Ahmad Parvinian

Efficacy and Safety of Flow-Directed Pulmonary Artery Catheter Thrombolysis for Treatment of Submassive Pulmonary Embolism

OBJECTIVE The purpose of this study was to assess the efficacy and safety of flow-directed catheter thrombolysis for treatment of submassive pulmonary embolism (PE). MATERIALS AND METHODS In this single-institution retrospective study, 19 patients (nine men and 10 women; mean age [± SD], 54 ± 13 years) with submassive PE underwent catheter-directed thrombolysis between 2009 and 2013. Presenting symptoms included dyspnea in 18 of 19 (95%) cases. Submassive PE was diagnosed by pulmonary CT arteriography and right ventricular strain. PE was bilateral in 17 of 19 (89%) and unilateral in two of 19 (11%) cases. Thrombolysis was performed via a pulmonary artery (PA) catheter infusing 0.5- 1.0 mg alteplase per hour and was continued to complete or near complete clot dissolution with reduction in PA pressure. IV systemic heparin was administered. Measured outcomes included procedural success, PA pressure reduction, clinical success, survival, and adverse events. RESULTS Procedural success, defined as successful PA catheter placement, fibrinolytic agent delivery, PA pressure reduction, and achievement of complete or near complete clot dissolution, was achieved in 18 of 19 (95%) cases. Thrombolysis required 57 ± 31 mg of alteplase administered over 89 ± 32 hours. Initial and final PA pressures were 30 ± 10 mm Hg and 20 ± 8 mm Hg (p < 0.001). All 18 (100%) technically successful cases achieved clinical success because all patients experienced symptomatic improvement. Eighteen of 19 (95%) patients survived to hospital discharge; 18 of 19 (95%) and 15 of 16 (94%) patients had documented 1-month and 3-month survival. One fatal case of intracranial hemorrhage was attributed to supratherapeutic anticoagulation because normal fibrinogen levels did not suggest remote fibrinolysis; procedural success was not achieved in this case because of early thrombolysis termination. No other complications were encountered. CONCLUSION Among a small patient cohort, flow-directed catheter thrombolysis with alteplase effectively dissolved submassive PE and reduced PA pressure. Postprocedure short-term survival was high, and patients undergoing thrombolysis required close observation for bleeding events.

Development, growth, propagation, and angiographic utilization of the rabbit VX2 model of liver cancer: a pictorial primer and "how to" guide

The VX2 tumor is a leporine anaplastic squamous cell carcinoma characterized by rapid growth, hypervascularity, and facile propagation in the skeletal muscle. Since its introduction over 70 years ago, it has been used to model a variety of malignancies, and is commonly employed by interventional radiologists in preclinical investigations of hepatocellular carcinoma. However, despite the widespread and lasting popularity of the model, there are few technical resources detailing its use. Herein, we present a comprehensive pictorial outline of the technical methodology for development, growth, propagation, and angiographic utilization of the rabbit VX2 liver tumor model.

Characteristics of Primary and Secondary Hepatic Malignancies Associated with Hepatopulmonary Shunting

