RETROESOPHAGEAL SUBCLAVIAN ARTERIES: SURGICAL MANAGEMENT OF SYMPTOMATIC CHILDREN

Aberrant subclavian arteries, which form a type of vascular ring, elicit symptoms of dysphagia and chronic respiratory problems. Simple division of the encircling vessel has been the accepted treatment but has frequently led to various long-term complications. These include ischemia of the arm, which in turn results in claudication and the subclavian-vertebral "steal syndrome." Improved methods of reconstructive vascular surgery allow reestablishment of direct flow to the subclavian artery by means of graft insertion or reimplantation of the aberrant artery. With the use of these newer techniques, vascular continuity has been restored in two young patients.     

MODIFIED LEAD FOR PERMANENT TRANSVENOUS CARDIAC PACING

A modified pacemaker lead that can be inserted by percutaneous puncture of the subclavian vein, as in the Seldinger technique, has been designed for permanent cardiac pacing. Its use may be advantageous when isolation of an adequate vein for electrode insertion is difficult or impossible.     

Piercing the left lung with a pacemaker lead,an uncommon complication

Although percutaneous insertion of pacemaker leads is a simple and safe method, it remains a procedure with a relatively high complication rate. We describe an uncommon and avoidable complication of this technique: piercing the lung with a pacemaker lead in an obese patient after direct puncture of the subclavian vein.     

Complications of central venous catheterization from an anatomical point of view

For access to the central venous system numerous percutaneous methods and approaches exist. Questions are often raised concerning which approach is the safest. In 18 human cadavers, we punctured the internal jugular vein via an anterior and posterior approach and the subclavian vein via an infraclavicular route to determine which of these approaches is better with respect to success rate and frequency of puncture complications. The position of the needles was assessed by dissection. Successful venipunctures were achieved in 81% by the posterior approach, as opposed to 58% by the anterior approach and the infraclavicular route. The lowest frequency of complications was attained by the posterior approach (17%) too, whereas the anterior approach (33%) and the subclavian route (25%) had higher complication rates. The main complication of posterior and anterior approaches was inadvertent arterial puncture (9 vs. 19%). At the subclavian approach puncture of a 'wrong' vein was frequent (14%), and the complications included a case of pleura lesion. In conclusion the posterior approach to the internal jugular vein is superior to the other investigated approaches, and therefore, it can reasonably be proposed as a usual route for the insertion of a central venous catheter.     

Extensive Thrombosis Following Lead Extraction: Further Justification for Routine Post-operative Anticoagulation

Lead extraction is becoming increasingly common as indications for pacing and ICD insertion expand. Periop management varies between extraction centers, and no clinical guidelines have addressed the need for perioperative anticoagulation. We report a case of massive thrombosis which occurred shortly after laser lead extraction and is undoubtedly related to the trauma of the extraction and ensuing hypercoagulabiilty. Routine post-operative anticoagulation has been advocated as a means to prevent access vein (subclavian) stenosis, but many centres do not employ a routine post-extraction anticoagulation strategy. Pulmonary embolism following lead extraction is a known complication of this procedure and late mortality following lead extraction is a significant and underappreciated problem. We propose that further research attention should be directed at addressing the issue of routine post-extraction anticoagulation.     

Ethyl alcohol-induced cardiovascular malformations in the chick embryo

Chick embryos incubated for 72-80 hours were exposed to various volumes (0.20-0.40 m1/egg) of 50% ethyl alcohol. Examination of embryos at day 14 of incubation showed that higher doses of ethanol decreased the survival rate of embryos compared with control embryos. Three major categories of cardiovascular malformations were observed in this study: intracardiac anomalies characterized primarily by isolated ventricular septal defect, ventricular septal defect with overriding aorta, double outlet right ventricle or common aorticopulmonary trunk; aortic arch anomalies; and subclavian artery anomalies. Frequencies of embryos with intracardiac anomalies were equal to or greater than 64.8% in the six groups exposed to ethanol. Administration of ethanol also induced high frequencies of embryos with subclavian artery anomalies (11.2-89.1%). Absence or hypoplasia of the right and/or left secondary subclavian artery was commonly associated with persistence of the corresponding primary subclavian artery. Bilateral absence and/or hypoplasia of the secondary subclavian arteries was more common than unilateral anomalies, whereas absence of the left secondary subclavian artery was more commonly observed than an absent right secondary subclavian artery. No embryos in the two control groups combined (n = 94) demonstrated aortic arch or subclavian artery anomalies.     

