Biomedical subjects

Diego Miotto

Publications and source records attributed to Diego Miotto.

14 recordsLinked to original sources

PubMed2006

Dynamic testing with high-dose adrenocorticotrophic hormone does not improve lateralization of aldosterone oversecretion in primary aldosteronism patients.

OBJECTIVE: Diagnosing aldosterone-producing adenoma (APA) involves a demonstration of the lateralization of aldosterone oversecretion because adrenal incidentalomas are common in hypertensive individuals and many small-sized APA escape identification with available imaging techniques. However, because of the pulsatile pattern of aldosterone secretion this can be a difficult undertaking. Stimulation of aldosterone secretion before adrenal vein sampling (AVS) can overcome this difficulty, but anecdotal data exist. We, therefore, prospectively investigated the usefulness of AVS with dynamic testing in primary aldosteronism (PA) patients. METHODS: We enrolled 24 consecutive consenting patients with a biochemical diagnosis of PA from a tertiary referral centre to measure the effects of adrenocorticotrophic hormone (ACTH) on selectivity, the lateralization of aldosterone secretion to the APA side, and adverse effects. After correcting the hypokalemia we performed bilateral AVS. After 3 h supine resting, blood was simultaneously obtained from both sides. A high-dose ACTH (250 mug intravenous) bolus was then administered and AVS was repeated after 30 min. RESULTS: AVS was bilaterally selective in 88% of patients; no adverse effects occurred. Of the 21 patients with bilaterally selective AVS, three had idiopathic hyperaldosteronism and 18 an APA that was surgically removed in 12 with an ensuing fall in blood pressure at follow-up. After ACTH patients showed a significant increase (P = 0.007) of aldosterone from contralateral adrenal vein blood, but not from the APA gland. Therefore, lateralization of aldosterone secretion on the APA side did not improve. CONCLUSION: AVS is safe and accurate for identifying APA. However, at a statistical power of 99%, these results do not support the usefulness of high-dose ACTH testing to improve the diagnostic accuracy of AVS.

Adenoma↗

PubMed2006

Double vena cava filter insertion in congenital duplicated inferior vena cava: a case report and literature review.

The complex embryogenesis of the inferior vena cava (IVC) may result in several anomalies, often presenting as an incidental radiological finding. In addition to the differential diagnosis with pathological lesions, recognizing IVC defects is crucial for invasive procedures. This report describes a patient with a right femoral vein thrombosis who could not be given anticoagulant therapy due to a concomitant acute cerebral hemorrhage. He was found to have an asymptomatic duplicated IVC with interiliac communication. A filter had to be inserted in each vena cava to prevent pulmonary embolism. A review of the literature dealing with the few reported cases of filter insertion in congenital duplicated IVC is presented.

Aged, 80 and over↗

PubMed2005

Arterio-venous gradient of endothelial progenitor cells across renal artery stenosis.

A role for circulating progenitor cells have been recently demonstrated in many pathological conditions. Endothelial progenitor cells (EPCs) localize at sites of ischemia and stimulate neovasculogenesis. This small study was carried out to assess whether selective blood sampling during renal angiography could demonstrate an arterio-venous gradient of EPCs in 5 patients with renal artery stenosis. Surprisingly, we found that EPCs were more abundant in venous than in arterial blood, suggesting that the kidney subjected to chronic ischemia may become a source rather than a target of EPCs.

Endothelium, Vascular↗

PubMed2005

Isolated hepatocyte transplantation for Crigler-Najjar syndrome type 1.

