Hydrodynamic thrombectomy of hemodialysis fistulas: first clinical results

PURPOSE: A hydrodynamic thrombectomy system was used for the treatment of recent dialysis shunt thrombosis. PATIENTS AND METHODS: Sixteen shunt thromboses in 14 patients were included in the study. There were seven polytetrafluoroethylene grafts and nine native arteriovenous fistulas. Occlusion time ranged from 6 to 48 hours, and thrombus length ranged from 4 to 40 cm. RESULTS: Thrombectomy was technically successful in 15 of 16 instances. No significant residual thrombus was found in 15 cases. In one case, half of the thrombus remained in the vessel and the procedure failed technically. One embolus to the radial artery occurred after balloon dilation following hydrodynamic thrombectomy and was removed percutaneously. Early rethrombosis within 24 hours occurred in five shunts; four more rethrombosed within 2 weeks to 3 months. Eleven shunts were available for follow-up. Cumulative patency was 41% after 6 months. CONCLUSION: Hydrodynamic thrombectomy is a promising concept for declotting of both hemodialysis grafts and native shunts and may offer an alternative to thrombolysis and surgical thrombectomy.     

Mixed bacterial meningitis: a complication of ventriculo- and lumboperitoneal shunts

Infectious complications of ventriculo- and lumboperitoneal shunts in two patients are presented. Cerebrospinal fluid infection due to aerobic and anaerobic enteric flora was characteristic of each case. Both infections occurred several months after shunt surgery and were associated with colonic perforation by the distal limb of the peritoneal catheter. These cases emphasize this unusual hazard of peritoneal shunts and demonstrate methods for diagnosis and effective therapy.     

Gram-negative cerebrospinal fluid shunt-associated infections

Twenty hydrocephalic children with cerebrospinal fluid (CSF) shunts over an 11-year period were seen with Gram-negative central nervous system (CNS) infections. Seventeen infections were with single organisms and three were mixed. Sixteen of 20 (80%) of the infections occurred within five months of shunt surgery. Complete shunt removal or replacement in a new site plus systemic and intraventricular antibiotics resulted in a 100% (9/9) cure rate. Systemic and intraventricular antibiotics alone or in combination with incomplete shunt removal generally were unsuccessful. Significant morbidity and mortality were associated with these infections. Of the 18 patients with follow-up data, seven (39%) died with the infection, four (22%) sustained definite CNS damage, three (17%) were retarded after infection but their preinfection status was unknown, and only four (22%) patients escaped without definite sequela. Early recognition and appropriate therapy, hopefully, will improve the current bleak prognosis     

Outcome of 100 patients after transjugular intrahepatic portosystemic shunt for variceal hemorrhage

OBJECTIVES: One hundred consecutive patients with recurrent or refractory acute variceal hemorrhage treated with a transjugular intrahepatic portosystemic shunt (TIPS) from June 1990 to June 1993 at Oregon Health Sciences University or the Portland Veterans Affairs Medical Center were evaluated to assess shunt patency and clinical outcome, including complications of TIPS, rebleeding, and survival. METHODS: Success of shunt placement, reduction in portal pressure, complications, survival, recurrent hemorrhage, severity of ascites, hepatic encephalopathy before and after TIPS, and shunt patency were assessed in each patient. RESULTS: The mean follow-up period was 17.7 months (range, 0.1-56.7 months). TIPS was successfully completed in all patients, with a mean reduction in portosystemic gradient from 24 to 11 mm Hg. Major complications occurred in 11 patients, including one death. Survival after TIPS was 85% at 30 days, 71% at 1 yr, and 56% at 2 yr. Variceal bleeding stopped within 24 hours after TIPS in all eight patients with active hemorrhage. Recurrent variceal hemorrhage occurred in 18 patients at a mean of 4.3 months (range, 1-713 days) after TIPS. The cumulative rate of recurrent variceal bleeding was 20% at 1 yr and 25% at 2 yr after TIPS. Recurrent variceal bleeding was associated with shunt stenosis or occlusion in all patients with endoscopically documented variceal hemorrhage, which was successfully managed by reopening obstructed shunts and performing variceal embolization. The prevalence of ascites was significantly reduced among surviving patients evaluated 3 months after TIPS (67 vs 25%, p < 0.005). Three months after TIPS, the incidence of new or worsening hepatic encephalopathy was 20%, but encephalopathy improved in an equal proportion of patients. Seventy-three of 77 (95%) shunts examined for patency were open at the last follow-up examination. However, most shunts required intervention to maintain patency, and only 48% (37 of 77) were primarily patent at a mean of 168 days (range, 2-538 days) of follow-up. Shunt stenosis or occlusion, as determined by venography, became increasingly frequent with longer follow-up (52% at 3-9 months and 70% at 9-15 months). CONCLUSIONS: TIPS is effective in lowering elevated portal pressures in patients with refractory variceal hemorrhage, has acceptable postprocedure complication and mortality rates, ameliorates ascites, and in, a minority of patients, worsens encephalopathy. Shunt stenosis occurs in the majority of patients but can be effectively treated by interventional techniques to maintain patency. The incidence of recurrent variceal hemorrhage is low and is associated with shunt stenosis or occlusion.     

