Long-term outcomes of great saphenous vein harvest techniques for infrainguinal arterial bypass in a Medicare-matched registry database.

OBJECTIVE: Long-term outcomes for harvesting techniques for great saphenous vein (GSV) and its impact on the outcomes of infrainguinal arterial bypass remains largely unknown. Endoscopic GSV harvesting (EVH) has emerged as a less invasive alternative to conventional open techniques. Using the Vascular Quality initiative Vascular Implant Surveillance & Interventional Outcomes Network (VQI-VISION) database, we compared the long-term outcomes of infrainguinal arterial bypass using open and endoscopic GSV harvest techniques. METHODS: Patients who underwent infrainguinal GSV bypass between 2010 and 2019 were identified in the VQI-VISION Medicare linked database. Long-term outcomes of major/minor amputations, and reinterventions up to 5 years of follow-up were compared between continuous incisions, skip incision, and EVH, with continuous incisions being the reference group. Secondary outcomes included 30- and 90-day readmission, in addition to surgical site infections and patency rates at 6 months to 2 years postoperatively. Survival analysis using Kaplan-Meier curves and Cox regression hazard models were utilized to compare outcomes between groups. To adjust for multiple comparisons between the study groups, a P value of 2.5% was considered significant. RESULTS: Among the 8915 patients included in the study, continuous and skip vein harvest techniques were used in 44.4% and 43.4% of cases each, whereas 12.3% underwent EVH. The utilization of EVH remained relatively stable at around 12% throughout the study period. Compared with GSV harvest using continuous incisions, EVH was associated with higher rates of reintervention at 1 year (46.5% vs 41.3%; adjusted hazard ratio [aHR], 1.22; 95% confidence interval [CI], 1.06-1.41; P = .01]. However, no significant difference was observed between EVH and continuous incisions, and between skip and continuous incisions in terms of long-term reintervention or major and minor amputations on adjusted analysis. Compared with continuous incision vein harvest, both EVH and skip incisions were associated with lower surgical site infection rates within the first 6 months post-bypass (aHR, 0.53; 95% CI, 0.35-0.82 and aHR, 0.68; 95% CI, 0.53-0.87, respectively). Loss of primary, primary-assisted, and secondary patency was higher after EVH compared with continuous incision vein harvest. Among surgeons performing EVH, comparable long-term outcomes were observed regardless of low (<4 cases/year), medium (4-7 cases/year), or high procedural volumes (>7 cases/year). CONCLUSIONS: Despite higher 1-year reintervention rates, EVH for infrainguinal arterial bypass is not associated with a significant difference in long-term reintervention or amputation rates compared with other harvesting techniques. These outcomes are not influenced by procedural volumes for EVH technique.

Osteochondroma as an Unusual Cause of Popliteal Artery Pseudoaneurysm and Occlusion.

Osteochondromas are the most common benign bony tumour, usually occurring in the 2nd/3rd decade of life and generally asymptomatic. However, there have been reports of bony tumours causing arterial vascular injuries via erosion into vessel walls. We present a case of a 16-year-old M with no significant past medical history who presented with acute-on-chronic Right Lower Extremity (RLE) pain and numbness who was found to have a popliteal artery pseudoaneurysm and occlusion. We will discuss our initial work up, management, outcomes and follow up and compared our results with an English language literature search for comparable cases.

An Interesting Case of a Patient With Disabling Bilateral Lower Extremity Claudication and a Persistent Sciatic Artery.

A persistent sciatic artery is a rare congenital anomaly. This case report highlights the treatment for a patient with a persistent sciatic artery no longer in continuity with the internal iliac artery and atherosclerotic peripheral vascular disease resulting in disabling bilateral lower extremity claudication. It highlights the types and anatomic locations of the sciatic artery and discusses an effective way to treat a patient with arterial insufficiency and this variant anatomy as well as other treatment options.

Clinical and laboratory characteristics of patients with novel coronavirus disease-2019 infection and deep venous thrombosis.

