Transhepatic intravascular ultrasound for evaluation of portal venous involvement in patients with cancer of the pancreatic head region.

The aim of this study was to evaluate the ability of intravascular ultrasound to diagnose tumor involvement of the portal and the superior mesenteric veins using the preoperative percutaneous, transhepatic approach, and to compare the findings with those made at concomitant direct portography, surgery, and histopathological examination. Ten patients with a preoperative diagnosis of a resectable tumor in the pancreatic head region were examined with percutaneous transhepatic portography (PTP) and intravascular ultrasound (IVUS). The surgeon's intraoperative evaluation and the histopathological examination in combination revealed tumor involvement of the portal or superior mesenteric veins in six of the ten patients. Percutaneous transhepatic portography suggested tumor involvement of the veins in six patients but two of the examinations were false positive and another two were false negative. Intravascular ultrasound showed signs of tumor involvement in eight patients. The examination was, however, false positive in two patients, but there were no false negatives. Complications of the percutaneous transhepatic procedure occurred in six patients including severe pain, bleeding, and related death. Percutaneous transhepatic IVUS of the portal vein may be a useful tool in the preoperative selection of the subgroup of patients with tumor of the pancreatic head region that could benefit from surgery. There is a need for technical improvement as well as studies with larger patient series to definitely decide the role of the technique.

Interstitial laser thermotherapy in pig liver: effect of inflow occlusion on extent of necrosis and ultrasound image.

BACKGROUND/AIMS: The aim was to investigate the effect of blood inflow occlusion on lesion size and ultrasonographic findings during interstitial laser thermotherapy of normal liver. METHODOLOGY: Pigs were treated with or without hepatic inflow occlusion at a laser power of 3W or without inflow occlusion at 5 W (target temperature 43 degrees C). The thermotherapy system consisted of an Nd:YAG laser and a temperature feedback circuit. Ultrasonography was performed immediately after treatment. Lesion size was determined using light microscopy including immunohistochemistry with bromodeoxyuridine. RESULTS: Hyperechoic ultrasonographic changes were observed after treatment with inflow occlusion or when there was carbonization. If carbonization did not occur, unoccluded blood flow was associated with hypoechoic lesions. Following inflow occlusion, maximum lesion width 2 and 6 days after thermotherapy averaged 21.9 +/- 1.3 and 20.2 +/- 0.8 (means +/- SEM) mm, respectively. This was larger than the corresponding values of 10.8 +/- 0.8 and 11.1 +/- 2.0 observed after treatment without inflow occlusion at 3W (p < 0.01). Increase in laser power from 3 to 5W in experiments without inflow occlusion produced early carbonization and a slight increase in lesion size that did not match that produced by inflow occlusion. Ultrasound gave a correct prediction of necrosis size after treatment with inflow occlusion but overestimated the necrosis when inflow occlusion was not used. Ultrasound was furthermore unable to predict size of necrosis in individual experiments. CONCLUSION: Blood flow has a major influence on lesion size in interstitial laser thermotherapy of the liver and affects ultrasonographic images. Also, it appears that intraoperative ultrasonography cannot monitor lesion size with an accuracy that is sufficient for clinical use.

Mesocaval interposition shunting in the treatment of bleeding oesophageal varices.

OBJECTIVE: To assess the longterm results of mesocaval interposition shunt in the treatment of bleeding oesophageal varices. DESIGN: Retrospective study. SETTING: University hospital, Sweden. SUBJECTS: 60 patients with bleeding oesophageal varices in all Child's classes. 20 of whom were operated on as emergencies, and 40 as elective cases. INTERVENTIONS: A 14 mm polytetrafluoroethylene graft was used as an interposition shunt between the superior mesenteric vein and the vena cava. MAIN OUTCOME MEASURES: Rebleeding rate, portal blood flow, hepatic encephalopathy, morbidity, mortality, and survival. RESULTS: Rebleeding was rare and occurred mainly during the first 4 months after operation, (n = 5) in 10% of the patients, and at the 24 month follow-up, (n = 4) in 11% of the patients. Portal flow was measured preoperatively in 33 patients and in 22 (67%) it was hepatopetal. During follow-up it was reversed and after 24 months no patient had hepatopetal flow. Hepatic encephalopathy was present in 18 patients (20%) during follow-up. Shunts thrombosed in 9 patients (15%), 8 of which required reoperation. There was no operative mortality, but 4 patients (7%) died within 30 days of surgery. The main late cause of death (18/26) was liver failure. The 1 year survival was 80%, the 3 year survival 70% and the 5 year survival 60%. CONCLUSIONS: The mesocaval interposition shunt gives good longterm results and can be recommended both as an emergency and an elective procedure for patients with portal hypertension and bleeding oesophageal varices that are unresponsive to sclerotherapy.

