Iliac vein stent migration with extensive cardiac damage in a patient with May-Thurner syndrome.

In May-Thurner syndrome, or iliac vein compression syndrome, the left common iliac vein is compressed between the right common iliac artery and corresponding vertebral body, increasing patient risk for deep vein thrombosis. Iliac vein stenting for patients with symptomatic May-Thurner syndrome has become standard practice in many centers. This article describes a patient whose stent embolized completely to the right ventricle, destroying most structures in its path.

Race and survival among diabetic patients after coronary artery bypass grafting.

BACKGROUND: Diabetes is a known predictor of decreased long-term survival after coronary artery bypass grafting (CABG). Differences in survival by race have not been examined. METHODS: A retrospective cohort study was conducted for CABG patients between 1992 and 2011. Long-term survival was compared in patients with and without diabetes and stratified by race. Hazard ratios (HR) and 95% confidence intervals (CI) were computed using a Cox regression model. RESULTS: Out of the 13,053 patients undergoing CABG, 35% (black n = 1,655; white n = 2,884) had diabetes at the time of surgery. The median follow-up for study participants was 8.2 years. Long-term survival after CABG was similar between black and white diabetic patients (no diabetes, HR = 1.0; white diabetic patients, adjusted HR = 1.5, 95%CI = 1.4-1.6; black diabetic patients, adjusted HR = 1.5, 95%CI = 1.4-1.7). CONCLUSION: A survival disadvantage after CABG was not observed among black versus white diabetic patients in our study.

The effect of preoperative ß-blocker use and race on long-term survival after coronary artery bypass grafting.

OBJECTIVE: To date, racial differences in the long-term survival of coronary artery bypass grafting (CABG) patients who receive preoperative ß-blockers have not been specifically examined. The purpose of this study was to examine the effect of preoperative ß-blockers on long-term survival among black CABG patients and to compare the magnitude of this effect with white patients. DESIGN: A retrospective cohort study. SETTING: A tertiary referral heart hospital. PARTICIPANTS: 13,354 patients undergoing CABG between 1992 and 2011. MEASUREMENTS AND MAIN RESULTS: Hazard ratios (HR) and 95% confidence intervals (CI) were computed using a Cox regression model. A total of 1,448 (62%) black and 6,094 (55%) white patients had a history of preoperative ß-blocker use. Among black patients, those receiving ß-blockers survived longer than those not receiving ß-blockers (adjusted HR = 0.77, 95% CI = 0.67-0.88). The survival advantage was comparable to that observed among white patients (adjusted HR = 0.88, 95% CI = 0.82-0.93). CONCLUSION: Black CABG patients benefited from preoperative ß-blockers and the magnitude of the effect was comparable to that among white patients.

Propagating nanocavity-enhanced rapid crystallization of silicon thin films.

We demonstrate a mechanism of solid-phase crystallization (SPC) enabled by nanoscale cavities formed at the interface between an hydrogenated amorphous silicon film and embedded 30 to 40 nm Si nanocrystals. The nanocavities, 10 to 25 nm across, have the unique property of an internal surface that is part amorphous and part crystalline, enabling capillarity-driven diffusion from the amorphous to the crystalline domain. The nanocavities propagate rapidly through the amorphous phase, up to five times faster than the SPC growth rate, while "pulling behind" a crystalline tail. Using transmission electron microscopy it is shown that twin boundaries exposed on the crystalline surface accelerate crystal growth and influence the direction of nanocavity propagation.

Reconstruction of a left main coronary artery aneurysm using a radial artery patch.

A left main coronary artery aneurysm is a rare anomaly. There are no standardized treatment guidelines given the infrequency of reported cases. A 70-year-old African American female with an enlarging distal left main coronary artery aneurysm was taken to the operating room for surgical intervention. The patient underwent a successful open surgical repair of the aneurysm with reconstruction of the distal left main using a radial artery patch. No coronary bypasses were necessary. Aneurysm ligation with concomitant coronary artery bypass grafting is commonly reported but reconstruction may be preferable when the anatomy is suitable. Preservation of nonobstructed native coronary artery circulation should also be considered to avoid life-long graft dependency.

