Endoscopic Endonasal Skull Base Surgery Research Articles

Endoscopic endonasal skull base surgery in the pediatric population

The use of endoscopic endonasal surgery (EES) for skull base pathologies in the pediatric population presents unique challenges and has not been well described. The authors reviewed their experience with endoscopic endonasal approaches in pediatric skull base surgery to assess surgical outcomes and complications in the context of presenting patient demographics and pathologies. A retrospective review of 133 pediatric patients who underwent EES at our institution from July 1999 to May 2011 was performed. A total of 171 EESs were performed for skull base tumors in 112 patients and bony lesions in 21. Eighty-five patients (63.9%) were male, and the mean age at the time of surgery was 12.7 years (range 2.3-18.0 years). Skull base tumors included angiofibromas (n = 24), craniopharyngiomas (n = 16), Rathke cleft cysts (n = 12), pituitary adenomas (n = 11), chordomas/chondrosarcomas (n = 10), dermoid/epidermoid tumors (n = 9), and 30 other pathologies. In total, 19 tumors were malignant (17.0%). Among patients with follow-up data, gross-total resection was achieved in 16 cases of angiofibromas (76.2%), 9 of craniopharyngiomas (56.2%), 8 of Rathke cleft cysts (72.7%), 7 of pituitary adenomas (70%), 5 of chordomas/chondrosarcomas (50%), 6 of dermoid/epidermoid tumors (85.7%), and 9 cases of other pathologies (31%). Fourteen patients received adjuvant radiotherapy, and 5 received chemotherapy. Sixteen patients (15.4%) showed tumor recurrence and underwent reoperation. Bony abnormalities included skull base defects (n = 12), basilar invagination (n = 4), optic nerve compression (n = 3) and trauma (n = 2); preexisting neurological dysfunction resolved in 12 patients (57.1%), improved in 7 (33.3%), and remained unchanged in 2 (9.5%). Overall, complications included CSF leak in 14 cases (10.5%), meningitis in 5 (3.8%), transient diabetes insipidus in 8 patients (6.0%), and permanent diabetes insipidus in 12 (9.0%). Five patients (3.8%) had transient and 3 (2.3%) had permanent cranial nerve palsies. The mean follow-up time was 22.7 months (range 1-122 months); 5 patients were lost to follow-up. Endoscopic endonasal surgery has proved to be a safe and feasible approach for the management of a variety of pediatric skull base pathologies. When appropriately indicated, EES may achieve optimal outcomes in the pediatric population.

MR imaging evaluation of endoscopic cranial base reconstruction with pedicled nasoseptal flap following endoscopic endonasal skull base surgery

IntroductionPostoperative CSF leak is the most common complication of endoscopic endonasal approach (EEA) to skull base lesions. Endoscopic multilayer closure of skull base defect using pedicled nasoseptal flaps (NSF) based off the sphenopalatine artery reduces CSF leaks. EEA robustly expands in surgical arena, yet postoperative imaging evaluation remains poorly studied. This work illustrates normal MR imaging appearance of skull base reconstruction utilizing NSFs during immediate postoperative period. MethodsWe retrospectively identified patients who had skull base reconstructions utilizing NSFs following EEAs and immediate postoperative-enhanced brain MRI. NSFs and free grafts were evaluated for signal intensity, thickness, configuration, enhancement, vascular pedicle of NSF, relationship in multilayer reconstruction, and defect coverage. Imaging findings were correlated with surgical technique and CSF leaks. ResultsTwenty-eight patients had 26 multilayer reconstructions and 34 NSFs. Twenty-nine NSFs showed enhancing C-shaped arc at the skull base. Of those, 26 flaps (90%) were confidently identified by visualization of their vascular pedicles, 3 were not distinguishable from adjacent mucosa and pedicles were not identified. Five NSFs showed no enhancement (1 CSF leak). Twenty-seven enhancing NSFs approximated defects with close abutment to free grafts. One flap was displaced; one incompletely covered the defect (2 CSF leaks). Fisher exact test demonstrated an association between incomplete defect coverage and displacement of NSFs with CSF leak (P=0.05). ConclusionEndoscopic skull base reconstruction utilizing NSF has characteristic MR imaging appearance. Non-enhancing mucosal gap or displacement of NSF may indicate incomplete defect coverage, identifying patients at risk for CSF leak.

