Introductory section

I. Does the abdominal wall incision in emergency surgery cases influence the incidence of incisional hernia, burst abdomen, or open abdomen?

I.1 When urgent access to the peritoneal cavity is required, we recommend midline laparotomy because it is faster and allows the best approach to the abdomen. When clinical circumstances allow, we suggest avoiding a midline incision for an alternative incision (2A).

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I.2 We recommend AGAINST midline incision as the extraction site when laparoscopic interventions are performed (1A).

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An appropriate incision is fundamental to performing any surgical operations, and the choice of incision in case of laparotomy depends on the anatomical site of interest, elective or emergency setting, and personal preference. Laparotomy incisions can be classified as follows:

Midline—a vertical incision through the skin, subcutaneous tissue, linea alba, and peritoneum.

Paramedian—the ‘conventional medial incision’ in which the rectus sheath and muscles are transected close to the linea alba and the ‘lateral incision’ in which rectus is transected near the lateral border.

Transverse—a possible supraumbilical transverse incision for access to the upper abdomen or a ‘Pfannenstiel’ infraumbilical transverse incision for access to the lower abdomen.

Oblique—a typical subcostal/Kocher incision or the McBurney incision.

In the literature, many randomized trials and systematic reviews with a high certainty evidence compared midline incisions to alternative incisions: the incisional hernia rate was significantly lower after non-midline incisions, for both transverse and oblique approaches [21,22,23,24]. In addition, a transverse incision appears to have less negative impact on pulmonary function, wound dehiscence, burst abdomen, and postoperative pain than a midline laparotomy [25, 26].

On the other hand, midline laparotomy is faster and allows the best access to all the organs of the peritoneal cavity: it is still the incision of choice in an emergency setting when a patient in a hemodynamically unstable condition needs to be explored [13, 15].

Therefore, our group recommends a different laparotomy incision from the classic midline approach when clinical circumstances allow: when preoperative imaging clearly identifies the site of pathology, a transverse incision can be used for emergency general surgery. For example, a transverse incision can be the best approach for advanced appendicitis and then could be extended medially to perform a right colectomy if necessary; similarly, a subcostal incision can be used for a complicated duodenal perforation. In addition, when emergency surgery is performed laparoscopically, we recommend avoiding midline incisions for the extraction site. However, the lack of evidence regarding the length and the location of these alternative incisions must be considered as a limitation.

Section 1

1. What is the optimal technique to close a laparotomy incision?

1.1 Continuous versus interrupted suture

The current evidence does not suggest any difference in the incidence of incisional hernia or dehiscence between continuous or interrupted sutures for fascial closure. However, the time taken for fascial closure is less with continuous closure. Therefore, we suggest a continuous suture technique of the midline abdominal wall incision in emergency settings (2A).

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The literature search identified five large meta-analyses addressing the evidence on suture technique in terms of continuous versus interrupted methods [1, 14, 27,28,29]. Additionally, some well-designed randomized clinical trials were considered [30, 31]. Guidelines from the European Hernia Society—in the original 2015 version—recommended continuous closure of the midline abdominal wall, but the updated version in 2022 also considered more recent evidence and downgraded the certainty of evidence with a weak strength of recommendation due to the inconsistency of the results [13, 15]. Most of the evidence related to elective surgery, and clear data in the emergency setting are lacking. Therefore, in line with the evidence from Peponis et al. randomized clinical trial, we infer that there is no significant difference between continuous or interrupted sutures in the closure of abdominal wall incision, but the continuous technique might be preferred based on the elective surgery evidence because it is faster [1, 14, 27,28,29,30,31,32].

1.2 Closure versus non-closure of the peritoneum

We recommend AGAINST separate closure of the peritoneum during the abdominal wall closure of emergency laparotomy (1B).

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Regarding the closure of the peritoneal layer in a midline laparotomy, the Cochrane Systematic review by Gurusamy et al. [33] concluded that there is no short-term or long-term benefit in peritoneal closure. This review included five randomized clinical trials (RCTs): inclusion criteria in the studies were heterogeneous—the type of incision, elective, or emergency setting—but the studies concluded that closure of the peritoneum is unnecessary [34,35,36,37,38]. There is considerable uncertainty in the benefits or harms of the single-layered closure of the peritoneum as a separate layer, but this procedure is likely to increase operating time in emergency surgery.

