Fast, High-Fidelity Addressed Single-Qubit Gates Using Efficient Composite Pulse Sequences.

We use electronic microwave control methods to implement addressed single-qubit gates with high speed and fidelity, for ^{43}Ca^{+} hyperfine "atomic clock" qubits in a cryogenic (100 K) surface trap. For a single qubit, we benchmark an error of 1.5×10^{-6} per Clifford gate (implemented using 600 ns π/2 pulses). For 2 qubits in the same trap zone (ion separation 5 µm), we use a spatial microwave field gradient, combined with an efficient four-pulse scheme, to implement independent addressed gates. Parallel randomized benchmarking on both qubits yields an average error 3.4×10^{-5} per addressed π/2 gate. The scheme scales theoretically to larger numbers of qubits in a single register.

Experts' perspectives on SwissDRG: Second class care for vulnerable patient groups?

On the 1st of January 2012, Switzerland introduced the diagnosis-related group hospital tariff structure (SwissDRG). It was recognised that healthcare provided to the most vulnerable patient groups would be a challenge for the new SwissDRG. Coincident with the implementation of SwissDRG, we explored hospital experts' perceptions of which patient groups are vulnerable under the SwissDRG system, what has changed for this group, as well as solutions to ensure adequate access to health care for them. We interviewed 43 experts from 40 Swiss hospitals. Participating experts named several vulnerable patient groups who share some common characteristics. These hospital experts were concerned about the patient groups that are not financially profitable and questioned the practicability of the current regulation. At the same time, they highlighted the complexity associated with caring for this group under the new SwissDRG and reported measures at the macro, meso, and micro levels to protect vulnerable patient groups from negative effects. To curb negative outcomes for vulnerable patient groups after the introduction of the SwissDRG, the Swiss legislation has introduced various instruments including the acute and transitional care (ATC) measures. We conclude that ATC measures do not produce the expected effect the legislators had hoped for. More health data is needed to identify situations where vulnerable patient groups are more susceptible to inadequate health care access in Switzerland.

Implementation status of error disclosure standards reported by Swiss hospitals.

QUESTION UNDER STUDY: To establish at what stage Swiss hospitals are in implementing an internal standard concerning communication with patients and families after an error that resulted in harm. METHODS: Hospitals were identified via the Swiss Hospital Association's website. An anonymous questionnaire was sent during September and October 2011 to 379 hospitals in German, French or Italian. Hospitals were asked to specify their hospital type and the implementation status of an internal hospital standard that decrees that patients or their relatives are to be promptly informed about medical errors that result in harm. RESULTS: Responses from a total of 205 hospitals were received, a response rate of 54%. Most responding hospitals (62%) had an error disclosure standard or planned to implement one within 12 months. The majority of responding university and acute care (75%) hospitals had introduced a disclosure standard or were planning to do so. In contrast, the majority of responding psychiatric, rehabilitation and specialty (53%) clinics had not introduced a standard. CONCLUSION: It appears that Swiss hospitals are in a promising state in providing institutional support for practitioners disclosing medical errors to patients. This has been shown internationally to be one important factor in encouraging the disclosure of medical errors. However, many hospitals, in particular psychiatric, rehabilitation and specialty clinics, have not implemented an error disclosure policy. Further research is needed to explore the underlying reasons.

Instability of the sternoclavicular joint: current concepts in classification, treatment and outcomes.

