A multi-center, double blind randomized controlled trial evaluating flap fixation after mastectomy using sutures or tissue glue versus conventional closure: protocol for the Seroma reduction After Mastectomy (SAM) trial

Prospective Study to Evaluate Efficacy of Single Versus Double Drains in Breast Cancer Patients Undergoing Surgery

Seroma formation is a common sequel following modified radical mastectomy (MRM), which hinders healing, may prolong hospital stay, and cause a delay in adjuvant treatment. Closed suction drains have been used to prevent formation of seroma; however, the use of a single drain in the axilla along with draining the mastectomy flaps and axilla separately remains a topic of debate. This prospective randomized dual-arm study was conducted in the Department of Endocrine Surgery. All female patients with carcinoma breast diagnosed on core tissue biopsy, undergoing modified radical mastectomy, upfront or post neoadjuvant systemic therapy were included. Patients were randomized into two groups. In the first group, a single drain was placed in the axilla whereas in the second group, a drain each was placed below the mastectomy flaps and the axilla. Patients' particulars and the weight of the mass excised along with the operative details were documented. The volume of the drain was recorded daily. The flap drain was removed on postoperative day 5 and the axillary drain was removed when the drain volume was less than 30 mL/24 h for 2 consecutive days. The period of drain placement, volume of drainage, volume of seroma (if formed), and other complications (if any) were recorded. Patients in the single drain group had a significantly earlier drain removal time as compared to those with double drains (p = 0.01). The number of patients in whom seroma formation had occurred was more in the double drain group, but the difference was not significant. The average volume of aspirated seroma fluid was insignificantly more in the single drain group. The only other complication noticed was flap necrosis-in 5% patients of the double drain group. Total volume of drainage (p < 0.0001) and type of drain (p = 0.0208) were associated with higher rates of seroma formation, whereas BMI (p = 0.0516), weight of excised breast mass (p = 0.407), and age (p = 0.6379) were not associated with the rate of seroma formation. Outcomes in terms of drain volume or seroma formation were statistically indifferent between the two groups. Still, use of only a single axillary drain should be promoted, keeping in mind the earlier drain removal period, better patient compliance, and reduced hospital stay.

Prospective Study on Avoiding Seroma Formation by Flap Fixation After Modified Radical Mastectomy

INTRODUCTION

Seroma development after mastectomy is a common complication. Continued seroma causes increased outpatient visits, repeated aspirations, infection, delayed healing, delayed adjuvant therapy, and increased cost. Various treatments are being attempted to prevent and reduce seroma development. We examined the effects of flap fixation on seroma using absorbable sutures after modified radical mastectomy (MRM).

METHODS

The prospectively recorded data of patients who underwent surgery for breast cancer were analyzed retrospectively. 72 consecutive patients who underwent MRM were included in the study. Patients who underwent MRM in the same way by the same surgeon were divided into two groups: the group whose wound was closed by fixing the flap to the chest wall with an absorbable suture (group A), and the group whose wound was closed with the classical method (group B). The groups were compared in terms of seroma development, clinicopathological data, and early complications.

RESULTS

Drain removal time and the total amount of drained fluid in group A patients were significantly lower than drain removal time and the total amount of drained fluid in group B patients (P < .001). Similarly, the amount of aspirated seroma in the control examinations of group A patients was significantly lower than that in group B (P < .05). Group B needed re-aspiration significantly more than group A (P < .05).

CONCLUSIONS

Flap fixation with suture after MRM is a method that reduces seroma formation and the amount of drained fluid, enables early removal of the drain, prevents delay in starting adjuvant treatment, is more comfortable for the patient and physician, and is also inexpensive.

Clinical effectiveness of microporous polysaccharide hemospheres in mastectomy for patients with breast cancer

Background

Microporous polysaccharide hemospheres (MPH) are hydrophilic particles administered to reduce the incidence of seroma after mastectomy, but their clinical effectiveness remains controversial. Because a previous randomized, controlled study in a small cohort could not demonstrate the effectiveness of MPH in breast surgery, we evaluated their effectiveness in surgery for breast cancer in a larger cohort.

Methods

Medical records of 352 patients who underwent total mastectomy for breast cancer were retrospectively reviewed. Clinical data were compared between 126 patients who received MPH during surgery (MPH group) and 226 who did not (control group) according to surgical procedures. Patients were significantly older in the MPH group than in the control group because of selection bias, but other factors, such as body mass index and number of dissected lymph nodes, did not differ between groups.

