- Email: [email protected]
The Evolution of Image Guidance in Transsphenoidal Pituitary Surgery
Perspectives Commentary on: Initial Experience of Real-Time Intraoperative C-Arm Computed– Tomography-Guided Navigation Surgery for Pituitary Tumors by Mori et al. pp. 319-326.
Gail L. Rosseau, M.D. Chief of Cranial Base Surgery Department of Neurosurgery NorthShore University HealthSystem
The Evolution of Image Guidance in Transsphenoidal Pituitary Surgery Gail L. Rosseau
T
hroughout the history of neurosurgery, transsphenoidal surgical approaches have fueled innovations. The challenge of operating in a very small space, the so-called “high-priced real estate” of the sellar region (Heffez D, personal communication), packed as it is with carotid arteries, optic and other cranial nerves, has consistently driven improvements in imaging. The goal of maximal, safe removal of commonly occurring pituitary tumors has led to the introduction of technical advances at regular intervals. The major early transitions along this timeline, as well as more recent advancements in transsphenoidal surgery, merit review (3). It is now well known that Oskar Hirsch and Harvey Cushing were the early pioneers of transsphenoidal surgery. By 1929, Cushing abandoned the technique, but Norman Dott learned the transsphenoidal approach from Cushing and continued to use this approach on pituitary cases in Scotland. In France, Gerard Guiot, inspired by Dott, adopted his technique. Jules Hardy in Canada and Edward Laws in the United States were other key players in the resurrection and preservation of the transsphenoidal approach (8). The initial improvements to the transsphenoidal surgical approach were improvements in direct vision, with advances from headlight illumination to microscopic illumination. Guiot used an intraoperative radiofluoroscopic technique for image guidance. He and the other early pioneers used lateral x-ray, intraoperative fluoroscopy, and pneumoencephalography of the suprasellar space to guide and facilitate safe and maximal tumor removal (8). In the 1990s, the endoscope was introduced, providing superior illumination and appreciation of depth perception (6, 10). Subsequent advances have largely been tied to advances in radiology, coupled with stereotactic technology and computer modeling. Jane et al. described the use of fluoroscopic frameless stereotaxy for transsphenoidal surgery in 2001 (5). Gong et al.
Key words 䡲 Digital subtraction angiography 䡲 DynaCT 䡲 Endovascular surgery 䡲 Pituitary surgery 䡲 Transsphenoidal surgery
Abbreviations and Acronyms CT: Computed tomography DSA: Digital subtraction angiography HOR: Hybrid operating room MRI: Magnetic resonance imaging
WORLD NEUROSURGERY 79 [2]: 249-250, FEBRUARY 2013
evaluated endoscopic transsphenoidal surgery with and without the use of image guidance in 2007 and concluded that image guidance provided millimetric accuracy and added to the safety of the procedure (4). These and other reports have culminated in the contemporary and widespread use of image guidance systems. Such systems have become standard technology that provides continuous 3-dimensional information for the accurate performance of nearly all neurosurgical procedures, including transsphenoidal surgery (1). Imaging advances have been capitalized upon by the creation of an entirely new type of operating suite that permits magnetic resonance imaging (MRI) of the operative site in real time. Martin et al. reported the first 5 patients with pituitary macroadenomas who underwent transsphenoidal resection of their tumors in the intraoperative MRI unit at the Brigham and Women’s Hospital (7). They demonstrated that intraoperative imaging allowed accurate localization of the lesions, identification of pertinent surrounding structures, and the evaluation of the extent of each resection. This revolutionary device was heralded as an important tool for the surgical management of pituitary tumors, allowing for greater visual accuracy and surgical precision and a faster procedure without radiation exposure or the need for additional personnel (9). The cost and inconvenience of the system led to variations on the theme. Steinmeier et al. reported a “twin operating theater,” consisting of a conventional operating theater with complete neuronavigation equipment, which allowed surgery with magnetically incompatible instruments, conventional instrumentation and operating microscope, and a radiofrequency-shielded operating room designed for use with an intraoperative MRI scanner. The twin operating theater was presented as an alternative to a dedicated MRI system (13). Solheim et al. have published their experience with 2-dimensional, high-resolution ultrasound images, which can be used to ensure orientation in the midline for the surgical approach, to