Intravascular ultrasound for evaluation of portal venous involvement in pancreatic cancer.

The aim of this study was to evaluate the accuracy of intravascular ultrasound (IVUS) in diagnosing tumour involvement of the portal vein in patients with exocrine cancer of the head of the pancreas. Seven consecutive patients with a preoperative diagnosis of carcinoma, preoperatively deemed to be resectable, were examined with IVUS of the portal vein during surgery. The IVUS catheters were 6.2 F (2.0 mm) in diameter with a 20-MHz transducer and were introduced into the portal vasculature through the mesenteric superior vein. All patients had tumour extending to the portal vein as demonstrated at histopathological examinations in six cases and at surgical dissection in one case. The IVUS technique correctly identified all these patients, whereas five patients were incorrectly deemed at surgery not to have tumour involvement of the portal vein. These results indicate that IVUS is a very sensitive method for the evaluation of tumour involvement of the portal vein.

[Endoscopic retrograde cholangio- pancreatography. An overview of procedures at the Natinal University Hospital in Reykjavik 1983-1992.].

INTRODUCTION: In this retrospective study we analysed all ERCP procedures performed at the National University Hospital in Reykjavik, Iceland, for the period 1983-1992. MATERIAL: A total of 644 procedures were performed on 477 patients. RESULTS: The main indication for a diagnostic ERCP was suspected choledocholithiasis in 58.8% of cases. Cannulation of the papilla of Vater was successfully achived in 94% of patients and in 82% the desired duct was visualised. Juxtapapillary diverticula were found in 14.5% of patients. The success at cannulation was significally less in that group. Choledocholithiasis was found in 19.4% more often in the patients with diverticula, 29.5 vs. 18.8%. The number of therapeutic interventions was 158 performed on 84 patients (24.5% of all ERCP). The most common procedure was sphincterotomy, performed in 84% of cases. Stone extraction was successfully achived in 58% of all attempts. The overall complications rate was 7%, most frequently acute pancreatitis (4.7%) followed by cholangitis (1.9%) and bleeding (0.3%). The complications were mild in the majority of cases but serious ones did occur and were fatal in three (0.5%) patients related to severe pancreatitis. CONCLUSION: The results of this retrospective study in Iceland are comparable to what others have reported previously.

Lymph nodes in the hepato-duodenal ligament. A comparison between ultrasound and low-field MR imaging.

PURPOSE: We investigated whether a low-field MR unit (0.2 T) could demonstrate and determine the size of the lymph nodes in the hepato-duodenal ligament that were previously found on ultrasound. MATERIAL AND METHODS: Eighteen patients were examined with ultrasound, MR and liver biopsy on consecutive days. RESULTS: Two-thirds of the enlarged nodes detected by ultrasound were also detected with the low-field MR technique. However, the size of the nodes was slightly larger on ultrasound. CONCLUSION: Compared to low-field MR, ultrasound appears to be superior in the evaluation of lymph nodes in the liver hilus.

Interstitial laser treatment of malignant tumours: initial experience.

This is a prospective pilot investigation of interstitial laser treatment. Twelve patients were treated at 13 sites: seven patients had metastatic or primary liver cancer (with a total of 21 tumour nodules), two had pancreatic carcinoma and four patients had disease at other sites. Treatments were performed with an Nd-YAG laser, using a high power (6 or 10 W), short-time (5 min) technique or a feedback system for temperature regulation at low power (3 W) for 12-16 min. Treatment with high power invariably resulted in rapid carbonization of tissue, which may have contributed to the postoperative death in one patient. The local effect of treatment could be evaluated in 13 hepatic tumours (1.0-10 cm in diameter): 100% necrosis was seen in five and >50% necrosis in the remaining eight. Two tumours were eradicated, five became smaller, and six remained unchanged in size or showed continued growth. Treatment removed or alleviated symptoms in 7/8 symptomatic patients. The feedback system made it possible to avoid carbonization and allowed better control of the tissue temperature. The main problem with either method was to monitor tissue changes in real time, and ultrasonography was found to be of little help in this respect. It is concluded that interstitial laser treatment is a promising method for treatment of tumours. Further development should focus on real-time monitoring and increased volume effect without carbonization.

