High incidence of (ultra)low oesophageal temperatures during cryoballoon pulmonary vein isolation for atrial fibrillation.

BACKGROUND: Low oesophageal temperatures (OTs) during cryoballoon pulmonary vein isolation (PVI) have been associated with complications. This study assessed the incidence of low OT in clinical practice during cryoballoon PVI and verified possible predictive values for low OT. METHODS: Consecutive patients who underwent PVI using the second-generation cryoballoon were retrospectively included. The distance from the oesophagus to the different pulmonary veins (PVs) (OP distance), body mass index (BMI), sex, age, balloon temperature and application time were studied as potential predictors of low OTs. Computed tomography was performed before the procedure to determine the OP distance. OT was measured using an oesophageal temperature probe. Applications were ended prematurely if the OT reached <16 °C. Low and ultralow OT were defined as OT <20 and <16 °C respectively. RESULTS: Two hundred and four patients were included. Low OT was observed in 54 patients (26%) and 27 patients (13%) reached ultralow OTs. OP distance was the only predictor of low OTs after multivariate analysis. A cut-off value of 19 mm showed 96.2% sensitivity and 37.8% specificity in predicting low OTs. No clinically relevant relation was found between low OTs and BMI, age, sex, balloon temperature or application duration. CONCLUSIONS: The incidence of low OT was 26% for cryoballoon PVI. OP distance was the only predictor of low OTs. Since an OP distance <19 mm was present in all patients in at least one PV, we recommend routine OT measurement during PVI cryoballoon therapy to prevent oesophagus-related complications.

Technical Feasibility and Design of a Shape Memory Alloy Support Device to Increase Ejection Fraction in Patients with Heart Failure.

PURPOSE: Heart failure is increasingly prevalent in the elderly. Treatment of patients with heart failure aims at improving their clinical condition, quality of life, prevent hospital (re)admissions and reduce mortality. Unfortunately, only a select group of heart failure patients with reduced ejection fraction are eligible for Cardiac Resynchronization Therapy where 30-40% remain non-responders and need left ventricular support. The aim of this study is to investigate if a shape memory alloy (SMA) is able to increase the ejection fraction of a mono-chamber static heart model by 5%. METHODS: A pediatric ventilation balloon was used as a heart model (mono-chamber). Flexinol®, a SMA, was placed around the heart model in multiple configurations and activated using pulse width modulation techniques to determine influence of diameter and configuration on volume displacement. Furthermore, pressure within the heart model was measured with a custom-made pressure sensor. RESULTS: SMA with a diameter of 0.38 mm, placed in a spiral shape and activated with a duty cycle of 80% and a frequency of 50/min gave the highest ejection fraction increase of 3.5%. CONCLUSIONS: This study demonstrated the feasibility of volume displacement in a static heart model by activation of SMA-wires. Configuration, duty cycle, frequency, pulse intervals and diameter were identified as important factors affecting the activation of SMA-wires on volume displacement. Future research should include the use of parallel SMA-wires, prototype testing in dynamic or ex vivo bench models.

Clinical recognition of acute aortic dissections: insights from a large single-centre cohort study.

AIMS: Acute aortic dissection (AD) requires immediate treatment, but is a diagnostic challenge. We studied how often AD was missed initially, which patients were more likely to be missed and how this influenced patient management and outcomes. METHODS: A retrospective cohort study including 200 consecutive patients with AD as the final diagnosis, admitted to a tertiary hospital between 1998 and 2008. The first differential diagnosis was identified and patients with and without AD included were compared. Characteristics associated with a lower level of suspicion were identified using multivariable logistic regression, and Cox regression was used for survival analyses. Missing data were imputed. RESULTS: Mean age was 63 years, 39% were female and 76% had Stanford type A dissection. In 69% of patients, AD was included in the first differential diagnosis; this was less likely in women (adjusted relative risk [aRR]: 0.66, 95% CI: 0.44-0.99), in the absence of back pain (aRR: 0.51, 95% CI: 0.30-0.84), and in patients with extracardiac atherosclerosis (aRR: 0.64, 95% CI: 0.43-0.96). Absence of AD in the differential diagnosis was associated with the use of more imaging tests (1.8 vs. 2.3, p = 0.01) and increased time from admission to surgery (1.8 vs. 10.1 h, p < 0.01), but not with a difference in the adjusted long-term all-cause mortality (hazard ratio: 0.76, 95% CI: 0.46-1.27). CONCLUSION: Acute aortic dissection was initially not suspected in almost one-third of patients, this was more likely in women, in the absence of back pain and in patients with extracardiac atherosclerosis. Although the number of imaging tests was higher and time to surgery longer, patient outcomes were similar in both groups.

