transfer offers both theoretical and practical advantages despite the morbidity associated with increased operative time and potential flap failure. Methods: Retrospective review of a prospectively collected head and neck reconstruction database. Subsequent case note review. Results: We describe the clinical presentation, reconstructive options, and clinical course of five patients who each underwent free flap reconstruction of an anterior skull base defect using bony tissue to replicate midfacial structures. Two patients had nasal bone reconstruction using osteofascial radial forearm free flap reconstruction. Three patients required osteofascial and osteocutaneous fibula and radial forearm free flaps to reconstruct a combination of nasal and malar defects involving the zygoma, maxilla, and mandibular ramus. There was no flap failure. Conclusions: The transfer of vascularized bony tissue in anterior skull base reconstruction is both safe and practical; “like for like” tissue reconstruction may provide superior cosmetic and functional outcomes.

The Controversies in Skull Base Trauma

We have 21yy.(1992–2013) experiences and prospective study of skull base trauma. Our surgery group have more than 331 patients: the anterior skull base, middle, posterior open trauma.During anterior skull base reconstruction we protected the olfactory structures in 91%. Mortality v our series is 1,7%, morbidity posttraumatic 17%, postoperative 0,6%. Follow up in this series is 21 years.

Efficacy of a new instrument for dural defect repair in anterior skull base reconstruction: a technical note

The anterior skull base is a deep and narrow area, which makes dural repair technically challenging. The goal of this study was to demonstrate the efficacy of a new instrument for anterior skull base dural repair. Ten patients underwent surgery via the transbasal approach, combined with either a transfacial or a transnasal endoscopic resection. The dural repair was performed prior to tumor resection, and the new instrument was used to suture the fascia lata in an underlay fashion. The repaired dural defect was then covered with a pericranial flap. The follow-up period ranged from 2 to 18 months, with an average follow-up time of 8.7 months. During this period, none of the patients experienced cerebrospinal fluid leakage, meningitis, tension pneumocephalus, abscess formation, or flap necrosis. Our findings suggest that the use of this instrument combined with the technique of suturing the fascia lata in an underlay fashion and covering it with a pericranial flap, may be an effective alternative approach to anterior skull base reconstruction.

Use of the external pectoralis myocutaneous major flap in anterior skull base reconstruction

Despite the emergence of free tissue transfer, the pectoralis major myocutaneous flap (PMMF) still has a role in anterior base skull reconstruction (when free tissue transfer is not feasible). The aim of this study is to evaluate the results of external PMMF in anterior skull base reconstruction. A retrospective study from 1977 to 2006 was conducted at Yale New Haven Hospital. 16 patients (mean age 64 years), presenting with a malignant tumour of the anterior base skull, were included. The primary pathology was recurrent squamous carcinoma. Tumour resection resulted in orbital exenteration in 60%, and bone resection of the anterior skull base in 81% of patients. The initial skin defect was 49cm2 (range 16–100cm2). The PMMF was the primary reconstructive choice in 87%, and utilized after free flap failure in two cases. Three minor complications were noted. Orbital exenteration and anterior base skull resection is a surgical procedure that leads to significant reconstructive challenges. The PMMF remains a safe and versatile reconstructive tool in anterior skull base tumour resection. The externalized pedicle allows this flap to reach periorbital and anterior skull base.

Assessment of frontal lobe sagging after endoscopic endonasal transcribriform resection of anterior skull base tumors: Is rigid structural reconstruction of the cranial base defect necessary?

The endoscopic endonasal transcribriform approach (EETA) is a viable alternative option for resection of selected anterior skull base (ASB) tumors. However, this technique results in the creation of large cribriform defects. Some have reported the use of a rigid substitute for ASB reconstruction to prevent postoperative frontal lobe sagging. We evaluate the degree of frontal lobe sagging using our triple-layer technique [fascia lata, acellular dermal allograft, and pedicled nasoseptal flap (PNSF)] without the use of rigid structural reconstruction for large cribriform defects. Retrospective analysis. Nine patients underwent an EETA for resection of large ASB tumors from August 2010 to November 2011. The degree of frontal lobe displacement after EETA, defined as the ASB position, was calculated based on the most inferior position of the frontal lobe relative to the nasion-sellar line defined on preoperative and postoperative imaging. A positive value signified upward displacement, and a negative value represented inferior displacement of the frontal lobe. The average cribriform defect size was 9.3 cm(2) (range, 5.0-13.8 cm(2) ). The average distance of postoperative frontal lobe displacement was 0.2 mm (range, -3.9 to 2.9 mm) without any cases of significant brain sagging. The mean follow-up period was 10.1 months (range, 4-19 months). There were no postoperative CSF leaks. Rigid structural repair may not be necessary for ASB defect repair after endoscopic endonasal resection of the cribriform plate. Our technique for multilayer cranial base reconstruction appears to be satisfactory in preventing delayed frontal lobe sagging.

