[Can preoperative prostate MRI before radical prostatectomy predict extracapsular extension and the side of the index lesion?]. / L'IRM de la prostate préopératoire avant prostatectomie radicale peut-elle prédire l'extension extracapsulaire et le côté de la lésion de référence?

AIM: To evaluate the role of preoperative multi-parametric magnetic resonance imaging (MP-MRI) in patients undergoing radical prostatectomy. Specifically, the accuracy of MP-MRI in detecting extracapsular extension (ECE) and individuating the side of the index lesion have been explored. METHODS: Thirty-five consecutive patients undergoing radical prostatectomy have been retrospectively analyzed. The MRI exam incorporated T2-weighted imaging, diffusion-weighted imaging and dynamic contrast enhancement in all patients. χ(2) test was performed to assess an association between an MP-MRI suggestive of ECE and pathologic ECE; similar tests were performed to study the association between the MRI-detected side of the index lesion and its true localization on final pathology. Univariate logistic regression models were constructed to evaluate possible predictors of ECE, including MP-MRI suspected ECE. RESULTS: Seventeen percent (6/35) of men presented ECE on final pathology. MP-MRI was predictive of pathologic ECE with a negative predictive value and specificity of 93% and 90%, respectively. Global accuracy of MP-MRI in predicting ECE was 86%. MRI-detected ECE was significantly predictive of pathologic ECE on logistic regression (OR: 17.3, 95% CI: 2.2-138.2, P=0.007). Moreover, MRI significantly predicted the side of the index lesion (P=0.012). CONCLUSIONS: In this single center cohort, preoperative MP-MRI was significantly predictive of ECE and side of the index lesion. Further studies are necessary to individuate patients who can benefit from preoperative MP-MRI. LEVEL OF EVIDENCE: 5.

Heterogeneously integrated III-V-on-silicon multibandgap superluminescent light-emitting diode with 290 nm optical bandwidth.

A broadband superluminescent III-V-on-silicon light-emitting diode (LED) was realized. To achieve the large bandwidth, quantum well intermixing and multiple die bonding of InP on a silicon photonic waveguide circuit were combined for the first time, to the best of our knowledge. The device consists of four sections with different bandgaps, centered around 1300, 1380, 1460, and 1540 nm. The fabricated LEDs were connected on-chip in a serial way, where the light generated in the smaller bandgap sections travels through the larger bandgap sections. By balancing the pump current in the four LEDs, we achieved 292 nm of 3 dB bandwidth and an on-chip power of -8 dBm.

Trans-obturator vaginal tape (TOT) for female stress incontinence: one year follow-up in 120 patients.

OBJECTIVES: The aim of this study was to evaluate the effectiveness of a new minimally invasive surgical procedure, the Trans-obturator Vaginal Tape (TOT) in the treatment of female urodynamic stress incontinence (USI) and to analyse functional results and quality of life after one year of follow up. MATERIAL AND METHOD: 120 consecutive women with stress urinary incontinence underwent the procedure since February 2002 under general or loco-regional anesthesia. Minimum follow up was one year (range 12-30 months). Mean age was 58 years (range 31-86). 70% of the patients had pure USI. 5 patients were previously operated for USI. In 10 cases, concomitant repair of pelvic floor defects was mandatory. Collection of the data included operative time, pre- and post-operative complications. Patients were post-operatively assessed at one week, one month and one year. A validated urinary incontinence-specific measure of Quality of Life (QoL) questionnaire (Contilife) was sent and completed 12 months after surgery. RESULTS: The mean operative time was 12 min (range 6-30) with a catheterisation time of 0,9 day (range 0-2). No severe bleeding was observed. There were 13 minor lateral tears of the vagina without any sequelae. Three perforations of the urethra and one of the bladder occurred during the learning phase. In two cases a re-intervention was necessary for tape removal when the injury was not recognised during the procedure. Two transient urinary retention needed a supra pubic catheter and tape release. Eleven women presented transient voiding outflow obstruction. After one month, 93% patients were cured with no pad and a negative cough test with a full bladder. Uroflowmetry did not show any significant changes between pre- and post-operative time in all the population. De novo urgency occurred only in 2.5% and persistent dysuria (Qmax <10 ml/s and/or post-void residual volume >120 cc) in 4%. 80% of patients were completely dry after one year and 12% were greatly improved. According to the pre-operative maximal urethral closure pressure, continence rate was 86% above 30 cm H2O and 76% below 30 cm H2O respectively. Global satisfaction of women at 1 year was 78% with good scores based on daily and effort activities, self-image, emotional and sexual activities. CONCLUSIONS: TOT is a safe and effective new minimal invasive procedure for USI with a low rate of complications. To confirm the success of TOT, longer follow up in large population is mandatory to assess the reliability of this attractive technique.

Novel concept for a noninvasive cardiopulmonary monitor for infants: a pair of pajamas with an integrated sensor module.

We present a noninvasive cardiopulmonary monitor for use in infants in which sensors are incorporated into conventional pajamas. It consists of dry electrodes for picking up the electrocardiogram and of two capacitive based elastic strain gauges for the measurement of thoracic and abdominal respiratory movements. The quality of the signals was assessed by performing at home seven sleep recordings in parallel with a conventional system and 16 overnight sleep recordings. In the former tests, the acquisition of all mean R-R intervals agreed in both systems with an accuracy of 15.6 ms, determined by the sampling frequency of the commercial system. For the overnight recordings, more than 99% of the R peaks were correctly detected. In 1.5%, both respiratory traces were simultaneously out of range. Finally, it was observed that more saturated episodes and less errors in R-peak detection appeared in prone than in supine position. In summary, these results demonstrated that the dry electrodes can be a good alternative to the sticking electrodes, and that this simple system is reliable. In contrast with the existing monitors, skin irritations are avoided, redundancy of respiratory signals is provided and user-friendliness of the system is reached.