Results

When analyzed by use of axillary manipulation, the drain placement period and drainage volume were significantly less in the MPH group than in the control group for patients with mastectomy and sentinel lymph node biopsy. Only drainage volume was significantly less in the MPH group for patients with mastectomy and axillary lymph node dissection. The frequency of total postoperative complications, such as seroma requiring puncture, did not differ between groups.

Conclusions

Use of MPH may decrease the postoperative drainage volume and drain placement period in mastectomy for patients with breast cancer.

Current use of drains and management of seroma following mastectomy and axillary surgery: results of a United Kingdom national practice survey

PURPOSE

Up to 40% of the 56,000 women diagnosed with breast cancer each year in the UK undergo mastectomy. Seroma formation following surgery is common, may delay wound healing, and be uncomfortable or delay the start of adjuvant treatment. Multiple strategies to reduce seroma formation include surgical drains, flap fixation and external compression exist but evidence to support best practice is lacking. We aimed to survey UK breast surgeons to determine current practice to inform the feasibility of undertaking a future trial.

METHODS

An online survey was developed and circulated to UK breast surgeons via professional and trainee associations and social media to explore current attitudes to drain use and management of post-operative seroma. Simple descriptive statistics were used to summarise the results.

RESULTS

The majority of surgeons (82/97, 85%) reported using drains either routinely (38, 39%) or in certain circumstances (44, 45%). Other methods for reducing seroma such as flap fixation were less commonly used. Wide variation was reported in the assessment and management of post-operative seromas. Over half (47/91, 52%) of respondents felt there was some uncertainty about drain use after mastectomy and axillary surgery and two-thirds (59/91, 65%) felt that a trial evaluating the use of drains vs no drains after simple breast cancer surgery was needed.

CONCLUSIONS

There is a need for a large-scale UK-based RCT to determine if, when and in whom drains are necessary following mastectomy and axillary surgery. This work will inform the design and conduct of a future trial.

The QUILT study: quilting sutures in patients undergoing breast cancer surgery: a stepped wedge cluster randomized trial study

BACKGROUND

Seroma is the most common complication following breast cancer surgery, with reported incidence up to 90%. Seroma causes patient discomfort, is associated with surgical site infections (SSI), often requires treatment and increases healthcare consumption. The quilting suture technique, in which the skin flaps are sutured to the pectoralis muscle, leads to a significant reduction of seroma with a decrease in the number of aspirations and surgical site infections. However, implementation is lagging due to unknown side effects, increase in operation time and cost effectiveness. Main objective of this study is to assess the impact of large scale implementation of the quilting suture technique in patients undergoing mastectomy and/or axillary lymph node dissection (ALND).

METHODS

The QUILT study is a stepped wedge design study performed among nine teaching hospitals in the Netherlands. The study consists of nine steps, with each step one hospital will implement the quilting suture technique. Allocation of the order of implementation will be randomization-based. Primary outcome is 'textbook outcome', i.e.no wound complications, no re-admission, re-operation or unscheduled visit to the outpatient clinic and no increased use of postoperative analgesics. A total of 113 patients is required based on a sample size calculation. Secondary outcomes are shoulder function, cosmetic outcome, satisfaction with thoracic wall and health care consumption. Follow-up lasts for 6 months.

DISCUSSION

This will be one of the first multicentre prospective studies in which quilting without postoperative wound drain is compared with conventional wound closure. We hypothesize that quilting is a simple technique to increase textbook outcome, enhance patient comfort and reduce health care consumption.

Fibrin Glue Sealant: An Effective Modality to Mitigate Postoperative Seroma After Modified Radical Mastectomy

Introduction Modified radical mastectomy is a common modality used in treating breast cancer and often presents a series of post-operative challenges. Seroma formation is the most common complication with no single method shown to be reliably effective against it. Fibrin glue is one such modality. There is a paucity of studies describing the utility of fibrin glue to prevent seroma formation. Aim To evaluate the effect of intraoperative application of fibrin glue sealant on drain output and seroma formation in patients undergoing modified radical mastectomy by comparing outcomes between the two groups. Method This is a prospective observational study. Fibrin glue application was done intra-operatively prior to closure in one group. Standard closure procedures with drain placement were undertaken in another group and their outcomes were analyzed for both groups. Results Drain output on postoperative day 1 (POD 1) as well as total drain output were recorded for both groups and the difference in mean was found to be significant (p<<0.05 and 0.049, respectively. Distribution of patients according to the volume of seroma formation was done; this difference of means was also found to be significant (p=0.004). Further, the difference of mean for the number of days the drain was in-situ was found to be significant. Conclusion Fibrin sealant used during modified radical mastectomy closures decreased the rates and volumes of seroma formation. This led to quicker drain removals and less patient discomfort.

