Spinal cord perfusion after extensive segmental artery sacrifice: can paraplegia be prevented?
OBJECTIVE
Understanding the ability of the paraspinal anastomotic network to provide adequate spinal cord perfusion pressure (SCPP) critical for both surgical and endovascular repair of thoracoabdominal aortic aneurysms (TAAA).


METHODS
To monitor pressure in the collateral circulation, a catheter was inserted into the distal end of the divided first lumbar segmental artery (SA) of 10 juvenile Yorkshire pigs (28.9+/-3.8kg). SA pairs from T3 through L5 were serially sacrificed at 32 degrees C; SCPP and function - using motor-evoked potentials (MEPs) - were continuously monitored until 1h after clamping the last SA. Intermittent aortic and SCPP monitoring was continued for 5 days postoperatively, along with evaluation of motor function.


RESULTS
A mean of 14.4+/-0.7 SAs were sacrificed without loss of MEP. SCPP (mmHg) dropped from 68+/-7 before SA clamping (77% of aortic pressure) to 22+/-6 at end clamping, and 21+/-4 after 1h, reaching its lowest point - 19+/-4 - after 5h. Postoperatively, SCPP recovered to 33+/-6 at 24h; 42+/-10 at 48h; 56+/-14 at 72h; 62+/-15 at 96h, returning to baseline (63+/-20) at 120h. Despite comparable SCPP patterns, four pigs did not fully regain the ability to stand. Six animals recovered: two could stand and four could walk.


CONCLUSIONS
Interruption of all SAs at 32 degrees C in this pig model results in a spectrum of cord injury, with normal function in a majority of pigs postoperatively. The short duration of low SCPP suggests that hemodynamic manipulation lasting only 24-48h may allow routine complete preservation of normal cord function despite sacrifice of all SAs.
Etz
Christian D
CD
Department of Cardiothoracic Surgery, Mount Sinai School of Medicine, New York, NY 10029, USA. christian.etz@mountsinai.org
Homann
Tobias M
TM
Plestis
Konstadinos A
KA
Zhang
Ning
N
Luehr
Maximilian
M
Weisz
Donald J
DJ
Kleinman
George
G
Griepp
Randall B
RB
D000818:Animals; D001011:Aorta / Q000503:physiopathology / Q000601:surgery; D001014:Aortic Aneurysm / Q000503:physiopathology / Q000601:surgery*; D001158:Arteries / Q000601:surgery; D001794:Blood Pressure / Q000502:physiology; D002574:Cervical Vertebrae; D003097:Collateral Circulation / Q000502:physiology*; D004195:Disease Models, Animal; D019054:Evoked Potentials, Motor / Q000502:physiology; D005260:Female; D007432:Intraoperative Period; D009068:Movement / Q000502:physiology; D009336:Necrosis; D010264:Paraplegia / Q000517:prevention & control*; D010477:Perfusion / Q000379:methods*; D011184:Postoperative Period; D013116:Spinal Cord / Q000098:blood supply* / Q000473:pathology; D013552:Swine; D013904:Thoracic Vertebrae