Introduction: We investigated the association between two newly measured parameters,infundibulochiasmatic (IC) angle and anterior third ventricular height (TVH) and the success of ETV in the early and late postoperative periods in order to establish a set of parameters for the evaluation of the success of the procedure and a plan for radiological follow-up.
Methods: CISS MRI in 78 consecutive patients undergoing ETV due to obstructive hydrocephalus between 2010 and 2015 were reviewed to assess the IC angle and anterior TVH prior to and following ETV. The association between the postoperative changes in these values and the clinical success of ETV was analyzed.
Results: Of 78 consecutive procedures, 70 were successful (89,8%) whereas 8 procedures failed (10,2%). In 24-hour postoperative MR images of the successful ETV procedures; the mean IC angle declined significantly from 114,2 to94,6(17,1% reduction) and anterior TVH declined significantly from 15 to 11,2 (25,5% reduction) compared to those of the preoperative MRI. In 1-month MR images of the successful procedures; subsequent reduction of IC angle (11%) and decrease in anterior TVH (16,9%) were still significant but not as dramatic as those of 24-hour postoperative MRI. Six-month and 1-year postoperative MR images showed no significant further change in the IC angle and anterior TVH (Table 1, Figure 2,3,4). In unsuccessful procedures, the IC angle and anterior TVH did not change significantly (Table 1). Reduction rates of IC angle and anterior TVH in 24-hour postoperative MRI were significantly associated with the success rate of ETV procedures.
Conclusions: Assessment of the IC angle and anterior TVH in 24-hour postoperative MRI is useful in determining the clinical success of ETV and these two measurements could be used as radiological follow-up parameters.
Patient Care: It will make possible to detect any failure of ETV in very early postoperative time so as to be able to consider alternative treatment methods. It will also allow the neurosurgeons to follow-up the patients having undergone the procedure in a more accurate way.
Learning Objectives: By the conclusion of this session, participants should be able to: 1)Learn the importance of 24-h postoperative MRI in the assessment of ETV success, 2)Become aware of the configurational changes occurring in the third ventricle after an ETV, 3)Learn to use the suggested parameters for the follow-up of patients undergoing ETV.