A best evidence topic (BET) gives evidence-based answers to common clinical problems, using a systematic approach of literature reviewing. This BET was constructed using a design described by the International Journal of Surgery [1]. This framework was applied because a previous literature search suggested that the available evidence is of inadequate quality to conduct a meaningful systematic review or meta-analysis.

A 55-year-old male patient with incarcerated/strangulated inguinal hernia is undergoing emergency open hernia repair with mesh or non-mesh, primary tissue repair. The patient is wondering which technique provides a lower incidence of wound infection.

Does [use of mesh] affects [the infection rate] in patients with [incarcerated/strangulated inguinal hernia].

Search Strategy

1. Embase 2010 to October 2021 Using the Ovid Interface:

[Incarcerated/strangulated inguinal hernia] AND [mesh] AND [infection].

1. Medline Using the Pubmed Interface:

[Incarcerated/strangulated inguinal hernia] AND [mesh] AND [infection].

The results were limited to English articles and human studies.

Search Outcome

We identified 148 potentially relevant articles. After exclusion of duplicate references, nonrelevant literature, 23 candidate articles were considered. After careful review of the full text of these articles, 10 studies were identified to provide the best evidence to answer the question.

See the table

Tension-free hernia repair has been regarded as the gold-standard treatment for elective inguinal hernias repair, but the use of prosthetic mesh in acutely incarcerated or strangulated inguinal hernias is controversial. In this article, we have reviewed the best studies which compared the emergency repair of acutely incarcerated or strangulated inguinal hernias by prosthetic mesh with non-mesh primary tissue repair. Our main aim is to compare the incidence of wound infection. All ten studies in our review reported no statistically significant increase in incidence of wound infection when mesh was used in the repair of strangulated/incarcerated inguinal hernia.

Tatar C [2] conducted a study of total of 151 patients admitted with incarcerated inguinal hernia. The patients were divided into two groups. Group 1 consisted of 112 patients treated with mesh-based repair, while Group 2 consisted of 39 patients treated with tissue repair techniques. In Group 1, it was observed that eight (7.14%) of the patients had wound infections. In Group 2, one (2.56%) of the patients had a wound infection. There were no statistically significant differences between the two groups with respect to the ratio of wound infection (P = >0.3023). The study concluded that in urgent groin hernia repair surgeries, poly-propylene mesh can be safely used even in the patients undergoing bowel resection. However, this study was conducted in single centre and there was no period for follow up.

Else bae M [3] included 54 patients in the study. They were randomized into two groups 1 and 2 (27 patients in each group). Group 1 patients underwent repair utilizing mesh according to Lichtenstein “tension-free” technique, group 2 patients underwent Bassini technique. Complications following Lichtenstein “tension-free” technique were groin ecchymosis and seroma in one patient and wound infection in another patient. The latter was a superficial incision site infection and was treated in a conservative way. Postoperative wound sepsis occurred in three cases following Bassini operation. Although, the conclusion was the use of Lichtenstein “tension-free” technique in emergency treatment of strangulated inguinal hernia is safe, effective with an acceptably low rate of postoperative complications and without recurrence, the study was conducted in a single centre, the sample number was small and there was selection bias.

T Sakamoto [4], extracted data for 688 patients with incarcerated or strangulated inguinal hernia between April 2012 and March 2017. They divided patients into 2 groups, Group1: 223, Mesh repair, Group2: 445 Non-mesh repairs. Outcome of the two groups before and after adjustment by overlap propensity score weighting. The incidence of surgical-site infection was similar between the two groups (2.7 vs. 3.4%, P = 0.63). The conclusion was the incidence of surgical-site infection did not differ significantly or clinically between the mesh repair and non-mesh repair groups. However, the present study has several limitations. First, the database did not have data on wound classification. Second, the details of the surgical techniques were unknown, third, there may have been unmeasured confounders, such as postoperative drain placement. Finally, data on long-term outcomes, such as late infection or hernia recurrence, were lacking.

