Pediatric skull base reconstruction: case report of a tunneled temporoparietal fascia flap

Side-door temporoparietal fascia flap: First experience with a novel technique for anterior skull base reconstruction

BACKGROUND

Modern achievements in transnasal endoscopic skull base (SB) surgery have led to complex resections that render reconstruction a challenge. Temporoparietal fascia flap (TPFF) is a suitable option for SB reconstruction. The side-door TPFF technique for anterior SB reconstruction is described here for the first time in a real-life surgical setting.

METHODS

Patients affected by a SB malignancy who underwent cranioendoscopic resection were included. For reconstruction, a multilayer reconstruction technique including side-door TPFF transposition was employed.

RESULTS

TPFF transposition was performed in five patients. The TPFF could be easily transposed via a side-door approach. It adequately covered the edges of the defect and supported optimal healing of the surgical site. During follow-up, vitality and integration of the TPFF were assessed endoscopically and radiologically.

CONCLUSIONS

The TPFF side-door transposition technique is a valuable option in anterior SB reconstruction that can provide fast and effective healing, especially in patients needing adjuvant radiotherapy.

Special Considerations in Pediatric Endoscopic Skull Base Surgery

Originally pioneered in adults, endoscopic endonasal approaches for skull base pathology are being increasingly applied as a minimally invasive alternative for young children. Intrinsic anatomic differences between these patient populations have sparked discussions on the feasibility, safety, and efficacy of these techniques in pediatric patients. This work aims to serve as a primer for clinicians engaged in the rapidly evolving field of pediatric endoscopic skull base surgery. A succinct overview of relevant embryology, sinonasal anatomy, and diagnostic workup is presented to emphasize key differences and unique technical considerations. Additional discussions regarding select skull base lesions, reconstructive paradigms, potential surgical complications, and postoperative care are also highlighted in the setting of multidisciplinary teams.

The Temporoparietal Fascia Flap Transposition Technique for Ventral Skull Base Reconstruction: Anatomic Analysis and Surgical Application

BACKGROUND AND OBJECTIVES

The temporoparietal fascia (TPF) flap is an alternative for revision endoscopic skull base reconstruction in the absence of the nasoseptal flap, and we aimed to investigate the anatomy and surgical application of TPF flap transposition in endoscopic endonasal surgery.

METHODS

Six lightly embalmed postmortem human heads and 30 computed tomography angiography imaging scans were used to analyze the anatomic features of the TPF flap transposition technique. Three cases selected from a 512 endoscopic endonasal cases database were presented for the clinical application of the TPF flap.

RESULTS

The TPF flap, composed by the deepest 3 scalp layers (galea aponeurotica, loose areolar connective tissue, and pericranium), can be harvested and then transposed through the infratemporal-maxillary-pterygoid tunnel to the ventral skull base. The superficial temporal artery as its feeding artery, gives frontal and parietal branches with similar diameter (1.5 ± 0.3 mm) at its bifurcation. The typical bifurcation was present in 50 sides (83.3%), with single (frontal) branch in 5 sides (8.3%), single (parietal) branch in 2 sides (3.3%), and multiple branches (>2) in 3 sides (5%). The transposed TPF flap was divided into 3 parts according to its anatomic location: (1) infratemporal part with an area of 19.5 ± 2.5 cm2, (2) maxillary part with an area of 23.7 ± 2.8 cm2, and (3) skull base part with an area of 44.2 ± 4 cm2. Compared with the nasoseptal flap, nasal floor flap, inferior turbinate flap, and extended septal flap, the coverage area of the skull base part of the TPF flap was significantly larger than any of them (P < .0001).

CONCLUSION

The TPF flap technique is an effective alternative for endoscopic endonasal skull base reconstruction. The TPF flap could successfully cover large skull base defects through the infratemporal-maxillary-pterygoid tunnel.

Pediatric Endoscopic Endonasal Skull Base Surgery: A Retrospective Review Over 11 Years

OBJECTIVE

To show the safety and efficacy of the endoscopic endonasal approach (EEA) for skull base surgery in pediatric patients through descriptive analysis of cases over an 11-year period.

