RAPN is a minimally invasive option for patients with small renal masses undergoing partial nephrectomy. However, it requires multiple port holes that widely range from near the xiphoid process to below the umbilicus. Jin et al. reported no significant difference in postoperative pain between patients who underwent RAPN and laparoscopic partial nephrectomy. The NRS scores in the RAPN group anesthetized by general anesthesia only were 5.9, 3.5, and 2.8 at POD 0, 1, and 2, respectively [11].
Although epidural anesthesia could provide reliable pain relief, it has several side effects, including paresthesia, hypotension, urinary disturbance, and epidural hematoma, which increase the risk of anticoagulant therapy in the early postoperative period.
QLB are classified into three main types: posterior, lateral, and anterior approach [12]. The anterior QLB has been reported to have great efficacy in hip surgery and lower abdominal surgery [1,2,3]. Recent studies have shown that the anterior QLB is suitable for flank surgery rather than abdominal surgery with a midline incision [4, 5, 13]. The anterior QLB, especially the subcostal anterior QLB, have been suggested to be effective in nephrectomy [6, 7]. We chose the anterior QLB at L2 level, which we are familiar with, rather than the subcostal anterior QLB. Moreover, the anterior QLB at L2 level had a wide anesthetized range but a variable pattern [13].
ESPB has quickly become a popular technique for thoracic, abdominal, and extremity surgeries since its first report in 2016 [14]. The efficacy of ESPB is considered to involve both the ventral and dorsal rami of the spinal nerves; however, the exact pathway of local anesthetic diffusion remains unclear.
We hypothesized that the combined use of QLB and ESPB could increase the probability and range of the effect by devising the puncture site. A previous case report on the combined use of ESPB and QLB for hip surgery highlighted the importance of their mutual increase in effectiveness and complementing each other’s missing aspects [15]. In the present cases, both patients weighed over 50 kg. Therefore, the maximum dose of ropivacaine (3 mg/kg) was 150 mg. In QLB, it is believed that the analgesia is due, in part, to the local anesthetic (LA) spread along the thoracolumbar and endothoracic fascia into the paravertebral space. In ESPB, LA diffuses anteriorly to the ventral and dorsal rami of the spinal nerves and through the intertransverse connective tissue to enter the paravertebral space due to the discontinuity of the intercostal muscles. According to previous reports, these fascial plane blocks rely on a high-volume, low-concentration technique for optimal efficacy. We therefore decided to use as much local anesthetics as possible within the range currently reported and applied 0.25% ropivacaine 30 mL [16, 17].
The postoperative pain evaluation with NRS was performed at 2 h, 24 h, and 48 h after surgery. There was an increase in NRS on movement between 24 and 48 h after surgery despite the same condition for IV-PCA and postoperative rehabilitation. From these results, we considered that the combination of QLB and ESPB was effective for more than 24 h, but less than 48 h, after surgery. As the single-shot technique was used in these cases, there is a need for additional studies to assess nerve block strategies using catheter placement for better analgesia. This is because the NRS score was 5 on movement at 48 h after surgery in case 1, which suggests that a single injection resulted in recurrent pain.
Each anesthesiologist determined the dose of fentanyl for IV-PCA. Fentanyl usage was large in case 2. The mechanism underlying postoperative pain in partial nephrectomy is considered to involve port pain, small incisions for tumor extraction, pelvic organ nociception, diaphragmatic irritation, ureteric colic, and urinary catheter discomfort [18]. Although the effect range of QLB and ESPB appears appropriate in case 2, the patient presented with visceral pain, which was attributed to the placement of a single J ureteral stent that was removed at POD 4. Generally, 80% of patients with indwelling urinary stents feel uncomfortable and often complain of flank pain [19, 20]. We recognized that the continued use of IV-PCA during single J stent placement resulted in increased fentanyl usage in case 2. Despite the facts mentioned above, good analgesia was obtained under the combination of QLB and ESPB with IV-PCA connected.
To our knowledge, this is the first report of the combined use of ESPB and anterior QLB for RAPN. These cases indicate that the combined use of ESPB and anterior QLB is an effective postoperative analgesia strategy in RAPN.