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. 2025 Aug 29;29(1):264. doi: 10.1007/s10029-025-03430-8

Subcutaneous versus retromuscular approach for the minimally invasive surgical treatment of rectus diastasis with concomitant ventral hernia: systematic review and meta-analysis of current techniques

Lidia Castagneto-Gissey 1,✉, Maria Francesca Russo 1, Piergaspare Palumbo 1, James Casella-Mariolo 2, Vito D’Andrea 1, Maria Irene Bellini 1, Giulio Illuminati 1, Giovanni Casella 1
PMCID: PMC12397138  PMID: 40879817

Abstract

Purpose

This systematic review and meta-analysis aims to evaluate the outcomes of laparoendoscopic extraperitoneal techniques for repairing rectus diastasis (RD) with concomitant ventral hernias, focusing on recurrence rates, surgical site occurrences, and the effectiveness of various surgical approaches and mesh placement sites.

Methods

A comprehensive literature search was conducted using PubMed and the Cochrane Library, adhering to PRISMA guidelines. Prospective and retrospective cohort studies involving adults with RD and concomitant ventral hernias were included. Surgical techniques were classified based on working space (subcutaneous vs. retromuscular) and wall repair technique (stapled vs. fascial plication suture). The primary outcome was recurrence of RD or hernia, and secondary outcomes included seroma, surgical site infections (SSIs), and bleeding.

Results

Twenty-two studies comprising 1,616 patients were analyzed. Mean age was 45.6 years, BMI 30.5 kg/m², with a mean follow-up of 10.5 months. All studies were non-randomized and rated as having a “Serious” risk of bias using the ROBINS-I tool. Recurrence occurred in 19 patients (0.99%), with no significant differences between subcutaneous and retromuscular approaches (0.93% vs. 1.16%, p = 0.802) or between stapled and fascial plication techniques (0% vs. 1.18%, p = 0.090). Seroma rates were significantly higher in the subcutaneous group compared to retromuscular approach (11.8% vs. 0.70%, p < 0.001). SSIs were more common in subcutaneous approaches (2.33% vs. 0.58%, 0.005). Bleeding was low across all groups (1.3%), with higher rates in the stapled compared to the fascial plication group (6.39% vs. 0.37%, p < 0.001).

Conclusions

Laparoendoscopic extraperitoneal approaches for RD and ventral hernia repair demonstrate favorable outcomes, with low and comparable recurrence rates among subgroups. The subcutaneous approach is associated with a higher risk of seroma formation while the stapled technique may increase bleeding risk. Further studies with higher methodological quality are needed to guide optimal technique selection.

Keywords: Rectus diastasis, Ventral hernia, Umbilical hernia, Hernia repair, Recurrence, Seroma

Introduction

The definition, classification, and management of rectus diastasis (RD) remains complex and a topic of debate, with a range of surgical techniques currently available. To address these shortcomings, the European Hernia Society (EHS) has established a Clinical Practice Guideline for RD management [1]. Nevertheless, precise criteria for defining RD are limited, with RD generally described as an abnormal divarication of the rectus abdominis muscles resulting from thinning and widening of the linea alba greater than 2 cm. Furthermore, the EHS guidelines for the management of RD recommend that, in the absence of new research, it is essential to thoroughly discuss treatment options with patients, ensuring they are well-informed and fully understand the procedures they are consenting to [1].

Over recent decades, minimally invasive surgery has seen significant advancements, fundamentally changing how abdominal wall defects are treated and resulting in reduced pain and better cosmetic outcomes. Managing RD when combined with epigastric and/or umbilical hernias is a debated issue that presents challenges within the abdominal wall reconstruction field. Current guidelines from both the EHS and the American Hernia Society recommend mesh-based repair for RD with concomitant umbilical and epigastric hernias [1]– [2], while for smaller hernias (less than 1 cm), plication of the anterior rectus sheath may suffice [3].

There are currently two main methods for addressing RD alongside ventral hernia repair: either an anterior subcutaneous approach with plication of the anterior rectus sheath or a posterior retromuscular approach [3]. Endoscopic subcutaneous dissection followed by plication of the linea alba with an onlay mesh has emerged as the most commonly reported technique [4]. Each technique offers its own set of benefits and drawbacks, making it practical to classify surgical approaches based on whether they access the abdominal wall from a subcutaneous or retromuscular position relatively to the rectus muscle.

In the late 1990 s, an innovative endoscopic technique for treating ventral hernias with concurrent RD was introduced [5]– [6]. Since then, variations of this technique have been published under different names in various countries, though they maintain the same fundamental surgical concept and mesh placement, with only slight technical modifications.

Presently, no conclusive data exists to guide surgeons in choosing the optimal approach. Rather, each technique is classified by its approach to the abdominal wall, either anterior or posterior to the rectus muscle, although an attempt at classifying and summarizing the characteristics of the main minimally invasive techniques has been made [7].

This systematic review and meta-analysis aims to analyze the outcomes of new laparoendoscopic extraperitoneal techniques with subcutaneous or retromuscular approach for repairing RD with concomitant ventral hernias, highlighting the potential advantages, complications and recurrence rates each technique offers.

Methods

Search strategy and selection of trials

A systematic review and metanalysis was carried out according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA Statement) criteria [8]. This study was registered to the PROSPERO International prospective register of systematic reviews (Registration Number: CRD42025630612). The ROBINS-I tool was used to assess the risk of bias of the studies included in this study [9].

The search for articles was carried out using Pubmed and the Cochrane library. All searches in the electronic databases were carried out through December 2024. The terms of search, extracted from the Medical Subjects Heading (MeSH) were “laparoscopic surgery” OR “minimally invasive surgery” OR “endoscopic surgical procedure” AND “diastasis recti” OR “rectus diastasis” OR “rectus abdominis diastasis” AND “ventral hernia” OR “abdominal hernia” OR “umbilical hernia” OR “epigastric hernia”. Studies were included only if the primary focus of the article was the surgical minimally invasive repair of both rectus diastasis and primary/incisional ventral hernia.

