BBI Contributing Writer

SAN FRANCISCO, California – Among the myriad of topics discussed at the annual conference of the American College of Obstetricians and Gynecologists (ACOG; Washington), meeting here in late May, incontinence, cervical pathology, and 3-D imaging were some of the highlights. All three of these areas have been heavily impacted by new technologies.

Most of the presentations on incontinence involved various surgical corrections. Robert Summitt and his group at the University of Tennessee Medical Center (Memphis, Tennessee) performed a multi-center, randomized comparison of 28 laparoscopic and 34 transabdominal Burch procedures for the treatment of stress incontinence. The laparoscopic Burch had a longer operating time (173.2 minutes versus 118.6 minutes), but a shorter mean hospital stay (1.4 days vs. 2.1 days) than the transabdominal Burch. No significant differences were found in complications, post-operative fever, mean time to resumption of voiding, objective surgical success (at both 1 and 3 years) and at urodynamic measures (at both 1 and 3 years).

Armando Hernandez-Rey and his group at the University of Miami's Jackson Memorial Hospital (Miami, Florida) performed a retrospective analysis of 50 patients with genuine stress incontinence, comparing patient satisfaction in patients receiving the standard Burch procedure with patients undergoing the paravaginal Burch procedure. Patients receiving the standard Burch reported having a more complicated hospital course (20% vs. 12%), and greater frequency of detrussor instability (16% vs. 8%), but a lower incidence of urinary tracts symptoms (28% vs. 12%) and a lower amount of patient satisfaction (56% vs. 76%) when compared with patients receiving the laparoscopic Burch procedure.

Steven Speights and his group at Northside Hospital (Atlanta, Georgia) examined the incidence of lower urinary tract injury during laparoscopic Burch and/or paravaginal repair among 159 patients. Most patients in the study had both the Burch standard repair and the Burch paravaginal repair. The Burch laparoscopic repair was found to have less blood loss, better visualization, and a resulting lower rate of urinary tract injury (2.5% vs. 10%) than the standard Burch repair.

David Asbery and his associates at the Coastal Area Health Education Center (Wilmington, Delaware) assessed the outcome of needle suspension in 82 women with genuine stress urinary incontinence due to pelvic prolapse, of which 72% received anterior repair and 47% underwent posterior repair. The subjective cure rate was 68% and the objective cure rate was 66%. Improvement of symptoms after the procedure was reported by 80% of patients. Worse symptoms after the procedure were reported by 10% of patients.

Use of a vaginal patch sling was the topic of three presentations. Magdy Mikhail and Hector Rosa of the Albert Einstein College of Medicine (Bronx, New York) studied pressure transmission ratios on coughing (an indication of the relative efficiency with which intra-abdominal pressure increases are transmitted to the bladder and urethra) in 44 women with genuine stress incontinence, before and after performing vaginal patch sling procedures. Their findings suggest that the vaginal patch sling restores continence by repositioning the proximal urethra into the abdomen such that it is exposed to intra-abdominal pressure increases on coughing. In a separate presentation, Mikhail and Rosa looked at outflow urinary resistance (derived from the measurement of voiding detrussor pressure and maximum urinary flow rate) in the same group of patients. No changes were found when comparing pre-operative and post-operative measurements, indicating an absence of outflow obstruction, perhaps because the vaginal patch provides elevation and support alongside most of the urethral length, thus avoiding a valvular effect at the bladder neck. In a separate study, Mikhail and Rosa used urodynamics to compare the clinical efficacy of the vaginal patch sling and retropubic needle suspension in 41 women with genuine stress incontinence. At follow-up, 94% of the vaginal patch patients and 71% of the needle suspension patients had clinical and urodynamic improvement of their genuine stress urinary incontinence on the basis of a negative standing stress test and positive maximal closure pressure on cough.

