Renal duplex sonography: main renal artery versus hilar analysis

OBJECTIVE: The purpose of this study was to compare the accuracy of main renal artery Doppler scanning interrogation and hilar analysis to diagnose hemodynamically significant renal artery disease. METHODS: From January 1998 to August 1999, 41 patients had renal duplex sonography with both main renal artery interrogation and hilar analysis followed by angiography. They form the basis of this review. The sample consisted of 24 men and 17 women, with a mean age of 68.9 +/- 10.2 years, who provided 80 kidneys for comparative analysis. Significant renal artery disease revealed through angiography was defined as >/= 60% diameter-reducing stenosis or occlusion. Peak systolic velocity (PSV) (in meters per second) and the presence of poststenotic turbulence (PST) were determined from main renal artery interrogation. Acceleration time (AT) (in milliseconds) was measured by means of hilar analysis. Significant renal artery stenosis was defined by a PSV of 2.0 m/s or more and a PST or an AT more than 100 ms. Sensitivity analyses of both PSV and AT were examined, and 95% CIs were computed. Receiver operating characteristic curves were used to estimate optimal values for PSV and AT. RESULTS: Angiography revealed hemodynamically significant fibromuscular dysplasia in 5 kidneys (4 patients), atherosclerotic stenosis >/= 60% in 48 kidneys (30 patients), and renal artery occlusion in 4 kidneys (4 patients). Kidneys with significant renal artery stenosis had a higher PSV (2.54 +/- 0.11 vs 1.28 +/- 0.08, P <.001) and AT (82.43 +/- 7.2 vs 30.0 +/- 2.8, P <.001) compared with those without stenosis. Compared with angiography, a PSV of 2.0 m/s or more and PST demonstrated a sensitivity of 91%, specificity of 96%, and overall accuracy of 92% for detection of significant renal artery stenosis. Two of five studies with false-negative results reflected diseased polar vessels. By contrast, AT of more than 100 ms had a sensitivity of 32%, specificity of 100%, and overall accuracy of 54%. Receiver operating characteristic curve analysis revealed a PSV of more than 1.8 m/s and an AT of 58 ms or greater as optimal values. With an AT of 58 ms or more, the sensitivity was 58%, and specificity was 96%, with an overall accuracy of 70%. There were no apparent associations between PSV or AT and type or location of renal artery lesion, serum creatinine level, or end-diastolic ratio. CONCLUSION: Main renal artery interrogation is an accurate screening test to detect significant stenosis or occlusion of the main renal artery. Hilar analysis alone does not provide sufficient sensitivity to be used as a sole screening study. Neither method detects the presence of renovascular disease associated with polar vessels.     

The clinical utility of carotid duplex scanning

We retrospectively compared the results of duplex scanning (DS) with contrast angiography (CAN) in the evaluation of 119 patients whose 238 carotid arteries were evaluated by both methods within a four-week period. The results of all patients were then categorized by two different definitions of severity of stenosis. Category A classified 1-29% stenosis as mild, 30-69% stenosis as moderate, and 70-99% diameter reduction as severe stenosis. Category B defined mild stenosis as 1-19% lumen diameter reduction, moderate as 20-49% stenosis, and severe as 50-99% stenosis. The findings by each classification were compared in 60 patients with hemispheric symptoms and in 59 patients with nonspecific symptoms. CAN was our "gold standard", and exhibited greater sensitivity, specificity, accuracy, and predictive values than DS. Carotid arteries with 70% stenosis were identified by DS with greater specificity, accuracy, and predictive values than were arteries with 50% stenoses. Only the sensitivity was comparable in categorizations A and B (80% and 83%). All parameters of measurement were superior in patients with hemispheric symptoms. DS alone cannot substitute for CAN in selecting patients for carotid endarterectomy because its error rate exceeded acceptable rates of complications for carotid artery surgery. The false positive rate of DS was 4%. DS failed to diagnose 7 of 19 carotid artery occlusions, 9 of 11 ulcerated plaques, 7 of 119 instances of aortic arch disease, and 13 cases of severe intracranial artery stenosis.     