Transjugular intrahepatic portosystemic shunts in liver transplant recipients: technical analysis and clinical outcome.

OBJECTIVE: The purpose of this study is to compare the technical success of transjugular intrahepatic portosystemic shunt (TIPS) in transplanted versus nontransplanted livers and to assess the clinical outcome of TIPS in liver transplant recipients. MATERIALS AND METHODS: A retrospective audit of patients receiving a TIPS was performed in two institutions during 1996-2009. The technical success of the TIPS was compared for transplanted versus nontransplanted livers. Clinical success was defined as graft survival longer than 1 month with improvement in symptoms. The cohort was divided into grafts that survived less than 3 months versus 3 months or more. The model for end-stage liver disease (MELD) scores and portosystemic gradients before and after TIPS creation were evaluated for predictive value for graft survival. The TIPS stent type, MELD scores and portosystemic gradients before and after TIPS creation, and causes of liver disease were evaluated for their predictive value for ascites response after TIPS creation. RESULTS: Thirty-nine TIPS in transplanted livers were found, representing 5.5% (39/715) of all TIPS procedures performed and 2.0% (39/1992) of all liver transplant recipients. Ninety percent of TIPS in transplanted livers had ascites. The median time from transplant to creation of the TIPS was 29 months (2-127 months). The median MELD score was 16 before and 22 after the TIPS procedure. The technical success rates for TIPS were 97% (38/39) in transplanted livers versus 97% (657/676) in nontransplanted livers (p = 1.00). Intent-to-treat clinical success rates were 36% for all indications versus 31% for ascites only. There were no predictors for ascites response. Six-, 12-, and 24-month graft survival rates were 43%, 32%, and 22%, respectively. One-year graft survival for a MELD score less than 17 versus a score of 17 or higher was 54% versus 8%, respectively (p < 0.05). CONCLUSION: Transplantation does not pose a technical challenge to TIPS creation. One third of patients have a favorable outcome. MELD score is the only predictor of graft survival.

Impact of race and postoperative atrial fibrillation on long-term survival after coronary artery bypass grafting.

BACKGROUND AND AIM: Postoperative atrial fibrillation (POAF) is a known predictor of in-hospital morbidity and short-term survival after coronary artery bypass grafting (CABG). The impact of race and long-term survival has not been examined in this population. We aimed to examine the influence of these factors on long-term survival in patients undergoing CABG. METHODS: Patients undergoing first-time, isolated CABG between 1992 and 2011 were included in this study. Long-term survival was compared in patients with and without POAF and stratified by race. Hazard ratios (HR) and 95% confidence intervals (CI) were computed using a Cox regression model. RESULTS: A total of 2,907 (22%) patients developed POAF (black n=370; white n=2,537) following CABG (N=13,165). Median follow-up for study participants was 8.2 years. Long-term survival after CABG differed by POAF status and race (no POAF: HR=1.0; white POAF: adjusted HR=1.1, 95% CI=1.06-1.2; black POAF: adjusted HR=1.4, 95% CI=1.2-1.6; pTrend=0.0002). lack POAF patients also died sooner after surgery than their white counterparts (adjusted HR=1.2, 95% CI=1.02-1.4). CONCLUSION: Black race was a statistically significant predictor of decreased survival among POAF patients after CABG. This finding provides useful outcome information for surgeons and their patients.

The impact of prior percutaneous coronary intervention on long-term survival after coronary artery bypass grafting.