The Supraclavicular Fossa Ultrasound View for Central Venous Catheter Placement and Catheter Change Over Guidewire

The supraclavicular fossa ultrasound view can be useful for central venous catheter (CVC) placement. Venipuncture of the internal jugular veins (IJV) or subclavian veins is performed with a micro-convex ultrasound probe, using a neonatal abdominal preset with a probe frequency of 10 Mhz at a depth of 10-12 cm. Following insertion of the guidewire into the vein, the probe is shifted to the right supraclavicular fossa to obtain a view of the superior vena cava (SVC), right pulmonary artery and ascending aorta. Under real-time ultrasound view, the guidewire and its J-tip is visualized and pushed forward to the lower SVC. Insertion depth is read from guidewire marks using central venous catheter. CVC is then inserted following skin and venous dilation. The supraclavicular fossa view is most suitable for right IJV CVC insertion. If other insertion sites are chosen the right supraclavicular fossa should be within the sterile field. Scanning of the IJVs, brachiocephalic veins and SVC can reveal significant thrombosis before venipuncture. Misplaced CVCs can be corrected with a change over guidewire technique under real-time ultrasound guidance. In conjunction with a diagnostic lung ultrasound scan, this technique has a potential to replace chest radiograph for confirmation of CVC tip position and exclusion of pneumothorax. Moreover, this view is of advantage in patients with a non-p-wave cardiac rhythm were an intra-cardiac electrocardiography (ECG) is not feasible for CVC tip position confirmation. Limitations of the method are lack of availability of a micro-convex probe and the need for training.     

Role of the vascular laboratory in the diagnosis of aortic arch occlusive disease: Screening of 2000 patients

A significant difference in bilateral systolic brachial artery pressures and the presence of systolic bruit over a subclavian artery suggests occlusive disease in the innominate or subclavian arteries. Two thousand patients with these signs underwent ultrasonography of the carotid, subclavian, and brachial arteries in our laboratory. Doppler recordings of a vertebral artery, with hyperemia testing of the ipsilateral arm, identified those with a subclavian steal syndrome. In each case, angiography confirmed the laboratory diagnosis. The effectiveness of corrective surgery was evaluated noninvasively. Illustrative cases are presented and discussed.     

Thoracic aorta dissection associated with aberrant right subclavian artery: treatment with endovascular stent-graft placement

Dissecting aneurysm is the condition produced by separation of the layers of the arterial wall by circulating blood. Although rare, the coexistence of aortic dissection and aberrant right subclavian artery may be catastrophic. In this study we report the endovascular treatment of a patient with thoracic aorta dissection associated with aberrant right subclavian artery. Aortic clamping proximal to the left subclavian artery in a patient with an aberrant right subclavian artery slows or eliminates flow to both vertebral arteries. Endovascular repair eliminates the complications associated with aortic clamping during surgical repair in the presence of an aberrant right subclavian artery; therefore, it should be considered the treatment of choice in this situation.     

The significance of subclavian artery injection prior to surgical myocardial revascularization

Successful arterial revascularization using the internal thoracic artery is dependent on unobstructed inflow through the subclavian artery. Systematic physical examination should discover subclavian stenosis; however, simple routine injection into the orifice of the subclavian artery during the diagnostic catheterization may avoid a catastrophic outcome.     

Analysis of sequence diversity among IS6110 sequence of Mycobacterium tuberculosis: possible implications for PCR based detection

The IS6110 belongs to the family of insertion sequences (IS) of the IS3 category. This insertion sequence was reported to be specific for Mycobacterium tuberculosis complex and hence is extensively exploited for laboratory detection of the agent of tuberculosis and for epidemiological investigations based on polymerase chain reaction. IS6110 is 1361-bp long and within this sequence different regions have been utilized as targets in the identification of M. tuberculosis by PCR. However, the results are not always consistent, specific and sensitive. In recent years, a few clinical investigations raised concerns over IS6110 specificity and sensitivity in the diagnosis of tuberculosis due to false-positive (homology with other target DNA besides M. tuberculosis) or false negative (due to absence of copies of IS6110) results with IS6110 specific primers. To unravel the variations in IS6110 sequences, an insilico analysis of IS6110 sequence of different strains of M. tuberculosis was carried out. Our results of comparative analysis of IS6110 insertion sequences of M. tuberculosis complex suggests that, IS6110 insertion sequences harbored variations in its sequence, which is evident from the phylogenetic analysis. Importantly, IS6110 sequence has divergence within the copies of same strain and formed different clusters. A list of IS6110 specific primers used in various clinical investigation of tuberculosis was obtained from the literature and their performance scrutinized. Our study emphasizes the need to develop PCR assays (multiplex format) targeting more than one region of the genome of M. tuberculosis.     

