Belgian and European Experience with the European Homograft Bank (EHB) Cryopreserved Allograft Valves.-Assessment of a 20 Year Activity

European Homograft Bank (EHB) has been selecting, preparing, storing and distributing the cryopreserved allograft valves in Belgium and some other European Countries since 1989. It was established in 1988 by a pathologist and the cardiac and vascular surgeons from Belgian and other European centres as an inter-university, international nonprofit association. Due to its neutral behavior and very high quality criteria, European Homograft Bank became one of the prominent heart valve banks in Europe and wider. It collaborates with the transplant coordination in donor selection as well as with the huge network of the implanting surgeons in Belgium and other European Countries. The EHB responsible discusses with the implanting surgeon the allograft selection on basis of the indication and the patients state of emergency.

A total of 8.911 donor heart valves have been evaluated in EHB during the last 20 years. After selection, 5.258 allograft valves (1.996 aortic, 3.189 pulmonary and 73 mitral) were cryopreserved and stored in vapors of liquid nitrogen between 6 weeks and 5 years. A total of 4.516 allograft valves (1.391 aortic, 2.620 pulmonary and 48 mitral) were implanted in the left or right ventricular outflow tract for replacement of the diseased aortic or pulmonary valve and for mitral or tricuspid valve replacement or repair. In 1.380 cases the allograft valves were used for right ventricular outflow tract reconstruction as part of the Ross-procedure, whereas in 668 cases the allograft valve served for replacement of the aortic valve for endocarditis. The most important indications for use of cryopreserved allograft valves were: important cardiac and valve malformation in children, female patients of child-bearing age with diseased cardiac valves, cases with contra-indication for anti-coagulation and the patients with severe endocarditis with septal or annular abscesses. Although the number of the donation increased by year, the available allograft valves in stock are still insufficient to respond to all the surgeons’ request for different indications.     

Cemented hemiarthroplasty or hip replacement for intracapsular neck of femur fracture? A comparison of 7732 matched patients using national data

Background

The treatment of choice for intracapsular neck of femur (NOF) fractures in younger, more active patients remains unknown. Some surgeons advocate total hip replacement (THR).

Aim

This study aimed to compare complications following THR and hemiarthroplasty using the Hospital Episode Statistics (HES) database in England.

Method

Dislocation and revision rates were extracted for all patients with NOF fracture who underwent either cemented hemiarthroplasty or cemented THR between January 2005 and December 2008. To make a ‘like for like’ comparison all 3866 THR patients were matched to 3866 hemiarthroplasty patients (from a total of 41,343) in terms of age, sex and Charlson score.

Results and conclusion

Eighteen-month dislocation was significantly higher in the THR group (2.4% vs. 0.5%, odds ratio (OR) 3.90 (2.99–5.05), p < 0.001). This difference was sustained at the 4-year stage (2.9% vs. 0.9%, OR 3.18 (1.58–6.94), p = 0.001) in a subset of patients with longer follow-up. There was no significant difference in revision rate up to 4 years (1.8% vs. 2.1%, OR 0.85 (0.46–1.55), p = 0.666). In this national analysis of matched patients short- and medium-term dislocation rates following THR were significantly higher than following cemented hemiarthroplasty, without any difference in revision rates at 4 years. The low risk of dislocation may be acceptable in order to experience the apparent functional benefits of THR.     

A standardised investigative strategy prior to revisional oesophageal surgery in children: High incidence of unexpected findings

Background/Purpose

Revisional oesophageal reconstructive surgery carries uncommon and unusual risks related to previous surgery. To provide maximum anatomical detail and facilitate successful outcome, we report a standardised pre-operative investigative strategy for all such patients.

Methods

Prospective 8-month cohort study following the introduction of this strategy. All patients underwent high resolution thoracic contrast CT scan and micro-laryngo-bronchoscopy by a paediatric ENT surgeon in addition to upper gastrointestinal contrast study, oesophagoscopy, and echocardiogram.

Results

Seven children (median age 5.6 months [range 2.2–60]) completed the pathway. Four were referred with recurrence of a previously divided tracheo-oesophageal fistula (3 congenital, 1 acquired) and 3 (all with oesophagostomy) for oesophageal replacement for congenital isolated oesophageal atresia (OA, n = 1) and failed repair of OA with distal TOF with wide gap (n = 2). Overall, unanticipated findings were demonstrated in 6/7 children and comprised severe tracheomalacia and right main bronchus stenosis requiring aortopexy (n = 1), vocal cord palsy (n = 2), extensive mediastinal rotation (n = 1), proximal tracheal diverticulum (n = 1), severe subglottic stenosis requiring airway reconstruction (n = 1), proximal tracheal diverticulum (n = 1), right sided aortic arch (n = 1) and left sided aortic arch (previously reported to be right sided, n = 1).

