Subclavian artery supply disruption sequence: hypothesis of a vascular etiology for Poland, Klippel-Feil, and Möbius anomalies

A hypothesis is presented to explain the pathogenesis of the Poland, Klippel-Feil, and Möbius anomalies, isolated absence of the pectoralis major with breast hypoplasia, isolated terminal transverse limb defects, and the Sprengel anomaly. We propose that these conditions are the result of an interruption of the early embryonic blood supply in the subclavian arteries, the vertebral arteries and/or their branches, and hypothesize that the occlusions occur at specific locations in these vessels during or around the sixth week of embryologic development and produce predictable patterns of defects. The term subclavian artery supply disruption sequence (SASDS) is suggested for the group of birth defects represented by the above conditions. Possible causes for interruption of embryonic blood supply are discussed.

Kommerell's diverticulum and right-sided aortic arch: a cohort study and review of the literature

We report four consecutive cases of Kommerell's aneurysm of an aberrant left subclavian artery in patients with a right-sided aortic arch and the results of a systematic review of the literature. In our cohort of patients, three had an aneurysm limited to the origin of the aberrant subclavian artery, causing dysphagia and cough, and one had an aneurysm involving also the distal arch and the entire descending thoracic aorta, causing compression of the right main-stem bronchus. A left subclavian-to-carotid transposition was performed in association with the intrathoracic procedure, and a right thoracotomy was used in all patients. One of the patients underwent surgery with deep hypothermia and circulatory arrest, and the others with the adjunct of a left-heart bypass. The repair was accomplished with an interposition graft in two patients and with endoaneurysmorrhaphy in the others. The postoperative course was complicated by respiratory failure and prolonged ventilation in one patient, and one patient died because of severe pulmonary emboli. The survivors are alive and well at a follow-up of 1 to 3 years. Only 32 cases of right-sided aortic arch with an aneurysm of the aberrant subclavian artery have been reported: 12 were associated with aortic dissection, and 2 presented with rupture. Surgical repair was accomplished in 29 patients. A number of operative strategies were described: right thoracotomy, bilateral thoracotomy, left thoracotomy with sternotomy, sternotomy with right thoracotomy, and left thoracotomy. In only 12 cases was the subclavian artery reconstructed. We believe that a right thoracotomy provides good exposure and avoids the morbidity associated with bilateral thoracotomy or sternotomy and thoracotomy. We feel that a left subclavian-to-carotid transposition completed before the thoracic approach revascularizes the subclavian distribution without increasing the complexity of the intrathoracic procedure.

Major Vascular Anomalies in Turner Syndrome

BACKGROUND

Turner syndrome (TS) is associated with aortic coarctation and dissection; hence, echocardiographic evaluation of all patients is currently recommended. X-ray angiography in clinically symptomatic patients has suggested a range of other vascular anomalies, but the true prevalence of such lesions in TS is unknown. To better understand the prevalence and pathogenesis of cardiovascular defects in TS, we prospectively evaluated a group of asymptomatic adult volunteers with TS using magnetic resonance (MR) angiography.

METHODS AND RESULTS

A total of 85 adults with TS and 27 normal female adult volunteers underwent gadolinium-enhanced 3D MR angiography. A high prevalence of aortic anomalies was seen in women with TS, including elongation of the transverse arch (49%), aortic coarctation (12%), and aberrant right subclavian artery (8%). Venous anomalies were also prominent, including persistent left superior vena cava (13%) and partial anomalous pulmonary venous return (13%). None of these anomalies were found in healthy female controls. The constellation of elongation of the transverse arch, aortic coarctation, and persistent left superior vena cava was significantly associated with women with TS. Neck webbing and increased thoracic anterior-to-posterior dimension diameters were strong predictors for arterial and venous anomalies.

CONCLUSIONS

Thoracic vascular anomalies are common in TS, occurring in approximately 50% of a group not preselected for cardiovascular disease. The highly significant association between neck webbing, increased chest diameter, and these vascular anomalies suggests that in utero, centrally localized lymphatic obstruction may contribute to these cardiovascular deformities in TS. Improved recognition of these often-undetected vascular lesions may be important for identification of patients in need of closer cardiovascular monitoring.

