Renal artery revascularization after unsuccessful percutaneous therapy: a single centre experience.

PURPOSE: This retrospective review describes the long time effect of surgical revascularization after unsuccessful early or mid-term failure of percutaneous transluminal renal angioplasty (PTRA). METHODS: From January 1995 to January 2005, 60 out of 696 patients operated due to renal artery occlusive disease (17 fibromuscular dyplasia (FMD): mean age, 33.4 years; 43 atherosclerotic disease (ASD): mean age, 62.46 years) after unsuccessful PTRA underwent surgical revascularization for renal artery stenosis at our institution. The mean duration from failed PTRA to operation was 1.74 years. Out of the 68 renal arteries, 44 were pretreated with angioplasty alone (19, FMD; 25, ASD), and 24 were treated with PTRA and stent (all ASD). Operative management, response of renal function and hypertension as well as survival were compared to the literature. RESULTS: Fifty-nine per cent (n = 40) of the renal arteries were treated by transaortic thrombendarterectomy, 37% (n = 25) by bypass. Thirty-day and in-hospital mortality was 0% in all pretreated patients; after a mean of 4.16 years, it was 16.6% (only atherosclerotic). There was a significant decrease in systolic blood pressure values for all patients early after surgery as well as in follow-up. Creatinine remained stable in the patients with FMD, and there was an insignificant increase in creatinine level in the atherosclerotic patients. Hypertension was improved or healed in 32.5% of all pretreated patients, in cases with FMD in 54%, in atherosclerotic cases in 22.2%. Re-stenoses occurred in 26% of cases with FMD and in 18% of patients with atherosclerotic RAS. CONCLUSION: Surgical renal artery revascularization after failed PTRA is feasible and safe and systolic blood pressure can be lowered. The higher rate in re-stenoses in both the literature as well as in our own experience may be explained by the alterations in the renal artery after interventional treatment.

Surgical treatment for agenesis of the vena cava: a single-centre experience in 15 cases.

OBJECTIVE: Agenesis of the inferior vena cava (IVC) is a rare vascular malformation. Deep vein thrombosis (DVT) and bilateral pelvic thrombosis develop quite frequently, making surgical therapy necessary. PATIENTS AND METHODS: Between 1982 and 2006, 15 patients (nine male, six female, mean age 28 standard deviance 9 years) with agenesis of the IVC (IVCA) were treated surgically because of acute or subacute DVT. These patients underwent bilateral transfemoral ante- and retrograde thrombectomy of the iliofemoral and sometimes popliteal veins and replacement of the IVC with an external ring supported PTFE-graft. Bi- or unilateral arteriovenous fistulae were created in the femoral region. The fistulae were closed, on average, 8 months after trans-arterial venography was performed. These patients were examined clinically and by duplex ultrasound imaging during follow-up to assess graft patency and to allow CEAP classification. Patients were assessed for the development of post-thrombotic syndrome (PTS). RESULTS: No patient died during any part of their treatment or within 60 days. Primary patency of the venous reconstruction was 53%, secondary and long time follow-up patency was 83%. The mean duration of follow-up was 41 SD 12 months. Minor complications were observed in five cases (33%). PTS showed no progression during a follow-up of 41 SD 12 months in all patients. There was no change in the CEAP clinical stage during follow-up nor did any leg ulcer develop. CONCLUSION: A surgical approach to restore venous patency is effective and appears to prevent the deterioration of CVI over time.

[Occlusive aortic disease as coral reef aorta--experience in 80 cases]. / Der stenosierende Aortenprozess als Coral Reef Aorta--Erfahrungen in 80 Patienten.