Tomaoglu K [5] conducted the study on 301 patients who underwent emergency surgery for incarcerated and strangulated abdominal wall hernias (inguinal, umbilical, incisional, femoral, epigastric, and Spigelian hernias). Overall, 226 patients (75.1%), group 1, underwent hernia repair with a monofilament polypropylene mesh, whereas 75 (24.9%), group 2, patients underwent primary hernia repair. The conclusion was, the use of prosthetic materials may be taken into consideration in the management of strangulated abdominal wall hernias as well, in patients either with or without organ resection.

Ueda J [6], included 27 patients who underwent emergency surgical interventions for incarcerated groin and required small-intestinal resection during the interventions. The patients were divided into two groups: those who underwent a repair with a prosthetic mesh (10 patients) and those who underwent a primary hernia repair (17 patients). The study supported the emergency use of prosthetic mesh in cases with an incarcerated groin hernia with small intestinal resection. However, the study was based on small group of patients and selection bias cannot be excluded.

Derici H [7] included 131 patients with incarcerated inguinal hernia who underwent surgery were divided into two groups; Lichtenstein (tension free) repair group (29 patients), and those who underwent primary tissue repair group 2 (102 patients). Intestinal resection and anastomosis were performed in 25 patients (6 patients in group 1 and 19 patients in group 2). No significant difference (P=0.495) in the outcome was found. The conclusion was, Lichtenstein method can be reliably applied in patients with incarcerated inguinal hernias; it causes a reasonable rate of infective complications, it does not extend length of hospital stay, and it does not cause recurrence even after a long-term follow-up.

Bessa [8] conducted a prospective study on 234 patients with strangulated/Incarcerated groin hernia, all underwent mesh repair. The patients were divided into 2 groups based on the content of the hernia if it was viable or not, group1: 193 patients with viable contents of the hernia, group2: 41 patients, non-viable. There was no statistically significant difference in the incidence of wound infection between two groups. They concluded that the use of prosthetic mesh repair in the emergency management of the acutely incarcerated and/or strangulated groin hernias is safe. The presence of non-viable intestine cannot be regarded as a contraindication for prosthetic repair.

Jing Liu [9] studied total of 146 patients with strangulated/incarcerated groin hernia, all of them had mesh repair, of those 119 patients had viable content of the hernia sac, which did not require resection, while 20 patient had bowel resection and 2 had omentum resection .6 patients (4.1%) from total of 146 developed wound infection which was statistically not significant (P 0.207). The study concluded that Open preperitoneal prosthetic mesh repair can be safely per-formed in patients with acutely incarcerated or strangulated inguinal hernia without contaminated hernia content. Mesh repair is not contraindicated in patients with bowel resection. However, the selection bias was exclusion the patient who had contaminated hernia contents.

Hentati H [10], published a systematic review study which included 413 patients with strangulated inguinal hernia and underwent emergency surgery. The aim of the study was to determine whether the mesh repair technique is associated with a higher risk of surgical site infection than non-mesh techniques for strangulated inguinal hernias in adults. Mesh repair was used in 196 patients while anatomical tissue repair in 217 patients. They concluded that he meshes repair technique is a good option for the treatment of strangulated inguinal hernias in adults, giving an acceptable wound infection rate and fewer recurrences than non-mesh repair.

Sawayama [11] conducted a retrospective study in total of 110 patients underwent emergency surgery for an incarcerated groin hernia. The patients were classified into two groups: those who underwent bowel resection (resection group1) 39 patients, and those who did not (non-resection group2) 71 patients. The hernia was repaired with mesh in ten of the 39(25.6 %) patients with bowel resection and 64 of the 71(90.1 %) patients without bowel resection. There were no wound infections in 64 patients with mesh repair in the non-resection group. Two of the 10 patients with mesh repair in the resection group suffered from wound infection. They concluded that mesh repair for the patients with bowel resection is not contraindicated, as long as the clean contamination of the wound was maintained during surgery.

One randomised controlled trial, one systematic review, one prospective study and 7 retrospective studies proved that there is no statistically significant increase in the incidence of wound infection when mesh repair is used for strangulated /incarcerated inguinal hernia.

Limitation of this Review

• Small sample size in some articles
• Single centre
• Shorter period of follow in some articles

Ethical Approval: Not applicable.

Sources of Funding: None.

Conflicts of Interest: None.

Provenance and Peer Review

Not commissioned, externally peer reviewed.

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