Aberrant subclavian artery: surgical treatment in thirty-three adult patients

PURPOSE

Because of the scarcity of large series in the literature, our experience with surgery for aberrant subclavian arteries (aSA) in adults was reviewed.

METHODS

During the last 16 years we have surgically treated 33 adult patients with aSA. Twenty-eight patients had a left-sided aortic arch with a right aSA whereas five had a right-sided aortic arch with a left aSA. Eleven patients (group 1) had dysphagia caused by esophageal compression by a nonaneurysmal aSA; five patients (group 2) had ischemic symptoms caused by occlusive disease of a nonaneurysmal aSA; 10 patients (group 3) had aneurysms of the aSA with or without symptoms caused by esophageal compression or arterial thromboembolism; and seven patients (group 4) had an aSA arising from a diseased (usually aneurysmal) thoracic aorta. In all cases the divided aSA was revascularized, most often by direct transposition into the ipsilateral common carotid artery. Nine of the 16 patients in groups 1 and 2 underwent operation with a cervical approach alone. In the remaining seven, the cervical approach was combined with a median sternotomy (six cases) or a left thoracotomy (one case). In the 17 patients in groups 3 and 4, either a cervical approach (two cases), a median sternotomy (four cases), or a two-staged approach combining a supraclavicular incision on the side of the aSA with a posterolateral thoracotomy on the side of the aortic arch (11 cases) was used. Aortic cross-clamping was required in 12 of these patients to perform the transaortic closure of the origin of the aSA with patch angioplasty (three cases), or prosthetic replacement of the descending thoracic aorta (nine cases). Cardiopulmonary bypass was used in six patients (including three with hypothermic circulatory arrest).

RESULTS

Four patients, all in groups 3 and 4, died after operation: two of multiorgan failure, one of heart failure, and one of esophageal rupture. Satisfactory clinical and anatomic results were obtained in the remaining 29 patients.

CONCLUSIONS

The surgical approach to aSA must be flexible and adapted to the anatomic conditions found. We recommend routine reconstruction of the aSA to avoid ischemic complications in the vertebrobasilar territory or upper extremity. Provision should be made for cardiopulmonary bypass in patients with aneurysm of aSA or associated aortic aneurysm.

Right aortic arch. Types and associated cardiac anomalies

An analysis was made of 78 pathologic specimens in which a right aortic arch was present. In four, the right arch was part of a double aortic arch. In 74 cases the right aortic arch was the only arch. The cases of right aortic arch could be subdivided into two groups as follows: (1) that with a retroesophageal aortic segment (three cases) and (2) that without a retroesophageal segment (71 cases).

The latter cases could be subdivided according to the nature of the origin of the branches of the arch as follows: (1) mirror image branching (60 cases), (2) aberrant left subclavian artery (ten cases) and (3) isolation of left subelavian artery (one case).

Congenital heart disease, of which the tetralogy of Fallot was the most common, was observed in each of the cases of right arch without retroesophageal aortic segment. Such an association was seen in one of three cases of right aortic arch with retroesophageal aortic segment and in three of the four cases of double aortic arch.

The potential for significant tracheal and esophageal obstruction is present in double aortic arch, in right aortic arch with retroesophageal segment and in right aortic arch without retroesophageal segment but with an aberrant left subelavian artery. In the latter condition, significant esophageal and tracheal compression depends upon the presence of a left-sided ductus arteriosus. This state was observed in five of ten cases with right aortic arch and aberrant left subelavian artery.

The aberrant right subclavian artery (arteria lusoria): the morphological and clinical aspects of one of the most important variations--a systematic study of 141 reports

The most important abnormality of the aortic arch is arguably the presence of an aberrant right subclavian artery (arteria lusoria). If this vessel compresses the adjacent structures, several symptoms may be produced. The aim of the study is to present the morphological and clinical aspects of the aberrant right subclavian artery. Three different databases searched for a review of pertinent literature using strictly predetermined criteria. Of 141 cases, 15 were cadaveric and 126 were clinically documented. The gender distribution of the subjects was 55.3% female and 44.7% male. The mean age of the patients at symptoms onset was 49.9 ± 19.4 years for all patients but 54.0 ± 19.6 years and 44.9 ± 18.1 years for female and male subjects, respectively (P = 0.0061). The most common symptoms in this group were dysphagia (71.2%), dyspnea (18.7%), retrosternal pain (17.0%), cough (7.6%), and weight loss (5.9%). The vascular anomalies coexisting with an arteria lusoria were truncus bicaroticus (19.2%), Kommerell's diverticulum (14.9%), aneurysm of the artery itself (12.8%), and a right sided aortic arch (9.2%). In conclusion, compression of adjacent structures by an aberrant right subclavian artery needs to be differentiated from other conditions presenting dysphagia, dyspnea, retrosternal pain, cough, and weight loss.

