Endoscopic endonasal compared with microscopic transsphenoidal and open transcranial resection of craniopharyngiomas

Surgical management of pituicytomas: case series and comprehensive literature review

OBJECTIVE

Pituicytomas are rare neoplasms that typically present as solid, noninfiltrative tumors occupying the sella and/or suprasellar space for which there is no consensus on optimal surgical management. We aimed to define a preferred surgical strategy for these tumors based on our clinical experience and comprehensive review of the world literature.

DESIGN

Case series and review of the literature.

METHODS

We documented the clinical, radiographic, and surgical findings of three patients with pituicytoma treated at our institution, as well as complications and long-term outcomes. A comprehensive review of the medical literature identified all cases of pituicytoma for which data regarding surgical approach, outcome and complications could be extracted. We compared our results with published data.

RESULTS

All three cases at our institution achieved gross total removal. Two patients underwent an expanded endoscopic endonasal transsphenoidal and transplanum (EETS-TP) approach, while one tumor was removed via craniotomy. Post-operatively all patients developed pan-hypopitutarism. The patient undergoing craniotomy suffered profound visual loss but no other neurological complications were noted. A literature review identified 67 reported cases of pituicytoma. Surgical data was available in 60 cases. Surgical approach was documented in 57 patients. Sixty-three surgeries were performed in which approach and extent of resection was available. Gross total removal was obtained in 33 % of craniotomies, 42 % of transsphenoidal procedures, and 100 % of expanded transsphenoidal procedures. Neurological complications including visual loss, hemiparesis and cranial nerve palsies were reported after craniotomy, but not after transsphenoidal approaches. Overall EETS-TP approaches were associated with the highest rate of gross total removal and no visual or neurological complications.

CONCLUSIONS

EETS-TP surgery is the preferred strategy for surgical removal of pituicytoma. EETS-TP and transsphenoidal approaches are associated with higher rates of gross total removal and lower rates of neurological complications than craniotomy. Gross total removal should be the intended goal of surgery.

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.

Management of craniopharyngiomas

Craniopharyngiomas are rare epithelial tumours arising along the path of the craniopharyngeal duct. Their pathogenesis remains uncertain and they can present with a variety of manifestations attributed to pressure effects to surrounding structures. The optimal management of craniopharyngiomas remains challenging mainly due to their sharp, irregular borders and their tendency to adhere to vital neurovascular structures making surgical manipulations potentially hazardous to vital brain areas. Non-aggressive surgery followed by radiotherapy is currently the most widely used option possibly achieving the most optimal long-term outcome. Other treatment modalities including intracystic irradiation, intracystic instillation of antineoplasmatic agents and stereotactic radiotherapy are also available in our armamentarium. The long-term morbidities related with the craniopharyngiomas and their treatment remain significant, with hypothalamic damage playing the protagonist role and requiring further studies to identify measures that will improve the prognosis of the patients.

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.

Unilateral Basal interhemispheric approach through the sphenoid sinus to retrochiasmatic and intrasellar craniopharyngiomas: surgical technique and results

OBJECTIVE

In the treatment of craniopharyngioma, complete surgical removal offers the best chance of cure and recurrence prevention. The basal interhemispheric approach involves problems with difficulty resecting tumors in the retrochiasmatic space located behind the optic chiasm and inability to resect, under direct view, tumors extending into the sella turcica. We report our approach via the sphenoid sinus devised to resolve these problems.

METHODS

A unilateral basal interhemispheric approach is planned for tumor resection. In cases in which the prechiasmatic space is too narrow to be utilized or the tumor has extended into the sella turcica, the prechiasmatic space is expanded by shaving the sphenoid surface and the tuberculum sellae. If the tumor inside the sella turcica needs to be removed, the anterior wall of the sella turcica also is shaved to permit tumor resection.

RESULTS

This technique was applied to 7 cases in total (in 3 cases to achieve prechiasmatic space expansion and in 4 cases for intrasellar tumor resection). Gross total removal was achieved in 6 cases and subtotal removal in 1. Of the 6 cases with preoperative visual field defects, 5 showed alleviation of these defects. The 5 patients with partial hypopituitarism developed complete panhypopituitarism postoperatively. All 7 patients have not suffered from postoperative cerebrospinal fluid leakage and meningitis.

CONCLUSIONS

This approach allowed a working space to be secured even in cases with a narrow prechiasmatic space, allowing tumor freeing from the lower plane of the optic nerve and safe resection of the intrasellar tumor.

Comparative effectiveness of treatment options for pediatric craniopharyngiomas

OBJECT

No clear treatment guidelines for pediatric craniopharyngiomas exist. The authors developed a decision analytical model to evaluate outcomes of 4 surgical approaches for craniopharyngiomas in children, including attempted gross-total resection (GTR), planned subtotal removal plus radiotherapy, biopsy plus radiotherapy, and endoscopic resections of all kinds.

