Seroma Rates Are Not Increased When Combining Liposuction With Progressive Tension Suture Abdominoplasty: A Retrospective Cohort Study of 619 Patients

Abstract

Background

Several studies have demonstrated that progressive tension sutures (PTS) reduce seroma. Many fear that adding liposuction to abdominoplasty will increase seroma rates and avoid drainless abdominoplasty when performing concomitant liposuction.

Objectives

We sought to identify whether liposuction increases seroma in PTS and non-PTS abdominoplasty.

Methods

In this retrospective study, 619 patients underwent abdominoplasty between 2009 and 2017, of which 299 patients had drainless abdominoplasty with PTS and 320 had drain-based abdominoplasty. We compared complications among PTS patients with and without liposuction and among drain-based abdominoplasty patients with and without liposuction.

Results

Demographics were similar between PTS and drain patients and between liposuction and nonliposuction PTS. Mean liposuction volume with PTS was 1592 ± 1048 mL. Seroma in the PTS group was found to be 2.6%, which is consistent with previous data. PTS without liposuction had a rate of seroma of 6.67% compared to a rate of 2.2% with liposuction; these rates were not significantly different (P = 0.20). A total of 207 patients had drain-based abdominoplasty with liposuction, and 113 had it without liposuction. Seroma with liposuction was 9.17% and without liposuction was 6.19%, although these differences were not significant (P = 0.52). PTS lipoabdominoplasty had less seroma compared with drain-based lipoabdominoplasty (P = 0.01).

Conclusions

Liposuction was performed in 80% of the patients, and patients with lipoabdominoplasty were not at a higher risk of seroma, in the drain group or the PTS group. More patients may allow validation that liposuction may actually be protective with PTS. Regardless, there is no increase in seroma with the addition of liposuction to PTS drainless abdominoplasty.

Level of Evidence: 3

Abdominoplasty has undergone much evolution in the last 30 years, from initial debates regarding safety, to combined procedures, to advanced methods for reducing morbidity and consistently enhancing aesthetic outcomes. Previous studies have demonstrated the safety in combining liposuction with abdominoplasty^1-3 as well as breast surgery.^4-6 Over the course of the last 10 years, evidence has mounted in support of the application of progressive tension sutures (PTS) in abdominoplasty to reduce rates of seroma and eliminate drains from routine use.^7-13 Although seroma can be managed posttreatment,¹⁴ prevention is preferred. Animal models have demonstrated the value of at least quilting sutures to reduce seroma.^15,16 Others have reported utilizing glue techniques, but they have only been utilized with lipoabdominoplasty,^17-19 and others have advocated running continuous suture variations^20,21 to try to reduce treatment time while reducing seroma.^22-24 In the reconstructive world, this technique has been adapted for abdominal donor site closure^25-27 and latissimus harvest site closure as well as other areas to reduce seroma.²⁸ Recently, authors have gone as far as to even advocate techniques without drains and without PTS; however, these are very early findings.²²

A logical next question is then: is it safe to combine this procedure with liposuction? Studies have demonstrated the safety of combining liposuction and abdominoplasty.³ In the literature, there is one study that examined seroma in a small retrospective cohort, finding a significant increase in the risk of seroma in traditional abdominoplasty ranging from 16% with drains to 31% without drains with liposuction.²⁹ These authors postulate that an increased wound area leads to more inflammatory fluid production, and these patients all had drains to avoid seroma, although they were not protective considering the relatively high rate when compared with PTS abdominoplasty. Another study showed increased rates of seroma with liposuction in PTS, but the findings were not significant, because the sample size was relatively small (n = 24) and the overall rate of seroma was fairly high in the non-PTS group (26%).³⁰ Pollock and Pollock described 67% of patients receiving liposuction in addition to PTS in their large cohort study; however, they did not compare the rates of seroma in just the liposuction group to known published rates, and their study only had one seroma overall, making any comparisons difficult.⁷ The ideal study would compare the same surgeons utilizing different techniques in similar patient populations, although this is difficult to achieve, because no practice wants to test these hypotheses with a technique that they may consider inferior. Controlled trials have been attempted, although the sample size needed to power these type of studies is large. In addition, these controlled trials had inadequate power, because the control group was identified to have unacceptably high rates of seroma after enrolling just 10 patients.³¹

Here we present a retrospective cohort study of 619 abdominoplasty patients, in which we examine the risk of seroma when liposuction is performed concurrently.

