Chronic type B aortic dissection in association with Hemolyticuremic syndrome in a child
A 9-year-old male child weighing 23.5 kg was admitted in December 2012 with complains of vomiting, oliguria, edema face and pallor for 4 days. There was no history of fever, diarrhea and frank hematuria, pain in abdomen, pain in chest, dyspnea, dysuria or joint pain. Child had a history of similar complains in February 2012 when he was admitted in our institute and was diagnosed to have hemolytic uremic syndrome (HUS). He had undergone six sessions of plasma exchanges and alternate day hemodialysis (HD) during his stay in hospital. He was discharged on continuous ambulatory peritoneal dialysis (CAPD) with tablet nifedipine- retard 10 mg twice-a-day, tablet clonidine (0.1 mg) half-tablet twice-a-day and tablet sodium bicarbonate (500 mg) twice-a-day. In May 2012, his CAPD catheter was removed when his urine output was increased to 1.5 L/day and he was maintaining serum creatinine of 0.6 mg/day. He was continued on anti-hypertensive medication and he was on monthly follow-up evaluation.\nOn examination, child was well-built, well-nourished, intelligent with normal skin texture without any bruises on joints, having a height of 130 cm, upper segment 66 cm, lower segment 64 cm with an arm span of 126 cm without any abnormal phenotypic feature. His pulse was 100 beat/minhaving bilateral symmetry, blood pressure 200/100 mm of Hg in both upper limb in a sitting position and 206/100 mm of Hg in both lower limbs in lying down position. Femoral, popliteal and dorsalis pedis arteries were equally palpable on both sides. There were no parasternal murmurs on auscultation. Respiratory system was normal on examination and fundus examination was normal. On investigation, urine examination showed albumin +2, sugar nil, 30-40 dysmorphic red blood cells/high power field, hemoglobin 13.1 g/dL, platelet-100,000/cm, peripheral smear showed many schistocytes suggestive of hemolysis. Direct Coomb's test was negative. Blood urea was 154 mg/dL, serum creatinine-5.36 mg/dL, lactate dehydrogenase (LDH) 1317 U/L, high-sensitivity C-reactive protein 2.7 μg/mL (reference range 1-3 μg/mL), serum sodium 138 meq/L, serum potassium 4.8 meq/L, serum C3 level 68 mg/dL (reference level 90-207 mg/dL) serum C4 level 30 mg/dL (reference level 17.4-52.4 mg/dL), ultrasound abdomen showed right kidney 8.4 cm × 3.1 cm and left kidney 8.7 cm × 3.1 cm with increased echogenicity without stone or hydronephrosis. Right internal double lumen catheter (DLC) was inserted for management and X-ray chest was taken to confirm the position of DLC, which showed widening of the mediastinum and well-defined soft-tissue opacity in left paratracheal and left paracardiac region and shadow of aortic knob and descending aorta was not visualized. Contour of right cardiac border was normal and catheter tip was in the right atrium. X-ray chest of previous admission was brought out and it was showing normal cardiac shadow []. Transthoracic echocardiography showed normal aortic valve, ascending aorta and cardiac chambers. Doppler of the abdominal aorta and computed tomography with contrast (CT angio) showed dissection of aorta arising distal to the left subclavian artery and extending up to bifurcation of the aorta with a diameter of descending thoracic aorta 4 cm and abdominal aorta 38 mm with central patent lumen of 2.4 cm and intimal flap within with false lumen diameter of 0.4 cm with partial peripheral thrombus in true lumen [Figures and ]. CT angio showed two left renal arteries and one right renal artery of normal caliber without any aortic branch vessel involvement []. As the child is asymptomatic and has type B dissection of the aorta with a diameter of less than 4 cm, he was started on conservative management with beta blocker and other anti-hypertensive medications along with CAPD and other supportive medications on surveillance monitoring. For his relapse of HUS child was given alternate day hemodialysis and five sessions of plasma exchange each of 1L volume when his platelet count reached 320,000/cu mm and LDH 240 U/L. His oliguria persisted to 300 mL/day and serum creatinine remained 4.28 mg/dL. Renal biopsy was performed, which showed acute on chronic HUS []. CAPD catheter was again inserted and peritoneal dialysis cycles were restarted and his anti-hypertensive requirement included tablet atenolol (50 mg/day), tablet minoxidil (2.5 mg twice a day), tablet prazosin (slow release) (5 mg/day), tablet losartan (50 mg twice a day) and he is maintaining blood pressure of 110/70 mm of Hg at the time of discharge. His father was trained to measure blood pressure at home and keeps a record of same and he has been informed about warning symptoms and child is prohibited from weight lifting.