METHODS

The study comprised 94 patients undergoing EEA for skull base surgery, between January 2007 and June 2018, at 2 tertiary pediatric hospitals. Descriptive statistics are presented regarding the presentation, intraoperative details, and complications.

RESULTS

Over the study period, 130 surgeries were performed in 94 patients: 94 primary surgeries and 36 reoperations. The mean patient age was 13.8 years and 48.9% of patients were female. Presenting signs/symptoms included endocrinopathies (56.4%), vision abnormalities (37.2%), and cranial nerve deficits (20.2%). EEA alone was used in 95.7% of primary surgeries and 91.7% of reoperations. Diseases treated included craniopharyngioma (18.1%), pituitary adenoma (17.0%), Rathke cleft cyst (13.8%), chordoma (9.6%), osteosarcoma (5.3%), juvenile nasopharyngeal angiofibroma (4.3%), skull base fracture (4.3%), and encephalocele (3.2%). A lumbar drain was used in 20.2% of primary surgeries and 25% of reoperations. A nasoseptal flap was used in 36.2% of primary surgeries and 25% of reoperations. Postoperative complications included cerebrospinal fluid leak (12.8%), sinusitis (7.4%), bacterial meningitis (3.2%), and carotid artery injury in 1 reoperation.

CONCLUSIONS

EEA for anterior cranial base disease is safe and efficacious in pediatric patients and can be used to treat many of the rare and heterogenous diseases that arise in this anatomic location. Management strategies and rates of sinonasal and intracranial complications including cerebrospinal fluid leak rate are similar to those reported in adult cohorts.

Endoscopic Endonasal Repair of Recurrent Cerebrospinal Fluid Leak With Adipofascial Anterolateral Thigh Free Flap: Case Report and Review of Literature

Background. Cerebrospinal fluid leaks are the most common complication of endoscopic endonasal skull base tumor resection. The workhorse nasoseptal flap or other vascularized intranasal flaps may not be a viable option in patients who have previously undergone surgery or local radiation; in these cases, pericranial flaps may also be unavailable. Free flap reconstruction in patients undergoing endoscopic resection is challenging because of limited exposure. The transmaxillary approach has recently been reported for free flap reconstruction of these defects. This report describes a patient with a pituitary tumor who underwent craniotomy and resection of a pituitary mass via an endoscopic endonasal approach. Postoperatively, the patient developed a high flow cerebrospinal fluid leak that did not resolve with lumbar drain and attempts at endoscopic revision of nasoseptal flap. An adipofascial anterolateral thigh free flap was harvested, based on the descending branch of the lateral circumflex femoral vessels. An upper gingivobuccal sulcus incision was used to access the maxilla. Openings were created in the anterior and medial maxillary sinus to create a passage to the sphenoid sinus. The flap was inset into the defect via this transmaxillary channel. The pedicle was tunneled subcutaneously through the cheek to recipient facial vessels. The procedure resulted in complete resolution of cerebrospinal fluid rhinorrhea and pneumocephalus. Imaging at 18 months showed the flap in good position. This report describes the technique in detail along with a review of the current literature.

Management of pediatric clival chordoma with extension to the craniocervical junction and occipito-cervical fusion: illustrative case

BACKGROUND

Chordomas are rare malignant neoplasms that develop from the primitive notochord with < 5% of the tumors occurring in pediatric patients younger than the age of 20. Of these pediatric chordomas, those affecting the craniocervical junction (C1–C2) are even more rare; therefore, parameters for surgical management of these pediatric tumors are not well characterized.

OBSERVATIONS

In this case, a 3-year-old male was found to have a clival chordoma on imaging with extension to the craniocervical junction resulting in spinal cord compression. Endoscopic-assisted transoral transclival approach for clival tumor resection was performed first. As a second stage, the patient underwent a left-sided far lateral craniotomy and cervical laminectomy for resection of the skull base chordoma and instrumented fusion of the occiput to C3. He made excellent improvements in strength and dexterity during rehab and was discharged after 3 weeks.

