A feasibility study of three-dimensional ultrasound imaging of the vagina under distension.

BACKGROUND: The distension properties of the vagina are critical to its function including support of surrounding organs, childbirth, and intercourse. It could be altered by many pathophysiological processes like pregnancy, radiotherapy, and reconstruction surgery. However, there are no clinically available diagnostic tools capable of quantifying the distension properties of the vagina. PURPOSE: A proof-of-concept study was designed to assess the feasibility of a novel three-dimensional (3D) ultrasound imaging technique that allows quantitative evaluation of the vagina under distension. METHODS: Patients with symptomatic pelvic organ prolapse (POP) were recruited for the study. An ultrathin, oversized bag was inserted into the vagina and filled with water using a modified urodynamics system. The instilled water volume and intravaginal pressure were continuously recorded. At maximum vaginal capacity, 3D transintroital ultrasound of the distended vagina and surrounding pelvic structures was performed. Exams were performed in duplicate for each patient, two hours apart (round A and round B). Following the development of a 3D surface model of the distended vagina from each scan, several measurements were obtained, including cross-sectional area, anteroposterior (AP) length and lateral width in the plane of minimum hiatal dimensions (PMHD), AP and lateral diameter at the pubic symphysis (PS) level, maximum and minimum diameter, and maximum vertical length. To assess repeatability between measurements in two rounds, the coefficient of variation (CV) and the intraclass correlation coefficient (ICC) were calculated for each measurement. Correlations between physical measurements including the pelvic organ prolapse quantification (POP-Q) system and vaginal diameter measurements, and obtained metrics were also assessed. RESULTS: Sixteen patients with POP (average age 69 years) completed both rounds of imaging. There was sufficient echogenicity on 3D transintroital ultrasound of the distended vaginal wall to establish boundaries for 3D surface models of the vagina. Overall, all metrics had good or excellent reliability (ICC = 0.77-0.93, p < 0.05; CV = 3%-18%) except maximum diameter, which demonstrated only moderate reliability (ICC = 0.67, p = 0.092). Strong correlations were found between physical exam measurements including D point of POP-Q, introitus diameter and lateral diameter at apex, and maximum vaginal capacity, maximum vertical length, lateral diameter at PS, minimum diameter, and distended PMHD measurements. The results demonstrated that this system could generate 3D models of the shape of the distended vagina and provide multiple metrics that could be reliably calculated from automated analyses of the models. CONCLUSIONS: A novel system for evaluation of the distension properties of the vagina was developed and preliminary evaluation was performed. This system may represent a technique for evaluation of the biomechanical and structural properties of the vagina.

Evaluation of Adjunctive Azithromycin Prophylaxis in Women Undergoing Cesarean Delivery in a Setting With Low Baseline Incidence of Surgical Site Infection.

OBJECTIVE: The purpose of this quality improvement study was to determine the effect of adding azithromycin to standard antibiotic prophylaxis on the rates surgical site infection (SSI) in women undergoing both elective and non-elective cesarean deliveries at our centre. METHODS: A before-and-after quality improvement study was conducted at the Regina General Hospital in Regina, Saskatchewan. Data collected from 989 women who had a caesarean delivery between June 1, 2016 and June 30, 2017 were compared with those from 1033 women who had a caesarean delivery between August 1, 2017 and July 31, 2018, after the introduction of adjunctive azithromycin prophylaxis. The primary outcome measure was the change in the incidence of SSI up to 30 days following surgery. Secondary outcome measures included timing of azithromycin prophylaxis and the number of women who did not receive azithromycin. RESULTS: Surgical site infection rates decreased from 3.5% to 2.9% after adjunctive azithromycin prophylaxis was introduced. The absolute reduction in SSIs of 0.6% was not statistically significant (P = 0.42). There were no differences in SSI rates between the elective and non-elective subgroups. CONCLUSION: Adding azithromycin to the standard antibiotic prophylaxis for cesarean delivery showed no statistically significant reduction in SSI rates in a population with low baseline rates of SSI.