Mathematical assessment of qualitative diagnostic calibration for respiratory inductive plethysmography.

We present a critical assessment of qualitative diagnostic calibration (QDC), which claims to provide a relative calibration of respiratory inductive plethysmography during natural breathing (Sackner MA, Watson H, Belsito AS, Feinerman D, Suarez M, Gonzalez G, Bizousky F, and Krieger B. J Appl Physiol 66: 410-420, 1989). QDC computes the calibration factor (K) by considering breaths of constant tidal volume (VT) and provides a criterion to select breaths when VT is unknown. We applied QDC on uncalibrated data constructed from simulated sets of thoracic and abdominal volumes, with a predefined K. As expected, QDC yields a correct K when applied to breaths at constant VT. In breathing at quasi-constant VT, the criterion for breath selection is shown to bias the results toward K = 1. For spontaneous breathing, the calculated K deviates from its predefined value and depends heavily on the selection criterion. We conclude that QDC will only provide a correct calibration factor when applied to an entire set of breaths with constant or quasi-constant VT. More generally, physiological conclusions based on QDC should be critically evaluated on a case-by-case basis.

Naso-oesophageal probes decrease the frequency of sleep apnoeas in infants.

The objective of the study was to determine whether a naso-oesophageal probe modifies sleep and cardiorespiratory patterns in infants with repeated obstructive apnoeas. Two polygraphic recording sessions were conducted in random order for 2 nights on 35 infants suspected to have repeated obstructive sleep apnoeas. One sleep study was performed with a pH probe inserted through the nasal passage down to the distal portion of the oesophagus. The other session was conducted without any naso-oesophageal probe (the baseline study). For the 25 infants who presented repeated obstructive apnoeas during baseline studies, the presence of the probe was associated with a small, but significant, decrease in the number of central apnoeas (median frequency of 18.5 apnoeas per hour without a probe; 16.1 per hour with the probe; P=0.040), and obstructive apnoeas (median of 1.9 apnoeas per hour without a probe; 0.6 per hour with the probe; P=0.016). The presence of the probe was also associated with a small increase in percentage non-rapid eye movement (NREM) sleep frequency. The changes were statistically significant only for infants who had no obstructive apnoea during baseline studies (29 vs. 31%). The presence of a naso-oesophageal probe significantly modifies the infants' respiratory characteristics during sleep. These findings should be considered when reporting and interpreting sleep studies in infants.

Measurement of thoracoabdominal asynchrony: importance of sensor sensitivity to cross section deformations.

Discrepancies in the assessment of thoracoabdominal asynchrony are observed depending on the choice of respiratory movement sensors. We test the hypothesis that these discrepancies are due to a different dependence of the sensors on cross-sectional perimeter and area variations of the chest wall. First, we study the phase shift between perimeter and area (Phi(PA)) for an elliptical model, which is deformed by sinusoidal changes of its principal axes. We show that perimeter and area vary sinusoidally in the physiological range of deformations, and we discuss how Phi(PA) depends on the ellipticity of the cross section, on the ratio of transverse and dorsoventral movement amplitudes, and on their phase difference. Second, we compute the relationship between perimeter, area, and the output of the inductive sensor, and we proceed by comparing inductive plethysmography with strain gauges for several cross section deformations. We demonstrate that both sensors can provide different phase information for identical cross section deformations and, hence, can estimate thoracoabdominal asynchrony differently. Furthermore, the complex dependence of the inductive sensor on perimeter and area warns against this sensor for the evaluation of thoracoabdominal asynchrony.

Chest wall motion during tidal breathing.

We have used an automatic motion analyzer, the ELITE system, to study changes in chest wall configuration during resting breathing in five normal, seated subjects. Two television cameras were used to record the x-y-z displacements of 36 markers positioned circumferentially at the level of the third (S1) and fifth (S2) costal cartilage, corresponding to the lung-apposed rib cage; midway between the xyphoid process and the costal margin (S3), corresponding to the abdomen-apposed rib cage; and at the level of the umbilicus (S4). Recordings of different subsets of markers were made by submitting the subject to five successive rotations of 45-90 degrees. Each recording lasted 30 s, and three-dimensional displacements of markers were analyzed with the Matlab software. At spontaneous end expiration, sections S1-3 were elliptical but S4 was more circular. Tidal changes in chest wall dimensions were consistent among subjects. For S1-2, changes during inspiration occurred primarily in the cranial and ventral directions and averaged 3-5 mm; displacements in the lateral direction were smaller (1-2 mm). On the other hand, changes at the level of S4 occurred almost exclusively in the ventral direction. In addition, both compartments showed a ventral displacement of their dorsal aspect that was not accounted for by flexion of the spine. We conclude that, in normal subjects breathing at rest in the seated posture, displacements of the rib cage during inspiration are in the cranial, lateral outward, and ventral directions but that expansion of the abdomen is confined to the ventral direction.

A comparison of pO2, pCO2, pH and bicarbonate in blood from the carotid and coccygeal arteries of calves.

A technique is described for the subcutaneous deviation of the carotid artery into the jugular groove of calves weighing between 90 and 200 kg. This makes sampling arterial blood or chronic cannulation for further experimentation very easy. Values of oxygen tension, carbon dioxide tension, pH and bicarbonate concentration in blood sampled from the ventral coccygeal artery were compared with the values obtained in blood from carotid artery puncture. The high correlations observed indicate that blood samples from the ventral coccygeal artery can be used for measurement of blood gases and pH in calves.