Renal artery stenosis: evaluation with colour duplex ultrasonography

Background: Detection of renal artery stenoses (RAS) by means of duplex Doppler ultrasound with direct scanning of the main renal arteries is subject to numerous limitations. Using semiquantitative analysis of the Doppler curve, which can be recorded from intrarenal arteries, it is possible to detect RAs unaffected by the problems of direct Doppler scanning of the renal arteries. Method: Both angiography of the renal arteries and colour duplex ultrasonography (US) of the intrarenal vessels (interlobar arteries) were performed in 214 patients (53.2±15.1 years) with severe arterial hypertension. Angiography was used as 'gold standard' in the diagnosis of RAS and the Doppler results were compared with the subsequent findings on angiography. At angiography, the reduction of diameter >70% was assessed as haemodynamically effective RAS. For the duplex Doppler diagnosis of RAS the following parameters were calculated: (a) resistive index (RI) of each kidney, and (b) side-to-side differences of the resistive indices (&Dgr;RI) between the right and left kidney. Results: Angiography demonstrated 59 RAS (>70%) in 53 patients, including six with bilateral RAS. By means of duplex US we found a significant difference of RI between kidneys with RAS (0.48±0.11) and without RAS (0.63±0.08; P<0.001). In addition, a significant difference of the &Dgr;RI was noted in patients with RAS (24.4%±12.5%) and the controls without RAS (3.6%±2.7%). Using a combination of both RI and &Dgr;RI, threshold values of RI=0.45 resp. &Dgr;RI=8% yields a sensitivity of 92.5% and a specificity of 95.7% in the detection of haemodynamically effective RAS. Conclusion: Colour duplex US with calculation of the RI and &Dgr;RI of intrarenal arteries is a valuable non-invasive test assessing the haemodynamic effects of RAS. Low costs and safety support the use of the Doppler technique in screening for renovascular disease.     

Renal transplant blood flow evaluation by ultrasonic duplex scanning

The transplant blood flow was measured renal transplantation by ultrasonic duplex scanner composed of pulsed Doppler flowmeter and real-time B-mode linear scanner in 32 patients. The blood flow information could be obtained from anywhere of interest within the renal transplant. Then blood flow in 3 regions including renal hilum, central echoes and renal parenchyma were measured. The parenchymal peripheral blood flow was not always similar to the hilar central blood flow. Parenchymal blood flow was the most correlated with graft function and decreased remarkably during acute rejection episode. This method enabled detection of occurrence of acute rejection in the course of post-cadaver transplant ATN. Prolongation of delta t (acceleration time) in Doppler spectrogram from parenchyma was also reliable evidence for the deterioration of graft function. Ultrasonic duplex scanning is a useful method in managing post-transplantation patients because intrarenal hemodynamics can be evaluated by this method.     

Renal vein thrombosis after renal transplantation--early diagnosis by duplex sonography prevented fatal outcome.

Sir, Complete renal vein thrombosis (RVT) after renal transplantationhas an incidence of 0.55 to 3.4% [1–4] and accounts forup to one-third of early allograft losses [1,2]. In a largeseries, 73% were detected with a median delay of 8 days [2]suggesting that RVT develops gradually, presumably beginning     

Angiodynography (color-coded duplex sonography) in the evaluation of vasculogenic impotence.

The penile arteries of 18 men with erectile dysfunction were examined by angiodynography (color-coded duplex sonography). Blood flow velocity was measured before and after intracavernous injection of papaverine/phentolamine. The angiodynographic findings were compared to arteriography. Normal values of peak flow velocity (after injection) were obtained from 6 men with normal arteriographic findings (deep artery greater than 25 cm/s, superficial artery greater than 30 cm/s). Angiodynography enables good imaging of the four penile arteries superior to duplex sonography. A strong correlation with the arteriographic findings could be found. Thus noninvasive angiodynography may replace penile arteriography for the routine evaluation of impotence.     