One alternative to the vaginal patch sling is a rectus muscle suburethral sling, where a pedicled rectus muscle flap is moved through the space of Retzius, under the urethra, and then attached to either Cooper's ligament or the fascia of the obturator internus. Jeffrey Mangel and his group at St. Luke's Hospital (Bethlehem, Pennsylvania) performed this procedure in 35 women with complex stress urinary incontinence. At follow-up, either by physical examination or by phone interview, 28 patients were found to be satisfied with the results of the procedure, three patients had persistent stress urinary incontinence, two patients had no stress urinary incontinence, but had developed new urge incontinence, and two patients who had mixed incontinence pre-operatively had only urge incontinence post-operatively. The investigators favor this technique, despite the need for a midline abdominal incision, because, unlike synthetic sling materials, muscle has no erosion potential. Also, the muscle has its own blood supply and should have greater longevity than either autologous or donor fasica.

Since endogenous tissue repairs are not always possible, there is continued interest in the use of synthetic sling materials. Two presentations given at this meeting pertained to the Vessica bone-anchored sling from Boston Scientific (Natick, Massachusetts). Charles Ascher-Walsh and his colleagues at Presbyterian Hospital (New York) reviewed their results in 30 women with either stress urinary incontinence, intrinsic sphincter deficiency, or both. They found that 28 patients were completely dry and two were improved at an average follow up of 267 days. Three slings ultimately had to be removed, however – two for tissue rejection (at an average of 438 days) and one due to persistently elevated post-void residual volume. In an separate presentation, Ascher-Walsh examined the return of normal voiding function in the same group of patients, comparing three different sling materials: protogen, fascia, and alloderm. The average time to return of normal voiding, 10 days, was not found to differ significantly when comparing the three different sling materials.

Gerard Pregenzer and Marlan Schwartz of Somerset Hospital (Warren, New Jersey) gave two presentations on their laparoscopic approach to bladder neck suspension for treating women with a hypermobile urethra and genuine stress urinary incontinence. The procedure was performed in 80 women over the course of four years. At an average follow-up of 36 months, the overall success rate was more than 98%. Fifteen of the patients also had a significant lateral wall defect near the vagina, requiring the placement of a polyprolene mesh adjacent to the urethra, attached to the vaginal fascia and the arcus tendinus using a laparoscopic stapler.

Tension Free Vaginal Tape from Johnson & Johnson (New Brunswick, New Jersey) was the topic of two talks at the ACOG meeting. Anne Hardart and her colleagues at the University of Southern California School of Medicine (Los Angeles, California) compared pre- and post-operative (follow-up at an average of four months) values of outflow urinary resistance (derived from the measurement of voiding detrussor pressure and maximum urinary flow rate) in 18 women treated for genuine stress urinary incontinence. All were found, subjectively and objectively, to be cured of their incontinence, but post-operatively both mean detrussor pressure and mean urethral resistance increased significantly, and eight patients did not have adequate voiding studies. In addition, in nine of the 10 patients with adequate voiding studies, hypermobility was not corrected by the procedure. Robert Moore and his group at Northside Hospital reported on the use of Tension Free Vaginal Tape in 15 women with advanced pelvic organ prolapse and stress urinary incontinence. Advanced pelvic organ prolapse was corrected vaginally (eight Lefort partial colpocleises, four total colpocleises, and three anterior repairs with colpoectomy) prior to the completion of the Tension Free Vaginal Tape procedure. All patients had successful surgical repair, but no long-term follow up was reported.

Only one presentation dealt with the use of bulking agents for the treatment of incontinence. Roger Andersen of the Women's Continence and Urology Center (Seattle, Washington) performed a randomized clinical trial comparing Contigen from Bard Urological (Covington, Georgia) and Duraphere from Advanced UroScience (St. Paul, Minnesota) in 52 women diagnosed intrinsic sphincter deficiency on the basis of urodynamics. Andersen presented results indicating only that both materials can be injected using lidocaine, allowing the procedure to be well tolerated by the patient. Data comparing the two bulking agents was conspicuously absent.

