ultrasound-guided serratus plane block vs paravertebral block for chronic post-mastectomy pain.

Conditions: Post-mastectomy Pain Syndrome

Summary: compare the analgesic efficacy between ultrasound paraverbral block and serratus block in post mastectomy pain.

it is reported that postmastectomy pain syndrome (pmps) is a common problem, ranging from 25% to 60%. the pain is localized in the axilla, medial upper arm, breast, and/or chest wall and lasting beyond three months after surgery when all other causes of pain such as infection have been eliminated. the pain seriously affects the patient's mood, everyday activities, and social function and causes heavy economic burden for the healthcare system. postmastectomy pain syndrome (pmps) itself is not a specific diagnosis but rather describes a cluster of symptoms frequently observed in breast cancer survivors following treatment. many patients will experience short-term nociceptive pain after breast cancer treatment. however, with pmps, patients frequently experience persistent neuropathic-type pain: burning, tingling, aching, a subjective sense of "tightness" around the chest wall, or even phantom breast or nipple pain. neuropathic pain results from dysfunction of the peripheral nerves caused by surgery, radiation, or neurotoxic chemotherapies. currently, there are a wide variety of approaches to treat this type of pain. physical therapy has been employed as a modality to improve physical function. as far as interventional procedures, intercostal nerve blockade, stellate ganglion blockade, and paravertebral blockade have all been utilized with varying degrees of success. paraverberal blocks have superseded thoracic epidurals when it comes to choice of a regional anaesthesia technique to provide analgesia for breast surgery. the injection of local anaesthetic solution in the paravertebral space results in a unilateral block, which is sensory, motor, and sympathetic. the uptake of the local anaesthetic solution is enhanced due to the absence of fascial sheaths binding the spinal nerves. another potential target for an interventional procedure for chronic pain after treatment for breast cancer is the serratus plane. the serratus plane block is a novel ultrasound-guided nerve block, which is able to anesthetize the hemithorax. the serratus plane block relies on the fact that there are branches of the intercostal nerves following within 2 potential spaces, one superficial and one deep, surrounding the serratus anterior muscle. the serratus anterior muscle arises as strips from the first 9 ribs and converges posteriorly on the scapula to form the medial wall of the axilla. the innervation of the serratus anterior muscle is via the long thoracic nerve (bell's nerve), and the nerve itself is covered by the fascia of the serratus anterior muscle and lies anterior to the muscle.

Eligibility criteria:
inclusion criteria: * patients have postmastectomy pain of neuropathic nature, dn4 * 4 for at least 3ms duration. * the intensity of postmastectomy pain on vas score ≥ 5. * unsatisfactory treatment with 1st line antineuropathic drugs, pregabalin(150 mg daily) or deloxetine(60mg daily). exclusion criteria: * infection of the skin at or near site of needle puncture. * coagulopathy . * drug hypersensitivity or allergy to the studied drugs. * central or peripheral neuropthy . * significant organ dysfunction . * morbid obesity (bmi\>35kg/m2) . * vertebral anomalies.