METHODS

This retrospective cohort study was conducted in accordance with the Helsinki and Nuremberg principles with written consent from all included patients. Initial chart review ranging from January 2007 to February 2017 produced 619 abdominoplasty patients. These were consecutive patients, and their surgeries were performed in an outpatient surgical center. Groups compared included classic drain-based abdominoplasty (n = 320) and PTS abdominoplasty (n = 299). In our review of patients with drain-based abdominoplasty, we excluded four patients from the study, because there was incomplete information on the location or volume of liposuction. Also, those groups were subdivided into groups with and without liposuction.

Demographic data were collected, including between the PTS and abdominoplasty groups, as well as between the liposuction and no-liposuction groups. Fisher’s exact tests were utilized for categorical comparisons and t tests were utilized for numerical data. Groups were compared utilizing Fisher’s exact tests to identify differences in rates of seroma formation. Primary outcomes were seroma formation, and secondary outcomes included all other complications.

RESULTS

Demographics

Demographics of this study are presented in Table 1. No statistically significant differences were found between demographic groups, representing similar groups for comparison between PTS and drains and between liposuction and no liposuction (Table 2). There were 292 females and 7 males in the PTS group, and 305 females and 15 males in the drain-based abdominoplasty group. The mean age was 45.1 years (range, 19-77 years) in the PTS group and 44.2 years (range, 22-76 years) in the drain-based group. The mean follow-up time was 4.98 months in the PTS group (range, 0-69 months) and 9.38 months in the drain group (range, 0-80 months).

The mean age of the patients was 45 years (range, 19-77 years), and there were several smokers and diabetic patients. The mean body mass index (BMI) was 25.5 kg/m² and there were no significant differences in BMI between each group. Pretreatment Caprini scores in the PTS group patients were 3.8 on average (Figure 1).

Demographics were further analyzed to compare groups of patients within each group; patients with concurrent liposuction were compared with patients without concurrent liposuction in PTS and in drain-based abdominoplasty. Importantly, there were no significant differences in the groups of patients that had lipoabdominoplasty and in those that had abdominoplasty alone.

Liposuction Areas and Volumes

Patients in the PTS group and drains group who had liposuction either had it in the abdomen, mons, trunk (bilateral), or thighs (bilateral). The thigh areas were in continuity with the abdominal liposuction cavity. Furthermore, those patients with thigh liposuction were typically higher-volume liposuction patients and thus were included to best reflect the overall population of our lipoabdominoplasty patients. Within the PTS group, the mean volumes by zone were reported to be: mons, 122 ± 76 mL (range, 50-300 mL); flank, 832 ± 585 mL (range, 87-3200 mL); thighs, 404.5 ± 284 mL (range, 88-1450 mL); abdomen, 384 ± 431 mL (range, 50-2000 mL); and total, 1593 ± 1048 mL (range, 0-5000 mL). We found contiguous and noncontiguous liposuction areas, although all patients who had concomitant liposuction had at least one area of contiguous or overlapping liposuction.

Seroma Was Not Increased in Lipoabdominoplasty vs Abdominoplasty PTS Patients

Overall the rate of seroma in the PTS group was found to be 2.6%, which is consistent with previously reported rates of seroma when utilizing this technique. This was in comparison to an overall rate of 8.5% in the drains group, and these values were significantly different (P = 0.005).

Within the PTS group, patients without liposuction had a higher rate of seroma of 6.67% compared with a rate of 2.2% in PTS patients with liposuction, but these rates were not found to be significantly different (P = 0.20).

