Endoscopic distinction between capsule and pseudocapsule of pituitary adenomas

Role of Immediate Postoperative Prolactin Measurement in Female Prolactinoma Patients: Predicting Long-Term Remission After Complete Tumor Removal

BACKGROUND

Transsphenoidal surgery is one of the important treatment options in the management of prolactinomas; however, complete resection of the tumor does not always lead to endocrinological remission. While many studies have investigated preoperative factors associated with surgical outcome, little has been known about the relationship between postoperative factors and long-term surgical outcomes; moreover, there is no consistency in results. The aim of this study was to demonstrate the reliability of immediate postoperative prolactin levels as predictors of long-term outcomes.

METHODS

A total of 105 female patients who underwent complete removal of their histologically confirmed prolactinomas were included, and their medical records were retrospectively reviewed. To evaluate the predictability of immediate postoperative prolactin levels for long-term remission, prolactin levels were measured at 2, 6, 12, 18, 24, 48, and 72 h after surgery.

RESULTS

From the 105 included patients, 95 (90.5%) and 10 (9.5%) belonged to the remission and non-remission groups, respectively. A significant difference was observed in the prolactin level measured 6 h after surgery between the remission and non-remission groups, and this difference stayed apparent until 72 h after surgery. We derived a cut-off value for every postoperative time point that showed a significant relationship with disease remission.

CONCLUSION

Our study suggests that immediate postoperative measurement of prolactin levels is a reliable predictor of long-term remission and can contribute to early identification of patients who require adjuvant treatment after surgery.

Endoscopic endonasal surgery for non-invasive pituitary neuroendocrinology tumors with incomplete pseudocapsule

Background

Pituitary neuroendocrinology tumors (PitNETs) with pseudocapsule can be effectively removed by the pseudocapsule-based extracapsular resection technique. In the areas without pseudocapsule, the tumor cells can spread into the adjacent tissues at the cellular level, which brings a great challenge to achieving total tumor resection.

Methods

Our surgical strategy for PitNETs with an incomplete pseudocapsule is to combine the pseudocapsule-based extracapsular resection technique with the intensive excision technique for the removal of the tumor. Specifically, the pseudocapsule-based extracapsular resection technique is applied in the areas with pseudocapsule, while in the areas without pseudocapsule, the intensive excision technique bounded by adjacent normal structures is adopted. Moreover, a pathological examination was performed to determine the situations of pseudocapsule and tumor cell remnant.

Results

All growth hormone-secreting PitNETs achieved biochemical remission after surgery. There was no deterioration of pituitary functions postoperatively, and the preoperative hypopituitarism had improved in all patients postoperatively. In total, two cases suffered a transient diabetes insipidus, and intraoperative cerebrospinal fluid leakage was observed in two cases but no postoperative cerebrospinal fluid leakage in all cases. There was no recurrence during the follow-up. The fragmental pseudocapsule and small tumor remnants were found in the majority of suspicious tissues by histological staining.

Conclusion

The effectiveness and safety of the surgical strategy were preliminarily explored for removing PitNETs without incomplete pseudocapsules. In overview, the pseudocapsule-based extracapsular resection technique is applied in areas with pseudocapsule, while the intensive excision bounded by adjacent normal structures is adopted in other areas.

The effect of endoscopic transsphenoidal somatotroph tumors resection on pituitary hormones: systematic review and meta-analysis

PURPOSE

Currently, endoscopic transsphenoidal surgery is the main treatment for pituitary neuroendocrine tumors (PitNETs). Excision of the tumor may have positive or negative effects on pituitary endocrine function, and the pituitary function of somatotroph tumors is a point of particular concern after the operation. This study aimed to conduct a meta-analysis on the effect of endoscopic transsphenoidal somatotroph tumor resection on pituitary function.

METHODS

A systematic literature search was conducted for articles that included the evaluation of pituitary target gland before and after endoscopic transsphenoidal pituitary tumor resection and were published between 1992 and 2022 in PubMed, Cochrane, and Ovid MEDLINE.

