Mario Stalder

Ten-year comparison of pericardial tissue valves versus mechanical prostheses for aortic valve replacement in patients younger than 60 years of age.

OBJECTIVE Aortic valve replacement using a tissue valve is controversial for patients younger than 60 years old. The long-term survival in this age group, the expected event rates during long-term follow-up, and valve-related complications are not clearly determined. METHODS From January 2000 to December 2009, overall survival, valve-related events, and echocardiographic outcomes were analyzed in all patients younger than 60 years of age, who underwent biologic aortic valve replacement. Patients who received a Perimount Carpentier-Edwards pericardial tissue valve (n = 103) were selected and compared with a propensity matched group of 103 patients who received aortic valve replacement using a mechanical bileaflet valve. The mean follow-up was 33 ± 24 months (range, 2-120), and the mean age at implantation was 50.6 ± 8.8 years (bioprosthesis, 55 ± 8.9 years; mechanical valve, 50 ± 8.6 years; P = .03). RESULTS Survival was significantly reduced in patients after biologic aortic valve replacement (90.3% vs 98%; P = .038). Freedom from all valve-related complications (bioprosthesis, 54.5%; mechanical valve, 51.6%; P = NS) and freedom from reoperation (bioprostheses, 100%; mechanical valve, 98%; P = NS) were comparable in both groups. The average transvalvular mean (11.2 ± 4.2 mm Hg vs 10.5 ± 6.0 mm Hg, P = .05) and peak (19.9 ± 6.7 mm Hg vs 16.7 ± 8.0 mm Hg, P = .03) gradients were greater after biologic aortic valve replacement. Regression of the left ventricular mass index was more pronounced after mechanical valve replacement (118.5 ± 24.9 g/m(2) vs 126.5 ± 38.5 g/m(2); P = NS). The echocardiographic patient-prosthesis mismatch was greater at follow-up after biological aortic valve replacement (0.876 ± 0.2 cm(2)/m(2) vs 1.11 ± 0.4 cm(2)/m(2); P = .01). Oral anticoagulation was a protective factor for survival among the bioprosthetic valve patients (P = .024). CONCLUSIONS In the present limited cohort of patients younger than 60 years old, biologic aortic valve replacement was associated with reduced mid-term survival compared with survival after mechanical aortic valve replacement. Despite similar valve-related event rates in both groups, the better hemodynamic performance of the mechanical valves and/or protective effect of oral anticoagulation seemed to improve the outcome. The transcatheter valve-in-valve intervention as potential treatment of tissue valve degeneration should not be considered the sole bailout strategy for younger patients because no evidence is available that this would improve the outcome.

Arterial access through the right subclavian artery in surgery of the aortic arch improves neurologic outcome and mid-term quality of life

BACKGROUND We have shown that selective antegrade cerebral perfusion improves mid-term quality of life in patients undergoing surgical repair for acute type A aortic dissection and aortic aneurysms. The aim of the study was to assess the impact of continuous cerebral perfusion through the right subclavian artery on immediate outcome and quality of life. METHODS Perioperative data of 567 consecutive patients who underwent surgery of the aortic arch using deep hypothermic circulatory arrest have been analyzed. Patients were divided into three groups, according to the management of cerebral protection. Three hundred eighty-seven patients (68.3%) had deep hypothermic circulatory arrest with pharmacologic protection with pentothal only, 91 (16.0%) had selective antegrade cerebral perfusion and pentothal, and 89 (15.7%) had continuous cerebral perfusion through the right subclavian artery and pentothal. All in-hospital data were assessed, and quality of life was analyzed prospectively 2.4 +/- 1.2 years after surgery with the Short Form-36 Health Survey Questionnaire. RESULTS Major perioperative cerebrovascular injuries were observed in 1.1% of the patients with continuous cerebral perfusion through the right subclavian artery, compared with 9.8% with selective antegrade cerebral perfusion (p < 0.001) and 6.5% in the group with no antegrade cerebral perfusion (p = 0.007). Average quality of life after an arrest time between 30 and 50 minutes with continuous cerebral perfusion through the right subclavian artery was significantly better than selective antegrade cerebral perfusion (90.2 +/- 12.1 versus 74.4 +/- 40.7; p = 0.015). CONCLUSIONS Continuous cerebral perfusion through the right subclavian artery improves considerably perioperative brain protection during deep hypothermic circulatory arrest. Irreversible perioperative neurologic complications can be significantly reduced and duration of deep hypothermic circulatory arrest can be extended up to 50 minutes without impairment in quality of life.

