COSMETIC Natural Evolution of Seroma in Abdominoplasty Marcello Di Martino, M.D., M.S. Fábio X. Nahas, M.D., Ph.D. Alexandro K. Kimura, M.D., M.S. Natasha Sallum, M.D. Lydia M. Ferreira, M.D., Ph.D. São Paulo, Brazil
Background: Abdominoplasty is one of the most performed aesthetic surgical procedures, and seroma is a common local complication. The aim of this study was to investigate the beginning of seroma formation after abdominoplasty and its progression. Methods: Twenty-one female patients underwent standard abdominoplasty. To investigate seroma formation, abdominal ultrasound was performed in five regions of the abdominal wall (i.e., epigastric, umbilical, hypogastric, right iliac fossa, and left iliac fossa regions) at five different time points: postoperative days 4, 11, 18, 25, and 32. Results: The incidence of seroma was 4.8 percent on postoperative day 4, 38.1 percent on postoperative day 11, 33.3 percent on postoperative day 18, 23.8 percent on postoperative day 25, and 19 percent on postoperative day 32. The left iliac fossa region had the highest relative volume of fluid collection on postoperative day 4, as did both the right iliac fossa and left iliac fossa regions on postoperative day 11. At other time points, the relative volume of fluid collection was significantly higher in the right iliac fossa region. Conclusion: The highest incidence of seroma occurred on postoperative day 11, and the iliac fossae were the most common locations of seroma. (Plast. Reconstr. Surg. 135: 691e, 2015.) CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.
A
bdominoplasty is one of the most performed aesthetic surgical procedures and was the fourth most popular procedure worldwide in 2012, according to the International Society of Aesthetic Plastic Surgery.1 Patients with marked skin excess and laxity of the musculoaponeurotic layer, with or without hernia or excess abdominal fat, are considered appropriate candidates for abdominoplasty.2 Seroma is the most common local complication associated with abdominoplasty, with incidence rates ranging from 1 to 57 percent and an average incidence of 10 percent accepted by most authors.3,4 Seroma can be defined as an exudate fluid collection formed deeper to flap elevation areas,5,6 with predominance of neutrophils and high protein content.7 There are controversies about the moment seroma actually develops in the postoperative period. Some authors believe that the highest incidence of seroma occurs between the second and third postoperative weeks8,9; however, there are no studies evaluating the beginning of seroma formation or its peak volume after From the Division of Plastic Surgery, Department of Surgery, Federal University of São Paulo. Received for publication January 30, 2014; accepted August 25, 2014. Copyright © 2015 by the American Society of Plastic Surgeons DOI: 10.1097/PRS.0000000000001122
abdominoplasty. Understanding the period when seroma begins to form and when it reaches the largest volume is important for the physician’s practice, because a rapid action toward controlling this complication may prevent pseudobursa. This secondary complication requires surgical intervention with an operative time that may be as long as that of abdominoplasty itself.10 The objective of this study was to evaluate the beginning and progression of seroma following abdominoplasty.
PATIENTS AND METHODS This prospective clinical trial was approved by the Research Ethics Committee of the Federal University of São Paulo and performed in accordance with the ethical standards of the 1964 Declaration of Helsinki and its subsequent amendments. Written informed consent was obtained from all patients before their inclusion in the study, and anonymity was ensured. The study was conducted between January of 2008 and March of 2009. Twenty-one female patients were consecutively selected from the Clinic for Abdominal Disclosure: The authors have no financial interest to declare in relation to the content of this article. No outside funding was received.
