Endoscopic endonasal transsphenoidal approach improves endocrine function and surgical outcome in primary craniopharyngioma resection: a systematic review and meta-analysis.

BACKGROUND: Craniopharyngiomas (CPs) are generally derived from the craniopharyngeal duct epithelium, accounting for 38% and 24.5% of mortality in pediatric and adult patients, respectively. At present, the widespread application of the endoscopic endonasal transsphenoidal approach (EEA) has led to controversy between the traditional microscopic transcranial approach (TCA) and EEA in relation to the surgical management of CPs. OBJECT AND METHOD: We performed a systematic review and meta-analysis comparing the complications, surgical outcomes, and endocrine functions of patients with CPs to provide evidence-based decision-making in their surgical management. RESULT: Overall, 11 observational studies with 12,212 participants were included in the meta-analysis, in which five of them only included an adult population, three of them only included a child population, and the other three studies included a mixed population (adult and child). In pediatric patients, the EEA achieved a higher gross total resection (GTR) rate (odds ratio (OR) = 5.25, 95%CI: 1.21-22.74), lower recurrence rate (OR = 0.54, 95%CI: 0.31-0.94, p = 0.030), and less hypopituitarism (OR = 0.34, 95%CI: 0.12-0.97, p = 0.043). In adult patients, EEA significantly improved mortality (OR = 0.09, 95%CI: 0.06-0.15, p < 0.001) and visual outcomes (visual improvement: OR = 3.42, 95%CI: 1.24-9.40, p = 0.017; visual deficit: OR = 0.30, 95%CI: 0.26-0.35) with decreases in postoperative stroke (OR = 0.58, 95%CI: 0.51-0.66, p < 0.001), hydrocephalus, and infections (OR = 0.32, 95%CI: 0.24-0.42, p < 0.001). CONCLUSION: Compared with the traditional TCA in primary CP resection, the development and wide application of EEA optimistically decreased the recurrence rate of CP, alleviated hypopituitarism with improvement in the GTR rate of pediatric patients, and significantly improved the visual outcomes, hydrocephalus, postoperative stroke, survival, and infection rates of the patients. Therefore, EEA is an optimal approach for primary CP resection.

Advances in surgical approaches for refractory pituitary adenomas.

Refractory pituitary adenomas are difficult to control tumors that progress through optimal surgical, medical, and radiation management. Repeat surgery is a valuable tool to reduce tumor volume for more effective radiation and/or medical therapy, and to decompress critical neurovascular structures. Advances in surgical techniques and technologies, including minimally invasive cranial approaches, intraoperative MRI suites, and cranial nerve monitoring, have improved surgical outcomes and expanded indications. Today, repeat transsphenoidal surgery has similar complications rates to upfront surgery in historical cohorts. The decision to operate on refractory adenomas should be made with multidisciplinary teams, balancing the benefit of tumor reduction with the potential for complications, including cranial nerve injury, carotid injury, and cerebrospinal fluid leak.

[Surgical Approaches to Craniopharyngiomas].

Surgical treatment of craniopharyngioma still presents several challenges. The tumor recurs at a high rate when its removal is insufficient. However, total resection of the tumor has a high risk of complications owing to its proximity to the hypothalamus and the pituitary stalk. In addition, tumor control by radiation treatment is insufficient for long follow-up periods of over 10 years. Therefore, various treatments have been selected, ranging from partial tumor removal followed by radiation to total tumor removal, even if it involves sacrificing pituitary functions. In this article, we explain the surgical treatment with a focus on endoscopic endonasal surgery for craniopharyngiomas.

A survey of surgically resected pituitary incidentalomas and a comparison of the clinical features and surgical outcomes of non-functioning pituitary adenomas discovered incidentally versus symptomatically.

