Closed Incision Negative Pressure Therapy Versus Standard of Care Over Closed Plastic Surgery Incisions in the Reduction of Surgical Site Complications: A Systematic Review and Meta-Analysis of Comparative Studies

Surgical site complications (SSCs)—such as surgical site infections (SSIs), wound dehiscence, seroma, excessive drainage, skin necrosis, and scarring—are common occurrences in plastic surgery procedures, and SSC rates as high as 80% have been reported for some procedures.¹ SSCs are not only detrimental to patient health and recovery, they also result in increased rates of health care utilization as well as costs.² The high rates of SSCs can be attributed to both the characteristics of certain procedures and of the patients that commonly undergo these surgeries. Many plastic surgery procedures—particularly reconstruction surgeries—involve extensive undermining, potential space for fluid collection, the risk for compromised flap perfusion, and long and/or complex incision patterns, which increase the risk of complications. Patients who undergo such procedures often have characteristics and comorbid conditions that further increase the risk of complications that can impair and delay healing, such as obesity, diabetes, hypertension, advanced age, and previous chemotherapy.³

Closed incision negative pressure therapy (ciNPT)  has emerged in recent years as a way to help manage incisions across a variety of surgical specialties.³ Initially used in orthopedic procedures in 2006 as a method to provide a clean, dry wound environment in the immediate post-operative period,^4,5 ciNPT is a type of negative pressure wound therapy (NPWT) that utilizes foam-based dressings over closed incisions.⁶ The system can help alleviate tension across a wound, hold the incision edges together, protect the incision from external infection, and remove fluid and infectious materials.^3,5,6  One manufacturer’s device (3M Prevena Incision Management System, 3M Company) is a disposable, single-use system with a replaceable canister and a variety of one-piece reticulated open cell foam (ROCF) dressing options for different incision lengths and a variety of anatomical locations.  This system provides continuous negative pressure at -125 mmHg and is used in the operating room over closed incisions. Other available ciNPT devices utilize different negative pressure settings, dressings, and canisters  and may lack an audible alarm for negative pressure failure. These system differences may impact post-surgical outcomes. For instance, in a recent meta-analysis, Singh et al  found that patients receiving standard dressings were 3.17 times more likely to develop an SSI than patients receiving -125 mmHg ciNPT with ROCF dressings.⁷ However, no significant differences in SSI development were observed for patients receiving standard dressings versus -80 mmHg ciNPT with multilayer absorbent dressings.⁷

There is growing evidence that ciNPT can be beneficial and improve outcomes across surgical specialties, ⁸ including orthopedic,^9-10 abdominal,¹¹ vascular, and thoracic procedures^12,13; however, the benefit of ciNPT in plastic surgery remains unclear. The objective of this systematic review and meta-analysis was to examine the impact of one ciNPT device on risk of SSCs including SSIs, wound dehiscence, seroma, excessive drainage, skin necrosis, and scarring, as well as related health care utilization and costs following plastic surgery.

This systematic literature review and meta-analysis were conducted to assess the effect of ciNPT versus traditional postsurgical dressings over closed incisions for plastic surgery procedures. Outcomes included SSCs (surgical site infections, seroma, dehiscence, skin necrosis, prolonged drainage), scarring, return to the operating room (OR), and length of stay. The review conformed to the statement and reporting check list of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses.¹⁴

Literature Search

A systematic literature search using PubMed, EMBASE, and QUOSA was performed, focusing on English-language publications comparing ciNPT to traditional SOC dressings between January 2005 and July 2021. The following search terms were used: (“negative pressure wound therapy” OR “negative pressure” OR “negative pressure therapy” OR “NPWT”) AND (“Prevena” OR “ciNPT” OR “prophylactic NPWT” OR “preventive NPWT” OR “incision management” OR “incisional management” OR “closed incision negative pressure wound therapy” OR “closed incision negative pressure therapy”). Inclusion criteria consisted of published abstracts or manuscripts written in English that compared the use of one manufacturer’s ciNPT over closed incisions to traditional postoperative dressings or SOC following plastic surgery procedures. Exclusion criteria included meta-analysis, preclinical studies (animal or bench studies), veterinary studies, pediatric patient population, non-comparative studies, use of non-ciNPT device, and surgeries that were not plastic surgery procedures.

Studies were selected for inclusion after a review of titles and abstracts to identify additional studies for further review. Abstracts and articles that met all the inclusion criteria and none of the exclusion criteria underwent a full-text assessment by two independent reviewers. When disagreement occurred, a third person reviewed the article, and a consensus on eligibility was reached.

