Treatment of pituitary tumors: surgery

Risk Factors for Isolated Sphenoid Sinusitis after Endoscopic Endonasal Transsphenoidal Pituitary Surgery

(1) Background: Transsphenoidal pituitary surgery can be conducted via microscopic or endoscopic approaches, and there has been a growing preference for the latter in recent years. However, the occurrence of rare complications such as postoperative sinusitis remains inadequately documented in the existing literature. (2) Methods: To address this gap, we conducted a comprehensive retrospective analysis of medical records spanning from 2018 to 2023, focusing on patients who underwent transsphenoidal surgery for pituitary neuroendocrine tumors (formerly called pituitary adenoma). Our study encompassed detailed evaluations of pituitary function and MRI imaging pre- and postsurgery, supplemented by transnasal endoscopic follow-up assessments at the otolaryngology outpatient department. Risk factors for sinusitis were compared using univariate and multivariate logistic regression analyses. (3) Results: Out of the 203 patients included in our analysis, a subset of 17 individuals developed isolated sphenoid sinusitis within three months postoperation. Further scrutiny of the data revealed significant associations between certain factors and the occurrence of postoperative sphenoid sinusitis. Specifically, the classification of the primary tumor emerged as a notable risk factor, with patients exhibiting nonfunctioning pituitary neuroendocrine tumors with 3.71 times the odds of developing sinusitis compared to other tumor types. Additionally, postoperative cortisol levels demonstrated a significant inverse relationship, with lower cortisol levels correlating with an increased risk of sphenoid sinusitis postsurgery. (4) Conclusions: In conclusion, our findings underscore the importance of considering tumor classification and postoperative cortisol levels as potential predictors of postoperative sinusitis in patients undergoing transsphenoidal endoscopic pituitary surgery. These insights offer valuable guidance for clinicians in identifying at-risk individuals and implementing tailored preventive and management strategies to mitigate the occurrence and impact of sinusitis complications in this patient population.

Approach to the Patient With Treatment-resistant Acromegaly

Although most tumors in patients with acromegaly are benign and are cured or controlled by surgery and/or first-generation somatostatin receptor ligands therapy, some can behave more aggressively and are resistant to these standard therapies. Acromegaly, if left untreated, is a rare and chronic disorder, commonly caused by a GH-producing pituitary adenoma and is associated with significant comorbidities and an increased mortality. Transsphenoidal surgery is considered the mainstay of acromegaly management, but medical therapy has an increasingly important role. However, disease activity is not fully controlled in a significant number of patients treated with surgery and/or high-dose first-generation somatostatin receptor ligand monotherapy. In these circumstances, therefore, repeated surgery, second-line medical therapy, and radiotherapy, alone or combined as multimodal therapeutic strategies should be considered, in a patient-centered perspective.

Early postoperative MRI and detection of residual adenoma after transsphenoidal pituitary surgery

OBJECTIVE

Current practice guidelines recommend delayed (≥ 3 months after operation) postoperative MRI after transsphenoidal surgery for pituitary adenomas, although this practice defers obtaining important information, such as the presence of a residual adenoma, that might influence patient management during the perioperative period. In this study, the authors compared detection of residual adenomas by means of early postoperative (EPO) MRI (< 48 hours postsurgery) with both surgeon intraoperative assessment and late postoperative (LPO) MRI at 3 months.

METHODS

Adult patients who underwent microscopic transsphenoidal surgery for pituitary adenomas with MRI preoperatively, < 48 hours after the operation, 3 months postoperatively, and yearly for 4 years were included. The presence or absence of residual tumor was assessed intraoperatively by a single surgeon and postoperatively by 2 neuroradiologists blinded to the intraoperative assessment and other postoperative imaging studies. The presence of residual tumor was confirmed by reresection, tumor growth on imaging, or hormonal evidence. Interreader reliability was calculated at each imaging time point. Specificity, sensitivity, positive predictive value, and negative predictive value for EPO and LPO imaging and intraoperative assessment were determined.

RESULTS

In total, 102 consecutive patients who underwent microscopic transsphenoidal resection of a pituitary adenoma were included. Eighteen patients (18%) had confirmed residual tumors (12 confirmed by tumor growth, 5 by surgery, and 1 by biochemical evidence of persistent disease). Interreader reliability for detecting residual tumor on EPO MRI was almost perfect (κ = 0.88) and significantly higher than that for LPO MRI (κ = 0.69, p = 0.03). EPO MRI was highly specific for residual tumor (98%), a finding similar to that for intraoperative assessment (99%, p = 0.60) and significantly higher than that for LPO MRI (81%, p < 0.001). Notably, EPO MRI was significantly more sensitive for residual tumor (100%) than both intraoperative assessment (78%, p = 0.04) and LPO MRI (78%, p = 0.04). EPO MRI had a 100% negative predictive value and was used to find 4 residual tumors that were not identified intraoperatively. Residual tumors found on EPO MRI allowed for reresection during the same hospitalization for 3 patients.

