- Email: [email protected]
Exclusive Endoscopic Occipital Transtentorial Approach for Pineal Region Tumors
Technical Note
Exclusive Endoscopic Occipital Transtentorial Approach for Pineal Region Tumors Motoki Tanikawa1, Hiroshi Yamada1, Tomohiro Sakata1, Yasuhiko Hayashi2, Yasuo Sasagawa2, Tadashi Watanabe3, Tetsuya Nagatani3, Mitsuhito Mase1
OBJECTIVE: Removal of pineal region tumors, which are deeply placed and encircled by intricate neurovascular structures, is challenging to neurosurgeons. The aim of this study was to present our experience with the exclusive endoscopic occipital transtentorial approach (EEOTA) used for removal of pineal region tumors.
-
METHODS: A retrospective review was performed of patients who underwent surgery using the EEOTA to remove pineal region tumors from May 2016 to August 2018. The details of the EEOTA procedure were confirmed.
-
RESULTS: Five patients underwent surgery via the EEOTA for treatment of pineal region tumors. In all cases, it was possible to perform the EEOTA less invasively through a keyhole craniotomy approximately 2.0e2.5 cm in size. The EEOTA produced an excellent view and provided natural and automatic orientation. There was essentially no blind spot in this procedure, even for the floor or ipsilateral wall of the third ventricle. Gross total resection was achieved in 4 cases. In the patient with atypical teratoid rhabdoid tumor, we abandoned gross total resection because of a hardened adhesion to the tectum and the great cerebral vein and its tributaries. Two patients presented with transient upper gaze palsy immediately after surgery but experienced complete recovery during the follow-up period.
-
CONCLUSIONS: The EEOTA is a very promising technique for removal of pineal region tumors and has the
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Key words Endoscope - Occipital transtentorial approach - Pineal region tumor -
Abbreviations and Acronyms CSF: Cerebrospinal fluid EEOTA: Exclusive endoscopic occipital transtentorial approach OTA: Occipital transtentorial approach PR: Partial resection From the 1Department of Neurosurgery, Nagoya City University Graduate School of Medical Sciences, Nagoya; 2Department of Neurosurgery, Kanazawa University Graduate School of
WORLD NEUROSURGERY 131: 167-173, NOVEMBER 2019
potential for extensive and routine application for surgeons familiar with endoscopic surgery.
INTRODUCTION
A
ggressive surgical resection is a mainstay of management for almost all pineal region tumors except for pure germinoma and primary lymphoma, which have exquisite sensitivity to chemoradiotherapy.1-5 Advances in microsurgical technique and postoperative care in recent years have resulted in dramatic improvement of outcomes in the treatment of pineal region tumors.1-13 However, these tumors, which are deep-seated and surrounded by complicated and critical neurovascular structures,14 remain surgically challenging to neurosurgeons. Therefore, even an incremental refinement of the surgical procedure would be welcomed.
The occipital transtentorial approach (OTA), which is generally accepted to have originated from Poppen’s procedure in 196611,12 and later refined by Jamieson in 1971,8 is currently one of the most common operative techniques for pineal region tumors.1,3-5,7,9,15,16 This procedure has become firmly established over the past several decades; however, it still harbors some disadvantages, including the necessity of a relatively large bone opening, difficult orientation owing to the obliqueness of the approach, retraction injury to the occipital lobe and corpus callosum, and blind spots at the ipsilateral wall and the roof of the third ventricle.1,4-6,9,15 At the present time, endoscopy is gradually becoming used on a wide scale in neurosurgery and has replaced the microscope as the primary surgical tool in some procedures. Because the pineal region is positioned at the
Medical Sciences, Ishikawa; and 3Department of Neurosurgery, Japanese Red Cross Nagoya Daini Hospital, Nagoya, Japan To whom correspondence should be addressed: Motoki Tanikawa, M.D. [E-mail: [email protected]] Supplementary digital content available online. Citation: World Neurosurg. (2019) 131:167-173. https://doi.org/10.1016/j.wneu.2019.08.038 Journal homepage: www.journals.elsevier.com/world-neurosurgery Available online: www.sciencedirect.com 1878-8750/$ - see front matter ª 2019 Elsevier Inc. All rights reserved.
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TECHNICAL NOTE
Table 1. Characteristics of Patients Who Underwent Exclusive Endoscopic Occipital Transtentorial Approach for Pineal Region Tumors Case
Age, Sex
Clinical Presentation
Pathology
Maximum Diameter (mm)
Extent of Resection
Complications
1
10 years, male
Headache
Immature teratoma
35
GTR
None
2
66 years, female
Gait disturbance
Pineocytoma
30
GTR
Transient upper gaze palsy
3
7 years, male
Somnolence, diplopia
Immature teratoma
38
GTR
Transient upper gaze palsy
4
9 months, female
Macrocephaly
ATRT
48
PR
Asymptomatic subdural hygroma
5
21 years, male
Diplopia
Yolk sac tumor
15
GTR
None
GTR, gross total resection; ATRT, atypical teratoid rhabdoid tumor; PR, partial resection.
geometric center of the brain, and the corridor for a surgical approach to this region tends to be necessarily narrowed, deepened, and restricted, an endoscopic approach is clearly an appropriate procedure for these conditions and can be considered a potential solution to the disadvantages of a conventional microscopic approach. Some reports have described the effectiveness of an endoscopic infratentorial supracerebellar approach for pineal lesions,17,18 which is another common treatment for pineal region tumors.1,5,6,9,10,13 In May 2016, we adopted an exclusive endoscopic occipital transtentorial approach (EEOTA) for a pineal region immature teratoma for the first time, after thorough trials through cadaveric dissection.19 We describe the first case series of patients with pineal region tumor who were treated by EEOTA to assess the usefulness and elucidate the details of this procedure.
