Gernot Helweg

TRANSURETHRAL ULTRASOUND: EVALUATION OF ANATOMY AND FUNCTION OF THE RHABDOSPHINCTER OF THE MALE URETHRA

PURPOSE A combined anatomic-sonographic study was undertaken to investigate whether the anatomical arrangement and the contractions of the rhabdosphincter of the male urethra could be visualized by transurethral ultrasound. Furthermore, this new technique was compared with standard urodynamic tests. MATERIALS AND METHODS In 7 cadavers transurethral ultrasound was performed to define sono-morphological criteria of the rhabdosphincter, and the sonographic pictures were then compared to histological sections. In 48 patients the rhabdosphincter of the male urethra was investigated by transurethral ultrasound and urodynamic techniques. Of these patients 40 were completely continent after radical prostatectomy and 8 presented with urinary stress incontinence after transurethral resection of the prostate or radical prostatectomy. The decrease of the distance between the rhabdosphincter and the transducer during contraction served as quantitative parameter for the contractility of the muscle. RESULTS The anatomical arrangement and contractions of the rhabdosphincter loop could be clearly visualized on transurethral ultrasound (during contraction the rhabdosphincter retracts the urethra, pulling it towards the rectum). Ultrasound showed scars in 3 patients with postoperative urinary stress incontinence, thinning of the muscle in 3 complete atrophy of the rhabdosphincter in 2 and minimal contractions of the rhabdosphincter in 1. Urethral closure pressures were decreased and decrease in rhabdosphincter-transducer distance was statistically significantly decreased in the incontinent patients. CONCLUSIONS Our sono-morphological data and anatomical histological results strongly suggest that the rhabdosphincter constitutes the main component of the continence mechanism in post-prostatectomy patients. Unlike urethral pressure profiles, which can only reveal zones of higher intraluminal pressure between the bladder and the penile urethra, transurethral ultrasound is highly specific for measurement of the function of the rhabdosphincter.

Variability of Doppler parameters in the healthy kidney: an anatomic-physiologic correlation.

Contradictory results have been obtained in classifying various renal diseases when trying to use the resistive index measured by duplex Doppler technique in renoparenchymal arteries. These measurements may have been influenced by the lack of standardization of the anatomic site at which the renoparenchymal artery is sampled. To elucidate this influence, we measured the resistive index, peak systolic velocity, end diastolic velocity, and pulsatility index in 120 healthy kidneys at three different positions of the renal vasculature. The resistive index at the level of the interlobar‐arcuate arteries proved to be the parameter with the most consistent results and should be preferred in clinical applications.

Intraurethral ultrasound: diagnostic evaluation of the striated urethral sphincter in incontinent females

Abstract. The aim of our study was to evaluate the striated urethral sphincter (rhabdosphincter) in incontinent females by means of intraurethral ultrasound (IUUS). Thirty-four incontinent and 11 continent female patients were examined by means of 12.5-MHz endoluminal ultrasound (US). The distance between the inner contour of the sphincter muscle and the US catheter was measured in the contracted and the non-contracted condition. The US findings were correlated with those obtained by urodynamic studies. Partial or complete loss of sphincter function was detected in patients with stress urinary incontinence (SUI). Reduced sphincter function was not observed in patients with urge incontinence and continent volunteers. The findings on US were found to correlate well with the grade of SUI. The IUUS technique offers the benefit of direct visualization of the sphincter mechanism. Therefore, endoluminal US may become an important adjunct in the diagnostic evaluation of SUI and will possibly provide new insights for a better therapeutic strategy.

Age-Related Changes in Resistive Index Following Extracorporeal Shock Wave Lithotripsy

PURPOSE Changes in intrarenal vascular resistance after extracorporeal shock wave lithotripsy (ESWL*) were studied with Doppler ultrasound techniques. MATERIALS AND METHODS In 76 patients the resistive index was measured at an interlobar artery before and after ESWL in the treated and contralateral kidneys. The resistive index levels were compared to N-acetyl-beta-D-glucosaminidase levels in 40 patients. RESULTS We found an age-related positive linear correlation between post-therapeutic resistive index increases and patient age. N-acetyl-beta-D-glucosaminidase levels were also elevated after ESWL but these elevations were not age-related. CONCLUSIONS Elderly patients have a higher risk of post-ESWL renal tissue damage.

Bone mineral densitometry in dialyzed patients: quantitative computed tomography versus dual photon absorptiometry.