Crigler-Najjar syndrome type 1 (CN1) is an inherited disorder characterized by the absence of hepatic uridine diphosphoglucuronate glucuronosyltransferase (UDPGT), the enzyme responsible for the conjugation and excretion of bilirubin. We performed allogenic hepatocyte transplantation (AHT) in a child with CN1, aiming to improve bilirubin glucuronidation in this condition. A 9-year-old boy with CN1 was prepared with plasmapheresis and immunosuppression with prednisolone and tacrolimus. When a graft was made available, 7.5 x 10(9) hepatocytes were isolated and infused into the portal vein percutaneously. After 2 weeks phenobarbitone was added to promote the enzymatic activity of UDPGT of the transplanted hepatocytes. Nocturnal phototherapy was continued throughout the studied period. Total bilirubin was considered a reliable marker of allogenic cell function. There was no significant variation of vital signs nor complications during the infusion. Mean +/- SD bilirubin level was 530 +/- 38 micromol/L before and 359 +/- 46 micromol/L after AHT (t-test, p < 0.001). However, the introduction of phenobarbitone was followed by a drop of tacrolimus level with increase of alanine aminotransferase (ALT) and increase of bilirubin. After standard treatment of cellular rejection bilirubin fell again but from then on it was maintained at a greater level. After discharge the patient experienced a further increase of bilirubin that returned to predischarge levels after readmission to the hospital. This was interpreted as poor compliance with phototherapy. Only partial correction of clinical jaundice and the poor tolerability to nocturnal phototherapy led the parents to refuse further hepatocyte infusions and request an orthotopic liver transplant. After 24 months the child is well, with good liver function on tacrolimus and prednisolone-based immunosuppression. Isolated AHT, though effective and safe, is not sufficient to correct CN1. Maintenance of adequate immunosuppression and family compliance are the main factors hampering the success of this procedure.

Child↗

PubMed2004

Bone fractal analysis.

Fractal analysis is a quantitative method used to evaluate complex anatomic findings in their elementary component. Its application to biologic images, particularly to cancellous bones, has been well practiced within the past few years. The aims of these applications are to assess changes in bone and the loss of spongious architecture, indicate bone fragility, and to show the increased risk for fracture in primary or secondary osteoporosis. The applications are very promising to help complete the studies that can define bone density (bone mineral density by dual energy x-ray absorptiometry or quantitative computed tomography), and also have the capacity to distinguish the patients with a high or low risk for fracture. Their extension to the clinical fields, to define a test for fracture risk, is still limited by difficult application to the medical quantitative imaging of bones, between correct application at superficial bones and unreliable application to deep bones. The future evolution and validity do not depend upon fractal methods but upon well-detailed imaging of the bones in clinical conditions.

Absorptiometry, Photon↗

PubMed2004

Hypoxic antiblastic stop-flow limb perfusion: clinical outcome and pharmacokinetic findings of a novel treatment for in transit melanoma metastases.

Hypoxic antiblastic stop-flow perfusion (SFP) has recently been proposed as a therapeutic option for patients with locally advanced tumors. We report on the clinical and pharmacological results of our prospective study of limb SFP for the treatment of in transit melanoma metastases. Twenty-three patients with limb-sited melanoma metastases were treated with melphalan (10 mg/l) based pelvic (n=11, group A) or femoral (n=12, group B) SFP under hypoxic conditions. Systemic and locoregional toxicity, tumor response rate, and local progression-free survival were analyzed. Melphalan concentrations were measured in the perfusate and systemic circulation during SFP, and after 30-min hemofiltration. Perfusate-to-plasma leakage was assessed using a scintigraphic method. No postoperative deaths occurred. Mild locoregional toxicity was observed in 5 patients (18%), and systemic toxicity was mild to severe in 8 patients (30%), the incidence being higher in group A. Tumor response rate (complete + partial response) and time to local disease progression were significantly different in group A and B (9% vs 58% and 7 vs 13 months, respectively). The pharmacokinetic study showed that pelvic SFP was associated with a higher leakage rate and a lower area under the curve ratio than femoral SFP (44% vs 31% and 5.6 vs 9.8, respectively). Limb SFP is a feasible and relatively simple procedure. Toxicity and tumor response rates strictly depend upon drug leakage control. Further efforts should be made to exploit the potential anti-tumor activity of this novel locoregional drug delivery system.

Aged↗

PubMed2003

Hypoxic pelvic and limb perfusion with melphalan and mitomycin C for recurrent limb melanoma: a pilot study.

