Outcomes following endoscopic, expanded endonasal resection of suprasellar craniopharyngiomas: a case series

Comparative analysis of outcomes following craniotomy and expanded endoscopic endonasal transsphenoidal resection of craniopharyngioma and related tumors: a single-institution study

OBJECTIVE

Craniopharyngiomas and similar midline suprasellar tumors have traditionally been resected via transcranial approaches. More recently, expanded endoscopic endonasal transsphenoidal approaches have gained interest. Surgeons have advocated for both approaches, and at present there is no consensus whether one approach is superior to the other. The authors therefore compared surgical outcomes between craniotomy and endoscopic endonasal transsphenoidal surgery (EETS) for suprasellar tumors treated at their institution.

METHODS

A retrospective review of patients undergoing resection of suprasellar lesions at Cedars-Sinai Medical Center between 2000 and 2013 was performed. Patients harboring suspected craniopharyngioma were selected for extensive review. Other pathologies or predominantly intrasellar masses were excluded. Cases were separated into 2 groups, based on the surgical approach taken. One group underwent EETS and the other cohort underwent craniotomy. Patient demographic data, presenting symptoms, and previous therapies were tabulated. Preoperative and postoperative tumor volume was calculated for each case based on MRI. Student t-test and the chi-square test were used to evaluate differences in patient demographics, tumor characteristics, and outcomes between the 2 cohorts. To assess for selection bias, 3 neurosurgeons who did not perform the surgeries reviewed the preoperative imaging studies and clinical data for each patient in blinded fashion and indicated his/her preferred approach. These data were subject to concordance analysis using Cohen's kappa test to determine if factors other than surgeon preference influenced the choice of surgical approach.

RESULTS

Complete data were available for 53 surgeries; 19 cases were treated via EETS, and 34 were treated via craniotomy. Patient demographic data, preoperative symptoms, and tumor characteristics were similar between the 2 cohorts, except that fewer operations for recurrent tumor were observed in the craniotomy cohort compared with EETS (17.6% vs 42.1%, p = 0.05). The extent of resection was similar between the 2 groups (85.6% EETS vs 90.7% craniotomy, p = 0.77). An increased rate of cranial nerve injury was noted in the craniotomy group (0% EETS vs 23.5% craniotomy, p = 0.04). Postoperative CSF leak rate was higher in the EETS group (26.3% EETS vs 0% craniotomy, p = 0.004). The progression-free survival curves (log-rank p = 0.99) and recurrence rates (21.1% EETS vs 23.5% craniotomy, p = 1.00) were similar between the 2 groups. Concordance analysis of cases reviewed by 3 neurosurgeons indicated that individual surgeon preference was the only factor that determined surgical approach (kappa coefficient -0.039, p = 0.762) CONCLUSIONS: Surgical outcomes were similar for tumors resected via craniotomy or EETS, except that more CSF leaks occurred in the EETS cohort, whereas more neurological injuries occurred in the craniotomy cohort. Surgical approach appears to mostly reflect surgeon preference rather than specific tumor characteristics. These data support the view that EETS is a viable alternative to craniotomy, providing a similar extent of resection with less neurological injury.

Repair and prevention of cerebrospinal fluid leakage in transsphenoidal surgery: a sphenoid sinus mucosa technique

Cerebrospinal fluid (CSF) leakage is a common but sometimes serious complication after transsphenoidal surgery (TSS). To avoid this postsurgical complication, we usually repair the CSF leaking area using an autologous material, such as fat, fascia, or muscle graft and sometimes nasonasal septal flap. In this report, we propose a technique using a novel autologous material, sphenoid sinus mucosa (SSM), to repair intraoperative CSF leakage or prevent it postoperatively. On 26 February 2007, we introduced the technique of using SSM to repair or prevent CSF leakage in TSS. Until 30th of June 2014, we performed 500 TSSs for patients with pituitary or parasellar lesions. They were 195 men and 305 women with a mean age of 48.5 years (range, 5-85 years). We used SSM for patching or suturing the arachnoid laceration or dural defect, in lieu of fat or fascia harvested from abdomen or thigh, or made pedicle flap of SSM instead of nasonasal septal flap to cover the sellar floor. Comparing the previous 539 cases not using these techniques before 26 February 2007, intraoperative CSF leakage increased from 49 to 69.4% (p < 0.0001) due to more aggressive surgical technique, mainly related to more extensive approaches and lesion removals, but the rate of using fat was reduced significantly from 35.5 to 19.4% (p = 0.00021) in small or moderate CSF leaks during TSS without increasing the reoperation rate for postoperative CSF leaks (1.86 vs 1.2%, p = 0.45). The technique of using SSM to repair intraoperative CSF leaks or prevent them postoperatively in TSS was considered useful, effective, less invasive, easier for graft harvesting (same surgical field), and providing natural anatomical reconstruction, without potential donor site morbidity. We can recommend it as a standard method for CSF leaks repair and prevention in TSS.

Endoscopic endonasal surgery for sinonasal and skull base lesions in the pediatric population

Endoscopic endonasal skull base surgical techniques, initially developed in adult patients, are being utilized with increasing frequency in pediatric patients to treat sinonasal and skull base lesions. This article reviews the current state of endoscopic endonasal approaches to the skull base to both treat disease and reconstruct the skull base in pediatric patients. Sinonasal and skull base embryology and anatomy are reviewed as a foundation for understanding the disease processes and surgical techniques. Selected skull base pathologies and conditions that involve the pediatric skull base are also reviewed.

Endoscopic extended transsphenoidal resection of craniopharyngiomas: nuances of neurosurgical technique

Endoscopic approaches to the midline ventral skull base have been extensively developed and refined for resection of cranial base tumors over the past several years. As these techniques have improved, both the degree of resection and complication rates have proven comparable to those for transcranial approaches, while visual outcomes may be better via endoscopic endonasal surgery and hospital stays and recovery times are often shorter. Yet for all of the progress made, the steep learning curve associated with these techniques has hampered more widespread implementation and adoption. The authors address this obstacle by coupling a thorough description of the technical nuances for endoscopic endonasal craniopharyngioma resection with detailed illustrations of the important steps in the operation. Traditionally, transsphendoidal approaches to craniopharyngiomas have been restricted to lesions mostly confined to the sella. However, recently, endoscopic endonasal resections are more frequently employed for extrasellar and purely third ventricle craniopharyngiomas, whose typical retrochiasmatic location makes them ideal candidates for endoscopic transnasal surgery. The endonasal endoscopic approach offers many advantages, including direct access to the long axis of the tumor, early tumor debulking with minimal manipulation of the optic apparatus, more precise visualization of tumor planes, particularly along the undersurface of the chiasm and the roof of the third ventricle, and a minimal-access corridor that obviates the need for brain retraction. Although much emphasis has been placed on technical tenets of exposure and "how to get there," this article focuses on nuances of tumor resection "when you are there." Three operative videos illustrate our discussion of technical tenets.

Anatomic comparison of the endonasal and transpetrosal approaches for interpeduncular fossa access

OBJECT

The interpeduncular cistern, including the retrochiasmatic area, is one of the most challenging regions to approach surgically. Various conventional approaches to this region have been described; however, only the endoscopic endonasal approach via the dorsum sellae and the transpetrosal approach provide ideal exposure with a caudal-cranial view. The authors compared these 2 approaches to clarify their limitations and intrinsic advantages for access to the interpeduncular cistern.

