Incisional negative pressure wound therapy in bilateral breast reductions patients

Introduction: Incisional negative pressure wound therapy (iNPWT) has been applied to bilateral breast reduction patients and shown a reduction in surgical complications. However, its effects on opioid use and hospitalisation length in this patient group has not been investigated. Methods: In this single surgeon retrospective cohort study, 52 patients who underwent bilateral breast reduction were analysed, with 23 patients in the iNPWT cohort and 29 in the standard-ofcare (SOC) wound dressing cohort. Hospitalisation length, postoperative opioid use and surgical site complications were compared between cohorts. Mean (range) follow-up time was 369.15 (77–1329) days. Results: Hospitalisation length in days was significantly less in the iNPWT cohort (1.35) than the SOC cohort (2.03). Total ward opioid use was significantly reduced in the iNPWT cohort (45.50mg) compared to the SOC cohort (62.50mg). Discharge opioid prescription was significantly reduced in the iNPWT cohort (125.50mg) compared to the SOC cohort (230.00mg). The number of surgical site complications was significantly different between the groups (p=0.014). Discussion: This study suggests the use of iNPWT in bilateral breast reduction provides significant benefit through the reduction of hospitalisation, complications and opioid use. Conclusion: This is the first study to provide evidence for iNPWT in bilateral breast reduction in reducing postoperative opioid use and hospitalisation. It supports current literature showing a reduction in surgical site complications using iNPWT in bilateral breast reduction.


Introduction
Negative pressure wound therapy (NPWT) has been used since the early 1990s to promote wound healing through the application of subatmospheric pressure. 1 More recently, negative pressure therapy has been applied to postsurgical incision sites. Incisional negative pressure wound therapy (iNPWT) works through both micro-and macroscopic mechanisms to increase oxygen saturation and blood flow in the skin under the dressing, increase local tissue perfusion and decrease lateral tissue tension while increasing incisional apposition. [2][3][4] Breast reduction is a common plastic surgical procedure that aims to reduce the size of the breasts, alleviating shoulder and neck discomfort associated with oversized breasts. Although complications can be minimised through patient selection and procedural technique, complication rates have been reported to be as high as 53 per cent. 5-7 Wound healing issues, including dehiscence and superficial infection, make up a majority of complications. 8 However, other complications include hematoma, fat necrosis, nipple necrosis, pain, breast cellulitis and fungal dermatitis. 7,9,10 Previous studies have addressed the use of iNPWT in bilateral breast reduction and it has been found to result in fewer wound-healing complications while improving scar quality and aesthetic appearance. 11,12 Studies investigating outcomes in caesarian section suggest that iNPWT reduces hospitalisation length and reduces total opioid use and surgical site complications. 13,14 To our knowledge the effect of iNPWT on these outcomes in patients that have had bilateral breast reduction has not been assessed.
In 2016, opioid deaths accounted for 62 per cent of all drug-induced causes of death and pharmaceutical opioids were implicated in more drug-induced deaths than heroin. 15 At present, in Australia and internationally, there is a drive to decrease both inpatient opioid use and postoperative discharge opioid prescription due to the potential for addiction. [16][17][18] Moreover, there is signficant patient and community benefit in reducing hospitalisation length, opioid use and minimising wound complications. [19][20][21][22] The aim of the present study is to evaluate the effect of iNPWT in patients undergoing bilateral breast reduction with respect to opioid use, surgical site complications and hospitalisation length.

Methods
The present study was a retrospective cohort study

Surgical technique
All patients received general anaesthesia with a single dose of intravenous antibiotics (cephazolin).
Regional anaesthesia occurred in every case through single-shot pectoralis plane (PECs II) or thoracic paravertebral blocks using an appropriate dose of local anaesthetic. 23  Discharge criteria was defined as patient able to mobilise, subjective pain score less than four out of 10 and feeling subjectively well. Discharge criteria was the same for both cohorts.

