Laser-assisted Abdominoplasty Marking to Achieve a Better Design of Abdominal Scar

Summary:

Ensuring bilateral symmetry when marking for abdominoplasty incision is critical and can be challenging when using traditional landmarks. This study aims to compare the outcomes of laser-assisted abdominoplasty marking to the traditional method. In this prospective study, patients undergoing standard abdominoplasty were included. Abdomens were randomized to determine which half would serve as the dominant side for clinical marking. Marking was first performed using a traditional method and then using a laser level, and any differences were recorded. A total of 50 patients participated in the study. The distance between markings at the most lateral point was as high as 10.0 [7.0–10.0] mm (P < 0.001), as was that at 12 cm (7.0 [5.0–8.0] mm, P = 0.03). However, the difference at 6 cm was 1.0 [0.0–4.0] mm (P < 0.001). Using a laser level during abdominoplasty marking can increase symmetry of the marking.

Takeaways

Question: We try to find a way to improve the symmetry of abdominal marking. This study aims to compare the outcomes of laser-assisted abdominoplasty marking to the traditional method.

Findings: This prospective study found that the laser-assisted marking resulted in more symmetry of the abdominal marking compared with the traditional method.

Meaning: Using a laser level during abdominoplasty marking can increase the symmetry of the abdominal marking.

INTRODUCTION

In marking the incision for abdominoplasty, bilateral symmetry is crucial. It determines the scar outcome, which is one of the most common causes of patient dissatisfaction with the procedure.¹ Symmetry can be more easily achieved using a special ruler,² standardized template,³ specially designed instrument,⁴ or a marking grid drawn directly on the abdomen.⁵ These techniques allow points to be marked directly on the abdomen and help facilitate bilateral symmetry. However, abdomens vary in terms of protrusion, which is often asymmetrical. Using a rigid template in such instances can result in unequal vertical and horizontal measurements.

Laser-assisted marking is one method that has been developed to address this limitation. Instead of using a reference located on the abdomen, the laser level uses an outside reference point and projects the level onto the abdomen, thus mitigating issues caused by variations in abdominal protrusion. Moreover, laser levels are widely available for purchase around the world, but many other techniques require difficult-to-obtain or customized instruments.^2–5 This study aimed to compare the results of abdominoplasty marking using a laser level to those of a traditional method without using a laser level.

METHODS

Study Design

This prospective study was a collaborative effort between Mae Fah Luang University Hospital and QPrime hospital in Thailand. The study protocol was approved by the ethics committee and registered in the Thai Clinical Trials Registry (TCTR20220819002). The study period was from August 2022 to February 2023.

Participants

Patients over 18 years of age undergoing standard abdominoplasty were included. To represent most patients in normal circumstances, the participants had a body mass index of less than 30 kg/m² and normal symmetrical or mild asymmetrical abdomen, without significant asymmetry in hip height or severe scoliosis. Their exclusion criteria included abdominal wall defects, abdominal hernias, having undergone previous abdominal procedures, abdominal scars, and significant abdominal wall asymmetry.

Traditional Marking Definition

The patient was asked to stand with their back against the wall to immobilize the body while performing the marking process. The marking was started by identifying the midline of the abdomen, and the marking was made at an average of 7 cm superior to the vaginal introitus. Then, a horizontal curve line was drawn on each side without using a laser level.

Intervention

A split-wound/split-scar model was used to facilitate internal control and minimize the number of uncontrolled variables. The abdomen was divided in half (left and right) and the dominant side was chosen randomly by a coin toss. The dominant side was marked first, and then the surgeon marked the other side using a traditional clinical marking method. A laser level (Bosch GCL 2-15 G, Robert Bosch Power Tools GmbH, Stuttgart, Germany) was then used on the marked abdomen. Significant points were set at the midline, 6 cm, 12 cm, and the most lateral part of the marking, as shown in Figure 1. The laser level was set based on the marking on the dominant side and the laser-assisted marking was performed at 6 cm, 12 cm, and the most lateral part of the nondominant side. A line was then drawn connecting each point. The distance between the marks using the two methods was measured at 6 cm, 12 cm, and the most lateral part of the marking. Incisions were made based on the laser-assisted markings. The marking process is illustrated in the supplemental video. [See Video (online), which displays the laser-assisted abdominoplasty marking process.]

Fig. 1.

