Nonlocal Josephson Effect in Andreev Molecules.

We propose the "Andreev molecule," an artificial quantum system composed of two closely spaced Josephson junctions. The coupling between Josephson junctions in an Andreev molecule occurs through the overlap and hybridization of the junction's "atomic" orbitals, Andreev Bound States. A striking consequence is that the supercurrent flowing through one junction depends on the superconducting phase difference across the other junction. Using the Bogolubiov-de-Gennes formalism, we derive the energy spectrum and nonlocal current-phase relation for arbitrary separation. We demonstrate the possibility of creating a φ-junction and propose experiments to verify our predictions. Andreev molecules may have potential applications in quantum information, metrology, sensing, and molecular simulation.

Superconducting quantum node for entanglement and storage of microwave radiation.

Superconducting circuits and microwave signals are good candidates to realize quantum networks, which are the backbone of quantum computers. We have realized a quantum node based on a 3D microwave superconducting cavity parametrically coupled to a transmission line by a Josephson ring modulator. We first demonstrate the time-controlled capture, storage, and retrieval of an optimally shaped propagating microwave field, with an efficiency as high as 80%. We then demonstrate a second essential ability, which is the time-controlled generation of an entangled state distributed between the node and a microwave channel.

Comparative Doppler flow measurements of the ulnar artery and of the postanastomotic radial artery in radiocephalic arteriovenous fistulas to detect steal syndromes.

OBJECTIVE: This study aims to assess whether a comparison of the Doppler flow measurements of the ulnar artery and of the postanastomotic radial artery can help detect steal syndromes at the level of native dialysis fistulas of the wrist. PATIENTS AND METHODS: We have prospectively analyzed 35 distal radiocephalic arteriovenous fistulas presenting with postanastomotic radial artery Doppler inversion of flow. The flows of the ulnar artery and of the postanastomotic radial artery have been measured and compared. Subsequent clinical examination to detect any sign of ischemia at the hand level was performed and the results of medical imaging were confronted with the clinical data. RESULTS: A steal syndrome was discovered in a total of 6 patients (17%), 4 patients out of 23 displaying an ulnar flow lower than the postanastomotic radial one and 2 patients among 12 with an ulnar flow higher than the radial one. Sensitivity, specificity, positive predictive value and negative predictive value of the test were 67%, 34%, 17% and 83%, respectively. Paradoxically, the mean intensity of ulnar flow deficiency has been measured at 40% among true positive patients and at 70% among false positive ones. We have not been able to identify any difference, be it in terms of systolic upstroke time, maximum systolic speed, telediastolic speed or in terms of global architecture of the curves between the Doppler waveforms of 4 true positive and 4 false positive patients. CONCLUSION: The comparative Doppler study of the flows of the ulnar and postanastomotic radial arteries does not enable us to detect steal syndromes at the level of wrist dialysis fistulas. Hence we consider that a systematic study of the postanastomotic radial artery flow, during routine Doppler examination of distal dialysis fistulas, proves superfluous.

[Thrombosis of an aorto-iliac stent graft used for treating an iliocaval arteriovenous fistula following lumbar disc surgery]. / Thrombose d'une endoprothèse couverte aorto-bi-iliaque posée en cure d'une fistule artério-veineuse après chirurgie discale lombaire.

OBJECTIVES: Major vessel injury is a rare complication of spinal surgery. Iliac artery injury is the most common. Frequently, a chronic arteriovenous fistula develops. METHODS: We describe the case of a 63-year-old woman who had developed a chronic arteriovenous fistula following lumbar disc hernia surgery. The patient was treated using an Anaconda™ stent graft (Vascutek Terumo). After 2years, the prothesis thrombosed and an aorto-iliac bypass was performed. RESULTS: A gel soft prosthesis 18/9 (Vascutek Terumo) was implanted by laparotomy. The postoperative period was uneventful. A month later, the patient had recovered good lower limb function. CONCLUSION: The choice between endovascular versus open surgery must take into account the patient's age, the risk of long-term complications, and the need for radiographic surveillance. Curative open surgery remains a valid option for young patients.