Effect of Mastectomy Flap Fixation on Post-operative Fluid Drainage and Seroma Formation in Breast Cancer Patients A Double-blinded Randomised Control Trial

&lt;b&gt; Introduction:&lt;/b&gt; Post-operative seroma formation is one of the most common complications following modified radical mastectomy (MRM). Quilting is a technique where the mastectomy flaps are sutured to the underlying chest wall muscles with sutures, obliterating the dead space. The authors hypothesised that post-mastectomy dead space obliteration by intermittent mastectomy flap fixation leads to decreased drain output and seroma formation. &lt;/br&gt;&lt;/br&gt; &lt;b&gt; Material and methods: &lt;/b&gt; A double-blinded randomised control trial with two arms was conducted from November 2019 to March 2021 in our institute located in India. Patients with non metastatic breast carcinoma planned for MRM were randomly categorised into two groups of 35 patients each. In the test group, each flap was fixed to the underlying muscle using four intermittent 3-0 polyglactin sutures, which was followed by skin closure, and only skin closure was done in the control group. &lt;/br&gt;&lt;/br&gt; &lt;b&gt;Results:&lt;/b&gt; The test and control groups did not differ significantly with respect to demographic and tumour characteristics. The average drain output of the test group (155.43 ml) was significantly less than of the control group (206.29 ml). The overall incidence of seroma formation is lower in the test group (5.7%) when compared to the control group (28.6%). The duration of hospital stay in the test group (4.63 days) was significantly shorter when compared to the control group (6.66 days). There was no significant increase in the overall operating time or complications like surgical site infection or skin dimpling due to flap fixation. &lt;/br&gt;&lt;/br&gt; &lt;b&gt;Conclusions:&lt;/b&gt; Fixation of MRM flaps is associated with better post-operative outcomes related to drain output and seroma formation without a significant increase in other morbidities or usage of resources.

Complicated Wound Closure Following Mastectomy and Breast Reconstruction

Breast reconstruction incidence increased, including preventive surgery. In this context, providing women best surgical care and results is crucial, with minimum complications, such as wound dehiscence and skin flap necrosis. Tension-free closure of skin flaps is mandatory for successful healing. However, since this is not always possible, various techniques have been developed to reduce tension from wound-margins, facilitate primary wound-closure, and minimize and improve scarring. These techniques have not been investigated in breast surgeries. The aim of this study was to describe our experience with the Tension-Relief System in mastectomy and breast reconstructive patients, and the advantages of using this technique. The retrospective cohort consisted of 13 breasts of 11 women aged 29-74 years who underwent surgery with primary wound-closure using the System, in 2019-2020 in our department. It was applied averagely 19.7 days, demonstrated effectiveness in preventing complications and as secondary treatment following complications. This enabled avoiding further and more extensive surgeries, including donor-site morbidity when needed. In mastectomy and breast-reconstruction, the System minimizes complications and yields satisfactory aesthetic and functional outcomes, with minimal inconvenience to the patient, and good pain-control. The technique is low-cost, simple to use, and does not require special settings, surgical equipment, or particular skills.

Fibrin Sealants Do Not Reduce the Rate of Seroma Formation in Postmastectomy Breast Reconstruction: A Systematic Review and Meta-analysis

Background Breast reconstruction using deep inferior epigastric perforator (DIEP) and latissimus dorsi (LD) flaps following mastectomy are associated with seroma formation, most commonly at the donor site. We sought to perform an updated systematic review and meta-analysis on the effects of fibrin sealant on donor-site complications following DIEP and LD flap breast reconstruction.

Methods A comprehensive literature search was conducted (March 2021) in PubMed, OVID, and Cochrane databases. Articles analyzing the efficacy of fibrin glue in reducing donor-site morbidity in DIEP and LD breast reconstruction were included. The outcomes assessed were seroma formation and duration of drainage.

