Mapping the therapeutic landscape in emergency incisional hernia: a scoping review

Abdominal wall defects represent a major global health burden with increasing incidence [1]. Moreover, incisional hernias (IH), which can occur after every type of surgery accessing the abdominal wall, are common long-term complications that further exacerbate the issue. Despite recent efforts to optimize abdominal wall closure strategies and prevent the development of IH with the use of prophylactic meshes, the incidence varies depending on the surgical approach [2‐4]. Average rates of 5–20% are reported after laparotomies, and these rates can be exceeded in cases of open repair of abdominal aortic aneurysms [5‐8], obesity, and colorectal surgery [9]. In addition, recurrent incisional hernias account for a relatively large proportion of all incisional hernias, with a rate of around 20–25% [10, 11].

While the elective treatment of IH is a studied field, providing sufficient evidence to give recommendations in guidelines, evidence-based advice for managing the emergency presentation of incisional hernias is still controversial [12]. The urgent surgical management of IH presents formidable challenges, leading to worse outcomes than elective repair [13]. Severe pain and symptoms of acute bowel obstruction typically cause patients to present suddenly in the emergency department. These patients are often frail and have comorbid conditions that cannot be prehabilitated, negatively affecting postoperative outcomes. Additionally, ongoing therapies, such as oral anticoagulation or steroids, which cannot be rapidly antagonized, introduce a higher risk of complications [14, 15].

The major issue in emergency situations is that a localized abdominal wall condition can become a systemic problem, endangering patients’ lives through obstruction and/or strangulation of bowel loops, potentially causing systemic inflammatory response affecting multiple organs. If acute incarceration is diagnosed and manual reduction (taxis) fails or is deemed inappropriate, immediate surgical repair is indicated. Therefore, the timing of surgical intervention is crucial, as progression to systemic inflammatory response and sepsis is challenging to reverse and demands increasing expertise and resources for its effective management [12, 16].

Patients’ stability, bowel obstruction and massive tissue contamination caused by bowel perforation are major determinants in treatment choice, probably representing the most significant challenge for general and abdominal wall surgeons. Depending on the hernia morphology, localization, and patient condition, alternatives to open repair may be considered, subject to local availability and expertise. Additionally, although the use of mesh is the gold standard for preventing recurrences in incisional hernia repair (IHR), its use in contaminated or dirty situations poses a risk of subsequent colonization.

Members of the European Hernia Society (EHS) science wing conducted a comprehensive scoping review to uncover the available body of evidence and provide crucial insights for guideline developers. Focusing on emergency incisional hernia repair, this review aims to map the existing literature, identify research gaps, and inform the development of future guidelines.

This scoping review was conducted using the methodological framework proposed by Arksey and O’Malley and further refined by Levac et al. [17, 18].

The current literature on incisional hernias treated under emergency conditions clearly lacks robust evidence and standardization. The presence of a single RCT reflects the difficulty of conducting such research in a field where standardization is very difficult and patients arrive for surgical evaluation in various conditions, making controlling for confounders almost impossible, out of large-scale studies.

The pooled descriptive data reveal that emergency incisional hernias are most commonly observed in female, elderly, and comorbid patients. In terms of treatment, the open approach with synthetic mesh is the most employed technique. Notably, the overall postoperative complication rate for emergency incisional hernias was high, reflecting the challenging nature of managing these cases. Importantly, the definition of emergency hernia is not consistently provided in current literature. The different definitions of acutely symptomatic incisional hernia have created a heterogeneous group of publications in which it is also difficult to differentiate patients with incarceration, obstruction, or perforation on one side from those with adhesive small bowel syndrome associated with an incisional hernia on the other. The non-elective presentation of an abdominal wall defect has different implications on patients’ treatment and prognosis: a pathology mainly referred to a single anatomic area suddenly becomes a problem with systemic effects, requires fluid resuscitation and stabilization, and may or may not involve sepsis. The priorities of the treatment are directed at saving the patient’s life, preserving the bowel involved in the process, and then minimizing the need for further interventions by repairing the abdominal wall.

Methodologically, the first issue is represented by the fact that papers with a robust structure in the emergency IH setting are lacking (74% are cohort studies), as well as direct comparisons (9%) or unbiased evaluation. Accordingly, the analysis of this literature and the development of a treatment algorithm through PICO questions can be challenging, particularly for guideline developers. Nevertheless, it should be acknowledged that, in this area, the production of surgical clinical trials is two-fold complex. The first reason is connected to the well-known methodological problems typical of the surgical environment, which conflict with the conduction and results interpretation of trials [95]. The second is typical of the emergency area and is connected to time restraints that can interfere with the allocation of definitive treatment and endanger the life of the patient. Despite several methodologies that have been proposed, reliable studies are lacking or flawed by many biases.