MATERIALS AND METHODS From May 2016 to August 2018, 5 patients in the neurosurgery departments of Nagoya City University Hospital,
Figure 1. Exclusive endoscopic occipital transtentorial approach for pineal immature teratoma. (A) Dural opening just after gross total removal of the tumor. Right occipital lobe was protected by covering
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Kanazawa University Hospital, and Japanese Red Cross Nagoya Daini Hospital underwent surgery using EEOTA for pineal region tumors (Table 1). Complete informed consent was obtained from all 5 patients. We performed a retrospective chart review of the patients who underwent surgery using EEOTA, and the pertinent data have been compiled and are presented in this study. The study protocol was approved by the institutional review board or human research ethics committee at each participating institution. Surgical Procedure Patients were placed in a prone position with the head tilted and rotated toward the contralateral side and slightly extended to directly face the operator, who maintained both hands at a natural angle ergonomically. An occipital midline skin incision and keyhole craniotomy approximately 2.0e2.5 cm in size were made (Figure 1AeC). The dura mater was
with surgical patties. (B and C) All procedures were performed through a keyhole craniotomy 2.0e2.5 cm in size. Sup. Sag. Sinus, superior sagittal sinus; Tent., tentorium cerebelli; Occip. Lobe, occipital lobe.
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TECHNICAL NOTE
Figure 2. (A and B) Twisted spatula facilitates holding the occipital lobe obliquely upward in parallel with the tentorium, preventing interference with manipulations. (C) After retracting the right occipital lobe, sufficient space for manipulations was secured. Prominent tentorial sinuses were
opened with a semicircular incision, based on the superior sagittal sinus extending the full width of the craniotomy. An endoscope, rigid and fixed with an exclusive holder (HD EndoArm; Olympus Co., Tokyo, Japan), was subsequently introduced. We initially used a 4-mm-diameter and 0 angle scope, fixed at the upper side of the operative field, and operative instruments in both hands, including bipolar forceps, a microdissector, microscissors, and a suction device, were used almost in parallel in the lower operative field (Figure 2C). The falx cerebri, straight sinus, and tentorium cerebelli were identified in turn, while retracting the occipital lobe gently and in a stepwise fashion by a brain spatula, fixed with a self-retaining retractor, which was twisted (Figure 2AeC) to enable the holding of the occipital lobe obliquely upward in parallel with the tentorium and to reduce interference with manipulations. At that point, drainage of cerebrospinal fluid (CSF) from a catheter, if it had been placed beforehand, contributed to the smoothness of this process. After reaching the tentorial edge, the quadrigeminal cistern was identified, and the CSF was drained so that sufficient space for all manipulation was obtained. The tentorium was incised as far from the straight sinus as possible at the edge and as long as possible in the direction of the sinus confluence. In cases where the tentorial sinus was highly developed, however, the incision needed to follow a different direction and to extend as closely as possible to the straight sinus. Reflecting the incised tentorium on the falx cerebri, the cerebellum and the terminal portion of the great cerebral vein were exposed (Figure 3A). Then, using a 30 oblique scope inserted parallel to the medial surface of the occipital lobe, the adhesion between the cerebellum and the contralateral
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identified. Inset image shows positional relationship between the scope and instruments in both hands. Str. Sinus, straight sinus; Tent. Sinus, tentorial sinus; Tent., tentorium cerebelli.
tentorium was clearly exposed and dissected thoroughly (Figure 3B) so that a space between the tentorium and the cerebellum was created. In this process, the surgical instruments in both hands were used in the medial operative field and positioned vertically. This was a crucial process for EEOTA because advancing the endoscope into the space created produced comprehensive imaging of the surrounding structures on the same screen, including the cerebellum, the great cerebral vein and its tributaries, and the tectum, and rendered precise orientation natural and automatic (Figure 3C and D and Figure 4A). After a straight scope was introduced into the created space, the great cerebral vein and tributaries could be identified through the thickened arachnoid membrane of the quadrigeminal cistern (Figure 3C), which was then incised broadly by instruments in both hands positioned in parallel in the lower operative field. Dissecting the cerebellomesencephalic fissure thoroughly, the tectum, pineal body, and tumor were exposed, and a sufficient space for the manipulation was secured (Figure 3D and Figure 4A). For dissection of the deepest site of the cerebellomesencephalic fissure, especially on the ipsilateral side, the positioning of an oblique scope in the upper operative field and the use of the lower operative field for manipulation of instruments in both hands proved to be effective (Figure 3D). Precentral cerebellar veins were sacrificed if they obstructed the operative view and manipulation. Dissection of the tumor from the surrounding tissue, including the tectum, habenula, posterior commissure, internal cerebral vein, and thalamus, proceeded meticulously (Figure 4BeE). A 30 oblique scope positioned at the opposite side of the operative field produced an excellent operative view in the
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Figure 3. Exclusive endoscopic occipital transtentorial approach for pineal immature teratoma. Inset images show positional relationship between the scope and instruments in both hands. (A) Reflecting the incised tentorium on the falx cerebri, the cerebellum and the terminal portion of the great cerebral vein (the great vein of Galen) were exposed. (B) Inserting a 30 oblique scope parallel to the medial surface of the occipital lobe, the adhesion between the cerebellum and the contralateral tentorium was clearly exposed and dissected thoroughly so that a space between the tentorium and the cerebellum was created. In the process, surgical instruments in both hands were used in the medial operative field and positioned vertically. (C) After a straight scope was introduced in the created space, the great cerebral vein and
tributaries could be identified through the thickened arachnoid membrane of the quadrigeminal cistern, which was then incised broadly by instruments positioned in parallel in both hands in the lower operative field. (D) For dissection of the deepest site of the cerebellomesencephalic fissure, especially on the ipsilateral side, positioning an oblique scope in the upper operative field and using the lower operative field for manipulation of instruments in both hands were effective. V. of Galen, great vein of Galen; Occip. Lobe, occipital lobe; Str. Sinus, straight sinus; Contralat. Tent., contralateral tentorium; Qad. Cist., quadrigeminal cistern; Int. Occip. V., internal occipital vein; Basal V., basal vein.
third ventricle and allowed precise manipulation. When the mass occupied the operative space, central debulking and piece-by-piece dissection were performed to improve management of the tumor (Video 1).
