Access to the third ventricle is a veritable challenge to neurosurgeons. In this context, anatomical and morphometric studies are useful for establishing the limitations and advantages of a particular surgical approach. The transchoroidal approach is versatile and provides adequate exposure of the middle and posterior regions of the third ventricle. However, the fornix column limits the exposure of the anterior region of the third ventricle. There is evidence that the unilateral section of the fornix column has little effect on cognitive function. This study compared the anatomical exposure afforded by the transforniceal-transchoroidal approach with that of the transchoroidal approach. In addition, a morphometric evaluation of structures that are relevant to and common in the 2 approaches was performed.
The anatomical exposure provided by the transcallosal-transchoroidal and transcallosal-transforniceal-transchoroidal approaches was compared in 8 fresh cadavers, using a neuronavigation system. The working area, microsurgical exposure area, and angular exposure on the longitudinal and transversal planes of 2 anatomical targets (tuber cinereum and cerebral aqueduct) were compared. Additionally, the thickness of the right frontal lobe parenchyma, thickness of the corpus callosum trunk, and longitudinal diameter of the interventricular foramen were measured. The values obtained were submitted to statistical analysis using the Wilcoxon test.
In the quantitative evaluation, compared with the transchoroidal approach, the transforniceal-transchoroidal approach provided a greater mean working area (transforniceal-transchoroidal 150 ± 11 mm2; transchoroidal 121 ± 8 mm2; p < 0.05), larger mean microsurgical exposure area (transforniceal-transchoroidal 101 ± 9 mm2; transchoroidal 80 ± 5 mm2; p < 0.05), larger mean angular exposure area on the longitudinal plane for the tuber cinereum (transforniceal-transchoroidal 71° ± 7°; transchoroidal 64° ± 6°; p < 0.05), and larger mean angular exposure area on the longitudinal plane for the cerebral aqueduct (transforniceal-transchoroidal 62° ± 6°; transchoroidal 55° ± 5°; p < 0.05). No differences were observed in angular exposure along the transverse axis for either anatomical target (tuber cinereum and cerebral aqueduct; p > 0.05). The mean thickness of the right frontal lobe parenchyma was 35 ± 3 mm, the mean thickness of the corpus callosum trunk was 10 ± 1 mm, and the mean longitudinal diameter of the interventricular foramen was 4.6 ± 0.4 mm. In the qualitative assessment, it was noted that the transforniceal-transchoroidal approach led to greater exposure of the third ventricle anterior region structures. There was no difference between approaches in the exposure of the structures of the middle and posterior region.
The transforniceal-transchoroidal approach provides greater surgical exposure of the third ventricle anterior region than that offered by the transchoroidal approach. In the population studied, morphometric analysis established mean values for anatomical structures common to both approaches.
AggletonJP, McMackinD, CarpenterK, HornakJ, KapurN, HalpinS, : Differential cognitive effects of colloid cysts in the third ventricle that spare or compromise the fornix. 123:800–815, 200010.1093/brain/123.4.80010734011)| false
BellottiCPappadàGSaniROliveriGStangalinoC: The transcallosal approach for lesions affecting the lateral and third ventricles. Surgical considerations and results in a series of 42 cases. Acta Neurochir (Wien)111:103–1071991
BellottiC, PappadàG, SaniR, OliveriG, StangalinoC: The transcallosal approach for lesions affecting the lateral and third ventricles. Surgical considerations and results in a series of 42 cases. 111:103–107, 199110.1007/BF01400496)| false
FigueiredoEGZabramskiJMDeshmukhPCrawfordNRSpetzlerRFPreulMC: Comparative analysis of anterior petrosectomy and transcavernous approaches to retrosellar and upper clival basilar artery aneurysms. Neurosurgery58:1 SupplONS13–ONS212006
HernesniemiJ, LeivoS: Management outcome in third ventricular colloid cysts in a defined population: a series of 40 patients treated mainly by transcallosal microsurgery. 45:2–14, 199610.1016/0090-3019(95)00379-7)| false
NagasawaSMiyakeHOhtaT: [Transcallosal and transcortical approaches for tumors at the anterior part of the lateral ventricle: relations between visualized and ventricular size.]. No Shinkei Geka25:321–3271997. (Jpn)
NagasawaS, MiyakeH, OhtaT: [Transcallosal and transcortical approaches for tumors at the anterior part of the lateral ventricle: relations between visualized and ventricular size.]. 25:321–327, 1997. (Jpn)9125715)| false
PatelP, Cohen-GadolAA, BoopF, KlimoPJr: Technical strategies for the transcallosal transforaminal approach to third ventricle tumors: expanding the operative corridor. 14:365–371, 201410.3171/2014.6.PEDS145225105512)| false
PeltierJVerclytteSDelmaireCDeramondHPruvoJPLe GarsD: Microsurgical anatomy of the ventral callosal radiations: new destination, correlations with diffusion tensor imaging fiber-tracking, and clinical relevance. J Neurosurg112:512–5192010
PeltierJ, VerclytteS, DelmaireC, DeramondH, PruvoJP, Le GarsD, : Microsurgical anatomy of the ventral callosal radiations: new destination, correlations with diffusion tensor imaging fiber-tracking, and clinical relevance. 112:512–519, 20101961297410.3171/2009.6.JNS081712)| false
TsivilisD, VannSD, DenbyC, RobertsN, MayesAR, MontaldiD, : A disproportionate role for the fornix and mammillary bodies in recall versus recognition memory. 11:834–842, 200810.1038/nn.214918552840)| false
WenHT, RhotonALJr, de OliveiraE: Transchoroidal approach to the third ventricle: an anatomic study of the choroidal fissure and its clinical application. 42:1205–1219, 199810.1097/00006123-199806000-000019632178)| false
WinklerPA, WeisS, BüttnerA, RaabeA, AmiridzeN, ReulenHJ: The transcallosal interforniceal approach to the third ventricle: anatomic and microsurgical aspects. 40:973–982, 199710.1097/00006123-199705000-000209149256)| false
WoiciechowskyC, VogelS, LehmannR, StaudtJ: Transcallosal removal of lesions affecting the third ventricle: an anatomic and clinical study. 36:117–123, 1995770814710.1227/00006123-199501000-00015)| false