33rd Annual Scientific Meeting proceedings

Because of the size and weight of equine viscera, secure closure of the surgical wound is imperative. Furthermore, the closure should minimize incisional complications such as suture dehiscence, wound secretion/infection and abdominal hernia formation. Reported incisional complication rates vary from 3.9 % to 62 %. There is conflicting evidence that the number of layers in the celiotomy closure could influence linea alba incision healing and surgical incisional complications.

The Anglo-Saxon world merely supports the opinion that the closure of the peritoneum is not mandatory. The latest edition of the standard textbook “The Equine Acute Abdomen” (1) still reports the idea that the suture of the peritoneum may lead to enhanced rates of intra-abdominal adhesions. This derives from an experimental study (2) dating from 1973 which investigated the effect of suturing the peritoneum. A closer look at the original paper reveals that there was no significant difference between the groups concerning frequency of adhesion formation at the level of the median laparotomy wound, and that the suture had been performed using non-absorbable suture (Mersilene No. 2). The conclusion drawn from that study (2), namely that the suture of the peritoneum is harmful, should be revised. There is one study investigating the influence of the suture of the peritoneum on the development of incisional complications, demonstrating the beneficial influence of the suture of the peritoneum. The incisional complication rate was 3.9 % in horses having had suture of the peritoneum, while horses not having had suture of the peritoneum exhibited a significantly higher proportion (24 %) of patients developing incisional complications (3).

Closure of the linea alba with a simple continuous pattern is common because it is convenient, fast and has superior bursting strength compared to an interrupted cruciate pattern measured in a cadaver study (4). However, two retrospective studies have effectively used interrupted pattern in the linea alba with incisional complication rates of 4.29 % (5) and 9.52 % (6). In another cadaver study comparing suture materials, polydioxanone No. 7 had a higher bursting strength than polyglactin 910 No. 2 (7). In a retrospective study, the occurrence of incisional complications after closure with polydioxanone No. 7 was 25.3 % (8).

Closure of the subcutaneous tissue was reported in two study to decrease the risk of incisional complications (9, 10). In contrast to this finding, Coomer et al. (11) could not identify significant differences between techniques including or excluding the subcutaneous layer. These authors therefore, recommend a two layer suture technique, including sutures of the linea alba and skin only to close a laparotomy wound. However, the overall wound healing complication frequency of 21.4 % in this study was quite high. A modified subcuticular pattern that incorporates both the skin and subcutaneous tissue into one layer was reported to decrease the risk of incisional complications compared to closing three separate layers (12). In a prospective randomized study, antibacterial-coated suture material for subcutaneous closure did not decrease the likelihood of incisional complications (13).

Closure of the skin can be performed using absorbable or non-absorbable suture materials or skin staples. The use of skin staples was associated with enhanced risk of developing wound infection (14). Subcuticular absorbable staples were used with superior wound scores compared to conventional skin staples. In this prospective randomized study no surgical site infections were identified (15). However, subcuticular absorbable staples had the lowest ultimate failure load compare with metallic staples, nylon and polyglyconate suture (16). In a retrospective study, the occurrence of incisional complications did not differ between skin closure with n-butyl cyanoacrylate (15.9 %) or skin staples (19.1 %) (17). A prospective randomized study compared skin closures using a simple continuous versus an intradermal pattern. The overall prevalence of incisional complications was 9.5 % without statistically significant differences between both groups, but none of the animals in the intradermal suture pattern group developed incisional complications (18). Another prospective randomized study compared the zip skin closure system with conventional suture for skin closure in 8 horses. At 14 days postoperatively, the cosmetic appearance using the zip skin closure system was better than using sutured closure. Major incisional complications were found in 2 horses in the conventional suture group and none in the zip skin closure system group (19).  

We recommend four layer closure: peritoneum, linea alba and subcutaneous tissue in a simple continuous pattern, and skin in an intradermal pattern.       