Significant abdominal marking points were set at midline, 6 cm, 12 cm, and the most lateral point. The surgeon marked the dominant side first and then the opposite side using a traditional clinical technique. Laser-assisted marking was then performed and the difference at each point was measured.

Video 1. displays the laser-assisted abdominoplasty marking process.

Download video file ^{(54.5MB, mp4)}

Outcomes

The primary outcome was the distance between marks using the clinical method and those using the laser level at the most lateral point. Secondary outcomes were the distance between the two marks at 6 cm and 12 cm from the midline.

Sample Size

A pilot study conducted on 10 cases found a mean marking difference of 9.70 mm with an SD of 2.54. A previous study was conducted on the different distance between sides at which the patient could detect asymmetry, and it was found that more than 80% of the patients could detect asymmetry if the distance was 5 mm.⁶ Thus, a marking difference of at least 5 mm was considered significant in this study. A sample size of four was determined to be necessary to ensure a power of 0.9 and alpha of 0.05.⁷

Statistical Analysis

Data were analyzed using STATA/SE version 10.1. A one-sample Wilcoxon signed rank test was used to determine the distance between markings obtained using the two methods, and a distance of 5 mm or more was considered hypothetically significant. A Wilcoxon signed-rank test was used to determine the difference in satisfaction before and after surgery.

Results

Participants’ demographic data are shown in Table 1. The distance between markings at the most lateral point was as high as 10.0 [7.0–10.0] mm (P < 0.001), as was that at 12 cm (7.0 [5.0–8.0] mm, P = 0.03). However, the difference at 6 cm was 1.0 [0.0–4.0] mm (P < 0.001). Table 2 summarizes the distance between marks using the two methods.

Table 1.

Demographic Data (n = 50)

Demographic Data	N (%) or Mean ± SD
Age (y)	42.0 ± 7.4
Female sex	50 (100)
BMI (kg/m2)	22.2 ± 2.7
Diabetes	0 (0)
Hypertension	3 (6.0)
Dyslipidemia	3 (6.0)
Smoking	4 (8.0)
Alcohol use	9 (18.0)

Table 2.

The Distance between Marks Using the Two Methods

Different Distance	Median [Q1–Q3] (mm)	P
At 6 cm	1.0 [0.0–4,0]	P < 0.001
At 12 cm	7.0 [5.0–8.0]	0.03
At the most lateral part of the marking	10.0 [7.0–10.0]	<0.001

An example of cases using laser-assisted abdominoplasty marking is shown in Figure 2 and in Supplemental Digital Contents 1 and 2. (See figure, Supplemental Digital Content 1, which displays the preoperative photograph of a female patient undergoing standard abdominoplasty. http://links.lww.com/PRSGO/D425.) (See figure, Supplemental Digital Content 2, which displays the 1-month follow-up after abdominoplasty with laser-assisted marking. http://links.lww.com/PRSGO/D426.)

Fig. 2.

Results at the 6-month follow-up after abdominoplasty with laser-assisted marking.

DISCUSSION

This study found that marking using a traditional method resulted in bilateral asymmetry of up to 10 mm at the most lateral point. The wound outcome is one of the most important aspects in both surgeon and patient perspective.^8,9 A survey was conducted on the unsatisfied patient after abdominoplasty, and it was found that the majority of the reasons were due to dog ears and scars.¹ This major issue on the asymmetrical scar can be alleviated by using a laser level.

Generalization

The laser level is very easy to use. It takes approximately 5 minutes in the marking of the wound. It is also cheap and available in every country. It saves the valuable operating time that the surgeons do not need to repeatedly adjust the marking for the symmetry of the wound.

Limitations

Although the laser level facilitates symmetry, the accuracy of the incision is still largely dependent on the skill of the surgeon. An incision that does not accurately trace the marking may still result in asymmetry. Although the initial marking may be perfectly symmetrical, the final scar position may also be influenced by the amount of superior flap removed and the scar tension. The horizontal distance of the marking is another important factor. If the horizontal marking at 6 cm, 12 cm, and the most lateral part are significantly deviated between sides, the result of the laser-assisted marking can also be deviated.

CONCLUSION

Using a laser level during abdominoplasty marking can increase symmetry of the marking.

DISCLOSURES

The authors have no financial interest to declare in relation to the content of this article. This study was supported by Pheu Ter Foundation.