Captopril renography and duplex Doppler sonography in the diagnosis of renovascular hypertension

Background. The purpose of this prospective study was to determine the clinical usefulness of captopril renal scintigraphy and duplex Doppler sonography in detecting haemodynamically significant renal artery stenosis (⩾60%) and predicting cure or improvement of hypertension following revascularisation. Methods. Twenty-eight patients with moderate or high index of clinical suspicion of renovascular hypertension underwent both captopril renal scintigraphy and duplex Doppler sonography before undergoing renal angiography. Patients with angiographically proved (⩾60%) RAS were treated by percutaneous transluminal renal angioplasty unless it was contraindicated. Results. The results of captopril renal scintigraphy and duplex Doppler sonography were compared by renal angiography of 45 renal arteries in 28 patients. Eleven renal arteries were excluded from further comparison, because no accurate Doppler signal could be obtained. The sensitivity and specificity of captopril renal scintigraphy in the identification of RAS (⩾60%) was 78% and 81% respectively. The sensitivity of duplex Doppler sonography was 83% and the specificity was 81%. Positive predictive values of both tests for blood pressure cure or improvement after PTRA were 86% for CRS and 85% for DDS. Conclusions. Captopril renal scintigraphy and duplex Doppler sonography are comparable tests for detection of patients with haemodynamically significant renal artery stenosis (⩾60%). Positive predictive values of both tests for cure or improvement of hypertension after percutaneous transluminal renal angioplasty are good and comparable.     

左肾静脉压迫综合征29例报告

目的提高左肾静脉压迫综合征的诊治水平。方法回顾性地分析29例左肾静脉压迫综合征患者的临床资料。结果29例左肾静脉压迫综合征中表现血尿22例,蛋白尿5例,血尿合并蛋白尿2例。所有病例彩色多普勒超声示左肾静脉扩张段直径均为受压狭窄处的3倍以上,20例行MRA示左肾静脉受压。22例患者行保守治疗,随访观察病情发展,其中19例好转,3例加重。5例患者行左肾静脉内支架植入术,2例患者行肠系膜上动脉切断再植术,随访均症状消失,左肾静脉无明显受压。结论非肾小球性血尿或直立性蛋白尿为本病的主要临床表现。多普勒超声及MRA检查对本病具有重要的诊断价值。治疗上一般行保守治疗随访观察,对有肾功能损害或有并发症者行外科手术或介入治疗。     

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.     

左肾静脉压迫综合征(附10例报告)

目的　提高左肾静脉压迫综合征的诊治水平。　方法　回顾性分析 10例左肾静脉压迫综合征患者的临床资料。男 9例 ,女 1例。年龄 14～ 37岁 ,平均 2 4岁。临床表现血尿 7例 ,蛋白尿2例 ,血尿合并蛋白尿 1例。彩色多普勒超声示左肾静脉扩张段直径均为受压狭窄处 3倍以上 ,9例行磁共振血管成像 (MRA)示左肾静脉受压。　结果　患者行左肾静脉内支架植入术 7例 ,肠系膜上动脉切断再吻合术 3例 ,手术均获成功。术后电话或门诊随访 1～ 5年 ,患者症状消失 ,左肾静脉无明显受压。　结论　左肾静脉压迫综合征临床表现多为非肾小球性血尿或直立性蛋白尿。多普勒超声、MRA及膀胱镜检查结合临床症状并除外其他疾病可作出诊断。一般行保守治疗随访观察 ,对有肾功能损害或有并发症者行外科手术或介入治疗。     

Intraoperative renal duplex sonography: a valuable method for evaluating renal artery reconstructions.

OBJECTIVES: to determine the ability of duplex sonography to intraoperatively detect technical problems with renal artery reconstructions. DESIGN: retrospective evaluation of a standard protocol. PATIENTS AND METHODS: the outcome of intraoperative duplex was compared with postoperative angiography, surface duplex, MRA, echo or direct inspection in case of re-exploration in 77 renal artery reconstructions in 62 patients. These included six extracorporeal reconstructions, eight and 17 reconstructions with an artery and autogenous vein respectively, 10 renal artery re-implantations in the aorta (prosthesis), 32 endarterectomies and four reconstructions of kidney transplant vessels. RESULTS: intraoperative duplex was normal in 67/73 reconstructions with sufficient data. In six cases technical problems were revealed by intraoperative duplex and the reconstruction was re-explored. After re-exploration intraoperative duplex was normal in all cases. Confirmatory studies demonstrated normal results in 61/64 reconstructions with normal intraoperative duplex and abnormal results in 6/6 reconstructions with technical problems revealed by intraoperative duplex. Three reconstructions with normal intraoperative duplex occluded as demonstrated by angiography less than 2 weeks after surgery. CONCLUSIONS: renal duplex sonography is a valuable method available for intraoperative detection of technical problems. Haemodynamic duplex data were less important than B-mode imaging in discriminating between normal and abnormal reconstruction.     

