Pituitary & Skull Base Surgery Program

The Skull Base and Pituitary Tumor Program of Pickup Family Neurosciences Institute aligns neurosurgeons, otolaryngologists, neurologists, neuro-opthalmologists, neuroradiologists and endocrinologists around the care of patients with pituitary tumors and other neoplasms of the intricate skull base region. The latter includes meningiomas, craniopharyngiomas, schwannomas, epidermoid tumors, and other invasive tumors that affect this portion of the anatomy.

The program focuses on combining the latest advanced and emerging technology with minimally invasive techniques in order to offer the best possible outcomes to patients with these rare and complex tumors. The majority of these surgeries are done through tiny incisions or using naturally occurring orifices such as the nostrils.

Since 2014, the Skull Base and Pituitary Tumor Program has seen dramatic growth under the program direction of Robert Louis, M.D. In the years since the program’s inception, a total of 301 minimally invasive surgeries for tumor removal have been completed at Pickup Family Neurosciences Institute.

This rapid growth in case volume speaks to the obvious demand for this subspecialty of neurosurgery in Orange County, and the trust that patients with these tumors have placed in our hands. While case volumes by themselves are a great measure of growth, what counts is the effect on patient outcomes. Numerous studies have demonstrated that surgeons and centers with more experience and which perform higher numbers of these complex cases have higher success rates and lower rates of complications. Indeed, a significant minority of the cases treated in our program are repeat surgeries for inadequate treatment from other facilities. As a result, Pickup Family Neurosciences Institute at Hoag is establishing itself as the only Center of Excellence for Pituitary Surgery in Orange County. The four years of surgical outcome data, including remission and complication rates, are meeting or exceeding nationally established standards for pituitary surgery.

Image of Brain Scan, Surgical Theater, HOAG

Technological Advances – Precision Neurosurgery

Since 2015, minimally invasive neurosurgery has been guided using the Surgical Navigation Advanced Platform (SNAP), by Surgical Theater. This giant leap forward for planning and performing brain surgery is a system developed and based on flight simulator technology for F-16 fighter jets. It allows for Virtual Reality 360-degree reconstruction, planning, rehearsal and navigation for complex neurosurgical procedures. By performing a Virtual Reality “fly-through” on each case, our surgeons are literally able to practice an operation in 3-D before ever picking up the scalpel. The tool optimizes minimally invasive approaches, with smaller incisions, fewer complications, and better overall outcomes. In the three years since Surgical Theater was introduced, more than 1,200 neurosurgical surgical cases have been performed at Pickup Family Neurosciences institute using this innovative technology.

Building upon the same platform, in 2017, EndoSNAP was introduced at Hoag. This provides the additional capabilities of Augmented Reality for endoscopic cases. The split screen view provided by the EndoSNAP gives the surgeon a “heads-up display” and allows for pinpoint accuracy and improved visualization of critical structures. Dr. Louis has been at the forefront of the development and implantation of virtual reality and augmented reality guidance for neurosurgery and beyond. Hoag’s Pickup Family Neurosciences Institute remains the only center in California and ranks as the second highest volume center in the nation to use Augmented Reality in Neurosurgery.

The Skull Base and Pituitary Tumor Program’s technology enhanced clinical practice approach via implementation of a cutting-edge VR visualization platform was validated as shown by the following success measures:

  • Infection/Meningitis – 0.7%
  • Post-op CSF leak – 1.2%
  • Diabetes Insipidus – transient 36%, permanent 5%

Mass of the Pituitary gland due to auto-immune Granulomatous Hypophysitis

Mass of the Pituitary gland due to auto-immune Granulomatous Hypophysitis Mass of the Pituitary gland due to auto-immune Granulomatous Hypophysitis Mass of the Pituitary gland due to auto-immune Granulomatous Hypophysitis

Scan of a Brain Scan of a Brain Scan of a Brain


The Pituitary Program is led by Robert Louis, M.D., Board Certified Neurosurgeon and an expert in endoscopic and minimally invasive treatment of benign and malignant brain tumors, sellar, parasellar and skull base tumors. Dr. Louis’ unique background includes two fellowships in Complex Cranial Surgery and Minimally Invasive Skull Base and Pituitary Surgery.

Timothy Kelley, M.D., is the ENT surgeon and partners with Dr. Louis for many of these complex cases. His particular expertise lies in endoscopic sinus and skull base surgery.

Chris Duma, M.D., is the director of the Hoag Brain Tumor Program and also serves a pivotal role in the Skull Base and Pituitary Program. Drs. Louis, Duma, and Kelley often work together, combining their skills and expertise to ensure the best possible outcome for patients.

The multidisciplinary team also includes endocrinologists, neuro-radiologists, ophthalmologists, neurologists, pathologists and neuro-oncologists.