Reduced bone mineral density (BMD) increases risk of fractures, thus making it necessary to monitor patients suffering from chronic renal failure and consecutive disturbance of bone metabolism. In order to evaluate the reliability of available methods, bone mineral density of the lumbar spine assessed with single energy computed tomography (QCT) was compared with bone mineral density of the lumbar spine, femoral neck, Wards triangle and trochanteric region measured by dual energy photon absorptiometry (DPA) in 45 hemodialyzed patients with a mean hemodialysis duration of 35 +/- 26 months (SD). Depending on the measurement site and method 4-34% of dialyzed patients suffered from reduced BMD (z-score < -2). The highest correlation (r = 0.61, p < 0.01) was found between QCT of the spine, trabecular bone, and DPA of Wards triangle. One year after baseline measurement bone mineral density was reassessed after randomization to either QCT or DPA in 14 and 18 patients, respectively. Whereas lumbar spine and femoral neck did not change, mean BMD showed a decrease at the measurement sites of Wards triangle (DPA), trochanteric region (DPA) and trabecular bone of the spine (QCT), which, however, was statistically not significant. Cortical BMD of the spine assessed with QCT showed an increase. Although there is some reduction in bone density at most sites in hemodialyzed patients, no significant bone loss could be demonstrated over the course of 1 year.

Laparoscopic pyeloplasty for UPJ obstruction with crossing vessels: contrast-enhanced color Doppler findings and long-term outcome.

Objectives. To evaluate, in the present long-term follow-up study, contrast-enhanced color Doppler imaging (CDI) findings and the clinical outcome of patients with crossing vessels at the obstructed ureteropelvic junction (UPJ), who underwent laparoscopic pyeloplasty. In a previous study, contrast-enhanced CDI proved capable of detecting crossing vessels at the UPJ. Methods. A total of 23 patients, who had undergone laparoscopic pyeloplasty and displacement of crossing vessels for UPJ obstruction at least 2 years before this study (mean 27 months), underwent contrast-enhanced CDI, intravenous urography, and renography. Contrast-enhanced CDI was performed using intravenously administered Levovist to assess the displacement of the vessels relative to the UPJ. All patients completed analog follow-up pain scales and quality-of-life assessment questionnaires. Results. Contrast-enhanced CDI revealed a cranial displacement (mean 1.3 cm) of the crossing vessels from the UPJ in all 23 cases. Intravenous urography showed a decrease in the degree of hydronephrosis, with a success rate of 100% in low-grade and 86% in high-grade hydronephrosis. The split renal function improved from 39.7% to 48.1%. Analog pain scale measurements demonstrated a mean improvement in pain of 92% (range 73% to 100%) and a mean quality-of-life score of 94 (range 78 to 100). Conclusions. Our series of patients with crossing vessels at the UPJ treated by laparoscopic pyeloplasty showed an excellent long-term successful outcome. Contrast-enhanced CDI allows for preoperative detection, as well as postoperative assessment, of the displacement of the crossing vessel. We recommend that the presence of a crossing vessel be routinely determined preoperatively, because it may influence the choice of treatment modality and thereby the clinical outcome.

Age-Related Rhabdosphincter Function in Female Urinary Stress Incontinence Assessment of Intraurethral Sonography

Objective. To assess dynamic intraurethral sonography in the diagnostic evaluation of the function of the rhabdosphincter in female patients with urinary stress incontinence in relation to patient age. Methods. Sixty‐two patients with clinically proved urinary stress incontinence were investigated by means of intraurethral sonography with a 12.5‐MHz endoluminal 9F catheter. The omega‐shaped rhabdosphincter was visualized at rest and during voluntary contractions. Changes of muscle thickness and transducer‐sphincter distance were measured and considered as parameters of muscle function. The intraurethral sonographic data were compared with results of standard urodynamic tests. Results. Transducer‐sphincter distance and sphincter muscle thickness showed a significant decrease with positive linear dependency on patient age (P < .001). Patients with grade III urinary stress incontinence had complete loss of sphincter contractility. A negative correlation was revealed between urethral closure pressure and patient age. Conclusions. We found an age‐related decrease in rhabdosphincter function. Our results suggest that the rhabdosphincter is a substantial component of the continence mechanism in female urinary stress incontinence. Unlike urethral pressure profiles, which can only reveal zones of higher intraluminal pressure, transurethral sonography is highly specific for measurement of the function of the rhabdosphincter.

