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Featured researches published by R. Peter Lokken.


Journal of Vascular and Interventional Radiology | 2015

Root Cause Analysis of Rebleeding Events following Transjugular Intrahepatic Portosystemic Shunt Creation for Variceal Hemorrhage

Janesh Lakhoo; James T. Bui; Sean P. Zivin; R. Peter Lokken; Jeet Minocha; Charles E. Ray; Ron C. Gaba

PURPOSE To identify fundamental causes underlying recurrent variceal hemorrhage (VH) after transjugular intrahepatic portosystemic shunt (TIPS) to ascertain opportunities for improvement of TIPS-based management of VH and prevention of rebleeding. MATERIALS AND METHODS This single-center retrospective study comprised 166 patients (male-to-female ratio 101:65; median age, 52 y; median Model for End-Stage Liver Disease score, 14) who had TIPS created for VH in 1998-2014. Medical record review was used to identify patients who had recurrent VH events, and root cause analysis allowed identification of the most probable causal factors. A 5-person interventional radiology physician group generated quality improvement (QI) recommendations for process changes to address causal factors, with consensus achieved using a modified Delphi method. RESULTS Variceal rebleeding occurred after TIPS in 25 (15%) patients. The 1-, 3-, and 5-year variceal rebleeding incidence was 17%, 21%, and 21%, respectively. Variceal rebleeding was associated with high 90-day all-cause mortality incidence (10/25; 40%). Male sex (P = .018) and Model for End-Stage Liver Disease score (P = .009) were statistically associated with variceal rebleeding. The most common primary and secondary causes of recurrent VH were lack of or insufficient variceal embolization (64%). Other causal factors included TIPS stenosis or occlusion (28%) with recurrent portosystemic gradient (PSG) elevation (20%), severe coagulopathy (20%), inadequate portosystemic gradient reduction (12%), and TIPS underdilation (4%). To potentially address variceal rebleeding, 14 preventive QI recommendations were developed. CONCLUSIONS Although recurrent VH rates after TIPS are not trivial, rebleeding may be related to addressable underlying causal factors. Further investigation may assess the efficacy of QI-based procedure methodologic enhancements in reducing rebleeding incidence after TIPS.


Journal of Vascular and Interventional Radiology | 2017

Quality Improvement Guidelines for Transarterial Chemoembolization and Embolization of Hepatic Malignancy

Ron C. Gaba; R. Peter Lokken; Ryan Hickey; Andrew J. Lipnik; Robert J. Lewandowski; Riad Salem; Daniel B. Brown; T. Gregory Walker; James E. Silberzweig; Mark O. Baerlocher; Ana Echenique; Mehran Midia; Jason W. Mitchell; Siddharth A. Padia; Suvranu Ganguli; Thomas J. Ward; Jeffrey L. Weinstein; Boris Nikolic; Sean R. Dariushnia

From the Division of In ment of Radiology, Un 1740 West Taylor Stree Interventional Radiolog Northwestern Memoria (D.B.B.), Vanderbilt Univ Interventional Radiolog Therapy (S.G.), Massa Boston, Massachusetts Israel, New York, New Hospital, Barrie, Onta (A.M.E.), University of ventional Radiology (M Interventional Radiolog University School of M Radiology (S.A.P.), Dep at University of Californ Radiology (T.J.W.), Flor Radiology (J.L.W.), Dep Center, Boston, Massa Medical Center, Albany 2017. Address corres Fair Ridge Dr., Suite 40


Journal of Vascular and Interventional Radiology | 2016

Transjugular Intrahepatic Portosystemic Shunt Creation and Variceal Coil or Plug Embolization Ineffectively Attain Gastric Variceal Decompression or Occlusion: Results of a 26-Patient Retrospective Study

Janesh Lakhoo; James T. Bui; R. Peter Lokken; Charles E. Ray; Ron C. Gaba

PURPOSE To assess the efficacy of transjugular intrahepatic portosystemic shunt (TIPS) creation with or without variceal coil and/or plug embolization in decompressing or occluding gastric varices (GVs). MATERIALS AND METHODS In this retrospective study, 78 patients with GV bleeding who underwent TIPS creation with or without embolotherapy with metallic coils and/or plugs from 1999 to 2014 were identified. Individuals who had a bare-metal TIPS and/or lacked post-TIPS imaging or endoscopic follow-up were excluded. The final cohort included 26 patients (16 men; median age, 54 y; median Model for End-stage Liver Disease score, 16). Variceal types, supplying vessels, and postprocedure GV patency on cross-sectional imaging or endoscopy were assessed. The primary study outcome measure was GV patency rate as a surrogate for efficacy of TIPS creation with or without embolization. RESULTS GVs included gastroesophageal varix types 1 (n = 10) and 2 (n = 2), isolated GV types 1 (n = 4) and 2 (n = 2), and unspecified (n = 8). TIPS creation resulted in a median final portosystemic pressure gradient of 7 mm Hg. Multiple GV-supplying vessels (left/posterior/short gastric veins) were present in 65% of patients (n = 17). Embolization was performed in 69% (n = 18). Thirteen, four, and nine patients had imaging, endoscopic, or both imaging/endoscopic follow-up. GV patency rate was 65% (n = 17; 61%/75% with/without embolization) at a median of 128.5 days (range, 1-1,295 d) after TIPS creation. Incidence of recurrent bleeding was 27% (n = 7), and the 90-day mortality rate was 15% (n = 4). CONCLUSIONS In this study, most GVs showed persistent patency despite TIPS decompression and variceal embolization, and the incidence of recurrent bleeding was high. The findings suggest suboptimal efficacy for GVs, and indicate a need for study of alternative or adjunctive approaches to GV treatment, such as chemical obliteration.


