Optimizing working space in laparoscopy: CT measurement of the effect of pre-stretching of the abdominal wall in a porcine model

• Published in: Surgical endoscopy Vol. 28; no. 3; pp. 841 - 846
• Main Authors: Vlot, John, Wijnen, René, Stolker, Robert Jan, Bax, Klaas (N)
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01-03-2014; Springer Nature B.V
• Subjects: Abdomen; Abdominal Cavity - diagnostic imaging; Abdominal Cavity - physiopathology; Abdominal Surgery; Abdominal Wall - physiopathology; Abdominal Wall - surgery; Animals; Biometry - methods; Carbon Dioxide - administration & dosage; Compliance; Disease Models, Animal; Experiments; Female; Gastroenterology; Gynecology; Hepatology; Insufflation - methods; Laparoscopy; Laparoscopy - methods; Medicine; Medicine & Public Health; Organ Size; Pneumoperitoneum, Artificial - methods; Pressure; Proctology; Reproducibility of Results; Serendipity; Surgery; Swine; Tomography; Tomography, X-Ray Computed - methods; Germany; Animal model; Laparoscopy; Pre-stretching; CO; Pneumoperitoneum; Working space
• ISSN: 0930-2794; 1432-2218
• DOI: 10.1007/s00464-013-3229-4

Background
Determinants of working space in minimal access surgery have not been well studied. Using computed tomography (CT) to measure volumes and linear dimensions, we are studying the effect of a number of determinants of CO
2
working space in a porcine laparoscopy model. Here we report the effects of pre-stretching of the abdominal wall.
Methods
Earlier we had noted an increase in CO
2
pneumoperitoneum volume at repeat insufflation with an intra-abdominal pressure (IAP) of 5 mmHg after previous stepwise insufflation up to an IAP of 15 mmHg. We reviewed the data of this serendipity group; data of 16 pigs were available. In a new group of eight pigs, we also explored this effect at repeat IAPs of 10 and 15 mmHg. Volumes and linear dimensions of the CO
2
pneumoperitoneum were measured on reconstructed CT images and compared between the initial and repeat insufflation runs.
Results
Previous stepwise insufflation of the abdomen with CO
2
up to 15 mmHg significantly (
p
 < 0.01) increased subsequent working-space volume at a repeat IAP of 5 mmHg by 21 %, 7 % at a repeat IAP of 10 mmHg and 3 % at a repeat IAP of 15 mmHg. The external anteroposterior diameter significantly (
p
 < 0.01) increased by 0.5 cm (14 %) at repeat 5 mmHg. Other linear dimensions showed a much smaller change. There was no statistically significant correlation between the duration of the insufflation run and the volume increase after pre-stretching at all IAP levels.
Conclusions
Pre-stretching of the abdominal wall allows for the same surgical-field exposure at lower IAPs, reducing the negative effects of prolonged high-pressure CO
2
pneumoperitoneum on the cardiorespiratory system and microcirculation. Pre-stretching has important scientific consequences in studies addressing ways of increasing working space in that its effect may confound the possible effects of other interventions aimed at increasing working space.