Biomedical subjects

H van Ahlen

Publications and source records attributed to H van Ahlen.

At least 19 recordsLinked to original sources

PubMed1998

Simple reinforcement for thin nephrostomy catheters.

PURPOSE: Nephrostomy catheters are prone to kinking or damage because the thin, flexible silicone tube is too vulnerable against mechanical stress even when the proximal end is carefully fixed. We developed a simple method to reinforce the outside part of a thin catheter protruding from the skin. MATERIALS AND METHODS: We treated 7 children with nephrostomy catheters or ureteral stents with a diameter of 8F or smaller. After insertion a large plastic tube was wrapped around the small catheter, and fixed to the skin and to the peripheral collection system with adhesive tape. RESULTS: Handling of the catheters improved and there was less need for re-fixation. CONCLUSIONS: Thin nephrostomy catheters can be effectively protected by wrapping them into a larger, outer tube after insertion.

Child↗

PubMed1997

[Rational diagnosis and surgical therapy of renal cell carcinoma with tumor thrombosis in the vena cava].

Venous involvement in renal cell carcinoma (RCC) represents an advanced state of disease. Nonetheless, its influence on survival is rather secondary compared with that of local tumor growth, grading and metastasis. Since conservative treatment in advanced RCC is mainly ineffective, surgical management offers the most promising approach for potential cure. Only patients without metastasis, however, seem to benefit from an aggressive surgical intervention. The surgical technique itself is determined by the vena caval extent of the tumor thrombus. Preferably, noninvasive imaging techniques should provide information about metastasis and the extent of the tumor thrombus. Diagnostic efforts should be adapted to therapeutic feasibility and prognosis in every individual patient in order to avoid fatiguing and costly over-examination. The standards requested above can be realized by use of modern sonographic and computed-tomographic imaging techniques or by magnetic resonance imaging alone. Thus, nowadays, the essential diagnostics in RCC with vena caval involvement may dispense with angiographic examinations.

Carcinoma, Renal Cell↗

PubMed1997

Does the success of ureterointestinal implantation in orthotopic bladder substitution depend more on surgeon level of experience or choice of technique?

PURPOSE: We attempted to determine the relative risk of ureterointestinal anastomosis using 2 antireflux techniques of orthotopic bladder substitution, and we assessed the degree to which success is determined by surgeon experience. MATERIALS AND METHODS: A total of 120 patients underwent surgery, including 74 with the Hautmann (Le Duc) technique and 46 with a somewhat modified Studer (Nesbit/Studer) technique. The urologists who performed the operations were classified as expert, skilled and learner. Evaluation was done retrospectively. All patients in the Studer group, except 3 who died and 1 who was lost to followup, were monitored a minimum of 12 months. RESULTS: There was a 20.4% rate of nonneoplastic obstructions in the 142 ureters reimplanted with the Le Duc technique (Hautmann group). The variation in obstruction rates of 16.7, 18.2 and 25%, respectively, for expert, skilled and learning surgeons was statistically insignificant. Only 3 nonneoplastic obstructions (3.6%) developed in the 83 ureters reimplanted with the Nesbit/ Studer technique (Studer group). The variation in obstruction rates of 5.1, 0 and 3.6%, respectively, for expert, skilled and learner surgeons was statistically insignificant. CONCLUSIONS: The Nesbit/Studer technique results in a generally lower rate of ureterointestinal anastomotic stricture than the Le Duc technique. Using the Le Duc technique there was no statistically significant correlation between incidence of obstruction and surgeon level of experience, indicating that obstruction with this technique probably arises from other factors.

Adult↗

PubMed1996

[Superselective embolization of tumor nodes in solitary kidney in inoperable patients].

PURPOSE: Evaluation of superselective embolisation of renal tumours in inoperable patients with solitary kidneys. METHODS AND PATIENTS: Eight inoperable patients with solitary kidneys bearing tumour nodules underwent 1-3 superselective embolisation procedures with ethibloc (5x) or polyvinyl alcohol (1x). Renal function was monitored with creatinine levels. Tumour size was controlled every three months by means of sonography. RESULTS: Technical success rate was 100%. In 3/3 patients haematuria could be stopped. Post-embolisation renal function was unchanged in 6 patients and deteriorated in two patients; creatinine level rose to a maximum of 2.2 mg%. We observed no other side effects. Seven of eight patients died during a median follow-up period of 9.3 months (4-18 months); in two cases they died due to their underlying malignant disease. One patient had local tumour progress. CONCLUSIONS: Superselective embolisation of renal tumours in patients with solitary kidneys may be a helpful, well-tolerated therapeutic option in inoperable, symptomatic patients.