Vestigial retrorectal cystic tumors in adults: a review of 30 cases.

OBJECTIVES: Retrorectal tumors are uncommon. This is a report on a series of vestigial retrorectal cystic tumors in adults that were surgically removed at two medical centers in France. We also assessed the significance of imaging and, in particular, magnetic resonance imaging (MRI) in the management of these lesions. METHODS: The medical files of adult patients operated on for vestigial retrorectal cystic tumors over the past 15 years were retrospectively studied and, in particular, the radiological studies, the treatment and the histopathology. RESULTS: Thirty patients underwent surgery for vestigial retrorectal cystic tumor. A preoperative diagnosis was possible in almost all cases. The surgical procedure was justified by preoperative imaging and included the transanal approach (three cases), posterior approach (23 cases), anterior approach (two cases) and combined posterior and anterior approach (two cases). Imaging can identify a multilobular lesion that may require the use of a coccygeal approach to achieve complete resection. During a mean follow-up of 3.2 years (range 0.5-15 years), two patients had a local recurrence (successfully surgically removed), and a further two patients were lost to follow-up. Only one lesion was malignant. CONCLUSIONS: Preoperative imaging, and especially magnetic resonance imaging, enables both a specific diagnosis and the selection of the optimal surgical procedure for the treatment of vestigial retrorectal cystic tumors in adults.

Restricted swelling and its orientation effect on copolymer micellar solutions of hexagonal-packed cylinders under steady shear flow.

We investigate the structure of polystyrene-b-poly(acrylic acid, sodium salt) copolymer in aqueous solutions. We offer detailed characterization of the micellar solutions by scattering techniques and show that they form hexagonal-packed cylinders. The micelles follow the swelling law expected for cylinders, upon addition of water, down to a concentration threshold below which the distance cylinder-cylinder remains constant. The results suggest that the cylinders are aggregated. It is proposed that this micellar association is the cause of the unusual orientation of the cylinders in a steady shear flow field, where the cylinder axis is found to be parallel to the velocity gradient.

[Nicorandil-associated anal ulceration]. / Ulcérations anales induites par le nicorandil.

BACKGROUND: Nicorandil is a potassium-channel activator used in the treatment of angina pectoris. The first cases of anal ulcerations induced by nicorandil were published in 2002. CASE REPORT: A 71-year-old man presented with a 2-year history of anal ulcerations occurring within a few months of initiation of treatment with Nicorandil. Histological tests on a biopsy sample showed granulation tissue with non-specific chronic inflammation. Nicorandil was stopped and this resulted in complete healing of the ulcers after three months. DISCUSSION: Nicorandil can induce chronic and extensive anal ulcerations. The pathogenesis is unknown. Patients are usually treated with high doses of nicorandil. Dermatologists should be aware of this rare side-effect which heals after withdrawal of the drug.

Motional heterogeneity of intercalated species in modified clays and poly(epsilon-caprolactone)/clay nanocomposites.

Modified laponites and synthetic saponites are used as precursors for the preparation of poly(epsilon-caprolactone) (PCL)/clay nanocomposites. The structure and dynamics of species intercalated in the modified clays and the corresponding nanocomposites are characterized by X-ray diffraction and magic-angle spinning NMR. The influence of the headgroup, the hydrocarbon chain length, and the loading of the surfactant on the nanocomposite formation are discussed. The yield of PCL intercalation is related to the probability of direct polymer-clay interactions and to the size of the clay platelets. Relaxation times in the laboratory and rotating frames that allow characterization of fast and slow molecular dynamics in these systems are discussed, showing a motional heterogeneity of the intercalated species.

