Perspectives Commentary on: Partial Anterior Petrosectomies for Upper Basilar Artery Trunk Aneurysms: A Cadaveric and Clinical Study by Fukuda et al. pp. 1113-1119.
Juha Hernesniemi, M.D., Ph.D. Professor and Chairman Department of Neurosurgery Helsinki University Central Hospital
Approaches to Upper Basilar Artery Aneurysms Juha Hernesniemi and Felix Goehre
D
uring the last 3 decades, endovascular techniques have evolved rapidly, and upper basilar artery aneurysms that are closely related to the midbrain and brainstem are treated using endovascular techniques in many institutions. However, high rates of residual lesions and recurrent aneurysm growing are the drawbacks of endovascular treatment (11). The operative approach generally depends on the size, shape, and localization of the intracranial aneurysm, the degree of brain swelling, other patient comorbidities, and microsurgical experience. The exact aneurysm location is particularly important when choosing a surgical approach. In upper basilar artery aneurysm surgery, prevention of injury to brainstem perforators is crucial.
After detailed cadaver studies, Fukado et al. have further developed a “partial anterior transpetrosal approach” from the anterior transpetrosal approach and successfully applied it to a single clinical case of a ruptured right-sided basilar trunk aneurysm without complication. With endovascular techniques becoming more complex, the minimal invasiveness of microsurgical approaches is important. In addition, Fukado et al. compared different approaches to the upper basilar region using illustrative anatomic images. However, laboratory training including anatomic cadaver studies is essential for the training of young neurosurgeons (14). Reviewing our institutional experience from 2000e2013 with the management of 4867 cerebral aneurysms including 352 basilar aneurysms, extended skull base approaches are seldom necessary. We favor less invasive approaches when possible. The subtemporal approach described by Drake and further developed in recent decades is the most frequently used approach for operating on basilar tip, basilar SCA and proximal
Key words Aneurysm - Anterior transpetrosal approach - Basilar artery - Basilar trunk - Cadaver -
WORLD NEUROSURGERY 82 [6]: 1001-1002, DECEMBER 2014
PCA aneurysms (1-3, 8). Retraction of the temporal lobe is necessary and should be done carefully to minimize the risks of temporal lobe contusions or injury to the vein of Labbe´ (6). For sufficient exposure of the basilar artery below the basilar quadrifurcation, an incision of the edge of the tentorium is necessary (2, 3, 8). The subtemporal approach allows the application of revascularization procedures to the upper posterior circulation (12). The advantage of the subtemporal approach is that the posterior portion of the aneurysm can be visualized. The application of a temporary clip on the basilar artery below the SCA is practicable. The second most frequent approach to the upper posterior circulation according to the literature is the frontotemporal approach, described with various modifications (4, 13). After performing a frontotemporal craniotomy, it is necessary to dissect the sylvian fissure widely to obtain enough space for the aneurysm dissection in this deep corridor. It is often necessary to open the cavernous sinus and to remove the posterior clinoid process. The application of revascularization procedures to the upper posterior circulation is feasible via the temporal approach (15). To approach the midbasilar region, more invasive approaches are necessary (5). In our practice, we favor a modified supratentorial and infratentorial presigmoid approach. The craniotomy is performed in a combined subtemporal and retrosigmoid fashion. The mastoid and petrous bone then are drilled down, with preservation of the semicircular canals, to expose the dura mater anterior the sigmoid sinus. The aim is to expose the sigmoid sinus, the superior petrous sinus, and the posterolateral part of the middle fossa. Next, the presigmoid dura mater is opened a few millimeters in front of the sigmoid sinus, and
Department of Neurosurgery, Helsinki University Central Hospital, Helsinki, Finland To whom correspondence should be addressed: Juha Hernesniemi, M.D., Ph.D. [E-mail: [email protected]] Citation: World Neurosurg. (2014) 82, 6:1001-1002. http://dx.doi.org/10.1016/j.wneu.2014.06.034
www.WORLDNEUROSURGERY.org
1001
PERSPECTIVES
then the dura mater of the middle fossa is opened. The superior petrous sinus is divided after surgical ligation. Finally, the tentorium is cut carefully posterior to the insertion of the fourth nerve in front of the vein of Labbe´. Possible drawbacks are an injury to the sigmoid or transverse sinus, injury to the semicircular canals sinus, and postoperative cerebrospinal fluid leaks. For prevention, a meticulous dissection and closing procedure is necessary. Regardless of the approach adopted, cerebrospinal fluid release is pivotal to reach these deep structures without damaging the surrounding brain tissues. Randell et al. (10) published practical principles of neuroanesthesia in 2006 focusing on intracranial aneurysm surgery. An adenosine-induced cardiac arrest can provide a short flow reduction in case of intraoperative aneurysm rupture or to slack the aneurysm sack for the placement of a pilot clip (7). Indocyanine green videoangiography allows real-time evaluation of the aneurysm and provides immediate information for safe clipping in a deep narrow surgical corridor (9).
