The role of regional blocks in an early discharge breast reconstruction program

Background: Multiple advances are ongoing on breast cancer surgery, however it is still frequently associated with postoperative acute and chronic pain, nausea and vomiting. This is a major concern in immediate breast reconstruction patients which usually report higher pain levels. Acute post-surgical pain leads to delayed discharge, impaired immune functions, higher risk of cardiovascular complications and chronic pain. Hence, the importance of an appropriate perioperative pain management in these patients. Regional nerve blocks have demonstrated to be a good modality for pain control, with an opioid-sparing effect, which allows early discharge and reduced postoperative analgesic requirements. This is particularly relevant, since the reduced use of opioids, not only limits opioid-related side effects as nausea and constipation but may also prevent the risk of recurrence associated to the immunosuppressive effect of opioids on the breast cancer microenvironment. The aim of this study is to analyze the effect of regional block usage in perioperative adjuvant pain and nausea management aswell as its influence in early discharge and postoperative complications. Methods: After obtaining IRB, we retrospectively review medical and anesthetic reports of patients who underwent immediate and delayed breast reconstruction from 2017 to 2019 at the National Cancer Institute of Mexico. Surgical events were categorized according to the use of a regional nerve block as complement for general balanced anesthesia. Sociodemographic, clinical, surgical and anesthesiologic variables were collected. Data were analyzed using descriptive statistics such as means and deviated standards for quantitative variables; and medians and proportions for qualitative variables. A bivariate analysis was made taking as dependent variable the usage of regional nerve block. T-test or Mann-Whitney U test were used for quantitative variables, chi-square or Fisher exact test for qualitative variables. Results: A total of 692 breast reconstructive procedures, of which 106 (15.3%) had regional nerve blocks. We found no differences in age, diabetes mellitus, systemic hypertension and other comorbidities between both groups. Tumor characteristics, smoking and BMI were similar between the non-blocked and blocked groups. When analyzing surgical variables there were no differences in type of surgery (immediate or delayed breast reconstruction), presence of axillary lymph node dissection and drainage device usage. There were no significant differences in overall complications in the non-blocked group versus the blocked group (18.94% versus 18.87%, p=0.99). We found no significant differences in specific complications in the blocked group: cardiovascular (1.02% versus 0.94%, p=0.94); no hypertensive crisis; pneumothorax (0.17% versus 0.94%, p=0.17); hematoma (0 versus 0.68%, p=0.39); thrombosis (0 versus 0.85%, p=0.34); reintervention (9.22% versus 9.57%, p=0.94), nausea/vomiting (1.89% versus 0.17, p=0.01) and uncontrolled pain (1.37% versus 0.94%, p=0.72). When analyzing anesthetic variables, we found less steroid use in the blocked group (82.1% versus 91.3%, p=0.004); less doses of antiemesis drugs (5-HT3 antagonist) (4.6±4.45mg versus 5.9±4.55mg, p=0.002), less opioid need (tramadol) (42.5% versus 66.8%, p=0.000) and less fentanyl doses (355.4±184.7 mg versus 289.7 ± 148.0 mg, p=0.0012). Conclusions: Based on our results, we consider that the use of regional blocks as a perioperative pain management in breast reconstruction procedures is a safe intervention, which reduces the use of steroids, doses of antiemetics and opioid use. These findings suggest that further studies need to be performed to confirm which type of regional block has more benefits in terms of recovery time, opioid use and patient satisfaction. Citation Format: Juan Enrique Bargallo-Rocha, Daniela Vargas-Salas, Luz M Gutierrez-Zacarias, Juan A Torres-Dominguez, Judith Acosta-Violante, Horacio Vazquez-Morales. The role of regional blocks in an early discharge breast reconstruction program [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P6-14-04.