Spatial filtering of a six-wavelength DBR-RW laser in a MOPA system.

Lasing emission at multiple wavelengths can be used in different sensing applications and in optical telecommunication. In this work, we report a six-wavelength distributed Bragg reflector (DBR) laser, emitting around 976 nm with six ridge waveguide (RW) structures, where individual DBR gratings are combined into a common front section. These six elements are individually addressable and biased one at a time for individual wavelength selection. The drawback of this RW combination is observable in spatial characteristics where higher-order modes are supported. We addressed this issue by using a master oscillator power amplifier (MOPA) system that combines the six-wavelength MO laser with a tapered PA. Through this configuration, the PA acts as a spatial filter of the MO beam, providing a nearly diffraction-limited beam with M1/e22<1.5. In addition, the described MOPA system provides output powers around 4 W with spectral single-mode operation, with up to 9.36 nm of thermal wavelength tuning. We believe that the described MOPA configuration can be used in different applications, such as absorption spectroscopy.

Pulmonary arteriovenous malformations: a radiological and clinical investigation of 136 patients with long-term follow-up.

AIM: To assess the clinical outcome of patients with and without hereditary haemorrhagic telangiectasia (HHT) after embolisation of pulmonary arteriovenous malformations (PAVM) from a single national centre. MATERIALS AND METHODS: The present register-based observational study including all patients with PAVM treated with embolisation at a reference centre for HHT and PAVM was undertaken over a 20-year period. Demographic data, HHT genotyping, clinical presentation, and outcome were registered. Patients with HHT were compared to the patients without HHT. Clinical examination, contrast-enhanced echocardiography, and computed tomography (CT) were used to assess the clinical outcome at follow-up. RESULTS: One hundred and thirty-six patients with 339 PAVM underwent embolisation during the study period: 22 did not have HHT; 62% had HHT1, 10% had HHT2, 4% had JP-HHT, 8% had clinical HHT without identified genetic mutations. Solitary PAVM were more common among patients without HHT than with HHT. Mean follow-up after the first embolisation was 58 months. Mean age at first embolisation was 46.5 years, and at last follow-up 51.8 years. The clinical success without shunt at follow-up was 87%. The 30-day mortality related to the embolisation was 0%. Twenty patients died during follow-up (mean age 69 years). Most patients could be treated during one session, but many will need a long follow-up with repeated clinical examinations and embolisation. CONCLUSION: The majority of patients referred for embolisation of PAVM had HHT. Multiple PAVM is associated with HHT. Patients with PAVM should be screened for HHT and patients with HHT for PAVM. Embolisation is a safe procedure with high clinical success.

MR spectroscopy of hepatic fat and adiponectin and leptin levels during testosterone therapy in type 2 diabetes: a randomized, double-blinded, placebo-controlled trial.

BACKGROUND: Men with type 2 diabetes mellitus (T2D) often have lowered testosterone levels and an increased risk of cardiovascular disease (CVD). Ectopic fat increases the risk of CVD, whereas subcutaneous gluteofemoral fat protects against CVD and has a beneficial adipokine-secreting profile. HYPOTHESIS: Testosterone replacement therapy (TRT) may reduce the content of ectopic fat and improve the adipokine profile in men with T2D. DESIGN AND METHODS: A randomized, double-blinded, placebo-controlled study in 39 men aged 50-70 years with T2D and bioavailable testosterone levels <7.3 nmol/L. Patients were randomized to TRT (n = 20) or placebo gel (n = 19) for 24 weeks. Thigh subcutaneous fat area (TFA, %fat of total thigh volume), subcutaneous abdominal adipose tissue (SAT, % fat of total abdominal volume) and visceral adipose tissue (VAT, % fat of total abdominal volume) were measured by magnetic resonance (MR) imaging. Hepatic fat content was estimated by single-voxel MR spectroscopy. Adiponectin and leptin levels were measured by in-house immunofluorometric assay. Coefficients (b) represent the placebo-controlled mean effect of intervention. RESULTS: TFA (b = -3.3 percentage points (pp), P = 0.009), SAT (b = -3.0 pp, P = 0.006), levels of adiponectin (b = -0.4 mg/L, P = 0.045), leptin (b = -4.3 µg/mL, P < 0.001), leptin:adiponectin ratio (b = -0.53, P = 0.001) and HDL cholesterol (b = -0.11 mmol/L, P = 0.009) decreased during TRT compared with placebo. Hepatic fat content and VAT were unchanged. CONCLUSIONS: The effects of TRT on cardiovascular risk markers were ambiguous. We observed potentially harmful changes in cardiovascular risk parameters, markedly reduced subcutaneous fat and unchanged ectopic fat during TRT and a reduction in adiponectin levels. On the other hand, the decrease in leptin and leptin:adiponectin ratio assessments could reflect an amelioration of the cardiovascular risk profile linked to hyperleptinaemia in ageing men with T2D.

