The transsphenoidal approach

Meta-analysis of mortality in adults with growth hormone deficiency: Does growth hormone replacement therapy really improve mortality rates?

Growth hormone (GH) deficiency (GHD) is one of the most prevalent deficiencies in patients with hypopituitarism and several cohort studies have demonstrated an increased mortality risk in hypopituitary patients with a presumed GHD. The cause of the excess mortality is most likely multifactorial, including the etiology of the hypopituitarism, non-physiological replacement therapies (mostly glucocorticoid), tumor treatment and its side effects as well as untreated GHD. Several years later, other cohort studies that investigated life expectancy in patients with hypopituitarism on GH replacement therapy (GHRT) that showed a normalized mortality. By comparison of the distribution of characteristics of interest between cohorts, we discuss the existing literature to answer the following question: does growth hormone replacement really improve mortality rates in adult patients with hypopituitarism and GHD? We also conducted a meta-analysis of these studies. Since the literature suffers from selection and time bias (improvement of tumor management and other pituitary hormone replacement therapies), there is no high-quality evidence that replacement therapy for GHD really improves mortality. However, the available data does suggest that GHRT plays a significant part in the normalization of the mortality in patients with hypopituitarism.

Development and external validation of clinical prediction models for pituitary surgery

Introduction

Gross total resection (GTR), Biochemical Remission (BR) and restitution of a priorly disrupted hypothalamus pituitary axis (new improvement, IMP) are important factors in pituitary adenoma (PA) resection surgery. Prediction of these metrics using simple and preoperatively available data might help improve patient care and contribute to a more personalized medicine.

Research question

This study aims to develop machine learning models predicting GTR, BR, and IMP in PA resection surgery, using preoperatively available data.

Material and methods

With data from patients undergoing endoscopic transsphenoidal surgery for PAs machine learning models for prediction of GTR, BR and IMP were developed and externally validated. Development was carried out on a registry from Bologna, Italy while external validation was conducted using patient data from Zurich, Switzerland.

Results

The model development cohort consisted of 1203 patients. GTR was achieved in 207 (17.2%, 945 (78.6%) missing), BR in 173 (14.4%, 992 (82.5%) missing) and IMP in 208 (17.3%, 167 (13.9%) missing) cases. In the external validation cohort 206 patients were included and GTR was achieved in 121 (58.7%, 32 (15.5%) missing), BR in 46 (22.3%, 145 (70.4%) missing) and IMP in 42 (20.4%, 7 (3.4%) missing) cases. The AUC at external validation amounted to 0.72 (95% CI: 0.63-0.80) for GTR, 0.69 (0.52-0.83) for BR, as well as 0.82 (0.76-0.89) for IMP.

Discussion and conclusion

All models showed adequate generalizability, performing similarly in training and external validation, confirming the possible potentials of machine learning in helping to adapt surgical therapy to the individual patient.

History, Current Techniques, and Future Prospects of Surgery to the Sellar and Parasellar Region

The sellar and parasellar region can be affected by diverse pathologies. The deep-seated location and surrounding critical neurovascular structures make treatment challenging; there is no singular, optimal approach for management. The history and development of transcranial and transsphenoidal approaches by pioneers in skull base surgery were largely aimed at treating pituitary adenomas, which are the most common lesions of the sella. This review explores the history of sellar surgery, the most commonly used approaches today, and future considerations for surgery of the sellar/parasellar region.

Guanti bianchi technique for resection of selected pituitary adenomas

Introduction

Since the introduction of the endoscopic endonasal approach (EEA) to skull base, the nasal phase has been a true challenge as it represents the moment of definition of the corridor, thus defining the instruments maneuverability at tumor removal phase. The longstanding cooperation between ENT and neurosurgeons have provided the possibility of creating adequate corridor with maximal respect toward nasal structures and mucosa. This sparked the idea of entering the sella as thieves, so we named "Guanti Bianchi" technique a lesser invasive variation of the approach for the removal of selected pituitary adenoma.

Research Question

The purpose of this study is to present the preliminary results of "Guanti Bianchi" technique.

Material and Methods

Data from 17 patients undergoing "Guanti Bianchi" technique (out of 235 standard EEA) at our center, were retrospectively analysed. ASK Nasal-12, a quality-of-life instrument developed specifically to assess patient perception of nasal morbidity, was administered pre- and postoperatively.

Results

10 (59%) patients were men and 7 (41%) women. The mean age was 67.7 (range 35-88). The average duration of the surgical procedure was 71.17 minutes (range 45-100). GTR was achieved in all patients, no postoperative complications were observed. Baseline ASK Nasal-12 was near normal in all patients, 3/17 (17,6%) experienced transitory very mild symptoms without any worsening at 3 and 6 months.

Discussion and Conclusions

This minimally invasive technique does not require turbinectomy or carving of the nasoseptal flap, it alters the nasal mucosa as little as necessary, and it is quick and easy to perform.

Surgical Approaches to the Third Ventricle: An Update

The third ventricle is located in the deepest part of the brain and is delimited by both telencephalic and diencephalic structures. Its location makes every surgical procedure inside or around it quite challenging, due to the distance from the surface to the fragility of the neurovascular structures that is necessary to dissect before entering its cavity and to the narrow surgical corridors through which it is necessary to work. Its geometric localization inside the cranial cavity and the anatomical relationship with the interhemispheric fissure offers nevertheless to the surgeon an impressive variety of surgical approaches, which allow to reach every millimeter of the third ventricle lumen. Mastering properly all these approaches requires an impressive anatomical knowledge, the best available technology, and most refined technical skills, making the surgery of the third ventricle a point of excellence in the evolution of each neurosurgeon. The development of neuronavigation and neuroendoscopy has been a revolution in neurosurgery in the last 20 years and offered special advantages for the surgery of the third ventricle. In fact, the narrow corridors of approach make the precision of the neuronavigation and the enlightenment and magnification of the neuroendoscopy especially useful to reach the third ventricle cavity and working inside or around it. This chapter reviews the history of the surgery of the third ventricle and offers an update of the variety of surgical corridors identified and of the technology now available to properly work through them and inside the third ventricle cavity.

Use of balloon-assisted nasal access to augment endoscopic endonasal transsphenoidal approach: illustrative case

BACKGROUND

Pituitary adenoma is a neurosurgical pathology commonly resected via endoscopic endonasal approach. Septal and nasal passage anatomy can affect the surgical corridor and may require septoplasty or other techniques for expansion.

OBSERVATIONS

The authors presented a case of pituitary macroadenoma with septal deviation with use of balloon-assisted nasal access for surgery.

LESSONS

This technique enhanced surgical width of field and instrument maneuverability via septal medialization for successful tumor resection.

Dumbbell-shaped pituitary adenomas: prognostic factors for prediction of tumor nondescent of the supradiaphragmal component from a multicenter series

OBJECTIVE

Dumbbell-shaped pituitary adenomas (DSPAs) are a subgroup of macroadenomas with suprasellar extension that are characterized by a smaller diameter at the level of the diaphragma sellae opening compared with the supradiaphragmal tumor component (SDTC). Hence, DSPAs may be particularly prone to a nondescending suprasellar tumor component and risk for residual tumor or postoperative bleeding.

METHODS

A multicenter retrospective cohort analysis of 99 patients with DSPA operated on via direct endoscopic endonasal transsphenoidal approach between 2011 and 2020 was conducted. Patient recruitment was performed at two tertiary care centers (Medical University of Vienna and University of Southern California) with expertise in endoscopic skull base surgery. DSPA was defined as having a smaller diameter at the level of the diaphragma sellae compared with the SDTC.

