Abstract
We report two cases of dorsal root entry zone lesioning (DREZ-lesion) of brachial plexus avulsion injuries involving postoperative opioid dosage reduction. Case 1 involved a 44-year-old man who had taken morphine hydrochloride for more than one year prior to presentation. We planned opioid reduction after DREZ-lesion using an intravenous continuous infusion of fentanyl. However, opioid withdrawal symptoms appeared on postoperative day 1. Case 2 involved a 43-year-old man who had used opioids (most recently fentanyl transdermal one-day patch and tramadol) for pain relief for about 5 years prior to presentation. After DREZ-lesion, opioids were reduced by 20 mg oral morphine equivalents/day and he discontinued opioids without experiencing withdrawal symptoms. The intractable pain caused by brachial plexus avulsion injuries can potentially be relieved by DREZ-lesion. Non-cancer pain patients taking long-term opioids prior to surgery should not cease taking opioids immediately after DREZ-lesion despite postoperative pain relief. Managing perioperative opioid reduction appropriately is essential to limiting the side effects of opioid withdrawal.
