The impact of minimally invasive surgical approaches on surgical-site infections

Abstract

We performed a literature review to describe the risk of surgical-site infection (SSI) in minimally invasive surgery (MIS) compared to standard open surgery. Most studies reported decreased SSI rates among patients undergoing MIS compared to open procedures. However, many were observational studies and may have been affected by selection bias. MIS is associated with reduced risk of surgical-site infection compared to standard open surgery and should be considered when feasible.

Surgical-site infections (SSIs), defined as infections affecting the incision site or the deep tissue of the operative site, ¹ occur in 0.5%–3% of patients undergoing inpatient surgery. ^2–4 Overall, 21,186 SSIs were reported to the Center for Disease Control and Prevention’s National Healthcare Safety Network in 2021. ³ SSIs contribute to increased length of stay; each SSI associated with up to 11 additional hospital days ⁵ SSIs also contribute to increased mortality, with a 2- to 11-fold increase in risk of death among surgical patients with an SSI compared to those without an SSI. ^6,7 Additionally, SSIs are estimated to contribute $3.5–10 billion annually in healthcare costs. ⁸

Risk factors for SSI can be divided into intrinsic patient-related factors and procedure-related factors. ⁹ Up to 60% of SSIs are estimated to be preventable using evidence-based guidelines. ^10,11 Surgical approach may also affect the risk of SSI, and minimally invasive surgery (MIS) potentially decreases risk. The MIS technique entails the use of laparoscopic and/or robotic techniques to perform surgical procedures while avoiding the morbidity of conventional open surgical wounds. ¹² MIS is thought to reduce the risk of SSI due to smaller incisions, less retraction of the surgical site, and less local soft-tissue trauma. ¹³ We undertook a literature review to describe the risk of SSI in MIS compared to open surgery because a comprehensive review has not been published.

Methods

We searched the Medline database on June 9, 2023, for studies published in English and completed in the last 20 years that reported the incidence of SSI in patients undergoing MIS compared to open surgery. Search terms used included “minimally invasive surgery,” “laparoscopic surgery,” “robotic surgery,” “endoscopic surgery,” and “surgical site infection.” Studies were excluded if they lacked a control group of patients undergoing open surgery or if they were published prior to June 9, 2003.

Results

Our findings are summarized in Table 1. In total, 25 studies were identified, including randomized controlled trials, prospective cohort studies, and retrospective analyses of pre-existing clinical databases. ^13–37 A wide range of patient populations were studied, including infants, adults, and age-mixed populations. Orthopedic, abdominal, pelvic, and spinal surgeries were included, as were both elective and emergent procedures. Most studies compared laparoscopic surgeries to open surgeries; however, 4 included robotic approaches in their analyses. ^14,24,28,34 Moreover, 21 studies (84%) showed statistically significant decreases in the rate of SSI among patients undergoing MIS compared with open procedures. In addition, MIS was associated with decreased length of hospital stay in multiple studies. One study found decreased 30-day mortality among patients undergoing MIS for emergent indications as opposed to those who underwent open surgery. ²¹ Another study showed decreased hospital readmission rates among patients with septic arthritis undergoing arthroscopy compared to open arthrotomy. ¹⁸

Table 1. Summary of Studies Assessing Impact of Minimally Invasive Surgery on Frequency of Surgical-Site Infections

Note. OR, odds ratio; SSI, surgical site infections; MIS, minimally invasive surgery; LOS, length of stay; AS, arthroscopic surgery; LS, laparoscopic surgery; RS, robotic surgery; NS, not specified.

Discussion

In this literature review, we found that MIS is associated with decreased rates of SSI across many different surgical procedures and among a wide variety of patient populations. SSIs are serious healthcare-associated infections with a high burden of morbidity and mortality, as well as a substantial financial cost. ⁹ Numerous patient and procedural risk factors have been associated with increased risk of SSI among patients undergoing surgery, with the SHEA SSI Prevention Guideline recommending corresponding antimicrobial and procedural interventions to reduce these risks. ⁹ This guideline noted that MIS procedures may be associated with a lower risk of infection but called for additional data to guide further recommendations.

MIS procedures are distinguished from open procedures by method of access, method of exposure, and extent of operative trauma. ¹⁶ Patients undergoing MIS procedures are thought to have a decreased risk for SSI compared to those undergoing open procedures due to smaller surgical incisions, decreased tissue trauma and contamination, and elimination of surgical retraction. ¹⁶ Furthermore, SSIs occurring after MIS may be less severe given a smaller surgical site leading to a smaller affected anatomic area. Compared to those undergoing open surgeries, patients undergoing MIS experience less local tissue trauma, less systemic stress, decreased impairment of immediate postoperative pulmonary function, and improved immunologic response, all of which contribute to improved outcomes. ^38–42

However, the benefits of MIS may be overstated given several potential sources of bias. First, sicker patients or those undergoing more complex surgical procedures may be more likely to undergo open surgery instead of MIS ⁴³ ; therefore, there may be a selection bias for patients who are healthier at baseline and those with less complex surgical needs to be more likely to undergo MIS compared to open surgery. Randomized controlled trials (RCTs) minimize the impact of confounding factors; however, in this literature review, we only identified 4 RCTs, with mixed results and relatively small sample sizes. Additional well-designed RCTs are warranted for further investigation into the relationship between surgical approach and risk of SSI. Notably, many of the studies identified were retrospective, and therefore prone to selection and recall bias. Second, because performing MIS requires additional, specialized training on the part of surgeons, improved outcomes in MIS may be partly due to improved technical expertise and experience among surgeons performing MIS compared to those performing open surgical procedures. Finally, MIS procedures may be more likely to occur at more highly resourced referral centers, which may have more SSI prevention interventions in place than smaller, community centers.

In conclusion, MIS has many advantages over open surgery, including decreased risk of SSIs in addition to improved cosmesis, decreased pain, and shorter hospital length of stay. ⁴³ As a result, MIS may contribute to decreased morbidity, mortality, and costs compared to open surgery. However, the projected benefits may be due in part to a bias for healthier or less surgically complex patients to be more likely to be selected for MIS instead of open surgery. MIS may not be appropriate for all patients or all procedures, but should be considered, when feasible, to reduce the risk of SSI.