Treatment of retracted, postsurgical scars and reduction of locoregional edema using a combined three-dimensional approach of liposuction lipofilling, dissecting cannulas, and suspension sutures

Retracted postoperative scars on the abdomen and inguinal region are a common reason for consulting a plastic surgeon, usually after undergoing a cesarean section or appendicectomy. Scar formation is a multifactorial process, which is determined not only by the scar location and the mechanism of origin, but also by endogenous or exogenous factors [1].

The most common pathological scar formations correspond to keloids and hypertrophic scars, which can develop in the first 2 months after injuries to the deep dermis and subcutaneous tissue. Chronic inflammation of the reticular dermis is not infrequently followed by pain, itching, or restricted movement [2]. All these result in a loss of quality of life, mental health, and earning capacity for an estimated 100 million individuals per year in industrialized countries alone [2].

Hypertrophic and keloids scars represent a considerable challenge for the health care system, with recurrence rates of 45 to 100% [3]. In recent years, intensive research has been undertaken looking into conservative and adjuvant therapies for scar management [2, 3]. Exemplary meta-analyses have already demonstrated the prophylactic advantage of compression garments at a low compression level (15–25 mmHg), the use of silicone plasters, liquid silicone, and scar massage [4-6]. New approaches, such as the effect of botulinum toxin A injections and intradermal cytostatic drugs (bleomycin and 5-fluorouracil), have also been demonstrated as advantageous with prospective, double-blind, randomized controlled trials [5, 7].

The regenerative effect of lipofilling and the containing of mesenchymal stem cells (MSCs) for scar treatment were first demonstrated in detail by Rigotti et al. in radiodermatitis [8]. Subsequently, in 2008, Klinger et al. demonstrated the first successes of treating hypertrophic scars with adipogenic MSCs (ADSCs) [9]. Since then, numerous clinical studies in regenerative medicine followed on lipofilling and ADSCs in relation to the treatment of scars and wound healing disorders [5].

In contrast to hypertrophic scars, there are no described conservative measures or evidence of a therapeutic effect of MSCs for retracted scars [10]. Surgical resection of the retracted scar alone is rarely the optimal strategy. Particularly in the case of larger scars, serial excisions or tissue expansion would be necessary.

In retracted abdominal scars, the deformity is determined by adhesions to the deeper soft tissue and abdominal wall fascia, and furrows form parallel to the scar, which are visually enhanced by the accumulation of fatty tissue around the retracted scar [11]. The accompanying, sometimes extensive scarring of the subcutaneous tissue, can lead to further restrictions in locoregional lymphatic drainage [12]. Taken together, these scars can then pose a significant functional and aesthetic problem for the patient, requiring three-dimensional analysis and multimodal therapy.

The present study aimed to develop and evaluate a surgical strategy to improve retracted and lymphatic congestion scars on the abdomen and groin in a single surgical procedure without excisions and with a combination of liposuction, subcutaneous scar release with Toledo dissection cannulas, lipofilling, and suspension sutures.

Patient- and procedure-related outcomes, such as scar dimensions (pre- and postoperative), number of incisions required, average volume of aspirated adipose tissue, average amount of transferred adipose tissue (lipofilling) required, actual hospitalization time, number of revision procedures, and surgical complications, were pseudonymously documented and evaluated in an Excel file. The pseudonymized data and written consents for the study and publication of images were stored in encrypted form on a clinic server in accordance with the ethical approval.

In analogy with the Clavien-Dindo classification [15], all complications (wound dehiscence, wound infections, post-operative bleeding, seromas, fat necrosis, etc.) which resulted in a revision operation or hospitalization were classified as major complications (Clavien-Dindo grades 2 to 4). All possible complications that required some form of therapeutic modification of the intended and expected postoperative course were classified as minor complications (Clavien-Dindo grade 1). Postoperative ecchymosis, imperceptible seromas, swelling, and postoperative pain that could be treated on an outpatient basis were not considered complications, because they correspond to the normal healing process. Unscheduled reconsulting of the patients for dressing changes or wound controls, with no underlying surgical or medical complications, were equally assessed as a normal course.

Scoring instruments were used to quantify treatment outcomes (aesthetic and functional) as well as the effect on locoregional lymphoedema, psychological impact, and overall patient satisfaction. All data collected were tested for normal distribution using Shapiro–Wilk test (p < 0.05) in GraphPad Prism 8.0. Statistical significance (p < 0.05) was then tested using Wilcoxon matched pairs test (for non-parametric datasets) or t-test (for parametric datasets).

In this study, 22 patients underwent surgery using three-dimensional multimodal scar therapy. All patients were female and aged between 19 and 45 years (32.40 ± 7.96 years). In seven patients, the retracted scar resulted from appendectomy; in nine patients, the scar resulted from cesarean section; in five patients, the scar resulted from laparoscopic or open laparotomy; and in one patient, the retracted scar resulted from surgical exploration of the inguinal area (Table 2).