METHODS

Four fresh cadaver heads were studied. An endoscopic endonasal approach via the dorsum sellae with pituitary transposition was performed to expose the interpeduncular cistern. A transpetrosal approach was performed bilaterally, combining a retrolabyrinthine presigmoid and a subtemporal transtentorium approach. Water balloons were used to simulate space-occupying lesions. "Water balloon tumors" (WBTs), inflated to 2 different volumes (0.5 and 1.0 ml), were placed in the interpeduncular cistern to compare visualization using the 2 approaches. The distances between cranial nerve (CN) III and the posterior communicating artery (PCoA) and between CN III and the edge of the tentorium were measured through a transpetrosal approach to determine the width of surgical corridors using 0- to 6-ml WBTs in the interpeduncular cistern (n = 8).

RESULTS

Both approaches provided adequate exposure of the interpeduncular cistern. The endoscopic endonasal approach yielded a good visualization of both CN III and the PCoA when a WBT was in the interpeduncular cistern. Visualization of the contralateral anatomical structures was impaired in the transpetrosal approach. The surgical corridor to the interpeduncular cistern via the transpetrosal approach was narrow when the WBT volume was small, but its width increased as the WBT volume increased. There was a statistically significant increase in the maximum distance between CN III and the PCoA (p = 0.047) and between CN III and the tentorium (p = 0.029) when the WBT volume was 6 ml.

CONCLUSIONS

Both approaches are valid surgical options for retrochiasmatic lesions such as craniopharyngiomas. The endoscopic endonasal approach via the dorsum sellae provides a direct and wide exposure of the interpeduncular cistern with negligible neurovascular manipulation. The transpetrosal approach also allows direct access to the interpeduncular cistern without pituitary manipulation; however, the surgical corridor is narrow due to the surrounding neurovascular structures and affords poor contralateral visibility. Conversely, in the presence of large or giant tumors in the interpeduncular cistern, which widen the spaces between neurovascular structures, the transpetrosal approach becomes a superior route, whereas the endoscopic endonasal approach may provide limited freedom of movement in the lateral extension.

Expanding indications for the extended endoscopic endonasal approach to hypothalamic gliomas: preliminary report

Object In the last decade the indications for the endoscopic endonasal approach have been progressively expanded to include lesions that have not been traditionally considered amenable to resection through the transsphenoidal route. In this study, the authors analyze their experience with hypothalamic gliomas treated via the endoscopic endonasal approach. Methods Consecutive cases of hypothalamic gliomas treated since 2007 via an endoscopic endonasal approach were reviewed. Preoperative and postoperative neuroimaging as well as endocrinological, neurological, and visual symptoms were analyzed to assess the surgical outcome. Signs and symptoms of hypothalamic dysfunction including body mass index (BMI), memory, sleep-wake rhythm, and polyphagia were prospectively collected pre- and postoperatively to assess hypothalamic function. Quality of life was evaluated using the Katz scale. Results In the initial phase the endoscopic endonasal approach was adopted in 3 cases with a palliative intent, to obtain a biopsy sample or for debulking of the mass followed by radio- or chemotherapy. In 2 later cases it was successfully adopted to achieve gross-total tumor resection. Complications consisted of 2 postoperative CSF leaks, which required an endoscopic endonasal reintervention. Visual deficit improved in 3 cases and normalized in the other 2. Four patients developed diabetes insipidus, and 3 an anterior panhypopituitarism. All patients had a moderate increase in BMI. No patients presented with any other signs of hypothalamic damage, and their quality of life at follow-up is normal. Conclusions Despite the limitations of a short follow-up and small sample, the authors' early experience with the endoscopic endonasal approach has revealed it to be a direct, straightforward, and safe approach to third ventricle astrocytomas. It allowed the authors to perform tumor resection with the same microsurgical technique: dissecting the tumor with 2 hands, performing a central debulking, and controlling the bleeding with bipolar coagulation. The main limitations were represented by some anatomical conditions, such as the position of the chiasm and the anterior communicating artery complex and, finally, by the challenge of watertight plastic repair. To definitively evaluate the role of this approach in hypothalamic gliomas, a comparison with transcranial series would be necessary, but due to the rarity of these cases such a study is still lacking. The authors observed that more aggressive surgery is associated with a worse endocrinological outcome; thus they consider it to be an open question (in particular in prepubertal patients) whether radical removal is an advisable goal for hypothalamic gliomas.

Endoscopic Endonasal Approach for Craniopharyngiomas

The endoscopic endonasal approach for craniopharyngiomas is increasingly used as an alternative to microsurgical transsphenoidal or transcranial approaches. It is a step forward in treatment, providing improved resection rates and better visual outcome. Especially in retrochiasmatic tumors, this approach provides better lesion access and reduces the degree of manipulations of the optic apparatus. The panoramic view offered by endoscopy and the use of angulated optics allows the removal of lesions extending far into the third ventricle avoiding microsurgical brain splitting. Intensive training is required to perform this surgery. This article summarizes the surgical technique, outcome, and complications.

Long-term quality of life after endonasal endoscopic resection of adult craniopharyngiomas

OBJECT

Craniopharyngiomas are benign parasellar tumors for which surgical removal, although potentially curative, often leads to morbidity with resulting decreases in quality of life (QOL). The endonasal endoscopic approach is a minimal-access technique for removing these tumors and may reduce postoperative morbidity. The QOL following this method for resection of craniopharyngiomas has not been documented.

METHODS

The authors reviewed a database of consecutive endonasal endoscopic surgeries done at Weill Cornell Medical College. Adult patients with histologically proven craniopharyngiomas were included who had completed either only postoperative (> 9 months) or both pre- and postoperative QOL forms, the Anterior Skull Base Quality of Life (ASBQ) questionnaire, and the 22-Item Sinonasal Outcome Test (SNOT-22). Rates of gross-total resection (GTR), complications, and visual and endocrine function were collected. Retrospective independence (Wen score) was also assigned. A contemporaneous group of patients undergoing endonasal endoscopic pituitary macroadenoma resection was used as a control.

RESULTS

This study included 33 procedures performed in 31 patients. The average postoperative ASBQ score was 3.35 and the SNOT-22 score was 19.6. Better QOL was associated with GTR and postoperative radiation. Worse QOL was associated with persistent visual defects, hypopituitarism, tumor recurrence, increase in body mass index, and worsening Wen score. In a subset of 10 patients, both pre- and postoperative (> 9 months) QOL scores were obtained. Both ASBQ and SNOT-22 scores showed stability and a trend toward improvement, from 2.93 ± 0.51 to 2.96 ± 0.47 (ASBQ) and 23.7 ± 10.8 to 18.4 ± 11.6 (SNOT-22). Compared with 62 patients undergoing endoscopic pituitary macroadenoma resection, patients with craniopharyngiomas had worse postoperative QOL on the ASBQ (3.35 vs 3.80; p = 0.023) and SNOT-22 (19.6 vs 13.4; p = 0.12).

CONCLUSIONS

This report of validated site-specific QOL following endoscopic surgery for craniopharyngiomas shows an overall maintenance of postoperative compared with preoperative QOL. Better QOL could be seen in patients with GTR and radiation therapy, and worse QOL was found in patients with visual or endocrine deficits. Nevertheless, patients with craniopharyngiomas still had worse QOL than those undergoing similar surgery for pituitary macroadenomas, confirming the worse prognosis of craniopharyngiomas even when removed via a minimally invasive approach. These measures should serve as benchmarks for comparison with open transcranial approaches to similar tumors.

Extended Endoscopic Endonasal Approach to the Third Ventricle: Multimodal Anatomical Study with Surgical Implications

INTRODUCTION

A certain interest for the extended endoscopic endonasal approach for the management of sellar-suprasellar lesions extending inside the third ventricle has been growing in recent years. The aim of this anatomical study was to evaluate the possibilities in terms of exposure and access to the different areas of the third ventricle, with the endoscopic endonasal technique, as compared with the microscopic or endoscopic view provided via different transcranial approaches. The advantages and limitations of both surgical pathways were analyzed.