Conclusions

This standardised approach for this complex group of patients reveals a high incidence of unexpected anatomical and functional anomalies with significant surgical and possible medico-legal implications. We recommend these investigations during the pre-operative work-up prior to all revisional oesophageal surgery.     

Laser Doppler anemometry measurements of steady flow through two bi-leaflet prosthetic heart valves

Introduction

In vitro hydrodynamic characterization of prosthetic heart valves provides important information regarding their operation, especially if performed by noninvasive techniques of anemometry. Once velocity profiles for each valve are provided, it is possible to compare them in terms of hydrodynamic performance. In this first experimental study using laser doppler anemometry with mechanical valves, the simulations were performed at a steady flow workbench.

Objective

To compare unidimensional velocity profiles at the central plane of two bi-leaflet aortic prosthesis from St. Jude (AGN 21 - 751 and 21 AJ - 501 models) exposed to a steady flow regime, on four distinct sections, three downstream and one upstream.

Methods

To provide similar conditions for the flow through each prosthesis by a steady flow workbench (water, flow rate of 17L/min. ) and, for the same sections and sweeps, to obtain the velocity profiles of each heart valve by unidimensional measurements.

Results

It was found that higher velocities correspond to the prosthesis with smaller inner diameter and instabilities of flow are larger as the section of interest is closer to the valve. Regions of recirculation, stagnation of flow, low pressure, and flow peak velocities were also found.

Conclusions

Considering the hydrodynamic aspect and for every section measured, it could be concluded that the prosthesis model AGN 21 - 751 (RegentTM) is superior to the 21 AJ - 501 model (Master Series). Based on the results, future studies can choose to focus on specific regions of the these valves.     

Repair of aortic root in patients with aneurysm or dissection: comparing the outcomes of valve-sparing root replacement with those from the Bentall procedure

Introduction

Management of aortic root aneurysm or dissection has been the subject of much discussion that has led to some modifications. The current trend is a valve-sparing root replacement. We compared the outcome following valve sparing root repair with Bentall procedure.

Methods

We retrospectively evaluated 70 patients who underwent root replacement for aneurysm or dissection and compared the outcomes of valve-sparing root replacement with those of the Bentall procedure from January 2007 to December 2011 at our institution.

Results

Twenty-five patients had valve-sparing aortic root replacement (VSR, including reimplantation or remodeling) (23 males and 2 females), and 45 patients had the Bentall procedure (34 males and 11 females). Patients who underwent a VSR were younger with a mean age of 55.4 ± 14.8 years compared to those who underwent the Bentall procedure with a mean age of 60.6 ± 12.7 (P=ns). The preoperative aortic insufficiency (AI) in the VSR group was moderate in 8 (32%) patients, and severe in 6 (24%). Preoperative creatinine was 1 ± 0.35 mg/dl in the VSR group and 1.1 ± 0.87 mg/dl in the Bentall group. In the VSR group, 3 (12%) patients had emergency surgery; by contrast, in the Bentall group, 8 (17%) patients had emergent surgery. Concomitant coronary artery bypass grafting (excluding coronary reimplantation) was performed in 8 (32%) patients in the VSR group and in 12 (26.6%) patients in the Bentall group (P=0.78); additional valve procedures were performed in 2 (8%) patients in the VSR group and in 11 (24.4%) patients in the Bentall group. The perioperative mortality was 8% (n=2) and 13.3% (n=6), for the VSR and Bentall procedures, respectively (P=0.7, ns). The total duration of intensive care unit stay was 116.6 ± 106 hours for VSR patients and 152.5 ± 218.2 hours for Bentall patients (P=0.5). The overall length of stay in the hospital was 10 ± 8.1 days for VSR and 11 ± 9.52 days for Bentall (P=0.89). The one-year survival was 92% for the VSR group and 79.0% for the Bentall group. The seven-year survival for the VSR group was 92% and 79% for the Bentall group (95% CI [1.215 to 0.1275], P=0.1).

Conclusion

Aortic valve-sparing root replacement can be performed with acceptable morbidity and mortality with a comparable long-term survival to the Bentall procedure.     