CONCLUSIONS

EPO MRI after transsphenoidal pituitary surgery can be reliably interpreted and has greater sensitivity for detecting residual tumor than intraoperative assessment and LPO MRI. This result challenges current guidelines stating that delayed postoperative imaging is preferable to early imaging. Pituitary surgeons should consider performing EPO MRI either in addition to or instead of delayed imaging.

The optimal surgical techniques for pituitary tumors

In this paper, the currently used and well evaluated techniques for the surgery of pituitary tumors will be reviewed. Since the first surgical approaches to pituitary tumors more than 100 years have elapsed. Various surgical techniques have been developed, refined and standardized. Most of these tumors are to date treated via transsphenoidal approaches. Many pituitary adenomas, particularly, smaller, enclosed ones, can be completely excised and a selective adenomectomy is usually attempted. It leads to remission of hormonal oversecretion and also to recovery of pituitary function in many patients. The resection of pseudocapsule around the adenoma seems to improve the operative results further. Transcranial approaches, employing craniotomies, are still needed in some patients with pituitary adenomas and in many of those harbouring craniopharyngiomas. The operative techniques will be described and briefly commented. Moreover, the application and usefulness of several technical developments will be reviewed, such as the use of the endoscope, magnetic resonance imaging, fluorenscent dyes and neuronavigation. The use of the intraoperative Doppler probe, ultrasound and the value of intraoperative hormonal measurements will be briefly discussed. There is sufficient evidence that the best and optimal outcome in terms of tumor resection and correction of hormonal oversecretion as well as the lowest rate of complications are obtained in centers of excellence with sufficiently experienced, specialized surgeons and a high patient load.

The surgical treatment of acromegaly

PURPOSE

Surgical extraction of as much tumour mass as possible is considered the first step of treatment in acromegaly in many centers. In this article the potential benefits, disadvantages and limitations of operative acromegaly treatment are reviewed.

METHODS

Pertinent literature was selected to provide a review covering current indications, techniques and results of operations for acromegaly.

RESULTS

The rapid reduction of tumour volume is an asset of surgery. To date, in almost all patients, minimally invasive, transsphenoidal microscopic or endoscopic approaches are employed. Whether a curative approach is feasible or a debulking procedure is planned, can be anticipated on the basis of preoperative magnetic resonance imaging. The radicality of adenoma resection essentially depends on localization, size and invasive character of the tumour. The normalization rates of growth hormone and IGF-1 secretion, respectively, depend on tumour-related factors such as size, extension, the presence or absence of invasion and the magnitude of IGF-1 and growth hormone oversecretion. However, also surgeon-related factors such as experience and patient load of the centers have been shown to strongly affect surgical results and the rate of complications. As compared to most medical treatments, surgery is relatively cheap since the costs occur only once and not repeatedly. There are several new technical gadgets which aid in the surgical procedure: navigation and variants of intraoperative imaging.

CONCLUSIONS

For the mentioned reasons, current algorithms of acromegaly management suggest an initial operation, unless the patients are unfit for surgery, refuse an operation or only an unsatisfactory resection is anticipated. A few suggestions are made when a re-operation could be considered.

Binostril versus mononostril approaches in endoscopic transsphenoidal pituitary surgery: clinical evaluation and cadaver study

