Real-time intraoperative ultrasound guidance: the transrectal approach

Diagnostic Usefulness of Transrectal Ultrasound Compared with Transvaginal Ultrasound Assessment in Young Korean Women with Polycystic Ovary Syndrome

Objectives

To determine the diagnostic performance of transrectal ultrasound in virgin patients with polycystic ovary syndrome (PCOS) by receiver operating characteristic (ROC) curve analysis, compared with conventional transvaginal ultrasound assessment.

Methods

Ultrasound examinations were performed in 963 Korean women, with transvaginal transducers in 677 women and transrectal transducers in 286 women at Ewha Womans University Mokdong Hospital. Transvaginal ultrasound examinations were performed in 494 normal control women and 183 PCOS patients according to National Institutes of Health (NIH) PCOS diagnostic criteria. In virgin patients, transrectal ultrasound examinations were performed in 141 normal control women and 145 PCOS patients. ROC curves were calculated for ovarian volume and follicle number.

Results

By transvaginal ultrasound examination, the ovarian volume showed an area under the ROC curve (AURC) of 0.838. An ovarian volume decision threshold > 7 cm³ had a sensitivity of 73.0% and a specificity of 84.2% for the diagnosis of PCOS. The follicle number showed an AURC of 0.886. A follicle number decision threshold ≥ 9 had a sensitivity of 78.6% and a specificity of 87.2% for the diagnosis of PCOS. By transrectal ultrasound examination, the ovarian volume and the follicle number showed AURCs of 0.815 as same thresholds with a sensitivity of 67.2% and 66.4%, respectively and a specificity of 86.8% each. Ovarian volume and follicle number by transvaginal and transrectal ultrasound assessment had a high diagnostic power for PCOS screening.

Conclusion

Transrectal ultrasound assessment is as effective as conventional transvaginal ultrasound for the detection of PCOS in virgin patients.

Intraoperative imaging

Intraoperative image is a rapidly expanding field encompassing many applications that use a multitude of technologies. Some of the these applications have been in use for many years and are firmly embedded in, and indispensable to, clinical practice (e.g. the use of X-ray to locate foreign bodies during surgery or oocyte retrieval under ultrasound guidance. In others, the application may have been in use in one discipline but not yet fully explored in another. Examples include the use of intraoperative ultrasound with or without contrast enhancement for the detection of hepatic metastases not identified preoperatively, and the effect of such additional information on the ultimate operative procedure. Intraoperative identification of sentinel lymph nodes has been explored in many specialties to a varying extent, with the aim of fine tuning and avoiding unnecessary surgery. In both these instances, we do not know the long-term effect of these interventions on patient survival or quality of life. In this chapter, we will explore the available evidence on these applications and current advances in the new technology in general, with a specific focus on gynaecology.

Applications of intraoperative ultrasound in gynecological surgery

PURPOSE OF REVIEW

Gynecologists are well trained in office-based ultrasound, but are less experienced in the field of intraoperative ultrasound. Many gynecologic procedures may benefit from the use of real-time ultrasonography. The purpose of this review is to summarize the current use of intraoperative ultrasound in gynecologic procedures.

RECENT FINDINGS

Evaluation and assessment of the value of intraoperative ultrasound in gynecological procedures is essentially non-existent. The role of intraoperative ultrasound in gynecology is in its infancy, with anecdotal experience and literature involving predominantly case reports. Intraoperative ultrasound is helpful in laparoscopic myomectomy, particularly when the uterine contour is normal. It is also useful in defining pelvic anatomy in cases of complex reproductive procedures. Intraoperative ultrasound improves precision in characterizing ovarian lesions, particularly in the setting of endometriomas or dermoid cysts. It has been shown to decrease both operative time and complication rates in dilation and curettage procedures. Intraoperative ultrasound reduces recurrence and re-operation rates after hysteroscopy by facilitating more-complete resection of uterine myomas. Ultrasound guidance improves the efficiency of embryo transfer in in-vitro fertilization and could potentially be beneficial in other 'blind' gynecological procedures.

SUMMARY

Intraoperative ultrasound appears to be a safe and valuable tool for the gynecologic surgeon. Ultrasound improves visualization of anatomy, reduces complication and re-operation rates, and facilitates completion of more cases via less-invasive endoscopic approaches.