RESULTS

Sixty-eight studies that included biochemical remission rates in 4524 somatotroph tumors were concluded. According to the 2000 consensus, the biochemical remission rate after transsphenoidal endoscopic surgery was 66.4% (95% CI, 0.622-0.703; P = 0.000), the biochemical remission rate was 56.2% according to the 2010 consensus (95% CI, 0.503-0.620; P = 0.041), and with the rate of biochemical remission ranging from 30.0 to 91.7% with investigator's definition. After endoscopic resection, adrenal axis dysfunction was slightly higher than that before surgery, but the difference was not statistically significant. Hypothyroidism was 0.712 times higher risk than that before surgery (OR = 0.712; 95% CI, 0.527-0.961; P = 0.027). Hypogonadism was 0.541 times higher risk than that before surgery (OR = 0.541; 95% CI, 0.393-0.746; P = 0.000). Hyperprolactinemia was 0.131 times higher risk than that before surgery (OR = 0.131; 95% CI, 0.022-0.783; P = 0.026). The incidence of pituitary insufficiency was 1.344 times the risk before surgery after endoscopic resection of somatotroph tumors, but the difference was not statistically significant.

CONCLUSIONS

In patients with somatotroph tumors after undergoing endoscopic surgery, the risk of dysfunction and pituitary insufficiency tend to increase, while preoperative thyroid insufficiency, gonadal insufficiency, and hyperprolactinemia will be partially relieved.

Pseudocapsule-Based Resection for Pituitary Adenomas via the Endoscopic Endonasal Approach

Introduction

The endoscopic endonasal approach (EEA) is a safe and effective treatment for pituitary adenomas (PAs). Since extracapsular resection (ER) of PAs improves tumor resection and endocrine remission rates, the interface between the pseudocapsule and gland draws increasing attention. However, it is difficult to precisely dissect the tumor along the exact boundary, and complete removal of the tumor increases the risks of normal tissue damage and cerebrospinal fluid (CSF) leakage. In this study, we investigated the extracapsular resection as well as the pseudocapsule histology to evaluate the effectiveness and safety of pseudocapsule-related surgical interventions.

Methods

From December 2017 to December 2019, 189 patients of PAs via EEA in our single center were analyzed retrospectively. The images, operative details, and clinical follow-up of patients were collected. Sixty-four patients underwent pseudocapsule-based ER, and 125 patients also underwent traditional intracapsular resection (IR) with or without intensive excision for FPAs. The clinical characteristics, tumor resection, endocrinological outcomes, and postoperative morbidities of the two groups were compared. Informed consent for publication of our article was obtained from each patient. Histological examination of pseudocapsule was performed using hematoxylin and eosin and reticulin staining.

Results

The gross total recession was 62 (96.9%) in the ER group and 107 (85.6%) cases in the IR group, whereas the endocrine remission rate was 29/31 (93.5%) and 40/53 (75.5%) cases, respectively. Anterior pituitary functions were not aggravated postoperatively in any patient, but transient diabetes insipidus (DI) occurred more in the IR group (64.0%) than in ER (48.4%). Pseudocapsule specimens were obtained in 93 patients, and clusters of small cell aggregation were detected in 11 pseudocapsule specimens (11.8%) whereas other patients showed no remarkable developed pseudocapsule. Intraoperative CSF leak occurred more in the ER group (28.1%) than in the IR group (13.6%), but no difference was seen between two groups postoperatively. No case of intracranial hematoma or pituitary crisis occurred in both groups. After a mean follow-up of 22.8 months, tumor recurrence was observed in 4 (2.1%) cases.

Conclusion

Pseudocapsule-based extracapsular resection of PAs via EEA is an effective and safe procedure to achieve complete resection with high and sustained endocrine remission and without deteriorating pituitary function.