PURPOSE To identify liver tumor characteristics associated with low (<10%), intermediate (10%-20%), and high (>20%) lung shunt fraction (LSF) at technetium 99m ((99m)Tc) macroaggregated albumin (MAA) imaging performed before yttrium 90 ((90)Y) radioembolization (RE). MATERIALS AND METHODS In this single-center retrospective study, 141 patients (70 with hepatocellular carcinoma [HCC], 71 with other tumors; 95 men, 45 women; median age, 61 years) underwent mapping arteriography with (99m)Tc-MAA LSF calculation before (90)Y RE from 2006 to 2012. Tumor characteristics, including tumor type, index lesion size and morphologic structure (circumscribed, infiltrative), focality (solitary oligonodular, multinodular), disease distribution (unilobar, bilobar), tumor burden (≤50%, 50%), portal vein invasion (present, absent), and arterioportal shunting (present, absent) were correlated with (99m)Tc-MAA imaging-calculated LSFs at univariate and multivariate analysis. RESULTS Median LSF was 8.4% (HCC, 9.0%; other tumors, 8.3%). LSF greater than 20% occurred in 14% of HCCs, but only in 3% of other tumors (P = .004). For HCC, tumor morphologic structure (P = .022), tumor burden (P < .001), main portal vein invasion (P = .033), and arterioportal shunting (P < .001) were significantly associated with different LSF categories at univariate analysis; infiltrative morphologic structure, tumor burden greater than 50%, portal vein invasion, and shunting had confirmed association with high LSF at multivariate analysis. For other liver tumors, tumor size (P = .001) and tumor burden (P = .003) were significantly associated with different LSF categories at univariate analysis. Multivariate confirmation was precluded by small sample size. Patients underwent a median of one (90)Y RE session (range, one to six), with median per-treatment and cumulative lung doses of 6.0 Gy and 8.5 Gy, respectively. CONCLUSION LSF greater than 20% periodically occurs in HCC but is uncommon in other liver tumors. Specific tumor characteristics are associated with LSF greater than 20% and may indicate need for interventions to reduce LSF.

Ultrasound-guided intranodal lymphangiography followed by thoracic duct embolization for treatment of postoperative bilateral chylothorax

Percutaneous thoracic duct embolization (TDE) is a safe, effective, and minimally invasive option for treating chylothorax. A recent report demonstrated the feasibility of ultrasound‐guided intranodal lymphangiography as an alternative to pedal lymphangiography for visualization of the thoracic duct, promising relative technical ease and decreased procedure time for TDE.

Splenic artery embolization: a single center experience on the safety, efficacy, and clinical outcomes

PURPOSE We aimed to assess the safety, efficacy, and clinical outcomes of splenic artery embolization (SAE). MATERIALS AND METHODS A total of 50 patients (male:female, 33:17; mean age, 49 years) who underwent 50 SAEs between 1998 and 2011 were retrospectively studied. The procedure indications included aneurysm or pseudoaneurysm (n=15), gastric variceal hemorrhage (n=15), preoperative reduction of surgical blood loss (n=9), or other (n=11). In total, 22 procedures were elective, and 28 procedures were urgent or emergent. The embolic agents included coils (n=50), gelatin sponges (n=15), and particles (n=4). The measured outcomes were the technical success of the procedure, efficacy, side effects, and the 30-day morbidity and mortality rates. RESULTS All embolizations were technically successful. The procedure efficacy was 90%; five patients (10%) had a recurrent hemorrhage requiring a secondary intervention. Side effects included hydrothorax (n=26, 52%), thrombocytosis (n=16, 32%), thrombocytopenia (n=13, 26%), and postembolization syndrome (n=11, 22%). Splenic infarcts occurred in 13 patients (26%). The overall and procedure-specific 30-day morbidity rates were 38% (19/50) and 14% (splenoportal thrombosis, 3/50; encapsulated bacterial infection, 1/50; splenic abscess, 1/50; femoral hematoma requiring surgery, 1/50; hydrothorax requiring drainage, 1/50). The overall and procedure-specific 30-day mortality rates were 8% (4/50) and 0%. The multivariate analysis showed that advanced patient age (P = 0.037), postprocedure thrombocytopenia (P = 0.008), postprocedure hydrothorax (P = 0.009), and the need for a secondary intervention (P = 0.004) predicted the 30-day morbidity, while renal insufficiency (P < 0.0001), preprocedure hemodynamic instability (P = 0.044), and preprocedure leukocytosis (P < 0.0001) were prognostic factors for the 30-day mortality. CONCLUSION SAE was performed with high technical success and efficacy, but the outcomes showed nontrivial morbidity rates. Elderly patients with thrombocytopenia and hydrothorax after SAE, and patients who require secondary interventions, should be monitored for complications.

