Nonsurgical Postpartum Abdominal Rejuvenation: A Review and Our Experience
In my opinion, this is one of the best review articles I came across addressing postpartum changes of the abdominal region and all available non-surgical interventions that can be implemented to aesthetically improve those changes . Enjoy!
The article summarizes available nonsurgical modalities which address postpartum abdominal defects, including procedures that tone muscles, reduce fat, tighten skin, and improve the appearance of striae. Both the published literature and the authors’ experience favor a combination of treatments to address the various lamellae affected by pregnancy. Further clinical trials focusing on the postpartum patient would further help create a standardized approach for postpartum abdominal rejuvenation.
Abdominal appearance is a surrogate for overall health and attractiveness, and thus, abdominal rejuvenation is appealing to many postpartum patients. The term “mommy makeover” has become common vernacular to reference the combination of treatments aimed at targeting postpartum aesthetic concerns. Although traditionally the treatment of choice, abdominoplasty surgeries performed in 2019 decreased from 2018.1 Minimally invasive procedures do not provide the same results as an abdominoplasty, but their reduced morbidity and mortality warrant their consideration for abdominal rejuvenation. Virtually all abdominoplasties result in a perceptible scar (Figure 1), although the “mini abdominoplasty” effectively addresses moderate tissue redundancy while “hiding” the scar within a prior cesarean scar or in the bikini area.2 The most common complication of abdominoplasty is seroma, which necessitates aspiration and possible drain insertion. Other adverse events include atelectasis, hematoma, necrosis, infection, stricture formation, and sensory issues. More worrisome, abdominoplasty is the most common cosmetic procedure associated with venous thromboembolism.3 Aesthetic complications include accentuated flank fullness, lack of posterior abdominal curve, large migrating scars, and a “floppy belly” sensation because of residual poor muscle tone and skin laxity. Current techniques involve neoumbilocoplasty or recreation of the umbilicus. A poorly circumscribed neoumbilicus can give rise to significant psychological discomfort (Figure 2).4 Given these risks, for the right patient, less invasive procedures should be entertained for abdominal rejuvenation.
Figure 1.:
(A) Scar 1 year after traditional abdominoplasty. *Permission granted by Creative Commons Attribution (CC BY) from the article by Yaar and Serin: link. (B) Scar 1 year after abdominoplasty with inverted t-approach, which allows for a lower sitting transverse scar. *Permission granted by Creative Commons Attribution (CC BY) from the article by Yaar and Serin: link.
Poorly circumscribed neoumbilicus after traditional abdominoplasty. *Permission granted by Elsevier from Reho and colleagues article: link.
Pregnancy and Aging-Related Changes
Current birth rates show a trend toward older maternal age,5 and it has been purported that patients who become pregnant at a later age will have a more dramatic expansion of their abdominal wall because of progressive loss of collagen I and III in the abdominal myoaponeurosis with age.6,7 Both mechanical stress and hormonal changes in elastin throughout pregnancy, lead to increased skin laxity, striae gravidarum (SG), widening and distortion of the rectus abdominis (diastasis rectus [DR]) and transverse abdominus, as well as abdominal fat accumulation. Diastasis rectus is apparent at 14 weeks, continues to widen, and may persist beyond pregnancy in 32% to 46% of cases.8 Even in thin patients, stretching of the abdominal muscles relaxes the muscular corset, leading to abdominal protuberance. These changes cause truncal instability, commonly leading to issues such as low back pain and urinary incontinence. Although not dangerous, these changes considerably impact self-confidence and quality of life in many women.
In addition to pregnancy, cumulative sun-damage and weight fluctuations associated with aging, impact abdominal appearance. Collagen is increasingly degraded by matrix metalloproteinases, whereas fibroblasts assume a collapsed conformation which decreases their ability to produce collagen, altogether leading to skin laxity.9 Around menopause, women experience an increase in central obesity. Although estrogen decline increases visceral fat,10 the increase in subcutaneous fat is more likely related to low physical activity and a decreased ability of adipocytes to buffer dietary lipids.11,12 Abdominal adipocytes, in particular, have less beta-adrenergic receptors and thus a higher threshold for lipolysis.13 This may explain why despite lifestyle and dietary changes a disproportionate amount of “stubborn” fat remains in the abdominal region.
