Effects of Negative Pressure Wound Bandaging After Mastectomy (NEPTAM)

Project Plan

Title Is negative pressure wound therapy associated with a decreased risk of postoperative seroma in breast cancer patients who have undergone mastectomy?

Introduction Breast cancer is the most common cancer in women in Sweden as well as globally. In 2022, there were 2,3 million women diagnosed with breast cancer and 670 000 deaths globally (1). More than every tenth woman in Sweden will suffer from breast cancer during their lifetime. Since the 1970s the 10 year survival rate in Sweden has increased from around 54% to 88% and the 5 year survival rate has increased from around 69% to 93% (2).

There are two main types of surgical treatment for breast cancer, breast-conserving surgery and mastectomy. The number of mastectomies have gradually decreased because of decreased tumor size at diagnosis and an increased use of oncoplastic surgery and preoperative treatment. However, it still has an important role with indications like: inflammatory tumor, T4-tumor after preoperative treatment, large tumors that progress during preoperative treatment, local recurrence after previous partial mastectomy with radiotherapy, multicentric tumors, persisting positive margins after extended excision after partial mastectomy or contraindications for postoperative radiotherapy (2).

Wound complications after mastectomy such as surgical site infections (SSI), seromas, wound dehiscence, wound necrosis and hematoma are a frequently occurring problem (3, 4). The complications are a major cause of morbidity for patients and a significant cost burden for healthcare providers. Surgical site complications in breast cancer patients can also delay the initiation of adjuvant treatment and may negatively impact both recurrence risk and overall survival (4, 5).

There is research showing that Negative Pressure Wound Therapy (NPWT) reduces the risk for SSI with up to 33% compared to standard care, over a range of surgical specialties (6). It is also a promising technique for preventing and managing wound complications in high-risk closed incisions (3). NPWT is thought to reduce bacterial contamination, exudate and edema, promote lymphatic and local blood flow, and stimulate tissue granulation. No significant difference has been observed between -80mmHg and -125mmHg devices (6).

A systematic review and meta-analysis by Cagney et al has shown that prophylactic application of NPWT is associated with significantly fewer surgical site complications including SSI, seroma, wound dehiscence and wound necrosis for closed breast incisions in breast surgery, compared with conventional non-NPWT dressings, while there was no significant difference in rates of hematoma (5). A meta-analysis by Song et al showed similar results, however, with no significant difference in rates of seroma (7).

A range of studies looking at NPWT in various types of oncoplastic and reconstructive breast surgeries suggest an association with reduced postoperative wound complications (8-11). Some key findings are reduced mastectomy flap necrosis in skin-sparing and nipple-sparing mastectomy (12), improvement in quality of scarring in bilateral reduction mammoplasty (13), reduced development of major seroma, as well as reduced duration and total volume of seroma in prepectoral breast reconstruction (14). The cost-effectiveness of NPWT for reducing complications after breast surgery (8), especially in high-risk patients (9), has also been implied.

Looking at mastectomies specifically, a study by De Rooij et al evaluated postoperative wound complications following the use of NPWT in patients undergoing mastectomy. They suggested that it neither leads to fewer postoperative wound complications, nor leads to fewer patients requiring unplanned visits or fewer patients with clinically significant seroma (3). Esen et al, however, compared NPWT to conventional dressings in modified radical mastectomy (mastectomy + axillary lymph nodes) in high-risk patients and suggested that NPWT significantly reduced postoperative seroma, flap ischemia and flap dehiscence. No difference was determined regarding postoperative hematoma, flap necrosis and SSI (4).

Knowledge gap To summarize, there is limited research with contradictory results on whether NPWT decreases the risk of postoperative seroma and surgical site complications in patients who have undergone mastectomy.

Aim The aim of our study is to assess if PICO NPWT affects the risk of postoperative seroma in breast cancer patients who have undergone mastectomy compared to conventional dressings.

Hypothesis We hypothesize that PICO NPWT reduces the risk of postoperative seroma in breast cancer patients who have undergone mastectomy.

Material and methods Study design This is a randomized controlled trial comparing PICO negative pressure wound therapy to conventional dressings in breast cancer patients who have undergone mastectomy.

Setting It is a pilot single-center study at the district hospital Falu Lasarett in Sweden. The data collection will take place from Mars 2025 - September 2026. Data regarding patient characteristics and postoperative complications will be extracted from patient records.

Study size We will have a sample size of 64 patients based on power calculations (32 patients in the control group and 32 patients in the intervention group). Power calculations were based on 50% anticipated incidence of seroma in the control group, 10% anticipated incidence of seroma in the intervention group, a power of 90%, a P-value of 0.05 (alpha) and compensation of 20% loss to follow-up.

PICO NPWT PICO NPWT by Smith and Nephew will be used. The dressing size is 15 x 30cm. It will be applied directly on the skin in the operating theater. It is attached to a small device which is turned on continuously for 7 days and can be carried around in a pocket. It may only be paused for showers. Active drainage needs to be placed outside the dressing. If the patient has a pacemaker the device needs to be placed 10 cm apart. Contraindications for the PICO NPWT include oversensitivity to silicone and active bleeding.

Patient description Eligibility criteria

• Breast cancer patients undergoing mastectomy
• Female
• Age >18 years

Exclusion criteria:

• Direct reconstruction with implants
• The use of harmonic Johnson and Johnson instrument during surgery

Source and method of participant selection All patients with a newly diagnosed breast cancer come to the specialized surgical outpatient clinic for a primary visit to discuss their diagnosis and surgical treatment plan. They meet a breast surgeon and a contact nurse. All cases are discussed at a multidisciplinary conference. All breast cancer patients who are planned for a mastectomy will be offered to participate in the study. The type of wound dressing will be randomized during each surgery (by a program on the computer in the operation theatre). Baseline data will be recorded before randomization.

