[S2k guidelines on diagnostics, therapy and metaphylaxis of urolithiasis (AWMF 043/025) : Compendium]. / S2k-Leitlinie zur Diagnostik, Therapie und Metaphylaxe der Urolithiasis (AWMF 043/025) : Kurzfassung.

Every tenth German citizen will suffer from at least one urinary calculus during the lifetime. The diagnostics, treatment and follow-up treatment of urolithiasis are, therefore, part of the daily routine practice for all urologists in hospitals and private practices as well as in many other disciplines, such as general practitioners, internists, nephrologists and pediatricians. Although the diagnostics and therapy have experienced substantial alterations over the last 10 years, the possibilities of metabolic diagnostics and secondary prevention for patients at risk are, unfortunately and unjustly, in many places very poorly represented. The present S2k guidelines, which for the first time were established in an interdisciplinary consensus process, represent the current practical recommendations and, whenever possible, use tables and algorithms in order to facilitate easy reference in the routine daily work. Last but not least, this greatly simplifies the measures for metaphylaxis.

[Open and minimally invasive partial nephrectomy. Management of complications]. / Offene und minimal-invasive partielle Nephrektomie. Komplikationsmanagement.

Current guidelines increasingly recommend organ-preserving surgical procedures in the treatment of renal tumors. Both the open surgical and minimally invasive surgical techniques are well established. In the literature, various systems for the systematic evaluation of comorbidities and complications have been reported. Already while taking the patient's history and preoperative planning prior to partial nephrectomy, it is recommended that a detailed risk assessment be carried out regarding expected complications. Essentially the two critical factors - the comorbidities of the patient and anatomic complexity level of the tumor - should be evaluated in order to achieve the best possible selection of patients for a partial nephrectomy and the determination of the surgical method.

[Urolithiasis in childhood]. / Urolithiasis im Kindesalter.

Urinary stone disease is relatively rare in children with an overall incidence of 1-2 %; however, it is often associated with metabolic abnormalities that may lead to recurrent stone formation. Stone analysis and subsequent metabolic evaluation is therefore mandatory for this high-risk group after the first stone event. The objectives of stone management in children should be complete stone clearance, prevention of stone recurrence, preservation of renal function, control of urinary tract infections, correction of anatomical abnormalities and correction of the underlying metabolic disorders. The full range of minimally invasive procedures is available if active stone removal is necessary. The majority of stones in children can be managed either with extracorporeal shock wave lithotripsy which has a higher efficacy in children than in adults, percutaneous nephrolithotomy, ureterorenoscopy or a combination of these modalities while open or laparoscopic surgery is limited to well-selected cases with underlying anatomical abnormalities.

[Secondary malignancies in urinary diversions]. / Sekundärmalignome in Harnableitungen.

In contrast to ureterosigmoidostomy no reliable clinical data exist for tumor risk in different forms of urinary diversion using isolated intestinal segments.In 44 German urological departments, operation frequencies, indications, patient age, and operation dates of the different forms of urinary diversion, operated between 1970 and 2007, could be registered. The secondary tumors up to 2009 were registered as well and related to the numbers of the different forms of urinary diversions resulting in tumor prevalences.In 17,758 urinary diversions 32 secondary tumors occurred. The tumor risk in ureterosigmoidostomy (22-fold) and cystoplasty (13-fold) is significantly higher than in other continent forms of urinary diversion such as neobladders or pouches (p<0.0001). The difference between ureterosigmoidostomy and cystoplasty is not significant, nor is the difference between ileocecal pouches (0.14%) and ileal neobladders (0.05%) (p=0.46). The tumor risk in ileocecal (1.26%) and colonic neobladders (1.43%) is significantly higher (p=0.0001) than in ileal neobladders (0.5%). Of the 16 tumors that occurred following ureterosigmoidostomy, 16 (94%) developed directly at the ureterocolonic borderline in contrast to only 50% following urinary diversions via isolated intestinal segments.From postoperative year 5 regular endoscopic controls of ureterosigmoidostomies, cystoplasties, and orthotopic (ileo-)colonic neobladders are necessary. In ileocecal pouches, regular endoscopy is necessary at least in the presence of symptoms or should be performed routinely at greater intervals. Following neobladders or conduits, only urethroscopies for urethral recurrence are necessary.

