[Islet transplantation as a treatment for hypoglycemia unawareness syndrome. Evaluation of the pilot program and comparison with pancreas transplantation]. / Transplantace Langerhansových ostruvku v lécbe syndromu poruseného vnímání hypoglykemie. Vyhodnocení pilotního programu a porovnání s transplantací pankreatu.

Islet transplantation (ITx) started in 2005 in IKEM as a potentially safer alternative to pancreas transplantation (PTx), which so far had represented the method of choice in type-1 diabetic patients with conservatively intractable hypoglycemia unawareness syndrome. The aim of the study was to compare these two methods with regard to severe hypoglycemia elimination and to frequency of complications.Up to November 2015 a total number of 48 patients underwent ITx. The results from 22 patients with hypoglycemia unawareness were statistically analyzed. The mean number of transplanted islet equivalents was 12,096 (6,93316,705) IEQ/kg administered percutaneously in local anesthesia under radiological control to the portal vein. 44 patients underwent PTx from 1996. We evaluated glycated hemoglobin(HbA1c), insulin dose, fasting and stimulated C-peptide, frequency of severe hypoglycemia and complications. Medians (interquartile range) were analyzed using the Wilcoxon signed-rank test.One and two years after ITx, HbA1c decreased, C-peptide became significantly positive, insulin dose and frequency of severe hypoglycemia decreased and 18 % of ITx recipients were temporarily insulin-independent. Bleeding was present in 41 % of patients. One year after PTx, 73 % of patients were insulin and hypoglycemia-free, after two years 68 % of patients were insulin and hypoglycemia-free; graftectomy occurred in 20 % of recipients.Both methods led to restoration of insulin secretion and severe hypoglycemia elimination. PTx made more recipients insulin-independent at the cost of serious complications.

Comparison of the effect of stem cell therapy and percutaneous transluminal angioplasty on diabetic foot disease in patients with critical limb ischemia.

BACKGROUND AIMS: The aim of our study was to compare the effect of autologous stem cell therapy (SCT) and percutaneous transluminal angioplasty (PTA) on diabetic foot disease (DFD) in patients with critical limb ischemia (CLI). METHODS: Thirty-one patients with DFD and CLI treated by autologous stem cells and 30 patients treated by PTA were included in the study; 23 patients with the same inclusion criteria who could not undergo PTA or SCT formed the control group. Amputation-free survival, transcutaneous oxygen pressure (TcPO2) and wound healing were assessed over 12 months. RESULTS: Amputation-free survival after 6 and 12 months was significantly greater in the SCT and PTA groups compared with controls (P = 0.001 and P = 0.0029, respectively) without significant differences between the active treatment groups. Increase in TcPO2 did not differ between SCT and PTA groups until 12 months (both Ps < 0.05 compared with baseline), whereas TcPO2 in the control group did not change over the follow-up period. More healed ulcers were observed up to 12 months in the SCT group compared with the PTA and control groups (84 versus 57.7 versus 44.4 %; P = 0.042). CONCLUSIONS: Our study showed comparable effects of SCT and PTA on CLI, a major amputation rate that was superior to conservative therapy in patients with diabetic foot and an observable effect of SCT on wound healing. Our results support SCT as a potential promising treatment in patients with CLI and diabetic foot.

Manometric perfusion test in biliary strictures treatment.

BACKGROUND/AIMS: To assess the biliary manometric perfusion test (BMPT) for evaluating success in treating benign biliary strictures. METHODOLOGY: During 2003 to 2010, 29 patients were subjected to BMPT after percutaneous balloon dilatation treatment. Intrabiliary pressure less than 20cm of water was considered the success threshold. Results of BMPT evaluation were retrospectively compared with a similar group where the standard clinical test was used for evaluating treatment success. The clinical test group included 21 patients treated for biliary strictures from 1994 to 2006. RESULTS: The two groups were statistically similar by age and gender. The BMPT group was tested without complications and pressure inside the biliary tree was less than 20cm of water in 27 of 29 patients. Subsequently, catheters were removed from all 27. Three patients required re-interventions 13 days, 11 months and 32 months later. Kaplan-Meier survival analysis showed that the probability of biliary patency at 3 year was 82.2%. There was no significant difference between groups by this measure (log rank test, p=0.624). CONCLUSIONS: The manometric test is an alternative for evaluating success in treating benign biliary strictures. It is simple, less time-consuming, economical, safe, effective and more comfortable for patients than the clinical test.

