Long-Term Results of Endoscopic Endonasal Marsupialization of Rathke Cleft Cysts With Bioabsorbable Steroid-Eluting Stents-Technical Case Series and Review of the Literature.

BACKGROUND: Rathke cleft cysts (RCCs) are common benign skull-base lesions arising from embryologic remnants of Rathke pouch. Though frequently asymptomatic, RCCs can become symptomatic because of compression of adjacent neural structures. Transcranial and neuroendoscopic surgical treatments have been described for symptomatic RCCs, but recurrence rates remain as high as 30%. Bioabsorbable steroid-eluting (BASE) stents significantly decrease adhesions and recurrent ostia obstruction after endoscopic sinus surgery. We sought to use BASE stents to aid marsupialization of symptomatic RCCs. OBJECTIVE: To present long-term results of our initial experience with endoscopic-endonasal fenestration and placement of BASE stents for RCCs. METHODS: Patients undergoing neuroendoscopic transsphenoidal fenestration of RCCs with BASE stent placement were identified and their medical records retrospectively reviewed. RESULTS: Four patients underwent neuroendoscopic transsphenoidal fenestration and BASE stent placement from March 2016 to April 2018 for symptomatic RCCs. After the cyst contents were evacuated, a BASE stent was deployed in the cyst fenestration to prevent cyst wall regrowth or closure and facilitate marsupialization to the sphenoid sinus. No perioperative complications were encountered, and all patients reported symptom resolution by 2 weeks postoperatively. Postoperative endoscopic evaluation demonstrated epithelization of the cyst wall opening and patent marsupialization into the sphenoid sinus in all cases. After a mean follow-up of 56 ± 12 months, all patients remained asymptomatic with baseline visual function and no radiographic evidence of recurrence. CONCLUSION: Bioabsorbable steroid-eluting stent placement is a safe, facile, viable augmentation of neuroendoscopic technique for symptomatic RCCs with the potential to reduce long-term recurrence rates.

Extended Anterior Petrosectomy Through the Transcranial Middle Fossa Approach and Extended Endoscopic Transsphenoidal-Transclival Approach: Qualitative and Quantitative Anatomic Analysis.

BACKGROUND: Petroclival tumors and ventrolateral lesions of the pons present unique surgical challenges. This cadaveric study provides qualitative and quantitative anatomic comparison for an anterior petrous apicectomy through the transcranial middle fossa (TMF) and expanded endoscopic transsphenoidal-transclival approaches. METHODS: In 10 silicone-injected heads, the petrous apex and clivus were drilled extradurally using middle fossa and endonasal approaches. With in situ and frameless stereotactic navigation, we defined consistent points to compare working areas, bone removal volumes, approach angles, and surgical freedom. RESULTS: Mean exposed TMF area (21.03 ± 3.46 cm2) achieved a 44.71 ± 4.13° working angle to the brainstem between cranial nerves V and VI. Kawase's rhomboid area measured 1.76 ± 0.34 cm2, and bone removal averaged 1.20 ± 0.12 cm3 at the petrous apex. Surgical freedom on the lateral brainstem was higher halfway between cranial nerves V and VI at the center of the rhomboid compared with midline at the basilar sulcus (P < 0.01). After clivectomy and petrous apicectomy, mean exposed expanded endoscopic transsphenoidal-transclival area was 5.29 ± 0.66 cm2. Approach from either nostril showed no statistically significant differences in surgical freedom at the foramen lacerum and midpoint basilar sulcus. At the petrous apex, bone volume removed and area exposed were significantly larger for the TMF approach (P < 0.001). CONCLUSIONS: Expanded transclival anterior petrosectomy through the TMF approach provides an adequate corridor to lesions in the upper ventrolateral pons. The expanded endoscopic transsphenoidal-transclival approach better fits midline lesions not extending laterally beyond cranial nerve VI and C3 carotid when evaluating normal anatomic parameters.

Endoscopic endonasal treatment of maxillary nerve (V2) painful neuropathy: cadaveric study with clinical correlation.