In comparison, the drain-based abdominoplasty group exhibited a seroma rate of 9.17% with liposuction and a rate of 6.19% without liposuction, although these differences were also not found to be significant (P = 0.52).

There was a significant difference between PTS with liposuction (2.2%) and drains with liposuction (9.17%) (P = 0.01). Drain-based lipoabdominoplasty had more seroma than PTS-based lipoabdominoplasty.

Lipoabdominoplasty With Progressive Tension Suture

The mean liposuction volume in patients with PTS was 1592 ± 1048 mL. Figure 2 shows the number of patients who had each of the zones of liposuction performed, demonstrating the fact that most patients had flank liposuction and/or abdominal liposuction. Of the seroma patients who had PTS and liposuction, two patients had liposuction in three zones (flank, abdomen, and thighs or mons), one had liposuction in two zones (flank and abdomen), and three had liposuction in the flanks only. Statistically, it was not possible to correlate the number of zones of liposuction with the rate of seroma, because the rate of seroma was low and the number of seromas in each group was relatively similar.

Analysis of the number of zones of liposuction was performed, and most patients were found to have two zones of liposuction performed (Figure 3) in the PTS group.

DISCUSSION

Seroma has been demonstrated previously to be reduced with PTS, but few articles have described its incidence in combined liposuction. One of the most common questions at conferences during presentation on PTS is: did you do liposuction and what was the volume? Surgeons seem to think that liposuction increases rates of seroma, and we sought to figure this out. Pollock and Pollock did document contiguous liposuction⁷; however, they did not compare the groups of liposuction patients with nonliposuction patients. We sought to identify whether liposuction was an independent variable for seroma.

Overall several key findings were identified in this retrospective cohort study. First, PTS was again confirmed to have lower rates of seroma than drain-based abdominoplasty. The rates of seroma were no higher in the lipoabdominoplasty group with PTS compared with those with standard PTS. Demographics were similar, excluding the chance of bias for BMI or other wound-healing issues. Second, liposuction was found to be associated with higher seroma rates in drain-based abdominoplasty compared with nonliposuction drain-based abdominoplasty, although statistical examination failed to show significance. Third, liposuction was found to be associated with a lower rate of seroma in the PTS group compared with the group without liposuction, although again this could not be validated statistically. Finally, there was significantly less seroma in PTS liposuction patients compared with drain-based liposuction patients. PTS lipoabdominoplasty showed lower rates of seroma formation compared with drain-based lipoabdominoplasty.

On review of the findings, we were interested in why the rates of seroma were no higher in lipoabdominoplasty with PTS compared to PTS alone. Although significance was not shown, there was a lower rate of seroma when liposuction was performed concomitantly. We initially thought that this may be due to a selection bias, although the demographics proved similar. We then considered the fact that larger patients may receive more liposuction and their abdominoplasty flaps may anatomically be thicker and could obscure small seromas. This may lead to higher detection of seroma in thinner patients (who also tend to have less liposuction). There was no way to prove this theory, but we again showed similar demographics between the groups for BMI and volume of liposuction.

This trend had not yet been demonstrated in the literature; in fact, other studies had shown that liposuction increased the rate of seroma in drain-based and PTS abdominoplasty.^10,29,30 The authors acknowledged that they had low numbers and high rates of seroma, and the power was not sufficient to support any conclusions regarding liposuction; however, they did confirm that PTS reduced seroma, and liposuction had no effect on the rates of seroma in their studies. Although we agree that in this study and all studies, a power calculation in advance allows for ideal experimental design. However, there is little information on the rates of seroma in lipoabdominoplasty patients. Published papers focus on the patients with abdominoplasty but not lipoabdominoplasty. In retrospect, without good published rates, we thought that the best approach would be a post hoc power analysis. In this case, the post hoc power test comparing a seroma rate was 6.6 % in the group of 113 patients and 2.2% in the group of 207 patients, demonstrating an overall power of 50.7%. One hypothesis as to why liposuction may actually reduce the risk of seroma in PTS patients is that the liposuction pathways help to distribute the seroma fluid or to allow for pathways for resorption. In the comparison of PTS vs no PTS, the power was found to be 89.4%, which may be the highest post hoc power test calculated and reported yet, and suggests that PTS again does significantly reduce seroma.

