Structural deteriorations of the human peritoneum during laparoscopic cholecystectomy. A transmission electron microscopic study

Underneath Images and Robots, Looking Deeper into the Pneumoperitoneum: A Narrative Review

Laparoscopy offers numerous advantages over open procedures, minimizing trauma, reducing pain, accelerating recovery, and shortening hospital stays. Despite other technical advancements, pneumoperitoneum insufflation has received little attention, barely evolving since its inception. We explore the impact of pneumoperitoneum on patient outcomes and advocate for a minimally invasive approach that prioritizes peritoneal homeostasis. The nonlinear relationship between intra-abdominal pressure (IAP) and intra-abdominal volume (IAV) is discussed, emphasizing IAP titration to balance physiological effects and surgical workspace. Maintaining IAP below 10 mmHg is generally recommended, but factors such as patient positioning and surgical complexity must be considered. The depth of neuromuscular blockade (NMB) is explored as another variable affecting laparoscopic conditions. While deep NMB appears favorable for surgical stillness, achieving a balance between IAP and NMB depth is crucial. Temperature and humidity management during pneumoperitoneum are crucial for patient safety and optical field quality. Despite the debate over the significance of temperature drop, humidification and the warming of insufflated gas offer benefits in peritoneal homeostasis and visual clarity. In conclusion, there is potential for a paradigm shift in pneumoperitoneum management, with dynamic IAP adjustments and careful control of insufflated gas temperature and humidity to preserve peritoneal homeostasis and improve patient outcomes in minimally invasive surgery.

The "Dark Side" of Pneumoperitoneum and Laparoscopy

Laparoscopic surgery has been one of the most common procedures for abdominal surgery at pediatric age during the last few decades as it has several advantages compared to laparotomy, such as shorter hospital stays, less pain, and better cosmetic results. However, it is associated with both local and systemic modifications. Recent evidence demonstrated that carbon dioxide pneumoperitoneum might be modulated in terms of pressure, duration, temperature, and humidity to mitigate and modulate these changes. The aim of this study is to review the current knowledge about animal and human models investigating pneumoperitoneum-related biological and histological impairment. In particular, pneumoperitoneum is associated with local and systemic inflammation, acidosis, oxidative stress, mesothelium lining abnormalities, and adhesion development. Animal studies reported that an increase in pressure and time and a decrease in humidity and temperature might enhance the rate of comorbidities. However, to date, few studies were conducted on humans; therefore, this research field should be further investigated to confirm in experimental models and humans how to improve laparoscopic procedures in the spirit of minimally invasive surgeries.

Modes of carbon dioxide delivery during laparoscopy generate distinct differences in peritoneal damage and hypoxia in a porcine model

BACKGROUND

Insufflation with CO₂ can employ continuous flow, recirculated gas and/or additional warming and humidification. The ability to compare these modes of delivery depends upon the assays employed and opportunities to minimize subject variation. The use of pigs to train colorectal surgeons provided an opportunity to compare three modes of CO₂ delivery under controlled circumstances.

METHODS

Sixteen pigs were subjected to rectal resection, insufflated with dry-cold CO₂ (DC-CO₂) (n = 5), recirculated CO₂ by an AirSeal device (n = 5) and humidification and warming (HW-CO2) by a HumiGard device (n = 6). Peritoneal biopsies were harvested from the same region of the peritoneum for fixation for immunohistochemistry for hypoxia-inducible factor 1 alpha (HIF-1α) and scanning electron microscopy (SEM) to evaluate hypoxia induction or tissue/cellular damage, respectively.

RESULTS

DC-CO₂ insufflation by both modes leads to significant damage to mesothelial cells as measured by cellular bulging and retraction as well as microvillus shortening compared with HW-CO₂ at 1 to 1.5 h. DC-CO₂ also leads to a rapid and significant induction of HIF-1α compared with HW-CO₂.

CONCLUSIONS

DC-CO₂ insufflation induces substantive cellular damage and hypoxia responses within the first hour of application. The use of HW-CO₂ insufflation ameliorates these processes for the first one to one and half hours in a large mammal used to replicate surgery in humans.