Biliary obstruction following transjugular intrahepatic portosystemic shunt placement in a patient after liver transplantation: A case report.

BACKGROUND: Transjugular intrahepatic portosystemic shunt (TIPS) is a method used to decrease portal hypertension. Biliary stricture is the rarest of the complications associated with this procedure with only 12 cases previously reported in the literature. None of these cases have documented the resolution of biliary stenosis induced by a stent graft. The only curative solutions reported are liver transplantation or bypassing the stenosis with an artificial biliary tract using advanced endoscopic techniques. CASE SUMMARY: This is the first reported case of biliary obstruction secondary to TIPS placement in a transplanted liver. In our patient, a portosystemic shunt was created to treat severe veno-occlusive liver graft disease manifesting itself primarily by fluid retention. A cholestatic liver lesion and cholangitis with abscesses developed due to a stent graft-induced stricture in the dorsal segment of the right hepatic duct and the stricture diminished following percutaneous drainage. Endoscopic drainage was performed after unsuccessful removal of the percutaneous catheter resulting in a bilio-cutaneous fistula. Although the liver graft now functions well, the stricture remains refractory even after 44 mo of treatment. CONCLUSION: Biliary strictures caused by TIPS in both transplanted and native livers seem refractory to endoscopic treatment.

[Islet transplantation for treatment of type-1 diabetes mellitus]. / Lécba diabetu transplantací izolovaných Langerhansových ostruvku.

BACKGROUND: Organ pancreas transplantation represents the only method enabling long-term normalization of glucose metabolism in type-1 diabetic subjects so far. Unfortunately, surgical complications of this kind of therapy are still frequent. As a safer alternative, transplantation of isolated pancreatic islets was introduced at the Institute for Clinical and Experimental Medicine as a clinical experiment in the year 2005. METHODS AND RESULTS: We isolated the islets from pancreases of cadaveric donors which did not fulfil criteria to perform organ pancreas transplantation. Altogether, 36 islet implantations were performed in 28 C-peptide negative subjects suffering from type-1 diabetes by August 2010. In 15 subjects (21 implantations) the main indication was extremely instable course of diabetes due to the hypoglycaemia unawareness syndrome. In 5 and 3 cases, combined islet and kidney and islet and liver transplants were performed, respectively. In addition, islet autotransplantation was performed in 5 subjects undergoing total pancreatectomy. No patient died during the study period. In all but 1 patient with primary islet afunction, islet transplantation led to a complete cure of the hypoglycemia unawareness syndrome. Out of 15 patients, 11 subjects in this group showed a significant C-peptide production (> 0.2 pmol/ml) after 1 year. The mean insulin dose after allotransplantation decreased from 37 to 14 units per day and in 3 subjects, insulin therapy could be withdrawn. Serious technical complications occurred in 6 subjects, which only in 2 cases required surgical revision and did not cause long-term sequels. CONCLUSIONS: In comparison with organ pancreas transplantation, pancreatic islet transplantation represents a substantially safer method for restitution of endogenous insulin production. Though it eliminates serious hypoglycemic episodes in labile diabetes, complete insulin withdrawal is still often not possible. However, due to continuing progress in the laboratory techniques as well as in the transplant procedure itself, the results are steadily improving.

[Long-term follow-up of the first 500 liver transplant recipients transplanted at the Institute for Clinical and Experimental Medicine in Prague]. / Výsledky dlouhodobého sledování prvních 500 pacientu po transplantaci jater provedených v institutu klinické a experimentální medicíny v Praze.

