How Long Is Long Enough to Identify a Surgical Site Infection?

Ventral hernia repair using bioresorbable poly-4-hydroxybutyrate mesh in clean and contaminated surgical fields: a systematic review and meta-analysis

PURPOSE

Use of biologic or synthetic mesh in hernia repair shifts is based on evolving evidence. Poly-4-hydroxybutyrate (P4HB) biosynthetic mesh is a potential alternative to biologic and synthetic mesh in ventral hernia repair (VHR). This meta-analysis assesses the efficacy of P4HB mesh in clean and contaminated surgical settings.

METHODS

Two authors searched literature on PubMed, reviewing titles and abstracts of all articles to determine inclusion eligibility. Post-operative data were compared via transformation method to convert the proportion of patients with the outcome of interest into a suitable quantity for random-effects synthesis using STATA software.

RESULTS

Initial search yielded 287 citations. Six studies were included and categorized on whether hernia repairs were conducted in clean (CDC class I) or contaminated cases (CDC class II-IV). The pooled proportion of surgical site infection (SSI), surgical site occurrence (SSO), hernia recurrence, total surgical complications, and reoperation were calculated in 391 clean and 81 contaminated cases. For clean vs. contaminated cases, the following pooled proportions were noted: SSI (2% (CI 0-7%) vs 9% (CI 0-025) (p = 0.03), SSO: 14% (CI 5-25%) vs 35% (CI 22-50%) (p = 0.006), hernia recurrence (8% (CI 1-19%) vs 4% (CI 0-12%) (p = 0.769); surgical complications (17% (CI 6-32%) vs 50% (CI 27-72%) (p = 0.009). Reoperation data were available in 298 clean cases across four studies: 5% (CI 0-15%).

CONCLUSIONS

P4HB biosynthetic mesh may be more effective than previously thought, particularly in clean wounds. P4HB may also be superior to biologic mesh when compared to clinical trial data. Further research is necessary for more direct comparison.

Machine Learning Approaches for the Image-Based Identification of Surgical Wound Infections: Scoping Review

BACKGROUND

Surgical site infections (SSIs) occur frequently and impact patients and health care systems. Remote surveillance of surgical wounds is currently limited by the need for manual assessment by clinicians. Machine learning (ML)-based methods have recently been used to address various aspects of the postoperative wound healing process and may be used to improve the scalability and cost-effectiveness of remote surgical wound assessment.

OBJECTIVE

The objective of this review was to provide an overview of the ML methods that have been used to identify surgical wound infections from images.

METHODS

We conducted a scoping review of ML approaches for visual detection of SSIs following the JBI (Joanna Briggs Institute) methodology. Reports of participants in any postoperative context focusing on identification of surgical wound infections were included. Studies that did not address SSI identification, surgical wounds, or did not use image or video data were excluded. We searched MEDLINE, Embase, CINAHL, CENTRAL, Web of Science Core Collection, IEEE Xplore, Compendex, and arXiv for relevant studies in November 2022. The records retrieved were double screened for eligibility. A data extraction tool was used to chart the relevant data, which was described narratively and presented using tables. Employment of TRIPOD (Transparent Reporting of a Multivariable Prediction Model for Individual Prognosis or Diagnosis) guidelines was evaluated and PROBAST (Prediction Model Risk of Bias Assessment Tool) was used to assess risk of bias (RoB).

RESULTS

In total, 10 of the 715 unique records screened met the eligibility criteria. In these studies, the clinical contexts and surgical procedures were diverse. All papers developed diagnostic models, though none performed external validation. Both traditional ML and deep learning methods were used to identify SSIs from mostly color images, and the volume of images used ranged from under 50 to thousands. Further, 10 TRIPOD items were reported in at least 4 studies, though 15 items were reported in fewer than 4 studies. PROBAST assessment led to 9 studies being identified as having an overall high RoB, with 1 study having overall unclear RoB.