Elective nephron sparing surgery should become standard treatment for small unilateral renal cell carcinoma: Long-term survival data of 216 patients.

OBJECTIVES: Our experiences with elective nephron-sparing surgery (NSS) for renal cell carcinoma (RCC) in a consecutive series of 216 patients are presented. Clinicopathological features and long-term oncological outcome is compared to patients treated with radical nephrectomy (RN). METHODS: Between 1975 and 2002, NSS was performed in 488 patients; 311 of these patients had elective indications. Renal cell carcinoma was found in 241/311 patients (77.5%). Long-term follow up data could be obtained in 216/311 patients. Cancer-specific survival was estimated using the Kaplan-Meier method. Cox's regression analysis and log-rank tests were used to evaluate independent predictive values of different clinicopathological features. Survival data of the 216 patients after NSS surgery were compared to 369 patients with small RCC treated with RN. RESULTS: After a mean follow up of 66 months (median 64 months) 29 (13.4%) of 216 patients treated with NSS had died, 4 of them (1.8%) tumour-related. Tumour recurrence was detected in 12 patients (5.6%). 204 patients (94.4%) were free of tumour at last follow-up. Cancer specific survival rates at 5 and 10 years for patients treated with NSS (RN) were 97.8% (95.5%) and 95.8% (84.4%). CONCLUSIONS: Elective NSS surgery provides optimal long-term outcome in patients with small localized RCC. Compared to RN, renal parenchyma is preserved without any disadvantage in survival rates. Consequently elective NSS should be accepted as gold standard for small renal tumours.

[Interventional radiologic management for early post-transplant perfusion failure of renal allografts]. / Interventionelle radiologische Therapie früher postoperativer Perfusionsstörungen von Nierentransplantaten.

PURPOSE: Open surgery for correction of early vascular complications in allogenic kidney transplantation carries the risk for increased morbidity and graft loss. The question was raised whether modern interventional radiologic techniques, especially the use of vascular stents, could play an alternative therapeutic role in those complicated cases. MATERIAL AND METHODS: 3 patients with early postoperative perfusion failure of their renal grafts were referred to the radiologist after Doppler sonography. Immediate digital subtraction angiography was initiated and during the same session percutaneous transluminal angiography and placement of a vascular stent were performed to treat the vascular lesion. Anticoagulation was started with low-dose aspirin 100 mg/day. RESULTS: In all 3 patients an intimal dissection of the renal artery with formation of a relevant stenosis was found. Stenosis was corrected by angioplasty and stenting. In one case an accidentally found renal vein thrombosis was additionally treated by transcatheter thrombo-aspiration. No complications related to the interventions occurred. In 2 patients diuresis returned immediately and renal function remained stable in the longterm (follow-up 6 month). In one case massive peripheral arterial thrombosis had to be diagnosed in spite of successful recanalization of the renal artery. After explantation of the organ histology revealed extended parenchymal necrosis. CONCLUSIONS: The timely use of angiography after Doppler sonographic diagnosis for renal transplant perfusion failure is of help not only for exact diagnosis but also for immediate treatment. Radiologic interventional techniques should be regarded as potentially effective and safe for the treatment of early vascular complications after renal transplantation.

Adrenal metastases in 1635 patients with renal cell carcinoma: outcome and indication for adrenalectomy.

PURPOSE: Routine removal of the ipsilateral adrenal gland in patients with renal cell carcinoma who undergo nephrectomy has been a matter of dispute. In a retrospective study we screened for subgroups of patients with renal cell carcinoma from a large single center patient population who may have benefited from ipsilateral adrenalectomy. MATERIALS AND METHODS: Radical nephrectomy was performed in 1635 patients at a single institution between 1980 and 2000. A total of 1010 patients underwent radical nephrectomy plus ipsilateral adrenalectomy, whereas in 625 no simultaneous adrenalectomy was performed. Numerous clinical and histopathological parameters were investigated by univariate and multivariate statistical methods for their predictive value in regard to cancer specific survival. RESULTS: Metastases in the adrenal gland were found in 5.5% of patients (56 of 1010) undergoing nephrectomy with adrenalectomy. Of 30 patients with adrenal metastasis and preoperative computerized tomography/magnetic resonance imaging 23 were found to have histological evidence of cancer, approaching a false-negative rate of 23.3%. All patients with false-negative computerized tomography/magnetic resonance imaging had a primary tumor of greater than 4 cm. Patients with adrenal metastases predominately had pT3 or greater tumor stage (82%). Cancer specific survival rates (75% vs 73% for adrenalectomy vs no adrenalectomy) and postoperative complications rates (7% vs 8%) did not differ significantly between the 2 groups. The prognosis in patients with a solitary adrenal metastasis (18 of 56) was more favorable than in patients with additional metastatic sites (38 of 56). CONCLUSIONS: Adrenal metastases from primary renal cell carcinoma were found significantly more often in patients with advanced tumor stages. Ipsilateral adrenalectomy should be recommended for all resectable renal cell carcinoma with a primary tumor of greater than 4 cm or with nonorgan confined tumor stages (T3 or greater) since a false-negative rate of about 20% can be expected with current imaging techniques.