OBJECTIVE Over the past 2 decades, endoscopy has become an integral part of the surgical repertoire for skull base procedures. The present clinical evaluation and cadaver study compare binostril and mononostril endoscopic transnasal approaches and the surgical techniques involved. METHODS Forty patients with pituitary adenomas were treated with either binostril or mononostril endoscopic surgery. Neurosurgical, endocrinological, ophthalmological, and neuroradiological examinations were performed. Ten cadaver specimens were prepared, and surgical aspects of the preparation and neuroradiological examination were documented. RESULTS In the clinical evaluation, 0° optics were optimal in the nasal and sphenoidal phase of surgery for both techniques. For detection of tumor remnants, 30° optics were superior. The binostril approach was significantly more time consuming than the mononostril technique. The nasal retractor limited maneuverability of instruments during mononostril approaches in 5 of 20 patients. Endocrinological pituitary function, control of excessive hormone secretion, ophthalmological outcome, residual tumor, and rates of adverse events, such as CSF leaks and diabetes insipidus, were similar in both groups. In the cadaver study, there was no significant difference in the time required for dissection via the binostril or mononostril technique. The panoramic view was superior in the binostril group; this was due to the possibility of wider opening of the sella in the craniocaudal and horizontal directions, but the need for removal of more of the nasal septum was disadvantageous. CONCLUSIONS Because of maneuverability of instruments and a wider view in the sphenoid sinus, the binostril technique is superior for resection of large tumors with parasellar and suprasellar expansion and tumors requiring extended approaches. The mononostril technique is preferable for tumors with limited extension in the intra- and suprasellar area.

Multimodal Navigation in Endoscopic Transsphenoidal Resection of Pituitary Tumors Using Image-Based Vascular and Cranial Nerve Segmentation: A Prospective Validation Study

BACKGROUND

Transsphenoidal surgery (TSS) is the most common approach for the treatment of pituitary tumors. However, misdirection, vascular damage, intraoperative cerebrospinal fluid leakage, and optic nerve injuries are all well-known complications, and the risk of adverse events is more likely in less-experienced hands. This prospective study was conducted to validate the accuracy of image-based segmentation coupled with neuronavigation in localizing neurovascular structures during TSS.

METHODS

Twenty-five patients with a pituitary tumor underwent preoperative 3-T magnetic resonance imaging (MRI), and MRI images loaded into the navigation platform were used for segmentation and preoperative planning. After patient registration and subsequent surgical exposure, each segmented neural or vascular element was validated by manual placement of the navigation probe or Doppler probe on or as close as possible to the target.

RESULTS

Preoperative segmentation of the internal carotid artery and cavernous sinus matched with the intraoperative endoscopic and micro-Doppler findings in all cases. Excellent correspondence between image-based segmentation and the endoscopic view was also evident at the surface of the tumor and at the tumor-normal gland interfaces. Image guidance assisted the surgeons in localizing the optic nerve and chiasm in 64% of cases. The mean accuracy of the measurements was 1.20 ± 0.21 mm.

CONCLUSIONS

Image-based preoperative vascular and neural element segmentation, especially with 3-dimensional reconstruction, is highly informative preoperatively and potentially could assist less-experienced neurosurgeons in preventing vascular and neural injury during TSS. In addition, the accuracy found in this study is comparable to previously reported neuronavigation measurements. This preliminary study is encouraging for future prospective intraoperative validation with larger numbers of patients.

Neurosurgical Treatment of Acromegaly

Surgical removal of as much tumor mass as possible is usually considered the first step of treatment in acromegaly, unless the patients are unfit for surgery or refuse an operation. To date, in almost all cases, minimally invasive, transsphenoidal microscopic or endoscopic approaches are used. Whether a curative approach is feasible or a debulking procedure is planned, can be anticipated on the basis of preoperative magnetic resonance imaging. It mostly depends on localization, size, and the invasive character of the lesion. The surgical results depend on tumor-related factors such as size, extension, the presence or absence of invasion, and the magnitude of IGF-1 and growth hormone oversecretion, respectively. However, even surgeon-related factors such as experience and case load of the centers have been shown to strongly affect surgical results and complication rates. A reoperation can be considered at various stages in the treatment algorithm. There are several new technical gadgets which might aid in the surgical procedure: navigation, the Doppler probe, and variants of intraoperative imaging.

Novel Techniques in the Surgical Treatment of Acromegaly: Applications and Efficacy

Since the establishment of transsphenoidal microsurgery as the operative treatment of choice in most patients with acromegaly 40 years ago, a few novel technical developments have evolved. Their application, utility and efficacy will be briefly discussed in this review article, based on an analysis of published results and the authors' personal experience. The endoscope was additionally used to search for residual tumours in locations which could not be visualised with the operating microscope. In many centres it has by now fully replaced the operating microscope. Extended endoscopic operations hardly have limits in respect to accessible pathology. Overall, the results and complications reported from microsurgical and endoscopic series are comparable. Intraoperative magnetic resonance imaging allows depicting the completeness of a tumour resection. While in many patients additional tumour resections are performed on the basis of intraoperative imaging, the improvements in hormonal remission rates reported are less impressive. Neuronavigation uses imaging data to improve the surgeon's orientation, and it is certainly a major asset to the inexperienced. In high-caseload centres it is mainly appreciated in anatomical variants and reoperations. While the Doppler probe is a valuable and easily affordable gadget to avoid vascular arterial injury, intraoperative ultrasound imaging of tumour extension has a much poorer resolution than magnetic resonance imaging and is thus not widely implemented. The clinical value of intraoperative growth hormone measurements is controversially discussed. In summary, the application of modern technology has only led to a minor improvement of results, but it has widened the spectrum of accessible pathologies and increased the safety of the procedures for the patient. It is expected that outcomes will continue to improve as novel techniques and concepts are being developed.