Does thermodynamic stability of peritoneal collagen change during laparoscopic cholecystectomies? A differential scanning calorimetry (DSC) study

Background

Carbon dioxide pneumoperitoneum used during laparoscopic surgeries alters the integrity of the peritoneum and results in denudation of the basal lamina that might cause altered immune response, inhibited fibrinolysis, hypoxia, and acidosis. The changes in the structure of pneumoperitoneum were described as bulging of mesothelial cells, irregular cell junction’s cell membrane degradation, and mesodermal edema. As denaturation of peritoneal proteins reflects overall condition of its structure and interactions with the surrounding molecules, the physical status of collagen was assessed on the basis of parameters of thermal denaturation measured by DSC method.

Methods

Twenty-four female patients operated on due to cholelithiasis were enrolled in this study. Laparoscopic cholecystectomy was performed using standard four-trocar technique, and standard values of insufflated carbon dioxide pneumoperitoneum were used. After trocar placement, the first collection of peritoneal sample (sample A) was performed. The second peritoneal sample (sample B) was collected after the removal of gall bladder. Differential scanning calorimetry (Q200 calorimeter, TA Instruments) was performed on samples defrosted at room temperature.

Results

In all samples of peritoneum, a nonreversible endothermal process recognized as denaturation was observed. Sample B obtained at the end of surgery did not differ from sample A obtained at the beginning in terms of all parameters under study. Temperature of denaturation in A and B was correlated only marginally, but enthalpy and specific heat were significantly correlated. The analysis of data from DSC measurements did not reveal differences in physical stability of collagen in peritoneal samples obtained at the beginning and at the end of surgery. Significant negative correlations between duration of CO₂ pneumoperitoneum and enthalpy of denaturation in sample B were found.

Conclusions

Differences in enthalpy of denaturation may reflect a quantitative relation between amount of native collagen molecules in the sample and other, non-collagenous components or impaired collagen.

Effect of pneumoperitoneum pressure on hemodynamic parameters in patients undergoing laparoscopic gallbladder excision

AIM: To explore the relationship between the pressure of pneumoperitoneum and hemodynamic changes in patients undergoing laparoscopic gallbladder excision.

METHODS: Ninety-six patients who would undergo ASA class II line elective laparoscopic cholecystectomy were randomly and equally divided into two groups: I and II. The pneumoperitoneum pressure was set at 1.45 to 1.74 kPa in group I and at 1.05 to 1.23 kPa in group II. MAP, HR, CO, CI and SVR were recorded before pneumoperitoneum (T0), 5 (T1) and 25 min (T2) after pneumoperitoneum, and 10 min after deflation (T3). Meanwhile, blood platelet count (PLT), hematocrit (Hct), plasma concentrations of fibrinogen (Fib) and D-dimer were recorded preoperatively, immediately and three days after the operation respectively.

RESULTS: MAP, HR, CO, CI, SVR at T1 and T2 in both groups were significantly higher than that before the operation. The above five parameters were significantly lower in the high pressure group than in the low pressure group at T1 (112.2 mmHg ± 23.87 mmHg vs 89.7 mmHg ± 18.46 mmHg, 102.6 ± 18.53 mmHg vs 89.9 ± 9.77 mmHg; 105.6 time/min ± 15.07 time/minvs 77.4 time/min ± 15.41 time/min, 100.4 time/min ± 11.41 time/min vs 71.6 time/min ± 10.4 time/min; 7.5 L/min ± 1.76 L/min vs 4.1 L/min ± 1.25 L/min, 6.3 L/min ± 1.26 L/min vs 4.1 L/min ± 1.52 L/min; 4.5 (L•min)/m² ± 0.85 (L•min)/m²vs 3.1 (L•min)/m² ± 0.53 (L•min)/m², 4 (L•min)/m² ± 0.68 (L•min)/m²vs 3.2 (L•min)/m² ± 0.8 (L•min)/m²; 1422.6 (dyn•s)/cm^-5 ± 226.3 (dyn•s)/cm^-5vs 1204 (dyn•s)/cm^-5 ± 131.91 (dyn•s)/cm^-5, 1434 (dyn•s)/cm^-5 ± 296.17 (dyn•s)/cm^-5vs 1204.3 (dyn•s)/cm^-5 ± 153.5 (dyn•s)/cm^-5, all P < 0.05), but showed no significant differences between the two groups at T0 and T3. Postoperative PLT, Hct, plasma levels of Fib and D-dimers were significantly higher than preoperative values, and the increase in these four parameters was more significant in the high pressure group than in the low pressure group.

CONCLUSION: Appropriate pneumoperitoneum conditions can help maintain hemodynamic stability and improve the safety of laparoscopic surgery.