How do neuromuscular blockade (NMB) and pre-stretching affect abdominal insufflation dynamics, and how can surgical safety and efficiency during minimally access surgery (MAS) improve by novel insufflation techniques and trocar design?
This dissertation presents a series of studies in a porcine model which investigated the effects of NMB and pre-stretching on abdominal insufflation dynamics. For data acquisition and to maintain stable physiological conditions throughout the experiments, specialized tools were developed. A new method, endoscopic oscillometry, was introduced to monitor abdominal compliance in real time. To this respect, a novel fan-based insufflator was developed and tested to determine its ability to perform endoscopic oscillometry and in maintaining stable abdominal pressures compared to conventional systems.
The study found that NMB had minimal impact on abdominal compliance, but pre-stretching using repeated insufflation significantly influenced intra-abdominal compliance and volume. The fan-based insufflator, more specifically a centrifugal fan, demonstrated superior pressure stability, eliminating the pressure peaks observed with conventional insufflators. Additionally, various trocar designs were evaluated, particularly focusing on their performance in preventing air leaks and surgical smoke during MAS. It was found that trocar design played a critical role in air leak performance, with implications for patient safety, particularly concerning surgical smoke evacuation during the COVID-19 pandemic. The research concluded that improved insufflation control, particularly using a fan-based system, could enhance surgical outcomes by providing more stable operating conditions and reducing risks associated with air leaks and surgical smoke. Moreover, the pressure stability enhances respiratory conditions, as the abdomen exerts less upward pressure on the diaphragm. These findings have potential implications in paediatric, bariatric, robotic, and thoracic surgeries, where precise control over abdominal pressure is crucial. Further research, particularly in clinical settings, is needed to validate these findings and adapt the technology for broader use in surgery.