Case reports, editorials, letters, articles not in English were excluded. Studies examining intraperitoneal (i.e. IPOM/IPOM plus) approaches were also excluded.

The PICO strategy was used to formulate the guiding question: ‘In patients undergoing laparoscopic or minimally invasive surgery for rectus diastasis with concomitant ventral hernia (P), how do different surgical techniques (e.g., subcutaneous vs. retromuscular, onlay vs. sublay mesh placement, stapled vs. fascial plication suture,) (I) affect recurrence rates and surgical site occurrences (SSO) (e.g., seroma, bleeding, superficial skin infections) (O)?’ The eligibility criteria for selection of articles, according to the PICO strategy were: prospective or retrospective cohort studies with adults aged > 18 years with diastasis recti and concomitant primary/incisional ventral hernia (population); undergoing minimally invasive surgery for the repair of diastasis recti and ventral hernia (intervention); through different surgical techniques (i.e. stapled vs. fascial plication suture, subcutaneous vs. retromuscular, onlay vs. sublay mesh placement) (comparison); recurrence of RD/ventral hernia, SSOs (seroma, bleeding, surgical site infections) (outcomes).

Outcome measures

The primary outcome was RD/ventral hernia recurrence. Secondary outcomes included seroma formation, surgical site infections (SSIs), bleeding, and other SSOs such as hematomas and umbilical skin necrosis. Recurrence was defined as a distance between the inner edge of both recti > 20 mm at the supra and infraumbilical level and > 25 mm at umbilical level.

Data extraction

Two authors (M.F.R. and L.C-G) independently reviewed the title, abstract, and full text of the articles based on the inclusion and exclusion criteria. After the selection process, the following details were independently extracted from each article using a pre-specified data extraction form and entered into a database: first author, publication year, sex, age, BMI, mesh site, main working space, and other outcomes of interest, follow-up duration, recurrence rates, SSOs (seroma, SSI, bleeding and other complications). The surgical techniques were grouped based on factors such as the primary space used for defect repair (subcutaneous or retromuscular), the placement site of the mesh (onlay or sublay), use of endoscopic staplers (stapled or fascial plication suture technique).

Statistical analysis

Data analyses were carried out using Julius AI [10]. Meta-analysis of proportion was adopted to estimate the prevalence of phenomena of interest. The heterogeneity among the studies was checked using the Cochran’s Q [11] and the I2 statistical tests [12]. A Freeman-Tukey transformation [13] was used to calculate the weighted summary proportion under the fixed and random effects model [14]. Publication bias was evaluated through the Begg and Egger tests [15]. Subgroup analysis in terms of SSOs related to surgery, namely retromuscolar vs. subcutaneous, onlay vs. sublay and stapled vs. fascial plication suture techniques was conducted by OpenMeta[Analyst] [16].

Results

The literature search retrieved 2397 results, of which 322 were duplicates and excluded from the analysis. One thousand nine hundred twenty-two articles were excluded after title review. The abstracts of the remaining 153 articles were analysed and other 30 studies were excluded. Twenty-two studies were included in the final analysis (Fig. 1).

Fig. 1.

Fig. 1

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PRISMA 2020 flow diagram for the selection of studies

A total of 22 studies with 1616 patients (613 males, 952 females) were included. Two studies with 25 and 28 patients included, did not specify gender. The studies spanned from 2017 to 2024, with a mean age of 45.6 years, a mean BMI of 30.5 kg/m², and a mean follow-up duration of 10.5 months (Table 1). The studies employed different surgical techniques, with the main working space identified as being either subcutaneous or retromuscular, with mesh placed onlay or sublay.

Table 1.

Demographic and clinical characteristics of patients in the included studies

Author Year Surgical technique Type of study N° of patients Male Female Age (years) BMI (kg/m2) Defect size (cm) Mean Follow-up (months) Hernia Type
Schwarz et al. 2017 EMILOS Prospective 25 / / 53.4 30.3 35.5 cm2 (area) / Primary & DR
Li et al. 2021 eTPA Prospective 20 11 9 52.2 28.4 22 cm2 (area) 10 Primary & incisional& DR
Reinpold et al. 2018 MILOS Prospective 615 295 320 60.2 29.7 76.5 cm2 (area) 12 Incisional& DR
Manetti et al. 2020 MISAR Prospective 74 9 65 46.3 24.3 / 6 DR
Carrara et al. 2020 THT Prospective 110 8 102 43 21.7 16 cm 24 DR
Schwarz et al. 2017 MILOS Prospective 8 / / 53.5 25.5 15 cm2(area) 1 Primary & DR
Köckerling et al. 2017 ELAR Prospective 140 90 50 54.7 29.9 59.0 1 Primary, incisional & DR
Kohler et al. 2018 MILAR Prospective 20 3 17 41 25.3 15.0 5 Primary
Barchi et al. 2018 SVAWD Prospective 21 12 9 47.5 26.3 74.0 14 Incisional & DR
Claus et al. 2018 SCOLA Prospective 48 20 28 44.2 27.7 23.0 25 Primary
Dong et al. 2020 SCOLA Prospective 16 2 14 45.7 29 19.0 / Primary + DR
Muas et al. 2018 REPA Prospective 50 3 37 38 / 23 Primary & DR
Cuccomarino et al. 2020 REPA Prospective 124 6 118 42 22.5 / 12 DR
Signorini et al. 2023 REPA Retrospective 54 29 25 50.7 28.7 / 6 Primary & DR
Kler et al. 2020 TESLAR Retrospective 21 8 13 53 29.7 / / Primary & DR
Gandhi et al. 2020 EPAR Prospective 38 14 24 42 28.3 38.0 / Primary & incisional
Makam et al. 2023 SCOM Prospective 20 7 13 47 27.9 80.0 14 Primary& DR
Bellido-Luque et al. 2023 FESSA Prospective 28 28 / 53.4 29.1 37.0 17.3 Primary, incisional & DR
Shinde et al. 2022 SCOLA-modified Prospective 30 20 10 42.3 28.9 21.0 3 Primary & DR
Valenzuela Alpuche et al. 2024 PeTEP Retrospective 33 14 19 44.4 > 30 3 4 Primary & DR
Mandujano et al. 2022 R-eTEP Retrospective 57 20 37 54.8 32 30 cm2(area) 3.38 Primary & incisional
Arias-Espinosa et al.. 2024 R-PeTEP Retrospective 25 23 2 55 30.4 15 1 Primary & DR
Mehta et al. 2024 SCOLA Prospective 33 12 21 50 24.28 2.17 18 Primary & DR
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Methodological quality

