Johannes Bonatti

Multislice Computed Tomography in Infective Endocarditis Comparison With Transesophageal Echocardiography and Intraoperative Findings

OBJECTIVES The aim of this study was to assess the value of multislice computed tomography (CT) for the assessment of valvular abnormalities in patients with infective endocarditis (IE) in comparison with transesophageal echocardiography (TEE) and intraoperative findings. BACKGROUND Multislice CT has recently shown promising data regarding valvular imaging in a 4-dimensional fashion. METHODS Thirty-seven consecutive patients with clinically suspected IE were examined with TEE and 64-slice CT or dual-source CT. Twenty-nine patients had definite IE and underwent surgery. RESULTS The diagnostic performance of CT for the detection of evident valvular abnormalities for IE compared with TEE was: sensitivity 97%, specificity 88%, positive predictive value (PPV) 97%, and negative predictive value (NPV) 88% on a per-patient basis (n = 37; excellent intermodality agreement kappa = 0.84). CT correctly identified 26 of 27 (96%) patients with valvular vegetations and 9 of 9 (100%) patients with abscesses/pseudoaneurysms compared with the intraoperative specimen. On a per-valve-based analysis, diagnostic accuracy for the detection of vegetations and abscesses/pseudoaneurysms compared with surgery was: sensitivity 96%, specificity 97%, PPV 96%, NPV 97%, and sensitivity 100%, specificity 100%, PPV 100%, NPV 100%, respectively, without significant differences as compared with TEE. Vegetation size measurements by CT correlated (r = 0.95; p <0.001) with TEE (mean 7.6 +/- 5.6 mm). The mobility of vegetations was accurately diagnosed in 21 of 22 (96%) patients with CT, but all of 4 leaflet perforations (<or=2 mm) were missed. CT provided more accurate anatomic information regarding perivalvular extent of abscess/pseudoaneurysms than TEE. CONCLUSIONS Multislice CT shows good results in detecting valvular abnormalities in IE and could be applied in pre-operative planning and exclusion of coronary artery disease before surgery.

Simultaneous Hybrid COronary Revascularization Using Totally Endoscopic Left Internal Mammary Artery Bypass Grafting and Placement of RapamycIN Eluting Stents in the SAme IntervenTIONal Session

Objectives: Hybrid coronary revascularization procedures apply minimally invasive coronary artery bypass grafting (CABG) and percutaneous coronary intervention (PCI) for treatment of multivessel coronary artery disease. For logistic reasons simultaneous procedures would be desirable. In a pilot study the feasibility of simultaneous robotic totally endoscopic CABG and PCI using drug eluting stents was assessed. Patients and Methods: Five patients were scheduled to undergo simultaneous combined coronary inter- vention. A left internal mammary artery bypass graft was placed to the left anterior descending artery (LAD) in a completely endoscopic fashion using the daVinciTM telemanipulation system. PCI was carried out in the surgical operating room with the GE OEC9800 mobile coronary angiography C-arm. Rapamycin coated Cypher™ stents were placed into stenotic non-LAD targets. Results: The procedure was feasible in 4 patients, one patient was converted to a double CABG operation. There were no significant postoperative clinical complications and patients were discharged from intensive care unit and the hospital after 19 (18–61) hours and 6 (5–7) days respectively. At 6 months postoperatively all patients are free from angina. Conclusion: We conclude that simultaneous robotic totally endoscopic left internal mammary artery to LAD placement and PCI to non-LAD targets using drug eluting stents is feasible in one session.

Near infrared spectroscopy for controlling the quality of distal leg perfusion in remote access cardiopulmonary bypass

The prevention of leg ischemia is necessary in all patients undergoing femoral artery cannulation for extracorporeal circulation. Near infrared spectroscopy (NIRS) is an established non-invasive method for measuring tissue oxygen saturation. Ten patients underwent robotically assisted endoscopic coronary surgery or ASD repair on the arrested heart using aortic endo-occlusion catheters. They were monitored by transcutaneous NIRS (placed on both lower legs) for quality control of distal leg perfusion during femoral access cardiopulmonary bypass. The baseline NIRS values were 61 (52-80) on the cannulated side versus 70 (53-80) on the contralateral leg (p=n.s.). During clamping of the femoral artery for installation of the remote access perfusion system the tissue oxygen saturation dropped to 38 (18-58) (p=0.001 vs baseline) while it remained stable on the contralateral leg. After successful implantation of the distal leg perfusion the NIRS values normalized to similar amounts on both legs. We conclude that transcutaneous NIRS of the lower legs might be a useful non-invasive tool for monitoring leg perfusion in patients undergoing extracorporeal circulation via the femoral vessels.

Increased mortality and perioperative complications in patients with previous elective percutaneous coronary interventions undergoing coronary artery bypass surgery.

