Case 3/2016 - 58 Year-Old Hypertensive Male with End-Stage Renal Disease, Aortic Dissection, Fever and Hemoptysis

The patient was a 58-year-old male, who sought medical care at InCor complaining of dyspnea and fever.

Three years later, in 2003, the patient had encephalic vascular accident, with full recovery of force in his limbs and no sequelae.
On December 5 th , 2005, the patient sought medical care at Hospital Mandaqui, complaining of dyspnea and chest pain.
The investigation included coronary angiography (Jan 6 th , 2006), which revealed right coronary occlusion, 70% lesion in the middle portion of the anterior interventricular branch of the left coronary artery, 70% lesion in the first diagonal branch and irregularities in the circumflex branch. Flapping in the descending aorta was observed.
Renal failure was detected, and renal replacement therapy via hemodialysis was indicated.
The patient was discharged from that hospital on January 10 th , 2006, and referred to InCor.
On physical examination, the patient was pale, with heart rate of 63 bpm and blood pressure of 126/82 mm Hg. His examination of lungs, heart and abdomen was within the normal range. His lower limbs had decreased pulses and mild edema.
Magnetic resonance imaging of the thoracic aorta (January 23 rd , 2006) revealed aortic dissection right after the left subclavian artery emergence, extending to the abdominal aorta (Stanford type B dissection). The aorta diameter measures were as follows: root, 41 mm; ascending aorta, 34 mm; middle aortic arch, 25; descending aorta, 45 mm.
Magnetic resonance imaging of the abdominal aorta (January 23 rd , 2006) revealed dissection from the thoracic aorta to its bifurcation (beginning of the iliac arteries), with diameter ranging from 32 mm in the suprarenal region to 22 mm in the infrarenal region. The right renal artery emerged from the false lumen, while the left renal artery emerged from the true lumen, and both were occluded. In addition, the left common iliac was occluded, being filled through collateral circulation.
The possibility of surgery was considered, but expectant management was chosen, because of type B aortic dissection and lack of lower limb ischemia.
Three and a half weeks later, the patient returned to InCor (February 19 th , 2006) with dyspnea, fever and toxemia, in addition to passage of tarry stools suggestive of melena.
His physical examination (February 19 th , 2006) showed paleness, tachypnea, respiratory distress, heart rate of 60 bpm and blood pressure of 120/70 mm Hg. Lung auscultation revealed no respiratory sound in the lower 2/3 of the left hemithorax and diffuse rhonchi in both hemithoraces. The heart and abdomen examinations showed no abnormalities, and the lower limbs, no edema. The peripheral pulses were symmetric.

Clinical aspects
The patient had a previous diagnosis of arterial hypertension and chronic renal disease, with renal failure, being on renal replacement therapy via hemodialysis. He had chest pain and dyspnea. His clinical and laboratory assessments revealed coronary artery disease and chronic aortic dissection.
Chronic renal disease significantly progresses as age and cardiovascular disease advance, culminating with renal function worsening. The ARIC Study reports an increase in cardiovascular disease prevalence from 18% to 40% before the age of 65 years, from normal renal function to a glomerular filtration rate drop of 15 mL/min/1.73m², while, over the age of 65 years, that prevalence increases from 20% to 50%, with progressive renal function worsening. 1 In addition, with renal function deterioration, mortality due to cardiovascular disease increases, from 27.5% to 58%. 2,3 Specifically in individuals undergoing dialysis, cardiovascular causes account for 36% of the deaths in the first six months of that therapy. In addition, in that subgroup of patients dying from cardiovascular disease, 64% do it suddenly, 16% die from heart failure, 10%, from acute myocardial infarction, 6%, from encephalic vascular accident, and 4%, from other causes. After six months of dialysis, cardiovascular diseases account for 44.1% of the deaths, maintaining the proportion between the cardiovascular causes. 4 That association between atherosclerosis and renal disease is not random, resulting rather from the fact that those diseases share the same risk factors, with acceleration of atherosclerosis due to changes in the calcium and homocysteine metabolism in renal failure. 5 Those facts make coronary artery disease frequent in those patients, reaching almost 60% of the cases undergoing assessment for renal transplantation. 6 The pain of the patient in question might not have resulted from occlusion of the right coronary artery, because he already had myocardial infarction in the inferior wall seven years before the final event.
The expectant management with drug treatment for Stanford type B aortic dissection adopted in the present case is in accordance with the recommendations of international guidelines for such cases.
The endovascular treatment, which does not result in a mortality reduction, has potential complications inherent in the procedure, such as encephalic vascular accident, paraparesis and death, and those resulting from stent implantation, such as retrograde dissection and stent leak. [10][11][12] In the Internacional Registry of Acute Aortic Dissection (IRAD), 24% of type B dissections underwent emergency surgery in the first two weeks due to complications, such as poor perfusion, hemorrhagic pleural effusion, periaortic hematoma, refractory pain and hypertension. 13 The complications of the chronic phase of type B dissection are: aneurysmal dilation over 5.5 cm; 4-mm annual increase in aortic diameter; symptom recurrence despite optimal drug therapy. 14 In that same IRAD, 31% to 66% of the deaths after discharge were associated with dissection. 13

Postmortem examination
The patient's main disease was chronic aortic dissection, DeBakey type III (Stanford type B), extending from the aortic arch to the iliac bifurcation. The entrance orifice had 2 cm of extension. There was aortic rupture to the left lung and pleural cavity, with massive pulmonary hemorrhage (Figure 4), which was the final factor triggering death.
In association with dissection, the patient had systemic arterial hypertension, morphologically represented by benign nephrosclerosis and concentric left ventricular hypertrophy.
The microscopic study of the aorta evidenced aspects commonly related to aortic dissections, such as wall delamination of tunica media ( Figure 5A) and areas with mucoid material accumulation, in addition to an intense acute inflammatory process, with a large number of polymorphonuclear neutrophils ( Figure 5B) and numerous bacterial colonies of Gram-positive cocci ( Figure 5C). The other organs showed no infection.
In addition to aortic dissection, the patient had atherosclerosis, affecting the abdominal aorta, the cerebral territory, with old infarctions in the cerebellum and right temporal lobe, and the coronary arteries, with healed infarction in the left ventricular posterior wall (inferior, diaphragmatic). In addition, there was superficial chronic

Comments
Neither the patient's disease -aortic dissection in a hypertensive patient -nor his cause of death -aortic rupture to the lung -is uncommon. The patient had a period of relative stability; because the dissection was restricted to the descending aorta, and there was no lower limb ischemia, expectant management was adopted. Aortic rupture, however, was unexpected.
The postmortem examination evidenced an uncommon complication to be the cause of aortic rupture: bacterial colonization of the aortic wall, with numerous colonies of Gram-positive cocci and positive blood cultures for Staphylococcus aureus. That infection triggered intense acute inflammatory reaction, with inflammatory cells releasing lytic substances, which leads to tissue disintegration, including the extracellular matrix, and eventually caused aortic rupture.
The contamination of the false lumen with infectious agents is rare: PubMed system shows only ten cases, some of which in patients with neoplasms. [15][16][17][18][19] (Paulo Sampaio Gutierrez, MD)