Congenital alveolar capillary dysplasia--an unusual cause of respiratory distress in the newborn

The clinical and anatomical features of a patient with an unusual pulmonary malformation, is reported. The clinical course was consistent with the syndrome of persistent fetal circulation; morphologically, however, the patient was found to have a unique form of pulmonary dysplasia. Failure of formation and ingrowth of alveolar capillaries led to absence of normal air-blood barriers in this term infant. In addition anomalous veins were present in the bronchovascular bundles. Morphometric study indicated that the lungs were otherwise mature. This selective deficiency and dysplasia suggests that distal pulmonary epithelial and vascular development operate under separate control mechanisms.

Aberrant subclavian artery and Kommerell aneurysm: Surgical treatment with a standard approach

OBJECTIVE

We report our experience with a standard surgical technique for treatment of aneurysms associated with Kommerell diverticulum and aberrant subclavian artery.

METHODS

During a 10-year interval, 10 patients with aneurysms of Kommerell diverticulum and aberrant subclavian artery (8 right, 2 left) underwent surgical repair. All 10 patients had aneurysmal degeneration of the adjacent descending thoracic aorta and 7 had aneurysms of the nonaberrant subclavian artery that required treatment. Four of the patients with large Kommerell aneurysms underwent preliminary carotid-to-aberrant subclavian artery bypass and ligation of the subclavian artery proximal to the origin of the vertebral artery. All patients had graft replacement of the subclavian artery and descending thoracic aneurysms through a left thoracotomy using hypothermic cardiopulmonary bypass and circulatory arrest. Continuity of the aberrant subclavian artery was preserved in the 6 patients without prior carotid-to-subclavian artery bypass.

RESULTS

There were no in-hospital deaths. One patient required reoperation for bleeding, 1 patient developed recurrent laryngeal nerve injury, and 1 patient with delirium had evidence for infarction in the caudate nucleus but recovered completely. There were 4 late deaths from 1.5 to 44 months postoperatively. The remaining 6 patients are well from 8 to 131 months after operation.

CONCLUSIONS

Aneurysms of Kommerell diverticulum and coexisting aneurysms of the adjacent descending thoracic aorta and nonaberrant subclavian artery can be repaired safely with the technique we have utilized.

Surgical treatment of vascular rings: the Mayo Clinic experience

From 1947 through 1992, 37 Mayo Clinic patients underwent operation for the relief of tracheoesophageal obstruction that resulted from vascular rings and related entities. Of the 37 patients, 18 had a double aortic arch, 11 had a right aortic arch with an aberrant left subclavian artery, 4 had a left aortic arch with an aberrant right subclavian artery, 2 had a pulmonary artery sling, 1 had a right aortic arch with mirror-image branching and a left ligamentum arteriosum, and 1 had a left aortic arch, a right descending aorta, and a right ductus arteriosus. Symptoms consisted of stridor, recurrent respiratory infections, and dysphagia. The anomaly was approached through a left thoracotomy in 31 patients, through a right thoracotomy in 4, and through a median sternotomy in 2. Only one early postoperative death (3%) and no late deaths occurred. At long-term follow-up (maximal duration, 45 years), three patients had residual symptomatic tracheomalacia, one of whom required right middle and lower lobectomy for recurrent pneumonia. Magnetic resonance imaging is the imaging technique of choice for accurate delineation of the vascular and tracheal anatomy. When patients are symptomatic, vascular ring should be repaired. The surgical risk is minimal, and the long-term results are excellent.

