Nasrin Fatemi

Endonasal versus supraorbital keyhole removal of craniopharyngiomas and tuberculum sellae meningiomas.

OBJECTIVE Endonasal and supraorbital “eyebrow” craniotomies are increasingly being used to remove craniopharyngiomas and tuberculum sellae meningiomas. Herein, we assess the relative advantages, disadvantages, and selection criteria of these 2 keyhole approaches. METHODS All consecutive patients who had endonasal or supraorbital removal of a craniopharyngioma or tuberculum sellae meningioma were analyzed. RESULTS Of 43 patients, 22 had a craniopharyngioma (18 endonasal, 4 supraorbital), and 21 had a meningioma (12 endonasal, 7 supraorbital, 2 both routes); 33% had prior surgery. Craniopharyngiomas were primarily retrochiasmal in location in 78% of endonasal cases versus 25% of supraorbital cases (P = 0.08). Meningiomas were larger when approached by the supraorbital route versus the endonasal route (33 ± 10 versus 25 ± 8 mm, respectively; P = 0.008). Endoscopy was used in 84% of endonasal approaches and in 31% of supraorbital approaches (P = 0.001). Of patients having first-time surgery for a craniopharyngioma (n = 14) or meningioma (n = 15), total/near total removal was achieved in 83% and 80% of patients by the endonasal route and in 50% and 80% of patients by the supraorbital route, respectively. Vision improved in 87% and 70% of patients who had surgery by an endonasal versus supraorbital route, respectively (P = 0.3). Visual deterioration occurred in 2 patients with meningiomas, 1 by endonasal (7%), and 1 by supraorbital (11%) removal. The endonasal approach was associated with a higher rate of postoperative cerebrospinal fluid leaks (16 versus 0%; P = 0.3), 4 of 5 of which occurred in patients with meningioma. CONCLUSION The endonasal route is preferred for removal of most retrochiasmal craniopharyngiomas, whereas the supraorbital route is recommended for meningiomas larger than 30 to 35 mm or with growth beyond the supraclinoid carotid arteries. For smaller midline tumors, either approach can be used, depending on surgeon experience and tumor anatomy. Compared with traditional craniotomies, the major limitation of both approaches is a narrow surgical corridor. The endonasal approach has the added challenges of restricted lateral suprasellar access, a greater need for endoscopy, and a more demanding cranial base repair.

PITUITARY HORMONAL LOSS AND RECOVERY AFTER TRANSSPHENOIDAL ADENOMA REMOVAL

OBJECTIVETranssphenoidal adenomectomy carries the possibility of new pituitary failure and recovery. Herein, we present rates and determinants of postoperative hormonal status. METHODSAll consecutive patients who underwent endonasal transsphenoidal adenoma removal over an 8-year period were analyzed. Those with previous sellar radiotherapy were excluded. Pre- and postoperative hormonal status (at least 3 mo after surgery) were determined and correlated with clinical parameters using a multivariate statistical model. RESULTSOf 444 patients (median age 45 years, 75% macroadenoma, 19% with multiple operations), 9 had preoperative panhypopituitarism. Of the remaining 435 patients, new hypopituitarism occurred in 5.5% of patients (anterior loss in 5%; permanent diabetes insipidus in 2.1%; including 2 patients who had total hypophysectomy). Of 346 patients with preoperative hormonal dysfunction, 170 (49%) had improved function. “Stalk compression” hyperprolactinemia resolved in 73% of 133 patients; recovery of at least 1 other anterior axis (excluding isolated hypogonadism associated with “stalk compression” hyperprolactinemia) occurred in 24% of 209 patients. Multivariate analysis showed that new hypopituitarism was most strongly associated with larger tumor diameter (P = 0.04). Of 223 patients with an endocrine-inactive adenoma, new hypopituitarism was seen in 0, 7.2, and 13.6% of patients with tumor diameters of <20, 20 to 29, and ≥30 mm, respectively (P = 0.005). Multivariate analysis revealed that resolution of hypopituitarism was related to younger age (39 versus 52 years, P < 0.0001), absence of an intraoperative cerebrospinal fluid leak and, in patients with an endocrine-inactive adenoma, absence of systemic hypertension (24% versus 6%, P = 0.009). CONCLUSIONAfter transsphenoidal adenomectomy, new unplanned hypopituitarism occurs in approximately 5% of patients, whereas improved hormonal function occurs in 50% of patients. The likelihood of new hormonal loss or recovery appears to depend on several factors. New hypopituitarism occurs most commonly in patients with tumors larger than 20 mm in size, whereas hormonal recovery is most likely to occur in younger, nonhypertensive patients and those without an intraoperative cerebrospinal fluid leak.

