Assessment of the physical properties of endoscopic retrieval systems

A reliable method of retrieval of laparoscopically resected organs is required. The physical properties of three commercial systems available for clinical use (two plastic, one woven fabric) were examined.

Pig abdominal walls and gallbladders containing steel balls to represent gallstones were used to simulate organ retrieval on 60 occasions. The performance of retrieval bags was measured in terms of the temporal profile of pressure developed inside the bag, the force on the bag during withdrawal, and whether or not the bag could be retrieved intact. The force versus elongation relationship was also determined for each bag.

Although there was a wide range of maximum pressures recorded (14-320 mmHg) with each retrieval system, the mean pressures in the plastic systems were significantly higher. The forces recorded during attempted withdrawal of both plastic bags were significantly lower than those with the fabric system (BERT bag: mean (range) 87 (25-165) N; Endocatch: 40 (7-123) N; Endopouch: 40 (14-68) N; P = 0.005 Endocatch versus BERT, P = 0.004 Endopouch versus BERT). The BERT bags tore more easily at the site of the grasper.

Plastic retrieval systems were less likely to burst than fabric systems when subjected to simulated retrieval, and required less force for withdrawal. Plastic systems may therefore be associated with less tumour seeding or gallstone spillage as a consequence of bag disruption.