Carotid Injury during Endoscopic Endonasal Surgery: Incidence and Outcomes in 2015 Cases

Introduction: Injury to the internal carotid artery (ICA) during endoscopic endonasal skull base surgery (ESBS) is a feared complication that is not well studied or reported. The purpose of this study was to evaluate the incidence, identify potential risk factors, and present management strategies and outcomes of ICA injury during ESBS at our institution.

Is Endoscopic Endonasal Skull Base Surgery Better Than the Traditional Microscopic Approach? A Review of 184 Consecutive Operations

Objectives: The aim of this study was to compare outcome measures between microscopic and endoscopic transsphenoidal surgery for the resection of sellar and parasellar tumors.

Endoscopic endonasal skull base surgery

Skull base surgery has been transformed by the development of endoscopic techniques. Endoscopic procedures were first used for pituitary surgery and were then gradually extended to other regions. A wide range of diseases are now accessible to endoscopic skull base surgery. The major advantage of the endoscopic endonasal approach is that it provides direct anatomical access to a large number of intracranial and paranasal sinus lesions, avoiding the sequelae of a skin incision, facial bone flap or craniotomy, and brain retraction, which is inevitable with conventional neurosurgical incisions, resulting in decreased morbidity and mortality and, indirectly, decreased length of hospital stay and management costs. Moreover, the increasing number of publications in this field illustrates the growing interest in these techniques. This paper provides a review of endoscopic skull base surgery. The indications and general principles of endoscopic endonasal skull base surgery are described. Progress in exposure and especially reconstruction techniques is described. This progress now allows more extensive resections, while maintaining acceptable morbidity. The limits of this surgery are also discussed; in particular, although this surgery is often described as "minimally invasive", it is not completely devoid of morbidity.

Endoscopic Endonasal Skull Base Surgery in the Pediatric Population

Endoscopic Endonasal Skull Base Surgery in the Pediatric Population

Middle Turbinate Vascularized Flap: Applications in Skull Base Reconstruction

Background: The use of local vascularized flaps has had significant impact on postoperative cerebrospinal (CSF) leak rates following endoscopic endonasal skull base surgery (EESBS). The middle turbinate (MT) flap is one alternative for reconstruction of sphenoid and fovea ethmoidalis defects. In select cases, the MT flap is an excellent alternative to the nasoseptal flap.

A System for Video-Based Navigation for Endoscopic Endonasal Skull Base Surgery

Surgeries of the skull base require accuracy to safely navigate the critical anatomy. This is particularly the case for endoscopic endonasal skull base surgery (ESBS) where the surgeons work within millimeters of neurovascular structures at the skull base. Today's navigation systems provide approximately 2 mm accuracy. Accuracy is limited by the indirect relationship of the navigation system, the image and the patient. We propose a method to directly track the position of the endoscope using video data acquired from the endoscope camera. Our method first tracks image feature points in the video and reconstructs the image feature points to produce 3D points, and then registers the reconstructed point cloud to a surface segmented from preoperative computed tomography (CT) data. After the initial registration, the system tracks image features and maintains the 2D-3D correspondence of image features and 3D locations. These data are then used to update the current camera pose. We present a method for validation of our system, which achieves submillimeter (0.70 mm mean) target registration error (TRE) results.

Use of a side-cutting aspiration device for resection of tumors during endoscopic endonasal approaches

Accessing intra- and extradural tumors via an endonasal approach requires working safely in a relatively narrow area with unobstructed visibility. The authors describe their experience to highlight the utility of a side-cutting aspiration device for endoscopic endonasal resection of skull base tumors. The authors used this device in 13 nonconsecutive endoscopic endonasal procedures for different skull base tumors (8 pituitary macroadenomas, 2 craniopharyngiomas, 1 chordoma, 1 recurrent ependymoma, and 1 lymphoma). Illustrative cases and video are presented to demonstrate its use. The instrument was easy to use and effective in the removal of the lesions presented in this series. In 10 patients (77%), gross-total resection was possible; in the other 3 patients (23%), more than 80% of the tumor was resected. No collateral tissue damage or any other complication resulted from device-related debulking or aspiration. The side-cutting tissue resector is a safe, easy to use, and effective tool for internal debulking and extracapsular dissection of nonvascularized tumors that are too firm for bimanual suction or blunt ring curette dissection. It is particularly useful when working through a deep and narrow corridor such as is encountered in endoscopic endonasal skull base surgery.