MATERIALS AND METHODS

Ten human cadaver heads were dissected. In order to standardize the comparison between the endonasal and the transcranial routes, the third ventricle cavity has been divided into four areas by means of two ideal planes, one passing through the optic chiasm and the interthalamic commissure and one passing through the posterior edge of the foramen of Monro and the interthalamic commissure. Accordingly, two anterior (infundibular and foraminal) and two posterior (mesencephalic and tectal) areas have been defined.

RESULTS

The endoscopic endonasal approach allows for exploration and surgical maneuverability, especially in the anterior areas of the third ventricle. In the infundibular and foraminal areas the surgical maneuverability seems to be better as compared with that obtained inside the mesencephalic region, while via the endonasal route the tectal area could not be reached. In particular, the infundibular area can be explored either passing through the lamina terminalis or via the tuber cinereum; this latter trajectory enables visualization of the foramina of Monro and the floor of the third ventricle up to the pineal recess.

CONCLUSION

This anatomical study shows that the lamina terminalis and, above all, the tuber cinereum represent two safe entry points defining possible surgical corridors to be considered for the extended endoscopic endonasal approach to the third ventricle.

Endoscopic endonasal trans-sphenoid management of craniopharyngiomas

Introduction:

Craniopharyngiomas treatment has been challenging because of their anatomical location. The endoscopic endonasal (EE) trans-sphenoidal approach is indicated in sellar, supra sellar, selected intraventricular lesions in adults and children. We are reporting our initial experience of 44 patients managed by EE approach.

Materials and Methods:

This is a retrospective study of 44 craniopharyngiomas. The goal of surgery was gross-total resection in all cases. All patients underwent pre- and post-operative comprehensive ophthalmological and endocrinological evaluation. Lumbar drain at the start of the operation was used in all cases with tumor larger than 3 cm maximum diameter. Binostril technique vascularized nasoseptal flap and multilayer closure of the dural defect were used. Wide sphenoidotomy, posterior ethmoidectomy, tuberculum selle, and planum removal were performed in all cases. Perioperative antibiotic prophylaxis was used for 72 h.

Results:

There were 44 patients of age ranging from 8 to 65 (mean: 42) years. Diameter of the tumor varied from 3.1 cm to 6.6 cm (average: 4.3 cm). Visual and pituitary dysfunctions were observed in 44 and 33, respectively, before surgery. Vision improvement, gross-total removal, cerebrospinal fluid (CSF) leak and recurrence were observed in 34, 26, four and six patients, respectively. Average follow-up was 19 months.

Conclusion:

Endoscopic endonasal trans-sphenoidal approach for craniopharyngioma is safe and effective alternative to transcranial approach in selected patients. Although this technique is associated with effective tumor removal and improved visual outcome, CSF leak, and endocrine dysfunctions remain a major challenge.

Suprachiasmatic translamina terminalis corridor used in endoscopic endonasal approach for resecting third ventricular craniopharyngioma

OBJECT

The translamina terminalis corridor was used in the transcranial anterior route to treat third ventricular craniopharyngioma (TVC), which presents a challenge to neurosurgeons. The endoscopic endonasal approach (EEA) has recently been used to treat craniopharyngiomas. However, there are few reports of the EEA being used to treat TVC. The authors' novel surgical approach of treating selected TVC by the endoscopic endonasal route via the suprachiasmatic translamina terminalis (STLT) corridor is described.

METHODS

In this single-center study, the EEA via the STLT corridor was used to resect TVC with great upper and anterior extension causing bulged lamina terminalis, and TVC with a residual upper compartment, after routine infrachiasmatic transmetastalk corridor resection.

RESULTS

The STLT corridor was used in 3 patients. Gross-total resection was achieved in all cases. One patient achieved visual improvement, and the other 2 patients showed partial visual improvement. Leakage of CSF occurred in 1 patient. Postoperative hormone replacement therapy was required in all patients.

CONCLUSIONS

The STLT corridor is a complementary minimally invasive corridor used in the EEA for treating selected TVC. The STLT alone or combined with infrachiasmatic transmetastalk corridors should be selected depending on the size of suprachiasmatic and infrachiasmatic space.

Two alternative dural sealing techniques in posterior fossa surgery: (Polylactide-co-glycolide) self-adhesive resorbable membrane versus polyethylene glycol hydrogel

BACKGROUND

Post-operative cerebrospinal fluid (CSF) leak in posterior fossa surgery remains a significant source of morbidity. TissuePatchDural (TPD), a novel impermeable adhesive membrane, was used to reinforce dural closure. A comparison with one of the most commonly used dural sealing devices, DuraSeal, has been made.

METHODS

A retrospective, single-center study was conducted on 161 patients who underwent elective posterior fossa surgery. On surgeon's opinion, when a primary watertight closure was not possible, they received TPD or DuraSeal to reinforce dural closure.

RESULTS

Out of 161 patients analyzed, 115 were treated with TPD and 46 with DuraSeal. The post-operative leaks related purely to TPD or DuraSeal failure were recognized in 3 (2.6%) and 5 (10.86%) cases, respectively (P = 0.015). The presence of pre- and post-operative risk factors was associated with an increased incidence of CSF leak in both groups. TPD showed a better control in patients without these risk factors (P = 0.08). The incidence of CSF leak in patients who underwent posterior fossa surgery by craniectomy was statistically lower in TPD group compared to DuraSeal group (3.22% vs 17.8%, respectively; P = 0.008).

CONCLUSIONS

TPD seems to be a safe tool for use as an adjunct to standard dural closure in posterior fossa surgery, particularly in patients without pre- or post-oper ative risk factors, in those who did not develop hydrocephalus, and who underwent craniectomy. The CSF leak rate in TPD group was found to be lower or within the range of the more advanced alternative dural closure strategies, including polyethylene glycol (PEG)-based sealant.

Endoscopic endonasal skull base surgery: advantages, limitations, and our techniques to overcome cerebrospinal fluid leakage: technical note

In recent years, resections of midline skull base tumors have been conducted using endoscopic endonasal skull base (EESB) approaches. Nevertheless, many surgeons reported that cerebrospinal fluid (CSF) leakage is still a major complication of these approaches. Here, we report the results of our 42 EESB surgeries and discuss the advantages and limits of this approach for resecting various types of tumors, and also report our technique to overcome CSF leakage. All 42 cases involved midline skull base tumors resected using the EESB technique. Dural incisions were closed using nasoseptal flaps and fascia patch inlay sutures. Total removal of the tumor was accomplished in seven pituitary adenomas (33.3%), five craniopharyngiomas (62.5%), five tuberculum sellae meningiomas (83.3%), three clival chordomas (100%), and one suprasellar ependymoma. Residual regions included the cavernous sinus, the outside of the intracranial part of the internal carotid artery, the lower lateral part of the posterior clivus, and the posterior pituitary stalk. Overall incidence of CSF leakage was 7.1%. Even though the versatility of the approach is limited, EESB surgery has many advantages compared to the transcranial approach for managing mid-line skull base lesions. To avoid CSF leakage, surgeons should have skills and techniques for complete closure, including use of the nasoseptal flap and fascia patch inlay techniques.

