Trial Outcomes & Findings for PECS II vs. MTP for Analgesia After MRM (NCT NCT06187909)
NCT ID: NCT06187909
Last Updated: 2026-01-21
Results Overview
Visual Analogue Scale is a scale for pain assessment ranging from 0 to 10 where 0 is minimum and means no pain while 10 is maximum and means maximum pain which means worse outcome
Recruitment status
COMPLETED
Study phase
NA
Target enrollment
88 participants
Primary outcome timeframe
will be evaluated at hour-4 postoperatively
Results posted on
2026-01-21
Participant Flow
This was a single-center, prospective, randomized controlled trial conducted at Ain Shams University Hospital. A total of 112 patients scheduled for modified radical mastectomy were assessed for eligibility between November 2023 and July 2025.
Out of 112 screened patients, 24 were excluded (17 did not meet inclusion criteria, 7 declined participation), leaving 88 enrolled and randomly allocated to Group A (PECS II block, n=44) and Group B (MTP block, n=44). Four participants withdrew consent during follow-up, resulting in 84 completions (42 per group). All remaining participants were included in the final analysis, with no exclusions
Participant milestones
| Measure |
MTP Block Group
Forty-four ASA I-II female patients, aged 40-65 years and scheduled for modified radical mastectomy, received an ultrasound-guided midpoint transverse process to pleura (MTP) block. A high-frequency linear probe was placed parasagittally, approximately 3 cm lateral to the midline at the T2 and T6 vertebral levels. A 22-gauge echogenic needle was advanced in-plane to the midpoint between the transverse process and pleura, and 10 mL of 0.25% bupivacaine was injected at each level.
|
PECS II Block Group
Forty-four ASA I-II female patients, aged 40-65 years and scheduled for modified radical mastectomy, received an ultrasound-guided PECS II block. A high-frequency linear probe was placed beneath the clavicle to identify the intermuscular plane between the pectoralis major and minor, where 10 mL of 0.25% bupivacaine was injected. The probe was then repositioned laterally to identify the plane between the pectoralis minor and serratus anterior at the level of the third to fourth ribs, where another 10 mL of 0.25% bupivacaine was injected.
|
|---|---|---|
|
Overall Study
STARTED
|
44
|
44
|
|
Overall Study
COMPLETED
|
42
|
42
|
|
Overall Study
NOT COMPLETED
|
2
|
2
|
Reasons for withdrawal
| Measure |
MTP Block Group
Forty-four ASA I-II female patients, aged 40-65 years and scheduled for modified radical mastectomy, received an ultrasound-guided midpoint transverse process to pleura (MTP) block. A high-frequency linear probe was placed parasagittally, approximately 3 cm lateral to the midline at the T2 and T6 vertebral levels. A 22-gauge echogenic needle was advanced in-plane to the midpoint between the transverse process and pleura, and 10 mL of 0.25% bupivacaine was injected at each level.
|
PECS II Block Group
Forty-four ASA I-II female patients, aged 40-65 years and scheduled for modified radical mastectomy, received an ultrasound-guided PECS II block. A high-frequency linear probe was placed beneath the clavicle to identify the intermuscular plane between the pectoralis major and minor, where 10 mL of 0.25% bupivacaine was injected. The probe was then repositioned laterally to identify the plane between the pectoralis minor and serratus anterior at the level of the third to fourth ribs, where another 10 mL of 0.25% bupivacaine was injected.
|
|---|---|---|
|
Overall Study
Withdrawal by Subject
|
2
|
2
|
Baseline Characteristics
Race and Ethnicity were not collected from any participant.