The second methodological problem that we have encountered is connected to the heterogeneity of studies in terms of the type of defect enrolled. Almost 75% of studies dealt with a mixed group of patients operated on for an abdominal wall defect, irrespective of its nature, either primary inguinal, ventral, or incisional. This represents a major issue since inguinal hernias are treated according to defined procedures that have standard results, and the characteristics of the myopectineal orifice have principles of treatment totally different from those of other defects (surrounding bony structure and favorable anatomical planes). Moreover, pooling together primary ventral and incisional hernias frequently carries a major bias in interpreting results. It has been clearly shown in elective settings that IHs have unfavorable features and generally are more complex to repair: patients are older and more comorbid, defects have wider dimensions, are multiple (Swiss-cheese), adhesiolysis is frequently necessary, and the results of the repair are worse (longer LOS, more frequent complication, higher recurrence rates) [96]. The effect of the higher complexity is clearly amplified in emergency settings where mortality and complications rise, and the pooling with primary hernias introduces cases with similar presentations but more stable features. Accordingly, the presence of inguinal and primary ventral hernias can only mitigate the results and lead to an underestimation of the real burden of IH emergency treatment.

A third methodological problem arises from the type of outcomes, method of assessment and follow-up period chosen. Concerning outcomes, only preoperative surgical ones are analyzed, without any evaluation of patient-centered outcomes (PROMS) as already highlighted in the elective settings [97]. The method of outcome assessment is usually inconsistent and subjective, while the follow-up period is mainly focused on 3 months postoperatively.

In the present analysis, we have shown that the main concern for surgeons dealing with emergency IH repair is focused on technical aspects and factors predicting adverse outcomes. As shown in our analysis, the baseline risks of performing incisional hernia repair in the context of an emergency are 4% mortality and 31% morbidity, without possible distinction between aggravating patient, technical, and expertise factors. The armamentarium available for the surgeon is very limited and ranges from “damage control” strategies (open abdomen, planned incisional hernia) to suture repair or formal abdominal wall reconstruction (AWR).

The first factor that has a relevant impact on the choice of treatment is the patient’s condition in terms of stability and possible functional reserve. Information on patients’ stability was not possible to be retrieved. Nevertheless, our results suggest an elevated mean age and BMI in the emergency series; more importantly, patients presenting in the acute setting have a high ASA class on admission, explaining the possible increased risk of adverse events registered. The choice of treatment in this fragile cohort should be tailored, taking into consideration all the pre-existing conditions (diseases and medication) that cannot be preoptimized and will affect outcomes, reserving more aggressive strategies for the healthier and more stable subjects. No indication of a possible threshold to opt for treatment can be retrieved in the selected papers.

The second relevant variable in the management of acute IH is the presence and degree of bowel obstruction and the associated adhesive syndrome. It is known that extensive adhesive syndrome can be a factor of intra and postoperative complications as well as increased operative time. Ten Broek et al. showed that in the elective setting, adhesiolysis time longer than 30 min is a factor predictive of increased postoperative complications, higher rate of sepsis, and enterotomies [98]. Enterotomies and obstruction can change the strategy of repair by affecting the choice of material and/or the execution of a formal abdominal wall repair when the risk of a compartment syndrome is actual. This condition can only be worsened in emergency IHR. Of note is the fact that usually, incisional hernias are connected more frequently with adhesive small bowel in comparison to primary ventral, posing this type of problem more frequently.

The third relevant factor related to emergency IHR is the approach to a complex abdomen becoming acutely complicated. The complex abdomen has been defined by various experts. One of the first definitions was published by Slater et al. in 2014: in their description, the emergency setting was considered as one of the criteria connected with moderate complexity for the frequent association with hernia-complicating factors such as the presence of obstruction, previous meshes, infection, etc [99]. Recently EHS endorsed a revised definition of complex abdomen in which emergency setting disappeared and patient, hernia, abdominal wall and operation site-related factors were chosen with Delphi methodology by a group of experts as primary determinant of complexity [100]. Facing a complex abdomen in the emergency setting is a frequent situation that requires attention and expertise to be treated with success. This is particularly true when large defects and contamination are the dominant scenario of the emergency hernia. In this situation, the decision of whether to undertake the repair or adopt a conservative approach, the type of mesh, and the position can be challenging and expose the patient to a higher risk of septic complication and abdominal compartment syndrome. Interestingly, in the selected literature, data on hernia characteristics were reported in the minority of papers, a formal classification of defects is rarely retrieved, and a complete description of complexity is lacking, ultimately making it very difficult to evaluate criteria for choice of treatment.

