Background: In patients with large dural defects of the anterior and ventral skull base after endonasal skull base surgery, there is a significant risk of a postoperative cerebrospinal fluid leak after reconstruction. Reconstruction with vascularized tissue is desirable to facilitate rapid healing, especially in irradiated patients.

Methods: We developed a neurovascular pedicled flap of the nasal septum mucoperiosteum and mucoperichondrium based on the nasoseptal artery, a branch of the posterior septal artery (Hadad-Bassagasteguy flap [HBF]). A retrospective review of patients undergoing endonasal skull base surgery at the University of Rosario, Argentina, and the University of Pittsburgh Medical Center was performed to identify patients who were reconstructed with a vascularized septal mucosal flap.

Results: Forty-three patients undergoing endonasal cranial base surgery were repaired with the septal mucosal flap. Two patients with postoperative cerebrospinal fluid leaks (5%) were successfully treated with focal fat grafts. We encountered no infectious or wound complications in this series of patients. One patient experienced a posterior nose bleed from the posterior nasal artery. This was controlled with electrocautery and the flap blood supply was preserved.

Conclusion: The HBF is a versatile and reliable reconstructive technique for defects of the anterior, middle, clival, and parasellar skull base. Its use has resulted in a sharp decrease in the incidence of postoperative cerebrospinal fluid leaks after endonasal skull base surgery and is recommended for the reconstruction of large dural defects and when postoperative radiation therapy is anticipated.

A novel reconstructive technique after endoscopic expanded endonasal approaches : Vascular pedicle nasoseptal flap

Objective Reconstruction of the cranial base using vascularized tissue promotes rapid and complete healing, thus avoiding complications caused by persistent communication between the cranial cavity and the sinonasal tract. The Hadad-Bassagasteguy flap (HBF), a neurovascular pedicled flap of the nasal septum mucoperiosteum and mucoperichondrium based on the nasoseptal artery, seems to be advantageous for the reconstruction of the cranial base after endonasal cranial base surgery. Methods We performed a retrospective review of patients who underwent endonasal cranial base surgery at the University of Pittsburgh Medical Center from January 30, 2006 to January 30, 2007, identifying patients who experienced reconstruction with a vascularized septal mucosal flap (HBF). We analyzed the demographic data, pathological characteristics, site and extent of resection, use of cerebrospinal fluid (CSF) diversion techniques, and outcome. Results Seventy-five patients who underwent endonasal cranial base endoscopic surgery received repair with the HBF. In this population, we encountered eight postoperative CSF leaks (10.66%), all in patients who required intra-arachnoidal dissection. When we correct the statistical analysis to include only patients with intra- arachnoidal lesions, the postoperative CSF leak rate is 14.5% (eight of 55 patients). It is notable that six CSF (33%) leaks occurred in our first 25 repairs, whereas we encountered only two postoperative leaks (4%) in the last 50 patients. The corrected CSF leak rate, considering only intra-arachnoidal lesions, was two (5.4%) of 37 patients. This improvement in the CSF leak rate reflects our growing experience and comfort with this reconstructive technique. All of our failures could be matched to a specific technical mistake. In addition, we modified the flap-harvesting technique to allow for staged procedures and the removal of caudal lesions. These special circumstances require storage of the flap in the antrum during the removal of caudal lesions, and suturing of the flap in its original position for staged procedures. One patient experienced a posterior nose bleed from the posterior nasal artery. This was controlled with bipolar electrocautery, thereby preserving the flap blood supply. We encountered no infectious or wound complications in this series of patients. The donor site accumulates crusting, which requires debridement until mucosalization is complete; this usually occurs 6 to 12 weeks after surgery. Conclusion The HBF is a versatile and reliable reconstructive technique for repairing defects of the anterior, middle, clival, and parasellar cranial base. Its use has resulted in a significant decrease in our incidence of CSF leaks after endonasal cranial base surgery. Attention to technical details is of paramount importance to achieve the best outcomes.

Endoscopic reconstruction of the cranial base using a pedicled nasoseptal flap.