Department of Neurosurgery, NorthShore University HealthSystem, Evanston, Illinois, USA To whom correspondence should be addressed: Gail L. Rosseau, M.D. [E-mail: [email protected]] Citation: World Neurosurg. (2013) 79, 2:249-250. http://dx.doi.org/10.1016/j.wneu.2012.12.026
www.WORLDNEUROSURGERY.org
249
PERSPECTIVES
identify important neurovascular structures to be avoided during surgery, and for resection control and identification of normal pituitary tissue. They believe image resolution is far better than what can be achieved with current clinical MRI technology (12). Finally, recent advances in tumor-binding assays have been reported that permit the surgeon to distinguish normal pituitary tissue from adenoma, offering the potential for further improvement in completeness of tumor resection and preservation of endocrine function (2). In this issue, Mori et al. report their initial experience with a hybrid operating room (HOR), which provides real-time intraoperative C-arm computed tomography (CT)-guided navigation for pituitary tumors. The recent development of flat-panel technology allows for acquisition of CT-like images by using rotation of a C-arm digital subtraction angiography (DSA) system coupled to a frameless navigation system. Of 31 transsphenoidal surgical cases performed using this system and an endoscopic technique, 12 were imaged intraoperatively to rule out residual tumor. Additional tumor was detected in 9 of these 12 cases (75%), allowing additional tumor to be resected without moving the patients and adding only 15 additional minutes to the operation. They conclude that this is a relatively inexpensive adjunct to endoscopic transsphenoidal surgery, with improved resection and the potential for less injury to the internal carotid artery and other structures within the cavernous sinus. They note that the cost of this system is half the cost of intraoperative MRI, and requires no MR-compatible instrumentation. It can be conveniently parked on the ceiling and out of the way until ready for
REFERENCES 1. De Lara D, Ditzel Filho LF, Prevedello DM, Otto BA, Carrau RL: application of image guidance in pituitary surgery. Surg Neurol Int 3(Suppl 2):S73-S78. 2012. 2. Eljamel MS, Leese G, Moseley H: Intraoperative optical identification of pituitary adenomas. J Neurooncol 92:417-421, 2009. 3. Gandhi CD, Post KD: Historical movements in transsphenoidal surgery. Neurosurg Focus 11:E7, 2001. 4. Gong J, Mohr G, Vézina JL: Experimental Imageguided endoscopic pituitary surgery: a useful learning model. J Clin Neurosci 14:758-763, 2007.
use, allowing the surgeon to document the completeness of tumor resection and absence of hematoma at the operative site at the end of the surgery, in the operating room. In addition, the DSA technology would allow for the immediate endovascular treatment of the rarely occurring carotid injury, which could otherwise result in aneurysm or pseudoaneurysm formation, or frank hemorrhage. A major drawback of this imaging technique is metal artifacts. The authors developed a carbon fiber skull clamp for vascular cases in this HOR, but cranial immobilization is rarely needed or desirable in endoscopic transsphenoidal surgery. The small metal fiducials used in this system cause only minor artifacts in the frontal region and none near the sella. More data on cost and radiation exposure would be useful, as well as details of the timing of contrast injection to facilitate optimal image acquisition. Patients presenting with a history of previous transsphenoidal surgeries, anatomical variances of the sphenoid sinus, pediatric patients with a nonpneumatized sella, tumors with a close relation to the internal carotid arteries, and extrasellar tumors are the most important indications for image guidance in pituitary surgeries and the cases where such imaging is most likely to be of substantial benefit (11). As with all technologies, this is no substitute for thorough knowledge of the microscopic anatomy specific to the approach and meticulous position awareness and handling of surgical instruments during the procedure.
6. Jho HD: Endoscopic pituitary surgery. Pituitary 2:139-154, 1999.
11. Sandeman D, Moufid A: interactive image-guided pituitary surgery. an experience of 101 procedures. Neurochirurgie 44:331-338, 1998.