Aberrant right subclavian artery with left aortic arch: associated cardiac anomalies

Anomalous origin of the right subclavian artery (ARSA) from the aorta distal to the normally positioned left subclavian artery is a relatively frequent congenital anomaly in subjects with left aortic arch. The purpose of this study was to determine the relative frequency of associated cardiovascular anomalies in individuals with this anomaly. From the records of approximately 11,000 pathologic specimens in the Registry of Cardiovascular Disease of United Hospital (St. Paul, MN, USA), we found 128 (1.2%) with ARSA. Of the 128 ARSA, 117 (2.9%) occurred among 4102 instances of congenital heart disease. The 117 cases with congenital heart disease and ARSA were conotruncal anomalies in 38%, septal defects in 28%, obstructive anomalies of the left side of the heart in 21%, right heart anomalies in 5%, and miscellaneous conditions in the other 8%. Down syndrome existed in 14 (12%) of the 117 specimens with ARSA and some congenital cardiac anomaly; nine of the latter had an atrioventricular canal (AVC) malformation.

Aberrant right subclavian artery as a new cardiac sign in second- and third-trimester fetuses with Down syndrome

OBJECTIVE

The right subclavian artery arises normally as the first vessel from the brachiocephalic artery of the aortic arch. An aberrant right subclavian artery arises as a separate vessel from the aortic isthmus and crosses to the right, behind the trachea. This variant is present in <1% of the normal population; however, in subjects with Down syndrome, an incidence between 19% and 36% was reported. The purpose of this study was to assess the possibility of the detection of an aberrant right subclavian artery in fetuses with Down syndrome.

STUDY DESIGN

Fourteen consecutive fetuses with prenatally detected Down syndrome were examined between 18 and 33 weeks of gestation. The presence of an aberrant right subclavian artery was determined by visualization of the transverse 3-vessel trachea view of the upper thorax with color Doppler ultrasonography.

RESULTS

The right subclavian artery was visualized in 100% of fetuses (14/14) with Down syndrome. An aberrant right subclavian artery was identified in 35.7% of trisomy 21 fetuses (5/14). In 1 fetus, the aberrant right subclavian artery was the only abnormal ultrasound finding. In 3 fetuses, an aberrant right subclavian artery was associated with an intracardiac echogenic focus plus additional extracardiac markers. In the fourth fetus, an aberrant right subclavian artery was associated with an atrioventricular septal defect. All 9 fetuses with Down syndrome with a normal origin of the right subclavian artery had additional cardiac and/or extracardiac abnormalities. In 12 cases, pregnancy was terminated; 2 fetuses were live born.

CONCLUSION

This preliminary study suggests that the in utero identification of an aberrant right subclavian artery may be a new ultrasound marker to be found in fetuses with Down syndrome. Further studies are required to assess the incidence of aberrant right subclavian artery in normal fetuses.

Anomalies at the thoracic outlet are frequent in the general population

BACKGROUND

Abnormal anatomy at the thoracic outlet is frequent in patients operated on for thoracic outlet syndrome (TOS). The present study was designed to find out the rate of thoracic outlet anomalies in the general population.

METHODS

Fifty cadavers representing a general population were subjected to a total of 98 meticulously performed cervical dissections to ascertain the frequency of congenital anomalies in the thoracocervicoaxillary region.

RESULTS

During the 98 cervical dissections, 62 instances of abnormal anatomy of the thoracic outlet were found, and fully normal anatomy was found in 36 cases. Of the total 69 abnormalies, 66 could be classified according to Roos: 37 were type 3 abnormalities, 15 were type 5, 9 were type 11, and there was 1 each of type 4, type 6, type 7, type 9, and type 10 abnormalities. The remaining 3 abnormalities did not fit into Roos' classification. Only 10% (5/50) of the cadavers had a bilaterally normal anatomy.

CONCLUSIONS

The results demonstrate that abnormal structures, such as congenital bands in the thoracic outlet, are more common in the general population than had previously been described. We suggest that fibrous bands confer a predisposition for TOS following a certain degree of stress or injury.

Vascular anomalies and tracheoesophageal compression: a single institution's 25-year experience

BACKGROUND

Vascular rings are uncommon anomalies in which preferred strategies for diagnosis and treatment may vary among institutions. In this report, we offer a description of our approach and a review of our 25-year experience.

METHODS

A retrospective review was conducted of all pediatric patients with symptomatic tracheoesophageal compression secondary to anomalies of the aortic arch and great vessels diagnosed from 1974 to 2000.

