4. Discussion
Umbilical vein marsupialization in omphalophlebitis cases is indicated
when extensive infection and hepatic involvement prevents complete
resection.1,5-9,13,14 Reported umbilical vein
marsupialization complications include ascending infection, herniation
in calves, marsupialization site cellulitis, incisional infection,
peritonitis, or abscess formation.8,14,15,17,20 Two
umbilical vein marsupialization techniques to encourage sustained
drainage of the umbilical vein have been
described.5,6,8,9 One-stage marsupialization employs a
second paramedian incision for umbilical vein translocation while the
two-stage marsupialization procedure incorporates the umbilical vein
into the celiotomy incision.8,9,13-19
Reported advantages of the one-stage technique include a reduced risk of
herniation and incisional infection.8,10,13,15,18However, herniation secondary to one stage marsupialization has been
described in calves, with rates up to 40%.14,20 A
previous study in 1995 reported no herniation in 2 foals treated with
one-stage umbilical vein marsupialization.8 To the
authors’ knowledge, this is the first to report herniation as a sequela
to umbilical vein marsupialization in foals using a one-stage paramedian
translocation technique.
Normally, the healed marsupialized vein atrophies and the body wall
defect subsequently closes.10 Marsupialization site
herniation is thought to be linked with abdominal wall fragility created
through vein translocation or the presence of umbilical
infection.6,13,20-23 This was demonstrated by a study
in 2004, where heifers with umbilical infections were 5.65 times more
likely to develop a hernia than those without an umbilical
infection.21 Umbilical remnant inflammation or
infection is presumed to weaken the body wall, therefore delaying
umbilical closure.6,21 A previous study of umbilical
herniation in 44 foals reported no association between an umbilical
infection contributing to the development of an umbilical
hernia.24. However, in that study, the two foals that
developed herniation suffered from minor umbilical infections that were
responsive to medical management with
antimicrobials.24 In cases of extensive umbilical
infection, as in the present study, the infection is less likely to
respond to medical management and would require surgical intervention
for appropriate treatment, therefore increasing the risk for secondary
herniation.3,6,7 The authors in this study propose
that continued umbilical vein drainage may contribute to protracted
marsupialization site closure, resulting in postoperative hernia
formation.
None of the cases above were treated with the two-stage technique per
surgeon preference and to reduce the necessity for a second surgical
procedure. The two-stage technique incorporates the umbilical vein in
the linea alba closure, where a small hernia develops that requires
closure during a later procedure.10,13 A reduced risk
of peritoneal contamination is reported with the two-stage technique,
but the risk of herniation, incisional infection and dehiscence
significantly increases.13,14,19 A previous study
demonstrated this by reporting a 60% secondary herniation rate when
umbilical vein marsupialization was incorporated into the incisional
closure in calves with omphalophlebitis.19 Although
the cases reported in the present study developed a hernia at the
marsupialization site, the risk is suspected to be low as other studies
have not reported hernia formation in foals from a single stage
marsupialization.8
Previous studies have emphasized the importance of thorough and
persistent postoperative management, including prolonged antimicrobial
therapy and lavage of the marsupialization site, in order to achieve
adequate involution of the infected umbilical
vein.8,19 Though there is no proven method to prevent
herniation of the marsupialization site, studies have suggested
intraoperative and postoperative management to reduce the
risk.14 Due to the possibility of the technique
attaching the vein to the body wall as a cause of increased herniation
rates, it has been proposed to perform three-layer fixation of the
umbilical vein, incorporating the external rectus sheath, subcutaneous
tissues and skin into closure.14 Additionally, an
abdominal bandage has been suggested postoperatively to support the
incision site.13,18 Future studies evaluating the
effect of the three-layer fixation technique and abdominal bandage
application on herniation of the marsupialization site would be
indicated to determine the impact on herniation rates.
This study demonstrates that herniation can occur post-operatively
following a one-stage umbilical vein marsupialization technique in foals
diagnosed with omphalophlebitis. Consequently, owners should be advised
that a herniorrhaphy may be required, although the risk is suspected to
be low.
Author Contributions: Klein C, DVM: Drafted, revised, and
approved the submitted version of the manuscript; Caston S, DVM,
DACVS-LA: Revised the manuscript drafts critically and approved the
submitted version of the manuscript; Troy JR, DVM, DACVS-LA: Revised the
manuscript drafts critically and approved the submitted version of the
manuscript.
Disclosure : The authors have no conflicts of interest to
declare related to this report.