Anatomy
A thorough understanding of abdominal anatomy is essential to properly consult and treat aesthetic patients. The abdomen contains many tendinous intersections, such as the linea alba and semilunar line, which manifest as “valleys” between muscle mass “hills” (Figure 3). The lower abdomen is more convex because of both greater fat density and poor muscle tone. From superficial to deep, the distinct layers of the lateral abdomen are as follows: skin, subcutaneous tissue, superficial fascia, external oblique muscles, transversus abdominis muscle, transversalis fascia, preperitoneal adipose tissue, and peritoneum (Figure 3). The muscles include a more lateral group, which includes the transversus abdominis, and a more central group, which includes the rectus abdominis. The main vascular supply of the abdominal wall is the perforators of the deep inferior and superior epigastric arteries, a large portion of which exist within centimeters of the umbilicus (Figure 3). Abdominal fascia includes both muscular fascia as well as the superficial fascial system (SFS), Scarpa’s fascia, and Camper’s fascia. Extensions of the SFS, known as zones of adhesion, dive down to the underlying muscular fascia, preventing skin sagging but also accentuating the flanking fat compartments, leading to the appearance of “rolls.” Unaesthetic bulges are due to weight gain and subsequent increase in the deep subcutaneous fat compartment.
The surface anatomy and main vascular supply of the abdominal wall. Inset: layers of the abdominal wall.
In consulting patients, providers should identify which lamella(e) are aberrant, Patient goals should be distilled so that the patient and provider can jointly develop an approach that optimizes results and minimizes adverse events. Having illustrated the abdominal changes with pregnancy and accompanying aesthetic concerns, we will review the safety and efficacy of available procedures divided by muscle toning, fat reduction, skin tightening, and finally striae.
Muscle Toning
A well-supported abdomen has strong abdominal muscles; however, as discussed, the postpartum abdomen frequently has decreased muscle tone and separation of rectus abdominis (DR) and transversus abdominis.
High-Intensity Focused Electromagnetic Energy and Magnetic Muscle Stimulation
Before high-intensity focused electromagnetic (HIFEM) technology and magnetic muscle stimulation (MMS), a physical workout was the only means to tone and firm muscles. Mechanisms hinge on Faraday’s Law, which describes how an electric current produces a magnetic field and conversely, a changing magnetic field generates an electric current. Device hand pieces encase a rapidly moving magnet, which generates a magnetic field, up to 0.9 to 1.35 tesla, depending on the device. The magnetic field induces an electric current in the underlying tissue, resulting in muscle contraction. The process is relatively painless as technology bypasses the skin nociceptors.14 In a 30-minute session, almost 20,000 supramaximal muscle contractions are elicited, which cannot be achieved voluntarily. Treated muscles respond to this stress by thickening.
Initial evaluation of one HIFEM device, involved 22 patients, who received 4 30-minute abdominal treatments.15 MRI at 2 months after final treatment, revealed an average of 15.4% increase in rectus abdominis thickness, 10.4% reduction in DR, 18.6% reduction in adipose tissue, and a 3.8 cm reduction in subumbilical circumferance.15 The same authors confirmed maintenance of results at 1 year after final treatment in a series of 4 to 8 treatments.16 A study of another HIFEM device, involved 110 subjects treated in the abdomen, buttocks, or both sites, with 4 treatments.17 At 4 weeks after final treatment, a significant improvement in satisfaction and subject-rated improvement was noted.17
Treatment is well tolerated, with no downtime or adverse events documents. Patients can expect little to no pain during the procedure postprocedure muscle fatigue and soreness for 12 to 48 hours.18 We recommended HIFEM/MMS to lay the foundation for a more taut and rejuvenated appearance of the abdomen. Our patients tolerate 30-minute treatments well and enjoy both cosmetic results along with feeling greater core stability. For best results, our patients receive a series of 4 sessions spaced 2 to 3 days apart (Figure 4). Repeat treatments can be performed 1 month after this initial series. Of note, although previous porcine models suggested “spot lipolysis” of fat adjacent to contracting muscles, a recent study found no histological signs of fat cell inflammation or injury;19 thus, we combine HIFEM/MMS with fat reducing modalities discussed below.
Before and after: series of MMS treatments. MMS, magnetic muscle stimulation.
