Konstantinos Tsagakis

Cardioprotective and prognostic effects of remote ischaemic preconditioning in patients undergoing coronary artery bypass surgery: a single-centre randomised, double-blind, controlled trial

BACKGROUND Remote ischaemic preconditioning has been associated with reduced risk of myocardial injury after coronary artery bypass graft (CABG) surgery. We investigated the safety and efficacy of this procedure. METHODS Eligible patients were those scheduled to undergo elective isolated first-time CABG surgery under cold crystalloid cardioplegia and cardiopulmonary bypass at the West-German Heart Centre, Essen, Germany, between April, 2008, and October, 2012. Patients were prospectively randomised to receive remote ischaemic preconditioning (three cycles of 5 min ischaemia and 5 min reperfusion in the left upper arm after induction of anaesthesia) or no ischaemic preconditioning (control). The primary endpoint was myocardial injury, as reflected by the geometric mean area under the curve (AUC) for perioperative concentrations of cardiac troponin I (cTnI) in serum in the first 72 h after CABG. Mortality was the main safety endpoint. Analysis was done in intention-to-treat and per-protocol populations. This trial is registered with ClinicalTrials.gov, number NCT01406678. FINDINGS 329 patients were enrolled. Baseline characteristics and perioperative data did not differ between groups. cTnI AUC was 266 ng/mL over 72 h (95% CI 237-298) in the remote ischaemic preconditioning group and 321 ng/mL (287-360) in the control group. In the intention-to-treat population, the ratio of remote ischaemic preconditioning to control for cTnI AUC was 0·83 (95% CI 0·70-0·97, p=0·022). cTnI release remained lower in the per-protocol analysis (0·79, 0·66-0·94, p=0·001). All-cause mortality was assessed over 1·54 (SD 1·22) years and was lower with remote ischaemic preconditioning than without (ratio 0·27, 95% CI 0·08-0·98, p=0·046). INTERPRETATION Remote ischaemic preconditioning provided perioperative myocardial protection and improved the prognosis of patients undergoing elective CABG surgery. FUNDING German Research Foundation.

Aortoesophageal fistula after thoracic aortic stent-graft placement: a rare but catastrophic complication of a novel emerging technique.

OBJECTIVES Our goal was to report characteristics and outcomes of 6 patients with aortoesophageal fistula (AEF) after thoracic endovascular aortic repair (TEVAR). BACKGROUND Neurologic events are severe complications of TEVAR. With growing experience of TEVAR, other yet unexpected devastating complications have emerged. METHODS Between July 1999 and August 2008, 268 patients underwent TEVAR for various thoracic aortic diseases at our institution. RESULTS Six of 268 patients (age 49 to 77 years, 50% female patients) developed AEF (incidence 1.9%) within 1 to 16 months after the procedure. Indications for TEVAR were acute aortic dissection (n = 3), chronic aortic dissection (n = 1), and thoracic aortic aneurysm (n = 2). Four patients presented with sudden massive hematemesis whereas 2 patients were readmitted for new-onset fever and elevated markers of inflammation that preceded hematemesis. Esophago-gastro-duodenoscopy identified deep esophageal ulcerations at the level of the implanted aortic stent-graft in 4 patients, but only mild erosive lesions within the proximal esophagus without signs of active bleeding in the remaining 2 patients. Surgical repair was performed in only 1 patient and declined in the remaining because of comorbidities and multiorgan system failure. Despite this, all patients died due to fatal rebleeding (n = 4) or mediastinitis (n = 2). CONCLUSIONS AEF is a rare and unusual complication of TEVAR that occurs relatively early after the procedure and is almost invariably fatal. New-onset fever with elevated inflammatory markers or hematemesis should heighten clinical suspicion of AEF in TEVAR patients and prompt computed tomography or esophago-gastro-duodenoscopy in the hope of detecting, triaging, and treating this early to improve the otherwise dismal outcomes of these patients.

Combining Classic Surgery With Descending Stent Grafting for Acute DeBakey Type I Dissection

