Brain Metastases Resection: Risk Factors for Readmissions and Complications

Up to 40% of cancer patients will develop brain metastases, making the condition one of the most common malignancies found in the central nervous system. While innovative targeted therapies continue to expand treatment options for these patients, brain metastasis resection through craniotomy is still a core intervention to improve survival and relieve mass effect.

But nearly 1 in 6 patients who undergo a craniotomy will be readmitted within 30 days of their index surgical admission, according to a 2014 study.

Why? That’s what new research hoped to uncover.

Two recent studies published in 2021 evaluated brain surgery recovery in metastasis patients to better understand which factors are more likely to lead to unplanned readmissions, complications and mortality.

Here’s what they found:

Readmission Risk after Brain Metastases Resection

One study set out to develop a risk model in what the authors consider to be the first study to look at unplanned readmissions for patients with brain metastases using a national data set.

Inspired by the estimate that 70% of all-cause readmissions after neurosurgical procedures are avoidable, researchers at Baptist Health and Miami Cancer Institute in South Florida sought to establish risk management for craniotomies. Their stated goal was to both improve brain surgery recovery while mitigating the associated financial cost of such readmission care.

In their study published in Scientific Reports, Tonse et al. collected data from the Nationwide Readmissions Database from 2010 to 2014, focusing on the 44,846 index hospitalizations that occurred for patients who underwent resection of brain metastasis.

Here are key takeaways from their research on recovery after brain surgery:

Less than a fourth of patients had unplanned readmissions within 30 days of discharge.
17.8% of brain metastasis resection patients had unplanned readmissions within the first 30 days of discharge. The authors note that this readmission rate did not change significantly during the five-year study period.

The top reason for unplanned readmission of these patients was postoperative infection at 5.6%.
This was followed by convulsions (5.1%), intracerebral hemorrhage (4.5%), iatrogenic cerebrovascular infarction or hemorrhage (4.1%), and cerebral edema (2.4%).

Tonse et al. identified eight risk factors associated with an increase in 30-day unplanned readmission. They also noted that: patients with 3-plus comorbidities had a significantly higher risk of readmission, and that length of stay of 5 days or more significantly increased the rate of readmission compared to patients with a length of stay of less than 5 days.

The national expenditure for unplanned 30-day readmissions following resection for brain metastasis could be as high as $269.6 million per year.
This estimate was based on their findings that the median per-patient cost of unplanned 30-day readmissions following resection for brain metastasis was $11,109, which could equal $26.4 million per year at a single institution.

As noted earlier, there has been incredible progress in both brain metastases treatment options as well as neurosurgical advancements that would be expected to impact brain surgery recovery in the years since the study’s 2010 to 2014 data.

In response, the authors note that “there have been no recent studies or policy changes that have been implemented since that time period that would be expected to reduce the rate of readmissions appreciably beyond that described in the manuscript.”

To read the full breakdown of risk factors of unplanned readmission following brain metastasis resection, see the full study here.

Impact of Tumor Location and Patient Frailty

Another recent study, published in Frontiers in Oncology, evaluated the risk factors following resection for brain metastasis related to degree of patient frailty as well as tumor location. The study included 3,500 patients with brain metastases who underwent resection, with the following characteristics:

• • 55% were female and median age was 61 years
  • Infratentorial lesions represented 24% of cases
  • Median operative length was 139 minutes
  • Craniotomies for infratentorial lesions were associated with an average operative time 33 minutes longer than supratentorial approaches

Their research found that when it comes to brain surgery recovery and brain tumor location:

• • Infratentorial location was associated with increased odds for multiple 30-day medical complications, reoperation and unplanned readmission
  • Infratentorial location was associated with significant risk of unplanned readmission for hydrocephalus
  • There was no statistically significant association between tumor location and death

The study also assessed patient frailty via the modified frailty index (mFI) with one point assigned for congestive heart failure, chronic obstructive pulmonary disease, diabetes mellitus, hypertension, and non-independent functional status. A mFi-5 score of 0 was considered non-frail, 1 as pre-frail and 2-plus as frail.

Their research found that frailty was associated with:

• • Increased risk of reoperation after brain metastasis resection
  • Risk for surgical evacuation of hematoma
  • Death after discharge, but not before discharge

However, the authors point out that the lack of association between readmission and frailty may be due to the unique goals of care for brain metastases patients, which may include more palliative care versus further hospitalization.

In addition to evaluating tumor location and patient frailty as risk factors, the authors were also able to identify post-op complications timing based on their cohort of 3,500 brain metastasis patients undergoing resection:

• • Cardiac events usually occurred the day of operation, although infrequent
  • Cerebrovascular accidents happened at a median 2 days post-op
  • Patients experienced urinary tract infections and pneumonia at 5 to 6 days post-op
  • Surgical site infections occurred 2 weeks after operation

Both studies note that identifying risk factors and developing measures to prevent unplanned readmissions and complications are key to improving quality of life for the estimated 150,000 to 200,000 people diagnosed with a brain metastasis each year.