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Surgical approaches for brainstem tumors in pediatric patients.

Cavalheiro S, Yagmurlu K, da Costa MD, Nicácio JM, Rodrigues TP, Chaddad-Neto F, Rhoton AL - Childs Nerv Syst (2015)

Bottom Line: Eleven previously described "safe entry zones" were used.We describe a new safe zone located in the superior ventral pons, which we named supratrigeminal approach.The operative mortality seen in the first 2 months after surgery was 1.9 % (four patients), and the morbidity rate was 21.2 %.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurosurgery, Pediatric Oncology Institute, Federal University of Sao Paulo, Sao Paulo, Brazil. sergiocavalheironeuro@gmail.com.

ABSTRACT

Purpose: To analyze the pathways to brainstem tumors in childhood, as well as safe entry zones.

Method: We conducted a retrospective study of 207 patients less than 18 years old who underwent brainstem tumor resection by the first author (Cavalheiro, S.) at the Neurosurgical Service and Pediatric Oncology Institute of the São Paulo Federal University from 1991 to 2011.

Results: Brainstem tumors corresponded to 9.1 % of all pediatric tumors operated in that same period. Eleven previously described "safe entry zones" were used. We describe a new safe zone located in the superior ventral pons, which we named supratrigeminal approach. The operative mortality seen in the first 2 months after surgery was 1.9 % (four patients), and the morbidity rate was 21.2 %.

Conclusions: Anatomic knowledge of intrinsic and extrinsic brainstem structures, in association with a refined neurosurgical technique assisted by intraoperative monitoring, and surgical planning based on magnetic resonance imaging (MRI) and tractography have allowed for wide resection of brainstem lesions with low mortality and acceptable morbidity rates.

No MeSH data available.


Related in: MedlinePlus

a, b 2-year-old patient evolving to tetraparesis. A large tumor anterior to the medulla is present. The far lateral approach and trans-olivary point of entry was used for resection of a pilocytic astrocytoma. c, d Eleven-year follow-up, showing no evidence of tumor
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Fig20: a, b 2-year-old patient evolving to tetraparesis. A large tumor anterior to the medulla is present. The far lateral approach and trans-olivary point of entry was used for resection of a pilocytic astrocytoma. c, d Eleven-year follow-up, showing no evidence of tumor

Mentions: The medulla is perhaps the most difficult structure to be approached, due to the high density of nuclei located therein, the cranial nerve pairs from IX to XII. Lesions located in the anterior portion of the medulla are accessed via a far-lateral approach. This approach was initially described by Heros [27] and by George et al. [21] among approaches to the craniovertebral junction. There are many variations of approaches according to the part of condyle to be removed: transcondylar, supracondylar, and paracondylar exposure [56]. In children, it is possible to access the anterior portion of the medulla without removing the condyles (Fig. 20). The section of the dentate ligament next to the entry of the vertebral artery facilitates mobility of the medulla, and so the lateral access becomes easier, as it avoids opening the condyle. Access to the brainstem may be anterior to the olive, posterior to the olive, or sometimes through the olivary body, preferably in the postero-olivary sulcus (Figs. 20 and 21). It is possible to enter the medulla via the anterolateral sulcus. This entry zone is along the pre-olivary sulcus, between the caudal hypoglossal and the rostral C1 rootlets. It lies very near the pyramidal tract, next to its decussation, and should be used only for exophytic lesions [9]. The retro-olivary sulcus is a safe entry area. According to Recalde et al. [53], the olivary body offers a surgical space of approximately 13.5 mm in the craniocaudal axis, 7 mm in the transverse axis, and 2.5 mm in the anterodorsal axis. The entry zone is through the post-olivary sulcus located between the olive and the inferior cerebellar peduncle ventral to the glossopharyngeal and vagus rootlets [53].Fig. 20


Surgical approaches for brainstem tumors in pediatric patients.

Cavalheiro S, Yagmurlu K, da Costa MD, Nicácio JM, Rodrigues TP, Chaddad-Neto F, Rhoton AL - Childs Nerv Syst (2015)

a, b 2-year-old patient evolving to tetraparesis. A large tumor anterior to the medulla is present. The far lateral approach and trans-olivary point of entry was used for resection of a pilocytic astrocytoma. c, d Eleven-year follow-up, showing no evidence of tumor
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4564452&req=5

Fig20: a, b 2-year-old patient evolving to tetraparesis. A large tumor anterior to the medulla is present. The far lateral approach and trans-olivary point of entry was used for resection of a pilocytic astrocytoma. c, d Eleven-year follow-up, showing no evidence of tumor
Mentions: The medulla is perhaps the most difficult structure to be approached, due to the high density of nuclei located therein, the cranial nerve pairs from IX to XII. Lesions located in the anterior portion of the medulla are accessed via a far-lateral approach. This approach was initially described by Heros [27] and by George et al. [21] among approaches to the craniovertebral junction. There are many variations of approaches according to the part of condyle to be removed: transcondylar, supracondylar, and paracondylar exposure [56]. In children, it is possible to access the anterior portion of the medulla without removing the condyles (Fig. 20). The section of the dentate ligament next to the entry of the vertebral artery facilitates mobility of the medulla, and so the lateral access becomes easier, as it avoids opening the condyle. Access to the brainstem may be anterior to the olive, posterior to the olive, or sometimes through the olivary body, preferably in the postero-olivary sulcus (Figs. 20 and 21). It is possible to enter the medulla via the anterolateral sulcus. This entry zone is along the pre-olivary sulcus, between the caudal hypoglossal and the rostral C1 rootlets. It lies very near the pyramidal tract, next to its decussation, and should be used only for exophytic lesions [9]. The retro-olivary sulcus is a safe entry area. According to Recalde et al. [53], the olivary body offers a surgical space of approximately 13.5 mm in the craniocaudal axis, 7 mm in the transverse axis, and 2.5 mm in the anterodorsal axis. The entry zone is through the post-olivary sulcus located between the olive and the inferior cerebellar peduncle ventral to the glossopharyngeal and vagus rootlets [53].Fig. 20

Bottom Line: Eleven previously described "safe entry zones" were used.We describe a new safe zone located in the superior ventral pons, which we named supratrigeminal approach.The operative mortality seen in the first 2 months after surgery was 1.9 % (four patients), and the morbidity rate was 21.2 %.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurosurgery, Pediatric Oncology Institute, Federal University of Sao Paulo, Sao Paulo, Brazil. sergiocavalheironeuro@gmail.com.

ABSTRACT

Purpose: To analyze the pathways to brainstem tumors in childhood, as well as safe entry zones.

Method: We conducted a retrospective study of 207 patients less than 18 years old who underwent brainstem tumor resection by the first author (Cavalheiro, S.) at the Neurosurgical Service and Pediatric Oncology Institute of the São Paulo Federal University from 1991 to 2011.

Results: Brainstem tumors corresponded to 9.1 % of all pediatric tumors operated in that same period. Eleven previously described "safe entry zones" were used. We describe a new safe zone located in the superior ventral pons, which we named supratrigeminal approach. The operative mortality seen in the first 2 months after surgery was 1.9 % (four patients), and the morbidity rate was 21.2 %.

Conclusions: Anatomic knowledge of intrinsic and extrinsic brainstem structures, in association with a refined neurosurgical technique assisted by intraoperative monitoring, and surgical planning based on magnetic resonance imaging (MRI) and tractography have allowed for wide resection of brainstem lesions with low mortality and acceptable morbidity rates.

No MeSH data available.


Related in: MedlinePlus