BACKGROUND: Coral reef aorta (CRA) is described as rock-hard calcifications in the visceral part of the aorta. These heavily calcified plaques grow into the lumen and can cause significant stenoses, leading to malperfusion of the lower limbs, visceral ischaemia or hypertension due to renal ischaemia. PATIENTS/METHODS: From 1/1984 to 11/2008, 80 patients (26 m, 54 f, mean age 61.6, range 14 to 86 years) underwent treatment in the Department of Vascular Surgery and Kidney Transplantation, Heinrich-Heine-University Hospital for CRA. The present study is based on a review of patient records and prospective follow-up in our outpatient clinic. RESULTS: The most frequent finding was renovascular hypertension (n=33, 41.3%) causing headache, vertigo and visual symptoms. Intermittent claudication due to peripheral arterial occlusive disease was found in 35 cases (43.8%). 15 patients (18.8%) presented with chronic visceral ischaemia causing diarrhoea, weight loss and abdominal pain. 79 patients (98.7%) underwent surgery; in 73 (93.7%) aortic reconstruction was achieved with thromboendarterectomy, on an isolated suprarenal segment in 7 (9.3%), an infrarenal segment in 21 (26.6%), and the supra- and infrarenal aorta in 45 cases (60%). Desobliteration of renal arteries was performed in 47 (one-sided n=8, 10.1%; both arteries n=39, 49.4%); the aortic bifurcation was desobliterated in 37 (46.8%), extension into iliac arteries was necessary in 29 cases (one-sided n=4, 5.1%; both arteries n=25, 31.6%). The coeliac trunk was desobliterated in 43% (n=34), the superior mesenteric artery in 44.3% (n=35) and the inferior mesenteric artery in 20.3% (n=16). In 15 cases additional revascularisation (bypass, transposition, graft interposition) was necessary. Surgical access was via a left-sided thoracoabdominal incision in 56.4% (n=45) and via laparotomy in 41.8% (n=33). The 30-day lethality was 8.7% (n=7). Postoperative complications requiring corrective surgery occurred in 11 patients (13.9%). Almost ⅓ of the patients (n=19, 27.5%) returned for follow-up after a mean of 52.6 months (range 3 to 215 months). Of these, there was significant clinical and diagnostic improvement in 16 (84.2%) and 3 (15.8%) were unchanged. Impairment was not observed. CONCLUSION: In spite of the existing and improving surgical techniques for the treatment of CRA, procedures are challenging and should be performed in centres with expertise.

[Esophageal necrosis following endovascular treatment of a ruptured thoracal aortic aneurism: caused by mediastinal compartment syndrome]. / Osophagusnekrose nach endovaskulärer Versorgung eines rupturierten thorakalen Aortenaneurysmas : Folge eines mediastinalen Kompartments.

We report a case of acute esophageal necrosis after endovascular stenting for acute rupture of a thoracic aortic aneurysm into the mediastinum caused by mediastinal compartment syndrome and overstenting of intercostal arteries.

[Retrograde aortomesenteric loop bypass behind the left renal pedicle ("French bypass") in the treatment of acute and chronic mesenteric ischemia. Clinical experiences and long-term follow-up in 27 patients]. / Der retrograde aorto-mesenteriale Bypass mit links retrorenalem Verlauf ("französischer Bypass") bei der Behandlung der akuten und chronischen viszeralen Ischämie. Klinische Erfahrung und Langzeitverlauf bei 27 Patienten.

