Neurosurgery Blog

Neurosurgery 72:240–247, 2013

The efficacy of endoscopic transsphenoidal surgery (ETS) for Cushing disease has not been clearly established.

OBJECTIVE: To assess efficacy of a pure endoscopic approach for treatment of Cushing disease and determine predictors of remission.

METHODS: A prospectively acquired database of 61 patients undergoing ETS was reviewed. Remission was defined as postoperative morning serum cortisol of ,5 mg/dL or normal or decreased 24-hour urine-free cortisol level in follow-up.

RESULTS: Overall, hypercortisolemia resolved in 58 of 61 patients (95%) by discharge. Tumor size did not predict resolution of hypercortisolemia at discharge (microadenomas [97%], magnetic resonance imaging-negative Cushing [100%], macroadenomas [87%]). At 2- to 3-month evaluations, 45 of 49 patients (91.8%) were in remission. Fifty patients were followed for at least 12 months (mean, 28 months; range, 12-72). Forty-two (84%) achieved remission from a single ETS. In these patients, there was no significant difference in remission rates between microadenomas (93%), magnetic resonance imaging-negative (70%), and macroadenomas (77%). Patients with history of previous surgery (n = 14, 23%) were 9 times less likely to achieve follow-up remission (P = .021). In-house cortisol level of ,5.7 mg/dL provided the best prediction of follow-up remission (sensitivity 88.6%, specificity 83.3%). Postoperative diabetes insipidus occurred transiently in 7 patients (9%) and permanently in 3 (5%). One patient experienced postoperative cerebrospinal fluid leak that resolved with further surgery.

CONCLUSION: ETS for Cushing disease provides high rates of remission with low rates of complications regardless of size. Although patients with a history of previous surgery are less likely to achieve remission, the majority can still achieve remission following treatment.

KEYWORDS:

Acta Neurochir (2013) 155:125–130

Transphenoidal surgery is an effective treatment for acromegalic patients with growth hormone (GH) producing pituitary adenomas. Since acromegaly is a systemic disease which causes multiple bony alterations, we hypothesized that it could affect the sphenoid sinus anatomy. The aim of the study was to determine whether acromegalic patients have sphenoid sinus alterations with potential surgical impact.

Methods Fourty-six consecutive patients (23 acromegalics- GH group, 23 non-acromegalics-nGH group) undergoing transphenoidal surgery were included in this study. Preoperative volumetric CT scan of the head was used to assess the following anatomic characteristics: type of sphenoid sinus (sellar, pre-sellar, conchal); number of intrasphenoid septa; number of carotid-directed septa; intercarotid distance; depth of the sphenoid sinus; depth and size of the sella.

Results The sphenoid sinus was of the pre-sellar/conchal type in 26 % of the patients with acromegaly (n023) versus 9 % of the patients of the nGH group (n023). The number of intrasphenoid septations was significantly higher in the GH group than in the nGH group (P=.03). Interestingly, the intercarotid distance was smaller in GH patients than in nGH displaying a trend toward significance (P=.05). The sphenoid bone was deeper in the GH group as compared to the nGH group (P=.01) but the distance sphenoid sinus-sella was reduced (P<.01). Finally, the sella was not deeper, nor larger in acromegalic patients.

Conclusions The sphenoid sinus of acromegalic patients resulted in being deeper, characterized by more septa and by a reduced intercarotid distance. These alterations deserve special pre- and intraoperative care, being potentially responsible for surgical difficulties.

J Neurosurg / January 4, 2013. DOI: 10.3171/2012.11.JNS121190

Giant pituitary adenomas (> 4 cm in maximum diameter) represent a significant surgical challenge. Endoscopic endonasal surgery (EES) has recently been introduced as a treatment option for these tumors. The authors present the results of EES for giant adenomas and analyze the advantages and limitations of this technique.

Methods. The authors retrospectively reviewed the medical files and imaging studies of 54 patients with giant pituitary adenomas who underwent EES and studied the factors affecting surgical outcome.

