Abstract: Most previous studies of atherosclerosis in hyperlipidemic mouse models have focused their investigations on lesions within the aorta or aortic sinus in young animals. None of these studies has demonstrated clinically significant advanced lesions. We previously mapped the distribution of lesions throughout the arterial tree of apolipoprotein E knockout (apoE(-/-)) mice between the ages of 24 and 60 weeks. We found that the innominate artery, a small vessel connecting the aortic arch to the right subclavian and right carotid artery, exhibits a highly consistent rate of lesion progression and develops a narrowed vessel characterized by atrophic media and perivascular inflammation. The present study reports the characteristics of advanced lesions in the innominate artery of apoE(-/-) mice aged 42 to 60 weeks. In animals aged 42 to 54 weeks, there is a very high frequency of intraplaque hemorrhage and a fibrotic conversion of necrotic zones accompanied by loss of the fibrous cap. By 60 weeks of age, the lesions are characterized by the presence of collagen-rich fibrofatty nodules often flanked by lateral xanthomas. The processes underlying these changes in the innominate artery of older apoE(-/-) mice could well be a model for the critical processes leading to the breakdown and healing of the human atherosclerotic plaque.

Abstract: Background: Due to the highly lethal nature of trauma of the thoracic aorta and aortic arch branches (TA-AAB), autopsy studies are essential for the investigation of its epidemiologic characteristics. Methods: The reports of 11,446 consecutive medicolegal autopsies were reviewed. Among 1,980 injury-related fatalities, 251 victims (12.7%) with 302 TA-AAB injuries were found. Several trauma variables were recorded and their relations were examined. Results: Blunt TA-AAB injuries were recorded in 86.4% of the victims. They were located mainly at the aortic isthmus and distal descending thoracic aorta and were accompanied to a great extent by extrathoracic trauma. The vast majority of penetrating lacerations were located at the ascending aorta, arch, and arch branches and were mostly associated with other lethal intrathoracic injuries. All penetrating trauma victims died before reaching the hospital, whereas 5.5% of the blunt trauma victims were admitted to the hospital alive. Conclusion: Major differences between blunt and penetrating TA-AAB injuries were revealed, regarding their location, patterns of concomitant injuries, and victims' survival time. Patients injured in motor vehicle crashes, as opposed to various other causes of trauma, were found to have the best chances of reaching the hospital alive.

Abstract: Between January 1988 and December 1997 a total of 22 patients (age: 8 days-46 years) were operated for vascular airway compression syndromes with respiratory insufficiency. Vascular anomalies in tracheal compression were double aortic arch in 7 patients, (2 previously operated elsewhere), right aortic arch + left ligamentum arteriosum in 1, and pulmonary artery sling in 3. Three of these patients had secondary long-segment tracheomalacia. Compression of trachea and a main bronchus existed in 2 patients with right aortic arch + left ligamentum. Isolated main bronchus obstruction was present in 9 patients (abnormal insertion of ligamentum arteriosum in 1, status post (s.p.) previous operation for PDA in 4, s. p. surgery for coarctation in 1, right aortic arch + left ligamentum arteriosum in 2, and right lung aplasia + left ligamentum in 1). 3 of these cases had secondary long-segment bronchomalacia. All patients had a complex respiratory anamnesis [long-term intubation in 7, s.p. tracheostomy in 2 (over 3 months - 3 years), and progressive respiratory insufficiency in 13). In tracheal compression, surgical correction included transsection of the underlying ring or sling components (with additional anterior aortic arch translocation in 5 patients resection-reimplantation of left pulmonary artery in 3, segmental tracheal resection in 1, and external tracheal suspension in 2). In the 2 cases with compression of the trachea and a main bronchus, aortic "extension" by a prosthetic tube was necessary. In isolated main bronchus obstruction, surgical decompression basically consisted of transsection of the ligamentum arteriosum or resection of its scarry remnant forming the "corner point" of a compression between aorta and pulmonary artery. In 3 patients with secondary long-segment malacia, additional external bronchus suspension was performed. Effective decompression and re-expansion of the airway segment concerned was achieved, and was demonstrated by intraoperative endoscopy in all patients. There were 3 postoperative deaths (sepsis 2; massive, irreversible edema of the tracheal mucosa 1). Of the 19 surviving patients 16 could be extubated between the 1st and 17th (mean = 7.5) postoperative day. In 1 case the preoperative long-term tracheostomy had to be left in place for inoperable additional laryngeal stricture. 2 patients had to be reoperated (segmental cervical tracheal resection after 5 months for primary long-term intubation-related subglottic stenosis in 1, esophageal decompression for residual dysphagia after 57 months related to a traction phenomenon at the right descending aorta in the other), both with gratifying results. In all other patients clinical, endoscopic, and radiographic examinations (follow-up = 2 months - 6 years) demonstrate good results.