BACKGROUND: Between April 1995 and November 2005, 500 liver transplantations were performed in 476 patients of age from 3, till 70, at the Transplantation center of the Institute of Clinical and Experimental Medicine (IKEM) in Prague. The most common indications for liver transplantation were alcoholic liver cirrhosis (23%), hepatitis C cirrhosis (17%), and cholestatic cirrhosis (PBC and PSC, 9% each). Mean MELD score of recipients at the transplantation was 15-18 for each year of transplantation. Ten-years patient survival was 79.1 +/- 2.2%, and graft survival 74.1 +/- 2.1% respectively. Best patient and graft survival was achieved among patients transplanted for autoimmune liver diseases, the worst in group of patients with alcoholic cirrhosis. Malignancies were the most common cause of death during the period of follow-up (17 patients). METHODS AND RESULTS: Patients were followed longitudinally at the Department of hepatogastroenterology IKEM according to prospective protocol included protocol biopsies. Hypertension (in 71% of recipients), and overweight or obesity (in 56.3%), were the most prevalent medical complications among long-term survivors. Diabetes was found in 28.6%, of which 14.7% was de-nove diabetes after transplantation. Renal insufficiency (S-creatinin > 150 micromol/l) was present in 61 of 348 (17.6%) survivors. Out of these, 16 needed chronic hemodialysis, and 12 underwent kidney transplantation subsequently. Protocol biopsy at 5 years after transplantation was evaluated in a sample of 102 unselected liver transplant recipients. Normal liver was found in 4% of recipients, minor non-specific changes in 36% of them. Disease recurrence was present in all of 16 recipients transplanted for HCV cirrhosis, in one third of them graft cirrhosis was already present. Disease recurrence was found in patients transplanted for autoimmune disease frequently, PBC in 40%, PSC in 25%, and autoimmune hepatitis in 60% of recipients. Graft steatosis greater than 33% was present in 13% of recipients. CONCLUSIONS: Liver transplantation is highly effective method of treatment of end stage liver disease. Despite frequent medical complications, and disease recurrence on histological examination almost 80% of recipients transplanted in the liver transplantation program in IKEM survived more than 10 years after procedure. The survival achieved was far above that of the European liver transplant registry.

N-acetylcysteine attenuates iodine contrast agent-induced nephropathy in 5/6-nephrectomized rats.

AIMS: In the present study we tested the efficacy of N-acetylcysteine (NAC) to minimize nephrotoxic effects of iodine contrast agents in intact rats as well as in 5/6-nephrectomized (5/6-Nx) rats. METHODS: Rats were allocated to a group of intact rats (n = 42) and a group of 5/6-Nx rats (n = 42). After 1 month of recovery from surgery, 5/6-Nx rats and intact (sham-operated) animals received either 6 ml/kg body weight (b.w.) meglumine ioxithalamate (Telebrix 350) or 6 ml/kg b.w. iohexol (Omnipaque 350) intravenously with or without pretreatment with 100 mg/kg b.w. NAC. Plasma and urinary concentrations of creatinine, sodium and protein in 24-hour urine collections were determined prior to and on days 1, 3 and 7 after drug administration. RESULTS: In intact animals, contrast agents caused no significant changes in kidney function throughout the duration of the experiment. In contrast, significant increases in plasma creatinine levels and decreases in creatinine clearance were induced by both contrast agents in 5/6-Nx rats. These changes were significantly attenuated by NAC pretreatment. CONCLUSION: The results of the present study demonstrate that iodine contrast agent-induced nephropathy in 5/6-Nx rats is significantly attenuated by intravenous pretreatment with NAC.

Correction to: Interventional Radiological Treatment of Pediatric Liver Transplantation Complications.

In the original article, the following author name was incorrectly published and the corrected name is given below.