RESULTS

On preoperative MRI, all DSPAs were macroadenomas (maximum diameter range 17-71 mm, volume range 2-88 cm3). Tumor descent was found in 73 (74%) of 99 patients (group A), and nondescent in 26 (26%) of 99 patients (group B) intraoperatively. DSPAs in group A had a significantly smaller diameter (30 vs 42 mm, p < 0.001) and significantly smaller volume (10 vs 22 cm3, p < 0.001) than those in group B. The ratio of the minimum area at the level of the diaphragmal opening in comparison with the maximum area of the suprasellar tumor component ("neck-to-dome area") was significantly lower in group A than in group B (1.7 vs 2.7, p < 0.001). Receiver operating characteristic curve analysis revealed an area under the curve of 0.75 (95% CI 0.63-0.87). At a cutoff ratio of 1.9, the sensitivity and specificity for a nondescending suprasellar tumor component were 77% and 34%, respectively.

CONCLUSIONS

In the present study, the neck-to-dome area ratio was of prognostic value for prediction of intraoperative tumor nondescent in DSPAs operated on via a direct endonasal endoscopic approach. Pituitary adenoma SDTC nondescent carried the inherent risk of hemorrhagic transformation in all cases.

Role of Anterior Nasal Packing in Endoscopic Skull Base Surgery: Italian Survey

BACKGROUND

Nowadays, the endoscopic endonasal approach to sellar and parasellar region tumors is a common technique in neurosurgery, and surgical nuances, complications, and management strategies are shared in a multidisciplinary setting between neurosurgeons and ear, nose, and throat surgeons. Due to the heterogeneity of its variations, the role of the anterior nasal packing in endoscopic endonasal approach to the skull base surgery (EESBS) has not yet been unanimously accepted and no consensus or guidelines on its use exist.

MATERIALS AND METHODS

A survey containing 10 questions about indications, management advantages, and pitfalls of the use of anterior nasal packing in EESBS was created by using an online open-source tool (SurveyMonkey). The questionnaire was sent to 39 Italian neurosurgical departments, which routinely adopt the endoscopic endonasal approach.

RESULTS

Almost half of 39 selected centers (19; 48.7%) answered our survey. The main results can be summarized as 1) anterior nasal packing after EESBS is considered useful by 84% of participants, 2) prevention of epistaxis is the principal indication for anterior nasal packing, 3) the type of approach and skull base reconstruction influence the use of anterior nasal packing, and 4) nasal discomfort is considered the principal negative aspect of nasal packing.

CONCLUSIONS

Our study identified that anterior nasal packing is commonly adopted in certain conditions, namely when extensive nasal dissection is performed. Furthermore, the choice to adopt or not the anterior nasal packing should be tailored taking in account specific conditions, such as acromegaly and Cushing disease. It represents an important factor in reducing postoperative sinonasal complications of EESB.

Utility of intraoperative ultrasonography for resection of pituitary adenomas: a comparative retrospective study

BACKGROUND

The evolution of pituitary surgery has made it a safe and effective form of treatment; however, risks of inadequate tumor resection, cerebrospinal fluid (CSF) leak, pituitary dysfunction, and vascular injury still exist. The use of intraoperative ultrasonography (IOUS) in pituitary surgery has been well described. Recent advancements in ultrasound technology have allowed for expanded utility as described here.

METHODS

A retrospective review was performed between January 2016 and December 2019. One hundred thirty-eight patients (mean age 53.7 years, 47% females) were identified undergoing transsphenoidal surgery for pituitary tumors. Thirty-four patients had IOUS performed using a side-firing ultrasound probe, while 104 did not. Data was analyzed for preoperative (demographics, clinical, and radiographic features), perioperative (blood loss, operative time), and postoperative (complications, length of stay, hormone remission, and extent of resection) outcomes.

RESULTS

There were no significant differences in patient age, gender, tumor volume, Knosp grade, and hormone-secreting status between the two groups. Patients treated using IOUS had significantly higher rates of gross total resection (79% vs. 44%, p = 0.0008), shorter operative times (74 vs. 146 min, p < 0.0001), lower blood loss (119 vs. 284 cc, p < 0.0001), and hospital stays (2.9 vs. 4.2 days, p = 0.001). Overall complication rates were lower in the IOUS group compared to standard pituitary surgery but did not reach significance.

CONCLUSIONS

Recent improvements in ultrasound technology have allowed for miniaturization of probes capable of delivering high-resolution images. The use of IOUS in transsphenoidal pituitary surgery may significantly increase rates of gross total resection, while decreasing blood loss, hospital LOS, and operative time.

Evaluation of Long-Term Outcomes and Toxicity After Stereotactic Phosphorus-32-Based Intracavitary Brachytherapy in Patients With Cystic Craniopharyngioma

PURPOSE

Interstitial brachytherapy based on phosphorus-32 (P-32) has an established role as a minimally invasive treatment modality for patients with cystic craniopharyngioma. However, reporting on long-term outcomes with toxicity profiles for large cohorts is lacking in the literature. The purpose of this study is therefore to evaluate the long-term visual, endocrinal, and neurocognitive functions in what is the largest patient series having received this treatment to date.

METHODS AND MATERIALS

We retrospectively evaluated 90 patients with cystic craniopharyngiomas who were treated with stereotactic intracavitary brachytherapy between 1998 and 2010. Colloidal activity of injected radioisotope P-32 was based on an even distribution within the tumor. After treatment, patients were followed-up for a minimum of 5 years and over a mean of 121 months (60-192 months) to assess radiographic and clinical responses.

RESULTS

The 90 patients included in our study cohort underwent a total of 108 stereotactic surgical procedures for 129 craniopharyngioma-related cysts. Of the included tumors, 65 (72.2%) were associated with a single cyst, 15 (16.7%) were associated with 2 cysts, and 10 (11.1%) tumors had developed septations with 3 to 4 cysts. Stereotactic cyst puncture and content aspiration were used to drain a mean cyst fluid volume of 21.4 mL (1.0-55.0 mL). Each cyst was then instilled for interstitial brachytherapy with colloidal P-32 solution. Based on radiographic follow-up assessments, 56 cysts (43.4%) showed resolution and/or nonrecurrence, which was classified as a complete response to treatment; 47 cysts (36.4%) showed a partial response; and 5 cysts (3.9%) displayed a stable appearance. Treatment resulted in immediate and clinically significant vision improvement in 54 of 63 (86%) symptomatic patients, and this improvement was maintained. Progression-free survival rates at 5 and 10 years were 95.5% and 84.4%, respectively.

CONCLUSIONS

P-32-based interstitial brachytherapy can play an effective role in managing patients with cystic craniopharyngiomas. It can be considered a valid alternative to surgery in select patients with a favorable toxicity profile and long-term clinical outcomes.

The slope of the learning curve in 600 consecutive endoscopic transsphenoidal pituitary surgeries

BACKGROUND

Endonasal endoscopic transsphenoidal surgery (EETS) for pituitary adenoma has become a mainstay of treatment over the last two decades and it is generally accepted that once this learning curve is achieved, a plateau is reached with little incremental improvement.

OBJECTIVE

The objective of this study was to assess the slope of the learning curve over a long period of time for a variety of outcomes measures.

METHODS

We examined outcomes and complications in a consecutive series of 600 EETS for pituitary adenoma grouped into quartiles based on date of surgery.

RESULTS

GTR significantly increased across quartiles from 55 to 79% in the last quartile (p < 0.005). The rate of intraoperative CSF leak significantly decreased from 60% in the first quartile to 33% in the last quartile and the rate of lumbar drain placement from 28% in the first quartile to 6% in the last quartile (p < 0.005). Hormonal remission for secreting adenomas increased from 68% in the first quartile to 90% in the last quartile (p < 0.05). The rate of post-operative CSF leak trended lower (3% in first quartile to 0.7% in last two quartiles). The greatest improvement in outcome occurred between the first and second quartiles (19.9%), but persistent improvement occurred between the second and third (6.7%) and third and fourth quartiles (8.0%).

CONCLUSION

Although the slope of the learning curve is steeper earlier in a surgeon's experience, the slope does not plateau and continues to increase even over more than a decade.

