Biomedical subjects

F Karnel

Publications and source records attributed to F Karnel.

At least 19 recordsLinked to original sources

PubMed2005

[Technical feasibility of the implantation of a monorail stent system into the renal arteries without pre-dilatation].

PURPOSE: To evaluate the technical feasibility of the implantation of the monorail RX Herculink system into the renal arteries without pre-dilatation. MATERIALS AND METHODS: Forty-two patients (mean age 71 years) from four centers with a total of 44 renal artery stenoses underwent implantation of the RX Herculink stent. The mean grade of the stenosis was 83.8 %, the mean length 7.5 mm. The stenoses were ostial in 38 cases and in immediate proximity to the ostium in 6 cases. The mean follow-up-period was 57 weeks (24 - 176 weeks). RESULTS: In 42 cases, the implantation was successful without pre-dilatation. In 2 cases, pre-dilatation was carried out. In none of the cases, detachment of the stent from the balloon was observed. In one stenosis with a length of 17 mm, implantation of two stents was performed. In 9 cases, post-dilatation with a larger balloon or higher balloon pressure was necessary. Residual stenoses exceeding 30 % were not observed. Two patients developed local bleeding at the puncture site. During the follow-up, restenoses were observed in 5 stents after 26 to 126 weeks, which necessitated a second intervention in 3 cases (PTA in 2 cases, re-stenting in 1 case). The primary patency rate after 6 and 12 months was 0.92 +/- 0.056 according to Kaplan-Meier, the secondary patency rate after 6 and 12 months was 1.0 +/- 0.0. CONCLUSION: Implantation of the RX Herculink stent system into the renal arteries without pre-dilatation is technically feasible and safe. Even without pre-dilatation, the stent-system can be advanced through the stenosis without detachment. The complication rate is low. Our clinical results are comparable to previous studies.

Aged↗

PubMed2003

Child-Pugh versus MELD score in predicting survival in patients undergoing transjugular intrahepatic portosystemic shunt.

BACKGROUND: In patients undergoing transjugular intrahepatic portosystemic shunt (TIPS), prognostic scores may identify those with a poor prognosis or even those with a clear survival benefit. The Child-Pugh score (CPS) is well established but several drawbacks have led to development of the model of end stage liver disease (MELD). AIM: The aim of the study was to compare the predictive power of CPS and MELD, to validate the original MELD formula, and to assess the predictive value of the determinants used in the two prognostic scores outside of a study setting. PATIENTS: A total of 501 patients underwent elective TIPS placement and 475 patients fulfilled the inclusion criteria. METHODS: Data of all patients undergoing elective TIPS in one university hospital and four community hospitals in Vienna, Austria, between 1991 and 2001, were analysed retrospectively. The main statistical tests were Cox proportional hazards regression model, the log rank test, Kaplan-Meier analysis, and concordance c statistics. RESULTS: Median follow up was 5.2 years and median survival was 4.6 years. During follow up, 230 patients died, 75 within three months after TIPS placement. In stepwise proportional hazards analyses, independent predictors of death were creatinine level, bilirubin level, age, and refractory ascites. MELD was better in predicting survival in a stepwise Cox model but both scores were equally predictive in c statistics for one month, three month, and one year survival. Renal function was the strongest independent predictor of survival. CONCLUSIONS: Although MELD was the primary predictor of overall survival in multivariate analysis, c statistics showed that both scores can be used for patients undergoing TIPS with equal accuracy. For assessing prognosis in patients undergoing TIPS implantation, there seems little reason to replace the well established Child-Pugh score.

Adult↗

PubMed1999

Iliac artery aneurysm causing isolated superior gluteal nerve lesion.

Lesions of the superior gluteal nerve (SGN) lead to weakness of hip abduction, manifesting itself as a gait abnormality, with contralateral tilting of the pelvis with each step. Causes are numerous and may occur at different anatomical locations before the nerve enters the suprapiriform foramen, in the foramen itself, or after the nerve has exited the foramen. This case report describes an SGN lesion by a large iliac artery aneurysm in a patient presenting with a gait disorder.

Buttocks↗

PubMed1995

[Monoca silicone intubation of the lacrimal ducts after retrograde dilatation].