Endoscopic anatomy of the approaches to the sellar area and planum sphenoidale

The productive work between otolaryngologists and neurosurgeons has resulted in the emergence of endoscopic endonasal skull base surgery. The goal of the present study is to describe the endoscopic anatomy of the endonasal approach to the sellar region and planum sphenoidale, highlighting the key points of the surgical approach and the neurovascular landmarks. Descriptive study of the endoscopic endonasal dissection of 9 fresh cadavers with exposure of the anatomic structures. The endoscopic endonasal ethmoidectomy and sphenoidotomy allows an expanded access to the sellar area and planum sphenoidale. The surface anatomy of the sphenoid sinus is easily identifiable and provides safe landmarks, guiding the intracranial dissection. The endoscopic endonasal approach to the skull base by the ENT and neurosurgeon is feasible, but it requires adequate anatomical knowledge and endoscopic skills for its realization, which can be obtained by practicing in cadavers.

Endoscopic Endonasal Approach for Nonvestibular Schwannomas

Nonvestibular schwannomas of the skull base often represent a challenge owing to their anatomic location. With improved techniques in endoscopic endonasal skull base surgery, resection of various ventral skull base tumors, including schwannomas, has become possible. To assess the outcomes of using endoscopic endonasal approach (EEA) for nonvestibular schwannomas of the skull base. Seventeen patients operated on for skull base schwannomas by EEA at the University of Pittsburgh Medical Center from 2003 to 2009 were reviewed. Three patients underwent combined approaches with retromastoid craniectomy (n = 2) and orbitopterional craniotomy (n = 1). Three patients underwent multistage EEA. The rest received a single EEA operation. Data on degree of resection were found for 15 patients. Gross total resection (n = 9) and near-total (>90%) resection (n = 3) were achieved in 12 patients (80%). There were no tumor recurrences or postoperative cerebrospinal fluid leaks. In 3 of 7 patients with preoperative sensory deficits of trigeminal nerve distribution, there were partial improvements. Patients with preoperative reduced vision (n = 1) and cranial nerve VI or III palsies (n = 3) also showed improvement. Five patients had new postoperative trigeminal nerve deficits: 2 had sensory deficits only, 1 had motor deficit only, and 2 had both motor and sensory deficits. Three of these patients had partial improvement, but 3 developed corneal neurotrophic keratopathy. An EEA provides adequate access for nonvestibular schwannomas invading the skull base, allowing a high degree of resection with a low rate of complications.

Internal Carotid Artery Injury

Introduction: Endoscopic endonasal skull base surgery has become increasingly accepted for lesions involving the entire anterior skull base and upper cervical spine. However, major concerns exist regarding the frequency of and ability to control ICA injury during these approaches. Methods: All endoscopic endonasal approaches (EEAs) performed at the University of Pittsburgh Medical Center from January 1998 until June 2010 were evaluated to determine the frequency and outcomes of ICA injury. Results (ICA Injury during EEA): Out of 1,643 endoscopic endonasal surgeries (EESs) (leak repairs excluded), there were 6 ICA injuries (0.3%). The most common tumor type in which there was an ICA injury was chondroid tumor, with which there were three injuries (two chordomas and one chondrosarcoma) in 75 cases (4%). There were two injuries during 490 pituitary tumor surgeries (0.4%). The other ICA injury occurred during resection of a recurrent nasopharyngeal carcinoma. Four of the ICAs were sacrificed (either intra- or immediately postsurgery), and two were preserved. One of the preserved vessels went on to develop a pseudoaneurysm, which was successfully treated endovascularly. No patient suffered a new neurological deficit. There was one postoperative death due to cardiac ischemia in an older woman who had excessive blood loss during an attempt to preserve the vessel. One other patient who had an uneventful postoperative course died a month later of unrelated causes. Conclusions: The incidence of ICA injury during EES is low. Chondroid tumors have the greatest risk of ICA injury due to involvement and displacement of the vessel. An ICA injury can be controlled effectively to prevent exsanguination. However, current technology and instrumentation do not allow the repair of major injuries.