Interventional Radiological Treatment of Paediatric Liver Transplantation Complications.

PURPOSE: To assess the efficacy of percutaneous techniques in managing paediatric liver transplantation complications. MATERIAL AND METHODS: We carried out 105 paediatric cadaveric donor liver transplantations at our centre from 2001 to 2018. Percutaneous techniques were used to treat 25 cases involving transplantation complications in 23 patients. Biliary complications were treated in 14 cases (13.3%): 10 patients had bile duct obstruction, and 4 had biliary leaks. Vascular complications were treated in 11 cases (10.5%): 5 hepatic artery (HA) stenoses/occlusions, 2 inferior vena cava (IVC) stenoses, and 1 portal vein (PV) stenosis. Other interventions involved embolisation of the superior mesenteric artery branch to manage gastrointestinal bleeding in 2 patients and embolisation of an arteriobiliary fistula in 1 patient. RESULTS: Biliary: We carried out external-internal drainage and balloon dilatation of stenoses in 12 cases. The external-internal drainage catheter was removed after 6-8 weeks in 7 patients, with the remaining 5 patients with persisting stenosis assigned for retransplantation. We failed to cross anastomotic occlusions in 2 patients before completing the procedures using external drainage; both individuals subsequently underwent retransplantation. Vascular: We performed PTA/stenting of HA stenoses/occlusions in 4 out of 5 patients. After the procedure, all 4 patients showed liver function normalisation. All 3 cases of embolisation were technically and clinically successful. Both IVC and PV stenoses treated with dilatation/stenting were also successful. CONCLUSIONS: Percutaneous techniques used to treat biliary and vascular complications after liver transplantation in paediatric patients are safe and efficient.

Infragenicular stent implantation for below-the-knee atherosclerotic disease: clinical evidence from an international collaborative meta-analysis on 640 patients.

PURPOSE: To report a systematic review of the literature published on the outcomes of stenting for below-the-knee disease in patients with critical limb ischemia (CLI). METHODS: Potentially relevant studies of stent implantation in the infragenicular arteries in >or=5 patients with >or=1-month follow-up were systematically sought in BioMedCentral, ClinicalTrials.gov, The Cochrane Collaboration Register of Controlled Trials (CENTRAL), Google Scholar, and PubMed. Data were abstracted and pooled with a random-effect model to generate risk estimates with 95% confidence intervals (CI). Interaction tests were performed to compare different stent types. A risk of bias assessment was conducted separately, as were appraisals for small study bias, statistical heterogeneity, and inconsistency. RESULTS: Eighteen nonrandomized studies were retrieved comprising 640 patients. After a median follow-up of 12 months, binary in-stent restenosis occurred in 25.7% (95% CI 11.6% to 40.0%), primary patency in 78.9% (95% CI 71.8% to 86.0%), improvement in Rutherford class in 91.3% (95% CI 85.5% to 97.1%), target vessel revascularization in 10.1% (95% CI 6.2% to 13.9%), and limb salvage in 96.4% (95% CI 94.7% to 98.1%). Head-to-head comparisons showed that sirolimus-eluting stents were superior to balloon-expandable bare metal stents in preventing restenosis and increasing primary patency (both p<0.001); sirolimus-eluting stents were also better than paclitaxel-eluting stents in terms of primary patency (p<0.001) and repeat revascularizations (p = 0.014). CONCLUSION: Percutaneous infragenicular stent implantation after failed or unsuccessful balloon angioplasty is associated with favorable clinical results in patients with CLI. Notwithstanding limitations of primary studies, sirolimus-eluting stents appear superior to bare metal and paclitaxel-eluting stents in terms of angiographic and/or clinical outcomes.

Long-term follow-up of renal transplant patients with renal artery stenosis treated by percutaneous angioplasty.

