Summary
The closed inguinal approach in equine castration is a technique in which optimal surgical standards can be maintained. The inflammatory response to this method of castration was quantified by Serum Amyloid A (SAA) measurements to be 94 mg/l. on day three after surgery. The SAA value after field castrations, using a scrotal approach, was reported in literature by several authors to be between 480 - 708 mg/l on day three post-operatively (p.o.). The difference in SAA levels between these different approaches proved to be highly significant, quantifying a highly significant lower inflammatory response of the closed inguinal technique over regular field castrations using a scrotal approach.
Introduction
Castration of the male horse is the most frequent routine equine surgical procedure, traditionally performed in practice, referred to as field castrations. Reported complication rates for field castrations range from 10% to 48% (Moll et al.1995, May and Moll 2002, Mezerova et al. 2004, Mason et al. 2005, Kilcoyne et al. 2013a). The wide spread in reported complication rates may depend on variable field and stall conditions, differences in surgical experience and in applicable equipment and medication, differences in p.o. care and patient observation and differences in definition and recognition of complications. The majority of these complications, however, result from contamination (i.e. acute and chronic infections) and/or insufficient ligation (i.e. p.o. haemorrhage and eventrations). The contamination risk in field castrations requires intra- and p.o. antimicrobial treatment, and inflammatory responses are usually anticipated by anti-inflammatory medication. Castrations performed under acceptable surgical conditions show significant less complications than castrations performed under variable sub optimal field conditions (Mason, 2005). Castrations in this study were performed under optimal surgical conditions using a closed inguinal approach. The complication rate using this technique has been reported previously (Riemersma, 2005) to be 2% (11 out of 554 cases), without the routine use of antimicrobial or anti-inflammatory medication. The complication rate may be indicative for the quality of the surgical procedure, but the wide range of complications reported in literature makes this parameter less suitable for quantification of the quality of a surgical procedure, which is determined by its intended outcome and its p.o. inflammatory response caused either by trauma or by infection.
SAA proved to be the most sensitive acute phase reactant associated with inflammation after field castrations using a scrotal approach in either standing (Jacobsen et al.2005, Busk et al.2010), or recumbent horses (Haucke et al.2017, Bergstrom et al. 2021). Each of these authors compared 2 groups of horses: horses with or without post- operative fever (Jacobsen et al.2005), horses with or without peri-operative administration of Penicillin (Busk et al.2010), horses receiving a single dose of penicillin or a triple dose on three consecutive days (Haucke et al.2007) and horses receiving either Ceftiofur or Procaine penicillin intra-operatively (Bergstrom et al. 2021). Infection may not always be clinically evident until the fourth day after castration (Kilcoyne 2013b) and it has accordingly been stated by Jacobsen et al. (2005) and Haucke et al. (2007) that the SAA levels up to the first three days after surgery would rather be indicative for surgical trauma, unlike SAA levels recorded several days up to several weeks postoperatively which would be related to infection. Average SAA levels recorded at day three after field castration, have been reported to be 480-570 mg/l (Jacobsen et al. 2005), 543-708 mg/l (Busk et al. 2011), 698 mg/l (Haucke et al. 2017) and 570-608 mg/l (Bergstrom et al. 2021). These SAA levels, although recorded after different studies in different countries and even different continents, show remarkable resemblance in magnitude.
Hypothesis.
It is hypothesized that the third day p.o. value of the inflammatory marker SAA using a closed inguinal approach will be significantly lower than the values which have been presented in literature recorded at day three after field castrations.
Materials and Methods.