Identification of dipeptidyl peptidase IV as the antigen of a monoclonal anti-prostasome antibody

Two patients with previous distal splenorenal shunts (DSRSs) performed 6 years earlier underwent liver transplantation (LT). A preoperative selective mesenteric artery angiogram showed collateral veins draining mesenteric venous flow into the shunt. Intraoperative flow measurements were performed to assess the steal of portal venous flow by the shunt and determine the need for shunt occlusion. Portal vein, hepatic artery, and shunt flows were measured by ultrasound transit-time flow probes in the native liver and after graft implantation with and without temporary shunt occlusion. Hemodynamic studies showed that long-standing DSRSs are high-flow shunts that steal portal flow. After graft implantation, DSRS flows remained high. Occlusion of the shunts produced an increase in portal vein flow at an amount similar to those of splenorenal shunt. Thus, the flow measurements showed persistent steal by the shunts after graft implantation and, therefore, the DSRSs were occluded but splenectomy was not performed. We conclude that the decision to occlude a DSRS should be based on the demonstration of steal of portal flow by the shunt and reversibility once the shunt is occluded. Splenectomy is not required when the DSRS is occluded.     

Treatment of hemorrhages by rupture of cardio-tuberous varices with transjugular intrahepatic portasystemic shunt

Twelve consecutive patients admitted for bleeding from ruptured gastric varices were treated with transjugular intrahepatic portosystemic shunts and followed for a mean of 6 +/- 3 months (range: 8-293 days). The shunt was performed successfully in all 12 patients. The shunt occluded in 3 patients (respectively 19, 101 and 103 days after insertion) of whom one remained asymptomatic and two experienced rebleeding. Four patients presented with acute encephalopathy, spontaneously in two and after rebleeding in two. Three patients died, two after rebleeding and one of septic shock secondary to pneumonia. Overall, 9 patients survived a mean of 211 +/- 92 days with no rebleeding, 8 of whom have not yet experienced any complications. These results suggest that transjugular intrahepatic portosystemic shunts could be useful in treating hemorrhages from ruptured gastric varices and in preventing their recurrence.     

CT and MRI in detection of intrahepatic portosystemic shunts in patients with liver cirrhosis