OBJECTIVE: Early reports suggest that patients with novel coronavirus disease-2019 (COVID-19) infection carry a significant risk of altered coagulation with an increased risk for venous thromboembolic events. This report investigates the relationship of significant COVID-19 infection and deep venous thrombosis (DVT) as reflected in the patient clinical and laboratory characteristics. METHODS: We reviewed the demographics, clinical presentation, laboratory and radiologic evaluations, results of venous duplex imaging and mortality of COVID-19-positive patients (18-89 years) admitted to the Indiana University Academic Health Center. Using oxygen saturation, radiologic findings, and need for advanced respiratory therapies, patients were classified into mild, moderate, or severe categories of COVID-19 infection. A descriptive analysis was performed using univariate and bivariate Fisher's exact and Wilcoxon rank-sum tests to examine the distribution of patient characteristics and compare the DVT outcomes. A multivariable logistic regression model was used to estimate the adjusted odds ratio of experiencing DVT and a receiver operating curve analysis to identify the optimal cutoff for d-dimer to predict DVT in this COVID-19 cohort. Time to the diagnosis of DVT from admission was analyzed using log-rank test and Kaplan-Meier plots. RESULTS: Our study included 71 unique COVID-19-positive patients (mean age, 61 years) categorized as having 3% mild, 14% moderate, and 83% severe infection and evaluated with 107 venous duplex studies. DVT was identified in 47.8% of patients (37% of examinations) at an average of 5.9 days after admission. Patients with DVT were predominantly male (67%; P = .032) with proximal venous involvement (29% upper and 39% in the lower extremities with 55% of the latter demonstrating bilateral involvement). Patients with DVT had a significantly higher mean d-dimer of 5447 ± 7032 ng/mL (P = .0101), and alkaline phosphatase of 110 IU/L (P = .0095) than those without DVT. On multivariable analysis, elevated d-dimer (P = .038) and alkaline phosphatase (P = .021) were associated with risk for DVT, whereas age, sex, elevated C-reactive protein, and ferritin levels were not. A receiver operating curve analysis suggests an optimal d-dimer value of 2450 ng/mL cutoff with 70% sensitivity, 59.5% specificity, and 61% positive predictive value, and 68.8% negative predictive value. CONCLUSIONS: This study suggests that males with severe COVID-19 infection requiring hospitalization are at highest risk for developing DVT. Elevated d-dimers and alkaline phosphatase along with our multivariable model can alert the clinician to the increased risk of DVT requiring early evaluation and aggressive treatment.

Metformin does not reduce inflammation in diabetics with abdominal aortic aneurysm or at high risk of abdominal aortic aneurysm formation.

INTRODUCTION: The protective effect of diabetes mellitus on abdominal aortic aneurysm formation and growth has been repeatedly observed in population studies but continues to be poorly understood. However, recent investigations have suggested that metformin, a staple antihyperglycemic medication, may be independently protective against abdominal aortic aneurysm formation and growth. Therefore, we describe the effect of metformin in abdominal aortic aneurysm and at-risk patients on markers of inflammation, the driver of early abdominal aortic aneurysm formation and growth. METHODS: Peripheral blood was collected from patients previously diagnosed with abdominal aortic aneurysm or presenting for their U.S. Preventive Task Force-recommended abdominal aortic aneurysm screening. Plasma and circulating peripheral blood mononuclear cells were isolated using Ficoll density centrifugation. Circulating plasma inflammatory and regulatory cytokines were assessed with enzyme-linked immunosorbent assays. CD4+ cell phenotyping was performed using flow cytometric analysis and expressed as a proportion of total CD4+ cells. To determine the circulating antibody to self-antigen response, a modified enzyme-linked immunosorbent assay was performed against antibodies to collagen type V and elastin fragments. RESULTS: Peripheral blood was isolated from 266 patients without diabetes mellitus ( n=182), with diabetes mellitus not treated with metformin ( n=34), and with diabetes mellitus actively taking metformin ( n=50) from 2015 to 2017. We found no differences in the expression of Tr1, Th17, and Treg CD4+ fractions within diabetics ± metformin. When comparing inflammatory cytokines, we detected no differences in IL-1ß, IL-6, IL-17, IL-23, IFN-γ, and TNF-α. Conversely, no differences were observed pertaining to the expression to regulatory cytokines IL-4, IL-10, IL-13, TSG-6, or TGF-ß. Lastly, no differences in expression of collagen type V and elastin fragment antigen and/or antibodies were detected with metformin use in diabetics. CONCLUSION: Metformin in diabetics at-risk for abdominal aortic aneurysm or diagnosed with abdominal aortic aneurysm does not seem to alter the peripheral inflammatory environment.

