Content continues after advertisement

Surgeon's Corner: Friction Knots & the Aberdeen Knot

J. Brad Case, DVM, MS, DACVS, University of Florida

W. Alex Fox-Alvarez, DVM, MS, DACVS-SA, University of Florida

Surgery, Soft Tissue

|September 2016|Web-Exclusive

Sign in to Print/View PDF

Reliable vascular pedicle ligation is a required skill of any veterinarian performing surgery. Ineffective vascular ligation can be a life-threatening surgical error, leading to severe blood loss, repeated exploratory surgery, and death. Hemorrhage is the most common cause of death after ovariohysterectomy. Significant hemorrhage is a notable risk when ligating thick ovarian pedicles with high fat content; and the initial throw of the ligature is of critical importance. If the initial square throw is not tight or does not retain its initial tension, the ligated tissue and vessels will bleed despite successive tight square throws. This can occur due to elastic recoil of the tissue, or from uneven tension applied to the suture strands during subsequent throws. Friction knots are recommended to maintain extrinsic tension on the ligated tissues between the first and subsequent throws. The associated video demonstrates the proper technique to form the following 3 friction knots, along with the alternative Aberdeen knot used in subcutaneous and intradermal closures.

The surgeon’s knot is a simple, commonly used friction knot that is usually adequate for thinner vascular pedicles and when smaller suture material, such as 3-0 or 4-0, is preferred. However, this knot has been outperformed by other friction knots in several studies and is often inadequate for large, bulky pedicles.1,2,3

The strangle knot and Miller’s knot are both friction knots that require 2 initial passes around the vascular pedicle. The difference in formation is demonstrated in the video. These knots are secure, are easy to perform, and provide resistance to luminal pressures up to 2 to 3 times that of normal arterial blood pressure in dogs. 

The Aberdeen knot is an alternative knot used when ending a continuous suture line, most often for subcutaneous and intradermal closure. When used in subcutaneous closure, this knot allows the surgeon to continue directly to an intradermal closure without cutting the subcutaneous suture line. In addition, a 2-throw, 1-pass Aberdeen (as shown in the video) was found to be as strong as and less bulky than a traditional 4-throw square knot,4 which reduces foreign material in the closure and makes burying the knot easier.

References and Author Information

For global readers, a calculator to convert laboratory values, dosages, and other measurements to SI units can be found here.

All Clinician's Brief content is reviewed for accuracy at the time of publication. Previously published content may not reflect recent developments in research and practice.

Material from Clinician's Brief may not be reproduced, distributed, or used in whole or in part without prior permission of Educational Concepts, LLC. For questions or inquiries please contact us.


Clinician's Brief:
The Podcast
Listen as host Alyssa Watson, DVM, talks with the authors of your favorite Clinician’s Brief articles. Dig deeper and explore the conversations behind the content here.
Clinician's Brief provides relevant diagnostic and treatment information for small animal practitioners. It has been ranked the #1 most essential publication by small animal veterinarians for 9 years.*

*2007-2017 PERQ and Essential Media Studies

© 2023 Educational Concepts, L.L.C. dba Brief Media ™ All Rights Reserved. Terms & Conditions | DMCA Copyright | Privacy Policy | Acceptable Use Policy