CONCLUSIONS

Research on the image-based identification of surgical wound infections using ML remains novel, and there is a need for standardized reporting. Limitations related to variability in image capture, model building, and data sources should be addressed in the future.

Risk Factors for Surgical Site Infections Following Fasciotomy in Patients With Acute Compartment Syndrome: A Study on the February 2023 Kahramanmaraş Earthquake

INTRODUCTION

Surgical site infections (SSIs) developing after fasciotomy are difficult to treat, costly, and an important source of mortality and morbidity. This study aimed to determine the risk factors affecting the development of SSI in patients who underwent fasciotomy with the diagnosis of acute compartment syndrome (ACS) within 72 hours after two consecutive earthquakes of 7.7 and 7.6 magnitude that occurred in Kahramanmaraş on February 6, 2023.

METHOD

A total of 116 patients were retrospectively analyzed. Patients were divided into two groups: those who developed SSI and those who did not. In this study, variables such as basic demographic characteristics, time of fasciotomy, center performing fasciotomy, type of wound closure, affected extremity, concomitant renal failure, hyperbaric oxygen (HBO) therapy, blood creatine kinase (CK) level were examined.

RESULTS

Of 116 patients, 58 (50%) had SSI. It was statistically observed that patients who underwent treatment with vacuum-assisted closure (VAC), those who underwent primary closure with the shoelace method, those who went into renal failure, and those whose fasciotomy was performed in an earthquake zone had a higher incidence of SSI (p<0.001). Blood CK level above 17.839 seemed to be a risk factor according to receiver operating characteristic (ROC) analysis (P<0.01). Age (p=0.193), gender (p=0.125), fasciotomy time (p=0.843), lower extremity (p=0.234), upper extremity (p=0.806), and HBO treatment (p=0.56) were not associated with SSI. Infection was found to be a significant risk factor for amputation (p<0.001).

CONCLUSION

The use of VAC as a wound closure technique for SSI after fasciotomy in patients who developed ACS due to the earthquake, the presence of renal failure in the patients, and performing fasciotomy in the earthquake zone were independent risk factors. A blood CK level above 17.839 was also determined as a risk factor, but the confidence interval was found to be low.

At least ninety days of follow-up are required to adequately detect wound outcomes after open incisional hernia repair

INTRODUCTION

Incisional hernia repair (IHR) carries a high risk of wound complications. Thirty-day outcomes are frequently used in comparative-effectiveness research, but may miss a substantial number of surgical site occurrences (SSO) including surgical site infection (SSI). The objective of this study was to determine an optimal length of follow-up to detect SSI after IHR.

METHODS

All adult patients undergoing open IHR at a single academic center over a 3 year period were reviewed. SSIs, non-infectious SSOs, and wound-related readmissions were recorded up to 180 days. The primary outcome was the proportion of SSIs detected at end-points of 30, 60, and 90 days of follow-up. Time-to-event analysis was performed for all outcomes at 30, 60, 90, and 180 days. Logistic regression was used estimate the relative risk of SSI for relevant risk factors.

RESULTS

A total of 234 patients underwent open IHR. Median follow-up time of 102 days. Overall incidence of SSI was 15.8% with median time to occurrence of 23 days. Incidence of non-infectious SSO was 33.2%, and SSO-related readmission was 12.8%. At 30, 60, and 90 days sensitivity was 81.6%, 89.5%, and 92.1 for SSI, and 46.7%, 76.7%, and 83.3% for readmission. In regression analysis, body mass index (RR 1.08, 95% CI 1.00, 1.15, p = 0.04) anterior component separation (RR 4.21, 95% CI 2.09, 6.34, p = 0.003), and emergency surgery (RR 3.25, 95% CI 1.47, 5.02, p = 0.01), were independently associated with SSI after adjusting for age, sex, contamination class, and procedure duration.