Double flap technique for reconstruction of anterior skull base defects after craniofacial tumor resection: technical note

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.

The role of the superior turbinate flap in skull base reconstruction

We describe surgical treatment of a hemangiopericytoma in the anterior skull base and nasal cavity. The patient underwent a novel method of anterior skull base reconstruction, using the superior turbinate and cerebral falx, which was successful. The patient did not develop a cerebrospinal fluid leak or intracranial infection.

Tetrahedral silicon balloon for endoscopic skull base reconstruction

INTRODUCTION Advances in transnasal endoscopic approaches and the development of instrumentation and imaging technology have turned endoscopic endonasal surgery into the mainstay for treating inflammatory diseases and neoplasms involving the paranasal sinuses and skull base. The expanded endonasal approach (EEA) and its modifications provide access to the anterior skull base, planum, sphenoid, sella, clivus, cervical spine, and infratemporal fossa via the two nostrils. This approach enables endoscopic extradural and intradural tumor resection and skull base reconstruction in a single procedure. Technical advances in reconstruction methods and the development of vascularized locoregional flaps have improved our ability to seal the cranio-basal diaphragm after tumor extirpation. Use of a nasal septal flap (NSF) has reduced the rate of complications and allowed increasing numbers of patients with skull base neoplasms to undergo curative surgical resections by means of minimally invasive techniques. One drawback of this technique is the difficulty of stabilizing the multilayered reconstruction in place after its application. Currently, a 12-French Foley catheter latex balloon is used to support the multilayered reconstruction during the 1st week after surgery. The main disadvantages of this method are: 1) the balloon surface is spherical, thus providing inadequate support to the flat surfaces of the skull base; 2) decrease in the balloon’s volume due to frequent leaks may impair the support of the flap; 3) the latex balloon is weak and frequently bursts due to exposed bone chips; 4) inability to use this balloon in patients who are allergic to latex; and 5) it is inconvenient for patients because it interferes with their nasal breathing. An alternative support for skull base reconstruction that is free of these limitations is needed. In this report we describe a novel anatomically shaped graft stabilizer for endonasal skull base reconstruction.

Anteriorly Based Inferior Turbinate Flap for Endoscopic Skull Base Reconstruction

In the absence of the nasal septal flap, there is limited ability to reconstruct the anterior skull base because of the paucity of alternative intranasal vascularized flaps. In this article, the authors describe the anteriorly pedicled inferior turbinate flap (AITF) as a method for endoscopic reconstruction of anterior skull base defects. A case series with chart review of the demographic, clinical, surgical, and early follow-up data of patients who underwent endoscopic reconstruction of skull base defects by the AITF. An academic cancer center. The nature of the arterial blood supply of the inferior turbinate from the anterior ethmoidal artery was exploited to design an anteriorly pedicled flap. Flap survival, adequacy of the seal, and rate of complications were assessed. Seven patients were suitable to undergo anterior skull base reconstruction using the AITF with or without combinations with other flaps. Each had a high-flow intraoperative cerebrospinal fluid (CSF) leak. The reconstruction achieved covering of the anterior skull base, including the frontal sinus and cribriform plate, with no postoperative CSF leaks or any other complications. The AITF is well tolerated and is associated with good outcomes. Its length and angle of rotation allow reconstruction of skull base defects in the posterior frontal sinus wall and cribriform plate, especially when traditional reconstruction techniques are not possible.

Reliability of and Indications for Pericranial Flaps in Anterior Skull Base Reconstruction

Owing to changes in the treatment of skull-base tumors, such as perioperative radiotherapy and advances in approaching the skull base, the use of pericranial flaps should be reconsidered. Therefore, we reviewed the reliability of and indications for pericranial flaps in 26 cases in terms of patient background, the effects of preoperative and postoperative treatment, and the pattern of blood circulation. Flaps were harvested as 25 anteriorly based and 4 laterally based. As a result, postoperative complications were observed in 4 patients. No other risk factors, except for heavy smoking, were observed relative to patient background. Sixteen patients had perioperative radiotherapy, and complication rate was significantly higher in patients with preoperative radiotherapy than patients without preoperative radiotherapy (P=0.014). However, no complications, such as cerebral spinal fluid leakage and intracranial infection, were observed in patients receiving postoperative radiotherapy. Laterally based pericranial flaps had a high complication rate (25%), but it was not significantly higher than anteriorly based flaps (P=0.467). Five anteriorly based flaps were harvested with less feeding vessels as usual because of applying dismasking flap approach, but it did not lead to increasing in complication rate. We conclude that a pericranial flap can be used for skull base reconstruction even if postoperative radiotherapy is planned but might be avoided for patients who have received preoperative radiotherapy. In addition, particular care and flap design should be taken to preserve sufficient vascularity when pericranial flaps are raised as laterally based and less feeding vessels as usual.

