Parastomal hernia (PSH) is one of the most common and challenging complications following stoma formation, with reported incidence rates ranging from 30% to 50%, depending on the type of stoma and duration of follow-up [1, 2]. Surgical repair remains the mainstay of treatment for symptomatic cases, but the optimal technique continues to be debated due to high recurrence rates and the risk of mesh-related complications [3, 4]. Moreover, as the local treatment of these hernias requires extensive dissection of the stoma and mesh positioning in close proximity to the colon or small bowel, many surgeons remain hesitant to undertake this type of procedure [5].

Traditional approaches—including local fascial repair, stoma sitting, and mesh reinforcement—have evolved significantly over the past 2 decades. Sugarbaker, Keyhole, Sandwich, and hybrid 3D techniques have demonstrated clear advantages over non-mesh repairs, particularly in terms of lowering recurrence rates and enhancing long-term surgical outcomes [3, 6, 7]. However, intraperitoneal mesh placement could carry risks of bowel erosion, fistula formation, and infection, especially in the context of a contaminated field around the stoma [4, 6].

The Pauli repair, first described in 2016, advanced the field by combining lateralization of the stoma limb with retromuscular mesh placement and closure of the posterior sheath, thereby isolating the mesh from the peritoneal cavity and reducing the risk of mesh-related complications [8]. Subsequent adaptations of the Pauli technique utilizing minimally invasive and robotic platforms have demonstrated promising short-term outcomes, with enhanced visualization and precision facilitating complex dissection and mesh positioning [9]. Nevertheless, all published robotic Pauli repairs to date have described mesh placement in the retromuscular space. Notably, even so-called “preperitoneal” Pauli variants, such as those by Lambrecht et al. [10] and Almoguera González et al. [11], involved retrorectus dissection with partial transversus abdominis release, thus maintaining a retromuscular rather than a true preperitoneal plane.

Here we propose a novel robotic transabdominal preperitoneal intervention for PSH (TRAPPIST repair), with mesh positioned in the preperitoneal plane, which could offer anatomical and functional advantages.

Parastomal hernia repair remains a technically demanding procedure, with no universally accepted gold standard. Among mesh-based repairs, the Sugarbaker technique remains widely used and is associated with lower recurrence rates than keyhole repairs. However, the intraperitoneal position of the mesh in the Sugarbaker method carries an inherent risk of adhesions, fistulas, and mesh-related visceral complications. The Pauli technique represents a promising alternative with extraperitoneal mesh placement, but it is technically demanding, involving retromuscular dissection and potential disruption of the transversus abdominis muscle insertion, which contributes to its steep learning curve. Early series report morbidity rates as high as 34%, including seroma, surgical site infections, and postoperative ileus. Moreover, long-term data remain limited, with most studies based on small cohorts and short follow-up.

Several recent meta-analyses have evaluated different mesh placement techniques for PSH repair [13]. The Sandwich and Hybrid 3D techniques have shown superior performance in terms of recurrence reduction and cumulative complication rates compared to keyhole and classical Sugarbaker repairs. The Sandwich method, which combines keyhole and Sugarbaker principles with dual mesh placement, demonstrated favorable outcomes in recurrence prevention, but concerns remain regarding higher infection rates (6.4%) potentially related to the use of polypropylene mesh in an intraperitoneal position [13, 14].

The Hybrid 3D approach, utilizing preformed, anatomically contoured meshes in a preperitoneal plane, has been associated with reduced recurrence, fewer complications, and lower surgical site infection rates compared to traditional Sugarbaker repairs [7, 14–16]. Notably, this improved safety profile is likely attributed to the preperitoneal positioning of the mesh, which reduces direct bowel contact, rather than to the mesh material itself [17]. However, despite promising short-term data, the Hybrid 3D technique remains technically demanding, often requiring retroperitoneal dissection, multiple surgical stages, and advanced laparoscopic skills [18].

Overall, although different approaches show specific advantages, no single technique has emerged as superior in all clinical scenarios, and robust, long-term comparative data remain lacking. The preperitoneal approach described in this report combines the principles of anatomical reinforcement with minimal invasiveness. Placement of the mesh between the peritoneum and the posterior rectus sheath avoids direct intraperitoneal mesh contact, potentially reducing adhesions, bowel erosion, and mesh-related complications. The preperitoneal plane also offers enhanced tissue integration and mechanical stability. Interestingly, in 2021 Ayuso et al. described a robotic Sugarbaker repair in which an inferolateral preperitoneal flap was developed to increase mesh overlap [19]. This detail may be considered a conceptual step toward a fully preperitoneal approach, later realized in the TRAPPIST technique, which completely eliminates intraperitoneal mesh contact.

Recently, in abdominal wall surgery, concerns have been raised regarding the placement of retromuscular meshes and the disruption of the retromuscular plane, as this may complicate potential future procedures in the case of recurrence. In 2024, Valenzuela et al. published a study on patients with umbilical hernias and diastasis, employing an endoscopic totally preperitoneal (PeTEP) approach. They accessed the preperitoneal space via the Retzius space, achieving excellent outcomes and contributing to the growing popularity of the preperitoneal technique [20]. The following year, Muñoz-Rodríguez et al. described a cranial approach for the same procedure, further reflecting the increasing scientific interest currently surrounding preperitoneal plane surgery [21]. Compared to the retromuscular Pauli repair, our technique avoids disruption of the posterior rectus sheath and does not require opening the linea alba, preserving abdominal wall integrity and potentially minimizing the impact on core function. The use of a peritoneal flap allows wide lateral dissection without the need for transversus abdominis release (TAR), which is otherwise often necessary in retromuscular repairs.

In contrast to the classical Sugarbaker method, our approach places the mesh entirely within the preperitoneal compartment, with the peritoneum providing an additional protective barrier between the prosthesis and the abdominal viscera. This may reduce the risk of adhesions, mesh erosion, and complications from tacker fixation in proximity to the bowel.

Nevertheless, this technique also presents specific limitations. Dissecting the peritoneum in this anatomical region is not always straightforward and requires significant surgical expertise. Surgeons with prior experience in transabdominal preperitoneal (TAPP) repair of ventral hernias may find this step more intuitive. In patients with a particularly thin or fragile peritoneum, adequate dissection and flap creation may prove challenging, potentially limiting the feasibility of the procedure. Therefore, careful patient selection is critical.

We also believe that this technique could serve as a first-line attempt for PSH repair. If dissection proves technically unmanageable or the anatomical conditions are suboptimal, the procedure allows for conversion to a standard Sugarbaker or retromuscular Pauli repair as a bailout strategy. Robotic assistance facilitates this technically demanding approach, providing superior visualization, dexterity, and access to confined spaces, particularly around the stoma [9]. The lateralization of the bowel loop follows the protective principles of the Sugarbaker technique but avoids exposing the mesh intraperitoneally.

While this approach shows promise, it remains technically challenging and should be reserved for selected patients with favorable anatomy and minimal adhesions. Although we do not exclude the potential applicability of the TRAPPIST technique to EHS type II and IV hernias, its feasibility in cases with large concomitant midline defects may be considerably reduced due to the higher risk of peritoneal tears and technical difficulties in maintaining an intact preperitoneal plane. Further studies with larger cohorts and long-term follow-up are necessary to confirm the safety, efficacy, and recurrence rates of this technique.

TRAPPIST repair is feasible and may reduce mesh-related complications. However, it requires experience and careful patient selection. Thin peritoneum may limit feasibility, and conversion to Sugarbaker or Pauli remains an option. Further studies are needed to confirm long-term safety, efficacy, and the role of this approach in PSH repair.