Efficacy and Safety of Pectoral Nerve Block (Pecs) Compared With Control, Paravertebral Block, Erector Spinae Plane Block, and Local Anesthesia in Patients Undergoing Breast Cancer Surgeries: A Systematic Review and Meta-analysis

Reducing Disparities: Regional Anesthesia Blocks for Mastectomy with Reconstruction Within Standardized Regional Anesthesia Pathways

BACKGROUND

Recent data suggest disparities in receipt of regional anesthesia prior to breast reconstruction. We aimed to understand factors associated with block receipt for mastectomy with immediate tissue expander (TE) reconstruction in a high-volume ambulatory surgery practice with standardized regional anesthesia pathways.

PATIENTS AND METHODS

Patients who underwent mastectomy with immediate TE reconstruction from 2017 to 2022 were included. All patients were considered eligible for and were offered preoperative nerve blocks as part of routine anesthesia care. Interpreters were used for non-English speaking patients. Patients who declined a block were compared with those who opted for the procedure.

RESULTS

Of 4213 patients who underwent mastectomy with immediate TE reconstruction, 91% accepted and 9% declined a nerve block. On univariate analyses, patients with the lowest rate of block refusal were white, non-Hispanic, English speakers, patients with commercial insurance, and patients undergoing bilateral reconstruction. The rate of block refusal went down from 12 in 2017 to 6% in 2022. Multivariable logistic regression demonstrated that older age (p = 0.011), Hispanic ethnicity (versus non-Hispanic; p = 0.049), Medicaid status (versus commercial insurance; p < 0.001), unilateral surgery (versus bilateral; p = 0.045), and reconstruction in earlier study years (versus 2022; 2017, p < 0.001; 2018, p < 0.001; 2019, p = 0.001; 2020, p = 0.006) were associated with block refusal.

CONCLUSIONS

An established preoperative regional anesthesia program with blocks offered to all patients undergoing mastectomy with TE reconstruction can result in decreased racial disparities. However, continued differences in age, ethnicity, and insurance status justify future efforts to enhance preoperative educational efforts that address patient hesitancies in these subpopulations.

Efficacy and Safety of Nerve Block for Postoperative Analgesia in Patients Undergoing Breast Cosmetic Surgery: A Systematic Review and Meta-analysis of Randomized Controlled Trials

BACKGROUND

To evaluate the postoperative analgesic efficacy and safety of nerve block (NB) in patients undergoing breast surgery for cosmetic purposes.

METHODS

PubMed, Web of Science, Embase and Cochrane Libraries were searched from inception to September 2022, to identify all eligible randomized controlled trials (RCTs). Continuous data are presented as mean difference (MD) with 95% confidence intervals (CI), whereas dichotomous data are provided as odds ratios (OR) with 95% CI. This meta-analysis was performed in RevMan 5.4.

RESULTS

A total of 10 RCTs with 565 patients were meta-analyzed. Compared to the control group, the pain score of the NB group was significantly lower at postoperative 2, 3-4, 6-8, 12-16 and 24 h. Opioid consumption in the first postoperative 24 h was significantly lower in the NB group (MD = - 9.02, 95% CI - 14.29 to - 3.75, P < 0.05), I2 = 95%). In addition, the NB group showed a prolonged time to first postoperative analgesic requirement (MD = 43.15, 95% CI 4.74-81.56, P < 0.05, I2 = 96%), decreased incidence of additional postoperative analgesia (OR 0.14, 95% CI 0.07-0.28, P < 0.05, I2 = 0%) and reduced incidence of postoperative nausea or vomiting (OR 0.33; 95% CI 0.22-0.48; P < 0.05; I2 = 0%). There was no significant difference in operation duration between the two groups.

CONCLUSIONS

Nerve block is an effective and safe option for postoperative analgesia after breast cosmetic surgery.

LEVEL OF EVIDENCE II

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Brachial plexus blockade arising from a combined pectoralis (PECS) 1 and 2 block

We present a case of inadvertent spread of local anaesthetic from combined pectoralis (PECS) 1 and 2 fascial plane blocks that resulted in an incomplete brachial plexus block. An otherwise healthy 42-year-old woman with a body mass index of 23.3 kg.m-2 presented for unilateral mastectomy with immediate prosthetic reconstruction for breast cancer. No axillary dissection was performed. Because of service requirements, the blocks were performed at the conclusion of surgery. This may have resulted in greater cranial spread of the local anaesthetic due to surgical dissection along musculature and placement of the breast implant. Following emergence from general anaesthesia, the patient experienced numbness over the ipsilateral medial forearm extending to the little finger. Further examination with a finger-nose test revealed reduced coordination and joint proprioception of the ipsilateral arm. There was no detectable gross motor weakness. She was reviewed the following day (23 h after the blocks) by which time her symptoms had subsided entirely. We believe that this is the first documented brachial plexus block after injection of local anaesthetic into the pectoralis 1 and 2 fascial planes.

