Literature ReviewCavernous Sinus Invasion in Pituitary Adenomas: Systematic Review and Pooled Data Meta-Analysis of Radiologic Criteria and Comparison of Endoscopic and Microscopic Surgery
Introduction
The encroachment of cavernous sinus (CS) by pituitary adenomas, often termed CS invasion (CSI), is the most common and significant risk factor for their incomplete surgical resection.1, 2, 3, 4 Whether it is true invasion suggesting an aggressive process or mere opportunistic intrusion into the weak wall of the CS, the determination of CSI has been problematic. The varied radiologic criteria described are not universally accepted and may not reliably determine invasion. Direct observation is hence considered more accurate than radiology in the absence of histologic assessment of the integrity of the medial wall of CS, which is often not feasible.5, 6, 7 Nevertheless, direct observation too can be inaccurate depending on who is observing, with what degree of exposure, and potentially misleading because tumor has to be removed to evaluate the integrity of the medial CS wall.8, 9, 10, 11, 12, 13 These limitations have resulted in variable and inconsistent reports on the impact of CSI on pituitary adenoma surgery.14, 15, 16, 17, 18, 19
Endonasal endoscopic approaches to sella have often highlighted the panoramic view offered by the endoscope as one of the major advantages over the microscopic approach.2, 18, 20 The feasibility of wider exposure and the use of angled endoscopes have expanded surgical corridors to expose medial as well as lateral CS.2, 15, 21 Several investigators have reported on the enhanced surgical access to the CS with endoscope. However, these reports have generally been single-center series without direct comparison to microscope-based data.1, 2, 4, 15 Also, the efficacy and safety of endonasal endoscopic transcavernous approaches are still a matter of debate, compared with standard nonsurgical options such as stereotactic radiosurgery or radiotherapy in dealing with CS residual tumors.17, 22, 23
In this study, we performed a systematic literature review to examine how well radiographic criteria for CSI correlate with detection of CSI during surgery. We also assessed the efficacy of an endoscopic approach compared with a microscopic approach at removing pituitary tumors invading the CS. All series were included for the diagnostic evaluation of radiologic criteria for intraoperative CSI. However, for the comparative assessment of surgical efficacy between microscopic and endoscopic methods, only the series having arms of both components were included, because many of the sole microscopic series had patients either with unclear CS invasion with respect to resection rates or not comparable with the endoscopic series. The safety of an endonasal endoscopic approach for pituitary adenomas with CSI was also evaluated.
Section snippets
Study Selection
We performed a literature search using the PubMed gateway of the MEDLINE database. The following keywords were queried singly and in combination between the publication years 1993 and 2015: “pituitary adenoma”, “cavernous sinus”, “endonasal”, “trans-nasal”, and “endoscopy”. The search was limited to case series either in English or with an available English translation, and humans were specified as the study category. Reports published before 1993, when magnetic resonance imaging was less
Study Selection
A total of 112 published studies were identified through our initial search, of which 72 were rejected because they did not include original data; were purely anatomic, technical, or case reports; did not report CSI, GTR, or ER; included a mixture of approaches; or repeated data reported elsewhere. A total of 40 studies were included in this review (Figure 1).
CSI was variably defined as per the operative evidence, distinct criteria,20, 27, 28 or KS grades 2–414, 29, 30 or 3–431, 32, 33, 34, 35
Discussion
The enormous variations in reported prevalence of CSI based on direct intraoperative observation (9%2, 17–30%19) compared with radiographic assessment (30%28–63%29) in pituitary adenomas show the ambiguity in defining CSI. Our meta-analysis noted a significantly higher prevalence of CSI radiographically (43%) than the intraoperative findings (18%) suggest.
Several radiologic criteria have been described in the literature to predict the intraoperative evidence of CSI. Although KS grades were
References (48)
- et al.
Evaluation of magnetic resonance imaging criteria for cavernous sinus invasion in patients with pituitary adenomas: logistic regression analysis and correlation with surgical findings
Surg Neurol
(2006) - et al.
Endoscopic endonasal surgery in recurrent and residual pituitary adenomas after microscopic resection
World Neurosurg
(2012) - et al.
Evaluation of outcomes after endoscopic endonasal surgery for large and giant pituitary macroadenoma: a retrospective review of 39 consecutive patients
World Neurosurg
(2015) - et al.
Radiotherapy and stereotactic radiosurgery for pituitary tumors
Neurosurg Clin N Am
(2003) - et al.
Transition from microscopic to endoscopic transsphenoidal surgery for nonfunctional pituitary adenomas
World Neurosurg
(2015) - et al.
Endoscopic endonasal surgery for pituitary tumors. Results in a series of 121 patients operated at the same center and by the same neurosurgeon
Endocrinol Nut
(2014) - et al.
Magnetic resonance imaging appearance of the medial wall of the cavernous sinus for the assessment of cavernous sinus invasion by pituitary adenomas
J Neuroradiol
(2013) A role for centers of excellence in transsphenoidal surgery
World Neurosurg
(2013)- et al.
Endoscopic endonasal cavernous sinus surgery, with special reference to pituitary adenomas
Front Horm Res
(2006) - et al.
Surgical outcomes using a medial-to-lateral endonasal endoscopic approach to pituitary adenomas invading the cavernous sinus
J Neurosurg
(2014)
Extended transsphenoidal approach for pituitary adenomas invading the cavernous sinus using multiple complementary techniques
Pituitary
Endoscopic endonasal transsellar approach for laterally extended pituitary adenomas: volumetric analysis of cavernous sinus invasion
Pituitary
Cavernous sinus medial wall: dural or fibrous layer? Systematic review of the literature
Neurosurg Rev
Aggressive transsphenoidal resection of tumors invading the cavernous sinus in patients with acromegaly: predictive factors, strategies, and outcomes
J Neurosurg
Is there an identifiable intact medial wall of the cavernous sinus? Macro- and microscopic anatomical study using sheet plastination
Neurosurgery
Surgical complications associated with the endoscopic endonasal transsphenoidal approach for pituitary adenomas
J Neurosurg
Cavernous sinus invasion by pituitary adenoma: MR imaging
Radiology
Current state of the art in the diagnosis and surgical treatment of Cushing disease: early experience with a purely endoscopic endonasal technique
Neurosurg Focus
Endoscopic endonasal transsphenoidal surgery: experience with 50 patients
J Neurosurg
The value of immediate postoperative MR imaging following endoscopic endonasal pituitary surgery
Acta Neurochir (Wien)
Endoscopic endonasal transsphenoidal approach for pituitary adenomas invading the cavernous sinus
J Neurosurg
Pure endoscopic endonasal approach for pituitary adenomas: early surgical results in 200 patients and comparison with previous microsurgical series
Neurosurgery
Invasion of the cavernous sinus space in pituitary adenomas: endoscopic verification and its correlation with an MRI-based classification
J Neurosurg
Endoscopic endonasal approach for pituitary adenomas: a series of 555 patients
Pituitary
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Conflict of interest statement: The authors declare that the article content was composed in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.