BACKGROUND: Surgical access to the second (V2, maxillary) and third (V3, mandibular) branches of the trigeminal nerve (V) has been classically through a transoral approach. Increasing expertise with endoscopic anatomy has achieved less invasive, more efficient access to skull base structures. The authors present a surgical technique using an endoscopic endonasal approach for the treatment of painful V2 neuropathy. METHODS: Endoscopic endonasal dissections using a transmaxillary approach were performed in four formalin-fixed cadaver heads to expose the V2 branch of the trigeminal nerve. Relevant surgical anatomy was evaluated and anatomic parameters for neurectomy were identified. RESULTS: Endoscopic endonasal transmaxillary approaches completed bilaterally to the pterygopalatine and pterygomaxillary fossae exposed the V2 branch where it emerged from the foramen rotundum. The anatomy defined for the location of neurectomy was determined to be the point where V2 emerged from the foramen rotundum into the pterygopalatine fossa. The technique was then performed in 3 patients with intractable painful V2 neuropathy. CONCLUSIONS: In our cadaveric study and clinical cases, the endoscopic endonasal approach to the pterygopalatine fossa achieved effective exposure and treatment of isolated V2 painful neuropathy. Important surgical steps to visualize the maxillary nerve and its branches and key landmarks of the pterygopalatine fossa are discussed. This minimally invasive approach appears to be a valid alternative for select patients with painful V2 trigeminal neuropathy.

Incidence of epistaxis after endoscopic pituitary surgery: Proposed treatment algorithm.

Endoscopic transsphenoidal surgery for pituitary tumors is an increasingly common practice. Little has been reported on the incidence and treatment of postoperative epistaxis in this population. The aim of this study was to analyze the incidence of postoperative epistaxis and formulate a treatment algorithm based on our experience. We performed a case series with chart review. A total of 434 consecutive patients who had endoscopic transsphenoidal pituitary surgery were identified between April 2006 and November 2013. The incidence, clinical management, and outcomes were recorded. Based on the data, a treatment algorithm was constructed. Fifty-two percent of patients treated were female (mean age: 51.4 years). Tumor types included pituitary adenomas (73.3%), Rathke cleft cysts (19.6%), and other pathologies (6.7%). Eighteen patients reported an epistaxis event within 6 weeks of surgery (4.1%). Treatment included office cauterization in 7 (1.6%) patients, a return to the operating room for 5 (1.2%), nasal packing in 3 (0.7%), embolization in 2 (0.5%), and use of intranasal hemostatic agents in 1 (0.2%). Epistaxis after endoscopic pituitary surgery is concerning for rapid blood loss and risk of intracranial complications. Fortunately, in the absence of new cranial nerve palsy, most bleeding can be controlled with conservative measures such as topical cautery, hemostatic agents, and nasal packing. An algorithm is presented to help guide physician decision making in this clinical scenario.

Supraorbital vs Endo-Orbital Routes to the Lateral Skull Base: A Quantitative and Qualitative Anatomic Study.

BACKGROUND: Various extensions of the supraorbital approach reach the lateral and parasellar middle cranial fossa regions by removing the orbital rim and greater/lesser sphenoid wings. Recent proposals of a purely endoscopic ventral transorbital pathway to these regions heighten the need to compare these surgical windows. OBJECTIVE: To detail the lateral and parasellar middle cranial fossa regions and quantify exposures by 2 surgical windows (transcranial and transorbital) through anatomic study. METHODS: In 5 cadaveric specimens (10 sides), dissections consisted of 3 stages: stage 1 began with the supraorbital approach via the eyebrow; stage 2, endo-orbital approach via the superior eyelid, continued with removal of lesser and greater sphenoid wings; and stage 3, extended supraorbital, re-evaluated the gains of stage 2 from the perspective of stage 1. Operative working areas were quantified in Sylvian, anterolateral temporal, and parasellar regions; bone removal volumes were measured at each stage (nonpaired Student t-test). RESULTS: Visualization into the anterolateral temporal and Sylvian areas, though varied in perspective, were comparable with either eyelid or transcranial routes. Compared with transcranial views through a supraorbital window, the eyelid approach significantly increased exposure in the parasellar region with wider angle of attack (P < .01) and achieved comparable bone removal volumes. CONCLUSION: Stage 2's unique anatomic view of the lateral and parasellar middle cranial fossa regions paves the way for possible surgical application to select pathologies typically treated via transcranial approaches. Disadvantages may be the surgeon's unfamiliarity with the anatomy of this purely endoscopic, ventral route and difficulties of dural and orbital repair.