The retracted abdominal scars were measured before and after the surgical procedure. The scar lengths were heterogeneous, depending on the original causative surgery. There was no difference in pre- and postoperative scar lengths (13.47 ± 5.63 cm and 13.15 ± 5.42 cm). Liposuction and lipofilling required an average of 2.59 ± 0.73 incisions, 1.13 ± 0.24 l aspirated, and 30.77 ± 7.34 ml autologous fat transplanted (Table 3). No patient required an overnight stay beyond that planned (Table 3). No patient had an emergency, revision, or re-hospitalization. Accordingly, no major complication (Clavien-Dindo grade 2 to 4) was recorded in this study (Table 3). Overall, six out of 22 patients experienced a minor complication (Clavien-Dindo grade 1) (Table 3). While prophylactic antibiotics were prescribed in 3 cases for persistent local redness, another patient required the administration of an oral antibiotic for clinically confirmed postoperative infection. In two cases, there was a small, clinically noticeable seroma that required prolonged compression treatment by custom-made compression garments (Table 3). No seroma required puncture. The patient group experienced considerable weight loss in the postoperative period, from an average BMI preoperative of 24.95 ± 3.67 to a postoperative BMI of 24.15 ± 3.06 (Table 2).

There was a significant (p < 0.05) difference between pre- and postoperative self-assessment regarding scar aesthetics and social well-being (Fig. 5). While in the COPS-derived questions, the preoperative scar was rated significantly unaesthetic (clearly unattractive, score 2.93 ± 1.35), the aesthetic perception improved significantly postoperatively among patients (slightly unattractive, score 5.86 ± 1.14) (Fig. 5). Whereas before surgery the patients avoided half of certain activities or social contacts because of the unaesthetic scar, postoperatively, the patients reported that they would only avoid a quarter of such activities or social participation (Fig. 5). The average scores of social avoidance improved significantly from 5.52 ± 1.46, preoperatively, to 3.54 ± 2.09 after the intervention (Fig. 5). Although a clear statistical trend could be identified, the scar correction did not cause a significant improvement in the partner relationship (Fig. 5). The unaesthetic abdominal scar was considered a rather moderate burden on the romantic relationship preoperatively (score 3.63 ± 2.28), while this strain was reported as minimal after scar correction (score 2.60 ± 1.98) (Fig. 5).

In addition to the aesthetic perception, a positive effect was noted with regard to edema. The recurrent locoregional edema associated with hormonal fluctuations was reported to be less frequent and significantly milder after treatment (score 6.68 ± 1.06 on a scale of 0 to 8) (Fig. 5).

All patients stated that they would recommend this multimodal three-dimensional surgical technique to an acquaintance or relative with retracted scars in the abdomen or groin. Twenty-one out of 22 patients (95.45%) indicated retrospectively that they would prefer this type of scar correction again before any resection. The overall high patient satisfaction was found with an average score of 7.63 ± 0.58 points (scale from 0 to 8 points).

Retracted scars on the abdomen or groin are often too large and adherent to different layers for pure excision and primary suturing. Sometimes, the external scar may be fine and barely visible, with the retraction making them unsightly. On the other hand, the potential risks and costs of a horizontal abdominoplasty are usually disproportionate to the expected aesthetic benefits [20]. Excision of the scar and resuture may provide a temporary benefit, at the cost of having a fresh scar that then has to go through its maturing process, plus the risk of recurrence of the retraction. If patients also have edema in the region of the retracted abdominal scar, this indicates dysfunction of the lymphatic drainage likely because of deep scarring. Although these edemas are only described as transitory by patients and not included in the traditional definition of lymphoedema, they are subject to impaired lymphatic clearance [21].

The three-dimensional and multimodal therapeutic concept for the treatment of retracted post-surgical scars investigated in this study could be evaluated as effective and safe. Liposuction of the surrounding fat tissue visually compensated for the deepening of the scar. The combination of dissection and lipoaspiration was able to even out the perilesional area and volumize the scar, thereby resolving the lymphatic drainage disturbance. Subsequent lipofilling allowed unevenness to be evened out and the potentially beneficial pleiotropic effects of antifibrotic, immunomodulatory, and prolymphangiogenic ADSCs and adipocytes to be utilized [22-24]. Temporary suspension sutures were used to minimize the potential subcutaneous “dead space” after liposuction. This would have the advantage that the autologous fat would not lose site integrity and the risk of seroma formation would be minimized. In addition, potential paracrine mutual interference of fat cells and ADSCs would be favored with a smaller distance. The molecular foundations of the effect of our technique are not part of this clinical study.