BACKGROUND: In 2001 Leschi et al. published a new method to improve perfusion of the superior mesenteric artery (SMA) in operative therapy of acute and chronic visceral ischemia. They presented a retrograde aorto-mesenteric bypass following an arcuate course behind the left renal pedicle. Due to the intricate correct anatomic description of this vascular reconstruction this loop bypass was named the "French bypass". PATIENTS AND METHODS: In our department 84 patients underwent surgery because of an acute or chronic visceral ischemia between January 2002 and December 2007. Out of these patients 27 received a "French bypass". The pre-, intra-, and postoperative data were collected from the patient hospital files retrospectively. The follow-up consisted of a review of the patient history and clinical findings in an outpatient setting, combined with a duplex sonography of the visceral arteries. RESULTS: The group of 27 patients had an average age of 55.0 years: (range: 29-81 years) and consisted of 21 women (78.6 %) and 6 men (21.4 %). The cardinal symptom of all patients was abdominal pain of variable intensities. 14 patients complained about an increased pain post ingestion (abdominal angina) and 12 patients about an involuntary loss of weight. Bypass material was autologous saphenous vein in 18 patients (66.7 %) and in 9 patients (33.3 %) an 8-mm ring-enforced PTFE prosthesis. Apart from 10 patients who only received the French bypass, we performed comprehensive visceral revascularisations in 12 patients. Overall hospital mortality was 18.5 %; 4 out of the 5 deceased patients had undergone surgery due to acute visceral ischemia. The mortality of patients with acute visceral ischemia was 30.8 % and of patients with chronic visceral ischemia 7.1 %. Eight patients had a revision before -discharge from hospital (surgery n = 6, interventional n = 2). Primary and secondary patencies of the bypasses of the surviving patients were 54.6 % (12 out of 22 patients) and 81.8 % (18 out of 22 patients), respectively. Concerning the end-point "freedom from abdominal complaints" 14 out of 27 patients (51.9 %) benefited after a mean follow-up of 38.9 months (range: 3-84 months), 7 patients each in the acute and chronic visceral ischemia group. CONCLUSIONS: The implantation of a "French bypass" represents a good option to reconstruct the SMA, combining the advantages of ante- and retrograde visceral bypasses. Furthermore this -bypass procedure allows to reconstruct distal segments of the -superior mesenteric artery in cases when long distance and peripheral stenosis impeded local thromendarterectomy. Perioperative morbidity and mortality are acceptable when the acute clinical situation is taken into account. The long-term benefit for the patients with regard to the prevention of intestinal ischemia and also the freedom from complaints is high.

[Development of neointimal matrix after incorporation of modern alloplastic prostheses: comparison between ePTFE and Dacron]. / Entwicklung neointimaler Matrix nach Einheilen moderner Prothesen: Vergleich zwischen ePTFE und Dacron.

BACKGROUND: In the therapy for peripheral arterial occlusive disease there remain inadequacies in the use of alloplastic material concerning thrombogenicity and biological compliance. In the 1960s, Sparks tried to combine the advantages of alloplastic prostheses with those of autologous reconstructions by using incorporated prostheses. No extensive myointimal hyperplasia was noted, but besides infections aneurysmatic dilatation were limiting factors in clinical practice. MATERIAL AND METHODS: The incorporation of modern alloplastic prostheses without connection to circulation concerning the thickness of neointima as well as the percentage of smooth muscle cells was examined in a dog model. RESULTS: The thickness of the neointima increased significantly in Dacron grafts with a peak on day 70 (p = 0.022), additionally a significantly greater percentage of smooth muscle cells was noted in Dacron grafts after 44 and 58 days (p = 0.008, p = 0.036). CONCLUSION: Due to the decreased thickness of the incorporating matrix as well as the lower percentage of smooth muscle cells, PTFE grafts should be preferred for peripheral arterial revascularisation.

[Paradigm shift in the therapy of Wilkie's syndrome. From bowel reconstruction to transposition of the superior mesenteric artery]. / Paradigmenwechsel in der Behandlung des Wilkie-Syndroms : Von der Darmumleitung zur Transposition der A. mesenterica superior.

The superior mesenteric artery syndrome--also known as Wilkie's syndrome or as arteriomesenteric obstruction of the duodenum--is a rare condition of upper intestinal obstruction in which the third part of the duodenum is compressed by the overlying, narrow-angled superior mesenteric artery against the posterior structures. It is characterized by early satiety, recurrent vomiting, abdominal distention, weight loss and postprandial distress. When nonsurgical management is not possible or the problem is refractory, surgical intervention is necessary. Usually a reconstruction of the intestinal passage is performed. We report the first case of successful transposition of the superior mesenteric artery into the infrarenal aorta in the therapy of Wilkie's syndrome.

[Ruptured abdominal aortic aneurysm : perioperative indicators for the clinical course following conventional open surgery]. / Rupturiertes Bauchaortenaneurysma : Perioperative Prädiktoren für den klinischen Verlauf nach konventioneller offener Behandlung.