The causes of stenosis in the area of the nasolacrimal duct in adults are extremely variable. In general, the symptoms may vary, but most cases exhibit a common factor of circumstances in the prestenotic area which favor recurring inflammation. The treatment of these disorders is limited to either a conservative therapeutic approach to control inflammation, or surgically invasive measures. By using balloon catheters, which are usually applied in PTCA (percutaneous transluminal coronary angioplasty), dilatation of the relative postsaccal stenosis is obtained with the assistance of radiography. An exact diagnosis by means of various testing methods, including digital dacryocystography for the detailed localization and documentation of any pathological changes, is decisive for success. Only in cases of incomplete, postsaccal stenosis is retrograde balloon dilation of the distal nasolacrimal duct incated. The guide wire, designed for the PTCA balloon catheter set, is introduced via the canaliculus to the nasal cavity antegradely and caught with a thin hook and pulled from the naris. This is done under visual control using an image converter. The balloon catheter is retrogradely threaded over the guide wire. The balloon is then placed at the site of the pathological stenosis under X-ray control and dilated with high pressure. To assure permeability of the system, a monocanalicular silicone intubation has to be made immediately following this procedure. This procedure has been performed successfully on six patients; Follow-up time ranged from 6 to 22 months. The initial results are encouraging and sustain hope that this minimally invasive, interdisciplinary technique represents a new alternative in the treatment of incomplete, postsaccal lacrimal stenosis.

Adult↗

PubMed1994

[Ultrasound diagnosis of persistent varicocele after sclerotherapy].

252 consecutive patients with left-sided idiopathic varicocele were admitted into this prospective study. 30 patients did not receive a transcatheter sclerotherapy on account of their venous morphology on the selective phlebogram. Ultrasound examinations including Doppler sonography were performed before and 1, 3, and 6 to 12 (average 10) months after transcatheter sclerotherapy of the varicocele. For evaluation of therapeutic success the maximal diameter of the pampiniform plexus, the maximal diameter of the largest vein of the plexus, and, by means of Doppler ultrasound, reflux were measured. A continual decrease of these parameters was observed approximately one year after sclerotherapy. 9% of patients (20 patients) had a persisting varicocele. A premature decision for repeat sclerotherapy or operative correction of possibly persisting varicoceles can be avoided by employing a sonographical follow-up of more than 10 months.

Adolescent↗

PubMed1994

Retrograde dilation of postsaccal lacrimal stenosis.

The causes of nasolacrimal duct stenosis in adults can vary greatly. In general, the symptoms can also vary, but most cases share a tendency toward recurring inflammations in the prestenotic area. The treatment of these disorders is limited to either conservative therapy to control inflammation or surgically invasive measures. By using balloon catheters, usually applied in percutaneous transluminal coronary angioplasty (PTCA), dilation of the relative postsaccal stenosis can be performed under radiographic control. An exact diagnosis using various testing methods, including digital dacryocystography for detailed localization and documentation of any pathologic changes, is decisive to success. Only in cases of incomplete postsaccal stenosis is retrograde balloon dilation of the distal nasolacrimal duct indicated. A guide wire, designed for the PTCA balloon catheter set, is introduced via the canaliculus to the nasal cavity antegradely and caught with a thin hook and pulled from the naris, under visual control with an image converter. The balloon catheter is retrogradely threaded over the guide wire. The baloon is then placed at the site of the pathologic stenosis under radiographic control and dilated with high pressure. To ensure the permeability of the system, monocanalicular silicone intubation has to be performed immediately afterwards. This procedure has been performed successfully on 6 patients with a follow-up of 6 to 27 months. These initial results give rise to the hope that this minimally invasive, interdisciplinary technique represents a new alternative in the treatment of incomplete postsaccal lacrimal stenosis.

Adult↗

PubMed1994

Doppler sonography of varicocele: long-term follow-up after venography and transcatheter sclerotherapy.

Sixty-eight patients with unilateral left-sided idiopathic varicocele who had not been treated previously were examined with Doppler sonography before and 1, 3, and 12 months after selective venography with balloon occlusion and transcatheter sclerotherapy of the internal spermatic vein. Varicocele and its persistence or recurrence was diagnosed by reflux only. Reflux was differentiated into stop-type and shunt-type by Doppler sonography. The resolution of varicocele was defined by absence of any reflux. The rate of resolution was greatest 3 months after sclerotherapy (49 patients, 72%). The diagnosis of persisting or recurring varicocele at this time does not seem to be justified, however, as in our study both further improvement and deterioration were observed up to 12 months after treatment. Twenty patients (29%) had a persisting or recurring varicocele 12 months after sclerotherapy. Reflux is the parameter of significance for diagnosing varicocele and its persistence or recurrence after therapy. Improvement of clinical aspects of varicocele (e.g., sperm count, sperm motility, and conception rates) depends on therapy of even subclinical varicoceles. Therefore, diagnosis and retreatment of persistent or recurrent varicoceles seems essential. The high sensitivity of Doppler sonography permits adequate assessment of the therapeutic result and evaluation of real rates of persistent or recurrent varicoceles after venography with balloon occlusion and transcatheter sclerotherapy.

Adult↗

PubMed1994

[Percutaneous drainage of intra-abdominal abscesses in Crohn disease].

