Mario Bezzi

New ePTFE/FEP-covered stent in the palliative treatment of malignant biliary obstruction

PURPOSE To determine the technical efficacy and safety of an expanded polytetrafluoroethylene and fluorinated ethylene propylene (ePTFE/FEP)-covered metallic stent in the management of malignant biliary obstruction and to evaluate its clinical efficacy by estimating stent patency and patient survival rates. MATERIALS AND METHODS Twenty-six patients with common bile duct stricture caused by malignant disease were treated by placement of 29 stents. The stent consists of an inner ePTFE/FEP lining and an outer supporting structure of nitinol wire. Multiple wire sections elevated from the external surface provide anchoring. Stents are available in two versions, with or without holes in the proximal stent lining. Holes should provide drainage of the cystic duct or biliary side branches when covered by the proximal stent end. Clinical evaluation and assessment of serum bilirubin and liver enzyme levels were done before stent placement and at 1, 3, 6, and 9 months. Average follow-up duration was 5.4 months (range, 5 d to 12.5 mo). RESULTS Placement was successful in all cases. The 30-day mortality rate was 11.5%. The survival rates were 40% and 15% at 6 and 12 months, respectively. Eighty-four percent of patients had adequate palliative drainage during their lifetime. The stent patency rates were 91%, 77%, and 77% at 3, 6, and 12 months, respectively. Four patients (16%) presented with stent occlusion and needed repeat intervention. No migration occurred. Complications other than stent occlusion occurred in five patients (19%); among these, acute cholecystitis was observed in three patients (12%). CONCLUSION Preliminary results suggest that placement of this ePTFE/FEP-covered stent is feasible and effective in achieving biliary drainage. The percentage of patients undergoing lifetime palliation and the midterm patency are promising. However, the incidence of acute cholecystitis is high. Treatment of a larger group of patients is mandatory to validate these long-term results.

Clinical Experience with Covered Wallstents for Biliary Malignancies: 23-Month Follow-Up

AbstractPurpose: To evaluate the effectiveness of partially covered metallic Wallstents to prevent tumoral ingrowth in patients with neoplastic obstruction of the biliary tract. Methods: Twenty-one patients with malignant obstructive jaundice have been treated with Wallstents partially covered with a polyurethane polymer. In total, 36 covered stents (8 and 10 mm in diameter, 70 and 90 mm long) were deployed. All the stents were free from covering at both ends. Results: Jaundice was successfully treated in 100% of cases. There were no problems related to the releasing system during stent positioning, no major complications, and no incompatibility reactions to the materials composing the endoprostheses. At 23-month follow-up, 6 patients are still alive and 15 are dead; of these 15 patients, 11 died in the first 6 months and the last 4 died between 6 and 23 months. Seven patients had an obstructed stent; in four of these, cholangioscopy showed the presence of tumoral ingrowth and in one it showed necrotic tissue with biliary pigments and inflammatory cells. No biopsy specimen was obtained in the remaining two patients with stent obstruction. The follow-up, ranging from 7 to 23 months, showed a primary patency of 46.8% and 24.6% and an assisted patency of 66.3% and 59% at 6 months and 23 months, respectively. Conclusions: Covered metallic stents are effective and may produce improved survival in patients with malignant biliary obstruction (27.8% at 23 months). Stent patency, however, is similar to that of uncovered stents. Modifications in the design of the covering membrane may reduce stent obstruction resulting from disruption of the plastic covering.

Hepatic encephalopathy after transjugular intrahepatic portosystemic shunt. Incidence and risk factors

Forty-seven consecutive patients were prospectively evaluated to study the incidence of hepatic encephalopathy as well as modifications in the PSE index after TIPS. Various clinical, laboratory, and angiographic parameters were also recorded to identify risk factors for the development of post-TIPS hepatic encephalopathy (HE). Mean follow-up was 17±7 months. During follow-up, six patients died and one underwent transplantation. All other patients were followed for at least a year. Fifteen patients (32%) experienced 20 acute episodes of precipitated HE (hospitalization was necessary in 10 instances), and five patients (11%) presented a continuous alteration in mental status with frequent spontaneous exacerbation during follow-up. Both precipitated and spontaneous HE occurred more frequently during the first three months of follow-up. Moreover the PSE index was significantly worse than basal values one month after TIPS, thereafter returning to near basal values. HE was successfully treated in all patients but one who required a reduction in the stent/shunt diameter. Increasing age (>65 years) and low portacaval gradient (<10 mm Hg) were predictors of HE after TIPS. A gradual dilation of the stent/shunt should be performed to obtain a portacaval gradient >10 mm Hg to avoid an unacceptable rate of HE after TIPS.

