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Biomedical subjects

Brian Funaki

Publications and source records attributed to Brian Funaki.

At least 19 recordsLinked to original sources

Percutaneous treatment of venous outflow obstruction in pediatric liver transplants.

PURPOSE: To evaluate the efficacy and safety of percutaneous dilation in the treatment of impaired venous outflow in pediatric patients with liver transplants. MATERIALS AND METHODS: Review was undertaken of the records of 35 procedures to dilate impaired venous outflow in 16 consecutive children (aged 11 days to 17.8 years; mean, 7.2 +/- 5.8 y) after liver transplantation over a period of 8 years. Patients presented clinically with signs or symptoms of obstruction of the hepatic venous or inferior vena cava anastomosis and/or abnormal noninvasive imaging findings and were referred primarily to the interventional radiology department for treatment. None were excluded. Technical and clinical success rates were calculated. After venoplasty, patients with incomplete venographic resolution or pressure gradients exceeding 5 mm Hg were treated with stents. Seven died or required repeat transplantation during the study period for reasons unrelated to venous outflow obstruction. Patency rates were calculated for all other patients with sufficient follow-up in the pediatric hepatology clinic. RESULTS: The combined technical success rate for venoplasty (12 of 16) and stent placement (three of 16) was 94% (15 of 16), and the clinical success rate was 81% (13 of 16). One minor complication occurred: a transient hypoxic episode. Primary patency rates were 72.7% (eight of 11) at 3 months, 60% (six of 10) at 6 months, 55.6% (five of nine) at 12 months, 50% (four of eight) at 18 months, and 50% (three of six) at 36 months. Primary assisted and secondary patency rates were 90.9% (10 of 11) at 3 months, 90% (nine of 10) at 6 months, 88.9% (eight of nine) at 12 months, 87.5% (seven of eight) at 18 months, and 83.3% (five of six) at 36 months. CONCLUSIONS: Excellent technical and clinical success rates can be achieved with percutaneous dilation of impaired venous outflow after pediatric liver transplantation. Long-term patency may require repeated interventions.

Adolescent↗

Removal of Günther Tulip vena cava filter through femoral vein approach.

The Günther Tulip vena cava filter is designed for removal by the internal jugular vein approach with use of a blunted hook placed at the superior aspect of the filter. Removal of this filter was performed by the femoral approach in a patient with central venous occlusion that precluded removal by the conventional approach.

Anticoagulants↗

Percutaneous declotting of virgin femoral hemodialysis grafts.

OBJECTIVE: The objective of our study was to evaluate outcomes of percutaneous declotting procedures in patients with prosthetic femoral dialysis grafts. MATERIALS AND METHODS: A retrospective review of all pharmacomechanical femoral dialysis graft declotting procedures performed in our hospital between May 11, 1993, and April 30, 2003, was performed. A total of 110 procedures were performed on 25 patients (nine males, 16 females; age range, 17-80 years; mean age, 49 years) with 30 grafts. RESULTS: Technical success was 97.3%. Using life table analysis, 30-day postinterventional primary patency was 72%, 90-day primary patency was 46%, 180-day primary patency was 25%, and 365-day primary patency was 4%. The 30-day secondary postinterventional patency was 93%, 90-day secondary patency was 86%, 180-day secondary patency was 76%, and the 365-day secondary patency was 51%. An average of 1.96 declotting procedures were performed per year of dialysis. CONCLUSION: Percutaneous declotting of femoral hemodialysis grafts has technical success and patency rates similar to those for percutaneous declotting in the upper extremities. Results of this series exceeded criteria established by the National Kidney Foundation in the "Dialysis Outcome Quality Initiative" for immediate patency and unassisted 3-month patency.

Adolescent↗

Balloon dilatation of biliary-enteric strictures in children.