Endoscopic transorbital superior eyelid approach: anatomical study from a neurosurgical perspective.

OBJECTIVERecent studies have proposed the superior eyelid endoscopic transorbital approach as a new minimally invasive route to access orbital lesions, mostly in otolaryngology and maxillofacial surgeries. The authors undertook this anatomical study in order to contribute a neurosurgical perspective, exploring the anterior and middle cranial fossa areas through this purely endoscopic transorbital trajectory.METHODSAnatomical dissections were performed in 10 human cadaveric heads (20 sides) using 0° and 30° endoscopes. A step-by-step description of the superior eyelid transorbital endoscopic route and surgically oriented classification are provided.RESULTSThe authors' cadaveric prosection of this approach defined 3 modular routes that could be combined. Two corridors using bone removal lateral to the superior and inferior orbital fissures exposed the middle and anterior cranial fossa (lateral orbital corridors to the anterior and middle cranial base) to unveil the temporal pole region, lateral wall of the cavernous sinus, middle cranial fossa floor, and frontobasal area (i.e., orbital and recti gyri of the frontal lobe). Combined, these 2 corridors exposed the lateral aspect of the lesser sphenoid wing with the Sylvian region (combined lateral orbital corridor to the anterior and middle cranial fossa, with lesser sphenoid wing removal). The medial corridor, with extension of bone removal medially to the superior and inferior orbital fissure, afforded exposure of the opticocarotid area (medial orbital corridor to the opticocarotid area).CONCLUSIONSAlong with its minimally invasive nature, the superior eyelid transorbital approach allows good visualization and manipulation of anatomical structures mainly located in the anterior and middle cranial fossae (i.e., lateral to the superior and inferior orbital fissures). The visualization and management of the opticocarotid region medial to the superior orbital fissure are more complex. Further studies are needed to prove clinical applications of this relatively novel surgical pathway.

Paratrigeminal, Paraclival, Precavernous, or All of the Above? A Circumferential Anatomical Study of the C3-C4 Transitional Segment of the Internal Carotid Artery.

BACKGROUND: Although the term paraclival carotid pervades recent skull base literature, no clear consensus exists regarding boundaries or anatomical segments. OBJECTIVE: To reconcile various internal carotid artery (ICA) nomenclatures for transcranial and endoscopic-endonasal perspectives, we reexamined the transition between lacerum (C3) and cavernous (C4) segments using a C1-C7 segments schema. In this cadaveric study, we obtained a 360°-circumferential view integrating histological, microsurgical, endoscopic, and neuroradiological analyses of this C3-C4 region and identified a distinct transitional segment. METHODS: In 13 adult, silicone-injected, formalin-fixed cadaveric heads (26 sides), transcranial-extradural-subtemporal and endoscopic-endonasal CT-guided dissections were performed. A quadrilateral area was noted medial to Meckel's cave between cranial nerve VI, anterolateral and posterolateral borders of the lateral-paratrigeminal aspect of the precavernous ICA, and posterior longitudinal ligament. Endoscopically, a medial-paraclival aspect was defined. Anatomical correlations were made with histological and neuroradiological slides. RESULTS: We identified a distinct precavernous C3-C4 transitional segment. In 18 (69%) specimens, venous channels were absent at the quadrilateral area, on the paratrigeminal border of the precavernous ICA. A trigeminal membrane, seen consistently on the superior border of V2, defined the lateral aspect of the cavernous sinus floor. The medial aspect of the precavernous ICA corresponded with the paraclival ICA. CONCLUSION: Our study revealing the juncture of 2 complementary borders of the ICA, endoscopic endonasal (paraclival) and transcranial (paratrigeminal), reconciles various nomenclature. A precavernous segment may clarify controversies about the paraclival ICA and support the concept of a "safe door" for lesions involving Meckel's cave, cavernous sinus, and petrous apex.

Refining Operative Strategies for Optic Nerve Decompression: A Morphometric Analysis of Transcranial and Endoscopic Endonasal Techniques Using Clinical Parameters.

