Arterial stenosis complicating renal allotransplantation in man: a study of 38 cases.

Of 306 renal transplantations, stenosis of the artery supplying the grafted kidney was found in 38 patients three months to two years after they had undergone renal transplantation. The diagnosis was made by arteriography done because of refractory hypertension with or without impaired renal function in 36 patients and as a routine investigation in two normotensive patients. The stenosis was corrected surgically in 14 patients, with resultant lasting relief of hypertension in ten patients and improvement of renal function in five out of six patients with impaired renal function. Different types of stenosis were recognized: stenosis of the recipient artery, stenosis of the suture line, stenosis of the donor renal artery (segmental or diffuse) and multiple forms. The most frequent site of stenosis was the donor artery. There seems to be no single cause of stenosis: atheroma of the recipient vessels, faulty suture technique, hemodynamic disturbances, trauma to donor or recipient arteries account for some cases, whereas in other cases the evidence points to an immune mechanism. This complication of renal transplantation may be more frequent than is thought at present; therefore, routine renal arteriography should be performed at repeated intervals in all transplanted patients.     

Arterial stenosis in transplanted kidneys. 86 surgically treated cases

Eighty-six patients who had undergone renal transplantation three months to five years before, were operated on for a stenosis of the artery supplying the grafted kidney. The diagnosis was made by angiography performed because of refractory hypertension with or without impaired renal function. Surgical repair of the stenosis cured or improved arterial hypertension in 48 patients and improved renal function in 17 of 29 with impaired renal function. Different types of stenosis were recognized: stenosis of the recipient artery, stenosis of the suture line, stenosis of the donor renal artery (segmental or diffuse) and multiple stenoses. The most frequent site of stenosis was the donor artery. There seems to be no single cause of stenosis: atheroma of the recipient vessels, trauma to donor or recipient arteries, faulty suture techniques, hemodynamic disturbances account for some cases whereas in other cases the evidence points to an immune mechanism. This complication of renal transplantation appears now as the most frequent one; therefore, routine vascular investigations should be performed at repeated intervals in all transplanted patients. Surgical repair is indicated in tight stenoses with impending thrombosis and in stenoses responsible for severe hypertension which does not respond to anti-hypertensive treatment. The other patients with mild to moderate hypertension responding to medical treatment, without renal function impairment, and with moderate stenosis can be managed medically. In our experience, surgical correction of the stenosis is indicated approximately in one half of the patients in whom a stenosis has been discovered.(ABSTRACT TRUNCATED AT 250 WORDS)     

Angioplasty and stenting of arterial stenosis affecting renal transplant function

PURPOSE: To evaluate the efficacy of percutaneous angioplasty and stenting in cases of artery stenosis of the transplanted kidney or proximal iliac artery stenosis causing transplant dysfunction and/or increase of the arterial blood pressure. MATERIALS AND METHODS: Between January 1999 and June 2007, we evaluated 24 patients who had undergone renal transplantation and subsequently were diagnosed with refractory hypertension and transplant dysfunction for signs of possible renal transplant artery stenosis. Color Doppler ultrasonography and magnetic resonance angiography preceded the intrarterial angiographic investigation, with false-negative results in 18.2% and 13.6% of patients, respectively. In 2 of the 24 patients, angiography did not reveal arterial stenosis affecting the transplanted kidney. Two patients had severe ipsilateral iliac artery stenosis and the remaining 20 had transplant artery stenosis. Successful angioplasty and stenting were performed in these 22 patients. RESULTS: The method was technically feasible in 100%. The procedure-related morbidity was 0%. During the follow-up period (range: 3 to 104 months), two patients died with normal transplant function, two suffered transplant failure, and the remaining 18 still have normal transplant function and easily controlled hypertension. CONCLUSION: Percutaneous angioplasty and stenting in cases of arterial stenosis affecting the renal transplant function are safe and effective procedures. Even more, the strong clinical suspicion must lead to angiographic investigation regardless of the results of other imaging approaches.     

