Radiological prognostication in patients with head trauma requiring decompressive craniectomy: Analysis of optic nerve sheath diameter and Rotterdam CT Scoring System.
BACKGROUND
Optic nerve sheath diameter (ONSD) measured on CT scan has been shown to predict outcomes of patients with severe traumatic brain injury. No such relation has been studied in patients undergoing decompressive craniectomy (DC). We evaluated ONSD on admission CT scan to predict outcomes of patients undergoing DC along with Rotterdam CT Score (RCTS).


METHODS
This retrospective cohort study was approved by the institutional ethics committee. All the consecutive patients undergoing DC with available images and records were included. We measured ONSD 3mm behind the eyeball and calculated RCTS. Glasgow Outcome Scale (GOS) was measured at last follow-up. We analyzed the data on SPSS v 19. Receiver operator curve analysis (ROC) was done to measure the predictive values of ONSD and RCTS for mortality and unfavorable outcomes.


RESULTS
One hundred and seventeen patients were included. Twenty patients had bilateral DC. Mean GCS at presentation was 8.5±3.5. Mean follow-up was 7.5±1.2 months. Thirty-day mortality was 19%. Mean ONSD of both eyes was 6.73±0.89mm. Area under the curve (AUC) for bilateral mean ONSD as predictor of mortality was 0.49 [95%CI: 0.36-0.62]. AUC for RCTS was as a predictor of 30-day mortality was significant, i.e. 0.67 [95%CI: 0.572-0.820]. The difference of mean ONSD was also not significantly different between survivor and non-survivors.


CONCLUSIONS
Admission ONSD in DC patients is high but does not predict mortality and unfavorable outcomes. RCTS has a better prognostic value for predicting mortality and unfavorable outcomes in DC patients.
Section of Neurosurgery, The Aga Khan University Hospital, Stadium Road, Karachi 74800, Pakistan. Electronic address: shaiq_waqas@hotmail.com.
Muhammad
M
Waqas
Section of Neurosurgery, The Aga Khan University Hospital, Stadium Road, Karachi 74800, Pakistan. Electronic address: saqib_dmc@hotmail.com.
Saqib Kamran
SK
Bakhshi
Section of Neurosurgery, The Aga Khan University Hospital, Stadium Road, Karachi 74800, Pakistan. Electronic address: shahzad.shamim@aku.edu.
Muhammad Shahzad
MS
Shamim
Department of Radiology, Liaquat National Hospital Karachi, Karachi, Pakistan. Electronic address: salehaanwar@hotmail.com.
Saleha
S
Anwar
D000328:Adult; D000070642:Brain Injuries, Traumatic / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000601:surgery; D015331:Cohort Studies; D056424:Decompressive Craniectomy; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009900:Optic Nerve / Q000000981:diagnostic imaging* / Q000473:pathology*; D011379:Prognosis; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D014055:Tomography, Emission-Computed / Q000379:methods*
Decompressive craniectomy; Optic nerve sheath diameter; Outcomes; Rotterdam Computed Tomography Score; Traumatic brain injury