Artifact removal algorithms for stroke detection using a multistatic MIST beamforming algorithm.

Microwave imaging (MWI) has been recently proved as a promising imaging modality for low-complexity, low-cost and fast brain imaging tools, which could play a fundamental role to efficiently manage emergencies related to stroke and hemorrhages. This paper focuses on the UWB radar imaging approach and in particular on the processing algorithms of the backscattered signals. Assuming the use of the multistatic version of the MIST (Microwave Imaging Space-Time) beamforming algorithm, developed by Hagness et al. for the early detection of breast cancer, the paper proposes and compares two artifact removal algorithms. Artifacts removal is an essential step of any UWB radar imaging system and currently considered artifact removal algorithms have been shown not to be effective in the specific scenario of brain imaging. First of all, the paper proposes modifications of a known artifact removal algorithm. These modifications are shown to be effective to achieve good localization accuracy and lower false positives. However, the main contribution is the proposal of an artifact removal algorithm based on statistical methods, which allows to achieve even better performance but with much lower computational complexity.

A single-center analysis to evaluate kidney function parameters after liver transplantation in adult patients.

Severe renal dysfunction may occur after orthotopic liver transplantation (OLT). In this study, we retrospectively analyzed a single-center series of adult liver recipients (n = 62) seeking to identify patients prone to develop renal dysfunction during follow-up. Liver recipients (age range, 53.54 ± 8.19 years; female/male: 21/41) who underwent a first OLT from a brain dead donor were enrolled according to strict criteria. We enrolled only liver recipients with 5 serum creatinine (SCr) measurements after hospital discharge and at least 1 measurement/year with a follow-up period of not less than 2 years. We estimated glomerular filtration rate (eGFR) using the formula developed by the Mayo Clinic. The average rate of SCr change after OLT was 0.0065 ± 0.013 mg/dL/mo. By calculating the per-patient slope, the average rate of SCr change was 0.000165 ± 0.000383 mg/dL (0.000007 ± 0.000017 mg/dL/mo). In regression models evaluated with SCr as the dependent variable versus post-OLT time, no significance was observed (P = .130). The average rate of eGFR change after OLT was -0.462 ± 0.883 mL/min/mo. By calculating the per-patient slope, the average rate of eGFR change was -0.009 ± 0.0026 mL/min (-0.0004 ± 0.0012 mL/min/mo). In the regression models evaluated with eGFR as dependent variable versus post-OLT time, no significance occurred (P = .168). By applying the regression prediction to SCr at 3 to 5 versus the 1 to 2 post-OLT measurements, we noted 3 male liver recipients (MLR) whose SCr values were significantly higher than the predicted values: MLR1: P = .048 at measurement 4; MLR2: P = .019 at measurement 4; and MLR3: P = .017 at measurement 5. Conversely, we did not observed a significant difference between observed versus predicted eGFR values. Clinical decisions on immunosuppressive treatments for liver recipients should be determined also on the basis of the series of post-OLT kidney function, which should be studied with rigorous evaluation of fitted regression models.

Percutaneous embolization of periduodenal varix due to portal hypertension in a patient with kidney-pancreas transplantation: a case report.

Kidney-pancreas transplantation is a valid therapeutic option for patients with insulin-dependent diabetes mellitus. However, vascular complications associated with pancreas transplantation are not uncommon. Herein we have reported a 32-year-old woman with a history of insulin-dependent diabetes mellitus and celiac disease. She underwent liver transplantation for acute hepatitis. After 7 years, the patient developed end-stage kidney disease beginning hemodialysis and being listed for a kidney-pancreas transplantation, which was successfully performed when she was 29 years old with enteric diversion (Roux intestinal loop reconstruction). Five years after kidney-pancreas transplantation, she was admitted to our hospital with serious intestinal bleeding and poor liver function. The ultrasound showed a pattern like a arteriovenous fistula near the head of the pancreas. Computed Tomography was not diagnostic; an arteriogram showed the presence of a mesenteric varix and a mesenteric-caval shunt through the duodenum of the pancreatic graft. The liver biopsy and portal pressure gradient showed portal hypertension and liver cirrhosis. To obtain time a waiting a new liver, the patient underwent percutaneous embolization of the mesenteric varix through jugular access. The procedure was uneventful. The patient was successfully transplanted 2 months later. Pancreas function was always satisfactory.

Biochemical and morphologic effects after extended liver resection in rats: preliminary results.

