Grischa Hoffmann

Durability of Bioprosthetic Cardiac Valves

INTRODUCTION The choice of type of heart valve prosthesis is determined by the patients age since bioprostheses have a limited lifespan. This article reviews current recommendations and the literature on cardiac valve replacement. METHODS Selective literature search in Medline/PubMed back to 1996 and review of current national and international recommendations from specialist societies. RESULTS The recommendations guiding the type of heart valve replacement have been revised in recent years. Of particular interest are the new generation of biological prostheses with extended durability, a growing use of stentless bioprostheses, a decrease in mortality of reoperation and an increase in life expectancy. Comorbidities such as chronic renal insufficiency or chronic atrial fibrillation are no longer contraindications to bioprosthesis. The number of heart valve replacements in recent years rose despite a concomitant increase in valve repairs. Aortic valves are being increasingly replaced by bioprostheses. DISCUSSION The choice of heart valve prosthesis should be tailored to each patient taking into account the patients age, life expectancy, comorbidities, and life style. Different decisions may be made now than those based on earlier recommendations resulting in an individualized treatment, in patients over the age of 65 or 70.

Highly flexible nitinol mesh to encase aortocoronary saphenous vein grafts: first clinical experiences and angiographic results nine months postoperatively☆

Saphenous vein graft patency is frequently limited by degeneration. Experimental studies have indicated that rigid external support of venous grafts by a flexible, tubular nitinol mesh may improve graft patency. The study presented was part of a prospective, randomized, multicenter first-in-man trial investigating the safety and effectiveness of nitinol-supported venous grafts in coronary artery bypass graft (CABG) surgery. From our clinic, 25 subjects with multivessel coronary artery disease requiring saphenous vein graft CABG of the right coronary artery (RCA) and the circumflex artery were entered into the trial. Subjects were randomized to receive a mesh-supported graft on one of these arteries; the other vessel received an untreated vein graft. Graft patency was assessed by coronary angiography nine months after surgery. The implantation of mesh grafts was simple and safe. In 10 cases, a nitinol mesh-supported venous graft was anastomosed to the circumflex artery and in 15 cases to the RCA. All patients survived the observation period. A total of 72% of the patients underwent control coronary angiography. The patency rate of mesh-supported grafts was 27.8% nine months postoperatively. Conventional vein grafts showed an 85.7% patency, and arterial grafts had a 100% patency. No complications directly related to the implantation of mesh-supported grafts were observed. The promising experimental results of mesh-supported venous grafts could not be reproduced in the study presented. A critical item seems to be correct selection of nitinol mesh diameter, the anastomotic method and fixation of the mesh tube to the venous graft.

Prevention of surgical site sternal infections in cardiac surgery: a two-centre prospective randomized controlled study

OBJECTIVES Surgical site infection (SSI) of the sternum is a devastating complication in cardiac surgery. The aim of this prospective randomized controlled two-centre clinical study was to compare the use of a gentamicin-collagen sponge (Genta-Coll® resorb) and of a cyanoacrylate-based microbial skin sealant (InteguSeal®) on the SSI rate of the sternum. METHODS We analysed data from 996 consecutive patients following isolated coronary artery bypass grafting between 2012 and 2014. The patients were randomized into three groups: standard group (S-group), Genta-Coll group (G-group) and InteguSeal group (I-group). The primary study end-point was to analyse the incidence of superficial and deep sternal SSI. The secondary study end-point was to determine independent risk factors for an increased SSI rate. RESULTS Of the 996 patients investigated, 332 patients were in S-group, 336 patients in G-group and 328 patients in I-group. The mean age was 67.7 ± 9.4 years, 18.6% were women and the overall SSI rate was 6.2% with 2.2% deep sternal wound infections. SSI rates were 8.3% (S-group), 5.4% (G-group) and 4.9% (I-group) (P 0.16). Multiple regression analysis demonstrated a preoperative body mass index (BMI) of >30 kg/m2 (P 0.047), re-thoracotomy for postoperative bleeding (P < 0.001) and sternum instability (P < 0.001) as independent predictors for an increased SSI rate. CONCLUSIONS The application of InteguSeal® or Genta-Coll® resorb had no significant influence on the incidence of the sternal SSI rate in 996 consecutive cardiac surgery patients but demonstrated a trend towards a benefit from using these prophylactic approaches. Multiple regression analysis demonstrated a preoperative BMI of >30 kg/m2, re-thoracotomy for bleeding and sternum instability as independent predictors for an increased sternal SSI rate.