Utility of a Rotation-Suction Microdebrider for Removal of Solid Tumors in Endoscopic Endonasal Skull Base Surgery

Utility of a Rotation-Suction Microdebrider for Removal of Solid Tumors in Endoscopic Endonasal Skull Base Surgery

Endoscopic Endonasal Skull Base Surgery in Emerging Economies: A Three-Year Analysis of 71 Cases Performed at a Single Institution

Introduction: Performing complex skull base surgery has evolved into a specialty of its own. One of the greatest achievements has been the development of newer and better technologies to treat difficult cases. Nonetheless, many of these technologies are not always readily available in developing countries. Even so, fully endoscopic endonasal surgery (fEES) is being used more often every day regardless of these limitations. The purpose of this study was to retrospectively evaluate the experience at a single institution to determine the feasibility of performing fEES without access to the full spectrum of technologies currently available commercially but with comparable outcomes.

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

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. 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. 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 approach, except for 1 patient who required a transcranial repair. The incidence of postoperative CSF leaks decreased significantly with the adoption of vascularized tissue for reconstruction of the skull base (< 6%). Transient neurological deficits occurred in 20 patients (2.5%) and permanent neurological deficits in 14 patients (1.8%). Intracranial infection and systemic complications were encountered and successfully treated in 13 (1.6%) and 17 (2.1%) patients, respectively. Seven patients died during the 30-day perioperative period, 6 of systemic illness and 1 of infection (overall mortality 0.9%). Endoscopic endonasal skull base surgery provides a viable median corridor based on anatomical landmarks and is customized according to the specific pathological process. This corridor should be considered as the sole access or may be combined with traditional approaches. With the incremental acquisition of skills and experience, endoscopic endonasal approaches have an acceptable safety profile in select patients presenting with various skull base pathologies.

Anatomical considerations for endoscopic endonasal skull base surgery in pediatric patients

Pediatric skull base surgery is limited by several boney sinonasal landmarks that must be overcome prior to tumor dissection. When approaching a sellar or parasellar tumor, the piriform aperture, sphenoid sinus pneumatization, and intercarotid distances are areas of potential limitation. Quantitative pediatric anatomical measurements relevant to skull base approaches are lacking. Our goal was to use radio-anatomic analysis of computed tomography scans to determine anatomical limitations for trans-sphenoidal approaches in pediatric skull base surgery. A radio-anatomic cross-sectional survey. Measurements included the diameter of the piriform aperture, posterior extent of sphenoid sinus pneumatization, and intercarotid distances on fine-cut, age-stratified maxillofacial scans. Fifty pediatric (<18 years of age) and 10 adult patients were equally subdivided into seven age groups and compared to determine age-related differences in sphenoid sinus pneumatization, skull base thicknesses, and intercarotid distances. Piriform aperture width was significantly greater in adults than in patients under age 7 years (P <or= .002). Three fourths of the planum and sellar face and one half of the sellar floor were pneumatized by ages 6 to 7 years. Superior clival pneumatization was not evident until 12 years of age. Clival intercarotid distances were not different among groups. Drilling distances for trans-planar, trans-sellar, and trans-clival approaches are described. Several potential anatomic limits must be considered in pediatric skull base surgery, and these vary according to age. Piriform aperture is likely a limit only in the youngest patients (under 2 years). Sphenoid pneumatization to the planum and sella start at 3 years and complete by age 10 years. Clival intercarotid distances do not change significantly and are not prohibitively narrow in any age group.

