Safety and Effectiveness of Real-time Direct Vision Liposuction Performed Using Intraoperative Ultrasonography

Abstract

Background:

Liposuction is a frequently performed procedure for body contouring. Various advances, such as retraction technology and ultrasonography, have helped achieve better results, verify the correct anatomical level, and increase the safety of the procedure.

Methods:

The use of intraoperative ultrasonography during liposuction as part of a safety and effectiveness protocol is described in this study. Furthermore, a satisfaction survey was conducted to evaluate the techniques used and the naturalness of the results. Reduction of the deep fat layer at the abdominal and dorsal levels was evaluated via ultrasonography before, immediately after, and 6 months after liposuction. The satisfaction survey was conducted at the end of 6 months. Information regarding the incidence of complications was also obtained.

Results:

Eighty female patients (mean age: 20–38 y) from Peru, Mexico, Brazil, and Argentina scheduled to undergo liposuction were recruited in this multicenter study. Reduction of 99.26% and 99.07% in the deep fat layer was observed at the abdominal and dorsal levels, respectively. This reduction was maintained at 99.26% and 99.14% at the abdominal and dorsal levels, respectively, at 6 months. No intraoperative complications were encountered during the follow-up period (6 mo). The satisfaction survey revealed a high level of satisfaction with the results.

Conclusions:

The use of intraoperative ultrasonography aided in locating the anatomical repairs, thereby facilitating adequate infiltration and liposuction. No lesions or complications were encountered intraoperatively or during the follow-up period. The participants reported a high satisfaction rate at 6 months.

Takeaways

Question: Is liposuction performed with intraoperative ultrasonographic vision, which can effectively reduce the deep fat layer, associated with a good level of satisfaction?

Findings: The intraoperative ultrasonographic measurements revealed effectiveness in reducing the deep fat layer by more than 90% even at 6 months postoperatively.

Meaning: Liposuction performed using ultrasonographic vision effectively reduced the deep fat layer and was proven to be safe. The direct vision of structures will enable surgeons to avoid complications.

INTRODUCTION

Body contouring surgery, which is frequently performed in the field of plastic surgery, requires a more exhaustive and detailed training program that enables residents to hone the skills necessary to achieve satisfactory aesthetic results in terms of naturalness, based on the anatomy of each patient, while ensuring the safety of the procedure to avoid complications.^1–3 Technological advances have improved surgical outcomes and enhanced surgeons’ skills. This emphasizes an aspect of the training methodology that must be developed in different institutions. Ultrasonography is a fundamental imaging modality used to evaluate patients during the pre-, intra-, and postoperative periods. Ultrasonography shows the anatomy and uses imaging tools to identify support points, which help prevent complications.^3–5

Ultrasonography performed preoperatively aids in creating a presurgical design corresponding to the patient’s anatomy. This enables surgeons to achieve natural-looking results. Visualization of the location of the anatomical structures enhances the capacity for surgical planning. Intraoperative ultrasonography enables surgeons to avoid risks and operate in the correct location in real time. Furthermore, it facilitates adequate repositioning of the fat layer, thereby avoiding the risks and complications associated with penetrating inappropriate structures.^6,7

Intraoperative ultrasonography with Doppler capabilities improves the accuracy and safety of intramuscular graft placement for volumization. This technique helps avoid injury to surrounding anatomical structures and vascular compromise by guiding cannula placement within the intramuscular plane.^8–12

It is important to identify the plane while evaluating the anatomy of the fat layers. Recognizing the deep fat layer during the approach at the time of infiltration and liposuction plays a crucial role in obtaining good results.¹³ This study aimed to emphasize the importance of real-time ultrasonography in liposuction and develop a technique based on the patient’s anatomy that can achieve satisfactory aesthetic results.

MATERIALS AND METHODS

This multicenter prospective study enrolled 80 female patients from Peru (35), Mexico (25), Brazil (10), and Argentina (10) who underwent evaluation for body contouring surgery between May and October 2023. Liposuction of the abdomen and dorsal region (lower and upper back) was selected from various possible treatments. All patients 18–45 years of age who were scheduled to undergo liposuction were eligible for inclusion. The exclusion criteria were as follows: history of liposuction, uncontrolled chronic diseases, surgical risk of less than Goldman grade II, body mass index of more than 30 kg/m², and skin flaccidity in the abdomen and/or dorsolumbar region with a Matarasso grade of greater than 2. All patients received general anesthesia to perform the surgical procedures.