Our systematic application of the ROBINS-I tool revealed that all 22 non-randomized studies included in this review were classified as having a “Serious” overall risk of bias. All studies are retrospective or observational, not randomized controlled trials. According to the ROBINS-I tool, such studies are inherently at higher risk of bias, especially in domains like confounding, selection, and deviations from intended interventions. The studies were published between 2017 and 2024 (Figs. 1, 2 and 3).

Fig. 2.

Fig. 2

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ROBINS-I traffic-light plot

Fig. 3.

Fig. 3

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ROBINS-I summary plot

Heterogeneity

Heterogeneity varied across the outcomes analyzed, indicating differences in study populations, surgical techniques, and reporting methods. For seroma, substantial heterogeneity was observed (I² = 89%, p < 0.0001), suggesting that factors such as mesh placement technique, surgical approach to the abdominal wall, and patient characteristics, contributed to variability. The highest seroma rates were observed in the subcutaneous approach (16%, 95% CI: 8-28%) which may explain some of the observed heterogeneity.

In contrast, bleeding had significant heterogeneity (I² = 72.2%, p = 0.0001), implying considerable variability across studies in reporting this complication. The elevated heterogeneity was largely driven by outlier values, particularly from a subcutaneous study reporting a markedly high bleeding rate (0.64), in contrast to consistently low or zero rates in most other studies. However, in subgroups like the retromuscular and extraperitoneal approaches, heterogeneity was negligible (I² ≈ 0%), underscoring the low risk of bleeding in those anatomical planes.

For SSIs, moderate heterogeneity was observed (I² = 32.6%, p = 0.0753), indicating some variation in infection rates across studies. Slight variability may come from differences in antibiotic prophylaxis, wound care protocols, and patient comorbidities. Subgroup analysis revealed very low heterogeneity in retromuscular, extraperitoneal, and extra/preperitoneal approaches (I² = 0%), while the subcutaneous group contributed most of the variability. Although variability was present, it was modest and mostly attributable to the subcutaneous subgroup.

Primary Outcome

Studies were analysed according to the main working space (subcutaneous vs. retromuscular) and and wall repair technique (stapled vs. fascial plication suture, respectively) (Tables 2 and 3). Not all studies stated a clear definition of recurrence. Most studies diagnosed recurrence based on clinical examination or imaging [22]. A study reported hernia recurrence based on patient self-reporting with selective use of postoperative imaging [19].

Table 2.

Surgical technique, approach and mesh placement site

Main working space Mesh Site Wall repair technique
Schwarz et al. Retromuscular Sublay Fascial plication suture
Li et al. Retromuscular Sublay Fascial plication suture
Reinpold et al. Retromuscular Sublay Fascial plication suture
Manetti et al. Retromuscular Sublay Stapled
Carrara et al. Retromuscular Sublay Stapled
Schwarz et al. Retromuscular Sublay Fascial plication suture
Köckerling et al. Subcutaneous Onlay Fascial plication suture
Kohler et al. Subcutaneous Onlay Fascial plication suture
Barchi et al. Subcutaneous Onlay Fascial plication suture
Claus et al. Subcutaneous Onlay Fascial plication suture
Dong et al. Subcutaneous Onlay Fascial plication suture
Muas et al. Subcutaneous Onlay Fascial plication suture
Cuccomarino et al. Subcutaneous Onlay Fascial plication suture
Signorini et al. Subcutaneous Onlay Fascial plication suture
Kler et al. Subcutaneous Onlay Fascial plication suture
Gandhi et al. Subcutaneous Onlay Fascial plication suture
Makam et al. Subcutaneous Onlay Fascial plication suture
Bellido-Luque et al. Subcutaneous Onlay Fascial plication suture
Shinde et al. Subcutaneous Onlay Fascial plication suture
Valenzuela Alpuche et al. Subcutaneous Onlay Fascial plication suture
Mandujano et al. Preperitoneal Sublay Stapled
Arias-Espinosa et al.. Preperitoneal Sublay Stapled
Mehta et al. Subcutaneous Onlay Fascial plication suture
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Table 3.

Postoperative SSOs according to subgroups analysis

Retromuscular (n = 858) Subcutaneous (n = 714) p value
Recurrence 10 (1.16%) 6 (0.93%) 0.802
SSI 5 (0.58%) 15 (2.33%) 0.005
Seroma 6 (0.70%) 76 (11.8%) < 0.001
Bleeding 3 (0.35%) 2 (0.31%) 1.000
Other SSO 5 (0.58%) 10 (1.55%) 0.070
Stapled ( n  = 271) Fascial plication suture ( n  = 1380) p value
Recurrence 0 16 (1.18%) 0.090
SSI 4 (1.50%) 20 (1.48%) 1.000
Seroma 6 (2.25%) 96 (7.11%) < 0.001
Bleeding 17 (6.39%) 5 (0.37%) < 0.001
Other SSO 5 (1.87%) 10 (0.74%) 0.085
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Recurrence was reported in 19 patients (0.99%) across all studies. The comparison between subcutaneous and retromuscular approaches showed no significant difference in recurrence rates (subcutaneous: 0.93%, retromuscular: 1.16%, p = 0.802). A higher but not statistically significant recurrence rate was observed in fascial plication suture techniques compared to stapled techniques (1.18% versus 0%, respectively p = 0.090) (Table 3) (Fig. 4).

