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Biomedical subjects

K M Bron

Publications and source records attributed to K M Bron.

At least 37 records · Page 2Linked to original sources
PubMed1986

Hepatic artery thrombosis after liver transplantation: radiologic evaluation.

Hepatic artery thrombosis after liver transplantation is a devastating event requiring emergency retransplantation in most patients. Early clinical signs are often nonspecific. Before duplex sonography (combined real-time and pulsed Doppler) capability was acquired in October 1984, 76% of all transplants in this institution referred for angiography with a clinical suspicion of hepatic artery thrombosis had patent arteries. In an effort to reduce the number of negative angiograms, CT, real-time sonography, and pulsed Doppler have been evaluated as screening examinations to determine which patients need angiography. Of 14 patients with focal inhomogeneity of the liver architecture detected by CT and/or real-time sonography, 12 (86%) had hepatic artery thrombosis, one had slow arterial flow with hepatic necrosis, and one had a biloma with a patent hepatic artery. In 29 patients undergoing duplex sonography of the hepatic artery, six (21%) had absence of a Doppler arterial pulse. All six had abnormal angiograms: Four had thrombosis, one had a significant stenosis, and one had slow flow with biopsy-proven ischemia. Of 23 patients with a Doppler pulse, two had hepatic artery thrombosis at surgery. However, real-time sonography demonstrated focal inhomogeneity in the liver in both cases. Our data demonstrate that pulsed Doppler of the hepatic artery combined with real-time sonography of the liver parenchyma currently is the optimal screening test for selecting patients who require hepatic angiography after liver transplantation. A diagnostic algorithm is provided.

Adolescent↗
PubMed1986

Vascular complications after liver transplantation: a 5-year experience.

During the past 5 years, 104 angiographic studies were performed in 87 patients (45 children and 42 adults) with 92 transplanted livers for evaluation of possible vascular complications. Seventy percent of the studies were abnormal. Hepatic artery thrombosis was the most common complication (seen in 42% of children studied, compared with only 12% of adults) and was a major complication that frequently resulted in graft failure, usually necessitating retransplantation. In six children, reconstitution of the intrahepatic arteries by collaterals was seen. Three survived without retransplant. Arterial stenosis at the anastomosis or in the donor hepatic artery was observed in 11% of patients. Portal vein thrombosis or stenosis occurred in 13% of patients. Two children and one adult with portal vein thrombosis demonstrated hepatopetal collaterals that reconstituted the intrahepatic portal vessels. Uncommon complications included anastomotic and donor hepatic artery pseudoaneurysms, a hepatic artery-dissecting aneurysm, pancreaticoduodenal mycotic aneurysms, hepatic artery-portal vein fistula, biliary-portal vein fistula, hepatic vein occlusion, and inferior vena cava thrombosis.

Adolescent↗
PubMed1985

Angiography of liver transplantation patients.

Over 45 months, 119 angiographic examinations were performed in 95 patients prior to liver transplantation, and 53 examinations in 44 patients after transplantation. Transplantation feasibility was influenced by patency of the portal vein and inferior vena cava. Selective arterial portography, wedged hepatic venography, and transhepatic portography were used to assess the portal vein if sonography or computed tomography was inconclusive. Major indications for angiography after transplantation included early liver failure, sepsis, unexplained elevation of liver enzyme levels, and delayed bile leakage, all of which may be due to hepatic artery thrombosis. Other indications included gastrointestinal tract bleeding, hemobilia, and evaluation of portal vein patency in patients with chronic rejection who were being considered for retransplantation. Normal radiographic features of hepatic artery and portal vein reconstruction are demonstrated. Complications diagnosed using results of angiography included hepatic artery or portal vein stenoses and thromboses and pancreaticoduodenal aneurysms. Intrahepatic arterial narrowing, attenuation, slow flow, and poor filling were seen in five patients with rejection.

Adolescent↗
PubMed1985

Pediatric liver transplantation. Part I. Standardization of preoperative diagnostic imaging.

The preoperative radiologic imaging workups of 44 pediatric liver transplantation patients were reviewed. Biliary atresia (43%) and metabolic disorders (33%) with end-stage liver disease were the leading indications for pediatric liver transplantation at our institution. The radiologic imaging examinations included chest and skeletal radiography, upper gastrointestinal tract series, abdominal ultrasonography (US), computed tomography, angiography, and contrast echocardiography. Abdominal US (performed in 38 of 44 patients) was the pivotal screening imaging examination; it was invaluable in determining the patency and size of the extrahepatic portal vein and inferior vena cava. Angiography is mandatory if this vascular anatomy is not established with certainty on sonograms or if malrotation is seen on the upper gastrointestinal tract series. Congenital malrotation should be differentiated from small bowel malposition caused by portoenterostomy in patients with biliary atresia. Vascular anomalies, especially absent portal vein and/or inferior vena cava, in patients with biliary atresia and polysplenia syndrome may preclude liver transplantation.

Adolescent↗
PubMed1985

Pediatric liver transplantation. Part II. Diagnostic imaging in postoperative management.

The postoperative diagnostic imaging examinations of 44 children who underwent 59 orthotopic liver transplantations were reviewed. The imaging modalities used for the evaluation of suspected complications include plain roentgenography, ultrasonography (US), computed tomography (CT), nuclear scintigraphy, arteriography, percutaneous and operative cholangiography, and endoscopic retrograde cholangiopancreatography. The main postoperative complications included ischemia, thrombosis (hepatic artery and portal vein), infarction, obstruction or leakage of the biliary anastomosis, hepatic and perihepatic infection, and allograft rejection. US, the most frequently used abdominal imaging modality, was best suited for detection of biliary duct dilatation, fluid collections in or around the transplanted liver, and hepatic arterial, inferior vena caval, and portal vein thrombosis. CT was especially helpful in corroborating findings of infection and in locating abscesses. Technetium 99m sulfur colloid (early- and late-phase imaging) provided a sensitive, although nonspecific, means of assessing allograft vascularization and morphology. Angiography showed vascularity most clearly, and cholangiography was the most useful in the assessment of bile duct patency. A diagnostic imaging algorithm is proposed for evaluation of suspected complications.