Adult↗

PubMed1996

Modified ureteral stripping as an alternative to open surgical ureterectomy.

PURPOSE: Using a compression technique instead of the classical invagination technique in cases of total nephroureterectomy improves traction during transurethral stripping of the ureteral stump. MATERIALS AND METHODS: Eight patients underwent our modified compression technique. After nephrectomy a kinked 5F ureteral catheter is attached to the ureteral stump with a double ligation. Traction on the ureteral catheter is used to achieve ureteral compression. RESULTS: There were no intraoperative difficulties except for 1 dislodged ureteral catheter. No complications were associated with ureteral detachment or resection. CONCLUSION: Our technique offers an alternative to the classic invagination technique by increasing transurethral traction on the ureteral stump, while substantially decreasing the risk of ureteral catheter dislodgment.

Humans↗

PubMed1995

Opiate antagonists in erectile dysfunction: a possible new treatment option? Results of a pilot study with naltrexone.

Opioids have an inhibitory effect on sexual functions in both animals and humans. Twenty patients with idiopathic, nonvascular, nonneurogenic erectile dysfunction were treated with the opiate receptor antagonist naltrexone in a randomized, placebo-controlled, double-blind study for 8 weeks. Libido and frequency of sexual intercourse were not significantly altered, but early-morning erections increased significantly under naltrexone therapy. This response was not related to levels of androgens or gonadotropins, neither was it dose dependent. There was no change in any of the measured parameters under placebo. Further clinical studies with the substance should be conducted to evaluate its possible role in the oral treatment of male impotence.

Adult↗

PubMed1995

Surgical management of renal cell cancer with extension into the vena cava: usefulness of intra-operative sonography.

Intracaval tumour extension represents a significant surgical problem in patients with renal cell carcinoma. Although pre-operative imaging techniques provide sufficient visualization for the planning of the majority of operative procedures, intra-operative ultrasound is nonetheless beneficial in some cases. In 3 patients, the procedure has given an accurate evaluation of the extent of the tumour thrombus. It has allowed safe placement of instruments which had lessened the risk of thrombus dislodgement. Intra-operative sonography is simple to perform and can be considered a valuable new adjunct in the evaluation and management of renal cell carcinoma with intracaval tumour extension. New technological advances may eventually improve the quality of intra-operative imaging.

Carcinoma, Renal Cell↗

PubMed1994

The Alcock syndrome: temporary penile insensitivity due to compression of the pudendal nerve within the Alcock canal.

Penile insensitivity is a symptom commonly observed after traumatic or iatrogenic nerve lesions, or in association with neurological or vascular diseases. In contrast, we report 2 cases of intermittent genital hypesthesia that occurred in cyclists after long-term bicycle riding. Anatomical studies show that this condition was probably caused by an irritation of the pudendal nerve during its course through the Alcock canal as reported in the literature. No pathological findings were demonstrated on extensive physical examinations, medical history and all medical imagings (sonography of abdomen, prostate and testes, and magnetic resonance imaging of the pelvis and lumbar spine) as well as radiodiagnostics and Doppler sonography, nor was there evidence of other neurological disturbances. The symptoms in the 2 patients spontaneously resolved after 4 and 7 weeks, respectively, without specific medical therapy.

Bicycling↗

PubMed1994

Pharmacokinetics of vasoactive substances administered into the human corpus cavernosum.