Off-pump coronary artery bypass prevents visceral organ damage

OBJECTIVES Visceral malperfusion after coronary artery bypass grafting (CABG) results in high morbidity and mortality. This study was designed to evaluate the effect of CABG performed by surgical techniques on visceral perfusion and function. METHODS Pigs (n = 28) were studied in four groups: I. Sham; II. Off-pump coronary artery bypass grafting (OPCAB): 1 h stabilizer with 40 min intracoronary shunt; III. Extracorporeal circulation (ECC): 1 h ECC with 40 min aortic cross-clamping and cardioplegic arrest; IV. Impella: 1 h left ventricular blood-pump support and stabilizer with 40 min intracoronary shunt. A left internal mammary to left anterior descending coronary artery bypass was performed in Groups II-IV. All animals were observed for a further 240 min. During the experiment haemodynamics, creatinine clearance, intestinal fatty acid binding protein (iFABP), pancreatic (lipase and amylase) and liver enzymes (α-glutathione s-transferase, glutamate-oxaloacetate transaminase (GOT), gamma-glutamyl transferase (GGT), glutamate dehydrogenase and glutamate-pyruvate transaminase (GPT)) were measured. Visceral perfusion (VP) was assessed in both kidneys, intestine, pancreas, liver and spleen with 15 µm fluorescent microspheres. RESULTS During OPCAB surgery, VP decreased slightly. Renal functional parameters, iFABP, pancreatic and liver enzymes remained unchanged. ECC and Impella led to significantly reduced renal, pancreatic and intestinal blood flow (P < 0.05). Creatinine clearance, pancreatic and liver (GPT, GGT) enzymes were significantly decreased only after ECC (P < 0.05). ECC and Impella resulted in a significantly increased iFABP level (P < 0.05). GOT was elevated significantly after surgery in Groups II, III and IV (P < 0.05). CONCLUSIONS CABG with ECC or Impella leads to impaired visceral blood flow and function. OPCAB minimizes these procedure associated alterations.

Minimally invasive direct coronary artery bypass in a child with an occlusion of left main coronary artery after arterial switch operation

We present a case of a 13-year old girl experiencing recurring angina pectoris due to an occlusion of the left main coronary artery after arterial switch operation in infancy. To avoid a repeat sternotomy and the use of cardiopulmonary bypass, the patient underwent uncomplicated operative myocardial revascularization in the minimally invasive direct coronary artery bypass (MIDCAB) technique.

Short- and long-term follow-up after minimally invasive direct coronary artery bypass in octogenarians

OBJECTIVES Demographic changes lead to a rising incidence of octogenarians undergoing surgical revascularization of coronary artery disease. Minimally invasive direct coronary artery bypass (MIDCAB) represents a surgical treatment with reduced trauma and without the use of cardiopulmonary bypass. The aim of this study was to evaluate short- and long-term outcomes after MIDCAB in octogenarians. METHODS Between 1998 and 2012, 1060 patients underwent MIDCAB at our department. Among them, 72 patients (6.8%) were older than 80 years at the time of operation. Incidence of major adverse cardiac and cerebrovascular events (MACCEs) was compared between octogenarians [median age 82 (81; 85) years, 63.9% male] and younger MIDCAB patients [median age 64 (56; 70) years, 70.7% male] after 30 days and during follow-up. The impact of demographics and preoperative comorbidities on mortality during follow-up was analysed. RESULTS At baseline, the elderly group presented with a statistically significant higher logistic EuroSCORE I (9.2 vs 2.2%, P < 0.001). Within 30 days, octogenarians showed a mortality rate of 5.6% (younger patients 0.8%, P = 0.006) and an MACCE rate of 5.6% (younger patients 1.3%, P = 0.024). The median follow-up time of 30-day survivors was 5.5 (2.9; 7.6) years and follow-up completeness reached 96.9%. In the elderly group, 1-, 3- and 5-year survival rates were 89, 78 and 63% in comparison with 97, 94 and 90% in the younger group (P < 0.001), respectively. The estimated median survival time in octogenarians was 6.7 (CI 4.854; 8.629) years. Logistic regression showed preoperative renal impairment, peripheral arterial occlusive disease and pulmonary hypertension to have a stronger impact on mortality during follow-up than age above 80 years. CONCLUSIONS MIDCAB represents a safe treatment option in octogenarians and is associated with a good perioperative outcome and satisfying long-term results in octogenarians.

Impact of patient-prosthesis mismatch following aortic valve replacement on short-term survival: a retrospective single center analysis of 632 consecutive patients with isolated stented biological aortic valve replacement.

OBJECTIVES The impact of patient-prosthesis mismatch (PPM) after aortic valve replacement (AVR) on short-term and long-term mortality remains controversial. The objective of this study was to evaluate the incidence and severity of PPM and its impact on short-term survival in a large cohort of patients treated with isolated stented biological AVR in a single institution. METHODS We analyzed retrospectively data of 632 consecutive patients with aortic stenosis undergoing isolated stented biological AVR between January 2007 and February 2012 at our institution. PPM was defined as an indexed effective orifice area ≤ 0.85 cm(2)/m(2). Statistical analyses were performed to identify influencing variables on valve size implanted. RESULTS Of the 632 patients investigated, 46% were females and mean age was 71.9 ± 10.4 years. PPM was observed in 93.8% (593 of 632 patients). In 71% of the patients, moderate (0.65-0.85 cm(2)/m(2)) PPM was present and in 22.8% severe (< 0.65 cm(2)/m(2)) PPM was present. The 30-day mortality was 1.4% (9 of 632 patients) with all being females. PPM was not associated with increased 30-day mortality. Multiple regression analyses demonstrated the usefulness of sex, height, body mass index, and body surface area as simultaneous predictors of the valve size implanted (R(2)= 0.39). CONCLUSION PPM had no discernable impact on short-term survival, although it was present in 93.8% of our patients following isolated stented biological AVR.

