[Burst pressures of the central pulmonary artery after bipolar vessel sealing--examination in an ex vivo model].

BACKGROUND

In every pneumonectomy due to a malignant or benign pulmonary disease the pulmonary artery must be centrally ligated and dissected. If a thoracotomy is undertaken the vessel is usually doubly ligated with a non-absorbable suture and then dissected. Alternatively a vessel stapler can be used. In a thorascopic procedure only the stapler can be used. In the search for a cheaper alternative we investigated whether a bipolar instrument as employed in thorascopy could be used and reused. The aim of this study was to investigate the static pressure performance of the closed vessel in an ex vivo non-perfused vessel model.

MATERIAL AND METHODS

From freshly slaughtered pigs the heart-lung block was removed. The central pulmonary artery was exposed. For sealing the vessel we used the bipolar sealing system MARSEAL®, Brothers Martin company (Tuttlingen, Germany), consisting of an HF generator and a MARSEAL slim instrument. Two groups were formed: group A (n = 49) Stromart SealSafe®, step G5 (automatic performance regulation, duration of use depending on impedance) and group B (n = 58) bipolar Stromart "Macrocoag" (power: 120 W, constant duration of use: 15 s). At the end of the pulmonary artery a pressure probe was implanted to digitally measure the pressure at the vessel sealing suture. After sealing the end of the artery, the vessel was slowly filled via an external source in order to determine the burst pressure. The burst pressure was reached as soon as the vessel suture started to leak. The average values of the 2 groups were then compared (t test for independent variables, significance set at p < 0.05).

RESULTS

All examined vessels (n = 107) had the same vessel diameter of 15 ± 3 mm. The average value of the burst pressure in group A was 139.3 ± 62.17 mmHg, that in group B 124.8 ± 38.46 mmHg. The ranges of burst pressures were in group A 51-297.0 mmHg und in group B 60.75-244.5 mmHg. There was no significant difference between group A and group B (p = 0.071).

CONCLUSIONS

Satisfactory burst pressures in the central pulmonary artery can also be achieved with the bipolar sealing instrument MARSEAL® and the impedance-controlled Stromart SealSafe®. However, because of the large scattering of the measured values, further studies are required.