Multicenter external validation of the Zurich Pituitary Score

PURPOSE

Recently, the Zurich Pituitary Score (ZPS) has been proposed as a new quantitative preoperative classification scheme for predicting gross total resection (GTR), extent of resection (EOR), and residual tumor volume (RV) in endoscopic pituitary surgery. We evaluated the external validity of the ZPS.

METHODS

In three reference centers for pituitary surgery, the ZPS was applied and correlated to GTR, EOR, and RV. Furthermore, its inter-rater agreement was assessed.

RESULTS

A total of 485 patients (53% male; age, 53.8 ± 15.7) were included. ZPS grades I, II, III, and IV were observed in 110 (23%), 270 (56%), 64 (13%), and 41 (8%) patients, respectively. GTR was achieved in 358 (74%) cases, with mean EOR of 87.6% ± 20.3% and RV of 1.42 ± 2.80 cm³. With increasing ZPS grade, strongly significant decreasing trends for GTR (I, 92%; II, 77%; III, 67%; IV, 15%; p < 0.001) and EOR (I, 93.8%; II, 89.9%; III, 88.1%; IV, 75.4%; p < 0.001) were found. Similarly, RV increased steadily ([cm³] I, 0.16; II, 0.61; III, 2.01; IV, 3.84; p < 0.001). We observed intraclass correlation coefficients of 0.837 (95% CI, 0.804-0.865) for intercarotid distance and 0.964 (95% CI, 0.956-0.970) for adenoma diameter, and Cohen's kappa of 0.972 (95% CI, 0.952-0.992) for the ZPS grades.

CONCLUSIONS

Application of the ZPS in three external cohorts was successful. The ZPS generalized well in terms of GTR, EOR, and RV; demonstrated excellent inter-rater agreement; and can safely and effectively be applied as a quantitative classification of adenomas with relevance to surgical outcome.

Endoscopic Endonasal Transsphenoidal Surgery: History and Evolution

In previous decades, extensive and disfiguring transfacial and/or transcranial approaches were used to reach the sellar and parasellar areas. However, these surgical routes were burdened by severe complications and high mortality rates. Recently, the development of endoscopic endonasal techniques has revolutionized the surgical strategies for approaching the sella and adjacent areas and increased the development of transsphenoidal surgery. With these techniques, surgeons have been able to overcome the visual limitations of the open surgical approaches and access areas previously hidden from view. After the contributions of the Pittsburgh duo, Carrau and Jho, pioneers of pure endoscopic surgery, our school began to implement this technique, introducing technical innovations and variations, describing the anatomical details and defining new routes, and playing a key role in its widespread clinical application.

Pituitary Adenomas: What Are the Key Features? What Are the Current Treatments? Where Is the Future Taking Us?

Pituitary tumors are a heterogeneous group of lesions (usually benign) and proper understanding of the anatomy, physiology, and pathology of the hypothalamic/pituitary region is essential to make an accurate diagnosis and define the essential treatment options (i.e., surgery, medical therapies, and radiotherapy, alone or in combination). Surgery is the primary treatment for acromegaly, Cushing disease, thyroid-stimulating hormone-secreting adenomas, resistant prolactinomas, and nonfunctioning pituitary adenomas causing mass effect. Medical and radiation therapy are reserved in cases in which surgery is not possible or does not provide a complete cure. In the last decades, tremendous innovations (i.e., targeted drugs and refined surgical tools and techniques) have expanded the treatment strategies for pituitary adenomas. We herein report the current indications for and depiction of the surgical techniques in pituitary surgery, review current medical treatments, and provide a glimpse of future possibilities.

Utility of deep neural networks in predicting gross-total resection after transsphenoidal surgery for pituitary adenoma: a pilot study

OBJECTIVEGross-total resection (GTR) is often the primary surgical goal in transsphenoidal surgery for pituitary adenoma. Existing classifications are effective at predicting GTR but are often hampered by limited discriminatory ability in moderate cases and by poor interrater agreement. Deep learning, a subset of machine learning, has recently established itself as highly effective in forecasting medical outcomes. In this pilot study, the authors aimed to evaluate the utility of using deep learning to predict GTR after transsphenoidal surgery for pituitary adenoma.METHODSData from a prospective registry were used. The authors trained a deep neural network to predict GTR from 16 preoperatively available radiological and procedural variables. Class imbalance adjustment, cross-validation, and random dropout were applied to prevent overfitting and ensure robustness of the predictive model. The authors subsequently compared the deep learning model to a conventional logistic regression model and to the Knosp classification as a gold standard.RESULTSOverall, 140 patients who underwent endoscopic transsphenoidal surgery were included. GTR was achieved in 95 patients (68%), with a mean extent of resection of 96.8% ± 10.6%. Intraoperative high-field MRI was used in 116 (83%) procedures. The deep learning model achieved excellent area under the curve (AUC; 0.96), accuracy (91%), sensitivity (94%), and specificity (89%). This represents an improvement in comparison with the Knosp classification (AUC: 0.87, accuracy: 81%, sensitivity: 92%, specificity: 70%) and a statistically significant improvement in comparison with logistic regression (AUC: 0.86, accuracy: 82%, sensitivity: 81%, specificity: 83%) (all p < 0.001).CONCLUSIONSIn this pilot study, the authors demonstrated the utility of applying deep learning to preoperatively predict the likelihood of GTR with excellent performance. Further training and validation in a prospective multicentric cohort will enable the development of an easy-to-use interface for use in clinical practice.

Predicting extent of resection in transsphenoidal surgery for pituitary adenoma

BACKGROUND

The extent of resection (EOR) is a crucial outcome parameter in transsphenoidal pituitary surgery (TSS), and is linked to endocrinological outcome, postoperative morbidity, and mortality. We aimed to build a robust, quantitative, and easily reproducible imaging score able to predict EOR in TSS.

METHODS

The ratio (R) between the maximum horizontal adenoma diameter and intercarotid distance at the horizontal C4 segment was used to stratify our patient series in four classes: class I R ≤ 0.75, class II 0.75 < R ≤ 1.25, and class III R ≥ 1.25. Class IV included adenomas which completely encased the internal carotid artery. The resulting score was internally validated for robustness.

RESULTS

One hundred sixteen patients were included in the study, of which 96 (83%) for derivation and 20 (17%) for validation. EOR showed significant differences between grades (grade I, 100%; II, 97.9%; III, 94.2%; IV, 87.2%; all P < 0.05). The same applied to residual volume (RV) (grade I, 0 cm³; II, 0.08 cm³; III, 1.11 cm³; IV, 1.63 cm³; all P < 0.05). Differences in gross total resection (GTR) were statistically significant among classes I, II, and III (P < 0.05). The incidence of residual adenoma in the cavernous sinus increased also constantly from grade I up to grade IV although a significant difference was only found between grades III and II (P = 0.004). The score performed equally well in the validation cohort. Inter-observer agreement was high, with intraclass correlation coefficients > 0.89 for measurement of both the horizontal tumor diameter and the ICD among two independent raters (P < 0.001).

CONCLUSIONS

The proposed score is a simple and reproducible tool which reliably predicts surgical outcome including EOR, RV, and GTR of pituitary adenoma patients undergoing TSS.

Sinonasal outcome after endoscopic mononostril transsphenoidal surgery: A single center cohort study

OBJECTIVE

The endoscopic endonasal approach has been well established for skull base surgery. However, there are only few studies pointing out nasal complaints after surgery. In this study, the authors evaluated postoperative nasal complaints and complications after mononostril endoscopic procedures.

METHODS

All patients operated on parasellar and sellar pathologies at our department via an endoscopic mononostril transnasal transsphenoidal approach from January 2011 to May 2015 were analyzed. To assess specific postoperative nasal pathological conditions and complaints, a questionnaire was established. Applicable data of 79 patients with additional ENT follow-up could be included. Endpoints were the quantitative evaluation of complications and correlation of these data.