After hepatic resection and transplantation with a partial graft, death and regeneration of the hepatocytes coexist in the liver. However, when the functional liver mass is inadequate to ensure a proper balance between regeneration vs functional and metabolic demands, small-for-size syndrome develops. We assessed the early effects of extended hepatic resection on liver function in a rat model. Six male Sprague-Dawley rats underwent 80% resection of the liver, and 6 rats served as a control group. At 6 hours after resection, blood samples were obtained from the hepatic vein for measurement of reduced glutathione (GSH), oxidized glutathione (GSSG), and hepatic venous oxygen saturation (Shvo(2)), and for standard liver function tests including determination of concentrations of alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyl transpeptidase, and total bilirubin. The remnant lobe was removed for GSH assay and histopathologic analysis. In the resection group, values were significantly higher for ALT (P = .002), AST (P = .002), and Shvo(2) (P = .01), whereas a significant decrease was observed for blood GSH (P = .009) but not liver GSH. Also in the resection group, we observed characteristic hepatocyte vacuolization with a gradient from periportal acinar zone 1 to the centrolobular area, the presence of hemorrhagic necrosis, and several leukocyte adhesions. The Shvo(2) and GSH data suggest early alteration of oxygen metabolism, as demonstrated by the reduction in oxygen uptake and decreased liver GSH secretion, with preservation of hepatic GSH. Mitochondrial dysfunction and oxidative injury seem to have a crucial role in early onset of liver damage.

A 20-year period of orthotopic liver transplantation activity in a single center: a time series analysis performed using the R Statistical Software.

In many Western countries a "minimum volume rule" policy has been adopted as a quality measure for complex surgical procedures. In Italy, the National Transplant Centre set the minimum number of orthotopic liver transplantation (OLT) procedures/y at 25/center. OLT procedures performed in a single center for a reasonably large period may be treated as a time series to evaluate trend, seasonal cycles, and nonsystematic fluctuations. Between January 1, 1987 and December 31, 2006, we performed 563 cadaveric donor OLTs to adult recipients. During 2007, there were another 28 procedures. The greatest numbers of OLTs/y were performed in 2001 (n = 51), 2005 (n = 50), and 2004 (n = 49). A time series analysis performed using R Statistical Software (Foundation for Statistical Computing, Vienna, Austria), a free software environment for statistical computing and graphics, showed an incremental trend after exponential smoothing as well as after seasonal decomposition. The predicted OLT/mo for 2007 calculated with the Holt-Winters exponential smoothing applied to the previous period 1987-2006 helped to identify the months where there was a major difference between predicted and performed procedures. The time series approach may be helpful to establish a minimum volume/y at a single-center level.

Preliminary results of liver transplantation for hepatocellular carcinoma among allocation organ policy strategies, neoadjuvant treatments, and intention-to-treat analysis.

We retrospectively evaluated the impact of our strategy for patients with hepatocellular carcinoma (HCC) according to an intention-to-treat analysis and drop-out probability. We evaluated only patients within the Milan criteria. We analyzed the outcomes of neoadjuvant strategies for HCC, organ allocation policy, and systematic application of strategies to increase the deceased donor pool as the current tendency to expand transplantability criteria for those patients. Kaplan-Meier survival probability rates at 1, 3, and 5 years according to an intention-to-treat analysis were 87.02%, 74.53%, and 65.93% for transplanted patients (n=108), and 50%, 14.29%, and 14.29% for the excluded or waiting list group (n=13), respectively (P< .0001). Drop-out risk at 3, 6, and 12 months was 2.40%, 8.59%, and 16.54%, respectively. During the same period, the mortality probability rates at 3, 6, and 12 months among patients without HCC awaiting orthotopic liver transplantation (OLT) were 3.60%, 9.50%, and 18.34%, respectively. Drop-out rate was lower among patients treated before OLT (P< .0001). On the basis of the neoadjuvant treatment results to reduce drop-out risk, we suggest avoiding the high priority for the HCC cohort, particularly within the first 6 months from entrance on the waiting list, because this approach can reduce the chances of patients with end-stage liver disease (ESLD) alone.

Introducing ultrasound-guided vein catheterization into clinical practice: A step-by-step guide for organizing a hands-on training program with inexpensive handmade models.