Data Extraction

One independent reviewer completed data extraction from all eligible studies and a second reviewer validated the findings. Disagreements were resolved by discussion between the two reviewers or by the addition of a third reviewer. Extracted data included funding source(s), bias assessments, study design, publication status, study date range, number of study sites, study location, surgical procedures, high-risk enrollment criteria (if applicable), study objectives, control type, number of treatment days, follow-up period, number of patients/incisions, number of patients/incisions analyzed, and definition of SSC. Patient outcome data such as number of SSCs, SSIs, type of SSI, dehiscence, seroma, hematoma, skin necrosis, deaths, amputations, drainage volume, number of days with surgical drain, patients with post-operative pain, patients with post-operative antibiotic treatment, and quality of life/patient satisfaction measures were extracted. Additionally, health economic measures including hospital length of stay, readmissions, reoperations, and reported costs were extracted.

Statistical Analysis

To assess the effect of ciNPT versus SOC on dichotomous variables, weighted risk ratios were calculated to pool study and control groups in each publication for analysis. Mean differences were used to assess differences between continuous variables reported on the same scale. Standardized mean differences were used if outcomes were reported with different scales or measurement instruments. Treatment effects were combined, and the more conservative random effects model was used for each analysis performed, regardless of the heterogeneity assessment. All analyses were performed using Comprehensive Meta-Analysis Version 3 (Borenstein, M., Hedges L, Higgins J, & Rothstein H. Biostat Englewood, NJ 2013).

Economic Analysis

To evaluate the impact of ciNPT on the cost of patient care, the authors performed a cost analysis using the SSC rates from this meta-analysis and cost inputs obtained from the Premier Healthcare Database (PHD, Premier, Inc), a large, U.S. hospital-based, all-payer database including approximately 25% of annual inpatient admissions in the United States. To estimate the average cost of an SSC, the authors identified patients within PHD who underwent plastic surgery procedures in 2019 or 2020 and had an SSC as indicated by an ICD-10 diagnosis code and/or DRG (code 862-863, 856-858) for postoperative infections, including SSI, dehiscence, postoperative seroma, skin complication, and non-healing wounds.¹⁵ SSCs were included in the analysis if they were documented during index hospitalization as a secondary diagnosis or were listed as a primary diagnosis for a readmission or outpatient visit within 90 days of discharge. Propensity scoring was performed to create a matched set of patients with SSCs and a control group without SSCs to determine the incremental effect of an SSC on care costs. Costs represent estimated cost of care provided by PHD facilities and were calculated with relative value units or cost-to-charge ratios.

Using the SSC rates obtained in the meta-analysis and SSC cost data obtained from the PHD population, the mean per patient cost of an SSC was determined for all patients undergoing plastic surgery in the SOC group with and without ciNPT use. The difference in relative risk (RR) of SSC between patients in the ciNPT and SOC groups in the meta-analysis was used to estimate how ciNPT use in the SOC group would impact the SSC rate and the mean per patient cost of an SSC. The mean cost savings per patient that may be achieved with ciNPT use was calculated as the difference between the mean per patient cost of an SSC in the SOC group without ciNPT and the estimated mean per patient cost of an SSC in the SOC with ciNPT use plus the cost of the ciNPT device.

Literature Search

A total of 972 publications were identified during the literature search (Figure 1). After removal of duplicate publications and studies that did not meet the inclusion criteria, 84 studies were identified. Sixteen studies were specific to plastic surgery and included in the meta-analysis (Table 1). One was a randomized controlled trial (RCT), 4 were prospective studies, and 11 were retrospective studies. Four studies were conducted in the United States, 3 were conducted in Italy, 2 were conducted in Australia, and the remaining studies were conducted in Taiwan, Brazil, Denmark, Netherlands, Austria, Canada, and Germany. The studies focused on a variety of plastic surgery procedures, including abdominoplasty, body contouring, breast reconstruction (including donor site repair), breast reduction, panniculectomy with hernia repair, pilonidal cyst removal, pressure ulcer reconstruction, groin incision for inguinal lymph node dissection, and pectoralis flap for sternotomy wound infections.

