Narayan Karunanithy

Reperfusion Hemorrhage Following Acute Myocardial Infarction: Assessment with T2* Mapping and Effect on Measuring the Area at Risk

Research ethics committee approval and informed consent were obtained. The purpose of this study was to assess the feasibility of multiecho T2* mapping of the heart for detecting reperfusion hemorrhage following percutaneous primary coronary intervention (PPCI) for acute myocardial infarction, and to measure the effect of hemorrhage on quantifying the ischemic area at risk (IAR) on T2-weighted magnetic resonance images. Fifteen patients (mean age, 59 years; 13 men, two women) were imaged a mean of 3.2 days following PPCI. The mean area of hemorrhage, indicated by a T2* decay constant of less than 20 msec, was 5.0% +/- 4.9 (standard deviation) at the level of the infarct and this correlated with the infarct (r(2) = 0.76, P < .01) and microvascular obstruction (r(2) = 0.75, P < .01) volumes. When 5% or less hemorrhage was present, the IAR was underestimated by 50% at a standard deviation threshold level of five, compared with a boundary detection tool (21.8% vs 44.0%, P < .05). T2* mapping is feasible for quantifying post-reperfusion hemorrhage and boundary detection is required to accurately assess the IAR when hemorrhage is present.

Bayesian network meta-analysis of nitinol stents, covered stents, drug-eluting stents, and drug-coated balloons in the femoropopliteal artery

OBJECTIVE Several randomized controlled trials (RCTs) have shown the superiority of some of these technologies over balloon angioplasty, but direct comparisons between these treatment options are lacking. The authors conducted a network meta-analysis of RCTs comparing bare nitinol stents, covered nitinol stents, paclitaxel- or sirolimus-eluting stents (PES or SES), and paclitaxel-coated balloons (PCB) with plain balloon angioplasty or with each other in the femoropopliteal artery (PROSPERO registry: CRD42013004845). METHODS Sixteen RCTs comprising 2532 patients with 4227 person-years of follow-up were analyzed on an intention-to-treat basis. Bayesian random effects Poisson and binomial models were used for mixed treatment comparisons (WinBUGS). Clinical heterogeneity was accounted for by incorporating a meta-regression model on trial-specific baseline risk. End points included technical success, vascular restenosis, target lesion revascularization, and major amputations. Pairwise odds ratios and rate ratios (ORs and RRs) of absolute treatment effects were calculated, and the probabilities of each treatment being best are reported. Summary estimates are reported as the posterior median and associated credible intervals (CrIs) that serve the same purpose as confidence intervals in the context of the Bayesian framework. Extensive sensitivity, meta-regression, and network consistency analyses were performed to evaluate heterogeneity. RESULTS Technical success was highest with covered stents (pooled OR, 13.6; 95% CrI, 3.3-31.1, probability best 82%) followed by uncovered stents (pooled OR, 7.0; 95% CrI, 2.6-129, probability best 18%) when compared with balloon angioplasty (reference treatment). Vascular restenosis was lowest with PES (RR, 0.43; 95% CrI, 0.16-1.18, probability best 45%) followed by PCB (RR, 0.43; 95% CrI, 0.26-0.67, probability best 42%). Target lesion revascularization was lowest with PCB (RR, 0.36; 95% CrI, 0.23-0.55, probability best 56%) followed by PES (RR, 0.42; 95% CrI, 0.16-1.06, probability best 33%). Major amputations were rare in all treatment and control groups (pooled amputation rate of 0.7 events per 100 person-years). CONCLUSIONS Immediate technical success is better with the use of covered stents, whereas paclitaxel-eluting stents and paclitaxel-coated balloons offer the best long-term results in the femoropopliteal artery.

CT Angiography of Inferior Epigastric and Gluteal Perforating Arteries before Free Flap Breast Reconstruction

Muscle-sparing perforator free flap breast reconstruction with the use of an inferior epigastric or gluteal perforating artery to create a vascular pedicle is increasingly popular because it obviates breast implants and results in lower donor site morbidity than breast reconstruction with myocutaneous flaps. The tissue harvesting procedure for a perforator free flap involves dissecting the subcutaneous fat of the anterior abdominal wall or the buttock to locate and visually evaluate the perforating arteries so as to decide which one is most suitable for the vascular pedicle. The vessel selected depends on multiple anatomic and surgical considerations, and the decision-making process can be exceptionally time-consuming, in part because of the wide variation that occurs in vascular anatomy. Preoperative imaging can greatly improve the efficiency of the selection process. Doppler ultrasonography (US) is the most frequently used modality for vascular mapping, but the results are mixed because most perforating arteries have a diameter of less than 15 mm, the threshold for reliable visualization with US. A computed tomographic (CT) angiographic evaluation performed with the use of specific postprocessing and display techniques may be more accurate for identifying the most suitable vessel. CT angiography provides valuable information that can help optimize surgical planning, decrease time spent in the operating room, and improve the outcome of breast reconstruction surgery.