CONCLUSION

A considerable proportion of SSIs occurred beyond 30 days, but 90-day follow-up detected 92% of SSIs. Follow-up to 90 days captured only 83% of SSO-related readmissions. These results have implications for the design of trials evaluating wound complication after open IHR, as early endpoints may miss clinically relevant outcomes and underestimate the number needed to treat. Where possible, we recommend a minimum follow-up of 90 days to estimate wound complications following open IHR.

Hand port-site infection after hand-assisted laparoscopic donor nephrectomy for living-donor kidney transplantation: a retrospective cohort study

Background

Hand-assisted laparoscopic donor nephrectomy (HALDN) is widely performed to minimize burden on living kidney donors. However, hand port-site infections after HALDN may occur. This study aimed to assess the impact of donor characteristics including preoperative comorbidities and operative factors on hand port-site infection after HALDN.

Methods

In this single-center, retrospective cohort study, 1,260 consecutive HALDNs for living-donor kidney transplantation performed between January 2008 and December 2021 were evaluated. All living donors met the living kidney donor guidelines in Japan. Hand port-site infections were identified in 88 HALDN cases (7.0%). To investigate risk factors for hand port-site infection, donor characteristics including preoperative comorbidities such as hypertension, glucose intolerance, dyslipidemia, obesity, and operative factors such as operative duration, blood loss, preoperative antibiotic prophylaxis, and prophylactic subcutaneous suction drain placement at the hand port-site were analyzed using logistic regression analysis.

Results

In the multivariate analysis, significant differences were identified regarding sex (P = 0.021; odds ratio [OR], 1.971; 95% confidence interval [CI], 1.108-3.507), preoperative antibiotic prophylaxis (P < 0.001; OR, 0.037; 95% CI [0.011-0.127]), and prophylactic subcutaneous suction drain placement at the hand port-site (P = 0.041; OR, 2.005; 95% CI [1.029-3.907]). However, a significant difference was not identified regarding glucose intolerance (P = 0.572; OR, 1.148; 95% CI [0.711-1.856]). Preoperative comorbidities may not cause hand port-site infections within the donors who meet the living kidney donor guidelines. Preoperative antibiotic prophylaxis is crucial in preventing hand port-site infection, whereas prophylactic subcutaneous suction drain placement may increase the risk of hand port-site infection.

Surgical site complications in kidney transplant recipients: incidence, risk factors and outcomes in the modern era

BACKGROUND

Surgical site complications (SSCs) are an important source of morbidity after kidney transplantation. We assessed the incidence, risk factors, outcomes and economic impact of SSCs in a large, diverse population of kidney transplant recipients.

METHODS

We conducted a single-centre, observational cohort study of adult (age ≥ 18 yr) patients who underwent kidney transplantation between Jan. 1, 2005, and Dec. 31, 2015, with a minimum of 1 year of follow-up. Cases of SSC, including infections and wound dehiscence, were determined from patient records. Inpatient and outpatient hospital costs were determined 6 and 12 months after transplantation. We used the Kaplan-Meier product-limit method to determine the cumulative probability of SSCs and other outcomes. We evaluated risk factors and clinical outcomes using Cox proportional hazard ratios. Linear regression models were used to study the effect of SSCs on graft function.

RESULTS

The incidence rate of SSCs within 30 days after transplantation was 4.19 per 100 person-months. The cumulative probability of developing an SSC within 30 days after transplantation was 4.13% (95% confidence interval [CI] 3.23%-5.28%). Increased recipient body mass index (BMI) (hazard ratio [HR] 1.07, 95% CI 1.02-1.11), longer cold ischemic time (HR 1.05, 95% CI 1.01-1.09) and transplantation in 2010-2012 versus 2005-2009 (HR 2.20, 95% CI 1.19-4.04) were risk factors for SSC development. In multivariable stepwise Cox proportional hazard models, SSC was a significant risk factor for death-censored graft failure (HR 3.08, 95% CI 1.60-5.90) and total graft failure (HR 2.09, 95% CI 1.32-3.32). Cumulative median hospital costs were $2238.46 greater for patients with an SSC than for those without.