Evaluation of renal allograft function by Doppler spectrum analysis

A decreased renal function is rather common after renal transplantation. The causes of this decreased function are diverse and difficult to differentiate. Yet, duplex examination, and especially quantitative Doppler spectrum analysis of the blood velocities in the renal artery, may be an effective method for differentiating between some of these causes. Forty-five renal transplant recipients were included in this preliminary study. Doppler spectra were recorded from the renal artery to the allograft. Parameters were derived from every Doppler spectrum in order to characterize each spectrum. Renal allograft function was evaluated on the basis of a number of clinical parameters. A significant correlation was found between the clinical parameters and the Doppler spectrum parameters indicative for changes in the peripheral resistance. Patients with a normal renal allograft function showed Doppler spectra with a high diastolic flow, typical of a vascular bed with a low peripheral resistance. Patients with a decreased renal allograft function caused by a stenosis in the renal artery could be distinguished by a low peak velocity and a low pulsatility index. A decreased allograft function caused by allograft rejection or cyclosporin nephrotoxicity also led to characteristic arterial flow disturbances. In these cases, the peripheral resistance was increased, and this was primarily reflected in a decrease in the diastolic blood velocity. We conclude that quantitative analysis of the blood velocities in the renal artery by Doppler spectrum analysis seems to be a useful, noninvasive diagnostic tool that discriminates between some of the causes of a decreased renal allograft function.     

Color-coded duplex sonography study of arteriovenous fistulae and pseudoaneurysms complicating percutaneous renal allograft biopsy

BACKGROUND: The exact incidence and clinical impact of arteriovenous fistulae (AVF) and pseudoaneurysms as complications emerging from renal allograft biopsy are not well established. We therefore conducted a prospective study using color-coded duplex sonography (CCDS) to determine the frequency, clinical presentation and spontaneous occlusion rate of biopsy-related AVF and pseudoaneurysms in kidney transplant recipients. METHODS: We investigated 72 consecutive patients undergoing renal allograft biopsy using an automated biopsy technique. CCDS was performed before, immediately after and up to more than 6 months after biopsy. The diagnosis of AVF was based on the presence of perivascular vibration artifacts and detection of typical Doppler curves. Pseudoaneurysms were diagnosed based on the presence of"to-and-fro" signals. RESULTS: In 5 patients (6.9%), an AVF was detectable before biopsy. Post-biopsy AVF were found in 12 additional patients (16.7%) with a spontaneous occlusion rate of 50% within 48 hours and 75% after 4 weeks. Three (25%) AVF persisted longer than 1 year. Four patients (5.6%) were found to have pseudoaneurysms. All pseudoaneurysms were located closely to AVF and closed spontaneously. None of the post-biopsy AVF and pseudoaneurysms required specific therapy. In 2 patients (2.8%), allograft biopsy lead to significant hemorrhage independent of AVF or pseudoaneurysms. CONCLUSION: These results indicate that post-biopsy AVF and pseudoaneurysms are a frequent finding after automated renal allograft biopsy. The natural history of these lesions shows a high rate of early occlusion. The present data fail to demonstrate significant clinical impact of AVF and pseudoaneurysms after renal allograft biopsy.     

彩色多普勒对肾血管病变诊断价值探讨

以双功能和彩色多普勒超声诊断５５例肾血管病变，包括肾动脉狭窄、肾小动脉硬化、肾动脉发育不良、肾动静脉畸形、急性肾静脉血肾静脉曲张。与其中３８例有完整肾血管造影检查资料的结果对照，超声诊断符合率９５％。结果认为综合多普勒定量指标、典型的多普勒频谱形态和征象各的彩色血流图象，能够对多种肾血管病变出准确诊断。     

Real-time contrast-enhanced sonography in renal transplant recipients

Abstract:  Conventional colour Doppler ultrasonography (CDUS) is a well-established and the most frequently used imaging procedure to diagnose kidney allograft dysfunction. Unfortunately, this technique is limited to the estimation of the allograft perfusion in large arteries. Early diagnosis of vascular damage, i.e., chronic allograft nephropathy is essential for an early therapeutic intervention. CDUS is still limited in interpreting vascular integrity. In contrast-enhanced sonography (CES) is a feasible technique for quantitative analysis of kidney perfusion and early diagnosis of biopsy proven chronic allograft nephropathy. CES does not provide only quantitative information on microvascular perfusion of the renal allografts but also represents improved diagnostic significance compared with CDUS for the detection of chronic allograft nephropathy.     