Radiofrequency (RF) energy has been used in a variety of medical applications, from ablating aberrant conduction pathways in the heart to the treatment of benign prostatic hypertrophy. Donald Galen, of the Reproductive Science Center of the Bay Area (San Ramon, California), has developed a method for applying RF energy to treat certain patients with stress incontinence without the use of implantable materials. The radio frequency energy, applied via either a transvaginal or a laparoscopic probe, is used to heat and subsequently shrink collagen in the endopelvic facia surrounding the urethra, creating a functional sling lifting the bladder neck and urethra. The histologic studies indicate that, in animals, the periurethral tissue that shrinks 25% to 50% due to exposure to RF energy does not restretch during the healing time of 42 days. In two patients who initially received the procedure, normal tissue generation without adhesions was found at six-month follow-up. Subsequently, two parallel, independent prospective, comparative IDE studies have been conducted: one with 76 women receiving a laparoscopic approach and another with 17 patients receiving a transvaginal approach. In both, patients were followed up at three and six months post-procedure. All complications were resolved within one week of diagnosis with conservative management. Additional long-term follow-up is needed, but the transvaginal approach looks particularly promising.

The most conservative treatments for incontinence, behavioral therapy, were the topic of only one paper. Sandra Reilley, in private practice in Tacoma, Washington, reviewed the cure rate of behavioral therapy (primarily EMG biofeedback) in 321 women, of whom 35% had a primary diagnosis of stress incontinence, 33% had a primary diagnosis of urge incontinence and 12% had a primary diagnosis of mixed incontinence. Previous bladder suspension had been performed in 25% of these women, and 5% had a history of multiple operative procedures. Of this group of women, 73% completed behavioral therapy. Of those who completed behavioral therapy, 85% were cured of incontinence and the remainder improved both at discharge and at follow-up after two-years.

Cervical pathology

The PAP smear is an important tool in screening for cervical cancer. Nevertheless, the PAP smear has associated with it a variety of error sources which limit its effectiveness. Several presentations at this meeting dealt with ways of automating and improving the accuracy of screening for cervical pathology. Magdy Mikhail and Seymour Romney of the Albert Einstein School of Medicine sought a correlation between intercapillary distance and different grades of cervical intra-epithelial neoplasia. In 40 women with either grade II or grade III cervical intra-epithelial neoplasia, intercapillary distance between the farthest two intercapillary points within each single mosaic, as well as the mosaic perimeter and surface area, were measured using a computer-assisted measurement system. Using these parameters, the mean intercapillary distance for grade II was found to be 0.064 mm, while the mean intercapillary distance for grade III was found to be 0.117 mm.

The differences in all of the parameters were found to be statistically significant. The increase in each of these parameters is associated with an increase in the grade of neoplasia.

Brian Lentrichia and his group from Cytyc (Boxborough, Massachusetts) examined the compatibility of their company's Thin Prep PAP Test with sensitive-amplified DNA testing for Chlamydia trachomatis. The group studied cervical scrapes from 443 subjects, and a Thin Prep slide was prepared along with a conventional slide for each subject. Both of these slides were read using a direct fluorescence assay (DFA) for chlamydia. The results of reading from these slides were compared to control tests performed using Ligase Chain Reaction (LCR) for Chlamydia on each scraping sample. In the study, 410 specimens were found to be adequate. In eight of these specimens, the DFA results disagreed between the Thin Prep and the conventional slides. Among those eight discrepent samples, the LCR results favored Thin Prep results 50% of the time.

Kenneth Hatch of the University of Arizona Health Science Center (Tucson, Arizona) reviewed the results of a multicenter clinical outcome trial aimed at evaluating the performance of the Thin Prep PAP Test. A total of 7,933 evaluable patients at eight sites were screened using the Thin Prep PAP Test. Results were compared with those in a historical control cohort of 16,261 patients. The Thin Prep PAP Test was shown to significantly increase the detection of low- and high-grade intra-epithelial lesions, when compared with the conventional PAP test. In addition, the ratio of atypical squamous cells of undetermined significance to low-grade intra-epithelial lesions was only 1.2 for the Thin Prep PAP Test compared to 2.1 for the conventional PAP test. Thus, Thin Prep provides increased sensitivity without reducing specificity.

