Late Survival in Nonoperated Patients with Infrarenal Abdominal Aortic Aneurysm

OBJECTIVE/BACKGROUND

Historical studies report high rupture rates in patients with nonoperated abdominal aortic aneurysms (AAAs) of > 5.5 cm diameter, although a recent audit has questioned this.

METHODS

This was a retrospective review of 138/764 (18%) patients with AAAs evaluated in a preassessment anaesthetic clinic (PAC) between 2006 and 2012, who either did not undergo elective AAA repair or who underwent deferred repair. The remaining 626 underwent repair. Patients with severe comorbidities (dementia, advanced malignancy, life-expectancy < 1 year) and not referred to PAC were excluded.

RESULTS

At a median of 27 months, 71 (52%) died, 36 (51%) following rupture. Cumulative survival, free from rupture or surgery for acute symptoms, was 96% at 1 year, 84% at 3 years, and 64% at 5 years, where baseline AAA diameters were 5.5-6.9 cm. For diameters ≥ 7 cm, survival, free from rupture, was 65% at 1 year, 29% at 3 years, and 0% at 5 years. Median interval to rupture was 47 months (AAA diameter 5.5-6.9 cm) and 21 months where baseline diameters were ≥ 7 cm. Rupture accounted for 32% of late deaths in patients with AAAs of 5.5-5.9 cm diameter, 46% in those with AAAs measuring 6.0-6.9 cm in diameter, and 71% in patients with AAA measuring ≥ 7 cm in diameter.

CONCLUSION

Approximately half of all late deaths in this nonoperated cohort were not AAA related, suggesting that even had repair been undertaken, it would not have prolonged patient survival. The incidence of rupture in "high-risk" patients with an AAA < 7 cm diameter was < 5% at 1 year, thereby giving ample time to optimise risk factors and improve pre-existing medical conditions prior to undertaking a deferred intervention. Even if these patients did not undergo surgical repair, the risk of late rupture was relatively low. By contrast, nonoperated patients with AAAs ≥ 7 cm in diameter face a very high risk of rupture and will probably benefit from elective surgery, with the caveat that a higher procedural risk might have to be incurred.

Simulation as a tool to improve the safety of pre-hospital anaesthesia--a pilot study

We conducted a pilot study of the effects of simulation as a tool for teaching doctor-paramedic teams to deliver pre-hospital anaesthesia safely. Participants undertook a course including 43 full immersion, high-fidelity simulations. Twenty videos taken from day 4 and days 9/10 of the course were reviewed by a panel of experienced pre-hospital practitioners. Participants' performance at the beginning and the end of the course was compared. The total time from arrival to inflation of the tracheal tube cuff was longer on days 9/10 than on day 4 (mean (SD) 14 min 52 s (2 min 6 s) vs 11 min 28 s (1 min 54 s), respectively; p = 0.005), while the number of safety critical events per simulation were fewer (median (IQR [range]) 1.0 (0-1.8 [0-2]) vs 3.5 (1.5-4.8 [0-8], respectively; p = 0.011). Crew resource management behaviours also improved in later simulations. On a personal training needs analysis, participants reported increased confidence after the course.

Altered expression of anti-apoptotic proteins in non-involved tissue from cancer-containing breasts

In a previous investigation reduced apoptosis was identified in normal breast tissue from cancer-containing breasts away from the cancer in comparison to age-matched normal breast from women without cancer. The hypothesis for this study was that defects in expression of apoptotic regulatory and DNA repair proteins would facilitate persistence of genetic alterations and predispose to breast cancer development. Using immunohistochemistry normal breast from 120 age-matched women (58 with breast cancer, 62 without) was analysed for proliferation, apoptosis, bcl2, BAX, caspase 3, Hsp27, Hsp70, BRCA1, ATM and BARD1. All assessments were performed without knowledge as to whether it was a cancer case or control. A significant difference was found for apoptotic index which was higher in controls (P < 0.02). There was no change in apoptotic and proliferation index with age for cancer cases unlike controls. Higher expression of bcl2 (P = 0.001) and Hsp27 (P = 0.001) was found in normal breast from cancer-containing breast in comparison to controls. There were no differences in the other proteins. Apoptosis has been found to be reduced in normal breast in a separate cohort of women with breast cancer, along with increased expression of the anti-apoptotic proteins bcl2 and Hsp27. These alterations in apoptotic regulation would enhance tumour development. Further studies are needed to examine the value of these proteins as risk markers.