LESSONS

In pediatric patients with chordoma with extension to the craniocervical junction and spinal cord compression, decompression with additional occipito-cervical fusion appears to offer a good clinical outcome. Fusion performed as a separate surgery before or at the same time as the initial tumor resection surgery may lead to better outcomes.

Temporoparietal Fascia Flap Endonasal Transposition in Skull Base Reconstruction: Surgical Technique

Reconstruction of wide skull base defects resulting from multimodal treatment of cranial base malignancies are challenging.¹ Endonasal pedicled flaps (e.g., Hadad-Bassagusteguy flap)^1,2 are generally the first choice; however, inadequacy for the size and location of the defect or their unavailability are common occurrences in salvage reconstructions, and prior irradiation is an additional unfavorable condition for local flap viability. The temporoparietal fascia flap (TPFF)³ is a regional flap vascularized by the superficial temporal artery, which is able to survive and integrate even in postirradiated areas. Its properties, such as thinness, pliability, foldability, and the long pedicle, make it a versatile flap for reconstruction of various defects of the skull base, both in adults^3-7 and children.⁸ In lateral skull surgery, TPFF proved to be effective in patients at higher risk of cerebrospinal fluid leak,⁷ whereas its transposition into the nasal cavity through a temporal-infratemporal tunnel has been widely reported to repair defects of the ventral skull base.^3-6 It represents a safe and effective technique with minimal additional morbidity (potential alopecia or scalp necrosis).^4,5 A recently described modification of this technique supports TPFF transposition via a supraorbital epidural corridor to reach the anterior skull base, especially for large defects with supraorbital extension.⁶ The present video (Video 1) shows the step-by-step TPFF harvesting and endonasal transposition via a temporal-infratemporal tunnel to repair a wide middle cranial fossa defect resulting from osteoradionecrosis after endoscopic resection and heavy-particle radiation therapy for sinonasal adenoid-cystic carcinoma. At 6-months follow-up, optimal healing without complications was observed.

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.

Skull Base Reconstruction Using a Temporoparietal Galeal Flap in Simultaneous Transnasal and Transcranial Surgery for the Prevention of Carotid Blowout Syndrome: A Report of 3 Cases

Background  Carotid blowout syndrome (CBS) is a rare complication that usually occurs after removal of head and neck tumors. Since transnasal skull base surgery allows a wide exposure of the ventral skull base, neurosurgeons should pay attention to prevent this devastating complication. We present, three cases involving exposure of the internal carotid artery (ICA) at the skull base during the simultaneous transnasal and transcranial approach. Case Description  The first patient was a 69-year-old man with a recurrent chordoma. The exposed ICA was covered by an abdominal fat graft and nasoseptal flap, but he experienced CBS 2 months later and died. The second patient was a 66-year-old man with an intraosseous cavernous angioma of the petrous bone. The exposed ICA was covered by a temporoparietal galeal flap (TPGF), abdominal fat graft, and nasoseptal flap. The third patient was a 73-year-old man with skull base radiation necrosis and intracerebral abscess after proton beam therapy for orbital adenoid cystic carcinoma. The exposed ICA was covered by TPGF. The second and third patients' postoperative courses were uneventful. Conclusion  Based on our experience, a nasoseptal flap alone may be insufficient to protect ICA. TPGF is therefore another available reconstruction option that may help prevent CBS.

Side-Door Temporoparietal Fascia Flap: A Novel Strategy for Anterior Skull Base Reconstruction

BACKGROUND

The armamentarium for anterior skull base (ASB) reconstruction includes a variegate spectrum of grafts, endonasal pedicled flaps, regional pedicled flaps, and free flaps, which are selected to face specific scenarios. The use of a vascularized flap in case of large ABS defects ensures an adequate blood supply. The aim of this study was to evaluate the possible role of temporoparietal fascia flap (TPFF) in ASB reconstruction.

METHODS

Eight fresh-frozen head specimens were dissected to evaluate the adequacy of TPFF and pericranial flap (PF) for the reconstruction of ASB defects. The percentage of coverage of the ASB was calculated for TPFF and PF. An anatomic-radiologic analysis was performed to provide useful practical information for flap harvesting and positioning.