The majority of abcesses associated with Crohn's disease require surgical treatment. Since the postoperative rate of complications is high, particular care is needed in the choice of surgical therapy for patients with Crohn's disease. The interventional radiological method of percutaneous abcess drainage provides the surgeon with an alternative technique suitable both for the curative treatment of simple abcesses and for the palliation of complicated abcesses prior to elective surgical treatment. We have retrospectively analysed the drainage protocols, operation reports, and case histories of 7 patients with intra-abdominal abcesses in Crohn's disease. The results of our study emphasise the excellent clinical value of PAD in the treatment of abcesses associated with Crohn's disease.

Abscess↗

PubMed1993

Colour Doppler imaging of partial subclavian steal syndrome.

The case of a 67-year-old woman with symptoms related to the vertebro-basilar system and blood pressure difference of the upper extremities is presented. Colour-Doppler imaging (CDI) with additional spectral tracing revealed partial subclavian steal syndrome with retrograde flow in the left vertebral artery during systole, which could be significantly enhanced by reactive hyperemia after left arm exercise. Angiography confirmed a high-grade stenosis of the proximal subclavian artery and balloon angioplasty was performed. Noninvasive follow-up by CDI demonstrated regular antegrade vertebral artery flow at rest, but minimal retrograde systolic flow after left arm exercise.

Aged↗

PubMed1993

Difficulties in examination of the origin of the vertebral artery by duplex and colour-coded Doppler sonography: anatomical considerations.

Despite progress in ultrasonographic techniques visualisation of the origin of the vertebral arteries, particularly the left, by duplex and colour Doppler imaging, still poses a problem in a significant number of patients. In anatomical and radiological studies we demonstrated an anomalous origin in 6%, the left vertebral artery originating directly from the aorta in most cases. The origin from the subclavian artery was found to be posterior in 44% and inferior in 6%. The V1 segment of the vertebral artery (from its origin to the entry into the foramen transversarium) was tortuous in 47% of cases. These anatomical variants and variations in the course of the vessel contribute to the nonvisualisation of the origin of the vertebral artery by duplex and colour Doppler imaging. With respect to tortuosities technical modifications for better visualisation are suggested and possible implications for surgery are discussed.

Aged↗

PubMed1993

[Value of ultrasound in follow-up of biliary metal stents--initial results].

Self-expandable metallic biliary endoprostheses (= "stents") are an accepted therapeutic alternative in the palliative treatment of malignant biliary obstruction. The physiological direction of bile flow is re-established for a varying period of time. Sonography is an acutely available modality for the evaluation of symptomatic patients who are carriers of such endoprostheses. The cause of recurrent obstructive jaundice can be diagnosed quickly and a new intervention can be planned carefully.

Adenoma, Bile Duct↗

PubMed1993

[Ultrasound diagnosis of cervical lymph node tuberculosis].

Lymph node tuberculosis is the most frequent tuberculous manifestation in the otorhinolaryngological area. In 13 patients with histologically verified tuberculous lymphadenitis cervical sonographic examinations revealed characteristic findings. The sonographic features typical for this disease were multiple, enlarged, conglomerating roundish and oval lymph nodes. These lymph nodes were hypoechoic, exhibited dorsal sound amplification and had sharp margins. With caseation, however, there were blurred borders. In cold abscesses an inhomogeneous texture with inhomogeneous shadows was found. Differential diagnosis included non-specific abscess-forming lymphadenitis, lymph node metastases and malignant lymphoma. A tentative diagnosis of cervical lymph node tuberculosis may be made due to the polymorphous sonographic pattern if history and clinical findings are taken into account. A proper histological and microbiological work-up is still essential for confirmation of the sonographic diagnosis.

Adult↗

PubMed1993

[Doppler ultrasound of the saphenous vein as a bypass. Detection of arteriovenous fistulae].

In 13 patients who underwent a femorodistal revascularisation with an in situ saphena vein graft and who had been operated on by angioscopic technique, intraoperative angiography and postoperative colour-coded Doppler sonography and i.v./i.a. digital subtraction angiography (DSA) were performed to detect arteriovenous fistulas (AV fistulas). In intraoperative completion angiography no AV fistulas were seen. Colour-coded Doppler sonography and DSA studies performed three to five days postoperatively revealed AV fistulas in 8 patients. The fistulas could be exactly located by sonography, and, if confirmed haemodynamically significantly by i.v./i.a. DSA, they were marked on the skin and ligated. In the detection of AV fistulas in in situ saphenous vein grafts operated by angioscopic technique colour-coded doppler sonography and i.v./i.a. DSA showed equivalent results. In the detection of connections of AV fistulas to the deep draining veins the i.v./i.a. DSA was superior.