OBJECTIVES: Ruptured abdominal aortic aneurysms (rAAA) still represent a life-threatening vascular disease, with high mortality despite improved diagnostic tools and perioperative patient management. The aim of this study was to reveal predictors of perioperative mortality and survival after open (conventional) rAAA repair. PATIENTS AND METHODS: We analyzed data from our department containing 67 patient histories and clinical notes which were collected between January 1984 and December 2004. The study patients underwent emergent surgery for rAAA. In these cases we defined 72 preoperative, 47 intraoperative, and 39 postoperative variables for further analysis. RESULTS: Our results indicate that the worst survival prognosis could be defined in patients with rAAA and aneurysmatic inclusion of the iliac arteries with concomitant prolonged shock who received an aorto-iliac bypass. For these patients we calculated a cumulative 30-day survival rate of 59.7% and 1-year survival of 43.3%. An influence of age and comorbidity on the mortality rate could not be proven. Furthermore the conclusion cannot be drawn that postoperative course was influenced by intra- vs retroperitoneal rupture localization. CONCLUSION: This study provides evidence that neither old patient age nor comorbidities influence the mortality of patients suffering from rAAA, for whom time-consuming case selection according to previous morbidities should therefore be omitted. Instead we recommend conventional surgical repair as soon as possible to maximize the chances of survival.

[The Klippel-Trenaunay syndrom associated with multiple visceral arteries aneurysms]. / Das Klippel-Trenaunay Syndrom bei gleichzeitigem Vorliegen von Viszeralarterienaneurysmen.

The Klippel-Trenaunay-syndrom (KTS) is a congenital angiodysplasia of venous vessels characterized by three main symptoms: cutanous vascular naevi, hyperthropy of a limb and varicosis or venous malformations. The coincidence of KTS and arterial malformations such as renal artery aneurysm has been described twice in the literature. We report the case study of a 40-years-old male patient with KTS and aneurysms of a renal artery, the splenic artery, the superior mesenteric artery and of a popliteal artery and popliteal vein. After documenting the diagnostic and therapeutic course we describe this case as it relates to the clinical literature. In the differential diagnosis of KTS two different syndroms have to be pointed out: the Servelle-Martorell-syndrom and the Frederick Parkes Weber-syndrom.

[Extracranial aneurysm of the carotid artery in a 12-year-old girl]. / Aneurysma verum der Arteria carotis im Kindesalter.

Extracranial aneurysms of the carotid artery in childhood are rare, and we found just nine cases described in the literature within the last 20 years. We report on the clinical appearance, diagnosis, and therapy of a carotid artery aneurysm in a 12-year-old girl and review the literature.

[Salmonella enteritidis infected false aneurysm of the superficial femoral artery in an HIV seropositive patient]. / Salmonella enteritidis infiziertes falsches Aneurysma der Arteria femoralis superficialis bei einem HIV-seropositiven Patienten.

In the course of an infection with human immunodeficiency virus, a large variety of complications affecting all organ systems can occur. However, complications affecting the vascular system demanding surgical intervention are rare. In the case presented we report a 67-year-old HIV-seropositive patient who underwent surgery for a huge abscess in the thigh. Intraoperatively unexpectedly we found a mycotic aneurysm of the femoral superficial artery and the causactive bacterium proved to be Salmonella enteritidis. Because of the rising number of HIV-infected patients we suspect that the amount of complications involving the vascular system and demanding surgical intervention will also increase. Therefore, when diagnosing and deciding on therapy for patients with AIDS, the physician must be aware that vascular complications due as a result of HIV infection might occur more frequently in the future.

[Mycotic visceral artery aneurysm: clinical picture, diagnosis, differential therapy, and discussion of the literature]. / Das mykotische Viszeralarterienaneurysma. Klinik, Diagnostik und Differenzialtherapie mit Darstellung der Literatur.