Hypoxic pelvic and limb perfusion by means of a balloon occlusion technique was evaluated in patients with recurrent melanoma of the lower limbs who were non-responders to isolated hyperthermic limb perfusion or who were not eligible for this procedure. A pilot study was performed in 17 patients, who underwent hypoxic pelvic and limb perfusion with 50 mg/m(2) of melphalan or 50 mg/m(2) of melphalan and 25 mg/m(2) of mitomycin C. Each procedure was followed by haemofiltration. A leakage monitoring study was performed in five of the 17 patients. The response rate and time to disease progression were the primary endpoints, with overall survival as the secondary endpoint. During the procedures there were no technical, haemodynamic or vascular complications, and no deaths occurred during surgery or in the postoperative period. Significant leakage (median 40%) was measured in the five patients studied. No severe systemic or regional toxicity was observed. After one course of treatment, the objective response rate was 47% (95% confidence interval 22.5-71.5%), the median time to disease progression was 10 months (range 2-40 months), and the 3 year overall survival was 20%. Hypoxic pelvic and limb perfusion seems to be a safe and effective treatment for patients with unresectable recurrent limb melanoma who are not eligible for isolated hyperthermic limb perfusion. Due to the non-homogeneity of the study, with some patients receiving a combination of melphalan and mitomycin C and others receiving only melphalan, it is not possible to make definite conclusions with regard to efficacy. Further studies are necessary to establish whether the response rates can be improved by using different drug regimens.

Adult↗

PubMed2003

Morphological and functional modifications of the aneurysm-endograft complex following endoluminal exclusion in 30 consecutive cases.

Data from 30 consecutive excluded abdominal aortic aneurysms (AAA) have been analysed, to verify whether important morphological changes take place after exclusion, and whether these can be considered as risk factors for functional (leaks, flow alterations) and clinical complications (rupture, obstruction). All AAAs have been initially successfully excluded and patients have been followed up by clinical examinations and ct scan controls post-operatively, at the third and sixth month, then yearly. At a mean follow-up of 17 months, dimension of the proximal neck increased significantly (> 2 mm in diameter) in five pts and graft was distally dislodged in two. Maximum aneurysm diameter reduced significantly (at east 10% than originally) in half of the case and more than 25% in 10% of cases. Four AAAs presented an initial increase, that reduced only in two. Calculation of length of the AAA was unreliable due to tortuosity. Two secondary type II leaks and one secondary type III leak were observed associated to stable or slightly increased AAA diameter (the latter patient suddenly died probably for miocardial infarction, but a rupture could not be formally excluded). Marked tortuosity of the graft was seen in five patients, all associated with frank shrinkage of the aneurysmal sac. Parietal thrombosis without explanation was observed in five, and in one progressed to obstruction of an iliac branch. Two pts needed anticoagulation. These data indicate that endoluminal aneurysm exclusion can not be considered as a definitive solution, for long-term outcome is unforeseeable in a number of patients.

Adult↗

PubMed2002

Arteroportal fistulas between the accessory right hepatic, gastroduodenal and superior mesenteric arteries and portal vein: a difficult technical problem to overcome in liver transplantation.

BACKGROUND: Fistulous communications between the accessory right hepatic (ARHA), gastroduodenal (GD), and superior mesenteric (SMA) arteries and the portal vein (PV) may represent a contraindication for liver transplantation (LT). MATERIAL: A patient with HCV-related liver cirrhosis and progressive liver decompensation underwent preoperative LT work-up. Doppler ultrasound (DU), Angiography and MRI revealed arteroportal fistulas (APF) and diversion of mesenteric-splenoportal flow through spontaneous splenorenal shunts (SSRS) in the systemic circulation. The patient was transplanted and the ARHA and GDA were distally sectioned; the HA was anastomosed to the donor HA; the superior mesenteric vein (SMV) was detached from the splenopancreatic venous bed by sectioning and ligating the Henle trunk, by ligating an posterior-inferior pancreatic vein and, finally, by positioning an iliac vein interposition graft between the SMV and the donor PV. The postanastomotic SMV trunk and recipient PV were ligated below and above the pancreatic head, respectively. RESULTS: Reperfusion and late liver function were good. DU and MRI studies showed an effective portal flow and the maintenance of a normal splenopancreatic vein outflow through the SSRS. DISCUSSION: APF represent a serious clinical problem, particularly in patients who need LT. The persistence of arterial flow into the PV is dangerous for the long-term liver function. A particular surgical strategy, strictly tailored to the hemodynamic conditions, has to be planned. CONCLUSIONS: Extrahepatic multiple APF would no longer to represent a contraindication to LT, although this claim needs to be confirmed in the light of further experience and a longer-term follow-up.