BACKGROUND: Various approaches can be considered for decompression of the intracanalicular optic nerve. Although clinical experience has been reported, no quantitative study has yet compared the extent of decompression achieved by an endoscopic endonasal versus transcranial approach. OBJECTIVE: Toward this aim, our morphometric analysis compared both approaches by quantifying the circumferential degree of optic canal decompression that is possible before any meningeal violation, which would result in cerebrospinal fluid (CSF) leak. METHODS: From 10 cadaver heads, 20 optic canals were sequentially decompressed using an endoscopic endonasal approach and pterional craniotomy with extradural clinoidectomy. Dissections ended before violation of the sphenoid sinus during the transcranial approach, and before intracranial transgression from the endonasal corridor. Based on our study criteria, decompressions were not maximal for either approach, but were maximal before violating the other compartment. Decompression achieved from each approach was quantified using CT scans for each stage. RESULTS: Greater circumferential bony optic canal decompression was obtained from transcranial (245.2°) than endonasal (114.8°) routes (P < .001). By endonasal perspective, the anatomical point where the optic nerve traverses intracranially was approximated by the medial border of the anterior ascending cavernous internal carotid artery. CONCLUSION: Our morphometric analysis comparing optic canal decompression for endonasal and transcranial corridors provides important guidance for this location. Ample visualization and wide exposure can be achieved via a transcranial approach with limited risk of CSF leak. A landmark, where the intracanalicular segment ends and optic nerve traverses intracranially, can mark the extent of decompression safely obtained before risking CSF leak.

Operative Learning Curve After Transition to Endoscopic Transsphenoidal Pituitary Surgery.

BACKGROUND: No clear consensus yet defines the endpoints for operative learning curves in the transition to minimally invasive endoscopic techniques. This retrospective review of our first 202 patients who underwent endoscopic pituitary resection examines the statistical learning curve related to operative times-a measure of our surgical team's efficiency and complication rate, a reflection of surgical skill and maturity. METHODS: Retrospective chart review included patient demographic data, tumor type, operative time, complications, and follow-up. During the 5-year study period, surgeries were performed by an otolaryngology-neurosurgery team. Statistical analysis by Pearson's correlation delineated a learning curve for operative time and complications. RESULTS: Our learning curve showed comparable plateaus: 120 cases (48% males, 52% females) for operative time (mean, 134 minutes; range, 62-307 minutes) and 100 cases for incidence of cerebrospinal fluid (CSF) leak. The risk of CSF leak declined significantly with the surgeon's increasing experience. Complication rates were as follows: temporary nasal obstruction, 9.9%; CSF leak, 8.4%; postoperative epistaxis, 7%; sinusitis, 4.5%; septal osteomyelitis, 2.4%; postoperative sellar hematoma, 1.5%; anosmia, 0.5%; and septal perforation, 0.5%. The overall CSF leak rate included 5.5% intraoperative and 2.9% postoperative; most cases resolved with a lumbar drain. Four patients (2%) underwent postoperative surgical repair and lumbar drainage. CONCLUSION: Our learning curve-defined endpoints for 2 measures, operative time and complication rates, support improved outcomes for reduced CSF leaks, the most common complication, with increasing operative experience. We will continue to examine the implications related to safety, efficacy, and the need for subspecialization in this minimally invasive surgery.

The Medial Extra-Sellar Corridor to the Cavernous Sinus: Anatomic Description and Clinical Correlation.

OBJECTIVE: The zenith of surgical interest in the cavernous sinus peaked in the 1980s, as evidenced by reports of 10 surgical triangles that could access the contents of the lateral sellar compartment (LSC). However, these transcranial approaches later became marginalized, first by radiosurgery's popularity and lower morbidity, and then by clinical potential of endoscopic corridors noted in several qualitative studies. Our anatomic study, taking a contemporary look at the medial extra-sellar corridor, gives a detailed qualitative-quantitative analysis for its use with increasingly popular endoscopic endonasal approaches to the cavernous sinus. METHODS: In 20 cadaveric specimens, we re-examined the anatomic landmarks of the medial corridor into the LSC with qualitative descriptions and measurements. An illustrative case highlights a recurrent symptomatic pituitary adenoma that invaded the cavernous sinus approached through the medial corridor. RESULTS: The corridor's shape varied from tetrahedron to hexahedron. Comparing right and left sides, width averaged 3.6 ± 4.5 mm and 4.0 ± 4.4 mm, and height averaged 2.3 mm and 2.1 mm, respectively. About 35% of sides showed ample space for access into the cavernous sinus. Our case report of successful outcome lends support for the safety and efficacy of this endoscopic approach. CONCLUSIONS: Our re-examination of this particular surgical access into the LSC refines the understanding of the medial extra-sellar corridor as a main endoscopic access route to this compartment. Achieving safe access to the contents of the LSC, this 11th triangle is clinically relevant and potentially superior for select lesions in this region.