Placement Of A Coronary Sinus Pacing Lead From A Sub-occluded Left Subclavian Vein Using A Collateral Vein To The Right Subclavian Vein

Upgrading of a pacing system in the presence of a subclavian occlusion is technically challenging. We describe the case of a patient who underwent a successful upgrading procedure of an implantable cardioverter-defibrillator (ICD) to a biventricular defibrillator (ICD-CRT) in the presence of a suboccluded left subclavian vein, using a collateral vein that drained into the contralateral subclavian vein.     

易位子辅助膜蛋白插入热力学

易位子辅助膜蛋白插入内质网膜是膜蛋白质生物生成的关键过程。了解不同类分子插入生物膜的机制是预测溶质分子透膜速度的先决条件,这也是药物设计和药理学领域的关键因素。根据插入机制,可以设计插膜肽直接用于疾病治疗,或者作为载体有选择性地将药物靶向特定细胞。自从2004年第1个易位子通道蛋白（Sec）的晶体结构被解析后,近十几年来大量的实验和理论研究,都在致力于揭示Sec辅助膜蛋白插入过程的分子机制。本文总结了过去该领域的实验和分子动力学模拟研究进展,从热力学方面重点分析了造成膜蛋白插入自由能分子动力学模拟计算值,以及实验值间偏差的原因。其中,根据研究条件精确设置模拟参数、插入造成的膜变形对自由能计算有很大的影响;核糖体为新生肽插入到Sec通道过程提供了能量,核糖体与Sec的结合影响Sec侧门的开放程度和Sec通道的结构,从而降低膜插入自由能。Sec辅助膜蛋白插入是一个极其复杂的过程,但整个过程仍然符合热力学和动力学的基本原理,尽管疏水性是Sec辅助膜蛋白质插入的关键性因素,但也不能忽略动力学因素的影响。     

Surgical management of chronic occlusive disease of the aortic arch vessels and vertebral arteries.

Occlusive disease of the aortic arch vessels is relatively rare and often missed initially. Of 41 patients treated surgically for this condition over a 10-year period 38 had arteriosclerotic lesions, 2 had symptoms secondary to vasculitis (Takayasu''s arteritis) and 1 had a radiation injury to a subclavian artery. In 22 cases the left subclavian artery was involved; the right subclavian and innominate arteries were the next most commonly affected. Only four vertebral stenoses were treated. Most patients presented with a combination of arm and hindbrain ischemia that was shown radiologically to be associated with a subclavian steal syndrome, but in some only isolated arm symptoms or severe vertigo alone was experienced. There was a difference in blood pressure between the arms of at least 20 mm Hg in 88% of the patients. The treatment for 28 patients was creation of a carotid-subclavian bypass, for 6 the placement of a bypass graft from the ascending aorta to the subclavian or carotid artery or both, for a 3 a subclavian endarterectomy and for 4 vertebral angioplasty. There were no operative deaths, and 90% of the grafts were patent 1 to 72 months later. however, only 30 (73%) of the patients were asymptomatic and 9 (22%) had improved.     

Combined treatment of traumatic aortic transection and Kommerell diverticulum

We present the case of a 41-year-old male trauma patient admitted to the emergency department after being struck in a pedestrian versus a motor vehicle accident. Computed tomography revealed a traumatic transaction of the descending aorta with pseudoaneurysm and an aberrant right subclavian artery with Kommerell diverticulum. Surgical correction was accomplished with bilateral subclavian carotid bypass, with occlusion of both subclavian arteries followed by the placement of endovascular stent grafts to repair the aortic injury.     