www.PRSJournal.com
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Plastic and Reconstructive Surgery • April 2015 Wall Reconstruction at the Division of Plastic Surgery of the São Paulo Hospital. Inclusion criteria were age between 25 and 60 years, deformities of the skin and subcutaneous tissue of the abdominal wall (Nahas type III deformity)11,12 for which resection of infraumbilical skin and subcutaneous tissue was indicated, musculofascial defects (Nahas type A deformity)13 for which vertical plication of the anterior rectus sheath was indicated to correct diastasis recti, and body mass index less than 30 kg/m2. Exclusion criteria were weight loss of more than 12 kg, pregnancy in the past year, smoking habit, previous liposuction or other abdominal surgery, scars from previous abdominal surgery (except Pfannenstiel incision), combined surgical procedures (including liposuction), abdominal wall hernia, history of deep vein thrombosis or thrombophilia, lymphatic system diseases, and systemic diseases. The patients’ characteristics, including age, body mass index, and weight of resected skin and subcutaneous tissue, are listed in Table 1. All patients underwent standard abdominoplasty with a previously marked transversal suprapubic incision. All operations were performed by the same surgeon. Elevation of the upper flap from the underlying aponeurosis was performed using an electrocautery unit (Valleylab Force2; Pfizer, Inc., New York, N.Y.) with output power of 35 W set in the cutting or coagulation mode. The upper flap extended superiorly up to the xiphoid process and 3 cm laterally from the medial edges of the rectus abdominis muscle (Fig. 1). Diastasis recti was treated by midline plication in a single plane with inverting interrupted 2-0 monofilament nylon sutures. Liposuction was not performed and quilting sutures were not used in the procedure. Two 3.2-mm suction drains (Portovac; Kalmédica, Campinas, Brazil) were placed under the abdominal flap and removed when output was less than 40 ml/24 hours. Patients were instructed to wear a compression garment for 30 days and stay in the semi-Fowler position for 10 days. All patients were discharged within 24 hours after surgery, and early walking was encouraged on the first postoperative day. Lymphatic drainage was not used.
Fig. 1. Intraoperative view showing elevation of the upper flap, above the aponeurosis, extending 3 cm laterally from the medial edges of the rectus abdominis muscle, and superiorly up to the xiphoid process.
Ultrasound Evaluation Patients underwent ultrasound examination at five different time points: postoperative days 4, 11, 18, 25, and 32. All examinations were performed by the same examiner in five distinct regions of the abdominal wall: the epigastric, umbilical, hypogastric, right iliac fossa, and left iliac fossa regions. The regions were defined by the intersection of two horizontal lines and two vertical lines. The first horizontal line was positioned 3 cm above the umbilical scar, the second horizontal line was 3 cm below the umbilicus, and the two vertical lines were 4 cm lateral to the umbilicus (Fig. 2).
Table 1. Patients’ Characteristics (n = 21)
Mean Range
BMI (kg/m2)
Age (yr)
Resected Tissue Weight (g)
23.7 20–28
34.8 26–50
626.2 330–1035
BMI, body mass index.
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Fig. 2. Representation of the five regions defined for the detection of seroma formation by ultrasound: epigastric (EPI), umbilical (UMB), hypogastric (HYPO), right iliac fossa (RIF), and left iliac fossa (LIF) regions.
Volume 135, Number 4 • Seroma in Abdominoplasty Ultrasonography was performed with the patient in supine position, and the volume of seroma was measured in milliliters. Cases presenting a fluid volume greater than 20 ml for the five regions combined were considered positive for seroma.8 Ultrasound-guided aspiration was performed in patients with fluid collections greater than 20 ml. All fluid collections of patients diagnosed as positive for seroma were aspirated. These patients were then examined clinically for seroma formation at 4-day intervals and by ultrasound at 7-day intervals until the volume of fluid collection was less than 20 ml. Statistical Analysis The characteristics of patients were described according to seroma diagnosis and compared among them using the Mann-Whitney test.14 The presence and volume of seroma in each abdominal region at each time point were compared using the Friedman test followed by nonparametric multiple paired comparisons, if necessary.15 Generalized estimating equations with binomial marginal distribution and logit link function were used to check for changes in seroma formation during the follow-up period and differences in fluid collections between abdominal regions.16 The McNemar test was conducted to compare clinical with ultrasound diagnosis of seroma formation on postoperative day 11. All statistical tests were performed at a significance level of α = 0.05 (p < 0.05).
RESULTS The mean time to drain removal was 4.4 days. The incidence of seroma was 4.8 percent on postoperative day 4, 38.1 percent on postoperative day 11, 33.3 percent on postoperative day 18, 23.8 percent on postoperative day 25, and 19 percent on postoperative day 32. Risk of seroma formation on postoperative day 11 was 7.94 times as great on postoperative day 4 (p = 0.035) (Fig. 3). No significant difference in seroma formation was found between other time points. Patients presenting seroma at any time postoperatively had a significantly larger amount of resected tissue than those who had no seroma (Table 2). There were no significant differences in time to drain removal, body mass index, or age between patients with and without seroma. On postoperative day 11, the ratio of seroma formation diagnosed by ultrasound (38.1 percent) was significantly higher (p = 0.024) compared with that diagnosed clinically (23.3 percent), as depicted in Table 3. Total fluid collection analysis showed a significant increase in volume of fluid collection from postoperative day 4 to postoperative day 11 and from postoperative day 18 to postoperative day 25, and a significant decrease from postoperative day 25 to postoperative day 32. Only between postoperative days 11 and 18 was no significant difference in the volume of fluid collection (p = 0.584) observed (Tables 4 and 5). The left iliac fossa region had the highest relative volume of fluid collection on postoperative day 4 (Fig. 4), as did both the right iliac fossa and left iliac fossa regions on postoperative day 11 (Fig. 5).