Carotid plaque morphology: Correlation of duplex sonography with histology

This study attempted to determine whether images obtained during preoperative duplex scanning correlated with histologic studies of carotid endarterectomy plaque and, therefore, might be useful in subsequent studies of the importance of plaque morphology and intraplaque hemorrhage. Forty-six endarterectomy specimens from 44 patients with satisfactory preoperative images were evaluated. The plaques were marked for orientation at the time of removal, and each plaque was imaged by duplex scanning in a saline bath. Magnification radiographs were made. Specimens were embedded in paraffin and slices 6 mu thick were made for staining with hematoxylin and eosin, Masson's trichrome, a modified Verhoeff-vanGieson stain, and von Kossa's stain. Overall, correlation between the preoperative images and the histologic specimens were good to excellent in 42 of 46 specimens. Scanning did not identify three cases of extensive recent intraplaque hemorrhage, however, and one instance of plaque calcification was missed. We conclude that duplex images correlate well with histologic studies except in some cases of recent intraplaque hemorrhage. Duplex imaging is valuable in the correlation of plaque morphology with symptoms for long-term studies. The accuracy of the technique may be improved by using post-processing on static images and in vitro scanning of endarterectomy specimens.     

Non-invasive evaluation of vessels by duplex sonography prior to construction of arteriovenous fistulas for haemodialysis

Purpose: The prospective study was aimed at estimating the value of duplex sonography for imaging arteries before arteriovenous fistula (AVF) construction and of evaluating the influence of this method on the outcome of fistula construction. Methods: A total of 35 patients with end stage renal disease were examined by duplex sonography (DS) before AVF construction, and 27 of them with patent AVF were examined 1, 7 and 21 days after the operation. Filling artery flow was evaluated at 8 and 12 weeks. All AVFs were constructed on the forearm using native veins. Direct measurements of the arterial internal diameter during the operation were also performed. Results: The mean internal diameter of the arteries (IDA) detected by sonography 2.3±0.62 mm, with a direct measurement of 2.1±0.52 mm (mean±SD). The correlation coefficient of DS IDA with direct measurement IDA was 0.86. In group A (IDA⩽1.5 mm), immediate patency of the AVF was present in 45% (5/11), and in group B (IDA>1.5mm) 92% (22/24) (P <0.001). Before the construction, the mean volume flow through the radial arteries was 22±6.8 ml/min in group A and in group B 46±6.3 ml/min (P <0.001). If there was conversion of high-resistance triphasic Doppler flow signal to low-resistance biphasic flow signal after release of a fist (group D), the AVF was patent in 95% (21/22), compared with a 46% (6/13) rate of patency in the group without such a response (group C). In 27 patients with patent AVF fistula, arterial volume flow the first day after construction was 138.1±10.1 ml/min in group A and 184.2±12.6 ml/min in group B. After 1 week, the volume flow was 169±11.1 ml/min and 202.4±13.5 ml/min, respectively. After 3 weeks the arterial flow was 274.4±17.3 ml/min and 366.2±39.6 ml/min, respectively. After 12 weeks, the arterial flow was 4.8.5±87.7 ml/min in group A, and 561.8±131.3 ml/min in group B. The patency rate after 12 weeks was 26% in group A and 83% in group B. Conclusions: Duplex sonography could be a useful non-invasive method to evaluate arterial vessels prior to AVF construction. The relevant parameters measured by duplex sonography to evaluate the potential patency of the AVF are the arterial internal diameter and changes in the arterial Doppler flow signal.     