A spontaneous pre-anastomotic occlusion does not necessarily impair forearm native dialysis fistulas: echo-Doppler, 3D MR angiographic and digital subtraction angiographic imaging.

Renal transplantation is the choice treatment of end-stage renal disease. When it is not indicated or not immediately feasible, hemodialysis must be performed, preferably via a native arteriovenous fistula in the forearm. A pre-anastomotic occlusion of this type of fistula is often accompanied by a thrombosis of its draining vein. In some instances, the venous segment may remain permeable thanks to the development of arterial collateral pathways and may even allow efficient dialysis without any clinical syndrome of distal steal. We present the echo-Doppler, magnetic and angiographic characteristics of three of these collateralized shunts that have remained functional, in one of the cases following a percutaneous dilation.

Dynamic optical lattices: two-dimensional rotating and accordion lattices for ultracold atoms.

We demonstrate a novel experimental arrangement which can rotate a 2D optical lattice at frequencies up to several kilohertz. Ultracold atoms in such a rotating lattice can be used for the direct quantum simulation of strongly correlated systems under large effective magnetic fields, allowing investigation of phenomena such as the fractional quantum Hall effect. Our arrangement also allows the periodicity of a 2D optical lattice to be varied dynamically, producing a 2D accordion lattice.

Surgical treatment of nonaneurysmal aortic arch lesions in patients with systemic embolization.

PURPOSE: Atherosclerotic lesions of the aortic arch are potential sources of arterial embolism. Here we investigate whether surgery, with the necessary circulatory supports, can be proposed as a good option for treatment of this problem. Study of these lesions on a national scale in France has made possible the assessment for future indications of techniques and results of the surgical management of aortic arch lesions, which retrospectively proved to be embolic. METHODS: Thirty-eight patients, (19 men and 19 women) underwent surgery between 1976 and 1996 in 17 French cardiovascular surgical centers. The average age at the time of surgery was 49 +/- 12 years (range, 31 to 82 years). Atherosclerotic lesions were detected with transesophagial echocardiography (n = 19), angiography of the aortic arch (n = 16), computed tomography (n = 9), and magnetic resonance imaging (n = 10). Surgery consisted of thrombectomy and endarterectomy (n = 22), aortic resection and graft replacement (n = 10), and patch aortoplasty (n = 5; one thrombus disappeared spontaneously before surgery was performed). RESULTS: The average postoperative period was 30 months (range, 3 to 82 months). Contact was lost with four patients after a follow-up period of 12 months. On pathologic specimens obtained at surgery, an atherosclerotic plaque was found in 73% of the cases (n = 28). In 15% of the cases, the aorta appeared normal (n = 6) and four other types of lesion were identified: angiosarcoma (n = 1), ectasia at the insertion of the remains of the ductus arteriosus (n = 1), rupture of tunica intima (n = 1), and a fibroblastic plaque (n = 1). A thrombus was identified in 26 cases, attached to the arterial wall in 18 cases. When transesophagial echocardiographic results showed mobile lesions (n = 22), histopathologic examination of specimens allowed the detection of a thrombus in 18 cases and an atherosclerotic plaque with a mobile projection in four cases. The postoperative mortality rate was 2.6%. The morbidity rate (28.9%; n = 11) was related to neurologic complications (n = 6), vascular complications (n = 4), and infection (n = 1). Four cases (12%) were reoperated. CONCLUSION: Nonaneurysmal aortic arch lesions are a frequent and still underestimated source of stroke and peripheral embolization. Surgery with circulatory support can be recommended in good operative candidates with recurrent critical events despite medical management and with high embolic potential (young patients with no calcified plaques).

Infected aneurysms of neck and limb arteries: a retrospective multicenter study.