Closure of the peritoneum involves additional operating time and suture material, and no benefit is apparent from closure of peritoneum. Therefore, it does not seem necessary after a midline laparotomy, even in an emergency setting.

1.3 Mass closure versus layered closure

For closure of abdominal midline incision in emergency surgery, no difference between mass closure or layered closure was observed in terms of incisional hernia and wound complications: we suggest mass closure because it is faster than layered closure which might be highly important when emergency surgery is performed (2B).

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We used the EHS 2015 guidelines [13] definition of ‘mass closure’ versus ‘layered closure.’

Definitions proposed by Muysoms et al. (EHS 2015 guidelines) were:

Mass closure The midline incision is closed with a suture bite including all layers of the abdominal wall except the skin. With this approach, the suture includes the fascia layers, peritoneum (which may or may not be included), and superficial layers in a single bite. By definition, mass closure is a single-layer closure technique.

Layered closure The incision is closed with more than one separate layer of fascial closure. Specifically, if the incision is midline, there is only one layer of fascia. If the incision is paramedian, then there are two layers of rectus sheet above the arcuate line. With this approach, the peritoneal surface is normally closed separately as a different layer in the suture, and the same is done for the subcutaneous layer.

The following studies by Patel et al. and van Rooijen et al. in a systematic review and meta-analysis in 2018 analyzed the different impact of mass versus layered closure techniques in both elective and emergency settings. No difference was noted in terms of incisional hernia or wound complications, considering RCTs of moderate/low/very low certainty of evidence [1, 29, 39].

Therefore, we concluded that mass closure should be preferred because it is faster and no additional complications have been demonstrated, but the certainty of evidence is low due to the lack of specific data in emergency surgery and the low certainty of evidence from previous studies.

1.4 Suture Length-to-Wound Length ratio (SL/WL)

We recommend a suture-to-wound length ratio (SL/WL) of at least 4:1 for continuous closure of midline abdominal wall incisions in emergency surgery (1B).

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The suture technique investigated through the suture length-to-wound length ratio is of crucial importance to avoid the development of incisional hernia and wound complications. The beneficial effect of a high suture length (SL)/wound length (WL) ratio has already been demonstrated, and previous guidelines consider a critical value a ratio of 4:1 or more (Jenkins Rule) [13, 15, 40,41,42,43].

Recently, data from RCTs were summarized in both elective and emergency surgeries after vascular operations: abdominal closure with a suture-to-wound length ratio of more than 4:1 compared with less than 4:1 significantly reduces the risk of incisional hernia and other wound complications [44,45,46].

Therefore, a SL/WL ratio of 4:1 or higher reduces the risk of incisional hernia and wound complications. It is recommended to document and ascertain this ratio at every wound closure.

1.5 ‘Small bite’ technique versus ‘large bite’ technique

We suggest the closure of the midline laparotomy with a ‘small bite’ technique to prevent incisional hernia and wound complications in emergency surgery cases although the evidence stems from elective surgery cases (2C).

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The ‘small bite’ technique in the closure of midline laparotomy consists of a tissue stitch of approximately 5 mm from the median wound edges and a distance of approximately 5 mm from the other stitch allowing surgeons to include only the aponeurosis and to ensure adequate distribution of tension on the edge of the incision [47]. The ‘large bite’ technique consists of a distance from the wound edge and between stitches of more than 10 mm.

The positive effects of small stitches on wound healing have been widely expressed: aponeurosis has limited possibilities for regeneration and cannot bridge over a large defect. With a large stitch, not only aponeurosis tissue is included, but also fat and muscle. In combination with increased intra-abdominal pressure, soft tissue can be compressed and damaged. This can result in slackening and separation of wound edges, tissue devitalization, and infection. A separation of wound edges of more than 10/12 mm during the first postoperative period has been strongly associated with the development of an incisional hernia.