INTRODUCTION: Central vein catheterization (CVC) plays a central role in hospital patient management. Compared with the use of traditional anatomical landmarks, ultrasound-guidance is associated with higher CVC success rates, fewer complications, and more rapid central venous access. The use of US-guided CVC in clinical practice has not become widespread, largely because anesthesiology and general surgery residents receive limited training in this technique. To increase the use of US-guided CVC in our surgical department, we organized a hands-on training program based on the use of handmade models. METHODS: Three different models were constructed using plastic food-storage containers, segments of rubber tourniquet and silastic tubing (to simulate vessels), and agar gelatin. RESULTS: The hands-on training course allowed progressive acquisition of the basic hand-eye coordination skills necessary for performing US-guided venipuncture. The overall cost for each model was less than €5.00. DISCUSSION: The models described in this report are useful tools for teaching US-guided CVC. Thanks to their low-cost, they can be widely used to facilitate the introduction of this technique in clinical practice.

[Cystic lymphangioma of the adult: our experience and review of literature]. / Linfangioma cistico dell'adulto: nostra esperienza e revisione della letteratura.

Cystic lymphangioma is an uncommon benign pathology, usually reported in children, rarely in adult. Its embryopathogenesis is still controversial: it seems to arise from the lymphatic vessels, mainly in the cervico-cranial district. It is macroscopically characterised by multiple cystic non-communicating concamerations. Definitive diagnosis used to be intraoperative and was usually an unexpected finding. Nowadays, with modern imaging technologies, CT and MRI, diagnosis can be assumed before intervention even though certain diagnosis can still be reached only with histological examination. Imaging techniques can help for a precise mapping of the lesion and definition of its limits with the other structures, improving therapeutic success. Various therapeutical options are reported in literature, but complete surgical excision is still considered the best approach and the most successful. The Authors report their experience and review the literature on cystic lymphangioma in adult.

Split liver transplantation in Italy.

The role of split liver transplantation has been well established. The limitation to this technique is the number of potential recipients for a left lateral segment graft. The optimal use of the donor pool is to split the liver to provide 2 grafts suitable for adults obtaining right or left lobe. We explored the potential increase in the number of liver grafts gained from systematically using the technique of splitting on national basis. The crucial factor appeared to be creation of guidelines for the use of optimal livers to optimize organ allocation while minimizing pretransplantation mortality and maximizing post-orthotopic liver transplantation outcome.

Potential predictive value of the MELD score for short-term mortality after liver transplantation.

In the last years, a model for end-stage liver disease (MELD) was suggested as a disease severity score for patients with end-stage liver disease awaiting liver transplantation. In the early 2002, United Network for Organ Sharing (UNOS) has proposed to replace the current status 2A, 2B, and 3 by a modified version of the original MELD score based upon patient risk for 3-month mortality on the waiting list. In this study UNOS status and MELD score were evaluated retrospectively for postoperative 3-month mortality in patients who underwent liver transplantation from 2000 to 2001. Liver recipients were stratified for UNOS status 2A, 2B, and 3, and the corresponding MELD score was calculated for each patient. A receiver operating characteristic (ROC) analysis was performed for both conventional UNOS status and MELD score by fitting patient deaths within 3 months after liver transplantation. The MELD score revealed a better prediction rate for 3-month mortality after the first LT than conventional UNOS status, although no statistical significance was evident by ROC curve comparison. This preliminary study seems to suggest a potentially better predictive rate for the MELD score than conventional UNOS status concerning short-term mortality after liver transplantation.

[Total splenectomy for a recurrent giant splenic cyst]. / Splenectomia totale per voluminosa cisti splenica recidiva.

Primary splenic cysts are a rare finding. Some are large and require surgical removal. The Authors report a case of a recurrent huge splenic cyst in a 41-year-old female patient. A marsupialization was performed at another hospital 6 years before. Ultrasonography and computed tomography imaging revealed a cystic lesion in the spleen measuring approximately 20 cm in diameter. A total open splenectomy was performed. Postoperative course was uneventful. The histologic diagnosis was an epithelial cyst of the spleen with no atypical cells in the cyst wall, as previously found at the first operation. The epidermoid cysts have an epidermal lining, and prevention of recurrence is dependent on complete resection of the cyst wall preserving, whenever possible, the splenic tissue. Recurrence can be avoided with partial splenectomy in polar localization of the cyst, or complete removal of the cyst by "peeling" it off the splenic parenchyma. Marsupialization of the cyst, either via a laparoscopic or an open approach, is often ineffective.

[Infectious complications in liver transplant in Italy: current status and prospectives]. / Complicanze infettive nel trapianto di fegato in Italia: stato attuale e prospettive di studio.