Dexmedetomidine as an Adjuvant in Peripheral Nerve Block

Peripheral nerve block technology is important to balanced anesthesia technology. It can effectively reduce opioid usage. It is the key to enhance clinical rehabilitation as an important part of the multimodal analgesia scheme. The emergence of ultrasound technology has accelerated peripheral nerve block technology development. It can directly observe the nerve shape, surrounding tissue, and diffusion path of drugs. It can also reduce the dosage of local anesthetics by improving positioning accuracy while enhancing the block's efficacy. Dexmedetomidine is a highly selective drug α₂-adrenergic receptor agonist. Dexmedetomidine has the characteristics of sedation, analgesia, anti-anxiety, inhibition of sympathetic activity, mild respiratory inhibition, and stable hemodynamics. Numerous studies have revealed that dexmedetomidine in peripheral nerve blocks can shorten the onset time of anesthesia and prolong the time of sensory and motor nerve blocks. Although dexmedetomidine was approved by the European Drug Administration for sedation and analgesia in 2017, it has not yet been approved by the US Food and Drug Administration (FDA). It is used as a non-label drug as an adjuvant. Therefore, the risk-benefit ratio must be evaluated when using these drugs as adjuvants. This review explains the pharmacology and mechanism of dexmedetomidine, the effect of dexmedetomidine on various peripheral nerve block as an adjuvant, and compare it with other types of adjuvants. We summarized and reviewed the application progress of dexmedetomidine as an adjuvant in nerve block and look forward to its future research direction.

Regional anesthesia for breast cancer surgery: which block is best? A review of the current literature

Breast cancer is the most common type of cancer worldwide. Fortunately, continual advances in diagnosis and treatment are resulting in increased survival rates. Earlier detection and treatment, to include surgical resection, can greatly improve patients outcomes. However, due to the complex innervation of the breast, management of postoperative pain has proven difficult in the past. Approximately, half of all women who undergo breast cancer surgery report postoperative pain syndrome. The paravertebral block has long been the anesthesiologist's choice for mitigating pain during and after the procedure. Newer techniques such as the pectoral nerve block and erector spinae plane block may prove to have some additional benefits. This literature review compares the risks, benefits and specific uses of these three regional nerve blocks in women undergoing breast cancer surgery. It aims to better inform anesthesiologists when they are choosing which technique is best for their patients.

A French nationwide survey on the practice of regional anaesthesia for breast cancer surgery

BACKGROUND

To assess the impact of recent recommendations concerning regional anaesthesia for breast cancer surgery, a nationwide practice survey was carried out.

METHODS

This cross-sectional electronic survey, conducted in 2021, collected answers from a panel of anaesthetists currently working in French practicing centres. It addressed the sets of techniques they practiced for every type of surgical procedure and their perceptions of the difficulties and risks associated with these techniques.

RESULTS

The practice of regional anaesthesia was generally high (70%), involving all the current types of blocks. Surgeon-done infiltration was popular for lumpectomy only. For the other current procedures, the pectoralis nerve blocks were preferred to the paravertebral block, which was favoured for mastectomies, when a lymph node harvesting was planned, or for immediate or delayed pedicle flap. Catheters were mostly used for mastectomies with pedicle flap. The erector spinae plane block was emergent. Whatever the type of block, regional anaesthesia was preferentially started before surgery. Despite some deviations such as the adjunction of unlabelled molecules, the practice fitted well with the European recommendations, but training and within-centre guidance lacked standardisation. For each block, actual practice, perceived difficulty and risk were inter-correlated, but paravertebral block - either practiced or not - was considered as more difficult and riskier to perform than any other.

CONCLUSIONS

These encouraging results do not dispense with the need to improve anaesthetic practices both in quantity and quality. Such improvement in the anatomic fit to the procedure and in the timing of blocks will also have to be considered.

Metabolomic Impact of Lidocaine on a Triple Negative Breast Cancer Cell Line

Background: Metabolomics and onco-anesthesia are two emerging research fields in oncology. Metabolomics (metabolites analysis) is a new diagnostic and prognostic tool that can also be used for predicting the therapeutic or toxic responses to anticancer treatments. Onco-anesthesia studies assess the impact of anesthesia on disease-free and overall survival after cancer surgery. It has been shown that local anesthetics (LA), particularly lidocaine (LIDO), exert antitumor properties both in vitro and in vivo and may alter the biologic fingerprints of cancer cells. As LA are known to impair mitochondrial bioenergetics and byproducts, the aim of the present study was to assess the impact of LIDO on metabolomic profile of a breast cancer cell line.

Methods: Breast cancer MDA-MB-231 cells were exposed for 4 h to 0.5 mM LIDO or vehicle (n = 4). The metabolomic fingerprint was characterized by high resolution magic angle spinning NMR spectroscopy (HRMAS). The multivariate technique using the Algorithm to Determine Expected Metabolite Level Alteration (ADEMA) (Cicek et al., PLoS Comput. Biol., 2013, 9, e1002859), based on mutual information to identify expected metabolite level changes with respect to a specific condition, was used to determine the metabolites variations caused by LIDO.

Results: LIDO modulates cell metabolites levels. Several pathways, including glutaminolysis, choline, phosphocholine and total choline syntheses were significantly downregulated in the LIDO group.

Discussion: This is the first study assessing the impact of LIDO on metabolomic fingerprint of breast cancer cells. Among pathways downregulated by LIDO, many metabolites are reported to be associated with adverse prognosis when present at a high titer in breast cancer patients. These results fit with the antitumor properties of LIDO and suggest its impact on metabolomics profile of cancer cells. These effects of LIDO are of clinical significance because it is widely used for local anesthesia with cutaneous infiltration during percutaneous tumor biopsy. Future in vitro and preclinical studies are necessary to assess whether metabolomics analysis requires modification of local anesthetic techniques during tumor biopsy.