Chronically increased intra-abdominal pressure: validating a model.
BACKGROUND
Pregnancy is the only physiologic condition in which we encounter chronically elevated intra-abdominal pressure (IAP), while pathologically several pathologies, such as ascites and morbid obesity, are affected by this phenomenon. This paper introduces and validates a new model that is able to create and maintain chronically increased IAP, facilitating the study of phenomena related to chronically elevated IAP, i.e., obesity.


METHODS
An experimental device was implanted in 15 rabbits, which consisted of an intra-abdominal balloon (IAB), an external control valve, and a connecting tube. A Foley catheter was inserted in their urinary bladders. IAPs were measured simultaneously transvesically and via the device. During the acute phase, IAB was gradually inflated to 16 cmH(2)O, and IAPs were consecutively measured. During the chronic phase, residual IAPs were measured in a weekly rate for 8 weeks. Statistical significances, mean bias, and precisions were calculated.


RESULTS
During the acute phase, the saline in the IAB efficiently increases IAP to 16 cmH(2)O. IAPs measured both through the urinary bladder and the device correlate well with small bias and high precision. Our model maintains sufficiently chronically increased IAP for at least 8 weeks. No mortality was observed.


CONCLUSIONS
A rabbit model establishing and maintaining chronically increased IAP was successfully created and proved to be simple, effective, and repeatable. This model established chronically increased IAP permitting this way the study of its effect on organs and systems.
Papavramidis
Theodossis S
TS
3rd Department of Surgery, AHEPA University Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece. papavramidis@hotmail.com
Lazou
Thomai P
TP
Cheva
Angeliki
A
Gamvros
Orestis J
OJ
D000005:Abdomen / Q000502:physiology*; D000818:Animals; D008297:Male; D008991:Monitoring, Physiologic / Q000295:instrumentation* / Q000379:methods; D009765:Obesity / Q000150:complications* / Q000503:physiopathology; D011312:Pressure; D011817:Rabbits; D015203:Reproducibility of Results; D001743:Urinary Bladder / Q000502:physiology*; D014546:Urinary Catheterization
Dig Dis Sci. 1991 Oct;36(10):1473-80
1914772
Dis Manag. 2007 Oct;10(5):252-65
17961078
Arch Surg. 1999 Oct;134(10):1082-5
10522851
Mt Sinai J Med. 1995 Jan;62(1):62-9
7739589
J Clin Endocrinol Metab. 2004 Jun;89(6):2522-5
15181019
Obes Surg. 2004 May;14(5):589-600
15186624
Obes Surg. 2005 Oct;15(9):1225-32
16259876
Life Sci. 2006 Feb 28;78(14):1637-45
16313924
Br J Surg. 1995 Feb;82(2):235-8
7749700
Liver Int. 2007 Feb;27(1):54-60
17241381
J Intern Med. 1997 Jan;241(1):71-9
9042096
J Clin Endocrinol Metab. 2002 May;87(5):2084-9
11994345
Proc Natl Acad Sci U S A. 2003 Jun 10;100(12):7265-70
12756299
Mol Med. 1997 Jan;3(1):37-48
9132278
Int Braz J Urol. 2003 Jan-Feb;29(1):62-7
15745471
Indian J Gastroenterol. 1999 Apr-Jun;18(2):63-5
10319534
Acta Med Croatica. 2002;56(3):119-24
12630343
Am J Roentgenol Radium Ther Nucl Med. 1965 Apr;93:935-9
14268342
Int Urogynecol J Pelvic Floor Dysfunct. 1997;8(6):323-6
9609328
ASAIO Trans. 1990 Apr-Jun;36(2):95-103
2340214
Am Surg. 2009 Jun;75(6):504-8; discussion 508-9
19545099
Science. 1993 Jan 1;259(5091):87-91
7678183
Clin Infect Dis. 1993 Feb;16(2):219-22
8443300
Hernia. 2006 Jun;10(3):213-7
16261394
BMC Gastroenterol. 2009 Jun 06;9:42
19500396
Obstet Gynecol. 2004 Nov;104(5 Pt 2):1180-2
15516444
Surg Clin North Am. 2001 Oct;81(5):1063-75, vi
11589245
J Clin Endocrinol Metab. 1998 Mar;83(3):847-50
9506738
J Pediatr Surg. 2008 Sep;43(9):1711-7
18779012
Surg Obes Relat Dis. 2009 Sep-Oct;5(5):524-8
19560978
Toxicol Sci. 2006 Sep;93(1):205-12
16740615