Ex-Vivo Evaluation of the Effectiveness of Pulmonary Artery Sealing for VATS Procedure
We believe that most of the stress (patient and surgeon) during VATS anatomical lung
resection originates from manipulation of the pulmonary arteries. Endostaplers utilized
during VATS to seal the pulmonary arteries require a lot of space and manipulation of these
fragile vessels. Furthermore, the arteries must be completely dissected from the surrounding
tissues. This increases manipulations of pulmonary arteries during the procedure. Energy
sealing devices require much less space and dissection due to their size and sealing of the
arteries can be performed without complete dissection from the surrounding tissues. Thus,
the utilization of energy sealing devices will decrease excessive manipulations on the
pulmonary arterial branches during VATS anatomical lung resections which can render these
procedures easier and safer. This will not only decrease the stress on the patient, but also
on the surgeon and will hopefully allow more surgeons to adopt these minimally invasive
techniques which have been proven to be superior (length of stay, cost of care, pain,
morbidity post-op, atrial fibrillation, quality of life, systemic inflammation, ability to
receive adjuvant chemotherapy) to open thoracotomy.
The intraoperative techniques will not differ and blood vessel ligation will be performed
according to standard operative procedures either using staplers or direct ligation of the
After resection and delivery of the resected specimen out of the patient, the specimen will
be examined in vitro out of the operative field in a non-sterile field in the operative
room. The lobar pulmonary artery and its main segmental branches will be dissected.
Canulation of a major segmental branch will be performed using an arterial pressure
monitoring catheter. The canulation will be secured with ligation of 2-0 silk suture. A
three way valve will be attached directly to the arterial catheter. One branch of the three
way valve will be attached to a controlled pressure syringe pump and the other branch will
be attached to a digital manometer. All other segmental branches of the pulmonary artery
will be ligated to maintain the pressure throughout the catheterized segmental branch.
Normal 25 mmHg pressure will be obtained by inflating with normal saline. The lobar
pulmonary artery and the main segmental branches' diameters will be measured using a digital
caliper from the adventitia to the adventitia in the inflated portion with normal saline of
pressure 25 mmHg. The lobar pulmonary artery and the main segmental arteries will be sealed
using one of the main energy seals (Ligasure, Harmonic scalpel, Enseal, Thunderbeat,
unipolar or conventional bipolar cautery or application of metal or Hem-o-lok clips). The
sealing will be performed with a normal 25 mmHg intra-arterial pressure.
In bipolar sealing, the arterial wall will be compressed between the energy device jaws
until complete sealing is achieved. The artery will then be divided utilizing fine scissors.
In pulmonary arterial branches sealed with Harmonic scalpel, Thunderbeat and Enseal, the
arterial wall sealed will be divided in the same sealing step. In the Unipolar cautery
arterial sealing, a DeBakey forceps will be utilized to compress the arterial walls together
and then sealing will be performed with direct application of the unipolar cautery to the
forceps. Complete sealing achieved by complete carbonization of the arterial walls. The
artery will be divided with scissors after sealing.
After division of the pulmonary artery, normal saline solution will be injected through the
controlled pressure syringe pump to achieve an intraluminal pressure until the bursting
pressure is reached. Intraluminal pressure will be recorded and the bursting pressure will
The resected specimens will be divided into 8 groups according to the type of sealing
performed; (Ligasure, Harmonic scalpel, Enseal, Thunderbeat, Unipolar and conventional
bipolar cautery, Metal clip, and Hem-o-lok clip)
Endpoint Classification: Efficacy Study, Intervention Model: Single Group Assignment, Masking: Open Label, Primary Purpose: Treatment
Primary outcome for analysis will be intergroup comparison of mean pulmonary artery burst pressures.
Intergroup differences will be compared with the student's t-test. Multivariable logistic regression models will be employed in order to compare burst pressures between groups controlling for potential confounder (disease state, size of vessel sealed, age of patient, pulmonary lobe…).
Moishe Liberman, MD, PhD
Centre Hospitalier de l'Université de Montréal
Canada: Ethics Review Committee