Extensive Iatrogenic Aortic Dissection During Renal Angioplasty: Successful Treatment with a Covered Stent-Graft

Iatrogenic Aortic Dissection Associated With Cardiac Surgery: A Narrative Review

Iatrogenic aortic dissection (iAD) is a relatively rare but a life-threatening complication associated with cardiac surgery. All members of the team caring for cardiac surgical patients (surgeons, perfusionists, and anesthesiologists) must be familiar with this complication to minimize its incidence and improve outcome. The present narrative review focuses on iAD occurring intraoperatively and during the early postoperative period (within 1 month) of cardiac surgery. The review also addresses iAD that occurs late (beyond 1 month) after cardiac surgery and iAD associated with other procedures. iAD occurs in about 0.06% of cases when the ascending aorta is the site of arterial cannulation, in about 0.6% when the femoral or iliac arteries are used, and in about 0.5% when the axillary or subclavian arteries are used. Mortality is estimated to be 30% but is more than double if not recognized until the postoperative period. Site of origin of dissection is most commonly the arterial inflow cannula (∼33%). Other common sites are the aortic cross-clamp or partial occlusion clamp (∼29%) and the proximal saphenous vein anastomosis site (14%). Sixty percent of cases occur during coronary artery bypass graft (CABG) surgery and 17% during aortic valve surgery with or without CABG. iAD may be somewhat less common in off-pump versus on-pump CABG but is still not very rare. Risk factors, presentation, diagnosis, and management are reviewed in detail as is the key role of the use of echocardiography in the early diagnosis of iAD and for guiding its management.

When and How Should We Revascularize Patients With Atherosclerotic Renal Artery Stenosis?

Atherosclerotic renal artery stenosis is the leading cause of secondary hypertension and may lead to resistant (refractory) hypertension, progressive decline in renal function, and cardiac destabilization syndromes (pulmonary edema, recurrent heart failure, or acute coronary syndromes) despite guideline-directed medical therapy. Although randomized controlled trials comparing medical therapy with medical therapy and renal artery stenting have failed to show a benefit for renal artery stenting, according to comparative effectiveness reviews by the Agency for Healthcare Research and Quality, the trials may not have enrolled patients with the most severe atherosclerotic renal artery stenosis, who would be more likely to benefit from renal stenting. Because of limitations of conventional angiography, it is critical that the hemodynamic severity of moderately severe (50% to 70%) atherosclerotic renal artery stenosis lesions be confirmed on hemodynamic measurement. The authors review techniques to optimize patient selection, to minimize procedural complications, and to facilitate durable patency of renal stenting. The authors also review the current American College of Cardiology and American Heart Association guidelines and the Society for Cardiovascular Angiography and Interventions appropriate use criteria as they relate to renal stenting.

Renal Artery Stenosis: When to Revascularize in 2017

Atherosclerotic renal artery stenosis is the leading cause of secondary hypertension; it can also cause progressive renal insufficiency and cardiovascular complications such as refractory heart failure and flash pulmonary edema. Medical therapy including risk factor modification, renin-angiotensin-aldosterone system antagonists, lipid lowering agents, and antiplatelet therapy is the first line of treatment in all patients. Patients with uncontrolled renovascular hypertension despite optimal medical therapy, ischemic nephropathy, and cardiac destabilization syndromes who have severe renal artery stenosis are likely to benefit from renal artery revascularization. Screening for renal artery stenosis can be done with Doppler ultrasonography, computed tomographic angiography and magnetic resonance angiography. Invasive physiologic measurements are useful to confirm the severity of renal hypoperfusion and therefore improve the selection patients likely to respond to renal artery revascularization. Primary patency exceeds 80% at 5 years and surveillance for in-stent restenosis can be done with periodic clinical, laboratory, and imaging follow-up.

Aortic dissection after open repair of an infrarenal aortic aneurysm

INTRODUCTION

A case of thoracic-abdominal dissection after open surgical exclusion of an infrarenal aortic aneurysm is presented.

CASE PRESENTATION

A 62-year-old woman was diagnosed with an infrarenal abdominal aortic aneurysm with a rapid increase in maximal diameter. She underwent surgery for aneurysm exclusion by an end-to-end aortoaortic bypass with Dacron collagen (Intervascular; WL Gore & Associates Inc, USA). After 15 days, she was admitted to the emergency department with intense epigastric and lumbar pain. Computed tomography angiography with contrast revealed an aortic dissection with origin in the proximal bypass anastomosis and cranial extension to the thoracic aorta. The true lumen at the level of the eighth thoracic vertebra was practically collapsed by the false lumen. The celiac trunk, and the mesenteric and renal arteries were perfused by the true lumen. After the acute phase of the aortic dissection, surgical repair was planned. Two paths of false lumen were found - one at the thoracic aorta and the second in the proximal bypass anastomosis. Surgical repair comprised two approaches. First, a Valiant Thoracic stent graft (Medtronic Inc, UK) was implanted distal from the left subclavian artery, expanding the collapsed true lumen and covering the false and dissected lumen. Second, an infrarenal Endurant abdominal stent graft (Medtronic Inc) was implanted. This second device was complemented with an aortic infrarenal extension using a Talent abdominal stent graft (Medtronic Inc) in the infrarenal aortic neck to achieve a hermetic seal. The postoperative clinical course was uneventful, and her symptoms were completely resolved in six months.

CONCLUSION

Arteritis must be taken into account in young patients with high inflammatory markers. Covered stents and endoprosthetic devices seem to be effective methods to seal the dissected lumen.

Descending thoracic aortic dissections

Type B dissection has traditionally been managed medically if uncomplicated and surgically if associated with complications. This practice has resulted in most centers reporting significant morbidity and mortality if open repair is required. In the setting of malperfusion, operative repair has been conjoined with fenestration or visceral stenting to improve outcomes. Endovascular stent grafts seem to offer an attractive alternative in the acute complicated type B dissection, with reduced mortality and morbidity, particularly paralysis, compared with open repair. It is reasonable to consider endovascular stent grafts as another tool in managing dissection, but to recognize that open surgical repair still plays an important role, and that the data that define indications and outcomes are still emerging.