Abstract: PURPOSE To report endovascular repair of a DeBakey type I ascending aortic dissection. CASE REPORT Five months after aortocoronary bypass grafting, a 56-year-old woman demonstrated a persistent ascending aortic type I dissection whose entry tear proximal to the innominate artery spiraled down the descending thoracic aorta into the iliofemoral arteries. Repair was facilitated with a guidewire passed through a transseptal sheath in the right femoral vein. The guidewire traversed the right and left atria and the left ventricle and then exited into the ascending aorta and was exteriorized through the right femoral artery. A right brachial catheter aided contrast visualization of the innominate artery. Adenosine-induced elective cardiac arrest promoted precise placement of a customized polyester-covered balloon-expandable stent, which closed the aortic rent. CONCLUSIONS A transseptal approach enables the guidewire to follow the curvature of the aortic arch, providing precise control of the stent-graft delivery system. This case illustrates the applicability of endovascular techniques to repair ascending aortic pathologies using readily available techniques, equipment, and drugs.

Abstract: BACKGROUND Despite successful surgical repair of aortic coarctation, life expectancy is reduced, and up to one-third of patients remain or become hypertensive. So as to characterize the responses for blood pressure, we have studied 55 patients with surgically repaired coarctation. Their mean age was 11.3 +/- 5.97 years. We documented maximal uptake of oxygen, anaerobic threshold, plasma renin activity and blood pressures during a Bruce protocol treadmill test. The velocity across the site of repair as imaged by cross-sectional echocardiography was measured before and after exercise. We measured the changes in heart rate and blood pressure subsequent to an infusion of 1 ug per kg of isoprenalin, monitoring blood pressure over 24 hours in all patients. RESULTS When compared with 40 healthy age-matched controls, the patients with coarctation had a normal exercise capacity. Resting systolic blood pressures above the 95th percentile were present in 45% of the patients. Exercise-induced hypertension, and an elevation in the average systolic 24 hour blood pressures, were observed, but less frequently than elevated baseline values, suggesting that so-called white-coat" hypertension may be present in this population. Abnormal reactions and elevation of plasma renin activity were related to a history of paradoxical hypertension at the time of surgery. Attenuation of the circadian rhythm for blood pressure was a frequent finding, and may have implications in the development of long-term damage to end-organs. A high correlation was found between mean systolic blood pressure measured by 24 hour monitoring and left ventricular hypertrophy (r=0.65, p<0.05). CONCLUSIONS Abnormalities in blood pressure occurred independently of significant mechanical obstruction. Despite successful surgical repair, abnormalities in the shape of the aortic arch, reduced sensitivity of baroreceptor reflexes, and neurohumoral factors may all contribute to the development of hypertension.