RESULTS

There was no vascular injury or worsening of visual function. Two patients had persisting CSF fistula and one of them meningitis. There was a significant decrease of nasal complaints during follow up after 2 years (p < 0.001). Further surgical treatment by ENT physician was necessary in 11.4%. Resurgery significantly increased the risk of postsurgical complaints (p < 0.005). The use of a tamponade significantly reduced the risk of postsurgical reduced nasal airflow (p = 0.026) and sinusitis (p = 0.002).

CONCLUSIONS

Endoscopic endonasal procedures to skull base lesions achieve high radicality with low complication rates. However, they induce temporary and permanent nasal complaints and complications. Thereby, resurgeries increase the risk of nasal complaints and the use of nasal tamponades might increase the sinonasal outcome. Further prospective studies are necessary to objectify the evaluation of postsurgical nasal complications.

Management of non-functioning pituitary adenomas: surgery

Non-functional pituitary adenomas (NFPAs) are benign tumors of the pituitary gland that do not over-secrete hormonal products, therefore, they are generally detected through symptoms of mass effect, including headache, vision loss, or hypopituitarism. There are multiple pathological subtypes of NFPAs, such as null cell adenomas, silent gonadotrophs, silent somatotrophs, silent corticotrophs, and silent subtype 3, all of which can be classified based on immunohistochemical studies and electron microscopy. Despite these numerous pathological subtypes, surgical resection remains the first-line treatment for NFPAs. Diagnosis is best made using high resolution MRI brain with and without gadolinium contrast, which is also helpful in determining the extent of invasion of the tumor and recognizing necessary sinonasal anatomy prior to surgery. Additional pre-operative work-up should include full laboratory endocrine evaluation with replacement of hormone deficiencies, and ideally, full neuro-ophthalmologic exam. Although transcranial surgical approaches to the pituitary gland can be performed, the most common approach used is the transnasal transsphenoidal approach with endoscopic or microscopic visualization. This approach avoids retraction of the brain and cranial nerves during tumor removal. Surgery for symptoms caused by mass effect, including headaches and visual loss, are successfully treated with surgical resection, resulting in improvement in pre-operative symptoms as high as 90% in some reports. Although the risk of complications is low, major and minor events, such as permanent hypopituitarism, persistent CSF leak, and carotid artery injury can occur at rates ranging from zero to about 9%.

The endoscopic surgical resection of intrasellar lesions conserves the hormonal function: a negative correlation to the microsurgical technique

BACKGROUND

The endonasal endoscopic approach is still currently under investigation for sellar tumor surgery: a higher resection rate is to be expected and complications should be minimized. The authors report their surgical results of endonasal endoscopic neurosurgery with special focus on postoperative hypopituitarism in comparison to microsurgical procedures.

METHODS

Sixty patients received endoscopic endonasal transsphenoidal procedures for sellar pathologies. All patients were followed up prospectively. A second group of 60 patients received microsurgical transsphenoidal procedures for sellar pathologies in our neurosurgical department before and were prospectively followed until now. Special attention was paid to hormonal insufficiency and medical substitution.

RESULTS

Sixty-eight percent (41 of 60) of the patients who underwent microsurgical procedures showed a new persisting pituitary insufficiency postoperatively. Twenty-three patients (55.5%) were substituted with thyroxine, hydrocortisone and sexual hormones and one patient (2.5%) also with ADH cause of global pituitary insufficiency. In 19 cases without any hormonal insufficiency after microsurgical procedures nine patients (47%) showed remnant tumor in follow-up MRI. The patients who underwent endoscopic procedures for pituitary adenomas revealed significant (P<0.01) less new persistent hormonal insufficiency with 13% of all cases (8/60). Five patients (62.5%) were substituted with thyroxine and hydrocortisone, two patients (25%) substituted with thyroxine, hydrocortisone and sexual hormones and one patient also with ADH because of global pituitary insufficiency. Thereby, in follow-up MRI and hormonal testing, radical tumor resection was detected in 92% in the endoscopic group.

CONCLUSIONS

This study seems to indicate that a better intraoperative identification and preservation of pituitary gland is possible in endoscopic transsphenoidal surgery with consecutive lower postoperative hypopituitarism rate.

Investigating the application of diving endoscopic technique in determining the extent of pituitary adenoma resection via the trans-nasal-sphenoidal approach

The aim of the present study was to investigate the advantages and disadvantages of the diving endoscopic technique in pituitary adenoma surgery, and the application value in determining the extent of tumor resection. A total of 37 patients with pituitary adenoma initially underwent tumor resection under an endoscope-assisted microscope via standard trans-nasal-sphenoidal approach, and tumor cavity structure was observed by applying the diving endoscopic technique. Surgery was subsequently performed again under a microscope or endoscope. The diving endoscopic technique allowed surgeons to directly observe the structure inside a tumor cavity in high-definition. In the present study, 24 patients had pituitary macroadenomas or microadenomas that did not invade the cavernous sinus, and were considered to have undergone successful total resection. Among these patients, no tumor residues were observed through the diving endoscopic technique. Some white lichenoid or fibrous cord-like tissues in the tumor cavity were considered to be remnants of tumors. However, pathology confirmed that these were not tumor tissues. For tumors that invaded the cavernous sinus in 13 patients, observation could only be conducted under the angulation endoscope of the diving endoscope; i.e., the operation could not be conducted under an endoscope. The present study suggests that the diving endoscopic technique may be used to directly observe the resection extent of tumors within the tumor cavity, especially the structure of the tumor cavity inside the sella turcica. The present study also directly validates the reliability of pituitary adenoma resection under endoscope-assisted microscope. In addition, the diving endoscopic technique also allows the surgeon to observe the underwater environment within the sella turcica.

Preservation of hormonal function by identifying pituitary gland at endoscopic surgery

OBJECTIVE

The endonasal endoscopic approach has been established for perisellar tumor surgery with a higher resection rate and reduced complications. We analyzed the potential to identify the pituitary gland under endoscopic view, at surgery and see its relation to postoperative hormonal insufficiency in endonasal endoscopic procedures.

METHODS

Between January 2011 and January 2014, 70 cases of pituitary adenomas with preoperative intact pituitary function underwent endoscopic endonasal transsphenoidal procedures for intrasellar pathologies. Endocrinologists and neurosurgeons followed these patients prospectively. Special attention was paid to intraoperative identification of gland tissue, surgical complications, degree of resection and postoperative hormonal insufficiency.

RESULTS

The pituitary gland was identified in 57 out of 70 procedures (81.4%). Eleven percent (8 of 70 patients) had persistent pituitary insufficiency. Two of these 8 patients belonged to the group with pituitary gland identification (2 out of 57); thus, when the pituitary gland was identified during the procedure postoperative hormonal insufficiency was seen in 3.5% of cases. Failure of pituitary gland identification presented with hormonal insufficiency of 46.2%. In analysis with Fisher's exact test, there was a high significant correlation between the identification of the pituitary gland intraoperatively and normal pituitary function postoperatively (p<0.005). On follow up radical tumor resection was seen in 88% (62 of 70 patients).

CONCLUSIONS

This study indicates that identification and preservation of pituitary gland tissue and function is possible in endoscopic transsphenoidal surgery. This preservation of gland tissue is a positive predictor of postoperative normal pituitary function.

Prognosis of pituitary adenomas in the early 1970s and today-Is there a benefit of modern surgical techniques and treatment modalities?

OBJECTIVE

Neurosurgical techniques for the treatment of sellar pathologies have been evolving continuously over the last decades. Additionally to the innovation of approaches and surgical techniques, this progress yielded to the application of modern intraoperative surgical tools as well as peri- and intraoperative imaging. Until now, no long-term analysis of the impact of new therapy concepts on the patient's outcome exists. Aim of this study was to analyse the impact of new operative approaches on perioperative mortality and morbidity as well as the long-term outcome after pituitary surgery.