Object The middle third of the clivus and the region around the petrous internal carotid artery (ICA) is a difficult area of the skull base in terms of access. This is a deep area rich with critical neurovascular structures, which is often host to typical skull base diseases. Expanded endoscopic endonasal approaches offer a potential option for accessing this difficult region. The objective of this paper was to establish the clinical feasibility of gaining access to the paraclival space in the region of the middle third of the clivus, to provide a practical modular and clinically applicable classification, and to describe the relevant critical surgical anatomy for each module. Methods The anatomical organization of the region around the petrous ICA, cavernous sinus, and middle clivus is presented, with approaches divided into zones. In an accompanying paper in this issue by Cavallo, et al., the anatomy of the pterygopalatine fossa is presented; this was observed through cadaveric dissection for which an e...

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Expanded endonasal approach: fully endoscopic, completely transnasal approach to the middle third of the clivus, petrous bone, middle cranial fossa, and infratemporal fossa.

Object The development of endoscopic endonasal approaches, albeit in the early stages, represents part of the continuous evolution of skull base surgery. During this early period, it is important to determine the safety of these approaches by analyzing surgical complications to identify and eliminate their causes. Methods The authors reviewed all perioperative complications associated with endoscopic endonasal skull base surgeries performed between July 1998 and June 2007 at the University of Pittsburgh Medical Center. Results This study includes the data for the authors' first 800 patients, comprising 399 male (49.9%) and 401 female (50.1%) patients with a mean age of 49.21 years (range 3–96 years). Pituitary adenomas (39.1%) and meningiomas (11.8%) were the 2 most common pathologies. A postoperative CSF leak represented the most common complication, occurring in 15.9% of the patients. All patients with a postoperative CSF leak were successfully treated with a lumbar drain and/or another endoscopic appro...

Endoscopic endonasal skull base surgery: analysis of complications in the authors' initial 800 patients

The evolution of the endoscopic endonasal transsphenoidal technique, which was initially reserved only for sellar lesions through the sphenoid sinus cavity, has lead in the last decades to a progressive possibility to access the skull base from the nose This route allows midline access and visibility to the suprasellar, retrosellar and parasellar space while obviating brain retraction, and makes possible to treat transsphenoidally a variety of relatively small midline skull base and parasellar lesions traditionally approached transcranially

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Extended endoscopic endonasal approach to the midline skull base: the evolving role of transsphenoidal surgery.

Object The midline skull base is an anatomical area that extends from the anterior limit of the cranial fossa down to the anterior border of the foramen magnum. Resection of lesions involving this area requires a variety of innovative skull base approaches. These include anterior, anterolateral, and posterolateral routes, performed either alone or in combination, and resection via these routes often requires extensive neurovascular manipulation. The goals in this study were to define the application of the endoscopic endonasal approach and to become more familiar with the views and skills associated with the technique by using cadaveric specimens. Methods To assess the feasibility of the endonasal route for the surgical management of lesions in the midline skull base, five fresh cadaver heads injected with colored latex were dissected using a modified endoscopic endonasal approach. Full access to the skull base and the cisternal space around it is possible with this route. From the crista galli to the spi...

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Endoscopic endonasal surgery of the midline skull base: anatomical study and clinical considerations

Objective Suprasellar craniopharyngiomas have been classically removed using a variety of transcranial approaches. Historically, the transsphenoidal route was reserved for intrasellar-infradiaphragmatic, and preferably cystic, lesions. With the advent of the endoscope in transsphenoidal surgery, its obvious advantages combined with neurosurgeons' increasing interest in extended transsphenoidal approaches made suprasellar and even intraventricular craniopharyngiomas accessible for removal via such a low route. Patients and methods Between January of 2004 and April of 2006, six men and four women (mean age, 57.2 yr; range, 26-70 yr) underwent surgery for craniopharyngioma, including two intrasuprasellar, one suprasellar, six suprasellar-intraventricular, and one that was purely intraventricular. Three patients had undergone a previous transcranial surgery via the pterional approach, whereas one patient had undergone a transsphenoidal microsurgical approach. The surgical method consisted of an extended endoscopic transsphenoidal approach with removal of the upper half of the sella, the tuberculum sellae, and the posterior part of the planum sphenoidale, using a "three-four hands" technique. Results Total craniopharyngioma removal was achieved for seven patients, subtotal removal was possible for two patients, and one patient had a partial removal. Two patients developed a postoperative cerebrospinal fluid leak that required a successful endoscopic revision of the cranial base reconstruction. One patient died 5 weeks later because of hypothalamic dysfunction. All patients with visual field and/or visual acuity defect improved except one patient, in which we observed a slight worsening of visual acuity in one eye. Preoperative pituitary dysfunction did not improve in any patient. In three patients, we observed the new occurrence of permanent diabetes insipidus. One patient developed a sphenoid sinus mycosis, which was treated with antimycotic therapy. We did not observe carotid injury, epistaxis from the sphenopalatine artery, or airway difficulties. Conclusion For selected patients, the extended endoscopic endonasal approach for removal of suprasellar craniopharyngioma seems to provide a valid alternative to transcranial approaches.