REFERENCES 1. Drake CG, Peerless SJ, Hernesniemi JA: Surgery of Vertebrobasilar Aneurysms. London, Ontario Experience on 1767 Patients. Vienna: SpringerVerlag; 1996:21-26. 2. Hernesniemi J, Ishii K, Karatas A, Kivipelto L, Niemelä M, Nagy L, Shen H: Surgical technique to retract the tentorial edge during subtemporal approach: technical note. Neurosurgery 57(Suppl 4):E408, 2005. 3. Hernesniemi J, Ishii K, Niemelä M, Kivipelto L, Fujiki M, Shen H: Subtemporal approach to basilar bifurcation aneurysms: advanced technique and clinical experience. Acta Neurochir 94(Suppl 1):31-38, 2005. 4. Heros RC, Lee SH: The combined pterional/ anterior temporal approach for aneurysms of the upper basilar complex: technical report. Neurosurgery 33:244-251, 1993. 5. Kawase T, Toya S, Shiobara R, Mine T: Transpetrosal approach for aneurysms of the lower basilar artery. J Neurosurg 63:857-861, 1985. 6. Krayenbühl N, Oinas M, Erdem E, Krisht AF: The impact of minimizing brain retraction in aneurysm surgery: evaluation using magnetic resonance imaging. Neurosurgery 69:344-348, 2011.
1002
www.SCIENCEDIRECT.com
During the next decades, the microsurgical treatment of complex aneurysms will be gain in importance, including aneurysms after initial endovascular treatment, aneurysms with a complex angioarchitecture, and dolichoectatic aneurysms. Hemodynamic models will support the strategy planning for indirect treatment. Vascular reconstruction and protective bypasses will become more frequent. With cheaper and faster imaging and genetic analyses, we can screen aneurysms earlier. The stabilization of the aneurysm wall by conservative treatment and aneurysmspecific drugs will be possible. In summary, various approaches to upper basilar artery aneurysms are possible. It is technically more challenging to approach midbasilar aneurysms, and often skull base approaches are required. The trend is to minimize extended skull base approaches described earlier. Fukado et al. treated a ruptured basilar trunk aneurysm with a partial anterior transpetrosal approach after detailed cadaver laboratory studies. However, each basilar trunk aneurysm requires an individualized strategy that takes into account the aneurysm configuration, the angioarchitecture, and the patient’s condition.