Large Area of the False Lumen Favors Secondary Dilatation of the Aorta After Acute Type A Aortic Dissection

Background—Since 1994 patients with acute aortic dissection type A (AADA) are followed-up in our outpatient clinic. Early diagnosis of secondary dilatation of the diseased aorta is crucial to reduce late mortality in these patients. Aim of the present study is to asses the impact of a large volume in the false lumen of the diseased downstream aorta on secondary dilatation. Methods and Results—134 patients of 264 patients who underwent surgery for AADA (between January 1994 and June 2003) are followed-up at our outpatient clinic since 1994. 84 patients (62.7%) fulfilled the inclusion criteria. Areas of the true and the false lumens of the aorta were analyzed and a logistic regression was calculated at 5 levels of the aorta for each patient. Patients were divided in 3 groups: group 1 included 34 patients (40.5%) without progression, group 2 had 34 patients (40.5%) with slight progression, and group 3 had 16 patients (19.0%) with important progression, requiring surgery in all patients. In 87.5% of the patients the area of the original lumen was <0% in group 3, compared with 11.8% in group 2 and 8.8% in group 1 in relation to the total area of the aorta 6 months after surgery (P<0.001). Conclusion—A large false lumen, with an area of the true lumen <30% 6 months after surgery, is the strongest predictor for secondary dilatation of the diseased downstream aorta.

Mortality and neurologic injury after surgical repair with hypothermic circulatory arrest in acute and chronic proximal thoracic aortic pathology: effect of age on outcome.

Background— The goal of this study was to determine whether advanced age affects mortality and incidence of neurological injury in patients undergoing surgical repair with hypothermic circulatory arrest in acute and chronic thoracic aortic pathology. Methods and Results— A university center audit was done of 523 consecutive patients (median age, 64 years; interquartile range, 56–71 years) between 2005 and 2010. Mortality in acute type A aortic dissection (207 patients) was 9.7%, and in chronic ascending aortic aneurysms (316 patients) was 2.2% (P<0.001). Neurological injury was observed in 16.9% of patients with acute type A aortic dissection (chronic ascending aortic aneurysms, 7.9%; P=0.002). Multivariable regression analysis revealed hypothermic circulatory arrest >40 minutes (odds ratio [OR], 4.21; 95% confidence interval [CI], 1.60–11.06; P=0.004) and redo surgery (OR, 3.44; 95% CI, 1.11–10.64; P=0.03) but not age (OR, 1.98; 95% CI, 0.73–5.38; P=0.18) as independent predictor of mortality. Emergency surgery (OR, 3.27; 95% CI, 1.31–8.15; P=0.01) and extracardiac arteriopathy (OR, 2.38; 95% CI, 1.26–4.50; P=0.008) but not age (OR, 1.80; 95% CI, 0.93–3.48; P=0.08) were independent predictors of neurological injury. Conclusions— Age is not associated with increased risk for mortality and neurological injury in patients undergoing surgical repair for acute and chronic thoracic aortic pathology with hypothermic circulatory arrest. Extended hypothermic circulatory arrest times, reflecting the extent of disease, and redo surgery predict mortality, whereas emergency surgery and extracardiac arteriopathy predict neurological injury.

Clinical experience with the second-generation 3f Enable sutureless aortic valve prosthesis

OBJECTIVE The 3f Enable aortic bioprosthesis (ATS Medical, Inc, Minneapolis, Minn) represents a new generation of equine pericardial self-expanding valve designed for sutureless implantation. This study evaluated technical aspects of implantation and safety and effectiveness of the valve in the short term. METHODS In an outcome analysis of a consecutive series of 28 patients who underwent aortic valve replacement for aortic stenosis with the 3f Enable during an 18-month period, mean age was 75.7 +/- 6.6 years, 18 patients were female (64.2%), and mean EuroSCORE was 7.1% +/- 1.7%. RESULTS Most implanted valves were 23 mm in diameter (19-27 mm). Mean aortic crossclamp time was 39 +/- 15 minutes (29-103 minutes), mean cardiopulmonary bypass time was 58 +/- 20 minutes (41-127 minutes), mean hospital stay was 11 days (7-22 days), and 30-day mortality was 3.5%. Mean and peak intraoperative transvalvular pressure gradients were 6.1 +/- 2.6 and 18 +/- 5 mm Hg, respectively. Trivial and mild paravalvular leaks were observed in 1 patient each. One patient underwent reoperative aortic valve replacement 4 months after initial surgery for severe valve-unrelated paravalvular leakage. Five patients (18.5%) required permanent pacemakers. No patients were unavailable for follow-up. One-year survival was 86.2%. CONCLUSIONS The 3-f Enable aortic bioprosthesis can be implanted safely with favorable early hemodynamics. The self-expanding stent allows sutureless implantation with a large valve area. The procedure was fast, although not as fast as expected. This experience has led to continued design and procedural enhancements to facilitate and accelerate future implantation.