Infected aneurysms (IA) of neck and limb arteries are uncommon. This report describes the results of a retrospective study undertaken by the University Association for Surgical Research (AURC) to evaluate etiology, bacteriology, location, diagnostic features, and therapeutic methods associated with IA. A total of 58 IA in 52 patients were reviewed. The lesion was located in a lower extremity artery in 47 patients (81%), internal carotid artery in 7 (12%), and upper extremity artery in 4 (6%). Eleven patients had multilocular aneurysm (21%). Symptoms of local infection were observed in 43 patients (82.6%). Rupture or splitting was the presenting manifestation in 13 patients (25%). Primary IA following bacteremia or septicemia without endocarditis was the most common type of IA observed in 34 patients (65.3%). Twelve patients (23%) presented mycotic IA secondary to bacterial endocarditis. In the remaining six patients (11.5%), IA resulted from direct contamination or spreading from a contiguous infection site. Surgical treatment included ligation of the artery without reconstruction in 19 patients and exclusion bypass in 33 patients. The duration of antibiotic treatment ranged from 15 days to 3 months. No recurrence of aneurysm was observed but three patients developed bypass infection. Primary IA was associated with high mortality due to severe septicemia.

Ungual prostheses.

Whatever the origin and the nature of the trauma, behind every request for ungual prostheses there is always the question of how realistic the effect on others will be. Our publications in 1978, 1988 and 1999 and 30 years of experience in this field have consequently led to a comparative study on the evolution of the quality, fixation and indications of our prostheses. The replacement nail is still a difficult issue as sometimes it is simply a matter for the 'nail boutiques', but can even involve surgery in the more complex cases. Prostheses replicate the volume and shape of the finger. Treating a nail is an intricate task but an essential one for the aesthetic and functional comfort of the patient.

Rupture of internal iliac artery aneurysm into the bladder following aortic aneurysm repair.

This report describes a case of ruptured internal iliac artery aneurysm into the bladder after repair of an infrarenal abdominal aortic aneurysm. Aortic repair consisted of resection of the aneurysm followed by prosthetic interposition to reestablish arterial continuity. During the postoperative period, the patient had ischemia of left colon, which was successfully treated by the Hartmann procedure. A right internal iliac artery aneurysm measuring 50 mm in diameter was demonstrated by an abdominal CT scan during the initial hospitalization but was considered stable, since ultrasonography showed no change in diameter at 3 months and 1 year. The patient was lost from follow-up until 3 years later when he was hospitalized after rupture of the right iliac artery aneurysm, then measuring 120 mm in diameter, into the bladder. Surgical repair was undertaken. The procedure involved aortobifemoral bypass with suture of the bladder defect and branches of the internal iliac artery by the endoaneurysmal route. Postoperative recovery was uneventful. Upon reexamination 1 month after discharge from the hospital, the patient was asymptomatic. This rare case confirms the gravity of internal iliac artery aneurysm and the importance of therapeutic management to prevent rupture.

Aesthetic hand prosthesis: gadget or therapy? Presentation of a new classification.

Aesthetic prostheses must fulfill a functional as well as an aesthetic role. The function of these prostheses may be perceived as an additional passive support, or as an instrument of social function and an aid to the patient. This functional role has been observed in the continued use of these prostheses over several years. We reviewed our experience with prescription, fitting and follow-up care in 2847 patients. Classification of these patients was based on their age, level of amputation (with or without functional pinch) and cause of amputation. Analysis of the data ratifies our indications for prosthesis fitting. The long-term wearing of these aesthetic prostheses confirms their use as therapeutic tools.

Influence of respiratory disease on perioperative cardiac risk in patients undergoing elective surgery for abdominal aortic aneurysm.