Journal of Vascular and Interventional Radiology | 2016

Safety and Efficacy of Doxorubicin Drug-Eluting Embolic Chemoembolization of Hepatocellular Carcinoma Supplied by Extrahepatic Collateral Arteries

R. Peter Lokken; Nicholas Fidelman; K. Pallav Kolli; Robert K. Kerlan

PURPOSE To assess safety and efficacy of doxorubicin drug-eluting embolic (DEE) transarterial chemoembolization of hepatocellular carcinoma (HCC) by extrahepatic collateral arteries. MATERIALS AND METHODS Records of 177 patients with HCC who underwent 338 consecutive DEE chemoembolization procedures from 2011 to 2014 were retrospectively reviewed. A subgroup of 16 patients (13 men, 3 women, median age 66 y) underwent 24 procedures for 17 HCCs via extrahepatic arteries and was included in the study. Median tumor size was 3.1 cm (range, 1.0-10.3 cm). Extrahepatic collaterals included right inferior phrenic (19 procedures; 12 patients), adrenal (4 procedures; 3 patients), and cystic arteries (2 procedures; 2 patients). Radiographic response was assessed by Modified Response Evaluation Criteria in Solid Tumors criteria. Complications were defined by National Cancer Institute Common Terminology Criteria for Adverse Events. RESULTS DEE chemoembolization achieved stable disease in 6 (35.3%), partial response in 6 (35.3%), and complete response in 4 (23.5%) HCCs. Disease progression was ultimately observed in 8 tumors (47.1%), with mean time to progression of 8.3 months after chemoembolization (range, 2-13 mo). Three minor and 5 major complications occurred in 8 patients; 2 minor complications were rash in vascular distribution after right inferior phrenic artery DEE chemoembolization. The 5 major complications were transient hepatotoxicity that resolved within 4-80 days; 1 was accompanied by pleural effusion requiring hospitalization. A mean 13.4 months after DEE chemoembolization, 67% of transplant candidates proceeded to liver transplant. CONCLUSIONS DEE transarterial chemoembolization via extrahepatic collaterals was effective and facilitated bridging to transplant. It was generally well tolerated; transient hepatotoxicity was the most common major complication.


Journal of Vascular and Interventional Radiology | 2016

Filter Eversion Technique for Removal of Option ELITE Inferior Vena Cava Filters

Ashish R. Vyas; James T. Bui; Charles E. Ray; R. Peter Lokken; Ron C. Gaba

hemostasis. Before removal of the 14-F sheath, 2 180-cm 0.035-inch stiff guide wires (Lunderquist and Amplatz Super Stiff [Boston Scientific, Marlborough, Massachusetts) were advanced into the aorta. Subsequently, with manual compression over the puncture site, the large sheath was removed, and a 6-F introducer sheath (Avantiþ; Cordis Corporation) was advanced over 1 guide wire to reduce the arteriotomy lumen, and an 8-F Angio-Seal VIP device was advanced over the second guide wire and deployed followed by further manual compression for 2 minutes. While maintaining gentle traction on the suture of the deployed 8-F Angio-Seal VCD, the 6-F sheath was carefully removed and exchanged for a 6-F Angio-Seal VIP device over the remaining guide wire and deployed. Gentle traction was applied to both devices, and the access site was manually compressed for 3 minutes achieving complete hemostasis (Fig 2a). Ultrasound performed after deployment confirmed proper footplate deployment with no evidence of hematoma or pseudoaneurysm. The patient remained in the hospital for overnight observation and was discharged home the following day. He remained well on subsequent follow-up with a normal, palpable femoral arterial pulse and no hematoma or pseudoaneurysm on clinical examination of the access site. This was confirmed on a CT angiogram performed 6 weeks after the procedure (Fig 2b) showing resolution of the type 1 endoleak and appropriate VCD deployment. The pre-deployment ProGlide and double Angio-Seal techniques have been described for large-bore arterial access including percutaneous EVAR (1–4). However, there is a comparative lack of experience with the use of these techniques in access sites with scarring from previous surgical exposure or trauma. Because of heavy scarring in our patient, we chose not to use a suture-based VCD owing to previous reports of needle deflection with resultant deployment failure (2). As a collagen plug–based device is routinely used in smaller caliber (6–8 F) “hostile” access sites in our practice, we chose to adapt the double AngioSeal technique in this case with success. Both techniques are useful in the interventional radiology armamentarium for vascular closure of large-bore arterial access in elective and emergency settings, and individual operators can select a preferred technique based on their local experience with each device.


