Restoration of diaphragmatic function after diaphragm reinnervation by inferior laryngeal nerve; experimental study in rabbits.
OBJECTIVE
To assess the possibilities of reinnervation in a paralyzed hemidiaphragm via an anastomosis between phrenic nerve and inferior laryngeal nerve in rabbits. Reinnervation of a paralyzed diaphragm could be an alternative to treat patients with ventilatory insufficiency due to upper cervical spine injuries.


METHODS
Rabbits were divided into five groups of seven rabbits each. Groups I and II were respectively the healthy and the denervated control groups. The 3 other groups were all reinnervated using three different surgical procedures. In groups III and IV, phrenic nerve was respectively anastomosed with the abductor branch of the inferior laryngeal nerve and with the trunk of the inferior laryngeal nerve. In group V, the fifth and fourth cervical roots were respectively anastomosed with the abductor branch of the inferior laryngeal nerve and with the nerve of the sternothyroid muscle (originating from the hypoglossal nerve). Animals were evaluated 4 months later using electromyography, transdiaphragmatic pressure measurements, sonomicrometry and histological examination.


RESULTS
A poor inspiratory activity was found in quiet breathing in the reinnervated groups, with an increasing pattern of activity during effort. In the reinnervated groups, transdiaphragmatic pressure measurements and sonomicrometry were higher in group III with no significant difference with groups IV and V.


CONCLUSIONS
Inspiratory contractility of an hemidiaphragm could be restored with immediate anastomosis after phrenic nerve section between phrenic nerve and inferior laryngeal nerve.
Derrey
Stephane
S
Experimental Surgery Laboratory, Rouen University, School of Medicine, France. stephane.derrey@tiscali.fr
Verin
Eric
E
Laquerrière
Annie
A
de Barros
Angelique Boishardy
AB
Lacoume
Yann
Y
Fréger
Pierre
P
Marie
Jean Paul
JP
D000818:Animals; D003964:Diaphragm / Q000294:innervation* / Q000503:physiopathology*; D007823:Laryngeal Nerves / Q000601:surgery*; D009119:Muscle Contraction; D009121:Muscle Denervation; D010243:Paralysis / Q000503:physiopathology / Q000601:surgery; D010791:Phrenic Nerve / Q000503:physiopathology* / Q000637:transplantation*; D011817:Rabbits; D020127:Recovery of Function / Q000502:physiology*