The nurse navigator for the program is Lori Berberet, R.N., who helps coordinate the complex and often confusing journey from diagnosis to cure.

Surgical Outcomes

Composed of pituitary adenoma, craniopharyngioma, Rathke’s Cleft Cysts, meningioma, schwannoma, metastases, epidermoid, dermoid, hemangioma, hemangioblastoma, SNUC, Olfactory Neuroblastoma.

Biochemical Remission
for Functional Tumors
Visual Improvements
Gross Total Resection

Tumor Resections Designated as Skull Base/Pituitary/
Minimally Invasive
Total Surgical Cases


Lectures at National/International Conferences

Using Virtual Reality Technology across the Patient Treatment Continuum Results in Enhanced Patient Engagement and Satisfaction. HIMSS Physicians’ Executive Symposium. March 5, 2018. Las Vegas, NV.

Augmented Reality in Neuro-endoscopy Enhances Visualization of Critical Structures. Society for Brain Mapping and Therapeutics. April 15, 2018. Los Angeles, CA.

Using Virtual Reality Technology across the Patient Treatment Continuum Results in Enhanced Patient Engagement and Satisfaction. Becker’s Hospital Review 4th Annual Health IT + Revenue Cycle Conference. September 20, 2018. Chicago, IL.

Virtual Reality and Augmented Reality in Neurosurgery. Congress of Neurological Surgeons Annual Meeting. October 23, 2018. Houston Texas.

Extended Reality Technology Throughout the Patient Care Continuum. Mount Sinai School of Medicine - Digital Neurosurgery Symposium. December 7, 2018. New York, NY.

From Microchips to Microsurgery, Extending Lives with Extended Reality Technology. Intel Global Manufacturing Conference. December 13, 2018. Anaheim, CA.

Publications, Book Chapters Invited Lectures

Editor, Central and Peripheral Nervous System. Netter Atlas of Anatomy. Published 2018

Louis RG Jr, Whitesides JD, Kollias TF, Iwanaga J, Tubbs RS, Loukas M. Intercostal Nerve to Long Thoracic Nerve Transfer for the Treatment of Winged Scapula: A Cadaveric Feasibility Study. Cureus. 2017 Nov 30;9(11):e1898. doi: 10.7759/ cureus.1898. PubMed PMID: 29399426; PubMed Central PMCID: PMC5790210.

Barkhoudarian G, Farahmand D, Louis RG, Oksuz E, Sale D, Villanueva P, Kelly DF. Microsurgical Endoscope-Assisted Gravity-Aided Transfalcine Approach for Contralateral Metastatic Deep Medial Cortical Tumors. Oper Neurosurg (Hagerstown). 2017 Dec 1;13(6):724-731. doi: 10.1093/ons/opx067. PubMed PMID: 29186601.

Loukas M, Du Plessis M, Louis RG Jr, Tubbs RS, Wartmann CT, Apaydin N. The subdiaphragmatic part of the phrenic nerve - morphometry and connections to autonomic ganglia. Clin Anat. 2016 Jan;29(1):120-8. doi: 10.1002/ca.22652. Epub 2015 Oct 30. PubMed PMID: 26457392.

Oldfield EH, Vance ML, Louis RG, Pledger CL, Jane JA Jr, Lopes MB. Crooke’s Changes In Cushing’s Syndrome Depends on Degree of Hypercortisolism and Individual Susceptibility. JClin Endocrinol Metab. 2015 Aug;100(8):3165-71. doi: 10.1210/ JC.2015-2493. Epub 2015 Jul 6. PubMed PMID: 26147609.

Louis RG, Eisenberg A, Barkhoudarian G, Griffiths C, Kelly DF. Evolution of minimally invasive approaches to the sella and parasellar region. Int Arch Otorhinolaryngol. 2014 Oct;18(Suppl 2):S136-48. doi: 10.1055/s-0034-1395265. Review. PubMed PMID: 25992138; PubMed Central PMCID: PMC4399582.

Loukas M, Shane Tubbs R, Louis RG Jr, Apaydin N, Bartczak A, Vefali H, Alsaiegh N, Fudalej M. Erratum to: An endoscopic and anatomical approach to the septal papillary muscle of the conus. Surg Radiol Anat. 2015 Jul;37(5):569. doi: 10.1007/ s00276-015-1422-y. PubMed PMID: 25601580.

Dallapiazza R, Bond AE, Grober Y, Louis RG, Payne SC, Oldfield EH, Jane JA Jr. Retrospective analysis of a concurrent series of microscopic versus endoscopic transsphenoidal surgeries for Knosp Grades 0-2 nonfunctioning pituitary macroadenomas at a single institution. J Neurosurg. 2014 Sep;121(3):511-7. doi: 10.3171/2014.6.JNS131321. Epub 2014 Jul 4. PubMed PMID: 24995783.