PATIENTS AND METHODS

Three groups of patients were compared in this retrospective analysis of surgically treated pituitary adenomas between the years of 1963 and 2014. Group A contains 93 patients, treated between 1963-1980 with a mean follow-up of 12.1 years (±14.3years), group B comprises 89 patients treated between 1990 and 2000 with a mean follow-up of 10.1 years (±8.1years) and group C consists of 95 patients treated between 2011-2014 with a mean follow-up of 3.4 years (±1.9years).

RESULTS

The surgical treatment was performed significantly earlier today on smaller tumors with less preoperative complaints (p<0.01). Panhypopituitarism was detected only in 9.5% of the cases in group C compared to 50.8% in group A (p<0.01). Also, the incidence of revision surgery (5.6 vs. 2% vs 0%), postoperative hemorrhage (10.8% vs. 3.4% vs. 1%) and diabetes insipidus (34.4% vs. 11.2% vs. 5.2%) was decreased (p<0.01). Moreover, a significant postoperative improvement of ophthalmological complaints was detected (p<0.001). The long-term follow-up showed 40% of the entire recurrence rate occurring after the ninth postoperative year. The progression-free survival time increased significantly from group A to group B (p<0.05).

CONCLUSIONS

The results demonstrate a benefit of the recent developments of pituitary surgery in the short-term results as well as in the long-term outcome. The prognosis of pituitary adenoma patients could be improved by the introduction of new surgical approaches and techniques in the last decades. Also the perioperative morbidity and mortality rate has been reduced clearly since the 1970s. Furthermore our results emphasise the necessity of lifelong follow-up of all patients with successfully treated pituitary adenomas.

A New Irrigation System (Endosplash) for a Rigid Endoscope in Trans-sphenoidal Endoscopic Surgery

Obstruction of the visual field by blood is a major hindrance during endonasal endoscopic surgery, and a rapid and effective method for cleaning the lens is needed. We developed a new lens-cleaning system that does not employ a sheath or an irrigation-suction system. It is a 20-mm long cylinder with side holes that is attached to the barrel of the endoscope and is connected to a syringe containing saline. When the syringe is pressed, saline flows down to the tip along the barrel and washes the lens without requiring a sheath. We report the use of the system in six cases of endonasal endoscopic surgery. The lens was wiped significantly less often than during similar surgery performed without the use of this system. The Endosplash is simple and enables the surgeon to clean the lens with a single press of a syringe, thereby greatly enhancing the efficacy of endoscopic surgery.

Complications Related to the Endoscopic Endonasal Transsphenoidal Approach for Nonfunctioning Pituitary Macroadenomas in 300 Consecutive Patients

OBJECTIVE

To analyze complications of endoscopic transsphenoidal surgery (ETS) for nonfunctioning pituitary macroadenomas (NFPAs).

METHODS

A retrospective study of 300 NFPAs was performed. Complications and factors that could influence these complications were analyzed.

RESULTS

Visual and pituitary functions worsened in 2.4% and 13.7% of cases, respectively. Postoperative diabetes insipidus was permanent in 6.2% of cases. Postoperative meningitis occurred in 3.3% of patients. Meningitis was strongly associated with intraoperative cerebrospinal fluid (CSF) leaks (P = 0.01), postoperative CSF leaks (P = 0.0001), and operation times longer than 1 hour (P = 0.023). Detection of Staphylococcus aureus and preoperative treatment with mupirocin in the nostrils did not impact the occurrence of meningitis. Two patients with meningitis died (unique causes of death). Postoperative CSF leaks occurred in 2.7% of cases and were associated with intraoperative CSF leaks (P = 0.007) and permanent diabetes insipidus (P = 0.028). The rate of CSF leak decreased from 4% to 0.8% (P = 0.048) after we moved from a soft to hard reconstruction of the sella. The rate of postoperative epistaxis decreased from 6.7% to 1.25% after we stopped using monopolar coagulation (P = 0.013).

CONCLUSIONS

ETS permits a wide view, allowing good conditions for a satisfactory resection in the majority of NFPAs. Some pitfalls of endoscopy can lead to complications that improve with modification of the operative technique (i.e., CSF leak and postoperative epistaxis). This study confirms an acceptable rate of complications associated with ETS.

Pituitary Apoplexy

Pituitary apoplexy, a rare clinical syndrome secondary to abrupt hemorrhage or infarction, complicates 2%-12% of pituitary adenomas, especially nonfunctioning tumors. Headache of sudden and severe onset is the main symptom, sometimes associated with visual disturbances or ocular palsy. Signs of meningeal irritation or altered consciousness may complicate the diagnosis. Precipitating factors (increase in intracranial pressure, arterial hypertension, major surgery, anticoagulant therapy or dynamic testing, etc) may be identified. Corticotropic deficiency with adrenal insufficiency may be life threatening if left untreated. Computed tomography or magnetic resonance imaging confirms the diagnosis by revealing a pituitary tumor with hemorrhagic and/or necrotic components. Formerly considered a neurosurgical emergency, pituitary apoplexy always used to be treated surgically. Nowadays, conservative management is increasingly used in selected patients (those without important visual acuity or field defects and with normal consciousness), because successive publications give converging evidence that a wait-and-see approach may also provide excellent outcomes in terms of oculomotor palsy, pituitary function and subsequent tumor growth. However, it must be kept in mind that studies comparing surgical approach and conservative management were retrospective and not controlled.

Cesare Cavina (1888-1935): a father of transsphenoidal surgery

Among the fathers of transsphenoidal surgery, a relevant role should be reserved for Cesare Cavina (1888-1935). He had the merit to develop and popularize in Italy this approach for pituitary tumors, performing 47 transsphenoidal hypophysectomies out of his personal series of 66 patients between 1927 and 1935. He contributed to this surgery by introducing radiological control of the surgical trajectory to reduce the risk of complications and increase the safety of this approach. We think that both his short lifespan (he died when he was 47 years old) and the language of his papers (Italian and not English) are two important factors that have contributed to forgetting his role in the history of transsphenoidal surgery. We think that Prof. Cesare Cavina is definitively one of the fathers of transsphenoidal surgery and that it is important to preserve his memory.

Evolution of minimally invasive approaches to the sella and parasellar region

Introduction Given advancements in endoscopic image quality, instrumentation, surgical navigation, skull base closure techniques, and anatomical understanding, the endonasal endoscopic approach has rapidly evolved into a widely utilized technique for removal of sellar and parasellar tumors. Although pituitary adenomas and Rathke cleft cysts constitute the majority of lesions removed via this route, craniopharyngiomas, clival chordomas, parasellar meningiomas, and other lesions are increasingly removed using this approach. Paralleling the evolution of the endonasal route to the parasellar region, the supraorbital eyebrow craniotomy has also been increasingly used as an alternative minimally invasive approach to reach this skull base region. Similar to the endonasal route, the supraorbital route has been greatly facilitated by advances in endoscopy, along with development of more refined, low-profile instrumentation and surgical navigation technology.

Objectives This review, encompassing both transcranial and transsphenoidal routes, will recount the high points and advances that have made minimally invasive approaches to the sellar region possible, the evolution of these approaches, and their relative indications and technical nuances.

Data Synthesis The literature is reviewed regarding the evolution of surgical approaches to the sellar region beginning with the earliest attempts and emphasizing technological advances, which have allowed the evolution of the modern technique. The surgical techniques for both endoscopic transsphenoidal and supraorbital approaches are described in detail. The relative indications for each approach are highlighted using case illustrations.

Conclusions Although tremendous advances have been made in transitioning toward minimally invasive transcranial and transsphenoidal approaches to the sella, further work remains to be done. Together, the endonasal endoscopic and the supraorbital endoscope-assisted approaches are complementary minimally invasive routes to the parasellar region.