Pituitary tumors are discovered either incidentally by imaging studies (incidentalomas) or via evaluation of certain clinical symptoms (symptomatic tumors). In this study, we first surveyed patients with incidentalomas who underwent surgery. Cases included 62.3% non-functioning adenomas (NFPAs), 14.5% functioning adenomas, and 13.8% Rathke's cleft cysts. Next, we compared the clinical features and surgical outcomes of 145 patients whose preoperative diagnosis was NFPA (incidentalomas [n = 79] vs. symptomatic tumors [n = 66]). The patients with incidentalomas were older (59.9 vs. 55.3 years, p < 0.05) and had smaller tumors compared with the patients with symptomatic tumors (mean maximum diameter: 23.1 vs. 27.5 mm, p < 0.01). The main reason for undergoing imaging studies was headache (n = 25) in the incidentaloma group and visual disturbance (n = 46) in the symptomatic tumor group. The incidence of preoperative pituitary hormone deficiencies was lower in the incidentaloma than symptomatic tumor group (growth hormone deficiency: 37.7% vs. 66.7%, p < 0.01; gonadotropin deficiency: 19.0% vs. 39.4%, p < 0.01; adrenocorticotropic hormone deficiency: 3.8% vs. 18.2%, p < 0.01; thyroid stimulating hormone deficiency: 6.3% vs. 12.1%, p = 0.25). Postoperative pituitary function was better preserved in the incidentaloma than symptomatic tumor group (no deficiency: 58.2% vs. 28.8%, p < 0.01). The difference in postoperative complications between groups was not statistically significant (incidentalomas vs. symptomatic tumors: 21.5% vs. 19.7%, p = 0.84). In conclusion, incidentalomas were detected while smaller size and lower incidence of hormone deficiency than symptomatic tumors, and the pituitary hormones were also preserved after surgery. It is important to observe incidentalomas carefully and to judge whether to operate appropriately before they become symptomatic tumors.

Targeted systemic and peptide radio-ligand therapy for aggressive pituitary tumors and carcinomas.

Aggressive pituitary tumors comprise a rare but challenging subset of pituitary tumors. A major issue currently is the absence of a holistic definition that reliably identifies these tumors in a prospective manner. Although comprehensive evaluation of patient gender, age, local invasiveness, treatment responses, radiological and histopathological features may be informative to assess the potential for aggressiveness, a definitive diagnosis of this entity cannot be confidently made until disease progression is actually observed despite standard medical and surgical therapy. Failure to diagnose these aggressive pituitary tumors early may impede initiation of suitable intensive stepwise multimodal treatments, and lessen their ultimate therapeutic success. Even though current therapeutic options for aggressive pituitary tumors are suboptimal in many cases, large-scale randomized prospective clinic trials are impractical and will likely never be conducted due to the rarity of this disease entity. Therefore, the majority of novel therapies in this subset of tumors derive from case reports or small case series, which greatly reduces their validity to make strong recommendations. This chapter, as part of this series on aggressive pituitary tumors, focuses on the role of systemic targeted medical and peptide radio-receptor therapy in treatment of aggressive pituitary tumors and carcinomas, and discusses future directions in these fields.

Temozolomide therapy for aggressive pituitary tumours - current understanding and future perspectives.

The use of temozolomide (TMZ) for the management of aggressive pituitary tumours (APT) has revolutionised clinical practice in this field with significantly improved clinical outcomes and long-term survival. Its use is now well established however a large number of patients do not respond to treatment and recurrence after cessation of TMZ is common. A number of challenges remain for clinicians such as appropriate patient selection, treatment duration and the role of combination therapy. This review will examine the use of TMZ to treat APT including mechanism of action, treatment regimen and duration; biomarkers predicting response to treatment and patient selection; and current evidence for administration of TMZ in combination with other agents.

Trans-eyebrow supraorbital keyhole approach in suprasellar and third ventricular craniopharyngioma surgery: the experience of 27 cases and a literature review.

BACKGROUND: The trans-eyebrow supraorbital keyhole approach, a minimal transcranial approach, has been widely used in different types of surgery for sellar and parasellar lesions. In this study, we investigated the outcome of this approach in the surgical treatment of suprasellar and third ventricular craniopharyngioma. METHODS: Twenty-seven patients with suprasellar and third ventricular craniopharyngioma underwent surgery via a supraorbital approach between June 2007 and June 2018. The medical data and follow-up results were retrospectively analyzed. RESULTS: All tumors were located in the suprasellar region and the third ventricle. The mean tumor size was 29.1 mm. The mean follow-up period was 49.6 months. Gross total resection (GTR) was achieved in 23 patients (85.2%). Of 17 patients with preoperative visual impairment, 12 patients (70.6%) showed improvement. Following surgery, 11 patients exhibited new-onset anterior hypopituitarism, ten developed diabetes insipidus, and two became overweight. One residual tumor relapsed 1 year after surgery. No perioperative death, cerebrospinal fluid (CSF) rhinorrhea, or meningitis occurred. All patients exhibited satisfactory cosmetic results. At the last follow-up, the Extended Glasgow Outcome Scale Score was 8 in 25 patients (92.6%). CONCLUSION: The supraorbital trans-eyebrow keyhole approach is characterized by minimal invasion and a satisfactory cosmetic outcome. According to our experience, craniopharyngiomas located in the suprasellar region and the third ventricle can be safely resected via a trans-eyebrow supraorbital keyhole approach.