Endonasal transsphenoidal surgery and multimodality treatment for giant pituitary adenomas

Objective  Giant pituitary adenomas (≥40 mm) pose a major management challenge. We describe the experience of a single surgeon and a dedicated neuro‐endocrine team with multimodality treatment of these tumours in three specialized institutions.

Endonasal microscopic removal of clival chordomas

INTRODUCTION Clival chordomas have traditionally been removed using a variety of anterior and lateral skull base approaches. Herein, we evaluate the outcomes of patients who underwent an extended endonasal transsphenoidal removal of a clival chordoma. METHOD All consecutive patients with a clival chordoma treated using an endonasal microscope approach were identified. In 8 cases, frameless surgical navigation was used, and in 4 cases, endoscopic assistance was used. Patients treated with prior radiotherapy were excluded. RESULT Over 5 years, 18 procedures were performed on 14 patients (7 females; mean age, 47 years). Patients were followed from 3 to 58 months (median, 20 months). Mean tumor diameter was 32 +/- 17 mm; 7 (50%) patients had intradural extension. Postoperative MRIs after the initial operation showed gross total, near-total (>90%), and subtotal resection in 43%, 43%, and 14% of patients, respectively. Use of the endoscope was associated with gross total or near-total tumor removal in 4 of 4 cases. Tumor regrowth occurred in 2 (14%) cases 10 and 12 months after the initial surgery and before radiotherapy. Two patients had multiple operations, in one as a planned staged operation, and in the other, 3 additional debulkings were performed despite an initial gross total removal. Nine patients, all with CS invasion, had subsequent stereotactic radiation. Of 10 patients with cranial neuropathy, 80% improved or resolved including 75% and 67% of sixth and fifth CN palsies, respectively. Complications included one each of adrenal insufficiency and chemical meningitis. There were no CSF leaks or new neurological deficits. CONCLUSION In this small series with relatively short follow-up, endonasal microscopic removal of clival chordomas proved safe and elfective with gross total or near-total removal in 86% of patients and improvement of cranial neuropathy in 80% of patients. Endoscopy for aiding tumor removal and assessing completeness of resection, as well as surgical navigation, are recommended for all cases.

Pituitary function after endonasal surgery for nonadenomatous parasellar tumors: Rathke's cleft cysts, craniopharyngiomas, and meningiomas

BACKGROUND Transsphenoidal surgery for parasellar nonadenomatous lesions has the possibility to either improve or worsen pituitary hormonal function. Herein we present the rates and risk factors of new hormonal failure and recovery in patients undergoing surgery for either an RCC, craniopharyngioma, or tuberculum sella meningioma. METHODS All consecutive patients treated over an 8-year period by endonasal surgery for an RCC, craniopharyngioma, or tuberculum sella meningioma were analyzed. Patients treated with prior sellar radiotherapy were excluded. Preoperative and postoperative pituitary hormonal status was determined. Patient characteristics, tumor size, intraoperative and postoperative events, and extent of tumor resection were correlated with new or resolved hypopituitarism. RESULTS In total, 50 patients with an RCC, 18 with a craniopharyngioma and 13 with tuberculum sellae meningioma, were analyzed. New anterior pituitary failure and permanent DI occurred as follows: in RCCs, 6% and 2%; in craniopharyngiomas, 31% and 39%; and in meningiomas, 9% and 0%. Overall, improved hormonal function occurred in 57% of patients with an RCC including recovery of one or more anterior axes in 9 (41%) of 22 patients and resolution of hyperprolactinemia in 12 (67%) of 18 patients; no patients with a craniopharyngioma or meningioma had resolution of hypopituitarism. Younger age was predictive of hormonal recovery in patients with an RCC (P = .026). CONCLUSIONS New hypopituitarism after transsphenoidal surgery occurs in approximately one third of patients with a craniopharyngioma and in less than 10% of patients with an RCC or suprasellar meningioma. Hormonal function improves in the majority of patients undergoing drainage of an RCC but is unlikely to occur after removal of a craniopharyngioma or suprasellar meningioma.