Baseline characteristics by cohort
| Measure |
MTP Block Group
n=42 Participants
Forty-four ASA I-II female patients, aged 40-65 years and scheduled for modified radical mastectomy, received an ultrasound-guided midpoint transverse process to pleura (MTP) block. A high-frequency linear probe was positioned parasagittally about 3 cm lateral to the midline at the T2 and T6 vertebral levels. A 22-gauge needle was advanced in-plane, and 10 mL of 0.25% bupivacaine was injected at each level.
|
PECS II Block Group
n=42 Participants
Forty-four ASA I-II female patients, aged 40-65 years and scheduled for modified radical mastectomy, received an ultrasound-guided PECS II block with 20 mL of 0.25% bupivacaine (10 mL between the pectoralis major and minor, and 10 mL between the pectoralis minor and serratus anterior at the third to fourth ribs).
|
Total
n=84 Participants
Total of all reporting groups
|
|---|---|---|---|
|
Age, Continuous
|
42.4 years
STANDARD_DEVIATION 5.8 • n=42 Participants
|
41.2 years
STANDARD_DEVIATION 4.9 • n=42 Participants
|
41.8 years
STANDARD_DEVIATION 5.4 • n=84 Participants
|
|
Sex: Female, Male
Female
|
42 Participants
n=42 Participants
|
42 Participants
n=42 Participants
|
84 Participants
n=84 Participants
|
|
Sex: Female, Male
Male
|
0 Participants
n=42 Participants
|
0 Participants
n=42 Participants
|
0 Participants
n=84 Participants
|
|
Race and Ethnicity Not Collected
|
—
|
—
|
0 Participants
Race and Ethnicity were not collected from any participant.
|
|
weight
|
78.5 kilograms
STANDARD_DEVIATION 8.5 • n=42 Participants
|
79.1 kilograms
STANDARD_DEVIATION 8.5 • n=42 Participants
|
78.8 kilograms
STANDARD_DEVIATION 8.5 • n=84 Participants
|
|
height
|
1.68 meters
STANDARD_DEVIATION 0.06 • n=42 Participants
|
1.67 meters
STANDARD_DEVIATION 0.05 • n=42 Participants
|
1.675 meters
STANDARD_DEVIATION 0.055 • n=84 Participants
|
|
body mass index
|
27.9 kilograms per meter square
STANDARD_DEVIATION 2.3 • n=42 Participants
|
28.3 kilograms per meter square
STANDARD_DEVIATION 2.2 • n=42 Participants
|
28.1 kilograms per meter square
STANDARD_DEVIATION 2.25 • n=84 Participants
|
PRIMARY outcome
Timeframe: will be evaluated at hour-4 postoperativelyVisual Analogue Scale is a scale for pain assessment ranging from 0 to 10 where 0 is minimum and means no pain while 10 is maximum and means maximum pain which means worse outcome
Outcome measures
| Measure |
MTP Block Group
n=42 Participants
Forty-four ASA I-II female patients, aged 40-65 years and scheduled for modified radical mastectomy received an ultrasound-guided midpoint transverse process to pleura (MTP) block. A high-frequency linear probe was positioned parasagittally about 3 cm lateral to the midline at the T2 and T6 vertebral levels. A 22-gauge echogenic needle was advanced in-plane to the midpoint between the transverse process and pleura, and 10 mL of 0.25% bupivacaine was injected at each level.
|
PECS II Block Group
n=42 Participants
Forty-four ASA I-II female patients, aged 40-65 years and scheduled for modified radical mastectomy, received an ultrasound-guided PECS II block. Using a high-frequency linear probe, 10 mL of 0.25% bupivacaine was injected between the pectoralis major and minor muscles. The probe was then repositioned laterally to the plane between the pectoralis minor and serratus anterior at the third to fourth ribs, where another 10 mL of 0.25% bupivacaine was injected.
|
|---|---|---|
|
Post-operative Pain Severity Assessed by VAS at Hour-4
|
1.4 score on a scale
Standard Deviation 0.6
|
2.2 score on a scale
Standard Deviation 0.7
|
SECONDARY outcome
Timeframe: 24 hours postoperativelyComparison between postoperative pain severity after 2 hours, 4 hours, 8 hours, 12 hours, 18 hours and 24 hours postoperative between both groups using visual analogue score Visual Analogue Scale is a scale for pain assessment ranging from 0 to 10 where 0 is minimum and means no pain while 10 is maximum and means maximum pain which means worse outcome
Outcome measures
| Measure |
MTP Block Group
n=42 Participants
Forty-four ASA I-II female patients, aged 40-65 years and scheduled for modified radical mastectomy received an ultrasound-guided midpoint transverse process to pleura (MTP) block. A high-frequency linear probe was positioned parasagittally about 3 cm lateral to the midline at the T2 and T6 vertebral levels. A 22-gauge echogenic needle was advanced in-plane to the midpoint between the transverse process and pleura, and 10 mL of 0.25% bupivacaine was injected at each level.
