Thoracic Aortic Stent-Grafting for Acute, Complicated, Type B Aortic Dissections

Duplex Ultrasound Assessment and Outcomes of Renal Malperfusion Syndromes after Acute Aortic Dissection

BACKGROUND

We investigated the feasibility of renal duplex ultrasound in the identification of renal malperfusion in acute aortic dissection and evaluated whether intervention for renal malperfusion improved outcomes over best medical management alone.

METHODS

All patients with acute aortic dissections involving the renovisceral aorta who underwent a duplex ultrasound were included (2004-2016). We assessed duplex findings among patients who developed acute kidney injury (AKI; 50% increase in serum creatinine) and compared AKI, 30-day mortality, and overall survival among patients who underwent a procedure to treat malperfusion versus those who did not.

RESULTS

Of 37 patients with acute dissection involving the renovisceral aorta (73% were male, 59% had type B dissection, mean follow-up 4.6 ± 0.6 years), 70% developed AKI, 11% required dialysis, and 5% developed permanent dialysis dependence. AKI was correlated with higher peak creatinine levels (4.2 vs. 2.2 mg/dL, P < 0.001), although 30-day mortality and overall survival were similar (both, P ≥ 0.24). Progression to AKI was associated with significantly lower end-diastolic velocity (EDV) measurements on renal duplex (17 vs. 27 cm/sec, P = 0.03); an EDV threshold of 23 cm/sec had a positive predictive value of 85% for AKI. Operative intervention (n = 10) was associated with lower follow-up creatinine (0.9 vs. 2.1 mg/dL, P = 0.002), although there was no difference in progression to dialysis dependence, 30-day mortality, or overall survival (all, P ≥ 0.34).

CONCLUSIONS

Patients who developed AKI demonstrated characteristic renal duplex ultrasound findings with lower EDV measurements in the distal renal arteries bilaterally. Performing a renal malperfusion procedure was associated with normalization of postoperative creatinine without affecting 30-day mortality or overall survival.

TEVAR for type B aortic dissection in Japan

TEVAR is a new strategy for treating both acute and chronic type B aortic dissection. The JSC guidelines classify TEVAR as a Class I recommendation for cases of complicated acute type B dissection and a Class IIa recommendation for cases of chronic type B aortic dissection. While TEVAR has been primarily applied to treat complicated acute type B aortic dissection in Europe and the USA, the procedure remains an off-label treatment strategy for aortic dissection in Japan. The current state of TEVAR for type B aortic dissection in Japan from 2001 to 2011 is estimated in the annual reports of the Japanese Association for Thoracic Surgery. The number of acute type B aortic dissection patients treated with transluminal stent grafting increased rapidly after 2008, from 10 cases in 2001 to 76 cases in 2010. Meanwhile, the number acute type B aortic dissection patients treated with any type of surgery has increased gradually, from 100 cases in 2001 to 194 cases in 2009. The number of chronic type B aortic dissection patients treated with transluminal stent grafting increased abruptly in 2010, reaching 346 cases, which accounted for one-third of all surgical procedures for chronic type B aortic dissection. Furthermore, the number of open surgeries for chronic type B aortic dissection has also increased gradually, from 401 cases in 2001 to 947 cases in 2011. At present, open surgery, TEVAR and hybrid procedures are available to treat patients with type B aortic dissection. The use of a multidisciplinary team approach is mandatory when selecting the appropriate surgical strategy.

Aortic dissection and renal failure in a patient with severe hypothyroidism

Acute aortic dissection (AAD) is a life-threatening condition associated with high morbidity and mortality. The most important recognized acquired cause that leads to dissection is chronic arterial hypertension. With respect to the anuria and renal failure, aortic dissection is not something that is always considered and is still not a very common presentation unless both renal arteries come off the false lumen of the dissection. However, when present, preoperative renal failure in patients with acute type B dissection has been noted to be an independent predictor of mortality. Early recognition and diagnosis is the key and as noted by previous studies as well, almost a third of these patients are initially worked up for other causes until later when they are diagnosed with aortic dissection. Here we present a case of a patient presenting with severe hypothyroidism, long-standing hypertension, and anuria. Through the case, we highlight the importance of having aortic dissection as an important differential in patients presenting with anuria who have a long standing history of uncontrolled hypertension. Pathophysiology relating to severe hypothyroidism-induced renal dysfunction is also discussed.

Descending thoracic aortic surgery: update on mortality, morbidity, risk assessment and management

PURPOSE OF REVIEW

The purpose of this review is to summarize the literature on thoracic aortic surgery, as well as key management guidelines in the perioperative period. This is particularly timely, as endovascular techniques continue to evolve and become more available.

RECENT FINDINGS

Endovascular treatment of thoracic aortic disease is expanding in applications and case complexity.

SUMMARY

With the expanded use of endovascular techniques to treat aortic disease, midterm and long-term outcome studies and comparisons to open surgical approach are now being published with increasing frequency. This review analyzes the available literature on preventing adverse outcomes after descending thoracic aortic surgery, with specific attention to mortality, morbidity, risk assessment and management in the perioperative setting.