Impact of pneumoperitoneum on intra-abdominal microcirculation blood flow: an experimental randomized controlled study of two insufflator models during transanal total mesorectal excision
To compare changes in microcirculation blood flow (MCBF) between pulsatile and continuous flow insufflation.
Summary background data
Transanal total mesorectal excision (TaTME) was developed to improve the quality of the resection in rectal cancer surgery. The AirSeal IFS® insufflator facilitates the pelvic dissection, although evidence on the effects that continuous flow insufflation has on MCBF is scarce.
Thirty-two pigs were randomly assigned to undergo a two-team TaTME procedure with continuous (n = 16) or pulsatile insufflation (n = 16). Each group was stratified according to two different pressure levels in both the abdominal and the transanal fields, 10 mmHg or 14 mmHg. A generalized estimating equations (GEE) model was used.
At an intra-abdominal pressure (IAP) of 10 mmHg, continuous insufflation was associated with a significantly lower MCBF reduction in colon mucosa [13% (IQR 11;14) vs. 21% (IQR 17;24) at 60 min], colon serosa [14% (IQR 9.2;18) vs. 25% (IQR 22;30) at 60 min], jejunal mucosa [13% (IQR 11;14) vs. 20% (IQR 20;22) at 60 min], renal cortex [18% (IQR 15;20) vs. 26% (IQR 26;29) at 60 min], and renal medulla [15% (IQR 11;20) vs. 20% (IQR 19;21) at 90 min]. At an IAP of 14 mmHg, MCBF in colon mucosa decreased 23% (IQR 14;27) in the continuous group and 28% (IQR 26;31) in the pulsatile group (p = 0.034).
TaTME using continuous flow insufflation was associated with a lower MCBF reduction in colon mucosa and serosa, jejunal mucosa, renal cortex, and renal medulla compared to pulsatile insufflation.
KeywordsTransanal total mesorectal excision Randomized controlled trial Continuous insufflation Colored microspheres
The authors acknowledge Conmed Corporation for the partial support of the trial with unrestricted funds, as well as Ms. Anna Escalante, Ms. Elena Ramentol and Dr. Jacqueline van Laarhoven for their collaboration to the achievement of this work.
Conception and design: FBL, PT, RD, AML. Administrative support: none. Provision of study material or patients: FBL, PT, RD, AML. Collection and assembly of data: FBL, PT, MCA, JST, RB, AI, RP. Data analysis and interpretation: FBL, PT, JR, AML. Manuscript writing (including critical revising): all authors. Manuscript final approval: all authors.
This trial was partially supported by unrestricted funds from Conmed Corporation, which was used for the purchase of the colored microspheres, the PICCO catheter, several anesthetic fungible material and drugs, the process of the samples and to cover the costs of the animals and incineration. Moreover, it was also used for part-time employment of the person in charge of the tissue blood flow and endothelium-derived mediators’ analysis (Anna Escalante). The design of the study, the statistical analyses and the writing of the manuscript were performed independently of these funds.
Compliance with ethical standards
Conflict of interest
Apart from the funding previously mentioned, Dr. AM Lacy is a consultant for Medtronic, Conmed Corporation, Olympus Medical, Touchstone International Medical Science Co. Ltd., Applied Medical, and Johnson & Johnson. Dr. de Lacy, Dr. Taurà, Dr. Arroyave, Dr. Trépanier, Mr. Ríos, Dr. Bravo, Dr. Ibarzabal, Dr. Pena and Dr. Deulofeu have no other conflicts of interest or financial ties to disclose.
The Institutional Review Board of the Hospital Clinic approved this trial for the Care and Use of Laboratory Animals. The University of Barcelona Committee on Ethics in Animal Experimentation and the Catalan Department of the Environment Commission on Animal Experimentation granted ethical approval for the study (Reg. 0006S/11367/2015).