Importance of Doppler sonography in urology

There have been major advances in Doppler technology over the last 5 years which are particularly useful in the field of urology. In the early 1980s the clinical significance of Doppler was limited to the diagnosis of testicular torsion and its use was primarily intraoperative. Today, however, new advances, i.e. pulsed Doppler, duplex sonography, and color-coded duplex sonography (angiodynography), have cleared the way for totally new approaches to vascular impotence, renal artery stenosis, renal artery embolus, intratumor flow measurement, and control of renal transplants. These new technical advances will be exemplified in typical pathological states.     

Evaluation of renal transplant dysfunction by duplex Doppler sonography: a prospective study and review of the literature

A disconcertingly wide variation exists in the literature as to the accuracy of duplex Doppler sonography in the detection of acute renal transplant rejection. Sensitivities range from 9% to 76%. In an attempt to explain the disparity of results, we undertook a double-blind prospective study of the accuracy of duplex Doppler ultrasound in the detection of acute rejection in renal transplants. We scanned 49 consecutive patients with a total of 65 biopsies; 46 biopsies in 33 consecutive patients were included in our study. In our population, the prevalence of acute rejection was 61% (28/46). Using a resistive index (RI) cutoff of greater than 0.90 based on the main renal artery flow pattern, the sensitivity of our test was 43%, with a 67% specificity. The positive predictive value was 67%. Our results are contrasted and compared with the published data from other groups in a critical survey of the literature. We conclude that duplex Doppler sonography alone is inadequate to evaluate acute rejection in renal transplants.     

Role of resistive index in renal colic

We studied the role of duplex Doppler ultrasonography in the diagnosis of renal obstruction caused by ureteral calculi. Using duplex Doppler sonography, we evaluated the intrarenal hemodynamics of 27 patients who presented to the emergency department with renal colic. We performed Doppler ultrasonography on patients in whom US did not reveal any pathology causing renal colic and calculated and compared mean RI values of normal and obstructed kidneys and ΔRI values of each group. Threshold levels for the diagnosis of urinary tract obstruction (mean RI ≥ 0.70 and ΔRI ≥ 0.08) were used to determine the sensitivity and specificity of Doppler sonography for the diagnosis of urinary tract obstruction. Patients were investigated for revealing calculi diagnosis either by stone excretion history, intravenous pyelography or non contrast enhanced urinary computed tomography. A total of 162 intrarenal arterial Doppler recordings were made on 54 kidneys. Of the 16 patients with urinary obstruction, 11 (68%) had sonographic evidence of pelvicalyceal dilatation. The mean RI of the 16 obstructed and 11 unobstructed kidneys was 0.69 ± 0.04 and 0.61 ± 0.06 (mean ± standard deviation), respectively. The difference between the mean RI values for each group was statistically significant (P < 0.05). Mean RI values of the contralateral kidneys in the obstructed group and unobstructed group were 0.61 ± 0.03 and 0.59 ± 0.05, respectively. Also ΔRI value (0.07 ± 0.02) of obstructed kidney group was statistically higher than the ΔRI value (0.01 ± 0.03) of the unobstructed group (P < 0.05). The mean RI of the 16 obstructed kidneys (0.69 ± 0.04) was significantly greater than that of the 16 unobstructed contralateral kidneys (0.61 ± 0.03) (P < 0.05). This study supplements the existing evidence that, in acutely obstructed kidneys, renal Doppler recording can demonstrate altered renal perfusion before pelvicalyceal system dilatation and distinguish obstructed and unobstructed kidneys evaluated with suspicion of renal colic.     

彩色多普勒超声诊断早期移植肾急性排斥

目的探讨彩色多普勒超声图像数据分析在诊断早期移植肾急性排斥中的作用及临床价值.方法总结203例肾移植术后6～30d内行彩色多普勒超声检查,结合临床症状、生化检查并参照病理诊断,对二维灰阶图像、彩色血流图、血流频谱及阻力指数(RI)、搏动指数(PI)、收缩期与舒张期血流速度比(S/D)等参数进行回顾性分析.结果以彩色多普勒RI>0.78、PI>1.82、S/D>4.1为标准,结合彩色血流图及血流频谱形态,早期移植肾急性排斥正确诊断率可达85.7%.结论应用彩色多普勒超声诊断移植肾早期急性排斥并监测其功能恢复,具有快速、准确、无创等优点,可提早发现病情变化并指导治疗,提高移植肾存活率.     