The most controverted aspect of the proposed technique might be the need for suspension sutures. In a pilot group, we observed, with the use of sonography, that the lipotransfered fat grafts did not migrate after incorporating this technical refinement additionally to the other principles of the technique. Since the suspension sutures do not increase the risks, operation time, or cost considerably, we included them as a fourth pillar of our scar release technique. Nonetheless, to prove that the addition of the suspension sutures improves the clinical outcomes a case–control study is required. To demonstrate that it avoids fat graft migration, also a patient case–control comparison with MRI or ultrasonography or an equivalent preclinical model must be pursued.

A limitation of the technique is the unclear and uncontrollable fat resorption rate as well as the insufficient prevention of a possible migration of the lipofilling. Although, in the development of our technique, the suspension sutures and lipofilling were performed with intraoperative sonography and there were no changes in the first postoperative days, a long-term retention of the transplanted fat in the scar region was not investigated in detail. These intrinsic limitations of autologous adipose tissue transplantation are well-known and have been discussed extensively in peer-reviewed journals [4-6]. Technical recommendations from the literature have been considered to minimize fat resorption [25-27]. Whether postoperative compression prevents or even promotes the migration of fat tissue remains unclear and should consequently be assessed individually.

There are also limitations of the study, for example, the subjective assessment of the regional edema. Even though the locoregional edema was preoperatively identified by sonography and MRI, and thereby differentiated from fat maldistribution, the objectification of edema by volumetric analysis would have been additionally beneficial. Since conventional clinical measurements of edema in a region of the abdomen are not meaningful, modern methods such as infrared perometry or 3D laser scanners would have been useful for volumetric quantification pre- and postoperatively. However, these were not available and approved as medical devices in South America at the time of the study. The correction of locoregional edema was not followed up for more than 6 months in the collective. A few individual patients presented again > 2 years later for other reasons and did not report a recurrence of any edema around the scar. Consequently, we assume a long-term reduction of edema by correction of the lymphatic drainage. If the improvement is due to a correction of transluminal lymphatic drainage, an improvement of intrinsic matrix quality or neolymphangiogenesis are questions that should be investigated with molecular studies or lymphangiographic techniques in the future. Analogous to the diagnosis and microsurgical therapy of lymphoedema, our study could have benefited from preoperative imaging or intraoperative visualization of lymphatic drainage with indocyanine green near-infrared lymphography, Tc-99 lymphoscintigraphy, or lymphatic MRI[28]. Unfortunately, the technical conditions were not available for the study.

After the evaluation of the self-report questionnaires, there was a clear increase in self-esteem and patient satisfaction. At first glance, there is a dichotomy between a relatively high rate of minor complications (27.2%) and a high level of patient satisfaction as well as an objectified improvement in the functional, aesthetic, and psychosocial treatment outcome. This can be explained, among other things, by the fact that minor complications were defined extremely broadly in this study. Any change in the intended therapy was considered a minor complication. Retrospectively, customized compression garments (instead of using prefabricated compression) would probably have resulted in even fewer postoperative seromas. In 18.2% of patients with postoperative reddening of the scar in the first days, an incipient infection could not be distinguished certainly from a liposuction-related irritation or inflammatory perfusion change of the skin. To these patients, antibiotics were prescribed prophylactically. As postoperative prophylactic antibiotics were not provided, these cases were considered minor complications (Clavien-Dindo 1). Retrospectively, it is unclear whether patients would have benefited from postoperative antibiotics as prophylaxis with this technique. Although in our series > 80% of cases apparently did not require antibiotics postoperatively, we currently prescribe prophylactic antibiotics using cefuroxime for the first two postoperative weeks in this type of scar correction. Even when applying the strict Clavien-Dindo criteria for complications, the presented three-dimensional technique for scar correction proved to be safe with only minor complications. Individual patients lost considerable weight after the performed scar correction, and the average weight loss in the postoperative period was 0.8 points in the BMI. The postoperative weight loss might have indirectly influenced the quality-of-life questionaries to a more positive perception of the surgical technique. Mood changes might have an influence on the postoperative survey during the vacation season in summer in contrast to the cold winter of the preoperative surveying. The discussed weight changes of most of our patients could also be interpreted encouragingly. If our patients gain confidence, change their lifestyle, perform more sports, and thereby lose weight after the surgery, the positive feedback from the survey might not necessarily lose validity but gain real-life empirical legitimacy.

Retracted abdominal scars represent an aesthetically and functionally relevant impairment for many patients after oncological or general surgical procedures. For many plastic surgeons and patients, the resection of a larger retracted scar on the abdomen and groin in the sense of an abdominoplasty is not in proportion to the risks and the effort involved. In this study, we were able to show that the multimodal, three-dimensional combination of liposuction, scar release with the Toledo dissection cannula, lipofilling, and specifically placed Scarpa fascia suspension sutures consistently improved the results. In addition, there was a subjective reduction in locoregional edema postoperatively. All this significantly improved the self-esteem, aesthetic self-perception, and social competence of the 22 patients and led to a high level of satisfaction. A larger number of patients and a longer follow-up are necessary to validate the study results. In addition, the underlying molecular mechanisms should also be investigated in a further experimental study.