Arteriovenous Fistula↗

PubMed2002

Deliberate hypoxic pelvic and limb chemoperfusion in the treatment of recurrent melanoma.

BACKGROUND: The treatment of patients with advanced or recurrent pelvic melanoma, which are often associated with lesions in the lower limbs, is still unsatisfactory and controversial. A simplified hypoxic pelvic and limb perfusion has been recently recommended to provide therapeutic options for palliation and possibly cure. METHODS: A nonrandomized and noncontrolled phase II experimental study was performed in 11 patients with symptomatic unresectable recurrent melanoma of the pelvis and limb. Patients were submitted to hypoxic pelvic and limb perfusion with 25 mg/m(2) of melphalan, 50 mg/m(2) of cisplatin, 300 mg/m(2) of dacarbazine, and 75 mg/m(2) of epirubicin by means of a simplified balloon occlusion technique. Response rate and time to disease progression were the primary endpoints; overall survival was the secondary endpoint. RESULTS: During the procedures there were no technical, hemodynamic, or vascular complications, and no deaths occurred during surgery or in the postoperative period. Response rate was 82% (95% confidence interval, 58% to 100%). Median time to disease progression was 12 months (range 9 to 30 months). Three-year overall survival was 34%. CONCLUSIONS: Hypoxic pelvic and limb perfusion is a safe and good palliative treatment for patients with unresectable recurrent melanoma. Further studies are necessary to to confirm these data and to establish if refinements can be made with acceptable toxicity.

Adult↗

PubMed2002

Cavoportal hemitransposition: a successful way to overcome the problem of total portosplenomesenteric thrombosis in liver transplantation.

Orthotopic liver transplantation (OLT) may be feasible even in the presence of diffuse portal vein thrombosis (PVT) in the recipient, providing hepatopetal portal flow to the graft can be ensured. Cavoportal hemitransposition was used in selected cases in which no other salvage solutions were technically possible. We report our experience of two patients with diffuse thrombosis of the entire portal system. One patient also had thrombosis of a previous portacaval shunt with a synthetic interposition graft. Portal pedicle dissection and native hepatectomy (with or without vena cava removal) appeared difficult. Bleeding from the exposed area was severe, and in one case, a new laparotomy was necessary to stop the abdominal hemorrhage. The postoperative course was complicated by severe ascites (with fluid infection and surgically drained suprahepatic abscess in one case), renal insufficiency (requiring dialysis in one case), esophagogastric variceal bleeding (needing several sessions of endoscopic treatment), and bronchopneumonic infections (in one case, superinfection with Aspergillus fumigatus despite amphotericin B lipid complex therapy led to the patient's death from multiorgan failure). Our experience was compared with 17 other cases in the literature. Etiologic factors, preoperative diagnostics, surgical problems, and postoperative complications are focused on and discussed. Diffuse PVT no longer appears to be an absolute contraindication to OLT, although cavoportal hemitransposition needs further experience and long-term follow-up.

Anastomosis, Surgical↗

PubMed2002

Renal vein renin measurements accurately identify renovascular hypertension caused by total occlusion of the renal artery.