|
PECS II Block Group
n=42 Participants
Forty-four ASA I-II female patients, aged 40-65 years and scheduled for modified radical mastectomy, received an ultrasound-guided PECS II block. Using a high-frequency linear probe, 10 mL of 0.25% bupivacaine was injected between the pectoralis major and minor muscles. The probe was then repositioned laterally to the plane between the pectoralis minor and serratus anterior at the third to fourth ribs, where another 10 mL of 0.25% bupivacaine was injected.
|
|---|---|---|
|
Post-operative Pain Severity Assessed by VAS on Admission to Postanesthesia Care Unit (PACU), at Hour-2, Hour-8, Hour-12, Hour-18 and Hour-24.
Post-operative pain severity assessed by Visual analogue scale on admission to PACU
|
0.3 score on a scale
Standard Deviation 0.5
|
0.3 score on a scale
Standard Deviation 0.5
|
|
Post-operative Pain Severity Assessed by VAS on Admission to Postanesthesia Care Unit (PACU), at Hour-2, Hour-8, Hour-12, Hour-18 and Hour-24.
Post-operative pain severity assessed by Visual analogue scale at 2 hours postoperatively.
|
1.1 score on a scale
Standard Deviation 0.8
|
1.4 score on a scale
Standard Deviation 0.6
|
|
Post-operative Pain Severity Assessed by VAS on Admission to Postanesthesia Care Unit (PACU), at Hour-2, Hour-8, Hour-12, Hour-18 and Hour-24.
Post-operative pain severity assessed by Visual analogue scale at 8 hours postoperatively.
|
2.5 score on a scale
Standard Deviation 0.5
|
3.2 score on a scale
Standard Deviation 0.6
|
|
Post-operative Pain Severity Assessed by VAS on Admission to Postanesthesia Care Unit (PACU), at Hour-2, Hour-8, Hour-12, Hour-18 and Hour-24.
Post-operative pain severity assessed by Visual analogue scale at 12 hours postoperatively.
|
2.9 score on a scale
Standard Deviation 0.6
|
3.2 score on a scale
Standard Deviation 0.7
|
|
Post-operative Pain Severity Assessed by VAS on Admission to Postanesthesia Care Unit (PACU), at Hour-2, Hour-8, Hour-12, Hour-18 and Hour-24.
Post-operative pain severity assessed by Visual analogue scale at 18 hours postoperatively.
|
1.9 score on a scale
Standard Deviation 0.7
|
2.2 score on a scale
Standard Deviation 0.5
|
|
Post-operative Pain Severity Assessed by VAS on Admission to Postanesthesia Care Unit (PACU), at Hour-2, Hour-8, Hour-12, Hour-18 and Hour-24.
Post-operative pain severity assessed by Visual analogue scale at 24 hours postoperatively.
|
1.5 score on a scale
Standard Deviation 0.8
|
1.7 score on a scale
Standard Deviation 0.5
|
SECONDARY outcome
Timeframe: 24 hours postoperativelyComparison between both groups regarding the time of first needed dose of nalbuphine
Outcome measures
| Measure |
MTP Block Group
n=42 Participants
Forty-four ASA I-II female patients, aged 40-65 years and scheduled for modified radical mastectomy received an ultrasound-guided midpoint transverse process to pleura (MTP) block. A high-frequency linear probe was positioned parasagittally about 3 cm lateral to the midline at the T2 and T6 vertebral levels. A 22-gauge echogenic needle was advanced in-plane to the midpoint between the transverse process and pleura, and 10 mL of 0.25% bupivacaine was injected at each level.
|
PECS II Block Group
n=42 Participants
Forty-four ASA I-II female patients, aged 40-65 years and scheduled for modified radical mastectomy, received an ultrasound-guided PECS II block. Using a high-frequency linear probe, 10 mL of 0.25% bupivacaine was injected between the pectoralis major and minor muscles. The probe was then repositioned laterally to the plane between the pectoralis minor and serratus anterior at the third to fourth ribs, where another 10 mL of 0.25% bupivacaine was injected.