Outcomes

Study outcomes are summarized in Table 2. In the 11 studies that evaluated the effect of ciNPT on SSCs, ciNPT use was associated with a statistically significant reduction in risk of SSC (relative risk (RR) = 0.532, 95% confidence interval (CI): 0.396-0.715, P < .001) (Table 2, Figure 2). Use of ciNPT was also associated with a significant reduction in risk of dehiscence (RR = 0.475, 95% CI: 0.309-0.730, P = .001) and skin necrosis (RR = 0.460, 95% CI: 0.284-0.746, P = .002) (Table 2, Figures 3-4). There were no differences between groups in the risk of SSIs (RR = 0.76, 95% CI: 0.540-1.068, P = .113) and seromas (RR = 0.693, 95% CI: 0.318-1.540, P = .143) (Table 2, Figures 5-6). While not statistically significant, there was a decrease in the average volume of fluid removed from the drains (-157.5 mL, 95% CI: -327.2-12.15, P = .069) for patients receiving ciNPT (Table 2, Figure 7). These patients also had the drains in for 1.97 fewer days (P = .093) (Table 2, Figure 8). Three studies examined the impact of ciNPT on scarring using instruments such as the Vancouver Scar Scale (VSS), the Manchester Scar Scale, and the Observer and Patient Scar Assessments. Use of ciNPT was associated with statistically significant improvements in overall scar quality (P = 0.014) across these 3 studies (Table 2, Figure 9), and scar quality at 90 days (P < .001) (Table 2, Figure 10) and 12 months (P = 0.048) (Table 2, Figure 11) in the 2 studies that examined these endpoints.

In addition to SSCs, health utilization endpoints were also evaluated. There was a reduction in the rate of reoperations with ciNPT use that approached statistical significance (RR: 0.647, 95% CI: 0.401-1.044, P = .074) (Table 2, Figure 12). Hospital length of stay was decreased by 0.61 days for patients receiving ciNPT (95% CI: 0.338-0.882, P < .001) (Table 2, Figure 13). The estimated cost savings associated with ciNPT use was $674 (USD) per patient (Table 3).

To the authors’ knowledge, this study is the first published literature review and meta-analysis to examine the effects of ciNPT use compared with SOC specifically in plastic surgery procedures. The findings indicate that ciNPT is associated with a statistically significant reduction in risk of SSCs, including dehiscence and skin necrosis, across a variety of plastic surgery procedures. Use of ciNPT was also associated with statistically significant improvements in scar quality and reduced patient LOS. Although patients who received ciNPT demonstrated decreases in the volume of fluid removed from drains and a 1.97-day reduction in days spent with a drain, those differences—as well as the observed reduction in the rate of reoperations—only approached but did not reach statistical significance. Despite the lack of observed benefits for some outcomes, including no differences in the rates of SSIs and seromas between patients receiving ciNPT versus SOC, this study provides meaningful insight about the potential benefits of ciNPT use across plastic surgeries. This information is especially valuable given the lack of large studies on the topic, particularly RCTs. Additionally, the cost analysis found that use of ciNPT was associated with a potential savings of $674 (USD) per patient.

The observed reduction in the risk of dehiscence in plastic surgery procedures with ciNPT use is an important finding as dehiscence, or the separation of the margins of a clean closed incision, is one of the more common and dangerous complications of plastic surgery procedures and has high rates of morbidity and, in some cases, mortality.^2,5 Many of the procedures in the included studies, including breast reduction surgeries and breast reconstruction surgeries with a deep internal epigastric perforator (DIEP) or profunda artery (PAP) flap, have a greater risk of dehiscence due to tension at the incision site and the potential for compromised perfusion of the tissues within the operative site.² This risk rises dramatically for patients with comorbid conditions that negatively impact healing, which are common among patients undergoing these procedures.5,16  For instance, the incidence of dehiscence has been reported as 25% for elective, clean reduction mammaplasty procedures, but can be as high as 100% for obese patients undergoing large volume reductions.^5,17,18  

The use of ciNPT may help reduce the risk of dehiscence through several mechanisms. The device serves as a mechanical barrier to contamination, as it is applied in a sterile OR environment and requires fewer dressing changes than standard dressings, exerts appositional force across closed incisions while decreasing distraction tension across the wound, and removes exudate that can disrupt the wound or create an environment suitable for infections.⁵ Dehiscence is also correlated with SSI. Although this study did not demonstrate a reduction in the incidence of SSIs for patients receiving ciNPT, there can be discrepancies in coding SSI and dehiscence, and dehiscence can be caused by an SSI which could lead to SSI being recorded as dehiscence.² Notably, the majority of the included studies reported very low overall incidence of SSI. Thus, it is possible that risk reductions in SSI associated with ciNPT were captured as risk reductions in dehiscence.^2,19

