Ulrich F.W. Franke

A multicentre evaluation of the autograft procedure for young patients undergoing aortic valve replacement: update on the German Ross Registry

OBJECTIVES Conventional aortic valve replacement (AVR) in young, active patients represents a suboptimal solution in terms of long-term survival, durability and quality of life. The aim of the present work is to present an update on the multicentre experience with the pulmonary autograft procedure in young, adult patients. METHODS Between 1990-2013, 1779 adult patients (1339 males; 44.7 ± 11.6 years) underwent the pulmonary autograft procedure in 8 centres. All patients underwent prospective clinical and echocardiographic examinations annually. The mean follow-up was 8.3 ± 5.1 years (range 0-24.3 years) with a total cumulative follow-up of 14 288 years and 662 patients having a follow-up of at least 10 years. RESULTS The early (30-day) mortality rate was 1.1% (n = 19). Late (>30 day) survival of the adult population was comparable with the age- and gender-matched general population (observed deaths: 101, expected deaths: 91; P = 0.29). Freedom from autograft reoperation at 5, 10 and 15 years was 96.8, 94.7 and 86.7%, respectively, whereas freedom from homograft reoperation was 97.6, 95.5 and 92.3%, respectively. The overall freedom from reoperation was 94.9, 91.1 and 82.7%, respectively. Longitudinal modelling of functional valve performance revealed a low (<5%) probability of a patient being in higher autograft regurgitation grades throughout the first decade. Similarly, excellent homograft function was observed throughout the first 15 years. CONCLUSION The autograft principle results in postoperative long-term survival comparable with that of the age- and gender-matched general population and reoperation rates within the 1%/patient-year boundaries and should be considered in young, active patients who want to avoid the shortcomings of conventional prostheses.

Transcatheter Aortic Valve Replacement: Does Kidney Function Affect Outcome?

BACKGROUND Chronic kidney disease is a significant risk factor for mortality as well as acute kidney injury in cardiac surgery. The impact of contrast agent application on outcome is not well described in patients undergoing transcatheter aortic valve implantation. METHODS We analyzed data of 270 patients who underwent transcatheter aortic valve implantation (TAVI) between September 2008 and March 2012. Acute kidney injury was defined according to modified risk, injury, failure, loss and end-stage renal failure criteria. Patients on chronic hemodialysis were analyzed separately (n = 15). In 129 (47.8%) patients chronic kidney disease was apparent preoperatively. On average, 83.7 (± 32.4) mL of contrast agent were used per patient. RESULTS Postoperatively, 41 patients (15.2%) developed acute kidney injury. In 19 patients (7.1%) transient renal replacement therapy was necessary; no chronic hemodialysis was required. Thirty-day-mortality did not differ between patients with or without chronic kidney disease (7.0% vs 7.1%, p = 0.97). Additionally, chronic kidney disease had no influence on the incidence of postoperative acute kidney injury (12.8% vs 20.2%, p = 0.07) or postoperative hemodialysis (5.0% vs 10.5%, p = 0.08). No correlation between the amount of contrast agent applied and the incidence of acute kidney injury could be verified (p = 0.57). CONCLUSIONS Preoperative chronic kidney disease does not increase the risk of mortality and acute kidney injury after transcatheter aortic valve implantation. Acute kidney injury after TAVI is associated with an elevated risk of mortality. The amount of contrast agent applied intra-procedurally does not affect the risk of acute kidney injury.

Quality of life after aortic root surgery: reimplantation technique versus composite replacement.