Adolescent↗
PubMed1985

Cholangiography and interventional biliary radiology in adult liver transplantation.

Radiographic assessment of the biliary tract is often essential in patients who have undergone liver transplantation. T- or straight-tube cholangiography, percutaneous transhepatic cholangiography, and endoscopic retrograde cholangiography all may be used. A total of 264 cholangiograms in 79 adult liver transplant patients (96 transplants) was reviewed. Normal radiographic features of biliary reconstructive procedures, including choledochocholedochostomy and choledochojejunostomy, are demonstrated. Complications diagnosed by cholangiography included obstruction, bile leaks, and tube problems, seen in eight, 24, and 12 transplants respectively. Stretching and incomplete filling of intrahepatic biliary ducts were frequently noted and may be associated with rejection and other conditions. Transhepatic biliary drainage, balloon catheter dilatation of strictures, replacement of dislodged T-tubes, and restoring patency of obstructed T-tubes using interventional radiologic techniques were important in avoiding complications and additional surgery in selected patients.

Adolescent↗
PubMed1983

Low-dose streptokinase for occluded Hickman catheters.

In 14 patients, 16 episodes of occluded Hickman catheters were evaluated by contrast venography. In 13 instances, a fibrin sheath occluding the distal catheter was observed. A mechanical problem was responsible for occlusion in three catheters. Low-dose streptokinase effectively restored lumen patency in 12 catheters (92%) occluded by a fibrin sheath.

Catheterization↗
PubMed1982

Aneurysms in renal oncocytoma.

Renal oncocytoma is a nonaggressive lesion of the kidney that only recently has been defined as a separate entity pathologically. Clinically they are usually silent and are incidental findings on excretory urography. Sonography and computerized tomography demonstrate that it is a solid lesion, but it is only with angiography that a preoperative diagnosis can be suggested. The angiographic signs are summarized, and it is proposed that aneurysms in or associated with a mass now be included in the angiographic spectrum of oncocytoma.

Adenoma↗
PubMed1982

Cystic mesoblastic nephroma.

Mesoblastic nephroma is the most common solid renal neoplasm in the first few months of life. It has been recognized only recently as a distinct entity, having been classified previously as Wilms tumor. There are relatively few ultrasonic descriptions of this entity in the literature. We present an additional case featuring a large peripheral cystic component with a solid central core demonstrated on ultrasonograhy. This feature is not specific for mesoblastic nephroma and occurs in cystic Wilms tumor.

Diagnosis, Differential↗
PubMed1982

Diode array digital radiography: initial clinical experience.

Initial clinical results are described for a new method of digital radiography based on high-detail self-scanning linear diode arrays which overcome many of the limitations of present film or other digital methods. The technique uses a fan-shaped x-ray beam to produce a nearly scatter-free image on a phosphor strip that is fiber-optically coupled to six self-scanning arrays of light-sensitive diodes spaced 0.025 mm, thus providing 6,144 discrete sensors across the field of view. Because these diodes have a greatly expanded dynamic range and operate at very low noise, it becomes possible to visualize small density differences or contrast below 1% both in the light and dark areas of the image. Because of the efficiency of detection and display, radiation doses can be reduced for a given information content. Our preliminary clinical studies have shown to broad application of our method in examining the chest and abdomen and in performing intravenous digital arteriography.

Angiography↗
PubMed1981

Retroperitoneal malignant fibrous histiocytoma: the angiographic and computed tomographic features of an unusual tumor.

Malignant fibrous histiocytomas are uncommon retroperitoneal soft tissue tumors. We report a case of a malignant fibrous histiocytoma of the retroperitoneum that was anmgiographically hypervascular and indistinguishable from renal cell carcinoma. Computerized tomography of the abdomen demonstrated extensive psoas muscle infiltration by tumor. This feature may be useful in differentiating a renal cell carcinoma from a primary retroperitoneal sarcoma.

Adenocarcinoma↗
PubMed1979

Hepatic adenoma associated with portasystemic shunting in a young woman.

The development of a hepatic adenoma is described in a young female of reproductive age who had documented portasystemic shunting and hyperestrogenemia. The intrinsic hyperestrogenemia and the increased hepatic arterial blood flow, both of which occurred as a result of the portasystemic shunting secondary to portal venous obstruction, may have been important factors in the development of her hepatic tumor. We would postulate that prolonged endogenous hyperestrogenemia, like exogenous sex steroids, may predispose to hepatic adenoma formation.

Adult↗
PubMed1975

Postprandial rest pain and claudication of the lower extremity: A case report.

Postprandial rest pain and claudication in the lower extremities may occur in arteriosclerotic aortic occlusion when mesenteric and systemic collateral pathways provide inadequate blood flow to the extremity. The symptoms occur as a result of vasodilation of the distal mesenteric vascular bed with a concomitant increase in mesenteric blood flow which leads to a decrease in mesenteric artery to extremity collateral blood flow. This normal physiologic phenomenon, increase in mesenteric blood flow, causes the extremity pain. Such symptoms indicate a quite significant decrease in blood flow to the extremity, and prompt surgical correction is indicated. Aortofemoral reconstruction yields total reflief of the symptom complex.

Aortic Diseases↗