Technique
A 41-year-old man referred to our hospital with an exertional chest
pain. Coronary computed tomography (CT) angiography showed MB located
from the mid segment of the LAD to the first diagonal branch (Fig. 1A).
Preoperative CAG revealed severe stenosis of LAD at the site of MB
during systole (Fig. 2A). FFR at the lesion was 0.72 with 50 γ of
dobutamine administration. Medical therapy with beta blocker was
initiated, but the symptom did not improve. Since there was no long or
deep bridges, minimally invasive surgical unroofing (off-pump and left
mini-thoracotomy) was selected for early rehabilitation.
Surgical technique. After general anesthesia and double-lumen
endotracheal intubation, the patient was positioned at 30°right lateral
decubitus position. A 6-cm incision was made on the
4th intercoastal space. After pericardium was incised
anterolaterally, an octopus NUVO stabilizer (Medtronic Inc.,
Minneapolis, MN, USA) was inserted via 5thintercoastal space on the mid-clavicular line to stabilize the LAD. By
using VeriQ system probe (MediStim, Oslo, Norway), we confirmed the
location of MB and squeezing of the LAD(Fig. 1B and C). The LAD was
buried in the myocardium for 25 mm from the first diagonal branch (Fig.
3A). The epicardium at the MB was dissected with small circular knife
blade and fat above the LAD was removed using a Harmonic Scalpel
(Ethicon Endo- Surgery, Inc, Somerville, NJ). The MB was resected by
using small potts scissors. Intraoperative CAG showed residual squeezing
at the peripheral side of the MB. Therefore, additional unroofing was
performed and buried LAD was completely exposed (Fig. 3B and C).
Postoperative course was uneventful and CAG showed no residual squeezing
of the LAD (Fig. 2B). Postoperative FFR was 0.92 under 50 γ of
dobutamine administration. There was no wound trouble of the 6-cm main
incision at the left 4th intercoastal space and 1-cm
incision for stabilizer at the 5th intercoastal space
(Fig. 3D).