Type of data Outcome The primary outcome is postoperative seroma. We define seroma as clinically verified exudate in the wound cavity. The amount of seroma aspirated will be measured and recorded. The secondary outcome is other surgical site complications such as, surgical site infection, hematoma, wound dehiscence and necrosis. The follow up time will be 6 months. The outcomes will be measured by follow-up appointments at the outpatient clinic.

Standard care today includes the following visits to the outpatient clinic:

• Follow up after 1 day with a contact nurse to remove active drainage.
• Follow up after 2-3 weeks with a surgeon to receive the pathology report and continued treatment plan decided at the multidisciplinary conference.

The extra visits related to this study will be:

• Follow up after 7 days with a contact nurse for the intervention group to remove the PICO negative pressure wound therapy.
• Follow up after 6 months with a contact nurse for both groups (control group and intervention group).

Exposure PICO negative pressure wound therapy or conventional dressings.

Covariates High-risk groups include: BMI >30, smoking, diabetes, corticosteroids, anticoagulants, neoadjuvant chemotherapy, previous radiotherapy and immunosuppressive therapy. Age, sentinel node biopsy, axillary lymph node dissection and ASA classification will be noted.

Statistical methods and analyses The Statistical Programme SPSS will be used and the statistical analyses will be conducted by an external statistician from CKF Dalarna.

Ethical permit and review We have applied for an Ethical permit via Etikprövningens Myndighet (the Swedish Ethical Review Board). Ethical approval has been obtained with the approval number/ID 2025-00006-01. Patient data will be handled anonymously. Patients offered to participate in the study will sign a waiver of informed consent.

Funding Funding through surgical residency project.

References

1. World Health Organization. Breast cancer [Internet]. Geneva: World Health Organization; 2024[cited 2024-10-29]. Available from: https://www.who.int/news-room/fact-sheets/detail/breast-cancer
2. Regionala cancercentrum i samverkan. Bröstcancer Nationellt vårdprogram. Stockholm: Regionala cancercentrum i samverkan; 2024. Version: 5.1.
3. De Rooij L, Van Kuijk SMJ, Van Haaren ERM, Janssen A, Vissers YLJ, Beets GL, et al. Negative pressure wound therapy does not decrease postoperative wound complications in patients undergoing mastectomy and flap fixation. Scientific Reports. 2021; 11(1):1-7.
4. Esen E, Morkavuk SB, Turan M, Akyuz S, Guler S, Akgul GG, et al. The use of incisional negative pressure wound therapy on high-risk breast cancer mastectomy patients. Asian J Surg. 2024;(xxxx).
5. Cagney D, Simmons L, O´Leary DP, Corrigan M, Kelly L, O´Sullivan MJ, et al. The Efficacy of Prophylactic Negative Pressure Wound Therapy for Closed Incisions in Breast Surgery: A Systematic Review and Meta-Analysis. World J Surg. 2020;44(5):1526-1537.
6. Groenen H, Jalalzadeh H, Buis DR, Dreissen YEM, Goosen JHM, Griekspoor M, et al. Incisional negative pressure wound therapy for the prevention of surgical site infection: an up-to-date meta-analysis and trial sequential analysis. eClinicalMedicine. 2023;62:102105.
7. Song J, Liu X, Wu T. Effectiveness of prophylactic application of negative pressure wound therapy in stopping surgical site wound problems for closed incisions in breast cancer surgery: A meta-analysis. Int Wound J. 2023;20(2):241-250.
8. Tormey S, Earley H, Sloan S, Mathers H, Varzgalis M, Wahab SAE, et al. The role of prophylactic, single-use, negative pressure wound therapy dressings in wound management following breast surgery. Wounds International. 2021;12(4):30-36.
9. Vidya R, Khosla M, Baek K, Vinayagam R, Thekkinkattil D, Laws S, et al. Prophylactic Use of Negative Pressure Wound Therapy in High-risk Patients Undergoing Oncoplastic and Reconstructive Breast Surgery. Plast Reconstr Surg Glob Open. 2023;11(12):e5488.
10. Fogacci T, Cattin F, Semprini G, Frisoni G, Fabiocchi L, Samorani D. The negative pressure therapy with PICO as a prevention of surgical site infection in high-risk patients undergoing breast surgery. Breast J. 2020;26(5):1071-1073.
11. Warehem CM, Karamchandani MM, Ku GDLC, Gaffney K, Sekigami Y, Persing SM, et al. Closed Incision Negative Pressure Therapy in Oncoplastic Breast Surgery: A Comparison of Outcomes. Plast Reconstr Surg Glob Open. 2023;11(4):e4936.
12. Tang N, Li H, Chow Y, Blake W. Non-operative adjuncts for the prevention of mastectomy skin flap necrosis: a systematic review and meta-analysis. ANZ J Surg. 2023;93(1-2):65-75.
13. Tanaydin V, Beugels J, Andriessen A, Sawor JH, van der Hulst RRWJ. Randomized Controlled Study Comparing Disposable Negative-Pressure Wound Therapy with Standard Care in Bilateral Breast Reduction Mammoplasty Evaluating Surgical Site Complications and Scar Quality. Aest Plas Surg. 2018;42(4):927-935.
14. Ryu JY, Lee JH, Kim JS, Lee JS, Lee JW, Choi KY, et al. Usefulness of Incisional Negative Pressure Wound Therapy for Decreasing Wound Complication Rates and Seroma Formation Following Prepectoral Breast Reconstruction. Aesth Plast Surg. 2022;46(2):633-641.

Supervisor Rebecca Paul rebecca.paul@regiondalarna.se