cAMP and cGMP do not mediate the vasorelaxation induced by iodinated radiographic contrast media in isolated swine renal arteries.

PURPOSE: Vasodilatation is a frequent side effect of radiographic contrast media, partially due to a direct effect on vascular smooth muscles. Our purpose was therefore to examine any possible implication of the cyclic adenosine monophospate (cAMP) and cyclic guanosine monophosphate (cGMP) pathways in contrast media induced vasorelaxation. MATERIAL AND METHODS: Isolated segments of swine renal arteries were precontracted with 10 microM phenylephrine and relaxed with iomeprol before and after blockade of the cAMP and cGMP pathways. RESULTS: 80 mM and 160 mM of iomeprol significantly relaxed about 52% and 68% of the precontracted arterial rings, respectively. 10 microM of IBMX, a phosphodiesterase inhibitor, did not increase the relaxant effect of 80 mM iomeprol but increased the relaxations induced by 400 nM forskolin by about 1.9 times (which stimulates the production of cAMP), and by 1 microM sodium nitroprusside (which stimulates the production of cGMP). 1 microM of H89 (an inhibitor of the cAMP-dependent protein kinase), was able to reduce the relaxation induced by 4 microM forskolin by about 2.5 times but had no significant effect on the relaxation induced by 160 mM iomeprol. 10 microM of ODQ (an inhibitor of the soluble guanylate cyclase), could reduce the relaxation induced by 10 microM of SNP but not the one induced by 160 mM iomeprol. Moreover, the absence of endothelial cells did not alter the relaxation induced by iomeprol. CONCLUSION: The activation of the cAMP and cGMP pathways are not involved in the in vitro relaxation induced by iomeprol in swine renal arteries.

[Long-term outcome of conservative surgery for kidney cancer: survival, blood pressure, and renal function]. / Résultats à long terme de la chirurgie conservatrice pour le cancer du rein: survie, pression sanguine et fonction rénale.

PURPOSE: Nephron-sparing surgery (NSS) for renal cell carcinoma (RCC) remains controversial for elective indications (low stage RCC in the presence of a normal contralateral kidney). In this single center study survival rate and, as novel aspects, the frequency of postoperative arterial hypertension and renal function parameters were investigated to evaluate safety and efficacy of NSS. PATIENTS AND METHODS: The complete data of 248 patients operated nephron-sparing for RCC between 1975 and 1995 were evaluated. One hundred and seventy-five patients were treated for elective indication (95% with tumor stage T1 or T2), 73 patients for mandatory indication (bilateral tumors, solitary kidney, renal insufficiency). The mean follow-up was 75 months (maximum 23 years). RESULTS: Mean tumor-size was lower under elective (3.8 cm) than under mandatory (4.7 cm) indication. Overall tumor-specific survival after 5 years for both indications was 88%. Comparing preoperative vs. follow-up values, arterial blood pressure and serum-creatinine values remained unchanged for both indications. The incidence of postoperative proteinuria (19% imperative, 11% elective indication) was strongly related to hypertension. CONCLUSIONS: NSS for RCC under elective indication achieves patient survival comparable to the results of radical nephrectomy. The presented data do not indicate significant longterm complications such as arterial hypertension, proteinuria or deterioration of renal function as a result of glomerulosclerosis or hyperfiltration. This gives further argument for the concept of NSS in RCC as an alternative to radical nephrectomy in the presence of a healthy contralateral kidney.

[Bilateral kidney tumor. Therapy management and histopathological results with long-term follow-up of 66 patients]. / Der bilaterale Nierentumor. Therapiemanagement und histopathologische Ergebnisse mit Langzeitverlauf bei 66 Patienten.