Pedicled facial buccinator (FAB) flap: A new flap for reconstruction of skull base defects

The expansion of endoscopic endonasal skull base surgery has resulted in an increased demand for reconstructive options. Reconstruction with vascularized tissue has proven indispensable for reliably separating the cranial contents from the paranasal sinuses following extended endoscopic endonasal approaches (EEA). The introduction of the Hadad-Bassagasteguy flap (vascular pedicle nasoseptal flap, HBF) at our institution decreased our postoperative cerebral spinal fluid (CSF) leak rates from more than 20% to less than 5%. The HBF is not always available, as the nasoseptal area or its vascular supply can be compromised by tumor or prior surgery. In an attempt to keep pace with rapidly expanding reconstructive requirements, we present the anatomic and cadaveric foundations for novel modifications of the facial artery musculo (-mucosal) (FAM[M]) and buccinator flaps to allow vascularized reconstruction of the skull base. Feasibility. Cadaveric study. Using cadaver dissections and measurements, we investigated the feasibility of transposing pedicled buccinator myo/myomucosal flaps into the nasal cavity and skull base. Both muscular and myomuscular flaps were raised, and techniques for transposition into the nasal cavity were investigated. Three fresh and six preserved human specimens were dissected. Pedicled facial buccinator flaps with and without mucosa were transposed into the nasal cavity using a variety of maxillary osteotomies. No facial incisions were required. It was demonstrated that the flaps reach the anterior skull base and planum sphenoidale. The transposition of pedicled buccinator muscle flaps with and without mucosa into the nasal cavity could reach the anterior skull base and planum sphenoidale, if the appropriate surgical technique is used. The pedicled Facial Buccinator Flap holds significant potential as a reconstructive alternative for a variety of skull base defects, alone or in combination with existing reconstructive options. 2010.

A simple and versatile tissue adhesive applicator for endonasal endoscopic skull base surgery

Repair of dural defects following endonasal endoscopic cranial base surgery remains a challenge. A variety of reconstructive techniques have been described, many of which utilize tissue adhesives or glues. One of the main difficulties with the endonasal use of these sealants is the available applicators, which often result in the imprecise and excessive application of the material. In this report, we describe the modified use of straight and curved suction tips as simple and versatile rigid tissue adhesive/glue applicators for use during endonasal skull base surgery.

Middle turbinate preservation in endoscopic transsphenoidal surgery of the anterior skull base.

Endoscopic endonasal skull base surgery is a growing field in which the nasal corridors are used to address skull base lesions. Whether the middle turbinates must be removed for adequate exposure is controversial and not well addressed in the literature. This is a prospective, observational study of 163 consecutive cases of purely endoscopic endonasal transsphenoidal surgeries performed at a single tertiary care institution. The primary study outcome measurement is the feasibility of middle turbinate preservation in endoscopic transsphenoidal skull base surgery. The pathologies included 99 pituitary tumors, 15 craniopharyngiomas, 11 meningiomas, 11 Rathke's cleft cysts, 7 encephaloceles, 5 cerebrospinal fluid leak repairs, 9 clival chordomas, and 6 other pathologies of the sella. In patients undergoing surgery for a neoplasm, the average tumor size was 2.3 cm. The middle turbinate was preserved in 160/163 cases (98%). One hundred and twenty magnetic resonance imaging (MRI) studies were reviewed at a median of 16 months postoperatively and no patients (0%) developed frontal sinusitis. The middle turbinate can be preserved in nearly every endonasal, endoscopic transsphenoidal skull base case while still providing good exposure for successful tumor resection and skull base reconstruction. Postoperative sinonasal function may be better preserved with this technique.

Bone Removal With a New Ultrasonic Bone Curette During Endoscopic Endonasal Approach to the Sellar-Suprasellar Area

Accessing intradural lesions via an extended endoscopic endonasal approach requires a relatively large bony removal over the skull base. We describe the Sonopet ultrasonic bone curette with a new dedicated endonasal hand-piece. We used this ancillary device in 27 nonconsecutive endonasal procedures for different skull base lesions (18 standard pituitary operations and 9 extended approaches for either meningiomas or craniopharyngiomas). The ultrasonic bone curette with endonasal hand-piece was easy to use and effective during the removal of the bone covering or when close to the carotid and optic prominences, as well as in preserving the integrity of the superior intercavernous sinus. In only 1 case was small tearing of the dura mater observed during the bony removal. No cases of injury to the major neurovascular structures occurred. The Sonopet ultrasonic bone curette is a useful tool during endoscopic endonasal skull base surgery.