Description of human AAA by cytokine and immune cell aberrations compared to risk-factor matched controls.

BACKGROUND: The pathogenesis driving the formation of abdominal aortic aneurysms continues to be poorly understood. Therefore, we systemically define the cytokine and circulating immune cell environment observed in human abdominal aortic aneurysm compared with risk-factor matched controls. METHODS: From 2015 to 2017, a total of 274 patients donated blood to the Indiana University Center for Aortic Disease. Absolute concentrations of circulating cytokines were determined, using enzyme-linked immunosorbent assays while the expression of circulating immune cell phenotypes were assayed via flow cytometric analysis. RESULTS: Human abdominal aortic aneurysm is characterized by a significant depletion of the antigen-specific, CD4+ Tr1 regulatory lymphocyte that corresponds to an upregulation of the antigen-specific, inflammatory Th17 cell. We found no differences in the incidence of Treg, B10, and myeloid-derived suppressor regulatory cells. Similarly, no disparities were noted in the following inflammatory cytokines: IL-1ß, C-reactive protein, tumor necrosis factor α, interferon γ, and IL-23. However, significant upregulation of the inflammatory cytokines osteopontin, IL-6, and IL-17 were noted. Additionally, no changes were observed in the regulatory cytokines IL-2, IL-4, IL-13, TNF-stimulated gene 6 protein, and prostaglandin E2, but we did observe a significant decrease in the essential regulatory cytokine IL-10. CONCLUSION: In this investigation, we systematically characterize the abdominal aortic aneurysm-immune environment and present preliminary evidence that faulty immune regulation may also contribute to aneurysm formation and growth.

Ethnic minorities with critical limb ischemia derive equal amputation risk reduction from autologous cell therapy compared with whites.

OBJECTIVE: Ethnic minorities (nonwhites) with critical limb ischemia (CLI) have historically performed worse compared with whites with regard to major amputation risk reduction and amputation-free survival (AFS) after peripheral vascular intervention. This post hoc analysis was completed to determine whether this precedent also extended to treatment of CLI without a suitable revascularization option with intramuscular injections of concentrated bone marrow aspirate (cBMA). METHODS: The treatment arm of the randomized, double-blind, multicenter MarrowStim PAD Kit for the Treatment of Critical Limb Ischemia in Subjects with Severe Peripheral Arterial Disease (MOBILE) trial was stratified by ethnicity and evaluated for demographics, comorbidities, and outcomes. The primary and therapeutic end point was 1-year AFS and major amputation, respectively. Noninferiority analysis was performed with the margin set at historically reported hazard ratios. RESULTS: Thirty-seven minority (African American, Hispanic, other) CLI patients (9 placebo, 28 cBMA) with no suitable revascularization option were randomized to cBMA or placebo at a 3:1 ratio during the MOBILE trial. At 1-year follow-up for the treatment group, overall AFS was 80%. Of the 28 minority patients randomized to cBMA intervention, an 89% AFS rate was observed compared with 77% in whites. Specifically, 22 of 24 (92%) African Americans survived amputation free at 1-year follow-up. Noninferiority testing confirmed no difference between whites and the ethnic minority treated with cBMA with respect to major amputation reduction; however, noninferiority could not be confirmed with regard to AFS. No significant differences favoring whites treated with cBMA were noted in the secondary end points of vascular quality of life, limb pain, ankle-brachial index, toe-brachial index, transcutaneous oximetry, and 6-minute walk testing. CONCLUSIONS: This post hoc analysis of the MOBILE trial demonstrates noninferiority of cBMA intervention in minorities with no-option CLI for the therapeutic end point of major amputation prevention. cBMA represents a novel treatment paradigm and should be explored for minorities with poor revascularization options who face impending amputation secondary to progressive CLI.