Fig. 3. Incidence of seroma formation on postoperative days (PD) 4, 11, 18, 25, and 32. Asterisks indicate statistical significance (p < 0.05).
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Plastic and Reconstructive Surgery • April 2015 Table 2. Association of Seroma Formation with Resected Tissue Weight, Time to Drain Removal, Body Mass Index, and Age Variables
Seroma Minimum Maximum No.
Resected tissue No weight, g Yes Total Time to drain No removal, days Yes Total No BMI, kg/m2 Yes Total Age, yr No Yes Total
330 450 330 3 3 3 20 21 20 26 26 26
890 1035 1035 6 7 7 25 28 28 50 50 50
11 10 21 11 10 21 11 10 21 11 10 21
p 0.004* 0.051 0.173 0.863
BMI, body mass index. *Statistical significance (p < 0.05); Fisher’s exact test.
Table 3. Comparison of Clinical and Ultrasound Detection of Seroma Formation on Postoperative Day 11 Seroma Diagnosis Clinical Ultrasound
Yes
No
Total
% Seroma
5 8
16 13
21 21
23.3 38.1
p 0.024*
*Statistical significance (p < 0.05, McNemar test).
Table 4. Mean Volume of Fluid Collection Detected by Ultrasound for Each Time Point* Postoperative Day Mean, ml
4 3.04
11 53.3
18 63.6
25 83.8
32 23.8
*Mean volume of fluid collection, seroma (>20 ml).
Table 5. Multiple Comparisons of Fluid Collections between Postoperative Time Points Comparisons (POD) 4 vs. 11 11 vs. 18 18 vs. 25 25 vs. 32
Z
p
−6.52 0.55 3.61 4.82
Background: Abdominoplasty is one of the most performed aesthetic surgical procedures, and seroma is a common local complication. The aim of this study was to investigate the beginning of seroma formation after abdominoplasty and its progression. Methods: Twenty-one female patients underwent standard abdominoplasty. To investigate seroma formation, abdominal ultrasound was performed in five regions of the abdominal wall (i.e., epigastric, umbilical, hypogastric, right iliac fossa, and left iliac fossa regions) at five different time points: postoperative days 4, 11, 18, 25, and 32. Results: The incidence of seroma was 4.8 percent on postoperative day 4, 38.1 percent on postoperative day 11, 33.3 percent on postoperative day 18, 23.8 percent on postoperative day 25, and 19 percent on postoperative day 32. The left iliac fossa region had the highest relative volume of fluid collection on postoperative day 4, as did both the right iliac fossa and left iliac fossa regions on postoperative day 11. At other time points, the relative volume of fluid collection was significantly higher in the right iliac fossa region. Conclusion: The highest incidence of seroma occurred on postoperative day 11, and the iliac fossae were the most common locations of seroma. (Plast. Reconstr. Surg. 135: 691e, 2015.) CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.
A
bdominoplasty is one of the most performed aesthetic surgical procedures and was the fourth most popular procedure worldwide in 2012, according to the International Society of Aesthetic Plastic Surgery.1 Patients with marked skin excess and laxity of the musculoaponeurotic layer, with or without hernia or excess abdominal fat, are considered appropriate candidates for abdominoplasty.2 Seroma is the most common local complication associated with abdominoplasty, with incidence rates ranging from 1 to 57 percent and an average incidence of 10 percent accepted by most authors.3,4 Seroma can be defined as an exudate fluid collection formed deeper to flap elevation areas,5,6 with predominance of neutrophils and high protein content.7 There are controversies about the moment seroma actually develops in the postoperative period. Some authors believe that the highest incidence of seroma occurs between the second and third postoperative weeks8,9; however, there are no studies evaluating the beginning of seroma formation or its peak volume after From the Division of Plastic Surgery, Department of Surgery, Federal University of São Paulo. Received for publication January 30, 2014; accepted August 25, 2014. Copyright © 2015 by the American Society of Plastic Surgeons DOI: 10.1097/PRS.0000000000001122
abdominoplasty. Understanding the period when seroma begins to form and when it reaches the largest volume is important for the physician’s practice, because a rapid action toward controlling this complication may prevent pseudobursa. This secondary complication requires surgical intervention with an operative time that may be as long as that of abdominoplasty itself.10 The objective of this study was to evaluate the beginning and progression of seroma following abdominoplasty.
