Discussion
postoperative pain, tumor, ESPB, pneumothorax, cancer, chronic neuropathic pain, pain, constipation, PONV, NRS, nausea, vomiting
TUMOR, METASTASIS, PNEUMOTHORAX, ADVERSE EVENTS, CANCER, ADVERSE EFFECTS, SECONDARY, BREAST, CHRONIC PAIN, COMPLICATIONS
In our study the primary end point was to compare the TPV and ESP blocks in the control of post-operative pain after radical mastectomy with or without axillary emptying.As secondary end points, we evaluated the need of rescue analgesia, intra- and post-operative opioid consumption, PONV, length of stay, adverse events, chronic pain after 6 months and patients satisfaction regarding anesthesiologic procedure.We performed both TPV and ESP blocks on two levels. We highlight the importance to “block” the T2 nerve root because from the T2 spinal level originates the inter-costobrachial nerve, which is very important for the axilla innervation.Both the regional blocks reduced the intra- and post-operative opioid consumption, with a comparable duration of analgesic effect and stable hemodynamic profiles.At 2 and 6 postoperative hours, the NRS was significantly lower in Group TPVB than in Group ESPB; however, this difference did not lead to an increased request for rescue doses by patients.The NRS at 12, 24, and 36 postoperative hours did not show significant differences.The number of patients requiring intra-operative opioid administration (100 mcg of Fentanyl) was higher among those in Group ESPB; however, we found no statistically significant differences.No statistically significant data were recorded regarding the PONV episodes and length of stay.We did not observe any adverse events (through a clinical assessment of the patients), which is probably related to the great experience of the operators. All patients were absolutely satisfied with the anesthetic procedure and none developed chronic pain 6 months after surgery.Even if not included in our primary and secondary end points, we underline that there were no significant differences in the execution times of the two blocks.Despite the large number of analgesic modalities for postoperative pain management among women undergoing breast surgery, recent reports still highlight a significant post-operative pain burden in this population [Breast surgery is burdened by a high incidence of acute post-operative pain whose inadequate management increases the risk not only of chronic pain but also of in-hospital mortality and functional impairments [The analgesic and anesthetic effect of the TPV block is due to the direct contact of the LA injected into the paravertebral space with the roots of the spinal nerves as well as the spread in the epidural space. Thus, a thoracic paravertebral injection of LA results in ipsilateral somatic and sympathetic nerve blocks including the posterior ramus in multiple contiguous thoracic dermatomes [However, the risk of pneumothorax, the long time to perform the block, and the high level of skills needed make some inexperienced anesthesiologists to avoid the TPV block and use other techniques, such as the ESP block, a novel nerve-blocking technique first proposed by Forero et al. in 2016 [It is generally implemented through deposition of drugs into the fascial plane beneath the erector spinae muscle at the tip of the transverse process of the vertebra, thereby reducing the risk of pneumothorax and significant neurovascular damage.The ESP block allows anesthetic coverage similar to that of the TPV Block. It is considered a peri-paravertebral regional anesthesia technique which is supposed to block the dorsal and ventral rami of the thoracic and abdominal spinal nerves, and thereby block the anterior, posterior, and lateral thoracic and abdominal walls.The mechanism of action of the ESP block is probably related to the spread of the LA into the paravertebral space [This hypothesis is reinforced by the recent discovery that identifies two slits at the medial and lateral ends of the superior costo-transverse ligament (SCTL) that can act as channels to the thoracic paravertebral space [The TPV block is certainly one of the most effective techniques in pain control after radical mastectomy [Several previous studies, though, have documented that ultrasound-guided paravertebral block is an advanced regional anesthetic technique that requires a longer learning curve to manipulate the needle under ultrasonography guidance towards the paravertebral space [Krediet et al. [Nevertheless, the complications of TPV block like inadvertent pleural puncture and epidural or intrathecal spread are still a concern even with ultrasound utilization.Ultrasound-guided ESPB, which we preferably perform with an out of plane technique, has been originally described for pain relief in patients with chronic neuropathic pain. However, recent studies found it effective as a postoperative analgesic technique and to reduce the postoperative opioid consumption following breast surgery.Zhang et al. [Agarwal et al. [Unlike our study, they did not find statistically significant differences in postoperative NRS scores at rest and movement at 2 and 6 post-operative hours.The same observations were reported by Moustafa et al.[Most of the studies comparing TPV and ESP blocks in breast surgery involved the use of post-operative morphine while none of the patients in our study used post-operative morphine.The use of opioids, intra- and post-operative, in addition to having adverse effects such as nausea, vomiting, and constipation may potentiate the tumor cell survival and angiogenesis, which could lead to metastasis of cancer [In our hospital the TPV block has been performed for many years for both mastectomies and quadrantectomies, therefore, its effectiveness has been extensively confirmed even for interventions with awake patients [