Temporary neurological dysfunction after surgery of the thoracic aorta: a predictor of poor outcome and impaired quality of life

BACKGROUND Transient neurological dysfunction (TND) consists of postoperative confusion, delirium and agitation. It is underestimated after surgery on the thoracic aorta and its influence on long-term quality of life (QoL) has not yet been studied. This study aimed to assess the influence of TND on short- and long-term outcome following surgery of the ascending aorta and proximal arch. METHODS Nine hundred and seven patients undergoing surgery of the ascending aorta and the proximal aortic arch at our institution were included. Two hundred and ninety patients (31.9%) underwent surgery because of acute aortic dissection type A (AADA) and 617 patients because of aortic aneurysm. In 547 patients (60.3%) the distal anastomosis was performed using deep hypothermic circulatory arrest (DHCA). TND was defined as a Glasgow coma scale (GCS) value <13. All surviving patients had a clinical follow up and QoL was assessed with an SF-36 questionnaire. RESULTS Overall in-hospital mortality was 8.3%. TND occurred in 89 patients (9.8%). As compared to patients without TND, those who suffered from TND were older (66.4 vs 59.9 years, p<0.01) underwent more frequently emergent procedures (53% vs 32%, p<0.05) and surgery under DHCA (84.3% vs 57.7%, p<0.05). However, duration of DHCA and extent of surgery did not influence the incidence of TND. In-hospital mortality in the group of patients with TND compared to the group without TND was similar (12.0% vs 11.4%; p=ns). Patients with TND suffered more frequently from coronary artery disease (28% vs 20.8%, p=ns) and were more frequently admitted in a compromised haemodynamic condition (23.6% vs 9.9%, p<0.05). Postoperative course revealed more pulmonary complications such as prolonged mechanical ventilation. Additional to their transient neurological dysfunction, significantly more patients had strokes with permanent neurological loss of function (14.6% vs 4.8%, p<0.05) compared to the patients without TND. ICU and hospital stay were significantly prolonged in TND patients (18+/-13 days vs 12+/-7 days, p<0.05). Over a mean follow-up interval of 27+/-14 months, patients with TND showed a significantly impaired QoL. CONCLUSION The neurological outcome following surgery of the ascending aorta and proximal aortic arch is of paramount importance. The impact of TND on short- and long-term outcome is underestimated and negatively affects the short- and long-term outcome.

Deleterious outcome of No-React-treated stentless valved conduits after aortic root replacement: why were warnings ignored?

OBJECTIVE The implantation of a composite graft is the treatment of choice for patients with aortic root disease if the valve cannot be preserved and the patient is not a suitable candidate for a Ross procedure. Several years ago, the Shelhigh NR-2000C (Shelhigh, Inc, Millburn, NJ) was introduced in Europe. Being a totally biologic conduit and considering the lack of homografts, the graft seemed an ideal conduit for patients with destructive endocarditis, as well as for older patients who were not suitable candidates for oral anticoagulation. METHODS From 2001 until 2006, the Shelhigh NR-2000C stentless valved conduit was implanted in 115 patients for various aortic root pathologies. The conduit consists of a bovine pericardial straight graft with an incorporated porcine stentless valve. Aortic root repair was performed during standard cardiopulmonary bypass and mild hypothermia in the majority of patients. Deep hypothermic circulatory arrest combined with selective antegrade cerebral perfusion was used when the repair extended into the arch. RESULTS Seven patients with uncomplicated early outcome presented with unexpected sudden disastrous findings at the level of the aortic root, although 1-year follow-up computed tomographic scans were normal. Four of these patients underwent emergency operations because of desintegration of the graft, along with rupture of the aortic root. Retrospectively, the main findings were persistent fever or subfebrility over months and a halo-like enhancement on computed tomographic scans. Extensive microbiologic examinations were performed without finding a causative organism. CONCLUSION The use of the Shelhigh aortic stentless conduit can no longer be advocated, and meticulous follow-up of patients in whom this device has been implanted has to be recommended.

