Safety of a thermal vessel sealer on main pulmonary vessels.
OBJECTIVE
LigaSure (Valleylab, Tyco Healthcare, Boulder, CO) is a novel instrument with widespread use in various surgical disciplines for vessel sealing. It uses heat energy to denature collagen and elastin and achieve vessel sealing. We investigated the safety of LigaSure in pulmonary arteries (PA) and veins (PV).


METHODS
Twelve sheep were anesthetized and endotracheally intubated. Six underwent right lower lobectomy (Group 1) and six right upper lobectomy (Group 2). All of the vessels in both groups were divided with LigaSure. Diameters of vessels were measured. Intraoperatively, pulmonary artery pressures (PAP) were monitored in Group 1. Following vascular division, ephedrine was injected to increase PAP in Group 1. In Group 2, animals were followed and euthanized at 7 days. Both immediate and 7 day samples were obtained from divided vessel stumps. Conventional histology was done. Statistical analysis was performed using t-test and Fisher's exact test.


RESULTS
Mean diameter of PAs (n=9) divided in Group 1 was 8.3mm (3-11) and of PVs (n=8) was 10.4mm (4-15). Mean PAP increased from 18 (27/9) to 27 (45/18)mmHg after ephedrine injection. Dehiscence rate was 2/6 in PAs and 3/6 in PVs larger than 9 mm in diameter. Mean diameter of PAs (n=8) divided in Group 2 was 5.7 mm (3-7) and of PVs (n=9) was 4.6mm (4-6). No early or late (7 days) vascular disruption was seen in Group 2. Bleeding incidence was significantly different between groups (Fisher's exact test p=0.015). Overall no dehiscence was observed in vessels less than 7 mm in diameter. Histology of intraoperative samples showed thermal injury and necrosis. Seven day samples showed short segment necrosis limited to the vessel wall, fibrosis, thrombus formation without inflammation, and minimal granulation tissue.


CONCLUSIONS
LigaSure achieves perfect sealing in pulmonary vessels less than 7 mm in diameter in sheep intra- and postoperatively even following a pressure challenge. It can safely be used in segmental branches of PAs and PVs during open or thoracoscopic surgery.
Lacin
Tunc
T
Marmara University Hospital, Department of Thoracic Surgery, Istanbul, Turkey.
Batirel
Hasan Fevzi
HF
Ozer
Kursat
K
Demirutku
Alper
A
Ahiskali
Rengin
R
Yuksel
Mustafa
M
D000818:Animals; D016063:Blood Loss, Surgical / Q000517:prevention & control; D006488:Hemostasis, Surgical / Q000009:adverse effects / Q000295:instrumentation* / Q000379:methods; D006358:Hot Temperature / Q000627:therapeutic use*; D008026:Ligation / Q000295:instrumentation / Q000379:methods; D011489:Protein Denaturation; D011651:Pulmonary Artery / Q000473:pathology / Q000601:surgery*; D011667:Pulmonary Veins / Q000473:pathology / Q000601:surgery*; D034561:Sheep, Domestic; D013908:Thoracotomy; D016896:Treatment Outcome; D014656:Vascular Surgical Procedures / Q000295:instrumentation*