Purpose
To provide a uniform grading system to assess and minimize the risk of surgical and post-surgical complications in non-human primates undergoing multiple abdominal surgeries.
Definitions
- Laparotomy:
- A surgical incision into the abdominal cavity.
- Laparoscopy:
- A type of laparotomy that involves small incisions and the aid of a camera.
- Resection:
- The surgical removal of part or all of a tissue, structure, or organ.
Background
Penetration of the abdominal cavity and collection of tissue can provide critical scientific information1. Abdominal survival surgery has been conducted successfully in healthy macaques2. However, abdominal surgery often results in the development of peritoneal adhesions. Up to 93% of people who have abdominal surgery develop post-surgical peritoneal adhesions3. Although typically asymptomatic in people, adhesions can lead to small intestinal obstruction in people, abdominal pain, or nausea4. These can be difficult signs to evaluate in non-human animals.
Although less invasive, laparoscopic procedures still carry a risk for adhesion formation after repeat surgical procedures5. When scientifically justified and approved by IACUC, serial laparoscopic abdominal surgeries may be performed in some animals. To assess and minimize the risk of surgical and post-surgical complications in individual non-human primates undergoing multiple abdominal surgeries, this policy outlines an adhesion grading system for serial abdominal surgeries in non-human primates.
Policy
Prior to performing abdominal surgery, every non-human primate must undergo a pre-surgical examination by a WaNPRC clinical veterinarian or trained technician with previous adhesion scores and surgeries reviewed. Only animals deemed clinically stable may proceed with surgery.
At the initiation (prior to surgical manipulation) of any repeat survival abdominal surgery in a non-human primate, the degree of peritoneal adhesions will be graded by the WaNPRC surgeon (or designee) according to a modified Zühlke’s grading system6 shown in the table below. The location of the adhesion should be noted along with the score. The surgeon will approach the surgery as normally performed and should not extensively handle abdominal contents in order to provide a score, but will provide a score based on what is noted during the standard surgical approach.
| Adhesion Size/Extent | |||
| <1 cm2 | 1-3 cm2 | >3 cm2 | |
| No adhesions – Score 0 | N/A | N/A | N/A |
| Filmy adhesions: easy to separate by blunt dissection; no vascularization. | 1 | 2 | 3 |
| Stronger adhesions: blunt dissection possible with effort; sharp dissection may be preferred (beginning of vascularization) |
2 | 4 | 6 |
| Strong adhesions: separation possible by sharp dissection only; clear vascularization |
3 | 6 | 9 |
| Very strong adhesions: separation possible by sharp dissection only (organ strongly attached with severe adhesions and damage of organs hardly preventable) |
4 | 8 | 12 |
Adhesion score must be recorded in the animal’s record. If multiple adhesions are noted, the score is the sum of all individual adhesion scores.
For adhesions not within the target area:
If score <7 and adhesions are not within the target area, surgery can proceed, and the animal can undergo future abdominal survival surgeries if approved in the associated IACUC protocol. If score 7-10 and adhesions are not within the target area, surgery can proceed, unless a very strong adhesion is noted in which case a WaNPRC veterinarian must be contacted. WaNPRC veterinary approval is needed for any future abdominal surgeries and collections. If score >10 and adhesions are not within the target area, a WaNPRC veterinarian must be consulted prior to proceeding. Additional future abdominal surgeries may not be possible.
For adhesions within the target area:
Score the spleen and the liver target organs separately.
If score <3, surgery can proceed. The animal can undergo future abdominal survival surgeries if approved in the associated IACUC protocol. If score 4-6, WaNPRC veterinary approval is needed prior to proceeding with sample collections. If score >6, a WaNPRC veterinarian must be consulted. No sample collections may be obtained from that organ.
At veterinary discretion, a clinical monitoring case may be opened for any score that prohibits further sampling. Adhesion removals must be done only under the direction of a WaNPRC veterinarian.
References
- Mohan M, Kaushal D, Aye P, et al. Focused examination of the intestinal lamina propria yields greater molecular insight into mechanisms underlying SIV induced immune dysfunction. PLoS ONE (2012) 7(4): e34561
- Edghill-Smith YY, Aldrich K, Zhao J et al. Effects of intestinal survival surgery on systemic and mucosal immune responses in SIV-infected rhesus macaques. J Med Primatol (2002) 31: 313-322
- Menzies D, Ellis H. Intestinal obstruction from adhesions – how big is the problem? Ann R Coll Surg Engl (1990) 72: 60-63
- Catena F, Di Saverio S, Coccolini F, et al. Adhesive small bowel adhesions obstruction: Evolutions in diagnosis, management and prevention. World J Gastrointest Surg (2016) 8(3):222-231
- Diamond MP, Freeman ML, Clinical implications of postsurgical adhesions. Human Reproduction Update (2001) 7(6): 567-5765.
- Zühlke HV, Lorenz EM, Straub EM et al, Pathophysiology and classification of adhesions. Langenbecks Arch Chir Suppl II Verh Dtsch Ges Chir (1990) 345: 1009–16
Approval/Review Dates
Originally Approved: 10/20/2016
Last Reviewed/Revised by the IACUC: 11/14/2024