Results. Preoperative visual impairment was present in 45 patients (83%) and partial or complete pituitary deficiency in 28 cases (52%), and 7 patients (13%) presented with apoplexy. Near-total resection (> 90%) was achieved in 36 patients (66.7%). Vision was improved or normalized in 36 cases (80%) and worsened in 2 cases due to apoplexy of residual tumor. Significant factors that limited the degree of resection were a multilobular configuration of the adenoma (p = 0.002) and extension to the middle fossa (p = 0.045). Cavernous sinus invasion, tumor size, and intraventricular or posterior fossa extension did not influence the surgical outcome. Complications included apoplexy of residual adenoma (3.7%), permanent diabetes insipidus (9.6%), new pituitary insufficiency (16.7%), and CSF leak (16.7%, which was reduced to 7.4% in recent years). Fourteen patients underwent radiation therapy after EES for residual mass or, in a later stage, for recurrence, and 10 with functional pituitary adenomas received medical treatment. During a mean follow-up of 37.9 months (range 1–114 months), 7 patients were reoperated on for tumor recurrence. Three patients were lost to follow-up.

Conclusions. Endoscopic endonasal surgery provides effective initial management of giant pituitary adenomas with favorable results compared with traditional microscopic transsphenoidal and transcranial approaches.

Neurosurgery 71:916–926, 2012

Pituitary tumors and associated neuroendocrine disorders pose significant challenges in diagnostic and therapeutic management. Optimal care of the “pituitary patient” is best provided in a multidisciplinary collaborative environment that includes not only experienced pituitary practitioners in neurosurgery and endocrinology, but also in otorhinolaryngological surgery, radiation oncology, medical oncology, neuro-ophthalmology, diagnostic and interventional neuroradiology, and neuropathology.

We provide the background and rationale for recognizing pituitary centers of excellence and suggest a voluntary verification process, similar to that used by the American College of Surgeons for Trauma Center verification. We propose that pituitary centers of excellence should fulfill 3 key missions: (1) provide comprehensive care and support to patients with pituitary disorders; (2) provide residency training, fellowship training, and/or continuing medical education in the management of pituitary and neuroendocrine disease; and (3) contribute to research in pituitary disorders.

As this is a preliminary proposal, we recognize several issues that warrant further consideration including center and surgeon practice volume as well as oversight of the verification process.

Neurosurg Focus 32 (6):E5, 2012

Lateral sphenoid encephaloceles of the Sternberg canal are rare entities and usually present with spontaneous CSF rhinorrhea. Traditionally, these were treated via transcranial approaches, which can be challenging given the deep location of these lesions.

However, with advancements in endoscopic skull base surgery, including improved surgical exposures, angled endoscopes and instruments, and novel repair techniques, these encephaloceles can be resected and successfully repaired with purely endoscopic endonasal approaches. In this report, the authors review the endoscopic endonasal transpterygoid approach to the lateral recess of the sphenoid sinus for repair of temporal lobe encephaloceles, including an overview of the surgical anatomy from an endoscopic perspective, and describe the technical operative nuances and surgical pearls for these cases.

The authors also present 4 new cases of lateral sphenoid recess encephaloceles that were successfully treated using this approach.

J Neurosurg 116:272–279, 2012. DOI: 10.3171/2011.8.JNS11456

Dural invasion by adrenocorticotropic hormone (ACTH)-secreting adenomas is a significant risk factor for incomplete resection and recurrence in Cushing disease (CD). Since ACTH-producing adenomas are often the smallest of the various types of pituitary tumors at the time of resection, examining their invasion provides the best opportunity to identify the precise sites of early dural invasion by pituitary adenomas. To characterize the incidence and anatomical distribution of dural invasion by ACTH-secreting adenomas, the authors prospectively and systematically analyzed features of dural invasion in patients with CD.

Methods. The authors prospectively studied consecutive patients with CD undergoing the systematic removal of ACTH-secreting adenoma and histological analysis of the anterior sella dura as well as other sites of dural invasion that were evident at surgery. Clinical, imaging, histological, and operative findings were analyzed.