Perhaps the most interesting finding was that lipoabdominoplasty with PTS is associated with less seroma compared with traditional drain-based lipoabdominoplasty. This suggests that if all techniques and demographics are kept equal, PTS reduces the rate of seroma in lipoabdominoplasty. We advocate the use of PTS in all abdominoplasty, so it would be interesting to determine if drains with PTS had decreased seroma rates or rates like drains alone. Antonetti and Antonetti¹² examined this in their 2010 article with 516 cases. They showed in one group with 22 patients with drains and PTS a rate of seroma of 4.5% and in the group of PTS with no drains (55 patients) a rate of seroma of 1.7%. Again, the number of patients is low and the power does not support significance. Interestingly, the highest level of evidence on PTS was a meta-analysis that examined conventional drain-based abdominoplasty vs PTS with drains, vs PTS without drains.⁹ It found that PTS reduced seroma, although there was not any significant differences between PTS with drains and PTS without drains, ie, both had lower rates of seroma compared with drain-based conventional abdominoplasty, but the numbers were not significant to support PTS without drains.⁹ This study did not compare directly lipoabdominoplasty and abdominoplasty, and many of the studies included did not report those differences. Another systematic review and meta-analysis on this topic recently showed that PTS was an independent factor to reduce seroma, but it did not describe liposuction or compare drains with or without PTS.³²

We did not examine the mean skin weights, because these data are complex and misleading, with the abdominal tissue weights differing based on the amount of injected tumescence and the amount of liposuction before excision, especially in the case of fat grafting. For this reason, we did not analyze the weights for this study.

The number of smokers in this study was relatively high, and we tried to identify a significant difference in the rates of complications including seroma, but we found none. We do not believe that smoking is necessarily a mechanistic risk factor for seroma, but to prove it, we would need a huge number of smokers who had similar operations to identify differences in complication rates.

In the past, many patients had questions regarding PTS abdominoplasty, and the data clearly support the fact that PTS reduces seroma, with or without drains. The fear of seroma and other posttreatment complications led to slow uptake of the method for closure. Now many are adapting the PTS technique originally proposed many years ago by Pollock and Pollock and seeing the benefits. We would argue going forward that those who in the past were unclear on the utility of PTS when performing liposuction with abdominoplasty should integrate PTS with their standard lipoabdominoplasty to enjoy similar rates of protection against seroma.

Limitations

Bias is an inescapable confounder in all retrospective studies. In this study, we attempted to minimize bias through thorough examination of demographics and an ideal propensity match. However, one may argue that there may be bias in the selection, because patients who are candidates for liposuction would be expected to be slightly more obese and would be expected to be at slightly higher risk.

A prospective randomized trial is needed to examine PTS and the effects on seroma, as well as the role of concurrent liposuction. Unfortunately, in the aesthetic surgery patient, it is difficult to conduct these types of studies, because surgeons do not want to offer a potentially inferior technique. Furthermore, it is difficult to quantify the value of PTS in the posttreatment period, although anecdotally, patients and the staff are very happy to avoid drain care.

CONCLUSIONS

Concurrent liposuction does not raise the risk of posttreatment seroma in PTS no-drain abdominoplasty patients. Furthermore, PTS lipoabdominoplasty has a lower rate of posttreatment seroma than drain-based lipoabdominoplasty. Overall, PTS abdominoplasty has lower rates of seroma than drain-based abdominoplasty.

Disclosures

The authors declared no potential conflicts of interest with respect to the research, authorship, and publication of this article.

Funding

The authors received no financial support for the research, authorship, and publication of this article.

REFERENCES