Comparative Efficacy and Safety of Different Antiplatelet Agents for Prevention of Major Cardiovascular Events and Leg Amputations in Patients with Peripheral Arterial Disease: A Systematic Review and Network Meta-Analysis.

There is a lack of consensus regarding which type of antiplatelet agent should be used in patients with peripheral arterial disease (PAD) and little is known on the advantages and disadvantages of dual antiplatelet therapy. We conducted a systematic review and network meta-analysis of available randomized controlled trials (RCT) comparing different antiplatelet drugs (Aspirin, Ticlopidine, Clopidogrel, Ticagrelor, Cilostazol, Picotamide and Vorapaxar as monotherapies or in combination with aspirin) in PAD patients (PROSPERO public database; CRD42014010299).We collated evidence from previous relevant meta-analyses and searched online databases. Primary efficacy endpoints were: (1) the composite rate of major adverse cardiovascular events (MACE; including vascular deaths, non-fatal myocardial infarction and non-fatal stroke), and (2) the rate of major leg amputations. The primary safety endpoint was the rate of severe bleeding events. Bayesian models were employed for multiple treatment comparisons and risk-stratified hierarchies of comparative efficacy were produced to aid medical decision making. Number-Needed-to-Treat (NNT) and Number-Needed-to-Harm (NNH) are reported in case of significant results. We analyzed 49 RCTs comprising 34,518 patients with 88,358 person-years of follow-up with placebo as reference treatment. Aspirin, Cilostazol, Vorapaxar and Picotamide were ineffective in reducing MACE. A significant MACE reduction was noted with Ticagrelor plus aspirin (RR: 0.67; 95%CrI: 0.46–0.96, NNT = 66), Clopidogrel (RR: 0.72; 95%CrI: 0.58–0.91, NNT = 80), Ticlopidine (RR: 0.75; 95%CrI: 0.58–0.96, NNT = 87), and Clopidogrel plus aspirin (RR: 0.78; 95%CrI: 0.61–0.99, NNT = 98). Dual antiplatelet therapy with Clopidogrel plus aspirin significantly reduced major amputations following leg revascularization (RR: 0.68; 95%CrI: 0.46–0.99 compared to aspirin, NNT = 94). The risk of severe bleeding was significantly higher with Ticlopidine (RR: 5.03; 95%CrI: 1.23–39.6, NNH = 25), Vorapaxar (RR: 1.80; 95%CrI: 1.22–2.69, NNH = 130), and Clopidogrel plus aspirin (RR: 1.48; 95%CrI: 1.05–2.10, NNH = 215). Clopidogrel monotherapy showed the most favourable benefit-harm profile (79% cumulative rank probability best and 77% cumulative rank probability safest). In conclusion, Clopidogrel should be the indicated antiplatelet agent in PAD patients. Dual antiplatelet therapy with aspirin and Clopidogrel can reduce the rate of major leg amputations following revascularization, but carries a slightly higher risk of severe bleeding.

Targeted True Lumen Re-Entry With the Outback Catheter Accuracy, Success, and Complications in 100 Peripheral Chronic Total Occlusions and Systematic Review of the Literature

Purpose: To report a single-center experience with the Outback re-entry device for targeted distal true lumen re-entry during subintimal recanalization of chronic total occlusions (CTOs) and compare the results with a systematic review of the literature. Methods: Between February 2011 and July 2013, 104 Outback devices were employed in 91 patients (mean age 64±9 years; 57 men) for subintimal recanalization of 100 vessels with CTOs after initial failure of spontaneous reentry. Fifty-two cases involved a retrograde approach to aortoiliac occlusions and 48 were re-entry attempts in infrainguinal CTOs. Outcome measures included complications and technical success, defined as successful targeted re-entry at the preplanned site of the distal true lumen. To evaluate device accuracy, the re-entry distance (between the point of true vessel reconstitution and the eventual re-entry point) was measured. Results: Outback success was 93% (93/100); only 7 cases failed owing to heavy calcification (5/52 aortoiliac vs 2/48 infrainguinal, p=0.44). Re-entry was highly accurate, with a re-entry distance of ~1 cm in both subgroups (1.2±0.1 cm in aortoiliac vs 1.3±0.1 cm in infrainguinal, p=0.40). There were no major and 17 minor complications (9/52 aortoiliac vs 8/48 infrainguinal, p=0.93). Results are in line with the systematic review that identified 11 studies (only 1 randomized trial) involving mostly the femoropopliteal segment (119 aortoiliac and 464 infrainguinal segments). The pooled Outback success rate was 90% (95% confidence interval 85% to 94%) and the pooled complication rate was 4.3% (95% confidence interval 1.6% to 8.3%). Conclusion: The Outback device is safe and has a very high rate of achieving targeted true lumen re-entry, which minimizes the sacrifice of healthy vessel in the aortoiliac and infrainguinal arteries.