Aged↗

PubMed1993

Dynamic documentation of digital dacryocystography.

Digital dacryocystography has proved to be the optimum method of x-ray diagnostics in connection with managing obstructions of the lacrimal pathways. We present 50 patients in whom digital dacryocystography was performed with a computer-controlled x-ray unit and a C-arc coupled to an image intensifier TV-system. A nonionic water soluble contrast medium was used. The bilateral contrast medium filling process appearing on the monitor was simultaneously recorded on videotape. Videocassettes, with patient data attached, were stored in a videotape library, providing repeatable diagnostic documentation and an excellent base for scientific analyses.

Adult↗

PubMed1993

[The percutaneous aspiration and drainage of infected fluid retention after organ transplantation].

Local postoperative infections in immunosuppressed patients carry a high mortality rate. In this group of patients interventional radiological procedures are particularly valuable in diagnosis and treatment. We report on the results of radiologically controlled aspirations (11 cases) and drainage (37 cases) of infected fluid collections in 47 patients following transplantation of various organs. By percutaneous aspiration or drainage, 91.7% of infected fluid collections were successfully treated or the clinical condition of the patient improved so that surgical intervention could be avoided. The causative organism was identified and antibiotic treatment carried out in 72.9% (35 cases). Surgical intervention was necessary in only 4.3% (2/48). Needle aspiration or drainage of percutaneously accessible fluid collections thought to be infected appears to be particularly useful for transplant patients at increased risk and is a good alternative to surgical treatment.

Adult↗

PubMed1992

Renal transplant hemodynamics in children: prospective analysis of colour coded versus pulsed Doppler sonography.

In 30 children with renal allografts the diagnostic validity of pulsed Doppler (PD) versus colour coded Doppler (CD) sonography was assessed prospectively. 46 PD examinations were performed calculating the resistive index (RI) in the segmental arteries in comparison to 46 CD scans, where renal blood flow throughout the grey-scale image was displayed. In addition, point-spectral analysis with calculation of the RI was also performed on the CD scans. The time for examination ranged from five to ten minutes for the PD and from three to five minutes for the CD study. Concordant findings for the PD and CD technique were generally obtained (normal blood flow pattern on PD-excellent visualization of renal blood flow on CD, reduced or reversed diastolic flow on PD-poor visualization of renal blood flow on CD). There was close correlation of the RI values obtained by the PD and CD scans. CD sonography facilitated point-spectral analysis in shortening the time for examination. The ability to visualize focal hemodynamic alterations provided a higher diagnostic accuracy in comparison to PD sonography.

Adolescent↗

PubMed1992

[Saphenous vein bypass stenoses, early diagnosis with color coded Doppler sonography].

In a prospective study 54 patients with 62 saphenous vein arterial bypass grafts were examined by colour-coded Doppler sonography and angiography. Five cases of graft occlusion were diagnosed by colour-coded Doppler sonography and confirmed by angiography. In comparison with angiography, colour-coded Doppler sonography showed a sensitivity of 92% and a specificity of 100% in the detection of focal graft stenosis. Only two stenoses in the region of the distal anastomosis could not be detected by colour-coded Doppler sonography. In 28 cases a marked dilatation of the proximal anastomosis was found corresponding to the surgically used patch angioplasty. Within this dilated bypass segment, turbulence and flow reversal zones were demonstrated, which might be predisposing factors for graft stenosis. Colour-coded Doppler sonography can accurately detect saphenous vein arterial bypass graft stenoses and should be routinely used in postoperative screening.

Adult↗

PubMed1992

[Percutaneous CT-guided catheter drainage of intrathoracic fluid accumulations].

To verify the value of percutaneous CT-guided drainage of thoracic fluid collections we studied the outcome in 39 patients retrospectively. 24 (61.5%) of the fluid collections were located in the pleural space, 10 (25.6%) in the lungs and 5 (12.8%) in the mediastinum. 11 CT-guided drainages after a previous attempt were necessary in 9 patients, because of recurrent (n = 6) or residual (n = 5) fluid collections. 70% of the drainage procedures were done using Seldinger's, 30% using trocar technique, mainly with 8.3-12 F catheters. The mean duration of drainage was 10.7 days. In 28 patients (71.8%) the percutaneous CT-guided drainage was curative. In 9 cases (23.1%) the patient's course was stabilised and surgery could be applied electively. 2 patients (5.1%) died because of their underlying end-stage malignancy. None of the drainage procedures changed the patient's course to the worse. There was only 1 pneumothorax with no need of any treatment; no other complication occurred. Our results suggest that percutaneous CT-guided drainage of thoracic fluid collections is a safe and straightforward alternative to surgical treatment.

Adult↗