Results. Eighty-seven patients with CD (58 females and 29 males) were included in the study. Overall, dural invasion by an ACTH-positive adenoma was histologically confirmed in 30 patients (34%). Eighteen patients (60% of dural invasion cases, 21% of all patients) had evidence of cavernous sinus wall invasion (4 of these patients also had other contiguous sites of invasion), and 12 patients (40% of dural invasion cases) had invasion of the sella dura excluding the cavernous sinus wall. Eleven patients (13% all patients) had invasion of the routinely procured anterior sella dura specimen. Preoperative MR imaging revealed an adenoma in 64 patients (74%) but accurately predicted dural invasion in only 4 patients (22%) with cavernous sinus invasion and none of the patients with non–cavernous sinus invasion. Adenomas associated with dural invasion (mean ± SD, 10.9 ± 7.8 mm, range 2–37 mm) were significantly larger than those not associated with dural invasion (5.7 ± 2.1 mm, range 2.5–12 mm; p = 0.0006, Mann- Whitney test).

Conclusions. Dural invasion by ACTH-producing adenomas preferentially occurs laterally into the wall of the cavernous sinus. Preoperative MR imaging infrequently detects dural invasion, including cavernous sinus invasion. Invasion is directly associated with tumor size. To provide a biochemical cure and avoid recurrence after resection, identification and removal of invaded sella dura, including the medial cavernous sinus wall, are necessary.

J Neurosurg 116:373–384, 2012. DOI: 10.3171/2011.6.JNS081451

The authors report surgical and endocrinological results of a series of 73 cases of craniopharyngioma that they treated surgically since 1997 to demonstrate their change in treatment strategy and its effect on outcome compared with a previous series and results reported in the literature.

Methods. A total of 73 patients underwent surgery for craniopharyngiomas between May 1997 and January 2005. In patients with poor clinical or neuropsychological condition, even following pretreatment, only stereotactic cyst aspiration took place (8 cases). In the remaining patients, gross-total resection (GTR) was intended and appeared to be possible. The most frequent approaches were subfrontal (27 cases) and transsphenoidal (26 cases); in some cases, a multistep approach was used. The rate of GTR, complications, and functional outcome (comparing pre- and postoperative endocrine and neuropsychological testing) were evaluated. The mean duration of follow-up was 25.2 months.

Results. Gross-total resection was achieved in 88.5% of cases in which a transsphenoidal approach was used and 79.5% of those in which a transcranial approach was used (85.2% of those in which a subfrontal approach was used and 72.7% of those in which a frontolateral approach was used). In the total series, GTR was achieved in 83.1% of cases (vs 49.3% in the authors’ former series). The complication rate was 13.8% without any mortality. New endocrine deficits were observed more frequently in patients treated with transcranial approaches over the years (16.3%– 66.7% vs 2.6%–50.0%) but were less frequent after transsphenoidal approaches (5.2%–19.2% vs 2.9%–45.7%).

Conclusions. Open surgery with intended total resection remains the treatment of choice in most patients. Initial stereotactic cyst aspiration or medical pretreatment to improve the patients’ condition and adequate choice of surgical approach(es) are essential to achieve that goal. Nevertheless, a moderate increase in endocrinological deficits has to be accepted. The authors recommend using radiotherapy only in cases in which there are tumor remnants or disease progression after surgery.

Neurosurgery 70:70–81, 2012 DOI: 10.1227/NEU.0b013e31822dda2c

This is a retrospective study of 136 patients with Cushing disease treated with transsphenoidal microsurgery.

OBJECTIVE: To evaluate factors influencing immediate postoperative results and longterm outcomes.

METHODS: Data regarding clinical presentation, endocrine evaluation, imaging studies, surgical technique, immediate postoperative biochemical remission (IPBR), and longterm results were entered into a database and analyzed statistically. IPBR was based on biochemical evidence of adrenal cortical insufficiency and clinical evidence of such insufficiency.

RESULTS: IPBR for the entire series was 83.4%. In microadenomas, IPBR was 89.8% with a mean immediate postoperative plasma cortisol (IPPC) of 2.1 mg/dL (range, ,0.5-5.3). Positive magnetic resonance imaging (MRI) was associated with 18 times greater odds of finding microadenoma at surgery (P < .001) and with 4.1 times greater odds of IPBR (P = .07). In patients with a negative MRI, a positive inferior petrosal sinus sampling (IPSS) test was associated with 93% of IPBR (P = .004). IPBR in macroadenomas was 30.7%. Of patients followed for 12 months or longer, 34.8% required glucocorticoid replacement for the duration of follow-up. The mean follow-up in microadenomas was 68.4 months with a 9.67% incidence of recurrences. The estimated actuarial incidence of recurrences increased with the passage of time and IPPC of greater than 2 mg/dL was associated with higher incidence of recurrences, although without statistical significance (P = .08).

