Die Messung des infrapubischen Winkels in der 3-D-Perineal-Sonografie und seine Beziehung zu geburtshilflichen Parametern

Zusammenfassung

Ziel: Die 3-D-Sonografie bietet einige Vorteile gegenüber der 2-D-Sonografie in der Urogynäkologie. Neben den Weichteil-Strukturen ermöglicht die Darstellung der axialen Ebene die Identifikation des Levators und der Symphyse. Ziel dieser Arbeit war es, eine genaue Messung des infrapubischen Winkels sowie des Symphysenspalts durch Rotations-Anpassung zu beschreiben und die Inter-Observer-Variabilität zu bestimmen. Zusätzlich wurden die Korrelationen des infrapubischen Winkels mit dem Auftreten von Levator-Defekten und der Dauer der Austreibungsperiode untersucht.

Material und Methoden: Am 2. bis 3. Tag postpartal nach Vaginalgeburt wurde eine 3-D-Sonografie durchgeführt. Die Auswertung erfolgte unabhängig durch 2 Untersucher.

Ergebnisse: Es wurden 110 Datensätze erfasst. Für die Bestimmung des infrapubischen Winkels konnten 104 Datensätze (94,5 %), für die Messung der Symphysenspalt-Breite 87 (79,1 %) bearbeitet werden. Mit einem Pearson-Korrelations-Koeffizient von r = 0,76 für die Messung der Inter-Observer-Variabilität des infrapubischen Winkels bzw. r = 0,69 für die Messung des Symphysenspalts konnte eine sehr gute bzw. mäßig bis gute Korrelation nachgewiesen werden. Für beide Untersucher konnte mit p = 0,31 bzw. p = 0,78 keine Korrelation des infrapubischen Winkels mit der Dauer der Austreibungsperiode gefunden werden. Ebenso fand sich mit Werten von p = 0,59 bzw. p = 0,39 kein Zusammenhang des infrapubischen Winkels mit dem Auftreten von Levator-Defekten.

Schlussfolgerung: Mittels der 3-D-Sonografie können auch knöcherne Konturen mit einer guten Reproduzierbarkeit beurteilt werden. Der infrapubische Winkel scheint nur eine untergeordnete Rolle für die Dauer der Austreibungsperiode und die Entstehung von postpartalen Levator-Schäden zu spielen.

Abstract

Purpose: Ultrasound has achieved an indispensable role in urogynecology. The introduction of 3 D technology has enabled sonographers to visualize structures in the axial plane. The angle of the infrapubic arc may enable us to presume the shape of the pelvis. Our aim was to describe a method for measuring the infrapubic angle and the interpubic space with 3 D perineal ultrasound through 3 D rotation, correlating them with the length of the 2nd stage of labor and the rate of levator defects.

Materials and Methods: Women after vaginal delivery were recruited and underwent a 3 D perineal ultrasound on 2nd – 3 rd day postpartum. Volume datasets were analyzed to measure the infrapubic angle and the interpubic space independently by 2 urogynecologists. The interobserver reliability and the correlation between infrapubic arc angle and the length of the 2nd stage of labor and the occurrence of levator defects were calculated.

Results: 110 women were enrolled. With a correlation coefficient of 0.76, the relationship between the infrapubic angle measurements of the two observers was very good. A moderate to good correlation was found for the assessment of the interpubic gap, with r = 0.69. Between the infrapubic angle and length of the 2nd stage of labor, no statistical correlation for both observer measurements (p = 0.31; p = 0.78, respectively) was found. Also the correlation between the infrapubic arc angle and the occurrence of levator avulsions was not significant (p = 0.59; p = 0.39, respectively).

Conclusion: 3 D ultrasound technology enables us to identify and evaluate the interpubic gap and the infrapubic arc with a high inter-observer reproducibility. However, from our data, the infrapubic angle does not seem to influence the length of the 2^nd stage of labor and the occurrence of levator defects.

