Canis ISSN: 2398-2942

Congenital portosystemic shunt: attenuation

Synonym(s): Portosytemic shunt ligation

Contributor(s): Ed Hall, Mickey Tivers


  • Surgery to attenuate congenital portosystemic shunt (CPSS) aims to restore normal blood flow to the liver and hence resolve clinical signs associated with functional hepatic insufficiency.
  • A variety of techniques can be employed to achieve CPSS attenuation:
  • Complete attentuation of the CPSS either acutely or using a technique that achieves gradual attenuation is preferable.
    Should not be attempted in practice - refer for surgery.


Aims of surgery

  • Identify abnormal vessel and confirm diagnosis.
  • Provide acute or gradual attenuation of CPSS to redirect portal blood flow to liver.
  • Resolve clinical signs and hepatic insufficiency.
  • Liver biopsy to confirm diagnosis and rule out concurrent disease processes.


  • Attenuation associated with an improvement in or resolution of clinical signs.
  • Successful surgery obviates the need for long term medical management, which is attractive to many owners for reasons of convenience and finance.
  • Surgery likely to provide better overall outcome than medical management alone, with a better long term survival for surgically managed dogs reprted in one study.


  • Complicated surgery - refer to a specialist.
  • Also requires specialist anesthesia and postoperative care.
  • Specialized equipment and facilities often required.
  • Significant postoperative complications can occur.
  • Intrahepatic shunts are more challenging to treat surgically.


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  • Good if surgery successful.
  • Good to excellent outcome seen in 84-94% of surgically treated extrahepatic CPSS dogs and 50-100% of surgically treated intrahepatic CPSS dogs.