Perioperative Outcomes are Adversely Affected by Poor Pretransfer Adherence to Acute Limb Ischemia Practice Guidelines.

BACKGROUND: The accepted treatment for acute limb ischemia (ALI) is immediate systemic anticoagulation and timely reperfusion to restore blood flow. In this study, we describe the retrospective assessment of pretransfer management decisions by referring hospitals to an academic tertiary care facility and its impact on perioperative adverse events. METHODS: A retrospective analysis of ALI patients transferred to us via our Level I Vascular Emergency Program from 2010 to 2013 was performed. Patient demographics, comorbidities, Rutherford ischemia classification, time to anticoagulation, and time to reperfusion were tabulated and analyzed for correlation to incidence of major adverse limb events (MALEs), mortality, and bypass patency in the perioperative period (30-day postoperative). All intervals were calculated from the onset of symptoms and categorized into 3 subcohorts (<6 hr, 6-48 hr, and >48 hr). RESULTS: Eighty-seven patients with an average age of 64.0 (±16.2) years presented to outlying hospitals and were transferred to us with lower extremity ALI. The mean delay from symptom onset to initial referring physician evaluation was 18.3 hr. At that time of evaluation, 53.8% had Rutherford class IIA ischemia and 36.3% had class IIB ischemia. Seventy-six patients (87.4%) were started on heparin previous to transfer. However, only 44 patients (57.9%) reached therapeutic levels as measured by activated partial thromboplastin time before definitive revascularization. A delay of anticoagulation initiation >48 hr from symptom onset was associated with increased 30-day reintervention rates compared with the <6 hr group (66.7% vs. 23.5%; P < 0.05). However, time to reperfusion had no statistically significant impact on MALE, 30-day mortality, or 30-day interventional patency in our small cohorts. Additionally, patients with a previous revascularization had a higher 30-day reintervention rate (46.5%; P < 0.05). CONCLUSIONS: The practice of timely therapeutic anticoagulation of patients referred for ALI from community facilities occurs less frequently than expected and is associated with an increased perioperative reintervention rate.

Institutional experience with the Zenith Fenestrated aortic stent graft.