CONCLUSION

Increased BMI, longer cold ischemic time and the 2010-2012 transplantation period predisposed to SSCs. The development of SSCs was associated with a higher risk of graft failure. Strategies to minimize SSCs may improve outcomes after kidney transplantation and reduce costs.

Factors associated with 30-day soft tissue complications following upper extremity sarcoma surgery

BACKGROUND AND OBJECTIVES

The incidence of soft tissue complications following sarcoma surgery in the upper extremity is reportedly high. Therefore, this study assessed the National Surgical Quality Improvement Program (NSQIP) database to identify independent risk factors, while also reporting the incidence of soft tissue complications in the first 30 days after surgery.

METHODS

A total of 620 patients that underwent surgical treatment for upper extremity sarcoma were included from the NSQIP database. Soft tissue complications were defined as surgical site infection, wound dehiscence, or soft-tissue related reoperations. Clinically relevant patient and treatment characteristics were selected and analyzed.

RESULTS

The 30-day soft tissue complication rate was 4.7%. In the multivariable analysis, higher body mass index (p = .047) and longer operative times (p = .002) were independently associated with soft tissue complications.

CONCLUSIONS

Higher body mass index and longer operative times are risk factors for soft tissue complications following upper extremity sarcoma surgery. The soft-tissue complication rate following resection of upper extremity tumors is low in this national cohort, possibly due to the relatively small tumor size and low prevalence of radiotherapy.

Risk Factors for Surgical Site Infection After Laparoscopic Colectomy: An NSQIP Database Analysis

BACKGROUND

Surgical site infection (SSI) is a common complication after colon surgery. This study aimed to evaluate risk factors for SSI and its types in laparoscopic colectomy patients using the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) database.

MATERIALS AND METHODS

The NSQIP database was queried for patients undergoing laparoscopic colectomy from 2011 through 2017. Univariate analysis and multivariable logistic regression were used to evaluate risk factors associated with any SSI, superficial SSI, deep-incisional SSI, and organ-space SSI.

RESULTS

Of 72,519 patients, 4906 cases of SSI were identified: 2276 superficial SSI, 357 deep-incisional SSI, and 2483 organ-space SSI. Risk factors associated with superficial SSI were admission before procedure (adjusted odds ratio [AOR] = 1.31; 95% confidence interval [CI] 1.17-1.47; P < 0.01), smoking (AOR = 1.29; 95% CI 1.16-1.44; P < 0.01), and higher body mass index (AOR = 1.24 for every 5 kg/m² increase; 95% CI 1.20-1.27; P < 0.01). Deep-incisional SSI was associated with steroid use (AOR = 1.81; 95% CI 1.31-2.49; P < 0.01), admission before procedure (AOR = 1.66; 95% CI 1.30-2.13; P < 0.01), and smoking (AOR = 1.50; 95% CI 1.17-1.94; P < 0.01). Risk factors associated with organ-space SSI were wound class (AOR = 2.45 for class 4 versus ≤ 2; 95% CI 2.16-2.78; P < 0.01), chemotherapy within 90 d (AOR = 1.57; 95% CI 1.33-1.84; P < 0.01), and steroid use (AOR = 1.46; 95% CI 1.29-1.65; P < 0.01). Receipt of an oral antibiotic prep preoperatively was the strongest factor associated with SSI.

CONCLUSIONS

SSI types in patients undergoing laparoscopic colectomy have different risk factors. Modifiable risk factors may provide an opportunity to reduce SSI risk and its associated morbidity.

