Ultrasound Evaluation of Subclavian Artery and Internal Thoracic Artery Before Coronary Artery Bypass Grafting as Part of Preoperative Vascular Assessment.

RATIONALE AND OBJECTIVES: Noninvasive diagnostic imaging of subclavian artery (SCA) and internal thoracic artery (ITA) is crucial to the patients planning to use ITA for coronary artery bypass grafting (CABG). The guidelines have not yet provided guidance on screening high-risk groups. The present study aimed to evaluate the contribution of ultrasonography in the assessment of SCA and ITA, especially for the patients referred for CABG who planned to use ITA graft. MATERIALS AND METHODS: Patients diagnosed with multivessel coronary heart disease were enrolled and some of them planned CABG. Bilateral SCAs and ITAs were routinely evaluated by color Doppler ultrasound (CDUS) before operation. The luminal diameter and the peak systolic velocity of the proximal and distal parts of SCA and ITA were measured. Depending on the Doppler waveform, the lumen narrowing rate was calculated. RESULTS: The final analysis was carried out in 572 patients. Thirty-five patients had moderate (50%-69%), severe (70%-99%) stenosis or occlusion in the SCA (left-sided in 21 and right-sided in 14). One patient had severe proximal stenosis in left ITA and one patient had no flow in left ITA due to the occlusion in left SCA. One patient had anatomic variation of isolated right aortic arch with aberrant left SCA. All of those cases were confirmed with multidetector computed tomography angiography. CONCLUSION: CDUS could be used for the evaluation of SCA and ITA before CABG as part of presurgical vascular assessment and provide an import basis for the imaging diagnosis and surgical plan.

Functional Assessment and Evaluation of Outcome After Endovascular Therapy With Coverage of the Left Subclavian Artery in Case of Blunt Thoracic Aortic Injury.

BACKGROUND: Patients suffering blunt thoracic aortic injury (BTAI) can be treated by use of thoracic endovascular aortic repair (TEVAR). In this setting, the coverage of the left subclavian artery (LSA) is frequently necessary. Nevertheless, the functionality of the upper left extremity after TEVAR had been rarely analyzed. Thus, this study intends to underline the safety of TEVAR as well as to determine the functionality of the left arm after coverage of the LSA. METHODS: All patients suffering from BTAI treated by endovascular means in 3 centers (Aachen [Germany], Maastricht [Netherlands], and Innsbruck [Austria]) between 1996 and 2009 were retrospectively analyzed. The safety of the procedure had been assessed by the morbidity and mortality rate. The mid-term functional status of the upper left extremity was evaluated by using the DASH score (disabilities of the arm shoulder and hand). RESULTS: Forty-six patients (40 male, 6 female), mean age 39.4 ± 16.9 years suffered from BTAI caused by traffic accident (n = 31 [67.39%]), by skiing injury (n = 8 [17.39%]), and by fall (n = 7 [15.21%]). All patients underwent TEVAR, the technical success rate was 100%; 1 carotid-carotid subclavian bypass implantation was necessary. LSA coverage was performed in 76% (35/46) of the cases. Total complication rate was 17.3% (8/46); the endoleak rate was 8.6% (4/46) (2 × Ib, 1 × IIa, 1 × IV). Further complications were bypass and endograft occlusion. The postoperative mortality rate was 6% (3/46), the DASH score was completed in 65% (30/46). The study population reached a mean value of 17 ± 20, which is comparable to a nonharmed reference group (10.10 ± 14.68). A significant correlation between the DASH score and patients age could be demonstrated (2-sided P value: 0.0213). CONCLUSIONS: Endovascular therapy of BTAI revealed a good primary success rate. An adequate mid-term functional status of the upper left extremity could be assessed in comparison to a nonharmed reference group.

Routine revascularization is unnecessary in the majority of patients requiring zone II coverage during thoracic endovascular aortic repair: a longitudinal outcomes study using United States Medicare population data.

OBJECTIVE: We aimed to evaluate outcomes of thoracic endovascular aortic repair (TEVAR) with left subclavian artery (LSA) coverage without bypass (TEVAR + SUB) to TEVAR with coverage of the LSA with a bypass at the time of the initial procedure or later at a separate procedure (TEVAR + SUB + BYPASS). METHODS: The Centers for Medicare & Medicaid Services inpatient claims for 2006-2007 were queried using Current Procedural Terminology codes for TEVAR, TEVAR + SUB, TEVAR + SUB + BYPASS or later as a separate procedure. RESULTS: A total of 2676 patients underwent TEVAR; 869 (32.5%) underwent TEVAR + SUB and 49 (5.6%) TEVAR + SUB + BYPASS. At the time of the initial procedure, TEVAR + SUB + BYPASS was associated with a higher incidence of stroke compared to TEVAR + SUB (12.8% vs. 3.8 %; p = 0.0033). Among TEVAR + SUB, only 1.93% (50 patients) had a subsequent bypass performed during a one-year follow-up. Overall rates of morbidity (p = 0.004) and mortality (p = 0.011) trended towards significance in favor of TEVAR + SUB. CONCLUSIONS: TEVAR + SUB were associated with lower rates of mortality and complications. Only a small percentage of TEVAR + SUB required a bypass at one year after procedure. Our data suggest that routine LSA bypass during TEVAR is unnecessary and associated with increase morbidity and mortality.

