New CT measurements to assess decompression after hemicraniectomy: A two-center reliability study

Predicting Functional Outcome After Decompressive Craniectomy for Malignant Hemispheric Infarction: Clinical and Novel Imaging Factors

OBJECTIVE

Decompressive craniectomy (DC) is an established optional treatment for malignant hemispheric infarction (MHI). We analyzed relevant clinical factors and computed tomography (CT) measurements in patients with DC for MHI to identify predictors of functional outcome 3-6 months after stroke.

METHODS

This study was performed at 2 comprehensive stroke centers. The inclusion criteria required DC for MHI, no additional intraoperative procedures (strokectomy or cerebral ventricular drain placement), and documented functional status 3-6 months after the stroke. We classified functional outcome as acceptable if the modified Rankin Scale score was <5, or as unacceptable if it was 5 or 6 (bedbound and totally dependent on others or death). Multiple logistic regression analyzed relevant clinical factors and multiple perioperative CT measurements to identify predictors of acceptable functional outcome.

RESULTS

Of 87 identified consecutive patients, 66 met the inclusion criteria. Acceptable functional outcome occurred in 35 of 66 (53%) patients. Likelihood of acceptable functional outcome decreased significantly with increasing age (OR 0.92, 95% CI 0.82-0.97, P = 0.004) and with increasing post-DC midline brain shift (OR 0.78, 95% CI 0.64-0.96, P = 0.016), and decreased non-significantly with left-sided stroke (OR 0.30, 95% CI 0.08-1.10, P = 0.069) and with increasing craniectomy barrier thickness (OR 0.92, 95% CI 0.85-1.01, P = 0.076).

CONCLUSIONS

Patient age and the post-DC midline shift may be useful in prognosticating functional outcome after DC for MHI. Stroke side and craniectomy barrier thickness merit further ideally prospective outcome prediction testing.

Association Between Preoperative Midline Shift Growing Rate and Outcomes of Decompressive Craniectomy in Patients with Malignant Middle Cerebral Artery Infarction

BACKGROUND

Whether preoperative midline shift and its growing rate are associated with outcomes of decompressive craniectomy in patients with malignant middle cerebral artery infarction is unknown.

METHODS

We retrospectively included patients: 1) who underwent decompressive craniectomy for malignant middle cerebral artery infarction in West China Hospital from August 2010 to December 2, 2018) who had at least two brain computed tomography scans before decompressive craniectomy. Midline shift was measured on the first and last preoperative computed tomography scans. Midline shift growing rate was calculated by dividing Δmidline shift value using Δ time. The primary outcome was inadequate decompression of the mass effect. Secondary outcomes were 3 month death and unfavorable outcomes.

RESULTS

Sixty-one patients (mean age 53.7 years, 57.4% (35/61) male) were included. Median time from onset to decompressive craniectomy was 51.8 h (interquartile range: 39.7-77.8). Rates of inadequate decompression, 3 month death, 3 month modified Rankin Scale 5-6 and 4-6 were 50.8% (31/61), 50.9% (29/57), 64.9% (37/57) and 84.2% (48/57), respectively. The inadequate decompression group had a higher midline shift growing rate than the adequate decompression group (median: 2.7 mm/8 h vs. 1.4 mm/8 h, P=0.041). No intergroup difference of 3 month outcomes was found in terms of preoperative midline shift growing rate.

CONCLUSION

Higher preoperative midline shift growing rate was associated with inadequate decompression of decompressive craniectomy in patients with malignant middle cerebral artery infarction.

Limiting Brain Shift in Malignant Hemispheric Infarction by Decompressive Craniectomy

OBJECTIVE

Decompressive craniectomy (DC) improves functional outcomes in selected patients with malignant hemispheric infarction (MHI), but variability in the surgical technique and occasional complications may be limiting the effectiveness of this procedure. Our aim was to evaluate predefined perioperative CT measurements for association with post-DC midline brain shift in patients with MHI.

METHODS

At two medical centers we identified 87 consecutive patients with MHI and DC between January 2007 and December 2019. We used our previously tested methods to measure the craniectomy surface area, extent of transcalvarial brain herniation, thickness of tissues overlying the craniectomy, diameter of the cerebral ventricle atrium contralateral to the stroke, extension of infarction beyond the craniectomy edges, and the pre and post-DC midline brain shifts. To avoid potential confounding from medical treatments and additional surgical procedures, we excluded patients with the first CT delayed >30 hours post-DC, resection of infarcted brain, or insertion of an external ventricular drain during DC. The primary outcome in multiple linear regression analysis was the postoperative midline brain shift.

RESULTS

We analyzed 72 qualified patients. The average midline brain shift decreased from 8.7 mm pre-DC to 5.4 post-DC. The only factors significantly associated with post-DC midline brain shift at the p<0.01 level were preoperative midline shift (coefficient 0.32, standard error 0.10, p=0.002) and extent of transcalvarial brain herniation (coefficient -0.20, standard error 0.05, p <0.001).

CONCLUSIONS

In patients with MHI and DC, smaller post-DC midline shift is associated with smaller pre-DC midline brain shift and greater transcalvarial brain herniation. This knowledge may prove helpful in assessing DC candidacy and surgical success. Additional studies to enhance the surgical success of DC are warranted.