Self-expandable Nitinol Stent for the Management of Biliary Obstruction: Long-term Clinical Results

PURPOSE Technical characteristics and clinical efficacy of a new metallic stent for the management of biliary obstruction were investigated in a clinical study. PATIENTS AND METHODS From February 1991 to January 1993, 35 self-expandable, nickel-titanium alloy wire-mesh stents (diameter, 10 mm; length, 6 cm) were placed in 19 patients with obstructive jaundice due to cholangiocarcinoma (n = 6), pancreatic carcinoma (n = 5), lymph node metastasis to the liver hilum (n = 5), gallbladder carcinoma (n = 2), and intraductal papillary mucosal hyperplasia (n = 1). RESULTS Stent placement was successful in 18 of 19 patients. In one patient, stent dislodgement occurred after correct release; no other procedure-related complications or deaths occurred within 30 days following the procedure. Two (11%) of the remaining 18 patients are alive at 11 months; 16 (89%) died after a mean survival of 7.4 months. Two of three patients with stent obstruction underwent repeated intervention. Adequate palliation from jaundice was achieved without further intervention in 83% of cases. The mean stent patency was not less than 7 months. CONCLUSION Use of these metallic stents reestablished bile flow in the occluded biliary tree. Their efficacy and patency rate were also adequate.

Metallic stents in benign biliary strictures: Three-year follow-up

Eighteen patients with recurrent benign biliary strictures (BBS) were selected for metallic stents placement because they failed to respond to percutaneous balloon dilatation. None were candidates for surgical corrections. We used “Z” single or double stents in 17 cases and a Wallstent in 1 case. After more than 3 years of follow-up (average period 37 months, range 30–41 months), 10 patients (55.5%) were asymptomatic without signs of bile statis; 5 patients (27.7%) had recurrence of symptoms and were eventually retreated; and 3 patients (16.6%) died, 2 of obstructive jaundice and liver failure and 1 of metastatic gastric cancer. Recurrence was due to stent occlusion by tissue ingrowth in 3 cases, stent migration in 1 case, and an inflammatory lesion of the papilla of Vater in another case, with patency of the metallic stent. The overall patency rate, at 3-year follow-up was 68.7%. In our series, the main factor determining long-term patency of metallic stents has been reactive tissue ingrowth. Nevertheless, long-term results obtained with metallic stents in recurrent benign biliary strictures should be considered satisfactory. In selected patients, metallic stents may represent the only long-term treatment available for maintaining bile flow.

T1-weighted dual-echo MRI for fat quantification in pediatric nonalcoholic fatty liver disease

AIM To determine in obese children with nonalcoholic fatty liver disease (NAFLD) the accuracy of magnetic resonance imaging (MRI) in assessing liver fat concentration. METHODS A case-control study was performed. Cases were 25 obese children with biopsy-proven NAFLD. Controls were 25 obese children matched for age and gender, without NAFLD at ultrasonography and with normal levels of aminotransferases and insulin. Hepatic fat fraction (HFF) by MRI was obtained using a modification of the Dixon method. RESULTS HFF ranged from 2% to 44% [mean, 19.0% (95% CI, 15.1-27.4)] in children with NAFLD, while in the controls this value ranged from 0.08% to 4.69% [2.0% (1.3-2.5), P < 0.0001]. HFF was highly correlated with histological steatosis (r = 0.883, P < 0.0001) in the NAFLD children. According to the histological grade of steatosis, the mean HFF was 8.7% (95% CI, 6.0-11.6) for mild, 21.6% (15.3-27.0) for moderate, and 39.7% (34.4-45.0) for severe fatty liver infiltration. With a cutoff of 4.85%, HFF had a sensitivity of 95.8% for the diagnosis of histological steatosis ≥ 5%. All control children had HFF lower than 4.85%; thus, the specificity was 100%. After 12 mo, children with weight loss displayed a significant decrease in HFF. CONCLUSION MRI is an accurate methodology for liver fat quantification in pediatric NAFLD.

