Denervation and reinnervation of the heart after aortic surgery, estimated by 123I-metaiodobenzylguanidine scintigraphy.
OBJECTIVE
To investigate whether sympathetic nerve injury occurs during aortic surgery and how reinnervation takes place afterward.


METHODS
Imaging with 123I-metaiodobenzylguanidine (MIBG) was performed in 12 patients (aortic group) who underwent aortic surgery (ascending replacement 3, ascending-arch replacement 9) before and 3 weeks after surgery. In 8 of 12 patients, MIBG scintigraphy was performed 1 and 2 years after surgery. Twelve patients (control group) who underwent open-heart surgery (mitral valve repair: 11; tricuspid valve replacement: 1) were studied using MIBG scintigraphy. The heart-to-mediastinum (H/M) activity ratio was obtained from planar images. The myocardial single-photon-emission computed tomography image was divided into five segments and the regional tracer uptake was scored from 0 = absent to 3 = normal uptake.


RESULTS
No significant difference in the H/M ratio in either early and delayed planar scans was observed between both groups before surgery. The H/M ratios significantly decreased 3 weeks after surgery in the aortic group, whereas there was no significant change in the control group. The H/M ratio did not recover to the preoperative level within 2 years. In these 8 patients, the regional uptake of MIBG improved in the anterior and septal regions 1 year after surgery.


CONCLUSIONS
During ascending or ascending-arch replacement, the sympathetic nerve was globally denervated and slight reinnervation was observed within 2 years. The anterior and septal regions showed a rapid reinnervation, whereas other regions did not.
Miyamoto
Shinji
S
Department of Cardiovascular Surgery, Oita Medical University, Hasama-machi, Oita 879-5593, Japan.
Hadama
Tetsuo
T
Anai
Hirofumi
H
Sako
Hidenori
H
Wada
Tomoyuki
T
Iwata
Eriko
E
Nakayama
Kouichi
K
Takeoka
Hiroshi
H
Ono
Katsushige
K
D019797:3-Iodobenzylguanidine; D001011:Aorta / Q000601:surgery*; D001018:Aortic Diseases / Q000601:surgery; D019917:Blood Vessel Prosthesis Implantation; D006348:Cardiac Surgical Procedures; D002315:Cardiopulmonary Bypass; D006321:Heart / Q000000981:diagnostic imaging* / Q000294:innervation*; D006324:Heart Arrest, Induced; D006801:Humans; D007036:Hypothermia, Induced; D019275:Radiopharmaceuticals; D013562:Sympathectomy; D015899:Tomography, Emission-Computed, Single-Photon
D019275:Radiopharmaceuticals; D019797:3-Iodobenzylguanidine