Key words

3 D ultrasound - pelvis - pelvic organs

• Literatur

• 1 Bader W et al. Introital and perineal sonography in diagnosing stress urinary incontinence – possible clinical applications. Ultraschall in Med 2004; 25: 181-190
• 2 Braekken IH et al. Test-retest and intra-observer repeatability of two-, three- and four-dimensional perineal ultrasound of pelvic floor muscle anatomy and function. International urogynecology journal and pelvic floor dysfunction 2008; 19: 227-235
• 3 Dietz HP. Ultrasound imaging of the pelvic floor. Part II: three-dimensional or volume imaging. Ultrasound Obstet Gynecol 2004; 23: 615-625
• 4 Dietz HP. Why pelvic floor surgeons should utilize ultrasound imaging. Ultrasound Obstet Gynecol 2006; 28: 629-634
• 5 Dietz HP et al. Two-dimensional and three-dimensional ultrasound imaging of suburethral slings. Ultrasound Obstet Gynecol 2005; 26: 175-179
• 6 Dietz HP et al. Biometry of the pubovisceral muscle and levator hiatus by three-dimensional pelvic floor ultrasound. Ultrasound Obstet Gynecol 2005; 25: 580-585
• 7 Dietz HP et al. Anatomical assessment of the bladder outlet and proximal urethra using ultrasound and videocystourethrography. Int Urogynecol J Pelvic Floor Dysfunct 1998; 9: 365-369
• 8 Dietz HP et al. The “iris effect”: how two-dimensional and three-dimensional ultrasound can help us understand anti-incontinence procedures. Ultrasound Obstet Gynecol 2004; 23: 267-271
• 9 Handa VL et al. Architectural differences in the bony pelvis of women with and without pelvic floor disorders. Obstet Gynecol 2003; 102: 1283-1290
• 10 Harmanli OH et al. Narrow pubic arch and increased risk of failure for vaginal hysterectomy. Obstet Gynecol 2004; 104: 697-700
• 11 Maharaj D. Assessing cephalopelvic disproportion: back to the basics. Obstet Gynecol Surv 2010; 65: 387-395
• 12 Petri E et al. What is the place of ultrasound in urogynecology? A written panel. Int Urogynecol J Pelvic Floor Dysfunct 1999; 10: 262-273
• 13 Ridgeway BM et al. Variation of the obturator foramen and pubic arch of the female bony pelvis. Am J Obstet Gynecol 2008; 198: 546.e1-546.e4
• 14 Schaer G et al. Recommendations of the German Association of Urogynecology on functional sonography of the lower female urinary tract. Int Urogynecol J Pelvic Floor Dysfunct 1996; 7: 105-108
• 15 Shek KL et al. Intrapartum risk factors for levator trauma. BJOG 2010; 117: 1485-1492
• 16 Tunn R et al. MR imaging of levator ani muscle recovery following vaginal delivery. International urogynecology journal and pelvic floor dysfunction 1999; 10: 300-307
• 17 Tunn R et al. Updated recommendations on ultrasonography in urogynecology. Int Urogynecol J Pelvic Floor Dysfunct 2005; 16: 236-241
• 18 Valsky DV et al. Fetal head circumference and length of second stage of labor are risk factors for levator ani muscle injury, diagnosed by 3-dimensional transperineal ultrasound in primiparous women. Am J Obstet Gynecol 2009; 201: 91.e1-91.e7
• 19 Wentz KU et al. Pelvimetrie mittels verschiedener kernspintomographischer Techniken vs. digitale Bildverstärkerradiographie: Genauigkeit, Zeitbedarf und Energiebelastung. Geburtshilfe Frauenheilkd 1994; 54: 204-212
• 20 Yang JM et al. Biometry of the pubovisceral muscle and levator hiatus in nulliparous Chinese women. Ultrasound in obstetrics & gynecology: the official journal of the International Society of Ultrasound in Obstetrics and Gynecology 2006; 28: 710-716
• 21 Yeomans ER. Clinical pelvimetry. Clin Obstet Gynecol 2006; 49: 140-146