BACKGROUND Recent studies indicate the safety of the aortic valve reimplantation technique (David operation) in the long-term follow-up. The aim of this study was to compare the results of the David operation with those of the aortic composite replacement procedure, with the focus on quality of life (QoL). METHODS Within a 6-year period, 143 patients received either an aortic composite replacement (composite group, n = 67) or the David-I operation (David group, n = 76). The QoL of 108 patients (87% of the living patients) was evaluated postoperatively by the 36-Item Short Form Health Survey. A subgroup analysis of QoL excluded patients with aortic stenosis and type A acute aortic dissection. RESULTS Hospital survival rates (89.6% versus 97.4%, p = 0.102), as well as actuarial 1-year survival rate (86.6% versus 91.9%) and 3-year survival rate (81.1% versus 91.9%) proved more successful among the David group. Incidences of serious adverse events during the follow-up period (10.8% versus 28.3%, p = 0.008) were higher for patients of the composite group. The QoL was found to be compromised for patients of the composite group, in relation to all criteria outlined in the 36-Item Short Form Health Survey. Subgroup analysis without patients with dissection and aortic stenosis demonstrated a significantly better postoperative QoL for patients of the David group. Patients belonging to the composite group were more frequently compromised by prosthetic valve noise (p < 0.001). CONCLUSIONS This study demonstrates the superiority of the aortic valve reimplantation compared with the aortic composite replacement, regarding both clinical outcome and postoperative QoL.

Risk factors predicting the successful function and use of autogenous arteriovenous fistulae for hemodialysis.

BACKGROUND For patients with end-stage renal failure hemodialysis with an autogenous arteriovenous fistula (AVF) has proven to be the ideal vascular access. OBJECTIVE The aim of this study is to discover potential predictors of a well-functioning hemodialysis fistula. METHODS From December 2009 to March 2011, 80 patients undergoing first time AVF creation were enrolled in our retrospective study. We analyzed pre- and postoperative vessel diameters and flow characteristics gained by duplex ultrasonography (DUS) and intraoperative ultrasound transit-time flow measurements regarding intraoperative blood flow and pulsatility index (PI). Follow-up was defined until the end of the first month with regular hemodialysis, 10 weeks after AVF creation. We performed statistical analyses by employing Spearman correlation, t test, analysis of variance, χ2 test, and receiver operating characteristics (ROC). RESULTS At the end of the follow-up, 62 patients (78%) featured functioning AVFs and 18 patients (22%) featured nonfunctioning AVFs. Factors influencing AVF function were radial artery diameter (χ2 = 5.23, p = 0.02), intraoperative flow (χ2 = 7.09, p = 0.01), intraoperative PI (χ2 = 6.5, p = 0.01), and postoperative flow (χ2 = 16.29, p = 0.01). According to the ROC analyses, we could develop cut-off values for predicting an ideal AVF function: radial artery diameter more than 2.3 mm, cephalic vein diameter more than 2.7 mm, intraoperative mean flow more than 113 mL/min, PI less than 1.4, and postoperative mean flow more than 160 mL/min. CONCLUSION Intraoperative ultrasound transit-time flow measurements gained at surgery and postoperative follow-up with DUS can help identify AVFs that are unlikely to function and therefore need early intervention.

Severe Aortic Insufficiency After Transapical Aortic Valve Implantation

We report the dislocation of a stented aortic valve prosthesis two weeks after the uneventful transapical implantation in a female who had underwent mitral valve replacement and CABG six years before. The initial implantation of the Edwards Sapien aortic valve prosthesis (Edwards Lifesciences, Irvine, CA), as well as the postoperative recovery, was uneventfully. At the sixth postoperative day, the patient developed a progressive heart failure due to a severe aortic insufficiency. During conventional aortic valve replacement, the dislocated prosthesis was found in the left ventricle. After uncomplicated postoperative recovery, the patient could be discharged in a good physical condition. Preexisting mitral valve prosthesis seems to be an important, complicating goal for transcatheter aortic valve implantation.

Lipoprotein(a)-Associated Molecules Are Prominent Components in Plasma and Valve Leaflets in Calcific Aortic Valve Stenosis

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Enzymatically Modified Low‐Density Lipoprotein Is Present in All Stages of Aortic Valve Sclerosis: Implications for Pathogenesis of the Disease