Fig. 4.

Fig. 4

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Forest plots illustrating the proportion of recurrence rate across studies subgrouped by subcutaneous vs. retromuscular surgical approach (Panel A) and fascial plication suture vs. stapled technique (Panel B)

Secondary Outcomes

Several postoperative SSOs were reported across studies. The most common complications included:

  • Seroma

The incidence of seroma varied across different surgical approaches. The overall proportion of seroma was 6.8% (95% CI: 0.7-28%), with significant heterogeneity among studies (I² = 89%, p < 0.0001). Regarding the use of stapling methods, the stapled technique had a lower rate of seromas 2.25% compared to fascial plication suture which was associated with an 7.11% seroma rate (p < 0.001) (Fig. 5).

Fig. 5.

Fig. 5

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Forest plots illustrating the proportion of seromas across studies subgrouped by subcutaneous vs. retromuscular surgical approach (Panel B) and fascial plication suture vs. stapled technique (Panel B)

  • Bleeding

The bleeding rate was low overall at 1.3%. The rates of bleeding in the subcutaneous (0.31%) and retromuscular (0.35%) groups were comparable (p = 1.000). The stapled technique had a significantly greater risk of bleeding (6.39%) compared to fascial plication suture techniques (0.37%, p < 0.001) (Fig. 6).

Fig. 6.

Fig. 6

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Forest plots illustrating the proportion of bleeding across studies subgrouped by subcutaneous vs. retromuscular surgical approach (Panel A) and fascial plication suture vs. stapled technique (Panel B)

  • Surgical Site Infections

The overall incidence of SSIs was 1.5% (95% CI: 2-5%), with moderate heterogeneity across studies (I² = 32.6%, p = 0.0753). The retromuscular approach demonstrated a lower SSI rate of 0.58% (95% CI: 1-5%) compared with the subcutaneous subgroup showing a greater incidence at 2.33% (95% CI: 3-7%), (p = 0.005). There were no differences in terms of SSIs between stapled and fascial plication suture techniques (p = 1.00) (Fig. 7).

Fig. 7.

Fig. 7

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Forest plots illustrating the proportion of SSIs across studies subgrouped by subcutaneous vs. retromuscular surgical approach (Panel A) and fascial plication suture vs. stapled technique (Panel B)

  • Other Surgical Site Occurrences

SSOs were reported in 1.03% of subjects overall. Hematomas and umbilical skin necrosis were rare, with hematomas occurring in 0.87% and umbilical skin necrosis in 0.12%. Other minor complications, including wound infections and delayed healing, were reported at low rates across all subgroups. Surgical site occurrences showed some variation across different surgical techniques, though none of the differences reached statistical significance. In retromuscular versus subcutaneous approach, SSOs were reported in 0.58% and 1.55% of cases, respectively (p = 0.07). The stapled repair had a higher rate of 1.87% compared to 0.74% in fascial plication suture technique (p = 0.085).

Comparison of surgical techniques

Subcutaneous vs. Retromuscular approaches

The comparison between the subcutaneous and retromuscular approaches revealed significant differences in complication rates. Seroma formation was markedly higher in the subcutaneous approach (15.27%) compared to the retromuscular approach (0.70%) (p < 0.001). Similarly, SSIs were significantly more frequent in the subcutaneous group (2.66%) than in the retromuscular group (0.58%) (p < 0.001). However, recurrence rates (1.16% vs. 1.86%, p = 0.81) and bleeding (0.35% vs. 0.28%, p = 1.00) were comparable between the two approaches.

Fascial plication suture vs. Stapled techniques

The comparison between stapled and fascial plication suture techniques revealed no significant differences in SSIs (1.60% in fascial plication suture vs. 1.47% in stapled, p = 1.00), or bleeding (0.36% in fascial plication suture vs. 0% in stapled, p = 1.00). However, seroma was more frequent in fascial plication suture techniques compared to techniques where an endoscopic stapler was used (8.45% versus 0.37%; p = 0.012). Notably, recurrence was observed only in the fascial plication suture group (1.37%, p = 0.05), suggesting a potential advantage of stapling the linea alba in preventing recurrence.

Due to the significant disparity in the number of studies between the two subgroups, with the ‘Stapled’ subgroup consisting of only a single study reporting postoperative SSOs [18], this subgroup analysis lacks the necessary data variability to conduct a valid statistical test. Therefore, comparisons between these subgroups should be considered descriptive rather than conclusive.

Discussion

This meta-analysis focused exclusively on current minimally invasive approaches for the repair of RD with concomitant ventral hernias, excluding intraperitoneal techniques (e.g., IPOM/IPOM+) and transperitoneal approaches (e.g., ventral TAPP) where RD is not consistently the primary focus [23]. The rationale behind this choice was to highlight the distinctive innovation of extraperitoneal parietoscopic methods, which set them apart from traditional laparoscopic repairs. Moreover, transperitoneal techniques were excluded to maintain greater consistency and homogeneity within the analysis of fully extraperitoneal strategies, thereby highlighting the growing innovation and clinical relevance of minimally invasive parietoscopic approaches that avoid the peritoneal cavity.

A total of 22 articles were examined, covering various surgical techniques often described under numerous names despite sharing similar principles. Differences are primarily technical variations, making standardization difficult due to overlapping features. For simplicity and to improve clarity, this meta-analysis distinguished between subcutaneous (anterior) and retromuscular (posterior) approaches, focusing on the primary working space utilized during the surgical procedure and the site of mesh placement.