Patient-Directed Active Surgical Incisions Surveillance May Lead to Further Surgical Site Infection Reduction

Background: Surgical site infections have been a concern for many years, and decades-old articles demonstrate the benefit of surveillance and reporting of these infections with resulting decrease in incidence. Comprehensive surveillance is difficult and often incomplete and is hampered when patients must travel a distance for surgical care. In recent years there has been increasing interest in patient-generated health data (PGHD) that includes patients taking photographs of their surgical incisions. Methods: A selective review of articles on PGHD and photographic images was undertaken in combination with interviews of investigators in this field. Results: There is a possibility that a well-developed system to facilitate patient-provided images of the surgical incision to surgical care providers in a Health Insurance Portability and Accountability Act (HIPAA)-compliant manner could improve surgical surveillance and reduce unnecessary post-operative visits. Conclusions: Further study is required.

Systematic review of transversus abdominis release in complex abdominal wall reconstruction

BACKGROUND

Transversus abdominis release (TAR), as a type of posterior component separation, is a new myofascial release technique in complex ventral hernia repair. TAR preserves rectus muscle innervation, creates an immense retromuscular plane and allows bilaminar ingrowth of the mesh. The place of the TAR within the range of established anterior component separation techniques (CST) is unclear. Aim of this systematic literature review is to estimate the position of the TAR in the scope of ventral hernia repair techniques.

METHODS

MEDLINE, Embase, Pubmed and the Cochrane controlled trials register and Science citation index were searched using the following terms: 'posterior component separation', 'transversus abdominis release', 'ventral hernia repair', 'complex abdominal wall reconstruction'. To prevent duplication bias, only studies with a unique cohort of patients who underwent transversus abdominis release for complex abdominal wall reconstruction were eligible. Postoperative complications and recurrences had to be registered adequately. The rate of surgical site occurrences and recurrences of the TAR were compared with those after anterior CST, published earlier in two meta-analyses.

RESULTS

Five articles met our strict inclusion criteria, describing 646 TAR patients. Methodological quality per study was good. Mean hernia surface was 509 cm² and 88% of the hernias were located in the midline. Preoperative risk stratification was distributed in low risk (10%), co-morbid (55%), potentially contaminated (32%) and infected (3%). Pooled calculations demonstrated a mean SSO rate of 15% after TAR (20-35% after anterior CST) and a mean 2-year hernia recurrence rate of 4% (13% after anterior CST). Mean hernia surface was 300 cm² in anterior component separation studies.

CONCLUSION

This review demonstrates that the transversus abdominis release is a good alternative for anterior CST in terms of SSO and recurrence, especially in very large midline ventral hernias.

Laparoscopic ventral hernia repair using only 5-mm ports

BACKGROUND

The technique of laparoscopic ventral hernia repair has been evolving since it was first described over 20 years ago. We report a new technique where polyester mesh was back loaded through a 5-mm port site, coming into contact with the skin. This avoids the need for any 10-12-mm ports.

METHODS

A prospective database of laparoscopic ventral hernia repairs was examined. A single surgeon performed 344 laparoscopic ventral hernia repairs using this technique over 60 months. Follow-up was conducted by both clinical and independent phone review.

SURGICAL TECHNIQUE

Laparoscopic access was achieved via a 5-mm optical port, adding two, or occasionally three, 5-mm extra ports. Hernia contents were reduced and the extra-peritoneal fat excised; 5-mm tooth graspers were placed through the lateral port and then in a retrograde fashion through the uppermost port. The port was removed, and the mesh pulled back into the abdominal cavity and positioned with a minimum of 3-cm overlap. The mesh was fixed using absorbable tacks and sutures.

RESULTS

Most patients had primary umbilical hernias. There was one case of mesh infection due to enteric organisms. This occurred in a patient undergoing repair of a stoma site hernia, resulting from a Hartmann's procedure for perforated diverticulitis. There was no other evidence of acute or chronic mesh infection despite cutaneous contact with the mesh. In this series, there was an overall hernia recurrence rate of 2.4%.

CONCLUSION

Laparoscopic ventral hernia repair using only 5-mm ports is a safe, effective technique with no extra risk of infection.