Endoscopic endonasal surgery for pituitary adenomas

BACKGROUND

Pituitary surgery is a continuous evolving specialty of the neurosurgeons' armamentarium, which requires precise anatomic knowledge, technical skills, and integrated culture of the pituitary pathophysiology. Actually it cannot be considered only from a technical standpoint, but rather a procedure resulting from the close cooperation among different specialists (e.g., ophthalmologists, neuroradiologists, endocrinologists, neurosurgeons, otorhinolaryngologists, anesthesiologists, neurophysiologists, pathologists, instrument manufacturers).

METHODS

The "pure" endoscopic endonsal surgery is a procedure performed through the nose, with the endoscope alone throughout the whole approach and without any transsphenoidal retractor. The procedure consists of three main aspects: exposure of the lesion, removal of the relevant pathology, and reconstruction, going through three different steps, the nasal, the sphenoid, and the sellar phases.

CONCLUSIONS

The endoscopic approach offers some advantages due to the endoscope itself: a superior close-up view of the relevant anatomy and an enlarged working angle are provided with an increased panoramic vision inside the surgical area. Concerning results in terms of mass removal, relief of clinical symptoms, cure of the underlying disease, and complication rate, these are, at least, similar to those reported in the major microsurgical series, but patient compliance is by far better. Besides the advantages to the patients, the surgeons-because of the wider and closer view of the surgical target area and the increase of the scientific activity as from the peer-reviewed literature on the topic in the past 10 years, the smoothing of interdisciplinary cooperation-, and the institutions (shorter postoperative hospital stay and increase of the case load)- the adoption of endoscopy in transsphenoidal surgery has gained a strong foothold.

The current status of endoscopy in transsphenoidal surgery: an international survey

OBJECTIVE

A survey-based study was designed to assess opinions related to transsphenoidal endoscopy, to evaluate the current global attitudes of neurosurgeons regarding the use of this procedure, and to solicit basic data from key institutions worldwide, with the advantage that large series of cases become available for analysis.

METHODS

A web-based multi-item questionnaire was distributed to the surgical departments of 393 neurosurgical centers by means of an invitation e-mail. The questionnaire was composed of 2 sections: section 1 focused on the surgical technique for pituitary adenomas (standard technique), and section 2 concentrated on surgery for skull base tumors (extended technique). Each section was composed of 2 parts: multiple choice questions and free textual responses.

RESULTS

From a total of 393 neurosurgical centers, from 23 countries, that received the questionnaire, 87 of them (22%) submitted complete or incomplete responses. The surgical procedure, in 60 cases had been performed by a neurosurgeon, in 53 cases by a neurosurgeon and an otolaryngologist, and in 4 cases by an otolaryngologist only. The endoscope (2- and 3-dimensional) was used in 85.2% of transsphenoidal procedures versus the microscope in 14.8% of cases. The endonasal route was used for approach in 93.2% versus the sublabial route in 6.8% of cases. Computer-guided navigation was used by survey population in 71 cases, micro-Doppler in 51 cases, and Cavitron Ultrasonic Surgical Aspirator in 43 cases. Several hundreds of extrasellar tumors were operated using the extended technique.

CONCLUSIONS

Transsphenoidal endoscopy for pituitary and anterior skull base tumors has become established as a routine method of dealing with a variety of lesions. The level of interest in the neurosurgical surgery community is reflected by the geometric expansion of contributions to the literature on endoscopic surgery.

Expanding the borders: the evolution of neurosurgical approaches

In this article the authors discuss the development of neurosurgical approaches and the advances in science and technology that influenced this development throughout history. They provide a broad overview of this interesting topic from the first attempts of trephination by ancient cultures to the work of the pioneers of neurosurgery and the introduction of microsurgery.

Pro: endoscopic endonasal transsphenoidal pituitary surgery is superior to microscope-based transsphenoidal surgery

The introduction of the endoscope to transsphenoidal pituitary surgery is relatively new, but represents a major advancement in the field. The use of the endoscope to visualize the sella via a direct endonasal approach offers the surgeon dramatically better visualization as well as improved range of motion compared to the operating microscope. Growing evidence confirms that these improvements directly translate into better surgical resections and outcomes. Further, patient comfort and satisfaction are higher with the endonasal method compared with other transsphenoidal approaches, and it is a cost effective technology. This position paper will outline the reasons that endoscopic endonasal transsphenoidal surgery is the preferred method for pituitary surgery, and why it will likely be adopted as the standard technique for transsphenoidal surgery worldwide.

Development of intracranial approaches for craniopharyngiomas: an analysis of the first 160 historical procedures

Object

The development of surgical procedures for the removal of craniopharyngiomas (CPs) was greatly influenced by the enormous topographical and morphological heterogeneity displayed by these lesions. In this study the authors reviewed the intracranial approaches designed to treat CPs during the early historical period (1891–1938) with the aim of finding the CP topographical and pathological features that influence patient outcomes.

Methods

The authors conducted a systematic retrospective review of well-described cases of surgically treated CPs in publications from the period 1891–1938. Valuable information regarding the diagnosis of the lesion, type of craniotomy performed, CP topography, and outcome was selected from 418 reports included in medical publications from this period. The type of surgical procedure used, degree of tumor removal, CP position and histological variety, and clinical evidence of postoperative hypothalamic injury were the variables analyzed with the aim of defining their influence on the final patient outcome.

Results

A collection of 160 cases was eligible for analysis. Craniopharyngioma topography was significantly related to the existence of postoperative hypothalamic damage and the degree of tumor removal achieved (p < 0.001). The infundibulo-tuberal, or not strictly intraventricular, topography was associated with the highest rate of hypothalamic injury (84%) and impossibility of tumor removal (51%). This topography also showed the worst prognosis (p = 0.001). Additional variables correlated with patient outcome were the presence of hypothalamic damage, type of surgical approach used, and degree of tumor removal. Patients having a poor outcome, suffering from permanent coma, or dying after surgery presented with symptoms of hypothalamic injury in 40% of cases (p < 0.001). The surgical approach associated with the best outcome was the transsphenoidal (58%), followed by the subfrontal (45%) and the transcallosal (45%). Subtotal resection of the lesion yielded the best postoperative results, with only 17% of patients dying or suffering from a poor outcome, in contrast to the 39% reported for gross-total removal of the lesion (p = 0.001).

Conclusions

Two major variables influenced the results of early surgical experience with CPs for the period from 1891 to 1938: 1) the inaccuracy in defining CP topography with the diagnostic methods available at that time; and 2) the ignorance about the risks associated with the dissection of lesions showing tenacious adherence to the hypothalamus. The degree of functional and morphological disturbance of the hypothalamus caused by a CP remains a fundamental variable helping the surgeon to predict the risks associated with the radical excision of the tumor and patient outcome.

Craniocaudal extension as an indication of surgical outcome in transsphenoidal surgery for pituitary adenomas

Transsphenoidal approach is considered the treatment of choice for pituitary adenoma removal. Suprasellar extension is regarded a drawback for complete removal of these tumors through this approach. Evaluate the correlation between the preoperative radiologic craniocaudal extension on MRI of pituitary adenomas and the extent of tumor removal. A retrospective study. Tertiary care hospital. 560 patients underwent transsphenoidal removal of pituitary adenomas. The degree of removal of pituitary tumor in the follow-up imaging of the patients was correlated with the preoperative extension in mid-Coronal T1 W Gd. Tumors with suprasellar extension can be classified into: Type I tumors with extension confined to the sellar boundaries, resulted in complete removal in all cases (100%), type II tumors with suprasellar extension reaching the floor of the 3rd ventricle, resulted in complete removal in 70.2% of the cases, type III tumors with suprasellar extension above the 3rd ventricle, had only 13.5% of complete removal. Integration of radiologic findings into a scheme for the preoperative determination of possibility of total removal of the tumor through transsphenoidal approach, can give better correlation to the surgical outcome of pituitary tumors.