7. Martin CH, Schwartz R, Jolesz F, Black PM: transsphenoidal resection of pituitary adenomas in an intraoperative MRI unit. Pituitary 2:155-162, 1999.
12. Solheim O, Selbekk T, Løvstakken L, Tangen GA, Solberg OV, Johansen TF, Cappelen J, Unsgård G: Intrasellar ultrasound in transsphenoidal surgery: a novel technique. Neurosurgery 66:173-185, 2010.
8. Patel SK, Husain Q, Eloy JA, Couldwell WT, Liu JK: Norman Dott, Gerard Guiot, and Jules Hardy: key players in the resurrection and preservation of transsphenoidal surgery. Neurosurg Focus 33:E6, 2012.
13. Steinmeier R, Fahlbusch R, Ganslandt O, Nimsky C, Buchfelder M, Kaus M, Heigl T, Lenz G, Kuth R, Huk W: Intraoperative magnetic resonance imaging with the magnetom open scanner: concepts, neurosurgical indications, and procedures: a preliminary report. Neurosurgery 43:739-747, 1998.
9. Patel SN, Youssef AS, Vale FL, Padhya TA: Re-evaluation of the role of image guidance in minimally invasive pituitary surgery: benefits and outcomes. Comput Aided Surg 16:47-53, 2011.
Citation: World Neurosurg. (2013) 79, 2:249-250. http://dx.doi.org/10.1016/j.wneu.2012.12.026 Journal homepage: www.WORLDNEUROSURGERY.org Available online: www.sciencedirect.com
5. Jane JA Jr, Thapar K, Alden TD, Laws ER Jr: fluoroscopic frameless stereotaxy for transsphenoidal surgery. Neurosurgery 48:1302-1307, 2001.
250
www.SCIENCEDIRECT.com
10. Rosseau GL, Becker S: The endoscopic transsphenoidal approach: evolution and personal experience. J Bras Neurocirurg 19:30-35, 2008.
1878-8750/$ - see front matter © 2013 Published by Elsevier Inc.
WORLD NEUROSURGERY, http://dx.doi.org/10.1016/j.wneu.2012.12.026
Gail L. Rosseau, M.D. Chief of Cranial Base Surgery Department of Neurosurgery NorthShore University HealthSystem
The Evolution of Image Guidance in Transsphenoidal Pituitary Surgery Gail L. Rosseau
T
hroughout the history of neurosurgery, transsphenoidal surgical approaches have fueled innovations. The challenge of operating in a very small space, the so-called “high-priced real estate” of the sellar region (Heffez D, personal communication), packed as it is with carotid arteries, optic and other cranial nerves, has consistently driven improvements in imaging. The goal of maximal, safe removal of commonly occurring pituitary tumors has led to the introduction of technical advances at regular intervals. The major early transitions along this timeline, as well as more recent advancements in transsphenoidal surgery, merit review (3). It is now well known that Oskar Hirsch and Harvey Cushing were the early pioneers of transsphenoidal surgery. By 1929, Cushing abandoned the technique, but Norman Dott learned the transsphenoidal approach from Cushing and continued to use this approach on pituitary cases in Scotland. In France, Gerard Guiot, inspired by Dott, adopted his technique. Jules Hardy in Canada and Edward Laws in the United States were other key players in the resurrection and preservation of the transsphenoidal approach (8). The initial improvements to the transsphenoidal surgical approach were improvements in direct vision, with advances from headlight illumination to microscopic illumination. Guiot used an intraoperative radiofluoroscopic technique for image guidance. He and the other early pioneers used lateral x-ray, intraoperative fluoroscopy, and pneumoencephalography of the suprasellar space to guide and facilitate safe and maximal tumor removal (8). In the 1990s, the endoscope was introduced, providing superior illumination and appreciation of depth perception (6, 10). Subsequent advances have largely been tied to advances in radiology, coupled with stereotactic technology and computer modeling. Jane et al. described the use of fluoroscopic frameless stereotaxy for transsphenoidal surgery in 2001 (5). Gong et al.