Abstract: Aims: The purposes of this study were to compare the accuracy of multiplane vs. biplane transoesophageal echocardiography (TEE) in the diagnosis of aortic dissection and aortic intramural haematoma, and to test whether these techniques provide all the diagnostic information required to make management decisions. Methods and Results: Fifty-eight consecutive patients with clinically suspected aortic dissection were studied with multiplane TEE; all cases who required surgery underwent intraoperative monitoring with multiplane TEE. The following multiplane TEE data were analysed: the angle between current and 0° plane at which each view was obtained; the success rate in the evaluation of true and false lumen, entry tear, coronary artery involvement, aortic regurgitation, pericardial effusion. Advantages of multiplane over biplane TEE have been evaluated by the demonstration of usefulness of views obtained in planes other than 0°–20° or 70°–110°, assuming that with manipulation of a biplane probe a 20° arc could be added to the conventional horizontal and vertical planes. On the basis of TEE findings, aortic dissection was confirmed in 36 cases (18 type A, 12 type B, six intramural haematoma). The specificity and sensitivity of TEE in terms of the presence or absence of aortic dissection or intramural haematoma were 100%. An additional clinical value of multiplane over biplane TEE in the evaluation of ascending aorta, aortic arch, entry tears and coronary artery involvement was demonstrated. All cases with type A aortic dissection or intramural haematoma involving the ascending aorta had an operation that was performed immediately after the diagnosis (hospital mortality, 13%). Patients with type B aortic dissection were treated medically; 25% of these cases were operated later (hospital mortality, 0%). Conclusions: Multiplane and biplane TEE have excellent and similar accuracies in the evaluation of aortic dissection and intramural haematoma. Multiplane TEE improves the visualization of coronary arteries, aortic arch and entry tears; it appears to be an ideal method as the sole diagnostic approach before surgery in type A aortic dissection.

Abstract: Regular follow-up is required in patients with previous intervention for coarctation of the aorta to detect recoarctation or aneurysm formation. In this study we describe the findings encountered on routine follow-up exams and we compare the use of contrast-enhanced 3D MR angiography (CE MRA) with fast spin-echo MRI (FSE) to study the thoracic aorta after previous intervention. In 51 consecutive patients previously treated for aortic coarctation, 74 MR studies of the thoracic aorta were performed during a 2-year period using CE MRA and FSE MRI. The thoracic aorta was evaluated for abnormalities of course, caliber, shape, and pathology of side branches. The CE MRA and FSE MRI studies were evaluated side by side by consensus of two reviewers evaluating which MR technique depicted the abnormalities of the thoracic aorta the best. Of 74 exams, six clinically important abnormalities were found: four aneurysms and two restenoses. Two small pseudoaneurysms were missed on the FSE studies. Contrast-enhanced MRA was judged to visualize aortic abnormalities better than FSE (47 of 74 MR studies) especially for the transverse aortic arch, coarctation site, left subclavian artery, and aortic arch configuration. For the ascending aorta and distal descending aorta, CE MRA and FSE performed equally well. Aortic diameters measured at four levels in the first 18 MRI studies showed no significant differences in diameter when measured by FSE or CE MRA (p = not significant). Clinically important abnormalities, such as aneurysm formation and restenosis, can be present years after treatment for aortic coarctation. In the regular follow-up of these patients, CE MRA may provide additional diagnostic information compared with FSE and should be included as part of the routine exam.