Monitoring renal allograft rejection with duplex sonography

Thirty-six renal allograft recipients were monitored by serial duplex Doppler ultrasound studies post-transplant and during early rejection. A separate reproducibility study demonstrated no significant inter- or intra-operator variability in measurements of resistive index of an interlobar artery (RI) (2.1% [1.5%] and 3.2% [2.3%] respectively, mean [standard error] of coefficients of variance). Twenty-one patients had rejection within 3 weeks of transplantation. These grafts showed greater overall rises in the RI, from day 2 to day 5 post-transplant, than the grafts which had no rejection. Eleven of the 21 patients required more than one course of methyl-prednisolone for persistent or recurring rejection. These grafts had higher RI on the day rejection was diagnosed (81 [7.3], median [interquartile range]) compared with the remaining 10 patients (68.6 [8.7]). The 11 grafts with persistent rejection had higher RI (p less than 0.005, Mann-Whitney U-test) on day 2 post-transplant (76 [3.9]) compared with the 10 grafts successfully treated with a single course of methyl-prednisolone (63.2 [10.9]). This study demonstrates that grafts with an RI of greater than 70 on day 2 post-transplant are likely to have rejection requiring additional treatment (sensitivity--100%, specificity--80%). These patients may be candidates for earlier or alternative anti-rejection therapy.     

Intraoperative duplex sonography during renal artery reconstruction

To assess renal duplex sonography as an intraoperative study to detect technical defects during repair, 57 renal artery reconstructions in 35 patients were studied. Sixteen men and 19 women (mean age, 62 years) underwent unilateral (13 patients) or bilateral (22 patients) renal artery repair to 57 kidneys. Methods of repair included aortorenal bypass grafting in 29 cases (20 saphenous vein, 5 polytetrafluoroethylene, 4 Dacron), reimplantation in 7, transrenal thromboendarterectomy with patch angioplasty in 13, and transaortic extraction thromboendarterectomy in 8. Branch renal artery repair was required in six cases (five in vivo, one ex vivo). Fourteen patients had combined aortic replacement (11 patients: 8 abdominal aortic aneurysms, 3 aortic occlusions) or visceral artery reconstruction (three patients: three superior mesenteric artery thromboendarterectomies, one inferior mesenteric artery thromboendarterectomy). Intraoperative renal duplex sonography (mean scan time, 4.5 minutes) was complete in 56 of 57 repairs (98%), and renal duplex sonography was normal in 44 repairs (77%). Overall, B-scan defects were present in 13 repairs (23%). Six of these (11%) were defined as major B-scan defects by Doppler spectra with focal increases in peak systolic velocity greater than or equal to 2.0 meters/sec (major defect, mean renal artery peak systolic velocity, 3.1 m/sec), which prompted immediate operative revision. Seven B-scan defects were defined as minor by Doppler spectra (minor defect, mean renal artery, peak systolic velocity, 0.7 m/sec) and were not revised. Postoperative evaluation (range, 1 to 22 months; mean follow-up, 12.4 months) of 55 renal artery repairs in 34 operative survivors (surface renal duplex sonography, 33 patients; renal angiography, 9 patients) demonstrated 42/43 renal artery repairs with normal intraoperative renal duplex sonography, and 6/6 repairs with minor B-scan defects were patent and free of critical stenosis. Of the 6 renal artery revisions prompted by major B-scan defects, 4 remained patent, 1 stenosed, and 1 occluded. Our experience suggests that intraoperative renal duplex sonography during renal artery repair provides valuable anatomic and physiologic information. Renal artery repairs with normal renal duplex sonography and minor B-scan defects without Doppler spectral changes demonstrated 98% patency without critical stenosis at 12.4 months of mean follow-up. However, major B-scan defects defined by a focal increase in renal artery peak systolic velocity should be considered for immediate correction.     

