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Biomedical subjects

K M Bron

Publications and source records attributed to K M Bron.

At least 19 recordsLinked to original sources

Hepatic parenchymal perfusion defects detected with CTAP: imaging-pathologic correlation.

To determine whether characteristics of focal hepatic parenchymal perfusion defects detected with computed tomographic arterial portography (CTAP) correlate with underlying pathologic processes, 245 perfusion defects detected with CTAP in 60 patients who subsequently underwent definitive hepatic surgery were characterized by shape, location within the liver, and relative attenuation value and were prospectively correlated with sectioned pathologic specimens. Of 177 round perfusion defects, 102 (58%) were malignant and 75 (42%) were benign. Only one (2%) of 53 peripheral wedge-shaped defects was malignant. All 15 peripheral flat defects were benign. Defects in characteristic locations anterior to the porta hepatis (n = 15) and adjacent to the intersegmental fissure (n = 7) were uniformly benign. While 83 (56%) of 147 soft-tissue attenuation defects were malignant, only four (6%) of 68 intermediate-attenuation defects were malignant. Although these characteristics of parenchymal perfusion defects aid in differentiation of benign from malignant processes, all other types of perfusion defects are nonspecific and may require biopsy.

Adenoma, Bile Duct

Diagnostic value of brush cytology in the diagnosis of bile duct carcinoma: a study in 65 patients with bile duct strictures.

Malignant strictures of the extrahepatic bile ducts are difficult to distinguish from benign strictures, particularly in patients with primary sclerosing cholangitis. Because attempts at diagnosing small cancers with fine-needle aspiration biopsy are not possible in the absence of an associated mass lesion and because the sensitivity of exfoliative biliary cytology is controversial, brush cytology has been used as a potential means of establishing a specific diagnosis of bile duct carcinoma. Herein we report our experience with this technique when performed on 65 patients over a 5-yr period. Each had at least one brushing. Thirty-seven were found to have bile duct carcinoma and 28 were found to have benign strictures. Of these 37, the first brushing was positive for malignancy in 15 (40%), whereas four (11%) had cells suspected but not diagnostic of malignancy. Thirteen patients with bile duct carcinoma whose initial brushings were negative for malignancy had second brushings. Of these, five (38%) had malignant cells, whereas three (24%) yielded suspicious cells. Three of the eight whose first two brushings were negative for malignancy were found to have malignant cells on the third brushing. In contrast, of the 28 patients with benign strictures, malignant cells were never found. However, in two patients, suspicious cells were reported with the first but not the second brushing. A single negative or suspicious cytological finding decreased the probability of bile duct carcinoma to 43%. Two and three sequential negative tests reduced the probability to 32% and 0%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult

Pseudoaneurysms complicating organ transplantation: roles of CT, duplex sonography, and angiography.

In a retrospective study of proved pseudoaneurysms (PAs) in 15 patients with transplanted organs (11 liver, three kidney, one pancreas), the results of computed tomography (CT), duplex sonography, and angiography were reviewed. Of the 15 cases of PA, eight occurred at the arterial anastomosis and seven were nonanastomotic. Three of the eight anastomotic PAs were caused by infection. Of the seven nonanastomotic PAs, four were caused by percutaneous biopsy, two were caused by infection, and one was of undetermined cause. In nine (60%) of the 15 patients the PAs were incidentally detected at imaging studies performed for other reasons. Diagnosis requires a high degree of suspicion. CT was performed in nine cases and duplex sonography in ten. The diagnosis of PA was made with CT in six (67%) patients and with duplex sonography in five (50%). CT and duplex sonography could not enable diagnosis when the PA was small, when the arterial anastomosis was not included in the field of study, or when enhancement with intravenously administered contract material was suboptimal. Angiography depicted the PAs in all 15 patients. In three liver transplant recipients with gastrointestinal tract bleeding, the causative PAs were detected only with angiography.

Adult

Recurrent cholangiocarcinoma in the biliary tree after liver transplantation.

Four liver transplant recipients with recurrent cholangiocarcinoma (CCA) within the allograft biliary tree are described. One patient received a transplant for known CCA and three received transplants for end-stage primary sclerosing cholangitis, in which CCA was found within the hepatectomy specimen. All four developed biliary obstruction due to malignant stricture at the bile duct anastomosis 9-15 months after transplantation. Diagnosis of recurrent CCA was made by means of transhepatic brush biopsy in two patients. Recognition that the biliary tract, especially the anastomosis, is a site of recurrence of CCA should facilitate prompt diagnosis by means of transhepatic brush biopsy in patients with biliary obstruction due to stricture. In addition, because of an association between CCA and primary sclerosing cholangitis, preoperative bile duct biopsy should be considered for liver transplantation candidates with the latter condition. Positive biopsy findings may preclude transplantation.

Adult

The role of sonography and transhepatic cholangiography in the diagnosis of biliary complications after liver transplantation.