References

1. Freeman DE. Abdominal closure. In: The Equine Acute Abdomen, 2nd edn. White NA, Moore JN, Mair TS, eds. Jackson, Wyoming: Teton NewMedia 2008; 540–550.
2. Swanwick RA, Milne FJ. The non-suturing of parietal peritoneum in abdominal surgery of the horse. Vet Rec 1973;22:328–335.
3. Scharner D, Winter K, Brehm W, Kämpfert M, Gittel C. Incisional complications following ventral median coeliotomy in horses. Does suturing of the peritoneum reduce the risk? Tierärztliche Praxis: Ausgabe G, Großtiere/Nutztiere 2016;45(1):24-32.
4. Magee AA, Galuppo LD. Comparison of incisional bursting strength of simple continuous and inverted cruciate suture patterns in the equine linea alba. Vet Surg 1999; 28:442–447.
5. Rinnovati R, Romagnoli N, Stancampiano L, Spadari A. Occurrence of incisional complications after closure of equine ventral midline celiotomies with 2 polyglycolic acid in simple interrupted suture pattern. J Equine Vet Sci 2016;47:80-84.
6. Salciccia A, De Pouyade G, Gougnard A, Detilleux J, Caudron I, Verwilghen D, Serteyn D, Grulke S. Complications associated with closure of the linea alba using a combination of interrupted vertical mattress and simple interrupted sutures in equine laparotomies. Vet Rec 2020 Nov28;187(11):e94 doi: 10.1136/vr.105855
7. Anderson SL, Bracamonte JL, Hendrick S, Carmalt JL, Wilson DG. Ex vivo comparison of 7 polydioxanone, 2 polyglactin 910 for closure of ventral median celiotomy in horses. Vet Surg 2013; 42: 463–467.
8. Anderson SL, Bracamonte JL, Hendrick S, Barber SM, Carmalt JL, Wilson DG. Occurrence of incisional complications after closure of equine celiotomies with USP 7 polydioxanone. Vet Surg 2015;44:521–526.
9. Smith LJ, Mellor DJ, Marr CM, SW, Mair TS. Incisional complications following exploratory celiotomy: does an abdominal bandage reduce the risk? Equine Vet J 2007;39:277–283.
10. Isgren CM, Salem SE, Archer DC, Worsman FCF, Townsend NB. Risk factors for surgical site infection following laparotomy: Effect of season and perioperative variables and reporting of bacterial isolates in 287 horses. Equine Vet J 2017;49:39-44.
11. Coomer RPC, Mair TS, Edwards GB, Proudman CJ. Do subcutaneous sutures increase risk of laparotomy wound suppuration? Equine Vet J 2007;39:396–399.
12. Colbath AC, Patipa L, Berghaus, RD, Parks AH. The influence of suture pattern on the incidence of incisional drainage following exploratora laparotomy. Equine Vet J 2014; 46:156–160.
13. Bischofberger AS, Brauer T, Gugelchuk G, Klohnen A. Difference in incisional complications following exploratory celiotomies using antibacterial-coated suture material for subcutaneous closure: Prospective randomized study in 100 horses. Equine Vet J 2010;42:304–309.
14. Torfs S, Levet T, Delesalle C, Dewulf J, Vlaminck L, Pille F, Lefere L, Martens A. Risk factors for incisional complications after exploratory celiotomy in horses: Do skin staples increase the risk? Vet Surg 2010;39:616–620.
15. Biedrzycki AH, Brounts. Case series evaluating the use of absorbable staples compared with metallic staples in equine ventral midline incision. Equine vet Educ 2016;28:83-88
16. Biedrzycki AH, Markel MD, Brounts SH. Biomechanical evaluation of a novel subcuticular skin stapling device for use in equine abdominal surgeries. Vet Surg 2015;44:231-235
17. Martinez-Lopez J, Brown JA, Werre SR. Incisional complications after skin closure with n-butyl cyanoacrylate or stainless-stell skin staples in horses undergoing colic surgery. Vet Surg 2021;50:186-195
18. Scharner D, Gittel C, Winter K, Blaue D, Schedelbauer C, Vervuert I, Brehm W. Comparison of incisional complications between skin closures using a simple continuous or intradermal pattern: a pilot study in horses undergoing ventral median celiotomy. Peer J DOI 10.7717/peerj.5772
19. Klein CE, Engiles JB, Roessner HA, Hopster K, Hurcombe SD. Comparison of the zip skin closure system with conventional suture for skin closure of ventral midline incision in horses. AJVR 2022:84:455-465