Intraoperative unfolding and postoperative pruning of the pituitary gland after transsphenoidal surgery for pituitary adenoma: A volumetric and endocrinological evaluation

Pituitary Stalk Morphology as a Predictor of New-Onset Adrenocortical Insufficiency and Arginine Vasopressin Deficiency after Transsphenoidal Resections of Pituitary Macroadenomas: A Retrospective Single-Center Study with a Focus on iMRI

BACKGROUND

A new-onset adrenocortical insufficiency (NAI) is the most critical postoperative endocrinological complication after transsphenoidal surgery for macroadenomas. Because of increased mortality risk, arginine vasopressin deficiency (AVP-D) is also a relevant postoperative complication. This study aimed to identify easy-to-acquire magnet resonance imaging (MRI) aspects of the pituitary stalk to predict these insufficiencies after transsphenoidal surgery.

METHODS

Pituitary stalk morphology was reviewed intraoperatively and three months postoperatively in the MRIs of 48 transsphenoidal surgeries for macroadenomas. NAI was validated in endocrinological follow-up controls 10-14 months post-surgery.

RESULTS

Intraoperative pituitary stalk diameters were 0.5 mm larger in patients who developed NAI and AVP-D. The odds ratio was 29 for NAI and 6 for AVP-D in binary regression analysis. A value of 2.9 mm was identified as the optimal cut-off for the minimal pituitary stalk diameter regarding NAI, with a high specificity of 89%. There was no difference in pituitary stalk diameter regarding these insufficiencies three months post-surgery.

CONCLUSIONS

We identified an increased pituitary stalk diameter in intraoperative MRIs as a predictive factor of NAI and AVP-D after transsphenoidal surgery. These findings might improve the early detection of NAI and, thus, optimal management. However, validating these retrospective findings in prospective studies is obligatory.

Incidence and Prognostic Factors of Patients with Benign Pituitary Tumors Based on the Surveillance, Epidemiology, and End Results (SEER) Database

OBJECTIVE

To study the incidence and prognostic factors of patients with benign pituitary tumors based on the Surveillance, Epidemiology, and End Results (SEER) database.

METHODS

This was a retrospective cohort study. Patients with benign pituitary tumors reported in the Surveillance, Epidemiology, and End Results database from 2004 to 2016, who presented completed demographic and clinical data, were included in our study. The age-adjusted incidence rate was calculated and stratified by year at diagnosis, age, gender, and the pathological type of benign pituitary tumor. We used Kaplan-Meier curves and multivariable Cox regressions to determine the factors associated with overall survival.

RESULTS

A total of 29,967 patients were included in the study, of whom 26,691 (89.07%) survived and 3276 (10.93%) died. The age-adjusted incidence rate increased from 3.15 per 100,000 person-years in 2004 to 4.66 per 100,000 person-years in 2011 (annual percent change = 5.51, P < 0.001), and the subsequent growth trend from 2011 to 2016 was not statistically significant (annual percent change = 0.26, P = 0.711). Most patients were female, aged 60-79 years, and pituitary adenomas accounted for the main proportion of the incidence of benign pituitary tumors. Surgery was associated with the overall survival on the multivariable Cox regression model (hazard ratio = 0.677, 95% confidential interval: 0.629-0.727) and Kaplan-Meier curves, especially in pituitary adenoma. Radiation was not associated with the overall survival of benign pituitary tumor.

CONCLUSIONS

The overall incidence of benign pituitary tumors was low but showed an increasing trend. Surgery may be beneficial to the prognosis. It should be noted that benign pituitary tumors may not require excessive treatment, such as radiation.

Assessing the surgical outcome of the "chopsticks" technique in endoscopic transsphenoidal adenoma surgery

OBJECTIVE

The "chopsticks" technique is a 3-instrument, 2-hand mononostril technique that has been recently introduced in endoscopic neurosurgery. It allows a dynamic surgical view controlled by one surgeon only while keeping bimanual dissection. Being a mononostril approach, it requires manipulation of the mucosa of one nasal cavity only. The rationale of the technique is to reduce nasal morbidity without compromising surgical results and complication rates. There are, however, no data available on its results in endoscopic surgery (transsphenoidal surgery [TSS]) for pituitary adenoma.

METHODS

The authors performed a cohort analysis of prospectively collected data on 144 patients (156 operations) undergoing TSS using the chopsticks technique with 3T intraoperative MRI. All patients had at least 3 months of postoperative neurosurgical, endocrinological, and rhinological follow-up (Sino-Nasal Outcome Test-20 [SNOT-20] and Sniffin' Sticks). The surgical technique is described, and the achieved gross-total resection (GTR) and extent of resection (EOR) together with patients' clinical outcomes and complications are descriptively reported.

RESULTS

On 3-month postoperative MRI, GTR was achieved in 71.2% of patients with a mean EOR of 96.7%. GTR was the surgical goal in 122 of 156 cases and was achieved in 106 of 122 (86.9%), with a mean EOR of 98.7% (median 100%, range 49%-100%). There was no surgical mortality. At a median follow-up of 15 months (range 3-70 months), there was 1 permanent neurological deficit. As of the last available follow-up, 11.5% of patients had a new pituitary single-axis deficit, whereas 26.3% had improvement in endocrinological function. Three patients had new postoperative hyposmia. One patient had severe impairment of sinonasal function (SNOT-20 score > 40). The operation resulted in endocrine remission in 81.1% of patients with secreting adenomas.

CONCLUSIONS

This study shows that the chopsticks technique confers resection and morbidity results that compare favorably with literature reports of TSS. This technique permits a single surgeon to perform effective endoscopic bimanual dissection through a single nostril, reducing manipulation of healthy tissue and thereby possibly minimizing surgical morbidity.

The Zurich Pituitary Score predicts utility of intraoperative high-field magnetic resonance imaging in transsphenoidal pituitary adenoma surgery

BACKGROUND

It is currently unclear if there are subsets of patients undergoing transsphenoidal surgery (TSS) in which intraoperative high-field magnetic resonance imaging (3T-iMRI) is particularly advantageous. We aimed to investigate whether a radiological grading scale predicts the utility of 3T-iMRI in pituitary adenoma (PA) TSS.

METHODS

From a prospective registry, patients who underwent endoscopic TSS for PA using 3T-iMRI were identified. Adenomas were graded using the Zurich Pituitary Score (ZPS). We assessed improvement after 3T-iMRI in terms of gross total resection (GTR), residual volume (RV), and extent of resection (EOR).

RESULTS

Among 95 patients, rates of conversion to GTR after 3T-iMRI decreased steadily from 33% for grade I to 0% for grade IV adenomas, with a statistically significant conversion rate only for grade I (p = 0.008) and grade II (p < 0.001). All grade I adenomas were completely resected after 3T-iMRI. Median RV change was statistically significant for grades I to III, but not for grade IV (p = 0.625). EOR improvement ranged from a median change of 0.0% (IQR 0.0-4.5%) for grade I to 4.4% (IQR 0.0-9.0%) for grade IV, with a significant improvement only for grades I to III (p < 0.05).

CONCLUSIONS

Interestingly, this study shows that clinical utility of 3T-iMRI is highest in the more "simple" adenomas (ZPS grades I-II) than for the more "complex" ones (ZPS grade III-IV). Grade I adenomas are amenable to GTR if 3T-iMRI is implemented. In grade III adenomas, EOR and RV can be improved to clinically relevant levels. Conversely, in grade IV adenomas, 3T-iMRI may be of limited use.