A Comparative Study Between the Effectiveness of Preoperative ESPB Versus Preoperative PVPB in Decreasing PMPS. A Randomized Controlled Study

A Comparative Study Between the Effectiveness of Preoperative ESPB Versus Preoperative PVPB in Decreasing PMPS. A Randomized Controlled Study

A Comparative Study Between the Effectiveness of Preoperative Erector Spinae Plane Block Versus Preoperative Paravertebral Plane Block in Decreasing Post Mastectomy Pain Syndrome. A Randomized Controlled Study.

Breast cancer is considered the commonest malignancy affecting women with an incidence exceeding one million cases per year. Although it has a favorable prognosis with improved lines of treatment, some complications may still disturb the patient's life quality. One of these complications is post-mastectomy pain syndrome (PMPS) .Regional Anaesthesia (RA) is considered one of the most effective methods in reducing acute pain after breast surgeries, these include pectoral nerves block (PECS), serratus anterior plane block (SAPB), paravertebral plane block (PVPB) and erector spinae plane block (ESPB) . Our study is aiming for comparing the effect of preoperative PVPB versus preoperative ESPB in the prevention of PMPS in patients undergoing unilateral breast surgeries.

Breast cancer is considered the commonest malignancy affecting women with an incidence exceeding one million cases per year. Although it has a favorable prognosis with improved lines of treatment, some complications may still disturb the patient's life quality. One of these complications is post-mastectomy pain syndrome (PMPS) ¹. The International Association for Study of Pain (IASP) defines PMPS as chronic pain that persists more than 3 months in the anterior thorax, axilla &/or upper arm ². It is usually neuropathic in nature includes altered sensations such as dysesthesia, hypo or hyperesthesia, allodynia or particular qualities of dysesthesia e.g burning, dull aching sensations. It is usually of at least moderate intensity and may be either continuous or intermittent pain ³. The etiology and mechanism of PMPS remain incompletely clear yet. Some risk factors are believed to be associated with PMPS, including the presence and intensity of postoperative pain, the type of surgery, younger women, prior history of other types of pain and adjuvant therapies like chemo or radiotherapy ⁴. Regional Anaesthesia (RA) is considered one of the most effective methods in reducing acute pain after breast surgeries, these include pectoral nerves block (PECS), serratus anterior plane block (SAPB), paravertebral plane block (PVPB) and erector spinae plane block (ESPB) ⁵. Theoretically RA can minimize the development of PMPS by decreasing the afferent nociceptive input and central sensitization during the perioperative period, However clinically the role of RA in preventing PMPS is still under investigations ⁶. PVPB includes injecting local anesthetic in the paravertebral space where the spinal nerves exit from the intervertebral foraminae. Paravertebral space is bounded by the parietal pleura, superior costotransverse ligament, vertebrae, intervertebral foraminae and the heads of the ribs ⁷. While ESPB includes injection of the local anesthetic in the fascial plane between the vertebral transverse processes and the erector spinae muscle ⁸. Many studies were done in order to evaluate the efficacy of either ESPB or PVB in controlling acute postoperative pain after breast surgeries, some studies compared between them in controlling acute postoperative pain after breast surgeries ⁹. Also there are some studies that evaluate the effect of either ESPB or PVPB in the prevention of PMPS after breast surgeries ¹⁰, but still the comparison between the effect of preoperative ESPB versus the effect of preoperative PVPB in the prevention of PMPS in patients undergoing breast surgeries is still under investigated. Our study is aiming for comparing the effect of preoperative PVPB versus preoperative ESPB in the prevention of PMPS in patients undergoing unilateral breast surgeries.

This group will receive combined general anaesthesia with preoperative ultrasound guide paravertebral plane block

This group will receive combined general anaesthesia with preoperative ultrasound guided erector spinae plane block

This group will receive balanced general anesthesia using intravenous (0.1mg/kg) morphine, 30 mg ketorlac and 1 gm paracetamol).

With the patients are placed in the sitting position, counting down from C7 spinous process, a high frequency linear ultrasound probe is placed on the spinous process in the parasagittal plane at T5 level and then is slided laterally 2-3 cm to make the transverse processes clearly visualized . Under aseptic conditions, a 22-gauge block needle (50mm, B.Braun, Germany) is inserted using in-plane technique toward the paravertebral space, immediately above the pleura and below the superior costotransverse ligament. The position of the needle is confirmed by the descent of the pleura when injecting 2 to 3 ml of saline solution for hydrolocalization. Then 0.3ml/kg of bupivacaine 0.25% is injected under ultrasound guidance. Block success is defined as reduced sensitivity to cold and pinprick stimuli as compared with the contralateral side 20 minutes after local anesthetic injection.

With the patients are placed in the sitting position, counting down from C7 spinous process, a high frequency linear ultrasound probe is placed on the spinous process in the parasagittal plane at T5 level and then is slided laterally 2-3 cm to make the tips of the transverse processes clearly visualized . The following muscles seen from superficial to deep layer are trapezius, rhomboid major and erector spinae muscles. Under aseptic conditions, a 22-gauge block needle (50mm, B.Braun, Germany) is inserted using in-plane technique to reach the interfascial plane between the transverse process and the erector spinae muscle. Following confirmation of the accurate position of the needle tip with 3-5 ml normal saline solution, 0.3ml/kg of bupivacaine 0.25% is injected under ultrasound guidance. Block success is defined as reduced sensitivity to cold and pinprick stimuli as compared with the contralateral side 20 minutes after local anesthetic injection.

A junior pain physician is blinded to all treatment groups and asks about symptoms of PMPS including (pain, tingling, numbness, shooting pain, pricking pain or unbearable itching), site (chest wall, armpit, arm, shoulder or surgical scar) and grading scale using the brief pain inventory (BPI). Chronic pain is defined by a score of ≥ 3 on the single item (average pain) of the BPI. The BPI consists of three domains: (1) Pain intensity measured using the visual analogue scale (VAS) of 0 (no pain) to 10 (worst pain). (2) Pain that interferes with daily activities measured using a scale of 0 (no interference) to 10 (complete restriction to daily activities). (3) Percentage of relief provided by pain treatments measured using a scale of 0 (complete relief) to 10 (no relief) by the NRS.

• Assessment of acute postoperative pain using VAS (0 for no pain, 10 for the worst pain) at 0, 4, 8, 24 and 48 hours postoperatively.

Inclusion Criteria: Age ≥ 18 years and ≤ 60 years old. Female patients ASA ΙΙ, ΙΙΙ. Female patients scheduled for unilateral breast surgeries. Exclusion Criteria: Patient refusal. Patients have sepsis Patients known to have allergy against local anesthetics. Patients with prior surgery in areas above or below the clavicle or in the axillary region. Patients with opioid dependence, alcohol or drug abuse. Patient with coagulopathy. Patients with psychiatric illness that prevent them from proper pain perception and assessment. ASA 4 or higher.

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