METHODS

Pooled data, including the authors' own experience, were used to create evidence tables, from which incidence, relative risks, and summary outcomes in quality-adjusted life years (QALYs) were calculated for the 4 management strategies.

RESULTS

Quality-adjusted life years at the 5-year follow-up were 2.3 ± 0.1 for attempted GTR, 2.9 ± 0.2 for planned subtotal removal plus radiotherapy, 3.9 ± 0.2 for biopsy plus radiotherapy, and 3.7 ± 0.2 for endoscopic resection (F = 17,150, p < 0.001). Similarly, QALYs at 10-year follow-up were 4.5 ± 0.2 for attempted GTR, 5.7 ± 0.5 for planned subtotal removal plus radiotherapy, and 7.8 ± 0.5 for biopsy plus radiotherapy (F = 6,173, p < 0.001). On post hoc pairwise comparisons, the differences between all pairs compared were also highly significant (p < 0.001). Since follow-up data at 10 years are lacking for endoscopic cases, this category was excluded from 10-year comparisons.

CONCLUSIONS

Biopsy with subsequent radiotherapy is the preferred approach with respect to improved overall quality of life. While endoscopic approaches also show promise in preserving quality of life at five-year follow-up, there are not sufficient data to draw conclusions about this comparison at 10 years.

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.

Frontobasal interhemispheric approach for large superasellar craniopharyngiomas: do the benefits outweigh the risks?

OBJECTIVE

Large suprasellar craniopharyngiomas are surgically challenging. The aim of our study was to explore the therapeutic efficacy of the frontobasal interhemispheric approach for these lesions.

METHODS

Twenty-nine consecutive adult patients with large suprasellar craniopharyngiomas (diameter >4 cm) who underwent the frontobasal interhemispheric approach were retrospectively evaluated. Surgical and clinical outcomes were analyzed.

RESULTS

Gross total removal was achieved in 23 cases (79.3%) and subtotal removal in 6 cases (20.7%). The mean follow-up period was 76.5 ± 33.2 months (range, 12-132 months). Twenty-four patients (82.7%) had improvement of the visual impairment score (VIS) after surgery. VIS was unchanged in five patients (17.3%), and no patients experienced visual deterioration. Among 23 patients who had preoperative hypopituitarism, 8 (34.8%) had an improvement. Postoperative new or aggravated hypopituitarism was observed in four patients (13.8%). Permanent diabetes insipidus was observed in ten patients (34.4%). Postoperative anosmia occurred in two earlier cases (6.9%). There was no intracranial infection or cerebrospinal fluid fistula. At last follow-up, >9% BMI gain was observed in 34.5% of patients, and 65.5% of patients returned to work. Four patients (13.8%) suffered recurrence.

CONCLUSION

Although the frontobasal interhemispheric approach has some disadvantages, it provides ideal access to the suprasellar region and the third ventricle with limited brain retraction. The surgically visible angle is adequate; thus, vital structures can be better protected. For large suprasellar craniopharyngiomas, the benefits of this approach can outweigh its potential risks.

Surgical fidelity: comparing the microscope and the endoscope

BACKGROUND

Both the microscope and the endoscope are widely used as visualization tools in neurosurgery; however, surgical dexterity when operating with each may differ. The aim of this study was to compare the surgical fidelity when using each of these visualization tools.

METHODS

Junior residents and expert surgeons performed standardized motor tasks under microscopic and endoscopic visualization. Demerits for inaccuracy and time needed to complete the tasks were used to compare the surgeons' performance with the microscope and the endoscope. The participants also performed a motor task under direct vision using different instruments to evaluate whether the shape of the instrument had any impact on the surgical fidelity.

RESULTS

For the junior residents, the number of demerits accrued was lower with the microscope than with the endoscope, and the time needed to complete the tasks was also lower with the microscope. There was no difference in the number of demerits between the microscopic and the endoscopic experts, but the microscopic expert completed the task in a shorter time. There was no difference in demerits or performance time when comparing a short, straight instrument and a longer, bayoneted one.

CONCLUSIONS

For junior residents, surgical fidelity is higher with the microscope than with the endoscope. This difference vanishes with experience, but a slower speed of execution is observed with endoscopic visualization, both in junior and expert surgeons.

[Endonasal skull base endoscopy]

INTRODUCTION AND OBJECTIVE

The endoscopic endonasal techniques used in skull base surgery have evolved greatly in recent years. Our study objective was to perform a qualitative systematic review of the likewise systematic reviews in published English language literature, to examine the evidence and conclusions reached in these studies comparing transcranial and endoscopic approaches in skull base surgery.