OBJECTIVE: The objective of our study was to evaluate the efficacy and safety of balloon dilatation in the treatment of anastomotic strictures in children with liver transplants. MATERIALS AND METHODS: For a period of 7 years, we treated 20 consecutive biliary-enteric strictures in 19 children (age range, 13 months to 17.9 years, mean, 7.3 years) with balloon dilatation. Dilatation was performed between 30 days and 8.4 years (mean, 2.6 years) following surgical creation of the biliary-enteric anastomosis. Thirteen patients had left lateral segment liver transplant grafts, one patient had a split-liver, left-lobe graft, and five patients had whole liver grafts. RESULTS: Technical success was 100% and there were no procedure-related complications. One patient with a patent anastomosis underwent repeat transplantation 183 days after the procedure for chronic rejection. In 58% (11/19) of the remaining procedures, balloon dilatation resulted in biliary-enteric patency at one year, and continued patency ranges from 1.4 to 5.4 years (mean, 3.6 years). In 40% (8/20) of the procedures, the biliary-enteric stricture persisted after balloon dilatation, and these patients eventually underwent surgical revision, retransplantation, or endobiliary metallic stent placement. CONCLUSION: Balloon dilatation is a safe and effective treatment for biliary-enteric strictures following pediatric liver transplantation.

Adolescent↗

Microcatheter embolization of lower gastrointestinal hemorrhage: an old idea whose time has come.

Early attempts of using embolization for lower gastrointestinal hemorrhage were fraught with complications, most notably ischemic colitis or bowel infarction. Embolotherapy was eventually abandoned in favor of catheter-directed vasoconstriction (i.e., vasopressin infusion). This latter therapy is time and labor intensive. With the advent of microcatheter technology, superselective embolization emerged and is rapidly becoming the endovascular therapy of choice for patients with severe lower gastrointestinal hemorrhage refractory to medical management. Numerous studies on the subject have consistently reported high clinical success with low ischemic complications. This article will review the current status of co-axial microcatheter embolization with an emphasis on the technical aspects of the procedure.

Catheterization, Peripheral↗

Patterns of referral for inferior vena caval filtration: delays and their impact.

OBJECTIVE: We sought to study the referral patterns for inferior vena caval filtration and explore the relationship between delays in filter insertion and clinical outcomes. MATERIALS AND METHODS: We retrospectively reviewed 101 consecutive inferior vena caval filters inserted in 101 patients in a university hospital between the June 2000 and July 2001. A time line was created listing the time of diagnosis of deep venous thrombosis or pulmonary embolism, contraindication or complication of anticoagulation therapy, and time of insertion of inferior vena caval filter. RESULTS: The average elapsed time between the clinical indication for caval filtration and filter placement in all patients was 1.64 days (range, 0-17 days). Two patients (2%) sustained pulmonary emboli after being diagnosed with deep venous thrombosis before receiving a filter. The lengths of time between filter indication and insertion for these patients were 2 and 8 days. CONCLUSION: In our hospital, there are wide variations in perceived urgency of vena caval filtration. In two patients, delays longer than 24 hr between indication and insertion of inferior vena caval filters resulted in symptomatic pulmonary emboli.

Adult↗

Complication rates and patency of radiologically guided mushroom gastrostomy, balloon gastrostomy, and gastrojejunostomy: a review of 250 procedures.