Pseudocapsule and pseudocapsule-based extracapsular resection in pituitary neuroendocrine tumors

Since Costello et al. proposed the concept of pseudocapsule of pituitary neuroendocrine tumors (PitNETs) in 1936, many studies have been published on its occurrence, development process, histopathology, and morphology. Pseudocapsule has been proposed as the anatomical interface between PitNETs and normal pituitary gland, therefore the so-called pseudocapsule-based extracapsular resection (ER) technique was developed as an extracapsular surgery method for PitNETs,which differs from the conventional intracapsular resection (IR). In recent years, ER has also been widely used in patients of different tumor types, sizes, and age groups, because the pseudocapsule can be identified more clearly under the endoscopy. Endoscopic transsphenoidal resection for PitNETs has become the preferred surgical method. We reviewed relevant literatures in the past 10 years, showing that ER could achieve better rate of gross total resection (GTR) and biochemical remission, and reduce tumor recurrence than IR, without increasing postoperative complications. Therefore, the pseudocapsule and ER should be valued by neurosurgeons and actively promoted clinically.

Outcome of giant pituitary tumors requiring surgery

OBJECTIVE

The management of giant pituitary tumors is complex, with few publications and recommendations. Consequently, patient's care mainly relies on clinical experience. We report here a first large series of patients with giant pituitary tumors managed by a multidisciplinary expert team, focusing on treatments and outcome.

METHODS

A retrospective cohort study was conducted. Giant pituitary tumors were defined by a main diameter > 40mm. Macroprolactinomas sensitive to dopamine agonists were excluded. All patients were operated by a single neurosurgical team. After surgery, multimodal management was proposed, including hormone replacement, radiotherapy and anti-tumor medical therapies. Outcome was modeled using Kaplan-Meyer representation. A logistic regression model was built to identify the risk factors associated with surgical complications.

RESULTS

63 consecutive patients presented a giant adenoma, most often with visual defects. Patients were operated once, twice or three times in 59%, 40% and 1% of cases respectively, mainly through endoscopic endonasal approach. Giant adenomas included gonadotroph, corticotroph, somatotroph, lactotroph and mixed GH-PRL subtypes in 67%, 14%, 11%, 6% and 2% of patients respectively. Vision improved in 89% of patients with prior visual defects. Severe surgical complications occurred in 11% of patients, mainly for tumors > 50 mm requiring microscopic transcranial approach. Additional radiotherapy was needed for 29% of patients, 3 to 56 months after first surgery. For 6% of patients, Temozolomide treatment was required, 19 to 66 months after first surgery.

CONCLUSIONS

Giant pituitary tumors require multimodal management, with a central role of surgery. Most often, tumor control can be achieved by expert multidisciplinary teams.

[Algorithm for morphological diagnosis of neoplasms in the chiasmal-sellar region]

In the Turkish saddle area, there is a wide variety of pathological processes, the vast majority of which present as tumors of various origins (up to 90%). For a clear morphological verification of the diagnosis, it is proposed to use a diagnostic algorithm that includes the stages of differential diagnosis of normal adenohypophysis and neurohypophysis with tumors in the anterior and posterior lobes of the pituitary gland, non-pituitary origin neoplasms, as well as with non-tumor pathological processes (inflammation, cystic masses, and hyperplasia). For morphological diagnosis, histochemical and immunohistochemical methods are recommended using various staining techniques (silver impregnation, periodic acid Schiff reaction) of tissue specimens and antibody panels (pituitary hormones, low-molecular cytokeratins, pituitary transcription factors, neuroendocrine markers, etc.).

Endoscopic approach for giant pituitary adenoma: clinical outcomes of 205 patients and comparison of two proposed classification systems for preoperative prediction of extent of resection

OBJECTIVE

Giant pituitary adenoma is considered a challenging pathology for surgery owing to its complications and low resection rate. In this study, the authors present their experience of using the endoscopic endonasal approach to treat patients with giant pituitary adenoma, and they aimed to develop a classification system for prediction of extent of resection.

METHODS

The institutional medical records of patients diagnosed with giant pituitary adenoma who underwent endoscopic endonasal transsphenoidal surgery between August 1997 and December 2019 were retrospectively reviewed. Surgical and clinical outcomes were evaluated in detail. The effects of tumor characteristics on extent of resection were analyzed. The findings were used to develop two classification systems that could preoperatively predict extent of resection. Morphological score was based on tumor characteristics, and landmark-based classification was defined according to surgical zones based on neurovascular landmarks. The effects of change in surgical strategy, which aimed to maximize tumor resection and capsule dissection, on rates of resection and complications were evaluated before and after 2017.