OBJECTIVE: The Zenith Fenestrated (ZFEN; Cook Medical, Bloomington, Ind) aortic stent graft system was approved for commercial use by the Food and Drug Administration in April 2012. We report our single-center experience of 100 consecutive patients treated with the ZFEN platform from October 2012 to March 2017. METHODS: A retrospective review of our prospectively maintained fenestrated endovascular aneurysm repair (FEVAR) database at a tertiary care academic institution located in the Midwest United States was performed for descriptive analysis. All continuous variables are reported as a mean ± standard deviation and compared using two-sided Student t-tests. Categorical variables were compared using two-sided Fisher exact tests. RESULTS: All but one of the procedures were elective in nature. Overall intraoperative characteristics included a mean blood loss (estimated blood loss) of 388 ± 385 mL, fluoroscopy time of 63 ± 30 minutes, radiation dose of 437 ± 272 rad, contrast material volume of 99 ± 36 mL, and operative time of 236 ± 87 minutes. Average number of visceral arteries stented was 2.1 ± 0.5. Technical success was achieved in 98% of the patients. Statistically significant (P < .05) improvement in estimated blood loss (2.1-fold) was observed in the second half of our series. Interestingly, no improvements were made in terms of fluoroscopy time, radiation exposure, contrast material use, or operative time. However, procedural difficulty increased in the last half by number of visceral arteries stented as a surrogate (1.9 vs 2.2; P < .05). Mean length of stay was 3.6 ± 4.3 days. Perioperative mortality at 30 days was 2%. Perioperative morbidity included a 5% incidence of any bowel ischemia, 1% of spinal cord ischemia, 3% of renal failure requiring hemodialysis, 1% of stroke, and 4% of myocardial infarction. Average follow-up was 1.7 ± 1.4 years. Reintervention during the follow-up phase was 20%. Of the 209 visceral arteries stented, we noted 6 instances of stent thrombosis, 6 of kinking or stenosis, and 1 of stent fracture in follow-up. Endoleak, most commonly type II, was present or could not be excluded in 15% of all FEVARs at last available computed tomography angiography. CONCLUSIONS: In our experience, FEVAR with the ZFEN system continues to be safe and effective. There is a significant rate of reintervention observed, and close monitoring is fundamental to maintaining good clinical results.

Cryopreserved Homografts in Infected Infrainguinal Fields Are Associated with Frequent Reinterventions and Poor Amputation-Free Survival.

BACKGROUND: Single-length saphenous vein continues to be the conduit of choice in infected-field critical limb ischemia. However, half of these individuals have inadequate vein secondary to previous use or chronic venous disease. We reviewed our outcomes of infected-field infrainguinal bypasses performed with cryopreserved homografts (CHs), a widely accepted alternative to autogenous vein in this setting. METHODS: This is a retrospective, institutional descriptive analysis of infected-field infrainguinal revascularizations between 2012 and 2015. RESULTS: Twenty-four operations were performed in the same number of patients for limb ischemia with signs of active infection. The mean age of the cohort examined was 62.5 ± 14.4 (standard deviation) years. Mean Society of Vascular Surgery risk score was 3.9 with a baseline Rutherford's chronic ischemia score of 4.3 at presentation. Emergent procedures constituted 29% of cases, and the remainder cases were urgent procedures. The CH bypass captured was a reoperative procedure in all but one of the patients. Culture positivity was present in 75% of cases with Staphylococcus aureus (29%), the most commonly isolated organism. Thirty-day mortality and major adverse cardiovascular events were both 4%. Amputation-free survival (AFS) was 75% at 30 days. Similarly, 30-day reintervention was 38% with debridement (43%) and bleeding (29%), the most common indications. Average duration of follow-up was 27.9 ± 20.4 months (range: 0.5-60.4). Mean length of stay was 14.8 days. Reinfection requiring an additional procedure or antibiotic regimen separate from the index antibiotic course was 13%. Primary patency and AFS at 1 year was 50% and 58%, respectively. Primary patency and AFS at 2 years was 38% and 52%, respectively. Limb salvage at 1 and 2 years was 70% and 65%, respectively. Fifteen patients (63%) required reintervention during the follow-up period with 40% of those subjects undergoing multiple procedures. CONCLUSIONS: CHs remain a marginal salvage conduit in the setting of infection and no autogenous choices. Therefore, clinicians should individualize usage of this high-cost product in highly selected patients only.

Osteopontin may be a driver of abdominal aortic aneurysm formation.