Renal vein reconstruction with interposition allografts in cadaveric renal transplantation

Abstract. The short or injured renal vein in cadaveric transplantation is a surgical challenge. Over a 2-year period, we have performed ex vivo renal vein lengthening with an interposition vascular allograft in 17 recipients of cadaveric kidneys. Indications for renal vein extension allografts were a short right renal vein ( N = 12), procurement injury to the vein ( N = 4), and double renal vein ( N = 1). In six cases (35.3%), ex vivo renal artery reconstruction was performed in combination with the venous repair. Our preferred approach is to employ allograft material in ex vivo reconstruction under cold storage conditions. Bench surgery ranged from 10 to 30 min, and the mean in situ anastomosis time was 20 min. The mean length of renal vein prior to reconstruction was 12 mm, and the mean length of venous interposition allograft after revascularization was 27 mm. There were no episodes of vascular thrombosis or primary nonfunction. Three patients (17.6%) required postoperative hemodialysis for acute tubular necrosis, which was subsequently resolved. The mean serum creatinine at 1 month post-transplant was 1.7 mg/dl. These preliminary results suggest that ex vivo renal vein reconstruction with an interposition allograft is a safe and effective modality which should be added to the transplant surgeon's armamentarium in select cases.     

Farbduplexsonographische Befunde bei iatrogener arteriovenöser Fistel der A. vertebralis

The report describes a rare case of an iatrogenic arteriovenous fistula of the vertebral artery to the vertebral vein which arose after insertion of a central venous catheter via the jugular vein. We give special attention to the role of colour duplex sonography in the primary diagnosis of such fistulas. As can be seen from published reports with this non-invasive examination, the diagnosis of fistulas could not be established in all cases, where an abnormal communication between the vessels was later revealed by angiography. The most probable reason is the particular feature of the anatomical course of the vertebral artery which in its middle third is protected in a bony canal through the foramina transversaria of the cervical vertebrae and can be only partially visualised by sonography. Consequently only fistulas in the visible parts of the artery can be detected by sonography. In our case the most important criteria of duplex sonography for an arteriovenous fistula were fulfilled and the diagnosis was confirmed by angiography. This procedure with primary use of colour duplex sonography and additional clarification of uncertain findings by angiography, seems to be reasonable if the symptoms are compatible with the diagnosis of an arteriovenous fistula of the neck vessels.     

Renal vein reconstruction with interposition allografts in cadaveric renal transplantation

The short or injured renal vein in cadaveric transplantation is a surgical challenge. Over a 2-year period, we have performed ex vivo renal vein lengthening with an interposition vascular allograft in 17 recipients of cadaveric kidneys. Indications for renal vein extension allografts were a short right renal vein (N=12), procurement injury to the vein (N=4), and double renal vein (N=1). In six cases (35.3%), ex vivo renal artery reconstruction was performed in combination with the venous repair. Our preferred approach is to employ allograft material in ex vivo reconstruction under cold storage conditions. Bench surgery ranged from 10 to 30 min, and the mean in situ anastomosis time was 20 min. The mean length of renal vein prior to reconstruction was 12 mm, and the mean length of venous interposition allograft after revascularization was 27 mm. There were no episodes of vascular thrombosis or primary nonfunction. Three patients (17.6%) required postoperative hemodialysis for acute tubular necrosis, which was subsequently resolved. The mean serum creatinine at 1 month post-transplant was 1.7 mg/dl. These preliminary results suggest that ex vivo renal vein reconstruction with an interposition allograft is a safe and effective modality which should be added to the transplant surgeon's armamentarium in select cases.     

Nephrosonography and renal scintigraphy in evaluation of newborn with renomegaly

Prompt diagnosis of renomegaly in the newborn is necessary for appropriate medical or surgical management to insure maximal recovery of renal function. To investigate both renal structure and function without iodinated contrast infusion, combined ultrasonography and nuclear scintigraphy were evaluated in 17 newborns with renomegaly and 6 infants with cystic renal abnormalities detected in utero. In 18 patients, intravenous pyelography (IVP) and/or voiding cystourethrography (VCUG) were performed subsequently. While ultrasonography or scintigraphy alone provided the major diagnosis in 48 per cent and 30 per cent of cases, respectively, the combination of both studies yielded the major diagnosis in 87 per cent. Subsequent IVP was less informative than combined sonography and scintigraphy in 5 of 15 patients, and VCUG confirmed the final diagnosis in 4 of 13 patients. We conclude that initial evaluation of the newborn with renomegaly should comprise ultrasonography followed by nuclear scintigraphy. This combination of studies provides adequate information to determine subsequent management in nearly 90 per cent of cases without subjecting infants to the risks of contrast infusion or higher doses of diagnostic levels of radiation.     