RESULTS

This study included 205 patients, with a mean patient age of 46.95 years and mean preoperative tumor diameter of 46.56 mm. Gross-total resection (GTR) was achieved in 35.12% of patients, near-total resection (NTR) in 39.51%, and subtotal resection (STR) in 25.36%. Extent of resection differed significantly between the grades and zones of the classification systems (p < 0.001 for both). Among patients with grade 3 tumor, 75.75% of patients achieved STR, 21.21% achieved NTR, and 3.03% achieved GTR. Among patients with zone 3 tumor, 65.75% achieved STR, 32.87% achieved NTR, and 1.36% achieved GTR. Both grade 3 and zone 3 indicated limited extent of resection. The mean (range) follow-up duration was 50.16 (9-247) months. Postoperative recovery of at least one hormone axis was seen in 15.24% of patients with pituitary deficiency, and development of new hormonal deficiency was observed in 22.43% of patients. Complications included permanent diabetes insipidus (7.80%), cerebrospinal fluid leakage (3.90%), postoperative apoplexy (3.90%), meningitis (3.41%), and epistaxis (3.41%). The surgical mortality rate was 1.46%. Among 85 patients treated before 2017, 27.05% of patients achieved GTR, 37.64% achieved NTR, and 35.29% achieved STR; among 120 patients treated after 2017, 40.83% achieved GTR, 40.83% achieved NTR, and 18.33% achieved STR. Seven patients in the pre-2017 cohort had postoperative apoplexy versus only 1 patient in the post-2017 cohort. There were no statistically significant differences between the two periods in terms of the incidence rates of other complications.

CONCLUSIONS

Capsule dissection and GTR are valuable for preventing serious complications and reducing recurrence of giant adenoma. Treatment of giant pituitary adenoma may be better managed with the help of a classification system that provides information about extent of resection that can be achieved with an endoscopic approach.

Ophthalmoplegic complications in transsphenoidal pituitary surgery

OBJECTIVE

Ophthalmoplegia is a rare complication of transsphenoidal surgery, only noted in a few studies. The purpose of this study was to analyze the complications of cranial nerve III, IV, or VI palsy after transsphenoidal surgery for pituitary adenoma and understand its physiopathology and outcome.

METHODS

The authors retrospectively analyzed 24 cases of postoperative ophthalmoplegia selected from the 1694 patients operated via a transsphenoidal route in their department.

RESULTS

Two patients were operated on via microscopy and 22 via endoscopy. Patients operated on endoscopically had a greater risk of presenting with an extraocular nerve deficit postoperatively (p = 0.0115). It was found that an extension into or an invasion of the cavernous sinus (Knosp grade 3 or 4 on MRI, 18/24 patients) was correlated with a higher risk of postoperative ophthalmoplegia (p < 0.0001). The deficit was apparent immediately after surgery in 2 patients. For these 2 patients, the mechanisms of ophthalmoplegia were compression or intraoperative nerve lesion. The other 22 patients became symptomatic in the 12-72 hours following the surgery. The mechanisms implied in these cases were intrasellar compressive hematoma (4/22 cases), intracavernous hemorrhagic suffusion, or incomplete resection of the intracavernous portion of the tumor. All patients who did not present with oculomotor palsy immediately after surgery completely recovered their deficits in the 3 months that followed, while the other 2 experienced permanent damage.

CONCLUSIONS

Extraocular nerve dysfunction after transsphenoidal pituitary surgery is a rare complication that occurs more frequently in the case of the invasion or an important extension into the cavernous sinus. In this series, it also appears to be significantly more frequent in patients operated on via an endoscopic approach. Most patients have deficits that appear with a delay of 12-72 hours postoperatively and they are most likely to completely recover.