Electric Muscle Stimulation
Unlike the devices discussed above which harness electromagnetic energy to contract muscles, electrical muscle stimulation (EMS) uses solely electric stimulation. In EMS, electrical currents, ranging from 50 to 100 Hz, are applied transcutaneously through electrodes overlying the target muscles. A current EMS device includes 8 hand pieces, allowing for the simultaneous treatment of multiple areas. A benefit compared with HIFEM/EMS devices is that contraction can be elicited in multiple directions. A series of 4 45-minute sessions, spaced 48 hours apart, is recommended. Some believe EMS is more painful than HIFEM/MMS.20 Currently, there are no head-to-head studies of the various muscle stimulation devices.
Fat Reduction
Postpartum abdominal fat is difficult to reduce through diet and exercise alone. We use liposuction and less invasive modalities to address postpartum abdominal lipohypertrophy and contour irregularities.
Liposuction
Tumescent liposuction is the gold-standard for treating focal adiposities resistant to healthy diet and exercise. This technique uses small cannulas attached to a vacuum aspirator, inserted through small incisions, to extract superficial and deep subcutaneous fat. One treatment can reduce subcutaneous fat by 50% and significantly improve abdominal contour. Variations include power-assisted, ultrasound-assisted, laser-assisted, and radiofrequency -assisted. A 2018 review of various methods showed equivocal results among techniques for the abdomen.21 We only elect to use laser-assisted liposuction in secondary procedures where there is excessive fibrous tissue or in patients who have poor skin elasticity.
Tumescent liposuction has rare adverse events, and we have found that even at long-term follow-up (average 8.9 years) patient satisfaction is outstanding.22 Obviously, improper technique such as tunneling too superficially over a zone of adhesion can lead to skin dimpling and contour defects. Initial consult should assess for good muscle and skin tone, as both are necessary for postprocedure contraction. Although liposuction remains the gold standard, some of our patients desire less invasive modalities, and thus, we opt for the procedures discussed below.
Cryolipolysis
Cryolipolysis is a noninvasive technology that reduces fat based on the principle that fat is more susceptible to lower temperatures than water-rich cells.23 On cold exposure, a delayed lobular panniculitis is induced, leading to adipocyte apoptosis. On histology, an inflammatory response occurs by day 3 post-treatment, and phagocytosis of lipids occurs between days 14 and 30.24 A reduction of fat is usually apparent 2 to 3 months post-treatment. Current devices use a vacuum to elevate and compress target tissue between two cooling plates for 35 to 45 minutes, cooling tissue to approximately −5 to −10°C. A review of 19 studies found an average fat reduction, measured by ultrasound, ranging from 10.3 to 25.5 percent.25
An appealing feature of cryolipolysis is that there is no downtime. Side effects include transient mild paresthesia, erythema, and edema. One study confirmed that reduced sensation is not permanent.26 Paradoxical adipose hyperplasia (PAH) is rare and presents as tender discrete nodules 2 to 3 months after treatment. Reassuringly for the postpartum patient, PAH is seen disproportionately in men.27 We frequently incorporate cryolipolysis into abdominal rejuvenation and have observed that the abdomen is a particularly responsive site (Figure 5).
Before and after: series of cryolipolysis treatments.
Injection Lipolysis
Deoxycholic acid (DCA) is a detergent that causes lipolysis through adipocyte cell membrane disruption and lysis. A split-abdomen control trial, demonstrated that 2 to 4 abdominal DCA injections spaced 8 weeks apart, can effectively reduce abdominal fat thickness, with a mean decrease of 9.1 mm.28 Similarly, a case report demonstrated high patient satisfaction and elimination of lower abdominal protuberance with just 1 session using 4 cc of DCA.29
Patients should expect transient mild to moderate pain localized to the treatment area, along with swelling and bruising that can last a week. We use DCA to treat very small pockets of subcutaneous fat that cannot be treated with cryolipolysis, such as periumbilical fat, or foci of fat remaining after tumescent liposuction. We also minimize pain and edema by administering DCA with dilute triamcinolone (1 mg/mL) and lidocaine to a 0.1% concentration. These additions do not affect efficacy.30 Multiple treatments are usually needed, which can be expensive and time-consuming; thus, we only use DCA in certain scenarios.
