Elastic TPU Mesh as Abdominal Wall Inlay Significantly Reduces Defect Size in a Minipig Model

Background: The open abdomen with mesh implantation, followed by early reoperation with fascial closure, is a modern surgical approach in difficult clinical situations such as severe abdominal sepsis. As early fascial closure is not possible in many cases, mesh-mediated fascial traction is helpful for conditioning of a minimized ventral hernia after open abdomen. The aim of this study was to evaluate the clinical utilization of an innovative elastic thermoplastic polyurethane mesh (TPU) as an abdominal wall inlay in a minipig model. Methods: Ten minipigs were divided in two groups, either receiving an elastic TPU mesh or a nonelastic polyvinylidene fluoride (PVDF) mesh in inlay position of the abdominal wall. After 8 weeks, mesh expansion and abdominal wall defect size were measured. Finally, pigs were euthanized and abdominal walls were explanted for histological and immunohistochemical assessment. Results: Eight weeks after abdominal wall replacement, transversal diameter of the fascial defect in the TPU group was significantly smaller than in the PVDF group (4.5 cm vs. 7.4 cm; p = 0.047). Immunhistochemical analysis showed increased Ki67 positive cells (p = 0.003) and a higher number of apoptotic cells (p = 0.047) after abdominal wall replacement with a TPU mesh. Collagen type I/III ratio was increased in the PVDF group (p = 0.011). Conclusion: Implantation of an elastic TPU mesh as abdominal wall inlay is a promising approach to reduce the size of the ventral hernia after open abdomen by mesh-mediated traction. However, this effect was associated with a slightly increased foreign body reaction in comparison to the nonelastic PVDF.

Treatments and other prognostic factors in the management of the open abdomen: A systematic review

BACKGROUND

The open abdomen (OA) is an important approach for managing intra-abdominal catastrophes and continues to be the standard of care. Despite this, challenges remain with it associated with a high incidence of complications and poor outcomes. The objective of this article is to perform a systematic review in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines to identify prognostic factors in OA patients in regard to definitive fascial closure (DFC), mortality and intra-abdominal complications.

METHODS

An electronic database search was conducted involving Medline, Excerpta Medica, Central Register of Controlled Trials, Cumulative Index to Nursing, and Allied Health Literature and Clinicaltrials.gov. All studies that described prognostic factors in regard to the above outcomes in OA patients were eligible for inclusion. Data collected were synthesized by each outcome of interest and assessed for methodological quality.

RESULTS

Thirty-one studies were included in the final synthesis. Enteral nutrition, organ dysfunction, local and systemic infection, number of reexplorations, worsening Injury Severity Score, and the development of a fistula appeared to significantly delay DFC. Age and Adult Physiology And Chronic Health Evaluation version II score were predictors for in-hospital mortality. Failed DFC, large bowel resection and >5 to 10 L of intravenous fluids in <48 hours were predictors of enteroatmospheric fistula. The source of infection (small bowel as opposed to colon) was a predictor for ventral hernia. Large bowel resection, >5 to 10 and >10 L of intravenous fluids in <48 hours were predictors of intra-abdominal abscess. Fascial closure on (or after) day 5 and having a bowel anastomosis were predictors for anastomotic leak. Overall methodological quality was of a moderate level.

LIMITATIONS

Overall methodological quality, high number of retrospective studies, low reporting of prognostic factors and the multitude of factors potentially affecting patient outcome that were not analyzed.

CONCLUSION

Careful selection and management of OA patients will avoid prolonged treatment and facilitate early DFC. Future research should focus on the development of a prognostic model.

LEVEL OF EVIDENCE

Systematic review, level III.

Bedside dressing changes for open abdomen in the intensive care unit is safe and time and staff efficient

Background

Patients with an open abdomen (OA) treated with temporary abdominal closure (TAC) need multiple surgical procedures throughout the hospital stay with repeated changes of the vacuum-assisted closure device (VAC changes). The aim of this study was to examine if using the intensive care unit (ICU) for dressing changes in OA patients was safe regarding bloodstream infections (BSI) and survival. Secondary aims were to evaluate saved time, personnel, and costs.

Methods

All patients treated with OA in the ICU from October 2006 to June 2014 were included. Data were retrospectively obtained from registered procedure codes, clinical and administrative patients’ records and the OR, ICU, anesthesia and microbiology databases. Outcomes were 30-, 60- and 90-day survival, BSI, time used and saved personnel costs.

Results

A total of 113 patients underwent 960 surgical procedures including 443 VAC changes as a single procedure, of which 165 (37 %) were performed in the ICU. Nine patients died before the first scheduled dressing change and six patients were closed at the first scheduled surgery after established OA, leaving 98 patients for further analysis. The mean duration for the surgical team performing a VAC change in the ICU was 63.4 (60.4–66.4) minutes and in the OR 98.2 (94.6–101.8) minutes (p < 0.001). The mean duration for the anesthesia team in the OR was 115.5 minutes, while this team was not used in the ICU. Personnel costs were reduced by €682 per procedure when using the ICU. Forty-two patients had all the VAC changes done in the OR (VAC-OR), 22 in the ICU (VAC-ICU) and 34 in both OR and ICU (VAC-OR/ICU). BSI was diagnosed in eight (19 %) of the VAC-OR patients, seven (32 %) of the VAC-ICU and eight (24 %) of the VAC-OR/ICU (p = 0.509). Thirty-five patients (83 %) survived 30 days in the VAC-OR group, 17 in the VAC-ICU group (77 %) and 28 (82 %) in the VAC-OR/ICU group (p = 0.844).

Conclusions

VAC change for OA in the ICU saved time for the OR team and the anesthesia team compared to using the OR, and it reduced personnel costs. Importantly, the use of ICU for OA dressing change seemed to be as safe as using the OR.

Uninsured status may be more predictive of outcomes among the severely injured than minority race

AIM

Worse outcomes in trauma in the United States have been reported for both the uninsured and minority race. We sought to determine whether disparities would persist among severely injured patients treated at trauma centres where standard triage trauma protocols limit bias from health systems and providers.

METHODS

We performed a retrospective analysis of the 2010-2012 National Sample Program from the National Trauma Databank, which is a nationally representative sample of trauma centre performance in the United States. The database was screened for adults ages 18-64 who had a known insurance status. Outcomes measured were in-hospital mortality and post-hospital care.

RESULTS

There were 739,149 injured patients included in the analysis. Twenty-eight percent were uninsured, and 34 percent were of minority race. In the adjusted analysis, uninsured status (OR 1.60, 1.29-1.98, p<0.001) and black race (OR 1.24, 1.04-1.49, p=0.019) were significant predictors of mortality. Only uninsured status was a significant negative predictor of post-hospital care (OR 0.43, 0.36-0.51, p<0.001). As injury severity increased, only insurance status was a significant predictor of both increased mortality (OR 1.68, 1.29-2.19, p<0.001) and decreased post-hospital care (OR 0.45, 0.32-0.63, p<0.001).

CONCLUSION

Uninsured status is independently associated with higher in-hospital mortality and decreased post-hospital care in patients with severe injuries in a nationally representative sample of trauma centres in the United States. Increased in-hospital mortality is likely due to endogenous patient factors while decreased post-hospital care is likely due to economic constraints. Minority race is less of a factor influencing disparate outcomes among the severely injured.