7. Luostarinen T, Takala RS, Niemi TT, Katila AJ, Niemelä M, Hernesniemi J, Randell T: Adenosineinduced cardiac arrest during intraoperative cerebral aneurysm rupture. World Neurosurg 73:79-83, 2010. 8. McLaughlin N, Martin NA: Extended subtemporal transtentorial approach to the anterior incisural space and upper clival region: experience with posterior circulation aneurysms. Neurosurgery 10(Suppl 1):15-23, 2014. 9. Raabe A, Beck J, Gerlach R, Zimmermann M, Seifert V: Near-infrared indocyanine green video angiography: a new method for intraoperative assessment of vascular flow. Neurosurgery 52: 132-139, 2003.
in the posterior circulation. J Neurosurg 56:205-215, 1982. 13. Yasargil MG, Antic J, Laciga R, Jain KK, Hodosh RM, Smith RD: Microsurgical pterional approach to aneurysms of the basilar bifurcation. Surg Neurol 6:83-91, 1976. 14. Yonekawa Y, Frick R, Roth P, Taub E, Imhof HG: Laboratory training in microsurgical techniques and microvascular anastomosis. Oper Tech Neurosurg 2:149-158, 1999. 15. Zador ZL, Lu DC, Arnold CM, Lawton MT: Deep bypasses to the distal posterior circulation: anatomical and clinical comparison of pretemporal and subtemporal approaches. Neurosurgery 66:92-100, 2010.
10. Randell T, Niemelä M, Kyttä J, et al: Principles of neuroanesthesia in aneurysmal subarachnoid hemorrhage: the Helsinki experience. Surg Neurol 66:382-388, 2006. 11. Sekhar LN, Farzana T, Morton RP, Ghodke B, Hallam DK, Marber J, Kim LJ: Basilar tip aneurysms: a microsurgical and endovascular contemporary series of 100 patients. Neurosurgery 72: 284-298, 2013.
Citation: World Neurosurg. (2014) 82, 6:1001-1002. http://dx.doi.org/10.1016/j.wneu.2014.06.034 Journal homepage: www.WORLDNEUROSURGERY.org Available online: www.sciencedirect.com
12. Sundt TM Jr, Piepgras DG, Houser OW, Campbell JK: Interposition saphenous vein grafts for advanced occlusive disease and large aneurysms
1878-8750/$ - see front matter ª 2014 Published by Elsevier Inc.
WORLD NEUROSURGERY, http://dx.doi.org/10.1016/j.wneu.2014.06.034
Juha Hernesniemi, M.D., Ph.D. Professor and Chairman Department of Neurosurgery Helsinki University Central Hospital
Approaches to Upper Basilar Artery Aneurysms Juha Hernesniemi and Felix Goehre
D
uring the last 3 decades, endovascular techniques have evolved rapidly, and upper basilar artery aneurysms that are closely related to the midbrain and brainstem are treated using endovascular techniques in many institutions. However, high rates of residual lesions and recurrent aneurysm growing are the drawbacks of endovascular treatment (11). The operative approach generally depends on the size, shape, and localization of the intracranial aneurysm, the degree of brain swelling, other patient comorbidities, and microsurgical experience. The exact aneurysm location is particularly important when choosing a surgical approach. In upper basilar artery aneurysm surgery, prevention of injury to brainstem perforators is crucial.