PATIENTS AND METHODS This prospective clinical trial was approved by the Research Ethics Committee of the Federal University of São Paulo and performed in accordance with the ethical standards of the 1964 Declaration of Helsinki and its subsequent amendments. Written informed consent was obtained from all patients before their inclusion in the study, and anonymity was ensured. The study was conducted between January of 2008 and March of 2009. Twenty-one female patients were consecutively selected from the Clinic for Abdominal Disclosure: The authors have no financial interest to declare in relation to the content of this article. No outside funding was received.
www.PRSJournal.com
691e
Plastic and Reconstructive Surgery • April 2015 Wall Reconstruction at the Division of Plastic Surgery of the São Paulo Hospital. Inclusion criteria were age between 25 and 60 years, deformities of the skin and subcutaneous tissue of the abdominal wall (Nahas type III deformity)11,12 for which resection of infraumbilical skin and subcutaneous tissue was indicated, musculofascial defects (Nahas type A deformity)13 for which vertical plication of the anterior rectus sheath was indicated to correct diastasis recti, and body mass index less than 30 kg/m2. Exclusion criteria were weight loss of more than 12 kg, pregnancy in the past year, smoking habit, previous liposuction or other abdominal surgery, scars from previous abdominal surgery (except Pfannenstiel incision), combined surgical procedures (including liposuction), abdominal wall hernia, history of deep vein thrombosis or thrombophilia, lymphatic system diseases, and systemic diseases. The patients’ characteristics, including age, body mass index, and weight of resected skin and subcutaneous tissue, are listed in Table 1. All patients underwent standard abdominoplasty with a previously marked transversal suprapubic incision. All operations were performed by the same surgeon. Elevation of the upper flap from the underlying aponeurosis was performed using an electrocautery unit (Valleylab Force2; Pfizer, Inc., New York, N.Y.) with output power of 35 W set in the cutting or coagulation mode. The upper flap extended superiorly up to the xiphoid process and 3 cm laterally from the medial edges of the rectus abdominis muscle (Fig. 1). Diastasis recti was treated by midline plication in a single plane with inverting interrupted 2-0 monofilament nylon sutures. Liposuction was not performed and quilting sutures were not used in the procedure. Two 3.2-mm suction drains (Portovac; Kalmédica, Campinas, Brazil) were placed under the abdominal flap and removed when output was less than 40 ml/24 hours. Patients were instructed to wear a compression garment for 30 days and stay in the semi-Fowler position for 10 days. All patients were discharged within 24 hours after surgery, and early walking was encouraged on the first postoperative day. Lymphatic drainage was not used.
Fig. 1. Intraoperative view showing elevation of the upper flap, above the aponeurosis, extending 3 cm laterally from the medial edges of the rectus abdominis muscle, and superiorly up to the xiphoid process.
Ultrasound Evaluation Patients underwent ultrasound examination at five different time points: postoperative days 4, 11, 18, 25, and 32. All examinations were performed by the same examiner in five distinct regions of the abdominal wall: the epigastric, umbilical, hypogastric, right iliac fossa, and left iliac fossa regions. The regions were defined by the intersection of two horizontal lines and two vertical lines. The first horizontal line was positioned 3 cm above the umbilical scar, the second horizontal line was 3 cm below the umbilicus, and the two vertical lines were 4 cm lateral to the umbilicus (Fig. 2).
Table 1. Patients’ Characteristics (n = 21)
Mean Range
BMI (kg/m2)
Age (yr)
Resected Tissue Weight (g)
23.7 20–28
34.8 26–50
626.2 330–1035
BMI, body mass index.
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Fig. 2. Representation of the five regions defined for the detection of seroma formation by ultrasound: epigastric (EPI), umbilical (UMB), hypogastric (HYPO), right iliac fossa (RIF), and left iliac fossa (LIF) regions.
