A systematic review and meta-analysis of donor ischaemic preconditioning in liver transplantation.

Ischaemic preconditioning (IPC) is a strategy to reduce ischaemia-reperfusion (IR) injury. Its benefit in human liver transplantation is unclear. The aim of this study was to analyse the current evidence for donor IPC in liver transplantation. Systematic review and meta-analysis of studies involving IPC of liver transplant donors. Ovid Medline, Embase and Cochrane CENTRAL were searched up until January 2015. Data retrieved included the primary outcomes of 1-year mortality, incidence of primary graft non-function (PGNF) and retransplantation. Secondary outcomes included aspartate aminotransferase (AST) levels on day 3 post-op. Pooled odds ratios (ORs) were calculated for dichotomous data and mean weighted ratios for continuous data. Ten studies included 593 patients (286 IPC; 307 control). IPC was associated with a reduction in mortality at 1 year (6% vs. 11%) although this was not statistically significant (OR 0.54, 95% C.I. 0.28-1.04, P = 0.06). The IPC group had a significantly lower day 3 AST level (WMD -66.41iU, P = 0.04). This meta-analysis demonstrates that IPC reduces liver injury following transplantation and produces a large reduction in 1-year mortality which was not statistically significant. Confirmation of clinical benefit from IPC requires an adequately powered prospective RCT.

Impact of post mastectomy radiotherapy on the silicone breast implant.

Implant based reconstruction accounts for over half of breast reconstruction performed in the UK. Patients with implant based breast reconstructions undergoing post mastectomy radiotherapy are at increased risk of capsular contracture and reconstructive failure. This study sought to determine the effect of treatment dose radiotherapy on the bulk mechanical, surface chemical properties of silicone implants as well as their cellular response. Silicone breast implant shells were submitted to treatment dose radiotherapy, 2.67 Gy (one daily fraction) and 40.05 Gy (15 fractions) using non-irradiated shells as controls. Bulk mechanical and surface chemical properties of the shells were evaluated using tensile and tear testing, attenuated total reflectance - fourier transform infrared spectroscopy (ATR-FTIR), water contact angle measurements. HDFa cells were seeded on the shells and Alamar Blue assay was performed to study cell metabolic activity. Cell morphology was evaluated using phalloidin and DAPI staining. There was no significant difference in tensile, tear strength and Young's modulus however there was reduction in maximum elongation following irradiation. Irradiation of the shells did not significant alter spectroscopy measurements nor wettability of the shells. Cell metabolism was not significantly affected by irradiation. Further analysis is warranted of the micromechanical properties to fully elucidate the effect of irradiation on the breast implant which could explain the increased rate of capsular contracture and reconstructive failure in patients undergoing post-mastectomy radiotherapy.

Mechanical and surface chemical analysis of retrieved breast implants from a single centre.

INTRODUCTION: Breast implants are associated with complications such as capsular contracture, implant rupture and leakage often necessitating further corrective surgery. Re-operation rates have been reported to occur in up to 15.4% of primary augmentation patients and up to 27% in primary reconstructions patients within the first three years (Cunningham, 2007). The aim of this study was to examine the mechanical and surface chemical properties as well as the fibroblast response of retrieved breast implants in our unit to determine the in vivo changes which occur over time. METHODS: Ethical approval was obtained. 47 implants were retrieved. Implantation time ranged from 1 month to 388 months (Mean 106.1 months). Tensile strength, elongation, Young's modulus and tear strength properties were measured using Instron 5565 tensiometer on anterior and posterior aspects of the implant. Attenuated total reflectance-fourier transform infra-red spectroscopy (ATR-FTIR), wettability and scanning electron microscopy (SEM) analysis was performed on the shell surfaces. Bicinchoninic acid assay was performed to determine shell protein content. The fibroblast response was determined by seeding HDFa cells on the retrieved implants and cell metabolism measured using Alamar Blue™ assay. RESULTS: Mechanical properties fall with increasing duration of implantation. There were no significant changes in ATR-FTIR spectra between ruptured and intact implants nor significant changes in wettability in implants grouped into 5 year categories. SEM imaging reveals surface degradation changes with increasing duration of implantation. CONCLUSIONS: With increasing duration of implantation, mechanical properties of the breast implants fall. However this was not associated with surface chemical changes as determined by ATR-FTIR and wettability nor protein content of the shells. Thus the reduction in mechanical properties is associated with breast implant failure but further research is required to elucidate the mechanisms.

Determining the outcomes of post-mastectomy radiation therapy delivered to the definitive implant in patients undergoing one- and two-stage implant-based breast reconstruction: A systematic review and meta-analysis.

BACKGROUND: Post-mastectomy radiation therapy (PMRT) is known to increase the complication rate and implant loss in implant-based breast reconstruction. The purpose of this study was to systematically review the literature regarding the outcome of PMRT delivered to the permanent/definitive implant. METHODS: Systematic review and meta-analysis of studies involving immediate implant-based reconstruction and PMRT when delivered to the permanent implant. RESULTS: Seven studies included 2921 patients (520 PMRT, 2401 control). PMRT was associated with significant increase in capsular contracture (7 studies, 2529 patients, 494 PMRT, 2035 control, OR 10.21, 95% CI 3.74 to 27.89, p < 0.00001). In addition, PMRT was associated with a significant increase in revisional surgery (7 studies, 2921 patients, 520 PMRT, 2401 control, OR 2.18, 95% CI 1.33 to 3.57, p = 0.002) and reconstructive failure (6 studies, 2814 patients, 496 PMRT, 2318 control, OR 2.52, 95% CI 1.48 to 4.29, p+0.0007). Moreover, it was associated with a significant reduction in patient satisfaction (4 studies, 468 patients, 138 PMRT, 294 control, OR 0.29, 95% CI 0.15 to 0.57, p = 0.0003) and cosmetic outcome (4 studies, 1317 patients, 238 PMRT, 1009 control, OR 28, 95% CI. 0.11 to 0.67, p = 0.005). CONCLUSIONS: This meta-analysis demonstrates that within the first 5 years, post implant-based reconstruction for those patients who receive PMRT, the rates of adverse events are increased, and there is a significant reduction in patient satisfaction and cosmetic outcome.