Indication and limitations of endoscopic extended transsphenoidal surgery for craniopharyngioma

The transsphenoidal approach has been utilized in intrasellar craniopharyngioma surgeries. However, the advent of endoscopic extended transsphenoidal approach (EETSA) has expanded its indication to suprasellar craniopharyngiomas. We compared the indication and limitations of EETSA to those of uni-lateral basal interhemispheric approach (UBIHA), which presents similar indications for surgery. We analyzed 30 patients with tumors located below the foramen of Monro and the lateral boundary extending slightly beyond the internal carotid artery (UBIHA: N = 18; EETSA: N = 12). Postoperative magnetic resonance imaging (MRI) revealed gross total resection in 10 patients in the EETSA group (83.3%) and 12 in the UBIHA group (66.7%). Postoperative MRI in the EETSA group revealed residual tumor at the cavernous sinus in one patient, at the prepontine in one; in the UBIHA group, residual tumors were located in the retrochiasmatic area in two patients, infundibulum-hypothalamus in one, on the stalk in one, and in the intrasellar region in two. No intergroup differences were observed in the preservation of pituitary function and postoperative improvement of visual function. The extent of resection was better with EETSA than with UBIHA. EETSA is considered the first-line therapy because the distance between the optic chiasm and the superior border of the pituitary is large; the lateral extension does not go beyond the internal carotid artery; and the tumor does not extend inferiorly beyond the posterior clinoid process. However, in patients showing poorly developed sphenoid sinuses or pituitary stalks anterior to the tumor, surgery is difficult regardless of the selection criteria.

"Round-the-Clock" Surgical Access to the Orbit

Objective To describe an algorithm to guide surgeons in choosing the most appropriate approach to orbital pathology. Methods A review of 12 selected illustrative cases operated on at the neurosurgical department of University of Pittsburgh Medical Center over 3 years from 2009 to 2011 was performed. Preoperative coronal magnetic resonance imaging and/or computed tomography views were compared using a "clock model" of the orbit with its center at the optic nerve. The rationale for choosing an external, endoscopic, or combined approach is discussed for each case. Results Using the right orbit for demonstration of the clock model, the medial transconjunctival approach provides access to the anterior orbit from 1 to 6 o'clock; endoscopic endonasal approaches provide access to the mid and posterior orbit and orbital apex from 1 to 7 o'clock. The lateral micro-orbitotomy gives access to the orbit from 8 to 10 o'clock. The frontotemporal craniotomy with orbital osteotomy accesses the orbit from 9 to 1 o'clock; addition of a zygomatic osteotomy to this extends access from 6 to 8 o'clock. Conclusions Combined, the approaches described provide 360 degrees of access to the entire orbit with the choice of the optimal approach guided primarily by the avoidance of crossing the plane of the optic nerve.

Carotid artery injury during endoscopic endonasal skull base surgery: incidence and outcomes

BACKGROUND

Injury to the internal carotid artery (ICA) during endoscopic endonasal skull base surgery is a feared complication that is not well studied or reported.

OBJECTIVE

To evaluate the incidence, to identify potential risk factors, and to present management strategies and outcomes of ICA injury during endonasal skull base surgery at our institution.

METHODS

We performed a retrospective review of all endoscopic endonasal operations performed at our institution between 1998 and 2011 to examine potential factors predisposing to ICA injury. We also documented the perioperative management and outcomes after injury.

RESULTS

There were 7 ICA injuries encountered in 2015 endonasal skull base surgeries, giving an incidence of 0.3%. Most injuries (5 of 7) involved the left ICA, and the most common diagnosis was chondroid neoplasm (chordoma, chondrosarcoma; 3 of 7 [2% of 142 cases]). Two injuries occurred during 660 pituitary adenoma resections (0.3%). The paraclival ICA segment was the most commonly injured site (5 of 7), and transclival and transpterygoid approaches had a higher incidence of injury, although neither factor reached statistical significance. Four of 7 injured ICAs were sacrificed either intraoperatively or postoperatively. No patient suffered a stroke or neurological deficit. There were no intraoperative mortalities; 1 patient died postoperatively of cardiac ischemia. One of the 3 preserved ICAs developed a pseudoaneurysm over a mean follow-up period of 5 months that was treated endovascularly.

CONCLUSION

ICA injury during endonasal skull base surgery is an infrequent and manageable complication. Preservation of the vessel remains difficult. Chondroid tumors represent a higher risk and should be resected by surgical teams with significant experience.

Severe hyperthermia, hypernatremia, and early postoperative death after transethmoidal cavitron ultrasonic surgical aspirator (CUSA)-assisted diencephalic mass removal in 4 dogs and 2 cats

OBJECTIVE

To report clinical findings including severe hyperthermia and hypernatremia after transethmoidal Cavitron ultrasonic surgical aspirator (CUSA)-assisted diencephalic mass removal.

STUDY DESIGN

Retrospective case series.

ANIMALS

Dogs (n = 4) and 2 cats.

METHODS

Medical records (1997-2003) of dogs and cats that had transethmoidal CUSA-assisted diencephalic mass removal were reviewed. Retrieved data were: history, signalment, blood work, neurologic examination findings, MRI results, histopathology, postoperative complications, pre- and postoperative medical therapy, and outcome.

RESULTS

Tumor types included: meningioma (n = 3), choroid plexus papilloma (1), astrocytoma (1), and pituitary macroadenoma (1). Median onset of hyperthermia was 3.5 hours (range: 1-6 hours) after extubation; median high temperature at onset was 40.3°C, (range: 39.6-41.7°C). Median onset of hypernatremia (median, 172 mmol/L; range: 168-196 mmol/L) was 4.5 hours (range: 1-9 hours) after extubation. Median time of death after hyperthermia was 10.5 hours (range: 6-13 hours) and after extubation was 13.5 hours (range: 11-15 hours).

CONCLUSIONS

Transethmoidal CUSA-assisted diencephalic mass removal is associated with early postoperative hyperthermia, hypernatremia, and death, and cannot be recommended.

Craniopharyngioma

This report is a review of findings on the diagnosis, treatment, clinical course, and prognosis of craniopharyngioma patients. Craniopharyngiomas are rare, partly cystic and calcified embryonic malformations of the sellar/parasellar region with low histological grade (WHO I°). A bimodal age distribution has been shown, with peak incidence rates in childhood-onset at 5-14 years and adult-onset craniopharyngioma at 50-74 years. Clinical manifestations are related to hypothalamic/pituitary deficiencies, visual impairment, and increased intracranial pressure. If the tumor is favorably localized, the therapy of choice is complete resection, with care taken to preserve optical and hypothalamic functions. In patients with unfavorable tumor localization (i.e., hypothalamic involvement), recommended therapy is a limited hypothalamus-sparing surgical strategy followed by local irradiation. Although overall survival rates are high (92%), recurrences and progressions are frequent. Irradiation has proven effective in reducing recurrences and progression, and timing of postsurgical irradiation in childhood-onset cases is currently under investigation in a randomized multinational trial (KRANIOPHARYNGEOM 2007). Anatomical involvement and/or surgical lesions of posterior hypothalamic areas can result in serious quality of life-compromising sequelae such as hypothalamic obesity, psychopathological symptoms, and/or cognitive problems. It is crucial that craniopharyngioma be managed as a frequently chronic disease, providing ongoing care of pediatric and adult patients' clinical and quality of life consequences by experienced multidisciplinary teams.

The endoscopic endonasal approach for the management of craniopharyngiomas: a series of 103 patients

OBJECT

Despite their benign histological appearance, craniopharyngiomas can be considered a challenge for the neurosurgeon and a possible source of poor prognosis for the patient. With the widespread use of the endoscope in endonasal surgery, this route has been proposed over the past decade as an alternative technique for the removal of craniopharyngiomas.

METHODS

The authors retrospectively analyzed data from a series of 103 patients who underwent the endoscopic endonasal approach at two institutions (Division of Neurosurgery of the Università degli Studi di Napoli Federico II, Naples, Italy, and Division of Neurosurgery of the Bellaria Hospital, Bologna, Italy), between January 1997 and December 2012, for the removal of infra- and/or supradiaphragmatic craniopharyngiomas. Twenty-nine patients (28.2%) had previously been surgically treated.