Extended endoscopic transsphenoidal approach for extrasellar craniopharyngiomas.

Object The extended transsphenoidal approach to the suprasellar region has the advantages of minimal invasiveness and brain manipulation in the surgical treatment of small to medium lesions. At the same time, however, it carries a higher risk of postoperative cerebrospinal fluid (CSF) leakage and related complications than those for the standard transsphenoidal approach. Effective reconstruction of large skull base defects is a major concern in such extended approaches and remains challenging. Methods Between January 2004 and April 2006, 21 patients affected by different suprasellar lesions underwent the extended endoscopic endonasal transtuberculum-transplanum approach. Three different techniques were used for the skull base reconstructions. In all cases, dehydrated human pericardium (Tutoplast) for dural reconstruction and a copolymer of l-lactic acid and glycolic acid (LactoSorb) as a bone substitute were used. Collagen sponges, fibrin glue, and an inflated Foley balloon catheter were also used to fill...

Skull base reconstruction in the extended endoscopic transsphenoidal approach for suprasellar lesions.

Objective Tuberculum sellae meningiomas are classically removed through several different surgical transcranial approaches, including the pterional transsylvian route. Recently, the indications for the transsphenoidal technique, traditionally proposed only for the treatment of intrasellar lesions, have been extended to include lesions located in the supra- and parasellar areas and, among them, tuberculum sellae meningiomas. We describe the surgical technique for the purely endoscopic endonasal variant of the extended transsphenoidal "low route" to tuberculum sellae meningiomas. Patients and methods Over a 22-month period, six patients (three men and three women; mean age, 56.1 yr; age range, 44-70 yr) underwent an extended endoscopic transsphenoidal approach for the treatment of tuberculum sellae meningiomas. Two lesions were less than 2 cm and four were between 2 and 4 cm in size. The details of the surgical technique have been described. Results Gross total removal of the lesion, without the need for brain retraction and with minimal neurovascular manipulation, was achieved in five patients (83.3%), whereas in one patient, only subtotal removal was possible (>90%) because the mass extended into the right optic canal. Four patients with preoperative visual function defects had complete recovery, whereas two patients experienced a temporary worsening of vision. Both of these patients fully recovered within a few days. One patient had a postoperative cerebrospinal fluid leak that required three operations for cranial base defect repair. This patient showed rapid and unexpected worsening with respect to level of consciousness and anisocoria. An intraventricular hemorrhage was discovered, and the patient died 6 days later. Another patient developed new permanent diabetes insipidus that required hormonal replacement therapy. Conclusion In experienced hands and in carefully selected patients, the extended endoscopic transsphenoidal approach may constitute a viable alternative to transcranial approaches for tuberculum sellae meningioma. At present, the major limits of the approach include the lack of a reliable technique for the reconstruction of a cranial base defect and inadequate follow-up.

Andrea Messina

Papers

Extended endoscopic endonasal approach to the midline skull base: the evolving role of transsphenoidal surgery.

Endoscopic endonasal surgery of the midline skull base: anatomical study and clinical considerations

Extended endoscopic transsphenoidal approach for extrasellar craniopharyngiomas.

Skull base reconstruction in the extended endoscopic transsphenoidal approach for suprasellar lesions.

Extended endoscopic transsphenoidal approach for tuberculum sellae meningiomas.