Surgical approach to pituitary tumors

Pituitary surgery is a continuously evolving specialty of neurosurgery that requires precise anatomical knowledge, technical skills, and an integrated appreciation of pituitary pathophysiology. It involves close cooperation between different specialists, i.e., the endocrinologist, neurosurgeon, neuroradiologist, pathologist, ophthalmologist, and others. It is currently possible to manage many of the different pituitary syndromes with more than one option, including medical, surgical, and radiotherapeutic options, either alone or in various combinations. In recent decades, the transsphenoidal midline route became the standard approach to the pituitary area, this being a less traumatic direct route to the sella, avoiding brain retraction and providing excellent visualization, with a lower morbidity and mortality rate as compared to transcranial procedures. Most pituitary adenomas can be managed and removed through a standard transsphenoidal approach, either microscopic or endoscopic. More recently, the introduction of the endoscope in the extended endoscopic endonasal approach has become more widespread. Here we report current indications and give a step-by-step account of the surgical techniques used in pituitary surgery, focusing on the "dangerous keypoints". We also describe possible complications of each kind of procedure.

Endoscopic anatomy of sellar region

The transsphenoidal approach is the preferred access used in surgical treatment of most sellar region pathologies. The use of endoscopy is advantageous, and it is considered a good alternative to the traditional microsurgical technique. The purpose of this study is to recognize and describe anatomical variations of the sphenoid sinus and the sellar region, mainly describing the anatomy of the posterior wall of the sphenoid sinus and analyzing intercarotid distances in 3 regions. Thirty sphenoid blocks treated with formaldehyde were injected and dissected. Using endoscopy, anatomical variations were studied and the intercarotid distances were measured at the tuberculum sellae, sellar floor and clivus. The types of sphenoid sinus found were: conchal in 1 (4.76 %), pré-sellar in 2 (9.52 %) and sellar in 19 (85.7 %) specimens. The mean distance found from the sphenoid sinus ostium to the sella turcica was 19 mm (±6.5) mm. The mean intercarotid distances found at the tuberculum sellae, sellar floor and clivus were respectively 13.32, 18.00 and 18.90 mm. Endoscopy, with its magnification and lighting provide a panoramic view of deep fields. The anatomical variations described in this study support the need for a careful evaluation of preoperative images in each case.

Endoscopic endonasal transsphenoidal approach to sellar lesions: a detailed account of our mononostril technique

Objective The endonasal endoscopic approach is currently under investigation for perisellar tumor surgery. A higher resection rate is to be expected and nasal complications should be minimized. Here, the authors report their technique of transnasal endoscopic neurosurgery after 218 procedures. Methods Between October 2000 and September 2011, 210 patients received 218 endoscopic endonasal transsphenoidal procedures for perisellar lesions. Procedures were video recorded. The surgical technique was carefully analyzed. These cases were prospectively followed. Results Standard technique was mononostril approach with 0-degree optics. 30-degree and-after availability-45-degree optics were used for assessment of radicality. On follow-up, magnetic resonance imaging revealed radical tumor resection in 94 out of 104 cases (90.3%). Recurrent tumor growth was observed in five younger patients (2.2%). There was no mortality and a low complication rate. Three patients (1.4%) complained postoperatively of nasal congestion or reduced nasal air flow; however, no complaints were considered to be severe. Conclusion In comparison with other literature reports, the results are comparable or even better with respect to surgical radicality. The very low rate of nasal complaints is particularly remarkable. The technique has been shown to be safe and successful with a high radicality and only minor complications.

Endoscopic endonasal transsphenoidal removal of recurrent and regrowing pituitary adenomas: experience on a 59-patient series

OBJECTIVE

The nature of the pituitary adenomas itself exposes the possibility of a recurrence of the tumor. The aim of this study was to evaluate the effectiveness of the endoscopic endonasal transsphenoidal approach for the removal of recurrent and residual pituitary adenomas, already treated by a microscopic or endoscopic transsphenoidal approach or by a transcranial route.

METHODS

A total of 59 adult patients with a recurrent or regrowing pituitary adenoma underwent surgery using a pure endoscopic endonasal transsphenoidal approach. Of these patients, 31 were previously operated on by a microsurgical transsphenoidal approach, 22 by means of an endoscopic transsphenoidal route, and 6 via a transcranial route. The patient series has been divided into 3 tiers according to the primary surgery, and the results were evaluated accordingly.

RESULTS

Gross total removal was achieved in 37 of our cases (62.7%). According to prior surgery at primary disease, we found that in the subgroup of patients who underwent a microsurgical transsphenoidal approach we achieved gross total removal in 23 cases (74.2%; 23 of 31), whereas in the group of patients who underwent the endoscopic endonasal approach, gross total removal was attained respectively in 13 cases (59.1%; 13 of 22) and in only 1 case of those who underwent the transcranial approach (16.7%; 1 of 6). Postoperative complications included 1 case (1.7%) of cerebrospinal fluid leak and meningitis, and 1 with an hematoma in the tumor field (1.7%); both needed surgical reoperation.

CONCLUSIONS

The endoscopic endonasal approach is a safe and effective procedure for the management of recurrent and/or regrowing pituitary tumors previously treated by either a microsurgical or an endoscopic approach.

Norman Dott, Gerard Guiot, and Jules Hardy: key players in the resurrection and preservation of transsphenoidal surgery

Developed over a century ago, the transsphenoidal approach to access lesions of the pituitary gland and sella turcica has transformed the field of neurosurgery, largely due to the work of Oskar Hirsch and Harvey Cushing. Furthermore, its use and modification in the early 1900s was perhaps one of Cushing's greatest legacies to skull base surgery. However, Cushing, who had worked relentlessly to improve the transsphenoidal route to the pituitary region, abandoned the approach by 1929 in his pursuit to master transcranial approaches to the suprasellar region. Hirsch and a few other surgeons continued to perform transsphenoidal operations, but they were unable to maintain the popularity of the approach among their peers.

During a time when transsphenoidal surgery was on the brink of extinction, a critical lineage of 3 key surgeons—Norman Dott, Gerard Guiot, and Jules Hardy—would resurrect the art, each working to further improve the procedure. Dott, Cushing's apprentice from 1923 to 1924, brought his experiences with transsphenoidal surgery to Edinburgh, Scotland, and along the way, developed the lighted nasal speculum to provide better illumination in the narrow working area. Guiot, inspired by Dott, adopted his technique and used intraoperative radiofluoroscopic technique for image guidance. Hardy, a fellow of Guiot, from Montreal, Canada, revolutionized transsphenoidal microsurgery with the introduction of the binocular microscope and selective adenomectomy.

The teachings of these pioneers have endured over time and are now widely used by neurosurgeons worldwide. In this paper, we review the lineage and contributions of Dott, Guiot, and Hardy who served as crucial players in the preservation of transsphenoidal surgery.

Sphenoid sinus pyocele after transsphenoidal approach for pituitary adenoma

Transsphenoidal pituitary adenoma surgery is related to a low morbidity rate. The complications that can occur are classified as intra- and extracranial. The aim of the study is to discuss one group of these complications involving the sphenoid sinus: mucocele and its possible transformation into pyocele. We evaluate clinical presentation, management strategy and the outcome after long-term follow-up presenting an explicative case and a review of the literature. A patient presented to our outpatient clinic 8 months after transsphenoidal surgery for selective removal of a pituitary adenoma because of an acute onset of frontal headache during an airplane travel, fever and pulsating sensation in left eye and ear. MRI revealed a contrast-enhancing lesion in the left inferior portion of the sphenoid sinus. An endonasal endoscopic revision of the sphenoid sinus was performed. After opening of the scar to enter in the left sinus a pyocele was found and treated with drainage and marsupialisation. Development of sphenoid sinus pyocele is an extremely rare postoperative complication of transsphenoidal surgery. This lesion should be taken in consideration in patients presenting with retroorbital headache of acute onset and fever after pituitary surgery. Diagnosis can be suspected on the MRI studies and confirmed by a targeted flexible endoscope examination. Endoscopic drainage with wide opening of the sphenoid sinus and marsupialisation is the treatment of choice to avoid recurrences.