Anorexia nervosa with massive pulmonary air leak and extraordinary propagation.

A rare case combining pneumothorax, pneumomediastinum, pneumopericardium, pneumoperitoneum, pneumorrhachis, air in retroperitoneum and extensive subcutaneous emphysema simultaneously in a severely anorectic male with BMI 9.2 (22.8 kg) and multiple vomitings is presented. This unusual condition was treated successfully with conservative medical approach in a specialized somatic unit for anorexia nervosa.

A new nitinol stent for use in superior vena cava syndrome. Initial clinical experience.

AIM: The aim of the study was to assess the early clinical experience with the Zilver Vena stent in treating patients with malignant superior vena cava syndrome. METHODS: Demographic, procedural, and follow-up data of 12 patients (seven women; mean age 69 years) treated for superior vena cava syndrome with in all 21 Zilver Vena stents between March 2012 and October 2013 were retrospectively reviewed. All cavographies and contrast enhanced CT related to the treatment and during follow-up were evaluated and the patients had clinical follow-up until dead. They were all in terminal state at the time of stent deployment. RESULTS: All patients had superior vena cava obstruction and clinical superior vena cava syndrome caused by malignant expansive mediastinal disease (eight patients non-small cell lung cancer and four small cell lung cancer). The technical success with deployment of the stents in the intended position was 75%. Good clinical effect with resolution of superior vena cava syndrome was achieved in 11 of the 12 patients (92%). CONCLUSION: The Zilver Vena stent appeared to be safe, easy to deploy, and showed good clinical outcome. The high radial force of the stent might be of advantage in these patients with expanding masses around the superior vena cava.

Concept for power scaling second harmonic generation using a cascade of nonlinear crystals.

Within the field of high-power second harmonic generation (SHG), power scaling is often hindered by adverse crystal effects such as thermal dephasing arising from the second harmonic (SH) light, which imposes limits on the power that can be generated in many crystals. Here we demonstrate a concept for efficient power scaling of single-pass SHG beyond such limits using a cascade of nonlinear crystals, in which the first crystal is chosen for high nonlinear efficiency and the subsequent crystal(s) are chosen for power handling ability. Using this highly efficient single-pass concept, we generate 3.7 W of continuous-wave diffraction-limited (M(2)=1.25) light at 532 nm from 9.5 W of non-diffraction-limited (M(2)=7.7) light from a tapered laser diode, while avoiding significant thermal effects. Besides constituting the highest SH power yet achieved using a laser diode, this demonstrates that the concept successfully combines the high efficiency of the first stage with the good power handling properties of the subsequent stages. The concept is generally applicable and can be expanded with more stages to obtain even higher efficiency, and extends also to other combinations of nonlinear media suitable for other wavelengths.

Endovascular repair of postoperative vascular graft related complications after aorto-iliac surgery.

AIM: Para-anastomotic aneurysms, leakage due to anastomotic failure, aorto- and arterioenteric fistulas are some of the serious complications after aorto-iliac surgical reconstructions. Treatment of these complications is challenging and is either done by open surgery or by endovascular therapy. The mortality and morbidity is higher compared to the initial treatment. We present twelve patients with these complications which were treated by an endovascular approach. METHODS: From January 2008 through January 2013 our radiological records were searched for cases with post surgical vascular complications treated with endovascular intervention. These comprised of anastomotic pseudoaneurysm, suture leakage and arterial enteric fistulas. Patients with limb occlusions were not included in this study. RESULTS: Twelve patients with graft related complications treated with endovascular intervention were recorded. There were four women and eight men with a mean age 75,3 years (range 48-80). At the time of diagnosis, 9 patients (75%) had symptoms and three (25%) was incidentally discovered. Six patients had leakage due to suture failure. All infective parameters were within normal limits. Four patients presented with anastomotic pseudoaneurysms without leak, of which three had proximal anastomotic pseudoaneurysms and one had distal iliac anastomotic pseudoaneurysm. Implanted stent graft were Endurant (Medtronic) bifurcated endoprostheses in three patients and Excluder (Gore) prosthesis in a two cases. Tubular Medtronic endoprosthesis was implanted in one case and in two cases aortic cuff was used. Fluency periphery stent grafts were used in four cases. There was a 100% technical success. Intervention related early mortality was 8%. One patient with pseudoaneurysm died 28 months after endovascular treatment because of cardiac infarct and one patient with previously infected arterio-enteric fistula and advanced malignancy died 7 months after second endovascular treatment. Overall the mortality was 25%. There was no procedure related morbidity or complications during hospitalization and follow-up of mean 12, 3 months (range 1-36 months) in the other 9 patients. There were no complications like endoleaks or limb occlusions. CONCLUSION: Endovascular treatment of vascular graft related postsurgical complications is a valuable therapeutic option followed by lower mortality and morbidity rates compared with re-operation. Short and midterm follow-up is without severe complications and if it occurs most of them can be treated by endovascular means again.