MATERIAL AND METHODS

We searched the references on the MEDLINE and EMBASE electronic databases selecting the systematic reviews, meta-analyses and evidence based medicine reviews on skull based pathologies published from January 2000 until January 2013. We focused on endoscopic impact and on microsurgical and endoscopic technique comparisons.

RESULTS

Full endoscopic endonasal approaches achieved gross total removal rates of craniopharyngiomas and chordomas higher than those for transcranial approaches. In anterior skull base meningiomas, complete resections were more frequently achieved after transcranial approaches, with a trend in favour of endoscopy with respect to visual prognosis. Endoscopic endonasal approaches minimised the postoperative complications after the treatment of cerebrospinal fluid (CSF) leaks, encephaloceles, meningoceles, craniopharyngiomas and chordomas, with the exception of postoperative CSF leaks.

CONCLUSIONS

Randomized multicenter studies are necessary to resolve the controversy over endoscopic and microsurgical approaches in skull base surgery.

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.

Patterns in neurosurgical adverse events: intracranial neoplasm surgery

Object

Neurosurgery is a high-risk specialty currently undertaking the pursuit of systematic approaches to measuring and improving outcomes. As part of a project to devise evidence-based safety interventions for specialty surgery, the authors sought to review current evidence in cranial tumor resection concerning the frequency of adverse events in practice, their patterns, and current methods of reducing the occurrence of these events. This review represents part of a series of papers written to consolidate information about these events and preventive measures as part of an ongoing effort to ascertain the utility of devising system-wide policies and safety tools to improve neurosurgical practice.

Methods

The authors performed a PubMed search using search terms “intracranial neoplasm,” “cerebral tumor,” “cerebral meningioma,” “glioma,” and “complications” or “adverse events.” Only papers that specifically discussed the relevant complication rates were included. Papers were chosen to maximize the range of rates of occurrence for the reported adverse events.

Results

Review of the tumor neurosurgery literature showed that documented overall complication rates ranged from 9% to 40%, with overall mortality rates of 1.5%–16%. There was a wide range of types of adverse events overall. Deep venous thromboembolism (DVT) was the most common adverse event, with a reported incidence of 3%–26%. The presence of new or worsened neurological deficit was the second most common adverse event found in this review, with reported rates ranging from 0% for the series of meningioma cases with the lowest reported rate to 20% as the highest reported rate for treatment of eloquent glioma. Benign tumor recurrence was found to be a commonly reported adverse event following surgery for intracranial neoplasms. Rates varied depending on tumor type, tumor location, patient demographics, surgical technique, the surgeon's level of experience, degree of specialization, and changes in technology, but these effects remain unmeasured. The incidence on our review ranged from 2% for convexity meningiomas to 36% for basal meningiomas. Other relatively common complications were dural closure–related complications (1%–24%), postoperative peritumoral edema (2%–10%), early postoperative seizure (1%–12%), medical complications (6%–7%), wound infection (0%–4%), surgery-related hematoma (1%–2%), and wrong-site surgery.

Strategies to minimize risk of these events were evaluated. Prophylactic techniques for DVT have been widely demonstrated and confirmed, but adherence remains unstudied. The use of image guidance, intraoperative functional mapping, and real-time intraoperative MRI guidance can allow surgeons to maximize resection while preserving neurological function. Whether the extent of resection significantly correlates with improved overall outcomes remains controversial.

Discussion

A significant proportion of adverse events in intracranial neoplasm surgery may be avoidable by use of practices to encourage use of standardized protocols for DVT, seizure, and infection prophylaxis; intraoperative navigation among other steps; improved teamwork and communication; and concentrated volume and specialization. Systematic efforts to bundle such strategies may significantly improve patient outcomes.

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.

Dr. Otto “Tiger” Freer: inventor and innovator

Every neurosurgeon develops his or her own standard approach to common intracranial pathologies in terms of the order in which different stages are performed and which instruments are used to perform individual tasks. The majority of the basic steps in performing a craniotomy are learned through repetition and practice during residency training. Significant amounts of energy are devoted to mastering technical skills and developing an operative rhythm. What often receives little attention is the historical origin of the instruments that make the work possible. The Freer elevator represents a particularly interesting example. To people unfamiliar with the accomplishments of turn-of-the-century laryngologist Otto “Tiger” Freer, it can be assumed that the name of the instrument in one's hand is simply named for what it can do, that is, to “free” the nasal mucosa from the bony and cartilaginous septum during the transsphenoidal approach. The technique this master surgeon spent his life and career perfecting is now repeated almost daily by skull base neurosurgeons approaching pathologies from the inferior frontal lobe to the foramen magnum. In reviewing his life and work, the authors of this paper discovered an interesting creative process that led to the design of the eponymous instrument. Additionally, they discovered important advances toward the development of the transnasal approach and in our understanding of the anterior skull base. They present a historical perspective on the life and accomplishments of Dr. Freer and the ubiquitous surgical instrument that he invented and popularized.