Portal vein thrombosis and stenosis in pediatric liver transplantation.

The aim of this study was to determine the outcome of venous conduits used in living donor liver transplantation (LDLT). We analyzed the portal vein complications in 66 LDLT recipients and 48 cadaveric reduced-size liver transplant (RLT) recipients performed from November 1989 through January 1995. Three different venous conduits were utilized in the LDLT recipients: Group 1, reconstructed vein from the living donor, n=18; Group 2, cadaveric cryopreserved iliac vein, n=37; and Group 3, cadaveric cryopreserved femoral vein, n=11. Overall, 47 percent of the patients were less than one year of age; the age distribution was not significantly different among the groups. The incidence of early thrombosis was significantly greater in LDLT Group 1, (33%) than any of the other groups (LDLT Group 2, 8%; LDLT Group 3, 9%; and RLT, 4%:P<0.0005 vs. reduced graft and < 0.03 vs. other LDLT groups). The incidence of late portal vein stenosis or thrombosis was significantly higher in the LDLT Group 2, (51%) than any of the other groups (LDLT 1, 16%; LDLT Group 3, 9%; RLT 4%;P<0.005 vs. cadaveric and < 0.02 vs. LDLT Group 1 and LDLT Group 3). Five year arterial graft and patient survival for patients who have experienced portal vein thrombosis or stenosis is 61% and 67%, respectively, versus 67% and 71% for those patients who have not experienced portal vein pathology, P=ns. Based on this experience, we recommend avoiding the use of cryopreserved iliac vein for portal vein reconstruction in liver transplantation. Every effort should be taken to eliminate the need for venous conduits in liver transplantation. If venous conduits must be utilized, cryopreserved femoral veins seem to provide superior patency rates. Careful clinical and ultrasonopraphic monitoring of patients at high risk for late venous thrombosis permits therapy with excellent graft and patient survival.

Magnetic resonance angiography in the preoperative evaluation of abdominal aortic aneurysms.

Magnetic resonance angiography (MRA) and magnetic resonance imaging (MRI) are noninvasive techniques of visualizing blood vessels without the use of intravenous contrast or ionizing radiation. This prospective study assessed preoperative MRA and MRI in the evaluation of 28 patients with abdominal aortic aneurysm (AAA). MRI and MRA accurately predicted the extent of cephalad AAA, the patency of the superior mesenteric artery, and the course of the left renal vein, but were less accurate in defining the extent of caudal AAA, flow of the inferior mesenteric artery, and multiple renal arteries. This study suggests that MRI and MRA are alternatives to the combination of angiography and computed tomographic scan in the preoperative evaluation of patients with suspected AAA and no evidence of mesenteric or renal ischemia. When combined with preoperative segmental Doppler arterial studies, an accurate surgical plan may be formulated. Further refinements in image acquisition and postprocessing software analysis will advance the use of MRI and MRA for complete evaluation prior to elective AAA repair.

Percutaneous transluminal mesenteric angioplasty.

The endovascular treatment of chronic mesenteric ischemia remains in its infancy. This state is most certainly related to the small patient population affected by this devastating condition and the surgeon's limited desire to pursue percutaneous options for this group. Surgical trepidation is not unwarranted because in many facets mesenteric angioplasty is similar to percutaneous carotid intervention. Interventions in these vessels represent manipulation of terminal and unduplicated arterial systems. Complications compromising flow to either vascular bed can yield rapid grave outcomes. Despite this risk, early experience with mesenteric angioplasty for chronic ischemia suggests that it is a viable treatment alternative and that it can be performed with relative safety. A randomized prospective trial of mesenteric angioplasty with operative bypass grafting appears to be the next logical step.

Transjugular intrahepatic portosystemic shunt creation in children: initial clinical experience.

PURPOSE: To assess an initial clinical experience with the creation of a transjugular intrahepatic portosystemic shunt (TIPS) in children. MATERIALS AND METHODS: Twelve consecutive patients with complications of portal hypertension underwent TIPS creation at our institution between July 1993 and September 1996. There were six boys and six girls aged 2 years 5 months to 16 years 10 months (median, 9 years 2 months) who weighed 13.9-80.9 kg (median, 27.65 kg). A standard radiographic technique was used. RESULTS: Thirteen procedures were performed to achieve 12 successful TIPS creations. One child with a reduced-size liver transplant had to undergo two procedures for a successful TIPS creation. No major procedural complications or morbidity occurred. In 10 children, TIPS patency was documented by means of pathologic inspection at orthotopic liver transplantation (median shunt duration, 53 days). Shunt stenosis developed in one child at 186 days but was treated successfully. Two children had functional shunts at 301 and 357 days, respectively. No episodes of repeat variceal hemorrhage were noted. One child developed postprocedural encephalopathy, which responded to medical therapy. CONCLUSION: This initial clinical experience suggests that TIPS creation is technically feasible and is as safe in children as in adults. TIPS creation can aid in the management of portal hypertension in children, especially in those needing temporary relief before liver transplantation.

