Abstract
Introduction and hypothesis
A correlation exists between external anal sphincter (EAS) damage during birth and the subsequent development of fecal incontinence. This study evaluated the effect of delivery-related trauma on EAS innervation by means of intra-anal EMG performed with a rectal probe with 16 silver electrodes equally spaced along the circumference, before and after delivery.
Methods
Pre-partum EMG measurements were performed on 511 women, by nine clinical partners from five European countries at the 28th to 34th gestational weeks and the 6th to 8th post-delivery weeks; 331 women returned, after delivery, for the second test. The innervation zones (IZ) of EAS single motor units were identified by means of an EMG decomposition algorithm.
Results
The subjects were divided into four groups according to the delivery mode (Caesarean, vaginal with no evident damage, spontaneous lacerations and episiotomies). The number of IZs before and after delivery was compared. In the 82 women who underwent right mediolateral episiotomy, a statistically significant reduction of IZs was observed, after delivery, in the right ventral quadrant of the EAS (side of the episiotomy). Women who had Caesarean section, spontaneous lacerations or lack of evident damage did not present any significant change in the innervation pattern.
Conclusions
Right episiotomy reduces the number of IZs on the right-ventral side of the EAS. The fast and reliable test proposed indicates the sphincter innervation pattern before delivery and helps obstetricians to evaluate the risks and to choose the preferred side of the episiotomy, if deemed necessary at the time of delivery.
References
Sultan AH, Kamm MA, Bartram CI, Hudson CN (1993) Anal sphincter trauma during instrumental delivery. Int J Gynaecol Obstet 43(3):263–270
Fenner DE, Genberg B, Brahma P, Marek L, DeLancey JO (2003) Fecal and urinary incontinence after vaginal delivery with anal sphincter disruption in an obstetrics unit in the United States. Am J Obstet Gynecol 189(6):1543–1549, discussion 1549–1550
Andrews V, Sultan AH, Thakar R, Jones PW (2006) Risk factors for obstetric anal sphincter injury: a prospective study. Birth 33(2):117–122
Thacker SB, Banta HD (1983) Benefits and risks of episiotomy: an interpretative review of the English language literature:1860–1980. Obstet Gynecol Surv 38:322–338
Woolley RJ (1995) Benefits and risks of episiotomy: a review of the English-language literature since 1980. Part I. Obstet Gynecol Surv 50:806–820
Woolley RJ (1995) Benefits and risks of episiotomy: a review of the English-language literature since 1980. Part II. Obstet Gynecol Surv 50:821–835
Sartore A, De Seta F, Maso G et al (2004) The effects of mediolateral episiotomy on pelvic floor function after vaginal delivery. Obstet Gynecol 103:669–673
Graham ID, Carroli G, Davies C, Medves JM (2005) Episiotomy rates around the world: an update. Birth 32(3):219–223
Handa VL, Blomquist JL, McDermott KC, Friedman S, Muñoz A (2012) Pelvic floor disorders after vaginal birth: effect of episiotomy, perineal laceration, and operative birth. Obstet Gynecol 119(2 Pt 1):233–239
Dudding TC, Vaizey CJ, Kamm MA (2008) Obstetric anal sphincter injury: incidence, risk factors, and management. Ann Surg 247(2):224–237
Edwards NI, Jones D (2001) The prevalence of fecal incontinence in older people living at home. Age Aging 30:503–507
Fitzgerald MP, Weber AM, Howden N, Cundiff GW, Brown MB (2007) Risk factors for anal sphincter tear during vaginal delivery. Obstet Gynecol 109(1):29–34
Kudish B, Blackwell S, McNeeley S et al (2006) Operative vaginal delivery and midline episiotomy: a bad combination for the perineum. Am J Obstet Gynecol 195:749–754
McKinnie V, Swift SE, Wang W et al (2005) The effect of pregnancy and mode of delivery on the prevalence of urinary and fecal incontinence. Am J Obstet Gynecol 193:512–517
Pirro N, Sastre B, Sielezneff IJ (2007) What are the risk factors of anal incontinence after vaginal delivery? J Chir (Paris) 144(3):197–202
Pretlove SJ, Thompson PJ, Toozs-Hobson PM, Radley S, Khan KS (2008) Does the mode of delivery predispose women to anal incontinence in the first year postpartum? A comparative systematic review. BJOG 115(4):421–434
Wheeler TL, Richter HE (2007) Delivery method, anal sphincter tears and fecal incontinence: new information on a persistent problem. Curr Opin Obstet Gynecol 19(5):474–479