Bilateral renal cell carcinoma is detected at an incidence rate of 1.6-6% of all renal tumors. The management, histopathological results and the long-term follow-up of 66 patients with bilateral renal cell carcinoma (29 synchronous, 37 asynchronous tumors) are presented in this issue. The incidence rate of bilateral renal cell carcinoma (RCC) at our hospital was 3.5%. Nephron-sparing surgery should be used first for the smaller and favourably located tumor when radical nephrectomy of the contralateral tumor is necessary. Thus, the patients can be spared dialysis. The histopathological results showed a significantly higher incidence rate of chromophil RCCs in cases of synchronous bilateral renal tumors (36%). The 5-year survival rate was 82%. Patients with asynchronous renal cell carcinomas were significantly younger than those with synchronous RCCs (median age: 60.2 years). The histopathological results were similar to unilateral renal cell carcinomas. Clear cell carcinoma was detected in 70% of cases. The 5-year survival rate was 61% and lower than that of synchronous tumors (82%). There was no significant difference because of the small number of cases. Current standardised techniques of nephron-sparing surgery achieve good survival rates, therefore making bilateral nephrectomy only necessary in very poor cases. In cases of chromophil renal cell carcinomas, the contralateral kidney should always be carefully examined, because these tumors were significantly more often detected to be bilateral. The risk of also developing a tumor in the contralateral kidney increases with decreasing age at first manifestation (< 55 years, 6%). Especially in those younger than 55 years, partial nephrectomy seems to be recommended for unilateral renal tumors in patients with a normal contralateral kidney (tumor size < 4 cm in diameter).

Diagnosis of nonpalpable testes in childhood: comparison of magnetic resonance imaging and laparoscopy in a prospective study.

In a prospective study, the accuracy of magnetic resonance imaging (MRI) and laparoscopy in the diagnosis of nonpalpable testes was evaluated. Advantages and disadvantages of the two procedures were compared. 29 boys with unilateral nonpalpable testis underwent MRI. When MRI failed to demonstrate a testis, laparoscopy with a 1.9 mm mini-laparoscope was performed. All cases were verified by operative exploration of the inguinal region. MRI demonstrated 10 inguinal and 7 abdominal testes. MRI revealed no testis in 12 boys. The false positive rate was 32%, correct negative findings were confirmed in four patients. When laparoscopy was performed, preservable testis could be demonstrated in 8 of 12 patients (1 abdominal, 7 inguinal) which otherwise were not visible on MRI. The correct positive rate was 100%. We encountered no complications with laparoscopy. In summary, laparoscopic evaluation is recommended as the preferable method in pediatric cases of nonpalpable testes.

[Value of ultrasound in early diagnosis of renal cell carcinoma]. / Stellenwert der Sonographie in der Frühdiagnostik des Nierenzellkarzinoms.

The importance of ultrasonography in early detection of renal cell carcinoma was analyzed for 1854 patients, who were operated from 1975 to 1997. The 5-year survival rate of all patients amounts to 75%, the 10- and 20-year survival rate was 68% and 64%. While from 1975 to 1986 tumor symptoms like hematuria (30%), abdominal pain (19%) and palpable mass (3%) lead to diagnosis of renal cell carcinoma in 56% of all cases, there were only 26% from 1987 to 1997. 83% of asymptomatical tumors from 1987 to 1997 were accidentally detected by means of ultrasonography in a kidney independent examination. These tumors are significantly smaller (5.5 cm) than the tumors of symptomatical patients (7.8 cm) and show often a significantly lower local tumor stage, a better tumor grade, frequently lymph nodes, which are free of tumor infiltration and more rarely distant metastasis. The 5-year survival rate of patients with incidental tumors, detected by ultrasonography (82%) was significantly better (log rank < 0.001) in comparison with the symptomatical patients (72%). These results verify 1. The effectivity of ultrasonography in early diagnosis of renal cell carcinoma and 2. The advantage of survival on patients with early tumor detection. That's why asymptomatic patients, who selected under risk factors should be examinated by ultrasonography consistently too.

[Urologic importance of interventional radiology techniques]. / Importance des techniques radiologiques interventionnelles d'un point de vue urologique.