anesthesia, allowed manipulation to proceed smoothly. In all cases, it was possible to perform the EEOTA less invasively through a keyhole craniotomy. In 4 cases, achieve gross total resection was achieved (Figures 4E and 5 and Table 1). In 1 patient with atypical teratoid rhabdoid tumor, we abandoned gross total resection owing to a deep solid portion that was hardened and adhered RESULTS strongly to the tectum and the great cerebral vein The present study included 5 patients, 3 male and 2 Video available at and its tributaries (Figure 5G and H). Bleeding from www.sciencedirect.com female, ranging in age from 9 months to 66 years an unexposed bridging vein occurred in 1 patient (Table 1). The maximum diameter of tumors ranged but was well controlled with no difficulty using the from 15 to 48 mm. All patients had hydrocephalus oblique scope and malleable instruments. The tentorial incision and received endoscopic third ventriculostomy and biopsy, and was shorter than we had expected owing to the presence of 2 were treated by neoadjuvant chemoradiotherapy before the tentorial sinus in 2 patients (Figure 2C). Even in these cases, tumor removal via the EEOTA. Histologically, we identified 2 by incising the tentorium as close to the straight sinus as immature teratomas, 1 pineocytoma, 1 atypical teratoid possible and taking advantage of endoscopic surgery, we could rhabdoid tumor, and 1 yolk sac tumor. accomplish the subsequent procedures smoothly. Two patients presented with upper gaze palsy immediately after surgery, but In 3 cases (cases 2, 3, and 5), draining CSF through lumbar they experienced complete recovery during the follow-up drainage, which was placed immediately after induction of
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TECHNICAL NOTE
Figure 4. Exclusive endoscopic occipital transtentorial approach for pineal immature teratoma. Inset images show positional relationship between scope and instruments in both hands. (A) Dissecting the cerebellomesencephalic fissure thoroughly, the tectum, pineal body, and tumor were exposed, and sufficient space for manipulation was secured. (BeD) Dissection of the tumor from surrounding tissue, including the tectum, habenula, posterior commissure, nternal cerebral
period. One infant case (case 4) had an asymptomatic subdural hygroma postoperatively and was followed with no treatment being necessary (Table 1).
DISCUSSION We present the first case series of patients who underwent surgery via the EEOTA for treatment of a pineal region tumor. In 2016, our team documented the first EEOTA for a pineal immature teratoma,19 which was performed after elaborate trials through cadaveric dissection. Thereafter, we very carefully selected candidates for the surgery and have so far performed the EEOTA in 5 patients with pineal region tumor. We found the EEOTA to be a very promising technique with the advantages of endoscopic surgery, and although it has some similarities to a conventional microscopic OTA, it is substantially different. A conventional microscopic OTA is performed through a relatively large skin flap and bone window, which is usually required from the parieto-occipital fissure to the transverse sinus in a craniocaudal direction and several centimeters from the superior sagittal sinus in width in the horizontal direction.1,5,9 By contrast, the EEOTA described in this study could be performed via a short linear skin incision and a keyhole craniotomy. Furthermore, the retraction of the occipital lobe, which is indispensable for an OTA but risks causing homonymous hemianopsia,4,5,9,15 can also be
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vein, and thalamus, proceeded carefully. A 30 oblique scope positioned at the opposite side of the operative field produced an excellent operative view in the third ventricle and allowed precise manipulation. (E) Final view after gross total removal of the tumor. Int. Occip. V., internal occipital vein; V. of Galen, great vein of Galen; Precent. Cer. V., precentral cerebellar vein; Basal V., basal vein; Int. Cer. V., internal cerebral vein; Mam. Body, mammillary body.
reduced in the endoscopic approach because excessive retraction at the entrance was impossible through a narrow bone window and unnecessary on account of a bright internal panoramic view being secured. No patients in the present study experienced homonymous hemianopsia postoperatively. Loss of orientation is also a major disadvantage of a conventional microscopic OTA because of the obliqueness of the approach.1,5,9 In the EEOTA, however, this disadvantage can be eliminated by the well-exposed operative view, with its precise imaging of surrounding structures on the same screen. Furthermore, there were almost no blind spots with the EEOTA, even in the roof and ipsilateral wall of the third ventricle, which often become blind spots in conventional microscopic OTA.5,9,15 In a conventional microscopic OTA, use of a transfalcine route has been reported to enhance exposure of the contralateral operative field.5 It is unknown whether this route would be efficacious for the EEOTA, as it was not used in the current series. However, it seems that such a route, which is thought to achieve its result by changing the trajectory through a large bone opening, might not be suited to the EEOTA. Retraction or incision of the splenium, which is occasionally performed in a conventional microscopic OTA for dissection of a portion in the third ventricle,1,5,9,15 was unnecessary in the present series. Despite the predicted difficulty in manipulation capability through such a narrow corridor in the EEOTA, there was virtually no
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Figure 5. Preoperative and postoperative magnetic resonance imaging. (A and B) Case 1. (C and D) Case 2. (E and F) Case 3. (G and H) Case 4. (I and J) Case 5. Axial, sagittal, and coronal sections of T1-weighted images with gadolinium enhancement in cases 2, 3, and 5; axial and sagittal sections of T1-weighted images with gadolinium enhancement
stress during surgery because the corridor was still wider compared with standard endoscopic surgeries, such as endonasal and transcylinder approaches. Ma and Lan20 also reported the possibility of a microscopic OTA through a keyhole bone window in cadaveric dissection, although they also asserted the necessity for a more delicate microsurgical technique. In contrast, the closely magnified views of the endoscopic procedure allow precise manipulation of instruments and finer dissection. Therefore, the EEOTA can be considered in certain ways an easier procedure than a conventional microscopic OTA and by no means an extraordinary procedure that can be performed only by selected surgeons, but rather one that has potential for extensive and routine application for surgeons familiar with endoscopic surgery. In the EEOTA, the possibility of bleeding from an unexposed bridging vein must be taken into consideration. One patient in the present series experienced bleeding from an unexposed bridging
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and sagittal section of T2-weighted image in case 1 and 4. Postoperative magnetic resonance imaging revealed gross total removal of the tumor in cases 1, 2, 3, and 5 (B, D, F, and J) and incomplete removal with the portion strongly adhered to the tectum and the great cerebral vein and its tributaries remaining in case 4 (H).