CONCLUSION: In microadenomas, a positive MRI and positive IPSS test were associated with a higher incidence of IPBR. Recurrences increased with the passage of time, and an IPPC of greater than 2 mg/dL may be associated with higher incidence of recurrences.

Neurosurgery 70:110–124, 2012 DOI: 10.1227/NEU.0b013e31822e8ffc

The endoscopic, endonasal, extended transsphenoidal approach is a minimal-access technique for managing craniopharyngiomas. Outcome measures such as return to employment and body mass index (BMI) have not been reported and are necessary for comparison with open transcranial approaches. Most prior reports of the endoscopic, endonasal approach have reported unacceptably high cerebrospinal fluid (CSF) leak rates.

OBJECTIVE: To assess the outcome of endoscopic, endonasal surgery in a consecutive series of craniopharyngiomas with special attention to extent of resection, CSF leak, return to employment, and BMI.

METHODS: Twenty-six surgeries were performed on 24 patients at Weill Cornell Medical College-New York Presbyterian Hospital. Five patients had recurrent lesions. Gross-total resection (GTR) was attempted in 21 surgeries. Indications for intended subtotal resection were advanced age, medical comorbidities, preservation of pituitary function, and hypothalamic invasion.

RESULTS: Mean tumor diameter was 2.9 cm. GTR (18 surgeries) or near-total (.95%) resection (2 surgeries) was achieved in 95% when GTR was the goal. Seven patients received postoperative radiation therapy. Mean follow-up was 35 months with no recurrences in GTR cases and stable disease in all patients at last follow-up. Vision improved in 77%. Diabetes insipidus and panhypopituitarism developed in 42% and 38%, respectively. A more than 9% increase in BMI occurred in 39%; 69% returned to their preoperative profession/schooling. The postoperative CSF leak rate was 3.8%.

CONCLUSION: Minimal-access, endoscopic, endonasal surgery for craniopharyngioma can achieve high rates of GTR with low rates of CSF leak. Return to employment and obesity rates are comparable to microscope-assisted transcranial and transsphenoidal reports.

Neurosurgery 69:1058–1069, 2011 DOI: 10.1227/NEU.0b013e318228bcea

Rathke cleft cysts (RCCs), benign remnants of the Rathke pouch typically arising in the sella, sometimes have suprasellar extension. Purely suprasellar RCCs are rarely reported.

OBJECTIVE: To compare the presentations, surgical outcomes, and pathology of purely suprasellar RCCs and sellar-based RCCs.

METHODS: We retrospectively reviewed records, magnetic resonance images, laboratory results, and pathology of 151 RCC patients surgically managed at our institution from 1989 to 2009. The RCCs were classified as purely sellar (type I, n = 76), sellar with suprasellar extension (type II, n = 56), or purely suprasellar (type III, n = 19).

RESULTS: The RCCs with a suprasellar component (types II and III) more commonly presented with visual dysfunction (P < .001). Complete cyst drainage occurred in 89%, 55%, and 38% of type I, II, and III RCCs, respectively (P < .001). Vision improved in 100%, 55%, and 33% and headache improved in 74%, 64%, and 29% of type I, II, and III patients, respectively (P = .02). Temporary or permanent postoperative diabetes insipidus occurred in 5%, 16%, and 21% of type I, II, and III patients, respectively. (P < .001). In a multivariate analysis, RCC type was the only factor predicting recurrence. Kaplan-Meier 3-year recurrence/progression rates were 0%, 16%, and 29% for type I, II, and III RCCs, respectively (P , .001, type I vs II, type I vs III; P = .5 type II vs III).