The present study indicates that laparoendoscopic extraperitoneal techniques for repairing RD with concomitant ventral hernias are generally effective in terms of recurrence rates and SSOs. A major finding is the low overall recurrence rate of 0.99%, which highlights the efficacy of these minimally invasive techniques. Notably, there was no significant difference in recurrence rates between the subcutaneous and retromuscular approaches, which suggests that both surgical approaches are equally effective in terms of preventing RD and hernia recurrence. Interestingly, a higher but not significant difference was found in terms of recurrence between fascial plication suture of the linea alba compared to the use of endoscopic linear stapling devices (1.18% versus 0%, respectively; p = 0.09). Nevertheless, the definition of recurrence varied significantly across studies or was not defined at all, which may have affected the interpretation of results.

Additionally, this study did reveal differences in postoperative SSOs between the surgical approaches. Eight techniques were included in the retromuscular group versus 15 in the subcutaneous one. Seroma formation, a common complication in abdominal wall surgery, was notably higher in the subcutaneous approach compared to the retromuscular approach (11.8% versus 0.70%, p < 0.001). This finding aligns with the literature, where the dissection of the subcutaneous plane, although providing easier access, might lead to a greater risk of serum accumulation and subsequent seroma formation compared to the retromuscular approach [24]. Similarly, onlay mesh placement was associated with a higher rate of seroma development compared to the sublay placement (16.01% versus 3.06%, p < 0.001). This could also be attributed to the anatomical differences in the way the mesh is positioned, with the onlay mesh being placed subcutaneously rather than beneath the rectus muscles, which may be more prone to causing fluid accumulation in the early postoperative period [25].

The complication rates for SSIs and bleeding were low across all approaches. Significant differences were observed between stapled and fascial plication suture techniques (6.39% vs. 0.37%, p < 0.001) while no significant difference was found between subcutaneous and retromuscular dissection with regards to bleeding rates. The minimal rates of bleeding and SSIs are consistent with the general safety of minimally invasive techniques, which are designed to reduce tissue trauma and improve recovery times [26]. Bleeding was the fourth most frequently reported complication after seroma, SSIs and recurrence. Conversely to what has been previously suggested [7], although posterior methods require a dissection mainly occurring in the more vascularized retromuscular space, bleeding was not significantly increased in this group compared to the subcutaneous technique (0.35% and 0.31%, respectively; p = 1.00). The stapled division of the linea alba, while efficient for accessing the retrorectus space, may be associated with an increased risk of bleeding. This is likely related to the fact that endoscopic linear staplers are primarily intended for bowel resection and anastomosis, not for abdominal wall dissection—a use that is considered off-label. Applying the stapler in this context may result in suboptimal tissue compression or inappropriate staple height, leading to inadequate hemostasis and a higher incidence of bleeding. On the other hand, SSIs, although relatively low overall, were more commonly encountered in the subcutaneous approach compared to the retromuscular (2.33% versus 0.58%, p = 0.005) group.

Two techniques employing staplers for linea alba fascia division, cross-over and stapled plication were analyzed [17]– [18]. While effective for small defects, these methods face challenges in maintaining tension in the posterior plane, particularly for larger hernias. According to a study on an ex vivo model, stapled sutures are capable of withstanding high loads, but their rigidity makes them less deformable compared to handsewn sutures [27]. Authors suggest that this characteristic renders them more appropriate for smaller defects and/or RD, where the anticipated tissue displacement is minimal. In contrast, for larger defects, where tissue displacement is more significant, reinforcing the stapled suture with an oversewing technique enhances its deformability. Hence, stapled plication methods could be proposed for subjects with smaller midline defects and RD but could be less indicated for the treatment of larger ventral hernias.

Fifteen included studies employed an anterior approach with the subcutaneous space serving as the primary operative field. These techniques were previously analyzed in a review exclusively focusing on laparoendoscopic subcutaneous onlay repair and examined the outcomes of 13 studies across 10 countries employing similar surgical methods to address small midline ventral hernias combined with RD [4]. The Authors highlighted the overlapping likenesses of the various surgical terms and proposed merging them under the term ‘Endoscopic Onlay Repair (ENDOR)’. They advocate for this unified term, aiming to foster shared knowledge and improved outcomes in future research.

Since Bellido-Luque’s pivotal 2015 publication [23], the preaponeurotic plane has gained prominence as a suitable area for treating midline defects. Subsequently, other researchers published similar approaches that typically involve subcutaneous dissection, anterior fascia plication with or without onlay mesh placement. These techniques demonstrated low complication rates, despite holding a greater risk of seroma formation (11.8% subcutaneous vs. 0.70% retromuscular approach, p < 0.001). This higher incidence is hypothesized to result primarily from subcutaneous dissection and the onlay mesh placement site. Kler et al. [21] reported the highest seroma rate at 81%, potentially due to a higher proportion of biologic mesh use (57%). Seromas were primarily managed conservatively through observation or fine-needle aspiration [4].

While onlay repairs face challenges such as higher rates of seroma, retromuscular mesh placement is often preferred for its lower complication rates. Despite these concerns, anterior approaches provide key advantages, including reduced risk of visceral injury, easier instrument use compared to posterior methods, and complete hernia sac removal, which delivers excellent cosmetic results, particularly for thinner patients. On the other hand, posterior extraperitoneal approaches offer significant advantages, including placement of mesh in an ideal space, namely the retromuscular area, and good functional results with minimal need for drainage. However, these techniques demand expertise due to their steep learning curve and potential complications, such as bulging and hematomas [17].