Abstract: 1289 ntimal sarcoma of the aorta is a rare and aggressive tumor with a propensity to metastasize to bone and visceral organs, including the liver, kid- neys, adrenal glands, and lung. The most common modes of presentation are embolic phenomena, which often require emergent surgical intervention. When the diagnosis is confirmed, surgical resection can be curative; however, most cases are diagnosed at au- topsy (1). The prognosis is dismal, with death resulting in most patients. We describe a case of intimal sarcoma of the aortic arch with embolus to the brain, ultimately result- ing in the patient's demise. imaging and MR angiography of the brain showed a left-sided occlusion of the M 1 seg- ment of the middle cerebral artery with in- farction of the parasylvian cortex and deep white matter of the frontal lobe. Carotid MR angiography showed no evidence of occlu- sion, dissection, or stenosis of the intracranial carotid arteries. The report of transesophageal echocardiog- raphy that had been performed at another hospital described a diffuse 0.5-cm-thick aortic atheroma in the distal aortic arch and descending thoracic aorta. MR imaging of the chest was performed and showed a 4.2 〈 2.2 〈 1.5 cm lobulated mass along the right inferior aspect of the aortic arch. The mass occupied 70% of the arch lumen and displayed peripheral contrast enhancement after IV gadolinium administration (Figs. 1A-1C). Differential diagnosis included a hy- povascular neoplasm such as leiomyoma or leiomyosarcoma, aortic sarcoma, organizing or mycotic thrombus, and angiosarcoma. Organiz- ing thrombus was believed to be less likely be- cause of the peripheral enhancement and the lobulated contour of the lesion. Angiosarcoma was believed to be less likely because of the lack of central enhancement. Left atrial myx- oma with embolization to the aortic arch was also believed to be unlikely because of the ab- sence of abnormality within the heart. High- grade stenosis and occlusion of the left subcla- vian and left common carotid arteries were present proximally, as was a 3-cm splenic mass thought to represent hemangioma or metastasis. Before further evaluation could be per- formed, the patient developed hemorrhagic transformation of her brain infarction and died. Autopsy revealed a large aortic arch mass with tissue characteristics consistent with an intimal sarcoma (Fig. 1D). Intraarterial tumor throm- bus was present in the left subclavian, left common carotid, and right brachiocephalic ar- teries. Left middle cerebral artery infarction caused by embolus was seen with resulting hemorrhage and brain herniation. Multifocal splenic infarction caused by intraarterial tumor thrombus was also found, as well as a coinci- dental renal cell carcinoma.

Abstract: Objective: Advances in surgical technique have improved early survival after surgery of the ascending aorta. However, follow-up data document serious late complications, mainly evolutive peri-prosthetic false aneurysms. Magnetic resonance imaging (MRI) has proved to be highly effective for monitoring these complications. This study evaluates 10 years of experience with routine MRI for follow-up. Methods: Since January 1988, 114 patients with replacement of the ascending aorta either for type A acute dissection (group I, 45 patients) or aneurysms (group II, 69 patients) were followed up with annual MRI. Prosthetic replacement was either limited to supra-coronary ascending aorta (45%, 51/114) or extended to the aortic root and/or the aortic arch (55%). Biological glue was always utilized. MRI focused on peri-prosthetic haematoma, analyzing signal intensity changes and volume augmentation for early detection of false aneurysms, and on persistent residual dissection with or without evolutive aortic aneurysm distant to the prosthesis. Results: Peri-prosthetic hematomas were almost equally found in both groups (26 (58%) in group I and 42 (61%) in group II) and were detected within the first year. Peri-prosthetic false aneurysms developed in 15 patients (group I, seven; group II, eight) as a complication of pre-existing hematomas and were indicated for elective reoperation. Forty-three (96%) of patients in group I had persistent residual dissection. Five patients in group I and two in group II needed reoperation for evolutive aortic aneurysm. In total, 22 of 114 (19%) patients were reoperated on during follow-up (12 (27%) in group I and ten (15%) in group II) Operative mortality was 13% (3/22). Freedom from reoperation at 1 year/5 years was: group I, 93%/84%; group II, 98%/88%. Conclusion: Peri-prosthetic haematoma occurs equally after aneurysm or dissection repairs and is a pre-existing condition for peri-prosthetic false aneurysm; biological glue or extended repair do not prevent late complications. Long-term MRI follow-up allows successful elective reoperation for life-threatened but asymptomatic patients.

