The Use of Micro Retractor in Endoscopic Endonasal Posterior Pseudocapsule Resection of Pituitary Macroadenoma. Technical Note

BackgroundThe endoscopic endonasal approach and extra-pseudocapsule resection may be the main progress in modern pituitary surgery. However, for pituitary macroadenomas, discerning the pseudocapsule in the posterior plane of the tumor may be difficult. When the anterior-inferior debulking is performed, the early subsidence of the thinning normal pituitary gland and enlarged diaphragm may obstruct the surgical dissection view.MethodWe describe the technique of using a micro retractor for the endoscopic endonasal posterior pseudocapsule resection of pituitary macroadenomas. This micro retractor that was 2 mm in width was placed at the 12 o’clock position on the nostrils, and the end was fixed in the flexible arms of the self-retaining retractor system. The head of the micro retractor elevated the herniated diaphragm sellae in order to continue the posterior pseudocapsule resection of the pituitary macroadenoma.ResultThe technique was performed very easily and no complication was observed.ConclusionThe use of this micro retractor can increase the view of the posterior margin of the adenomas to facilitate the pseudocapsule dissection.

Diaphragm Sellae Meningioma: Distinct Clinical, Anatomic, and Surgical Considerations: 2-Dimensional Operative Video

Nestled in the parasellar region, surrounded by critical neurovascular structures, diaphragm sellae meningiomas although rare present distinct clinical, radiological, and surgical considerations.1-3 Consequently, they present surgical challenges that could be overcome with technical nuances. The origin of this meningioma on the diaphragm creates a distorted anatomy, which must be comprehended for the safe approach and resection. Three distinct subtypes of diaphragm sellae meningiomas are described, each with distinctive clinical presentations and surgical treatment implications.2 Type A originates from the upper leaf of diaphragm sellae pushing the stalk posteriorly. It usually presents with unilateral visual loss. Type B originates from the upper leaf of the diaphragm sellae pushing the stalk anteriorly. It presents with few visual symptoms, but memory disturbance and hypopituitarism are common. Type C originates from the inferior leaf of the diaphragm sellae (intrasellar meningioma) presenting with bitemporal hemianopsia and hypopituitarism. Recognizing these variations in this rare tumor subtype is critical to minimizing potential adverse outcomes associated with operative treatment. The cranial approach has been the recommended route for these lesions with an exception of the intrasellar type.1,3 In this article, we depict the pathological anatomy and demonstrate the surgical nuances in handling diaphragm sellae meningioma resection through a cranio-orbital approach4 in a patient who had an unsuccessful trans-sphenoidal resection attempt. The patient consented for the procedure. Image at 1:38 from Al-Mefty O, Operative Atlas of Meningiomas, © LWW, 1997, with permission. Image at 8:56 from Kinjo et al,2 Diaphragma sellae meningiomas, case reports, Neurosurgery, 1995, 36(6), 1082-1092, by permission of the Congress of Neurological Surgeons.

Anatomical Considerations of the Endonasal Transsphenoidal Approach

The sellar contents are separated from the sphenoidal sinus by a tiny sheath of bone that compris es the sellar floor, making the transsphenoidal approach the most used surgical route to intrasellar lesions. The transsphenoidal approach can be initiated in three different ways: 1) cutting the mucosa over the alveolar part of maxilla (sublabial transsphenoidal), 2) cutting along the anterior nasal mucosa adjacent to the columella (transeptal transsphenoidal), and 3) cutting the mucosa over the sphenoidal rostrum (endonasal transsphenoidal). Each cavernous sinus has four dural walls. The lateral, superior and posterior walls are composed of endosteal and periosteal dura leaflets. Unlike the other dural walls, the medial wall is formed of a single, thin dural sheath, an anatomical fact that help explains the lateral expansion of a pituitary adenoma. In the center, the diaphragm sellae has an opening through which the infundibulum courses, linking the pituitary gland to the floor of the third ventricle. The morphology of this opening is quite variable among individuals. On average, the anteroposterior distance of the diaphragm opening was 7.26 mm + 1.99 mm, varying from 3.4 mm up to 10.7 mm. The lateral distance of the diaphragm opening was 7.33 mm + 2.79 mm, varying from 2.8 mm up to 14.1 mm.

Surgically Treated Tuberculum Sellae and Diaphragm Sellae Meningiomas

OBJECTIVE: The visual outcome in patients with tuberculum and diaphragm sellae meningiomas treated with microsurgery was evaluated. Prognostic and diagnostic values of short- and long-term postoperative visual outcome and etiology for postoperative visual deterioration are discussed with special attention. METHODS: Clinical data for 30 surgically treated patients with tuberculum and diaphragm sellae meningiomas were reviewed retrospectively. The mean duration of the follow-up period was 75.9 months (range, 12–151 mo). Mean tumor diameter and volume was 25.9 mm (range, 16.3–63.3 mm) and 12.4 cm3 (range, 2.3–125.6 cm3). A visual impairment score was used to assess the short-term (≤2 wk after surgery) and the long-term (>6 mo after surgery) postoperative visual outcome. Various predictive factors for visual outcome were tested statistically. RESULTS: Complete resection was achieved in 23 out of 30 (76.7%) patients. Average preoperative, short- and long-term visual impairment scores were 48.2, 43.4, and 40.9, respectively. Favorable visual outcome was achieved in 80% of patients in the short term and 70% in the long term. Short-term postoperative aggravation of visual function was an ominous sign of further aggravation or at least of little hope for recovery, whereas there was a tendency to improve in the long term if short-term postoperative visual function showed favorable outcome. Recurrence or regrowth of tumor fully was responsible for late deterioration of visual function. No significant prognostic factor for visual outcome could be found. CONCLUSION: Short-term postoperative visual outcome was a strong indicator of permanent visual outcome after surgery for tuberculum sellae and diaphragm sellae meningiomas.