PURPOSE: To compare complication rates and tube performance of percutaneous mushroom gastrostomy, balloon gastrostomy, and gastrojejunostomy. METHODS: Between September 9, 1999 and April 23, 2001, 203 patients underwent 250 radiologically guided percutaneous gastrostomy and gastrojejunostomy procedures. Follow-up was conducted through chart reviews and review of our interventional radiology database. Procedural and catheter-related complications were recorded. Chi-square statistical analysis was performed. RESULTS: In patients receiving mushroom-retained gastrostomy catheters (n = 114), the major complication rate was 0.88% (n = 1), the minor complication rate was 5.3% (n = 6), and the tube complication rate was 4.4% (n = 5). In patients receiving balloon-retained gastrostomy tubes (n = 67), the major complication rate was 0, the minor complication rate was 4.5% (n = 3), and the tube complication rate was 34.3% (n = 23). In patients receiving gastrojejunostomy catheters (n = 69), the major complication rate was 1.4% (n = 1), the minor complication rate was 2.9% (n = 2), and the tube complication rate was 34.8% (n = 24). No statistically significant differences were found between procedural or peri-procedural complications among the different types of tubes. Mushroom-retained catheters had significantly fewer tube complications (p < 0.01). CONCLUSIONS: Percutaneous gastrostomy and gastrojejunostomy have similar procedural and peri-procedural complication rates. Mushroom gastrostomy catheters have fewer tube-related complications compared with balloon gastrostomy and gastrojejunostomy catheters. In addition, mushroom-retained catheters exhibit the best overall long-term tube patency and are therefore the gastrostomy catheter of choice.

Aged↗

Delayed 99mTc-labeled erythrocyte scintigraphy in patients with lower gastrointestinal tract hemorrhage: effect of positive findings on clinical management.

RATIONALE AND OBJECTIVES: This study was performed to determine whether the results of delayed technetium 99m (99mTc)-labeled erythrocyte scintigraphy for lower gastrointestinal tract hemorrhage resulted in different clinical management and outcome from that in cases in which the results of initial scintigraphy were negative or equivocal. MATERIALS AND METHODS: The authors retrospectively reviewed all 398 99mTc-labeled erythrocyte scintigraphic studies obtained emergently for lower gastrointestinal tract hemorrhage at their institution between January 1, 1994, and December 7, 2001. Of 67 patients who underwent delayed studies, 37 had positive findings (average delay, 18.4 hours; range, 6-25 hours) and 30 had negative findings (average delay, 20.1 hours; range, 8-26 hours). Clinical management and outcome were compared between these two groups with respect to duration of hospitalization, volume of blood transfusion, mortality, and the percentage who were treated conservatively or referred for angiography, endoscopy, and/or surgery. RESULTS: Patients with positive delayed studies were referred more frequently for angiography than those with negative studies (35% vs 0%, P < .01). There were no significant differences between patients with positive findings and patients with negative findings with respect to mortality (8% vs 0%, P < .32), transfusion requirements (5.6 vs 3.2 units, P < .20), hospitalization (9.5 vs 6.1 days, P < .11), the percentage treated conservatively (35% vs 37%, P < .90), or the percentages referred for endoscopy (49% vs 60%, P < .50) or for surgery (24% vs 17%, P < .64). CONCLUSION: Positive findings at delayed scintigraphy resulted in increased referrals for angiography but had no other effect on clinical course or outcome of lower gastrointestinal tract hemorrhage.

Angiography↗

MR Imaging of arrhythmogenic right ventricular cardiomyopathy: morphologic findings and interobserver reliability.

BACKGROUND: Magnetic resonance (MR) imaging is frequently used to diagnose arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D). However, the reliability of various MR imaging features for diagnosing ARVC/D is unknown. The purpose of this study was to determine which morphologic MR imaging features have the greatest interobserver reliability for diagnosing ARVC/D. METHODS: Forty-five sets of films of cardiac MR images were sent to 8 radiologists and 5 cardiologists with experience in this field. There were 7 cases of definite ARVC/D as defined by the Task Force criteria. Six cases were controls. The remaining 32 cases had MR imaging because of clinical suspicion of ARVC/D. Readers evaluated the images for the presence of (a) right ventricle (RV) enlargement, (b) RV abnormal morphology, (c) left ventricle enlargement, (d) presence of high T(1) signal (fat) in the myocardium, and (e) location of high T(1) signal (fat) on a Likert scale with formatted responses. RESULTS: Readers indicated that the Task Force ARVC/D cases had significantly more (chi(2) = 119.93, d.f. = 10, p < 0.0001) RV chamber size enlargement (58%) than either the suspected ARVC/D (12%) or no ARVC/D (14%) cases. When readers reported the RV chamber size as enlarged they were significantly more likely to report the case as ARVC/D present (chi(2)(= )33.98, d.f. = 1, p < 0.0001). When readers reported the morphology as abnormal they were more likely to diagnose the case as ARVC/D present (chi(2) = 78.4, d.f. = 1, p < 0.0001), and the Task Force ARVC/D (47%) cases received significantly more abnormal reports than either suspected ARVC/D (20%) or non-ARVC/D (15%) cases. There was no significant difference between patient groups in the reported presence of high signal intensity (fat) in the RV (chi(2) = 0.9, d.f. = 2, p > 0.05). CONCLUSIONS: Reviewers found that the size and shape of abnormalities in the RV are key MR imaging discriminates of ARVD. Subsequent protocol development and multicenter trials need to address these parameters. Essential steps in improving accuracy and reducing variability include a standardized acquisition protocol and standardized analysis with dynamic cine review of regional RV function and quantification of RV and left ventricle volumes.