Screening for transplant renal artery stenosis in hypertensive recipients using digital subtraction angiography

Digital subtraction angiography was used in 10 renal allograft recipients with sustained hypertension after transplantation to detect transplant renal artery stenosis. Recipients with end-to-end vascular anastomoses were visualized adequately in the anteroposterior projection. Two cases of transplant renal artery stenosis were identified by digital subtraction angiography and then verified by catheter angiography. Patients with end-to-side vascular anastomoses may require additional oblique projections. Digital subtraction angiography is a safe, noninvasive and cost-effective screening procedure to diagnose transplant renal artery stenosis in most recipients. Catheter angiography can be applied more selectively to those recipients with stenosis observed by digital subtraction angiography or when more detailed imaging is required.     

移植肾动脉血流峰值速度加快与移植肾动脉狭窄相关性研究

目的:探讨肾移植术后半年内移植肾动脉血流峰值速度加快与移植肾动脉狭窄相关性。方法:回顾性分析我院102例肾移植患者术后半年内移植肾多普勒超声图像检查结果及临床资料,比较患者收缩期血流峰值速度(PSV)、血压及移植肾功能。结果:102例患者中,有27例患者出现较高的PSV,其中4例患者呈现持续性PSV升高,经行移植肾动脉造影检查而确诊为移植肾动脉狭窄(TRAS),行经皮肾动脉支架植入术(PTRAS)后,PSV降至正常,血压恢复正常,随访6~13个月未见狭窄复发。结论:在肾移植术后半年内,移植肾动脉PSV加快未必是肾动脉狭窄,可先随访观察,若超声提示PSV呈持续性升高,尤其是伴顽固性高血压,则需行移植肾动脉造影明确是否是TRAS。PTRAS是TRAS安全有效的治疗方法。     

Transplant renal artery stenosis: potential role of ischemia/reperfusion injury and long-term outcome following angioplasty

PURPOSE: We assess long-term arterial pressure, renal function, and patient and graft survival in recipients of cadaveric kidney transplant with or without transplant renal artery stenosis. We also evaluate the risk factors for transplant renal artery stenosis. MATERIALS AND METHODS: We reviewed and analyzed baseline clinical, immunological and outcome data for 26 patients with transplant renal artery stenosis before and after angioplasty, and 72 without stenosis on angiography. We also analyzed graft and patient survival in 304 cases in which angiography was not performed. RESULTS: The incidence of transplant renal artery stenosis was 6.6% (26 of 402 patients). Acute rejection episodes (42 versus 22%, p <0.05) and delayed graft function (50 versus 32%, p <0.10) were more frequent, and mean cold ischemia time plus or minus standard error (29.2+/-1.7 versus 24.8+/-1.3 hours, p <0.01) was longer in patients with than without transplant renal artery stenosis. The technical success of angioplasty was 92.3%. Restenosis was documented in 6 of 26 patients (23.1%). Revascularization resulted in a decrease in arterial pressure and better renal function. The 8-year patient (100, 98.6 and 95.7%, respectively) and graft (88.1, 88.9 and 89.3%, respectively) actuarial survival rates were similar among patients with or without transplant renal artery stenosis, and those who did not undergo angiography. CONCLUSIONS: Transplant renal artery stenosis had no detectable influence on long-term arterial pressure control, renal function, and patient and graft survival rates, which were similar to those in patients without stenosis. Long cold ischemia time may have a role in the development of transplant renal artery stenosis through ischemia/reperfusion injury.     

Severe Renal Vein Stenosis of a Kidney Transplant with Beneficial Clinical Course after Successful Percutaneous Stenting

A 51‐year‐old renal transplant recipient presented with marked renal function deterioration 13 months after renal transplantation. After exclusion of ureteral obstruction, transplant artery stenosis and acute rejection, the diagnosis of a severe renal vein stenosis was made by an MR scan. After angiographic confirmation of the stenosis, treatment was attempted with percutaneous stent angioplasty. The long‐term clinical course was favorable, with marked improvement in renal function. Transplant renal vein stenosis is a rare, but potentially curable, cause of renal allograft functional deterioration.     

