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.