How to manage the left subclavian artery during endovascular stenting for thoracic aortic dissection? An assessment of the evidence.

BACKGROUND: Despite the publication of recent guidelines for management of the left subclavian artery (LSA) during endovascular stenting procedures of the thoracic aorta, specific management for those presenting with dissection remains unclear. This systematic review attempts to address this issue. METHODS: Systematic assessment of the published data on thoracic aorta dissection was performed identifying 46 studies, which incorporated 1,275 patients. Primary outcomes included the prevalence of left arm ischemia, stroke, spinal cord ischemia, endoleak, stent migration, and mortality. Outcomes were compared between patients with and without LSA coverage and revascularization incorporating factors such as the number of stents used, length of aorta covered, urgency of intervention, and type of dissection (acute or chronic). Statistical pooling techniques, χ(2) tests, and Fisher's exact testing were used for group comparisons. RESULTS: As compared with other outcomes, LSA coverage without revascularization in the presence of aortic dissection is much more likely to be complicated by left arm ischemia (prevalence increased from 0.0% to 4.0% [p = 0.021]), stroke (prevalence increased from 1.4% to 9.0% [p = 0.009]), and endoleak (prevalence increased from 4.0% to 29.3% [p = 0.001]). However, revascularization was not shown to reverse these effects. Longer aortic coverage (≥ 150 mm) was associated with an increased prevalence of spinal cord ischemia (from 1.3% to 12.5% [p = 0.011]) and mortality (from 1.3% to 15.6% [p = 0.003]). CONCLUSION: In patients undergoing endovascular stenting for thoracic aortic dissection, in cases where LSA coverage is necessary, revascularization should be considered before the procedure to avoid complications such as left arm ischemia, stroke, and endoleak, and where feasible, an appropriate preoperative assessment should be carried out.

Preoperative assessment of anatomical suitability for thoracic endovascular aortic repair.

Endovascular treatment of descending thoracic aortic pathologies requires a preoperatively determined interventional strategy. Its feasibility depends mainly on anatomic factors: the morphology of the proximal and distal fixation sites, the diameter and disease state of the access vessels. These factors represent important predictors of success and the most important exclusion criteria. Current diagnostic evaluation of aortic aneurysm for endovascular repair relies primarily on CT scan associated with 3D-reconstruction to assess the anatomical suitability for endograft implantation. In patients with an inadequate length of the proximal or distal neck, the left subclavian artery or the coeliac trunk can be overstented to effectively exclude thoracic aortic lesions. Deliberate coverage of aortic side branches should be decided prior to the procedure (guided by a extensive anatomical assessment) or carefully be avoided in order to reduce major morbidity, especially cerebral embolization, spinal cord ischemia and ischemic abdominal complications.

Modified Blalock-Taussig shunt patency for pulmonary atresia: assessment with electron beam CT.

PURPOSE: The purpose of this work was to evaluate electron beam CT (EBCT) for the noninvasive assessment of modified Blalock-Taussig (BT) shunt patency in patients with pulmonary atresia. METHOD: Five infants and children with pulmonary atresia and modified BT shunts underwent contrast-enhanced EBCT. Modified BT shunts from the subclavian artery to the pulmonary artery were performed to improve the pulmonary blood flow. Electrocardiogram (ECG)-triggered EBCT was obtained with a 100 ms exposure, 3 mm section thickness, and 2 mm table feed after intravenous administration of contrast material. Three-dimensional (3D) or maximum intensity projection (MIP) EBCT images were compared with conventional angiography. The visibility of modified BT shunts was graded and recorded with use of a four-point scale. RESULTS: Satisfactory visualization was achieved in both 3D and MIP EBCT images to evaluate modified BT shunt patency. CONCLUSION: Contrast-enhanced 3D or MIP EBCT imaging with ECG trigger may be used as an effective substitute to evaluate modified BT shunts with low radiation dose exposure.