BACKGROUND: Previous studies examining the influence of prior percutaneous coronary intervention (PCI) on long-term survival after coronary artery bypass grafting (CABG) have reported conflicting results. The purpose of this study was to further examine the influence of prior PCI on long-term survival after CABG at a large tertiary referral heart institute. METHODS: Long-term survival between 1992 and 2011 was compared in non-emergent CABG cases with and without prior PCI. Hazard ratios (HR) and 95% confidence intervals (CI) were computed using a Cox regression model. RESULTS: A total of 2532 (19%) patients had prior PCI before CABG (n=13,354). The median follow-up for study participants was 8.1 years. The median survival for patients with and without prior PCI was 15 years and 14 years, respectively (p<0.0001). Long-term survival was similar between patients with and without prior PCI after adjusting for age, sex, race, hypertension, coronary artery disease severity, congestive heart failure, and prior stroke (adjusted HR=0.99, 95%CI=0.91-1.06). CONCLUSION: Findings from outcomes research are important in the planning of appropriate postoperative patient care. Our study provides additional evidence that prior PCI is not a significant predictor of long-term survival after CABG.

Delayed left ventricle-to-right atrial fistula following aortic valve replacement.

Fistula development between the left ventricular outflow tract and right atrium is a rare complication of aortic valve replacement (AVR), typically seen with calcific aortic stenosis or endocarditis. The case is reported of a left ventricle-to-right atrial fistula following mechanical AVR for aortic insufficiency.

An acute animal model of aortic stenosis: initial attempts at leaflet modification.

BACKGROUND AND AIM OF THE STUDY: Percutaneous valve insertion is an emerging treatment for aortic stenosis (AS). To date, no large animal model exists that replicates human calcific AS; moreover, the absence of any valve pathology in currently available animal models prevents their use in any realistic assessment of percutaneous aortic valve therapy. Hence, the aim of the present study was to create an acute large animal model in which human calcific AS could be simulated. METHODS: Ten domestic swine underwent open-heart surgery utilizing cardiopulmonary bypass (CPB) and cardioplegic arrest. The aortic valve annulus and leaflets were injected with cyanoacrylate, after which epicardial echocardiography was used to assess the creation of AS. At the time of animal sacrifice, the hearts were harvested for gross and histopathological examination. RESULTS: The leaflet and annular injections were performed successfully in all animals. Subsequently, seven animals were weaned from CPB and underwent post procedural echocardiographic evaluations, whereby the treated valves were harvested for gross and histological examination. CONCLUSION: Cyanoacrylate can be injected into the porcine aortic valve and annulus to create a model that resembles human calcific AS in the acute setting. Additional long-term follow up studies must be conducted, however, before this model can be utilized in the development of percutaneous valve therapy.

Three-dimensional echocardiographic features of unicuspid aortic valve stenosis correlate with surgical findings.

A unicuspid aortic valve (UAV) is a rare congenital defect that may manifest clinically as severe aortic stenosis or regurgitation in the third to fifth decade of life. This report describes two cases of UAV stenosis in adult patients diagnosed by transesophageal echocardiography (TEE). The utility of three-dimensional TEE in confirming valve morphology and its relevance to transcatheter valve replacement are discussed.

Increased propensity for cell death in diabetic human heart is mediated by mitochondrial-dependent pathways.

Progressive energy deficiency and loss of cardiomyocyte numbers are two prominent factors that lead to heart failure in experimental models. Signals that mediate cardiomyocyte cell death have been suggested to come from both extrinsic (e.g., cytokines) and intrinsic (e.g., mitochondria) sources, but the evidence supporting these mechanisms remains unclear, and virtually nonexistent in humans. In this study, we investigated the sensitivity of the mitochondrial permeability transition pore (mPTP) to calcium (Ca(2+)) using permeabilized myofibers of right atrium obtained from diabetic (n = 9) and nondiabetic (n = 12) patients with coronary artery disease undergoing nonemergent coronary revascularization surgery. Under conditions that mimic the energetic state of the heart in vivo (pyruvate, glutamate, malate, and 100 µM ADP), cardiac mitochondria from diabetic patients show an increased sensitivity to Ca(2+)-induced mPTP opening compared with nondiabetic patients. This increased mPTP Ca(2+) sensitivity in diabetic heart mitochondria is accompanied by a substantially greater rate of mitochondrial H(2)O(2) emission under identical conditions, despite no differences in respiratory capacity under these conditions or mitochondrial enzyme content. Activity of the intrinsic apoptosis pathway mediator caspase-9 was greater in diabetic atrial tissue, whereas activity of the extrinsic pathway mediator caspase-8 was unchanged between groups. Furthermore, caspase-3 activity was not significantly increased in diabetic atrial tissue. These data collectively suggest that the myocardium in diabetic patients has a greater overall propensity for mitochondrial-dependent cell death, possibly as a result of metabolic stress-imposed changes that have occurred within the mitochondria, rendering them more susceptible to insults such as Ca(2+) overload. In addition, they lend further support to the notion that mitochondria represent a viable target for future therapies directed at ameliorating heart failure and other comorbidities that come with diabetes.