Aortic arch morphometry in living humans

Anatomical features of the aortic arch such as its steepness, the take‐off angles and the distances between its supra‐aortic branches can influence the feasibility and difficulty of interventional and/or surgical maneuvers. These anatomical characteristics were assessed by means of 3D multiplanar reconstruction of thoracic angio‐computed tomography scans of 92 living patients (79 males, 13 females, mean age 69.4 ± 9.9 years) carried out for various indications (gross pathology of the thoracic aorta excluded). There was a significant variation of all measured parameters between the subjects – a standard aortic arch (i.e. with all measured parameters within 2 SD) does not seem to exist. There were no significant differences between genders but some of the parameters correlated significantly to age.

Minimized cardiopulmonary bypass combined with a smart suction device: the future of cardiopulmonary bypass?

OBJECTIVE The standard heart-lung machine is a major trigger of systemic inflammatory response and the morbidity attributed to conventional extracorporeal circulation (CECC) is still significant. Reduction of blood-artificial surface contact and reduction of priming volume are principal aims in minimized extracorporeal circulation (MECC) cardiopulmonary bypass systems. The aim of this paper is to give an overview of the literature and to present our experience with the MECC-smart suction system. METHODS AND RESULTS At our institution, 1799 patients underwent isolated coronary artery bypass grafting (CABG) surgery, 1372 with a MECC-smart suction system and 427 with CECC. All in-hospital data were assessed and the results were compared between the 2 groups. Patient characteristics and the distribution of EuroSCORE risk profile in our collective were similar between both groups. Average age in the MECC collective was 67.5 +/- 11.4 years and average EuroSCORE was 5.0 +/- 1.5. Average number of distal anastomoses was similar to the average number encountered in patients undergoing CABG surgery with CECC (3.3 +/- 1.0 for MECC versus 3.2 +/- 1.1 for CECC; P = ns). Myocardial protection is superior in MECC patients with lower postoperative maximal cTnI values (11.0 +/- 10.8 micromol/L for MECC versus 24.7 +/- 25.3 micromol/L for CECC; P < .05). Postoperative recovery was faster in patients operated on with the MECC-smart suction system and discharge from the hospital was earlier than for CECC patients (7.4 +/- 1.9 days for MECC versus 8.8 +/- 3.8 days for CECC; P < .05). CONCLUSIONS The MECC-smart suction system is a safe perfusion technique for CABG surgery. In patients operated on with this system, the clinical outcome seems to be better than in patients operated on with CECC. This promising and less damaging perfusion technology has the potential to replace CECC systems in CABG surgery.

Technical advances improved outcome in patients undergoing surgery of the ascending aorta and/or aortic arch: ten years experience

BACKGROUND Several technical advances in thoracic aortic surgery, such as the use of antegrade cerebral perfusion, avoidance of cross-clamping and the application of glue, have beneficially influenced postoperative outcome. The aim of the present study was to analyse the impact of these developments on outcome of patients undergoing surgery of the thoracic aorta. METHODS AND RESULTS Between January 1996 and December 2005, 835 patients (37.6%) out of 2215 aortic patients underwent surgery on the thoracic ascending aorta or the aortic arch at our institution. All in-hospital data were assessed. Two hundred and forty-one patients (28.8%) suffered from acute type A dissection (AADA). Overall aortic caseload increased from 41 patients in 1996 to 141 in 2005 (+339%). The increase was more pronounced for thoracic aortic aneurysms (TAA) (+367.9%), than for acute type A aortic dissections (+276.9%). Especially in TAA, combined procedures increased and the amount of patients with impaired left ventricular function (EF <50%) raised up from 14% in 1996 to 24% in 2005. Average age remained stable. Logistic regression curve revealed a significant decrease in mortality (AADA) and in the overall incidence of neurological deficits. CONCLUSIONS Technical advances in the field of thoracic aortic surgery lead to a decrease of mortality and morbidity, especially in the incidence of adverse neurological events, in a large collective of patients. Long-term outcome and quality of life are better, since antegrade cerebral perfusion has been introduced.