Suture Technique
Incisional hernias are the most common long-term complication after laparotomy (4). They are reported in the literature with a frequency of 11-16% (13). The actual incidence is likely much higher, considering that up to 30% of these hernias remain asymptomatic (5).
The INSECT study published in 2009 (2) compared the postoperative course of 625 patients in a three-arm study of single button suture vs. rapidly and slowly absorbable continuous loop suture. No significant differences were found between the methods regarding the formation of incisional hernias or other criteria (wound dehiscence, wound infections, pulmonary complications). This study also showed more postoperative abdominal wall hernias than previously assumed, with results up to 25% per clinic. The INSECT study sparked intense discussions, leading to increased awareness of abdominal wall closure to reduce the rate of incisional hernias.
From 1998 to 2010, a total of 6 meta-analyses on this topic were published. The works of Weiland et al. and Hodgson et al. favor continuous sutures [3,6]. Rucinski et al. also preferred continuous sutures the following year, focusing on the choice of suture material (7). Van’t Riet et al. published a meta-analysis in 2002 comparing single button vs. continuous fascial sutures after median laparotomy for the first time. No significant difference regarding incisional hernia formation was objectively found. Most included studies still favored continuous sutures, arguing that they are faster and easier to perform (8). Gupta et al. published similar results in 2008, but for the first time, preferred single button sutures (9). In a 2010 meta-analysis comparing continuous vs. single button sutures in elective primary and secondary median laparotomy, Diener et al. evaluated continuous suture technique as the better method (10). Overall, the trend in suture technique for median laparotomy, despite variable results and different arguments, seems to lean towards continuous fascial sutures for elective procedures.
Clinical studies by Israelsson [15,16] demonstrated the prophylactic value of continuous sutures with a suture-to-wound length ratio of at least 4:1 in preventing incisional hernias after laparotomy closure. The effect of the advocated ratio of at least 4:1 and continuous sutures is due to a reduction in tissue-damaging tensile forces in each stitch and a large amount of "reserve material" in the suture spiral, preventing an inadequate increase in suture tension during abdominal distension. The negative impact of high suture tension on perfusion, collagen synthesis, and mechanical strength of the laparotomy wound is experimentally proven (17). Peritoneum, fat tissue, and muscle offer minimal holding power for the suture material and become necrotic under the influence of suture tension within hours, contributing to the loosening of the suture material (18). Only the bradytrophic fascial tissues are mechanically resistant and durable (19).
Small Tissue Bites
The research group of Israelsson initially demonstrated in experimental studies (19) and then in randomized clinical studies (20) that an innovative "short stitch" technique, reducing wound edge stitch distances from 10 mm to 5-8 mm, can reduce tissue trauma, infection rates, and the formation of incisional hernias. This study showed a twofold increased risk of wound infection and a fourfold increased risk of incisional hernias in the "long stitch" group.
Suture Material
Numerous studies and meta-analyses have clearly shown the superiority of slowly absorbable (and non-absorbable) over rapidly absorbable suture material in the short-term (postoperative wound dehiscence) and long-term (incisional hernia) postoperative course [2,10]. Non-absorbable materials, however, lead to a 48% higher rate of suture fistulas and an increase in postoperative wound pain with persistent mechanical irritation of the tissue (7). For the preferred continuous fascial suture, loop sutures of size 1 should be used. With a distance of 1 cm between stitches and 1 cm from the wound edge to the fascial entry point, a suture length consumption of at least four times the incision length is required (10).
A variety of materials are available for skin closure. There are no conclusive randomized studies. However, skin staples seem to have the lowest infection rate in contaminated wounds (22).
Wound Drains
There is currently no consensus on the value of subcutaneous sutures or subcutaneous wound drains. Several studies show a lower incidence of subcutaneous hematomas, seromas, and wound infections after suturing the subcutaneous tissue. The benefit of drainage placement has not been confirmed in previous studies [10,11].
Peritoneal Suture
The separate peritoneal suture is now considered obsolete in abdominal surgery. It does not contribute to the mechanical strength of the abdominal wall incision and likely leads to increased peritoneal necrosis formation, causing pain and adhesions in the laparotomy area [14,21].
Wound Dehiscence
Wound dehiscence is a postoperative complication with high morbidity and mortality. Incidence rates vary between 0.5 and 3% [23,24,25,26]. Predisposing factors are either patient-related or due to the surgical technique or surgeon. There is no consensus on the ideal method or material for abdominal wall closure [27,34,35]. Regarding the risk of wound dehiscence, the full-thickness closure is superior to the layered closure of the abdominal wall [28,29]. The single button technique seems inferior to the continuous suture due to a lack of tension distribution from stitch to stitch [27,28,30]. An important causal aspect is the pathological increase in intra-abdominal pressure as a result of ileus, paralysis, peritonitis, or hematomas (31). Wound dehiscence is a complication in the early postoperative phase. Most authors attribute suture failure to the cutting of the threads through the fascial edge towards the incision [7,28,32]. Wound dehiscence can be treated by definitive closure of the abdominal wall or the primary placement of a pressure-relieving laparostomy with early elective abdominal wall closure [35,36].