OBJECTIVE: Our goal was to determine the prevalence and anatomic location of intrahepatic portosystemic shunts (IPSs) in patients with hepatic cirrhosis as shown by CT and MRI. MATERIALS AND METHODS: We retrospectively reviewed CT and MR scans of 33 cirrhotic patients who had IPSs. In addition, two series of 100 consecutive CT or MR were reviewed to determine the prevalence of IPSs and the percentage of intrahepatic and extrahepatic paraumbilical veins. RESULTS: Intrahepatic portosystemic shunts were divided into three groups according to the intrahepatic course: paraumbilical shunt between the left portal vein and the paraumbilical vein anterior to the liver (n = 29); inferior vena caval shunt between the posterior branch of the right portal vein and the inferior vena cava (n = 2); and miscellaneous (n = 2). Shunts of the paraumbilical type ran through the medial (n = 23), lateral (n = 3), or both medial and lateral (n = 3) segments of the left lobe of the liver. Twenty-five patients had one shunt, and four had more than one. Six cases were also associated with extrahepatic paraumbilical veins. CONCLUSION: Intrahepatic portosystemic shunts, especially the paraumbilical type, were not infrequently visualized in patients with hepatic cirrhosis.     

CT-angiography as a non-invasive method for the evaluation of the patency of TIPSS (transjugular intrahepatic portasystemic shunt)

PURPOSE: To evaluate the feasibility of determining patency of the transjugular intrahepatic portosystemic shunt (TIPSS) by non-invasive CT angiography (CTA). MATERIALS AND METHODS: (1) Non-enhanced scanning of the shunt. (2) Bolus tracking by injecting 20 ml of non-ionic contrast material through a cubital vein access to determine the time to maximal shunt enhancement. (3) Contrast-enhanced spiral CT study applying a delay according to the time to peak of the shunt, 3 mm collimation, 5 mm table feed and 3 mm reconstruction interval. (4) 3D and multiplanar reconstructions. (5) Evaluation of the questions: intrahepatic shunt patent or not; evidence of intimal hyperplasia; evidence of stenosis and potential location. (6) Transjugular portography via the stent. (7) Comparison of angiographic findings and CT morphology. RESULTS: Eight patients had inconspicuous CTA. Four of them had a normal shunt at angiography, four had slight intimal hyperplasia. No intervention was necessary in these patients. CTA of three patients showed intimal hyperplasia (lumen reduction between 10% and 50%). The diagnosis was angiographically confirmed in all cases. Due to a high portosystemic gradient intervention was required in all. In five patients CTA and angiography showed a stenosis (reduction of shunt lumen > 50%). All required a revision including stent placement or PTA of the shunt tract. Four shunts were occluded; all occlusions were shown both in CTA and angiography. CONCLUSIONS: None of the shunts with normal findings at CTA required revision. All shunts conspicuous on CTA resulted in revision. In this study, CTA turned out to be an accurate, non-invasive method to evaluate the patency of TIPSS.     

A comparison between ventriculo-peritoneal and ventriculo-atrial cerebrospinal fluid shunts in relation to rate of revision and durability

Results of 884 first-time shunts inserted in the time period from 1958 to 1989 are retrospectively evaluated, 1) to perform a durability analysis of a shunt based on Kaplan-Meyer method, 2) to compare the rate of revision for ventriculo-atrial (VA) and ventriculo-peritoneal (VP) shunts, 3) to compare the durability of a VA shunt with a VP shunt and 4) to do a stratified durability analysis comparing the VA and VP shunts in relation to the following background variables: shunt type, time period and age of the patient. Furthermore the specific complications related to VA and VP shunts are identified based on findings in the literature. Overall one-year shunt durability is 57% and five-year shunt durability is 37%. The median shunt durability is 1.68 years. Revision rate is 51% for VA shunts and 38.5% for VP (p < 0.05). Shunt durability is longer for VP shunts though the difference is not significant (p < 0.1). By use of stratified analysis of shunt durability no differences however are found between the two shunting methods. Hence the apparent difference in revision rate between VA and VP shunts seems secondary to variations in follow-up time and variations in background variables. To supplement our statistical analysis we have performed a literature study to look at the specific complications associated with VA and VP shunts. It seems as if the specific complications in relation to the VA shunting method are more severe than in relation to the VP shunting method.     