OBJECTIVE: Previous in vitro and animal studies have suggested that osteopontin (OPN), an inflammatory extracellular matrix protein, is involved in the formation and growth of abdominal aortic aneurysms (AAAs). However, the mechanism by which this occurs continues to be nebulous. The relationship between OPN and inflammation-suppressing lymphocytes present in the human AAA condition was investigated and presented herein. METHODS: Serum OPN concentrations were measured in healthy, risk factor-matched non-AAA and AAA patients by enzyme-linked immunosorbent assay (ELISA). Immunohistochemistry was used to determine the source of OPN secretion using aortic tissue collected from multiorgan donors and AAA patients undergoing open surgical repair. Vascular smooth muscle cells (VSMCs) were exposed to various inflammatory mediators, and OPN expression was evaluated by quantitative reverse transcriptase-polymerase chain reaction and ELISA. The inflammatory nature of OPN and the aortic wall was determined using a TR1 suppressor cell induction assay as a surrogate and characterized by ELISA and fluorescence-activated cell sorting. RESULTS: OPN was found to be elevated in both the plasma and aortic homogenate of AAA patients compared with controls. On immunohistochemistry, OPN localized to the tunica media of the diseased aorta but was minimally expressed in healthy aorta. In vitro, cigarette smoke extract was the most potent stimulator of OPN secretion by VSMCs and increased both messenger RNA and supernatant concentrations. OPN demonstrated an ability to inhibit the induction of interleukin 10-secreting TR1 lymphocytes, a depleted population in the AAA patient, from naive precursors. Last, neutralizing receptor targets of OPN in the setting of AAA homogenate coincubation abrogated the inhibition of TR1 induction. CONCLUSIONS: OPN, secreted by the VSMCs of the tunica media, is elevated in the circulating plasma and aortic wall of patients with AAA. It can inhibit the induction of the TR1 suppressor cell, leading to an overall proinflammatory state contributing to progressive aortic wall breakdown and dilation.

Results of nonoperative management of acute limb ischemia in infants.

OBJECTIVE: Acute limb ischemia (ALI) in infants poses a challenge to the clinician secondary to poor operative outcomes, limb loss risk, and lifelong morbidity. This retrospective study reviewed a 10-year institutional experience with the nonoperative management of ALI in infants. METHODS: Infants (aged ≤12 months) diagnosed with ALI by duplex ultrasound and treated with initial nonoperative management at a tertiary care children's hospital were identified through vascular laboratory arterial duplex ultrasound records and International Classification of Diseases and Current Procedural Terminology codes associated with ALI. Demographics of the patients, injury characteristics, treatment administered, and outcomes were abstracted by chart review and presented using descriptive statistics. RESULTS: During the study period, a total of 25 (28% female) infant patients were diagnosed with ALI. The average age for this cohort was 3.5 ± 3.2 months (standard deviation). Most cases were secondary to iatrogenic injury (88%) from arterial cannulation. Injury sites were more concentrated to the lower extremities (84%) compared with the upper. Absence of Doppler signals was noted in 64% of infants, whereas limb cyanosis was observed in 60% at the time of presentation. Infants were initially treated with anticoagulation (80%) when possible. Two patients failed to respond to nonoperative management and required thrombolysis secondary to progression of thrombus burden while anticoagulated. There were no major (above-ankle) amputations at 30 days. Three deaths occurred within 30 days; all were unrelated to limb ischemia. In the 30-day survivors, overall duration of follow-up was 53.5 ± 38.5 months. One infant required above-knee amputation 6 weeks after diagnosis, resulting in an overall limb salvage rate of 96% on follow-up. Long-term morbidity included two patients with a chronic wound of the affected limb and one patient with limb length discrepancy. No subjects reported claudication at the latest follow-up appointment. In addition, all patients were independently ambulatory except for one adolescent girl who was using a walker with leg braces. CONCLUSIONS: In contrast to the adult population, ALI in infants can be managed with anticoagulation alone with good results. Long-term follow-up continues to demonstrate excellent functional results and minimal disability.

Rationale and Design of the ARREST Trial Investigating Mesenchymal Stem Cells in the Treatment of Small Abdominal Aortic Aneurysm.