The sternoclavicular joint (SCJ) is a pivotal articulation in the linked system of the upper limb girdle, providing load-bearing in compression while resisting displacement in tension or distraction at the manubrium sterni. The SCJ and acromioclavicular joint (ACJ) both have a small surface area of contact protected by an intra-articular fibrocartilaginous disc and are supported by strong extrinsic and intrinsic capsular ligaments. The function of load-sharing in the upper limb by bulky periscapular and thoracobrachial muscles is extremely important to the longevity of both joints. Ligamentous and capsular laxity changes with age, exposing both joints to greater strain, which may explain the rising incidence of arthritis in both with age. The incidence of arthritis in the SCJ is less than that in the ACJ, suggesting that the extrinsic ligaments of the SCJ provide greater stability than the coracoclavicular ligaments of the ACJ. Instability of the SCJ is rare and can be difficult to distinguish from medial clavicular physeal or metaphyseal fracture-separation: cross-sectional imaging is often required. The distinction is important because the treatment options and outcomes of treatment are dissimilar, whereas the treatment and outcomes of ACJ separation and fracture of the lateral clavicle can be similar. Proper recognition and treatment of traumatic instability is vital as these injuries may be life-threatening. Instability of the SCJ does not always require surgical intervention. An accurate diagnosis is required before surgery can be considered, and we recommend the use of the Stanmore instability triangle. Most poor outcomes result from a failure to recognise the underlying pathology. There is a natural reluctance for orthopaedic surgeons to operate in this area owing to unfamiliarity with, and the close proximity of, the related vascular structures, but the interposed sternohyoid and sternothyroid muscles are rarely injured and provide a clear boundary to the medial retroclavicular space, as well as an anatomical barrier to unsafe intervention. This review presents current concepts of instability of the SCJ, describes the relevant surgical anatomy, provides a framework for diagnosis and management, including physiotherapy, and discusses the technical challenges of operative intervention.

Balloon sclerotherapy: a new method for the treatment of truncal varicose veins.

BACKGROUND: Truncal varicose veins may be treated by conventional surgery or endovenous therapy. Endovenous ablation, such as laser or radiofrequency treatment, is less invasive but technically demanding, not cheap and has still the possibility of important side-effects. Moreover the treatment requires in the best case tumescent anesthesia. Catheter based endovenous sclerotherapy has the potential of systemic effects of sclerosing agent and air. We therefore aimed to develop a simple, minimal-invasive and cheap method for the treatment of truncal varicose veins reducing the potential risk of systemic effects of the sclerosing agent to a minimum. METHODS: A double lumen double balloon catheter was developed. Thereby a treatment site within a vein can be isolated from blood for localized administration of a sclerotherapeutic agent. Later, a substantial portion of the therapeutic agent can be removed from the isolated segment thus minimizing the amount necessary. Occlusion of longer varicose segments is achieved by pointwise repetition of the manoeuvre or careful retraction of the expanded balloons with the "catched" sclerotherapeutic agent in between. RESULTS: The application was filed as United States Patent No. 6,726,67 B2. 18 balloon prototypes successfully passed an extensive test series (leak tests, dimension tests, mandrel--, guide wire--and introducer compatibility tests, destructive tests). Three patients with varicosity of the greater saphenous vein and the vena saphena accessoria lateralis, respectively, were successfully treated with complete occlusion of the vessels 10, 6 and 2 months after the intervention. CONCLUSIONS: Balloonsclerotherapy combines two well-established procedures (balloon catheter therapy and sclerotherapy, namely) and promises to be a minimal-invasive and cheap endovenous therapy of truncal varicose veins, requiring local anesthesia at the puncture site only and reducing possible systemic side effects of the sclerosing agent.

Severe potential consequences of delayed diagnosis in patients with hip claudication.

Delayed diagnosis in patients with hip claudication can lead to severe consequences. We report on patients with ischaemic hip claudication which had primarily been attributed to coxarthrosis. One patient went through a variety of treatments including hip arthroplasty. The second patient had a life-threatening abdominal aortic aneurysm (AAA) which remained undiagnosed. Orthopaedic surgeons should maintain a high degree of suspicion for vascular disease. Moreover, we strongly advocate that all men over 60 years old who seek medical advice for whatever reason should be screened once for AAA by ultrasonography.

Measurement of the lymphatic clearance of the human skin using a fluorescent tracer.