Adult↗

Gender does not influence outcomes after iliac angioplasty.

The current study was undertaken to evaluate the potential influence of gender on iliac angioplasty outcomes. All iliac angioplasty procedures performed at a tertiary care center from 1994 to 1999 were reviewed. One hundred four angioplasties with or without stenting were performed in 44 women (56 limbs) and 40 men (48 limbs). Age and atherosclerotic risk factors were similar in men and women. Iliac angioplasty was performed for limb salvage in 41% of patients (39% female vs. 44% male; p = 0.65). There were no differences in degree of stenosis, lesion length, or initial angioplasty site. Female iliac arteries were more likely to be occluded (21% vs. 6%; p = 0.03); mean iliac artery luminal diameter was smaller in women than in men (6.5 +/- 0.5 mm vs. 8.2 +/- 0.6 mm; p < 0.001). After a median follow-up of 13 months, there were no significant differences in 2-year primary patency, endovascular primary-assisted patency, or limb salvage rates between women and men. Despite having smaller iliac arteries and a higher incidence of arterial occlusion before treatment, women had outcomes similar to those of men after iliac angioplasty. The current results support the initial use of angioplasty to treat common and external iliac artery occlusive disease in both women and men.

Aged↗

Devastating and fatal complications associated with combined vascular and bile duct injuries during cholecystectomy.

HYPOTHESIS: Multiple centers have reported on bile duct injuries after cholecystectomy, but few have reported on the impact of concomitant vascular injuries. DESIGN: Twenty-seven life-threatening complex injuries (CIs) (Bismuth level III, IV, or V or combined arterial-ductal injuries) were retrospectively compared with 22 noncomplex injuries (NCs) (level I or II). SETTING: Tertiary referral center. MAIN OUTCOME MEASURES: The incidence and level of biliary and arterial injuries and their resulting morbidity and mortality. RESULTS: Bismuth classifications of all injuries were as follows: level I in 6 patients (12%), II in 19 (39%), III in 12 (24%), IV in 8 (16%), and V in 4 (8%). Diagnosis was based on peritonitis (n = 13 [27%]), endoscopic retrograde pancreatography (n = 19 [39%]), and percutaneous transhepatic cholangiography (n = 7 [14%]). Delayed referral was more common in levels I through IV (100 days) than in level V (15 days) (P<.001). Repairs were attempted in level IV (75%), III (67%), V (25%), and II (11%). Thirteen arterial injuries (26%) occurred irrespective of ductal injury level: I (n = 1), II (n = 3), III (n = 1), IV (n = 5), and V (n = 3). There was, however, a higher incidence of repairs before referral in the CI group (59% vs 5%; P<.01), with resulting higher rates of complication (70% vs 23%; P<.01). Five deaths occurred in the CI group vs 1 in the NC group (P =.14). In univariate analysis, the presence of arterial injury vs no arterial injury was a predictor of mortality (5 [38%] of 13 patients vs 1 [3%] of 36 patients; P<.001). CONCLUSION: Bile duct injuries after cholecystectomy can be morbid and lethal with the incidence of arterial injury grossly underestimated.

