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.