vein around the parieto-occipital fissure and was managed successfully by using an oblique scope and malleable instruments. The most effective countermeasure for this complication was considered to be simply to perform as gentle a retraction of the occipital lobe and as gradual drainage of CSF as possible. Even in a conventional microscopic OTA via a wide craniotomy, unexposed bridging veins inevitably pose the risk of bleeding. The endoscopic setting is likely to be more appropriate for dealing with bleeding from unexposed bridging veins. With the atypical teratoid rhabdoid tumor in the present series, we had to leave a portion of tumor remaining, which was hard and adhered strongly to the tectum and the great vein of Galen and its tributaries. In this case, we thought we achieved a result equivalent to a conventional microscopic approach in the same conditions, although this was conjecture only. Resection of a hard and large tumor through the narrow endoscopic corridor, especially for an extra large tumor that extends close to the
WORLD NEUROSURGERY, https://doi.org/10.1016/j.wneu.2019.08.038
TECHNICAL NOTE
opening, would present difficulties, although this could not be verified because no such tumors were included in the present study. At the same time, removal of such hard and extra large tumors must also be difficult using a conventional microscopic approach. All things considered, a tumor that is difficult to remove by a conventional microscopic approach, particularly a large, hard, and adhesive tumor, must also be considered difficult to remove when using the EEOTA. An infratentorial supracerebellar approach, such as the occipital transtentorial approach, is also a common procedure for pineal region tumors.1,5,6,9,10,13 Each has advantages and disadvantages, as reported elsewhere, and the choice to use either approach ultimately depends on the surgeon’s experience and preference, although the surgeon needs to take into account the size of the tumor, anatomic features of the tumor extension, the relationship of the tumor to the deep veins, and the intended extent of tumor removal.1,4-6,9,15,16 We selected the occipital transtentorial approach in the current series mainly based on preference. Use of an endoscope can have the capability to overcome certain disadvantages of either approach. Indeed, the utility of an endoscopic infratentorial supracerebellar approach for a pineal region tumor has already been reported.17,18 However, the difficulty with regard to positioning either the patient or the
REFERENCES 1. Azab WA, Nasim K, Salaheddin W. An overview of the current surgical options for pineal region tumors. Surg Neurol Int. 2014;5:39. 2. Bruce JN, Ogden AT. Surgical strategies for treating patients with pineal region tumors. J Neurooncol. 2004;69:221-236. 3. Konovalov AN, Pitskhelauri DI. Principles of treatment of the pineal region tumors. Surg Neurol. 2003;59:252-270. 4. Qi S, Fan J, Zhang X, Zhang H, Qiu B, Fang L. Radical resection of nongerminomatous pineal region tumor via the occipital transtentorial approach based on arachnoidal consideration: experience on a series of 143 patients. Acta Neurochir (Wien). 2014;156:2253-2262. 5. Sonabend AM, Bowden S, Bruce JN. Microsurgical resection of pineal region tumors. J Neurooncol. 2016;130:351-366. 6. Bruce JN, Stein BM. Surgical management of pineal region tumors. Acta Neurochir (Wien). 1995;134: 130-135. 7. Hernesniemi J, Romani R, Albayrak BS, et al. Microsurgical management of pineal region lesions: personal experience with 119 patients. Surg Neurol. 2008;70:576-583.
surgeon can be considered an unresolved disadvantage of an endoscopic infratentorial supracerebellar approach1,4,5,9,15,16 because it is essentially an approach from a suboccipital opening. No comparable difficulty arises in an OTA, which is an approach from a supratentorial opening. Instead, incising the tentorium is an unavoidable procedure in an OTA. For 2 patients in the present study, the presence of the tentorial sinus shortened the tentorial incision and narrowed the approach corridor. Endoscopic manipulation can be considered more favorable under such conditions than microscopic OTA.
CONCLUSIONS The EEOTA is a very promising technique for removal of pineal region tumors based on the advantages of endoscopic surgery, including less invasiveness, a bright panoramic magnified view, and the absence of blind spots. Furthermore, the EEOTA can be considered in some ways an easier procedure than a conventional microscopic OTA and to have the potential for extensive and routine application by surgeons familiar with endoscopic surgery, although a large number of patients will need to be evaluated in future studies to clarify the efficacy and safety of this approach.
8. Jamieson KG. Excision of J Neurosurg. 1971;35:550-553.
pineal
tumors.
9. Little KM, Friedman AH, Fukushima T. Surgical approaches to pineal region tumors. J Neurooncol. 2001;54:287-299. 10. Pluchino F, Broggi G, Fornari M, Franzini A, Solero CL, Allegranza A. Surgical approach to pineal tumours. Acta Neurochir (Wien). 1989;96: 26-31. 11. Poppen JL. The right occipital approach to a pinealoma. J Neurosurg. 1966;25:706-710. 12. Poppen JL, Marino R Jr. Pinealomas and tumors of the posterior portion of the third ventricle. J Neurosurg. 1968;28:357-364. 13. Stein BM. The infratentorial supracerebllar approach to pineal lesions. J Neurosurg. 1971;35: 197-202. 14. Yamamoto I, Kageyama N. Microsurgical anatomy of the pineal region. J Neurosurg. 1980;53:205-221. 15. Hart MG, Santarius T, Kirollos RW. How I do it— pineal surgery: supracerebellar infratentorial versus occipital transtentorial. Acta Neurochir (Wien). 2013;155:463-467. 16. Reid WS, Clark WK. Comparison of the infratentorial and transtentorial approaches to the pineal region. Neurosurgery. 1978;3:1-8.
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17. Shahinian H, Ra Y. Fully endoscopic resection of pineal region tumors. J Neurol Surg B Skull Base. 2013;74:114-117. 18. Tseng KY, Ma HI, Liu WH, Tang CT. Endoscopic supracerebellar infratentorial retropineal approach for tumor resection. World Neurosurg. 2012;77: 398-400. 19. Tanikawa M, Yamada H, Kitamura T, Sakata T, Mase M. Endoscopic occipital transtentorial approach for pineal region tumor. Oper Neurosurg. 2018;14:206-207. 20. Ma Y, Lan Q. An anatomic study of the occipital transtentorial keyhole approach. World Neurosurg. 2013;80:183-189.
Conflict of interest statement: The authors declare that the article content was composed in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. Received 15 May 2019; accepted 6 August 2019 Citation: World Neurosurg. (2019) 131:167-173. https://doi.org/10.1016/j.wneu.2019.08.038 Journal homepage: www.journals.elsevier.com/worldneurosurgery Available online: www.sciencedirect.com 1878-8750/$ - see front matter ª 2019 Elsevier Inc. All rights reserved.