CONCLUSION: The RCCs with a suprasellar component are neurosurgically challenging because of their proximity to the optic chiasm and infundibulum. Compared with sellar-based RCCs, RCCs with a suprasellar component more frequently present with visual dysfunction, are more difficult to completely eliminate, recur more frequently, and are associated with higher postoperative endocrine morbidity, and their preoperative visual dysfunction and headache less frequently improve with surgery. These factors must be considered during the treatment of RCCs with a suprasellar component.

Neurosurgery 69:284–293, 2011 DOI: 10.1227/NEU.0b013e31821bc44e

Nonfunctioning pituitary adenomas recur after microsurgery. Gamma Knife radiosurgery (GKRS) has been used to treat recurrent adenomas.

OBJECTIVE: To evaluate the long-term rates of tumor control and development of hypopituitarism in patients with nonfunctioning pituitary adenomas after GKRS.

METHODS: Forty-eight patients with a nonfunctioning pituitary adenoma treated between 1991 and 2004 at the University of Virginia were studied. All patients had more than 4 years of clinical and imaging follow-up.

RESULTS: All patients underwent follow-up imaging and endocrine evaluations, with a duration ranging from 50 to 215 months (median, 80.5 months) and 57 to 201 months (median, 95 months), respectively. New hormone deficiency after GKRS occurred in 19 of 48 patients (39%). Corticotropin/cortisol deficiency developed in 8% of patients, thyroid hormone deficiency in 20.8%, gonadotropin deficiency in 4.2%, growth hormone/insulin-like growth factor 1 in 16.7%, and diabetes insipidus in 2%. Panhypopituitarism including diabetes insipidus developed in 1 patient. Overall, control of tumor volume was 83%. Tumor volume decreased in 36 patients (75%), increased in 8 patients (17%), and was unchanged in 4 patients (8%). Tumor volumes greater than 5 mL at the time of GKRS were associated with a significantly greater rate of growth (P = .003) compared with an adenoma with a volume of 5 mL or less.

CONCLUSION: GKRS resulted in a high and durable rate of tumor control in patients with a nonfunctioning pituitary adenoma. A higher preoperative tumor volume was associated with an increased rate of tumor growth.

Neurosurg Focus 31 (1):E1, 2011. DOI: 10.3171/2011.5.FOCUS1183

The aim of this paper is to provide a comprehensive review of clinical, imaging, and histopathological features, as well as operative and nonoperative management strategies in patients with Rathke cleft cysts (RCCs).

A literature review was performed to identify previous articles that reported surgical and nonsurgical management of RCCs.

Rathke cleft cysts are often incidental lesions found in the sellar and suprasellar regions and do not require surgical intervention in the majority of cases. In symptomatic RCCs, the typical clinical presentation includes headache, visual loss, and/or endocrine dysfunction. Visual field testing and endocrine laboratory studies may reveal more subtle deficiencies associated with RCCs. When indicated, the transsphenoidal approach typically offers the least invasive and safest method for treating these lesions.

Various surgical strategies including cyst wall resection, intralesional alcohol injection, and sellar floor reconstruction are discussed. Although headache and visual symptoms frequently improve after surgical drainage of RCCs, hypopituitarism and diabetes insipidus are less likely to do so.

A subset of more aggressive, atypical RCCs associated with pronounced clinical symptoms and higher recurrence rates is discussed, as well as the possible relationship of these lesions to craniopharyngiomas.

Rathke cleft cysts are typically benign, asymptomatic lesions that can be monitored. In selected patients, transsphenoidal surgery provides excellent rates of improvement in clinical symptoms and long-term cyst resolution. Complete cyst wall resection, intraoperative alcohol cauterization, and sellar floor reconstruction in the absence of a CSF leak are not routinely recommended.

J Neurosurg Pediatrics 7:000–000, 2011.DOI: 10.3171/2011.2.PEDS10278

Pituitary adenomas are uncommon in childhood. Although medical treatment can be effective in treating prolactinomas and some growth hormone (GH)–secreting tumors, resection is indicated when visual function is affected or the side effects of medical therapy are intolerable. The authors of this report describe their 10-year experience in managing pituitary adenomas via the microscopic endonasal transsphenoidal approach in a pediatric population.