The ultrasonography protocol described in this work, elaborated by the author (R.M.M.C.), elucidates the habitual transducer maneuvers performed during surgical procedures. All surgical procedures were performed by 4 plastic surgeons trained in performing liposuction using intraoperative ultrasonography. Philips Ultrasound with L12-4 transducer was used for all procedures. All information and follow-up data were saved in a database created using Microsoft Excel v19.00. All statistical analyses were performed using SPSS software v.25.0.

All patients signed an informed consent form, in addition to providing authorization for the use of their image in the present study. The ethical evaluation was carried out by a local committee, which assessed the guidelines in favor of the protection and care of the study participants. This study adhered to the guidelines of the Declaration of Helsinki.

INFILTRATION AND LIPOSUCTION WITH THE AID OF ULTRASONOGRAPHY

Ultrasonography was performed initially during infiltration. Targeted infiltration was performed using the superwet technique with normal saline solution and epinephrine (1:1,000,000 concentration) with the deep fat layer set as the target anatomical level.

Infiltration was performed using a 3-mm Mercedes-type straight cannula and a closed circuit. The incision points were at the inframammary and suprapubic level, which were designated previously by performing ultrasonography longitudinal to the cannula until the deep fat layer was reached. The transducer was placed in a transverse position to verify the correct structural level to prevent perforation of the abdominal cavity. Infiltration was performed subsequently. The same procedure was repeated in the dorsal region, where the incisions were made at the intergluteal level and below the shoulder blade. (See Video 1 [online], which illustrates the infiltration process guided by intraoperative ultrasonography in the abdominal and dorsal regions.)

Video 1. This video illustrates the infiltration process guided by intraoperative ultrasonography in the abdominal and dorsal regions.

Download video file ^{(91.4MB, mp4)}

Basket- and Mercedes-type cannulas (3, 4, and 5 mm) and a suction machine (160 mmHG) were used to perform liposuction. The fat collection system comprised sterile bottles of 2000 mL, with decantation of at least 20 minutes. Deep liposuction with angled cannulas of 35–40 cm in length was performed in these anatomic zones. Therefore, the longitudinal view of each cannula was maintained with transversal verification to ensure that the cannulas were in the deep fat layer and that the muscle fascia or the abdominal cavity was not perforated.

Two operators (the surgeon and assistant) performed the following maneuvers. The surgeon manipulating the cannula directed the cannula at an angle of 30–45 degrees toward the deep layer using the dominant hand. The nondominant hand was used to position it at the level of the patient’s body. The assistant placed the transducer in a longitudinal position in front of the surgeon’s hand to follow the longitudinal direction of the cannula and verify the position of the tip of the cannula. The passage of the cannula through the fascia that divides the superficial fat layer from the deep fat layer must be visualized at this level to avoid perforating the muscular fascia. This requires the transducer to be placed in a transverse position to verify the plane of the deep fat layer.

The movements performed during liposuction were constant. The assistant maintained the transducer in the longitudinal position to enable direct visualization of the reduction of the deep fat layer. The transducer was placed transverse to the cannula to verify its correct positioning if the anatomical point was suspected to be lost. The final point of liposuction was evidenced when the deep fat layer disappeared completely in the longitudinal and transverse positions. Verification was performed to ensure that the superficial fat layer was intact and that the surrounding structures, such as fascia and muscles, had no lesions. (See Video 2 [online], which illustrates the abdominal and dorsal liposuction process guided by intraoperative ultrasonography.)

Video 2. This video illustrates the abdominal and dorsal liposuction process guided by intraoperative ultrasonography.

Download video file ^{(86.8MB, mp4)}

ULTRASONOGRAPHY MEASUREMENTS

Ultrasonography is performed throughout the procedure, as the deep fat layer and the surrounding structures must be visualized to determine the effectiveness and safety of the procedure. Variations in the visualization of the deep fat layer occur during this period. The increase in thickness owing to the infiltration was achieved using the superwet technique with normal saline solution and epinephrine (1:1,000,000 concentration). While the infiltration is being done, the ultrasound allows us to observe the widening of this layer without modification of the superficial fat layer due to the containment that generates the dividing fascia between the layers and its collapse due to the suction of the deep fat layer. Ultrasonography measurements were performed at 3 different time points in this study: before infiltration, immediately after suctioning the entire fat layer, and 6 months after surgery.