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Exclusive Endoscopic Occipital Transtentorial Approach for Pineal Region Tumors Motoki Tanikawa1, Hiroshi Yamada1, Tomohiro Sakata1, Yasuhiko Hayashi2, Yasuo Sasagawa2, Tadashi Watanabe3, Tetsuya Nagatani3, Mitsuhito Mase1
OBJECTIVE: Removal of pineal region tumors, which are deeply placed and encircled by intricate neurovascular structures, is challenging to neurosurgeons. The aim of this study was to present our experience with the exclusive endoscopic occipital transtentorial approach (EEOTA) used for removal of pineal region tumors.
-
METHODS: A retrospective review was performed of patients who underwent surgery using the EEOTA to remove pineal region tumors from May 2016 to August 2018. The details of the EEOTA procedure were confirmed.
-
RESULTS: Five patients underwent surgery via the EEOTA for treatment of pineal region tumors. In all cases, it was possible to perform the EEOTA less invasively through a keyhole craniotomy approximately 2.0e2.5 cm in size. The EEOTA produced an excellent view and provided natural and automatic orientation. There was essentially no blind spot in this procedure, even for the floor or ipsilateral wall of the third ventricle. Gross total resection was achieved in 4 cases. In the patient with atypical teratoid rhabdoid tumor, we abandoned gross total resection because of a hardened adhesion to the tectum and the great cerebral vein and its tributaries. Two patients presented with transient upper gaze palsy immediately after surgery but experienced complete recovery during the follow-up period.
-
CONCLUSIONS: The EEOTA is a very promising technique for removal of pineal region tumors and has the
-
Key words Endoscope - Occipital transtentorial approach - Pineal region tumor -
Abbreviations and Acronyms CSF: Cerebrospinal fluid EEOTA: Exclusive endoscopic occipital transtentorial approach OTA: Occipital transtentorial approach PR: Partial resection From the 1Department of Neurosurgery, Nagoya City University Graduate School of Medical Sciences, Nagoya; 2Department of Neurosurgery, Kanazawa University Graduate School of
WORLD NEUROSURGERY 131: 167-173, NOVEMBER 2019
potential for extensive and routine application for surgeons familiar with endoscopic surgery.
INTRODUCTION
A
ggressive surgical resection is a mainstay of management for almost all pineal region tumors except for pure germinoma and primary lymphoma, which have exquisite sensitivity to chemoradiotherapy.1-5 Advances in microsurgical technique and postoperative care in recent years have resulted in dramatic improvement of outcomes in the treatment of pineal region tumors.1-13 However, these tumors, which are deep-seated and surrounded by complicated and critical neurovascular structures,14 remain surgically challenging to neurosurgeons. Therefore, even an incremental refinement of the surgical procedure would be welcomed.
The occipital transtentorial approach (OTA), which is generally accepted to have originated from Poppen’s procedure in 196611,12 and later refined by Jamieson in 1971,8 is currently one of the most common operative techniques for pineal region tumors.1,3-5,7,9,15,16 This procedure has become firmly established over the past several decades; however, it still harbors some disadvantages, including the necessity of a relatively large bone opening, difficult orientation owing to the obliqueness of the approach, retraction injury to the occipital lobe and corpus callosum, and blind spots at the ipsilateral wall and the roof of the third ventricle.1,4-6,9,15 At the present time, endoscopy is gradually becoming used on a wide scale in neurosurgery and has replaced the microscope as the primary surgical tool in some procedures. Because the pineal region is positioned at the
Medical Sciences, Ishikawa; and 3Department of Neurosurgery, Japanese Red Cross Nagoya Daini Hospital, Nagoya, Japan To whom correspondence should be addressed: Motoki Tanikawa, M.D. [E-mail: [email protected]] Supplementary digital content available online. Citation: World Neurosurg. (2019) 131:167-173. https://doi.org/10.1016/j.wneu.2019.08.038 Journal homepage: www.journals.elsevier.com/world-neurosurgery Available online: www.sciencedirect.com 1878-8750/$ - see front matter ª 2019 Elsevier Inc. All rights reserved.
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TECHNICAL NOTE
Table 1. Characteristics of Patients Who Underwent Exclusive Endoscopic Occipital Transtentorial Approach for Pineal Region Tumors Case
Age, Sex
Clinical Presentation
Pathology
Maximum Diameter (mm)
Extent of Resection
Complications
1
10 years, male
Headache
Immature teratoma
35
GTR
None
2
66 years, female
Gait disturbance
Pineocytoma
30
GTR
Transient upper gaze palsy
3
7 years, male
Somnolence, diplopia
Immature teratoma
38
GTR
Transient upper gaze palsy
4
9 months, female
Macrocephaly
ATRT
48
PR
Asymptomatic subdural hygroma
5
21 years, male
Diplopia
Yolk sac tumor
15
GTR
None
GTR, gross total resection; ATRT, atypical teratoid rhabdoid tumor; PR, partial resection.
geometric center of the brain, and the corridor for a surgical approach to this region tends to be necessarily narrowed, deepened, and restricted, an endoscopic approach is clearly an appropriate procedure for these conditions and can be considered a potential solution to the disadvantages of a conventional microscopic approach. Some reports have described the effectiveness of an endoscopic infratentorial supracerebellar approach for pineal lesions,17,18 which is another common treatment for pineal region tumors.1,5,6,9,10,13 In May 2016, we adopted an exclusive endoscopic occipital transtentorial approach (EEOTA) for a pineal region immature teratoma for the first time, after thorough trials through cadaveric dissection.19 We describe the first case series of patients with pineal region tumor who were treated by EEOTA to assess the usefulness and elucidate the details of this procedure.