Various Strategies of Transsphenoidal Pseudocapsule-Based Extracapsular Resection in Noninvasive Functional Pituitary Adenomas and their Effectiveness and Safety

Introduction

Increasing attention has been paid to the pseudocapsule-based extracapsular resection in transsphenoidal surgery for pituitary adenomas. Prior reports focused more on Cushing disease or nonfunctional pituitary adenomas. In this study we present systematic research, especially concerning all kinds of noninvasive functional pituitary adenomas (NIFPAs) adopting various strategies of extracapsular resection, in order to evaluate the effectiveness and safety of these surgical methods for NIFPAs.

Materials and Methods

From October 2008 to November 2014, 116 patients suffering from NIFPAs underwent pseudocapsule-based extracapsular resection (ER) with different surgical strategies; that is, by a microscope or endoscope via the endonasal transsphenoidal approach. During the same period, 90 patients suffering NIFPAs also underwent traditional transsphenoidal intracapsular resection (IR). In different postoperative periods, we re-examined the endocrine series and recorded the complications. Enhanced magnetic resonance imaging examination was also performed three months later.

Results

In the ER and IR group, the tumors were completely removed in 97 (83.7%) and 62 (68.9%) cases, whereas the endocrine disorders were remitted in 89 (76.7%) and 53 (58.9%) cases, respectively. Statistical analyses to compare the overall complete resection rates and the overall endocrine remission rates in both groups showed significant differences (P = 0.028 and 0.006, respectively). Intraoperative rhinorrhea occurred in 26.7% patients of the ER group and 13.3% of the IR group, showing a significant difference (P = 0.019). Transient diabetes insipidus occurred in 73.3% patients of the ER group and 63.3% of the IR group, with no difference between groups (P = 0.126). There was no case with intracranial hematoma or pituitary crisis in both the groups.

Conclusion

With our various surgical strategies of ER, the patients can achieve content imaging resection, high and sustained endocrine remission, which are effective and safe for NIFPAs.

ICAR: endoscopic skull-base surgery

BACKGROUND

Endoscopic skull-base surgery (ESBS) is employed in the management of diverse skull-base pathologies. Paralleling the increased utilization of ESBS, the literature in this field has expanded rapidly. However, the rarity of these diseases, the inherent challenges of surgical studies, and the continued learning curve in ESBS have resulted in significant variability in the quality of the literature. To consolidate and critically appraise the available literature, experts in skull-base surgery have produced the International Consensus Statement on Endoscopic Skull-Base Surgery (ICAR:ESBS).

METHODS

Using previously described methodology, topics spanning the breadth of ESBS were identified and assigned a literature review, evidence-based review or evidence-based review with recommendations format. Subsequently, each topic was written and then reviewed by skull-base surgeons in both neurosurgery and otolaryngology. Following this iterative review process, the ICAR:ESBS document was synthesized and reviewed by all authors for consensus.

RESULTS

The ICAR:ESBS document addresses the role of ESBS in primary cerebrospinal fluid (CSF) rhinorrhea, intradural tumors, benign skull-base and orbital pathology, sinonasal malignancies, and clival lesions. Additionally, specific challenges in ESBS including endoscopic reconstruction and complication management were evaluated.

CONCLUSION

A critical review of the literature in ESBS demonstrates at least the equivalency of ESBS with alternative approaches in pathologies such as CSF rhinorrhea and pituitary adenoma as well as improved reconstructive techniques in reducing CSF leaks. Evidence-based recommendations are limited in other pathologies and these significant knowledge gaps call upon the skull-base community to embrace these opportunities and collaboratively address these shortcomings.

Outcome of endoscopic vs microsurgical transsphenoidal resection for Cushing's disease

INTRODUCTION

It is unclear whether the proportions of remission and the recurrence rates differ between endoscopic transsphenoidal surgery (TS) and microscopic TS in Cushing's disease (CD); thus, we conducted a systematic review and meta-analysis to evaluate studies of endoscopic TS and microscopic TS.

METHODS

We conducted a comprehensive search of PubMed to identify relevant studies. Remission and recurrence were used as outcome measures following surgical treatment of CD.