Background We have demonstrated previously that enzymatically degraded low‐density lipoprotein (eLDL) is an essential causative component for the initiation of atherosclerosis. Here, we investigated the different stages of human aortic valve sclerosis for the presence of eLDL and effectors of the innate immune system, as well as the interaction of eLDL with isolated valvular interstitial cells/myofibroblasts to discover possible pathways leading to aortic valve sclerosis. Methods and Results Human aortic valvular tissue was obtained from 68 patients undergoing valve replacement surgery. Patients were classified into 3 groups (mild, moderate, or severe aortic valve sclerosis), and clinical data for statistical analysis were gathered from all patients. Immunohistochemical staining demonstrated extensive extracellular deposits of eLDL throughout all grades of aortic valve sclerosis. Complementary analysis of lipid composition revealed higher concentrations of the decisive components of eLDL (ie, unesterified cholesterol and linoleic acid) compared with internal control tissues. Further, the complement component C3d and terminal complement complexes colocalized with eLDL compatible with the proposal that subendothelially deposited eLDL is enzymatically transformed into a complement activator at early stages of valvular cusp lesion development. Gene expression profiles of proteases and complement components corroborated by immunohistochemistry demonstrated an upregulation of the protease cathepsin D (a possible candidate for LDL degradation to eLDL) and the complement inhibitor CD55. Surprisingly, substantial C‐reactive protein expression was not observed before grade 2 aortic valve sclerosis as investigated with microarray analysis, reverse transcription–polymerase chain reaction analysis, and immunohistochemistry. Finally, we demonstrated cellular uptake of eLDL by valvular interstitial cells/myofibroblasts. Conclusions The present study is a startup of a hypothesis on the pathogenesis of aortic valve sclerosis declaring extracellular lipoprotein modification, subsequent complement activation, and cellular uptake by valvular interstitial cells/myofibroblasts as integral players.

Aortic diameter remodelling after the frozen elephant trunk technique in aortic dissection: results from an international multicentre registry†

OBJECTIVES The frozen elephant trunk (FET) technique allows one-stage hybrid repair approach in aortic dissection (AoD). Even if the effect of the FET technique on promoting false lumen (FL) thrombosis has been proved in the past, the relative importance of FL thrombosis on aortic remodelling at different levels of the distal aorta and the magnitude of this effect is not well known. The aim of the study was to evaluate aortic remodelling following a FET technique for AoD. METHODS A multicentre international registry database was searched to identify all patients who underwent a FET procedure for an AoD. A total of 383 patients with AoD were operated on between January 2005 and March 2014 with the FET technique; 137 patients (65 acute AoD and 72 chronic AoD) who survived the initial repair with at least a 1-year follow-up CT scan were included in the study. RESULTS The rate of FL thrombosis was higher in the mid-descending thoracic aorta (99.3%) and lower in the distal abdominal aorta (13.9%) but similar between acute and chronic AoDs. The negative remodelling rate was similar between acute and chronic AoDs in the abdominal aorta, but chronic AoD exhibited a higher rate of negative remodelling in the descending thoracic aorta (33% vs 17.5%, P  = 0.040). CONCLUSIONS The FET technique provides an effective treatment for AoD, promoting FL thrombosis and remodelling in the descending thoracic aorta. Changes in the diameter of the aortic lumen depend mainly on the status of the FL and are similar between acute and chronic AoD. Changes in the diameter of true lumen are affected by both the FL status and the timing of the presentation. However, increased FL thrombosis and positive remodelling rates are not maintained at the level of the abdominal aorta, and strict follow-up is mandatory to detect early changes in the aortic dimensions, which may warrant further interventions.

Transapical aortic valve implantation and minimally invasive off-pump bypass surgery

Transcatheter aortic valve implantation (TAVI) has gained increasing popularity for high-risk patients with symptomatic aortic valve stenosis. A concomitant coronary artery disease leads to a complicated management and an increased perioperative risk. This case report describes the successful total arterial coronary revascularization of the left anterior descending and the left marginal branch of the circumflex artery utilizing the left internal mammary artery (LIMA) and left radial artery in off-pump technique in combination with the transapical transcatheter aortic valve implantation via minimally invasive anterolateral access in the fifth intercostal space.

Minimally invasive Ross procedure through partial upper sternotomy

The Ross procedure has gained increasing interest for therapy of aortic valve pathologies in young adults because of excellent long-term results. This case report describes the first published experiences of the Ross procedure performed through a minimally invasive access in two consecutive patients. The limited access is associated with only a slightly prolonged aortic cross-clamp time. Consequently, a minimal access method does not result in an increased risk for patients.