title: Augmented venous return for minimally invasive open heart surgery with selective caval cannulation.
abstract: OBJECTIVE
  Minimally invasive open heart surgery involves limited intrathoracic cannulation sites necessitating cardiopulmonary bypass to be initiated via peripheral access using percutaneous cannulae with the tip placed into the right atrial cavity. However, surgery involving the opening of the right heart obliges the surgeon to maintain the end of the cannulae into the vena cavae. The impeded venous return due to the smaller diameter may be alleviated by inserting a centrifugal pump in the venous line.
  
  
  METHODS
  Right anterior mini-thoracotomy and exposure of the femoral site were performed before the patient was heparinized. Cannulation of the femoral artery, the inferior vena cava via the femoral vein and the superior vena cava through the mini-thoracotomy was performed and cardiopulmonary bypass was initiated. Venous drainage was augmented with the centrifugal pump. Cardiac arrest was provoked and both vena cavae were snared before performing the intracardiac procedure.
  
  
  RESULTS
  Twenty consecutive patients were operated on using this technique (15 males/five females; age: 44.8 +/- 14.3 years; bodyweight: 73.5 +/- 15.1 kg; body surface area: 1.8 +/- 0.2 m2; theoretical blood flow rate: 4.4 +/- 0.5 l/min). The cannula sizes were 21.9 +/- 2.2 Fr for the femoral artery, 26.5 +/- 1.7 Fr for the inferior vena cava and 23.8 +/- 2.5 Fr for the superior vena cava. Venous drainage through the single inferior vena cava cannula was 2.1 +/- 0.6 l/min (48.8 +/- 13.3% of the theoretical flow). Adding the superior vena cava cannula increased the venous flow to 3.1 +/- 0.4 l/min (70.7 +/- 9.6% of the theoretical value, P < 0.005). The use of the centrifugal pump increased the flow to 4.1 +/- 0.6 l/min (93.4 +/- 8.9% of the theoretical flow, P < 0.001) with a mean inlet negative pressure of -69 +/- 10.2 mmHg. The mean bypass time was 64.0 +/- 24.6 min for a mean operative time of 226.3 +/- 61.0 min. Minimum venous saturation was 69.4 +/- 8.5%.
  
  
  CONCLUSIONS
  Despite the smaller diameter of the vena cavae compared to the right atrium, and a smaller internal diameter of percutaneous cardiopulmonary bypass cannulae compared to classic ones; the centrifugal pump improves the venous drainage significantly so that minimally invasive open heart procedures can be performed under optimal and safe perfusion conditions.
authors.affiliation: Department of Cardiovascular Surgery, University Hospital (CHUV), Lausanne, Switzerland.
authors.forename: D
authors.initials: D
authors.lastname: Jegger
authors.forename: H T
authors.initials: HT
authors.lastname: Tevaearai
authors.forename: J
authors.initials: J
authors.lastname: Horisberger
authors.forename: X M
authors.initials: XM
authors.lastname: Mueller
authors.forename: Y
authors.initials: Y
authors.lastname: Boone
authors.forename: N
authors.initials: N
authors.lastname: Pierrel
authors.forename: I
authors.initials: I
authors.lastname: Seigneul
authors.forename: L K
authors.initials: LK
authors.lastname: von Segesser
mesh_terms: D000328:Adult; D002315:Cardiopulmonary Bypass / Q000379:methods* / Q000401:mortality; D002406:Catheterization, Peripheral / Q000379:methods*; D003327:Coronary Disease / Q000601:surgery; D005260:Female; D005263:Femoral Artery / Q000601:surgery*; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures / Q000379:methods* / Q000401:mortality; D011446:Prospective Studies; D015996:Survival Rate; D013908:Thoracotomy; D016896:Treatment Outcome; D014682:Vena Cava, Inferior / Q000601:surgery*