BACKGROUND To possibly prevent late complications after classic type A aortic dissection repair, the radical concept of ascending/arch replacement with simultaneous antegrade descending stent grafting using a hybrid prosthesis was applied and compared with conventional repair leaving the distal false lumen untreated. METHODS Between January 2001 and October 2007, of 71 consecutive patients with acute type A aortic dissection (AAAD), 45 had DeBakey type I dissection and underwent emergency surgery within 24 hours after onset of symptoms. These patients were separated into group 1 (n = 23) undergoing conventional surgery, and group 2 (n = 22) undergoing combined repair with antegrade stent grafting. RESULTS Patients were comparable for baseline characteristics, but more group 2 patients had severely compromised hemodynamics (p = 0.05) and cerebral malperfusion at arrival (p < 0.01). Intraoperative and postoperative characteristics were similar, with an overall hospital mortality of 16% (5 [22%] versus 2 [9%], group 1 versus group 2; p = 0.22). At a mean follow-up time of 48 months for group 1 versus 23 months for group 2 (p < 0.01), late mortality did not differ between groups (p = 0.38) and was mainly related to additional surgical procedures and persisting neurologic sequelae and not to the aortic pathology. Persisting distal false lumen patency was observed in 89% of group 1 versus 10% of group 2 patients (p < 0.01). CONCLUSIONS This hybrid approach to patients with type I acute aortic dissection is technically feasible without increasing the operative risk and offers the chance of persistent occlusion of the persistent graft distal false lumen.

Multicenter early experience with extended aortic repair in acute aortic dissection: Is simultaneous descending stent grafting justified?

OBJECTIVE In acute type A aortic dissection, the extension of repair to downstream aorta has been controversially discussed. We present the early results of a multicenter study using a hybrid stent graft prosthesis. METHODS Between January 2005 and January 2010, the data from 191 patients after combined proximal aortic replacement and antegrade stent grafting were collected in the database of the International E-vita open Registry. Of the 191 patients, 68 underwent surgery for acute aortic dissection and were included in the present study. Hypothermic circulatory arrest and selective cerebral perfusion were routinely used. Computed aortic imaging was performed for false lumen evaluation during follow-up. RESULTS The in-hospital mortality rate was 13% (9/68). Along the stent graft, the rate of immediate complete false lumen thrombosis was 86% (51/59) and increased during follow-up (23 ± 17 months) to 94% (46/49). Distally, complete or partial false lumen thrombosis was initially observed in 61% (36/59) and in 82% (40/49) after follow-up. The 1- and 3-year actuarial survival rate was 82% and 74%, respectively. CONCLUSIONS Extended thoracic aortic repair of acute aortic dissection with a hybrid stent graft is feasible at acceptable early mortality and promotes false lumen thrombosis around the stent graft and below.

Prognostic value of preoperative cardiac troponin I in patients undergoing emergency coronary artery bypass surgery with non-ST-elevation or ST-elevation acute coronary syndromes.

Background— Cardiac troponin I (cTnI) is a highly sensitive and specific biomarker which has been shown to predict patient outcome pre- and postoperatively following elective coronary artery bypass surgery (CABG). Whether preoperatively elevated cTnI levels similarly predict the outcome in patients undergoing emergency CABG with acute myocardial infarction (AMI) is currently unknown. Methods and Results— A possible correlation between preoperative cTnI and in-hospital mortality and major adverse cardiac events (MACE) was investigated in 57 patients with ST-elevation AMI (STEMI) in group 1 and 197 with Non-ST-elevation AMI (NSTEMI) in group 2, who were operated within 24 hours after onset of symptoms. Primary study end point was all-cause in-hospital mortality. Secondary end points were low cardiac output syndrome (LCOS) and hospital course. CTnI levels on admission were higher in group 1 compared with group 2 (7.1±1.8 versus 1.4±1.8 ng/mL; P<0.001). Overall in-hospital mortality was higher in group 1 compared with group 2 (14.3 versus 4.1%; odds ratio [OR], 3.9, 95% confidence interval [CI], 1.3 to 12.3; P<0.01). LCOS occurred in 16/57 (28.1%), and 18/197 (9.1%) patients, respectively (OR, 3.9, 95% CI, 1.7 to 8.8; P<0.001). Postoperative ventilation time, intensive care, and hospital stay were significantly longer in group 1 versus group 2. Multivariate logistic regression analyses revealed preoperative cTnI as the strongest independent predictor for in-hospital mortality (P<0.001) and MACE (P<0.001) in all AMI patients, regardless whether ST-elevation was included as an additional risk factor or not. Conclusions— Preoperative cTnI measurement before emergency CABG appears as a powerful and independent determinant of in-hospital mortality and MACE in acute STEMI and NSTEMI.

Arch replacement and downstream stent grafting in complex aortic dissection: first results of an international registry.