Blood pressure changes after extracorporeal shock wave nephrolithotripsy: prediction by intrarenal resistive index

In order to identify a high-risk group for the development of arterial hypertension after extracorporeal shock wave nephrolithotripsy (ESWL), we correlated the increase in renovascular resistance induced by ESWL in 79 normotensive patients with changes in arterial blood pressure occurring 20 (+-3) months after therapy. Renal vascular resistance was measured as resistive index (RI) by duplex Doppler sonography in both kidneys. Mean RI before treatment was 0.620±0.035 (SD). After treatment, we observed a significant and age-dependent increase in the RI in the treated kidney to 0.673 ± 0.06. Of the patients with a post-ESWL RI> 0.690, 39% developed hypertension. Posttherapy RI values surpassing 0.690 showed a 0.8 sensitivity and a 0.7 specificity in predicting arterial hypertension. Intrarenal Doppler ultrasound (US) is useful to find the high-risk group for arterial hypertension after ESWL.

Sonographie der Schulter

ZusammenfassungDer Stellenwert der Schultersonographie unter standardisierten Untersuchungsbedingungen und entsprechender Erfahrung des Untersuchers ist unbestritten. Insbesondere im Bereich der Traumatologie ist die Wertigkeit bei Rotatorenmanschettenläsionen mit entsprechendem operativem Korrelat statistisch gut abgesichert. Die Overall-Sensitivität bei Rotatorenläsion liegt heute bei ca. 95 %. Partielle und Totalrupturen der Rotatorenmanschette sowie das Impingementsyndrom fallen unter den Sammelbegriff Subakromialsyndrome und sind sonographisch sowohl in statistischer als auch dynamischer Untersuchungstechnik gut beurteilbar. Eine wesentliche Bedeutung hat die sonographische Normalwertbestimmung von Schulterweichteilen als metrisches Fundament zur Bewertung pathologischer Veränderungen. Ein definiertes Staging (prä- wie postoperativ) ermöglicht eine exakte Operationsplanung sowie eine genaue Therapiekontrolle. Die Beurteilung der Gleitlager als indirekter Hinweis auf Traumen bzw. bei entsprechender Klinik als Anhaltspunkt entzündlicher Veränderungen mit exsudativ proliferativen Gelenkergüssen oder im Rahmen der Tendinitis calcarea ist heute sonographischer Untersuchungsstandard. Die Indikation für andere Untersuchungsverfahren wie Arthroskopie, Kontrast-CT oder MRT ist dadurch zurückgedrängt.SummarySonography of the shoulder joint is a well-established technique in the hands of the experienced examiner, when using a standardized protocol. It has proved invaluable in assessing pathological soft tissue changes, especially after trauma. The static evaluation of anatomy and dynamic assessment of function are especially helpful in both preoperative staging and postoperative follow-up. The normal anatomy, examination techniques, including our own variations, and pathological conditions are discussed. The findings and various classifications of impingement syndrome, rotator cuff injuries, biceps tendon lesions and inflammatory changes are examined. Review of the major articles in the literature shows excellent correlation with our results, the overall sensitivity in the case of rotator cuff lesions being over 90 %. A well-performed ultrasound examination in most cases obviates the need for the more invasive arthroscopy and the more cumbersome and expensive MRI examinations.

Diagnostik von Überlastungsschäden bei Sportkletterern

ZusammenfassungSportklettern zeigt eine zunehmende Popularität sowohl im Elitesport als auch im leistungsorientierten Breiten- und Schulsport. Dadurch kommt klettertypischen Beschwerden eine zunehmende medizinische Bedeutung zu. Bei dieser Sportart stehen Überlastungen (“overuse”) hauptsächlich im Bereich der oberen Extremität an erster Stelle der Beschwerden. Neben der klinischen Untersuchung, welche in der Akutphase limitiert sein kann, ist die bildgebende Diagnostik zur exakten Abklärung notwendig, um ein adäquates therapeutisches Management zu gewährleisten. Im Rahmen dieser Arbeit wird ein Überblick über den Einsatz der unterschiedlichen Bildgebungsmodalitäten wie konventionelles Röntgen, Ultraschall und Magnetresonanztomographie bei den klettertypischen Beschwerdebildern gegeben.AbstractSport climbing shows an enormous increase in participation, evolving to more popularity, including even school sport activity on high standards. Therefore the number of climbing related injuries is increasing and becomes a more frequently encountered medical problem. Typical climbing associated injuries involve predominantly the upper limb. Overuse injuries are the most common climbing related injuries.The clinical examination is the first line investigation, which is often limited especially in the acute phase. However, an exact diagnosis is desireable for therapeutic management. Imaging modalities have shown to be capable for detection of climbing related injuries. An overview about the current use of x-ray, ultrasound and magnetic resonance imaging in different climbing related overuse injuries is presented.