A comparison between collaborative and single surgeon approach in endoscopic endonasal surgery to sphenoid sinus.

PURPOSE: Endoscopic endonasal transsphenoidal surgery (EETS) requires abundant collaborative work between neurosurgeon and ear, nose, and throat (ENT) surgeon. In low-volume centers, however, the surgery may be carried out completely and solely by a neurosurgeon. The current study evaluates the differences in both technique and complications in the approach to the sphenoid sinus for endoscopic endonasal approach (EEA) performed solely by a single neurosurgeon compared to collaborative effort between neurosurgery and otolaryngology. METHODS: The study comprises 50 consecutive patients with intra-sellar pituitary lesions undergoing EETS. Half of the patients were operated completely by single neurosurgeon (group A) and the other half by collaboration between single ENT surgeon, as a primary surgeon during nasal step, and the neurosurgeon (group B). Both groups were assessed intra-operatively as to operative technique, average time of EEA to sphenoid sinus, and presence of endonasal structural difficulties and complications. RESULTS: A significant difference was recorded between both groups regarding average time of EEA to sphenoid sinus (P < 0.001) and incidence of intraoperative nasal complications (P = 0.006). There was a difference between ENT surgeon and neurosurgeon adopting the same approach to sphenoid sinus. Sphenoid sinus approaches from group B characterized by their short duration (mean 10 vs 22 min) and low incidence of intraoperative endonasal complications (4.8% vs 28%). CONCLUSION: Study results emphasized the necessity of collaboration between neurosurgeon and ENT surgeon in endoscopic endonasal approaches, to efficiently deal with intraoperative endonasal difficulties and complications which pose difference for both surgeons performing the same surgical procedure.

An unusual pituitary adenoma coexistent with bilateral meningiomas: case report.

The association of pituitary adenomas and meningioma is rare. We present the case of a 46 year old lady who initially presented with large bilateral meningiomas and acromegaly. Histology demonstrated mammosomatotroph cell adenoma co-expressing Growth Hormone. This appears to be the first description of mammosomatotroph cell adenoma associated with meningiomas in the literature.

Pituitary metastasis: is there still a place for neurosurgical treatment?

Pituitary metastases are uncommon, ranging from 1 to 5 % of all metastases. Between 10 and 30 % of pituitary lesions are symptomatic responsible for diabetes insipidus, visual field defect or cranial nerve palsy. Primary sites are lung or breast in two-thirds of cases. There is no current reference concerning treatment of such lesions. Overall survival is poor and depends on primary site. Although the role of surgery is currently limited, discussion is warranted in several indications for diagnostic or symptomatic purposes. We report two cases of symptomatic pituitary metastases in a context of breast cancer and review the litterature concerning the role of surgery and other treatment modalities.

Chronic cluster headache and the pituitary gland.