OBJECTIVES Arch replacement combined with antegrade stent grafting of the descending aorta represents a hybrid surgical approach for extensive thoracic aortic disease. This multicentre study evaluates the early results of this method in complex aortic dissection (AD). METHODS Retrospective data acquisition was achieved by institution of an international registry. A hybrid stent graft with integrated vascular prosthesis for arch replacement (E-vita open®) was used. From January 2005 to March 2009, 106 patients (mean age 57; 77% male) with complex AD (55 acute, 51 chronic) were studied. RESULTS As many as 49/106 (46%) patients underwent emergency surgery. Stent-graft deployment and arch replacement (95 total, 11 subtotal) were performed under hypothermic circulatory arrest (HCA (8±6min) and selective antegrade cerebral perfusion (SACP) (74±23min). Stent-graft placement into the true lumen was successful in all but one case (99%). Ascending aortic replacement was performed in 91/106 (86%), aortic valve repair/replacement in 49/106 (46%), coronary artery bypass grafting (CABG) in 17/106 (16%) and mitral valve repair in 2/106 (2%). Cardiopulmonary bypass (CPB) and cardiac arrest times were 242±64 and 144±44min, respectively. In-hospital mortality was 12% (13/106; six acute, seven chronic AD) and new strokes observed in 5/106 (5%). The false lumen (FL) was evaluated in 96/106 (91%) patients postoperatively. At first follow-up computed tomography (CT)-examination, thoracic FL thrombosis was 93% (76 complete, 13 partial) and 58% (31 complete, 25 partial) in the thoraco-abdominal aorta. CONCLUSIONS By combining arch replacement with downstream stent grafting, one-stage repair of complex aortic dissection with almost unanimous thoracic FL thrombosis can be achieved at acceptable perioperative risk.

Hybrid operating room concept for combined diagnostics, intervention and surgery in acute type A dissection †

OBJECTIVES In acute type A dissection (AAAD), it is commonly decided to carry out immediate surgical repair without invasive diagnostics. The hybrid operating room (Hybrid OR) concept encompasses simultaneous haemodynamic control, non-invasive and invasive diagnostics and immediate surgical and/or interventional treatment. Results over a seven-year period are presented here. METHODS From March 2004 to March 2011, 1883 cardiological and surgical patients were treated in a Hybrid OR. Of these, 124 patients (age 60 ± 13, 64% male) diagnosed with AAAD were operated upon. External computed tomography (CT) was available for 87% (108/124) of cases and angiography in 15% (19/124). Preoperative transoesophageal echocardiography (TEE) was done in all patients and angiography in 57% (71/124). Surgery was performed without angiography in 27% (34/124), of which 14% (17/124) was due to shock. Postoperative control angiography followed in 18% (22/124) due to suspected ongoing malperfusion. RESULTS Preoperative angiography was performed in 71 patients, and no angiography related complications were observed during the procedure. A total of 32% (23/71) of these underwent coronary artery bypass graft (CABG)--for newly-diagnosed coronary artery disease in 21% of cases and for coronary malperfusion in 11%. Visceral/peripheral malperfusion syndromes, necessitating primary endovascular intervention, were detected in 23% (16/71). Ascending aorta replacement was performed in 100% (124/124) of patients, arch replacement in 88% (109/124) and descending aorta repair in 35% (44/124). Five postoperative endovascular interventions became necessary due to persistent malperfusion. In-hospital mortality was 13% (12/90) in patients who had undergone preoperative invasive diagnostics and 24% (8/34) in patients who had not. CONCLUSIONS The Hybrid OR concept enables the exact diagnosis of coronary status and downstream malperfusion sites and influences the design of surgical and/or endovascular treatment, without time delay and at negligible risk to the patient.

Aortic Remodeling in Type B Aortic Dissection: Effects of Endovascular Stent-Graft Repair and Medical Treatment on True and False Lumen Volumes:

Purpose: To analyze aortic remodeling processes in terms of true (TL) and false lumen (FL) volumes in patients with type B aortic dissection undergoing thoracic endovascular aortic repair (TEVAR) versus patients treated medically. Methods: Serial contrast-enhanced computed tomography (CT) scans of 27 type B dissection patients (24 men; mean age 60±13 years) who underwent TEVAR (n=17) or medical therapy only (n=10) were analyzed. TL and FL volumes over the entire descending aorta at baseline and at follow-up were quantified by 3-dimensional reconstruction. Results: Follow-up in the 27 patients was a mean 14±6 months. TEVAR resulted in a continued gain in total TL volume (132±56 mL at baseline, 164±51 mL early after TEVAR, and 220±68 mL at follow-up, p<0.001), whereas TL volume was almost unchanged in the medical therapy group (113±34 to 120±41 mL, p=0.195). Total FL volume decreased significantly in TEVAR patients during follow-up (257±147 mL at baseline to 178±140 mL, p<0.001), whereas there was no significant change in FL volume in the medical therapy patients. The increase of TL and the decrease of FL volume in the TEVAR group were mainly observed in the descending thoracic aorta. Conclusion: TEVAR for type B aortic dissection results in a significant increase in TL and a decrease in FL volumes, not only acutely but also over time due to continued remodeling processes primarily in the thoracic aorta, with little impact on abdominal aortic volumes. Our data provide insight into the mechanism of a potential therapeutic benefit of TEVAR over medical therapy in type B dissection, which remains to be confirmed in a randomized clinical trial.