The use of duplex Doppler ultrasonography to evaluate renal allograft dysfunction

This study evaluated the utility of duplex Doppler sonograms (DS) and the resistive index (RI) in the identification and differential diagnosis of various causes of renal allograft dysfunction. The efficacy of DS and RI was studied either during acute episodes of allograft dysfunction or during periodic posttransplantation longitudinal analyses. The unique features of each renal allograft results in poor correlative value for single isolated measurements of RI. We observed that the highest RIs were in ATN and that an RI of 0.9 was not specific for acute vascular rejection. Also, an RI of 0.9 was rare in acute cellular rejection. RI could not distinguish acute rejection, chronic rejection, CsA toxicity, or obstruction, although the mean RI was significantly different from normal in these groups. Serial studies of RI did document a change at the time of a clinical event compared to baseline. It is concluded that RI is not specific to any one clinical entity.     

Membranous glomerulopathy following kidney transplantation. Association with renal vein thrombosis in two of nine cases

The association of renal vein thrombosis and membranous glomerulopathy in native kidneys has been well documented. However, this association has only occasionally been described following renal transplantation. A review of 693 renal transplant recipients revealed 77 (11%) in whom persistent, heavy proteinuria (greater than 2 g/24 hr) developed. Renal histology was available in all 77 patients. A diagnosis of membranous glomerulopathy was made in 7 patients. Two further cases were added on the basis of biopsy findings--1 patient had a protein excretion of 1.7 g/24 hr, the other had microscopic hematuria and red cell casts in the urine. Renal venography was performed in 4 cases. The decision to perform venography was based on clinical criteria (thrombophlebitis or marked edema of the leg on the side of the allograft), and/or histological criteria (associated interstitial edema and venous congestion). Renal vein thrombosis was present in 2 patients. Three of the 9 patients had membranous glomerulopathy as the cause of their end-stage renal disease; 2 of these patients had received kidneys from living-related donors. Four of the patients were classified as having de novo membranous glomerulopathy on the basis of having a different cause for their end-stage renal disease. Two patients were classified as having unspecified membranous glomerulopathy; both of these patients had had chronic glomerulonephritis, but there was lack of characterization of the original glomerular disease. Seven of the 9 patients continued to have stable allograft function 1-12 months after the diagnosis of membranous glomerulopathy was made in the renal allograft. The remaining 2 patients both had associated renal vein thrombosis; 1 had progressive deterioration of renal function and returned to dialysis 24 months after the diagnosis of membranous glomerulopathy had been made, while the other died of unrelated causes 27 months after the diagnosis had been made.     

Duplex Doppler sonography in patients with acute renal colic: Prospective study and literature review

PURPOSE: To determine the value of duplex Doppler sonography in the diagnosis of acute urinary obstruction. MATERIALS AND METHODS: In 46 healthy individuals and 42 patients with urinary obstruction confirmed by intravenous urography, 176 kidneys were examined with duplex Doppler sonography. The mean intra-arterial resistive index value and the difference of mean resistive index values between both kidneys were determined for each person. Resistive index and delta resistive index values were compared with urographic findings in the 42 patients. RESULTS: In the 46 healthy individuals, the mean resistive index and delta resistive index values were 0.59 +/- 0.05 and 0.03 +/- 0.01. In the 14 patients with complete urinary obstruction, these values were 0.70 +/- 0.06 and 0.09 +/- 0.02, whereas in the 28 patients with partial urinary obstruction, these values were 0.64 +/- 0.06 and 0.03 +/- 0.05. Urographic findings and duplex Doppler sonography were correlated in the 42 patients, with a resistive index = 0.65 and delta resistive index = 0.05 as discriminatory thresholds for obstruction. In patients with complete obstruction, the diagnostic sensitivity of these values was 64% and 100% with a specificity of 82% and 89%, respectively. In patients with partial obstruction, the sensitivity of these values was 54% and 46% with a specificity of 82% and 89%, with respect to the control group of healthy individuals. CONCLUSION: Delta resistive index is a very sensitive and specific parameter in the sonographic diagnosis of complete urinary obstruction but insensitive in partial urinary obstruction. Duplex Doppler sonography is recommended in cases where intravenous urography is contraindicated.