RESULTS

The authors achieved overall gross-total removal in 68.9% of the cases: 78.9% in purely infradiaphragmatic lesions and 66.3% in lesions involving the supradiaphragmatic space. Among lesions previously treated surgically, the gross-total removal rate was 62.1%. The overall improvement rate in visual disturbances was 74.7%, whereas worsening occurred in 2.5%. No new postoperative defect was noted. Worsening of the anterior pituitary function was reported in 46.2% of patients overall, and there were 38 new cases (48.1% of 79) of postoperative diabetes insipidus. The most common complication was postoperative CSF leakage; the overall rate was 14.6%, and it diminished to 4% in the last 25 procedures, thanks to improvement in reconstruction techniques. The mortality rate was 1.9%, with a mean follow-up duration of 48 months (range 3-246 months).

CONCLUSIONS

The endoscopic endonasal approach has become a valid surgical technique for the management of craniopharyngiomas. It provides an excellent corridor to infra- and supradiaphragmatic midline craniopharyngiomas, including the management of lesions extending into the third ventricle chamber. Even though indications for this approach are rigorously lesion based, the data in this study confirm its effectiveness in a large patient series.

A Perfusion-based Human Cadaveric Model for Management of Carotid Artery Injury during Endoscopic Endonasal Skull Base Surgery

Objective To create and develop a reproducible and realistic training environment to prepare residents and trainees for arterial catastrophes during endoscopic endonasal surgery. Design An artificial blood substitute was perfused at systolic blood pressures in eight fresh human cadavers to mimic intraoperative scenarios. Setting The USC Keck School of Medicine Fresh Tissue Dissection Laboratory was used as the training site. Participants Trainees were USC neurosurgery residents and junior faculty. Main Outcome A 5-point questionnaire was used to assess pre- and posttraining confidence scores. Results High-pressure extravasation at normal arterial blood pressure mimicked real intraoperative internal carotid artery (ICA) injury. Residents developed psychomotor skills required to achieve hemostasis using suction, cottonoids, and muscle grafts. Questionnaire responses from all trainees reported a realistic experience enhanced by the addition of the perfusion model. Conclusions The addition of an arterial perfusion system to fresh tissue cadavers is among the most realistic training models available. This enables the simulation of rare intraoperative scenarios such as ICA injury. Strategies for rapid hemostasis and implementation of techniques including endoscope manipulation, suction, and packing can all be rehearsed via this novel paradigm.

Endoscopic endonasal skull base approach for parasellar lesions: Initial experiences, results, efficacy, and complications

BACKGROUND

Endoscopic surgery is suitable for the transsphenoidal approach; it is minimally invasive and provides a well-lit operative field. The endoscopic skull base approach through the large opening of the sphenoid sinus through both nostrils has extended the surgical indication for various skull base lesions. In this study, we describe the efficacy and complications associated with the endoscopic skull base approach for extra- or intradural parasellar lesions based on our experiences.

METHODS

Seventy-four cases were treated by an endoscopic skull base approach. The indications for these procedures included 55 anterior extended approaches, 10 clival approaches, and 9 cavernous approaches. The operations were performed through both the nostrils using a rigid endoscope. After tumor removal, the skull base was reconstructed by a multilayered method using a polyglactin acid (PGA) sheet.

RESULTS

Gross total resection was achieved in 82% of pituitary adenomas, 68.8% of meningiomas, and 60% of craniopharyngiomas in anterior extended approach and in 83.3% of chordomas in clival approach, but only in 50% of the tumors in cavernous approach. Tumor consistency, adhesion, and/or extension were significant limitations. Visual function improvements were achieved in 37 of 41 (90.2%) cases. Cerebrospinal fluid (CSF) leakage (9.5%), infections (5.4%), neural injuries (4.1%), and vascular injuries (2.7%) were the major complications.

CONCLUSIONS

Our experiences show that the endoscopic skull base approach is a safe and effective procedure for various parasellar lesions. Selection of patients who are unlikely to develop complications seems to be an important factor for procedure efficacy and good outcome.

Tumors of the anterior skull base

A variety of histologic tumor types are present in the anterior skull base. Primary tumors of this area may be derived from the bone, paranasal sinuses, nasopharynx, dura, cranial nerves, pituitary gland and brain. Symptoms are caused mostly through mass effect but, if the tumor becomes aggressive, also through invasion. Selection of surgical approaches to the anterior skull base is based upon balancing risk reduction with maximizing extent of resection. Here we review a spectrum of neoplastic entities found in the anterior skull base in adults and discuss clinical and radiographic presentation, treatment options, and outcomes. Surgical resection remains the mainstay in treatment of these tumors, particularly in the hands of experienced surgeons exercising proper patient and case selection.

One-piece modified gasket seal technique

Objectives Review the effectiveness of a modified gasket seal technique utilizing a porous high-density polyethylene plate/rectus sheath fascia construct without fat grafting for primary closure of anterior defects following endoscopic skull base surgery. Design Retrospective review (2011-2012). Setting Single academic medical center. Methods A retrospective review of five patients who underwent expanded endoscopic endonasal surgery for various pathologies (two craniopharyngiomas, two tuberculum meningiomas, and one planum meningioma) was performed. Skull base closure was performed using a one-piece modified gasket seal technique. Primary outcome measures included postoperative cerebrospinal fluid (CSF) leaks and donor site morbidity. Results There were no postoperative CSF leaks. Two patients experienced aseptic meningitis treated with a 14-day course of steroids. Two patients experienced new postoperative chronic/recurrent sinusitis treated with oral antibiotics and topical nasal therapy. There was no donor site morbidity such as infection, hematoma, or hernias. Conclusions The one-piece modified gasket-seal closure is a safe and effective method for reconstruction of endonasal defects of the anterior skull base. Rectus sheath fascia is an appropriate dural substitute for free tissue grafting with low donor site morbidity. The construction of the one-piece graft significantly decreases operative time and lowers the learning curve for multilayered closure.

Microsurgical resection of extensive craniopharyngiomas using a frontolateral approach: operative technique and outcome

OBJECT

An extensive craniopharyngioma is a tumor that extends into multiple compartments (subarachnoid spaces) and attains a size larger than 4 cm. A wide spectrum of approaches and strategies has been used for resection of such craniopharyngiomas. In this report the authors focused on the feasibility and efficacy of microsurgical resection of extensive craniopharyngiomas using a frontolateral approach.

METHODS

A retrospective analysis was performed on 16 patients with extensive craniopharyngiomas who underwent operations using a frontolateral approach at one institution. The preoperative and postoperative clinical and radiological data, as well as the operative videos, were reviewed. The main focus of the review was the extent of radical tumor removal, early postoperative outcome, and approach-related complications.

RESULTS

Gross-total resection of craniopharyngioma was achieved in 14 (87.5%) of 16 cases. Early after surgery (within 3 months), 1 patient showed improvement in hormonal status, while in the remaining 15 patients it worsened. No major neurological morbidity was observed. Two patients experienced temporary psychotic disorders. Visual function improved in 6 patients and remained unchanged in 9. One patient experienced a new bitemporal hemianopsia. Three patients with features of short-term memory disturbances at presentation did show improvement after surgery. There were no deaths or significant approach-related morbidity in this patient series. Only 1 patient required revision surgery for a CSF leak.

CONCLUSIONS

The safe and simple frontolateral approach provides adequate access even to extensive craniopharyngiomas and enables their complete removal with a reasonable morbidity and approach-related complication rate.