De Leeuw JW, Vierhout ME, Struijk PC, Hop WC, Wallenburg HC (2001) Anal sphincter damage after vaginal delivery: functional outcome and risk factors for fecal incontinence. Acta Obstet Gynecol Scand 80(9):830–834
Tincello DG, Williams A, Fowler GE et al (2003) Differences in episiotomy technique between midwives and doctors. BJOG 110:1041–1044
Podnar S, Lukanovic A, Vodusek DB (2000) Anal sphincter electromyography after vaginal delivery: neuropathic insufficiency or normal wear and tear? Neurourol Urodyn 19(3):249–257
Gregory WT, Lou JS, Simmons K, Clark AL (2008) Quantitative anal sphincter electromyography in primiparous women with anal incontinence. Am J Obstet Gynecol 198(5):550.e1–550.e6
Merletti R, Bottin A, Cescon C, Farina D, Mesin L, Gazzoni M, Martina S, Pozzo M, Rainoldi A, Enck P (2004) Multichannel surface EMG for the non-invasive assessment of the anal sphincter muscle. Digestion 69:112–122
Enck P, Franz H, Azpiroz F, Fernandez-Fraga X, Hinninghofen H, Kaske-Bretag K, Bottin A, Martina S, Merletti R (2004) Innervation zones of the external anal sphincter in healthy male and female subjects. Digestion 69:123–130
Cescon C (2006) Automatic location of muscle innervation zones from multi-channel surface EMG signals. Proceedings of the IEEE International Workshop on Medical Measurement and Applications (MeMeA2006), Benevento, Italy
Ullah K, Afsharipour B, Cescon C, Merletti R (2014) Automatic detection of motor unit innervation zones of the external anal sphincter by multichannel surface EMG. XX Congress of the Int. Society for Electrophysiology and Kinesiology, Rome, July 2014 (in press)
Wietek BM, Hinninghofen H, Jehle EC, Enck P, Franz HB (2007) Asymmetric sphincter innervation is associated with fecal incontinence after anal sphincter trauma during childbirth. Neurourol Urodyn 26(1):134–139
Cescon C, Merletti R (2010) Conic disposable rectal probe. International patent nr. TO2009A000814
Holobar A, Zazula D (2007) Multichannel blind source separation using convolution kernel compensation. IEEE Trans Signal Process 55:4487–4496
Holobar A, Enck P, Hinninghofer H, Merletti R (2008) Decomposition of surface EMG from external anal sphincter. XVII Congress of the International Society of Electrophysiology and Kinesiology, Niagara Falls, Ontario
Zuur AF, Ieno EN, Walker NJ, Saveliev AA, Smith GM (2009) Mixed effects models and extensions in ecology with R (Statistics for Biology and Health). Springer, Berlin Heidelberg, New York
Oberwalder M, Dinnewitzer A, Baig MK, Thaler K, Cotman K, Nogueras JJ, Weiss EG, Efron J, Vernava AM, Wexner SD (2004) The association between late-onset fecal incontinence and obstetric anal sphincter defects. Arch Surg 139(4):429–432
Carroli G, Belizan J, Stamp G (1999) Episiotomy for vaginal birth. Cochrane Database Syst Rev CD000081, doi:10.1002/14651858
Acknowledgements
This work was sponsored by Projects TASI (Else Kroner-Fresenius-Stiftung, Compagnia di San Paolo) and TASI-2 (Compagnia di San Paolo). The authors are grateful to Professor Mauro Gasparini for help with statistical analysis, and to Doctors Eleonora Ester Raimondi, Dace Rezeberga, Olesja Zelenova, Pier Dino Rattazzi, Luigi Spagna, Adolf Lukanovic, Anna Maria Paoletti, Donatella Marongiu, Maggiorino Barbero, Vicky Rabino, Lena Martynshyn, Marina Storoshuk, and Milena Ludescher for their help in recruiting patients and taking EMG measurements.
Conflict of interest
None of the authors has any conflict of interest.
Number of authors
Nine clinical institutions and one engineering institution participated in this multicentre study. Six authors are from six clinical institutions and two from the engineering institution that proposed and coordinated the study. A smaller number of authors would strongly penalise institutions that contributed substantially to the multicentre study.
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Cescon, C., Riva, D., Začesta, V. et al. Effect of vaginal delivery on the external anal sphincter muscle innervation pattern evaluated by multichannel surface EMG: results of the multicentre study TASI-2. Int Urogynecol J 25, 1491–1499 (2014). https://doi.org/10.1007/s00192-014-2375-0
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DOI: https://doi.org/10.1007/s00192-014-2375-0