We retrospectively reviewed perioperative cardiac complications in a series of 214 patients who underwent surgical treatment for infrarenal aortic aneurysm between 1992 and 1996. There were 192 men and 22 women, with a mean age of 68.3 years. Cardiac risk factors included angina in 28% of patients and previous myocardial infarction in 25%. Resting electrocardiography was normal in 80 patients (37.5%). Depending on clinical findings, thallium-201 scintigraphy was undertaken in 76 patients (35.5%) and led to elective coronary arteriography in 22 patients (10%). Results of coronary arteriography revealed lesions in 14 patients. Aortic reconstruction was performed by the transperitoneal route in all patients. Procedures consisted of aortoaortic bypass (63%), aortobiiliac bypass (27.5%), or aortobifemoral bypass (9.5%). Nine patients (4.2%) died within the first 30 postoperative days. The cause of death was myocardial infarction (MI) in two patients (1%), colonic necrosis in two (1%), acute pancreatitis in one (0.5%), acute renal insufficiency in three (1.4%), and multiple organ failure in one patient (0.5%). Nonfatal cardiac complications were observed in 15 patients (7%). Statistical analysis of risk factors revealed two predictors of perioperative cardiac complications, i.e., history of chronic bronchitis and reoperation. On review of the literature, we cannot propose a routine preoperative work-up. Prospective multicentric studies are needed to determine the predictive value of current preoperative screening methods.

[Mechanical system of left ventricle cannulation: control of tightness by experimental left ventricular assistance]. / Système mécanique de canulation ventriculaire apicale: contrôle de l'étanchéité par assistance ventriculaire gauche expérimentale.

We have designed a mechanical device for left ventricular apex cannulation (SCAV). It will be used to implant a ventricular connection for a skeletal muscle ventricle placed in apicoaortic configuration without cardio-pulmonary bypass. The aim of this study was to assess the tightness of the ventricular connection at 48 hours. We used a left ventricular assist device (Biomedicus centrifugal pump) placed between the apex of the left ventricle and the descending thoracic aorta on 10 female sheep. The ventricular connection between the apex of the left ventricle and the Biomedicus was carried out with the SCAV and without cardio-pulmonary bypass. The intra-operative mortality was 10% (1 sheep) due to ventricular fibrillation. Three sheep died early in the run of the ventricular assistance due to technical assistance problems not related to the SCAV. The full ventricular assistance could be managed in 6 sheep through 32 h 30 (range from 15 to 46 h). No death occurred in these 9 sheep due to cardiac hemorrage or tamponade. The average apical bleeding in the pericardial drain was 157 ml (range from 20 to 270 ml). The tightness of the ventricular connection was proved by this study. The SCAV may be suitable for apical implantation of a skeletal muscle ventricle in sheep.

[Vascular complications during surgery of lumbar disk herniation. Apropos of 3 personal cases and 37 cases from a national investigation]. / Accidents vasculaires au cours de la chirurgie de la hernie discale lombaire. A propos de 3 cas personnels et de 37 cas colligés dans une enquête nationale.

Three personal cases of iatrogenic vascular complications (two arterial wounds and one arteriovenous fistula) induced by lumbar herniation surgery led to a French national investigation among vascular and neurosurgical units where 37 other such cases have been discovered over 10 years (1984-1994). In 23 cases, the initial symptomatology was collapses by arterial (22 cases) or venous (one case) hemorrhage requiring emergency vascular repair surgery; in 17 cases an arterio-venous fistula was found in a period varying from a few hours to 5 years after surgery; it was revealed by cardiac failure, lower limb edema or abdominal thrill. Among the 40 cases, 77% occurred at the L4-L5 level; the mortality was 5%, and the morbidity was 27%. Origin, causes and prevention are discussed.

[Arterial vascularization of the foot. Its importance in operations of revascularization of the lower limb]. / Vascularisation artérielle du pied. Son importance dans les interventions de revascularisation du membre inférieur.

Vascularization of the foot was studied using 50 intraoperative arteriograms on single legs and 50 cadaver injections. Arterial vascularization was shown to depend on supramalleolar anastomoses, the primary plantar arch and secondary arches. Anastomotic routes are essential for the permeability of femorotibial bypasses and cicatrization of distal trophic lesions when only one tibial artery remains permeable and must be revascularized.

Retrograde cerebral perfusion: anatomic study of the distribution of blood to the brain.

