Study Shows That $250 Million Could Be Saved Continued...

The flow rate measured for different Veress needles ranged 0.85 to 2.38 L/min at PRef. The flow limiting factor for Veress needles was the inner diameter of 2 mm or the insufflation supply if smaller than 2 mm. Disposable trocars have a flow rate of 3.75 to 9.61 L/min and an insufflation diameter of 1.5 to 2.5 mm. With disposable trocars evaluated in this study, high flow insufflation > 10 L/min is not possible without exceeding the normal pressure limit of 12 mmHg. Reusable trocars offer much greater gas flow rates of up to 21 L/min because their insufflation diameter is up to 4,3 mm..

Figure 6: Gas flow regression curves for reusable trocars with 10 mm optic: 1. Olympus 10 mm, 2. Wolf 10 mm, 3. Storz 26020 11 mm, 4. Olympus A5675 11 mm, 5. Storz 30104T 12 mm, 6. Storz 30104K, 7. Olympus A5359 11 mm and 8. HiTec 11 mm.

Suggested Improvements
Jacobs offers the following recommendations for designing a flow-optimized insufflation system capable of providing flow rates of greater than 10 L/min without exceeding safe pressure levels. The annular space left for insufflation should be at least 2.5 mm for flow rates in excess of 10 L/min and the ideal annular space should be at least 3.5 mm for a flow rate of at least 20 L/min. A resistance-optimized system should also abandon the standard Luer Lock supply. The hose can easily be attached to the trocar stopcock without the Luer Lock as shown by the devices provided by HiTec, Tuttlingen, Germany. The advantages of a flow and resistance optimized insufflation system are that the nominal abdominal pressure is maintained more accurately and regulation of the entire system is improved. This eliminates the time delay until normal sight and work conditions are established. The result is that the surgeon does not lose spatial orientation and the optic does not need to be cleaned because it contacted the body or irrigation fluids. Besides reducing surgical costs, the patient also benefits because the operation time and the anesthesia time is reduced. Saving 3-5 minutes during every procedure performed about 2 million times alone in the US a year can lead to enormous financial savings of up to $ 250 million

Jacobs' study clearly indicates that not nearly enough attention has been paid to the flow resistance in insufflation devices although they have a large influence on the system's performance. Resistance is clearly the weakness in the entire insufflation system. Measurements also show that insufflation systems with all their components have to be seen as complete systems. For high flow efficiency they cannot be combined randomly. To provide optimum performance, all single components have to be designed as a system to minimize resistance. Improved insufflation components are more efficient and faster. Surgeons need to demand better components and manufacturers should publish comparable reference values about the specific flow properties of their products.


References: Jacobs VR et al: Specific resistance of Veress needles, disposable and reusable trocars limiting CO2 gas flow performance in laparoscopy and pelviscopy. Min Invas Ther Allied Technol 1999, 8(1), 37-47

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