Intraoperative ultrasound during a laparoscopic myomectomy

OBJECTIVE

To report a gynecologic use of a laparoscopic ultrasound transducer to isolate a myoma for surgical removal.

DESIGN

Case report.

SETTING

University-based infertility practice.

PATIENT(S)

A 44-year-old woman gravida 1 para 1 with history of a first trimester miscarriage who desired pregnancy as a participant in the donor egg program.

INTERVENTION(S)

Before she entered the assisted reproduction program, a patient was found to have a myoma that was greater than 2 cm with both intramural and submucosal components. During the laparoscopic evaluation, a laparoscopic ultrasound transducer helped identify and properly locate the myoma in what otherwise appeared to be a normal uterus. Appropriate laparoscopic hysterotomy incision was then made, thereby minimizing uterine trauma.

MAIN OUTCOME MEASURE(S)

Appropriately placed hysterotomy incision and successful reconstruction of uterus.

RESULT(S)

After the successful laparoscopic myomectomy, the patient achieved a pregnancy in our donor oocyte program.

CONCLUSION(S)

Laparoscopic intraoperative ultrasound can help gynecologic surgeons complete a laparoscopic myomectomy.

Uterine perforation at the time of brachytherapy for carcinoma of the cervix

OBJECTIVE

The reported incidence of uterine perforation by tandems at the time of vaginal brachytherapy for management of cervical cancer ranges from 1.75% to 10% per application. The potential ramifications of afterloading a tandem that is outside the uterine cavity within the pelvis are sufficiently severe, in terms of bowel injury, that a reliable means of determining tandem positioning at the time of placement is essential.

METHODS

We examined a representative patient that underwent tandem placement for Federation Internationale of Gynecologic Oncologist (FIGO) stage Ib1 cervical Squamous Cell Carcinoma (SCCA). The information provided by conventional radiographic assessment and clinical impression was not helpful in ultimately determining tandem placement.

RESULTS

Direct endoscopic visualization provided accurate and irrefutable evidence of tandem location and positioning prior to leaving the operating room.

CONCLUSION

A variety of techniques have been described to assist in accurate placement of the uterine tandem prior to afterloading, when utilizing definitive chemoradiation in the management of cervical carcinoma. These include postoperative plain films or computerized tomography, versus intraoperative transabdominal or transrectal ultrasound guidance at the time of placement. Postoperative techniques that confirm perforation necessitate a second visit to the operating room, a second general anesthetic, as well as a treatment delay that may impact negatively upon central control rates in the long term. Intraoperative techniques have their limitations as well, particularly in the obese patient. With difficult or questionable insertions, direct endoscopic evaluation at the time of tandem insertion is the only means of knowing definitively the location of the tandem prior to leaving the operating room.

Transrectal scanning: an alternative when transvaginal scanning is not feasible

OBJECTIVE

In scanning the female pelvis the clear images of transvaginal sonography (TVS) result from placing the transducer close to the region of interest. The advantages of TVS over transabdominal sonography (TAS) and transperineal sonography are well documented. Transrectal scanning is proposed mostly for ultrasound guidance in draining a pelvic abscess. Our aim was to investigate the applicability of transrectal scanning (TRS) for cases in which TVS is impossible.

METHODS

Forty-two patients with an absolute or a relative contraindication to TVS were scanned transabdominally and transrectally. The TRS was performed using a transvaginal probe, which was lubricated and slowly advanced into the rectum. The technique used was similar to that of TVS. Images were compared for resolution and quality.

RESULTS

All scans were completed without significant patient discomfort or complaints. TRS was clearly superior to TAS in 31 cases. In nine cases TAS furnished some clinical information but TRS yielded better images. Only in one such case was TAS similar in quality to TRS. In four obese patients TAS did not reveal sufficient pelvic anatomy to generate a clinical diagnosis, whereas TRS revealed two sets of normal ovaries and two patients with ovarian cysts. In the two cases with vaginal agenesis TRS revealed the diagnosis of Rokitansky-Küster syndrome. In three of the four patients with ruptured membranes the cervix could be measured precisely.

CONCLUSION

Transrectal scanning should be used liberally after proper patient selection and counseling. The images obtained are superior to TAS and comparable to those obtained by TVS.