Mr Editor

Infection at the operating site (ISO) is the most common postoperative surgical complication in general surgery. This is more frequent in cases of emergency interventions, compromises the patient's prognosis, causes high health costs, and significantly increases the risk of reintervention. Negative pressure therapy (NPT) is an innovative strategy that was proposed about two decades ago, and has been gradually replicated around the world. This means that there are still many gaps in the evidence when it is used in many diseases and under different contexts. Nevertheless, it allows obtaining conclusive results in the time of healing, reduction of complications (mainly dehiscence and ISO), decrease in hospital stay, among other factors.

In Latin America, there is very little evidence on the use of this strategy, and it is null regarding its use in emergency cases without being able to determine its impact on our environment. Recently, Lakhani et al³conducted a meta-analysis of 7 studies with a total of 1199 patients, where they evaluated the ISO rate in patients undergoing emergency laparotomy in whom NPT was used (n=566) vs. control group (standard care, n=633). The NPT group had a lower infection rate (13.6% vs. 25.1%), with a 57-percentage point reduction in the probability of presenting ISO (OR 0.43; 95% CI: 0.30 - 0.62).

Additionally, the probability of dehiscence when using NPT was found to be 0.36 (7.7% vs. 16.9%; 95% CI: 0.19 - 0.72) times, compared to not using it. Also, the incidence of general complications was significantly lower in the NPT group (15.9% vs. 30.4%; OR 0.41; 95% CI: 0.28 - 0.59)³, unlike the outcomes of hospital stay and readmission. Authors conclude that using NPT is significantly associated with lower incidence of ISO, complications associated with ISO and dehiscence in emergency laparotomy³, therefore, it should be considered as prophylactic management. This may be the only meta-analysis to date that has evaluated these outcomes, although it included both prospective and retrospective studies.

Norman et al²updated in May 2022 the most recent version of the meta-analysis led by the Cochrane collaboration, on the use of TPN for healing surgical wounds by primary closure. And, although this scenario is completely different from emergency laparotomy, the meta-authors analyzed 68 randomized controlled trials with a total of 13,340 patients, where they found that of 6384 patients in whom mortality was reported, This was lower in the TPN group (0.84%) vs. standard care (1.17%), but with an imprecise estimate (RR 0.78; 95% CI: 0.47 - 1.30). However, the estimate found on the incidence of ISO was statistically significant and, in favor of the use of TPN (8.7% vs. 11.7%; RR 0.73; 95% CI 0.63 - 0.85), in a pool of 11,403 individuals². Regarding cost-effectiveness analyses, the evidence is very heterogeneous and imprecise, concentrating only in cases of caesarean sections in obese women, arthroplasty, repair of fractures of lower limbs, and vascular surgeries². Thus, the actual impact of the NPT on cost-effectiveness and cost-utility is not known.

Particularly in Latin America, some studies have been carried out, such as that of Lozano-Balderas et al⁴, who conducted a randomized controlled trial to evaluate the association between the use of TPN and ISO in 81 laparotomies with class III and IV contaminated surgical wounds undergoing primary, late primary and TPN closure. The incidence of ISO was found to be 0% in the TPN group, compared with 37% and 17%, for primary closure and late primary closure⁽⁴⁾. In Colombia, Ordoñez et al.⁵discussed the use of this therapy in damage control management, where they highlight the progress in wound management in laparotomies, but that there were still gaps such as the lack of primary data in that country⁵. This makes it difficult to reproduce this strategy in the Latin American context, where resources are limited and interventions supported by solid evidence must be used. However, in accordance with the objectives set by global surgery⁶, it is necessary to stimulate and support the development of therapeutic strategies that have a substantial and positive impact on disease indicators, quality of life and functional capacity of surgical patients.

Finally, although the evidence suggests that the usefulness of PND in emergency laparotomy is very clear, there are no Latin American studies that can corroborate the performance of this option, which should awaken the initiative of academic surgeons, with the approach of this research idea. If so, an instrument with the potential to modify protocols and algorithms in acute surgical care is very close, to favor the prognosis of these patients.