Minimally invasive management of adult craniopharyngiomas: An analysis of our series and review of literature

Background:

Craniopharyngiomas (CPs) are slow growing tumors with an incidence of between 1.2% and 4.6%, having a bimodal age distribution typically peaking in childhood and in adults between 45 and 60 years. Recurrences occur even after documented gross total resections necessitating a combination of therapeutic strategies. Obtaining a cure of this tumor in adults without producing major side effects continues to remain elusive.

Methods:

We describe our results in 11 patients with CP treated in a minimally invasive fashion using a combination of techniques like burr hole aspiration, Ommaya reservoir placement, ventriculo-peritoneal (VP) shunting and focal radiation (Gamma Knife stereotactic radiosurgery/Intensity modulated radiotherapy [GKRS/IMRT]).

Results:

Visual function remained intact in all patients; endocrine status remained stable with two patients developing new postoperative diabetes insipidus. There was no periprocedural morbidity or mortality, with hospital stays for any in-patient procedure being 48 hours or less.

Conclusions:

Minimally invasive techniques such as cyst aspiration, insertion of a catheter with Ommaya reservoir, when combined with stereotactic radiosurgery/IMRT is an effective and safe option for management and long-term control of adult CPs. We believe the Ommaya catheter by itself could act as a stent, creating a tract allowing gradual drainage of cyst fluid and stabilization without necessitating any further interventions in selected cases.

Initial experiences with endoscopic rhino-neurosurgery in Amsterdam

Endoscopic surgery of the skull base has been on the rise for several years. Endoscopic access for surgery can be achieved from the frontal sinus anteriorly along the skull base to the odontoid process posterior inferiorly. An endoscope is inserted through one nasal corridor and allows visualization of the working field and up to three surgical instruments can be used to address the lesion. This is called the "two nostrils-four hands technique". This is a retrospective study of 67 cases. Setting of the study is an Amsterdam University hospital. Cases were identified in the department of otorhinolaryngology and department of neurosurgery database. All patients operated between 1 January, 2008 and 1 February, 2012 with pituitary tumours that extend beyond the sella, sinonasal tumours and all non-pituitary skull-base tumours were included. Mean tumour diameter was 3.8 cm. We performed a near-to-gross total resection in 92% of cases where we intended to perform a total resection. The most frequent complication was CSF leakage. This study demonstrates that this technique is safe and reliable. What is needed is a dedicated team, which includes a dedicated anesthesiologist, endocrinologist, ophthalmologist, and radiation oncologist.

The risk of meningitis following expanded endoscopic endonasal skull base surgery: a systematic review

Objective To examine the risk of postoperative meningitis following expanded endoscopic endonasal skull base (EESB) surgery. Setting A systematic analysis of publications identified through searches of the electronic databases from Embase (1980-July 17, 2012), Medline (1950-July 17, 2012), and references of review articles. Main Outcome Measures Incidence of meningitis following EESB surgery. Results A total of 2,444 manuscripts were selected initially, and full-text analysis produced 67 studies with extractable data. Fifty-two contained data regarding the frequency of postoperative meningitis. The overall risk of postoperative meningitis following EESB surgery was 1.8% (36 of 2,005). For those reporting a cerebrospinal fluid (CSF) leak, meningitis occurred in 13.0% (35 of 269). For those not reporting a CSF leak, meningitis occurred in 0.1% (1 of 1,736). The odds ratio for the development of meningitis in the presence of a postoperative CSF leak was 91.99 (95% confidence interval, 11.72-721.88; p < 0.01). There was no difference in reported incidence of meningitis or CSF leak between anterior and posterior cranial fossa surgery. There was one reported case of meningitis-related mortality following EESB surgery. Conclusion The evidence in skull base surgery is limited. This study demonstrates a low incidence of meningitis (1.8%) following EESB procedures. The incidence of meningitis from EESB surgery without an associated CSF leak is uncommon.

Single-surgeon fully endoscopic endonasal transsphenoidal surgery: outcomes in three-hundred consecutive cases

The objective of this study was to evaluate outcomes of endoscopic transsphenoidal surgery using a single-surgeon technique as an alternative to the more commonly employed two-surgeon, three-hand method. Three hundred consecutive endoscopic transsphenoidal procedures performed over a 5 year period from 2006 to 2011 were reviewed. All procedures were performed via a binasal approach utilizing a single surgeon two handed technique with a pneumatic endoscope holder. Expanded enodnansal cases were excluded. Surgical technique, biochemical and surgical outcomes, and complications were analyzed. 276 patients underwent 300 consecutive surgeries with a mean follow-up period of 37 ± 22 months. Non-functioning pituitary adenoma (NFPA) was the most common pathology (n = 152), followed by growth hormone secreting tumors (n = 41) and Rathke's cleft cysts (n = 30). Initial gross total cyst drainage based on radiologic criteria was obtained in 28 cases of Rathke's cleft cyst, with 5 recurrences. For NFPA and other pathologies (n = 173) gross total resection was obtained in 137 cases, with a 92% concordance rate between observed and expected extent of resection. For functional adenoma, remission rates were 30/41 (73%) for GH-secreting, 12/12 (100%) for ACTH-secreting, and 8/17 (47%) for prolactin-secreting tumors. Post-operative complications included transient (11%) and permanent (1.4%) diabetes insipidus, hyponatremia (13%), and new anterior pituitary hormonal deficits (1.4%). CSF leak occurred in 42 cases (15%), and four patients required surgical repair. Two carotid artery injuries occurred, both early in the series. Epistaxis and other rhinological complications were noted in 10% of patients, most of which were minor and diminished as surgical experience increased. Fully endoscopic single surgeon transsphenoidal surgery utilizing a binasal approach and a pneumatic endoscope holder yields outcomes comparable to those reported with a two-surgeon method. Endoscopic outcomes appear to be better than those reported in microscope-based series, regardless of a one or two surgeon technique.

The artery of Percheron: an anatomic study with potential neurosurgical and neuroendovascular importance

BACKGROUND

One variant branch of the P1 segment of the posterior cerebral artery (PCA) is the artery of Percheron (AOP). This unilateral trunk supplies thalami and potentially mesencephalic structures. As studies of this vessel are scant in the literature and damage to this artery can have catastrophic results, the authors performed this study to better elucidate its morphology.

MATERIALS AND METHODS

Twenty-five adult latex-injected cadaveric heads underwent brain removal and microdissection with specific attention to the presence of the AOP. When identified, measurements were made and observations given to the origin and course of this vessel. A case illustration is also presented that demonstrates bilateral thalamic and midbrain infarctions most likely due to thrombosis of the AOP.

RESULTS

An AOP was identified in three specimens (12%)-2 right and 1 left side (1 male and 2 female specimens) and arose, on average, 8 mm lateral to the basilar artery bifurcation. The average diameter was 2.1 mm, and the length between the origin and brain penetration had a mean distance of 1.5 cm. In all specimens, the AOP had a coiled appearance, especially in its proximal extraparenchymal segment. The contralateral P1 segment of the PCA was not absent or hypoplastic in any of the three specimens. All arteries supplied small branches to the ipsilateral and contralateral thalami and midbrain.

CONCLUSIONS

Knowledge of the AOP may be important during surgical or neuroendovascular approaches to the basilar bifurcation or during interpretation of imaging, especially in patients presenting with bilateral thalamic and midbrain infarctions.