Maternal shunt dependency: implications for obstetric care, neurosurgical management, and pregnancy outcomes and a review of selected literature

OBJECTIVE: Because more women with cerebrospinal fluid shunts are surviving to child-bearing age, neurosurgeons, obstetricians, and other health care professionals require information about the care of these patients, especially during pregnancy and delivery. The purpose of this study was to gather comprehensive data from women with shunts regarding their clinical histories during and immediately after pregnancy. The following questions were addressed. 1) How does maternal shunt dependency influence the course of pregnancies and pregnancy outcomes? 2) What neurosurgical complications characterize this population of patients? 3) What complications of shunt dependency influence obstetric management, including prenatal testing and delivery? METHODS: A total of 37 respondents (age, 18-41 yr), accounting for 77 pregnancies, completed a questionnaire providing information on maternal background and medical history, shunt performance during pregnancy, management of delivery, pregnancy outcomes, and unusual complications. RESULTS: Fifty-six pregnancies resulted in live births; of these, 47 occurred in women with ventriculoperitoneal shunts. Three women underwent therapeutic abortions, 1 experienced preterm delivery, and 8 experienced 17 miscarriages. Four women experienced seizures during pregnancy, five reported third-trimester headaches, and eight described abdominal pains during the first and third trimesters. Four babies were diagnosed as having congenital defects. Shunt malfunctions and revisions occurred 10 times in 7 women, either during pregnancy or within 6 months after delivery. No acute malfunctions occurred during delivery. Forty-seven cases, representing 84% of all pregnancies, exhibited no shunt malfunctions or revisions. CONCLUSION: This study extends previous observations to a larger population of shunt-dependent mothers. The results suggest that maternal shunt dependency entails a relatively high incidence of complications but that proper care of these patients can lead to normal pregnancies and deliveries.     

Prospective randomized comparison of surgical versus endovascular management of thrombosed dialysis access grafts

PURPOSE: Salvage of thrombosed prosthetic dialysis shunts can be performed using surgical or endovascular techniques. A prospective randomized trial was designed to compare the efficacy of these two methods in restoring dialysis access function. METHODS: One hundred fifteen patients with thrombosed dialysis shunts were randomized prospectively to surgical (n = 56) or endovascular (n = 59) therapy. In the surgical group, salvage was attempted with thrombectomy alone in 22% and with thrombectomy plus graft revision in 78%. In the endovascular group, graft function was restored with mechanical (82%) or thrombolytic (18%) graft thrombectomy followed by percutaneous angioplasty. RESULTS: Stenosis limited to the venous anastomotic area was the cause of shunt thrombosis in 55% of patients, and long-segment venous outflow stenosis or occlusion was the cause in 30%. In 83% of the surgical group and in 72% of the endovascular group, graft function was immediately restored (p = NS). The postoperative graft function rate was significantly better in the surgical group (p < 0.05). Thirty-six percent of grafts managed surgically remained functional at 6 months and 25% at 12 months. In the endovascular group, 11% were functional at 6 months and 9% by 12 months. Patients with long-segment venous outflow stenosis or occlusion had a significantly worse patency rate than those with venous anastomotic stenosis (p < 0.05). CONCLUSIONS: Neither surgical nor endovascular management resulted in long-term function for the majority of shunts after thrombosis. However, surgical management resulted in significantly longer primary patency in this patient population, supporting its use as the primary method of management in most patients in whom shunt thrombosis develops.     

Pulmonary regurgitation in large atrial shunts without pulmonary hypertension

Seven patients with pulmonary regurgitation (PR), normal pulmonary artery (PA) pressures and large left-to-right atrial shunts are reported. Six had secundum atrial septal defects (ASD) and one had anomalous pulmonary venous drainage. These comprised 4% of 180 patients with atrial shunts and normal PA pressures. Pulmonary regurgitation was diagnosed clinically by mid-frequency diastolic decrescendo murmurs beginning after the pulmonic component of the second heart sound, and diagnoses were confirmed by catheterization. In two patients who had serial preoperative catheterizations over 8 and 16 years, PR progressed in one and was present only on the second study in the other. All patients underwent shunt correction, at which time the pulmonic anulus and artery appeared dilated, but the pulmonic valves were normal and did not require revision. In all patients the PR murmur disappeared after shunt correction alone, and on chest X-ray both PA and overall heart size decreased. Although it is known that pulmonary regurgitation occurs with atrial septal defects and pulmonary hypertension, the present study demonstrates that it also occurs with high flow atrial shunts, in which setting it has different implications and is reversible with shunt correction alone.     