OBJECTIVE: To assess the usefulness of indexes derived from renal vein renin measurements. DESIGN: A 12-year prospective study. SETTING: A tertiary institutional referral centre. PATIENTS AND METHODS: Between 1988 and 2000, we studied 152 consecutive hypertensive patients with a high pre-test probability of renovascular hypertension (RVH). RVH was diagnosed retrospectively on the basis of reduction in blood pressure after correction of ischaemia at follow-up. Renal vein renin measurements were used to calculate the ratios: Visch/Vctl (renal vein renin ratio; RVRR); Vctl/Viivc; (Visch - Viivc)/Viivc; (Vctl - Viivc)/Viivc, where Visch and Vctl indicate plasma renin activity (PRA) in the ischaemic and contralateral renal veins, respectively, and Viivc denotes PRA in the infrarenal inferior vena cava. A receiver operator characteristics (ROC) curve analysis was used to determine the cut-off value of renal vein renin measurement indexes that provided the best discrimination between patients with and without RVH and to identify patients with RVH caused by total occlusion of the renal artery. RESULTS: Sixty-seven patients were diagnosed as having RVH: 51 had significant renal artery stenoses (RVH non-occluded) and 16 had total renal artery occlusion (RVH occluded). Of the remaining 85 patients in whom RVH was excluded (non-RVH group), 27 had reno-parenchymal hypertension and 58 had essential hypertension. Of the renal vein renin measurement indexes, only RVRR and (Visch - Viivc)/Viivc in RVH-occluded patients differed significantly (P < 0.005) from those in the non-RVH group and showed the best performance by ROC curve analysis. This analysis also showed that, at any cut-off value, RVRR was far more accurate for identification of RVH-occluded patients than for identification of RVH non-occluded patients, both in the subgroup with unilateral and, even more so, in those with bilateral renal artery lesions. The best trade-off between sensitivity and false-positive rate was provided by cut-off values of 1.55 and 1.70 of the RVRR for identification of non-occluded and occluded RVH, respectively. CONCLUSIONS: RVRR is more useful for establishing an indication for nephrectomy in patients with renal artery occlusion than for identifying those patients with renal artery stenosis who will benefit from revascularization. In patients with RVH with bilateral renal artery lesions, lateralization of renin secretion occurs only in the presence of total renal artery occlusion. Different cut-off values are necessary for identification of non-occluded and occluded RVH.

Adolescent↗

PubMed2002

Twin pregnancy following endoluminal exclusion of an iliac arteriovenous fistula.

PURPOSE: To demonstrate the sustained efficacy of stent-graft exclusion of a pelvic arteriovenous fistula (AVF) in a woman who became pregnant after treatment. CASE REPORT: An iatrogenic iliac arteriovenous fistula caused by redo surgery for a herniated disk in a 23-year-old woman was successfully treated with percutaneous endoluminal exclusion. Intravascular ultrasound was particularly useful for localization of the fistula during the procedure. The patient subsequently became pregnant, and serial Doppler studies were used to monitor the stent-graft until the uneventful delivery of twins by Caesarian section. At 36 months after endograft implantation, the patient has no complaints relative to the device. CONCLUSIONS: Uncomplicated twin pregnancy following stent-graft repair of an AVF in the pelvis appears feasible.

Adult↗

PubMedDate not supplied

Preoperative selective portal vein embolization (PSPVE) before major hepatic resection. Effectiveness of Doppler estimation of hepatic blood flow to predict the hypertrophy rate of non-embolized liver segments.

Hepatocellular carcinoma may be unresectable for volumetric reasons. The future remaining liver after hepatectomy might be too small to ensure survival. Preoperative selective portal vein embolization of the tumorous lobe can induce hypertrophy of the future remaining liver and enable safer surgery. A 76-year-old patient with hepatocellular carcinoma needed right lobectomy however, the future remaining liver was judged insufficient to ensure an uneventful postoperative course. The left lobe to whole liver volumetric ratio was to small (29.7%) and a preoperative selective portal vein embolization of the right portal branch via a percutaneous, transhepatic, contralateral approach was performed without side effects. A Doppler estimation of left branch portal blood flow and velocity was carried out before and after preoperative selective portal vein embolization. After 21 days the left lobe volume increased by about 44.2% with a safe left lobe/whole liver ratio of 40.8%. The portal blood flow and portal blood flow velocity showed an increase of 253% and 122%, respectively. A right lobectomy was performed without complications. Three months later, computed tomography scan showed no hepatocellular carcinoma recurrence. Preoperative selective portal vein embolization is a safe technique which can enable major hepatectomy to be performed in situations otherwise judged unresectable for a life-threatening volumetric insufficiency. The portal blood flow and portal blood flow velocity evaluations can easily predict the hypertrophy rate of non-embolized liver segments.

Aged↗