Skeletal muscle ventricles with a single-limb conduit: the importance of hemodynamic design.
BACKGROUND
Skeletal muscle ventricles (SMVs) connected to the descending thoracic aorta have the potential for providing long-term diastolic augmentation. A successful existing design employs a bifurcated conduit, but aortic constriction between the limbs of the conduit is required to ensure obligatory flow-through. Here we evaluate an alternative approach in which connection to the aorta is made by a single-limb conduit.


METHODS
In two groups of dogs SMVs were constructed from the left latissimus dorsi muscle and connected to the circulation via a single-limb conduit of length 110-120 mm (Group 1, n = 5) or 70 mm (Group 2, n = 5). The animals were followed over 10 weeks.


RESULTS
Although all animals showed significant augmentation of diastolic aortic pressure at the outset, substantial thrombus developed in the SMVs of both groups. The results were analyzed by reference to design criteria for a single-limb conduit SMV, developed from empirical, in-vitro flow studies and formulated mathematically.


CONCLUSIONS
The SMVs constructed in this experiment appeared to meet the criteria for adequate mixing of blood within the ventricle. They did not, however, achieve adequate exchange of blood with the circulation. Thrombosis was therefore attributable to excessive residence time of blood in the SMV and conduit. Both the experimental study and the mathematical analysis point to the need for SMVs of this configuration to be constructed closer to the aorta. Preliminary results are reported for such an experiment in the pig, in which the SMV was thrombus-free when terminated electively after 1 week.
Salmons
Stanley
S
Wayne State University School of Medicine, Department of Surgery, Detroit, Michigan, USA.
Greer
Kevin
K
Shortland
Adam
A
Jarvis
Jonathan C
JC
Lu
Huiren
H
Bastian
Steven
S
Hammond
Robert
R
Stephenson
Larry
L
D000818:Animals; D001013:Aorta, Thoracic / Q000601:surgery; D001243:Assisted Circulation; D001794:Blood Pressure / Q000502:physiology; D001807:Blood Vessel Prosthesis; D003097:Collateral Circulation / Q000502:physiology; D004285:Dogs; D005121:Extremities / Q000098:blood supply* / Q000601:surgery*; D005500:Follow-Up Studies; D006352:Heart Ventricles / Q000601:surgery; D023421:Models, Animal; D008955:Models, Cardiovascular; D018482:Muscle, Skeletal / Q000098:blood supply / Q000502:physiology / Q000601:surgery; D009200:Myocardial Contraction / Q000502:physiology; D011183:Postoperative Complications / Q000209:etiology / Q000401:mortality; D019739:Skeletal Muscle Ventricle; D013318:Stroke Volume / Q000502:physiology; D016019:Survival Analysis; D013552:Swine; D013927:Thrombosis / Q000209:etiology / Q000401:mortality; D013997:Time Factors; D016896:Treatment Outcome; D016276:Ventricular Function