The pharmacokinetics of vasoactive substances injected into the corpus cavernosum for the treatment of erectile dysfunction have not been investigated to date. We measured the local intracavernous and peripheral venous concentration curves of papaverine and prostaglandin E1, and its primary metabolite 15-keto-13,14-dihydro-prostaglandin E1 in an intra-individual comparison after intracavernous injection. Papaverine was measured with high performance liquid chromatography and prostaglandin E1 was measured with a specially adapted radioimmunoassay. The results demonstrate that papaverine is slowly draining into the systemic circulation, showing slightly elevated levels in the peripheral blood 30 and 60 minutes after injection. Prostaglandin E1 shows a much faster decrease in local concentrations with no measurable increase in the periphery, probably due to the short half-time after lung passage. Measurement of the primary metabolite proves a local degradation of prostaglandin E1 in the corpus cavernosum into the biologically inactive 15-keto-13,14-dihydro-prostaglandin E1, which also shows a slight increase in the peripheral circulation due to the longer half-time of approximately 8 minutes. The data provide good explanation for the clinical finding of a markedly decreased incidence of priapism with the use of prostaglandin E1, which can be shown to be locally metabolized, compared to papaverine, which is retained in the corpus cavernosum in cases of nonvenogenic impotence.

Alprostadil↗

PubMed1994

[Diagnosis of urethral diverticulum in women].

Urethral diverticula have proved to be a common cause of recurrent urinary tract infections in female subjects. Positive-pressure urethrography, mostly performed by means of double-balloon catheters, has hitherto been regarded as the method of choice for their detection. Unfortunately, the few existing commercial catheter devices have certain disadvantages, which have led to a lack of acceptance of this important technique and restricted its use. We therefore present an improved tool for positive-pressure urethrography and a synopsis of diagnostic visualization procedures for urethral diverticula in women.

Diverticulum↗

PubMed1993

[Diagnostic evaluation of acute scrotum--testicular perfusion scintigraphy].

The method of and the results obtained with testicular scintigraphy in the differential diagnosis of acute scrotal pain are described. Both sensitivity and specificity were found to be high and in excess of 90%. Misinterpretation of findings is rare and is seldom reported except in case reports. Normal findings usually genuinely reflect absence of disease, and only in the case of suboptimal imaging conditions they might correspond to a false-negative finding in the presence of acute torsion. Chronic torsion may be missed on scintigraphy because of intermediate normalization of arterial perfusion at the time of the investigation. Missed torsion presents a characteristic activity pattern. The halo sign is a proven sign of avitality of the testicle. Orchitis and epididymitis are correlated with hyperperfusion and hyperaemia and are reliably diagnosed by scanning. When testicular scintigraphy is needed immediate availability is essential. In a nuclear medicine department with standard equipment, the investigation can be started within 5 min; it takes about 15 min to perform and the findings can be evaluated within another 5 min. Acute testicular torsion that has already been reliably diagnosed by clinical examination is not an indication for testicular perfusion scintigraphy. This diagnostic procedure is, however, valuable if the clinical findings are equivocal and, especially, if a conservative treatment is planned.

Acute Disease↗

PubMed1991

Static and dynamic radionuclide imaging in the diagnosis of the acute scrotum.

In the acute scrotum, diagnosis can be difficult in certain cases. In 107 patients the value of static and dynamic radionuclide imaging was evaluated. Static images provide a sensitivity and reliability of over 90%. Quantitative measurements do not give additional information in the differential diagnosis of these patients. Generally, scintigraphy can only be advocated if available as an emergency procedure. It is not necessary in cases with clinically obvious diagnosis of acute testicular torsion or epididymitis, but can be very helpful and reliable in unclear cases, i.e. for the evaluation of testicular perfusion after scrotal trauma.

Acute Disease↗

PubMed1989

Intracavernous self-injection of prostaglandin E1 in the therapy of erectile dysfunction.

The efficacy of intracavernous autoinjection therapy with prostaglandin E1 was investigated over a period of up to six months in 187 patients with long-term erectile dysfunction. All patients had to undergo an investigation program consisting of routine laboratory tests, directional doppler sonography of the penile arteries, measurements of the BCR-latencies, as well as intracuvernum drug testing with PGE1. Six months follow-up results are available so far in 115 patients. The mean injection dose was 13.5 mcg PGE1 at the beginning of therapy and 12.8 mcg PGE1 at the end of therapy. An average of 24 prostaglandin E1 injections per patient was given. In 16.6% of the 187 patients slight to moderate pain occurred at the injection site, not influencing sexual intercourse. No priapisms lasting more than six hours were observed. A significant improvement of the blood flow in the deep and dorsal penile arteries was shown by penile doppler sonography after 6 months treatment. The efficacy and tolerability of the therapy were designated as very good to good in 91% respectively in 98% of the patients. 94% of the patients would like to continue the therapy. The results indicate that PGE1 due to its erectile potency and great tolerability will occupy an important position in the therapy of the erectile dysfunction.

