Comparison of median sternotomy closure‐related complication rates using orthopedic wire or suture in dogs: A multi‐institutional observational treatment effect analysis

Abstract

Objective To determine and compare median sternotomy (MS) closure‐related complication rates using orthopedic wire or suture in dogs. Study design Multi‐institutional, retrospective observational study with treatment effect analysis. Animals 331 client‐owned dogs, of which 68 were excluded. Methods Medical records of dogs with MS were examined across nine referral centers (2004–2020). Signalment, weight, clinical presentation, surgical details, complications, and outcomes were recorded. Follow‐up was performed using patient records and email/telephone contact. Descriptive statistics, treatment effect analysis and logistic regression were performed. Results Median sternotomy closure was performed with wire in 115 dogs and suture in 148. Thirty‐seven dogs experienced closure‐related complications (14.1%), 20 in the wire group and 17 in the suture group. Twenty‐three were listed as mild, four as moderate and 10 as severe. Treatment effect analysis showed a mean of 2.3% reduction in closure‐related complications associated with using suture versus wire (95% CI: −9.1% to +4.5%). In multivariable logistic regression, the only factor associated with increased risk of closure‐related complications was dog size (p = .01). This effect was not modified by the type of closure used (interaction term: OR = 0.99 [95% CI: 0.96/1.01]). Conclusion The incidence of closure‐related complication after MS was low compared to previous reports. The likelihood of developing a closure‐related complication was equivalent between sutures and wires, independent of dog size, despite a higher proportion of complications seen in larger dogs (≥20 kg). Clinical significance Use of either orthopedic wire or suture appear to be an appropriate closure method for sternotomy in dogs of any size.

Closure-related complications after median sternotomy in cats: 26 cases (2010–2020)

“…11 In that study the incidence of postoperative complications was lower than previously reported (14%) and was not associated with the method of closure, irrespective of body weight. 11 However, to our knowledge, there is a paucity of literature related to MS in cats, particularly pertaining to sternal closure complications. Some studies suggest that small dogs and cats may be less susceptible to complications arising from sternotomy closure, 12,13 and body weight has been correlated with increased risk of sternotomy closure-related complications in dogs.…”

“…This is lower than the 8% rate of mild complications reported in dogs. 11 No seroma, wound dehiscence or wound effusion occurred in the cats included in our study, which were responsible for the largest portion of complications (n = 23/37; 62%) noted in dogs in one large retrospective study of MS. 11…”

“…Some studies suggest that small dogs and cats may be less susceptible to complications arising from sternotomy closure, 12,13 and body weight has been correlated with increased risk of sternotomy closure-related complications in dogs. 11…”

What is the value of statistical testing of observational data?

“…As an example, a comparison of the incidence of wound breakdown following suture or wire closure of sternotomy incisions in dogs was able to conclude that there was likely little difference in probability of failure between methods. 12 However, the 95% confidence intervals on the estimate indicated that the data were compatible with the possibility that there might be as much as a 10% lower rate of complications associated with sutures. This result is clearly important information for a clinician: either method of closure is an appropriate choice but if there is any uncertainty it is probably best to choose suture.…”

“…Notably, the results focus on effect sizes, rather than whether a treatment is “significantly different” from another. As an example, a comparison of the incidence of wound breakdown following suture or wire closure of sternotomy incisions in dogs was able to conclude that there was likely little difference in probability of failure between methods 12 . However, the 95% confidence intervals on the estimate indicated that the data were compatible with the possibility that there might be as much as a 10% lower rate of complications associated with sutures.…”