BACKGROUND: Cluster headache is classified as a primary headache by definition not caused by an underlying pathology. However, symptomatic cases of otherwise typical cluster headache have been reported. CASE PRESENTATION: A 47-year-old male suffered from primary chronic cluster headache (CCH, ICHD-3 beta criteria fulfilled) since the age of 35 years. A magnetic resonance imaging (MRI) study of the brain in 2006 came back normal. He tried several prophylactic treatments but was never longer than 1 month without attacks. He was under chronic treatment with verapamil with only a limited effect on the attack frequency. Subcutaneous sumatriptan 6 mg injections were very effective in aborting attacks. By February 2014 the patient developed a continuous interictal pain ipsilateral to the right-sided cluster headache attacks. An indomethacin test (up to 225 mg/day orally) was negative. Because of the change in headache pattern we performed a new brain MRI, which showed a cystic structure in the pituitary gland. The differential diagnosis was between a Rathke cleft cyst and a cystic adenoma. Pituitary function tests showed an elevated serum prolactin level. A dopamine agonist (cabergoline) was started and the headache subsided completely. Potential pathophysiological mechanisms of pituitary tumor-associated headache are discussed. CONCLUSION: Neuroimaging should be considered in all patients with CCH, especially those with an atypical presentation or evolution. Response to acute treatment does not exclude a secondary form of cluster headache. There may be shared pathophysiological mechanisms of primary and secondary cluster headache.

[Clinical and morphological characteristics, diagnostic criteria, and outcomes of surgical treatment of TSH-secreting pituitary adenomas]. / Kliniko-morfologicheskie kharakteristiki, diagnosticheskie kriterii i rezul'taty khirurgicheskogo lecheniya TTG-sekretiruyushchikh adenom gipofiza.

Thyrotropinomas (TSH-secreting tumors) are a rare type of pituitary adenomas, which account for about 0.5-2.0% of all pituitary tumors. The criterion of thyrotropinoma is visualization of the tumor in the presence of a normal or elevated level of the thyroid-stimulating hormone (TSH) in the blood and elevated concentrations of free T4 (fT4) and free T3 (fT3). OBJECTIVE: To study the clinical, diagnostic, and morphological characteristics and treatment outcomes of TSH-secreting pituitary tumors. MATERIAL AND METHODS: The study included 21 patients aged from 15 to 67 years with pituitary adenoma and a normal or elevated blood TSH level combined with elevated fT4 and fT3 levels who were operated on at the Neurosurgical Institute in the period between 2002 and 2015. Before surgery, in the early postoperative period, and 6 months after surgery, the patients were tested for levels of TSH, fT4, fT3, prolactin, cortisol, the luteinizing hormone (LH), the follicle-stimulating hormone (FSH), estradiol/testosterone, and the insulin-like growth factor (IGF-1). The thyroid status was evaluated using the following reference values: TSH, 0.4-4.0 mIU/L; fT4, 11.5-22.7 pmol/L; fT3, 3.5-6.5 pmol/L. An immunohistochemical study of material was performed with antibodies to TSH, PRL, GH, ACTH, LH, FSH, and Ki-67 (MiB-1 clone); in 13 cases, we used tests with antibodies to somatostatin receptors type 2 and 5 and to D2 subtype dopamine receptors. RESULTS: Thyrotropinomas were detected in patients aged from 15 to 67 years (median, 39 years), with an equal rate in males (48%) and females (52%). Before admission to the Neurosurgical Institute, 11 (52%) patients were erroneously diagnosed with primary hyperthyroidism; based on the diagnosis, 7 of these patients underwent surgery on the thyroid gland and/or received thyrostatics (4 cases). Hyperthyroidism symptoms were observed in 16 (76%) patients. The blood level of TSH was 2.47-38.4 mIU/L (median, 6.56); fT4, 22.8-54.8 nmol/L (median, 36); fT3, 4.24-12.9 pmol/L (median, 9.66). Tumors had the endosellar localization in 4 (19%) cases and the endo-extrasellar localization in 17 (91%) cases. Total tumor resection was performed in 7 (33%) patients. All these tumors had the endosellar and endo-suprasellar localization. No total resection was performed in patients with infiltrative growth of adenoma (invading the skull base structures). An immunohistochemical study of tumor resection specimens detected only TSH expression in 3 (14%) cases; 18 (86%) tumors were plurihormonal and secreted TSH and GH and/or PRL. Of 13 tumors, expression of the type 2 dopamine receptor was detected in 9 (69%) cases; expression of somatostatin receptors type 5 and type 2 was found in 6 (46%) and 2 (15%) cases, respectively. CONCLUSION: The criterion for total tumor resection was a postoperative decrease in the TSH level to 0.1 mIU/L or less. Total resection was performed in 33% of patients with tumors of only the endosellar and endo-suprasellar localization. In most cases, tumors were plurihormonal and secreted TSH and GH and/or PRL.

