Background

Extrahepatic portosystemic liver shunts are a vascular malformation that occurs primarily in dogs and cats. These manifest as an abnormal connection between the portal and systemic venous systems, resulting in the total or partial diversion of portal blood flow away from the liver ( ‑ Extrahepatic portosystemic shunt). Medical management has the potential to control clinical signs of hepatic dysfunction, but surgical intervention is associated with increased survival time and remains the treatment of choice.

Aneroid ring constrictor surgery is the most widely used gradual vascular occlusion technique in dogs. The Aneroid ring constrictor (ARC) is placed around the shunt and a key is inserted to secure the vessel (Figure Right ‑ Ameroid ring constrictor (ARC) and key). Thereafter, the hygroscopic casein interior expands over time to gradually occlude the shunt.

Technology Overview

Market Research & Customer Discovery: (Frontline Consultants Ltd)

Currently, haemostats, mosquito, allis tissue, and standard right-angled forceps are used to hold and manoeuvre the ARC during surgery. However, these instruments struggle to grasp the ARC effectively. Presently, there is no alternative instrumentation.

Several disadvantages were highlighted with the current equipment:

Surgeon must often detrimentally alter their hand position on the forceps
Surgical field can be obstructed due to hand position resulting from the altered grip or using fingers
Once the ARC is around the vessel, it is difficult to manoeuvre to a position where the key can be inserted
ARC can twist on the vessel
Forceps jaws and box lock can be bent/damaged/blunted when clamping on to metal out with their intended purpose
ARC can also be damaged by instruments not designed to hold it
Difficult to learn this surgery using standard forceps
ARC and key are often dropped in the surgical cavity

The solution

A novel set of forceps has been designed with a right-angled configuration and curved jaws which are optimised for holding the ARC. These jaws can be attached to standard or laparoscopic surgical equipment and are procedure specific to enhance control during ARC placement. Further, with the exception of the jaws, they are similar in all other ways to conventional forceps. Hence, the surgeon will be familiar with how they feel and will receive the haptic feedback to which they are accustomed.

The research team at the University of Strathclyde develops the technology by using their expertise in 3D modelling and experience with laparoscopic device design to develop these forceps for open and minimally invasive surgery.

Benefits

These forceps provide a number of benefits to the surgeon for both open and laparoscopic ARC surgery:

General:

Reduced operating time and complexity
Reduced time under anaesthesia
Enhanced control of ARC placement while maintaining haptic feedback
Positioning of ARC and therefore insertion of the key is easier
The ARC can be grasped circumferentially, increasing the contact area and grip provided by the jaws
A gap in the jaws means the shunt can be slotted in, unobstructed, while the jaws remain locked around the ARC
Can be re-sterilised and reused
Simple to use
Procedure specific instrumentation will not become damaged or damage the ARC

Open Surgery:

A neutral hand position can be maintained in the finger rings, meaning surgical field of view is maximised
Ergonomic pronation and supination of the wrist allows for fine control for rotating the ARC into place

Laparoscopic Surgery:

Procedure specific instrumentation maintains control of the ARC during laparoscopic surgery where there is no way for the surgeon to alter their grip as they do during open surgery
Reduced trauma to the patient

Opportunity

License to Third Party

Novel Forceps for Veterinary Surgery

Seeking