Brief Summary

This study hypothesizes that in immediate breast reconstruction following tumor resection, the application of inactivated Pseudomonas aeruginosa preparation (PAP) may reduce infection rates by decreasing postoperative drainage output and shortening drainage tube removal time. Additionally, the local aseptic inflammation induced by PAP may promote fibrous capsule formation around the implant, shorten postoperative shaping time, and improve patients' quality of life and satisfaction. To test this hypothesis, the investigators designed a study to evaluate the efficacy of PAP compared with PI/TAB irrigation alone. Primary endpoints include drainage tube removal time and capsular contracture rate (assessed by Baker grade). Secondary endpoints include infection rate, total drainage volume, and postoperative BREAST-Q scores. Different concentrations of PAP will also be evaluated to determine the optimal therapeutic concentration.

Detailed Description

Postoperative infection rates in breast implant procedures range from 1% to 35%. Infection necessitates antibiotic treatment, may lead to unnecessary reoperations, and contributes to patient dissatisfaction. Inflammation and infection around the implant can promote biofilm formation, leading to capsular contracture (CC) following breast implant surgery. In patients undergoing breast reconstruction after tumor resection, postoperative infection may also delay adjuvant cancer treatment. Consequently, various antimicrobial irrigation solutions are routinely employed in immediate breast reconstruction after cosmetic surgery or tumor resection to reduce infection and CC rates, including 10% povidone-iodine (PI) and triple antibiotic solutions.

PI irrigation was first introduced by Burkhardt et al. in the 1980s for cosmetic breast surgery, followed by the development of a broader-spectrum triple antibiotic solution (TAB) by Adams et al. In 2000, the FDA prohibited the use of PI with breast implants due to concerns regarding higher contracture rates and potential degradation of silicone implants. Subsequent research by Adams et al. led to the development of a PI-free irrigation solution (TAB), which demonstrated comparable efficacy, albeit with slightly reduced coverage against Gram-negative bacteria. In August 2017, based on accumulated long-term data, the FDA lifted the restriction on PI use with implants, permitting its application for bacterial/biofilm mitigation and antimicrobial prophylaxis. Subsequent studies comparing the antimicrobial efficacy of PI and TAB have yielded mixed results, and a meta-analysis found no significant difference in CC rates between the two irrigation methods. However, the FDA withdrew bacitracin injections in 2020 due to safety concerns. As a result, standardization of antimicrobial irrigation solutions for implant-based immediate breast reconstruction remains lacking.

Notably, immediate reconstruction following tumor resection differs fundamentally from cosmetic surgery. For instance, the 14-point plan for cosmetic breast surgery recommends avoiding drainage tubes, a practice often unfeasible in immediate reconstruction, where two drainage tubes are typically placed for 4-7 days postoperatively. Breast surgeons aim to minimize drainage tube duration owing to the increased risk of surgical site infection (SSI). In immediate reconstruction, capsule formation time is prolonged compared with augmentation surgery, potentially leading to implant displacement and contracture.

PAP, derived from an inactivated PA-MSHA strain, has been shown by Long et al. to reduce postoperative drainage and shorten drainage tube removal time. PAP may also promote fibrous capsule formation, thereby reducing infection rates and improving patients' quality of life.

Postoperative infection rates in breast implant cases range from 1% to 35%. Infection requires antibiotic treatment, leads to unnecessary reoperations, and results in dissatisfaction. Inflammation and infection around the implant can cause biofilm formation, leading to capsular contracture (CC) after breast implant surgery. Postoperative infection may also delay adjuvant cancer treatment for patients undergoing breast reconstruction after tumor resection. Therefore, various antimicrobial irrigation solutions are commonly used in immediate breast reconstruction after cosmetic surgery or tumor resection to reduce infection and CC rates, such as 10% povidone-iodine (PI) and triple antibiotic solution.PI irrigation was proposed by Burkhardt et al. in the 1980s and used in cosmetic breast surgery, followed by the development of a broader-spectrum triple antibiotic solution (Betadine triple, BT) by Adams et al. Unfortunately, the FDA banned the use of PI with breast implants in 2000 due to reports of higher contraction rates and potential degradation of silicone implants. After further research, Adams et al. designed a PI-free irrigation solution (TAB) that was also effective, though with slightly lower coverage of Gram-negative bacteria.In August 2017, the FDA lifted the restriction on PI use with implants based on long-term data, allowing PI to be used for bacterial/biofilm mitigation and antimicrobial prophylaxis. Subsequent studies compared the antimicrobial efficacy of PI and TAB, with mixed results. A meta-analysis found no significant difference in CC rates between PI and TAB irrigation. However, the FDA withdrew bacitracin injections in 2020 due to safety concerns. As a result, there is still a lack of standardization in the choice of antimicrobial solutions for implant irrigation in immediate breast reconstruction surgery.

On the other hand, immediate reconstruction after tumor resection has different principles from cosmetic surgery, such as avoiding drainage tubes in the 14-point plan for breast cosmetic surgery. This is often not feasible in immediate reconstruction, where two drainage tubes are typically placed for 4-7 days postoperatively. Breast surgeons aim to minimize drainage tube time due to increased SSI risk. In immediate reconstruction, the capsule formation time is longer than in augmentation surgery, leading to potential implant displacement and contracture. PAP, prepared from an inactivated PA-MSHA strain, was shown to reduce drainage and shorten tube removal time by Long et al.. PAP may promote fibrous capsule formation, reducing infection rates and improving patient quality of life.

Inclusion Criteria:

• Age 18 and above
• Female
• Preoperative pathological confirmation of invasive breast cancer or ductal carcinoma in situ
• Clinical T1 and T2 (maximum tumor diameter ≤5 cm)
• Clinically negative axillary lymph nodes (clinical examination and ultrasound suggest negative axillary lymph nodes; fine needle aspiration is negative for suspected axillary lymph node abnormalities)
• No clinical or radiological evidence of distant metastasis
• Patients undergoing skin-sparing mastectomy or breast-conserving surgery - BMI < 35
• Patients without lactational apoptosis or with mild breast apoptosis
• Implant volume < 500 milliliters (11) Able and willing to sign the informed consent form (ICF)

Exclusion Criteria:

• Breast patients with moderate to severe breast development, or patients who require subcutaneous mastectomy using Wise mode or other breast lift methods
• Body mass index >=35
• Patients who underwent symmetrical breast surgery immediately or later on the unaffected side
• Patients with locally advanced breast cancer receiving neoadjuvant therapy
• Patients who are currently participating in other clinical trials, which may have an impact on participation in this trial
• Neoadjuvant therapy has been completed, and there is a clear indication for adjuvant radiotherapy after surgery
• History of previous breast cancer (patients with ipsilateral recurrence after breast-conserving surgery)
• Pregnant and lactating women
• Smoking history
• History of previous diabetes mellitus