It's not just for laparoscopy anymore: use of insufflation under ultrasound and fluoroscopic guidance by Interventional Radiologists for percutaneous placement of intraperitoneal chemotherapy catheters.

OBJECTIVES: While intraperitoneal (IP) chemotherapy has shown significant survival benefits, the ability to successfully deliver IP chemotherapy has been limited. In GOG 172, surgically-placed IP catheters had a reported complication rate of 34%. In addition, IP catheters have to be placed surgically. We have developed a novel percutaneous placement technique for IP catheters in patients without ascites. METHODS: This study was a retrospective analysis of all patients receiving percutaneously-placed IP catheters from 12/2008 to present. Catheters were placed using a two-step technique under conscious sedation. IP access was gained using ultrasound-guided peritoneal puncture over the right lobe of the liver. A 5 Fr catheter was placed into the peritoneal cavity and the abdomen insufflated with carbon dioxide (CO(2)). Access was gained in the RLQ once distention separated the bowel from the abdominal wall. A 14.5 Fr multi-side hole catheter was coiled in the pelvis, and a reservoir tunneled onto the lower anterior chest wall. For this analysis, abstracted data included patient demographics, indication for catheter placement, complications (procedural and with chemotherapy delivery), fluoroscopy time, and timing/indication of catheter removal. RESULTS: Eleven patients received IP catheters. The mean age was 58 years, mean body mass index was 27.1, and mean number of days from surgical debulking was 38. There were two stage 2, and eight stage 3 patients. Two patients had fallopian tube, and nine patients had ovarian cancer. All patients had an optimal debulking procedure. Seven of 11 patients also obtained central intravenous access when the IP port was placed. Follow-up data were as follows: Average fluoroscopy time was 9 min. One patient (9%) had an intra-procedural complication but the catheter was successfully placed. Zero patients had catheter-related complications in the course of receiving chemotherapy. Five of the 11 patients (45%) completed the planned IP chemotherapy treatments, with three additional patients (27%) currently receiving therapy. The remaining three patients (27%) discontinued chemotherapy for reasons unrelated to IP catheter function: two due to chemotherapy side effects, and one with sepsis from a perforated diverticulum. CONCLUSIONS: Thus far, our experience with percutaneous placement of IP catheters is associated with a low risk of catheter-related complications and high technical success rates. CO(2) insufflation may make peritoneal puncture easier and potentially safer. This procedure offers an alternative to surgical placement, even in patients without clinically significant ascites.

Effect of transjugular intrahepatic portosystemic shunt placement on renal function: a 7-year, single-center experience.