Volume 135, Number 4 • Seroma in Abdominoplasty Ultrasonography was performed with the patient in supine position, and the volume of seroma was measured in milliliters. Cases presenting a fluid volume greater than 20 ml for the five regions combined were considered positive for seroma.8 Ultrasound-guided aspiration was performed in patients with fluid collections greater than 20 ml. All fluid collections of patients diagnosed as positive for seroma were aspirated. These patients were then examined clinically for seroma formation at 4-day intervals and by ultrasound at 7-day intervals until the volume of fluid collection was less than 20 ml. Statistical Analysis The characteristics of patients were described according to seroma diagnosis and compared among them using the Mann-Whitney test.14 The presence and volume of seroma in each abdominal region at each time point were compared using the Friedman test followed by nonparametric multiple paired comparisons, if necessary.15 Generalized estimating equations with binomial marginal distribution and logit link function were used to check for changes in seroma formation during the follow-up period and differences in fluid collections between abdominal regions.16 The McNemar test was conducted to compare clinical with ultrasound diagnosis of seroma formation on postoperative day 11. All statistical tests were performed at a significance level of α = 0.05 (p < 0.05).
RESULTS The mean time to drain removal was 4.4 days. The incidence of seroma was 4.8 percent on postoperative day 4, 38.1 percent on postoperative day 11, 33.3 percent on postoperative day 18, 23.8 percent on postoperative day 25, and 19 percent on postoperative day 32. Risk of seroma formation on postoperative day 11 was 7.94 times as great on postoperative day 4 (p = 0.035) (Fig. 3). No significant difference in seroma formation was found between other time points. Patients presenting seroma at any time postoperatively had a significantly larger amount of resected tissue than those who had no seroma (Table 2). There were no significant differences in time to drain removal, body mass index, or age between patients with and without seroma. On postoperative day 11, the ratio of seroma formation diagnosed by ultrasound (38.1 percent) was significantly higher (p = 0.024) compared with that diagnosed clinically (23.3 percent), as depicted in Table 3. Total fluid collection analysis showed a significant increase in volume of fluid collection from postoperative day 4 to postoperative day 11 and from postoperative day 18 to postoperative day 25, and a significant decrease from postoperative day 25 to postoperative day 32. Only between postoperative days 11 and 18 was no significant difference in the volume of fluid collection (p = 0.584) observed (Tables 4 and 5). The left iliac fossa region had the highest relative volume of fluid collection on postoperative day 4 (Fig. 4), as did both the right iliac fossa and left iliac fossa regions on postoperative day 11 (Fig. 5).
Fig. 3. Incidence of seroma formation on postoperative days (PD) 4, 11, 18, 25, and 32. Asterisks indicate statistical significance (p < 0.05).
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Plastic and Reconstructive Surgery • April 2015 Table 2. Association of Seroma Formation with Resected Tissue Weight, Time to Drain Removal, Body Mass Index, and Age Variables
Seroma Minimum Maximum No.
Resected tissue No weight, g Yes Total Time to drain No removal, days Yes Total No BMI, kg/m2 Yes Total Age, yr No Yes Total
330 450 330 3 3 3 20 21 20 26 26 26
890 1035 1035 6 7 7 25 28 28 50 50 50
11 10 21 11 10 21 11 10 21 11 10 21
p 0.004* 0.051 0.173 0.863
BMI, body mass index. *Statistical significance (p < 0.05); Fisher’s exact test.
Table 3. Comparison of Clinical and Ultrasound Detection of Seroma Formation on Postoperative Day 11 Seroma Diagnosis Clinical Ultrasound
Yes
No
Total
% Seroma
5 8
16 13
21 21
23.3 38.1
p 0.024*
*Statistical significance (p < 0.05, McNemar test).
Table 4. Mean Volume of Fluid Collection Detected by Ultrasound for Each Time Point* Postoperative Day Mean, ml
4 3.04
11 53.3
18 63.6
25 83.8
32 23.8
*Mean volume of fluid collection, seroma (>20 ml).
Table 5. Multiple Comparisons of Fluid Collections between Postoperative Time Points Comparisons (POD) 4 vs. 11 11 vs. 18 18 vs. 25 25 vs. 32
Z
p
−6.52 0.55 3.61 4.82