Key words 䡲 Digital subtraction angiography 䡲 DynaCT 䡲 Endovascular surgery 䡲 Pituitary surgery 䡲 Transsphenoidal surgery
Abbreviations and Acronyms CT: Computed tomography DSA: Digital subtraction angiography HOR: Hybrid operating room MRI: Magnetic resonance imaging
WORLD NEUROSURGERY 79 [2]: 249-250, FEBRUARY 2013
evaluated endoscopic transsphenoidal surgery with and without the use of image guidance in 2007 and concluded that image guidance provided millimetric accuracy and added to the safety of the procedure (4). These and other reports have culminated in the contemporary and widespread use of image guidance systems. Such systems have become standard technology that provides continuous 3-dimensional information for the accurate performance of nearly all neurosurgical procedures, including transsphenoidal surgery (1). Imaging advances have been capitalized upon by the creation of an entirely new type of operating suite that permits magnetic resonance imaging (MRI) of the operative site in real time. Martin et al. reported the first 5 patients with pituitary macroadenomas who underwent transsphenoidal resection of their tumors in the intraoperative MRI unit at the Brigham and Women’s Hospital (7). They demonstrated that intraoperative imaging allowed accurate localization of the lesions, identification of pertinent surrounding structures, and the evaluation of the extent of each resection. This revolutionary device was heralded as an important tool for the surgical management of pituitary tumors, allowing for greater visual accuracy and surgical precision and a faster procedure without radiation exposure or the need for additional personnel (9). The cost and inconvenience of the system led to variations on the theme. Steinmeier et al. reported a “twin operating theater,” consisting of a conventional operating theater with complete neuronavigation equipment, which allowed surgery with magnetically incompatible instruments, conventional instrumentation and operating microscope, and a radiofrequency-shielded operating room designed for use with an intraoperative MRI scanner. The twin operating theater was presented as an alternative to a dedicated MRI system (13). Solheim et al. have published their experience with 2-dimensional, high-resolution ultrasound images, which can be used to ensure orientation in the midline for the surgical approach, to
Department of Neurosurgery, NorthShore University HealthSystem, Evanston, Illinois, USA To whom correspondence should be addressed: Gail L. Rosseau, M.D. [E-mail: [email protected]] Citation: World Neurosurg. (2013) 79, 2:249-250. http://dx.doi.org/10.1016/j.wneu.2012.12.026
www.WORLDNEUROSURGERY.org
249
PERSPECTIVES
identify important neurovascular structures to be avoided during surgery, and for resection control and identification of normal pituitary tissue. They believe image resolution is far better than what can be achieved with current clinical MRI technology (12). Finally, recent advances in tumor-binding assays have been reported that permit the surgeon to distinguish normal pituitary tissue from adenoma, offering the potential for further improvement in completeness of tumor resection and preservation of endocrine function (2). In this issue, Mori et al. report their initial experience with a hybrid operating room (HOR), which provides real-time intraoperative C-arm computed tomography (CT)-guided navigation for pituitary tumors. The recent development of flat-panel technology allows for acquisition of CT-like images by using rotation of a C-arm digital subtraction angiography (DSA) system coupled to a frameless navigation system. Of 31 transsphenoidal surgical cases performed using this system and an endoscopic technique, 12 were imaged intraoperatively to rule out residual tumor. Additional tumor was detected in 9 of these 12 cases (75%), allowing additional tumor to be resected without moving the patients and adding only 15 additional minutes to the operation. They conclude that this is a relatively inexpensive adjunct to endoscopic transsphenoidal surgery, with improved resection and the potential for less injury to the internal carotid artery and other structures within the cavernous sinus. They note that the cost of this system is half the cost of intraoperative MRI, and requires no MR-compatible instrumentation. It can be conveniently parked on the ceiling and out of the way until ready for
REFERENCES 1. De Lara D, Ditzel Filho LF, Prevedello DM, Otto BA, Carrau RL: application of image guidance in pituitary surgery. Surg Neurol Int 3(Suppl 2):S73-S78. 2012. 2. Eljamel MS, Leese G, Moseley H: Intraoperative optical identification of pituitary adenomas. J Neurooncol 92:417-421, 2009. 3. Gandhi CD, Post KD: Historical movements in transsphenoidal surgery. Neurosurg Focus 11:E7, 2001. 4. Gong J, Mohr G, Vézina JL: Experimental Imageguided endoscopic pituitary surgery: a useful learning model. J Clin Neurosci 14:758-763, 2007.
