Ultrasound-guided Multilevel Erectorspinae Plane Block Versus Thoracic Epidural Analgesia for Prevention of Post Mastectomy Pain Syndrome for Breast Cancer Patients

Inclusion Criteria: * Female patients age ≥ 18 years and ≤ 65 Years. * Type of surgery; Modified Radical Mastectomy (MRM) * Physical status ASA II, III. * Body mass index (BMI): \> 20 kg/m2 and \< 35 kg/m2. Exclusion Criteria: * Patient refusal. * Allergy or a contraindication to the drug used in the study, e.g. local anesthetics, opioids. * History of psychological disorders. * History of chronic pain. * Contraindication to regional anesthesia e.g. sepsis, peripheral neuropathies and coagulopathy. * Advanced chronic renal disease, which is defined as a chronic kidney disease (CKD) in which there is a severe reduction in glomerular filtration rate (GFR \< 30 ml/min) and includes stages 4 and 5 of the CKD classification. * Decompensated cirrhosis, which is defined as an acute deterioration in liver function in a patient with cirrhosis and is characterized by jaundice, ascites, hepatic encephalopathy, hepatorenal syndrome, or variceal hemorrhage. * Severe heart disease which is defined as NYHA class iii (moderate symptoms with less than normal activity, marked limitation of function status) or NYHA class IV (severe symptoms with features of heart failure with minimal activity or at rest and severe limitation of functional status) * Severe lung disease which includes oxygen saturation of blood less than 92%, RR more than 20, FEV1/FVC ratio less than 60%. * Pregnancy.