The initial measurement was performed according to the measurement protocol with the patient in the dorsal decubitus position. The fat layers in the abdominal and dorsal regions were located by placing the transducer in a longitudinal position from cephalad to caudal to visualize the extent of fatty tissue and its superficial and deep components. Liposuction was performed in this area subsequently. This measurement enabled surgeons to confirm the absence of hernias or eventrations with visceral content or vascular structures. The transducer was placed in a transverse position to determine the depth of the fat layer. The distance between the dividing fascia and the premuscular fascia, which is the limit of the deep fat, was measured subsequently.

Six months postoperatively, the deep fat layer was located using the dividing fascia and premuscular fascia as anatomical repair points. The measurements were standardized and taken into account in the abdominal region: the middle anatomical points were located in the hypochondrium, flanks, and iliac fossa at the level of the anterior axillary line (Fig. 1). The evaluation points in the dorsal region corresponded to 3 points in the lateral region of the longissimus muscle at the level of the scapular line: the upper point was below the last rib, the lower point was above the iliac crest, and the middle point was equidistant from the upper and lower points (Fig. 2).

Fig. 1.

Locations where ultrasound measurements were performed in the abdominal region: hypochondrium, flanks, and iliac fossa at the level of the anterior axillary line.

Fig. 2.

Locations where ultrasound measurements were performed in the dorsal region: lateral region of the longissimus muscle at the level of the scapular line. The upper point is below the last rib, the lower point is above the iliac crest, and the middle point is equidistant from the upper and lower points.

RESULTS

Eighty female patients undergoing liposuction in the abdominal and dorsal regions were evaluated. The mean age of the patients was 28.4 years (20–38 y). The mean body mass index was 25.8 kg/m² (22–29.7 kg/m²). All patients had a surgical risk of Goldman grade I (100%). The median duration of surgery was 200.7 minutes (180–220 min). Complications, such as surgical site infections, visceral perforation, and bleeding with subsequent shock or death, did not occur during the 6-month follow-up period (Table 1). Ultrasonography measurements were acquired at 6 points at the level of the deep fat layer in the abdominal region. The points were distributed at the right and left lateral levels. Ultrasonography measurements were acquired at 6 specific points in the dorsal region (Tables 2, 3). A reduction of 99.26% and 99.07% in the deep fat layer was observed at the abdominal and dorsal levels, respectively. The reduction was maintained at 99.26% and 99.14% at the abdominal and dorsal levels, respectively, at 6 months postoperatively (P < 0.001).

Table 1.

Descriptive Data of the Variables: Age, Weight, Height, BMI, and Surgical Time

Variables	Mean	SD	Minimum	Maximum
Age, y	28.4	5.6	20.0	38.0
Weight, kg	70.8	3.8	65.0	78.0
Size, cm	165.9	3.9	160.0	172.0
BMI, kg/m2	25.8	1.8	22.0	29.7
Surgery time, min	200.7	11.9	180.0	220.0

BMI, body mass index.

Table 2.

Ultrasound Measurements in the Abdomen

Ultrasound Measurements in the Abdomen	n	Minimum	Maximum	Mean	SD	Mean Ranges	P  *
R1 right
Before surgery, mm	80	41.0	85.0	63.8	8.9	3.00
Immediately after surgery, mm	80	0.0	1.0	0.5	0.3	1.49
6 mo after surgery, mm	80	0.0	1.0	0.5	0.3	1.51	<0.001
R2 right
Before surgery, mm	80	44.0	89.0	64.3	9.5	3.00
Immediately after surgery, mm	80	0.0	1.0	0.5	0.3	1.58
6 mo after surgery, mm	80	0.0	0.9	0.4	0.3	1.43	<0.001
R3 right
Before surgery, mm	80	40.0	84.0	64.7	8.8	3.00
Immediately after surgery, mm	80	0.0	1.0	0.5	0.3	1.46
6 mo after surgery, mm	80	0.0	1.0	0.5	0.3	1.54	<0.001
S1 left
Before surgery, mm	80	44.0	85.0	64.9	9.5	3.00
Immediately after surgery, mm	80	0.0	1.0	0.4	0.3	1.43
6 mo after surgery, mm	80	0.0	1.0	0.5	0.3	1.58	<0.001
S2 left
Before surgery, mm	80	43.0	89.0	65.1	9.2	3.00
Immediately after surgery, mm	80	0.0	1.0	0.5	0.3	1.45
6 mo after surgery, mm	80	0.0	1.0	0.5	0.3	1.55	<0.001
S3 left
Before surgery, mm	80	46.0	87.0	65.5	9.2	3.00
Immediately after surgery, mm	80	0.0	1.0	0.5	0.3	1.46
6 mo after surgery, mm	80	0.0	1.0	0.5	0.3	1.54	<0.001

^*Significance level.