MATERIALS AND METHODS From May 2016 to August 2018, 5 patients in the neurosurgery departments of Nagoya City University Hospital,
Figure 1. Exclusive endoscopic occipital transtentorial approach for pineal immature teratoma. (A) Dural opening just after gross total removal of the tumor. Right occipital lobe was protected by covering
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Kanazawa University Hospital, and Japanese Red Cross Nagoya Daini Hospital underwent surgery using EEOTA for pineal region tumors (Table 1). Complete informed consent was obtained from all 5 patients. We performed a retrospective chart review of the patients who underwent surgery using EEOTA, and the pertinent data have been compiled and are presented in this study. The study protocol was approved by the institutional review board or human research ethics committee at each participating institution. Surgical Procedure Patients were placed in a prone position with the head tilted and rotated toward the contralateral side and slightly extended to directly face the operator, who maintained both hands at a natural angle ergonomically. An occipital midline skin incision and keyhole craniotomy approximately 2.0e2.5 cm in size were made (Figure 1AeC). The dura mater was
with surgical patties. (B and C) All procedures were performed through a keyhole craniotomy 2.0e2.5 cm in size. Sup. Sag. Sinus, superior sagittal sinus; Tent., tentorium cerebelli; Occip. Lobe, occipital lobe.
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Figure 2. (A and B) Twisted spatula facilitates holding the occipital lobe obliquely upward in parallel with the tentorium, preventing interference with manipulations. (C) After retracting the right occipital lobe, sufficient space for manipulations was secured. Prominent tentorial sinuses were
opened with a semicircular incision, based on the superior sagittal sinus extending the full width of the craniotomy. An endoscope, rigid and fixed with an exclusive holder (HD EndoArm; Olympus Co., Tokyo, Japan), was subsequently introduced. We initially used a 4-mm-diameter and 0 angle scope, fixed at the upper side of the operative field, and operative instruments in both hands, including bipolar forceps, a microdissector, microscissors, and a suction device, were used almost in parallel in the lower operative field (Figure 2C). The falx cerebri, straight sinus, and tentorium cerebelli were identified in turn, while retracting the occipital lobe gently and in a stepwise fashion by a brain spatula, fixed with a self-retaining retractor, which was twisted (Figure 2AeC) to enable the holding of the occipital lobe obliquely upward in parallel with the tentorium and to reduce interference with manipulations. At that point, drainage of cerebrospinal fluid (CSF) from a catheter, if it had been placed beforehand, contributed to the smoothness of this process. After reaching the tentorial edge, the quadrigeminal cistern was identified, and the CSF was drained so that sufficient space for all manipulation was obtained. The tentorium was incised as far from the straight sinus as possible at the edge and as long as possible in the direction of the sinus confluence. In cases where the tentorial sinus was highly developed, however, the incision needed to follow a different direction and to extend as closely as possible to the straight sinus. Reflecting the incised tentorium on the falx cerebri, the cerebellum and the terminal portion of the great cerebral vein were exposed (Figure 3A). Then, using a 30 oblique scope inserted parallel to the medial surface of the occipital lobe, the adhesion between the cerebellum and the contralateral
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identified. Inset image shows positional relationship between the scope and instruments in both hands. Str. Sinus, straight sinus; Tent. Sinus, tentorial sinus; Tent., tentorium cerebelli.
tentorium was clearly exposed and dissected thoroughly (Figure 3B) so that a space between the tentorium and the cerebellum was created. In this process, the surgical instruments in both hands were used in the medial operative field and positioned vertically. This was a crucial process for EEOTA because advancing the endoscope into the space created produced comprehensive imaging of the surrounding structures on the same screen, including the cerebellum, the great cerebral vein and its tributaries, and the tectum, and rendered precise orientation natural and automatic (Figure 3C and D and Figure 4A). After a straight scope was introduced into the created space, the great cerebral vein and tributaries could be identified through the thickened arachnoid membrane of the quadrigeminal cistern (Figure 3C), which was then incised broadly by instruments in both hands positioned in parallel in the lower operative field. Dissecting the cerebellomesencephalic fissure thoroughly, the tectum, pineal body, and tumor were exposed, and a sufficient space for the manipulation was secured (Figure 3D and Figure 4A). For dissection of the deepest site of the cerebellomesencephalic fissure, especially on the ipsilateral side, the positioning of an oblique scope in the upper operative field and the use of the lower operative field for manipulation of instruments in both hands proved to be effective (Figure 3D). Precentral cerebellar veins were sacrificed if they obstructed the operative view and manipulation. Dissection of the tumor from the surrounding tissue, including the tectum, habenula, posterior commissure, internal cerebral vein, and thalamus, proceeded meticulously (Figure 4BeE). A 30 oblique scope positioned at the opposite side of the operative field produced an excellent operative view in the
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Figure 3. Exclusive endoscopic occipital transtentorial approach for pineal immature teratoma. Inset images show positional relationship between the scope and instruments in both hands. (A) Reflecting the incised tentorium on the falx cerebri, the cerebellum and the terminal portion of the great cerebral vein (the great vein of Galen) were exposed. (B) Inserting a 30 oblique scope parallel to the medial surface of the occipital lobe, the adhesion between the cerebellum and the contralateral tentorium was clearly exposed and dissected thoroughly so that a space between the tentorium and the cerebellum was created. In the process, surgical instruments in both hands were used in the medial operative field and positioned vertically. (C) After a straight scope was introduced in the created space, the great cerebral vein and
tributaries could be identified through the thickened arachnoid membrane of the quadrigeminal cistern, which was then incised broadly by instruments positioned in parallel in both hands in the lower operative field. (D) For dissection of the deepest site of the cerebellomesencephalic fissure, especially on the ipsilateral side, positioning an oblique scope in the upper operative field and using the lower operative field for manipulation of instruments in both hands were effective. V. of Galen, great vein of Galen; Occip. Lobe, occipital lobe; Str. Sinus, straight sinus; Contralat. Tent., contralateral tentorium; Qad. Cist., quadrigeminal cistern; Int. Occip. V., internal occipital vein; Basal V., basal vein.
third ventricle and allowed precise manipulation. When the mass occupied the operative space, central debulking and piece-by-piece dissection were performed to improve management of the tumor (Video 1).