The lymphatic clearance of the human skin at the instep of the foot was measured in 20 healthy volunteers (mean age +/- SD 33.8 +/- 10.5 years). Ten microliters of fluorescein isothiocyanate-dextran 150,000 were injected intradermally and the fluorescent light intensity of the deposit was measured 10 min and 24 h after injection by window densitometry. Fluorescent light intensity decreased by 31.2 +/- 13.5 arbitrary units (p < 0.0001) or by a factor of 4.1 +/- 3.9. Reproducibility was tested 2-6 weeks later in 7 subjects and an intraclass reliability of 0.76 was found. These are the first measurements of the lymphatic clearance of the human skin using a fluorescent tracer. The method is easier and safer than the isotope clearance technique and small areas of the human skin can be investigated. The data found form a basis with which to compare measurements made in patients with different forms of edema.

Long-term results of percutaneous thrombo-embolectomy in patients with infrainguinal embolic occlusions.

BACKGROUND: The aim of the study was to review early and long term clinical results of percutaneous thrombo-embolectomy in patients with acute embolic occlusions of the infrainguinal arteries. METHODS: Retrospective analysis of consecutive cases. A total of 88 procedures in 84 patients were performed between 1986 and 1996 in a University Hospital (46 men, 42 women; mean age 67.6 +/- 14.4 years). Patients with a history of chronic symptomatic arterial occlusive disease were not included in the analysis. Indications for treatment were severe claudication (n = 45 procedures) and limb threatening ischaemia (n = 43 procedures). Percutaneous thrombo-embolectomy was performed via an ipsilateral approach by means of an end hole aspiration catheter. Local thrombolysis or balloon angioplasty was used as appropriate during the intervention. Follow-up included clinical data, ankle pressure measurements, pulse volume recordings and duplex sonography or angiography if indicated. RESULTS: Technical success was achieved in 85 (96.6%) of the 88 procedures. Two patients (2.3%) suffered major and two patients (2.3%) minor complications. One patient died within 30 days after the procedure. Mean follow-up was 3.7 +/- 2.9 years. Twelve patients (16%) were lost to follow-up. Primary clinical success rate was 88.4% at one and 81.7% at two years and declined to 76.5% at eight years. Out of the 16 interval failures 10 (63%) were due to recurrent embolism to the same leg. They resulted in nine catheter reinterventions and one bypass graft. Six patients were treated conservatively. Cumulative mortality was 11.7% at one year and increased to 29.5% at eight years. CONCLUSIONS: From our single centre experience we conclude that catheter treatment of acute embolic occlusion of infrainguinal arteries is safe and has favourable long-term RESULTS. We therefore regard the technique as a less invasive alternative to surgery.

Repair of infrapopliteal postembolectomy complications with variant embolization techniques.

Infrapopliteal pseudoaneurysms and arteriovenous fistulae are known complications of Fogarty balloon embolectomy. Management of these complications in two patients with associated critical foot ischemia by modified interventional embolization techniques is described.

Absence of functional lymphatics within a murine sarcoma: a molecular and functional evaluation.

Despite a clinically recognized association between the lymphatics and metastasis, the biology of tumor-lymphatic interaction is not clearly understood. We report here that functional lymphatic capillaries are absent from the interior of a solid tumor, despite the presence within the tumor of the lymphangiogenic molecule vascular endothelial growth factor (VEGF)-C and endothelial cells bearing its receptor, VEGF receptor 3. Functional lymphatics, enlarged and VEGF receptor 3 positive, were detected in some tumors only at the tumor periphery (within 100 microm of the interface with normal tissue). We conclude that although lymphangiogenic factors are present, formation of functional lymphatic vessels is prevented, possibly due to collapse by the solid stress exerted by growing cancer cells.

Effect of venous and lymphatic congestion on lymph capillary pressure of the skin in healthy volunteers and patients with lymph edema.

