Progress observed in minimally invasive surgery involves the development of new methods of vessel occlusion. They should be characterized by resistance, simplicity of application, and relatively low price. This study aimed to compare the methods most often used nowadays. According to the results obtained, endostaplers were the least resistant to ex vivo–generated hydrostatic pressure. Statistically significant higher values were obtained in the case of clips and ligations. Moreover, these methods did not differ significantly. In addition, higher mean pressure values for occlusion were obtained in veins than in arteries in every method evaluated. Nevertheless, these results were not statistically significant. These observations could be attributed to the histological structure and vulnerability of the vessels’ walls. The effectiveness of hemostasis maintenance with vascular ligation depends on the technique chosen by the operator. Therefore, to minimize the risk of a human mistake and potentially dangerous hemorrhage, two ligatures are applied for the proximal part of the stump in pulmonary vessels in both lobectomies and pneumonectomies. The pressure generated in the vessels occluded with ligatures significantly exceeded physiological conditions (the lowest pressure at which leakage was observed was 525 mmHg). In a separate study by Lim et al., the authors compared both veins and arteries collected from rabbits occluded with the use of ligatures, and similar values were observed [
4]. Moreover, Rajbabu et al. have not observed leakage from the vessel occluded with ligatures with values lower than 300 mmHg (maximum pressure used during their experiment) [
5]. Therefore, the above studies confirm that ligation is a safe method for occluding supplying vessels. It can be used to occlude vessels of various diameters, from large pulmonary arteries to small segmental vessels. Pressure values obtained with the use of Endo GIA Tri-Staple™ endostaplers were significantly lower (arteries = 262.5 mmHg: veins = 300 mmHg) than in the case of linen ligatures and Click’aV Plus™ polymer clips. Similar results were observed by Joseph et al., who used swine renal arteries [
6]. The authors observed leakage in the staple line in 50% of cases with an average pressure of 273 mmHg (237–322 mmHg). There was no leakage in vessels closed with polymer clips and ligatures with values below 800 mmHg [
6]. Other studies also report high pressures obtained in vessels occluded with clips and ligatures (300–1800 mmHg) [
2,
7‐
9]. Caution is required while using a stapler as improper fastening may reduce its effectiveness [
10,
11]. This is crucial especially in minimally invasive techniques, where straightened access increases the risk of excessive pressure or vessel torsion. This may result in dangerous and difficult-to-stop hemorrhage requiring conversion to thoracotomy. Staplers can be used for the occlusion of vessels of various diameters. Furthermore, they are used to occlude bronchi and to resect pulmonary parenchyma. In the present study, similar pressures were obtained in vessels occluded with clips and ligatures. Lim et al. achieved the pressure of 548.02 ± 277.71 mmHg in the case of arteries occluded with Hem-o-Lok clips, while significantly lower values were obtained in the case of veins (79.84 ± 47.04 mmHg) [
4]. However, such discrepancy in the results obtained is difficult to explain. It could result from a different structure of clip serration. In the conducted study, we have not observed clips sliding off the vessel, which can indicate good stability in the tissue. In a study by Saki et al., the clips did not slide off with the strength below 11.8 N which makes them safe in the situation of accidental pulling [
12]. While applying a clip, it is important to avoid slamming the wall of the vessel in the latch, as it can lead to detachment, and consequently, hard-to-control hemorrhage. Various sizes of clips are available in the market. Unfortunately, for the time being, they are not big enough to be applied to the left or right pulmonary artery or upper pulmonary vein. However, Lucchi et al. supplied pulmonary veins with the largest clips with good results [
13]. The described methods of vessel occlusion complement each other in clinical practice. Because of the low cost and habits of the operators, ligatures will constitute the basic tool used for pulmonary vessel management in open surgical procedures for a long time. It should be noted that pressure values on which leakage was observed were significantly higher than the physiological pressure within both pulmonary and systemic circulation. However, in patients with high, uncontrolled blood pressure surges, polymer clips and ligatures seem to be safer.