In radiology several therapeutical methods were developed and introduced into clinical routine in the last 10 to 15 years. In part these techniques are in competition with established surgical procedures although their main advantage is significantly less invasion. For the urologist diagnostic radiological procedures like selective blood sampling from renal or suprarenal vessels for hormone determination or CT-guided biopsy of retroperitoneal tumors are of special interest as well as procedures with therapeutic aims such as placement of drainage-tubes, percutaneous therapy of varicoceles and arterial endovascular interventions for hemorrhage or vascular wall stenosis. The role of these interventional techniques relevant for urology is described and critically discussed.

Pediatric laparoscopy for nonpalpable testes with new miniaturized instruments.

New miniaturized pediatric telescopes (1.9 or 3.5 mm) and reusable instruments (3.5-mm trocars, scissors, graspers) were used for the first time in a prospective study to evaluate handling safety and efficacy in laparoscopic diagnosis of unilateral nonpalpable testes. The results were confirmed during the same anesthesia by open operation for either orchiopexy or removal of rudimentary spermatic cord structures. Laparoscopy in 13 boys revealed one abdominal testis, 5 vanishing testes, and 7 cases of inguinal retention associated with an open inner inguinal ring. The illumination and detail resolution of the minitelescope were excellent. The 3.5-mm instruments were fully functioning with regard to tissue dissection. No complications occurred. Without technical disadvantages but with increased safety for the patient, the new miniaturized pediatric laparocopic instruments indeed realize a step forward to minimal invasion in infants and children.

[Seminal vesicle cysts associated with ipsilateral renal agenesis. Diagnosis, and long-term clinical course]. / Samenblasenzysten bei ipsilateraler Nierenagenesie. Bildgebende Diagnostik, Klinik und Langzeitverlauf.

Congenital seminal vesicle cysts associated with ipsilateral renal agenesis or dysplasia are rare malformations. Even though they are more often diagnosed today due to the introduction of advanced, sectional imaging techniques as CT and MRI, no reliable data about the prevalence of this malformation are available. This study reports seven consecutive cases, with long-term follow-up in five cases (26-119 months, mean 52 months). All patients underwent sonography, excretory urography, CT and MRI. Only two of seven patients presented nonspecific symptoms of the lower urinary tract; five were asymptomatic. In all cases sonography revealed the cystic character of the retrovesical enlargement. The anatomy of the lower pelvis was most accurately shown on MRI, which depicted the ectopic insertion of the ureter into the seminal vesicle in five cases. Cysts demonstrated high signal intensities in T1- and T2-weighted spin-echo images. In five cases the CT density was over 40 HU. Whereas one patient (15 years) presented significant enlargement of the cysts 10 years after primary diagnosis with compression of the urinary bladder, four patients showed no changes of their malformation in the follow-up examinations. The present data therefore support the concept of treating only symptomatic patients.

Laparoscopic nephrectomy: the experience of the laparoscopy working group of the German Urologic Association.

PURPOSE: The centers of the laparoscopy working group of the German Urologic Association collected data to prove the efficacy, safety and reproducibility of laparoscopic nephrectomy. MATERIALS AND METHODS: At 14 centers 482 laparoscopic nephrectomies have been performed until December 1996 via a transperitoneal approach in 344 (71%) and a retroperitoneal approach in 138 (29%). All 482 laparoscopic nephrectomies were performed by a total of 20 surgeons with an average of 24 procedures per surgeon (range 4 to 105). The indications for nephrectomy were benign renal pathology in 444 patients (92%), including renovascular disease in 28%, hydronephrosis in 20%, reflux nephropathy in 15%, chronic pyelonephritis in 12%, end stage nephrolithiasis in 11%, renal dysplasia in 4% and renal tuberculosis in 1%. Of the remaining 38 patients (8%) laparoscopic radical nephrectomy was performed for renal cell carcinoma in 5% and for upper tract transitional cell carcinoma in 3%. RESULTS: Operating time depended mainly on the pathology of the kidney (that is small dysplastic organ versus large hydronephrosis) and the learning curve of the surgeon. However, the average operating time did not vary significantly among the different centers (maximum 277.6 and minimum 81.9 minutes). Intraoperative or perioperative complications were noted in 29 patients (6.0%), including bleeding in 22 (4.6%), bowel injury in 3, hypercarbia in 2 and pleura lesion in 1 and pulmonary embolism in 1. The conversion rate was 10.3% (bleeding, bowel injury, difficult dissection), including 4 patients with renal tuberculosis, 2 with xanthogranulomatous nephritis, and 1 each following renal trauma and embolization. The re-intervention rate was 3.4% due to bleeding in 6 cases, abscess formation in 3, intestinal stenosis in 2 and a pancreatic fistula and port hernia in 1. Mean hospital stay was 5.4 days. CONCLUSIONS: Laparoscopic nephrectomy has become a well established procedure in those urology departments focusing on laparoscopy. The indications and results are reproducible at these centers. However, for patients with severe perinephritis (that is renal tuberculosis, xanthogranulomatous nephritis, posttraumatic atrophy) a higher likelihood of open conversion must be considered.