We retrospectively reviewed the results of real-time sonography in 41 patients in whom biliary complications after liver transplantation were documented by percutaneous transhepatic cholangiography. Abnormalities included bile duct stricture (26 cases), occluded internal biliary stent (six cases), common duct redundancy with resultant functional biliary obstruction (three cases), bile leak (three cases), choledocholithiasis (two cases), and an abscess in a cystic duct remnant (one case). Sonography was abnormal in 22 of the 41 cases (sensitivity, 54%). Bile duct dilatation was the positive sonographic finding in 19 (86%) of the 22 abnormal examinations. In the remaining 19 patients, sonography was normal. Sonography is not a reliable test for the early detection of biliary abnormalities after liver transplantation. Percutaneous transhepatic cholangiography should be performed in patients with suspected biliary complications after liver transplantation.

Biliary Tract Diseases

Diagnostic and interventional radiology in liver transplantation.

Diagnostic and interventional radiology play major roles in the evaluation and management of liver transplant patients. This article begins with a discussion of imaging techniques used in the preoperative evaluation of transplant candidates. Surgical approaches and normal posttransplant anatomy are presented. An in-depth discussion of the radiologic evaluation of posttransplantation complications follows, with numerous illustrative cases. Finally, the role of interventional radiology in the nonoperative management of certain complications, especially biliary problems, is discussed.

Humans

Percutaneous transhepatic cholangiography and biliary drainage after liver transplantation: a five-year experience.

Evaluation of the biliary tract by percutaneous transhepatic cholangiography (PTC) is often required in liver transplant patients with an abnormal postoperative course. Indications for PTC include failure of liver enzyme levels to return to normal postoperatively, an elevation of serum bilirubin or liver enzyme levels, suspected bile leak, biliary obstructive symptoms, cholangitis, and sepsis. Over a 5-year period 625 liver transplants in 477 patients were performed at the University Health Center of Pittsburgh. Fifty-three patients (56 transplants) underwent 70 PTCs. Complications diagnosed by PTC included biliary strictures, bile leaks, bilomas, liver abscesses, stones, and problems associated with internal biliary stents. Thirty-two percutaneous transhepatic biliary drainage procedures were performed. Ten transplantation patients underwent balloon dilatation of postoperative biliary strictures. Interventional radiologic techniques were important in treating other complications and avoiding additional surgery in many of these patients.

Adolescent

Treatment of iatrogenic biliary obstruction by balloon dilatation of a biliary jejunal fistula.

Biliary obstruction and multiple hepatic abscesses occurred in a patient after ligation of a segmental branch of the right hepatic duct. The patient was successfully managed by transhepatic biliary drainage and balloon dilatation of an internal fistula that developed between the ligated duct and a Roux limb of jejunum. Internal biliary fistulas may be dilated using interventional radiologic techniques to permit nonobstructed bile flow. Implications for the nonsurgical treatment of biliary strictures are discussed.

Angioplasty, Balloon

Liver transplant rejection: angiographic findings in 35 patients.

Rejection, the leading cause of liver allograft dysfunction, is usually detected by liver biopsy. The purpose of this study was to determine if there are angiographic findings that correlate with this posttransplantation complication. In a retrospective study, the angiograms of 35 patients with histologically proven allograft rejection were reviewed. The examinations were done because of suspected posttransplantation vascular complications. Abnormal hepatic arteriograms were observed in 30 (86%). Eleven (37%) of the 30 had hepatic artery thrombosis (all had acute rejection). Nineteen (63%) of the 30 had varying degrees of intrahepatic arterial narrowing (14 had acute and five had chronic rejection). Additional findings in patients with acute rejection included stretching of the intrahepatic arterial tree (five cases) and slow flow, poor peripheral arterial filling, and a decrease in the number of intrahepatic arteries (10 cases total). Intrahepatic branch vessel stenoses and occlusions were seen in four patients with chronic rejection. We conclude that there is good correlations between the angiographic findings and histologic evidence of rejection. Although angiography is not advocated as a test for transplant rejection, detection of certain findings raises the possibility of rejection.

Adult

Cholangiographic findings in hepatic artery occlusion after liver transplantation.

Because the hepatic artery provides the only blood supply to the biliary tree of a liver allograft, posttransplantation arterial occlusion may result in a biliary complication. Cholangiograms were reviewed retrospectively in 31 transplant patients who had proved complete or partial occlusions of the hepatic artery (thrombosis in 29 and marked stenosis in two). Cholangiograms were abnormal in 26 (84%). The most common abnormality, seen in 16 patients, was nonanastomotic contrast leakage from the donor intra- or extrahepatic bile ducts. Strictures of the donor biliary tree occurred in 14 patients, four of whom also had a nonanastomotic bile leak. In 12 of the 14, the strictures were nonanastomotic. Other findings included poor filling of the intrahepatic bile ducts, generalized donor ductal dilatation and irregularity, and intraductal filling defects. Sixteen (89%) of 18 transplants with nonanastomotic contrast leakage had occlusions of the hepatic artery. Of 21 transplants with nonanastomotic strictures, 12 (57%) had occlusions of the hepatic artery. Only two (10%) of 20 transplants with biliary anastomotic strictures had arterial occlusion. We conclude that liver transplant recipients who exhibit nonanastomotic contrast leakage or nonanastomotic strictures on cholangiography should be evaluated for occlusion of the hepatic artery as the probable cause.