PURPOSE OF THE STUDY: To evaluate if renal angioplasty (PTRA) in patients with transplanted kidney and renal artery stenosis (TRAS) can have long-term effect on hypertension and renal function. MATERIALS AND METHODS: Within a 24-year time period, 58 PTRAs in 55 adults (three times Re-PTRA) with transplanted kidney were performed. The group included 34 males and 21 females, average age 41+/-10.6 (18-72) years. After exclusion of 7 technical failures, 51 PTRAs were followed at 1 week, 6 months and 1-3 years after PTRA. Hypertension improvement was defined as mean arterial pressure (MAP) decrease of at least 15% from the pre-PTRA value. Graft function was evaluated by serum creatinine (Scr) and creatinine clearance (Ccr) levels, and the improvement was defined as a 20% change. Clinical FU was 3 years. RESULTS: PTRA technical success was 88.4%. In 51 kidney recipients at the end of FU, blood pressure improved in 65.2% of patients (MAP decreased from 123+/-13.1 to 107+/-12.1 mmHg), but no patient remained normotensive medication free. Graft function improved in 44.8% of patients and was stabilized in 20.7% of them (average Ccr before PTRA: 0.48+/-0.29, after PTRA: 0.78+/-47 ml/s). PTRA complications were observed in 25.5% of procedures, most often with no clinical sequel. Thirty days mortality was 1.8% (one patient). CONCLUSIONS: PTRA results in kidney recipients are valuable mainly in preserving graft function.

Benefits of Islet Transplantation as an Alternative to Pancreas Transplantation: Retrospective Study of More Than 10 Ten Years of Experience in a Single Center.

BACKGROUND: Pancreas transplantation (PTx) represents the method of choice in type 1 diabetic patients with conservatively intractable hypoglycemia unawareness syndrome. In 2005, the Institute for Clinical and Experimental Medicine (IKEM) launched a program to investigate the safety potential of islet transplantation (ITx) in comparison to PTx. AIM: This study aims to compare the results of PTx and ITx regarding severe hypoglycemia elimination, metabolic control, and complication rate. METHODS: We analyzed the results of 30 patients undergoing ITx and 49 patients treated with PTx. All patients were C-peptide-negative and suffered from hypoglycemia unawareness syndrome. Patients in the ITx group received a mean number of 12,349 (6,387-15,331) IEQ/kg/person administered percutaneously into the portal vein under local anesthesia and radiological control. The islet number was reached by 1-3 applications, as needed. In both groups, we evaluated glycated hemoglobin, insulin dose, fasting and stimulated C-peptide, frequency of severe hypoglycemia, and complications. We used the Mann Whitney test, Wilcoxon signed-rank test, and paired t-test for analysis. We also individually assessed the ITx outcomes for each patient according to recently suggested criteria established at the EPITA meeting in Igls. RESULTS: Most of the recipients showed a significant improvement in metabolic control one and two years after ITx, with a significant decrease in HbA1c, significant elevation of fasting and stimulated C-peptide, and a markedly significant reduction in insulin dose and the frequency of severe hypoglycemia. Seventeen percent of ITx recipients were temporarily insulin-independent. The results in the PTx group were comparable to those in the ITx group, with 73% graft survival and insulin independence in year 1, 68% 2 years and 55% 5 years after transplantation. There was a higher rate of complications related to the procedure in the PTx group. Severe hypoglycemia was eliminated in the majority of both ITx and PTx recipients. CONCLUSION: This report proves the successful initiation of pancreatic islet transplantation in a center with a well-established PTx program. ITx has been shown to be the method of choice for hypoglycemia unawareness syndrome, and may be considered for application in clinical practice if conservative options are exhausted.

Executive summary of the joint position paper on renal denervation of the Cardiovascular and Interventional Radiological Society of Europe and the European Society of Hypertension.