Bacterially infected arterial aneurysms were named mycotic aneurysms by William Osler in 1885 due to their morphology. This rare vascular disease is mainly localized in the femoral artery but also occurs in the aorta and visceral arteries. After the first surgically treated mycotic visceral aneurysm in 1949, we found 36 casuistics in the literature. We report on two patients treated in our department with mycotic visceral aneurysms and discuss the literature concerning topography, differential diagnosis, and surgical management.

[Reconstruction of the inferior vena cava for extended resection of malignant tumors]. / Rekonstruktion der Vena cava inferior zur erweiterten Resektion maligner Tumoren.

OBJECTIVES: Malignant tumor invasion in the inferior vena cava (IVC) has for a long time been the limiting factor in the resection of retroperitoneal tumors. The clinical outcome in these patients depends on vascular surgical techniques, the central role of which is played by IVC reconstruction. METHODS: Within the last 7 years, 9,085 vascular reconstructive procedures were performed in our department. Six patients suffered from retroperitoneal invasion of tumor into the IVC. After tumor resection, the involved IVC segments were replaced by polytetrafluorethylene (PTFE) grafts to restore IVC continuity. In three patients, an adjunctive arteriovenous (AV) fistula was constructed. RESULTS: The graft patency after a mean follow-up of 30.2 months (range 1 to 79) was 83.3%. The only graft occlusion occurred in a patient without AV fistula. There were no perioperative deaths and no major complications demanding reoperation. CONCLUSION: In patients with tumor involvement of the IVC, clinical outcome depends on vascular surgical coprocedure. After resection of the IVC, a PTFE graft should be interposed in combination with an AV fistula. Anticoagulation and CT scan are recommended after 3 months before ligation of the AV fistula.

Gadofosveset-enhanced MR imaging for the preoperative evaluation of potential living kidney donors: correlation with intraoperative findings.

PURPOSE: The purpose of this study was to evaluate the blood pool contrast agent gadofosveset for MR angiography (MRA) of the renal vasculature in living kidney donors (LKD). MATERIALS AND METHODS: Of the 28 consecutive potential LKDs (13 men, 15 women; mean age 55.14 years ± 11.97) initially included in this prospective study, 20 patients underwent surgery and were considered for further evaluation. 7 acquisitions of a 3D T 1-weighted FLASH sequence were performed following administration of gadofosveset for the assessment of the vascular anatomy and collecting system at predefined time points at 1.5 T. All MR exams were prospectively analyzed by 2 radiologists in consensus mode prior to surgery. In addition, ROI-based relative SNR measurements were performed in the vena cava inferior and abdominal aorta. RESULTS: MR image acquisition was completed in all 20 potential living donors. In 8 donors an additional CT scan was available for further comparison with the collateral anatomy, resulting in a total of 28 analyzed kidneys. MRA disclosed 36 renal arteries, since 8 accessory arteries were found in 8 subjects. One accessory artery and one case of fibromuscular dysplasia were missed by MRA. The venous anatomy and the collecting system were assessed correctly with MRI. In addition, MRI diagnosed two renal cell carcinomas. The overall sensitivity and positive predictive value of gadofosveset-enhanced MRI on a per kidney basis were 92.9 % and 100 %, respectively. CONCLUSION: Gadofosveset enables accurate evaluation of potential LKDs.

Fibromuscular dysplasia in living renal donors: still a challenge to computed tomographic angiography.