The aim of the present study was to assess the influence of venous and lymphatic congestion on lymph capillary pressure (LCP) in the skin of the foot dorsum of healthy volunteers and of patients with lymph edema. LCP was measured at the foot dorsum of 12 patients with lymph edema and 18 healthy volunteers using the servo-nulling technique. Glass micropipettes (7-9 microm) were inserted under microscopic control into lymphatic microvessels visualized by fluorescence microlymphography before and during venous congestion. Venous and lymphatic congestion was attained by cuff compression (50 mm Hg) at the thigh level. Simultaneously, the capillary filtration rate was measured using strain gauge plethysmography. The mean LCP in patients with lymph edema increased significantly (p < 0.05) during congestion (15.7 +/- 8.8 mm Hg) compared to the control value (12.2 +/- 8.9 mm Hg). The corresponding values of LCP in healthy volunteers were 4.3 +/- 2.6 mm Hg during congestion and 2.6 +/- 2.8 mm Hg during control conditions (p < 0.01). The mean increase in LCP in patients with lymph edema was 3.4 +/- 4.1 mm Hg, and 1.7 +/- 2.0 mm Hg in healthy volunteers (NS). The maximum spread of the lymph capillary network in patients increased from 13.9 +/- 6.8 mm before congestion to 18.8 +/- 8.2 mm during thigh compression (p < 0.05). No increase could be observed in healthy subjects. In summary, venous and lymphatic congestion by cuff compression at the thigh level results in a significant increase in LCP in healthy volunteers as well as in patients with lymph edema. The increased spread of the contrast medium in the superficial microlymphatics in lymph edema patients indicates a compensatory mechanism for lymphatic drainage during congestion of the veins and lymph collectors of the leg.

Inguinal mass as a late complication of hip arthroplasty. Differential diagnosis and treatment from a vascular surgical perspective.

We report on three patients with a symptomatic inguinal mass as a late complication of repetitive arthroplastic hip surgery. In one case, there was a false aneurysm and in two cases a so-called "synovial cyst". A synovial cyst is usually an enlarged iliopsoas bursa in communication with the capsule of the hip joint. Hypersecretion in arthritic joints may cause expansion of this bursa. Compression of the common femoral and external iliac veins may lead to outflow obstruction and leg swelling. The most important diagnostic tools are plain films of the hip joint and ultrasound of the groin including colour-coded assessment of the femoral vessels. Symptomatic cysts usually need removing by an anterior approach. Loose arthroplastic components can be causative and should be replaced.

Dose-dependent increase of transcapillary diffusion of sodium fluorescein after histamine microinjections.

BACKGROUND: To study the dose-dependent effects of histamine on capillary permeability in human skin, using the microinjection technique. PATIENTS AND METHODS: Eight healthy volunteers (2 w, 6 m; mean age 33 years) were included in the study. On two separate occasions, glass microcannulas with a tip diameter of 7 to 9 microns were inserted into the subepidermal layer of the skin at the distal medial tibia surface of each lower limb with a micromanipulator. In each subject, 0.5 microliter of 3 different concentrations of histamine solution (0.1/1000, 0.01/1000 and 0.001/1000) were injected and compared to the solvent (0.9% NaCl). Transcapillary diffusion of intravenously administered Na-fluorescein was assessed simultaneously using two fluorescence videomicroscopy systems. Off-line video densitometry was performed in an area of 0.56 mm2 around the injection sites and fluorescence light intensities were measured in arbitrary units (AU) at 10, 30, 60, 120 and 600 s after dye appearance. RESULTS: Compared to the solvent histamine microinjections resulted in a dose-dependent increase of mean fluorescence light intensities (FLI). Whereas mean FLI for the 0.001/1000 histamine injection was only significantly elevated 10 min after dye appearance (p < 0.05) an increase of mean FLI was already observed 10 s after dye appearance following the 0.1/1000 histamine injection (p < 0.05), which was more pronounced at later time points (p < 0.001). Mean FLI's for the 0.01/1000 histamine solution were in between and resulted in significantly elevated values 1 min to 10 min after dye appearance (p < 0.05). CONCLUSIONS: We conclude that the microinjection technique together with fluorescence videomicroscopy described previously [6] is able to document a dose-dependent effect of histamine microinjections on skin capillary permeability. The technique may facilitate to determine appropriate dosages not only of histamine in order to test the effect of antagonists on human skin capillary permeability.

Fluorescence microlymphography of the upper extremities. Evaluation with a new computer programme.

