Benefits Seen With Use of Regional Blocks For Bilateral Mastectomy With Reconstruction

Author: Michael Vlessides

Anesthesiology News

Regional blocks appear to offer benefits in patients undergoing bilateral mastectomy with immediate reconstruction that extend well beyond the ambulatory surgery setting.

“Over the past decad e, we’ve seen a significant increase in breast reconstruction after mastectomy, a lot of which is happening in the outpatient setting,” said Hanae K. Tokita, MD, the director of regional anesthesia at the Josie Robertson Surgery Center, part of Memorial Sloan Kettering Cancer Center, in New York City. “Nevertheless, pain continues to be a major problem after this surgery.

“Traditionally, opioids have been given for this procedure, but they contribute to postoperative nausea and vomiting in this high-risk patient population,” Dr. Tokita said. “Several regional anesthesia approaches have been described in these patients, but we still lack high-quality evidence with respect to whether regional blocks are effective in this patient population.”

To address this question, Dr. Tokita and her colleagues analyzed retrospective data from 713 patients who underwent bilateral mastectomy with immediate tissue expander reconstruction under general anesthesia at her institution between April 2017 and December 2018. Patients were stratified according to whether or not they received regional anesthesia (paravertebral or serratus plane blocks, with or without pectoralis nerve blocks).

The researchers measured a variety of PACU outcomes, including opioid consumption, maximum pain score, hours to first ambulation and length of stay. Post-discharge outcomes included patient-reported severity of pain and fatigue for 10 days, as well as transfer to hospital, 30-day urgent care visit and hospital readmission rates.

“All of our blocks are placed preoperatively by a dedicated regional anesthesiologist,” Dr. Tokita said. Choice of block was left to the discretion of the clinician performing the procedure. All participants underwent general endotracheal anesthesia and were managed under standardized enhanced recovery pathways.

In presenting the study at the 2019 annual meeting of the American Society of Anesthesiologists (abstract A1012), Dr. Tokita reported that 639 patients received a regional block and 74 did not. The most common regional approach was the paravertebral block, followed by serratus blocks.

“Patients who were older and had higher [body mass index] tended to decline the blocks, though we’re not exactly sure why,” she noted.

The study found that use of regional blocks was associated with significantly lower median intraoperative fentanyl consumption (225 vs. 125 mcg; P<0.001). In addition, block patients needed a median of 5.7 hours (interquartile range [IQR], 4.4-10.3 hours) to their first ambulation, compared with 7.3 hours among their counterparts who did not receive a block (IQR, 5.9-12.1 hours).

Multivariable analysis also demonstrated that women who received the blocks had lower maximum postoperative pain scores (6.8 vs. 7.3; P=0.018). Furthermore, block patients were discharged 30 minutes earlier than those who did not receive a block (P=0.005). All patients who undergo the procedure stay overnight at the institution.

“We thought the blocks would have a greater impact on our discharge time, but 30 minutes is not really clinically significant and likely reflects logistic factors,” Dr. Tokita said. “We also didn’t find any difference in terms of postoperative nausea and vomiting, which we were also expecting to see, although the overall rate was low.”

Post-op Block Benefits Linger

Regarding postoperative opioid consumption, women who did not receive a regional block had an 80% increased chance of being in a higher quartile for usage (odds ratio, 1.80; 95% CI, 1.20-2.70; P=0.004).

No differences were observed between groups in acetaminophen or ketorolac consumption. The groups proved similar in incidence of adverse outcomes, hospital admissions, visits to urgent care and 30-day readmission rates.

The researchers also used a novel electronic data collection tool to track post-discharge symptom levels for 10 days after surgery. It found that among the 559 patients who completed at least one survey (78% response rate), the odds for moderate or worse pain was 0.58 times lower in women who received a block (95% CI, 0.34-0.97; P=0.04), a benefit that persisted for the entire 10-day period at home.

“I think this was an interesting outcome, for several reasons,” Dr. Tokita explained. “First, we never really know whether regional blocks help after patients go home, so it’s nice to see that there appears to be some beneficial effect of the nerve blocks that persists.

“Secondly, any perioperative intervention that helps decrease pain and hopefully improve quality of recovery after discharge is especially important in patients with breast cancer. These tend to be younger women who are eager to resume their home and work life, and some of them even need to resume further cancer treatment. So anything we can do to facilitate them getting back on their feet sooner is very important.

“Finally, chronic pain is very common in this patient population. I think it would be interesting to see in the future if having a regional block helps reduce the progression to the chronic pain state,” Dr. Tokita noted.

Although the investigators were encouraged by their findings, they also recognized the need for more work in this area. “In terms of regional anesthesia research, we need to move beyond objective measures like pain scores and opioid consumption and really incorporate subjective patient-reported outcomes data into our work,” Dr. Tokita said. “The way we see it, nothing matters more than a patient’s experience of a particular intervention.”

Session co-moderator Rajeev Subramanyam, MBBS, MD, MS, suggested a way to improve the trial’s methodology. “It’s good to show regional anesthesia is beneficial,” said Dr. Subramanyam, the associate division chief for Quality and Safety, General Anesthesiology at the Children’s Hospital of Philadelphia.

“But in this case, you have a very skewed sample size in terms of your patient population,” he said, “which runs the possibility of type 2 error”—that is, a false-negative finding. “So you might consider matching patients without a block to the patients with a block.”

“We’re in the early stages of a prospective, randomized trial that will hopefully address these issues,” Dr. Tokita replied.