BACKGROUND: Computed tomographic angiography has become the standard evaluating method of potential living renal donors in most centers. Although incidence of fibromuscular dysplasia is low (3.5-6%), this pathology may be relevant for success of renal transplantation. The incidence of FMD in our population of LRD and reliability of CTA for detecting vascular pathology were the aims of this study. MATERIALS AND METHODS: 101 living renal donors, examined between 7/2004 and 9/2008 by CTA, were included in a retrospective evaluation. The examinations were carried out using a 64 Multi-detector CT (Siemens Medical Solutions, Erlangen). The presence or absence of the characteristic signs of fibromuscular dysplasia, as "string-of-beads" appearance, focal stenosis or aneurysms, were assessed and graded from mild (=1) to severe (=3). Furthermore, vascular anatomy and arterial stenosis were investigated in this study. Retrospective analysis of CTA and ultrasound were compared with operative and histological reports. RESULTS: Four cases of fibromuscular dysplasia (incidence 3.9%) in 101 renal donors were diagnosed by transplanting surgeons and histopathology, respectively. Three cases could be detected by CTA. In one donor even retrospective analysis of CTA was negative. Ten accessory arteries, 14 venous anomalies and 12 renal arteries stenosis due to atherosclerosis were diagnosed by CTA and could be confirmed by the operative report. CONCLUSION: CTA is sufficient for detection of hemodynamic relevant stenosis and vascular anatomy. Only one patient with a mild form of FMD was under estimated. Therefore, if the CTA shows slightest irregularities which are not typical for atherosclerotic lesions, further diagnostic work up by DSA might still be necessary.

[Dignity of carotid body tumors. Review of the literature and clinical experiences]. / Dignität von Glomus-caroticum-Tumoren. Literaturübersicht und klinische Erfahrungen.

INTRODUCTION: Tumors of the carotid body are rare paragangliomas (incidence 0.012%) originating from sympathetic fibres of the carotid bifurcation. Growth is slow and they frequently become symptomatic through local mechanical compression of neighboring vascular and neural structures. The aim of this study is to present the diagnosis, therapy and course in patients with a carotid body tumor treated at our department of the Düsseldorf University Hospital and to discuss rates of recurrence and also dignity during the long-term follow-up. PATIENTS AND METHODS: Included in this retrospective study were all patients treated for a carotid body tumor between January 1988 and June 2008. At follow-up examination the current history was recorded and a physical examination, sonography and duplex sonography were carried out. Furthermore each patient completed the questionnaires QLQ-C30 of the European Organisation for Research and Treatment of Cancer (EORTC) and the module for head and neck QLQ-H&N35 to assess quality of life. RESULTS: In our collective of 36 patients consisting of 13 men (36%) and 23 women (64%) with an average age of 48.33 years (range 17-78 years), 16 patients presented with a local neck swelling and 5 patients each had difficulties swallowing or hoarseness, respectively. Preoperatively Horner's syndrome was found in one patient. A total of 22 tumors were found on the right side of the neck (52.38%), 20 were found on the left side (47.62%) and 6 patients showed a bilateral carotid body tumor (16.67%), 3 of which were bilaterally excised. The other 3 patients are still under surveillance without surgery. Altogether surgery of 39 carotid body tumors was performed in 36 patients. In all 39 cases (primary surgery n=34, recurrence surgery n=5) the tumors were macroscopically excised in toto. Parts of the vagus nerve had to be resected in 3 patients (7.69% Shamblin type II n=1, Shamblin type III n=1) and resection of blood vessels was necessary during 10 operations. The survival rate after 1 year was 100%, after 2 years 96.3% and after 5 years 92.6%. A local recurrence was diagnosed in 2 patients (5.13%). In one patient a second operation was necessary and in the other patient there was a non-progressive swelling in the carotid bifurcation which had existed for 14 years and which was conservatively left untreated. Peripheral neural lesions could be found in 12% (3/25) at long-term follow-up. None of the patients showed evidence of local or remote metastasization of a carotid body tumor. CONCLUSIONS: Surgical extirpation of carotid body tumors can be regarded as the only curative option with an overall mortality of 0%. Morbidity is low when applying vascular surgical techniques (2.56% for central lesions). The incidence of peripheral nervous lesions is high reflecting the radicality of the resection (64.10%) but is outweighed by the benefits. In the long-term follow-up the rate of permanent peripheral neural lesions decreased to 12%. Due to a potentially infiltrating and disseminating growth, carotid body tumors should be regarded as semi-malignant and should therefore be indicated for surgery at the time of diagnosis. Whether the incidence of carotid body tumors will rise due to increased routine diagnostic examination of the head and neck region using sonography and tomography remains to be seen.

Renal cysts in living donor kidney transplantation: long-term follow-up in 25 patients.

