title: A modified Glenn shunt reduces right ventricular stroke work during left ventricular assist device therapy.
abstract: OBJECTIVE
  Right ventricular (RV) failure is a major cause of morbidity and mortality after left ventricular assist device (LVAD) placement and remains hard to predict. We hypothesized that partial surgical exclusion of the RV with a modified Glenn shunt during LVAD treatment would reduce RV stroke work.
  
  
  METHODS
  An LVAD was implanted in eight pigs and a modified Glenn shunt was constructed. A conductance pressure-volume catheter was placed in the right ventricle through the apex. Haemodynamic data and pressure-volume loops were obtained at the following time periods: (i) baseline, (ii) open shunt, (iii) LVAD with closed shunt and (iii) LVAD and open shunt.
  
  
  RESULTS
  During LVAD therapy, the right atrial (RA) pressure increased from 9 mmHg (9-9) to 15 mmHg (12-15), P = 0.01. RV stroke volume increased from 30 ml (29-40) to 51 ml (42-53), P < 0.01. Also, RV stroke work increased to 708 mmHg ml (654-1193) from 535 mmHg ml (424-717), P = 0.04, compared with baseline. During LVAD therapy in combination with a Glenn shunt, the RA pressure decreased from 15 mmHg (12-15) to 10 mmHg (7-11) when compared with LVAD therapy only, P = 0.01. A decrease in RV stroke work from 708 mmHg ml (654-1193) to 465 mmHg ml (366-711), P = 0.04, was seen when the LVAD was combined with a shunt, not significantly different from the baseline value (535 mmHg ml). The developed pressure in the right ventricle decreased from 29 mmHg (26-32) to 21 mmHg (20-24), P < 0.01. The pressure-volume loops of the RV show a significant reduction of RV stroke work during the use of the shunt with LVAD treatment.
  
  
  CONCLUSIONS
  A modified Glenn shunt reduced RV volumes, RV stroke work and RA pressure during LVAD therapy in an experimental model of heart failure in pigs.
authors.affiliation: Department of Cardiothoracic Surgery, Uppsala University Hospital, Uppsala, Sweden.
authors.forename: Petter
authors.initials: P
authors.lastname: Schiller
authors.affiliation: Department of Cardiothoracic Surgery, Uppsala University Hospital, Uppsala, Sweden.
authors.forename: Per
authors.initials: P
authors.lastname: Vikholm
authors.affiliation: Department of Cardiothoracic Surgery, Uppsala University Hospital, Uppsala, Sweden laila.hellgren.johansson@akademiska.se.
authors.forename: Laila
authors.initials: L
authors.lastname: Hellgren
mesh_terms: D000818:Animals; D006348:Cardiac Surgical Procedures / Q000379:methods* / Q000706:statistics & numerical data*; D006352:Heart Ventricles / Q000503:physiopathology* / Q000601:surgery*; D006353:Heart-Assist Devices; D013552:Swine; D018497:Ventricular Dysfunction, Right / Q000503:physiopathology*
keywords: Glenn shunt; Left ventricular assist device; Right heart failure; Right ventricular stroke work