[Diagnosis of non-palpable testis: value of a new miniaturized laparoscope]. / Diagnostik des nicht tastbaren Hodens: Stellenwert eines neues, miniaturisierten Laparoskops.

Laparoscopy and magnetic resonance imaging (MRI) are competitive tools in the diagnosis of nonpalpable testis. We investigated 29 boys for this indication with MRI. If MRI failed to locate the testis, laparoscopy was performed with a new, miniaturized set of pediatric instruments (1.9-mm optic). MRI revealed 10 inguinal and 7 abdominal testes. There was no false-positive finding. In 12 boys MRI showed no testis. Four cases were true negative, 8 false negative (32%). In these 8 MRI-negative patients, laparoscopy revealed 7 inguinal and 1 abdominal testis. The optical quality of the mini-telescope was sufficient for a 100% correct diagnosis. Laparoscopy-related complications did not occur. In summary, laparoscopic evaluation is the preferred method in pediatric cases of nonpalpable testes.

[Diagnosis of non-palpable testis in childhood: laparoscopy or magnetic resonance tomography?]. / Diagnostik des nicht tastbaren Hodens im Kindesalter: Laparoskopie oder Kernspintomographie?

Laparoscopy and magnetic resonance imaging (MRI) are competetive tools in the diagnostic of non-palpable testis. Advantages and disadvantages of this methods will be demonstrate. 29 boys investigated for this indication with MRI. In case MRI failed to locate the testis laparoscopy was performed with a new miniaturized set of pediatric instruments (1.9 mm optic). The aim of laparoscopy was the identification of the spermatic duct and vessels and their topographic relation to the internal inguinal ring. All findings were verified by open surgical procedures. MRI revealed 10 inguinal and 7 abdominal testis. There was no false positive finding. In 12 boys MRI showed no testis. 4 cases were correct negative, 8 cases were false negative (32%). In these 8 MRI-negative patients laparoscopy revealed 7 inguinal and 1 abdominal testis. The optical quality of the mini-telescope was sufficient for a 100% correct diagnosis. Laparoscopy related complications did not occur. Laparoscopy proved to be a powerful low risk diagnostic method in non-palpable testis with high sensitivity and specifity (100% correct positive, 0% false negative). Therefore lapraroscopy is recommended as primary diagnostic access for this indication. In the same anesthesia a optimal therapy is possible. Nevertheless a positive MRI-finding locates the testis reliably, whereas a negative finding always needs further exploration because testis might have been missed.

[Renovascular arterial hypertension: current aspects of physiopathology, diagnosis and treatment]. / L'hypertension artérielle réno-vasculaire: aspects actuels de la physiopathologie, du diagnostic et du traitement.

Renovascular hypertension is a potentially curable, secondary form of hypertension. It is caused by renal ischemic disease, which remains a significant clinical problem because of the increasing incidence of atherosclerosis with aging of the overall population. The role of the reinin-angiotensin system in renovascular hypertension has been consolidated by the discovery of angiotensin II receptor subtypes, various tissue renin-angiotensin systems and the function of angiotensin II as a vascular growth factor. To date renal vein renin estimation and converting enzyme renography seem to be the most reliable investigations to demonstrate the hypertensive role of a kidney before revascularization. Percutaneous transluminal angioplasty is a successful treatment in selected forms of renal artery stenosis. Open surgery consists of either bypass procedure or renal autotransplantation with extracorporeal reconstruction of the renal vasculature in cases of aneurysms or segmental renal artery stenoses. Control of hypertension and, increasingly important, preservation of renal function can be safely and successfully achieved, on the basis of careful diagnosis and individual selection of the therapeutic procedure are performed.