OBJECTIVE The relationship between previous percutaneous coronary intervention and perioperative outcome after coronary artery bypass grafting remains undetermined. The aim of the study was to investigate whether previous elective percutaneous coronary intervention influences the outcome of elective coronary artery bypass grafting. METHODS Between 2002 and 2007, 4412 consecutive patients underwent first-time open surgery at the Innsbruck Medical University. After excluding patients with a history of emergency percutaneous coronary intervention, we isolated 306 patients with elective percutaneous coronary intervention during the last 24 months before isolated coronary artery bypass grafting (group 1). Those patients were compared with 452 consecutive age-, gender-, and EuroSCORE-matched patients without a history of percutaneous coronary intervention (group 2), in terms of 30-day mortality, major adverse cardiac events, and perioperative complications. RESULTS Both groups were comparable concerning preoperative linear EuroSCORE (group 1: 4.83 +/- 0.18, group 2: 4.72 +/- 0.14, P = .63). Patients who underwent previous elective percutaneous coronary intervention before coronary artery bypass grafting had an increase in perioperative mortality (group 1: 4.4% vs group 2: 2.4%, P < .001) and major adverse cardiac events (group 1: 7.9% vs 4.3%, P < .001). In addition, the incidence of bleeding complications (group 1: 5.9% vs group 2: 3.8%, P = .017) and the number of blood products (group 1: 1.70 +/- 0.31 vs 0.61 +/- 0.17, P < .001) used were higher in patients of group 1. A higher incidence of acute renal failure (5.9% vs 2.7%, P = .025) and renal replacement therapy (3.6% vs 1.7%, P = .03) was observed in patients of group 1. CONCLUSION Patients with a history of elective percutaneous coronary intervention before referral to coronary artery bypass grafting have a worse perioperative outcome in terms of mortality, major adverse cardiac events, and perioperative complications compared with patients without a history of percutaneous coronary intervention. This fact should be considered in risk stratification for patients who are scheduled for elective coronary artery bypass grafting.

Endovascular Repair of Acute Type B Aortic Dissection: Midterm Results

Purpose: To evaluate midterm results of endovascular stent-graft placement for acute Stanford type B dissection (TBD). Methods: A retrospective review was conducted of 35 consecutive patients who were treated with stent-graft implantation for acute TBD between July 1996 and July 2007. Computed tomographic (CT) volumetric analysis of the true lumen (TL) and false lumen (FL) changes in 23 patients was performed, as well as evaluation of the influence of re-entry points and length of stent-graft coverage on volume changes. In addition, complications were evaluated. Follow-up was performed at 6 and 12 months and yearly thereafter Results: The technical success rate was 82.7%, and the 30-day mortality rate was 8.5%. Mean follow-up was 34 months. The overall survival rate at 5 years was 78.4%. Complications included retrograde type A dissections in 3 patients during the perioperative period and in 1 patient during midterm follow-up. In addition, 5 early and 3 late endoleaks were observed. Three patients were converted to open surgery and 2 needed secondary interventions. In the stented segment, stabilization of the aorta was achieved even during midterm follow-up, with a TL volume increase of 59% at 5 years and nearly stable FL volume. The segment from the distal end of the stent-graft to the celiac artery, however, showed unstable TL and FL volumes, with high standard deviations after the first postinterventional year and circumferential aneurysmal dilatation of the aorta immediately adjacent to the stent-graft in 5 patients. The abdominal aorta showed no substantial volume changes over time. The length of stent-graft coverage and the occurrence of reentries greatly influenced FL volume changes distal to the stent-graft. Conclusion: Serious complications can occur during and after endovascular repair of TBD. Therefore, it should be reserved for high-risk patients.

Leoligin, the major lignan from Edelweiss, inhibits intimal hyperplasia of venous bypass grafts

Aims Despite the lower patency of venous compared with arterial coronary artery bypass grafts, ∼50% of grafts used are saphenous vein conduits because of their easier accessibility. In a search for ways to increase venous graft patency, we applied the results of a previous pharmacological study screening for non-toxic compounds that inhibit intimal hyperplasia of saphenous vein conduits in organ cultures. Here we analyse the effects and mechanism of action of leoligin [(2S,3R,4R)-4-(3,4-dimethoxybenzyl)-2-(3,4-dimethoxyphenyl)tetrahydrofuran-3-yl]methyl (2Z)-2-methylbut-2-enoat, the major lignan from Edelweiss (Leontopodium alpinum Cass.). Methods and results We found that leoligin potently inhibits vascular smooth muscle cell (SMC) proliferation by inducing cell cycle arrest in the G1-phase. Leoligin induced cell death neither in SMCs nor, more importantly, in endothelial cells. In a human saphenous vein organ culture model for graft disease, leoligin potently inhibited intimal hyperplasia, and even reversed graft disease in pre-damaged vessels. Furthermore, in an in vivo mouse model for venous bypass graft disease, leoligin potently inhibited intimal hyperplasia. Conclusion Our data suggest that leoligin might represent a novel non-toxic, non-thrombogenic, endothelial integrity preserving candidate drug for the treatment of vein graft disease.