Renal denervation (RDN) was reported as a novel exciting treatment for resistant hypertension in 2009. An initial randomized trial supported its efficacy and the technique gained rapid acceptance across the globe. However, a subsequent large blinded, sham arm randomized trial conducted in the USA (to gain Food and Drug Administration approval) failed to achieve its primary efficacy end point in reducing office blood pressure at 6 months. Published in 2014 this trial received both widespread praise and criticism. RDN has effectively stopped out with clinical trials pending further evidence. This joint consensus document representing the European Society of Hypertension and the Cardiovascular and Radiological Society of Europe attempts to distill the current evidence and provide future direction and guidance.

Primary Whipple disease of the brain: case report with long-term clinical and MRI follow-up.

Whipple disease (WD) is a rare systemic disorder caused by the bacteria Tropheryma whipplei. In its classic form, it manifests with gastrointestinal problems including diarrhea, abdominal pain, and weight loss. However, various other systems can be affected, including the central nervous system (CNS). Even more rarely, the CNS is primarily affected without gastrointestinal symptoms and with a negative small bowel biopsy. The incidence of primary CNS WD is unknown. We report the case of a young female with the primary CNS form of WD. In this report, we highlight the main clinical features and diagnostic procedures that lead to the diagnosis and comment on the treatment and clinical response. We stress the importance of neuroimaging and brain biopsy. A unique feature of this case is that the patient has been followed up for 12 years. At the time of diagnosis, no neurological manifestations were detected, although a tumor-like lesion in the right temporal lobe and hypothalamic infiltration were present on magnetic resonance imaging (MRI). The first neurological manifestations developed 2 years later despite recommended antibiotic treatment, with cognitive impairment developing more than 10 years later. According to the MRI findings and clinical course, the disease was active for several years when multiple lesions on MRI appeared despite antibiotic therapy. In the discussion, we compare the present case with similar cases previously reported and we elaborate on the similarities and discrepancies in clinical features, diagnostic procedures, results, and treatment options.

Nephrostomy in early posttransplantation period in patients with nonfunctional graft and nondilated collecting system.

BACKGROUND: The purpose of our study was to determine whether renal function can be restored by early nephrostomy in patients who fail to develop renal function immediately after transplantation. METHODS: Between 2001 and 2010, we have performed external/internal nephrostomy in 13 patients during the early posttransplant period. The reason for the procedure was graft nonfunction with oliguria/anuria in the presence of normal renal perfusion, absence of signs of rejection, and/or renal collecting system dilation. The nephrostomy was created under ultrasound/fluoroscopic guidance. RESULTS: Nephrostomy was technically successful in all cases. On days 1-3 following nephrostomy creation, 10 of 13 patients showed an increase in diuresis and subsequent graft function development. Once the obstruction had been removed, the graft remained functional for months up to years posttransplantation. Three patients failed to respond to nephrostomy. There were no nephrostomy-related complications. CONCLUSIONS: Our study documents that, in patients who failed to develop graft function posttransplant for unknown reasons, nephrostomy may result in graft function development.

Percutaneous transluminal angioplasty of hepatic artery stenosis in patients after orthotopic liver transplantation: mid-term results.

PURPOSE: This study was designed to present our experience with percutaneous treatment of hepatic artery stenosis in orthotopic liver transplant patients and to evaluate the efficacy, technical outcomes, and mid-term clinical results of the procedure. METHODS: Twenty-two percutaneous transluminal angioplasties (PTAs) were performed in 19 liver transplant recipients at our institution between 1998 and 2010. Stents were placed into the hepatic/celiac artery in 16 PTAs, but balloon dilatation alone was performed in 6 because of the anatomical condition of the vessel. PTA/stenting was indicated in 17 patients because of elevated liver enzymes; 2 patients were asymptomatic. The objective of treating stenosis was prevention of long-term complications, including thrombosis. RESULTS: Technical success was achieved in all patients. There was only one complication: dissection of the treated artery without any subsequent adverse effects. In all patients, elevated liver enzyme levels improved after treatment. No restenosis was observed in any patient during a mean follow-up of 2.6 years (1 month to 5.5 years). CONCLUSIONS: Percutaneous angioplasty/stent placement is a safe method for the treatment of hepatic artery stenosis after orthotopic liver transplantation, with a high technical success rate and promising mid-term results.