供肾动脉带主动脉袖口预防移植肾动脉狭窄

目的:探讨供肾动脉带主动脉袖口预防移植肾动脉狭窄的效果。方法:对955例(1030例次)行肾移植患者的肾移植供肾动脉,全部采用主动脉袖口与受者髂内动脉吻合。应用彩色多普勒血流B超及移植肾动脉血管造影排除移植肾动脉狭窄。结果:955例(1030例次)肾移植无一例出现移植肾动脉狭窄。结论:供肾动脉带腹主动脉袖口可以防止移植后肾动脉狭窄发生。     

Captopril-induced acute renal failure in a kidney transplant recipient

A living related kidney transplant recipient with normal renal function and severe hypertension secondary to renal artery stenosis, was treated with captopril and developed reversible renal failure requiring temporary hemodialysis. This complication of captopril, an angiotensin converting enzyme inhibitor, has been reported previously in hypertensive patients with renal artery stenosis with and without a kidney transplant. It is recommended that this drug be used with caution in this setting.     

Post-Transplant Renal Artery Stenosis: Impact of Therapy on Long-Term Kidney Function and Blood Pressure Control

Purpose

We assessed the long-term outcome of different treatment methods for transplant renal artery stenosis.

Materials and Methods

Outcome data for 23 patients with transplant renal artery stenosis treated during a 16-year period were reviewed and analyzed.

Results

There was a higher incidence of renal artery stenosis in cadaveric donor kidneys compared to living donor kidneys (2 percent versus 0.3 percent, p less than 2), and in cadaveric kidneys from pediatric donors less than 5 years old compared to those from adults (13.2 percent versus 1.3 percent, p less than 0.01). Six patients underwent primary medical treatment for renal artery stenosis, with a successful outcome in 4 (mean followup plus or minus standard error 57 plus/minus 22 months) and failure in 2. Of the patients 16 were treated with percutaneous transluminal angioplasty, including 12 who were cured or improved with respect to hypertension (followup 44.7 plus/minus 7.6 months). Five patients underwent surgical revascularization for renal artery stenosis with postoperative improvement of hypertension (followup 18.8 plus/minus 11.6 months). Overall, 21 of 23 patients (91 percent) were treated successfully for transplant renal artery stenosis with cure or improvement of associated hypertension. Posttreatment renal function was stable or improved in 18 patients, while renal function deteriorated due to parenchymal disease in 3.

Conclusions

Most patients with transplant renal artery stenosis can be treated successfully. Percutaneous transluminal angioplasty is the initial interventive treatment of choice for high grade renal artery stenosis. Surgical revascularization is indicated if percutaneous transluminal angioplasty cannot be done or is unsuccessful.     

Anastomotic line renal artery stenosis after transplantation

We report on 5 patients with renal artery stenosis after renal transplantation. Renal arteriography showed the stenosis to be localized at the line of arterial anastomosis. The patients presented with refractory hypertension, with or without renal failure, 10 days to 13 months after transplantation. Percutaneous transluminal balloon angioplasty in 4 patients failed in 3 and produced temporary improvement in 1. Resection of the stenosis resulted in dramatic improvement of the clinical state in all 5 patients. Histological examination of the resected stenotic segment revealed a nodular fibrotic lesion at the anastomotic line in all cases, and was associated with extensive calcification in 3. Anastomotic line stenosis should be recognized as a specific entity causing transplant renal artery stenosis. The pathological changes observed explain the failure of transluminal angioplasty and suggest that surgical repair is the treatment of choice. Possible factors in the etiology of anastomotic line stenosis are discussed.     