Extracorporeal membrane oxygenation for acute respiratory distress syndrome in adults: an analysis of differences between survivors and non-survivors

Objectives: Over the last decade, extracorporeal membrane oxygenation (ECMO) has become a promising option for patients with severe acute respiratory distress syndrome (ARDS). In this single-center observational cohort study, data from a patient group with severe ARDS treated with ECMO was analyzed. Methods: Data from 46 patients [median age 54 years (18 to 72), male: 65.2%] were evaluated retrospectively between January 2009 and September 2015. Results: Diagnosis leading to ARDS was pneumonia in 63.1% of the patients. The median SOFA Score was 13 (10 to 19) and the median LIS was 3.5 (2.67 to 4). The median duration of ECMO support was 12 days (1 to 86). Twenty-eight patients (60.9%) were successfully weaned from ECMO and 22 patients survived (47.8%). Non-survivors needed significantly more frequent renal replacement therapy (37.5% vs. 18.2%; p<0.01) and transfusion of red blood cell concentrates [0.4 units (0.3 to 1.2) vs. 0.9 units (0.5 to 1.6); p<0.01] during ECMO support compared to patients who survived. Conclusion: This report suggests that ECMO currently allows treatment of severe ARDS with presumed improved survival. The incidence rate of acute kidney injury and transfusion are associated with adverse outcomes.

Impact of Gender on Outcome in Octogenarians after Coronary Artery Bypass Grafting

Background Increasing life expectancy makes cardiac surgery in octogenarians not very uncommon. In this study, the impact of gender on outcome of octogenarians after coronary artery bypass grafting (CABG) was assessed. Materials and Methods We retrospectively studied 485 octogenarians (176 females: mean age 82.4 ± 2.2 years vs. 306 males: mean age 82.2 ± 2.4 years) who underwent isolated CABG using extracorporeal circulation between January 2005 and December 2012. Results No significant differences were noted between both gender groups with regard to preoperative risk factors. At baseline, the groups differed significantly with respect to mean logistic European System for Cardiac Operative Risk Evaluation (EuroSCORE) (women: 22.3 ± 17.4% vs. men: 17.5 ± 13.3%; p < 0.001). Likewise, EuroSCORE II differs significantly between women and men in our cohort (women: 16.7 ± 11.9% vs. men: 13.9 ± 10.7%; p = 0.008). Intraoperatively, the number of distal anastomoses (3.1 ± 0.9 vs. 3.2 ± 0.8), the mean extracorporeal circulation time (99 ± 31 vs. 102 ± 29 minutes), and the mean aortic cross‐clamp time (63 ± 31 vs. 60 ± 19 minutes) were similar in both groups. Postoperatively, no significant differences in complications and major morbidity were observed between the groups. The 30‐day mortality (women 8.0 vs. men 9.7%; p = 0.62) were without statistical significance between the groups. Conclusion Outcome of octogenarians after CABG resulted in acceptable mortality. Female gender was not associated with increased risks for morbidity and mortality after surgery. Satisfactory outcomes encourage the offering of surgery in octogenarians.

Impact of Patient-Prosthesis Mismatch following Aortic Valve Replacement on Long-Term Survival and Quality of Life

BACKGROUND  The impact of patient-prosthesis mismatch (PPM) after aortic valve replacement (AVR) on long-term survival and quality of life (QoL) remains controversial. The objective of this study was to evaluate the impact of PPM on long-term survival and QoL in a large cohort of patients treated with isolated stented biological AVR in a single-center experience. METHODS  We analyzed data of 632 consecutive patients following isolated stented biological AVR between 2007 and 2012 at our institution. We evaluated the QoL (393 evaluable patients) using the Short Form 12-item Health Survey (SF-12) questionnaire via telephone call and the impact of PPM on long-term survival (533 evaluable patients) by Kaplan-Meiers estimate. RESULTS  Severe PPM (<0.65 cm2/m2) had a negative impact on physical component summary (PCS) score (SF-12) compared with patients with moderate or no PPM (p = 0.014), while the mental component summary (MCS) score (SF-12) was not affected by the degree of PPM (p = 0.133). Long-term survival was not different among the three different PPM groups investigated (p = 0.75). CONCLUSION  Severity of PPM demonstrated no influence on long-term survival and MCS score (SF-12), but it was associated with a lower PCS score (SF-12) in patients with severe PPM.