After detailed cadaver studies, Fukado et al. have further developed a “partial anterior transpetrosal approach” from the anterior transpetrosal approach and successfully applied it to a single clinical case of a ruptured right-sided basilar trunk aneurysm without complication. With endovascular techniques becoming more complex, the minimal invasiveness of microsurgical approaches is important. In addition, Fukado et al. compared different approaches to the upper basilar region using illustrative anatomic images. However, laboratory training including anatomic cadaver studies is essential for the training of young neurosurgeons (14). Reviewing our institutional experience from 2000e2013 with the management of 4867 cerebral aneurysms including 352 basilar aneurysms, extended skull base approaches are seldom necessary. We favor less invasive approaches when possible. The subtemporal approach described by Drake and further developed in recent decades is the most frequently used approach for operating on basilar tip, basilar SCA and proximal
Key words Aneurysm - Anterior transpetrosal approach - Basilar artery - Basilar trunk - Cadaver -
WORLD NEUROSURGERY 82 [6]: 1001-1002, DECEMBER 2014
PCA aneurysms (1-3, 8). Retraction of the temporal lobe is necessary and should be done carefully to minimize the risks of temporal lobe contusions or injury to the vein of Labbe´ (6). For sufficient exposure of the basilar artery below the basilar quadrifurcation, an incision of the edge of the tentorium is necessary (2, 3, 8). The subtemporal approach allows the application of revascularization procedures to the upper posterior circulation (12). The advantage of the subtemporal approach is that the posterior portion of the aneurysm can be visualized. The application of a temporary clip on the basilar artery below the SCA is practicable. The second most frequent approach to the upper posterior circulation according to the literature is the frontotemporal approach, described with various modifications (4, 13). After performing a frontotemporal craniotomy, it is necessary to dissect the sylvian fissure widely to obtain enough space for the aneurysm dissection in this deep corridor. It is often necessary to open the cavernous sinus and to remove the posterior clinoid process. The application of revascularization procedures to the upper posterior circulation is feasible via the temporal approach (15). To approach the midbasilar region, more invasive approaches are necessary (5). In our practice, we favor a modified supratentorial and infratentorial presigmoid approach. The craniotomy is performed in a combined subtemporal and retrosigmoid fashion. The mastoid and petrous bone then are drilled down, with preservation of the semicircular canals, to expose the dura mater anterior the sigmoid sinus. The aim is to expose the sigmoid sinus, the superior petrous sinus, and the posterolateral part of the middle fossa. Next, the presigmoid dura mater is opened a few millimeters in front of the sigmoid sinus, and
Department of Neurosurgery, Helsinki University Central Hospital, Helsinki, Finland To whom correspondence should be addressed: Juha Hernesniemi, M.D., Ph.D. [E-mail: [email protected]] Citation: World Neurosurg. (2014) 82, 6:1001-1002. http://dx.doi.org/10.1016/j.wneu.2014.06.034
www.WORLDNEUROSURGERY.org
1001
PERSPECTIVES
then the dura mater of the middle fossa is opened. The superior petrous sinus is divided after surgical ligation. Finally, the tentorium is cut carefully posterior to the insertion of the fourth nerve in front of the vein of Labbe´. Possible drawbacks are an injury to the sigmoid or transverse sinus, injury to the semicircular canals sinus, and postoperative cerebrospinal fluid leaks. For prevention, a meticulous dissection and closing procedure is necessary. Regardless of the approach adopted, cerebrospinal fluid release is pivotal to reach these deep structures without damaging the surrounding brain tissues. Randell et al. (10) published practical principles of neuroanesthesia in 2006 focusing on intracranial aneurysm surgery. An adenosine-induced cardiac arrest can provide a short flow reduction in case of intraoperative aneurysm rupture or to slack the aneurysm sack for the placement of a pilot clip (7). Indocyanine green videoangiography allows real-time evaluation of the aneurysm and provides immediate information for safe clipping in a deep narrow surgical corridor (9).
REFERENCES 1. Drake CG, Peerless SJ, Hernesniemi JA: Surgery of Vertebrobasilar Aneurysms. London, Ontario Experience on 1767 Patients. Vienna: SpringerVerlag; 1996:21-26. 2. Hernesniemi J, Ishii K, Karatas A, Kivipelto L, Niemelä M, Nagy L, Shen H: Surgical technique to retract the tentorial edge during subtemporal approach: technical note. Neurosurgery 57(Suppl 4):E408, 2005. 3. Hernesniemi J, Ishii K, Niemelä M, Kivipelto L, Fujiki M, Shen H: Subtemporal approach to basilar bifurcation aneurysms: advanced technique and clinical experience. Acta Neurochir 94(Suppl 1):31-38, 2005. 4. Heros RC, Lee SH: The combined pterional/ anterior temporal approach for aneurysms of the upper basilar complex: technical report. Neurosurgery 33:244-251, 1993. 5. Kawase T, Toya S, Shiobara R, Mine T: Transpetrosal approach for aneurysms of the lower basilar artery. J Neurosurg 63:857-861, 1985. 6. Krayenbühl N, Oinas M, Erdem E, Krisht AF: The impact of minimizing brain retraction in aneurysm surgery: evaluation using magnetic resonance imaging. Neurosurgery 69:344-348, 2011.