Central Aortic Blood Pressure From Ultrasound Wall-Tracking of the Carotid Artery in Children Comparison With Invasive Measurements and Radial Tonometry

Differences between central aortic root (c) and peripheral (p) systolic blood pressure (SBP) may be particularly marked in children, but noninvasive methods for assessing cSBP in children have not been validated. We compared estimates of cSBP obtained from radiofrequency ultrasound wall tracking of the carotid artery (ART.LAB system) with that measured directly by a catheter in the aortic root at the time of arterial cannulation. Carotid waveforms were calibrated from invasive measurements of mean and diastolic pressures. In 9 children aged 10.5±5.0 years (mean±SD), cSBP obtained from carotid wall tracking was highly correlated with invasive measures of cSBP (r=0.99) with mean (±SD) difference 3.9±2.5 mm Hg. Second, we compared values of cSBP obtained from the carotid with those obtained using noninvasive applanation tonometry at the radial artery and a radial-to-aortic transfer function (SphygmoCor). Both carotid and radial tonometric measurements were calibrated from the same peripheral mean and diastolic measurements of blood pressure obtained by sphygmomanometry. In 84 children aged 13.2±3.2 years, there was excellent agreement between the 2 methods (r=0.95; P<0.001) with mean difference 0.71±3.7 mm Hg (95% confidence interval =−1.53 to 1.01). This invasive validation study confirms that cSBP as estimated by carotid wall tracking provides an acceptable measurement of true cSBP when calibration is from true mean and diastolic pressures. Close agreement of cSBP obtained by carotid wall tracking and radial tonometry suggests that these provide similar results when calibrated from the same peripheral blood pressure measurements.Differences between central aortic root (c) and peripheral (p) systolic blood pressure (SBP) may be particularly marked in children, but noninvasive methods for assessing cSBP in children have not been validated. We compared estimates of cSBP obtained from radiofrequency ultrasound wall tracking of the carotid artery (ART.LAB system) with that measured directly by a catheter in the aortic root at the time of arterial cannulation. Carotid waveforms were calibrated from invasive measurements of mean and diastolic pressures. In 9 children aged 10.5±5.0 years (mean±SD), cSBP obtained from carotid wall tracking was highly correlated with invasive measures of cSBP ( r =0.99) with mean (±SD) difference 3.9±2.5 mm Hg. Second, we compared values of cSBP obtained from the carotid with those obtained using noninvasive applanation tonometry at the radial artery and a radial-to-aortic transfer function (SphygmoCor). Both carotid and radial tonometric measurements were calibrated from the same peripheral mean and diastolic measurements of blood pressure obtained by sphygmomanometry. In 84 children aged 13.2±3.2 years, there was excellent agreement between the 2 methods ( r =0.95; P <0.001) with mean difference 0.71±3.7 mm Hg (95% confidence interval =−1.53 to 1.01). This invasive validation study confirms that cSBP as estimated by carotid wall tracking provides an acceptable measurement of true cSBP when calibration is from true mean and diastolic pressures. Close agreement of cSBP obtained by carotid wall tracking and radial tonometry suggests that these provide similar results when calibrated from the same peripheral blood pressure measurements. # Novelty and Significance {#article-title-25}

Vascular manifestations of syndromic aortopathies: role of current and emerging imaging techniques

Patients with connective tissue diseases such as Marfans syndrome, Loeys-Dietz syndrome, and vascular Ehlers-Danlos syndrome comprise a small but important group of patients who present early with acute aortic syndrome comprising aneurysmal dilation, rupture, or aortic dissection. Cardiovascular pathologies are an important yet treatable cause of morbidity and mortality in these patients. Imaging plays an important role in initial diagnosis, surveillance, and identification of complications. Furthermore, these patients are prone to developing complications in other vascular territories. Effective screening and surveillance will allow early diagnosis and elective treatment thus reducing the morbidity and mortality associated with presentation with acute complications. In this article, we will provide an overview of the role of magnetic resonance and computed tomography angiography in the management of syndromic aortopathies.