Cerebral abscesses among Danish patients with hereditary haemorrhagic telangiectasia.

BACKGROUND: Hereditary haemorrhagic telangiectasia (HHT) is a dominantly inherited disease characterized by a wide variety of clinical manifestations, including pulmonary arteriovenous malformations (PAVMs), which due to paradoxical embolization may cause cerebral abscess. OBJECTIVE: To estimate the risk of cerebral abscess among patients with HHT. METHODS: All patients with HHT included in the Danish HHT data base, between January 1995 and October 2012, have been clinically evaluated for the presence of neurological symptoms and history of previous cerebral abscess. RESULTS: A total of 337 patients with HHT have been included in the Danish database. Of these, 264 were screened for the presence of PAVM. In 117 patients, a PAVM was diagnosed; among these, we identified nine patients with a history of cerebral abscess. The prevalence of cerebral abscess among patients with HHT and PAVM was therefore 7.8%. The patients with a history of cerebral abscess were genetically evaluated, and seven had ENG mutations, one had an ALK1 mutation, and in one case, a mutation could not be identified. CONCLUSION: Patients with untreated PAVM have a considerable risk of sustaining cerebral abscesses. A cerebral abscess may be the first symptom leading to an HHT diagnosis. Patients with unexplained cerebral abscess should be evaluated for HHT and PAVM.

National mutation study among Danish patients with hereditary haemorrhagic telangiectasia.

Hereditary haemorrhagic telangiectasia (HHT) is an autosomal dominantly inherited vascular disease characterized by the presence of mucocutaneous telangiectasia and visceral arteriovenous malformations (AVM). The clinical diagnosis of HHT is based on the Curaçao criteria. About 85% of HHT patients carry mutations in the ENG, ACVRL1 or SMAD4 genes. Here, we report on the genetic heterogeneity in the Danish national HHT population and address the prevalence of pulmonary arteriovenous malformations (PAVM). Probands of 107 apparently unrelated families received genetic testing, including sequencing and multiplex ligation-dependent probe amplification (MLPA) analyses of ENG, ACVRL1 and SMAD4. These 107 families included 320 patients confirmed to have HHT either clinically or genetically. In 89% of the probands (n=95), a mutation was identified. We detected 64 unique mutations of which 27 (41%) were novel. Large deletions were identified in ENG and ACVRL1. The prevalence of PAVM was 52.3% in patients with an ENG mutation and 12.9% in the ACVRL1 mutation carriers. We diagnosed 80% of the patients clinically, fulfilling the Curaçao criteria, and those remaining were diagnosed by genetic testing. It is discussed when to assign pathogenicity to missense and splice site mutations. The adding of an extra criterion to the Curaçao criteria is suggested.

Simultaneous dual wavelength eye-tracked ultrahigh resolution retinal and choroidal optical coherence tomography.

We demonstrate an optical coherence tomography device that simultaneously combines different novel ultrabroad bandwidth light sources centered in the 800 and 1060 nm regions, operating at 66 kHz depth scan rate, and a confocal laser scanning ophthalmoscope-based eye tracker to permit motion-artifact-free, ultrahigh resolution and high contrast retinal and choroidal imaging. The two wavelengths of the device provide the complementary information needed for diagnosis of subtle retinal changes, while also increasing visibility of deeper-lying layers to image pathologies that include opaque media in the anterior eye segment or eyes with increased choroidal thickness.

Optical coherence tomography for imaging of skin and skin diseases.

Optical coherence tomography (OCT) is an emerging imaging technology based on light reflection. It provides real-time images with up to 2-mm penetration into the skin and a resolution of approximately 10 microm. It is routinely used in ophthalmology. The normal skin and its appendages have been studied, as have many diseases. The method can provide accurate measures of epidermal and nail changes in normal tissue. Skin cancer and other tumors, as well as inflammatory diseases, have been studied and good agreement found between OCT images and histopathological architecture. OCT also allows noninvasive monitoring of morphologic changes in skin diseases and may have a particular role in the monitoring of medical treatment of nonmelanoma skin cancer. The technology is however still evolving and continued technological development will necessitate an ongoing evaluation of its diagnostic accuracy. Several technical solutions are being pursued to further improve the quality of the images and the data provided, and OCT is being integrated in multimodal imaging devices that would potentially be able to provide a quantum leap to the imaging of skin in vivo.