anesthesia, allowed manipulation to proceed smoothly. In all cases, it was possible to perform the EEOTA less invasively through a keyhole craniotomy. In 4 cases, achieve gross total resection was achieved (Figures 4E and 5 and Table 1). In 1 patient with atypical teratoid rhabdoid tumor, we abandoned gross total resection owing to a deep solid portion that was hardened and adhered RESULTS strongly to the tectum and the great cerebral vein The present study included 5 patients, 3 male and 2 Video available at and its tributaries (Figure 5G and H). Bleeding from www.sciencedirect.com female, ranging in age from 9 months to 66 years an unexposed bridging vein occurred in 1 patient (Table 1). The maximum diameter of tumors ranged but was well controlled with no difficulty using the from 15 to 48 mm. All patients had hydrocephalus oblique scope and malleable instruments. The tentorial incision and received endoscopic third ventriculostomy and biopsy, and was shorter than we had expected owing to the presence of 2 were treated by neoadjuvant chemoradiotherapy before the tentorial sinus in 2 patients (Figure 2C). Even in these cases, tumor removal via the EEOTA. Histologically, we identified 2 by incising the tentorium as close to the straight sinus as immature teratomas, 1 pineocytoma, 1 atypical teratoid possible and taking advantage of endoscopic surgery, we could rhabdoid tumor, and 1 yolk sac tumor. accomplish the subsequent procedures smoothly. Two patients presented with upper gaze palsy immediately after surgery, but In 3 cases (cases 2, 3, and 5), draining CSF through lumbar they experienced complete recovery during the follow-up drainage, which was placed immediately after induction of
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Figure 4. Exclusive endoscopic occipital transtentorial approach for pineal immature teratoma. Inset images show positional relationship between scope and instruments in both hands. (A) Dissecting the cerebellomesencephalic fissure thoroughly, the tectum, pineal body, and tumor were exposed, and sufficient space for manipulation was secured. (BeD) Dissection of the tumor from surrounding tissue, including the tectum, habenula, posterior commissure, nternal cerebral
period. One infant case (case 4) had an asymptomatic subdural hygroma postoperatively and was followed with no treatment being necessary (Table 1).
DISCUSSION We present the first case series of patients who underwent surgery via the EEOTA for treatment of a pineal region tumor. In 2016, our team documented the first EEOTA for a pineal immature teratoma,19 which was performed after elaborate trials through cadaveric dissection. Thereafter, we very carefully selected candidates for the surgery and have so far performed the EEOTA in 5 patients with pineal region tumor. We found the EEOTA to be a very promising technique with the advantages of endoscopic surgery, and although it has some similarities to a conventional microscopic OTA, it is substantially different. A conventional microscopic OTA is performed through a relatively large skin flap and bone window, which is usually required from the parieto-occipital fissure to the transverse sinus in a craniocaudal direction and several centimeters from the superior sagittal sinus in width in the horizontal direction.1,5,9 By contrast, the EEOTA described in this study could be performed via a short linear skin incision and a keyhole craniotomy. Furthermore, the retraction of the occipital lobe, which is indispensable for an OTA but risks causing homonymous hemianopsia,4,5,9,15 can also be
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vein, and thalamus, proceeded carefully. A 30 oblique scope positioned at the opposite side of the operative field produced an excellent operative view in the third ventricle and allowed precise manipulation. (E) Final view after gross total removal of the tumor. Int. Occip. V., internal occipital vein; V. of Galen, great vein of Galen; Precent. Cer. V., precentral cerebellar vein; Basal V., basal vein; Int. Cer. V., internal cerebral vein; Mam. Body, mammillary body.
reduced in the endoscopic approach because excessive retraction at the entrance was impossible through a narrow bone window and unnecessary on account of a bright internal panoramic view being secured. No patients in the present study experienced homonymous hemianopsia postoperatively. Loss of orientation is also a major disadvantage of a conventional microscopic OTA because of the obliqueness of the approach.1,5,9 In the EEOTA, however, this disadvantage can be eliminated by the well-exposed operative view, with its precise imaging of surrounding structures on the same screen. Furthermore, there were almost no blind spots with the EEOTA, even in the roof and ipsilateral wall of the third ventricle, which often become blind spots in conventional microscopic OTA.5,9,15 In a conventional microscopic OTA, use of a transfalcine route has been reported to enhance exposure of the contralateral operative field.5 It is unknown whether this route would be efficacious for the EEOTA, as it was not used in the current series. However, it seems that such a route, which is thought to achieve its result by changing the trajectory through a large bone opening, might not be suited to the EEOTA. Retraction or incision of the splenium, which is occasionally performed in a conventional microscopic OTA for dissection of a portion in the third ventricle,1,5,9,15 was unnecessary in the present series. Despite the predicted difficulty in manipulation capability through such a narrow corridor in the EEOTA, there was virtually no
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Figure 5. Preoperative and postoperative magnetic resonance imaging. (A and B) Case 1. (C and D) Case 2. (E and F) Case 3. (G and H) Case 4. (I and J) Case 5. Axial, sagittal, and coronal sections of T1-weighted images with gadolinium enhancement in cases 2, 3, and 5; axial and sagittal sections of T1-weighted images with gadolinium enhancement
stress during surgery because the corridor was still wider compared with standard endoscopic surgeries, such as endonasal and transcylinder approaches. Ma and Lan20 also reported the possibility of a microscopic OTA through a keyhole bone window in cadaveric dissection, although they also asserted the necessity for a more delicate microsurgical technique. In contrast, the closely magnified views of the endoscopic procedure allow precise manipulation of instruments and finer dissection. Therefore, the EEOTA can be considered in certain ways an easier procedure than a conventional microscopic OTA and by no means an extraordinary procedure that can be performed only by selected surgeons, but rather one that has potential for extensive and routine application for surgeons familiar with endoscopic surgery. In the EEOTA, the possibility of bleeding from an unexposed bridging vein must be taken into consideration. One patient in the present series experienced bleeding from an unexposed bridging
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and sagittal section of T2-weighted image in case 1 and 4. Postoperative magnetic resonance imaging revealed gross total removal of the tumor in cases 1, 2, 3, and 5 (B, D, F, and J) and incomplete removal with the portion strongly adhered to the tectum and the great cerebral vein and its tributaries remaining in case 4 (H).