|
|---|---|---|
|
Time of First Rescue Analgesia
|
12.8 hours
Standard Deviation 0.8
|
7.9 hours
Standard Deviation 1.2
|
SECONDARY outcome
Timeframe: 24 hours postoperativelyComparison between both groups regarding total consumed nalbuphine in first 24 hours postoperative
Outcome measures
| Measure |
MTP Block Group
n=42 Participants
Forty-four ASA I-II female patients, aged 40-65 years and scheduled for modified radical mastectomy received an ultrasound-guided midpoint transverse process to pleura (MTP) block. A high-frequency linear probe was positioned parasagittally about 3 cm lateral to the midline at the T2 and T6 vertebral levels. A 22-gauge echogenic needle was advanced in-plane to the midpoint between the transverse process and pleura, and 10 mL of 0.25% bupivacaine was injected at each level.
|
PECS II Block Group
n=42 Participants
Forty-four ASA I-II female patients, aged 40-65 years and scheduled for modified radical mastectomy, received an ultrasound-guided PECS II block. Using a high-frequency linear probe, 10 mL of 0.25% bupivacaine was injected between the pectoralis major and minor muscles. The probe was then repositioned laterally to the plane between the pectoralis minor and serratus anterior at the third to fourth ribs, where another 10 mL of 0.25% bupivacaine was injected.
|
|---|---|---|
|
Cumulative Post-operative Nalbuphine Consumption in the First 24 Hours
|
8.3 milligrams
Standard Deviation 2.6
|
13.3 milligrams
Standard Deviation 3.6
|
SECONDARY outcome
Timeframe: 24 hours postoperativelyComparison between both groups regarding postoperative side effects and complications
Outcome measures
| Measure |
MTP Block Group
n=42 Participants
Forty-four ASA I-II female patients, aged 40-65 years and scheduled for modified radical mastectomy received an ultrasound-guided midpoint transverse process to pleura (MTP) block. A high-frequency linear probe was positioned parasagittally about 3 cm lateral to the midline at the T2 and T6 vertebral levels. A 22-gauge echogenic needle was advanced in-plane to the midpoint between the transverse process and pleura, and 10 mL of 0.25% bupivacaine was injected at each level.
|
PECS II Block Group
n=42 Participants
Forty-four ASA I-II female patients, aged 40-65 years and scheduled for modified radical mastectomy, received an ultrasound-guided PECS II block. Using a high-frequency linear probe, 10 mL of 0.25% bupivacaine was injected between the pectoralis major and minor muscles. The probe was then repositioned laterally to the plane between the pectoralis minor and serratus anterior at the third to fourth ribs, where another 10 mL of 0.25% bupivacaine was injected.
|
|---|---|---|
|
Incidence of Postoperative Side Effects and Complications
Hematoma
|
9 Participants
|
12 Participants
|
|
Incidence of Postoperative Side Effects and Complications
Nausea
|
2 Participants
|
8 Participants
|
|
Incidence of Postoperative Side Effects and Complications
vomiting
|
1 Participants
|
3 Participants
|
|
Incidence of Postoperative Side Effects and Complications
pneumothorax
|
1 Participants
|
0 Participants
|
Adverse Events
MTP Block Group
Serious events: 1 serious events
Other events: 12 other events
Deaths: 0 deaths
PECS II Block Group
Serious events: 0 serious events
Other events: 23 other events
Deaths: 0 deaths
Serious adverse events
| Measure |
MTP Block Group
n=42 participants at risk
Forty-four ASA I-II female patients, aged 40-65 years and scheduled for modified radical mastectomy received an ultrasound-guided midpoint transverse process to pleura (MTP) block. A high-frequency linear probe was positioned parasagittally about 3 cm lateral to the midline at the T2 and T6 vertebral levels. A 22-gauge echogenic needle was advanced in-plane to the midpoint between the transverse process and pleura, and 10 mL of 0.25% bupivacaine was injected at each level.