Clinical implications

The present findings support the use of laparoendoscopic extraperitoneal techniques for repairing RD with concomitant small-to-moderate size ventral hernias. These techniques offer favorable outcomes with low recurrence rates and minimal postoperative SSOs. However, careful consideration should be given to the increased risk of seroma formation associated with the subcutaneous approach and onlay mesh placement, and augmented bleeding risk with the use of endoscopic staplers as these factors may influence the decision-making process when selecting the optimal technique for individual patients. Surgeon expertise and appropriate case selection remain critical factors, especially as these techniques require a learning curve and often entail advanced laparoscopic or endoscopic skills [3, 7, 20].

Study limitations and future research

Despite the promising findings, several limitations must be considered. The included studies were observational in nature with retrospective analysis. This introduces potential bias and confounding factors, particularly in the choice of surgical technique and patient selection. Additionally, the lack of detailed data on specific patient factors (e.g., comorbidities, prior abdominal surgery) and long-term outcomes limits the ability to fully assess the impact of the different techniques on perioperative outcomes. The reviewed studies included small patient populations and lacked long-term follow-up, limiting conclusions about recurrence and outcomes. Included studies did not differentiate complication rates based on gender, hence a subgroup analysis with regards to gender influence on the main outcomes was not possible.

Methodological quality of included studies varied, with most being retrospective case series or small prospective cohort studies, limiting the overall strength of evidence and increasing the risk of selection bias. Heterogeneity in surgical techniques, follow-up duration, and outcome reporting further affected comparability. Additionally, many studies lacked standardized definitions for complications such as seroma and recurrence.

The variability in surgical techniques, despite being categorized into clear subgroups, still leaves room for variation in execution. Furthermore, this meta-analysis could not account for the learning curve in the earliest cases, which may have negatively affected outcomes. However, it is reasonable to assume that surgeons developed the necessary skills in an experimental setting before performing surgery on the patients included in each study.

Future studies should aim to include larger, multicenter, randomized controlled trials with longer follow-up periods to confirm these findings, possibly standardizing these approaches and their names. Moreover, further exploration into the long-term outcomes, particularly regarding patient satisfaction with cosmetic results and quality of life, would be beneficial in establishing optimal surgical approaches for RD and ventral hernia repair.

Conclusions

In conclusion, laparoendoscopic extraperitoneal approaches for the repair of RD with concomitant ventral hernias appear to be safe and effective, with low recurrence rates and a limited incidence of major complications. The subcutaneous approach with an onlay mesh placement was associated with a higher risk of seroma formation, while careful consideration should be given to the augmented bleeding risk linked to the off-label use of endoscopic staplers for linea alba division. Standardizing surgical approaches and conducting larger, multicenter trials would be beneficial for confirming the findings and guiding clinical decision-making.

Author contributions

All authors contributed to the study conception and design. Literature review, data collection and analysis were performed by [MFR, LCG, JCM, PP, MIB, VD, GI, GC]. The first draft of the manuscript was written by [MFR, LCG, JCM] and all authors commented on previous versions of the manuscript. All authors read and approved the final manuscript.

Funding

No funding was received for this study.

Declarations

Ethics approval

Ethical approval was waived by the local Ethics Committee of Sapienza University of Rome in view of the nature of the study (systematic review and meta-analysis).

Conflict of interest

All authors state that they have no conflict of interest.