RESULTS

The TPFF was easily transposed to the ABS defect through an epidural corridor; the edges of the TPFF were successfully placed in the intradural space, in the epidural space, or on the extracranial surface of the ABS defect. The PF was particularly adequate for median defects, and the TPFF was shown to be useful also in cases with paramedian-supraorbital extension. The median percentage of coverage of the ASB was significantly higher for TPFF (85.1%) than PF (65.7%) (P = 0.018).

CONCLUSIONS

The supraorbital epidural corridor is a possible novel pathway for transposition of the TPFF for ASB reconstruction. Side-door TPFF was shown to be an ideal choice for large ASB defect with lateral supraorbital extension and could be useful in the scenario of salvage reconstruction for recurrent ABS cerebrospinal fluid leak.

Endoscopic Resection of Pediatric Skull Base Tumors: An Evidence-Based Review

Objectives  To perform a systematic review examining experiences with endoscopic resection of skull base lesions in the pediatric population, with a focus on outcomes, recurrence, and surgical morbidities. Methods  PubMed/MEDLINE, Cochrane Library, Embase, and Web of Science databases were evaluated. Studies were assessed for level of evidence. Bias risk was evaluated using the Cochrane Bias tool, Grades of Recommendation, Assessment, Development and Evaluation (GRADE), and Methodological Index for Non-Randomized Studies (MINORS) criteria. Patient characteristics, pathology, site of primary disease, presenting symptoms, stage, procedure specific details, and complications were evaluated. Results were reported using the Preferred Reporting Systems for Systematic Reviews and Meta-Analysis guidelines. Results  Ninety-three studies met criteria for inclusion, encompassing 574 patients with skull base tumors. The GRADE and MINORS criteria determined the overall evidence to be moderate quality. The most common benign and malignant pathologies included juvenile nasopharyngeal angiofibromas ( n  = 239) and chondrosarcomas ( n  = 11) at 41.6 and 1.9%, respectively. Of all juvenile nasopharyngeal angiofibroma tumors, most presented at stage IIIa and IIIb (25.8 and 27.3%, respectively). Nasal obstruction (16.5%) and headache (16.0%) were common symptoms at initial presentation. Surgical approaches included endoscopic endonasal ( n  = 193, 41.2%) and endoscopic extended transsphenoidal ( n  = 155, 33.1%). Early (< 6 weeks) and late (>6 weeks) complications included cerebrospinal fluid leak ( n  = 36, 17.3%) and endocrinopathy ( n  = 43, 20.7%). Mean follow-up time was 37 months (0.5-180 months), with 86.5% showing no evidence of disease and 2.1% having died from disease at last follow-up. Conclusion  Endoscopic skull base surgery has been shown to be a safe and effective method of treating a variety of pediatric skull base tumors. If appropriately employed, the minimally invasive approach can provide optimal results in the pediatric population.

Role of transcranial sphenoidotomy in skull base surgery: classification of surgical techniques based on the surgical anatomy of the sphenoid sinus

OBJECTIVE

Although sphenoidotomy is more commonly performed via the transnasal approach than via the transcranial approach, transcranial sphenoidotomy (TCS) remains indispensable for en bloc resection of locally advanced sinonasal malignant tumors (SNMTs) extending to the skull base. TCS also enables transsphenoidal transposition of the temporoparietal galeal flap (TPGF) to compensate for the lack of vascularized reconstructive tissue after endoscopic transnasal skull base surgery. The objective of this study was to review the authors' surgical experience using TCS with an emphasis on the surgical anatomy of the sphenoid sinus and on the purpose of TCS. Relevant anatomy is further illustrated through cadaveric dissection and photo documentation.

METHODS

The authors reviewed the records of 50 patients who underwent TCS at the Nagoya University Hospital, Fukushima Medical University Hospital, or Aichi Medical University Hospital over the course of 7 years (between January 2011 and November 2017). The authors also performed cadaveric dissection in 2 adult cadaveric skull base specimens.