RESULTS

A total of 24 cohort studies involving 1670 adult patients were included in the comparison. Among these studies, 702 patients across 9 studies underwent endoscopic TS, and 968 patients across 15 studies underwent microscopic TS. Similar baseline characteristics were observed in both groups. There was no significant difference in remission between the two groups: 79.7% (95% CI: 73.1-85.0%) in the endoscopic group and 76.9% (95% CI: 71.3-81.6%) in the microscopic group (P = 0.485). It appears that patients who underwent endoscopic surgery experience recurrence less often than patients who underwent microscopic surgery, with recurrence proportions of 11.0% and 15.9%, respectively (P = 0.134). However, if follow-up time is taken into account, both groups had a recurrence rate of approximately 4% per person per year (95% CI: 3.1-5.4% and 3.6-5.1%, P = 0.651).

CONCLUSIONS

We found that remission proportion and recurrence rate were the same in patients who underwent endoscopic TS as in patients who underwent microscopic TS. The definition of diagnosis, remission and recurrence should always be considered in the studies assessing therapeutic efficacy in CD.

The Surgical Side Effects of Pseudocapsular Resection in Nonfunctioning Pituitary Adenomas

OBJECTIVE

Pseudocapsular resection is a useful surgical technique for removing functioning pituitary adenomas; however, the significance of this procedure in nonfunctioning pituitary adenomas (NFPAs) had not been discussed in detail. We clarify the safety of pseudocapsular resection in NFPAs based on the incidence of surgical complications and evaluation of pituitary function.

METHODS

In 143 patients, initial surgery for NFPAs was performed with preoperative and postoperative pituitary provocation tests. Patients were categorized into 3 groups: total group (n = 65), in which the pseudocapsule was totally removed; partial group (n = 11), in which the pseudocapsule was partially removed; and nonremoval group (n = 67), in which the pseudocapsule was not removed or did not exist. The main outcome measure was the incidence of surgical complications and postoperative pituitary functions.

RESULTS

Intraoperative cerebrospinal fluid leakage and temporary diabetes insipidus occurred more frequently in the total group than in the nonremoval group; however, the differences were not statistically significant. There was no difference in the incidence of any other complications, including postoperative cerebrospinal fluid leakage and permanent diabetes insipidus, between the total and nonremoval groups. Postoperative anterior pituitary function improved to the same degree in both the total and the nonremoval groups. Univariate and multivariate analyses revealed that pseudocapsular resection was not a factor in the postoperative deterioration of pituitary function.

CONCLUSIONS

Pseudocapsular resection in NFPAs does not increase the risk of surgical complications or aggravate postoperative pituitary function.

Time to Revive the Value of the Pseudocapsule in Endoscopic Endonasal Transsphenoidal Surgery for Growth Hormone Adenomas

OBJECTIVE

To investigate the role of endoscopic endonasal transsphenoidal surgery and the pseudocapsule in the treatment of growth hormone adenomas.

METHODS

The study included 43 patients (age range, 21-64 years) with growth hormone adenomas treated with an endoscopic endonasal approach. We compared the tumor characteristics and surgical outcomes of cases with (group A, 21 cases, from November 2013 to January 2015) and without (group B, 22 cases, from October 2011 to October 2013) extra-pseudocapsule resection.

RESULTS

The preoperative demographics, tumor characteristics, and surgical complications were not significantly different between groups A and B. Postoperative remission without adjuvant therapy was achieved in 18 of 21 cases (85.7%) in group A, which was significantly greater than that observed in group B (12 of 22 cases [54.4%]). In group A, the pseudocapsules were verified by endoscopy and histopathology. The pseudocapsule was removed en bloc with the whole adenoma in only 5 cases (23.8%). For the remaining 16 patients (76.2%), following extra-pseudocapsule dissection, incomplete pseudocapsule removals with intracapsule procedures were achieved.

CONCLUSIONS

The combination of extra-pseudocapsule resection and endoscopy led to a high rate of gross total tumor resection and endocrinologicl remission in acromegalic patients compared with the group with intracapsular resection. Extra-pseudocapsule resection resulted in no additional postoperative complications.

