Analysis of 287 patients with aortic dissection: General characteristics, outcomes and risk factors in a single center

Hemodynamic Study of Stanford Type B Aortic Dissection Based on Ex Vivo Porcine Aorta Models

Background:

In this study, we aimed to evaluate hemodynamic influence of the dissected aortic system via various ex vivo type B aortic dissection (AD) models.

Methods:

Twenty-four raw porcine aortas were harvested and randomly divided into 4 groups to create various aortic models. Model A was the control group, while models B to D indicated the AD group, where models B and C presented a proximal primary entry with the false lumen (FL) lengths of 15 and 20 cm, respectively, and model D presented a 20 cm FL with a proximal primary entry and a distal reentry. All the aortic models were connected to a mock circulation loop to attain the realistic flow and pressure status. The flow distribution rate (FDR) of the aortic branches was calculated. Doppler ultrasound was applied to visualize the AD structure and to attain the velocity of flow in both the true and false lumens. Several sections of the AD were stained with hematoxylin and eosin for histologic evaluation after the experiment.

Results:

This study demonstrated that higher pressures were found for the AD group compared with the control group. The mean systolic pressures at the inlet of models A to D were 113.34±0.81, 120.58±0.52, 117.76±0.82, and 115.87±0.42 mm Hg, respectively. The FDRs of the celiac artery in models A to D were 8.65%, 8.32%±0.15%, 7.87%±0.13%, and 8.03%±0.21%, respectively. By ultrasound visualization, the velocity of the flow at the entry to the FL in the AD group ranged in 10 to 92 cm/s. The dissection flap presented pulsatile movement, especially in the models B and C which contained 1 primary entry without distal reentries. Histological examinations indicated that AD was located between the intimal and medial layers.

Conclusions:

Our ex vivo models demonstrated that the configuration of the dissected aorta influenced the pressure distribution. Moreover, the dissection flap affected the FDR of the aortic branches that possibly inducing malperfusion syndrome.

Recent evolution in use and effectiveness in mainland China of thoracic endovascular aortic repair of type B aortic dissection

A meta-analysis was performed on 175 studies selected among those published in mainland China between 2008 and 2015 on thoracic endovascular aortic repair (TEVAR) for type B aortic dissection (AD). Most TEVAR were performed in Shanghai, Beijing, Hubei and Guangdong in patients with mean age of 53.9 years, and acute (70%) or chronic (30%) type B AD. Procedural success rate was 99.1 ± 0.8%. Major complication rate was 1.7 ± 2.3%, with paraplegia in 0.4 ± 0.0%. Overall in-hospital mortality rate was 1.6 ± 0.9% with AD rupture in 30% (about 40% during first postoperative day); follow-up mortality rate was 2.3 ± 1.1%, with AD rupture in 39.2% (50% within first year). Compared with 2001–2007 data from China, there appeared to be improvement in rates of major complications, paraplegia and in-hospital mortality. Compared with 1999–2004 Western data, rates of procedural success, stroke, and paraplegia appeared similar, while those for major complications, in-hospital mortality, retrograde type A dissection and follow-up mortality appeared lower. Compared with more recent Western data (2006–2013) on acute complicated type B AD, stroke, paraplegia, in-hospital mortality and follow-up mortality appeared lower. Therefore, in mainland China, safety for TEVAR of type B AD appeared better between 2008 and 2015 than in previous periods in China or Western countries.

Are Women Who Exit Colposcopy Without Treatment at Elevated Risk for Cervical Cancer?

OBJECTIVE

This study aims to estimate the risk of cervical cancer and impact of treatment and other factors in women referred for high-grade (HG) and low-grade (LG) cytologic changes and discharged from colposcopy.

MATERIALS AND METHODS

A retrospective cohort study identified 14,787 and 41,916 women with a first-time HG and LG cytologic abnormality between 2007 and 2010 and underwent colposcopy within 1 year. Treatment status was determined within the episode of care. Incidence of cervical cancer postcolposcopy was determined up to March 2015. Logistic regression assessed impact of colposcopic care and patient factors on cancer risk.

RESULTS

A total of 62% HG and 28.5% LG had treatment. A total of 28% and 37% with HG and LG abnormalities had only 1 colposcopic evaluation. Subsequent cancer incidence in the untreated HG group was 1.1% versus 0.3% in the treated group. For the LG group, cancer rates were 0.08% in both treatment groups. In the HG group, those with initial colposcopy only and no treatment had an elevated risk [adjusted odds ratio = 6.6 (95% CI = 3.9-11)] compared with treatment with multiple follow-ups. Other significant factors were advancing age and no screening postcolposcopy. For the LG group, those with initial colposcopy only were more at risk regardless of treatment [adjusted odds ratio = 3.8 (95% CI = 1.8-8.1)] compared with multiple colposcopies.

CONCLUSIONS

Women who are untreated, with index HG cytology, remain at elevated risk for cervical cancer when the colposcopic episode is limited to 1 examination. Centralized programs are required to ensure that such women are not discharged prematurely or lost to follow up from colposcopy and subsequent screening.

Correlation of computed tomography angiography parameters and shock index to assess the transportation risk in aortic dissection patients

BACKGROUND

Aortic dissection (AD) is a serious, life-threatening disease. It is currently crucial for AD patients to be transferred to a specialised hospital in a safe and timely manner. For this reason, the search for clinical and imaging changes related to transportation risk is becoming increasingly important.

PURPOSE

The transportation risks of AD patients were assessed by studying the correlation between computed tomography angiography (CTA) parameters and shock index.

MATERIALS AND METHODS

Thirty-six cases of AD confirmed with 64-slice volumetric CT (VCT) (18 cases of Stanford type A and 18 cases of type B) were divided into a high-risk group (14 cases, six Stanford type A and eight type B) and a low-risk group (22 cases, 12 Stanford type A and 10 type B) according to the modified Early Warning Score. The shock index (ratio of heart rate to systolic blood pressure) and measured CTA parameters were compared between the high-risk group and the low-risk group, and the correlation between the measured CTA parameters and shock index was analysed.

RESULTS

The shock index and ratio of false/true lumen were compared between Stanford type A and type B, and no statistically significant differences were found. The shock index and ratio of false/true lumen were compared between the high-risk group and low-risk group, revealing a statistically significant difference (p < 0.05). Moreover, a significant linear correlation was found between the ratio of false/true lumen and the shock index (r = 0.691; p = 0.001).

CONCLUSION

The higher the shock index and the ratio of false/true lumen are, the greater the transportation risk for AD patients. The shock index and the ratio of false/true lumen proved to be essential clinical and radiological indices for assessing the transportation risk of AD patients.