Sigmoidocele

Sigmoidocele may be internal if it is only detectable on defecography, or external if it detectable without imaging and associated with a rectocele or rectal prolapse. It is a type of posterior compartment prolapse.

Sigmoidocele may be classified according to size relative to the pubococcygeal line.The "pubococcygeal line" (PCL) is a reference line which may be drawn on defecography. It extends from the inferior (lower) border of the pubic symphysis to the last coccygeal joint. See Bordeianou et al. 2018.

• Small: less than 3 cm between pubococcygeal line and the most inferior (lowest) point of the hernial sac.
• Moderate: 3–6 cm pubococcygeal line and the most inferior point of the sac.
• Large: more than 6 cm pubococcygeal line and the most inferior point of the sac.

The severity of sigmoidocele can be described with reference to the position of the lowest loop of the sigmoid relative to lines drawn on defecography:

• First-degree sigmoidocele: above the pubococcygeal line.
• Second-degree sigmoidocele: below the pubococcygeal line but above the ischiococcygeal line.The "ischiococcygeal line" is a reference line which may be drawn on defecography. It extends from the inferior (lower) border of the ischium to the last coccygeal joint. See Bordeianou et al. 2018.
• Third-degree sigmoidocele: below the ischiococcygeal line.

Sigmoidocele may not cause any symptoms.{{cite book | vauthors = Steele SR, Maykel JA, Wexner SD |title=Clinical Decision Making in Colorectal Surgery |date=11 August 2020 |publisher=Springer International Publishing |location=Cham |isbn=978-3-319-65941-1 |edition=2nd |language=en |pages=22, 23}}

• Obstructed defecation syndrome. It has been suggested that a sigmoidocele does not cause obstruction, but rather is a compensatory mechanism which increases rectal pressure and helps evacuation in the presence of excessive perineal descent.{{cite book |editor1-last=Brown |editor1-first=SR |editor2-last=Hartley |editor2-first=JE |editor3-last=Hill |editor3-first=J |editor4-last=Scott |editor4-first=N |editor5-last=Williams |editor5-first=G |title=Contemporary Coloproctology |date=2012 |publisher=Springer |location=London Heidelberg |isbn=978-1-4471-5856-1 |pages=391 |language=en}}
• Incomplete evacuation of rectal contents.{{cite book | vauthors = Herold A, Lehur PA, Matzel KE, O'Connell PR |title=European Manual of Medicine: Coloproctology |date=2017 |location=Berlin, Germany |isbn=978-3-662-53210-2 |edition=Second |language=en |pages=9,129}}
• Bulge in posterior (back) wall of vagina.{{cite book |editor1-last=Zbar |editor1-first=AP |editor2-last=Wexner |editor2-first=SD |title=Coloproctology |date=18 March 2010 |publisher=Springer London |isbn=978-1-84882-755-4 |language=en |pages=140–143}}

The phenomenon is caused by a weak section of fascial supports of the vagina (the uterosacral cardinal ligament complex and rectal vaginal septum), which allows a section of peritoneum containing the sigmoid colon to prolapse out of normal position and descend between the rectum and the vagina.

The mesentery of the sigmoid colon (the structure which attaches the colon to the abdominal wall) is termed the mesosigmoid. This structure is very flexible, which means that the sigmoid colon is very mobile and may change position. During defecation it may be pushed down, eventually causing sigmoidocele.

Sigmoidocele may be associated with descending perineum syndrome.{{cite journal |last1=Schwandner |first1=O |last2=Poschenrieder |first2=F |last3=Gehl |first3=HB |last4=Bruch |first4=HP |title=[Differential diagnosis in descending perineum syndrome]. |journal=Der Chirurg; Zeitschrift für alle Gebiete der operativen Medizen |date=September 2004 |volume=75 |issue=9 |pages=850–60 |doi=10.1007/s00104-004-0922-9 |pmid=15258747}}

It is not possible to differentiate between a rectocele and a sigmoidocele on vaginal examination. Defecating proctography will demonstrate a sigmoidocele during straining.

Surgery is considered if there is a significant hernia combined with symptoms of obstructed defecation.

Laparoscopic ventral mesh rectopexy has been used to correct sigmoidocele. This procedure involves inserting a mesh between the rectum and the vagina. The mesh is suspended from the sacral promontory without tension. This acts to support the recto-vaginal septum and elevate a deep pouch of Douglas. If there is prolapse of the middle compartment, sacrocolpopexy may be carried out to surgically correct all pelvic prolapse problems in the same procedure.{{cite book | vauthors = Steele SR, Hull TL, Hyman N, Maykel JA, Read TE, Whitlow CB |title=The ASCRS Textbook of Colon and Rectal Surgery |date=20 November 2021 |publisher=Springer Nature |location=Cham, Switzerland |isbn=978-3-030-66049-9 |edition=4th |language=en |page=1014}}

Other treatment options are anterior resection, sigmoidopexy with rectocele repair,{{cite book |editor1-last=Schlachta |editor1-first=CM |editor2-last=Sylla |editor2-first=P |title=Current Common Dilemmas in Colorectal Surgery |date=2018 |publisher=Springer Nature |isbn=978-3-319-70117-2 |pages=184, 186 |doi=10.1007/978-3-319-70117-2 |url=https://link.springer.com/book/10.1007/978-3-319-70117-2 |language=en}} or sigmoidectomy.

Sigmoidocele normally occurs in females, and is uncommon. Sigmoidocele is detected about 4-5% of the time when defecography is carried out.{{cite book | vauthors = Ratto C, Parrello A, Dionisi L, Litta F |title=Coloproctology: Colon, Rectum and Anus: Anatomic, Physiologic and Diagnostic Bases for Disease Management |date=2014 |publisher=Springer International Publishing |location=Cham, Switzerland |isbn=978-3-319-10154-5 |language=en |pages=229, 280}}

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{{Female diseases of the pelvis and genitals}}

Category:Noninflammatory disorders of female genital tract

Category:Colorectal surgery

Category:Gynaecology