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Thoracoabdominal Aortic Aneurysm |
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Hernan A. Bazan, Nicholas J. Morrissey, and Larry H. Hollier |
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A 72-year-old white male presented to his primary-care physician with a history of left chest pain for the past month. The pain was dull and constant and radiated to the back,medial to thescapula. He denied anew cough orworseningshortness ofbreath. He had no recent weight loss, and his appetite was good. He had a history of hypertension, which was currently controlled medically, and a significant 60 pack-a-year smoking history. In addition, he suffered a myocardial infarction (MI) 5 years ago. The patient denied any history of claudication, transient ischaemic attacks or stroke. He had undergone surgery in the past for bilateral inguinal hernias, and underwent cardiac catheterization after his MI.
On physical examination, the patient was thin but did not appear malnourished. Vital signs were heart rate 72 beats/min, blood pressure 140/80 mmHg, respiratory rate 18/min, and temperature 36.8°C. His head and neck examination was remarkable for bilateral carotid bruits. Cardiac examination revealed a regular rate and rhythm without murmurs. Abdominal examination revealed no bruits and a palpable aortic mass. His femoral and popliteal pulses were normal (2+); Posterior tibial pulseswere1+bilaterally,anddorsalispedissignalsweredetectableonlybyDoppler. No prominent popliteal pulses were appreciated. Routine blood work was unremarkable, and an electrocardiogram (ECG) revealed changes consistent with an old inferior wall MI and left ventricular (LV) hypertrophy. Chest X-ray (Fig. 5.1) was remarkable for a tortuous aorta, which had calcification within the wall and appeared dilated. There were no pleural effusions, but both hemidiaphragms did demonstrate some flattening, and bony structures were normal. Lung fields were clear of masses
or consolidation.
H.A. Bazan ( )
Ochsner Clinic Foundation, Department of Surgery, Section of Vascular/Endovascular Surgery, New Orleans, LA 70121, USA
e-mail: hbazan@ochsner.org
G. Geroulakos and B. Sumpio (eds.), Vascular Surgery, |
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DOI: 10.1007/978-1-84996-356-5_5, © Springer-Verlag London Limited 2011 |
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H.A. Bazan et al. |
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Fig. 5.1 Chest X-ray demonstrating a tortuous and dilated descending thoracic aorta suggestive of a thoracoabdominal aortic aneurysm
Question 1
Which of the following is the single most likely diagnosis causing this man’s pain?
A.Acute MI
B.Acute aortic dissection
C.Thoracic aortic aneurysm
D.Lung cancer
E.Pneumonia
Question 2
Which of the following studies should be performed in this patient in order to plan therapy?
A.Aortography
B.Computed tomography (CT) scan of chest
C.Carotid duplex studies
D.Cardiac stress test
E.Arterial blood gas (ABG) analysis
Although aortography was routinely done before, CT scan of the chest and abdomen was obtained (Fig. 5.2) and deemed sufficient for operative planning. Findings were consistent with a thoracoabdominal aneurysm without concomitant dissection of the aorta. There was
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Fig. 5.2 CTA scan demonstrating aneurysmal dilatation of the descending thoracic aorta
no evidence for acute leak or rupture, and the maximal diameter of the thoracic aorta was 7.3 cm.
Question 3
In the Crawford classification system for thoracoabdominal aortic aneurysms (TAAAs), which represents the most extensive TAAA?
A.Type I
B.Type II
C.Type III
D.Type IV
The patient underwent a cardiac stress test, which was normal. Carotid duplex studies revealed minimal atherosclerotic disease with bilateral stenoses of less than 50%. ABG analysis showed pH 7.38, pCO2 42 and pO276 on room air.
Question 4
Which of the following management schemes seems most reasonable for this patient?
A.Observation with annual follow-up chest CT
B.Repair of thoracoabdominal aneurysm after bilateral carotid endarterectomies
C.Cardiac catheterization followed by repair of TAAA
D.Elective repair of TAAA
The patient is scheduled for elective repair of his TAAA. He expresses concern about the possibility of complications from the surgery. You explain to him the most likely complications related to this surgery.
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Question 5
Of the following, which is not a common complication following TAAA repair?
A. Pulmonary
B. Cardiac
C. Renal
D. Gastrointestinal
The patient seems most concerned about the risk of postoperative paralysis. You explain to him that there are things you can do to decrease his risk of suffering these complications, although nothing can eliminate the risk.
Question 6
Which of the following technical modifications is not believed to be beneficial in the prevention of spinal cord dysfunction following TAAA repair?
A. Tumor necrosis factor-a monoclonal antibody B. Cerebrospinal fluid drainage
C. Reimplantation of key intercostal arteries D. Epidural cooling
The patient undergoes repair of TAAA and tolerates the procedure well. Postoperatively, the chest tubes are draining 100–150 cm3 blood/h for the first 3 h. In addition, urine output is steady at 500 cm3/h. The patient has transient drops in blood pressure to a systolic blood pressure in the 70s, with central venous pressure dropping to 5 mmHg.
Question 7
(a) Outline the initial work-up and potential correction of the bleeding problem described above in order to prevent a return to the operating room. (b) What fluid resuscitation approach should be taken to stabilize this patient’s hemodynamic status?
The patient’s temperature is 34.6°C, international normalized ration (INR) is 1.7 and partial thromboplastin time (PTT) is 50 s (control, 34 s). Platelet count is 33,000. After infusion of warm fluids, the use of a warming blanket, and platelet and fresh frozen plasma (FFP) transfusions, the parameters return to normal and the drainage from the chest tubes decreases to about 10–20 cm3/h. On the second postoperative day, the patient is noted to have loss of motor function in his lower extremities.
Question 8
What therapeutic intervention, if carried out in a timely fashion, may restore this patient’s neurological function partially or fully?