BACKGROUND: To evaluate the initial lymphatics of the superficial skin in healthy volunteers using fluorescence microlymphography and to establish controls values for comparison with lymphedema patients. METHODS: Fluorescence microlymphography was performed on the hand dorsum, on the lower and the upper arm in 12 healthy subjects (58.7+/-8.0 years). At each of these sites 10 microl FITC-dextran was injected subepidermally using a steel cannula. The studies were recorded on video tape using a fluorescence microscope and a CCD video camera. Final magnification was 24 and 62. The maximum spread of the fluorescent contrast medium was measured 10 minutes after injection. The area of the visualized lymph capillaries was determined using a computer programme. SETTING: University Hospital, Department of Medicine, Division of Vascular Medicine (Angiology). RESULTS: The mean area of the visualised lymph capillary network 95.3+/-41.3 mm2 (42-174 mm) at the upper and 89.4+/-45.5 mm2 (44-171 mm). The maximum spread was 4.8+/-3.5 mm (1.9-13.6 mm) and 4.4+/-3.7 mm, respectively. The mean diameter of the lymph capillaries was 84.1+/-19.9 microm and 75.5+/-14.8 microm, respectively. CONCLUSIONS: The extension of the lymph capillary network at the upper and lower arm are comparable to those at the lower extremities. Considering the two-dimensional nature and the irregular shape of the network the area measurement seems to be more appropriate than the maximum spread in one direction.

Lymphatic microangiopathy of the skin in systemic sclerosis.

METHODS: The cutaneous capillary lymphatic system in patients with systemic sclerosis was investigated using fluorescence microlymphography. The distal upper limbs of 16 healthy controls (mean age 62.3+/-13.1 yr) and 16 patients with systemic sclerosis (mean age 58.9+/-13.6 yr) were examined and the following parameters were evaluated: (a) single lymphatic capillaries; (b) lymphatic capillary network and cutaneous backflow; (c) extension of the stained lymphatics; (d) diameter of single lymphatic capillaries. RESULTS: At the finger level, lymphatic capillaries were lacking in five patients, while they were present in all controls (P < 0.05). Extension of the stained lymphatics was increased in 11 patients (8.1+/-6.0 mm) compared to the 16 healthy controls (2.0+/-1.2 mm) (P < 0.0001). Cutaneous backflow was observed in three patients (P < 0.05). At the hand level, lymphatic network extension was significantly different between patients (3.8+/-2.4 mm) and controls (1.2+/-0.8 mm) (P < 0.01); however, no significant differences were found at the forearm level. CONCLUSION: Lesional skin in patients with systemic sclerosis exhibits evidence of lymphatic microangiopathy.

Lymphoedema, lymphatic microangiopathy and increased lymphatic and interstitial pressure in a patient with Parkinson's disease.

New microvascular findings in a woman with Parkinson's disease and lower leg oedema are presented. Microlymphography showed enhanced filling of the microlymphatic network with the fluorescent contrast medium comparable to the findings in lymphoedema. The microlymphatic and interstitial pressures of the skin were increased (27 mm Hg and 16 mm Hg respectively). The increased interstitial and microlymphatic pressures are the result of insufficient venous and lymphatic drainage due to impairment of calf muscle function during walking in Parkinson's disease. Manual lymph drainage and compression therapy, in combination with improvement of calf muscle function, resulted in regression of the oedema.

Spontaneous reversibility of early reobstruction following percutaneous transluminal angioplasty.

Early reocclusion and late restenosis are well-known problems after percutaneous transluminal angioplasty (PTA). We report here on a phenomenon not described so far in two patients with peripheral arterial occlusive disease who had PTA of the common iliac and the superficial femoral artery, respectively. Both had a good hemodynamic and clinical initial result. However, within two days after PTA symptomatic reobstruction occurred documented by noninvasive measurements. Noteworthy, this reobstruction was spontaneously reversible within days. The possible pathomechanism is discussed.

Long-term results after recanalisation of chronic iliac artery occlusions by combined catheter therapy without stent placement.