Analysis of operative efficacy for giant pituitary adenoma

BACKGROUND

Surgical treatment of giant pituitary adenomas is difficult due to complicated dissection of the sellar area. The extent of tumor resection affects the efficacy of surgical treatment. This study is to investigate the efficacy of microsurgical treatment for giant pituitary adenoma and to analyze the relationship between treatment efficacy and tumor resection extent.

METHODS

A retrospective analysis was performed in 36 patients who received microsurgery to remove giant pituitary adenomas. The sizes of tumors before and after surgery were calculated with a novel method called the "platform-like volume calculation formula". The relationships between extent of resection and the visual impairment recovery, and improvement of serum hormone level before and after operation were analyzed.

RESULTS

Two deaths were observed after surgery. And the gross and near-total resection was achieved in 8 cases, subtotal resection in 8 cases, mostly partial resection in 15 cases, and partial resection in 5 cases. The average resection rate was 72.8%. The resection rate of tumor with cavernous sinus invasion was significantly lower than those of patients without cavernous sinus invasion (P < 0.05). The improvement rate of hormone level in functional adenoma was 80.0%. Follow-up observations were carried out for 3 ~ 28 months in 25 cases. Visual improvement was observed in 64.0% of the cases.

CONCLUSIONS

Microsurgical treatment can improve the visual impairment of the majority of cases and significantly decrease the serum hormone levels of functional adenoma. The extent of resection was significantly associated with cavernous sinus invasion.

[Macular pathology as a cause of visual impairment?]

This article reports a case of a pituitary adenoma as the cause of unilateral visual impairment and concomitant unilateral macular pathology. Pituitary adenomas can be classified into hormone-secreting and inactive tumors of the adenohypophysis and lead to typical symptoms in cases of hypersecretion of hormones or hypopituitarism. A pituitary adenoma classically presents with bitemporal hemianopia when compression occurs at the optic chiasm. Imaging is crucial in diagnosing pituitary adenomas. Microsurgical or endoscopic transsphenoidal surgery, hormone therapy and radiotherapy are the treatment options.

Intraoperative magnetic resonance imaging during surgery for pituitary adenomas: pros and cons

Surgery for pituitary adenomas still remains a mainstay in their treatment, despite all advances in sophisticated medical treatments and radiotherapy. Total tumor excision is often attempted, but there are limitations in the intraoperative assessment of the radicalism of tumor resection by the neurosurgeon. Standard postoperative imaging is usually performed with a few months delay from the surgical intervention. The purpose of this report is to review briefly the facilities and kinds of intraoperative magnetic resonance imaging for all physician and surgeons involved in the management of pituitary adenomas on the basis of current literature. To date, there are several low- and high-field magnetic resonance imaging systems available for intraoperative use and depiction of the extent of tumor removal during surgery. Recovery of vision and the morphological result of surgery can be largely predicted from the intraoperative images. A variety of studies document that depiction of residual tumor allows targeted attack of the remnant and extent the resection. Intraoperative magnetic resonance imaging offers an immediate feedback to the surgeon and is a perfect quality control for pituitary surgery. It is also used as a basis of datasets for intraoperative navigation which is particularly useful in any kind of anatomical variations and repeat operations in which primary surgery has distorted the normal anatomy. However, setting up the technology is expensive and some systems even require extensive remodeling of the operation theatre. Intraoperative imaging prolongs the operation, but may also depict evolving problems, such as hematomas in the tumor cavity. There are several artifacts in intraoperative MR images possible that must be considered. The procedures are not associated with an increased complication rate.

Intraoperative handheld optical coherence tomography forward-viewing probe: physical performance and preliminary animal imaging

A prototype intraoperative hand-held optical coherence tomography (OCT) imaging probe was developed to provide micron resolution cross-sectional images of subsurface tissue during open surgery. This new ergonomic probe was designed based on electrostatically driven optical fibers, and packaged into a catheter probe in the form factor of clinically accepted Bayonet shaped neurosurgical probes. Optical properties of the probe were measured to have a ~20 μm spot size, 5 mm working distance and 4 mm field of view. Feasibility of this probe for structural and Doppler shift imaging was tested on porcine femoral blood vessel imaging.

