Do we need long-term follow-up after EVAR and TEVAR or can we simplify surveillance protocols?

Endovascular repair is an increasingly preferred treatment modality for aortic pathology. Concerns regarding durability and postimplant complications have let to recommendations for rigorous surveillance regimens which are not entirely data-driven. Besides the costs of an excessive imaging follow-up protocol, deleterious effects may arise from repeated contrast administration and radiation exposure. Due to improvements in selection, planning and execution, coupled with technical improvements in devices, reported complications following endovascular repair have gradually decreased since the pivotal reports. Although late failure may be multifactorial and therefore not totally preventable with any surveillance regimen, patients may be stratified according to the expected risk (balanced by the potential benefit gained with surveillance) and be offered an individualized surveillance program. In this review, we aimed to describe current strategies for surveillance, modern outcomes after abdominal and thoracic endovascular repair, and proposed risk-adapted strategies for postoperative surveillance.

N-acetylcysteine prevents neointima formation in experimental venous bypass grafts

Background

Neointima formation, mainly characterized by smooth muscle cell proliferation, is an important cause of venous bypass graft failure. The therapeutic potential of the antioxidant N-acetylcysteine (NAC) to attenuate smooth muscle cell proliferation and neointima formation was examined in vivo. The effects of NAC on hyperoxia-induced venous smooth muscle cell (VSMC) cytokine production and proliferation were addressed in vitro.

Methods

Rats underwent autologous epigastric vein-to-femoral artery interposition grafting. Fourteen rats received oral NAC, and a similar control group received saline. Histomorphometric analysis was performed after 7 days or 3 weeks. Cytokine analysis and cell proliferation assay were performed in cultured human VSMCs after hyperoxic or normoxic exposure and NAC administration.

Results

NAC-treated rats displayed a threefold reduction in neointimal area, a sixfold reduction in stenosis rate, and a twofold reduction in VSMC proliferation after vein graft surgery. Incubation of VSMCs in 70 per cent oxygen stimulated the release of mitogenic inflammatory cytokines interleukin (IL) 6 and IL-8. Cytokine-rich medium from these VSMCs induced proliferation of normoxic VSMCs. NAC inhibited hyperoxia-induced cytokine release and VSMC proliferation.

Conclusion

NAC attenuated neointima formation and vein graft stenosis by reducing VSMC proliferation in vivo, and prevented hyperoxia-induced cytokine production and VSMC proliferation in vitro.

Effects of epoetin alfa on blood transfusions and postoperative recovery in orthopaedic surgery: the European Epoetin Alfa Surgery Trial (EEST)

BACKGROUND AND OBJECTIVE

Preoperative epoetin alfa administration decreases transfusion requirements and may reduce transfusion complications, such as postoperative infection due to immune suppression and thus hospitalization time. This study examined the impact of preoperative epoetin alfa administration on postoperative recovery and infection rate.

METHODS

In an open randomized controlled multicentre trial in patients undergoing orthopaedic surgery, the effects of preoperative administration of epoetin alfa vs. routine care were compared in six countries. Haemoglobin (Hb) values, transfusions, time to ambulation, time to discharge, infections and safety were evaluated in patients with preoperative Hb concentrations 10-13g dL(-1) (on-treatment population: epoetin n = 460; control n = 235), from study entry until 4-6 weeks after surgery. Outcome was also compared in patients with and without transfusion.

RESULTS

Epoetin-treated patients had higher Hb values from the day of surgery until discharge (P < 0.001) and lower transfusion rates (12% vs. 46%; P < 0.001). Epoetin treatment delivered no significant effect on postoperative recovery (time to ambulation, time to discharge and infection rate). However, the time to ambulation (3.8+/-4.0 vs. 3.1+/-2.2days; P < 0.001)and the time to discharge (12.9+/-6.4 vs. 10.2+/-5.0 days; P < 0.001) was longer in the transfused than in the non-transfused patients. Side-effects in both groups were comparable.

CONCLUSIONS

Epoetin alfa increases perioperative Hb concentration in mild-to-moderately anaemic patients and thus reduces transfusion requirements. Patients receiving blood transfusions require a longer hospitalization than non-transfused patients.