How to improve performance of robotic totally endoscopic coronary artery bypass grafting

BACKGROUND We investigated whether specific surgical measures during the learning curve can influence procedural performance in robotic totally endoscopic coronary artery bypass grafting (TECAB). METHODS From 2001 to 2006, 70 patients underwent TECAB using the da Vinci telemanipulation system (Intuitive Surgical, Sunnyvale, CA). The following measures were employed with the intent to improve procedure performance: (1) introduction of a fixed team of surgeons at case 14; (2) application of fibrin glue to seal the anastomosis at case 28; and (3) use of a fourth port for transthoracic assistance at case 49. RESULTS All 3 measures resulted in a reduction of operating room (OR) time (27%, 20%, and 20%). Use of a stable OR team and peri-anastomotic fibrin glue reduced the rate of conversions and on-table revisions from 39% to 9% (P = .006) and from 26% to 7% (P = .038), respectively. Peri-anastomotic fibrin glue significantly reduced postoperative revisions for bleeding. Using transthoracic assistance, anastomotic time was shortened from 35 minutes (range 23-67) to 25 minutes (range 16-100) (P < .001). CONCLUSION The 3 measures can improve intraoperative and clinical results in TECAB.

Left main compression syndrome by idiopathic pulmonary artery aneurysm caused by medial necrosis Erdheim-Gsell combined with bicuspid pulmonary valve.

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Everolimus attenuates neointimal hyperplasia in cultured human saphenous vein grafts

OBJECTIVE Neointimal hyperplasia is the first step in a cascade leading to a reduced patency rate of saphenous vein grafts in comparison to arterial grafts in coronary artery bypass grafting. Using cultured human saphenous vein grafts as a model for coronary artery bypass grafting, we investigated if the mammalian target of rapamycin inhibitor everolimus attenuates neointimal hyperplasia. METHODS Saphenous vein grafts from 10 patients undergoing coronary artery bypass grafting were processed as follows: from each patient, one segment served as baseline control at day 0. Two segments were cultured in a neointimal hyperplasia model separately. One received no treatment and the other everolimus (1 microM). All vein grafts underwent histomorphometric analysis, assessment of proliferation by Ki-67 immunostaining and quantification of phospho-S6 ribosomal protein using western blot analysis. RESULTS Everolimus treatment resulted in reduced neointimal hyperplasia (thickness 3.7+/-1.2 microm) compared to untreated controls (10.1+/-2.5 microm, p=0.008). The intima/intima+media-ratio was reduced in the everolimus group (0.10+/-0.02) compared to untreated controls (0.24+/-0.07, p=0.008). The number of Ki-67 positive proliferating cells in everolimus treated vein grafts (15+/-7 cells/high power field) showed a tendency of reduction compared to untreated controls (36+/-20 cells/high power field, p=0.036). Finally, everolimus treatment resulted in downregulation of S6 ribosomal protein phosphorylation in comparison to untreated controls. CONCLUSION Everolimus is able to reduce neointimal proliferation in cultured human saphenous vein grafts by inhibition of the mammalian target of rapamycin, even though different transfection methods are to be evaluated for a clinical application in coronary artery bypass grafting.

Direct comparison of relaxation and cGMP production in human coronary by-pass grafts in response to stimulation with natriuretic peptides and a nitric oxide donor.

In the present study, we investigated the vasodilator properties of A-type, B-type and C-type natriuretic peptides (ANP, BNP and CNP respectively) and the NO (nitric oxide) donor sin-1 (3-morpholino-sydnonimine) in human by-pass grafts. In contrast with previous studies, the same vessel was used to demonstrate a direct link between cGMP production and functional relaxation. Remnants of the IMA (internal mammary artery) and SV (saphenous vein) were obtained from 82 patients undergoing coronary artery by-pass grafting. The responses to cumulative concentrations of ANP, BNP, CNP and sin-1 in vessel rings pre-contracted with a thromboxane A2 agonist (U46619) were measured in an organ bath. Additionally, intracellular cGMP production after single submaximal dose application of these drugs to vessel rings was determined by a RIA. ANP (P=0.001) and sin-1 (P<0.001) caused significant concentration-dependent relaxation of the IMA. In the SV, only sin-1 (P<0.001) induced marked concentration-dependent relaxation. At a single submaximal concentration, significant relaxation as well as intracellular cGMP production were found in response to ANP, BNP and sin-1 in the IMA. In contrast, in the SV, only sin-1 significantly induced cGMP production and relaxation. There was a moderate, but significant, correlation between intracellular cGMP net production and net relaxation in the IMA. In conclusion, ANP, as the most powerful relaxant of all the natriuretic peptides tested on the IMA, may be a possible alternative vasorelaxant to overcome peri-operative vasospasm in this artery. In contrast with sin-1, ANP and BNP were not effective vasorelaxants of the SV. Net relaxation in response to natriuretic peptides correlated with cGMP net concentrations in the IMA.