Utility of three-dimensional computed tomography for anatomical assistance in endoscopic endonasal transsphenoidal surgery.

Endoscopic endonasal transsphenoidal surgery (ETSS) has been widely applied to pituitary adenomas. However, anatomical orientation is difficult when structures of the sphenoidal sinus are complicated. This study investigated the usefulness of three-dimensional computed tomography (3D-CT) modeling in planning surgical procedures for ETSS and providing anatomical guidance during surgery. CT data from 99 consecutive patients with pituitary adenoma treated between January 2008 and March 2014 were used to reconstruct 3D-CT models. Based on these images, the architecture of sphenoidal sinus, particularly structures surrounding the sellar floor, was visualized for preoperative simulation of surgical procedures. These 3D-CT images were also compared to surgical views during ETSS to evaluate applicability of the images. These models clearly demonstrated the morphology of the nasal cavity and structures of the sphenoidal sinus, including bony prominences of the internal carotid arteries (ICAs) and optic canals by successively eliminating sphenoidal structures. The 3D-CT images permitted determination of the maximum marginal line of the opening of the sellar floor by presenting vital structures such as ICAs and optic canals. With this 3D-CT model, the surgeon could access the sella more easily, open the floor widely enough for each individual patient, and resect the tumor maximally without complications. Preoperative 3D-CT models distinctly visualized the optic canals, bilateral ICAs, and complicated structures of sphenoidal septa. The 3D-CT images were useful for preoperative planning and as a road map during endoscopic surgery for pituitary adenoma, facilitating maximum tumor resection without complications.

Invasive adenoma and pituitary carcinoma: a SEER database analysis.

Invasive pituitary adenomas and pituitary carcinomas are clinically indistinguishable until identification of metastases. Optimal management and survival outcomes for both are not clearly defined. The purpose of this study is to use the Surveillance, Epidemiology, and End Results (SEER) database to report patterns of care and compare survival outcomes in a large series of patients with invasive adenomas or pituitary carcinomas. One hundred seventeen patients diagnosed between 1973 and 2008 with pituitary adenomas/adenocarcinomas were included. Eighty-three invasive adenomas and seven pituitary carcinomas were analyzed for survival outcomes. Analyzed prognostic factors included age, sex, race, histology, tumor extent, and treatment. A significant decrease in survival was observed among carcinomas compared to invasive adenomas at 1, 2, and 5 years (p = 0.047, 0.001, and 0.009). Only non-white race, male gender, and age ≥65 were significant negative prognostic factors for invasive adenomas (p = 0.013, 0.033, and <0.001, respectively). There was no survival advantage to radiation therapy in treating adenomas at 5, 10, 20, or 30 years (p = 0.778, 0.960, 0.236, and 0.971). In conclusion, pituitary carcinoma patients exhibit worse overall survival than invasive adenoma patients. This highlights the need for improved diagnostic methods for the sellar phase to allow for potentially more aggressive treatment approaches.

Transsphenoidal cyst cisternostomy with a keyhole dural opening for sellar arachnoid cysts: technical note.

A less invasive transsphenoidal approach with a keyhole dural opening for intrasellar arachnoid cysts is described. This approach was used to address seven sellar cystic lesions with suprasellar extension; they were six intrasellar arachnoid cysts (IACs) and one Rathke's cleft cyst (RCC). In all cases, preoperative MRI revealed cerebrospinal fluid (CSF) intensity on both T1- and T2-weighted images. On preoperative contrast-enhanced MRI, five of the six IACs manifested posterior displacement of the flattened pituitary gland toward the dorsum sellae; one of the six IACs and the RCC exhibited a flattened pituitary gland on the anterior surface of the cyst. Wide cyst cisternostomy through a keyhole dural opening was carried out safely using a microscope with the support of a thin angled endoscope (30° and/or 70°, diameter 2.7 mm). As we aimed to avoid iatrogenic injury of the pituitary function, we found it difficult to obtain a sufficiently wide and precise opening of the cyst wall when the pituitary gland was located on the anterior surface of the cyst wall. Our approach facilitates safe cyst cisternostomy as wide as that obtainable by transcranial manipulation. In addition, CSF leakage is prevented by dural plasty using the fascia lata and stitching with 6-0 monofilament sutures. This technique can be adapted to address various sellar cystic lesions. However, as the posterior or anterior displacement of the normal pituitary gland in the presence of IACs or RCCs, respectively, affects the width of the cyst opening, our technique is more suitable for IACs than RCCs.