RESULTS

Of the 50 patients included in this study, 44 underwent craniofacial resection (CFR) for en bloc resection of SNMTs involving the anterior and/or lateral skull base, and 6 underwent transsphenoidal transposition of the TPGF flap. The authors categorized the TCS procedures according to the portion of the sphenoid sinus wall involved (i.e., superior, lateral, and superolateral). Superior sphenoidotomy was used in patients requiring anterior CFR. Lateral sphenoidotomy was further divided into 2 subtypes, with type 1 procedures performed for the transsphenoidal transpositioning of the TPGF, and type 2 procedures used in patients requiring lateral CFR. Superolateral sphenoidotomy was used in anterolateral CFR.

CONCLUSIONS

TCS still represents a useful tool in the armamentarium of neurosurgeons treating central skull base lesions. The newly proposed surgical classification facilitates a profound understanding of TCS and how to incorporate this technique into clinical practice.

A Systematic Review of Secondary Cerebrospinal Fluid Leaks

Background

Secondary cerebrospinal leaks (CSF) are leaks that recur after an initial endoscopic repair of CSF leaks. Identification of characteristics that could predict secondary leaks may allow surgeons to plan repairs with the knowledge that these defects are more likely to fail.

Objective

To identify characteristics that could predict secondary CSF leaks.

Methods

A search of all studies that reported outcomes after endoscopic repair of CSF leaks was conducted by using medical literature data bases. Studies with the following criteria were included: written in the English language, secondary CSF leaks after primary repair, and assessment of success of fistula repair. Data extracted included the etiology of the leak, site of the leak, reconstructive materials used, and success of the repair.

Results

Ninety-four studies, from 1988 to 2015, with a total of 3149 primary CSF leaks were included. Sixty-three studies (67%) had a success rate of ≥80%; 77 studies (82%) had secondary leak rates of <40%. For 88 of the 94 studies (94%), the success rate after secondary repair improved to 81.0–100%. Of 48 studies that included leaks of more than one site, the sphenoid was the most common site of leak in 26 studies (55%), the ethmoid was the most common site in 16 studies (34%), and the cribriform was the most common site in 11 studies (23%).

Conclusion

The rate of secondary CSF leaks was low due to advances in endoscopic repair techniques. Spontaneous and iatrogenic CSF leaks were more likely to recur, especially without adequate control of underlying factors, such as increased intracranial pressure and obesity. Further studies with consistent reporting are required for more definitive conclusions about secondary CSF leaks.

Utilization of a submental island flap and 3D printed model for skull base reconstruction: Infantile giant cranio-cervicofacial teratoma

Transcranial masses in the infant population can leave considerable skull base defects following resection. Traditional reconstructive techniques can result in significant morbidity or poor cosmetic results. We present a case of a large skull base defect in a six week-old infant, after removal of a giant cranio-cervicofacial teratoma, which was reconstructed using a versatile submental island flap. Additionally, preoperative planning and intraoperative navigation was advanced with the use of a 3D constructed model of the patient's mass.

The temporoparietal fascia flap folded into a ball in the treatment of retroauricular cerebrospinal fluid fistulae after posterior fossa surgery

BACKGROUND

Skull base and posterior fossa surgeries are sometimes complicated by cerebrospinal fluid (CSF) fistulae, which may be challenging to treat. They can lead to meningitis, increasing global morbidity and mortality. In case of failed medical treatment, revision surgery may be required. "Fat packing" (adipose tissue grafts) is usually used to close the communication between the intracranial contents and the cutaneous tissue, and to fill the dead space created by the skull base surgery. Vascularised flaps can also be used. They seem more efficient, especially in multi-operated patients or after radiotherapy, when cutaneous tissue is adhesive and fragile.

METHODS

Temporoparietal fascia (TPF) flap is a regional flap; it has reliable blood supply and can cover temporal and retroauricular defects. Folded into a ball, it can fill small dead spaces and can be skin grafted in case of cutaneous defect.

RESULTS AND CONCLUSIONS

We present a simple surgical solution to manage recurrent retroauricular CSF fistulae after posterior fossa surgery using a pedicled TPF flap folded into a ball.