Predictors of Postoperative Visual Outcomes following Surgical Operation for Craniopharyngiomas

Background: Craniopharyngiomas frequently present with visual deterioration due to involvement of the optic apparatus. Although visual improvement is a primary goal of surgical intervention, the predictors of postoperative visual change are not well characterized in the current literature.

Objective: This study intends to investigate and characterize preoperative, intraoperative, and postoperative variables related to surgical intervention of craniopharyngiomas to identify predictors of postoperative visual change. Such findings aim to improve shared decision-making between surgeons and patients by facilitating a better understanding of the visual outcomes to expect following surgical intervention.

Methods: A retrospective chart review was conducted of 97 total craniopharyngioma operations, corresponding to 67 patients undergoing at least one craniopharyngioma surgery at one of two medical centers (a tertiary care academic medical center and a related teaching hospital) between 2014 and 2019. Information was collected regarding demographics, comorbidities, radiological characteristics, laboratory studies, operative details, radiation therapy, hormone replacement, length of hospitalization, and vision. Visual acuity (VA) and visual fields (VF) were scored and combined quantitatively into visual impairment (VI) scores, according to guidelines defined by the German Ophthalmological Society. The difference between postoperative and preoperative VI scores served as the primary measure for visual change.

Results: Among the 67 total patients reviewed, preoperative and postoperative ophthalmological assessments were available for 47 patients, corresponding to 61 total operations. The age range was 4 to 73 years and 27 (57%) patients were female. Visual improvement followed 36 (59%) of those operations, while vision remained stable after 15 (25%) operations and deteriorated after 10 (16%) operations. For these 61 operations, the mean estimated preoperative cyst volume was 26.5 ± 47.3 cm³, mean maximum cyst dimension was 3.01 ± 1.16 cm, mean length of ICU stay was 3.65 ± 3.96 days, and mean length of total hospitalization was 8.20 ± 9.62 days. Radiologic involvement of the anterior cerebral arteries (ACAs) occurred in 27 (44%) of the operations.

First, a simple linear regression analyzed a subset of 36 of these operations that corresponded to a patient’s first craniopharyngioma surgery. Significant predictors for visual deterioration were increased preoperative cyst volume and maximum dimension (p = 0.017 and p = 0.041), radiologic involvement of the ACAs (p = 0.018), increased length of ICU and total hospitalization days (p = 0.004 and p = 0.014), and worse preoperative VA and VI scores (p < 0.001 each).

A sensitivity analysis performed a mixed-effects linear regression involving all 61 operations to account for repeat surgeries. This analysis also found that all the above variables were significant predictors of postoperative visual worsening, except for preoperative cyst volume and dimension (p ≤ 0.02 each). Newly identified predictors of worsening VI score included preoperative desmopressin replacement (p = 0.027) as well as worse preoperative and postoperative VA, VF, and VI scores (p < 0.05 each). Length of visual symptoms experienced preoperatively was not a significant predictor.

Conclusion: Vision improved in a majority of the operations reviewed in this study. Significant predictors of worsened VI score included greater preoperative cyst size, radiologic involvement of the ACAs, increased length of ICU and total hospitalization days, preoperative desmopressin replacement, and preoperative/postoperative VA, VF, and VI measurements.