Colour duplex sonography in the assessment of impotence

We present our experience with colour duplex sonography (Acuson 128) in the assessment of 83 impotent men. Cavernosal artery measurements were taken before and after the intracorporeal injection of papaverine. The peak velocities following papaverine injection correlated well with the degree of clinical response. Percentage diameter change corresponded with some groups of clinical erection grade, although it was not as good a discriminator as peak velocity. Twelve patients with 24 cavernosal arteries were also examined using pharmacological selective arteriography. Correlation between duplex sonography and arteriography showed an accuracy of 87.5%, specificity of 100.0% and sensitivity of 82.4%. All patients with a clinically good response following papaverine injection had peak bilateral cavernosal artery velocities greater than or equal to 25 cm/s. Amongst the remaining suboptimal responders, 18 also had this finding. Fifteen of these underwent pharmacological cavernosography and 14 exhibited venous leakage. Duplex sonography is a valuable and non-invasive tool in the assessment of impotence and can provide valuable information in deciding the course of further evaluation and treatment. The procedure was always completed more quickly with the guidance of colour Doppler.     

Color-coded duplex sonography for diagnosis of testicular torsion

By color-coded duplex sonography moving structures are visualized as red or blue colors within a normal gray-scale B-mode ultrasound image. Thus, blood flow even within small vessels can be visualized clearly. Color-coded duplex sonographic examination was performed in 11 patients who presented with scrotal pain. This method proved to be reliable to differentiate between testicular torsion and testicular inflammation. By clearly demonstrating a lack of intratesticular blood flow in testicular torsion, while avoiding flow in scrotal skin vessels being misinterpreted as intratesticular blood flow, this method significantly decreases the number of patients in whom surgical evaluation is necessary to exclude testicular torsion.     

Evaluation of the vertebral arteries with duplex sonography

Using duplex sonography, we have routinely evaluated the vertebral arteries as part of the carotid artery examination in 453 consecutive patients over a 6-month period. Sixty-two of these 906 vessels could not be adequately evaluated, primarily because these vessels lay too deep within the vertebral structures, resulting in a technical failure rate of 6.8%. For the remaining 844 vessels, 74.4% were considered normal by Doppler flowmeter spectral analysis. Angiographic correlation was available for 224 vessels; of 155 judged normal by duplex sonography, 144 (93%) were shown to be normal or have only mild atherosclerotic disease. Eleven vessels were considered either occluded or to have severe disease by duplex sonography, and angiography showed this to be the case in 10 (91%) vessels. Unusually strong vertebral artery flow was associated with hemodynamically significant carotid or contralateral vertebral atherosclerotic disease or subclavian steal 82% of the time. Twelve cases of subclavian steal, only one of which was symptomatic, were identified by duplex sonography; four of these were confirmed by angiography. Angiographic correlation was available for 229 vessels in which duplex evaluation showed vertebral artery flow to be moderately damped. In 11 of these (38%), angiography showed greater than 50% stenosis. Angiography judged the remaining 18 vessels in this group normal; these vessels may represent a small subgroup of patients with normal anatomy or only mild atherosclerotic disease, but with hemodynamic dysfunction that can be identified with the duplex technique.     

Renal radiosurgery: initial clinical experience with histological evaluation

The purpose of this study was to determine whether radiosurgical technology can be safely applied to renal tumors. Patients received radiosurgical treatment of renal lesions. At 8 weeks after radiosurgical treatment, patients underwent a partial or radical nephrectomy and histologic evaluation. The patients received a radiation dose of 4 Gy per fraction for 4 fractions. Patients were followed, and radiation-induced toxicities were noted. Three patients were treated for a minimum of 1 year of follow-up. All patients completed the treatments, tolerating each of the 4 fractions with no adverse events. No acute toxicities or changes in renal function were noted. None of the patients had any evidence of acute radiation injury or toxicity noted at the time of surgery or within the subsequent 12 months after the radiosurgical treatment. The last patient treated was found to have a cavity with no microscopic evidence of viable tumor after radiosurgical treatment; pathology was consistent with necrotic renal cell carcinoma, papillary type. The other 2 tumors demonstrated pathologic evidence of viable renal cell carcinoma (grade I and grade II). Tumor size remained relatively unchanged for 8 weeks after the radiosurgical treatment in all patients. The authors are extremely encouraged and cautiously optimistic with the initial results. Radiosurgery for renal tumors appears to be safe at this initial dose level.     

