Shunt disconnection is less likely using a surgeon's knot compared with a surgical constrictor knot

Area of Science:

• Neurosurgery
• Biomedical Engineering
• Materials Science

Background:

• Ventriculo-peritoneal (VP) shunt malfunction is a frequent complication in neurosurgery.
• Shunt disconnection at the valve level can lead to malfunction.
• Previous research indicated the constrictor knot's superiority over the surgeon's knot for ligatures.

Purpose of the Study:

• To compare the security of the surgeon's knot versus the constrictor knot in securing shunt tubing to a valve.
• To determine which knot offers superior resistance to disconnection.

Main Methods:

• A Medtronic shunt valve was connected to a peritoneal catheter using both the surgeon's knot and the constrictor knot.
• The force required to detach the shunt tubing from the valve at the knot site was measured in Newtons (N).

Main Results:

• The surgeon's knot demonstrated a mean pull-off force of 11.7 N.
• The constrictor knot showed a mean pull-off force of 8.9 N.
• A statistically significant difference favored the surgeon's knot.

Conclusions:

• The surgeon's knot is significantly more robust than the constrictor knot for securing peritoneal catheters to cerebrospinal fluid shunt valves.
• This enhanced security may reduce VP shunt disconnection and subsequent malfunction.