Veterinary laparoscopy is being increasingly utilized for a variety of surgical procedures in small animals due to the established benefits of decreased surgical trauma, decreased postoperative pain, faster recovery times, and decreased infection rates. The feasibility and success of any laparoscopic procedure relies on establishing sufficient working space through pneumoperitoneum, typically by carbon dioxide (CO2) insufflation, to achieve safe visualization and enable the manipulation of instrumentation. Failure to achieve and maintain adequate working space may result in prolonged surgical times, surgical errors, and may even necessitate conversion to an open procedure. Particularly at higher intra-abdominal pressures (IAP), adverse effects on systemic cardiorespiratory and metabolic status associated with CO2 insufflation have been reported, such as vascular ischemic injury and hypoperfusion to intra-abdominal organs. Thus, an appropriate balance between IAP and working space is necessary to maintain an operative field while limiting negative sequelae associated with pneumoperitoneum. Several human and animal model studies have identified promising avenues that may assist with optimization of working space at lower IAPs. Of most promise is the use of abdominal wall prestretching. Pre-stretching involves transient insufflation of the abdomen at higher pressures to achieve stretching of the musculature and allow additional working space when subsequently desufflated to a lower IAP. Studies confirming the utility of these techniques in optimizing laparoscopic working space in veterinary patients are lacking. Both the optimal method for maximizing working space and the duration of action of the effect of this intervention remains to be established.

Our primary objective for this project is to determine whether transient pre-stretching of the canine abdominal wall in dogs undergoing laparoscopic procedures increases intra-abdominal volumes and working space at lower IAPs. Our secondary objective is to determine whether the working space at lower IAPs achieved by prestretching is equivalent to that achieved by the current standard of care (SOC) of insufflation at 10 mmHg. Our last objective is to determine the duration of effect of increased working space gained from pre-stretching and if the working space decreases over time. The overall goal of this project is to investigate the effects of prestretching on working space in laparoscopy. This study’s clinical impact will refine the methodology used in standard laparoscopy to increase laparoscopic procedure success while simultaneously minimizing patient morbidity and mortality.