Outcomes
Opioid use was measured in oral morphine equivalents. 24 Total discharge prescription opioid dose was defined as the total amount of opioids provided at discharge for use as an outpatient.
Inpatient opioid use was measured from the time a patient was received on the ward to the time they were discharged. This will be referred to as total

Demographics
There were 29 patients in the SOC cohort and 23 in the iNPWT cohort. Patient demographic and  Table 2.

Length of stay
Hospitalisation length was significantly different between the SOC and iNPWT cohorts (p<0.001).
The mean (standard deviation-SD) length of stay for the SOC cohort was 2.03 (SD=0.33) days and the mean for the iNPWT cohort was 1.35 (SD=0.49) days. The mean difference was 0.69 days (33.99%).
Savage, Jain, Champion, Snell: Incisional negative pressure wound therapy in bilateral breast reductions patients

Effect of iNPWT on opioids and opioid prescription
There was a significant difference in total discharge opioid prescription (p<0.001

Surgical site complications
There was a statistically significant difference between the SOC and iNPWT cohorts in terms of frequency of surgical site complication (p=0.014). The number of patients with surgical site complications in the SOC cohort was 13 (44.80%) while the iNPWT had three (13.00%).
The complications that occurred have been stratified into categories in Table 2. More than one complication occurred in some patients. These were included in the categories for

Discussion
The that were not prescribed. Additionally, discharge opioid prescription is correlated with an increased risk of opioid abuse. 16,29 Of note, no patients in the iNPWT group requested further prescriptions.
We found the iNPWT group to have a statistically significant reduction in total ward opioid use. This is consistent with the findings of a randomised controlled trial involving 92 patients undergoing caesarean delivery which found a significant reduction in total postoperative opioid use. 14 We found no significant difference in daily ward opioid use. This suggests that the lower total postoperative opioid use was due to hospitalisation length rather than wound therapy cohort. Nevertheless, the combination of reduced total ward opioid use and reduced discharge opioid prescriptions means that patients were exposed to a lower opioid dose overall. Inpatient opioid use has been shown to be correlated with opioid use at postoperative day 90. 30 A reduction in total opioid use therefore has significant implications for patients.
Our results showed a significant reduction in surgical site complications using iNPWT. This is consistent with previous studies investigating iNPWT in bilateral breast reduction. 11,12 This has also been shown in other contouring surgery. 31 The overall proportion of patients having at least one surgical site complication in this study was 30.7 per cent. This is consistent with a cohort study investigating drained and drainless breast Savage, Jain, Champion, Snell: Incisional negative pressure wound therapy in bilateral breast reductions patients reduction, which found a complication rate of 27 per cent. 32 The most common complications in the SOC cohort were wound breakdown (24.1%) and wound infection (13.8%). The most common complications in the iNPWT cohort were wound infection (8.6%) and suture abscess (4.3%). There were no cases of wound breakdown in the iNPWT cohort. The significant reduction in wound breakdown in the iNPWT cohort is consistent with current literature. 11 Incisional negative pressure wound therapy has been shown to reduce hospitalisation length in pressure ulcer and orthopaedic surgery. 33,34 We found a significant reduction in hospitalisation length in the iNPWT cohort. Reduced hospitalisation is associated with significant benefits to both patient (decreased respiratory and thromboembolic complications) and the community (allocation of resources and access). [19][20][21][22] Multiple regression analysis allowed for investigation of factors affecting opioid use. Age was a predictor of total and daily opioid use which is supported in the literature. 35 However, the cohorts did not differ in a statistically significant manner in relation to age. Opioid use in the immediate postoperative period was also a predictor of total and daily opioid use. However, the cohorts did not differ in a statistically significant manner in relation to immediate postoperative period opioid use. Although the cohorts differed significantly in terms of skin resection pattern and regional anaesthetic block type, these factors were shown to not influence opioid use.

Disclosure
The authors have no financial or commercial conflicts of interest to disclose.