Lowering the risk of dehiscence and other SSCs is crucial in plastic surgeries, as these complications pose a threat to aesthetic surgical outcomes,^5,15,20-22 mental health,^2,22 and timely auxiliary care.^3,23 Highly visible scarring is often a source of patient dissatisfaction and may result in later revisions.²² Although only 3 of the studies included in this analysis examined the impact of ciNPT on scarring,^1,22,24 use of ciNPT was associated with statistically significant improvements in scar quality in all the studies. These improvements included postoperative scar pigmentation, vascularity, and pliability.^1,22 In addition, many patients undergoing plastic surgery procedures may have endured recent emotional burdens or psychological distress from previous procedures, such as unilateral or bilateral mastectomy in the case of breast reconstruction surgeries or bariatric procedures prior to body contouring.^2,22 Therefore, reducing complications and optimizing aesthetic outcomes is also important to preserving or improving the mental health of these patients. Fang et al noted that in addition to observing measurable improvements in outcomes, the researchers felt that ciNPT provided patients with both continuous therapy and reassurance.²² Lastly, reducing complications from these procedures is particularly important in cancer reconstructions, as SSCs in these cases may also delay the beginning of adjuvant therapies,^24,25 and have been associated with a significantly greater risk of developing systemic recurrence of cancer following breast reconstruction procedures.^3,23

This study also demonstrates how use of ciNPT can translate to decreased health care utilization and costs for patients. SSCs that occur in post-bariatric patients can result in a threefold increase in the cost of care¹; by comparison, the cost of ciNPT is relatively low (roughly $650 per patient). Findings from this study’s cost analysis indicated that use of ciNPT may result in a cost savings of $674 (USD) per patient after factoring in the cost of the device due to the reduction in SSCs and associated LOS. These savings may be even greater if ciNPT use is limited to high-risk patients who are most likely to benefit from the therapy. Cost savings may also be achieved through the reduction of dressing changes with ciNPT. Abatangelo et al found that use of ciNPT in post-bariatric abdominoplasty procedures led to a decrease in dressing changes in both the inpatient (1.8 vs. 3.5) and outpatient settings (3.6 vs. 6.8).¹ In addition to being cost-saving, reducing the number of dressing changes can limit patient discomfort and improve patient satisfaction.

This study has several limitations. Most of the included studies were small studies, and only one was an RCT. However, despite the inherent biases found in observational studies, they can provide useful data regarding effectiveness of interventions in real world settings. There may have been selection bias regarding patients who received ciNPT, as use of the therapy was based on the surgeons’ discretion in many of the studies. As a result, patients who received ciNPT were more likely to be at higher risk for complications based on the presence of certain comorbidities or preoperative factors, although most of the included studies featured procedures that generally have higher rates of complications due to both procedure- and patient-related factors. Most of the included studies attempted to control for differences in observed characteristics with statistical modeling, but differences in unobserved covariates may have impacted study outcomes. The fact that improvements in a variety of outcomes were noted with ciNPT use compared to SOC across studies, despite greater risk of SSC in some of the intervention groups, demonstrates the potential effectiveness of ciNPT in these high-risk patient populations. Variations in training on ciNPT use, application of the device, surgical technique, surgeon experience, SOC, and underlying hospital infection rates may have varied among sites, which may have contributed to differences in observed findings across studies. This review also included studies on an assortment of surgical procedures that reported on a variety of outcomes, and ciNPT may be more effective in reducing SSCs for certain plastic surgery procedures than others. This meta-analysis only included studies that used one commercially available ciNPT device, and findings from this study may not be applicable to other available ciNPT systems.

The findings from this study indicate that ciNPT may be effective in reducing the incidence of SSCs, particularly dehiscence, skin necrosis, and be associated with improvements in scar quality in patients undergoing plastic surgery procedures. Use of ciNPT may also result in decreased LOS and costs of care. However, additional research in the form of larger studies and RCTs is needed to determine how to optimize use of ciNPT across patient populations and plastic surgery procedures.

The authors thank Willie M Heard III, PhD, (3M), for assistance with manuscript preparation and editing.

Affiliations: ¹Plastic Surgery, Vancouver, WA; ²University of Miami Health System and Miller School of Medicine, Miami, FL; ³University of Maryland School of Medicine, Baltimore, MD; ⁴3M Company, St. Paul, MN

Correspondence: Ashley Collinsworth, ScD, MPH; ACollinsworth@mmm.com

Disclosures: AG and DS are paid consultants of 3M. RS, AC, CB, and LG are paid employees of 3M.

An erratum to this article has been published.