Should transjugular intrahepatic portosystemic shunt stent grafts be underdilated

Although underdilation of transjugular intrahepatic portosystemic shunt (TIPS) stent grafts is commonly performed to limit complications arising from excessive portosystemic shunting, it is uncertain whether underdilated stents retain their smaller diameter indefinitely or eventually expand to nominal caliber. In this investigation, postprocedure computed tomography (CT) was used to compare diameters of underdilated TIPSs and TIPSs expanded to a nominal diameter of 10 mm in 61 cases. The groups had comparable shunt diameters on post-TIPS imaging (9.8 mm vs 9.9 mm; P = .079), with similar incidences of hepatic encephalopathy (34% vs 20%; P = .372), indicating stent self-expansion over time, and bringing into question the advantages of underdilation for customization of shunt caliber.

Transjugular intrahepatic portosystemic shunt for the treatment of medically refractory ascites

PURPOSE This study was performed to assess the safety, efficacy, and clinical outcomes of transjugular intrahepatic portosystemic shunt (TIPS) creation for treatment of medically refractory ascites and to identify prognostic factors for clinical response, morbidity, and mortality. MATERIALS AND METHODS In this retrospective study, 80 patients (male:female, 52:28; mean age, 56 years; mean Model for End-Stage Liver Disease [MELD] score, 15.1) who underwent elective TIPS creation for refractory ascites between 1999-2012 were studied. A medical record review was performed to identify data on demographics, liver disease, procedures, and outcome. The influence of these parameters on 30-day, 90-day, and one-year mortality was assessed using binary logistic regression. Overall survival was analyzed with Kaplan-Meier statistics. RESULTS TIPS was successfully created using covered (n=70) or bare metal (n=10) stents. Hemodynamic success was achieved in all cases. The mean final portosystemic pressure gradient (PSG) was 6.8 mmHg. Thirty-day complications included mild encephalopathy in 35% of patients. Clinical improvement in ascites occurred in 78% of patients, with complete resolution or a ≥50% decrease in 66% of patients. No predictors of response or optimal PSG threshold were identified. The 30-day, 90-day, and one-year mortality rates were 14%, 23%, and 33%, respectively. Patient age (P = 0.026) was associated with 30-day mortality, while final PSG was associated with 90-day (P = 0.020) and one year (P = 0.032) mortality. No predictors of overall survival were identified. CONCLUSION TIPS creation effectively treats medically refractory ascites with nearly 80% efficacy. The incidence of mild encephalopathy is nontrivial. Older age and final PSG are associated with mortality, and these factors should be considered in patient selection and procedure performance.

Survival benefit of TIPS versus serial paracentesis in patients with refractory ascites: a single institution case-control propensity score analysis

AIM To compare the impact of covered stent-graft transjugular intrahepatic portosystemic shunt (TIPS) versus serial paracentesis on survival of patients with medically refractory ascites. MATERIALS AND METHODS In this retrospective study, cirrhotic patients who underwent covered stent-graft TIPS for refractory ascites from 2003-2013 were compared with similar patients who underwent serial paracentesis during 2009-2013. Demographic and liver disease data, Model for End-Stage Liver Disease (MELD) scores, and survival outcomes were obtained from hospital electronic medical records and the social security death index. After propensity score weighting to match study group characteristics, survival outcomes were compared using Kaplan-Meier statistics with log-rank analysis. RESULTS Seventy TIPS (70% men, mean age 55.7 years, mean MELD 15.1) and 80 paracentesis (58% men, mean age 53.5 years, mean MELD 22.5) patients were compared. The TIPS haemodynamic success rate was 100% (mean portosystemic pressure gradient reduction 13 mmHg). Paracentesis patients underwent a mean of 7.9 procedures. After propensity score weighting to balance group features, TIPS patients showed a trend toward enhanced survival compared with paracentesis patients (median survival 1037 versus 262 days, p = 0.074). TIPS conferred a significant increase or trend toward improved survival compared with paracentesis at 1 (66% versus 44%, p = 0.018), 2 (56% versus 38%, p = 0.057), and 3 year (49% versus 32%, p = 0.077) time points. Thirty and 90 day mortality rates were not statistically increased by TIPS. CONCLUSION Covered stent-graft TIPS improves intermediate- to long-term survival without significantly increasing short-term mortality of ascites patients, and suggests a greater potential role for TIPS in properly selected ascitic patients when medical management fails.