use, allowing the surgeon to document the completeness of tumor resection and absence of hematoma at the operative site at the end of the surgery, in the operating room. In addition, the DSA technology would allow for the immediate endovascular treatment of the rarely occurring carotid injury, which could otherwise result in aneurysm or pseudoaneurysm formation, or frank hemorrhage. A major drawback of this imaging technique is metal artifacts. The authors developed a carbon fiber skull clamp for vascular cases in this HOR, but cranial immobilization is rarely needed or desirable in endoscopic transsphenoidal surgery. The small metal fiducials used in this system cause only minor artifacts in the frontal region and none near the sella. More data on cost and radiation exposure would be useful, as well as details of the timing of contrast injection to facilitate optimal image acquisition. Patients presenting with a history of previous transsphenoidal surgeries, anatomical variances of the sphenoid sinus, pediatric patients with a nonpneumatized sella, tumors with a close relation to the internal carotid arteries, and extrasellar tumors are the most important indications for image guidance in pituitary surgeries and the cases where such imaging is most likely to be of substantial benefit (11). As with all technologies, this is no substitute for thorough knowledge of the microscopic anatomy specific to the approach and meticulous position awareness and handling of surgical instruments during the procedure.
6. Jho HD: Endoscopic pituitary surgery. Pituitary 2:139-154, 1999.
11. Sandeman D, Moufid A: interactive image-guided pituitary surgery. an experience of 101 procedures. Neurochirurgie 44:331-338, 1998.
7. Martin CH, Schwartz R, Jolesz F, Black PM: transsphenoidal resection of pituitary adenomas in an intraoperative MRI unit. Pituitary 2:155-162, 1999.
12. Solheim O, Selbekk T, Løvstakken L, Tangen GA, Solberg OV, Johansen TF, Cappelen J, Unsgård G: Intrasellar ultrasound in transsphenoidal surgery: a novel technique. Neurosurgery 66:173-185, 2010.
8. Patel SK, Husain Q, Eloy JA, Couldwell WT, Liu JK: Norman Dott, Gerard Guiot, and Jules Hardy: key players in the resurrection and preservation of transsphenoidal surgery. Neurosurg Focus 33:E6, 2012.
13. Steinmeier R, Fahlbusch R, Ganslandt O, Nimsky C, Buchfelder M, Kaus M, Heigl T, Lenz G, Kuth R, Huk W: Intraoperative magnetic resonance imaging with the magnetom open scanner: concepts, neurosurgical indications, and procedures: a preliminary report. Neurosurgery 43:739-747, 1998.
9. Patel SN, Youssef AS, Vale FL, Padhya TA: Re-evaluation of the role of image guidance in minimally invasive pituitary surgery: benefits and outcomes. Comput Aided Surg 16:47-53, 2011.
Citation: World Neurosurg. (2013) 79, 2:249-250. http://dx.doi.org/10.1016/j.wneu.2012.12.026 Journal homepage: www.WORLDNEUROSURGERY.org Available online: www.sciencedirect.com
5. Jane JA Jr, Thapar K, Alden TD, Laws ER Jr: fluoroscopic frameless stereotaxy for transsphenoidal surgery. Neurosurgery 48:1302-1307, 2001.
250
www.SCIENCEDIRECT.com
10. Rosseau GL, Becker S: The endoscopic transsphenoidal approach: evolution and personal experience. J Bras Neurocirurg 19:30-35, 2008.
1878-8750/$ - see front matter © 2013 Published by Elsevier Inc.
WORLD NEUROSURGERY, http://dx.doi.org/10.1016/j.wneu.2012.12.026