Adult↗

Endovascular intervention for the treatment of acute arterial gastrointestinal hemorrhage.

The treatment of arterial gastrointestinal hemorrhage continues to evolve. Currently, most interventional radiologists approach bleeding both in the upper and lower gastrointestinal tract with intention to treat. Embolization has replaced local vasoconstrictive therapy as the catheter-based treatment of choice in many hospitals. Coaxial microcatheters have simplified embolotherapy and enabled lower gastrointestinal bleeding to be treated safely and effectively.

Acute Disease↗

Long-term venous complications after full-size and segmental pediatric liver transplantation.

OBJECTIVE: To assess the long-term incidence of venous complications, including portal vein and hepatic vein stenoses, in both whole cadaveric and reduced-size cadaveric and living related liver transplants in a pediatric population, and to assess the therapeutic modalities in the treatment of these lesions. SUMMARY BACKGROUND DATA: A shortage in appropriate-sized liver grafts for pediatric patients led to the use of segmental liver grafts, which became the predominant graft used in 325 of 600 (54%) transplants at the authors' institution. To assess the long-term impact of this strategy, the authors examined the incidence of late (>90 days) venous complications and the efficacy of all therapeutic interventions. METHODS: Six hundred pediatric liver transplants were performed in 325 patients, with reduced-size or split (RSS; n = 207), living related (LRD; n = 118), or full-size cadaveric grafts (FS; n = 275) from 1988 to 2000. All transplants identified with late portal vein or vena caval stenoses or thromboses from a cohort of 524 grafts with survival greater than 90 days were reviewed for demographics, symptoms, therapeutic intervention, recurrence, morbidity, and mortality. RESULTS: Fifty lesions were identified in 49 patients (38 portal vein and 12 hepatic vein-cava stenoses). Sex distribution was similar between portal vein and hepatic vein to cava, as was the mean patient age. Portal vein stenoses occurred in 32 LRD, 3 RSS, and 3 FS, while hepatic vein-cava stenoses occurred in 2 LRD, 8 RSS, and 2 FS. In the 38 portal vein stenoses, 9 had prior perioperative portal vein and/or 5 hepatic artery thrombectomies. Portal vein stenoses were identified after bleeding (17/38), ascites (6/38), increased liver function tests (6/38), splenomegaly (5/38), or screening ultrasound (4/38). Portal vein stenosis was associated most often with cryopreserved vein for portal conduits. Excluding conduits, the incidence of late portal vein complications was reduced to 1%. Lesions became symptomatic at a mean of 50.8 +/- 184.2 months posttransplant. All patients underwent venous angioplasty with a 66% (25/38) success rate, while 7 of 25 required further angioplasty and stenting. In the 13 unsuccessful angioplasties, 8 required surgical shunts for complete portal vein thrombosis. Recurrence occurred in 9 patients: all were amenable to stenting. Nine patients (24%) eventually died of sepsis (4) and surgical deaths at shunt or retransplant (5). Hepatic vein-cava stenoses occurred after a mean of 37.2 +/- 35.2 months, presenting with ascites (n = 10), increased liver function tests (n = 2), and splenomegaly (n = 2). All patients were diagnosed by venogram and managed by balloon dilatation alone (n = 6) or stented (n = 4), with an 80% (10/12) success, with two late recurrences amenable to repeat angioplasty or stenting. Long-term survival was 80% at 1 year. CONCLUSIONS: The use of segmental grafts without venous conduits is not associated with a significant rate of long-term venous complication. When late venous complications do occur, venous angioplasty and stenting are both a safe and effective management modality. If necessary, venous angioplasty may be repeated with the placement of a stent. When this is required, care must be taken to place the stent in a position where the metallic object will not interfere with future surgical manipulations should retransplantation be necessary.

Anastomosis, Surgical↗