Treatment of congenital extrahepatic portosystemic shunts in dogs: A systematic review and meta-analysis

Abstract

Background: Several options have been proposed for the treatment of congenital extrahepatic portosystemic shunts (cEHPSS) in dogs, but formal comparisons among different treatment options are currently unavailable. A previous evidence-based review (2012) found low quality of evidence for papers assessing the treatment of cEHPSS in dogs.

Objectives: To assess the quality of evidence available in the treatment of cEHPSS, summarize the current state of knowledge with respect to outcome after cEHPSS management, and compare different treatment techniques.

Animals: Not used.

Methods: A bibliographic search was performed without date or language restrictions. Studies were assessed for quality of evidence (study design, study group sizes, subject enrollment quality, and overall risk of bias) and outcome measures reported (perioperative outcome, clinical outcome, and surgical or interventional outcome), all reported with 95% confidence intervals. A network meta-analysis was performed.

Results: Forty-eight studies were included. Six retrospective studies (grade 4b) compared 2 techniques and 7 were abstracts (grade 5). The quality of evidence was low and risk of bias high. Regarding surgical outcome, statistically significant superiority of ameroid constrictor over thin film band was observed (P = .003). No other comparisons were statistically significant.

Conclusions and clinical importance: The evidence base of choice of treatment of cEHPSS in dogs remains weak despite recent publications on the subject. Ameroid is superior to thin film band in causing EHPSS closure. Blinded randomized studies comparing different treatment modalities, which routinely include postoperative imaging to assess cEHPSS closure and acquired portosystemic shunt development are essential.

Keywords: liver; meta-analysis; portosystemic shunt; systematic review; treatment.

Figure 1

Flow diagram for inclusion of studies in the combined systematic review and meta‐analysis. Source: Moher D, Liberati A, Tetzlaff J, Altman DG, The PRISMA Group. Preferred reporting items for systematic reviews and meta‐analyses: the PRISMA statement. PLoS Med. 2009;6(7):e1000097. https://doi.org/10.1371/journal.pmed1000097

Figure 2

A, Network graph of the perioperative outcome; B, perioperative outcome with ligation divided in complete and partial ligation; and C, clinical outcome with ligation divided in complete and partial ligation. The nodes in the graph represent the different treatments. The line between treatment shows that there is at least 1 study comparing these 2 treatments. The thickness of the line is proportional to the inverse SE of the direct treatment comparison

Figure 3

Forest plot comparing perioperative outcome of ligation and thin film band in regard to ameroid constrictor. No statistically significant differences were noted. CI, confidence interval; OR, odds ratio

Figure 4

Forest plot comparing perioperative outcome of complete ligation, partial ligation and thin film band in regard to ameroid constrictor. No statistically significant differences were noted. CI, confidence interval; OR, Odds ratio

Figure 5

Forest plot comparing clinical outcome of complete ligation, partial ligation and thin film band in regard to ameroid constrictor. No statistically significant differences were noted. CI, confidence interval; OR, Odds ratio

Figure 6

Forest plot comparing clinical outcome in ameroid constrictor versus ligation. Odds ratio (95% confidence interval [CI]) of clinical success between the 2 techniques. No statistically significant differences were noted

Figure 7

Forest plot comparing surgical outcome in partial versus complete ligation. Odds ratio (95% confidence interval [CI]) of surgical success between the 2 techniques. No statistically significant differences were noted

Figure 8

Forest plot comparing surgical outcome in ameroid constrictor versus thin film band. Odds ratio (95% confidence interval [CI]) of surgical success between the 2 techniques. The common estimated OR was 36.58 (95% CI, 3.29‐407.10), showing a statistically significant association (P = .003) between the 2 techniques, with increased odds of successful cases in the ameroid technique