RESULTS

Thirty-one patients (38%) of eighty-two patients (mean age, 1.7 years), were identified with double aortic arch, 22 patients (27%) with right arch left ligamentum, and 20 patients (24%) with innominate artery compression. Our diagnostic approach emphasized barium esophagram, along with echocardiography. This regimen was found to be reliable for all cases except those with innominate artery compression for which bronchoscopy was preferred, and except those with pulmonary artery sling for which computed tomography or magnetic resonance imaging, in addition to bronchoscopy, were preferred. Left thoracotomy was the most common operative approach (70 of 82; 85%). Ten patients (12%) had associated heart anomalies, and 6 (7%) patients underwent repair. Complications occurred in 9 (11%) patients and led to death in 3 (4%) patients.

CONCLUSIONS

In our practice, barium swallow and echocardiography are sufficient in diagnosing and planning the operative strategy in the majority of cases, with notable exceptions. Definitive intraoperative delineation of arch anatomy minimizes the risk of misdiagnosis or inadequate treatment.

Vascular origin of Poland syndrome? A comparative rheographic study of the vascularisation of the arms in eight patients

Vascularization of the arms has been studied by impedance plethysmography (rheography) in eight children with Poland syndrome, a common malformation characterized by unilateral hand anomaly and ipsilateral aplasia of the inferior head of the pectoralis major muscle. A marked decrease of the velocity of the systolic increase in the arterial volume (Velm) was shown in the affected arms, and the difference between the two arms was significantly higher in the patients than in a control group (P less than 0.02). These results, which are also observed in stenotic atherosclerosis, support the hypothesis of hypoplasia of the ipsilateral subclavian artery as the origin of the malformation, although a local anomaly in arterial-wall viscosity cannot be ruled out. The opacification of the aortic arch in another patient confirmed this hypothesis. Aortography in further patients will be necessary to substantiate our results. However, this technique is not without danger and should only be used during the first months of life when a vascular operation can be envisaged.

Aberrant subclavian artery (arteria lusoria): sex differences in the prevalence of various forms of the malformation. Evaluation of 1378 observations

43 original and 1335 previously published observations of aberrant subclavian artery (A. lusoria) were analyzed. The sex distribution varied for different types of the malformation: females predominated over males in instances of right aberrant subclavian artery and if pre-stenotic A. lusoria was combined with coarctation of the aorta. Male predominance was found in cases of combination of post-stenotic A. lusoria with coarctation and of aberrant left subclavian artery. An equal sex distribution was observed for A. lusoria combined with interruption of the aortic arch. Clinical, pathological and embryological aspects of the condition are discussed.

Dysphagia lusoria: clinical aspects, manometric findings, diagnosis, and therapy

OBJECTIVE

The lusorian artery is a rare anomaly of the right subclavian artery. This artery arises from the aortic arch distal of the left subclavian artery, crossing the midline behind the esophagus. Normally this anomaly causes no symptoms. Sometimes dysphagia first appears above the age of 40 yr.

METHODS

In the period of 1992-1997, the diagnosis of an aberrant right subclavian artery was made in five patients with dysphagia who were referred to a small community hospital. A sixth patient had a right-sided aorta with an aberrant left subclavian artery.

RESULTS

Endoscopy revealed a pulsating impression in the esophagus of three patients. Four patients had coexisting esophageal abnormalities. Barium contrast examination of the esophagus showed a characteristic diagonal impression at the level of the fourth thoracic vertebra in all patients. Computed tomography and angiography confirmed the diagnosis and excluded aneurysms. Manometric investigation of the esophagus revealed nonspecific abnormalities in five patients. Drug treatment was sufficient in three patients (mean follow-up, 6.2 yr). Three patients were operated upon because of persistent dysphagia. Through a cervical approach the artery was ligated near its root and connected with the right carotid artery. Postoperatively two patients became symptom-free, the other patient still has intermittent dysphagia.

CONCLUSION

Dysphagia can be caused by a rare anomaly of the subclavian artery. The diagnosis can be overlooked at endoscopy, but barium contrast study of the esophagus will reveal the abnormality. In patients with coexisting esophageal abnormalities the finding may be incidental and specific conservative treatment may be sufficient. Manometry cannot be used to diagnose this condition or to predict surgical outcome. When the symptoms are intractable, surgical correction should be considered even if coexisting esophageal abnormalities are present.