Extracapsular en bloc resection in pituitary adenoma surgery

PURPOSE

A pituitary pseudocapsule often contains tumor tissue and should be removed for radical resection. It can be used as a surgical plane for more radical resection of the tumor in many cases of pituitary adenomas. We evaluated the advantages and disadvantages of extracapsular en bloc capsulectomy.

METHODS

From 1992 until 2011, 1,089 treated patients were grouped according to the resection technique: en bloc capsulectomy, fragmented capsulectomy, or piecemeal resection. Their surgical and endocrinological outcomes and complications were evaluated.

RESULTS

Extracapsular tumor resection was performed in 263 patients; en bloc capsulectomy in 94 patients and fragmented capsulectomy in 169, whereas piecemeal resection was performed in 826. Extracapsular resection was performed more frequently in prolactin- and thyroid-stimulating hormone-secreting tumors. Total resection was more frequently achieved in extracapsular resection and its chance was 100% when tumors were removed in an en bloc fashion. For the functioning pituitary adenomas, endocrinological remission was achieved in all patients whose tumors were removed in an en bloc fashion and there was no recurrence. Postoperative cerebrospinal fluid (CSF) rhinorrhea developed in 4.2 and 2.7% in the extracapsular resection group and the piecemeal resection groups, respectively. The chance of postoperative aggravation of pituitary function was not statistically different between groups.

CONCLUSIONS

Extracapsular resection is critical for radical tumor resection and endocrinological remission. The removal of a pseudocapsule does not increase the risk of postoperative hypopituitarism nor postoperative CSF rhinorrhea.

Transsphenoidal surgery for acromegaly: predicting remission with early postoperative growth hormone assays

BACKGROUND

Early detection of residual disease may benefit management strategies in patients undergoing transsphenoidal surgery for acromegaly. This requires establishing objective thresholds for early postoperative growth hormone (GH) assays, and incorporating these parameters into a scale for outcome prediction.

METHOD

We analyzed a database containing the records of 86 patients who had undergone gross total transsphenoidal resection of GH-secreting pituitary adenomas. Early postoperative biochemical testing included a morning fasting basal GH assay on the first postoperative day (POD1) and a second GH assay following suppression with 100 g of oral glucose on the seventh postoperative day (POD7). Remission was defined as a normal IGF-1 with either a GH nadir <0.4 ng/ml following suppression with oral glucose or a basal fasting GH <1 ng/ml on follow-up dated >3 months after surgery. Receiver operator characteristic (ROC) curves identified optimal thresholds for all biochemical parameters. Logistic regression analysis assessed the statistical significance of factors associated with cure. A point system was developed, employing regression coefficients obtained from the multivariate statistical model to quantify the impact of each predictor on cure.

RESULTS

Remission was achieved in 34.6 % of patients and was associated with smaller, non-invasive tumors with lower preoperative, POD1 and POD7 GH levels. Optimal thresholds obtained from the ROC analysis suggested that lower POD1 and POD7 GH values provided good sensitivity and specificity for cure, despite modest predictive values. The model with the best ability to predict outcome included size, POD1 GH and POD7 GH levels, with a score of ≥95 demonstrating high specificity for prediction of remission.

CONCLUSION

Early postoperative GH assays are highly sensitivity and specific. The scoring system that we propose provided excellent predictive value and requires further validation in larger cohorts and in different populations. The model may help guide the intensity of follow-up and enable early identification of residual disease.

Contemporary neurosurgical techniques for pituitary tumor resection

Approximately 5,000 trans-sphenoidal surgeries are performed for resection of pituitary tumors each year in the United States. The rise in popularity of the trans-spehnoidal approach, though described nearly a century ago, has been facilitated over the last decades by advances in technique and technology. In this review, we discuss the relative strengths of microscopic and endoscopic techniques for pituitary tumor resection. However, despite being the standard of care for patients with most pituitary tumors, cure rates for many subtypes of pituitary lesions, such as secretory macroadenomas or tumors with significant cavernous sinus invasion, remain unsatisfactory. We also describe two more recent advances in neurosurgical technique which may offer promise of increased rates of surgical cure: pseudocapsular resection and cavernous sinus approaches.