AWD is a serious surgical complication, but data regarding the best treatment is lacking, and the heterogeneity of the techniques makes comparisons between different therapies difficult [1, 14, 15]. Our research aimed to determine the efficacy of the posterior CS with TAR and retro-muscular mesh insertion in repair of primary AWD in terms of AWD recurrence, IH, SSO, and mortality. This is the first large-scale study of this technique's efficacy in treating AWD.

We reported no recurrence of AWD and an 8.9% incidence rate for IH at the three-year follow-up. The SSO risk for SSI, wound seroma, and wound hematoma was 7.9%, 12.4%, and 2%, respectively. A 2.5% mortality rate was observed. Cardiopulmonary complications were the causes of postoperative mortality (two patients with pulmonary embolism and three patients with myocardial infarction). Local wound complications did not cause the death. All the patients required long-term hospitalization after surgery. None required long-term intubation after repair. All of them died within three months of reconstructive surgery. Root cause analysis confirmed no preventable deaths.

Subramonia et al. evaluated vacuum-assisted wound closure (VAWCM) as a temporary wound cover. However, authors reported wound closure necessity in 39% of patients, logistical difficulties with repeated dressings every 2–3 days, enteric fistulae, IH (n = 12), prolonged hospital stay (39 days), and prolonged ICU stay (22 days) [5]. Heller et al. confirmed these disadvantages, except that few patients can be treated in outpatient clinics [6]. Other centers using VAWCM reported 70–100% successful fascial closure rates but high IH rates [7, 8]. Another study evaluated Bogota bag closure for AWD with similar disadvantages and a high mortality rate (28.6%) [26]. In our study, although posterior CS with TAR with mesh has the disadvantage of abdominal wall trauma and is a technically demanding procedure, closure of the AWD was successful in all cases and prevented exposure of the viscera, so there was no enterocutaneous fistula. A fistula can occur due to an iatrogenic injury to the bowel, but in our patients, careful adhesiolysis was performed. Also, the mesh is inserted in the retro-muscular space away from the abdominal viscera, thus reducing the risk of bowel erosion from contact with the mesh. In contrast to VAWCM, the posterior CS with TAR and retro-muscular mesh insertion has no AWD recurrence, a low incidence of IH (8.9%), a shorter hospital stay (12 ± 1 days), and is potentially less expensive. Multiple previous studies agreed with our results regarding the role of posterior CS with TAR as efficient methods for closure of AWD as regards low IH rates up to 8% but with 15% SSI. They attributed the low recurrence hernia rate due to the mesh inserted in retromuscular space [27,28,29].

Other studies evaluated mass closure with or without retention sutures [11, 12], elastic silicone U-shaped loop sutures [13], and a mass closure technique with 3 cm “large bites” in 5 mm “small steps” [10]. These techniques were not advocated due to the inconvenience, pain, and high prevalence of IH (25–43%) caused by ischemia at the defect edge by the loop, while the previous study [10] showed a recurrence of AWD in 13% of patients.

Our study did not use a retention suture as a supportive treatment. Instead, we addressed the retracted fascial defect by dissection of the preperitoneal space by TAR, and this enabled us to approximate both the anterior and posterior rectus sheath medially easily, even after the debridement of the ischemic fascial edge. Furthermore, our results showed that in 91 patients (45% of cases), the cause of AWD was cut through sutures due to the tension closure. Retraction of the fascial defect prevents easy closure of the fascial defect, so our main goal was to approximate the anterior and posterior fascial sheath without tension. Obtaining adequate durability of repair of AWD is one of the main goals in AWD surgery, nil AWD recurrence and a low incidence of IH in our series is comparable to the previous studies [10,11,12]. Other possible explanations for the low incidence of IH in our study include preserving perforating neurovascular bundles during dissection and using abdominal binders to support the wound in all cases during the postoperative period.

Previous research suggested that the cause of AWD could be the cutting of sutures through tissues [1, 30] or intra-abdominal abscesses [31], or impaired facial tissue quality [10, 14, 15]. Due to proper selection, no cases in our study demonstrated intra-abdominal abscesses. Additionally, fascial necrosis was reported in 5% of cases, and easy medialization of the fascial defect in our technique helps debridement of necrotic fascia without tension on closure.

The high recurrence and IH following AWD treatment may support mesh repair. We believe that mesh augmentation, when indicated, is an effective adjunct to AWD closure method, potentially lowering the risk of IH. Our series has confirmed the importance of mesh placement in the retro-muscular space because placing the mesh in this location helps mesh fixation to the posterior surface of the rectus muscle even when the intra-abdominal pressure is increased.

Paterson et al. stated that retro rectal mesh to close the AWD was associated with low IH but increased wound complications [4]. This concept was confirmed by Van’t et al. [32], while Scholtes et al. confirmed the opposite results, with a better outcome even in intra-abdominal infection [3].

EHS clinical guidelines recommended slowly absorbable continuous monofilament sutures following suture wound/wound length over four (i.e., PDS) for AWD closure with mesh augmentation whenever fascial closure is possible. They did not recommend a particular mesh or insertion site, but SSO may increase. CS must be chosen carefully. They also noted the lack of supporting data [17]. Our results suggest that posterior CS can safely and effectively manage AWD with TAR reinforced by retromuscular mesh with low morbidity and mortality.

In our series, SSI is low in incidence, probably due to the selection of cases of AWD (Grade 1A). Infected mesh occurred in 3% (6 patients) presented by sinuses discharging trivial pus, and all were cured with conservative management within three months of diagnosis. Cohort type may explain the low incidence of chronic SSI. Furthermore, our surgical technique included a sharp dissection of the retro-muscular space, suture ligation of blood vessels and harmonic scalpel rather than diathermy, and drain placement and removal only when the effluent volume was less than 20–50 cc, and finally, abdominal binder placement in all cases. Studies have confirmed the important role of the abdominal binder in preventing SSO and IH [33, 34]. However, other study denied this role [35]. We recommend that mesh be added to the posterior CS to reduce the incidence of IH and prevent AWD recurrence, even at the expense of SSO, which appears to be expected, but most SSO is self-limited.

Our study confirmed that time from AWD to surgery, emergency surgery, infected mesh, ileus, and SSI are predictors of IH as almost 74.8% of the AWD appeared after emergency laparotomy, which is higher than in previous studies (30–55%) [4, 36]. This could be explained by the fact that surgical strategies vary between centers. Our results confirmed that the length of the fascial defect and operative time were not risk factors for IH, probably due to adequate release of the anterior and posterior rectus sheath with tension-free closure of the fascial defect. These predictive factors are important to be considered by surgeons to minimize surgical repair failure.

This study did not exclude emergency surgery or obese patients with the highest risk of AWD recurrence.

It is a consecutive series of patients, and selection bias was largely eliminated. The patients who lost to follow-up are also excluded, and this may skew the results as some of these patients might have developed complications and been treated elsewhere. Surgical experience is another factor that could have affected the outcomes, but all operations were conducted by consultant surgeons. The study does not compare various interventional techniques. Our future aim is to plan a study to compare the outcomes of our technique with other standard procedures.

This study did not assess any potential risks associated with future abdominal wall surgical therapy or the possibility of a negative effect on core abdominal wall and spine stability.