Subclavian artery stenting: Immediate and mid term clinical follow-up results

BACKGROUND: Intravascular stents are increasingly being used to treat subclavian artery obstructive disease. This study aimed to assess the immediate and mid-term clinical outcome of subclavian artery stenting. METHODS AND RESULTS: Total occlusion of the subclavian artery was seen in 7 (28%) out of the 25 consecutive patients treated for subclavican artery stenosis. Mean lesion length was 14 +/- 4.3 mm. The mean preprocedure diameter stenosis was reduced from 83.2 +/- 14.9% to 9.6 +/- 5.4% postprocedure. Procedural success was achieved in all patients. Clinical follow-up was obtained in all patients. The initial success was maintained at follow-up (mean = 12 +/- 4 months) in 24 (96%) patients. Recurrence of symptoms occurred in 1 (4%) patient who had an angiographically documented restenosis four months after the procedure. It was successfully redilated. CONCLUSION: Stenting for subclavian artery obstructive disease is safe, technically feasible and has favorable clinical outcomes. It may be considered as the therapy of choice for subclavian artery obstructive disease.     

11 例锁骨下动脉瘤腔内介入治疗体会

目的：总结锁骨下动脉瘤腔内介入治疗的经验。方法：11 例锁骨下动脉瘤,其中7 例真性动脉瘤4 例假性动脉瘤,均采用覆 膜支架腔内隔绝术进行治疗。结果：本组11 例患者腔内介入治疗成功率100%,共置入覆膜支架12 枚,无严重并发症发生,均痊 愈出院。经平均32.5 个月随访,全部患者无明显内漏发生,无动脉瘤复发,除3 例患者出现覆膜支架内轻度狭窄（<30%）外,余介 入治疗患者的锁骨下动脉血流均通畅。结论：腔内覆膜支架隔绝术治疗锁骨下动脉瘤是一种安全、有效的治疗手段。     

The association of a retroesophageal right subclavian artery, a right-sided terminating thoracic duct, and a left vertebral artery of aortic origin: anatomical and clinical considerations

The findings in a cadaver demonstrated: (a) an aberrant retroesophageal right subclavian artery (RRSA); (b) a thoracic duct (Th.d.) terminating at the junction of the right internal jugular and subclavian veins ('venous angle'), and (c) a left vertebral artery (LVA) of aortic origin. The origin of the RRSA from the aortic arch was distal and medial to the left subclavian artery and it reached the upper extremity by crossing posterior to the esophagus. The Th.d. ran a normal retroesophageal course in the mediastinum, until it was intercepted by the anomalous subclavian artery. At this level the Th.d. was deflected towards the right and, accompanied by the anomalous artery, reached the right venous angle. The LVA arose from the aortic arch between the left common carotid and the left subclavian arteries, and ascended to the transverse foramen of C6. The practical importance of associations in general is discussed, and the special diagnostic and surgical significance of the RRSA and Th.d. is stressed.     

The origin, growth, use, size and form of the ligamentum phrenicopericardium of Canis lupus (L. 1758) compared to Canis lupus f. familiaris

The Lig. phrenicopericardiacum of wolves who lived in captivity has been examined with regard to the following aspects: origin, run, insertion, size (breadth and length), and form. The findings of investigations were compared with the corresponding ones stated in the literature for dogs; the correspondences as well as the differences between the both species were pointed out and the possible reasons for them were discussed.     

Modulation of the pHLIP transmembrane helix insertion pathway

The membrane-associated folding/unfolding of pH (low) insertion peptide (pHLIP) provides an opportunity to study how sequence variations influence the kinetics and pathway of peptide insertion into bilayers. Here, we present the results of steady-state and kinetics investigations of several pHLIP variants with different numbers of charged residues, with attached polar cargoes at the peptide's membrane-inserting end, and with three single-Trp variants placed at the beginning, middle, and end of the transmembrane helix. Each pHLIP variant exhibits a pH-dependent interaction with a lipid bilayer. Although the number of protonatable residues at the inserting end does not affect the ultimate formation of helical structure across a membrane, it correlates with the time for peptide insertion, the number of intermediate states on the folding pathway, and the rates of unfolding and exit. The presence of polar cargoes at the peptide's inserting end leads to the appearance of intermediate states on the insertion pathway. Cargo polarity correlates with a decrease of the insertion rate. We conclude that the existence of intermediate states on the folding and unfolding pathways is not mandatory and, in the simple case of a polypeptide with a noncharged and nonpolar inserting end, the folding and unfolding appears as an all-or-none transition. We propose a model for membrane-associated insertion/folding and exit/unfolding and discuss the importance of these observations for the design of new delivery agents for direct translocation of polar therapeutic and diagnostic cargo molecules across cellular membranes.