Development of a thinner and more flexible type of minihysteroscope with a controlled 90-degree bendable tip for vision-guided endometrium biopsy

STUDY OBJECTIVE: Evaluation of the uterine cavity is limited with rigid 5-mm hysteroscopes because of the need for cervical dilatation, reduced movements inside the uterus, and no option for vision-guided biopsy. In cooperation with PolyDiagnost GmbH, Pfaffenhofen, Germany, a new type of flexible minihysteroscope with bendable tip was developed and evaluated. DESIGN: Prospective and parallel observational interindividual evaluation of flexible minihysteroscope and standard hysteroscope for diagnostic hysteroscopy (Canadian Task Force classification II-3). SETTING: Obstetrics and gynecology department of a university clinic. PATIENTS: Nine women, average age 65.0 years (range 46-89 years), with indications for diagnostic hysteroscopy. INTERVENTIONS: After defining requirements, a novel, thinner, and more flexible minihysteroscope, 18-cm long with a 2.67-mm outer diameter, was developed with straight zero-degree scope, 70-degree vision field, and 6000-pixel resolution. Two working channels, 1.2 mm and 0.55 mm, allow suction-irrigation and introduction of a 1.0-mm biopsy forceps or cytology brush. The tip of the instrument is 90-degree stageless bendable to both sides. Diagnostic hysteroscopy was performed with flexible minihysteroscope followed by standard rigid hysteroscopy to verify results. MEASUREMENTS AND MAIN RESULTS: From July 2003 through March 2004, both procedures were performed in nine patients with identical visual and histologic results. No complications occurred. No cervix-dilating instruments were necessary for introduction of the flexible minihysteroscope. Visualization of the entire uterine cavity is improved with the flexible scope because a bendable tip allows better peripheral vision (e.g., of the openings of the tubes). However, movement of the tip should be performed carefully due to potential risk of uterine perforation. CONCLUSION: This new flexible minihysteroscope is less invasive compared with standard rigid hysteroscopy, which supports performance of ambulatory hysteroscopy and makes increased movements and vision-guided biopsy inside the uterine cavity possible.