Recurrent craniopharyngiomas in children and adults: long-term recurrence rate and management.

BACKGROUND: The significance of the majority of the factors influencing the recurrence rate (RR) of craniopharyngiomas remains unclear, and the management of this significance is controversial. The present study aimed to evaluate the influence of patient age and tumor topography on the RR, the efficacy of radiotherapy, and the safety of surgery for recurrences. METHODS: The RR was analyzed in 38 children (follow-up, 2-256 months [mean, 147.6]) and 63 adults (follow-up, 2-221 months [mean, 100.2]. The efficacy of 18 sessions of radiotherapy (13 patients) and the outcome of 52 secondary surgeries (37 patients) were evaluated. RESULTS: The RR reached 39.5% in children and 22.2% in adults (p = 0.053). After radical tumor removal, the RR in children (36.7%) was significantly higher (p = 0.024) than that in adults (14%). In children after radical removal of intraventricular and extraventricular craniopharyngiomas (IECs), the RR was higher (60%; p = 0.071) than in extraventricular (intrasellar and suprasellar; purely suprasellar extraventricular) tumors (25%). Radical removal of 50% of tumors was achieved (73.1% in children; 26.9% in adults; p = 0.002) in 56.7% of the first and 40.9% of further recurrences. There was no early mortality after 52 surgeries; functional worsening (endocrine, 2; obesity, 2; visual, 3) occurred after 7/52 secondary surgeries. Recurrence occurred after 9/18 sessions of radiotherapy. CONCLUSIONS: The RR was higher in children than in adults and in IECs relative to other topographic groups. Children with IECs represent a risk group. The efficacy of radiotherapy was inconclusive. Early detection of recurrences enabled safe excision with low morbidity.

[Advances in the surgical treatment of tumors of the pituitary region : rhino-neurosurgical transnasal endoscopic surgery]. / Fortschritte in der chirurgischen Behandlung von Tumoren der Hypophysenregion : Rhinoneurochirurgische transnasale endoskopische Operationstechnik.

Conventional microscopic surgery of pituitary adenomas offers excellent results with regard to local tumour control and endocrine function. Overall patient morbidity and mortality is low. However, recent studies demonstrate further improvements in tumour resection control and more favourable endocrine/ophthalmologic results when endoscopic techniques are applied, as well as an overall reduction in peri-interventional morbidity. Additionally, use of endoscopic techniques in rhino-neurosurgical cooperation achieved better specifically rhinologic results and improved subjective comfort for patients. The cooperative rhino-neurosurgical approach not only allows for optimal treatment of the primary pituitary pathology, but also treatment of additional nasal and paranasal pathologies, such as a deviated septum or disturbed drainage of the paranasal sinus.

[Clinically active pituitary tumors]. / Klinisch aktive Hypophysentumoren.

The widespread use of diagnostic imaging has led to an increase in the incidence of pituitary tumors. The majority of incidentalomas are hormone-inactive (HI) pituitary microadenomas. The most common clinically relevant pituitary adenomas are prolactin-secreting, followed by HI, and far less common are growth hormone (GH)-, adrenocorticotropic hormone (ACTH)- and thyroid-stimulating hormone (TSH)-secreting adenomas. Pituitary adenomas are usually benign, although aggressive growth and invasion occurs in individual cases. Very rarely, they give rise to metastases and are then termed pituitary carcinomas. All pituitary tumors require endocrine testing for pituitary hormone excess. In addition to the medical history and clinical examination, laboratory diagnostics are very important. Symptoms such as irregular menstruation, loss of libido or galactorrhea often lead to the timely diagnosis of prolactinomas, and hyperprolactinemia can easily confirm the diagnosis (considering the differential diagnoses). Diagnosis is more difficult for all other hormone-secreting pituitary adenomas (acromegaly, Cushing's disease, TSHoma), as the symptoms are often non-specific (i.e., headaches, weight gain, fatigue, joint pain). Furthermore, comorbidities such as hypertension, diabetes, and depression are such widespread diseases that pituitary adenomas are rarely considered as the underlying cause. Timely diagnosis and appropriate treatment have a significant impact on morbidity, mortality, and quality of life. Therefore, the role of primary care physicians is very important for achieving an early diagnosis. In addition, patients with pituitary adenomas should always be referred to endocrinologists to ensure optimal diagnosis as well as treatment.

