Pain in a case of RSH was successfully relieved by RSB. It was shown that continuous RSB can be an effective analgesic technique for postoperative RSH. According to a review of RSH [1], abdominal pain is usually reported as severe, sharp, and persistent. Conservative management can be selected in hemodynamically stable patients if the hematoma stops expanding. However, in the present case, the patient could hardly walk or eat for about 2 weeks. A previous study showed that ultrasound-guided continuous RSB provides effective postoperative analgesia equivalent to that of epidural anesthesia even in open abdominal surgery [3]. In addition, RSB has the potential benefit of avoiding the critical complications of epidural anesthesia, such as hematoma, nerve injury, motor weakness, and hypotension [4].
There were several possible causes of the RSH in the present case: surgical procedures, loss of coagulation factors due to intraoperative bleeding, and twisting of the rectus muscle caused by postoperative nausea and vomiting. In the surgical process, it was likely that massive bleeding caused a hemorrhagic tendency due to loss of coagulation factors. Moreover, the patient was administered 1500 mL of colloid fluid before FFP administration, which might have caused temporary dilutional coagulopathy. It is unknown why and when RSH occurred; however, even if the surgeons did not cause direct damage to the inferior epigastric artery, retractors can also damage the rectus muscle or branches of vessels and cause RSH in a patient with such a hemorrhagic tendency.
For safe block procedures, ultrasound guidance enables administration of a local anesthetic and placement of a catheter into the correct plane, and it reduces the risk of peritoneal and vascular punctures. Below the arcuate line, the posterior rectus sheath is absent, and RSH therefore tends to extend beyond the midline and posteriorly [1]. Moreover, it increases the risk of peritoneal puncture. In the present case, RSH developed immediately left lateral to the umbilicus (Fig. 2). When RSB was performed, the site of RSH was checked, and the needle could be safely inserted into the lateral umbilicus with ultrasound guidance. A hematoma is generally one of the risk factors for surgical site infection [5]. Therefore, care must be taken regarding the location of the catheter and infectious spread around the catheter. Local anesthetic agents have vasodilating actions [6]. Therefore, ropivacaine may release the spasm of the inferior epigastric artery to cause re-bleeding. In this case, whether the inferior epigastric artery or branches had been damaged in the perioperative period could not be checked. However, we should determine the vital signs and size of the RSH after continuous RSB to detect re-bleeding. In addition, RSB should not be performed together with anticoagulant therapy.
For RSH patients, we should consider RSB if there is no active bleeding or hemorrhagic tendency. Severe abdominal pain can continue for several weeks, and it can greatly degrade patients’ ADL. Some postoperative RSH cases may remain unrecognized, and there may be many “hidden” postoperative RSH cases. Further studies on the efficacy and safety of continuous RSB for RSH cases are needed.
In conclusion, continuous RSB can be an effective analgesic technique for postoperative RSH.