BACKGROUND: Abdominal aortic aneurysms (AAAs) are a major source of morbidity and mortality despite continuing advances in surgical technique and care. Although the inciting factors for AAA development continue to be elusive, accumulating evidence suggests a significant periaortic inflammatory response leading to degradation and dilation of the aortic wall. Previous human trials have demonstrated safety and efficacy of mesenchymal stem cells (MSCs) in the treatment of inflammation-related pathologies such as rheumatoid arthritis, graft versus host disease, and transplant rejection. Therefore, herein, we describe the Aortic Aneurysm Repression with Mesenchymal Stem Cells (ARREST) trial, a phase I investigation into the safety of MSC infusion for patients with small AAA and the cells' effects on modulation of AAA-related inflammation. METHODS: ARREST is a phase I, single-center, double-blind, randomized controlled trial (RCT) investigating infusion both dilute and concentrated MSCs compared to placebo in 36 small AAA (35-45 mm) patients. Subjects will be followed by study personnel for 12 months to ascertain incidence of adverse events, immune cell phenotype expression, peripheral cytokine profile, and periaortic inflammation. Maximum transverse aortic diameter will be assessed regularly for 5 years by a combination of computed tomography and duplex sonography. RESULTS: Four patients have thus far been enrolled, randomized, and treated per protocol. We anticipate the conclusion of the treatment phase within the next 24 months with ongoing long-term follow-up. CONCLUSIONS: ARREST will be pivotal in assessing the safety of MSC infusion and provide preliminary data on the ability of MSCs to favorably modulate the pathogenic AAA host immune response. The data gleaned from this phase I trial will provide the groundwork for a larger, phase III RCT which may provide the first pharmaceutical intervention for AAA.

Staged endovascular repair of an abdominal aortic aneurysm adjacent to a chronic high-flow iliocaval traumatic arteriovenous fistula.

Large-vessel chronic traumatic arteriovenous fistulas are a rare complication after trauma. Delayed presentation can consist of one or more features of high-output cardiac failure, pulsatile abdominal mass, bruit, limb ischemia, and venous congestion. We describe a patient with a complex iliocaval fistula secondary to a remote gunshot wound associated with a large 8.5-cm aortic aneurysm. Informed consent of the patient was obtained for publication of the case.

XIAP antagonist embelin inhibited proliferation of cholangiocarcinoma cells.

Cholangiocarcinoma cells are dependent on antiapoptotic signaling for survival and resistance to death stimuli. Recent mechanistic studies have revealed that increased cellular expression of the E3 ubiquitin-protein ligase X-linked inhibitor of apoptosis (XIAP) impairs TRAIL- and chemotherapy-induced cytotoxicity, promoting survival of cholangiocarcinoma cells. This study was undertaken to determine if pharmacologic antagonism of XIAP protein was sufficient to sensitize cholangiocarcinoma cells to cell death. We employed malignant cholangiocarcinoma cell lines and used embelin to antagonize XIAP protein. Embelin treatment resulted in decreased XIAP protein levels by 8 hours of treatment with maximal effect at 16 hours in KMCH and Mz-ChA-1 cells. Assessment of nuclear morphology demonstrated a concentration-dependent increase in nuclear staining. Interestingly, embelin induced nuclear morphology changes as a single agent, independent of the addition of TNF-related apoptosis inducing ligand (TRAIL). However, caspase activity assays revealed that increasing embelin concentrations resulted in slight inhibition of caspase activity, not activation. In addition, the use of a pan-caspase inhibitor did not prevent nuclear morphology changes. Finally, embelin treatment of cholangiocarcinoma cells did not induce DNA fragmentation or PARP cleavage. Apoptosis does not appear to contribute to the effects of embelin on cholangiocarcinoma cells. Instead, embelin caused inhibition of cell proliferation and cell cycle analysis indicated that embelin increased the number of cells in S and G2/M phase. Our results demonstrate that embelin decreased proliferation in cholangiocarcinoma cell lines. Embelin treatment resulted in decreased XIAP protein expression, but did not induce or enhance apoptosis. Thus, in cholangiocarcinoma cells the mechanism of action of embelin may not be dependent on apoptosis.