PURPOSE: Transjugular intrahepatic portosystemic shunt (TIPS) creation has been shown to improve renal function in small series of patients with hepatorenal syndrome. The present study examined the effect of TIPS creation on renal function in a large series of patients undergoing TIPS creation who had varying degrees of baseline renal function. MATERIALS AND METHODS: All de novo TIPS creations during a 7-year period at a single institution were retrospectively reviewed regardless of indication. Pre- and postprocedural laboratory values were obtained and used to calculate Model for End-Stage Liver Disease (MELD) scores and glomerular filtration rates. Subanalysis was performed based on degree of renal insufficiency and indication for the procedure. RESULTS: A total of 201 successful conventional TIPS procedures were identified. Of those, 72 patients were excluded for lack of follow-up, death during the same hospitalization, lack of TIPS function, or end-stage renal failure requiring dialysis before TIPS creation, leaving 129 procedures. Patients with preprocedural creatinine levels of 1.2-1.9 mg/dL (n = 45) showed an improvement in mean creatinine from 1.5 to 1.1 mg/dL (P < 10(-12)) and patients with preprocedure creatinine levels greater than 2.0 mg/dL (n = 21) showed an improvement from 2.8 to 1.5 mg/dL (P < 10(-5)). MELD scores decreased in patients with creatinine levels greater than 2.0 mg/dL from 22.1 to 19.2 (P < 0.005) but increased in all other patient groups. Amount of iodinated contrast medium administered did not affect creatinine level changes. CONCLUSIONS: TIPS creation improves renal dysfunction in chronic liver disease. Patients with poorer renal function benefit the most from TIPS creation.

Successful Percutaneous Endovascular Repair in a Very Large, Symptomatic, Non-ruptured Abdominal Aortic Aneurysm with Severe Neck Angulation.

Percutaneous endovascular aneurysm repair (PEVAR) is a minimally invasive treatment option for patients with abdominal aortic aneurysms (AAA). PEVAR allows for the lower incidence of vascular access site complications and decreased procedure time, yet the utility of this technique depends on the anatomical characteristics of the aneurysm. A detailed evaluation of the access site vessels and aneurysm neck anatomy are critical for standard patient and device selection. An 84-year-old male presented to our institution with the sudden onset of abdominal pain and confusion. Subsequent imaging demonstrated the presence of a 9.5 cm fusiform, infrarenal abdominal aortic aneurysm with a greater than 60-degree neck angulation and bilateral common iliac aneurysms. The patient underwent percutaneous endovascular aneurysm repair (PEVAR), and a type IB endoleak seen at the end of the case was treated successfully. At the one-year follow-up, the patient remained asymptomatic with the AAA stable in size.  This case represents the largest reported symptomatic unruptured AAA repaired with a completely percutaneous technique to date. Building up the stent-graft from the bifurcation with a unibody modular device may allow for support to address the severe angulation of a very hostile neck. PEVAR is a viable option in patients with symptomatic AAA and can be performed despite severe aneurysm neck angulation.

Endovascular management of a large post-traumatic iliac arteriovenous fistula: utilization of a septal occlusion device.

We describe the management of a large iliac arteriovenous fistula in a 48-year-old patient presenting with heart failure and pulmonary hypertension. The presumptive etiology was a left-lower back stab wound approximately 20 years earlier. A large communication between the left internal iliac artery and the left internal iliac vein was successfully treated with a septal occlusion device.

MIR-206 regulates connexin43 expression during skeletal muscle development.

Skeletal myoblast fusion in vitro requires the expression of connexin43 (Cx43) gap junction channels. However, gap junctions are rapidly downregulated after the initiation of myoblast fusion in vitro and in vivo. In this study we show that this downregulation is accomplished by two related microRNAs, miR-206 and miR-1, that inhibit the expression of Cx43 protein during myoblast differentiation without altering Cx43 mRNA levels. Cx43 mRNA contains two binding sites for miR-206/miR-1 in its 3'-untranslated region, both of which are required for efficient downregulation. While it has been demonstrated before that miR-1 is involved in myogenesis, in this work we show that miR-206 is also upregulated during perinatal skeletal muscle development in mice in vivo and that both miR-1 and miR-206 downregulate Cx43 expression during myoblast fusion in vitro. Proper development of singly innervated muscle fibers requires muscle contraction and NMJ terminal selection and it is hypothesized that prolonged electrical coupling via gap junctions may be detrimental to this process. This work details the mechanism by which initial downregulation of Cx43 occurs during myogenesis and highlights the tight control mechanisms that are utilized for the regulation of gap junctions during differentiation and development.