Endoventriculoplasty using autologous endocardium for anterior left ventricular aneurysms.

BACKGROUND: There is currently consensus that endoventriculoplasty is the treatment of choice for an anterior left ventricular aneurysm. We describe here a new technique of endoventriculoplasty using autologous endocardium for left ventricular anterior aneurysm. METHOD: From 1990 until 2003, 49 patients underwent endoventriculoplasty using autologous pericardium at the Thoraxcenter of the University Hospital of Groningen in the Netherlands (28 patients) and at the Department of Cardio Thoracic Surgery of the University Hospital of Pisa in Italy (21 patients). Mean logistic EuroSCORE and mean ejection fraction were 15.7 +/- 6.7 and 31 +/- 9 %, respectively. RESULTS: Overall 30-day mortality was 4.1 %. Causes of in-hospital mortality were low output syndrome (1 patient) and ventricular fibrillation (1 patient). Postoperative complications were myocardial infarct (4.1 %), low output syndrome (6.1 %), renal failure (4.1 %), neurological events (2.0 %), atrial fibrillation (14.3 %), ventricular fibrillation or tachycardia (6.1 %), ARDS (4.1 %), re-operation for bleeding (4.1 %), and major wound infection (2.0 %). CONCLUSION: Our analysis shows that endoventriculoplasty with autologous endocardium is a safe procedure and improves the outcome in high-risk patients with ventricular aneurysm.

Mixed self-assembly of poly(ethylene oxide)-b-poly(epsilon-caprolactone) copolymers and sodium dodecyl sulfate in aqueous solution.

Interaction of amphiphilic poly(ethylene oxide)-b-poly(epsilon-caprolactone) copolymers with anionic sodium dodecyl sulfate (SDS) has been investigated in aqueous solution. Formation of mixed micelles has been confirmed by surface tension measurements, whereas the influence of the surfactant on the copolymer self-assembling has been studied by measurement of the 1H NMR self-diffusion coefficients and by small-angle neutron scattering. As a rule, the surfactant decreases the heterogeneity of the micellar structures formed by the copolymer in water. Moreover, increasing the content of SDS results in the increasingly more important extension of the poly(ethylene oxide) (PEO) corona chains and the copolymer micelle deaggregation. The stability of the micelles against SDS increases with the length of the hydrophobic block. Preliminary two-dimensional NMR measurements with nuclear Overhauser enhancement have confirmed the spatial vicinity between SDS and the constitutive blocks of the copolymer.

Solid-state NMR study of intercalated species in poly(epsilon-caprolactone)/clay nanocomposites.

The structure and dynamics of surfactant and polymer chains in intercalated poly(epsilon-caprolactone)/clay nanocomposites are characterized by (31)P magic-angle spinning (MAS) and (13)C cross-polarization MAS NMR techniques. To obtain hybrid materials with the low polymer content required for this study, in situ intercalative polymerization was performed by adapting a published procedure. After nanocomposite formation, the chain motion of the surfactant is enhanced in the saponite-based materials but reduced in the Laponite ones. Compared to the starting clay, the trans conformer population of the surfactant hydrocarbon chain in the nanocomposite decreases for the saponite systems. Mobility of the polymer chain is higher in the nanocomposites than in the bulk phase. The charge of the modified saponite does not significantly influence chain mobility in the nanocomposites.

Self-assembly of poly(ethylene oxide)-b-poly(epsilon-caprolactone) copolymers in aqueous solution.