A Short Trapezoidal Speculum for Suprasellar and Infrasellar Exposure in Endonasal Transsphenoidal Surgery

OBJECTIVE A key limitation of the transsphenoidal approach for suprasellar and infrasellar lesions is restricted exposure. Microscope and endoscope-assisted procedures have traditionally used an oval-shaped speculum, the distal end of which restricts superior and inferior visualization. To improve visualization and use of the endoscope, shorter specula, with a trapezoidal distal end, were designed. METHODS The new specula have a working length of 60 mm. The proximal 20-mm segment is oval-shaped to conform to the nostril; the middle 20-mm segment has vertically oriented blades; and the distal 20-mm segment transitions to a trapezoidal orientation, with the distal blades angled 15 degrees upward and outward on the suprasellar speculum, or 15 degrees downward and outward on the infrasellar speculum. Both specula have a 5-degree distal outward flare. The upward-angled trapezoidal 60-mm speculum was compared with 70- and 80-mm oval specula in a transsphenoidal clay model. A pen light was projected from the nasal speculum end to a target 100 mm away using a blade opening width of 16 mm. Line drawings were made to quantify the impact of speculum length on the horizontal angle of exposure. The clinical utility of the trapezoidal specula was also assessed. RESULTS In the model, the 60-mm upward-angled trapezoidal speculum yielded a surface area illumination of 759 mm2, as compared with 579 and 432 mm2 with the 70-and 80-mm oval specula, an increase in exposure of 31 and 76%, respectively. In the line drawings, the 60-mm speculum provided a horizontal angle of exposure of 30 degrees, as compared with 26 and 23 degrees for the 70- and 80-mm specula, an increase of 17 and 33%, respectively. In patients, provided sufficient mucosa and bone are removed from the posterior nasal cavity, the trapezoidal specula provide an expanded working volume that facilitates endoscopy. CONCLUSION Short upward- or downward-angled trapezoidal endonasal specula increase parasellar surface area exposure and the horizontal angle of exposure. Initial clinical experience suggests that reducing the speculum length and eliminating the distal curved blades result in greater instrument maneuverability and enhanced visibility for removing parasellar tumors.

Endoscope-Assisted Skull Base Surgery

The direct endonasal transsphenoidal approach to the sella with the operating microscope was first described over 20 years ago. Over the last decade, this minimally invasive technique has evolved into an effective skull base approach for pituitary adenomas and many other parasellar tumors. This expansion of the endonasal technique has resulted largely from development of refined instrumentation and greater use of endoscopy. By taking advantage of the expanded panoramic vision provided by the endoscope, one can visualize areas of the skull base not possible with the operating microscope. Our use of endoscopy has increased over time, particularly for extended endonasal transsphenoidal cases. In a total of 900 endonasal microscopic approaches performed since 1998, endoscopic assistance was utilized in 20% of all cases and in 66% of the last 100 cases. In 129 extended endonasal procedures for parasellar pathology, endoscopy was used in 63% of cases overall and in 84% of the last 25 cases. In 109 extended procedures for tumor removal in 97 patients (including 22 pituitary adenomas, 18 meningiomas, 17 craniopharyngiomas, 14 clival chordomas, and 26 other lesions), endoscopic assistance was used in 64% of these procedures. Total or near-total (>90%) tumor removal was achieved in 70% of patients operated with endoscopic assistance compared to only 41% of those operated without endoscopic assistance (p = 0.003); other factors including prior surgery, prior radiotherapy and cavernous sinus invasion were also strongly associated with subtotal tumor removal (p

Craniopharyngioma: Comparison Between Supra-orbital Versus Endonasal Keyhole Approaches

Craniopharyngiomas represent one of the most challenging brain tumors to treat. In recent years, minimally invasive keyhole approaches have been increasingly used to remove these sellar, suprasellar and parasellar lesions. Of these approaches, the two most commonly used are the extended endonasal transsphenoidal route and the supraorbital eyebrow craniotomy. Although both approaches may be appropriate for a given patient, in many cases one route offers a better opportunity for safe and maximal tumor removal. Based on our combined experience using the endonasal and supra-orbital approaches for craniopharyngiomas, the endonasal route is preferred for removal of most retrochiasmal craniopharyngiomas and those lesions that are predominantly sellar in location. In contrast, those tumors that are predominantly prechiasmal or with prominent lateral extensions (a minority of craniopharyngiomas), the supra-orbital route is recommended. In some complex tumors with both prechiasmal and retrochiasmal extensions, either route may be appropriate. An additional key factor is surgeon experience with these keyhole approaches and conventional approaches. Compared to conventional larger craniotomies, the major limitation of both the endonasal and supraorbital approaches is a narrow surgical corridor. The endonasal approach has the added challenges of restricted lateral access, a greater need for endoscopy as well as a more demanding skull base repair. Herein, we review in this chapter the use of the supraorbital and endonasal approaches and summarize tumor and patient characteristics that help determine the optimal surgical route.