Infundibular Hemangioblastoma in a Patient with Neurofibromatosis Type 1: Case Report and Review of the Literature.

BACKGROUND: Supratentorial hemangioblastomas are rare tumors, most commonly occurring in the sellar/suprasellar region, cerebrum, and ventricle. They are generally found in patients with von Hippel Lindau disease but have infrequently been reported in patients without this syndrome. CASE DESCRIPTION: A 35-year-old woman with a history of neurofibromatosis type 1 presented to our care with visual loss and headaches. Magnetic resonance imaging of the brain demonstrated an 8-mm cystic, contrast-enhancing lesion abutting the optic chiasm and optic tracts. The patient's endocrine profile was unremarkable. The tumor was resected using an endoscopic expanded transsphenoidal approach. Pathologic evaluation was consistent with hemangioblastoma. Postoperatively, the patient experienced an improvement in her visual symptoms. CONCLUSIONS: Hemangioblastoma should be included in the differential of sellar/suprasellar mass lesions, particularly in patients with von Hippel Lindau disease. Small suprasellar lesions may be safely and effectively removed using an expanded transsphenoidal approach.

Causes for 30-Day Readmission following Transsphenoidal Surgery.

OBJECTIVE: The Affordable Care Act Readmissions Reduction Program introduced reimbursement policy changes resulting in penalties for hospitals with higher-than-average readmission rates among several categories, including elective surgical cases. We examined the rate of complications resulting in 30-day readmission following endoscopic transsphenoidal surgery. STUDY DESIGN: Case series with chart review. SETTING: Academic tertiary care center. METHODS: A database of 466 consecutive patients who underwent endoscopic transsphenoidal surgery at a tertiary care center between April 2006 and July 2014 was reviewed for 30-day causes for readmission, length of stay, level of care required, and average cost. RESULTS: Twenty-nine readmissions were identified within our study period, indicating a 30-day readmission rate of 6.2%. Among all patients, rates of 30-day readmission were 2.1% for epistaxis, 1.5% for hyponatremia, 0.9% for cerebrospinal fluid leak, and 1.7% for other medical conditions. Average cost per readmission ranged from $6011 for hyponatremia to $24,613 for cerebrospinal fluid leak. CONCLUSION: Overall, the rate of 30-day readmission following endoscopic pituitary surgery is low. However, common causes of readmission do add significant cost to the overall care of this patient population. Special attention to surgical technique to prevent epistaxis and cerebrospinal fluid rhinorrhea, as well as multidisciplinary team management to avoid postoperative endocrine dysfunction, is critical to minimize these complications.

Medial and Superior Orbital Decompression: Improving Access for Endonasal Endoscopic Frontal Sinus Surgery.

OBJECTIVE: Visualization by Draf I-III endoscopic access to the frontal sinus via drainage pathways is sometimes inadequate. We compare lateral frontal sinus exposures by Draf approaches versus our modification of removing the medial-superior wall of the orbit while preserving the periorbita. METHODS: Twenty cadaveric heads dissected using Draf IIB, III, and modified Draf III with medial and superior orbital decompression (MSOD) underwent thin-cut computed tomography (CT) scanning. Under image guidance, measurements extended from the midline crista gali to the most lateral point of the frontal sinus. A case report shows the modified Draf III improved frontal sinus access. RESULTS: Comparing Draf IIB and III with Draf III with MSOD, respectively, distances between midline and most lateral point averaged 19.1 mm, 23.7 mm, and 30.4 mm (left) and 18.7 mm, 25.1 mm, and 32.2 mm (right). Differences between Draf III with/without MSOD were 6.65 mm (left) and 7.09 mm (right); 12 heads were excluded because of under-pneumatization of the sinuses. CONCLUSIONS: Draf III with MSOD extended surgical access to lateral regions of the frontal sinus. This extension achieved better visualization and instrumentation with minimal removal of the frontal bone's orbital segment anterior and superior to the anterior ethmoidal artery while preserving the periorbita.