Redefining the structure of the mouse connexin43 gene: selective promoter usage and alternative splicing mechanisms yield transcripts with different translational efficiencies.

The connexin43 (cx43) gene was originally described as consisting of two exons, one coding for most of the 5'-untranslated region (5'-UTR), and the other for the protein sequence and 3'-UTR. We now report that in mouse four additional exons are expressed, all coding for novel 5'-UTRs. Altogether, we found nine different cx43 mRNA species (GenBank accession numbers NM010288, and AY427554 through AY427561) generated by differential promoter usage and alternative splicing mechanisms. The relative abundance of these different mRNAs varied with the tissue source. In addition, the different transcripts showed varying translational efficiencies in several cell lines, indicating the presence of cis-RNA elements that regulate cx43 translation. We propose that it is the promoter driving the expression of the cx43 gene that determines exon choice in the downstream splicing events in a cell-type-dependent fashion. This in turn will affect the translation efficiency of the transcript orchestrating the events that lead to the final expression profile of cx43. Since a similar organization of the cx43 gene was also observed in rat it is likely that the complex regulation of cx43 expression involving transcription, splicing and translation mechanisms is a common trait conserved during evolution.

Management of gastric varices in the pediatric population with balloon-occluded retrograde transvenous obliteration (BRTO) utilizing sodium tetradecyl sulfate foam sclerosis with or without partial splenic artery embolization.

It is unknown whether spontaneous gastrorenal shunts actually develop in the pediatric population. The minimum age documented in studies from Asia is 32 (range 32-44) years. This study describes three pediatric patients undergoing balloon-occluded retrograde transvenous obliteration (BRTO) for bleeding gastric varices with two of the three patients undergoing combined partial splenic embolization. The first BRTO is a selective-BRTO via a surgical splenorenal shunt (15 years old) and the other two patients underwent conventional-BRTO via a spontaneous gastrorenal shunt (8 and 14 years old). The recurrent significant bleeding that they exhibited before the combined endovascular therapy did not recur for an average of 7.1 (range 1.4-14) months. In the second patient, quantitative digitally subtracted angiography was utilized to evaluate the inline portal venous flow before and after BRTO.

Liberal use of delayed sternal closure for postcardiotomy hemodynamic instability.

BACKGROUND: The purpose of this retrospective study was to evaluate the current incidence, survival, and predictors of mortality for open chest management at our center. METHODS: Our database was analyzed to identify adult postcardiotomy patients who left the operating room without primary sternal closure. Medical records were reviewed to determine mortality, postoperative complications, and pertinent hemodynamic data. RESULTS: From November 1997 to June 2000, 5,177 adults underwent cardiac procedures at our center. The incidence of open chest management was 1.7% (87 of 5,177), including 0.7% (16 of 2,254) for isolated coronary artery bypass grafting, 1.6% (15 of 912) for isolated valve, and 5.6% (47 of 839) for combined valve/coronary bypass. Hospital survival was 76% (66 of 87). Major complications included deep sternal infection (n = 4), stroke (n = 8), and dialysis (n = 13). Predictors of mortality by univariate analysis included ventricular assist device insertion (p = 0.003), new onset hemodialysis (p < 0.0005), reoperation for bleeding (p = 0.002), sternal infection (p = 0.042), mean length of delay before sternal closure (survivors = 3.2 days, nonsurvivors = 6.2 days; p = 0.031), higher mean dose of epinephrine at the time of chest closure (2.5 microg versus 0.9 microg, p = 0.011), and longer duration of high dose inotropic therapy (110 hours versus 43 hours, p = 0.002). Multivariate analysis showed ventricular assistance and reoperation for bleeding as independent predictors of in-hospital death with odds ratios of 3.8 and 3.4, respectively. CONCLUSIONS: Liberal use of open chest management is useful in patients with postcardiotomy shock, and can be carried out with a relatively low incidence of sternal complications. Patients who require ventricular assistance or exploration for ongoing mediastinal bleeding continue to have a high mortality rate.