Concerning details of treatment, most papers with a primary focus on treatment have, as their main aim, the analysis of different mesh types and minimally invasive approaches (robotic and laparoscopic) showing a sort of spin in emergency literature directed at the analysis of new therapeutical opportunities and their possible role without considering the actual clinical questions.

The use of prostheses in the context of emergency is a significant topic of debate. Factors such as the risk of colonization of synthetic prostheses, the degree of wound contamination, and uncertainties about the early behavior of absorbable meshes in contaminated fields complicate the evaluation of their effectiveness. Additionally, concerns about the risk of recurrence with biological meshes and ambiguities related to bio-like meshes prevent drawing definitive conclusions about their roles. In the current selection of articles, direct comparisons between different mesh types and their indications for use in emergencies were not available.

Minimally invasive surgery, even if feasible and possibly beneficial on general morbidity, by simply allowing inspection of the abdominal cavity, suffers from the fact that it can be accomplished in a highly selected group of stable patients where the obstruction is not already fully developed, and generalized peritonitis is not present. Moreover, the presence of intense adhesive small bowel syndrome can make this a challenging approach limited to experts. Accordingly, even if clinically relevant, the use of minimally invasive surgery addresses only a small proportion of the possible scenarios involved in an emergency and is currently recommended for early stages where a single band of adhesion is suspected [98].

The last update of inguinal hernia treatment guidelines from EHS has attempted to define on what is an emergency inguino-femoral hernia, pointing to the concept of the sudden change of the clinical status of the hernia (acute irreducibility – strangulation), abandoning the concept of chronic incarceration. Acute incisional hernia represents a more nuanced condition where time has relevance in both the development of obstruction and contamination and, finally, in treatment. If accepted as a generalization, the acute presentation of IH can be approximated to small bowel obstruction (SBO) caused by the IH or complicated by the IH in which surgery must take place in a timely fashion and where the repair of the abdominal wall gap is a complicating factor. Currently, a wide and inconsistent definition of emergency incisional hernia has been provided in the selected papers, explaining the extreme heterogeneity of cases collected and making it hard to draw an effective treatment algorithm. According to this concept, it is of interest that only two studies have assessed the role of CT specifically in the scenario of complicated incisional hernia, evaluating its possible impact on reducing treatment delay. Nevertheless, CT is considered the test of choice for evaluating patients with SBO [98]. This imaging technique improves the identification of high-grade obstructions and those that are unlikely to resolve non-operatively. Furthermore, CT scans have approximately 90% accuracy in predicting strangulation and the need for urgent surgical operations. This exam could represent the initial step in defining and stratifying patients with SBO and IH.

The first advantage of having a standardized classification could be the possibility of conducting homogenous studies with more reliable results that could allow data collection to inform guideline development, in which different scenarios are addressed with sufficient clarity to be reproducible by the general surgeon in the emergency setting. Other advantages include the possibility of exploring different treatments and their role being limited to certain subgroups only. Of interest could be the evaluation of non-operative management in stable patients with large defects, damage control strategies in unstable patients with SBO, and the role of suture and mesh repair in this context.

This scoping review has several limitations. Restricting the search to English-language publications may have introduced bias, potentially excluding relevant studies in other languages. The exclusion of conference abstracts and studies where full texts were unavailable could have led to the omission of potentially valuable data, particularly in a field with limited literature. Additionally, the focus on studies published between 2000 and 2024 ensured contemporary relevance but may have excluded earlier foundational research. While these limitations may affect the comprehensiveness of the findings, the review provides a detailed mapping of the existing literature on emergency incisional hernia repair and highlights key gaps for future research.

This scoping review reveals a significant gap in evidence guiding the diagnosis and management of emergency incisional hernias. Key issues identified include inconsistent definitions of emergency presentation, limited characterization of hernia defects and clinical scenarios, and a lack of standardized outcome reporting. Current literature emphasizes that management in this setting should prioritize addressing immediate life-threatening conditions, such as bowel obstruction, perforation and sepsis, while minimizing unnecessary dissection to prevent the spread of infection or disruption of anatomical planes. Although comprehensive guidelines are not yet available, these principles underscore the need to balance effective intervention with harm reduction and highlight the critical need for further research to develop more standardized management strategies. To advance the field, future research should focus on developing a unified classification system for emergency incisional hernias, careful selection of reference standards, and better characterization of defect types and bowel involvement. Evaluating the role of imaging in decision-making could enhance preoperative planning and optimize treatment strategies. Further studies should also aim to analyse the complex interactions among patient conditions, hernia characteristics, and the degree of bowel involvement. This approach would help better define optimal treatment strategies for this frail patient population, which is at higher risk of complications. Given the difficulty of performing randomized trials in this context, multicenter-matched cohort studies and registry-based studies should continue to be promoted to support evidence-based guidelines for this challenging patient population.