High-Intensity Focused Ultrasound
High-intensity focused ultrasound (HIFU) focuses acoustic energy (2 MHz, >1,000 W/cm2) on target tissue, instantaneously transforming into heat, leading to tissue temperatures of 55 to 70°C. This thermogenesis causes a coagulative necrosis of adipocytes while sparing the surrounding tissues and epidermis. A 95% resorption of disrupted adipocytes is seen by 18 weeks.31 High-intensity focused ultrasound has also been observed to induce neocollagenesis and thus can concurrently tighten and lift the skin. Several studies have shown a significant reduction in abdominal fat thickness and reduction in waist circumference measurement from baseline after HIFU treatment. A study of one device comparing 5 different protocols involving low (30 J/cm2) and high (60 J/cm2) fluences, as well as grid repeat and site repeat techniques, found that a single treatment, regardless of the protocol, led to a significant change from baseline in waistline measurement, with a mean reduction of 2.3 cm at 12 weeks post-treatment.32
High-intensity focused ultrasound has been shown to have an excellent safety profile by sham-controlled studies.33 Side effects include transient mild to moderate discomfort, bruising, and edema. Treatment of the abdominal region is associated with mild to moderate pain during the procedure.31
Skin Tightening
Skin laxity on the abdomen is more challenging compared with the face or neck, because of the greater surface area and less fascia and pilosebaceous units. In addition, the deeper depth of fascia is more difficult to reach.
Microfocused Ultrasound with Visualization
Compared with HIFU, microfocused ultrasound (MFU) uses shorter pulse durations (50–200 ms), higher frequencies (4–7 MHz), and decreased energy (0.5–10 J). Focused acoustic energy generates thermal coagulation zones at predefined depths of 1.5, 3.0, and 4.5 mm. The goal is to target the superficial fascia so that the periumbilical skin is lifted. A current device incorporates high-resolution ultrasonography, up to 8 mm, ensuring proper treatment depth; this technology is known as MFU with visualization (MFU-V).
A split-abdomen study comparing one single-plane (4.5 mm) MFU-V abdominal session with dual-plane (4.5 and 3.0 mm) found that both protocols at 1, 3, and 6 months post-treatment had significant improvement in laxity, and no significant difference between protocols existed.33 Interestingly, the study found that postpartum patients had the most pronounced improvement in laxity and reduction in waist circumference.34 A recent study of 20 postpartum women treated with MFU-V using a triplanar approach to treat the lower abdomen found significant improvements in laxity, patient satisfaction, and histological increases in collagen and fibrous septae, compared with control.35
Microfocused ultrasound side effects include bruising, tenderness, and edema, which resolve after a few weeks. Treatment in the abdominal region has a median pain score of 4.29 to 5.25 on a 10 point scale.34 Preventative pain control should be considered so that a high density of energy can be delivered and thus results are optimized.36 We frequently address abdominal laxity with a combination of MFU-V and biostimulatory fillers such as calcium hydroxyapatite (CaHA) and poly-l-lactic acid (PLLA) (Figure 6). These treatments can be performed on the same day, although MFU-V is performed first, because the fillers affect target tissue depth. When mapping out the treatment site, the mid abdominal area above and below the umbilicus are most commonly targeted. Generally, maintenance treatments are needed less frequently in those ages 35 to 45 versus over 50.36
Before and after: series of MFU-V, diluted CaHA, and nonablative fractional laser. CaHA, calcium hydroxyapatite; MFU, microfocused ultrasound.
Monopolar Radiofrequency
In monopolar radiofrequency (MRF), energy flows from an electrode in the handpiece to a passive electrode placed distally on the patient. The natural resistance of fat and fibrous tissue to the movement of electrons within a RF field translates to heat. The goal is to heat the target tissue to 65°C to 75°C, so that collagen is partially denatured and assumes a random coil formation.37 One device delivers a controlled pulse for 1 to 2 seconds at a depth of 1 to 3 mm. The device also includes cryogen delivery to prevent inadvertent damage to the epidermis and dermis, vibration, and retrofeedback energy in the latest version.
A study by Kist and colleagues38 revolutionized MRF, by demonstrating collagen changes were most pronounced with protocols using multiple passes with lower fluences versus more painful single passes with higher fluences. Because RF involves thermogenesis and patient comfort feedback is necessary, treatment may be uncomfortable. In our practice, we frequently use MRF to improve abdominal skin laxity. It is important to set expectations with patients. Monopolar RF will not produce the dramatic results of an abdominoplasty but can produce a modest lifting effect. We often combine MRF with either a fat reduction technology or dermal fillers.