Abstract: To reassess the independent risk factors for lacunar stroke and to clarify the role of potential embolic sources, we conducted a case-control study using transesophageal echocardiography and duplex ultrasonography. Among 62 consecutive patients with their first lacunar stroke and 202 normal controls, we found that hypertension (p < 0.001), smoking (p = 0.001), and aortic arch atheroma (p = 0.006) were independently associated with an increased risk of lacunar stroke. Whether proximal aortic arch atheroma is mechanistically associated with lacunar stroke or merely coexistent is uncertain.

Abstract: Objective To establish in-utero reference ranges for fetal transverse aortic arch diameter (TAD) and distal aortic isthmus diameter (DAID) using high-resolution ultrasound techniques. Design A prospective, cross-sectional study was performed on 125 normal singleton pregnancies between 14 and 38 weeks' gestation. Transverse and diameter and DAID were measured by transvaginal ultrasonography until 17 weeks' gestation, and by abdominal ultrasound between 18 and 38 weeks' gestation. Results Transverse arch diameter as a function of gestational age was expressed by the regression equation TAD = − 1.17 + 0.169 X GA, and DAID = − 1.39 + 0.189 X GA; TAD and DAID are transverse aortic and distal aortic isthmus diameters expressed in millimeters and GA is gestational age in weeks. The correlation r = 0.924 and 0.938 was found to be highly statistically significant (P < 0.001) for TAD and DAID. The normal mean of TAD and DAID per week and the 95% prediction limits were also defined. Conclusions The normative data established by us may be helpful in the prenatal diagnosis of congenital heart defects, including abnormal growth of the aortic arch.

Abstract: Assessment of recurrent coarctation after the Norwood procedure by routine measures is complicated by the unusual physiology caused by the presence of a modified Blalock-Tausig shunt with distal aortic arch obstruction. We present a new index that uses 2-dimensional measurement of the reconstructed aortic arch, which is highly sensitive and specific in identifying recurrent coarctation after the Norwood procedure in children with hypoplastic left heart syndrome.

Abstract: Subclavian steal syndrome (SSS) is a condition secondary to an occlusion in the proximal subclavian artery, in which the blood supply to the arm is sustained by reversal of flow in the ipsilateral vertebral artery. We describe two similar cases of SSS due to a right aortic arch with isolated left subclavian artery. Diagnosis was made with magnetic resonance imaging (MRI) and angiography (MRA), which was confirmed by Doppler ultrasound and X-ray angiography. The exact anatomic relationships of the vascular structures were well demonstrated on contrast-enhanced MRA, while flow reversal was documented on flow-encoded MRI datasets. We conclude that the combination of different MRI modalities forms an accurate and reliable alternative in the diagnostic workup of patients with suspected SSS.