vein around the parieto-occipital fissure and was managed successfully by using an oblique scope and malleable instruments. The most effective countermeasure for this complication was considered to be simply to perform as gentle a retraction of the occipital lobe and as gradual drainage of CSF as possible. Even in a conventional microscopic OTA via a wide craniotomy, unexposed bridging veins inevitably pose the risk of bleeding. The endoscopic setting is likely to be more appropriate for dealing with bleeding from unexposed bridging veins. With the atypical teratoid rhabdoid tumor in the present series, we had to leave a portion of tumor remaining, which was hard and adhered strongly to the tectum and the great vein of Galen and its tributaries. In this case, we thought we achieved a result equivalent to a conventional microscopic approach in the same conditions, although this was conjecture only. Resection of a hard and large tumor through the narrow endoscopic corridor, especially for an extra large tumor that extends close to the
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opening, would present difficulties, although this could not be verified because no such tumors were included in the present study. At the same time, removal of such hard and extra large tumors must also be difficult using a conventional microscopic approach. All things considered, a tumor that is difficult to remove by a conventional microscopic approach, particularly a large, hard, and adhesive tumor, must also be considered difficult to remove when using the EEOTA. An infratentorial supracerebellar approach, such as the occipital transtentorial approach, is also a common procedure for pineal region tumors.1,5,6,9,10,13 Each has advantages and disadvantages, as reported elsewhere, and the choice to use either approach ultimately depends on the surgeon’s experience and preference, although the surgeon needs to take into account the size of the tumor, anatomic features of the tumor extension, the relationship of the tumor to the deep veins, and the intended extent of tumor removal.1,4-6,9,15,16 We selected the occipital transtentorial approach in the current series mainly based on preference. Use of an endoscope can have the capability to overcome certain disadvantages of either approach. Indeed, the utility of an endoscopic infratentorial supracerebellar approach for a pineal region tumor has already been reported.17,18 However, the difficulty with regard to positioning either the patient or the
REFERENCES 1. Azab WA, Nasim K, Salaheddin W. An overview of the current surgical options for pineal region tumors. Surg Neurol Int. 2014;5:39. 2. Bruce JN, Ogden AT. Surgical strategies for treating patients with pineal region tumors. J Neurooncol. 2004;69:221-236. 3. Konovalov AN, Pitskhelauri DI. Principles of treatment of the pineal region tumors. Surg Neurol. 2003;59:252-270. 4. Qi S, Fan J, Zhang X, Zhang H, Qiu B, Fang L. Radical resection of nongerminomatous pineal region tumor via the occipital transtentorial approach based on arachnoidal consideration: experience on a series of 143 patients. Acta Neurochir (Wien). 2014;156:2253-2262. 5. Sonabend AM, Bowden S, Bruce JN. Microsurgical resection of pineal region tumors. J Neurooncol. 2016;130:351-366. 6. Bruce JN, Stein BM. Surgical management of pineal region tumors. Acta Neurochir (Wien). 1995;134: 130-135. 7. Hernesniemi J, Romani R, Albayrak BS, et al. Microsurgical management of pineal region lesions: personal experience with 119 patients. Surg Neurol. 2008;70:576-583.
surgeon can be considered an unresolved disadvantage of an endoscopic infratentorial supracerebellar approach1,4,5,9,15,16 because it is essentially an approach from a suboccipital opening. No comparable difficulty arises in an OTA, which is an approach from a supratentorial opening. Instead, incising the tentorium is an unavoidable procedure in an OTA. For 2 patients in the present study, the presence of the tentorial sinus shortened the tentorial incision and narrowed the approach corridor. Endoscopic manipulation can be considered more favorable under such conditions than microscopic OTA.
CONCLUSIONS The EEOTA is a very promising technique for removal of pineal region tumors based on the advantages of endoscopic surgery, including less invasiveness, a bright panoramic magnified view, and the absence of blind spots. Furthermore, the EEOTA can be considered in some ways an easier procedure than a conventional microscopic OTA and to have the potential for extensive and routine application by surgeons familiar with endoscopic surgery, although a large number of patients will need to be evaluated in future studies to clarify the efficacy and safety of this approach.
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9. Little KM, Friedman AH, Fukushima T. Surgical approaches to pineal region tumors. J Neurooncol. 2001;54:287-299. 10. Pluchino F, Broggi G, Fornari M, Franzini A, Solero CL, Allegranza A. Surgical approach to pineal tumours. Acta Neurochir (Wien). 1989;96: 26-31. 11. Poppen JL. The right occipital approach to a pinealoma. J Neurosurg. 1966;25:706-710. 12. Poppen JL, Marino R Jr. Pinealomas and tumors of the posterior portion of the third ventricle. J Neurosurg. 1968;28:357-364. 13. Stein BM. The infratentorial supracerebllar approach to pineal lesions. J Neurosurg. 1971;35: 197-202. 14. Yamamoto I, Kageyama N. Microsurgical anatomy of the pineal region. J Neurosurg. 1980;53:205-221. 15. Hart MG, Santarius T, Kirollos RW. How I do it— pineal surgery: supracerebellar infratentorial versus occipital transtentorial. Acta Neurochir (Wien). 2013;155:463-467. 16. Reid WS, Clark WK. Comparison of the infratentorial and transtentorial approaches to the pineal region. Neurosurgery. 1978;3:1-8.
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17. Shahinian H, Ra Y. Fully endoscopic resection of pineal region tumors. J Neurol Surg B Skull Base. 2013;74:114-117. 18. Tseng KY, Ma HI, Liu WH, Tang CT. Endoscopic supracerebellar infratentorial retropineal approach for tumor resection. World Neurosurg. 2012;77: 398-400. 19. Tanikawa M, Yamada H, Kitamura T, Sakata T, Mase M. Endoscopic occipital transtentorial approach for pineal region tumor. Oper Neurosurg. 2018;14:206-207. 20. Ma Y, Lan Q. An anatomic study of the occipital transtentorial keyhole approach. World Neurosurg. 2013;80:183-189.
Conflict of interest statement: The authors declare that the article content was composed in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. Received 15 May 2019; accepted 6 August 2019 Citation: World Neurosurg. (2019) 131:167-173. https://doi.org/10.1016/j.wneu.2019.08.038 Journal homepage: www.journals.elsevier.com/worldneurosurgery Available online: www.sciencedirect.com 1878-8750/$ - see front matter ª 2019 Elsevier Inc. All rights reserved.
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