Methods. They performed a retrospective review of a surgical case series based at a single institution and consisting of 34 consecutive pediatric patients with endocrine-active (32 patients) and endocrine-inactive (2 patients) adenomas. These patients were surgically treated via an endonasal transsphenoidal approach between 1999 and 2008. Patient charts were reviewed, and clinical data were compiled and analyzed using the chi-square and Kaplan-Meier tests.

Results. The patient cohort consisted of 20 girls and 14 boys, with ages ranging from 9 to 18 years and a median age of 16 years. Thirty-two patients (94%) underwent surgery for endocrine-active tumors, including 10 (29%) with Cushing disease, 21 (62%) with prolactinomas, and 1 (3%) with GH-secreting tumors. Two patients with nonsecreting adenomas underwent surgery for apoplexy. The mean tumor volume was 5.4 cm3, and 13 patients (38%) had suprasellar extension and 7 (21%) had cavernous sinus invasion. Gross-total resection was achieved in 26 patients (76%), although it was significantly less likely to be achieved in the setting of cavernous sinus invasion (p < 0.001) but was unaffected by suprasellar extension. Residual tumor was treated with radiation therapy in 6 patients (18%). The average duration of hospital stay was 1.6 days. The median follow-up time was 18 months. After surgery, 19 patients (56%) had normal hormone function without adjuvant therapy, 8 (24%) had normal function with adjuvant therapy, and 5 (15%) had persistently elevated hormone levels. Patients with a macroprolactinoma were significantly more likely to require postoperative adjuvant therapy than were those with a microprolactinoma (p < 0.03).

Conclusions. Endonasal transsphenoidal resection is a safe, well-tolerated, and potentially curative treatment option for pituitary adenomas in children. Despite the technical challenges associated with this approach in the pediatric population, these tumors can be effectively managed with minimal morbidity. Endocrine function is usually preserved, and the majority of patients will not require lifelong medical therapy.

Acta Neurochir (2011) 153:799–806. DOI 10.1007/s00701-011-0961-1

In the past several years, increasing attention has been paid to the utility of a pseudocapsule in transphenoidal surgery for pituitary adenomas. However, prior studies focused more on the histological structure of the pseudocapsule and surgical technique. The objective of this study was to evaluate the overall therapeutic effectiveness of transsphenoidal pseudocapsule-based extracapsular resection for pituitary adenomas.

Methods Between January 2004 and October 2007, 78 patients with pituitary adenomas underwent transsphenoidal pseudocapsule-based extracapsular removal surgery (extracapsular resection group, ER group). During the same period, 64 patients underwent transsphenoidal intracapsular resection operations (intracapsular resection group, IR group).

Results Complete resection rates were achieved in 90.6%, 84.6% and 65.5%, 52.6% of modified Hardy types II and III in the ER and IR groups, showing a significant difference (both P<0.05). Statistical significance in the remission rates was also found between the two groups with modified Hardy types II and III, respectively (both P<0.05). Complications occurred in 29.5% of the ER group and 26.6% of the IR group, with no difference between groups (P>0.05). The recurrence rate of the ER group (2.56%) was lower than that of the IR group (14.06%).

Conclusion The transsphenoidal pseudocapsule-based extracapsular resection approach provides a more effective and safe alternative compared to the traditional intracapsular one because of its higher tumor removal and remission rates, and lower recurrence rate.

J Neurosurg 114:336–344, 2011.DOI: 10.3171/2010.8.JNS10290

The 2004 WHO classification of pituitary adenomas now includes an “atypical” variant, defined as follows: MIB-1 proliferative index greater than 3%, excessive p53 immunoreactivity, and increased mitotic activity. The authors review the incidence of this atypical histopathological subtype and its correlation with tumor subtype, invasion, and surgical features.

Methods. The records of 121 consecutive patients who underwent transsphenoidal surgery for pituitary adenomas during an 18-month period were retrospectively reviewed for evidence of atypical adenomas.

