Initial experience with a physiologic morcellating resectoscope

Investigation of often-reported ten percent hysteroscopy fluid overfill: Is this accurate?

STUDY OBJECTIVE

A key component of hysteroscopic complications, such as fluid overload and severe dilutional hyponatremia, is the failure to anticipate and quickly recognize fluid deficits. The purpose of this study was to measure the volume and mass of irrigation fluid bags to assess the overfill of 3 common types of hysteroscopy irrigation fluids, 0.9% normal saline solution, 3% sorbitol, and 1.5% glycine, to challenge the often-quoted standard of assumption that overfill may be as high as 10% of the bag's volume.

DESIGN

Ten cases of irrigation fluid were tested. The volume and weight of drained fluid from 18 bags of 0.9% normal saline solution 2000 mL, 12 bags 3% sorbitol 3000 mL, 8 bags of 1.5% glycine 3000 mL, and 4 bags of 0.9% normal saline solution 5000 mL were measured. Institutional review board exemption was obtained.

MEASUREMENTS AND MAIN RESULTS

Ten cases of irrigation fluid were obtained. The volume and weight of drained fluid from 18 bags of 0.9% normal saline solution 2000 mL, 12 bags of 3% sorbitol 3000 mL, 8 bags of 1.5% glycine 3000 mL, and 4 bags of 0.9% normal saline solution 5000 mL were measured. By volume, varying by the type of fluid tested, the maximum observed overfill was between 3.3% to 5.0%. For confirmation, each bag was also weighed and found to have a maximum overfill between 2.8% to 5.6%, varying with the volume and type of fluid measured. These findings were then compared with the manufacturer-provided overfill range of 1.5% to 6.0%. No underfill was observed.

CONCLUSION

Contrary to assertions over the last 25 years that overfill is 10% or higher as a rule, it appears more reasonable to assume that the degree of overfill is contingent on the type and volume of fluid used and is more likely closer to 2.8% to 5.6%. Therefore an accurate collecting system and weight measurement is more precise.

New developments in ambulatory hysteroscopic surgery

In the last decade, advancements have been made in hysteroscopic techniques, instrumentation and indications. Vaginoscopic hysteroscopy is performed without medication, cervical dilation and use of vaginal speculum or cervical tenaculum. To prevent complications during uterine access, both misoprostol and laminaria are equally effective for cervical priming. The use of normal saline to distend the uterus prevents hyponatraemia, but hypervolaemia may still be a major problem. Irrigant fluid deficit is best monitored by automated devices. Bipolar electrosurgical systems do not require dispersive return electrodes and do not generate stray currents, thus minimizing the risk of electrical burns. Tissue debulking and extraction are facilitated by vaporizing electrodes or morcellators. Hysteroscopic indications have expanded to include diagnosis and treatment of missed abortion, and cervical and interstitial pregnancies. The most important advancement of hysteroscopy has been proximal tubal access for sterilization.

Instrumentation and distention media for the hysteroscopic treatment of abnormal uterine bleeding

New hysteroscopes and resectoscopes with continuous-flow designs have greatly facilitated diagnostic and therapeutic hysteroscopy. Saline is the ideal distending medium for hysteroscopic procedures in which mechanical or bipolar instruments are used; 5% mannitol may be the safest medium for resectoscopic surgery. Regardless of the medium chosen, careful fluid monitoring is essential.