Table 3.

Ultrasound Measurements in the Dorsolumbar Area

Measurements in Dorsolumbar Area	n	Minimum	Maximum	Mean	SD	Mean Ranges	P  *
T1 right
Before surgery, mm	80	50.0	60.0	55.3	3.1	3.00
Immediately after surgery, mm	80	0.0	1.0	0.5	0.3	1.61
6 mo after surgery, mm	80	0.0	1.0	0.4	0.3	1.39	<0.001
T2 right
Before surgery, mm	80	50.0	60.0	55.0	3.1	3.00
Immediately after surgery, mm	80	0.0	1.0	0.5	0.3	1.53
6 mo after surgery, mm	80	0.0	1.0	0.5	0.3	1.48	<0.001
T3 right
Before surgery, mm	80	50.0	60.0	54.7	3.4	3.00
Immediately after surgery, mm	80	0.0	1.0	0.5	0.3	1.61
6 mo after surgery, mm	80	0.0	1.0	0.4	0.3	1.39	<0.001
V1 left
Before surgery, mm	80	50.0	60.0	55.2	3.0	3.00
Immediately after surgery, mm	80	0.0	1.0	0.5	0.3	1.50
6 mo after surgery, mm	80	0.0	1.0	0.5	0.3	1.50	<0.001
V2 left
Before surgery, mm	80	50.0	60.0	54.4	3.1	3.00
Immediately after surgery, mm	80	0.0	1.0	0.5	0.3	1.48
6 mo after surgery, mm	80	0.0	1.0	0.5	0.3	1.53	<0.001
V3 left
Before surgery, mm	80	50.0	60.0	55.6	3.1	3.00
Immediately after surgery, mm	80	0.0	1.0	0.5	0.3	1.54
6 mo after surgery, mm	80	0.0	1.0	0.5	0.3	1.46	<0.001

^*Significance level.

All patients participated in a follow-up survey 6 months postoperatively. The questionnaire comprised 6 questions pertaining to the aesthetic results. (See survey, Supplemental Digital Content 1, which shows the satisfaction survey, https://links.lww.com/PRSGO/E91.) The satisfaction index was very high in a certain percentage of patients (Tables 4, 5). Similarly, lesions in the abdominal or dorsal regions suggestive of fibrosis or burns were not observed in a substantial percentage. Positive lifestyle changes were observed in a large percentage of patients. The study observed no fibrosis, skin burns, or other serious complications (surgical site infections, pulmonary embolism, chronic pain, visceral perforation, or death) during follow-up.

Table 4.

Q1: On a Scale of 1–10, How Would You Rate the Naturalness of the Results? (%)

Result	n	%
Not natural	0	0.0
Not very natural	0	0.0
Very natural	80	100.0

Table 5.

Satisfaction Results in Percentages (%)

	Qualification
Questions	Strongly Agree (A)	Agree (B)	Neither Agree nor Disagree (C)	Disagree (D)	Strongly Disagree (E)	Total
Q2: How beautiful do you consider the results of liposuction?	77.5	22.5	0.0	0.0	0.0	100.0
Q3: Do the results of your surgery meet your expectations?	93.75	6.25	0.0	0.0	0.0	100.0
Q4: Have you noticed any skin irregularities in your abdomen following liposuction?	0.0	0.0	0.0	2.5	97.5	100.0
Q5: Have you noticed any skin irregularities in your back following liposuction?	0.0	0.0.	0.0	2.5	97.5	100.0
Q6: Have the postoperative results led to a change in habits such as diet or physical effort?	87.5	12.5	0.0	0.0	0.0	100.0

DISCUSSION

Body contouring is a common procedure performed in the field of plastic surgery. Liposuction is the most frequently performed procedure among these, as it is frequently requested by patients.^14,15