Results. Eighteen adenomas (15%) met the criteria for atypical lesions; 17 (94%) of the 18 were macroadenomas. On imaging, 15 (83%) demonstrated imaging evidence of surrounding invasion, compared with 45% of typical adenomas (p = 0.004). Atypical tumors occurred in 12 female (67%) and 6 male (33%) patients. Patient age ranged from 16 to 70 years (mean 48 years). Nine patients (50%) had hormonally active tumors, and 9 had nonfunctional lesions. Four (22%) of the 18 patients presented to us with recurrent tumors. Immunohistochemical analysis demonstrated the following tumor subtypes: GH-secreting adenoma with plurihormonal staining (5 patients [28%]); null-cell adenoma (5 patients [28%]); silent ACTH tumor (3 patients [17%]), ACTH-staining tumor with Cushing’s disease (2 patients [11%]), prolactinoma (2 patients [11%]), and silent FSH-staining tumor (1 patient [6%]). The MIB-1 labeling index ranged from 3% to 20% (mean 7%).

Conclusions. Atypical tumors were identified in 15% of resected pituitary adenomas, and they tended to be aggressive, invasive macroadenomas. More longitudinal follow-up is required to determine whether surgical outcomes, potential for recurrence, or metastasis of atypical adenomas vary significantly from their typical counterparts.

J Neurosurg 114:329–335, 2011. (DOI: 10.3171/2010.5.JNS091821)

The authors assessed the feasibility, anatomical accuracy, and cost effectiveness of frameless electromagnetic (EM) neuronavigation in conjunction with portable intraoperative CT (iCT) registration for transsphenoidal adenomectomy (TSA).

Methods. A prospective database was established for data obtained in 208 consecutive patients who underwent TSA in which the iCT/EM navigation technique was used. Data were compared with those acquired in a retrospective cohort of 65 consecutive patients in whom fluoroscope-assisted TSA had been performed by the same surgeon. All patients in both groups underwent transnasal removal of pituitary adenomas or neuroepithelial cysts, using identical surgical techniques with an operating microscope. In the iCT/EM technique–treated cases, a portable iCT scan was obtained immediately prior to surgery for registration to the EM navigation system, which did not require rigid head fixation. Preexisting (nonnavigation protocol) MR imaging studies were fused with the iCT scans to enable 3D navigation based on MR imaging data. The accuracy of the navigation system was determined in the first 50 iCT/EM cases by visual concordance of the navigation probe location to 5 preselected bony landmarks. For all patients in both cohorts, total operating room time, incision-to-closure time, and relative costs of imaging and surgical procedures were determined from hospital records.

Results. In every case, iCT registration was successful and preoperative MR images were fused to iCT scans without affecting navigation accuracy. There was 100% concordance between probe tip location and predetermined bony loci in the first 50 cases involving the iCT/EM technique. Total operating room time was significantly less in the iCT/EM cases (mean 108.9 ± 24.3 minutes [208 patients]) compared with the fluoroscopy group (mean 121.1 ± 30.7 minutes [65 patients]; p < 0.001). Similarly, incision-to-closure time was significantly less for the iCT/EM cases (mean 61.3 ± 18.2 minutes) than for the fluoroscopy cases (mean 71.75 ± 19.0 minutes; p < 0.001). Relative overall costs for iCT/EM technique and intraoperative C-arm fluoroscopy were comparable; increased costs for navigation equipment were offset by savings in operating room costs for shorter procedures.

Conclusions. The use of iCT/MR imaging–guided neuronavigation for transsphenoidal surgery is a time-effective, cost-efficient, safe, and technically beneficial technique.

Neurosurgery 67:949–956, 2010 DOI: 10.1227/NEU.0b013e3181ec4379

Acromegaly is a disorder characterized by hypersecretion of growth hormone caused by a growth hormone–secreting pituitary adenoma.

OBJECTIVE: To evaluate the long-term efficacy and safety of repeat transsphenoidal surgery for persistent or recurrent acromegaly.

METHODS: We retrospectively reviewed records for 53 acromegalic patients who underwent repeat transsphenoidal surgery for persistent or progressive acromegaly at Toranomon Hospital between 1987 and 2006. Multivariate logistic regression was performed to evaluate preoperative factors influencing the surgical outcome.