INTRODUCTION: The acceptance of a living donor kidney bearing cysts might implicate complications after the transplantation due to the natural history of renal cysts. We have presented our experience with transplantation of living donor kidneys containing cysts but not polycystic disease. PATIENTS AND METHODS: We retrospectively reviewed donor and recipient records of all living kidney transplants performed between January 1997 and April 2008. We analyzed serum creatinine and urea levels, as well as ultrasound scans concerning cyst size and morphology at hospital discharge as well as at 12 and 24 months after transplantation. RESULTS: Among 268 living kidney transplantations, we noted 25 donors with renal cysts. In the computed tomography scan reports, 19 kidneys were described to show a single and six, multiple cysts. The size of 10 single cysts was <5 mm; the other nine were a mean of 17.33 mm. Two of the multiple cyst kidneys had lesions <5 mm; in four kidneys, the mean cyst size was 27.25 mm. The renal function of the recipients was normal or almost normal at discharge with a tendency to lower levels at 12 and 24 months after transplantation. Ultrasound revealed changes in cyst diameter among 6/23 kidneys; the mean diameter increased after 12 months, namely, 8.25 mm to 11.5 mm after 24 months. The subgroup of patients with enlarged cysts showed creatinine and urea levels slightly higher than in the entire group. No aspects of malignancy were found, according to the Bosniak and Israel classification system. One suspicious cyst was tomographically confirmed to be hemorrhagic without any need for treatment. None of the living donors had any problems related to the donor nephrectomy or a need for dialysis due to renal insufficiency in the long term. In addition, the living donors who had even beforehand cystic lesions in their contralateral nonremoved kidney at the time of transplantation did not show complications upon follow-up. CONCLUSIONS: In our study, 25 living donor kidneys carried cysts. Neither cyst-related complications nor dysfunction of the transplanted organs occurred. An unroofing or excision of the cyst was generally not necessary. Regular ultrasound scans and optional computed tomography scans are recommended for follow-up. Based on this experience, we concluded that kidneys presenting cystic diseases should be considered to be suitable for transplantation without a hazard to the recipients, thus extending the pool of organs.

[Functional MRI of transplanted kidneys using diffusion-weighted imaging]. / Funktionelle MRT der Transplantatnieren: klinische Wertigkeit der Diffusionsbildgebung.

PURPOSE: Contrast-enhanced MRI is considered problematic in renal allograft recipients due to the association of gadolinium administration and the development of NSF. Therefore, we assessed the clinical value of mono- and biexponential analysis of diffusion-weighted imaging (DWI). MATERIALS AND METHODS: A total of 32 patients were divided into four groups: (a) patients with stable function of renal allograft for at least 6 months, (b) patients with acute deterioration of allograft function, patients who recently underwent transplantation (< 14 days) with good (c) or decreased (d) renal function. T 2w ax. and T 1w cor. and a diffusion-weighted sequence with 16 b-values (b = 0 - 750 s/mm (2)) were performed on a 1.5 T scanner (Magnetom Avanto, Siemens Medical Solutions). ROI-based analysis of the renal cortex was analyzed using the software "Table Curve 2D". RESULTS: Monoexponential analysis showed an ADC (mono) of 1961 +/- 104 1801 +/- 150, 2053 +/- 169 and 1720 +/- 191 10 (-6)mm (2) /sec for patient group a, b, c and d respectively. The difference in ADC (mono) between group (a) and (b) (p < 0.006) and between group (c) and (d) (p < 0.04) was statistically significant. Biexponential analysis revealed a mean perfusion fraction of 0.21, 0.23, 0.32 and 0.24 for group (a), (b), (c) and (d), respectively. Biexponential ADC showed a higher numerical accuracy. There were no statistically significant inter-group differences in diffusion (ADC (D)) and perfusion (ADC (P)). CONCLUSION: Unenhanced evaluation of renal allografts with DWI is feasible. ADC (mono) of renal cortex correlates with renal function. The significance of the higher numerical accuracy of biexponential analysis in clinical settings requires further evaluation in larger-scale studies.