title: A new simplified volume-loaded heterotopic rabbit heart transplant model with improved techniques and a standard operating procedure.
abstract: BACKGROUND
  The classic non-working (NW) heterotopic heart transplant (HTX) model in rodents had been widely used for researches related to immunology, graft rejection, evaluation of immunosuppressive therapies and organ preservation. But unloaded models are considered not suitable for some researches. Accordingly, We have constructed a volume-loaded (VL) model by a new and simple technique.
  
  
  METHODS
  Thirty male New Zealand White rabbits were randomly divided into two groups, group NW with 14 rabbits and group VL with 16 rabbits, which served as donors and recipients. We created a large and nonrestrictive shunt to provide left heart a sufficient preload. The donor superior vena cave and ascending aorta (AO) were anastomosed to the recipient abdominal aorta (AAO) and inferior vena cava (IVC), respectively.
  
  
  RESULTS
  No animals suffered from paralysis, pneumonia and lethal bleeding. Recipients' mortality and morbidity were 6.7% (1/15) and 13.3% (2/15), respectively. The cold ischemia time in group VL is slight longer than that in group NW. The maximal aortic velocity (MAV) of donor heart was approximately equivalent to half that of native heart in group VL. Moreover, the similar result was achieved in the parameter of late diastolic mitral inflow velocity between donor heart and native heart in group VL. The echocardiography (ECHO) showed a bidirectional flow in donor SVC of VL model, inflow during diastole and outflow during systole. PET-CT imaging showed the standard uptake value (SUV) of allograft was equal to that of native heart in both groups on the postoperative day 3.
  
  
  CONCLUSIONS
  We have developed a new VL model in rabbits, which imitates a native heart hemodynamically while only requiring a minor additional procedure. Surgical technique is simple compared with currently used HTX models. We also developed a standard operating procedure that significantly improved graft and recipient survival rate. This study may be useful for investigations in transplantation in which a working model is required.
authors.affiliation: 1 Department of Cardiac Surgery, Beijing Anzhen Hospital, Capital Medical University, Beijing Institute of Heart, Lung and Blood Vessel Diseases, Beijing 100029, China ; 2 Department of Pediatric Heart center, Beijing Anzhen Hospital, Capital Medical University, Beijing 100029, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Lu
authors.affiliation: 1 Department of Cardiac Surgery, Beijing Anzhen Hospital, Capital Medical University, Beijing Institute of Heart, Lung and Blood Vessel Diseases, Beijing 100029, China ; 2 Department of Pediatric Heart center, Beijing Anzhen Hospital, Capital Medical University, Beijing 100029, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Zheng
authors.affiliation: 1 Department of Cardiac Surgery, Beijing Anzhen Hospital, Capital Medical University, Beijing Institute of Heart, Lung and Blood Vessel Diseases, Beijing 100029, China ; 2 Department of Pediatric Heart center, Beijing Anzhen Hospital, Capital Medical University, Beijing 100029, China.
authors.forename: Xu-Dong
authors.initials: XD
authors.lastname: Pan
authors.affiliation: 1 Department of Cardiac Surgery, Beijing Anzhen Hospital, Capital Medical University, Beijing Institute of Heart, Lung and Blood Vessel Diseases, Beijing 100029, China ; 2 Department of Pediatric Heart center, Beijing Anzhen Hospital, Capital Medical University, Beijing 100029, China.
authors.forename: Bing
authors.initials: B
authors.lastname: Li
authors.affiliation: 1 Department of Cardiac Surgery, Beijing Anzhen Hospital, Capital Medical University, Beijing Institute of Heart, Lung and Blood Vessel Diseases, Beijing 100029, China ; 2 Department of Pediatric Heart center, Beijing Anzhen Hospital, Capital Medical University, Beijing 100029, China.
authors.forename: Jin-Wei
authors.initials: JW
authors.lastname: Zhang
authors.affiliation: 1 Department of Cardiac Surgery, Beijing Anzhen Hospital, Capital Medical University, Beijing Institute of Heart, Lung and Blood Vessel Diseases, Beijing 100029, China ; 2 Department of Pediatric Heart center, Beijing Anzhen Hospital, Capital Medical University, Beijing 100029, China.
authors.forename: Long-Fei
authors.initials: LF
authors.lastname: Wang
authors.affiliation: 1 Department of Cardiac Surgery, Beijing Anzhen Hospital, Capital Medical University, Beijing Institute of Heart, Lung and Blood Vessel Diseases, Beijing 100029, China ; 2 Department of Pediatric Heart center, Beijing Anzhen Hospital, Capital Medical University, Beijing 100029, China.
authors.forename: Li-Zhong
authors.initials: LZ
authors.lastname: Sun
keywords: Heterotopic heart transplantation (HTX); standard operating procedure; volume-loaded model (VL model)