Sellar Reconstruction and Rates of Delayed Cerebrospinal Fluid Leak after Endoscopic Pituitary Surgery.

Objectives Delayed cerebrospinal fluid (CSF) leaks are a complication in transsphenoidal surgery, potentially causing morbidity and longer hospital stays. Sella reconstruction can limit this complication, but is it necessary in all patients? Design Retrospective review. Setting Single-surgeon team (2005-2012) addresses this trend toward graded reconstruction. Participants A total of 264 consecutive patients with pituitary adenomas underwent endoscopic transsphenoidal resections. Sellar defects sizable to accommodate a fat graft were reconstructed. Main outcomes Delayed CSF leak and autograft harvesting. Results Overall, 235 (89%) had reconstruction with autograft (abdominal fat, septal bone/cartilage) and biological glue. Delayed CSF leak was 1.9%: 1.7%, and 3.4% for reconstructed and nonreconstructed sellar defects, respectively (p = 0.44). Complications included one reoperation for leak, two developed meningitis, and autograft harvesting resulted in abdominal hematoma in 0.9% and wound infection in 0.4%. Conclusion In our patients, delayed CSF leaks likely resulted from missed intraoperative CSF leaks or postoperative changes. Universal sellar reconstruction can preemptively treat missed leaks and provide a barrier for postoperative changes. When delayed CSF leaks occurred, sellar reconstruction often allowed for conservative treatment (i.e., lumbar drain) without repeat surgery. We found universal reconstruction provides a low risk of delayed CSF leak with minimal complications.

Comparing operative exposures of the le fort I osteotomy and the expanded endoscopic endonasal approach to the clivus.

Objectives We compare surgical exposures to the clivus by Le Fort I osteotomy (LFO) and the expanded endoscopic endonasal approach (EEEA). Methods Ten cadaveric specimens were imaged with 1.25-mm computed tomography. After stereotactic navigation, EEEA was performed followed by LFO. Clival measurements included lateral and vertical limits to the midline lower extent of exposure (t test). Results For EEFA and LFO, respectively, maximal lateral exposure in millimeters (mean ± standard deviation) was 24.5 ± 3.7 and 24.5 ± - 3.8 (p = 0.99) at the opticocarotid recess (OCR) and 25.1 ± - 4.1 and 24.1 ± - 3.0 (p = 0.53) at the foramen lacerum level; lateral reach at the hypoglossal canals was 39.0 ± - 5.88 and 56.1 ± - 5.3 (p = 0.0004); and vertical extension was 56.0 ± - 4.1 and 56.3 ± - 3.4 (p = 0.78). Conclusions For clival exposures, LFO and EEEA were similar craniocaudally and laterally at the levels of the OCR and foramen lacerum. LFO achieved greater exposure at the level of the hypoglossal canal.

Complex anatomy of the sphenoid sinus: a radiographic study and literature review.

Objectives Nasal endoscopic approaches to the sphenoid sinus are challenging. Variations in septation, shape, and dimensions have a critical impact on surgical planning of the skull base. Previous anatomical studies have small numbers or a limited description of this complex structure. The present study is a radiographic analysis of the septation and dimensions of the sphenoid sinus. Design and Methods High-resolution surgical-guidance computed tomography images of the sinuses from 90 patients at a tertiary care medical center between 2002 and 2007 were studied. Multiple anatomical measurements from axial and sagittal images were obtained and analyzed with imaging and statistical software. Results Of the 90 patients studied, 9% had presellar, 37% sellar, and 54% postsellar pneumatization. In 34%, the posterior extent of the intersinus septum involved the bony covering of the carotid artery. The average presellar width of the sinus was 1.3 cm, the average midline presellar depth was 1.4 cm, and the average infrasellar midline depth was 2.6 cm. Conclusions Approaching the skull base through the sphenoid sinus requires a tailored process based on anatomy. Septal involvement of the carotid artery occurs frequently. Pneumatization patterns are potentially disorienting, and awareness of the sinus's posterior and lateral extensions is critical.

Segments of the internal carotid artery during endoscopic transnasal and open cranial approaches: can a uniform nomenclature apply to both?

