By Kristina Rebelo
SAN DIEGO -- October 12, 2009 – A new, neuronavigational, software-driven, image-guidance multidimensional system is superior to fluoroscopy in cases of minimally invasive pituitary surgery, according to a presentation here on October 4 at the American Academy of Otolaryngology-Head and Neck Surgery Foundation (AAO-HNSF) Annual Meeting 2009.
The retrospective study examined 121 consecutive patients who underwent pituitary surgery between 1998 and 2007 in a Florida hospital. Presenting symptoms were vision changes, vision loss, and an uncontrolled hormonal response, such as those seen in acromegaly. All patients were treated by the same neurosurgeon, Fernando Vale, MD, at the same institution, undergoing transnasal transsphenoidal pituitary surgery.
"Compared to the standard intraoperative fluoroscopy, with [this neuronavigational system] we were better able to get to the tumour and able to image the tumour better. It was faster and more cost-effective, and most of all, it is [performed] without ionising radiation exposure to the surgeon and patient," said lead investigator, Samip Patel, MD, University of South Florida, College of Medicine, Tampa, Florida. "Also, it decreases operating preparation time and cuts down operating times by about 25 minutes on average -- and greater adequate tumour resection was achieved with the use of [this neuronavigational system]."
Of the 121 patient charts, 72 patients met the study criteria. Nineteen patients (10 female; age range, 15 to 83 years) were treated using intraoperative fluoroscopy. Fifty patients (31 female; age range, 17 to 82 years) were treated using the new neuronavigational system. Three patients (2 female; age range, 21 to 63 years) were treated using both fluoroscopy and the new image-guidance system, which was done while the neurosurgeon was learning to use image guidance.
The average preparation and surgical times, respectively, were as follows: fluoroscopy 70.84 minutes and 128.16 minutes; neuronavigational system 63.30 minutes and 109.38 minutes; and fluoroscopy + neuronavigational system 92 minutes and 156.30 minutes.
Complications noted in the group on which fluoroscopy was used were as follows: 4 (21%) residual tumours; 3 (16%) intraoperative cerebrospinal fluid (CSF) leaks; and 1 (5%) case of diabetes insipidus. Complications experienced by the group on which the neuronavigational system was used were 4 (8%) residual tumours, 8 (16%) intraoperative CSF leaks, 3 (6%) cases of diabetes insipidus, and 2 (4%) postoperative CSF leaks. In the group on which both fluoroscopy and the neuronavigational system were used, complications were 1 (33%) residual tumour and 1 (33%) intraoperative CSF leak.
The cost of one C-arm fluoroscope runs about $250,000, compared to the lease cost of $35,000 per month for 4 of the image-guidance, neuronavigational units.
"Wearing lead in the operating room -- required with fluoroscopy -- can be cumbersome," noted Dr. Patel. "This new technology is a safe and effective means of performing pituitary surgery. As a resident, I came into the program and we were already using the [neuronavigational system] and you don't realise that this isn't a widespread modality. It's advanced and you don't take into account that surgeons who have trained prior to now may not be using the more advanced technology."
[Presentation title: Image Guidance in Minimally Invasive Pituitary Surgery. Abstract SP195]