OBJECTIVES: to evaluate the long-term outcome after recanalisation of chronic iliac artery occlusions by combined catheter therapy without stent placement. DESIGN: retrospective study. MATERIAL AND METHODS: between 1979 and 1995 75 consecutive patients were treated (53 men, 22 women; mean age 63.1+/-13.7 years; mean length of the occluded segment 6.9+/-3.5 cm). The indication for treatment was incapacitating claudication (n=55) or chronic critical ischaemia (n=20). At follow-up clinical data, pulse volume and pressure measurements were recorded and duplex-sonography and/or angiography performed, if clinically indicated. RESULTS: mean follow-up was 7. 2+/-4.1 years. The primary clinical success rate was 64% at 12 months, 57% at 4 years and remained stable for up to ten years. The secondary clinical success rate after 12 months was 83% and remained stable at 81% for up to 10 years. Peripheral embolisation as complication of the intervention occurred in 18 patients (24%) and was treated by percutaneous thromboembolectomy in 15 patients during the same procedure. In the remaining three patients no intervention was necessary. One patient had to undergo surgery for a groin haematoma. CONCLUSIONS: recanalisation of segmental chronic iliac artery occlusions by catheter therapy without stent placement has favourable long-term results comparable to primary stent placement. Randomised controlled studies are required to determine the appropriate role of catheter therapy alone and primary or selective stenting for iliac artery occlusions.

Alveolar echinococcosis of the liver: sequelae of chronic inferior vena cava obstructions in the hepatic segment.

BACKGROUND: The clinical pattern and long-term course of chronic inferior vena cava (IVC) obstructions are variable and depend on the underlying cause, the segment involved, and the extension of secondary thrombosis. Pertinent data on IVC obstructions in well-defined series of patients are lacking. We report the sequelae of chronic IVC obstructions in the hepatic segment in 11 consecutive patients derived from a cohort of 104 patients with alveolar echinococcosis of the liver. METHODS: Based on the results of computed tomography scans, 11 patients (7 men, 4 women; mean age, 53.4 years) with IVC obstructions were selected from an ongoing prospective long-term chemotherapy trial comprising 104 patients with alveolar echinococcosis studied at yearly intervals according to a protocol. Obstruction of the IVC in the 11 patients existed for a mean duration of 8.6 years. In these patients, magnetic resonance imaging was performed to assess the morphologic features and extension of the IVC obstruction, as well as the collateral venous pathways. Patency and valvular function of the femoropopliteal veins were analyzed by color-coded duplex ultrasonography. RESULTS: Total occlusions of the IVC were evident in 8 patients (73%) and subtotal stenoses in 3 patients (27%). Only 4 patients (36%) exhibited signs and symptoms of chronic venous insufficiency of the lower extremities; 2 (18%) of the 4 had a history of swelling in the lower extremity. Seven patients (64%) had no lower extremity symptoms. One patient had a history of pulmonary embolism. Abdominal collateral veins were documented in 5 patients (45%) by using magnetic resonance imaging; however, they were clinically evident in only 3 patients (27%). In the 8 patients with IVC occlusion, thrombosis ended at the confluence of the hepatic veins. Obstruction of the IVC was limited to the hepatic segment in 2 patients (18%) and extended to the distal IVC or the iliofemoral veins in 6 patients (54%). Chronic venous insufficiency was present only if the femoropopliteal veins had been involved in the thrombotic process, showing residual venous obstruction, valvular incompetence, or both. Bilateral renal vein thrombosis with moderate proteinuria was observed in 2 patients (18%). The main collateral drainage was achieved through the ascending lumbar, azygos, and hemiazygos veins. CONCLUSIONS: In patients with alveolar echinococcosis, obstruction of the IVC in the hepatic segment often develops asymptomatically and rarely leads to the impairment of renal function. The collateral circulation fully compensates for obstruction of the IVC. Thrombotic involvement and valvular incompetence of the femoropopliteal veins seems to determine the development of chronic venous insufficiency of the lower extremities.