Recent advances in pituitary tumor management

PURPOSE OF REVIEW

Advances in the neurosurgical management of pituitary tumors have included the refinement of surgical access and significant progress in navigation technology to help further reduce morbidity and improve outcome. Similarly, stereotactic radiosurgery has evolved to become an integral part in pituitary tumors not amenable to medical or surgical treatment.

RECENT FINDINGS

The evolution of minimally invasive surgery has evolved toward endoscopic versus microscopic trans-sphenoidal approaches for pituitary tumors. Debate exists regarding each approach, with advocates for both championing their cause. Stereotactic and fractional radiosurgery have been shown to be a safe and effective means of controlling tumor growth and ensuring hormonal stabilization, with longer-term data available for GammaKnife compared with CyberKnife.

SUMMARY

The advances in trans-sphenoidal surgical approaches, navigation technological improvements and the current results of stereotactic radiosurgery are discussed.

The pseudocapsule surrounding a pituitary adenoma and its clinical significance

The transsphenoidal approach is currently considered the preferred first-line treatment for pituitary adenoma. With the discovery and application of the pseudocapsule surrounding a pituitary adenoma, transsphenoidal surgery of pituitary adenoma further falls into two categories: "extracapsular" and traditional "intracapsular" resection methods, on the basis of where dissection is performed with respect to the pseudocapsule. Thus, the pseudocapsule can be used as a plane to guide the operation, helps in total resection of pituitary adenoma, and can guide subsequent treatment after surgery.

The endoscopic diving technique in pituitary and cranial base surgery: technical note

OBJECTIVE

We used the diving technique to go beyond mere visualization of the surgical field and used it as an important step in removing the lesion itself, improving the optical field, and optimizing visualization with a dynamic fluid film lens. Likewise, having extended endoscopic endonasal surgery to the entire base of the skull and in particular to the sinus cavity, "diving surgery" has proven to be effective in visualizing and dissecting more extended tumors.

METHODS

We performed diving surgery in more than 350 surgical procedures to remove lesions in the sellar, sinus cavity, and clival regions. Intrasellar hydroscopy was performed in all cases to check that the lesion was removed completely and to gently dissect any intracavitary residual tumoral tissue. Diving surgery can be performed in the sellar cavity, in the cavernous sinus, and at the level of the posterior cranial fossa in the cavity obtained after clivectomy.

RESULTS

The hydrodissection and continuous flushing of the sellar cavity, together with better control of bleeding, allow the surgeon to perform piecemeal removal of the lesion with direct control of the cleavage plane and tumor residue and avoid blind curettage near the pituitary gland. This technique is particularly useful in identifying small infiltrations of the cavernous sinus and in checking the integrity of the pituitary stalk when instruments are introduced into the sella.

CONCLUSION

Diving surgery is a useful step in dealing with minor complications that can occur during endonasal endoscopic surgical procedures.

Outcome of using the histological pseudocapsule as a surgical capsule in Cushing disease

OBJECT

Many patients with Cushing disease still have active or recurrent disease after pituitary surgery. The histological pseudocapsule of a pituitary adenoma is a layer of compressed normal anterior lobe that surrounds the adenoma and can be used during surgery to identify and guide removal of the tumor. In this study the authors examined the results of using the pseudocapsule as a surgical capsule in the resection of adenomas in patients with Cushing disease.

METHODS

The authors reviewed a prospective database of data obtained in patients with Cushing disease who underwent surgery. The analysis included all cases in which a lesion was identified during surgery and in which the lesion was believed to be confined to the pituitary gland in patients with Cushing disease between January 1990 and March 2007. Since the objective was to determine the success of using the pseudocapsule as a surgical capsule, patients with invasive tumors and patients in whom no lesion was identified during surgery-challenging cases for surgical success-were excluded from analysis.

RESULTS

In 261 patients an encapsulated adenoma was identified at surgery. Tumor was visible on MR imaging in 135 patients (52%); in 126 patients (48%) MR imaging detected no tumor. The range of tumor size overlapped considerably in the groups with positive and negative MR imaging results, indicating that in addition to size other features of the adenoma influence the results of MR imaging. In 252 patients hypercortisolism resolved after the first operation, whereas in 9 patients (3 with positive MR imaging and 6 with negative MR imaging) early reoperation was required. Hypercortisolism resolved in all 261 patients (256 with hypocortisolism and 5 with eucortisolism) before hospital discharge. Forty-six patients (18%) had postoperative electrolyte abnormalities (30 with hyponatremia and 16 with diabetes insipidus), but only 2 patients required treatment at discharge. The mean clinical follow-up duration was 84 months (range 12-215 months). Six patients (2%) had recurrence of hypercortisolism, all of whom were treated successfully with reoperation.

CONCLUSIONS

Because of their small size, adenomas can be challenging to identify in patients with Cushing disease. Use of the histological pseudocapsule of an adenoma allows accurate identification of the tumor and helps guide its complete excision. With this approach the overall remission rate is high and the rate of complications is low.

The evolution of extracranial approaches to the pituitary and anterior skull base

The development of extracranial approaches to the anterior skull base has been a process in development for over a 100 years. Many neurosurgical (and non-neurosurgical) pioneers have contributed to its evolution. In this paper, we will review the major contributors and contributions to this evolving field.

Endoscopic pituitary surgery

Pituitary surgery is a continuous evolving speciality of the neurosurgeons' armamentarium, which requires precise anatomical knowledge, technical skills and integrated appreciation of the pituitary pathophysiology. What we consider "pure" endoscopic transsphenoidal surgery is a procedure performed through the nose and the sphenoid bone, with the endoscope alone throughout the whole approach to visualize the surgical target area and without the use of any transsphenoidal retractor. It offers some advantages due to the endoscope itself: a superior close-up view of the relevant anatomy and an enlarged working angle are provided with an increased panoramic vision inside the surgical area. Concerning results in terms of mass removal, relief of clinical symptoms, cure of the underlying disease and complication rate, they are, at least, similar to those reported in the major microsurgical series, but patient compliance is by far better. Furthermore transsphenoidal endoscopy brings advantages to the patient (less nasal traumatism, no nasal packing, less post-op pain and usually quick recovery), to the surgeon (wider and closer view of the surgical target area, increase of the scientific activity as from the peer-reviewed literature on the topic in the last 10 years, smoothing of interdisciplinary cooperation), to the institution (shorter post-op hospital stay, increase of the case load). Besides, further progress and technological advance are expected from the close cooperation between different technologies and industries. Continuing works in such field of "minimalism" will offer further possibilities to provide the surgeon with even more effectiveness and safety, and, on the other hand, the patient with improvement of results.

Endoscopic endonasal resection of a synchronous pituitary adenoma and a tuberculum sellae meningioma: technical case report

OBJECTIVE

The presence of a sellar macroadenoma with a concomitant tuberculum sellae meningioma typically requires a craniotomy for extirpation of the meningioma. We describe a single endoscopic approach for resection of both lesions.

PRESENTATION

A 52-year-old woman with complaints of continuous headache and right temporal visual field loss was found to have a 1.9 x 2.1 x 1.7-cm enhancing sellar mass on magnetic resonance imaging scans associated with a second enhancing extra-axial lesion at the planum sphenoidale measuring 1.0 x 0.6 cm and encroaching on the right optic nerve.

INTERVENTION

After the endoscopic transnasal resection of the pituitary tumor, the planum sphenoidale was drilled and the underlying dura was incised. The suprasellar tumor was identified and completely resected. Histological evaluation confirmed the concomitant presence of a meningioma and pituitary adenoma.

CONCLUSION

With advances in endoscopic and image-guidance technology and increasing understanding of the endoscopic anatomy of the sellar region, surgeons are capable of reaching both intrasellar and suprasellar/anterior cranial base region tumors through a single endoscopic approach. The use of endoscopes in transsphenoidal approaches may obviate the need for additional craniotomies in properly selected patients.