Footnotes

Publisher’s note

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References

  • 1.Hernández-Granados P, Henriksen NA, Berrevoet F et al (2021) European hernia society guidelines on management of rectus diastasis. Br J Surg 108:1189–1191. 10.1093/bjs/znab128 [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 2.Henriksen NA, Kaufmann R, Simons MP et al (2020) EHS and AHS guidelines for treatment of primary ventral hernias in rare locations or special circumstances. BJS Open 4:342–353. 10.1002/bjs5.50252 [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 3.Bittner R, Bain K, Bansal VK et al (2019) Update of guidelines for laparoscopic treatment of ventral and incisional abdominal wall hernias (International endohernia society (IEHS)): part B. Surg Endosc 33:3511–3549. 10.1007/s00464-019-06908-6 [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 4.Malcher F, Lima DL, Lima RNCL et al (2021) Endoscopic onlay repair for ventral hernia and rectus abdominis diastasis repair: why so many different names for the same procedure? Surg Endosc 35:5414–5421. 10.1007/s00464-021-08560-5 [DOI] [PubMed] [Google Scholar]
  • 5.Corrêa MA (1995) Videoendoscopic subcutaneous techniques for aesthetic and reconstructive plastic surgery. Plast Reconstr Surg 96:446–453. 10.1097/00006534-199508000-00030 [DOI] [PubMed] [Google Scholar]
  • 6.Champault GG, Catheline JM, Barrat C (1999) Parietoscopic treatment of abdominal wall defects: a report of 15 cases. Hernia 3:15–18. 10.1007/BF01576734 [Google Scholar]
  • 7.Ferrara F, Fiori F (2024) Laparoendoscopic extraperitoneal surgical techniques for ventral hernias and diastasis recti repair: a systematic review. Hernia 28:2111–2124. 10.1007/s10029-024-03144-3 [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 8.Page MJ, McKenzie JE, Bossuyt PM et al (2021) The PRISMA 2020 statement: an updated guideline for reporting systematic reviews . BMJ n71. 10.1136/bmj.n71 [DOI] [PMC free article] [PubMed]
  • 9.Sterne JA, Hernán MA, Reeves BC, Savović J, Berkman ND, Viswanathan M et al (2016) ROBINS-I: a tool for assessing risk of bias in non-randomised studies of interventions BMJ. 355:i4919. 10.1136/bmj.i4919 [DOI] [PMC free article] [PubMed]
  • 10.Caesar Labs, Inc (2024) Julius (April 7 version) [Large language model]
  • 11.Lau J, Ioannidis JP, Schmid C (1997) Quantitative synthesis in systematic reviews. Ann Intern Med 127:820–826 [DOI] [PubMed] [Google Scholar]
  • 12.Vos T, Barber RM, Bell B et al (2015) Global, regional, and national incidence, prevalence, and years lived with disability for 301 acute and chronic diseases and injuries in 188 countries, 1990–2013: a systematic analysis for the global burden of disease study 2013. Lancet 386:743–800 [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 13.Freeman MF, Tukey JW (1950) Transformations related to the angular and the square root. Ann Math Stat 21:607–611 [Google Scholar]
  • 14.DerSimonian R, Laird N (1986) Meta-analysis in clinical trials. Control Clin Trials 7:177–188 [DOI] [PubMed] [Google Scholar]
  • 15.Higgins JP, Thompson SG (2002) Quantifying heterogeneity in a meta-analysis. Stat Med 21:1539–1558. 10.1002/sim.1186 [DOI] [PubMed] [Google Scholar]
  • 16.Wallace BC, Dahabreh IJ, Trikalinos TA et al (2012) Closing the gap between methodologists and end-users: R as a computational back-end. J Stat Softw 49:5 [Google Scholar]
  • 17.Manetti G, Lolli MG, Belloni E, Nigri G (2021) A new minimally invasive technique for the repair of diastasis recti: a pilot study. Surg Endosc 35:4028–4034. 10.1007/s00464-021-08393-2 [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 18.Carrara A, Catarci M, Fabris L et al (2021) Prospective observational study of abdominal wall reconstruction with THT technique in primary midline defects with diastasis recti: clinical and functional outcomes in 110 consecutive patients. Surg Endosc 35:5104–5114. 10.1007/s00464-020-07997-4 [DOI] [PubMed] [Google Scholar]
  • 19.Dong CT, Sreeramoju P, Pechman DM et al (2021) Subcutaneous onlay endoscopic approach (SCOLA) mesh repair for small midline ventral hernias with diastasis recti: an initial US experience. Surg Endosc 35:6449–6454. 10.1007/s00464-020-08134-x [DOI] [PubMed] [Google Scholar]
  • 20.Fiori F, Ferrara F, Gobatti D et al (2021) Surgical treatment of diastasis recti: the importance of an overall view of the problem. Hernia 25:871–882. 10.1007/s10029-020-02252-0 [DOI] [PubMed] [Google Scholar]
  • 21.Kler A, Wilson P (2020) Total endoscopic-assisted linea alba reconstruction (TESLAR) for treatment of umbilical/parumbilical hernia and rectus abdominus diastasis is associated with unacceptable persistent seroma formation: a single centre experience. Hernia 24:1379–1385. 10.1007/s10029-020-02266-8 [DOI] [PubMed] [Google Scholar]
  • 22.Bellido-Luque J, Gomez-Rosado JC, Bellido-Luque A et al (2023) Severe rectus diastasis with midline hernia associated in males: high recurrence in mid-term follow-up of minimally invasive surgical technique. Hernia 27:335–345. 10.1007/s10029-022-02706-7 [DOI] [PubMed] [Google Scholar]
  • 23.Bellido Luque J, Bellido Luque A, Valdivia J et al (2015) Totally endoscopic surgery on diastasis recti associated with midline hernias. The advantages of a minimally invasive approach. Prospective cohort study. Hernia 19:493–501. 10.1007/s10029-014-1300-2 [DOI] [PubMed] [Google Scholar]
  • 24.Claus C, Malcher F, Cavazzola LT (2020) Comment to: TESLAR for treatment of umbilical/paraumbilical hernia and rectus abdominus diastasis is associated with unacceptable persistent seroma formation. Should subcutaneous endoscopic mesh placement be abandoned? Hernia 24:1411–1412. 10.1007/s10029-020-02285-5 [DOI] [PubMed] [Google Scholar]
  • 25.Deshpande GA, Tirpude B, Bhanarkar H et al (2024) Prospective, observational study of intraperitoneal onlay mesh repair with defect closure versus SCOLA for primary ventral hernia. J Minim Access Surg 20:397–402. 10.4103/jmas.jmas_223_23 [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 26.Forester E, Sadiq A (2023) Comparative analysis of the efficacy and functionality of abdominoplasty versus minimally invasive techniques in the surgical treatment of diastasis rectus abdominis in postpartum women. Surg Endosc 37:9052–9061. 10.1007/s00464-023-10540-w [DOI] [PubMed] [Google Scholar]
  • 27.Lauro E, Corridori I, Luciani L et al (2022) Stapled fascial suture: ex vivo modeling and clinical implications. Surg Endosc 36:8797–8806. 10.1007/s00464-022-09304-9 [DOI] [PubMed] [Google Scholar]