Twin valve caval stent for functional replacement of incompetent tricuspid valve: a feasibility animal study.

OBJECTIVE: To evaluate feasibility of a twin valve caval stent (TVCS) for functional replacement of an incompetent tricuspid valve (TV) in an acute animal study. METHODS: One swine and three sheep were used in the study. TVCS placement was tested in a swine with a normal TV. TVCS function was tested in three sheep with TV regurgitation created by papillary muscle avulsion. Cardiac angiograms and pressure measurements were used to evaluate TVCS function. Two sheep were studied after fluid overload. RESULTS: TVCS was percutaneously placed properly at the central portions of the superior vena cava (SVC) and inferior vena cava (IVC) in the swine. Papillary muscle avulsion in three sheep caused significant tricuspid regurgitation with massive reflux into the right atrium (RA) and partial reflux into the SVC and IVC. TVCS placement eliminated reflux into the SVC and IVC. After fluid overload, there was enlargement of the right ventricle and RA and significant increase in right ventricle, RA, SVC, and IVC pressures, but no reflux into the IVC and SVC. CONCLUSION: The results of this feasibility study justify detailed evaluation of TVCS insertion for functional chronic replacement of incompetent TV.

Treatment of venous aortorenal bypass graft aneurysm using a stent-graft.

We present the case of a 77-year-old male patient who had undergone a bilateral venous aortorenal bypass graft 30 years previously. Thirteen years previously, the patient was shown to have a decrease in renal function, with mild shrinking of both kidneys; additionally, a stenosis was found in the left proximal anastomosis. At the most recent follow-up visit (1 year previously), ultrasound revealed an aneurysm (42 mm in diameter) of the left renal bypass graft; the finding was confirmed by CT angiography. A significant ostial stenosis of the left renal bypass graft was also confirmed. It was decided to place a self-expandable stent-graft into the aneurysm while also attempting to dilate the stenosis. Proximal endoleak after stent-graft placement necessitated the implantation of another, balloon-expandable stent-graft into the bypass graft ostium. Postprocedural angiography and follow-up by CT angiography at 3 months confirmed good patency of the stent-grafts and complete thrombosis of the aneurysmal sac, with preserved kidney perfusion. Renal function remained unaltered, while the hypertension is better controlled.

Magnetic resonance imaging of pancreatic islets transplanted into the liver in humans.

BACKGROUND: In vitro labeling of pancreatic islets by iron nanoparticles enables their detection as hypoitnense spots on serial magnetic resonance (MR) images. We report the first results of a pilot trial aiming to test the feasibility and safety of this technique in humans. METHODS: Islets were labeled in culture with 5 µL/mL ferucarbotran for 6 to 48 hr and transplanted into the portal vein (12 infusions) in 8 C-peptide negative recipients. The liver area was examined the next day and 1, 4, and 24 weeks posttransplant using a 3T MR scanner. RESULTS: In all recipients, significant C-peptide levels and near-normal HbA1c values were achieved with 50% to 80% insulin dose reduction. No side effects related to the labeling procedure were documented. Typically, a significant islet spot number decrease (on average 60%) was detected at week 1 with subsequent only slight decrease for up to 24 weeks. In two subjects with labeling period of less than 6 and 10 hr, only few islet spots were detected corresponding to poor islet visualization in phantoms labeled for the same period of time. CONCLUSION: Pancreatic islets (PI) visualization was safe and successful in all recipients but was less efficient if labeling period was less than 16 hr. Significant decrease of islet spots occurred at week 1, suggesting early islet destruction or impaired engraftment. Afterward, the islet spot numbers remained stable for up to 24 weeks. Data show that MR detection of ferucarbotran-labeled islets enables their long-term noninvasive visualization and correlates with sustained C-peptide production.