BACKGROUND: Despite apparently good clinical results with retrograde cerebral perfusion during operation on the aortic arch, there is still concern about the real distribution of the blood injected in the superior vena cava to the brain, especially when the internal jugular vein is valvulated (88% of the cases). This anatomic study was carried out to determine how a liquid injected in the superior vena cava reaches the brain. METHODS: Three groups of adult cadavers (5, 5, and 3 cases, respectively) were injected with latex, colored blue, through a cannula in the superior vena cava. In group I, 600 mL of latex was injected. Group II was identical except that a catheter had been inserted, before the injection, into the internal jugular vein to collapse the internal jugular vein valve, when existing. In group III, the azygos vein was ligated. RESULTS: The internal jugular vein was not valvulated in 2 cases in group I. In those 2 cases, latex was found up to the jugular foramen. In the other cases in group I, and in all cases in group II, where the internal jugular vein was valvulated, the following veins were injected: internal jugular vein up to the valve (almost no latex beyond), azygos vein, inferior vena cava, renal veins, rachidian and perimedullar venous plexuses, and venous sinuses of the brain. In group III, no opacification was observed beyond ligated azygos vein or valvulated internal jugular vein. CONCLUSIONS: Despite the fact that this study was carried out on cadavers, one can assume that, during retrograde cerebral perfusion, the azygos vein system is a major way to the central nervous system when the internal jugular vein is valvulated.

Colour Doppler and duplex sonography and angiography of the carotid artery bifurcations. Prospective, double-blind study.

We undertook a prospective double-blind study of 128 carotid artery bifurcations using colour Doppler and duplex sonography and angiography. Sixty-four patients with cerebrovascular events were admitted for angiography. All underwent sonography within 24 h of angiography. Standard duplex sonography and colour Doppler imaging without spectral analysis were performed, on the same device, by two sonographers, using defined morphological and haemodynamic criteria. Digital radiological data on vessel diameter were interpreted independently by two radiologists. The two sonographic methods gave similar grading of stenosis, compared to angiography, with an accuracy ranging from 96% in severe to 83% in minor stenoses. Colour Doppler studies gave better area measurements than standard duplex sonography, except for major stenoses. Discrepancies between ultrasonography and angiography were due mainly to minor stenoses and large plaques of calcification on the vessel walls, which masked very segmental 70% stenoses in 2 cases. Angiography is limited by its own resolution, does not show uncalcified vessel walls and does not give cross-sectional data. It would therefore be inappropriate for showing small plaques, the full extent of ectasia or for defining the carotid bulb accurately. The advantages of colour methods were in investigating sinuous or deep vessels and hypoechoic plaques. Analysis of the residual lumen of a stenosis and its extent could be determined more rapidly. Haemodynamic quantification of stenoses by standard duplex sonography may be difficult because of limited sample volume and error in estimation of angle, whereas colour Doppler allows semiquantitative estimation of haemodynamics.(ABSTRACT TRUNCATED AT 250 WORDS)

[Hospital procedures and surgical management of patients with stab wounds to the heart]. / Prise en charge hospitalière et conduite chirurgicale dans les plaies du coeur par arme blanche.

Stab wounds of the heart are frequent: one case every two and a half months in our service. In our series of 9 cases, only three were alive at arrival to the emergency ward, but in all of these three, treatment was simple requiring only simple wound suture without extra-corporeal circulation. Based on our experience and the data in the literature, we propose cooperation between three teams for managing these patients: anaesthesists, echocardiographists and cardiothoracic surgeons. The patients are admitted directly to the cardiothoracic operating theatre where the echocardiographist and the surgery team take charge. The surgical procedure depends on the general situation and especially on whether or not the echocardiologist can confirm haemopericardium immediately. Every patient with possible wound to the heart or major vessels should be managed directly by the cardiothoracic surgery team before of formal diagnosis has been established.

[Angiographic study of collateral circulation in coronary occlusion]. / Etude angiographique de la circulation de suppléance au cours des occlusions coronaires.

To define the collateral circulation pathways between coronary arteries, 101 coronarographies of patients who had at least one occlusion of a coronary artery (left-anterior descending artery, circumflex, right coronary) were analysed. We found 12 collateral pathways for the right coronary, 8 for the anterior descending artery, and 4 for the circumflex artery. These collateral circulation pathways have been mapped and compared to those of literature.