Occlusion of pulmonary arteriovenous malformations by use of vascular plug.

Pulmonary arteriovenous malformations are commonly treated by embolization with coils or balloons to prevent cerebral complications and to raise the oxygenation of the blood. The Amplatzer vascular plug is a new occlusive device made of a self-expanding cylindrical nitinol mesh. It is fast and safe to position, and can be repositioned before final delivery. It is especially suited for embolization of large high-flow vessels as in pulmonary arteriovenous malformations with big feeding arteries. Two cases of successful use of the new device for treatment of large pulmonary arteriovenous malformations are described.

Imaging and interventional radiological treatment of hemoptysis.

Hemoptysis is coughing up blood originating from the lower respiratory tract. There are multiple causes of hemoptysis, from airway diseases, parenchymal diseases, cardiovascular diseases, and other causes. Hemoptysis may cease temporarily, but a possible life-threatening condition may still be present, requiring complete evaluation and probably treatment. Massive hemoptysis (>300 ml blood in 24 hours) seldom occurs but has high mortality. Diagnostic examinations include patient history, physical examination, bronchoscopy, laboratory tests, chest X-ray, computed tomography (CT) of the chest, pulmonary angiography, aortography, and angiography of the bronchials and other thoracic systemic arteries. Bronchoscopy together with clinical and radiological examinations indicates from which part of the lung the bleeding is occurring, yet the cause of hemoptysis cannot be determined in 20-30% of cases. One of the therapeutic measurements may be embolization of the bleeding vessel such as in pulmonary arteriovenous malformations or in bronchial or other systemic arterial branches supplying the bleeding lung segment. Systemic bronchial and non-bronchial collateral artery anatomy is very complex and variable, and it may be difficult to recognize how the systemic arteries or pulmonary arteries may be involved as a source of bleeding. Interventional treatments are effective and safe therapeutic methods which reduce the need for acute thoracic surgery. Embolization may be life saving, or it may postpone surgery and, in some situations, should be the treatment of choice.

Infrared thermography and ultrasonography to indirectly monitor the influence of liner type and overmilking on teat tissue recovery.

Eight Danish Holstein cows were milked with a 1-mm thick specially designed soft liner on their right rear teat and a standard liner mounted under extra high tension on their left rear teat. Four of the animals were overmilked for 5 min. Rear teats were subjected to ultrasound examination on the first day and to infrared thermography on the second day. Teats were submersed in ethanol 20 min post-milking on the second day. Ultrasonography measurements showed that teat canal length increased by 30-41% during milking. Twenty minutes after milking, teats milked with modified standard liners still had elongated teat canals while teats milked with the soft liner were normalized. Overmilking tended to increase teat wall thickness. Approximately 80% of variability in teat canal length, from before teat preparation to after milking, could be explained by changes during teat preparation. Thermography indicated a general drop in teat temperature during teat preparation. Teat temperature increased during milking and continued to increase until the ethanol challenge induced a significant drop. Temperatures approached pre-challenge rather than pre-milking temperatures within 10 minutes after challenge. Teat temperatures were dependent on type of liner. Mid-teat temperatures post-challenge relative to pre-teat preparation were dependent on overmilking. Thermography and ultrasound were considered useful methods to indirectly and non invasively evaluate teat tissue integrity.

Clinical symptoms according to genotype amongst patients with hereditary haemorrhagic telangiectasia.