Transjugular intrahepatic portosystemic shunt. Treatment of patients with recurrent bleeding from esophageal varices

We report the results of transjugular intrahepatic portosystemic shunt (TIPS) procedure in six patients with liver cirrhosis and recurrent bleeding or acute intractable bleeding from oesophageal varices in spite of multiple sessions of sclerotherapy. Median follow-up was 15 months (range 1-24 months). The procedure was technically successful in all patients without procedure-related morbidity or mortality. Four of the procedures were performed electively and two as an emergency procedure. The portosystemic pressure gradient decreased to below 12 mmHg following TIPS implantation and the shunt bloodflow was one quarter to three-quarters of the portal bloodflow determined by Doppler ultrasound. Recurrent bleeding occurred in one patient but was amenable to endoscopic sclerotherapy. In this patient the shunt had developed a stenosis that was treated by balloondilatation and insertion of an additional stent six months following the initial procedure, and no further bleeding occurred. The remaining five patients had no rebleeding episodes. Repeated Doppler examinations in the followup period demonstrated patency of all shunts. None of the patients developed portosystemic encephalopathy. One patient died of cerebral haemorrhage, unrelated to TIPS, 16 months following implantation. Another patient died 14 months following TIPS due to acute mesenteric occlusion and septicaemia. We conclude that TIPS is feasible and effective in selected patients with liver cirrhosis and persistent or recurrent variceal bleeding following repeated endoscopic therapy.     

French experience in the closure of atrial septal defects of the ostium secundum type with the Sideris button occluder

From February 1992 to November 1995, four French teams used the Sideris button occluder to close 122 ostium secundum, foramen ovale or surgical fenestration atrial septal defects in 121 patients aged 2 to 79 years with body weights of 10 to 96 kg. a left-to-right shunt in 110 cases (average QP/QS = 2.09) or right-to-left shunt in 12 cases. The usual type of prosthesis was used in 115 cases, 8 centered on a guide wire, reverse type in 5 cases and the "centering-device" type in 2 patients. Nineteen implantation attempts were abandoned before releasing the prosthesis. The immediate results were: closure of the atrial septal defect in 116 patients: 59 were completely occluded, 43 had minimal residual shunts. Five patients were operated for non-buttoning or malposition of the prosthesis. In one other case, the device was removed by catheterisation. During follow-up ranging from 1 month to 3 years, 20 patients were operated for varying complications, the commonest of which was malposition of the prosthesis (17 cases) with a shunt of variable volume. In one other case, a second device was inserted. Seventy-seven patients were reviewed at 1 year, 28 a 2 years and 6 at 3 years. The residual shunts decreased with time but only completely disappeared in half the cases. Secondary fractures not requiring surgery were observed in 5 patients. Failures and complications were the result of various causes which are discussed. Successive technological improvements and the experience of the medical teams should reduce this incidence, but caution is required especially in the treatment of young children.     

Angiographic characteristics of infarct-related and non-infarct-related stenoses in patients in whom stable angina progressed to acute myocardial infarction

OBJECT: This study was conducted to evaluate the results of shunting procedures for syringomyelia. METHODS: In a follow-up analysis of 42 patients in whom shunts were placed in syringomyelic cavities, the authors have demonstrated that 21 (50%) developed recurrent cyst expansion indicative of shunt failure. Problems were encountered in patients with syringomyelia resulting from hindbrain herniation, spinal trauma, or inflammatory processes. A low-pressure cerebrospinal fluid state occurred in two of 18 patients; infection was also rare (one of 18 patients), but both are potentially devastating complications of shunt procedures. Shunt obstruction, the most common problem, was encountered in 18 patients; spinal cord tethering, seen in three cases, may account for situations in which the patient gradually deteriorated neurologically, despite a functioning shunt. CONCLUSIONS: Placement of all types of shunts (subarachnoid, syringoperitoneal, and syringopleural) may be followed by significant morbidity requiring one or more additional surgical procedures.     