Different devices, such as retraction technology, closed circuits for fat aspiration and decantation,^4,5 and special cannulas, are used to improve the results of liposuction. Ultrasonography enables surgeons to visualize the specific location where liposuction and graft can be performed. Ultrasonography plays a fundamental role in obtaining successful surgical outcomes. It aids in achieving our idea of body harmony and beauty with respect to the anatomy of each patient. Furthermore, it ensures that the procedure is performed at the right level.^6–13

Classic liposuction training comprises performing liposuction by palpation. The cannulas are inserted at the level of the fat layers without visualizing whether infiltration and liposuction are being performed at the superficial or deep layer.^6–13

Training without ultrasonography guidance involves performing a procedure without direct vision. Consequently, surgeons cannot verify whether the level at which surgery is being performed is appropriate. Furthermore, the learning curve is greater, and the concepts of safety or structured anatomy are not considered. The removal of fat requires an effective approach at the level of the deep fat layer. Most complications, such as fibrosis or lesions observed in the skin, are associated with superficial liposuction. Therefore, the correct approach to liposuction should always be at the level of the deep layer.¹³ Visualization of the cannula enables surgeons to ensure that the level of insertion is adequate and does not extend into inappropriate regions and penetrate the abdominal cavity, thereby injuring visceral or vascular structures, resulting in devastating complications with high mortality.^16,17 Ultrasonography aids in preventing other injuries that can occur intraoperatively, as it enables surgeons to visualize structures, such as hernial sacs containing visceral or vascular structures, that could go unnoticed; these structures can be damaged during the entry of the cannulas.¹⁸

Ultrasonography measurements revealed a reduction in the deep fat layer in the abdominal and dorsal regions in an effective and safe way (Tables 2, 3) (Fig. 3). This reduction was maintained at 6 months postoperatively (Figs. 4–6).

Fig. 3.

Postoperative results in liposuction treatment in real time. Liposuction results before (A) and after (B) immediate liposuction using intraoperative ultrasonography.

Fig. 4.

Postoperative results in liposuction treatment in real time. Liposuction results before (A) and after (B) 3 months of liposuction using intraoperative ultrasonography, frontal view.

Fig. 6.

Postoperative results in liposuction treatment in real time. Liposuction results before (A) and after (B) 6 months of liposuction using intraoperative ultrasonography, dorsal view.

Fig. 5.

Postoperative results in liposuction treatment in real time. Liposuction results before (A) and after (B) 4 months of liposuction using intraoperative ultrasonography, dorsal view.

Currently, more advanced techniques that use ultrasound to perform fat grafting intramuscularly and subcutaneously in the gluteal region are being performed. A key element in all these procedures is achieving accurate anatomical placement of the grafting plane, ensuring safety and effectiveness. Given this evidence, our interest is to demonstrate ultrasound’s utility not only as a visualization and guidance tool for fat grafting, but also for the removal of deep fat, clearly identifying the correct surgical plane and avoiding risks associated with cannula movement in incorrect planes.^6–12,18,19

The satisfaction survey conducted in the present study revealed that the patients who underwent liposuction with ultrasonography guidance were satisfied with the surgical results. The patients did not report dissatisfaction with respect to the naturalness of the results (Supplemental Digital Content 1, https://links.lww.com/PRSGO/E91). The patients did not report developing skin lesions congruent with fibrosis or skin burns. A large percentage of patients were motivated to make lifestyle changes. Furthermore, complications such as fibrosis, surgical site infections, pulmonary thromboembolism, chronic pain, visceral perforations, or death were not encountered during the whole follow-up period (Figs. 4–6).

The main limitation of our study is the short follow-up time (6 mo); however, the results and methodology in this study are fundamental to establishing effectiveness, which can be extrapolated to other studies with similar characteristics and longer follow-up times. Ultrasound is one of the most useful tools in the care and safety of patients undergoing body contouring procedures such as liposuction.¹⁹ Another important limitation is that the satisfaction survey was conducted based on questions that the principal author deemed mandatory to analyze the performance of liposuction surgery; a validated scale was not used.

CONCLUSIONS

Intraoperative ultrasonography, which plays a fundamental role in liposuction, aids in the effective aspiration of the deep fat layer. Furthermore, it enables surgeons to perform the procedure safely, avoiding major complications (visceral or muscular perforation) and minor complications (fibrosis, irregularities, and skin burns). The responses to the postoperative survey revealed a high level of satisfaction with respect to the naturalness and aesthetic results.

DISCLOSURE

The authors have no financial interest to declare in relation to the content of this article.