Results A total of 17,265 articles were screened, and 9 articles were selected for analysis, which comprised 632 surgical sites in 611 patients. Comparing fibrin glue and quilting to quilting alone showed no significant difference in seroma formation (pooled risk ratio [RR]: 0.51; 95% confidence interval [CI]: 0.12, 2.25). Similarly, comparing fibrin glue alone to no fibrin glue showed no significant difference in seroma formation (pooled RR: 1.03; 95% CI: 0.66, 1.61) or duration of drain (pooled RR: −0.85; 95% CI: −4.09, 2.40); there was however a difference in duration of drain in those who received fibrin glue and quilting versus quilting alone (pooled RR: −2.13; 95% CI: −3.27, −0.99).

Conclusion The existing literature supports that the use of fibrin glue is not associated with a decrease in seroma formation in DIEP and LD flaps and is weakly associated with a reduction in the drainage duration only if used in conjunction with quilting.

Quilting following mastectomy reduces seroma, associated complications and health care consumption without impairing patient comfort

Background

An important complication following mastectomy is seroma formation. Quilting, in which skin flaps are sutured to the underlying muscle, is reported to reduce seroma incidence, but might induce pain and impair shoulder function. Main objective is to compare quilting with conventional wound closure, regarding seroma incidence, health care consumption, and patient discomfort.

Methods

In a combined prospective and retrospective study, 254 patients undergoing mastectomy and/or axillary lymph node dissection (ALND) were included. Patients received quilting sutures or conventional closure. Primary outcome was clinical significant seroma (CSS). In prospectively included patients shoulder function and analgesic use was observed.

Results

CSS incidence was 12.9% in the quilted versus 62.3% in the nonquilted cohort (p < 0.001). Surgical site infections were reported significantly less in the quilted cohort. Duration of hospital stay was shorter and outpatient clinic visits were less in the quilted cohort. Surgical procedure required 10 additional minutes for quilting. No significant differences were observed in postoperative shoulder function and analgesic use.

Conclusion

Quilting following mastectomy reduces CSS incidence. Quilting requires 10 additional minutes during surgery. It facilitates day treatment and results in less additional outpatient clinic visits culminating in reduced health care consumption. Shoulder function and pain are not affected by quilting.

Conventional suture with prolonged timing of drainage is as good as quilting suture in preventing seroma formation at pectoral area after mastectomy

Background

The aim of this study was to compare conventional suture with prolonged timing of drainage with quilting suture on the formation of seroma at pectoral area after mastectomy (ME) with sentinel lymph node biopsy (SLN) or axillary lymph node dissection (ALND) for breast cancer.

Methods

Three hundred and eighty-eight consecutive breast cancer patients were retrospectively analyzed and categorized into three groups. Patients in group 1 were with quilting suture, group 2 with conventional suture and 13–15 days drainage in situ, and group 3 with conventional suture and 20–22 days drainage. The primary outcome was the incidence of grades 2 and 3 seroma at anterior pectoral area within 1 month postoperatively. Cox regression was used for analysis.

Results

The incidence of grades 2 and 3 seroma was comparable among groups (9.5% vs. 7.9% vs. 5.3%, p = 0.437), as well as late grades 2 and 3 seroma among groups (4.3% vs. 2.9% vs. 1.5%, p = 0.412). Old age, high body mass index, and hypertension were independent risk factors for grades 2 and 3 seroma.

Conclusions

Prolonged timing of drainage to 13–15 days in conventional suture was long enough to decrease the incidence of grades 2 and 3 seroma as lower as that in quilting suture group at pectoral area within 1 month after mastectomy.

Negative pressure wound therapy does not decrease postoperative wound complications in patients undergoing mastectomy and flap fixation

Patients and breast cancer surgeons are frequently confronted with wound complications after mastectomy. Negative pressure wound therapy (NPWT) is a promising technique for preventing wound complications after skin closure in elective surgery. However, a clinical study evaluating postoperative complications following the use of NPWT, focusing solely on closed incisions in patients undergoing mastectomy, has yet to be performed. Between June 2019 and February 2020, 50 consecutive patients underwent mastectomy with NPWT during the first seven postoperative days. This group was compared to a cohort of patients taking part in a randomized controlled trial between June 2014 and July 2018. Primary outcome was the rate of postoperative wound complications, i.e. surgical site infections, wound necrosis or wound dehiscence during the first three postoperative months. Secondary outcomes were the number of patients requiring unplanned visits to the hospital and developing clinically significant seroma (CSS). In total, 161 patients were analyzed, of whom 111 patients in the control group (CON) and 50 patients in the NPWT group (NPWT). Twenty-eight percent of the patients in the NPWT group developed postoperative wound complications, compared to 18.9% in the control group (OR = 1.67 (95% CI 0.77–3.63), p = 0.199). The number of patients requiring unplanned visits or developing CSS was not statistically significant between the groups. This study suggests that Avelle negative pressure wound therapy in mastectomy wounds does not lead to fewer postoperative wound complications. Additionally, it does not lead to fewer patients requiring unplanned visits or fewer patients developing clinically significant seromas.