The changing spectrum of treatment for variceal bleeding

OBJECTIVE: The objective of this study was to assess the impact of endoscopic therapy, liver transplantation, and transjugular intrahepatic portosystemic shunt (TIPS) on patient selection and outcome of surgical treatment for this complication of portal hypertension, as reflected in a single surgeon's 18-year experience with operations for variceal hemorrhage. SUMMARY BACKGROUND DATA: Definitive treatment of patients who bleed from portal hypertension has been progressively altered during the past 2 decades during which endoscopic therapy, liver transplantation, and TIPS have successively become available as alternative treatment options to operative portosystemic shunts and devascularization procedures. METHODS: Two hundred sixty-three consecutive patients who were surgically treated for portal hypertensive bleeding between 1978 and 1996 were reviewed retrospectively. Four Eras separated by the dates when endoscopic therapy (January 1981), liver transplantation (July 1985), and TIPS (January 1993) became available in our institution were analyzed. Throughout all four Eras, a selective operative approach, using the distal splenorenal shunt (DSRS), nonselective shunts, and esophagogastric devascularization, was taken. The most common indications for nonselective shunts and esophagogastric devascularization were medically intractable ascites and splanchnic venous thrombosis, respectively. Most other patients received a DSRS. RESULTS: The risk status (Child's class) of patients undergoing surgery progressively improved (p = 0.001) throughout the 4 Eras, whereas the need for emergency surgery declined (p = 0.002). The percentage of nonselective shunts performed decreased because better options to manage acute bleeding episodes (sclerotherapy, TIPS) and advanced liver disease complicated by ascites (liver transplantation, TIPS) became available (p = 0.009). In all Eras, the operative mortality rate was directly related to Child's class (A, 2.7%; B, 7.5%; and C, 26.1 %) (p = 0.001). As more good-risk patients underwent operations for variceal bleeding, the incidence of postoperative encephalopathy decreased (p = 0.015), and long-term survival improved (p = 0.012), especially since liver transplantation became available to salvage patients who developed hepatic failure after a prior surgical procedure. There were no differences between Eras with respect to rebleeding or shunt occlusion. Distal splenorenal shunts (p = 0.004) and nonselective shunts (p = 0.001) were more protective against rebleeding than was esophagogastric devascularization. CONCLUSIONS: The sequential introduction of endoscopic therapy, liver transplantation, and TIPS has resulted in better selection and improved results with respect to quality and length of survival for patients treated surgically for variceal bleeding. Despite these innovations, portosystemic shunts and esophagogastric devascularization remain important and effective options for selected patients with bleeding secondary to portal hypertension.     

The role of endoscopic third ventriculostomy in the management of shunt malfunction

OBJECTIVE: To evaluate the effectiveness of third ventriculostomy as an alternative to shunt revision in the management of shunt malfunction and infection in obstructive hydrocephalus. METHODS: All of the clinical notes of 30 patients treated with third ventriculostomy for malfunctioning or infected shunts between January 1, 1974, and December 31, 1996, were retrospectively reviewed. Third ventriculostomy was performed under fluoroscopic control in the first seven patients and endoscopically in the remainder. A successful outcome was achieved if further shunt revision surgery was avoided. The median follow-up duration was 8.7 years RESULTS: Twenty-three patients (76.7%) experienced successful outcomes, resulting in shunt independence. Of the seven failures, three were technical failures at the time of surgery and the remaining four were manifest within a median of 10 days, resulting in shunt revision. There have been no delayed failures. CONCLUSION: Third ventriculostomy is a valuable alternative to shunt revision in patients affected by obstructive hydrocephalus presenting with shunt malfunction or infection. It should be considered in all suitable cases as the first-line treatment for obstructive hydrocephalus of all causes. Because all failures were manifest within a short time, it is likely that these successes will be durable.     