Abstract: A ventricular tunnel is a congenital abnormal paravalvular pathway between the aortic root and the left ventricular cavity bypassing the aortic valve and not penetrating the septal musculature.1 This cardiac anomaly was first described by Levy et al in 1982.2 Surgical closure is usually the treatment of choice. We report the first transcatheter closure of an aorto-left ventricular tunnel using an Amplatzer patent ductus arteriosus (PDA) occluder device (AGA Medical Corporation, Golden Valley, Minnesota). • • • This case concerns a 14-yearold boy whose mother had an uncomplicated pregnancy and an uneventful delivery. The initial neonatal examination did not reveal any heart problems or any other anomalies and the child was discharged after 48 hours. A diastolic murmur was first heard at 7 years of age during a routine check and he was referred to our outpatient clinic where the clinical diagnosis of aortic regurgitation (AR) was made. The echocardiogram showed a bleb in the right coronary sinus of Valsalva just to the left of the origin of the right coronary artery. He was clinically well and asymptomatic. Catheterization was performed in 1993 and confirmed mild AR without evidence of aortic valve prolapse or aneurysm formation. Left ventricular function, coronary arteries, and aortic arch were normal. The child has been under annual review and has remained symptom-free, with the same signs of mild AR. During the last evaluation in March 1999, the echocardiogram showed left ventricular volume overload due to an aorto-left ventricular tunnel and mild AR, although the aortic valve appeared normal. Catheterization was repeated to confirm the diagnosis and consider transcatheter closure. Under general anesthesia and transesophageal echocardiography control, a rightand left-sided cardiac catheterization was performed using a 6Fr sheath in the right femoral vein, a 5Fr sheath in the right femoral artery, and a 5Fr sheath in the left femoral artery. Separate arterial access was used to allow delivery of the device and ensure freedom of coronary flow before deployment. The patient weighed 61.6 kg, and 50 IU/kg of heparin was administered at the beginning of the procedure. The transesophageal echocardiogram showed a normally functioning but volume loaded left ventricle with mild AR. The aorto-left ventricular tunnel was sized at approximately 9 mm at its maximal diameter. Normal right-sided left ventricular and aortic pressures and saturations were recorded. Using a 5Fr pigtail and a 5Fr multitrack catheters (NuMed, Inc., Hopkinton, New York), angiography of the left ventricle, ascending aorta, and coronary arteries was performed to evaluate the anatomy. This showed an aorto-left ventricular tunnel arising from the right coronary sinus of Valsalva, but separate from the right coronary artery, and which drained into the left ventricle. The aorto-left ventricular tunnel measured 6.1 mm at its maximum diameter with a “windsock” shape (Figure 1). A 6Fr Gensini catheter was easily passed through the aorto-left ventricular tunnel into the left ventricle; an exchange guidewire was then introduced and stabilized in the left ventricle. The catheter was then replaced by an 7Fr delivery sheath and dilator which was advanced over the exchange wire into the left ventricle through the aorto-left ventricular tunnel. The dilator was removed and the delivery sheath was deaired. The correct position was confirmed by an injection of radiopaque contrast. A 10/8-mm Amplatzer PDA occluder device (AGA Medical Corporation, Minnesota) was mounted on a delivery wire and introduced into the delivery sheath through a loading device, and then advanced into the left ventricle through the aorto-left ventricular tunnel under fluoroscopic control. The device flange From The Heart Unit, Birmingham Children’s Hospital, Birmingham, United Kingdom. Dr. De Giovanni’s address is: The Heart Unit, Birmingham Children’s Hospital, Steelhouse Lane, Birmingham B4 6NH, United Kingdom. E-mail: [email protected]. Manuscript received November 9, 1999; revised manuscript received and accepted February 4, 2000. FIGURE 1. Anteroposterior projection: aorto-left ventricular tunnel angiography showing the “Windsock” shape.

Abstract: Purpose: To illustrate the clinical utility of a short acting opioid (remifentanil) based general anesthetic for Cesarean section in a parturient with compromised cardiac function. Clinical Features: A 23-yr-old primigravida, complicated by a recurrent aortic coarctation with an approximate 50% narrowing of the aortic arch, presented for elective Cesarean section at 37 wk gestational age. Initially asymptomatic, her clinical condition had deteriorated as the pregnancy progressed, with worsening episodes of mild chest pain and shortness of breath. A semi-elective Cesarean section under general anesthesia was planned at 37 wk to minimize the potential for aortic complications associated with the hemodynamic stress of labour. Remifentanil was infused at 0.05 to 0.1 µg·kg−1·min−1 with good sedation and analgesia for the placement of invasive monitors. The infusion was increased to 0.2 µg·kg−1·min−1 for induction, and combined with isoflurane 0.4 to 0.6% for maintenance of anesthesia. The patient maintained stable hemodynamics throughout and her trachea was extubated without difficulty at the end of the procedure. The newborn did not require tracheal intubation, mask ventilation or naloxone and was in excellent condition upon transfer to the well baby nursery. Conclusion: Remifentanil, when used as part of an opioid-based general anesthetic for Cesarean section, can provide maternal hemodynamic stability with minimal neonatal respiratory depression and should allow for immediate postoperative tracheal extubation of the mother.