Renal sonography in childhood lymphoma

The sonographic manifestations of 20 childhood abdominal biopsy-proved lymphomas were presented. Thirteen cases showed positive renal sonographic findings such as renomegaly, hyperechoic renal cortex, focal hypoechoic mass and hydronephrosis. The incidence of renal involvement was high in lymphoma detected by ultrasound. There was no difference between sonographic findings of Hodgkin and non-Hodgkin lymphoma. The ultrasound findings may be confirmed with gallium scanning. Ultrasound was more accurate in detecting renal lesions in lymphoma than computed tomography.     

Assessment of intraoperative duplex sonography during carotid endarterectomy]

INTRODUCTION: Carotid endarterectomy (CEA) for prevention of strokes mandates a high amount of experience and a meticulous surgical technique. Intraoperative morphologic as well as hemodynamic monitoring of the endarterectomized arteries is rarely performed. The purpose of this study was to determine the value of intraoperative colour-coded-duplex-sonography to recognize eventual intraoperative technical problems that might result in serious cerebral damage. METHODS: Prospective analysis of the medical data of all patients who underwent CEA for treatment of high-grade carotid stenosis between 1996 and 1999. Adequacy of the repair was assessed intraoperatively by duplexsonography. RESULTS: Of 142 consecutive patients with a median age of 68 (43-84) years, 104 (73 %) were men and 38 (27 %) were women. 9 patients (6 %) had bilateral CEAs. Intraoperative duplexsonography revealed abnormalities during 11 (7 %) of 151 CEAs. 4 (3 %) were considered major and underwent immediate revision. There was one (0.7 %) temporary neurologic deficit (hyperperfusion syndrome) and 2 (1.3 %) cases of fatal intracerebral hemorrhage. 6 (4 %) postoperative surgical complications occurred, i. e. 3 cases of major wound hematoma (with revision) and 3 cases of temporary cranial nerve palsy. Median length of follow-up was 11 (3-35) months. No late neurologic event occurred during follow-up. 5 (3 %) patients developed asymptomatic restenosis. DISCUSSION: Routine intraoperative duplexsonography is a valuable and reliable diagnostic tool to detect correctable technical problems during CEA that subsequently may lead to neurological deficits, fatal stroke or a high incidence of restenosis.     

Penile duplex sonography in the diagnosis of venogenic impotence

This study tested the hypothesis that measurements of cavernous arterial diastolic velocity and resistance index could provide a quantitative but noninvasive measure of penile corporal venous leakage. Seventy-four men were studied with duplex ultrasonography after intracavernosal injection of 60 mg of papaverine. Fourteen men had normal erection and served as controls. Sixty men had a 1-year history of transient fading or incomplete erections. In all subjects the peak systolic velocity and end-diastolic velocity were measured, and the resistance index was calculated (peak systolic velocity--end-diastolic velocity/peak systolic velocity). Men with normal erections had peak systolic velocities greater than 35 cm/sec and end-diastolic velocities less than 4.5 cm/sec (group 1). Patients with incomplete erections (group II) could be classified into three subgroups. Twenty-three patients with end-diastolic velocities greater than 4.5 cm/sec and normal peak systolic velocities greater than 35 cm/sec were suspected to have corporal venous leakage (group A). Eighteen patients had normal end-diastolic velocities less than 4.5 cm/sec. Twelve of this group had peak systolic velocities less than 35 cm/sec, and six had peak systolic velocities ranging from 37 to 44 cm/sec. These patients were suspected of having arterial insufficiency (group B). Fifteen patients with end-diastolic velocities greater than 4.5 cm and peak systolic velocities less than 35 cm were suspected of having both venous leakage and arterial insufficiency (group C). Twenty-one patients with abnormal diastolic flow underwent infusion pharmacocavernosometry to determine the saline maintenance infusion rate necessary to maintain an intracavernosal pressure of 90 to 100 mm Hg or a full erectile response.(ABSTRACT TRUNCATED AT 250 WORDS)