Endoscopic Endonasal Surgery for Pituitary Adenomas
Object. The purpose of this study was to analyze preoperative predictors of endocrinological remission following endonasal endoscopic resection of therapy-resistant prolactin-, growth hormone (GH)–, and adrenocorticotropic hormone (ACTH)–secreting pituitary adenomas and to establish benchmarks for cure by using the most recent consensus criteria.
Methods. The authors reviewed a prospective database of 86 consecutive functional pituitary adenomas that were resected by a purely endoscopic endonasal transsphenoidal technique. Extent of resection was evaluated on postoperative contrast-enhanced MR imaging. Endocrinological remission was defined according to the most recent consensus criteria.
Results. The majority of functional adenomas (62.8%) were classified as macroadenomas (> 1 cm in maximum diameter), and 20.9% of lesions had invaded the cavernous sinus (CS) at the time of surgery. A gross-total resection was achieved in 75.6% of all patients. The rate of endocrinological remission differed between various types of functional adenomas. Cure rates were 92.3% (microadenomas) and 57.1% (macroadenomas) for prolactinomas, 75% (microadenomas) and 40% (macroadenomas) for GH-secreting tumors, and 54.5% (microadenomas) and 71.4% (macroadenomas) for ACTH-secreting tumors. Lower rates of cure occurred in GH-secreting macroadenomas due to a high rate of CS invasion, and in ACTH-secreting adenomas due to a high rate of lesions that were not visible on preoperative MR imaging. Whereas univariate analysis showed that macroadenoma, suprasellar, cavernous extension, or extent of resection correlated with cure, on multivariate analysis, only extent of resection and suprasellar extension predicted cure. One patient developed postoperative meningitis that was complicated by hydrocephalus requiring a ventriculoperitoneal shunt. Two patients developed postoperative panhypopituitarism, and 2 patients suffered from CSF leaks, which were treated with lumbar CSF diversion.
Conclusions. This paper reports benchmarks for endocrinological cure as well as complications in a large series of purely endoscopic pituitary surgeries by using the most recent consensus criteria. The advantages of extended endonasal approaches are most profound in tumors with suprasellar extension and CS invasion.
The transsphenoidal approach for resection of a pituitary adenoma was first performed by Herman Schloffer more than 100 years ago. Subsequently, the transsphenoidal approach created great interest, and a variety of modifications of this approach were described shortly thereafter. As discussed in a report by Henderson, Harvey Cushing was the first to present a large clinical series of 231 transsphenoidal pituitary adenoma resections in 1939. However, because lack of adequate preoperative imaging made it impossible to foretell the size and configuration of the adenomas, he abandoned the procedure in favor of transcranial approaches. The majority of neurosurgeons followed Cushing's lead, and it was not until the advent of 2 technological milestones that the transsphenoidal technique resurfaced. First, the development of imaging techniques such as CT and MR imaging provided accurate information about the size and location of a lesion and allowed for appropriate patient selection and determination of the appropriate surgical access. Second, the introduction of the operating microscope and later endoscopy greatly improved intraoperative illumination and visualization. Although there are numerous studies reporting the endocrinological outcome following microsurgical transsphenoidal resection of functional pituitary adenomas, there is a paucity of literature reporting the endocrinological outcome following use of a purely endoscopic transsphenoidal technique. Moreover, continuous re-evaluation of endocrinological outcomes following surgical treatment of functional pituitary lesions is necessary to keep up with the latest definitions of postoperative endocrinological remission. Based on improvements in follow-up data, criteria for endocrinological remission following resection have constantly evolved over time. Here we present our singlecenter experience in which we used the latest criteria for an endocrinological cure for PRL-, GH-, and ACTH-secreting adenomas in a cohort treated with a purely endoscopic endonasal transsphenoidal technique.
Abstract and Introduction
Abstract
Object. The purpose of this study was to analyze preoperative predictors of endocrinological remission following endonasal endoscopic resection of therapy-resistant prolactin-, growth hormone (GH)–, and adrenocorticotropic hormone (ACTH)–secreting pituitary adenomas and to establish benchmarks for cure by using the most recent consensus criteria.
Methods. The authors reviewed a prospective database of 86 consecutive functional pituitary adenomas that were resected by a purely endoscopic endonasal transsphenoidal technique. Extent of resection was evaluated on postoperative contrast-enhanced MR imaging. Endocrinological remission was defined according to the most recent consensus criteria.
Results. The majority of functional adenomas (62.8%) were classified as macroadenomas (> 1 cm in maximum diameter), and 20.9% of lesions had invaded the cavernous sinus (CS) at the time of surgery. A gross-total resection was achieved in 75.6% of all patients. The rate of endocrinological remission differed between various types of functional adenomas. Cure rates were 92.3% (microadenomas) and 57.1% (macroadenomas) for prolactinomas, 75% (microadenomas) and 40% (macroadenomas) for GH-secreting tumors, and 54.5% (microadenomas) and 71.4% (macroadenomas) for ACTH-secreting tumors. Lower rates of cure occurred in GH-secreting macroadenomas due to a high rate of CS invasion, and in ACTH-secreting adenomas due to a high rate of lesions that were not visible on preoperative MR imaging. Whereas univariate analysis showed that macroadenoma, suprasellar, cavernous extension, or extent of resection correlated with cure, on multivariate analysis, only extent of resection and suprasellar extension predicted cure. One patient developed postoperative meningitis that was complicated by hydrocephalus requiring a ventriculoperitoneal shunt. Two patients developed postoperative panhypopituitarism, and 2 patients suffered from CSF leaks, which were treated with lumbar CSF diversion.
Conclusions. This paper reports benchmarks for endocrinological cure as well as complications in a large series of purely endoscopic pituitary surgeries by using the most recent consensus criteria. The advantages of extended endonasal approaches are most profound in tumors with suprasellar extension and CS invasion.
Introduction
The transsphenoidal approach for resection of a pituitary adenoma was first performed by Herman Schloffer more than 100 years ago. Subsequently, the transsphenoidal approach created great interest, and a variety of modifications of this approach were described shortly thereafter. As discussed in a report by Henderson, Harvey Cushing was the first to present a large clinical series of 231 transsphenoidal pituitary adenoma resections in 1939. However, because lack of adequate preoperative imaging made it impossible to foretell the size and configuration of the adenomas, he abandoned the procedure in favor of transcranial approaches. The majority of neurosurgeons followed Cushing's lead, and it was not until the advent of 2 technological milestones that the transsphenoidal technique resurfaced. First, the development of imaging techniques such as CT and MR imaging provided accurate information about the size and location of a lesion and allowed for appropriate patient selection and determination of the appropriate surgical access. Second, the introduction of the operating microscope and later endoscopy greatly improved intraoperative illumination and visualization. Although there are numerous studies reporting the endocrinological outcome following microsurgical transsphenoidal resection of functional pituitary adenomas, there is a paucity of literature reporting the endocrinological outcome following use of a purely endoscopic transsphenoidal technique. Moreover, continuous re-evaluation of endocrinological outcomes following surgical treatment of functional pituitary lesions is necessary to keep up with the latest definitions of postoperative endocrinological remission. Based on improvements in follow-up data, criteria for endocrinological remission following resection have constantly evolved over time. Here we present our singlecenter experience in which we used the latest criteria for an endocrinological cure for PRL-, GH-, and ACTH-secreting adenomas in a cohort treated with a purely endoscopic endonasal transsphenoidal technique.