Transcranial approach for pituitary adenomas - An evaluation of surgical approaches over two decades and factors influencing peri-operative morbidity

A simple surgical technique for sellar closure after transsphenoidal resection of pituitary adenomas in the context of risk factors for cerebrospinal fluid leaks and meningitis

OBJECTIVE

The transsphenoidal approach is the standard for most pituitary tumors. Despite low morbidity, postoperative CSF fistulas and meningitis are specific complications. Various surgical closure techniques for intraoperative CSF (iCSF) leak and sellar reconstruction have been described. For many years the authors have applied synthetic materials for iCSF leak repair and sellar closure in a standardized fashion in their department. Here they analyze the surgical outcome as well as risk factors for iCSF leak and meningitis.

METHODS

All patients with transsphenoidal resection of a pituitary adenoma performed by the same surgeon between January 2013 and December 2019 were screened retrospectively. A small amount of iCSF flow without a diaphragmatic defect was classified as a minor leak, and obvious CSF flow with or without a diaphragmatic defect was classified as a major leak. In case of iCSF leak, a fibrin- and thrombin-coated sponge was used to cover the diaphragmatic defect and another one was used for the sellar opening. A gelatin sponge was placed in the sphenoid sinus as an abutment. The primary and secondary outcomes were the number of postoperative CSF (pCSF) leaks and meningitis, respectively. Clinical, histological, and perioperative data from medical records were collected to identify risk factors for CSF leak and meningitis.

RESULTS

Of 417 transsphenoidal surgeries, 359 procedures in 348 patients with a median age of 54 years were included. There were 96 iCSF leaks (26.7%; 37.5% major, 62.5% minor). In 3 of 359 cases (0.8%) a pCSF fistula occurred, requiring revision surgery in 2 patients and a lumbar drain in 1 patient. Meningitis occurred in 3 of 359 cases (0.8%). All 3 patients recovered without sequelae after antibiotic therapy. According to univariate analysis, risk factors for iCSF leak were macroadenoma (p = 0.006) and recurrent adenoma (p = 0.032). An iCSF leak was found less often in functioning adenomas (p = 0.025). In multivariate analysis recurrent tumors remained as a risk factor (p = 0.021) for iCSF leak. Patients with iCSF leak were at increased risk for a pCSF leak (p = 0.005). A pCSF leak in turn represented the key risk factor for meningitis (p = 0.033).

CONCLUSIONS

Patients with macroadenomas and recurrent adenomas are especially at risk for iCSF leak. An iCSF leak in turn increases the risk for a pCSF leak, which carries the risk for meningitis. The authors' surgical technique leads to a very low rate of pCSF leaks and meningitis without using autologous graft materials. Hence, this technique is safe and improves patient comfort by avoiding the disadvantages of autologous graft harvesting.

Transcranial Surgery for Pituitary Tumors: A "Community Neurosurgery Experience"

Background

Despite the evolution of endoscopic techniques, large pituitary adenomas with unfavorable characteristics and irregular anatomical configurations continue to pose a challenge for the dexterity, skills, and patience of endoscopic surgeons. Transcranial surgery retains a significant role in these situations where the tumor access, hemostasis, and dissection around adjoining neurovascular tissues can be controlled efficaciously.

Objective

In this report, we describe our experience with transcranial surgery for pituitary adenomas highlighting its safety and versatility in peripheral centers.

Methods

We accessed the case files and imaging records of pituitary tumors operated between 2001 and 2019 at a private hospital in a major Indian city. The records were analyzed with emphasis on postoperative clinical course, visual, and endocrinological outcomes. The data was analyzed with respect to differences between transcranial and transsphenoidal procedures. Categorical variables were compared with Chi-square test/Fischer's exact test and difference in means evaluated with Welch's t-test.

Results

A total of 178 procedures were performed in 173 patients with pituitary adenoma, who were the subjects of this study. Ninety-eight (56.7%) patients were treated by transsphenoidal excision whereas 80 (46.2%) underwent transcranial procedures (75 primary and five secondary). In the patients operated transcranially, we observed three deaths and nine patients suffered from significant morbidity. Visual outcomes were similar to the group operated transsphenoidally. However, incidence of panhypopituitarism was significantly higher in transcranial procedures; the extent of resection was poorer than transsphenoidal surgeries owing to more extensive nature of tumors.

Conclusions

In low-volume centers, the endoscopic skills required for transsphenoidal resection of large and complex pituitary adenomas may be scarce. Transcranial surgery, dependent on familiar microsurgical techniques and equipment, may still be viable, safe, and an effective option.

Decision-Making and Management in a Patient With Coexistent Colloid Cyst and Pituitary Macroadenoma: A Case Report

The coexistence of separate and distinct primary intracranial tumors is rare. Specifically, there are no previous reports of a colloid cyst coexisting with a pituitary macroadenoma. We present the case of a 40-year-old male with a colloid cyst associated with mild enlargement of the right lateral ventricle and a coexistent pituitary macroadenoma with compression of the optic apparatus. An endoscopic endonasal transsphenoidal surgery (EETS) for resection of the pituitary mass was performed first due to the patient’s complaints of acute visual changes. He then underwent a right frontal craniotomy for resection of the colloid cyst one month later. The patient recovered without residual deficits in vision, and he did not require ventricular shunting after removal of the colloid cyst. We aimed to discuss our decision-making process and the management of these coexistent lesions. 

Comparative Proteomic Study Shows the Expression of Hint-1 in Pituitary Adenomas

Pituitary adenomas (PAs) can be unpredictable and aggressive tumors. No reliable markers of their biological behavior have been found. Here, a proteomic analysis was applied to identify proteins in the expression profile between invasive and non-invasive PAs to search for possible biomarkers. A histopathological and immunohistochemical (adenohypophyseal hormones, Ki-67, p53, CD34, VEGF, Flk1 antibodies) analysis was done; a proteomic map was evaluated in 64 out of 128 tumors. There were 107 (84%) invasive and 21 (16%) non-invasive PAs; 80.5% belonged to III and IV grades of the Hardy–Vezina classification. Invasive PAs (n = 56) showed 105 ± 43 spots; 86 ± 32 spots in non-invasive PAs (n = 8) were observed. The 13 most prominent spots were selected and 11 proteins related to neoplastic process in different types of tumors were identified. Hint1 (Histidine triad nucleotide-binding protein 1) high expression in invasive PA was found (11.8 ± 1.4, p = 0.005), especially at high index (>10; p = 0.0002). High Hint1 expression was found in invasive VEGF positive PA (13.8 ± 2.3, p = 0.005) and in Flk1 positive PA (14.04 ± 2.28, p = 0.006). Hint1 is related to human tumorigenesis by its interaction with signaling pathways and transcription factors. It could be related to invasive behavior in PAs. This is the first report on Hint expression in PAs. More analysis is needed to find out the possible role of Hint in these tumors.