Tag: skull base reconstruction

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Septal rhinopharyngeal flap: a novel technique for skull base reconstruction after endoscopic endonasal clivectomies

J Neurosurg 136:1601–1606, 2022

Endoscopic endonasal reconstruction techniques have improved CSF leak rates that were initially reported after surgery for cranial base and intradural lesions. However, wide surgical defects still pose a problem, especially if located in the clival region.

The authors propose and describe a novel reconstruction technique they call a septal rhinopharyngeal flap (SRF) specifically designed to address this issue. The SRF is formed by three components of mucosa: 1) septal, 2) rhinopharyngeal roof, and 3) rhinopharyngeal posterior wall components, which allows for the coverage of the tuberculum/ sellar region, midclivus, and lower clivus, respectively. A step-by-step procedure is described and its results analyzed in cases in which it has been used. The SRF was performed in 8 patients, which included diagnoses of 4 chordomas, 2 petroclival meningiomas, 1 invasive pituitary adenoma, and 1 chondrosarcoma. The size of the flap was considered optimal in all patients (100%). Postoperative MRI revealed contrast enhancement covering the entire surface of the flap. No CSF leaks were encountered after at least 1 postoperative year.

The SRF is a novel vascularized reconstruction technique specifically indicated for wide endosanasal clivectomies focused on the middle clivus with caudal extension into the lower clivus and craniocervical junction, as well as rostral extensions into the tubercular or planum sphenoidale. This new reconstruction technique could be added to the skull base reconstruction armamentarium as a safe and optimal option.

 

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The rhinopharyngeal flap for reconstruction of lower clival and craniovertebral junction defects

J Neurosurg 135:1319–1327, 2021

The endoscopic endonasal approach (EEA) to the lower clivus and craniovertebral junction (CVJ) has been traditionally performed via resection of the nasopharyngeal soft tissues. Alternatively, an inferiorly based rhinopharyngeal (RP) flap (RPF) can be dissected to help reconstruct the postoperative defect and separate it from the oropharynx. To date, there is no evidence regarding the viability and potential clinical impact of the RPF. The aim of this study was to assess RPF viability and its impact on clinical outcome.

METHODS A retrospective cohort of 60 patients who underwent EEA to the lower clivus and CVJ was studied. The RPF was used in 30 patients (RPF group), and the nasopharyngeal soft tissues were resected in 30 patients (control group).

RESULTS Chordoma was the most common surgical indication in both groups (47% in the RPF group vs 63% in the control group, p = 0.313), followed by odontoid pannus (20% in the RPF group vs 10%, p = 0.313). The two groups did not significantly differ in terms of extent of tumor (p = 0.271), intraoperative CSF leak (p = 0.438), and skull base reconstruction techniques other than the RPF (nasoseptal flap, p = 0.301; fascia lata, p = 0.791; inlay graft, p = 0.793; and prophylactic lumbar drain, p = 0.781). Postoperative soft-tissue enhancement covering the lower clivus and CVJ observed on MRI was significantly higher in the RPF group (100% vs 26%, p < 0.001). The RPF group had a significantly lower rate of nasoseptal flap necrosis (3% vs 20%, p = 0.044) and surgical site infection (3% vs 27%, p = 0.026) while having similar rates of postoperative CSF leakage (17% in the RPF group vs 20%, p = 0.739) and meningitis (7% in the RPF group vs 17%, p = 0.424). Oropharyngeal bacterial flora dominated the infections in the control group but not those in the RPF group, suggesting that the RPF acted as a barrier between the nasopharynx and oropharynx.

CONCLUSIONS The RPF provides viable vascularized tissue coverage to the lower clivus and CVJ. Its use was associated with decreased rates of nasoseptal flap necrosis and local infection, likely due to separation from the oropharynx.

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Middle turbinate vascularized flap for skull base reconstruction after an expanded endonasal approach

Acta Neurochir. DOI 10.1007/s00701-011-1064-8

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.

Material and methods 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.

Results 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.

Conclusions 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.

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High-viscosity polymethylmethacrylate cement for endoscopic anterior cranial base reconstruction

J Neurosurg 113:1100–1105, 2010. (DOI: 10.3171/2010.3.JNS09453)

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.

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