Effects of pneumoperitoneum and body position on the morphology of abdominal vascular structures analyzed in MRI

Abstract

Purpose: To analyze the complications of laparoscopy in different vascular structures using magnetic resonance imaging (MRI). MRI has become a key tool in laparoscopic surgery. During these procedures, pneumoperitoneum creation and placing the patient in the surgical position provoke different changes in the splachnic circulation. Materials and Methods:Ten pigs were included in the study. MRI studies of the abdominal area were carried out in four different situations of abdominal pressure and body position.Results: Changes in the area of the lumen of the portal vein and the abdominal aorta were analyzed in all situations. A significant reduction in the area of the abdominal aorta was observed after the pneumoperitoneum in supine and anti-Trendelemburg position. The lumen of the portal vein was significantly reduced in all analyzed situations except when placing the patient in anti-Trendelemburg without pneumoperitoneum, in which case the area was increased. Conclusion:The creation of pneumoperitoneum provokes morphological changes in the lumen of different abdominal vessels as a consequence of the increase of pressure. Furthermore, the combination of pneumoperitoneum together with the anti-Trendelemburg position results in a more significant reduction of the lumen of the portal vein and the abdominal aorta.

Effects of laparoscopy, laparotomy, and respiratory phase on liver volume in a live porcine model for liver resection

“…Decreased portal [ 33 – 35 ] and hepatic [ 36 – 39 ] blood flow was reported in several studies, although some studies did not find significant change of portal flow [ 30 , 40 ]. The diameter of the portal vein and mean luminal area of the portal vein were also found decreased in other studies, which is consistent with a decrease of the portal vein flow with pneumoperitoneum [ 41 , 42 ]. The pressure of the pneumoperitoneum was also shown to decrease the diameter of the Inferior vena cava [ 43 – 46 ] and to cause a decrease of the blood flow in the vena cava [ 42 ].…”

“…One possible explanation is that the pressure created in the abdominal cavity lead to a decrease in hepatic perfusion which finally caused the consistent decrease in liver volume. A study by Moyano-Cuevas et al [ 41 ] described an increase of liver volume after insufflating the abdomen with 14 mmHg of CO 2 . This contradicts our findings; however, our results seem to be more in line with the cardiovascular and other abdominal changes occurring during pneumoperitoneum [ 46 ].…”

“…Organ size was comparable to humans but less than in most western adult human livers [ 58 ]. The porcine model is well established in studies regarding the evaluation of the effects of pneumoperitoneum and for liver volumetry [ 7 ], whereas specific effects of respiration, pneumoperitoneum and laparotomy on liver volume had not been studied in detail in this model [ 25 , 26 , 33 – 35 , 41 , 59 ]. The application of the results in this study must be evaluated critically before using them in a clinical environment.…”