Adult

Noninfectious complications of long-term central venous catheters: radiologic evaluation and management.

During a 5-year period, 416 long-term double-lumen central venous catheters were inserted into 288 patients. In these patients, 106 catheter venograms and nine upper extremity venograms were performed. All studies were reviewed retrospectively to determine the nature and prevalence of noninfectious catheter-related complications, to evaluate the efficacy and safety of streptokinase therapy, and to determine if catheter venography should be performed before streptokinase therapy is started. Noninfectious complications occurred in 66 (23%) patients. Complications that resulted in catheter malfunction included deposition of fibrin around the catheter tip (formation of a fibrin sheath) in 44 (57%) instances, a constricting suture in six, abutment of the catheter tip against the venous wall in eight, catheter leak in two, and migration of the catheter completely out of the vein in three. Venous thrombosis developed in 11 patients. Treatment with low doses of streptokinase successfully relieved catheter obstruction due to a fibrin sheath in 27 (87%) of 31 instances. No bleeding complications occurred. Five patients had malpositioned catheters in the azygous, axillary, or internal jugular veins. By use of a deflector wire or snare inserted via the femoral vein, all five were relocated successfully into the superior vena cava. Recognition of noninfectious complications associated with use of long-term catheters is important for institution of appropriate therapy, which in many instances obviates removal of the catheter. Formation of a fibrin sheath in only 57% of cases of catheter malfunction provides an argument for performing catheter venography before streptokinase therapy is started. Low-dose streptokinase therapy for long-term central venous catheters occluded by a fibrin sheath is safe and efficacious.

Catheters, Indwelling

Percutaneous transhepatic balloon dilatation of benign biliary strictures.

Between February 1981 and June 1984, 15 patients with benign biliary strictures were treated with percutaneous transhepatic balloon dilatation. Three of these patients had received liver transplants. The treatment began with a course of balloon dilatation therapy, after which a stent catheter was left across the stricture. Six weeks later, after duct patency had been shown by cholangiography, the stent catheter was removed from all but two patients, both of whom had intrahepatic sclerosing cholangitis. After this procedure, six patients (40%), including two liver-transplant patients, were stricture-free after one treatment for periods ranging from 27 to 56 months, and were considered to be treatment successes. Nine patients (60%) suffered stricture recurrences. In eight of these patients, the stricture was heralded by symptoms of either cholangitis or jaundice; in one patient, who was on permanent catheter drainage, the stricture was discovered only on follow-up cholangiography. All successfully treated patients had only one stricture, while all patients with more than one stricture suffered recurrences. Our data also suggest a greater responsiveness for anastomotic strictures than for non-anastomotic strictures. Of the patients with recurrences, five had symptom-free intervals of 23 months or more (up to 31 months). The fact that strictures recurred after such long periods of time underscores the importance of long-term follow-up. In view of the number of patients helped, the favorable experience with post-liver-transplantation strictures, and the lack of any major complications in our series, percutaneous biliary balloon dilatation offers a viable alternative to surgical management of benign biliary strictures.

Adult

Hepatopetal collaterals after portal vein thrombosis following liver transplantation.

Two liver transplant patients with hepatopetal collaterals after portal vein thrombosis are described. Angiographically, the appearance is similar to cavernous transformation of the portal vein. The demonstration of hepatopetal collaterals is diagnostic of portal vein occlusion from whatever cause. After portal vein occlusion, collaterals develop from preexisting periportal vessels which undergo compensatory enlargement and reconstitute the intrahepatic portal vessels. In liver transplant patients, the collateral communications must arise de novo, since all potential collateral pathways are severed at the time of transplantation.

Adolescent

Repositioning catheters in surgically drained abscesses.

Primary percutaneous drainage of intraabdominal abscesses under local anesthesia is an accepted method of treatment, with low morbidity and mortality. This technique was extended to patients with recurrent or secondary abscesses after initial primary surgical drainage. Four patients had abscesses drained operatively but were reevaluated several weeks later for recurrent fever. Sinography demonstrated an inadequately drained abscess cavity. Under fluoroscopic control and using local anesthesia, new drains were inserted and repositioned to provide better drainage. Resolution of the abscess cavity was documented radiographically, with improvement in the patients' clinical status.

Abdomen

Pre- and intraoperative localization of small bowel arteriovenous malformation.

Patients with chronic gastrointestinal bleeding with no source found after standard radiographic and endoscopic procedures are diagnostic challenges. Since angiodysplasia is a frequent cause of such bleeding, selective angiography has become an essential diagnostic tool in identifying arteriovenous malformations (AVM) of the large and small bowel. In addition to preoperative identification, some method of intraoperative localization is essential to assure removal of the involved segment. In a patient with a 7-year history of gastrointestinal bleeding from an AVM of the small bowel, a technique of preoperative angiographic catheter placement with intraoperative confirmation of catheter position proved a useful way to find such small bowel lesions and insured adequate but not excessive resection.

Aged