BACKGROUND: Hereditary haemorrhagic telangiectasia (HHT) is a dominantly inherited disease, characterized by a wide variety of clinical manifestations, including epistaxis, gastrointestinal (GI) bleeding, pulmonary arteriovenous malformations (PAVMs) and neurological symptoms. HHT is a genetically heterogeneous disorder involving at least two loci; HHT 1 mapping to chromosome 9 q 34.1 (ENG) and HHT 2 mapping to chromosome 12 q 31 (ALK-1). OBJECTIVE: To evaluate and describe the diversity of clinical manifestations in a Danish population of HHT patients with known HHT 1 or HHT 2 subtype. DESIGN: Prospective clinical examination with genetic evaluation and follow-up. SETTING: Investigation centre was Odense University Hospital. All HHT patients in the County of Fyn were included. METHODS: HHT family members were invited to a clinical examination including registration of HHT manifestations, screening for PAVM and neurological evaluation. Blood tests were performed for analysis of disease-causing mutation, and clinical manifestations in the HHT subtypes were compared. The survival of the patients was studied in the follow-up period. RESULTS: Included in the study were 73 HHT patients representing 18 families. In 14 of the families we identified a disease-causing mutation. Thirty-nine patients (from 10 families) had HHT1 and 16 HHT patients from four families had HHT2. CONCLUSION: Amongst patients with HHT1 genotype the prevalence of PAVM was higher than amongst HHT patients with HHT2 genotype. HHT1 patients had experienced more severe GI bleeding than HHT2 patients. There was no significant difference in severity of epistaxis or age at debut. Finally the mortality over a 90-month observation period was not significantly increased.

Endovascular treatment of severe symptomatic stenosis of the internal carotid artery: early and late outcome.

OBJECTIVES: To report a 6 year experience with carotid percutaneous transluminal angioplasty (CPTA) in a selected group of patients. MATERIAL AND METHOD: We retrospectively reviewed our experience after performing 54 CPTAs, with (n=18) or without (n=36) stent deployment, over a period of 6 years from 1993 to 1999. All patients, except one, suffered from focal hemispheric neurologic symptoms. During the same time period 284 patients underwent carotid endarterectomy. The selection of the 54 patients (16%) for CPTA was based on the carotid angiogram and the sole inclusion criterion for endovascular treatment was a short, concentric, and smooth stenosis of more than 70% without ulceration or severe calcification. All patients who had a patent internal carotid artery after the last control were invited for a clinical duplex examination and all duplex examinations were carried out by a single experienced observer. RESULTS: Early outcome (<30 days): CPTA was judged technically successful in 50 cases (93%). Ten patients (18%) experienced a neurological event in relation to the procedure and one patient (2%) suffered a major stroke. One stent occluded within 30 days. LATE OUTCOME: Forty-six patients (85%) entered the follow-up study after a median of 34 months (range 1-80 months). Six patients (13%) had recurrent symptoms. The colour-duplex examination (n=45) showed internal carotid artery occlusion in 2 patients (5%), and restenosis (>70%) in 10 patients (22%). We found no significant difference in the reoccurrence of neurological symptoms or the rate of restenosis between patients treated with and without stent (Log Rank 0.28, p=0,59). ICA was patent without restenosis in 60% after 48 months in patients treated with CPTA alone, and in 76% after 3 months in patients treated with a stent (N.S.). CONCLUSION: CPTA in a selected group of patients has a mortality and major stroke rate comparable to that of carotid endarterectomy. However, the risk of transient neurological events was high, as well as the incidence of restenosis (>70%) after 3 years. We still consider CPTA an experimental procedure. The indications for this treatment must be clarified if CPTA should be an alternative to surgery with a comparable neurological complication rate.

[Endovascular treatment of uterine fibromas]. / Endovaskulaer behandling af uterusfibromer.

Uterine artery embolisation represents a promising new method of treating fibroid-related menorrhagia and pelvic pain. The procedure is performed under local analgesia and intravenous sedation. Both uterine arteries are selectively catheterised under fluoroscopic control. Microparticles suspended in contrast medium are used to embolise the uterine vascular bed. Ischaemic pain during the first day is treated with intravenous morphine. Patients treated with embolisation can expect excellent results with respect to menorrhagia, pelvic pain, and reduction in the fibroid tumour volume. Women undergoing uterine embolisation retain their potential for future pregnancies. The procedure is well tolerated by patients, and possesses the advantages of shorter hospitalisation and recovery time, as compared to hysterectomy.

[Pulmonary arteriovenous malformations. Current therapeutic principles]. / Pulmonale arteriovenøse malformationer. Moderne behandlingsprincipper.

Pulmonary arteriovenous malformations are congenital vascular malformations in the lungs, which act as shunts so that the blood is not oxygenated or filtered. These patients are typically hypoxaemic with exercise intolerance and are at high risk of paradoxical emboli to the brain. About 25% of patients with the Rendu-Osler-Weber syndrome (hereditary haemorrhagic telangiectasia) have these pulmonary malformations. A modern treatment strategy is embolisation with balloon or coils of the afferent arteries to the arteriovenous malformations. It is a minimally invasive procedure with a very high technical success and few complications. Embolisation prevents cerebral stroke and abscess and pulmonary haemorrhage and further raises the functional level. Screening for pulmonary arteriovenous malformations in patients at risk is recommended.