3-D ultrasound imaging

Three-dimensional ultrasound has reached a point where it can produce remarkable images, particularly of the fetus. Although much of the attention given to 3-D obstetric ultrasound has focused on the human interest images of the fetal face and upper body, the real utility of this technique is in clinical problem solving, greatly improving our understanding of anatomy and pathology. The detection of abnormalities still depends upon the use of conventional 2-D imaging, however. Whether 2-D or 3-D, high quality images are required to make accurate diagnoses. The 2-D multiplanar reconstruction of the 3-D image is a particularly powerful tool for diagnosis. It should be noted that since the acquisition of a 3-D image can take up to five seconds in black and white and up to 30 seconds for color mode, the target of imaging must remain motionless for a period of time, or a clear image cannot be obtained.

Currently, 3-D ultrasound is at a strange place. It is not as widely accepted in the U. S. as it is in Asia and Europe because radiologists and technologists in the U. S. are not yet convinced that the clinical return is commensurate with the technological investments. Image acquisition is still difficult, resolution is not as high as desired and the clinical indications have not been established in large-scale clinical trials. While obstetricians and their patients and families quickly see the advantages of 3-D, radiologists want more proof that it will add clinical value to their diagnoses, according to Dolores Pretorius, a professor of radiology at the University of California, San Diego (San Diego, California). Pretorius has reported on several studies where 3-D ultrasound was used to visualize the fetal face. In one of her previous studies (American Journal of Roetenology; 165, 1233; 1995), 3-D ultrasound revealed facial abnormalities (cleft palate, facial dysmorphia, dysplastic ears, facial dysmorphia and microgynathia) that are typically missed by 2-D ultrasound. Pretorius sited the work of another author, accepted for publication in Radiology, in which 3-D ultrasound spotted all 28 cases of cleft lip and 21 out of 23 cases of cleft palate, while 2-D ultrasound detected 26 out of 28 cleft lips and only 12 out of 19 cleft palates. Pretorius had a patient with bleeding into the head of the fetus, but she was not able to ascertain if blood was entering the brain parenchyma or the ventricle. With 3-D ultrasound, one sweep is taken through the brain, it is lined up symetrically in all three planes, and bleeding into the brain parenchyma can be addressed.

The 3-D multiplanar approach is unparalleled in imaging the neonatal brain and fetal spine, according to Michael Manco-Johnson of the University of Colorado Health Sciences Center (Denver, Colorado). A couple of sweeps through the anterior fontanel of a 28-week-old baby and a sufficient number of images can be obtained to document what is going on. The time required to acquire 3-D images is less than that needed for standard 2-D technique, and this decreases the amount of time the baby has exposure to pathogens. Once two or three good volume sets are acquired, it is possible to reconstruct all standard imaging planes in the department off-line. If the fetus has a congenital spine abnormality, a volume acquisition can be obtained through the fetal back, and the image through the spine axially, longitudinally and coronally, can be reconstructed to find the level and the extent of the lesion.

Beverly Coleman of the University of Pennsylvania (Philadelphia, Pennsylvania) is using ultrasound in research of complicated fetal anomalies. Her study is focussed on determining how information in the third plane and volume rendering can improve diagnosis and surgical planning for thoracic mass lesions, such as congenital diaphragmatic hernia. This can allow surgeons to triage patients for intervention, based on whether a large volume of the liver along with the stomach and bowel has herniated into the chest. Since the liver, bowel and lung look the same on a 2-D ultrasound gray scale, it is difficult to tell whether the liver is in the chest. Power Doppler can help, since it can visualize the blood vessels of the liver, but it requires oblique scanning and is very time consuming, requiring up to two hours to scan a fetus. Based on Coleman's success in acquiring coronal views of the spine in fetuses with myelomeningocele, in differentiating aqueductal stenosis from idiopathic ventricular enlargement and agenesis of the corpur callosum in the sagittal plane, and in imaging cervical teratoma, getting a volume rendering with 3-D ultrasound should make it easier to see the liver and diaphragm. It also should make it possible to obtain the true volume of a lung mass and to identify any normal uninvolved lung on the same side by acquiring the image, turning it around and looking at the visualized lung.

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