BACKGROUND: The classic anatomic view of the course of the internal carotid artery (ICA) and its segments familiar to neurosurgeons by a 3-dimensional microscopic cranial view may be challenging to understand when seen in the unique 2-dimensional view of transnasal endoscopic surgery. OBJECTIVE: We re-examined our 1996 classification of 7 (C1-C7) segments of the ICA, comparing the arterial course in cadaveric dissections for both a transnasal endoscopic transpenoidal approach and frontotemporal craniotomy. METHODS: Five formalin-fixed cadaveric heads injected with colored silicone underwent thin-cut computed tomographic scanning for bony and vascular analysis. The ICA's intracranial course viewed by transnasal endoscopic dissection was compared with the view of a bilateral frontotemporal crantiotomy, from the petrous (C2) to communicating (C7) segments. RESULTS: Refinement of our 1996 ICA classification provides an anatomical understanding for endoscopic exposures transnasally along an inferior skull base trajectory. The changing course of the ICA, initially termed loop is now termed bend (i.e., implying a change in direction). Four bends are described as the ICA enters into the skull base as C2, C3-C4, C4, and C4-C5. We discuss delineation of certain problematic ICA segments and identify landmarks for endoscopic endonasal approaches. CONCLUSIONS: Our classification of the segments of the ICA achieves consistency without sacrificing either clinical or anatomic accuracy for either transcranial or endoscopic approaches. Universal application of this established nomenclature can avoid new and misleading terms, respects anatomical landmarks delineating segments, and provides a universal language for clear communication between disciplines.

Endoscopic, endonasal variability in the anatomy of the internal carotid artery.

BACKGROUND: Classic three-dimensional schemas of the internal carotid artery (ICA) for transcranial approaches do not necessarily apply to two-dimensional endoscopic views. Modifying an existing ICA segment classification, we define endoscopic orientation for the lacerum (C3) to clinoid (C5) segments through an endonasal approach. METHODS: In 20 cadaveric heads, we classified endoscopic appearance based on shape and angulation of C3 to C5 segments. Distances were measured between both arteries, and between the ICA and pituitary gland. RESULTS: We identified 4 common ICA patterns: types I through III matched side-to-side, whereas type IV was asymmetric. In 80% of specimens, the pituitary gland had direct contact with the ICA. In 20% of specimens, a space existed between the pituitary gland and the cavernous segment. Access to the posterior aspect of the cavernous sinus medial to the cavernous segment was possible without retraction of the artery or pituitary gland. Spaces between the lacerum and cavernous segments were trapezoid (80%) and hourglass (20%). CONCLUSIONS: Distinguishing which ICA type courses between the lacerum and clinoid segments can help clarify the relationships between the artery and its surrounding structures during endoscopic approaches. Adapting the classic terminology of ICA segments provided consistency of endoscopic relevance, defined potential endoscopic corridors, and highlighted the critical step of arterial contact.

Short-Term Quality-of-Life Changes after Endoscopic Pituitary Surgery Rated with SNOT-22.

Objective Little data exist on short-term quality-of-life (QOL) outcomes, specifically sinonasal measures, after endoscopic pituitary surgery. Design Prospective case series assessed sinonasal QOL before and after the transnasal endoscopic approach to the sella with resection of nasal cavity and sinus tissues. Setting/Participants/Main Outcome Measures A total of 39 adults scheduled to undergo resection for a pituitary mass preoperatively completed the Sinonasal Outcome Test-22 (SNOT-22). Rating various QOL issues, testing repeated postoperatively at 1 month by 37 patients and 3 months by 35 patients, was analyzed (paired Student t test). Results SNOT-22 scores (5-point scale; total: 110) averaged 23.4 preoperatively and 27.6 at 1 month but had significantly improved to 16.2 at 3 months (p = 0.03). Emotional well-being parameters (e.g., sadness, frustration, concentration, productivity, fatigue) significantly improved 3 months postoperatively (p < 0.05). Physiologic parameters (e.g., olfaction, obstruction, postnasal drainage) that had worsened at 1 month (< 0.05) then normalized at 3 months. Conclusion Total ratings for sinonasal QOL shows that SNOT scores were comparable between preoperative and 1-month testing but were improved significantly at 3 months. Individual questions showed marked improvement in emotional well-being and temporary physiologic changes after surgery. Our findings give surgeons information about what patients can expect immediately after transnasal endoscopic pituitary surgery.