Development of an integrated stent graft-dacron prosthesis for intended one-stage repair in complex thoracic aortic disease.

Complex thoracic aortic disease involving the ascending aorta, the aortic arch and the descending aorta still represents a challenge for the cardiothoracic surgeon. The classic approach for this pathology consists of a two-stage strategy, summing up to a mortality up to 40%, with a 5% mortality for the waiting period between both surgical stages [1–3]. One-stage repair can be performed, if required, via a clamshell thoracotomy, but is associated with major surgical trauma and perioperative morbidity as pulmonary or renal dysfunction, indicating that elderly patients probably are poor candidates for this strategy [4]. With the introduction of endovascular stenting in combination with classic aortic arch surgery an attractive treatment alternative has emerged for facilitated repair of complex aneurysmal disease in the thoracic aorta [5, 6]. Modifying this new technique using self-expanding descending aortic stent grafts and the classic ascending and aortic arch replacement techniques seems to be the logical consequence for intended one-stage repair, which was started by our group 06/2001 [7, 8]. Standard thoracic aortic stent graft devices (e.g., Medtronic Talent©, Minneapolis, MN, USA) are designed for retrograde aortic delivery, which demonstrate shortcomings for the antegrade use: their stiffness limits steerability, causing problems to pass the angle between the distal aortic arch and proximal descending aorta, resulting in significant friction to the inner aortic wall. This is worsened by the stiff outer plastic sheath which frequently shows kinking when curved > 45°. The most rigid zone is identified to be at the proximal border between stent graft and tip of the introducer and at the distal site between stent graft and the wire-reinforced inner pusher, limiting continuous and precise stent graft opening. At that point the already opened distal bare springs only allow for minor correction in proximal direction in case of displacement. A second significant problem is caused by the longitudinal wire (connecting bar), which is positioned along the outer curvature of the stent. This force provokes the stent to straighten up resulting in a significant protrusion of the proximal bare springs into the aortic wall. To overcome those shortcomings, a new integrated stent graft-Dacron prosthesis for antegrade delivery through the open aortic arch into the descending aorta in an “elephant trunk”-like manner was created. This “Essen I prosthesis” (E-vita open; Jotec®, Hechingen, Germany [Figure 1]) consists of a polyester fabric with an extremely flexible Nitinol wire skeleton, fixed on the outer aspect of the fabric with polypropylene sutures. To increase flexibility, a longitudinal wire is abandoned, and no open bar ends or reinforced circular springs are incorporated distally or proximally. At the proximal end, a woven crimped vascular Dacron prosthesis of 7 cm length is incorporated continuously to the stent graft prosthesis, allowing for direct replacement of the aortic arch without an additional anastomosis like in classic elephant trunk operations, by simply pulling back the invaginated Dacron prosthesis at its sewn suture sling into the arch position. Stent graft re1 Department of Thoracic and Cardiovascular Surgery, West German Heart Center Essen, University Hospital Essen, Germany, 2 Department of Cardiology, West German Heart Center Essen, University Hospital Essen, Germany.

The frozen elephant trunk technique for the treatment of complicated type B aortic dissection with involvement of the aortic arch: multicentre early experience

OBJECTIVES Providing effective treatment for complicated type B aortic dissection (AD) with concomitant pathologies of the aortic arch or ascending aorta is challenging, especially if the aortic anatomy is contraindicated for thoracic endovascular aortic repair (TEVAR). We present the early results of a multicentre study using the frozen elephant trunk (FET) technique for type B AD. METHODS From January 2005 to March 2013, data from 465 patients who had undergone treatment with the FET technique were collected in the database of the International E-vita Open Registry. From this cohort, 57 patients who had a primary indication for surgery for type B AD were included in the present study. Their mean age was 58±12 years, and 72% had a chronic dissection. All operations were performed in circulatory arrest and bilateral antegrade cerebral perfusion. Computed aortic imaging was performed for false lumen (FL) evaluation during the follow-up. RESULTS The in-hospital mortality rate was 14% (8/57). Stroke and spinal cord injury occurred in 6 (10%) and 2 patients (4%), respectively. The rate of immediate FL thrombosis at the level of the stent graft was 75% (40/53) and increased to 97% (41/42) during the follow-up period (23±19 months). Distally, at the level of the abdominal aorta, the FL remained patent in 50% (21/42) of patients. The 1- and 3-year survival was 81 and 75%, respectively. CONCLUSION The FET technique is a feasible therapeutic option for complicated type B AD with involvement of the aortic arch if TEVAR is contraindicated. In contrast to conventional aortic surgery via a lateral thoracotomy, the FET procedure can provide simultaneous treatment of the ascending aorta and aortic arch.