Renovascular hypertension following renal transplantation

The authors address the multifactored origins of renovascular hypertension following renal transplantation and present the experience with digital subtraction angiography and percutaneous transluminal angioplasty as well as standard angiography and surgical repair in the diagnosis and treatment of transplant renal artery stenosis. The roles of the renin-angiotensin system of the native kidney and of the allograft in sustaining hypertension after transplantation are reviewed in detail.     

Donors with renal artery stenosis: fit to donate

Kidney donation from hypertensive donors is now an accepted norm in live related kidney transplantation. The use of hypertensive donors with renal artery stenosis due to atherosclerosis and fibromuscular dysplasia is still debated. The prime concern is about the deleterious effect of hypertension on the donor and the risk of recurrence of such lesions in the solitary kidney. Even as the response of atherosclerotic renal artery stenosis to revascularisation is unpredictable, there is an improvement in blood pressure following revascularisation of kidneys with fibro-muscular dysplasia. The first use of such kidney donors was reported in 1984 and, since then, there have been a few reports of successful use of kidneys from donors with renal artery stenosis. We report here two interesting cases of successful transplantation of kidneys from live related kidney donors with hypertension due to renal artery stenosis who became normotensive with good graft function in the recipient. We conclude that moderately hypertensive donors with renal artery stenosis are fit to donate.     

经皮穿刺血管成形术治疗移植肾动脉狭窄

为了观察血管成形术在移植肾动脉狭窄的治疗作用。我们将18例移植肾动脉狭窄并高血压的患者进行了血管成形术治疗。疗效以临床随访、血管造影和超声追踪为评价。结果18例患者手术均成功，成形术后，所有患者均治愈。认为血管成形术是移植肾动脉狭窄所致长期高血压和肾功能减退的有效的和首选的治疗方法。     

Mechanisms of posttransplant hypertension

Summary Hypertension is a common problem in renal failure patients both before and after renal transplantation. The stable allograft can maintain salt, volume, and blood pressure homeostasis and is not intrinsically a hypertensive model. The causes of severe posttransplant hypertension are multiple. Renal vascular tone, body salt and volume status, and renin release are all connected and influenced by immunosuppressive medications, allograft function, and native kidney presence and function. The role of each of these in posttransplant hypertension is reviewed. In most cases, severe hypertension in the stable transplant patient without rejection or transplant renal artery stenosis is greatly improved following native bilateral nephrectomy. Transluminal angioplasty is the preferred initial treatment for transplant renal artery stenosis.     

Common iliac artery stenosis presenting as renal allograft dysfunction in two diabetic recipients

BACKGROUND: Suprarenal common iliac artery stenosis is an uncommon but reversible cause of allograft dysfunction in renal transplant recipients. METHOD: We describe two diabetic renal transplant recipients with worsening hypertension, edema, and azotemia. Magnetic resonance angiography (MRA) demonstrated tight stenoses in the common iliac artery proximal to the allograft anastomosis site with patent renal transplant artery in both cases. These findings were later confirmed with carbon dioxide angiography. RESULTS: No acute rejection was noted on renal biopsy in either case. Placement of percutaneous iliac artery Wallstents resulted in decrease of serum creatinine from 6.5 to 2.0 mg/dl and 1.7 to 1.0 mg/dl within 2 and 4 weeks, respectively. CONCLUSION: Common iliac artery stenosis should be suspected in renal transplant recipients presenting with worsening hypertension, edema and azotemia. MRA for screening followed by carbon dioxide angiography and placement of intravascular stents for focal vascular obstructive lesions reverses allograft dysfunction.     