Utility of novel 3‐dimensional stereoscopic vision system for endoscopic sinonasal and skull‐base surgery

The objective of this pilot study was to evaluate the utility of novel 3-dimensional (3D) endoscopy during endoscopic sinonasal and skull base surgery. Eight surgeries were performed in 7 patients between August 2009 and March 2010 at a tertiary care academic medical center. A high-definition 2-dimensional (2D) endoscopy system was employed in all cases. The Visionsense stereoscopic system (Orangeburg, NY) was incorporated during key portions of the procedures. Two independent surgeons assessed utility of the technology for the following 2 variables: (1) ability to facilitate orientation and depth perception; and (2) impact on completeness of surgery and potential complications. The mean age was 50.4 years and the male:female ratio was 6:1. Indications included anterior skull base (ASB) tumor resection (5), directed skull base biopsies (2), and ethmoid dissection adjacent to dehiscent skull base/optic nerve in allergic fungal rhinosinusitis (1). Endoscopic orientation and depth perception was aided using the 3D endoscope in all cases. Additional interventions were performed in 3 cases (37.5%), including tumor resection (1) and removal of remnant ethmoid partitions (2). Limitations posed included inability to visualize a type III frontal cell (1) and loss of orientation during ASB reconstruction due to overmagnification (1). No complications were observed in this patient series. This preliminary study demonstrated the effectiveness of binocular 3D endoscopy during sinonasal and skull-base surgery. The technology facilitated depth perception and completeness of surgery without increase in complications. Additional experience is warranted to define its role in the endoscopic surgical paradigm.

Double Flap Technique for Reconstruction of Anterior Skull Base Defects after Craniofacial Tumor Resection

Background: 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 has been the gold standard for repair. However, flap necrosis and delayed CSF leaks can occur after adjuvant radiation therapy. We describe a double flap repair, where the pericranial flap is augmented inferiorly by a secondary vascularized nasoseptal flap (NSF) that is harvested and rotated using an endonasal endoscopic approach. This technique is illustrated in two patients who underwent resection of large sinonasal/anterior skull base malignancies with significant intracranial extension.

Microsurgical removal of olfactory groove meningiomas

To explore an effective method for further improving the surgical results of treatment of olfactory groove meningiomas. Sixty seven cases of olfactory groove meningiomas were treated by microneurosurgery, among which fifty seven were de novo cases, eight were recurrent tumors and the other two re-recurrent cases. Modified Derome approach was used in 12 cases, bilateral subfrontal approach in 28 cases, modified pterional approach in 21 cases and unilateral subfrontal approach in six cases. Tumors were resected microsurgically with radical removal of invaded dura, bone, and paranasal sinus mucosa. Reconstruction was performed in patients with skull base defect. Simpson grade I removal was accomplished in 59 cases, grade II in seven cases and grade IV in one case. Among 57 patients with de novo tumor, Simpson I resection was accomplished in 54 cases. Postoperative rhinorrhea and intracranial infection occurred in one case and was cured after temporal lumbar CSF drainage and antibiotic therapy. Two patients (2.9%) died within one month after operation, i.e.one aged patient of heart failure and the other of severe hypothalamus complication. Forty seven patients (72.3%) were followed up from one to ten years with an average of five years and four months. With the exception of two cases died, among the alive 45 patients, there were only three patients with tumor recurrence, which had undergone Simpson II or IV tumor resection. No recurrence was found in cases with Simpson I tumor removal. Previous blurred vision was not improved in three patients, hemiparalysis in two patients, and the other patients recovered well, resuming previous jobs or being able to take care themselves. Total tumor removal (Simpson I) should be the surgical goal for treatment of olfactory groove meningiomas, especially for de novo cases. An appropriate approach is fundamental in the effort to remove an OGM totally. Appropriate anterior skull base reconstruction with vascularized material is important and mandatory.

The Bipedicled Anterior Septal (BAS) Flap for Anterior Frontal Table and Skull Base Reconstruction: A Radioanatomic and Cadaveric Study

The Bipedicled Anterior Septal (BAS) Flap for Anterior Frontal Table and Skull Base Reconstruction: A Radioanatomic and Cadaveric Study