Adult↗

PubMed1989

[The significance of testicular scintigraphy for the differential diagnosis of the acute scrotum].

Scrotal scans were performed in 100 juvenile or grown-up patients suffering from acute scrotal pain. Employing the standard equipment of a nuclear medicine department this examination which takes only a few minutes, had a very high accuracy (93%). Especially each torsion was diagnosed correctly. Quantitative analysis of the scans did not yield additional information compared to visual evaluation, and was therefore abandoned. In three patients presenting with traumatic scrotal hematoma the testicular perfusion was judged correctly posttraumatically and in follow-up scans.

Acute Disease↗

PubMed1989

[Drug-induced priapism--a report of experiences in 101 cases].

Within a period of 3 1/2 years, 101 patients with drug-induced priapism lasting more than 6 h were observed. In 73 of the 101 patients (average age 47.4 years) with an average duration of priapism of 11.9 h priapism was interrupted by means including cavernosal puncture, evacuation, and injection of metaraminol. In 28 patients priapism subsided after an average duration of 8.8 h without medical intervention. Intracavernous blood gas analyses revealed unphysiological acid values with clearly negative excess base values. Nevertheless, in the present series only 3 patients had irreversible damage of cavernosal function as a sequela of priapism of more than 24 h duration. Intracavernosal injection of meta-ramininol was followed by severe hypertensive crisis in 2 patients. These results show convincingly that the demand for early interruption of drug-induced priapism within a time limit of 6 h is not based on objective necessity. Interruption of drug-induced priapism within 6-8 h seems to be adequate. Prostaglandin E1 has proved a reliable means of preventing priapism in the initial test period.

Adult↗

PubMed1988

[Disorders of the hypothalamo-hypophyseal-gonadal axis and erectile impotence].

In the course of a standardized diagnostic programme LH, FSH, testosterone, prolactin and oestradiol were measured in 204 patients with erectile impotence (mean age 47.6 years). A purely organogenic abnormality was found in 125 (61.3%), a mixed organogenic-psychogenic one in 39 (19.1%), and a purely psychogenic one in 40 (19.6%). Thirteen patients (6.3%) had an abnormality of the hypothalamic-hypophyseal-gonadal axis, nine in addition had severe organogenic changes as the clear cause of the impotence. History and clinical findings were unremarkable in only one patient. Routine determination of hormones would seem to be cost-effective only if an important organic deficit has been excluded as the cause of an erection abnormality and therapeutic consequences can be drawn from any abnormal hormone values that are obtained.

Adult↗

PubMed1988

Bulbocavernosus reflex latencies and somatosensory evoked potentials after pudendal nerve stimulation in the diagnosis of impotence.

The bulbocavernosus reflex (BCR) was examined in 39 normal potent men and in 252 patients with impaired potency of varying aetiology. For BCR evaluation minimum, maximum and mean latencies, the temporal dispersion in ten successive responses, together with minimum and maximum side differences from simultaneous recordings of the left and right bulbocavernosus muscles were determined. Pathological findings were detected in 125 patients. Somatosensory evoked potentials (SSEPs) recorded from the scalp after stimulation of the penile dorsal nerves and the terminal branches of the pudendal nerve were investigated in 30 controls and in 246 patients. An abnormal SSEP was found in 63 patients.

Adolescent↗

PubMed1988

[Value of imaging procedures in the diagnosis and staging of bladder tumors].

A retrospective study of 161 patients with carcinomas of the bladder was carried out to assess the value of CT (247 examinations), transurethral sonography (32 examinations), and the early results of MRT. For TA-T3a staging, according to the TNM classification of the IUCC, transurethral sonography was particularly valuable. CT is useful for demonstrating transmural tumour growth (T3b) and organ invasion (T4), involvement of regional lymph nodes and distant metastases. Tumours in the roof of the bladder and at its base are well shown by MR tomography, using multiplanar sections.

Adult↗