The associative behavior of monodisperse diblock copolymers consisting of a hydrophilic poly(ethylene oxide) block and a hydrophobic poly(epsilon-caprolactone) or poly(gamma-methyl-epsilon-caprolactone) block has been studied in aqueous solution. Copolymers have been directly dissolved in water. The solution properties have been studied by surface tension, in relation to mesoscopic analyses by NMR (self-diffusion coefficients), transmission electron microscopy, and small-angle neutron and X-ray scattering. The experimental results suggest that micellization occurs at low concentration (approximately 0.002 wt %) and results in a mixture of unimers and spherical micelles that exchange slowly. The radius of the micelles has been measured (ca. 11 nm), and the micellar substructure has been extracted from the fitting of the SANS data with two analytical models. The core radius and the aggregation number change with the hydrophobic block length according to scaling laws as reported in the scientific literature. The poly(ethylene oxide) blocks are in a moderately extended conformation in the corona, which corresponds to about 25% of the completely extended chain. No significant modification is observed when poly(gamma-methyl-epsilon-caprolactone) replaces poly(epsilon-caprolactone) in the diblocks.

[Abdominal management of rectocele and elytrocele: place of the laparoscopic approach]. / Traitement des rectocèles et des élytrocèles par voie abdominale: apport de la laparoscopie.

AIM OF THE STUDY: To report the results of abdominal promontory rectopexy and douglassectomy in the management of rectocele and enterocele. PATIENTS AND METHODS: Between 1992 and 2002, 72 patients were operated by one colorectal surgeon. Laparotomy was used in 37 cases between 1992 and 2001 and the laparoscopic approach in 35 cases from 1995 to 2002. Promontory rectal fixation required only one mesh secured between the anterolateral right side of the rectum and the lumbosacral ligament. The same mesh was used to fix the vagina or the cervix. Combined therapeutic or prophylactic urinary interventions are frequent in the series. RESULTS: The follow-up was more than one year in 63 patients with a mean value of 58 months with no patient lost. Recurrence of posterior vaginal prolapse was noted in only two cases. Dyschesia and urinary incontinence were improved respectively in 80 and 70% of the cases and a significant improvement in anal incontinence was observed in 95% of the patients. CONCLUSION: The abdominal way allows a suitable treatment in patients with advanced stage rectocele and enterocele and evidence of pelvic organ prolapse. The laparoscopic approach is superior in terms of morbidity and functional results.

A rare case of herniation of omentum into the pericardial cavity after using the right gastro-epiploic artery for coronary bypass grafting.

The right gastro-epiploic artery is frequently used as a conduit in coronary artery bypass grafting. A rare complication after this procedure is herniation of omentum or other gastrointestinal contents into the pericardial cavity. Clinical symptoms of this complications are acute abdominal pain, nausea, angina, dyspnea, vomiting or signs of pericardial compression. In this case-report we present one patient with a herniation of omentum into the pericardial cavity without any clinical symptoms of herniation.

[IMesenteric and mesocolic cystic lymphangiomas. Diagnostic and therapeutic management]. / Les lymphangiomes kystiques du mésentère et du méso-côlon. Prise en charge diagnostique et thérapeutique.

STUDY AIM: Study of clinical, diagnostic and therapeutic aspects of mesenteric and mesocolic cystic lymphangiomas. MATERIAL AND METHODS: 15 cases were retrospectively analysed: 5 adults (mean age 36.8 years, range 26 to 46) and 10 children (mean age 23 months, range 0 to 5 years). Diagnosis was prenatal in 1 case. Symptoms were: abdominal pain (80%), fever (20%), abdominal mass (46%), occlusive syndrome (33%), chylous ascitis 1 case. Tumours were mesenteric (86%) or mesocolic (13%). RESULTS: Complete resection was performed in 11 cases (including 10 bowel resections), incomplete resections in 3 and doxycycline sclerotherapy once. Mean follow-up is 5 years. One recurrence occurred 6 years after complete resection and 1 tumour increased after incomplete resection. Patient treated by sclerotherapy was non symptomatic with a 3.5 years follow-up after last injection. CONCLUSION: Mesenteric and mesocolic cystic lymphangiomas are congenital benign tumours. Complete resection should be performed whenever possible. Intracystic sclerotherapy with doxycyclin is possible for unresectable lymphangiomas.