Radiologic placement of subcutaneous infusion chest ports for long-term central venous access.

OBJECTIVE: The technical success and complications associated with radiologic placement of subcutaneous implantable chest ports for long-term central venous access were evaluated. MATERIALS AND METHODS: Between May 1, 1996, and December 31, 1996, 80 chest ports were placed in 80 consecutive patients using the right internal jugular vein as the preferred access route. All procedures occurred in interventional radiology suites with patients receiving conscious sedation. Both sonography and fluoroscopy were used for venipuncture and to guide port insertion. Follow-up was obtained by the clinical service and by performing chart reviews electronically. RESULTS: Technical success was 100%, and follow-up was obtained in all patients. One procedural complication occurred that was unrelated to actual catheter placement. Mean catheter use was 155 days (total, 12,168 days; range, 18-303 days). Confirmed catheter-related infection rate was 3%, or 0.016 per 100 access days; symptomatic catheter-related central venous thrombosis rate was 1%, or 0.008 per 100 access days; and 5% of catheters were removed prematurely. No instances of hematoma formation, catheter tip migration or malposition, symptomatic air embolism, spontaneous catheter fracture, or pneumothorax were found. CONCLUSION: With the benefit of both sonographic and fluoroscopic guidance, subcutaneous implantable chest ports can be inserted by radiologists with equal or lower complication rates than those reported in surgical series. Image-guided insertion of chest ports should replace rather than supplement unguided placement.

Wallstent deployment to salvage dialysis graft thrombolysis complicated by venous rupture: early and intermediate results.

OBJECTIVE: The feasibility of deploying Wallstents to treat venous rupture occurring during dialysis graft thrombolysis was determined. SUBJECTS AND METHODS: Between June 24, 1994, and February 19, 1997, 23 patients with venous rupture attributed to balloon angioplasty during dialysis graft thrombolysis were treated by Wallstent deployment across the area of rupture. Twenty-one ruptures occurred in peripheral veins and two occurred in central veins. Follow-up was provided by the clinical service at our institution and by electronic review of patients' charts. RESULTS: Stent placement allowed completion of graft thrombolysis in all 23 patients. Complications were limited to four moderate-sized hematomas of the arm, and a single pseudoaneurysm developed 6 months after stent placement in one 27-year-old patient. The primary patency rate of stents was 52% at 60 days, 26% at 180 days, and 11% at 360 days. The secondary patency rate was 74% at 60 days, 65% at 180 days, and 56% at 360 days. CONCLUSION: Treatment of venous ruptures using Wallstents is a safe alternative to intentional graft thrombosis. The patency rates of these devices are similar to those of venous stents placed for other indications.

Angioplasty treatment of portal vein stenosis in children with segmental liver transplants: mid-term results.

OBJECTIVE: Percutaneous venoplasty has showed excellent technical success and excellent early results in treating portal vein stenoses in children with reduced-size liver transplants. We review the mid-term results in 22 children in whom portal venoplasty was attempted. SUBJECTS AND METHODS: During 27 months, percutaneous transhepatic portal venoplasty was attempted in 22 children with portal vein stenoses. Patients presented with symptoms of portal vein hypertension or were identified by routine surveillance with posttransplantation Doppler sonography. All stenoses were verified with angiography. Venoplasty was performed by direct puncture of an intrahepatic portal vein before balloon angioplasty of the stenotic segment. Patients were followed up with sonographic surveillance, and reintervention was performed as needed. In patients who had suboptimal results after portal venoplasty or who developed recurrent stenoses, intravascular stents were placed across stenoses. RESULTS: In 16 of 22 patients, initial clinical and technical success was achieved. In the six patients who underwent unsuccessful procedures, complete occlusion of the portal vein precluded access to the extrahepatic portal vein. Of the 16 patients who underwent successful procedures, intravascular stents were placed at the time of initial venoplasty in five patients for elastic stenosis. In seven other patients, portal vein restenosis occurred after venoplasty (mean, 6.3 months), necessitating intravascular stent placement. Four patients who underwent successful venoplasty without stent placement have required no further intervention. Portal vein patency has been maintained in all 16 patients who underwent technically successful procedures for 4-29 months (mean, 20 months). CONCLUSION: In children with reduced-size liver transplants who experience delayed portal vein stenosis, percutaneous transhepatic portal venoplasty has achieved encouraging mid-term results. It is the procedure of choice in our hospital and often eliminates the need for surgical revision, portacaval shunting, or retransplantation.