Intravascular ultrasound of the portal vein--normal anatomy.

The purpose of this study was to evaluate the appearance of the normal portal vein with intravascular ultrasound. The portal vein was studied in 10 patients with colorectal carcinoma without known liver or pancreatic disease. For the intravascular portovenous examination, a 2.0-mm, 20-MHz ultrasound catheter was used. The field of view was 30 mm. The wall of the portal vein appeared as a single hyperechoic layer 0.5 to 0.8 mm in thickness. Normal structures adjacent to the portal vein, such as the common bile duct, the hepatic artery or small lymph nodes, were clearly separated from the lumen of the portal vein by the wall of the vein together with some periportal fat. In most cases the parenchyma of the pancreas could be separated from the wall of the vein.

Computed vs. film-screen magnification radiography of fingers in hyperparathyroidism. An ROC analysis.

One hundred randomly selected patients with suspected or known hyperparathyroidism were examined in a prospective study of the 2nd and 3rd fingers with film-screen and digital luminescence radiographs using magnification technique. The digital images were displayed on a work-station and printed as hard-copies. Two radiologists evaluated the film-screen images regarding subperiosteal and intracortical resorption and their results were defined as "gold standard" regarding the absence or presence of these changes. Four radiologists evaluated these changes in the 3 image forms and an ROC analysis was performed. Comparing the areas under the ROC curves no significant difference was found between the film-screen images and the 2 digital display forms. These results suggest that currently available digital systems provide adequate diagnostic accuracy for evaluation of subtle skeletal changes.

Mesocaval shunt or repeated sclerotherapy: effects on rebleeding and encephalopathy--a randomized trial.

BACKGROUND: Sclerotherapy is usually effective in controlling acutely bleeding esophageal varices. It may not be as effective as shunt surgery for prevention of rebleeding; therefore we undertook a prospective study comparing interposition mesocaval shunt (MCS) and repeated sclerotherapy. METHODS: Forty-five patients (mean age, 52.6 +/- 9.8 years) with variceal bleeding were randomized after emergency endoscopic sclerotherapy either to repeat variceal obliteration followed by regular check endoscopy (n = 21) or to elective interposition mesocaval shunting by use of 14 mm polytetrafluoroethylene graft (n = 24). There was an equal distribution of Child's classes in the two groups. RESULTS: In the sclerotherapy group 12 patients had recurrent hemorrhages causing five deaths compared with the shunt group, in which four patients had postoperative bleeding but without associated death. No difference was noted in the incidence of encephalopathy despite the development of total shunting 1 year after MCS. The median hospital stay was similar; 34.5 days (MCS) and 33 days (sclerotherapy). The number of intensive care unit days was also similar in the two groups. No difference was noted in survival in patients with Child's A and Child's B disease in the treatment groups. In patients with Child's C cirrhosis there was a statistically significant longer survival in patients undergoing MCS compared with patients undergoing sclerotherapy. CONCLUSIONS: The results of the study show that the rate of rebleeding is significantly higher after sclerotherapy than after mesocaval shunting. In patients with Child's C cirrhosis MCS may be an alternative to sclerotherapy for the prevention of rebleeding from esophageal varices in patients not suitable for transplantation.

[Medical imaging and the future.].

This article addresses the topic of medical imaging and the future, the effect of organisation and new technology. Examples of new and future technology such as computed radiology, three dimensional imaging, new intervention techniques and mixture of imaging modalities are discussed.

Film-screen vs. digital radiography in rheumatoid arthritis of the hand. An ROC analysis.

In a prospective investigation the diagnostic accuracy of film-screen and digital radiography in rheumatoid arthritis of hands was compared. Seventy hands of 36 patients with established rheumatoid arthritis were included in the study. Each of 11 joints in every hand was evaluated regarding the following radiologic parameters: soft tissue swelling, joint space narrowing, erosions and periarticular osteopenia. The digital images were obtained with storage phosphor image plates and evaluated in 2 forms; as digital hard-copy on film and on a monitor of an interactive workstation. The digital images had a resolution of either 3.33 or 5.0 lp/mm. ROC curves were constructed and comparing the area under the curves no significant difference was found between the 3 different imaging forms in either resolution group for soft tissue swelling, joint space narrowing and erosions. The film-screen image evaluation of periarticular osteopenia was significantly better than the digital hard-copy one in the 3.33 lp/mm resolution group, but no significant difference was found in the 5.0 lp/mm group. These results support the view that currently available digital systems are capable of adequate diagnostic performance.