Further investigation of the lateral approach for the resection of Knosp grade 4 pituitary adenomas in endoscopic endonasal surgery.

OBJECTIVE: The authors performed a further in-depth study of the lateral compartment of the cavernous sinus (LCCS) by the endoscopic endonasal approach to improve the safety and efficacy of the lateral approach for the removal of Knosp grade 4 pituitary adenomas (KG4PAs). METHODS: Twenty-three cadaveric specimens were used for endoscopic endonasal dissection, and the LCCS was exposed to observe the neurovascular and fibrous structures within. A subclassification of the lateral approach based on further knowledge of the LCCS was proposed and used to resect 86 KG4PAs, and the surgical outcomes of these cases were reviewed. Type A KG4PAs represent tumor that was mainly distributed in the posterosuperior and superolateral compartments, type B KG4PAs represent tumor that was mainly distributed in the anteroinferior compartments, and type AB KG4PAs represent tumor that extended into each compartment with characteristics of types 4A and 4B. RESULTS: The authors identified multiple fibers that anchored the horizontal segment of the internal carotid artery (ICA) to the abducens nerve. The fibers, the sympathetic nerve, and the inferior lateral trunk form a partition-like structure in the LCCS named the abducens nerve-ICA complex (AIC), and the LCCS can be divided into the superolateral and inferolateral compartments by the AIC. Accordingly, the lateral approach was subclassified into the lateral superior (LS) approach and the anterior inferior (AI) approach. The LS approach was mainly used to resect type A KG4PAs, whereas the AI approach was used to resect type B KG4PAs, and a combination of the two was used to resect type AB KG4PAs. The gross-total, subtotal, and partial resection rates were 81.4%, 12.8%, and 5.8%, respectively. The numbers of cases of postoperative transient cranial nerve palsy, postoperative permanent cranial nerve palsy, ICA injury, and CSF leakage were 6 (6.9%), 2 (2.3%), 1 (1.2%), and 1 (1.2%), respectively. CONCLUSIONS: This study revealed that the LCCS is divided by the AIC into the superolateral and inferolateral compartments, avoiding the misconception that the LCCS has vertical communication. Therefore, the lateral approach was subclassified into the LS approach and the AI approach for the resection of KG4PAs, which allowed a high gross-total resection rate with acceptable safety in the surgical treatment of KG4PAs.

A novel simple real-time electrooculographic monitoring system during transsphenoidal surgeries to prevent postoperative extraocular motor nerve dysfunction.

In transsphenoidal surgery (TSS) for pituitary tumors, the use of endoscopes allows approach to the lateral sides in and around the cavernous sinus. However, this approach is often associated with a risk of cranial nerve dysfunction causing impaired extraocular movement. We employed a novel, simple, and real-time monitoring system using electrooculography during TSS to avoid postoperative extraocular motor nerve dysfunction. A conventional electroencephalograph, which is available in every hospital, was used to detect effects induced by intraoperative manipulation on the cranial nerves related to extraocular movement (EOM) during TSS for pituitary adenomas. One hundred patients with pituitary adenomas who underwent endonasal endoscope-assisted TSS with EOM monitoring were included in the present study. When the extraocular motor nerves were stimulated mechanically directly or even indirectly by surgical procedures, abnormal extraocular muscle responses [electrooculograms (EOGm)] appeared on the monitor screen. When repeated or continuous EOGm were recorded, surgical procedures were discontinued briefly for around 5 to 10 s. The EOGm disappeared promptly when surgical procedures were stopped. Permanent extraocular dysfunction did not occur in the present series of patients. One, who was the fifth patient in the present series, of 100 patients (1.0 %) had transient delayed diplopia after TSS. We have not experienced any more postoperative EOM dysfunction since the first case. EOM monitoring during TSS is a novel, efficient, and simple method to prevent postoperative cranial nerve palsy related to EOM.