Iliac artery patency before and immediately after percutaneous transluminal angioplasty: assessment with time-of-flight MR angiography.

PURPOSE: To assess the efficacy of magnetic resonance (MR) angiography of iliac arteries before and immediately after percutaneous transluminal angioplasty (PTA). MATERIALS AND METHODS: In 14 patients with 22 diseased iliac artery segments (external or common), axial two-dimensional time-of-flight MR angiography was performed. Images were reconstructed with a maximum-intensity-projection (MIP) algorithm. MR angiography was performed 1-4 days after diagnostic digital angiography and 6-24 hours after PTA. Findings obtained before and immediately after PTA were compared for number and location of significant (ie, > 50%) stenoses, length and diameter of balloon to be employed, and diameter of the stenotic artery after PTA. Linear regression analysis was performed. RESULTS: Sensitivity and specificity of MR angiography for determination of significant stenoses were 95% and 97%, respectively. Before PTA, balloon dimensions depicted on MR angiograms and digital angiograms were well correlated (r = .76, P < .05). After PTA, MR angiograms and digital angiograms provided similar findings in all but one case. CONCLUSION: MR angiography helped determine if PTA is indicated and depicted iliac artery patency after PTA.

Portal vein stenosis in children with segmental liver transplants: treatment with percutaneous transhepatic venoplasty.

OBJECTIVE: We reviewed the early results of percutaneous portal venoplasty as a method of treating portal vein stenosis in 11 children with reduced-size liver transplants. SUBJECTS AND METHODS: Percutaneous transhepatic portal venoplasty was attempted in 11 children with portal vein stenoses over a period of 9 months. The venoplasty was performed by direct puncture of an intrahepatic portal vein followed by balloon angioplasty of the stenotic segment. Patients presented with symptoms of portal venous hypertension or were identified by routine surveillance with posttransplant Doppler sonography. All stenoses were verified with angiography before portal venoplasty was attempted. In patients with suboptimal results after portal venoplasty or who developed recurrent stenoses, intravascular stents were placed across stenoses. RESULTS: In eight of 11 patients, initial clinical and technical success was achieved. Intravascular stents were placed in two of these patients. In the three unsuccessful procedures, complete occlusion of the portal vein precluded vascular access. Two procedure-related complications and one nonprocedure-related complication developed. In one patient, the portal vein restenosed after 6 months, and a metallic intravascular stent was placed to alleviate the stenosis. Portal vein patency in all other successful procedures has been maintained for 3-9 months (mean, 6.1 months) without further intervention. CONCLUSION: Percutaneous transhepatic portal venoplasty of portal vein stenosis in children with living, related liver transplant donors has excellent early results. In patients with this complication, the procedure has become the initial choice in our hospital, eliminating the need for surgical revision, portacaval shunting, or retransplantation.

Radiologically guided placement of pull-type gastrostomy tubes.

PURPOSE: To evaluate percutaneous placement of pull-type gastrostomy tubes that has traditionally necessitated endoscopic guidance. MATERIALS AND METHODS: From September 1995 through March 1997, 63 pull-type gastrostomy tubes were placed in 64 patients. Retrograde catheterization of the esophagus was performed through the stomach. Then the gastrostomy tube was pulled through from the mouth into the stomach. RESULTS: Gastrostomy tube placement was successful in 63 (98%) of 64 patients in 65 attempts. One procedure was stopped when the patient reported chest pain after gastric insufflation, and a second placement attempt was initially unsuccessful. Major complications occurred in three (5%) patients: exit site infection necessitating tube removal (n = 2) and prolonged bleeding necessitating transfusion (n = 1). Minor complications occurred in six (9%) patients: failure of placement (n = 2), exit site infection (n = 1), leakage around the tube (n = 1), tube migration (n = 1), and inadvertent tube removal (n = 1). There were no cases of peritonitis, tract disruption, or gastrostomy-related death. CONCLUSION: Percutaneous placement of a pull-type gastrostomy tube was performed with a minimum risk of tract disruption and peritonitis. The tube was safely and effectively placed by radiologists.