Pituitary surgery for small prolactinomas as an alternative to treatment with dopamine agonists

Despite the fact that consensus guidelines recommend long-term dopamine agonist (DA) therapy as a first-line approach to the treatment of small prolactinoma, some patients continue to prefer a primary surgical approach. Concerns over potential adverse effects of long-term medical therapy and/or the desire to become pregnant and avoid long-term medication are often mentioned as reasons to pursue surgical removal. In this retrospective study, 34 consecutive patients (30 female, 4 male) preferably underwent primary pituitary surgery without prior DA treatment for small prolactinomas (microprolactinoma 1-10 mm, macroprolactinoma 11-20 mm) at the Department of Neurosurgery, University of Bern, Switzerland. At the time of diagnosis, 31 of 34 patients (91%) presented with symptoms. Patients with microprolactinomas had significantly lower preoperative prolactin (PRL) levels compared to patients with macroprolactinomas (median 143 μg/l vs. 340 μg/l). Ninety percent of symptomatic patients experienced significant improvement of their signs and symptoms upon surgery. The postoperative PRL levels (median 3.45 μg/l) returned to normal in 94% of patients with small prolactinomas. There was no mortality and no major morbidities. One patient suffered from hypogonadotropic hypogonadism after surgery despite postoperative normal PRL levels. Long-term remission was achieved in 22 of 24 patients (91%) with microprolactinomas, and in 8 of 10 patients (80%) with macroprolactinomas after a median follow-up period of 33.5 months. Patients with small prolactinomas can safely consider pituitary surgery in a specialized centre with good chance of long-term remission as an alternative to long-term DA therapy.

High-Definition Imaging in Endoscopic Transsphenoidal Pituitary Surgery

Background

The transsphenoidal approach to sellar lesions has evolved enormously since its first description in the early 20th century. Endoscopic surgical strategies have become an integral part of the surgical armamentarium. More recently, high-definition (HD) digital cameras with better image resolution were introduced, although their value for the surgical procedure remains equivocal. The purpose of this study was to compare the image quality of a standard-definition (SD) camera with a new HD camera.

Methods

A transsphenoidal pituitary adenomectomy was recorded simultaneously in HD and SD resolution. Eight experienced neurosurgeons were asked to identify predefined as well as not predefined anatomic structures in HD and SD. Additionally, the video quality of three complementary surgical sequences was rated with grades from 1 (“very good”) to 6 (“poor”).

Results

An average of 23.6 ± 2.7 predefined structures (84.38%) were identified in HD versus 17.6 ± 4.4 predefined structures (62.95%) identified in SD. This profound difference in the recognition of anatomic structures reached statistical significance (p = 0.012). Subjective impression of video quality was rated 1.9, 1.9, and 1.4 for the videos in HD and 3.5, 3.3, and 3.5 for the complementary videos in SD. These differences also reached statistical significance (p ≤ 0.005).

Conclusion

HD imaging in endoscopic transsphenoidal pituitary surgery accounts for significantly better identification of anatomic structures in comparison with SD images. Additionally, the subjective impression of video quality is significantly better in HD. This improved intraoperative orientation by better digital image quality might contribute to reduce the gap in intraoperative visual accuracy between microsurgery and endoscopy in pituitary surgery.

The role of outcomes data for assessing the expertise of a pituitary surgeon

PURPOSE OF REVIEW

Over the past four decades, advances in surgical technique, instrumentation, and anatomical knowledge have fueled the evolution and sophistication of transsphenoidal pituitary surgery. Paralleling these advances have been major improvements in endocrinological and overall clinical outcomes in patients with pituitary adenomas and other parasellar lesions such as Rathke's cleft cysts and craniopharyngiomas. In this review, we assess the impact of neurosurgeon expertise as a determinant of outcome in pituitary surgery.

RECENT FINDINGS

Published data since the 1980s indicate that remission rates, overall clinical outcomes and surgical complication rates in pituitary and parasellar surgery are related to neurosurgeon practice volume and cumulative clinical experience. More recently, pituitary surgery has been increasingly performed using an endonasal endoscopic approach. Reports over the last decade suggest when an experienced pituitary neurosurgeon performs a fully endoscopic or endoscope-assisted tumor removal; outcomes are similar if not better than when performed by a traditional microscopic transsphenoidal approach.