Further Reading


Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Tivers M S, Upjohn M M, House A K et al (2012) Treatment of extrahepatic congenital portosystemic shunts in dogs - what is the evidence base? JSAP 53 (1), 3-11 PubMed.
  • Greenhalgh S N, Dunning M D, McKinley T J et al (2010) Comparison of survival after surgical or medical treatment in dogs with a congenital portosystemic shunt. JAVMA 236 (11), 1215-1220 PubMed.
  • Hogan D F, Benitez M E, Parnell N K et al (2010) Intravascular occlusion for the correction of extrahepatic portosystemic shunts in dogs. JVIM 24 (5), 1048-1054 PubMed.
  • Berent A C & Tobias K M (2009) Portosystemic Vascular Anomalies. Vet Clin North Am Small Anim 39 (3), 513-541 PubMed.
  • Bussadori R, Bussadori C, Millán L et al (2008) Transvenous coil embolisation for the treatment of single congenital portosystemic shunts in six dogs. Vet J 176 (2), 221-226 PubMed.
  • Landon B P, Abraham L A & Charles J A (2008) Use of transcolonic portal scintigraphy to evaluate efficacy of cellophane banding of congenital extrahepatic portosystemic shunts in 16 dogs. Aust Vet J 86 (5), 169-179 PubMed.
  • Frankel D, Seim H, MacPhail C et al (2006) Evaluation of cellophane banding with and without intraoperative attenuation for treatment of congenital extrahepatic portosystemic shunts in dogs. JAVMA 228 (9), 1355-1360 PubMed.
  • Kummeling A, Teske E, Rothuizen J et al (2006) Coagulation profiles in dogs with congenital portosystemic shunts before and after surgical attenuation. JVIM 20 (6), 1319-1326 PubMed.
  • Lee K C, Lipscomb V J, Lamb C R et al (2006) Association of portovenographic findings with outcome in dogs receiving surgical treatment for single congenital portosystemic shunts: 45 cases (2000-2004). JAVMA 229 (7), 1122-1129 PubMed.
  • Mehl M L, Kyles A E, Hardie E M et al (2005) Evaluation of ameroid ring constrictors for treatment for single extrahepatic portosystemic shunts in dogs: 168 cases (1995-2001). JAVMA 226 (12), 2020-2030 PubMed.
  • Hunt G B, Kummeling A, Tisdall P L et al (2004) Outcomes of cellophane banding for congenital portosystemic shunts in 106 dogs and 5 cats. Vet Surg 33 (1), 25-31 PubMed.
  • Kummeling A, Van Sluijs F J & Rothuizen J (2004) Prognostic implications of the degree of shunt narrowing and of the portal vein diameter in dogs with congenital portosystemic shunts. Vet Surg 33 (1), 17-24 PubMed.
  • Hurn S D & Edwards G A (2003) Perioperative outcomes after three different single extrahepatic portosystemic shunt attenuation techniques in dogs: partial ligation, complete ligation and ameroid constrictor placement. Aust Vet J 81 (11), 666-670 PubMed.
  • Léveillé R, Johnson S E & Birchard S J (2003) Transvenous coil embolization of portosystemic shunt in dogs. Vet Radiol Ultra 44 (1), 32-36 PubMed.
  • Winkler J T, Bohling M W, Tillson D M et al (2003) Portosystemic shunts: diagnosis, prognosis, and treatment of 64 cases (1993-2001). JAAHA 39 (2), 169-185 PubMed.
  • Papazoglou L G, Monnet E & Seim H B 3rd (2002) Survival and prognostic indicators for dogs with intrahepatic portosystemic shunts: 32 cases (1990-2000). Vet Surg 31 (6), 561-570 PubMed.
  • Murphy S T, Ellison G W, Long M J et al (2001) A comparison of the Ameroid constrictor versus ligation in the surgical management of single extrahepatic portosystemic shunts. JAAHA 37 (4), 390-396 PubMed.
  • Hunt G B & Hughes J (1999) Outcomes after extrahepatic portosystemic shunt ligation in 49 dogs. Aust Vet J 77 (5), 303-307 PubMed.
  • White R N, Burton C A & McEvoy F J (1998) Surgical treatment of intrahepatic portosystemic shunts in 45 dogs. Vet Rec 142 (14), 358-365 PubMed.
  • Youmans K R & Hunt G B (1998) Cellophane banding for the gradual attenuation of single extrahepatic portosystemic shunts in eleven dogs. Aust Vet J 76 (8), 531-537 PubMed.
  • Hunt G B, Bellenger C R & Pearson M R B (1996) Transportal approach for attenuating intrahepatic portosystemic shunts in dogs. Vet Surg 25 (4), 300-308 PubMed.
  • Vogt J C, Krahwinkel D J, Bright R M et al (1996) Gradual occlusion of extrahepatic portosystemic shunts in dogs and cats using the ameroid constrictor. Vet Surg 25 (6), 495-502 PubMed.
  • Bostwick D R & Twedt D C (1995) Intrahepatic and Extrahepatic Portal Venous Anomalies in Dogs - 52 Cases (1982-1992). JAVMA 206 (8), 1181-1185 PubMed.
  • Hottinger H A, Walshaw R & Hauptman J G (1995) Long-Term Results of Complete and Partial Ligation of Congenital Portosystemic Shunts in Dogs. Vet Surg 24 (4), 331-336 PubMed.
  • Komtebedde J, Koblik P D, Breznock E M et al (1995) Long-Term Clinical Outcome after Partial Ligation of Single Extrahepatic Vascular Anomalies in 20 Dogs. Vet Surg 24 (5), 379-383 PubMed.
  • Smith K R, Bauer M & Monnet E (1995) Portosystemic Communications - Follow-up of 32 Cases. JSAP 36 (10), 435-440 PubMed.
  • Lawrence D, Bellah J R & Diaz R (1992) Results of Surgical-Management of Portosystemic Shunts in Dogs - 20 Cases (1985-1990). JAVMA 201 (11), 1750-1753 PubMed.
  • Swalec K M & Smeak D D (1990) Partial Versus Complete Attenuation of Single Portosystemic Shunts. Vet Surg 19 (6), 406-411 PubMed.
  • Mathews K & Gofton N (1988) Congenital Extrahepatic Portosystemic Shunt Occlusion in the Dog - Gross Observations during Surgical Correction. JAAHA 24 (4), 387-394 VetMedResource.
  • Johnson C A, Armstrong P J & Hauptman J G (1987) Congenital portosystemic shunts in dogs: 46 cases (1979-1986). JAVMA 191 (11), 1478-1483 PubMed.
  • Breznock E M (1979) Surgical manipulation of portosystemic shunts in dogs. JAVMA 174 (8), 819-826 PubMed.