Radiology | 2018

90Y Radioembolization for hepatic malignancy in patients with previous biliary intervention: Multicenter analysis of hepatobiliary infections

K. Devulapalli; Nicholas Fidelman; Michael C. Soulen; Matthew Miller; Matthew S. Johnson; Eric Addo; Ghassan El-Haddad; James Morrison; Khashayar Farsad; R. Peter Lokken; Ron C. Gaba; Jacob Fleming; Daniel B. Brown; Sharon W. Kwan; Steven C. Rose; Kevin A. Pennycooke; David M. Liu; Sarah B. White; Ripal T. Gandhi; Ann A. Lazar; Robert K. Kerlan

Purpose To determine the frequency of hepatobiliary infections after transarterial radioembolization (TARE) with yttrium 90 (90Y) in patients with liver malignancy and a history of biliary intervention. Materials and Methods For this retrospective study, records of all consecutive patients with liver malignancy and history of biliary intervention treated with TARE at 14 centers between 2005 and 2015 were reviewed. Data regarding liver function, 90Y dosimetry, antibiotic prophylaxis, and bowel preparation prophylaxis were collected. Primary outcome was development of hepatobiliary infection. Results One hundred twenty-six patients (84 men, 42 women; mean age, 68.8 years) with primary (n = 39) or metastatic (n = 87) liver malignancy and history of biliary intervention underwent 180 procedures with glass (92 procedures) or resin (88 procedures) microspheres. Hepatobiliary infections (liver abscesses in nine patients, cholangitis in five patients) developed in 10 of the 126 patients (7.9%) after 11 of the 180 procedures (6.1%; nine of those procedures were performed with glass microspheres). All patients required hospitalization (median stay, 12 days; range, 2-113 days). Ten patients required percutaneous abscess drainage, three patients underwent endoscopic stent placement and stone removal, and one patient needed insertion of percutaneous biliary drains. Infections resolved in five patients, four patients died (two from infection and two from cancer progression while infection was being treated), and one patient continued to receive suppressive antibiotics. Use of glass microspheres (P = .02), previous liver resection or ablation (P = .02), and younger age (P = .003) were independently predictive of higher infection risk. Conclusion Infectious complications such as liver abscess and cholangitis are uncommon but serious complications of transarterial radioembolization with 90Y in patients with liver malignancy and a history of biliary intervention.


Journal of Vascular and Interventional Radiology | 2017

Gastric Varices Bleed at Lower Portosystemic Pressure Gradients than Esophageal Varices

Joseph D. Morrison; Nasya Mendoza-Elias; Andrew J. Lipnik; R. Peter Lokken; James T. Bui; Charles E. Ray; Ron C. Gaba


Journal of Vascular and Interventional Radiology | 2017

Albumin-Bilirubin and Platelet-Albumin-Bilirubin Grades Accurately Predict Overall Survival in High-Risk Patients Undergoing Conventional Transarterial Chemoembolization for Hepatocellular Carcinoma

Jan Hansmann; Maximilian J. Evers; James T. Bui; R. Peter Lokken; Andrew J. Lipnik; Ron C. Gaba; Charles E. Ray


Journal of Vascular and Interventional Radiology | 2018

Characterization of an Inducible Alcoholic Liver Fibrosis Model for Hepatocellular Carcinoma Investigation in a Transgenic Porcine Tumorigenic Platform

Ron C. Gaba; Nasya Mendoza-Elias; Daniel P. Regan; Kelly D. Garcia; R. Peter Lokken; Regina M. Schwind; Michael Eichner; Faith M. Thomas; Lauretta A. Rund; Lawrence B. Schook; Kyle M. Schachtschneider


CardioVascular and Interventional Radiology | 2018

Albumin–Bilirubin and Platelet–Albumin–Bilirubin Grades Do Not Predict Survival After Transjugular Intrahepatic Portosystemic Shunt Creation

Ramzy C. Khabbaz; R. Peter Lokken; Yi Fan Chen; Andrew J. Lipnik; James T. Bui; Charles E. Ray; Ron C. Gaba

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Daniel B. Brown

Vanderbilt University Medical Center

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Nasya Mendoza-Elias

University of Illinois at Chicago

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Ann A. Lazar

University of California

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Boris Nikolic

Albert Einstein Medical Center

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Daniel P. Regan

Colorado State University

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Eric Addo

University of South Florida

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Ghassan El-Haddad

University of South Florida

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