Hydro-CT in patients with gastric cancer: Preoperative radiologic staging

A total of 35 patients (age range 35–78 years) with gastric tumors on the lesser curve, or in the antro-pyloric region, underwent angio-CT in the prone position after filling the stomach with 500 ml of water and intravenous administration of glucagon. The films were reviewed by three radiologists independently, staging each tumor according to the TNM classification preoperatively. The overall accuracy of tumor staging ranged between 66–77%, overstaging between 17–25%, and understaging between 3–8.5%. The diagnostic sensitivity, specificity, and accuracy for serosal invasion ranged between 90 and 100, 76 and 84, and 80–88%, respectively, and the overall accuracy for N staging was 46, 48, and 51% for the three observers. If, however, N1 and N2 tumors were considered as a single group, N-stage accuracy increased, ranging between 63 and 77%. The “K test” for analyzing the interobserver agreement was 60%, i.e., the diagnostic results are reproducible. Water filling of the stomach optimizes visualization of the gastric wall on contrast-enhanced CT. The prone position and drug-induced hypotony allows for good distension without any disturbing artifact reduction obscuring the lower gastric body.

Cystic lymphangioma of the spleen: US-CT-MRI correlation

Abstract. A case of a surgically confirmed cystic lymphangioma of the spleen is presented. Preoperative imaging consisted of US, contrast-enhanced CT and MRI, all showing a multiloculated lesion with small cystic cavities divided by thin septa, corresponding to dilated lymphatic spaces. Preoperative studies correlated well with the pathologic findings. Cystic lymphangioma of the spleen is a very rare condition and is usually solitary and asymptomatic. Large lymphangiomas may be an indication for splenectomy, since the risk of rupture is high even from minor abdominal trauma. Preoperative diagnosis may be achieved with correlated noninvasive imaging.

Type a Aortic Dissection Developing during Endovascular Repair of an Acute Type B Dissection

Purpose: To describe an extension of type B dissection into type A during endoluminal treatment of acute type B dissection. Case Report: A 57-year-old man with acute type B dissection underwent endovascular repair using 2 Excluder stent-grafts. Before releasing the second stent-graft, the patient complained of mild central chest pain, headache, and visual flashes, but no hemodynamic changes were noticed. An angiogram, performed soon afterwards, showed a retrograde extension of the dissection through the aortic arch involving both the left carotid artery and the ascending aorta. The procedure was completed, and the patient was transported to the operating room where the proximal ascending aorta was replaced. Spiral computed tomographic angiography performed 2 weeks after the procedure showed complete exclusion of the primary entry tear. At 6-month follow-up, the patient was asymptomatic; the left carotid artery dissection had disappeared. Conclusions: Endovascular repair of acute type B dissection is technically feasible, but longer experience will help prevent technical complications.

Is contrast-enhanced US alternative to spiral CT in the assessment of treatment outcome of radiofrequency ablation in hepatocellular carcinoma?

PURPOSE The present study was conducted to assess the efficacy of contrast-enhanced ultrasound with low mechanical index in evaluating the response of percutaneous radiofrequency ablation treatment of hepatocellular carcinoma by comparing it with 4-row spiral computed tomography. MATERIALS AND METHODS 100 consecutive patients (65 men and 35 women; age range: 62 - 76 years) with solitary hepatocellular carcinomas (mean lesion diameter: 3.7 cm +/- 1.1 cm SD) underwent internally cooled radiofrequency ablation. Therapeutic response was evaluated at one month after the treatment with triple-phasic contrast-enhanced spiral CT and low-mechanical index contrast-enhanced ultrasound following bolus injection of 2.4 ml of Sonovue (Bracco, Milan). 60 out of 100 patients were followed up for another 3 months. Contrast-enhanced sonographic studies were reviewed by two blinded radiologists in consensus. Sensitivity, specificity, NPV and PPV of contrast-enhanced ultrasound examination were determined. RESULTS After treatment, contrast-enhanced ultrasound identified persistent signal enhancement in 24 patients (24 %), whereas no intratumoral enhancement was detected in the remaining 76 patients (76 %). Using CT imaging as gold standard, the sensitivity, specificity, NPV, and PPV of contrast enhanced ultrasound were 92.3 % (95 % CI = 75.9 - 97.9 %), 100 % (95 % CI = 95.2 - 100 %), 97.4 % (95 % CI = 91.1 - 99.3 %), and 100 % (95 % CI = 86.2 - 100 %). CONCLUSION Contrast-enhanced ultrasound with low mechanical index using Sonovue is a feasible tool in evaluating the response of hepatocellular carcinoma to radiofrequency ablation. Accuracy is comparable to 4-row spiral CT.