Follow-up of infants after systemic-pulmonary shunts, performed with fresh frozen vein homografts. Postoperative angiographic assessment.

Ten of twenty-six modified Blalock-Taussig shunts performed with fresh frozen vein homograft were studied angiographically. In two of them the shunt was stenosed. The remaining eight shunts were satisfactory. Among them in four irregularities of the inner surface and in four spindle shape of the shunt were observed. The diameter ratio between subclavian artery and homograft at the time of operation and later as seen on the angiograms did not change. This suggests that spindle shape of homograft is caused by growth rather than by aneurysm formation.

Case management in cerebral revascularization.

PURPOSE: We examined the clinical and financial outcomes of case management coupled with the initiation of selective use of the intensive care unit (ICU) in all cerebral revascularization procedures. METHODS: Three hundred eighty-four procedures in 331 patients were retrospectively reviewed. Morbidity and mortality rates, hospital length of stay, cost, and ICU or hospital readmissions were examined. Hypertension was examined as an independent variable for its effect on patient outcome. RESULTS: Cerebral revascularization, including carotid endarterectomy, vertebral-carotid artery transposition, and subclavian-carotid artery transposition, yielded a 0.78% stroke rate and 0.26% perioperative death rate in this series. ICU admission was necessary in nine patients (2.3%) for cardiac or respiratory instability. Three patients (0.78%) required transfer to the ICU for management of hypertension or hypotension. The mean hospital length of stay after institution of case management was reduced by 2.1 days, and the mean cost was decreased by $1987, a savings of 28.9% of total hospital cost. CONCLUSION: The dual approach of case management and selective use of the ICU promotes quality patient care, conserves financial resources without adversely affecting morbidity or mortality rates, enhances physician/nurse collaboration, and improves patient satisfaction.

[Growth of the pulmonary arteries and morphological assessment after Blalock-Taussig shunts].

Clinical and angiographic results were studied after 121 classic Blalock-Taussig shunts (CBT) and 74 modified Blalock-Taussig shunts (MBT) with polytetrafluoroethylene grafts. 1. The actuarial shunt patency rate in all 195 patients showed a significant difference in patency between CBT and MBT at six months after operation. (CBT = 91.6%, MBT = 98.6%, p < 0.05). The patency rate of 4-mm MBT grafts was lower than that of CBT of grafts. 2. The 109 patients who underwent postoperative angiography were evaluated for morphological features of anastomosis. The incidence of pulmonary arterial stenosis caused by anastomosis was 15.3% with CBT and 18.9% with MBT; these values were not significantly different. The primary characteristic of CBT anastomosis was a funnel-shaped stenosis at the side of shunt vessel, but this feature did not disturb pulmonary artery growth. In contrast, MBT grafts sometimes narrowed along their entire length, causing deterioration of pulmonary artery growth. 3. The 60 patients in whom pre- and post-operative pulmonary artery sizes were able to be evaluated were studied for pulmonary artery growth. The development ratio (DR) was calculated as the ratio of postoperative to preoperative pulmonary artery index (post-PAI/pre-PAI). a) DR in patients with lower preoperative PAI was greater than that in patients with higher preoperative PAI. b) DR in patients under the age of 6 months was greater than that in older patients. c) There were no significant differences in DR between CBT and MBT or between pulmonary stenosis and pulmonary atresia. d) Relative to the BT shunt, the ipsilateral pulmonary artery grew to the same degree as the contralateral artery.(ABSTRACT TRUNCATED AT 250 WORDS)

[Assessment of Blalock-Taussig shunts in children with complex cardiac anomalies associated with reduced pulmonary blood flow and total anomalous pulmonary venous drainage].

Eleven patients with syndromes of asplenia and polysplenia associated with total anomalous pulmonary venous drainage (TAPVD) were underwent Blalock-Taussig (B-T) shunt operation for reduction of pulmonary blood flow. The age of patients at operation were 6 days to 5 years (average 19.5 +/- 18.7 month). There were seven patients in supracardiac type and four in cardiac type of TAPVD. All patients didn't present obstruction to pulmonary venous return (PVO) before B-T shunt operation. There were one early (9%) and two late deaths (20%) after surgery. Although the hospital death was related to perioperative errors. Two late deaths were not due to the PVO. One of infants had moderately pulmonary congestion and cardiac failure after shunt procedure. Two patients were measured pressure gradient (3 to 4 mmHg) between common pulmonary vein to atrium chamber before shunt procedure. Repeated catheterization revealed that 6 of them could be measured pressure gradient, 3 to 7 mmHg, and no patients had clinical sign of the PVO. Our results demonstrated that B-T shunt operation could be satisfactory for syndromes of asplenia and polysplenia associated with reduced pulmonary blood flow and TAPVD.

