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

Abstract

Background Hepatectomy, living donor liver transplantations and other major hepatic interventions rely on precise calculation of the total, remnant and graft liver volume. However, liver volume might differ between the pre- and intraoperative situation. To model liver volume changes and develop and validate such pre- and intraoperative assistance systems, exact information about the influence of lung ventilation and intraoperative surgical state on liver volume is essential. Methods This study assessed the effects of respiratory phase, pneumoperitoneum for laparoscopy, and laparotomy on liver volume in a live porcine model. Nine CT scans were conducted per pig (N = 10), each for all possible combinations of the three operative (native, pneumoperitoneum and laparotomy) and respiratory states (expiration, middle inspiration and deep inspiration). Manual segmentations of the liver were generated and converted to a mesh model, and the corresponding liver volumes were calculated. Results With pneumoperitoneum the liver volume decreased on average by 13.2% (112.7 ml ± 63.8 ml, p < 0.0001) and after laparotomy by 7.3% (62.0 ml ± 65.7 ml, p = 0.0001) compared to native state. From expiration to middle inspiration the liver volume increased on average by 4.1% (31.1 ml ± 55.8 ml, p = 0.166) and from expiration to deep inspiration by 7.2% (54.7 ml ± 51.8 ml, p = 0.007). Conclusions Considerable changes in liver volume change were caused by pneumoperitoneum, laparotomy and respiration. These findings provide knowledge for the refinement of available preoperative simulation and operation planning and help to adjust preoperative imaging parameters to best suit the intraoperative situation.

Morphologic Change of In Vivo Porcine Liver Under 13 mm Hg Pneumoperitoneum Pressure

“…In view of the difference between the results of this study and previous studies, we believe that the change in pig liver volume is still controversial under pneumoperitoneum pressure. Our research shows that the liver volume decreases under pneumoperitoneum pressure, consistent with a recent similar finding of Kenngott et al 14 The liver volume changes with the respiratory phase, which can be computed by 4D-CT in humans, Kenngott and colleagues reported that the porcine volume increased by 7.2% from expiration to deep inspiration. Surgical repositioning can give large deformation in the liver intraoperatively; when surgeons perform right hepatectomy, the patient is sometimes in the lateral (flank) position, while preoperative imaging is typically in the supine position; however, changes in liver volume changes are clear.…”

Generic surgical process model for minimally invasive liver treatment methods

“…Treatment area isolation-nondestructive (08b) Vessels isolation (1) This phase includes two categories of actions. In case of laparoscopic procedures (LLR and LLA), the surgeon can first isolate any relevant vessels (M01) and then occlude them temporarily (M02) in order to reduce bleeding during treatment of the target region (e.g.…”

“…To better expose this process, expert consensus meetings, national and international guidelines provide generalized recommendations on a high abstraction level based on the pillars of evidence-based medicine. In recent years, with the introduction of new technologies, tools and hybrid operating rooms (ORs), surgeries became increasingly convoluted 1 . Improving these highly complex surgical procedures is a shared concern of experts with different backgrounds.…”

“…Although the less invasive nature of MILT compared to open surgeries benefits the patient 16,17 , various challenges that can increase the risk of surgical errors remain, including inadequate visualization of the patient's internal structure, lack of tactile feedback and complex navigation towards target treatment lesions 18,19 . Moreover, the continuous change of the liver shape and location due to, e.g., pneumoperitoneum, patient respiration and manipulation of the liver during an intervention, add to these challenges 1 . Over the last three decades, a broad range of MILT techniques has been introduced.…”

Spectral organ fingerprints for machine learning-based intraoperative tissue classification with hyperspectral imaging in a porcine model

“…All animals used in the experimental laboratory were managed according to German laws for animal use and care, and according to the directives of the European Community Council (2010/63/EU) and ARRIVE guidelines 64 . Regular pigs (Sus scrofa domesticus) with a mean weight of 35 kg were chosen as model organism 4,[65][66][67][68] . Data from 46 pigs was included in the analyses.…”