RESULTS: Thirty-one patients (58.5%) met the criteria for cure on long-term follow-up endocrine findings. Furthermore, 17 patients were well controlled with normal insulinlike growth factor I levels without (2 patients) or with medication (15 patients), whereas insulin-like growth factor I levels were still above normal in 5 patients after postoperative adjuvant therapy. Only 1 patient was undergoing additional hormonal replacement after surgery, although transient cerebrospinal fluid leak, transient abducens nerve palsy, severe nasal bleeding, and pituitary abscess occurred in each patient, respectively. Multivariate analysis clarified that a favorable surgical outcome was achieved in patients without cavernous sinus invasion (hazard ratio 12.56), tumor segmentation (hazard ratio 5.82), or in those older than 40 years old (hazard ratio 3.21).

CONCLUSION: Repeat surgery can be performed safely with an approximately 60% long-term cure rate in this series. Reoperation should therefore be considered for persistent or recurrent disease in acromegalic patients in whom adjuvant therapy is not effective enough or cannot be accepted. The careful study of initial or preoperative magnetic resonance imaging and the use of micro-Doppler, endoscope, and eye movement monitoring device during surgery can help increase cure rate with a lower complication rate.

Neurosurg Focus 29 (4):E5, 2010. DOI: 10.3171/2010.7.FOCUS10153

Using strict biochemical remission criteria, the authors assessed surgical outcomes after endoscopic transsphenoidal resection of growth hormone (GH)–secreting pituitary adenomas and identified preoperative factors that significantly influence the rate of remission.

Methods. A retrospective review of a prospectively maintained database was performed. The authors reviewed cases in which an endoscopic resection of GH-secreting pituitary adenomas was performed. The cohort consisted of 26 patients who had been followed for 3–60 months (mean 24.5 months). The thresholds of an age-appropriate, normalized insulin-like growth factor–I concentration, a nadir GH level after oral glucose load of less than 1.0 μg/l, and a random GH value of less than 2.5 μg/l were required to establish biochemical cure postoperatively.

Results. Overall, in 57.7% of patients undergoing a purely endoscopic transsphenoidal pituitary adenectomy for acromegaly, an endocrinological cure was achieved. The mean clinical follow-up duration was 24.5 months. In patients with microadenomas (4 cases) the cure rate was 75%, whereas in patients harboring macroadenomas (22 cases) the cure rate was 54.5%. Cavernous sinus invasion (Knosp Grades 3 and 4) was associated with a significantly lower remission rate (p = 0.0068). Hardy Grade 3 and 4 tumors were also less likely to achieve biochemical cure (p = 0.013). The overall complication rate was 11.5% including 2 incidents of transient diabetes insipidus and 1 postoperative CSF leak, which were treated nonoperatively.

Conclusions. A purely endoscopic transsphenoidal approach to GH-secreting pituitary adenomas leads to similar outcome for noninvasive macroadenomas compared with traditional microsurgical techniques. Furthermore, this approach may often provide maximal visualization of the tumor, the pituitary gland, and the surrounding neurovascular structures.

J Neurosurg 112:1333–1339, 2010. DOI: 10.3171/2009.10.JNS09348

Acta Neurochir (2010) 152:1015–1020. DOI 10.1007/s00701-010-0629-2

The endoscopic endonasal transsphenoidal approach (EETA) to the pituitary is performed by ear, nose, and throat (ENT) surgeons in collaboration with neurosurgeons but also by neurosurgeons alone even though neurosurgeons have not been trained in rhinological surgery.

Purpose To register the frequency of endonasal anatomical variations and to evaluate whether these variations hinder the progress of EETA and require extra rhinological surgical skills.

Methods A prospective cohort study of 185 consecutive patients receiving an EETA through a binostril approach was performed. All anatomical endonasal variations were noted and the relevance for the progress of surgery evaluated.

Results In 48% of patients, anatomical variations were recognized, the majority of which were spinae septi and septum deviations. In 5% of patients, the planned binostril approach had to be converted into a mononostril approach; whereas in 18% of patients with an anatomical variation, a correction had to be performed. There was no difference between the ENT surgeon and the neurosurgeon performing the approach. Complications related to the endonasal phase of the surgery occurred in 3.8%. Fluoroscopy or electromagnetic navigation has been used during 6.5% of the surgeries.

Conclusion Although endonasal anatomical variations are frequent, they do not pose a relevant obstacle for EETA.