[Transnasal endoscopic approaches to the cranial base]

Recent advances in surgical endoscopy have made it possible to reach nearly the whole cranial base through a transnasal approach. These 'expanded approaches' lead to the frontal sinuses, the cribriform plate and planum sphenoidale, the suprasellar space, the clivus, odontoid and atlas. By pointing the endoscope laterally, the surgeon can explore structures in the coronal plane such as the cavernous sinuses, the pyramid and Meckel cave, the sphenopalatine and subtemporal fossae, and even the middle fossa and the orbit. The authors of this contribution use most of these approaches in their endoscopic skull base surgery. The purpose of this contribution is to review the hitherto established endoscopic approaches to the skull base and to illustrate them with photographs obtained during self-performed procedures and/or cadaver studies.

Value of Free-Run Electromyographic Monitoring of Extraocular Cranial Nerves during Expanded Endonasal Surgery (EES) of the Skull Base

Objective To evaluate the value of free-run electromyography (f-EMG) monitoring of extraocular cranial nerves (EOCN) III, IV, and VI during expanded endonasal surgery (EES) of the skull base in reducing iatrogenic cranial nerve (CN) deficits.

Design We retrospectively identified 200 patients out of 990 who had at least one EOCN monitored during EES. We further separated patients into groups according to the specific CN monitored. In each CN group, we classified patients who had significant (SG) f-EMG activity as Group I and those who did not as Group II.

Results A total of 696 EOCNs were monitored. The number of muscles supplied by EOCNs that had SG f-EMG activity was 88, including CN III = 46, CN IV = 21, and CN VI = 21. There were two deficits involving CN VI in patients who had SG f-EMG activity during surgery. There were 14 deficits observed, including CN III = 3, CN IV = 2, and CN VI = 9 in patients who did not have SG f-EMG activity during surgery.

Conclusions f-EMG monitoring of EOCN during EES can be useful in identifying the location of the nerve. It seems to have limited value in predicting postoperative neurological deficits. Future studies to evaluate the EMG of EOCN during EES need to be done with both f-EMG and triggered EMG.

Displacement of mammillary bodies by craniopharyngiomas involving the third ventricle: surgical-MRI correlation and use in topographical diagnosis

OBJECT

Accurate diagnosis of the topographical relationships of craniopharyngiomas (CPs) involving the third ventricle and/or hypothalamus remains a challenging issue that critically influences the prediction of risks associated with their radical surgical removal. This study evaluates the diagnostic accuracy of MRI to define the precise topographical relationships between intraventricular CPs, the third ventricle, and the hypothalamus.

METHODS

An extensive retrospective review of well-described CPs reported in the MRI era between 1990 and 2009 yielded 875 lesions largely or wholly involving the third ventricle. Craniopharyngiomas with midsagittal and coronal preoperative and postoperative MRI studies, in addition to detailed descriptions of clinical and surgical findings, were selected from this database (n = 130). The position of the CP and the morphological distortions caused by the tumor on the sella turcica, suprasellar cistern, optic chiasm, pituitary stalk, and third ventricle floor, including the infundibulum, tuber cinereum, and mammillary bodies (MBs), were analyzed on both preoperative and postoperative MRI studies. These changes were correlated with the definitive CP topography and type of third ventricle involvement by the lesion, as confirmed surgically.

RESULTS

The mammillary body angle (MBA) is the angle formed by the intersection of a plane tangential to the base of the MBs and a plane parallel to the floor of the fourth ventricle in midsagittal MRI studies. Measurement of the MBA represented a reliable neuroradiological sign that could be used to discriminate the type of intraventricular involvement by the CP in 83% of cases in this series (n = 109). An acute MBA (< 60°) was indicative of a primary tuberal-intraventricular topography, whereas an obtuse MBA (> 90°) denoted a primary suprasellar CP position, causing either an invagination of the third ventricle (pseudointraventricular lesion) or its invasion (secondarily intraventricular lesion; p < 0.01). A multivariate model including a combination of 5 variables (the MBA, position of the hypothalamus, presence of hydrocephalus, psychiatric symptoms, and patient age) allowed an accurate definition of the CP topography preoperatively in 74%-90% of lesions, depending on the specific type of relationship between the tumor and third ventricle.

CONCLUSIONS

The type of mammillary body displacement caused by CPs represents a valuable clue for ascertaining the topographical relationships between these lesions and the third ventricle on preoperative MRI studies. The MBA provides a useful sign to preoperatively differentiate a primary intraventricular CP originating at the infundibulotuberal area from a primary suprasellar CP, which either invaginated or secondarily invaded the third ventricle.

Craniopharyngioma: history

One of the most challenging parasellar tumors, the craniopharyngioma was first described by Friedrich Albert von Zenker in 1857. Following improved understanding of pituitary gland physiology and development, Jakob Erdheim became the first to accurately describe the histopathological characteristics of a craniopharyngioma. Babinski's described the clinical presentation of these patients, with "sexual infantilism and dystrophic adiposity." The first successful surgical resection of a craniopharyngioma was performed by A. E. Halstead of Chicago of July 21st, 1909. Harvey Cushing embraced the transsphenoidal approach for the majority of his pituitary operations, but favored the transcranial approach for craniopharyngiomas. The introduction of antibiotics, corticosteroids, and microscopy significantly improved surgical outcomes. As technology improved, trans-cranial and transsphenoidal approaches were implemented depending on tumor characteristics. Adjuvant therapy, such as stereotactic radiosurgery, radioisotope brachytherapy, and intracapsular chemotherapy have improved overall tumor control rates and decreased the incidence of complications. Building on over 100 years of surgery for "the most formidable of intracranial tumors," results continue to improve. Regardless, challenges continue to remain requiring surgical insight and innovation.

Surgery for craniopharyngioma

Craniopharyngiomas are rare benign sellar region tumors, which are diagnosed either in childhood or adolescence due to local mass effects on visual pathways, pituitary and hypothalamus, or because of an increased intracranial pressure resulting from obstructive hydrocephalus. The neurosurgeons challenge is to achieve tumor control without aggravating the symptoms. There are essentially two different surgical philosophies. Although only gross tumor resection has been proven to provide cure, the accompanying surgical hazard is substantial. Thus, less aggressive operations with partial or subtotal tumor resection or drainage of cystic portions followed by irradiation may relieve the patient's symptoms and benefit the patient more than a heroic tumor resection-since to date several variants of radiation therapy are available which also serve to control tumor progression. In the present brief review, the surgical techniques and outcomes of operations in craniopharyngiomas with special focus on the resulting morbidity and mortality are summarized.

Endoscopic endonasal skull base surgery in the pediatric population

OBJECT

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.

METHODS

A retrospective review of 133 pediatric patients who underwent EES at our institution from July 1999 to May 2011 was performed.

RESULTS

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.

CONCLUSIONS

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.

Value of multimodality monitoring using brainstem auditory evoked potentials and somatosensory evoked potentials in endoscopic endonasal surgery

OBJECTIVES

To evaluate the value of intraoperative neurophysiological monitoring (IONM) using brainstem auditory evoked potential (BAEP) and somatosensory evoked potential (SSEP) monitoring to predict and/or prevent postoperative neurological deficits during endoscopic endonasal surgery (EES).

METHODS

We retrospectively identified 138 consecutive patients who had BAEP monitoring in addition to SSEP monitoring during EES at our institution. We reviewed the postoperative clinical outcomes and neurophysiological changes independently.

RESULTS

The total of number of patients with any IONM changes was 10. The incidence of BAEP changes was 3.62%. The incidence of SSEP changes was 3.62% as well. One patient had changes in both BAEPs and SSEPs. Majority of the changes were observed during changes in mean arterial pressure (MAP) without any postoperative neurological deficits. There were two postoperative neurological deficits.

DISCUSSION

BAEPs and SSEPs provide unique information about integrity of brainstem function during EES procedures involving tumors in the and around clival region. We advocate a comprehensive multimodality approach to IONM during EESs including BAEPs and SSEPs depending on the location of the neural structures at risk.