SUMMARY

A focused clinical practice and large transsphenoidal surgical volume appear to be important outcome determinants for patients with pituitary and parasellar tumors. Strategies that may further improve patient outcomes include establishing guidelines for pituitary tumor centers of excellence and more focused residency and fellowship training in endonasal endoscopic transsphenoidal surgery. Encouraging regionalization of care to higher volume pituitary tumor centers of excellence and promoting patient education on the importance of surgical expertise may further enhance pituitary patient outcomes.

Surgical treatment of pituitary tumours

The surgical treatment of pituitary tumours underwent considerable evolution during the past centennial. Since Schloffer's first description, excellent surgeons refined the surgical techniques, utilised hormonal measurements and imaging investigations at different times to define surgical success or failure. To date, transsphenoidal surgery is the approach of choice for over 90% of pituitary tumours, but still transcranial operations are needed even in experienced hands when asymmetrical and large pituitary tumours with minor intrasellar components present. When the indication for surgery stands, the complication rate to date is relatively low, particularly if the surgeon and his or her centre have sufficient experience in the field. In microadenomas, the success rate reported from expert authors approaches 90%. Generally speaking, patients with non-functioning pituitary adenomas, acromegaly, thyrotropinomas and Cushing's disease are excellent candidates for primary surgical treatment. Re-operations are generally associated with less favourable outcomes. In prolactinomas, the primary therapy is medical; however, when dopamine agonists are not well tolerated or inefficient, an operative treatment should be considered. Although alternative medical treatments exist in acromegaly and thyrotropinomas, surgical treatment is relatively cheap. The implementation of endoscope-assisted, entirely endoscopic, image-guided surgery and intra-operative magnetic resonance (MR) imaging, particularly in combination with utilisation of the established microsurgical techniques, extends the surgical spectrum. Lesions become surgically accessible, which one did not dare to touch even a century ago. Moreover, it seems that the patient's safety has increased and more patients have their tumours completely resected, which is equivalent to a higher remission rate in hormonally active tumours.

Transcranial surgery for pituitary adenomas

Following a century of evolution and refinements in standard surgical techniques, the vast majority of operations for pituitary adenoma to date are performed utilizing transsphenoidal approaches. From current large series one obtains the impression that certainly less than 10% of these tumors require craniotomies. However, still several tumors, which's volume is mainly localized outside of the sella require transcranial approaches, of which the pterional and subfrontal routes are the most widely used. The goal of surgical treatment is rapid eradication of the tumor mass, decompression of visual pathways and elimination of hormonal oversecretion whilst preserving the normal gland and avoiding potential surgical complications. Even with microsurgical techniques and standardized approaches, there is still some mortality associated with transcranial approaches and morbidity is undoubtly higher than with transsphenoidal operations. However, a selection bias must be considered, which shifts tumors with a larger size, less favourable prognosis and higher complication rate into the transcranial series. Moreover, with extended transsphenoidal approaches, lesions have become accessible for transsphenoidal surgery, which previously have been considered as contraindications. In this article current indications and limitations for transcranial surgery of pituitary adenomas, the preoperative workup, surgical techniques, results, and complications are briefly reviewed.

Surgical treatment of nonfunctioning pituitary adenomas

Small nonfunctioning pituitary (micro)adenomas are encountered frequently as incidental findings. Large (macro)adenomas present with visual compromise, hypopituitarism or headache. Indications for surgery include loss of vision, diplopia, other symptoms of a space occupying intracranial lesion and documented tumor progression during serial imaging. Their primary treatment is surgical resection. To exclude medical treatment options, a preoperative endocrinological investigation is mandatory. To date, more than 90% of operations in patients with nonfunctioning pituitary adenomas are performed via the transsphenoidal route. There are several variations of transnasal surgery available, with and without dissection of the nasal septum. Only tumors where the predominant mass lesion is essentially located outside the sella require transcranial operations. These are usually performed via a frontotemporal or frontolateral craniotomy. Surgical decompression of visual pathways is usually followed by a rapid improvement of vision. Whether or not the tumor mass can be completely resected depends on the size and localization of the adenoma and the surgical expertise. Several patients experience an improvement of pituitary function. Potential complications of surgery include loss of vision, vascular injury, cerebrospinal fluid fistula, meningitis and hypopituitarism. Modern technical developments, such as the use of the endoscope, intraoperative magnetic resonance imaging and neuronavigation, are being increasingly appreciated by neurosurgeons throughout the world.