Older patient age may predict early mortality after transjugular intrahepatic portosystemic shunt creation in individuals at intermediate risk.

PURPOSE To identify prognostic factors for early mortality among patients with intermediate-risk Model for End-stage Liver Disease (MELD) scores undergoing transjugular intrahepatic portosystemic shunt (TIPS) creation. MATERIALS AND METHODS In this single-institution retrospective study, 47 patients (31 men; mean age, 54 y) with intermediate MELD scores (ie, 18-25) underwent TIPS creation between 1999 and 2012. Medical records were reviewed to identify demographic (age, sex), liver disease (Child-Pugh, MELD), and procedure data (indication, urgency, stent type, portosystemic pressure gradient reduction, complications), and the influence of these parameters on 90-day mortality was assessed by multivariate binary logistic regression analysis. RESULTS TIPSs were successfully created for variceal hemorrhage (n = 24), ascites (n = 17), hydrothorax (n = 5), and portal vein thrombosis (n = 1). Hemodynamic success rate was 94% (44 of 47), and mean portosystemic pressure gradient reduction was 13 mm Hg. The 90-day mortality rate was 36% (17 of 47). Patient age (P = .026) was significantly associated with 90-day mortality. Mean ages of living versus dead patients were 51 and 60 years, and mortality rates in patients aged 54 years or younger versus 55 years or older were 21% (five of 24) and 52% (12 of 23), respectively. There was no difference in MELD scores between these age groups (20.6 vs 21.0; P = .600), and MELD score was not a predictive factor on regression analysis. CONCLUSIONS Age is a prognostic factor for early mortality in TIPS recipients with intermediate MELD scores. Mortality rates are higher in patients at least 55 years of age, but MELD score does not predict survival in this subset. Age should be contemplated when selecting patients at intermediate risk for TIPS creation.

Transarterial Sorafenib Chemoembolization: Preliminary Study of Technical Feasibility in a Rabbit Model

PURPOSE To test the feasibility of targeted intraarterial administration of the tyrosine kinase inhibitor chemotherapeutic agent sorafenib to inhibit embolotherapy-induced tumor angiogenesis and reduce systemic drug side effects. MATERIALS AND METHODS The left hepatic lobes of five New Zealand White rabbits (mean weight, 2.7 kg±0.2) were treated with chemoembolization with sorafenib and ethiodized oil emulsion, followed by immediate euthanasia. Postprocedure noncontrast computed tomography (CT) was used to evaluate intrahepatic chemotherapy mixture distribution. Liquid chromatography/tandem mass spectrometry (LC-MS/MS) was then used to directly measure sorafenib concentration in the treated liver tissue. Histopathologic assessment of treated left lobes was performed to identify any immediate toxic effects of the sorafenib solution. RESULTS Lobar sorafenib chemoembolization was successfully performed in all cases via the left hepatic artery. Sorafenib and ethiodized oil (mean, 6.4 mg±3.8 and 0.95 mL±0.7, respectively) were injected, and CT confirmed targeted left hepatic lobe sorafenib emulsion delivery in all cases. Corresponding LC-MS/MS analysis yielded a mean sorafenib concentration of 94.2 μg/mL±48.3 in treated left lobe samples (n = 5), significantly greater than typical therapeutic drug levels (2-10 μg/mL) achieved with oral sorafenib systemic therapy. Histopathologic assessment showed only mild or moderate nonspecific ballooning degeneration in zone 3 hepatocytes, without tissue necrosis. CONCLUSIONS Targeted transarterial sorafenib delivery is feasible and results in higher tissue drug levels than reported for systemic sorafenib therapy, without immediate histopathologic tissue toxicity. Future studies should aim to determine the utility of sorafenib chemoembolization in reducing hypoxia-induced vasculogenesis in liver tumors.