|
PECS II Block Group
n=42 participants at risk
Forty-four ASA I-II female patients, aged 40-65 years and scheduled for modified radical mastectomy, received an ultrasound-guided PECS II block. Using a high-frequency linear probe, 10 mL of 0.25% bupivacaine was injected between the pectoralis major and minor muscles. The probe was then repositioned laterally to the plane between the pectoralis minor and serratus anterior at the third to fourth ribs, where another 10 mL of 0.25% bupivacaine was injected.
|
|---|---|---|
|
Respiratory, thoracic and mediastinal disorders
Pneumothorax
|
2.4%
1/42 • Number of events 1 • 24 hours postoperatively
Adverse events included block-related complications: vascular puncture, pneumothorax, and local anesthetic systemic toxicity. Events were assessed by anesthesiologists intraoperatively and during the first 24 hours after surgery.
|
0.00%
0/42 • 24 hours postoperatively
Adverse events included block-related complications: vascular puncture, pneumothorax, and local anesthetic systemic toxicity. Events were assessed by anesthesiologists intraoperatively and during the first 24 hours after surgery.
|
Other adverse events
| Measure |
MTP Block Group
n=42 participants at risk
Forty-four ASA I-II female patients, aged 40-65 years and scheduled for modified radical mastectomy received an ultrasound-guided midpoint transverse process to pleura (MTP) block. A high-frequency linear probe was positioned parasagittally about 3 cm lateral to the midline at the T2 and T6 vertebral levels. A 22-gauge echogenic needle was advanced in-plane to the midpoint between the transverse process and pleura, and 10 mL of 0.25% bupivacaine was injected at each level.
|
PECS II Block Group
n=42 participants at risk
Forty-four ASA I-II female patients, aged 40-65 years and scheduled for modified radical mastectomy, received an ultrasound-guided PECS II block. Using a high-frequency linear probe, 10 mL of 0.25% bupivacaine was injected between the pectoralis major and minor muscles. The probe was then repositioned laterally to the plane between the pectoralis minor and serratus anterior at the third to fourth ribs, where another 10 mL of 0.25% bupivacaine was injected.
|
|---|---|---|
|
Injury, poisoning and procedural complications
Hematoma
|
21.4%
9/42 • Number of events 9 • 24 hours postoperatively
Adverse events included block-related complications: vascular puncture, pneumothorax, and local anesthetic systemic toxicity. Events were assessed by anesthesiologists intraoperatively and during the first 24 hours after surgery.
|
28.6%
12/42 • Number of events 12 • 24 hours postoperatively
Adverse events included block-related complications: vascular puncture, pneumothorax, and local anesthetic systemic toxicity. Events were assessed by anesthesiologists intraoperatively and during the first 24 hours after surgery.
|
|
Gastrointestinal disorders
Nausea
|
4.8%
2/42 • Number of events 2 • 24 hours postoperatively
Adverse events included block-related complications: vascular puncture, pneumothorax, and local anesthetic systemic toxicity. Events were assessed by anesthesiologists intraoperatively and during the first 24 hours after surgery.
|
19.0%
8/42 • Number of events 8 • 24 hours postoperatively
Adverse events included block-related complications: vascular puncture, pneumothorax, and local anesthetic systemic toxicity. Events were assessed by anesthesiologists intraoperatively and during the first 24 hours after surgery.
|
|
Gastrointestinal disorders
Vomiting
|
2.4%
1/42 • Number of events 1 • 24 hours postoperatively
Adverse events included block-related complications: vascular puncture, pneumothorax, and local anesthetic systemic toxicity. Events were assessed by anesthesiologists intraoperatively and during the first 24 hours after surgery.
|
7.1%
3/42 • Number of events 3 • 24 hours postoperatively
Adverse events included block-related complications: vascular puncture, pneumothorax, and local anesthetic systemic toxicity. Events were assessed by anesthesiologists intraoperatively and during the first 24 hours after surgery.
|
Additional Information
Yasser Mohamed Reyad Ahmed El-Mansoury
Department of Anesthesia, Intensive Care, and Pain Management, Faculty of Medicine, Ain Shams University, Cairo, Egypt
Phone: 01000286206
Email: [email protected]
Results disclosure agreements
- Principal investigator is a sponsor employee
- Publication restrictions are in place