High-grade renal transplant artery stenosis after suboptimal angioplasty: favourable long-term outcome

The purpose of our report is to present the long-term outcomes of three renal transplant recipients with high-grade stenosis and suboptimal percutaneous angioplasty (PTA) because of technical difficulties. Two men and one woman of age 67, 53, and 54 years, who maintained functional cadaveric graft for 17, 9, and 13 years, and had diagnosed significant renal transplant artery stenosis at 2, 1, and 2 years after renal transplantation, respectively, were studied. Stenoses were diagnosed angiographically in the first patient and by Doppler in other two patients, then confirmed by angiography. All three patients had difficult-to-treat hypertension with deterioration of graft function in the presence of or after introducing ACE-inhibitor therapy. PTA was performed in all patients with suboptimal or unsuccessful results as assessed by angiography or control Doppler examination--the residual stenosis was significant and practically unchanged. Surgery was not performed because of high risk, so patients were further treated conservatively. Hypertension was treated avoiding ACE inhibitors. Twelve, 7, and 7 years after angioplasty the serum creatinine is stable in all patients, even decreased compared to pre-PTA and early post-PTA levels, namely, 134, 102, and 75 micromol/L, respectively. Control Doppler examinations revealed a residual stenotic jet in all patients, with slightly decreased peak systolic velocity over time, indicating a slightly decreased grade of stenosis. These observations suggest that renal transplant artery stenosis, even of high grade, can be stable, or even regress with time with excellent long-term graft survival. Randomized studies comparing conservative treatment versus revascularization are warranted.     

Post-transplant renal artery stenosis: a cause of anuria. Report of 2 cases corrected by revascularization

We report 2 cases of severe hypertension and acute onset of anuria after renal transplantation in which angiography revealed renal artery stenosis. After renal artery reconstructive surgery renal function returned to normal and the hypertension improved. A high index of suspicion is needed to make the diagnosis. Only by heightened awareness of this important entity will patients with post-transplantation anuria secondary to renal artery stenosis be identified. Such patients may benefit from renal artery revascularization to reverse this type of renal failure.     

Evaluation of transplant renal artery blood flow by Doppler sound-spectrum analysis

Doppler ultrasonography sound-spectrum analysis (SSA) was used to evaluate blood flow in the transplanted kidney and its renal artery. Seven patients with posttransplant hypertension and a bruit over the transplanted kidney were screened for renal artery stenosis (RAS). In five patients, RAS was diagnosed by SSA, and in two it was not. These findings were confirmed by subsequent angiography in all patients. Three patients studied after surgical correction of their RAS had improvement in their SSA patterns. Fourteen hypertensive patients with a cause other than RAS were evaluated by SSA. None of them had SSA findings suggestive of RAS. Doppler ultrasonography with SSA is an effective, noninvasive technique of monitoring transplant renal blood flow, especially in the screening of hypertensive transplant recipients for transplant RAS.     

Renal transplantation following previous heart, liver, and lung transplantation: an 8-year single-center experience

BACKGROUND: Long-term follow-up of heart, liver, and lung transplantation has led to an increased recognition of secondary end-stage renal failure (ESRF) in transplant recipients. This study examines our center's experience with renal transplantation following previous solid organ transplantation. METHODS: From January 1, 1992, to September 30, 1999, our center performed 18 renal transplants in previous solid organ recipients. During the same period, 815 total renal transplants were performed. One- and 3-year graft and patient survival, recipient demographics, donor type, and reason for transplantation were compared between these groups. RESULTS: Of the 18 recipients, 7 had prior heart transplants, 4 had prior liver transplants, and 7 had prior lung transplants. Cyclosporine toxicity contributed to renal failure in 17 (94.4%) of the patients-either as a sole factor (11 patients) or in combination with hypertension, renal artery stenosis, or tacrolimus toxicity (6 patients). Kaplan-Meier 1- and 3-year patient survival was 82.9% and 73.7%, compared with 95.5% and 90.7% in all renal transplant recipients. No surviving patient has suffered renal allograft loss. Mean current creatinine level is 1.4 mg/dL. CONCLUSIONS: Renal transplantation is an excellent therapy for ESRF following prior solid organ transplantation. One and 3-year patient and graft survival demonstrate the utility of renal transplantation in this patient population.