Celebrating the golden anniversary of anterior skull base surgery: reflections on the past 50 years and its historical evolution

With its inception nearly half a century ago through the pioneering work of Dandy, McLean, and Smith, anterior skull base (ASB) surgery is a relatively young discipline. It became a distinct entity in 1963 when Ketcham popularized the combined transcranial transfacial approach for en bloc resection of tumors of the paranasal sinuses extending into the anterior cranial fossa. However, because these procedures resulted in major morbidities and mortalities, alternative modes of treatment were sought. Since the 1970s, the introduction and promotion of the surgical endoscope by Messerklinger, Stammberger, and Kennedy, commenced the era of endoscopic sinus surgery. Thaler and colleagues described the utility of the endoscope for ASB surgery at the turn of the century. This allowed direct visualization and safer, more accurate removal of tumors. In 2001, Casiano reported the first purely endoscopic endonasal ASB resection, a novel technique that has been adopted by major skull base centers. The success of ASB surgery can be attributed to both the development of the skull base team as well as improvements in surgical techniques, instrumentation, and visualization technology. In this article, we review the historical evolution of ASB surgery as we approach the 50th anniversary since its recognition as a distinct entity.

A systematic review of published evidence on expanded endoscopic endonasal skull base surgery and the risk of postoperative seizure

Although postoperative seizure is an acknowledged risk following transcranial surgery, the incidence of seizure after removal of intradural pathology via an expanded endoscopic endonasal approach is not well defined. The current study was performed to systematically review the risk of seizure in patients undergoing endoscopic endonasal skull base (EESB) surgery. Embase (1980 to 9 March 2012) and Medline (1950 to 9 March 2012) were searched using a search strategy designed to include any studies that report the perioperative outcomes following EESB surgery. Outcomes of patients undergoing a simple closure of cerebrospinal fluid fistulae or encephaloceles and transellar approaches for pituitary or intrasellar lesions were excluded because this review is focused on large skull base defects. A title search selected those articles relevant to clinical series on expanded endoscopic approaches. A subsequent search of abstracts selected for manuscripts of any report that documented the presence or absence of postoperative seizure. A total of 2234 manuscripts were selected initially and full text analysis produced 67 studies with extractable data regarding the perioperative outcomes for EESB surgery. Of these manuscripts, seven reported the incidence of seizure following EESB procedures. Two of these studies were excluded due to duplication of authorship and institutional data. The overall risk of postoperative seizure following EESB surgery was estimated at 1.1% (six of 530). Subgroup analyses of data revealed that the risk of seizure following an endoscopic endonasal to the anterior cranial base was 2.3% (one patient of 43). For a posterior cranial base approach, the risk of seizure was indeterminate due to deficiency of reporting in the current literature. We concluded that the risk of seizure following an EESB procedure appears to be low (1%). However, the lack of reporting on the incidence of seizures or the use of antiepileptic prophylaxis following EESB procedure is a key limitation. Future EESB studies will need to include seizure as an outcome to accurately define this risk.

Minimally invasive approaches to the anterior skull base

The use of minimally invasive approaches to the anterior skull base is a valuable tool to improving the treatment in patients with aggressive anterior skull base neoplasms. This article discusses the history, advantages and disadvantages relative to open approaches, the corridors and pathways used in approach, the equipment and operating room setup, perioperative care, and complication avoidance. Although outcomes are difficult to compare to open approaches, due to often small and varying patient cohorts, these approaches continue to gain acceptance as an effective treatment of anterior skull base tumors in the experienced surgeon's hands with proper patient selection.

A Vascular Catastrophe during Endonasal Surgery: An Endoscopic Sheep Model

Internal carotid artery (ICA) injury is a dramatic complication of endonasal skull base approaches with massive bleeding. This study aims to design an animal model of ICA injury during endonasal skull base surgery. Eight sheep underwent ICA isolation followed by arterial pressure monitoring and placement of a rapid infuser. The Sinus Model Otorhino Neuro Trainer (Pro Delphus, Pernambuco, Brazil) nasal model was then modified. A novel posterior sphenoid wall was created, allowing the artery to be placed within and fixed to the model in a watertight fashion. A diamond-tipped bur allowed surgical exposure of the carotid artery. A standardized injury was created endoscopically. The "two-surgeon technique" allowed local packing measures to be performed. Outcome measures were mean arterial pressure (MAP) following injury, resuscitation fluid volume, survival time, and total blood loss. Mean preinjury weight was 51.8 ± 4.59 kg. All baseline hematologic parameters fell within normal limits. The mean preinjury and postinjury MAP was 65.7 ± 9.3 mm Hg versus 39.1 ± 6.9 mm Hg, respectively. The mean survival time was 50.25 ± 17.89 minutes, with mean resuscitation fluid volume of 10.89 ± 2.40 L and mean blood loss of 4943 ± 1089 mL. This model replicates the endoscopic surgical field of an ICA injury, with the potential to train endoscopic skull base teams in the skills require to manage an ICA injury.

Endoscopic endonasal infrasellar approach to the sellar and suprasellar regions: technical note

We report a technical variation of the endoscopic endonasal approach to the sellar and suprasellar regions which relies on the use of a 45-degree angled endoscope. The so-called "infrasellar approach" aims at excising lesions situated within the intermediate and posterior lobes of the pituitary gland without damaging the anterior lobe, thus potentially minimizing endocrinological morbidity. In this regard the endoscopic infrasellar approach might be advantageous in selected cases when compared with the traditional transsphenoidal approach with the microscope. We describe the technique and illustrate it with representative clinical cases.

Endoscopic, endonasal resection of craniopharyngiomas: analysis of outcome including extent of resection, cerebrospinal fluid leak, return to preoperative productivity, and body mass index

BACKGROUND

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.

The endoscopic endonasal approach for the management of craniopharyngiomas involving the third ventricle

The third ventricle has historically represented one of the most challenging areas to access surgically, so that lesions directly harboring into the ventricular chamber or secondarily extending into it from adjacent areas have been approached by means of different transcranial routes. The aim of this work is to report our experience with the endoscopic endonasal approach in the management of a series of patients affected by craniopharyngiomas, extending into or arising from the third ventricle, evaluating pros and cons of this technique, also in regards of the anatomy and the pathology dealt with. During the period between January 2001 and February 2011, 12 patients, 9 male and 3 female (mean age 50.4 years; range 12-68) underwent an endoscopic endonasal approach for the treatment of a craniopharyngioma involving or arising from the third ventricle. According to the grade of involvement of the third ventricle, we identified three main ventricular growth patterns: (1) stalk-infundibulum; (2) infundibulum-ventricular chamber; (3) stalk-infundibulum-ventricular chamber. Though gross total removal was achieved in eight patients (66.7%), in three patients (25%) was possible a near total removal (>95%) and only in one case (8.3%) tumor removal has been partial (<50%). The overall analysis revealed a rate of 77.8% improvement of post-operative visual defects. Concerning the complications, we reported an overall CSF rate of 16.7%; two patients developed a subdural hematoma that has been treated with a surgical drainage. One patient died after the occurrence of a brainstem hemorrhage. The endoscopic endonasal route provides a good exposure, especially of the sub- and retro-chiasmatic areas, as well as of the stalk-infundibulum axis, which represents, when directly involved by a lesion, a gate to access the third ventricle chamber. Despite this study reporting only a preliminary experience, it seems that in properly selected cases--namely tumors growing mostly along the pituitary stem-infundibulum-third ventricle axis--this approach could be advocated as a valid route among the wide kaleidoscope of surgical approaches to the third ventricle.