Fluoroscopically guided balloon dilatation for the treatment of achalasia: long-term outcomes.

To report the immediate and long-term outcomes following the fluoroscopically guided balloon dilatations performed in our department for the treatment of achalasia. We reviewed retrospectively all patients that underwent a fluoroscopically guided balloon dilatation because of achalasia in our department between April 2007 and September 2010. The follow-up was performed by interviews and/or investigation of the patients medical and imaging records. The primary endpoints of the study were technical success, clinical success, major complication rates, and repeat dilatation rates because of recurrence of clinical symptomatology. Secondary endpoints were the rate of minor complications and the dilatation-free interval. Various parameters that could affect the clinical outcome were also analyzed. Thirty-nine consecutive patients (20 female) with a mean age 44 ± 17 years underwent 69 dilatations, while 10/39 (25.6%) patients had a history of a previous laparoscopic myotomy. The most common symptom was dysphagia (64/69, 92.7%), while regurgitation and/or retrosternal pain were present in 12/39 (30.7%) and 9/39 (23%) of the cases, respectively. Technical success was achieved in 98.5% (68/69). There were no procedure-related major complications. The mean balloon diameter used was 30 ± 3.9 mm, and the mean period of follow-up was 27.7 ± 16.0 months. Excellent or good initial responses were noted in 54/66 cases (81.8%). A repeated dilatation to deal with recurrence of symptoms was performed in 69.4% of the cases (25/36). In the majority of the cases, two dilatations were needed in order to achieve long-term relief from symptoms. A dilatation-free interval of 4 years was observed in 26.4%. Clinical success was achieved in 30/36 patients (83.3%). Subgroup analysis did not detect significantly different recurrence rates in patients with and without previous laparoscopic myotomy (50% vs. 69% respectively), those of young age (75% < 21 years vs. 68.8% > 21 years), and male gender (71.4% male vs. 55.0% females). The high redilatation rate was attributed to the utilization of smaller balloons by less experienced operators. Fluoroscopically guided balloon dilatation is a safe and effective method for the treatment of achalasia. Young age and prior Hellers laparoscopic myotomy were not associated with increased rates of recurrence rate or clinical failure.

Informed consent: what do we tell patients about the risk of fatal pulmonary embolism after varicose vein surgery?

Objective: To obtain an estimate of the frequency of fatal pulmonary embolism (PE) after varicose vein surgery. Methods: Firstly by analysis of official statistics and secondly by a postal questionnaire to surgeons carrying out varicose vein surgery. The response rate from the questionnaire was 68% (391/576). Surgeons were asked if they had encountered PE after varicose vein surgery, whether the outcome was fatal and how many years they had spent in the specialty. Further calculations were based on data obtained from the Vascular Society of Great Britain and Ireland that suggest that on average about 120 cases are operated per year per consultant surgeon. Results: Analysis of the statistics available from official sources suggested that the risk of fatal PE after varicose vein surgery is about 1 in 15,000. Respondents to the questionnaire reported a total of 396 pulmonary emboli, of which 73 were fatal. From the questionnaire, we estimate that between one in three and one in four surgeons will encounter a fatality in the course of a full career. From knowledge of the length of time spent in the specialty by our respondents and using the figure of 120 operated cases per consultant per year, we obtained a higher estimate of the risk of fatal PE, around one in 10,000 cases. Conclusions: While the methods used to collect these figures are imperfect and open to criticism, they suggest a risk between one in 10,000 and one in 15,000. We think it is reasonable, when obtaining consent, to warn patients of the very small risk of fatal PE, using the more pessimistic figure of one in 10,000.

Successful exclusion of a large bronchopleural fistula using an Amplatzer II vascular plug and glue embolization

We report a case of a 63-year-old man with a complicated postsurgical bronchopleural fistula (BPF), which was treated with a minimally-invasive hybrid procedure using fluoroscopy, bronchoscopy, and thoracoscopy. A previous surgical attempt had failed to seal the pathologic tract. An Amplazter II vascular plug was successfully deployed into the BPF, followed by autologous blood and glue injection. An adjunctive endoscopically-guided glue embolization was deemed necessary. The 14-month clinical and imaging follow-up confirmed the successful exclusion of the BPF. No migration of the device was noted and the patient remained asymptomatic. The combined endoscopic and fluoroscopic guided management of a BPF using the Amplatzer II vascular plug and glue was proven safe and effective after mid-term follow-up.