The Annals of Thoracic Surgery, Vol 36, 258-264, Copyright © 1983 by The Society of Thoracic Surgeons
Circular esophageal myotomy in the rhesus monkey: anatomical and physiological effects
JR Hankins, HS Ormsbee 3d and JS McLaughlin
Thirty-one rhesus monkeys were divided into six groups: a control group of
4 monkeys in which resection of 33% of the thoracic esophagus with
end-to-end anastomosis was performed without myotomy, and test groups of 4
to 6 monkeys each in which circular myotomy in the proximal segment, distal
segment, or both was combined with a 25% or 33% resection. In the control
group, 2 of 4 monkeys survived. In the test groups, myotomy reduced
longitudinal tension by 20 to 58%. Among the survivors were 4 of 6 animals
that had 25% resection with proximal myotomy, 3 of 5 having 25% resection
with distal myotomy, and 3 of 4 having 25% resection with combined proximal
and distal myotomy. However, 4 of 5 monkeys that had 33% resection plus
proximal myotomy and all 5 having 33% resection plus distal myotomy died of
anastomotic leaks or strictures. Cineesophagography in surviving monkeys
showed no motility disturbance at the myotomy sites. Manometry in 5 monkeys
showed no change in resting lower esophageal sphincter pressure from that
measured preoperatively. Postmortem examination in long-term survivors
showed no stricture or dilatation at the myotomy sites. It is concluded
that circular myotomy in the rhesus monkey reduces longitudinal tension,
but compromise of the esophageal blood supply limits the usefulness of the
procedure in bridging long gaps in the esophagus. Myotomy did not result in
any motility disturbance or late anatomical sequelae, and therefore is
still a valid procedure to facilitate the repair of short defects.
