Endoscopic Endonasal Transsphenoidal Pituitary

ABSTRACT:Surgical approaches to the pituitary have undergone numerous refinements over the last 100 years. Fully endoscopic transsphenoidal approach has gained widespread use in all around the world.We report the results of a consecutive series of patients underwent pituitary surgery using a pure endoscopic endonasal approach andthe reults of evaluation of the efficacy and safety of this procedure. We reviewed a retrospective database of 80 consecutive pituitary adenomas that were resected by a purely endoscopic endonasal transsphenoidal technique.

Preoperative clinical condition of the patients, hormone profile, visual field, CT and MRI findings, Hardy-Vezina and Knosp scores were evaluated and pointed the importance of the parameters for surgery.Surgical technique, postoperative clinical condition of the patients, hormone profile, complications and follow-up period was reviewed.In conclusion endonasal endoscopic pituitary surgery is a safe and effective surgical technique.

INTRODUCTION:Prior to the mid-1800s the pituitary’s function and pathology were unknown.The transcranial approach to the pituitary was born in 1889 with Sir Victor Horsely, who performed transfrontal surgery to resect a pituitary adenoma (5,8). He went on to publish a total of ten operations in 1906, reporting a mortality rate of 20%. Several neurosurgeons then followed suit, and Paul and Caton performed the transtemporal approach with little success. Ultimately, the transcranial approach came with a high mortality rate of 20-80%, and so it was abandoned for a less invasive approach. The transsphenoidal surgery was first proposed by Giordano, who was chief of surgery at the University of Venice. He based his proposal on anatomic studies. Herman Schloffer, from Insbrook Austria, became the first to document transsphenoidal pituitary surgery in 1907. He did this via a 3 stage surgery where he performed a transfacial incision, a lateral rhinotomy along the left side of the nose up to the glabella, and reflecting the nose to the right. The next stage involved removal of the middle and inferior turbinates as well as the septum. He removed the anterior and posterior ethmoids. And in the final stage, he removed the volmer and rostrum of the sphenoid to finally arrive at the sella. Discontented with Schloffer’s approach, however, in 1910, Cushing incorporated Halstead’s sublabial incision and Kocher’s submucosal resection of the septum to perform a sublabial transeptal transsphenoidal approach, which is the surgery that is used to this day(8).

The versatility of the transsephenoidal approach was greatly expanded by using fluoroscopy and the operating microscope but for greater visuality and accuracy more modifications are needed. In 1990s, a collaboration of neurosurgeons and otolaryngologists described the pure endoscopic transsphenoidal technique, in which the endoscope is used alone for visualization without an accompanying microscope or transsphenoidal retractor(8).Although there are complications such as; anterior pituitary insufficiency, diabetes insipidus, cerebrospinal fluid fistulas, carotid artery injuries, hypothalamic injuries, loss of vision, and meningitis (6), the development of neuroendoscopy and the popularization of transsphenoidal endoscopic guided pituitary surgery have been associated with better tumor resection results. Detailed preoperative evaluation of the patient and the experience of the surgeon are two of the major factors to decrease mortality and the morbidity rate (7).

Keywords:Levetiracetam, Chick embryo, Neural tube defect

Amaç:Bu çalışmada yeni bir antiepileptik ajan olan levetirasetamın memelilerde embriyonel omurga gelişiminin ilk ayına uyan erken dönem civciv embriyo modelinde nöral tüp gelişimi üzerine olan etkilerinin incelenmesi amaçlanmıştır.

YÖNTEM ve GEREÇLER:Çalışma için spesifik patojen içermeyen 45 adet Atabey® cinsi döllenmiş tavuk yumurtası rastgele 5 gruba ayrıldı. Tüm yumurtalar 37.8±2°C sıcaklık ve % 60±5 nem oranında kuluçka makinasında inkübe edildi. Grup A kontrol grubu olarak ayrıldı. Diğer yumurtalara ise inkübasyonun 28. saatinde 10 μL hacim içerisinde in-ovo yöntem ile serum fizyolojik ve ilaç uygulamaları yapıldı. Grup B’ye distile su, Grup C’ye serum fizyolojik, Grup D’ye insanda kullanılan tedavi dozuna (10 mg/kg) eşdeğer dozda levatirasetam ( L8668 ) ve Grup E’ye bu tedavi dozunun 10 katı yükseklikte levetirasetam verildi. Tüm gruplardaki embriyolar 48. saatte yumurtadan çıkarılarak morfolojik ve histolojik olarak incelendi.

Bulgular:İnkübe edilen 45 adet embriyonun 41’inde nöral tüpün kapalı olduğu ve embriyonun normal gelişim gösterdiği görüldü.

SONUÇ:Levetirasetam’ın insan tedavi dozuna eşdeğer dozda ve bu değerin 10 katı yükseklikte verilen dozlarda civciv embriyosunda nöral tüp defekti oluşturmadığı gözlemlenmiştir.

Anahtar Sözcükler:Levetirasetam, Civciv embriyosu, Nöral tüp defekti