  • 28.Schwarz J, Reinpold W, Bittner R (2017) Endoscopic mini/less open sublay technique (EMILOS)—a new technique for ventral hernia repair. Langenbecks Arch Surg 402:173–180. 10.1007/s00423-016-1522-0 [DOI] [PubMed] [Google Scholar]
  • 29.Li B, Qin C, Bittner R (2020) Totally endoscopic sublay (TES) repair for midline ventral hernia: surgical technique and preliminary results. Surg Endosc 34:1543–1550. 10.1007/s00464-018-6568- [DOI] [PubMed] [Google Scholar]
  • 30.Reinpold W, Schröder M, Berger C et al (2019) Mini- or less-open sublay operation (MILOS): a new minimally invasive technique for the extraperitoneal mesh repair of incisional hernias. Ann Surg 269:748–755. 10.1097/SLA.0000000000002661 [DOI] [PubMed] [Google Scholar]
  • 31.Li B, Qin C, Bittner R (2020) Endoscopic totally extraperitoneal approach (TEA) technique for primary ventral hernia repair. Surg Endosc 34:3734–3741. 10.1007/s00464-020-07575-8 [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 32.Li B, Qin C, Liu D et al (2021) Subxiphoid top-down endoscopic totally preperitoneal approach (eTPA) for midline ventral hernia repair. Langenbecks Arch Surg 406:2125–2132. 10.1007/s00423-021-02259-w [DOI] [PubMed] [Google Scholar]
  • 33.Wang T, Tang R, Meng X et al (2022) Comparative review of outcomes: single-incision laparoscopic total extra-peritoneal sublay (SIL-TES) mesh repair versus laparoscopic intraperitoneal onlay mesh (IPOM) repair for ventral hernia. Updates Surg 74:1117–1127. 10.1007/s13304-022-01288-4 [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 34.Nakabayashi R, Matsubara T, Shimada G (2023) The endoscopic-assisted or endoscopic mini- or less-open preperitoneal (E/MILOP) approach for primary and incisional ventral hernia repair. Asian J Endosc Surg 16:482–488. 10.1111/ases.13206 [DOI] [PubMed] [Google Scholar]
  • 35.De-Carvalho JPV, Pivetta LGA, de Freitas Amaral PH et al (2023) Endoscopic mini-or less-open sublay operation (E/MILOS) in ventral hernia repair: a minimally invasive alternative technique. Rev Col Bras Cir 50 [DOI] [PMC free article] [PubMed]
  • 36.Köckerling F, Botsinis MD, Rohde C et al (2017) Endoscopic-assisted linea Alba reconstruction: new technique for treatment of symptomatic umbilical, trocar, and/or epigastric hernias with concomitant rectus abdominis diastasis. Eur Surg - Acta Chir Austriaca 49:71–75. 10.1007/s10353-017-0473-1 [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 37.Köhler G, Fischer I, Kaltenböck R, Schrittwieser R (2018) Minimal invasive linea alba reconstruction for the treatment of umbilical and epigastric hernias with coexisting rectus abdominis diastasis. J Laparoendosc Adv Surg Tech 28:1223–1228. 10.1089/lap.2018.0018 [DOI] [PubMed] [Google Scholar]
  • 38.Barchi LC, Franciss MY, Zilberstein B (2019) Subcutaneous videosurgery for abdominal wall defects: a prospective observational study. J Laparoendosc Adv Surg Tech 29:523–530. 10.1089/lap.2018.0697 [DOI] [PubMed] [Google Scholar]
  • 39.Claus CMP, Malcher F, Cavazzola LT et al (2018) Subcutaneous onlay laparoscopic approach (SCOLA) for ventral hernia and rectus abdominis diastasis repair: technical description and initial results. ABCD. Arquivos Brasileiros de Cirurgia Digestiva (São Paulo) 31:e1399. 10.1590/0102-672020180001e1399 [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 40.Fiori F, Ferrara F, Gentile D et al (2019) Totally endoscopic sublay anterior repair for ventral and incisional hernias. J Laparoendoscopic Adv Surg Techniques 29:614–620. 10.1089/lap.2018.0807 [DOI] [PubMed] [Google Scholar]
  • 41.Juárez Muas DM (2019) Preaponeurotic endoscopic repair (REPA) of diastasis recti associated or not to midline hernias. Surg Endosc 33:1777–1782. 10.1007/s00464-018-6450-3 [DOI] [PubMed] [Google Scholar]
  • 42.Cuccomarino S, Bonomo LD, Aprà F, Toscano A, Jannaci A (2022) Preaponeurotic endoscopic repair (REPA) of diastasis recti: a single surgeon’s experience. Surg Endosc 36(2):1302–1309. 10.1007/s00464-021-08405-1 [DOI] [PubMed] [Google Scholar]
  • 43.Signorini FJ, Chamorro ML, Soria MB et al (2023) Preaponeurotic endoscopic repair (REPA) indication in men could be controversial. Hernia 27:431–438. 10.1007/s10029-022-02716-5 [DOI] [PubMed] [Google Scholar]
  • 44.Gandhi JA, Shinde P, Kothari B et al (2020) Endoscopic preaponeurotic repair (EPAR) technique with meshplasty for treatment of ventral hernia and rectus abdominis diastasis. Indian J Surg. 10.1007/s12262-020-02189-9
  • 45.Makam R, Chamany T, Nagur B et al (2023) Laparoscopic subcutaneous onlay mesh repair for ventral hernia: our early experience. J Minim Access Surg 19:223–226. 10.4103/jmas.jmas_225_22 [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 46.Shinde PH, Chakravarthy V, Karvande R et al (2022) A novel modification of subcutaneous onlay endoscopic repair of midline ventral hernias with diastasis recti: an Indian experience. Cureus 14:1–9. 10.7759/cureus.26004 [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 47.Tsimoyiannis EC, Tassis A, Glantzounis G et al (1998) Laparoscopic intraperitoneal onlay mesh repair of incisional hernia. Surg Laparosc Endosc 8:360–362 PMID: 9799145 [PubMed] [Google Scholar]
  • 48.Mehta K, Parmar GVR (2024) An emerging, less explored subcutaneous onlay laparoscopic approach for ventral hernias with concomitant diastasis recti. Sci Rep 14:26938. 10.1038/s41598-024-78398-z [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 49.Mandujano CC, Lima DL, Xia J, Sreeramoju P, Malcher F (2022) An algorithmic approach for the MIS repair of ventral midline hernias associated with diastasis of the rectus abdominis muscle. J Abdom Wall Surg 1:10864 [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 50.Arias-Espinosa L, Claus CM, Malcher F, Valenzuela Alpuche HA (2024) Robotic preperitoneal extended totally extraperitoneal (R-PeTEP) technique description for ventral hernia repair: preliminary results. Updates Surg 76(7):2715–2722. 10.1007/s13304-024-02002-2 [DOI] [PubMed] [Google Scholar]
  • 51.Alpuche HAV, Torres FR, González JPS (2024) Early results of eTEP access surgery with preperitoneal repair of primary midline ventral hernias and diastasis recti. A 33 patient case series of PeTEP. Surg Endosc 38(6):3204–3211. 10.1007/s00464-024-10832-9 [DOI] [PubMed] [Google Scholar]

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