Hybrid repair of Kommerell diverticulum

OBJECTIVE

Kommerell diverticulum carries the risk of rupture or dissection if left untreated. Various methods of repair have been described, and options have recently expanded to include the hybrid approach. This study describes hybrid repair techniques for Kommerell diverticulum and assesses outcomes.

METHODS

Between 2005 and 2010, a total of 10 patients underwent hybrid repair of Kommerell diverticulum (3 right-sided arches) by elephant trunk with endovascular completion (n = 4), frozen elephant trunk (n = 3), or stent grafting with cervical debranching (n = 3). Mean age at procedure was 57 ± 25.5 years. Subclavian artery revascularization was performed preoperatively (n = 4), intraoperatively (n = 3), or postoperatively (n = 3), either as carotid-to-subclavian bypass (n = 7; n = 3 bilateral) or originating from the ascending aorta (n = 3). Data were obtained from the prospectively collected database and chart review.

RESULTS

There was no in-hospital mortality, nor were there any cases of respiratory or renal failure. There were no cases of paraplegia, but there was 1 stroke. Two patients had type 2 endoleaks develop; 1 required subclavian coil embolization. Mean hospital stay was 8.73 ± 4 days. After repair, there were no ruptures, no significant growth, and all patients remain free of symptoms.

CONCLUSIONS

Hybrid repair is a safe and effective surgical treatment option for Kommerell diverticulum. Selection of the specific type of intervention is based on patient anatomy and comorbid conditions.

Vascular rings: a practical approach to imaging diagnosis

Vascular ring is a term given to a combination of vascular and often ligamentous structures that encircle the trachea and esophagus. The diagnosis can be difficult because clinical symptoms can be variable and nonspecific, and because vascular arrangements that result in vascular rings in some patients do not form vascular rings in others. The clinical manifestations comprise a spectrum ranging from no symptoms to feeding difficulties, repeated infections, and life-threatening respiratory compromise. The diagnosis of vascular ring can be made by various imaging modalities. Therefore it is imperative that pediatric radiologists be familiar with the anatomic variants that can result in a symptomatic ring needing surgical repair, their imaging appearance and the appropriate imaging algorithm. The goals of this manuscript are to describe common and uncommon types of vascular rings, to simplify the differential diagnosis, and to outline the imaging options for accurate diagnosis.

Diagnosis and management of congenital vascular rings: a 22-year experience

Between 1968 and 1990, we operatively treated 39 patients (19 boys, 20 girls) with congenital aortic arch anomalies. Median age was 7 months (range, 1.5 months to 23 years). Thirty-seven patients (95%) had respiratory symptoms. Barium swallow was diagnostic in 95%. Right arch with aberrant left subclavian artery and double aortic arch were the most common types (11 each). Treatment of an aortic diverticulum was documented in 19 patients; the aortic diverticulum was excised (9), managed by aortopexy (7), or left in situ (3). Postoperative recovery was rapid, with a median intensive care unit stay of 2 days, time to oral feeding of 1 day, and postoperative time to discharge of 7 days. Two deaths occurred: 1 infant had undergone emergent operation for control of hemorrhage from an aortotracheal fistula due to tracheostomy tube erosion, and the other had multiple associated congenital heart defects. Postoperative complications included bleeding (1), pneumonia (5), and chylothorax (4). One boy had persistent severe symptoms due to an untreated aortic diverticulum and underwent subsequent excision of the aortic diverticulum with complete relief of symptoms. Median length of follow-up was 12.5 months, with at least 97% of survivors completely or nearly completely free of symptoms from the vascular ring. These results suggest that early repair of congenital aortic vascular rings, including fixating or excising an associated serious aortic diverticulum, is safe and effective and allows for normal tracheal growth.

Stent-graft therapy for subclavian artery aneurysms and fistulas: single-center mid-term results

PURPOSE

To evaluate the potential of covered stents to replace surgery in the treatment of subclavian artery aneurysms and traumatic injuries.

MATERIALS AND METHODS

Nine patients (five men, four women; age range, 20-83 years; mean, 54 years) with subclavian artery aneurysms (n = 5) or fistulas (n = 4) were treated with stent-grafts. All devices used were custom-made, consisting of polytetrafluoroethylene (PTFE)-covered Palmaz (n = 5), Wallstent (n = 2), Z stents (n = 8), or a polyester-covered Z stent (n = 1). One patient was lost to follow-up after 2 months. All others were followed up with clinical evaluation, computed tomography (CT), and/or ultrasound.