Trial registration: ClinicalTrials.gov number, NCT03942575. Date of registration: 08/05/2019.

The Effect of Low and High Vacuum Drainage on the Postoperative Drainage of Breast Cancer: Insights from a Prospective, Non-Inferiority, Randomized Clinical Trial

Background

Vacuum drains have been extensively applied to prevent seroma formation after breast surgery. However, the usage of negative suction drainage is mainly determined by surgeon’s experience and preferences. The aim of this study is to prospectively compare the drain effect after breast surgery between the low and high vacuum drains.

Methods

This prospectively randomized trial (from January 2018 to June 2019) involved 188 patients who were subjected to modified radical mastectomy (group A, n=128) or immediate breast reconstruction with implants (group B, n=60). In each group, patients were randomized to receive high vacuum drain (pressure=–98 kPa) or low vacuum drain (pressure=–12 kPa) after surgery. Days of drain permanence, which means the duration of drainage, was the primary endpoint.

Results

According to the comparison of days of drain permanence, the effect of a low vacuum drain is not inferior to a high vacuum drain in group A (pectoral drain, P<0.001; axillary drain, P<0.001) or group B (submuscular drain, P=0.002). The complications frequently occurred on patients with high vacuum drain (11.7%), such as seroma formation. The expense of low vacuum drain was significantly lower than high vacuum drain in both groups (P<0.01).

Conclusion

The drain effect of the low vacuum drain is not inferior to a high vacuum drain in both group A and group B. The low vacuum drain was effective, relatively cheap, and did not increase the incidence of complications; it is therefore more recommended after breast surgery.

Increasing the incidence of drain-free day-case mastectomies with the use of a fibrin tissue sealant; data from a single surgical center in the United Kingdom

Day-case mastectomy surgery provides benefits to both patients and hospitals. Key barriers are the use of a drain and the risk of postoperative seroma formation. We introduced the use of a tissue sealant (Artiss) into the surgical site (post-mastectomy without immediate reconstruction and postaxillary clearance) and evaluated its effect on our practice, particularly day-case rates. A prospective audit of 177 patients who underwent a simple mastectomy with or without axillary surgery, or axillary node clearance with or without breast-conserving surgery was conducted at a single surgical center in the UK between November 2015 and November 2016. Artiss was used in all operations and, where appropriate, the drain was omitted to facilitate day-case surgery. The clinical outcomes were compared between patients undergoing different operations and duration of hospital stay. There was no statistically significant difference between day-case patients and inpatients in seroma aspiration rates (24.5% and 21.7%, respectively; P = 0.381) or other complications (22.4% and 16.1%, respectively; P = 0.106). The day-case mastectomy rate increased from 3.9% in the first quarter to 45.5% in the final quarter, which was a significant increase reaching well beyond the national target. The use of Artiss enabled us to increase the drain-free day-case surgery rates over a 1-year period, exceeding the 30% target recommended by the British Association of Day Surgery. We did not observe any increase in patient morbidity, and the change was cost-effective. We have now implemented the routine use of Artiss in women undergoing simple mastectomy with or without axillary surgery and stand-alone axillary node clearances as part of enhanced recovery clinical pathways.

Mastectomy Without Drains Reduces Cost with No Detriment to Patient Outcome

Introduction 

Use of drains after mastectomy remains highly variable. This study aimed to establish whether simple mastectomy managed without a drain would cost less than the same procedure managed with a drain and whether there would be any difference in complications.

Methods 

Prospective data were collected on all patients undergoing simple mastectomy ± sentinel lymph node biopsy over sixteen months. Surgeons decided intra-operatively whether to place a drain. Data included operative details, mastectomy weight, length of stay and postoperative complications. Costing data were identified by combining hospital finance costs for admission and follow-up appointments along with the cost of consumables.