Subdermal Monopolar Radiofrequency
Subdermal monopolar RF (SMRF) delivers energy through subdermal cannulas, bypassing the epidermis and thus reducing collateral tissue damage. One device uses a 600 mm electrode enclosed in a 1 mm cannula, to deliver RF energy at the dermal hypodermal junction, heating tissue to temperatures between 55 and 70°C. A thermistor in the probe detects resistance changes and modulates RF output accordingly. In addition, an infrared camera monitors epidermal temperatures to prevent excess thermal damage. Subdermal monopolar RF induces neocollagenesis, leading to a skin tightening effect over 3 to 6 months. A study treating the upper arms found significant improvements in laxity at day 30 and 90 post-treatment along with most subjects being “extremely satisfied” or “satisfied.”39 Another study involving abdominoplasty tissue treated with SMRF, noted immediate dramatic tissue contraction in vitro.40 Initial studies show an excellent safety profile with erythema and bruising resolving by day 30 post-treatment.39 More studies are needed to evaluate efficacy and safety specific to the abdomen.
Microneedling
Microneedling involves either a mechanical or electric powered device that contains multiple fine sterile needles, typically 0.5 to 2 mm in length, which glide perpendicularly over the skin surface, creating hundreds of microchannels which stimulate a dermal wound healing cascade and collagen production. A retrospective analysis of 58 patients treated with microneedling for abdominal and arm laxity and striae showed high patient satisfaction, along with increased epidermal thickness seen on histology at 1 year.41 Generally 3 to 5 treatments spaced 2 to 4 weeks apart are recommended. Patients can expect transient mild pain, erythema, spotty bleeding, edema, and skin flaking. Microneedling with RF is a newer treatment for abdominal laxity, and further studies are needed to confirm efficacy and safety. In this procedure, needles deliver RF (usually bipolar) energy to intensify skin tightening.
Diluted Dermal Fillers
Although energy-based devices can help strengthen the collagen of the abdominal skin, often the postpartum abdominal skin requires more support. Injectable fillers, such as CaHA and PLLA, can provide either instant volumization through water binding and volume displacement at the injection site and/or through neocollagenesis. CaHA spheres act as a scaffold to be replaced by fibrovascular growth, whereas PLLA spheres elicit a subclinical foreign body response, lasting approximately 12 to 18 months and 2 to 3 years, respectively. In diluted (1:1) and hyperdiluted (1:2–1:4) concentrations, these injectables are excellent in addressing laxity. A study using 1:4 CaHA threaded throughout the abdomen found a statically significant increase of 26.7% in dermal thickness measured by ultrasound at 70 days post-treatment, and 90% of patients rated the results as much or very much improved.42 Generally, 1:1 CaHA at a volume of 1.5 mL for every 100 cm2 is used.43 Safety profiles are likely safer in diluted concentrations at non facial sites, which have less vascular danger zones. No reports of vascular occlusion after diluted CaHA have been reported. Nodules and delayed granuloma formation are a possible side effect. For the abdomen, multiple sessions are usually necessary, and we target the superior or periumbilical region where laxity is most pronounced.
STRIAE
Striae gravidarum, a specific subtype of striae distensae, are the second most common skin manifestation during pregnancy, behind pigmentation.44 Striae gravidarum are noted to cause emotional and psychological distress.45 Initial lesions are erythematous to violaceous (striae rubrae), and they later fade into hypopigmented atrophic lesions (striae albae). Striae are therapeutically challenging, and there is a paucity of large high quality controlled trials that support preventative topicals. Setting patient expectations is important, as improvement rather than clearance is the goal. In our practice, we frequently use nonablative fractional lasers (NAFLs) as there is less downtime, and some studies have shown similar outcomes to the ablative laser.46 We have observed decrease in striae diameter and improvement in appearance after several treatments with NAFL. Usually multiple treatments are needed, and lower densities and fluences should be used in patients with darker skin types. Combination with a biostimulatory filler to address depression and correct hypopigmentation is a common combination we use. Topical bimatoprost in conjunction with laser may also help with striae albae hypopigmentation.47
CONCLUSION
A combination of minimally and noninvasive procedures can rejuvenate the postpartum abdomen. We have reviewed many of the current treatments to tone muscles, reduce fat, tighten skin, and improve the appearance of SG.
We hope that our strategies can help guide physicians in tailoring plans for their unique patients. Further trials specific to the postpartum patient and combining multiple modalities will help in creating a standard approach for postpartum abdominal rejuvenation.
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