RESULTS

All devices were deployed successfully with exclusion of the aneurysms and fistulas. There were two procedure-related complications (22%), consisting of groin pseudoaneurysms requiring surgical repair 3 and 9 days after the procedure. One of those patients required additional oral antibiotic therapy for a postsurgical groin wound infection. One patient developed a stenosis at 12 months, which required angioplasty. The stent-graft thrombosed in one patient because of a kink 2 months after placement, which was successfully treated by thrombolysis and placement of a Wallstent. The primary and secondary patencies are 89% and 100%, respectively, after a mean follow-up of 29 months (2-66 mo).

CONCLUSION

Mid-term results of stent-graft therapy of subclavian artery aneurysms and fistulas are encouraging, with low morbidity and excellent clinical outcome.

Imaging strategies for vascular rings

Thirty-nine patients have undergone operation for relief of tracheoesophageal compression resulting from vascular rings and related entities at the Mayo Clinic. Nineteen patients had a double aortic arch, 11 patients had a right aortic arch with an aberrant left subclavian artery, 5 patients had a left aortic arch with an aberrant right subclavian artery, 2 patients had a pulmonary artery sling, 1 patient had a right aortic arch with mirror-image branching and a left ligamentum arteriosum, and 1 patient had a left aortic arch, a right descending aorta, and a right ductus arteriosus. Diagnostic examinations included chest radiography, barium esophagography, angiography, and, more recently, transthoracic echocardiography, computed tomography, and magnetic resonance imaging. A comparison among the various diagnostic techniques used in 12 patients during the last 12 years showed that angiography (n = 7), magnetic resonance imaging (n = 5), and computed tomography (n = 3) were the most reliable, as they always accurately delineated the anatomy. However, in the 6 patients who underwent transthoracic echocardiography, 1 of whom was an older child and 2 of whom were adults, the vascular abnormality was described correctly only once; in the other 5 patients, the results were false-negative or the technique failed to visualize the relevant vascular structures sufficiently. Currently, magnetic resonance imaging is our imaging technique of choice for the delineation of the vascular and tracheal anatomy in patients suspected of having a vascular ring.

Right aortic arch with isolation of the left subclavian artery: case report and review of the literature

Of the right aortic arch anomalies, a right arch with isolation of the left subclavian artery is the least common. Herein we describe a 52-year-old woman in whom this anomaly was discovered during cerebral angiography for evaluation of a giant symptomatic intracavernous carotid aneurysm. Isolation of the left subclavian artery may be suggested in a patient with a right arch in whom the blood pressure or pulse in the left upper extremity is diminished. Although the isolated left subclavian artery produces the hemodynamic alterations of a subclavian steal, review of the 39 cases reported in the literature revealed only 5 patients with symptoms suggestive of vertebrobasilar insufficiency and 5 patients with weakness of the left upper extremity. Although the patient we describe had no known heart disease, congenital heart disease was present in 23 of the 39 reported cases (59%), tetralogy of Fallot occurring most frequently.

Möbius sequence: further in vivo support for the subclavian artery supply disruption sequence

Möbius sequence consists of a congenital bilateral facial nerve palsy and external ophthalmoplegia often associated with malformations of the limbs and orofacial structures. The pathogenesis of the sequence is a subject of debate. However, a new hypothesis proposes that Möbius sequence results from an interruption of embryonic blood supply (subclavian artery supply disruption sequence). Here we present an infant with bilateral facial nerve palsy (VII), external ophthalmoplegia (IV, VI), paresis of cranial nerves V, IX, X, XI, and XII, absence of the pectoralis major muscle (Poland anomaly), terminal transverse limb defects, and absence of the right diaphragm. Also, he was found to have discrete foci of brainstem calcifications in the region of the dorsal respiratory group on both CT scan and the histologic sections with microscopic evidence of diffuse brainstem "injury." The anomalies and histopathology noted in this infant imply that vascular insufficiency prior to the sixth week of gestation involving the proximal sixth intersegmental artery may result in the manifestations presented in this report and lend further support for the existence of a subclavian artery supply disruption sequence.