Results 

One hundred and thirty mastectomies were performed on 119 patients. There was a significant difference in mastectomy weight between drain group patients (n=80, median: 730g) and no drain group patients (n=50, median: 424g) (p=<0.001). The mean cost for drain group patients was £639.77 whilst for the no drain group was £365.46, indicating a potential unit saving of £21944.93 over sixteen months. Length of stay was shorter in the no drain group (range: 1-2 days) than the drain group (range: 1-4 days). The presence or absence of drains did not influence complication rates, with no change in seroma interventions (p=0.803).

Conclusions 

Managing simple mastectomy patients without a drain resulted in no increase in complications or subsequent interventions for seroma. Significant cost savings to both the hospital and to the patient can be achieved by omitting drain use. Routine use of drains in patients undergoing simple mastectomy ± SNB may be unnecessary and costly.

Intraoperative hypertonic saline irrigation preventing seroma formation and reducing drain secretion in extended endoscopic hernia and linea alba reconstruction glue

PURPOSE

Subcutaneous Seroma formation (SF) is commonly seen after abdominal wall Hernia surgeries and reconstructive surgeries due to large dissecting dead space and is associated with increased morbidity. SF is common particularly after big abdominal wall hernia repairs and its treatment can be challenging and long. Current prevention methods are not consistent and the treatment includes repeated aspirations and drains, both are associated with higher risk for infections. The purpose of this article is to present a novel and simple technique of Intraoperative Hypertonic Saline Irrigation (IHSI) to abdominal wall subcutaneous large dead space, which prevent postoperative SF and enables early drain removal due to reduced secretions.

METHODS

Eight patients undergone the Extended Endoscopic Hernia & Linea Alba Reconstruction Glue surgery (eEHLARglue), for Ventral Hernias (VH) and Rectus Muscles Separation (RMS). An extensive Endoscopic 450cm² dissection free surface of the anterior Rectus fascia, is performed prior to Hernia dissection and closing of the RMS. It is followed by onlay mesh placing over the repaired Rectus muscles and the mesh is fused into the muscles by Fibrin Glue. The novel preventive method is based on Intraoperative Irrigation of the vast cavity through the two 10 mm JP closed system drains with 20 cc of NaCl 12% left at site for 10 min.

RESULTS

Our early results with all our patients show seroma prevention, lower secretion rate of 20 cc in 10 h and drain removal within 20-24 h.

CONCLUSIONS

IHSI enhance adhesion formation and reduce secretion rate in wide subcutaneous dissection space like in eEHLARglue, therefore enables early drain removal and prevent SF. As a result, reducing overall morbidity and hospitalization period, decreasing inconveniency and cost saving of multiple outpatient visits or additional surgery. This simple technique could be used in other potential postoperative SF surgeries. Further larger study with a longer follow up is advised.

Effect of topical microporous polysaccharide hemospheres on the duration and amount of fluid drainage following mastectomy: a prospective randomized clinical trial

Background

Seroma formation is the most common complication after mastectomy and places patients at risk of associated morbidities. Microporous polysaccharide hemospheres (MPH) consists of hydrophilic, plant based, polysaccharide particles and is currently used as an absorbable hemostatic agent. An animal model evaluating MPH and seroma formation after mastectomy with axillary lymph node dissection showed a significant decrease in seroma volume. Study aim was to evaluate topical MPH on the risk of post-mastectomy seroma formation as measured by total drain output and total drain days.

Methods

Prospective randomized single-blinded clinical trial of patients undergoing mastectomy for the treatment of breast cancer. MPH was applied to the surgical site in the study group and no application in the control group.

Results

Fifty patients were enrolled; eight were excluded due to missing data. Forty-two patients were evaluated, control (n = 21) vs. MPH (n = 21). No difference was identified between the two groups regarding demographics, tumor stage, total drain days, total drain output, number of clinic visits, or complication rates. On a subset analysis, body mass index (BMI) greater than 30 was identified as an independent risk factor for high drain output. Post hoc analyses of MPH controlling for BMI also revealed no statistical difference.

Conclusions

Unlike the data presented in an animal model, no difference was demonstrated in the duration and quantity of serosanguinous drainage related to the use of MPH in patients undergoing mastectomy for the treatment of breast cancer. BMI greater than 30 was identified as an independent risk factor for high drain output and this risk was not affected by MPH use. NCT03647930, retrospectively registered 08/2018.