[Angioplasty of a stenosed Blalock-Taussig shunt. Its long-term assessment]. / Angioplastia del Blalock-Taussig estenótico. Valoración a largo plazo.

A Blalock-Taussig shunt was performed in a child of 14 months diagnosed with tetralogy of Fallot associated with a complete atrioventricular defect. Seven months later, a balloon dilatation was performed because the shunt was stenosed in the site of the distal anastomosis. Repeat angiography we proved the patency of the shunt without restenosis 4 year later.

Modified Blalock-Taussig shunt in infants and young children. Clinical and catheterization assessment.

The effectiveness of 19 modified Blalock-Taussig shunts performed with expanded polytetrafluoroethylene was evaluated clinically and by cardiac catheterization with angiography 4 to 24 months after operation. Fifteen patients underwent operation in infancy. Conduit diameters included 4 mm (nine cases), 5 mm (eight cases), and 6 mm (two cases) sizes. Two of the 4 mm conduits failed after 1 year following implantation. The remaining 17 shunts (89%) remained widely patent. In patients with patent shunts, the oxygen saturation values were significantly improved from the preoperative values. Two children demonstrated associated subclavian artery occlusion distal to the graft anastomosis. There were no deaths. Thirteen children underwent more complete elective cardiac repair 5 to 24 months later. Although the modified Blalock-Taussig procedure is an effective short-term alternative to the classic Blalock-Taussig shunt, the effectiveness of the 4 mm diameter conduit may be limited without postoperative anticoagulant therapy.

Modified Blalock-Taussig shunt operation without cardiac catheterization: two-dimensional echocardiographic preoperative assessment in cyanotic infants.

Between May 1981 and December 1983, 25 infants with cyanotic congenital heart defects underwent 26 Blalock-Taussig shunt operations without cardiac catheterization and angiocardiography. In these infants, the diagnosis was established by 2-dimensional echocardiography (2-D echo) supplemented with clinical findings, chest x-ray and electrocardiography. The right and left pulmonary artery measurements, a prerequisite for a shunt operation, determined by 2-D echo were compared with those at surgery and had an excellent correlation (r = 0.94). No infant died as a consequence of an early shunt failure, and only 1 died of postoperative pyothorax. In conclusion, 2-D echo may eliminate the need for invasive investigation in selected patients undergoing the Blalock-Taussig anastomosis.

Postoperative angiographic assessment of modified Blalock-Taussig shunts using expanded polytetrafluoroethylene (Gore-Tex).

Thirty-six of 87 modified Blalock-Taussig shunts done with expanded polytetrafluoroethylene (Gore-Tex) were restudied angiocardiographically. In 7 patients the study was carried out within 1 month of the shunt operation because the patients failed to make satisfactory clinical progress. Two shunts were occluded and 1 ws stenosed; all 3 were in neonates. The remaining 29 patients were reinvestigated electively between 5 and 29 months postoperatively and had a 97% shunt patency rate. Because of the rather high incidence of irregular or stenosed shunts among neonates with 4 mm conduits, we now prefer to use a larger conduit even in this age group.

Echocardiographic assessment of a Blalock-Taussig shunt.

A case of echocardiographic confirmation of the patency of a Blalock-Taussig anastomosis is presented. Using the left atrium-to-aortic ratio (LA/Ao), we could document an increase in left atrial size representing an increase in pulmonary blood flow. This is the first report using echocardiography to prove the patency of a systemic-to-pulmonary artery anastomosis.

[Transoral Doppler ultrasound echography under local anaesthesia for the assessment of vertebral artery blood flow (author's transl)]. / Transorale Doppler-Sonographie unter Schleimhautanästhesie zur Beurteilung der Strömungsverhältnisse in den Aa. vertebrales (Vertebralis-Doppler)

Uncalibrated flow in the vertebral arteries was registered with a bidirectional CW Doppler ultrsound apparatus. It was applied to 20 patients, results being compared with aortic arch angiograms in which the extracranial part of all four cerebral vessels was seen. In 14 the vertebral arteries had a symmetrical flow and lumen, a similar symmetrical result being obtained with the Doppler. Hypoplasia of one vertebral artery was present in two patients the distinct asymmetry being recorded by the ultrasound. Three patients with central stenosis in one subclavian artery and subclavian "steal" were found to have reverse flow by the Doppler method in the vertebral artery on the side of the stenosis. Endarterectomy was performed on the affected subclavian artery in two of these patients: post-operative vertebral ultrasound recordings demonstrated a return to physiological flow direction in both vertebral arteries.