Impact of Pump Replacement on Outcome in Advanced Heart Failure Patients With Left Ventricular Assist System

Pump thrombosis is one of the major adverse events associated with the use of a left ventricular assist system (LVAS) in patients with advanced heart failure. We investigated the clinical implication of pump replacement because of thrombus formation. This study included 87 patients who underwent implantation of a Nipro (Toyobo) pulsatile extracorporeal LVAS intended as a bridge to transplantation and were alive more than 3 months after implantation. The pump of this device is translucent, and daily evaluation for signs of thrombus formation was performed. Pump replacement was performed for significant thrombus formation that became visible. Data collection including demographics as well as hematologic values were performed 1 day before (baseline) and 3 months after implantation, and all patients were followed for 2 years or until death. At 3 months after LVAS implantation, 41 patients (47.1%) had undergone pump replacement because of pump thrombus. Baseline body surface area <1.63 m² was a significant predictor of pump replacement (hazard ratio [HR] 2.15, P = 0.04). At 3 months after implantation, there was a significantly higher incidence of stroke (P < 0.05) as well as a significantly greater decrease in body weight (F = 4.92, P = 0.03) in patients who underwent pump replacement as compared to those without. The 2‐year mortality after implantation was 26.4%. Multivariate Cox regression analysis showed that pump replacement within 3 months after implantation was an independent predictor of mortality (HR 2.50, P = 0.03). In conclusion, pump replacement for thrombus formation may have a strong association with worse outcome. Our results reconfirm the clinical importance of device thrombus in the management of LVAS.     

下肢重建方式对Crowe Ⅳ型髋关节发育不良全髋关节置换术后疗效的影响

 目的 探讨不同重建方式恢复单侧Crowe Ⅳ型髋关节发育不良(developmental dysplasia of the hip,DDH)的患肢长度后关节功能与患者满意度的差异。方法 将21例拟行全髋关节置换术的单侧Crowe Ⅳ型DDH患者随机分为代偿长度组11例(转子下截骨后按照代偿法测得的双下肢长度差重建患肢长度)和绝对长度组10例(按照双下肢绝对长度差重建患肢长度)。平均随访10年,比较两组患者Harris髋关节评分和健康调查简表SF-36(the MOS item short form health survey,SF-36)评分;以翻修作为终点,采用Kaplan-Meier生存分析法评估假体生存率;根据症状及X线表现评价关节功能和假体松动情况。结果 17例获得随访,随访时间8~10年。两组患者Harris髋关节评分、主要的SF-36评分和假体生存率的差异无统计学意义,代偿长度组患者SF-36评分的“心理健康”项优于绝对长度组。10例出现聚乙烯磨损, 6例出现大转子区严重骨质疏松,3例骨溶解。5例翻修：1例感染、1例假体周围骨折、3例无菌性松动。结论 两种不同重建方式的全髋关节置换术后髋关节功能和假体生存率无差异。绝对长度组患者手术满意度低于代偿长度组,术后持续感觉双下肢不等长。     

全膝关节置换术中髌骨置换与否对早期疗效及膝前痛的影响

 目的 探讨全膝关节置换术中髌骨置换与否对早期疗效及膝前痛发生率的影响。方法 2010年6月至2011年6月拟行全膝关节置换术患者100例,随机分为两组：髌骨置换组43例50膝,髌骨未置换组57例66膝。比较术后6个月、12个月两组患者的西安大略和麦克马斯特大学(West Ontario and McMaster Universities,WOMAC)骨关节炎指数、美国膝关节外科协会(Knee Surgery Society,KSS)膝评分和功能评分、膝前痛视觉模拟评分(visual analogue scale,VAS)。结果 髌骨置换组与髌骨未置换组患者术后膝前痛VAS评分均较术前明显降低,两组间VAS评分及膝前痛发生率的差异无统计学意义。WOMAC骨关节炎指数6个月分别为28.8±11.2和18.6±7.2、术后12个月分别为20.7±6.2和16.0±5.5,KSS膝评分6个月分别为(87.0±8.3)分和(90.9±7.2)分、术后12个月分别为(84.2±10.6)分和(88.8±9.2)分,KSS功能评分术后6个月分别为(86.6±21.6)分和(84.9±16.5)分、术后12个月分别为(85.2±16.4)分和(91.0±10.0)分,组间差异均无统计学意义。髌骨轴位X线片示髌骨与股骨假体滑车吻合度良好,无不稳及脱位表现。术后1年内无翻修、髌骨表面再置换病例。结论 全膝关节置换术对改善因骨关节炎或类风湿关节炎导致的膝关节疼痛、功能受限有效;髌骨置换与否对术后短期疗效及膝前痛发生率没有影响。