Clinical and laboratory experience with heparin-impregnated silicone shunts for carotid endarterectomy

Our experience with use of a Silastic shunt for carotid endarterectomy is reviewed briefly, and the complication of shunt thrombosis despite intraoperative administration of heparin is noted. Of obvious importance are the reduction of blood flow and the possibility of embolization caused by accumulating thrombus. Shunt thrombosis has been abolished by the use of heparin-impregnated Silastic shunts. In experiments in dogs, such heparin-treated shunts showed greater thromboresistance than did untreated shunts.     

Transjugular intrahepatic portosystemic shunts (TIPS) in children

The transjugular intrahepatic portosystemic shunt procedure is an accepted treatment for adults with complications of portal hypertension. We performed a retrospective review of all pediatric TIPS placements performed at the University of California, San Francisco between 1990 and 1996. Twelve procedures were attempted in nine children, with a mean age (+/- SD) of 9.4 +/- 3.9 years (range, 5 to 15 years) and a mean weight of 31 +/- 18 kg (range, 16 to 70 kg). The indications for TIPS placement were portal hypertension complicated by chronic variceal hemorrhage not controlled with sclerotherapy (n = 7) and hypersplenism with thrombocytopenia (n = 2). TIPS placement was successfully completed initially in seven of nine (78%) patients. Unfavorable vascular anatomy was the cause of failure in two cases. The seven patients who underwent successful TIPS placement were followed up for an average of 136 days (range, 1 to 800 days); two still have patent shunts, three underwent liver transplantation, one had a splenorenal shunt after stenosis, and one died of underlying liver disease. Variceal bleeding was controlled in four of five patients who successfully underwent TIPS placement. Shunt occlusion occurred in four patients; patency was restored by transjugular shunt revision in three, and a splenorenal shunt was performed in one.     

Nontumorous arterioportal shunt mimicking hypervascular tumor in cirrhotic liver: two-phase spiral CT findings

PURPOSE: To determine the two-phase (hepatic arterial phase [HAP] and portal venous phase [PVP]) spiral computed tomographic (CT) findings of a nontumorous arterioportal shunt in the cirrhotic liver that can mimic a hypervascular tumor. MATERIALS AND METHODS: For 14 months, 803 patients with known or suspected hepatocellular carcinoma were referred for initial or repeated transcatheter arterial chemoembolization (TACE). Twenty-nine hyperattenuating lesions on HAP CT images obtained in 25 patients (23 men, two women; age range, 39-70 years) were regarded as nontumorous arterioportal shunts and were included in this study. The diagnosis of nontumorous arterioportal shunt was established by four radiologists who reviewed the two-phase spiral CT images and hepatic angiograms. RESULTS: The longest dimension of the lesion was 1.0-7.9 cm (mean dimension, 2.9 cm). The morphology at HAP CT was wedge-shaped in 25 (86%), geographic (ie, focal area with irregular outline) in two (7%), and nodular in two (7%) lesions. All lesions were homogeneous in attenuation. Hyperattenuating linear branching structures that represented early opacification of portal veins were demonstrated during the HAP in nine (31%) lesions. PVP CT images showed these lesions as isoattenuating (n = 20 [69%]) or slightly hyperattenuating (n = 9 [31%]). Iodized oil CT images showed faint or no accumulation of iodized oil in all lesions. CONCLUSION: In cirrhotic liver, nontumorous arterioportal shunts can be a cause of pseudolesions that mimic hypervascular tumors at two-phase spiral CT. Lesions that have the typical wedge-shaped and homogeneous appearance with or without internal linear branching structures during the HAP and that are isoattenuating or slightly hyperattenuating during the PVP can suggest this unusual condition.