Large RCTs of acceptable quality, systematic reviews, and previous guidelines have investigated outcomes from the closure techniques, showing that incisional hernias and wound complications are significantly lower with the ‘small bite’ suture technique [13, 15, 48, 49]. However, all the studies were in the elective setting. The only manuscript looking specifically at this comparison in the emergency setting was the one by Peponis et al. [31]. Therefore, we suggest using the ‘small bite’ technique with low certainty of evidence also in cases of midline emergency laparotomy, but future perspectives studies on this topic are necessary to prove the effectiveness of this technique.

Section 2

2. What is the optimal suture material to close a laparotomy incision?

2.1 Non-absorbable versus absorbable suture

There is currently no evidence to suggest that absorbable or non-absorbable sutures are better in terms of incisional hernia or surgical site infections. Absorbable sutures may decrease pain; therefore, we suggest slowly absorbable sutures for the closure of emergency laparotomy (2C).

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There are many RCTs of high and moderate certainty evidence and even some previous systematic reviews and meta-analyses which investigated incisional hernia rates and other wound complications for different suture materials [14, 29, 32, 50,51,52]. A possible bias looking at these trials could be a combination of different suture techniques. Nevertheless, all high-level evidence considered a laparotomy incision closure through a continuous running suture. Taking into account these considerations, evidence failed to identify a significant superiority of one suture material over the other to reduce incisional hernia rate after a midline laparotomy [13, 15]. Van’t Riet et al. systematic review, Naz et al. RCT, and mainly Patel et al. Cochrane review highlighted less wound pain and surgical site infections in the absorbable suture group compared to the non-absorbable, but they agree that there is no clear evidence for all the other outcomes [1, 27, 53]. Most of the studies we considered include both elective and emergency settings.

Therefore, we conclude that there is no clear evidence for a recommendation about suture material, but some evidence about secondary outcomes suggest that non-absorbable suture may be avoided after emergency midline laparotomy.

2.2 Rapidly absorbable suture versus slowly absorbable suture

When using an absorbable suture for the closure of midline incisions in the emergency setting, we suggest choosing a slowly absorbable material (2A).

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Randomized clinical trials and numerous systematic reviews reported a lower incisional hernia rate when closure of the midline incision is performed with a slowly absorbable suture, in both elective and emergency settings [27, 28, 30, 32, 52, 54,55,56]. Accordingly, Muysoms et al. (EHS 2015 guidelines) are not recommending the use of rapidly absorbable sutures—with a focus on the specific area of elective surgery—[13]. Most recent data do not confirm strong evidence supporting the implementation of slowly absorbable sutures: a trend of fewer incisional hernia and wound complications is confirmed but without statistical significance [14, 15, 29].

So, we recommend, based on the high and moderate certainty of evidence, a slowly absorbable suture for the closure of midline emergency laparotomy.

2.3 Monofilament suture versus multifilament suture

We recommend a monofilament suture material (slowly absorbable monofilament suture) in the closure of midline laparotomies in the emergency setting as they may decrease the incidence of incisional hernia (1A).

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Our literature research found evidence, suggesting that monofilament sutures are associated with a significantly lower risk of incisional hernia than multifilament sutures in both elective and emergency settings [1, 13, 15, 29]. On the other hand, no evidence specifically about wound complications—wound infections, wound dehiscence, wound sinus, and fistula formation—emerged from previous high/moderate certainty of evidence.

Therefore, according to our previous statements, if a slowly absorbable suture is used, a monofilament material is the only possible choice.

Because of the significant amount of data supporting the lower incidence of incisional hernia in emergency surgical settings with monofilament sutures, we have made a strong recommendation.

2.4 Antimicrobial-coated sutures

We recommend an antimicrobial-coated suture for the fascial closure of abdominal laparotomy in cases of clean-, clean-contaminated, and contaminated fields when it is available in the emergency setting (1B).

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Surgical site infections (SSIs) represent a common and serious complication of all surgical procedures, but it is even of greater concern in emergency surgery cases. Antimicrobial-coated sutures—typically triclosan-impregnated—have recently become a topic that generates considerable discussion, and is a well-known tool for preventing SSI, but they remain controversial due to elevated costs, worldwide availability, and the uncertainty in significant benefit for their use [