1002
www.SCIENCEDIRECT.com
During the next decades, the microsurgical treatment of complex aneurysms will be gain in importance, including aneurysms after initial endovascular treatment, aneurysms with a complex angioarchitecture, and dolichoectatic aneurysms. Hemodynamic models will support the strategy planning for indirect treatment. Vascular reconstruction and protective bypasses will become more frequent. With cheaper and faster imaging and genetic analyses, we can screen aneurysms earlier. The stabilization of the aneurysm wall by conservative treatment and aneurysmspecific drugs will be possible. In summary, various approaches to upper basilar artery aneurysms are possible. It is technically more challenging to approach midbasilar aneurysms, and often skull base approaches are required. The trend is to minimize extended skull base approaches described earlier. Fukado et al. treated a ruptured basilar trunk aneurysm with a partial anterior transpetrosal approach after detailed cadaver laboratory studies. However, each basilar trunk aneurysm requires an individualized strategy that takes into account the aneurysm configuration, the angioarchitecture, and the patient’s condition.
7. Luostarinen T, Takala RS, Niemi TT, Katila AJ, Niemelä M, Hernesniemi J, Randell T: Adenosineinduced cardiac arrest during intraoperative cerebral aneurysm rupture. World Neurosurg 73:79-83, 2010. 8. McLaughlin N, Martin NA: Extended subtemporal transtentorial approach to the anterior incisural space and upper clival region: experience with posterior circulation aneurysms. Neurosurgery 10(Suppl 1):15-23, 2014. 9. Raabe A, Beck J, Gerlach R, Zimmermann M, Seifert V: Near-infrared indocyanine green video angiography: a new method for intraoperative assessment of vascular flow. Neurosurgery 52: 132-139, 2003.
in the posterior circulation. J Neurosurg 56:205-215, 1982. 13. Yasargil MG, Antic J, Laciga R, Jain KK, Hodosh RM, Smith RD: Microsurgical pterional approach to aneurysms of the basilar bifurcation. Surg Neurol 6:83-91, 1976. 14. Yonekawa Y, Frick R, Roth P, Taub E, Imhof HG: Laboratory training in microsurgical techniques and microvascular anastomosis. Oper Tech Neurosurg 2:149-158, 1999. 15. Zador ZL, Lu DC, Arnold CM, Lawton MT: Deep bypasses to the distal posterior circulation: anatomical and clinical comparison of pretemporal and subtemporal approaches. Neurosurgery 66:92-100, 2010.
10. Randell T, Niemelä M, Kyttä J, et al: Principles of neuroanesthesia in aneurysmal subarachnoid hemorrhage: the Helsinki experience. Surg Neurol 66:382-388, 2006. 11. Sekhar LN, Farzana T, Morton RP, Ghodke B, Hallam DK, Marber J, Kim LJ: Basilar tip aneurysms: a microsurgical and endovascular contemporary series of 100 patients. Neurosurgery 72: 284-298, 2013.
Citation: World Neurosurg. (2014) 82, 6:1001-1002. http://dx.doi.org/10.1016/j.wneu.2014.06.034 Journal homepage: www.WORLDNEUROSURGERY.org Available online: www.sciencedirect.com
12. Sundt TM Jr, Piepgras DG, Houser OW, Campbell JK: Interposition saphenous vein grafts for advanced occlusive disease and large aneurysms
1878-8750/$ - see front matter ª 2014 Published by Elsevier Inc.
WORLD NEUROSURGERY, http://dx.doi.org/10.1016/j.wneu.2014.06.034