The impact of infections in orthotopic liver transplantation (OLT) is remarkable. Studies have shown that about 60% of patient may develop at least 1 infectious episode during the first 3 months after transplant. Within the frame of a Finalized Research Project of the Italian Ministry of Health, during the year 2000 a group of investigators belonging to the major Italian Liver Transplant Centers (LTC)--18 out of 20 Centers--met three times in Genoa with the aim of constituting a Research Group aimed at improving our knowledge of infectious complications in liver transplant recipients (PITF = Program of Infections in Liver Transplantation). The group first collected information about anti-infective procedure in LTC. The study shows that no Center is supported by a Intensive Care Unit (ICU) exclusively dedicated to the LTC, although 37% of them have a partially dedicated Unit. Surveillance cultures are routinely performed and are frequently used to address the choice of the antibacterial and antifungal regimes. Selective Bowel Decontamination is also very common. The management of CMV infection is usually performed as indicated in international guidelines.

["Occult" carcinoma of the thyroid: clinical, morphological, and biologic characteristics for a correct therapeutic regime]. / Il carcinoma "occulto" della tiroide: caratteristiche cliniche, morfologiche e biologiche per una corretta programmazione terapeutica.

The "occult" carcinoma of the thyroid is still a highly controversial topic. The controversies not only regard its diagnosis, treatment, natural history and, therefore, its biological potential, but also aspects of a nosological nature in that there is still no unequivocal acceptance of its originality, thus leading to discussions focused on its precise definition. On the basis of our experience and other published data, we have reached the following conclusions: a) the term "occult" carcinoma of the thyroid must be used to describe a neoplasia which does not exceed 1.5 cm in diameter, irrespective of the presence or otherwise of laterocervical adenopathy, and leaving aside the fact that it can be identified using clinical and instrumental tests; b) high-resolution echography and echo-guided FNA are fundamental instruments for a correct and early preoperative diagnosis; c) the clinical, morphological and, above all, biological (a very slowly evolving neoplasia) characteristics make the occult carcinoma of the thyroid seem to be a tumour with its own nosological identity; d) on the strength of the latter, and in particular in view of its natural history, conservative surgery (lobectomy with isthmectomy), in the differentiated forms, might play a primary role in the treatment of occult carcinoma of the thyroid in the very near future. However, at present complete thyroidectomy represents the treatment of choice even in differentiated forms, whereas lobectomy is only reserved for incidental cases of occult carcinoma discovered during the final histological test; e) lymphadenectomy is indicated in the event of lymph node involvement, not to achieve a longer survival rate but to reduce the incidence of recidivation in the form of lymph node metastases. In these cases, even the mere removal of macroscopically damaged lymph nodes is sufficient to ensure the virtual absence of recidivation on which, it is worth noting, metabolic radio-iodotherapy is efficacious in the large majority of cases.

[Is intraoperative cholangiography always indicated during videolaparoscopic cholecystectomy?]. / E sempre indicata la colangiografia intraoperatoria durante la colecistectomia videolaparoscopica?

Opinion is divided whether intra-operative cholangiography should be performed routinely or on a selective basis during laparoscopic cholecystectomy. The aims of the present study were to assess the safety, utility and indications of intraoperative cholangiography performed during laparoscopic cholecystectomy. 11 operative cholangiograms were attempted in 63 patients who underwent laparoscopic cholecystectomy (17.4%). Duration of post-operative hospitalization and interval to return to full activity were identical in the two groups. Cholangiography increased the duration of operation (mean 20.1 min: p < 0.01) and the total charges for the operation by almost L. 200,000. Cholangiograms were performed successfully in 100% of the patients and changed operative management in 2 patients. There was not false negative or positive study. No complications or deaths occurred that were due to cholangiography. In follow-up ranging from 1-9 months, there has been no clinical evidence of bile duct injury or retained common bile duct stones. The inescapable conclusion is that an absolute indication for performing cholangiography is unclear anatomy of biliary system. Whereas to document the presence of common bile duct stones, intra-operative cholangiography, neither routine nor selective, is needed. Patients who present with clinical or biochemical signs of choledocholithiasis, a history of cholangitis, acute biliary pancreatitis, or an abnormal CBD on sonogram should have preoperative ERCP and ES before contemplated laparoscopic cholecystectomy. Further advances and confidence with laparoscopic CBD exploration may further change the approach to these patients in the future. In this case selective intra-operative cholangiography is mandatory. However, additional prospective analysis of this patient subgroup is needed.