Title: Perineal hernia

{{Short description|Type of hernia}}
{{Infobox anatomy
| Name        = Perineum in humans
| Latin       =
| Image       = 1116 Muscle of the Female Perineum.png
| Caption     = The muscles of the female perineum
| Image2      = 1116 Muscle of the Male Perineum.png
| Caption2    = The muscles of the male perineum
}}
'''Perineal hernia''' is a [[hernia]] involving the [[perineum]] ([[pelvic floor]]).  The hernia may contain fluid, [[fat]], any part of the [[intestine]], the [[rectum]], or the [[urinary bladder|bladder]]. It is known to occur in [[human]]s, [[dog]]s, and other mammals, and often appears as a sudden swelling to one side (sometimes both sides) of the [[anus]].

A common cause of perineal hernia is surgery involving the perineum.{{medical citation needed|date=August 2023}} Perineal hernia can be caused also by excessive straining to defecate.{{medical citation needed|date=August 2023}} [[Atrophy]] of the [[levator ani muscle]] and disease of the [[pudendal nerve]] may also contribute to a perineal hernia.{{medical citation needed|date=August 2023}}

==In humans==
In humans, a major cause of perineal hernia is perineal surgery without adequate reconstruction.  In some cases, particularly surgeries to remove the coccyx and distal sacrum, adequate reconstruction is very difficult to achieve.  The posterior perineum is a preferred point of access for surgery in the [[pelvic cavity]], particularly in the [[presacral space]].  Surgeries here include repair of [[rectal prolapse]] and anterior [[meningocele]], [[radical perineal prostatectomy]], removal of [[tumor]]s including [[sacrococcygeal teratoma]], and [[coccygectomy]].  Perineal hernia is a common complication of coccygectomy in adults,&lt;ref name=&quot;pmid9207665&quot;&gt;{{cite journal
|vauthors=Zook NL, Zook EG | title   = Repair of a long-standing coccygeal hernia and open wound.
| journal = Plast. Reconstr. Surg.
| volume  = 100
| issue   = 1
| pages   = 96–9
| year    = 1997
| pmid    = 9207665
| doi     = 10.1097/00006534-199707000-00017 
}}&lt;/ref&gt;&lt;ref name=&quot;pmid9840311&quot;&gt;{{cite journal
|vauthors=García FJ, Franco JD, Márquez R, Martínez JA, Medina J | title   = Posterior hernia of the rectum after coccygectomy.
| journal = Eur J Surg
| volume  = 164
| issue   = 10
| pages   = 793–4
| year    = 1998
| pmid    = 9840311
| doi     = 10.1080/110241598750005462 
| doi-access= free
}}&lt;/ref&gt; but not in infants and children (see [[coccygectomy]]).

The standard surgical technique for repair of perineal hernia uses a prosthetic mesh,&lt;ref name=&quot;pmid10743431&quot;&gt;{{cite journal
|vauthors=Kumar A, Reynolds JR | title   = Mesh repair of a coccygeal hernia via an abdominal approach.
| journal = Annals of the Royal College of Surgeons of England
| volume  = 82
| issue   = 2
| pages   = 113–5
| year    = 2000
| pmid    = 10743431
| pmc     = 2503516 
}}&lt;/ref&gt; but this technique has a high rate of failure due to insufficient anchoring.  Promising techniques to reduce the rate of failure include an [[orthopedic]] anchoring system,&lt;ref name=&quot;pmid15580523&quot;&gt;{{cite journal
|vauthors=Berrevoet F, Pattyn P | title   = Use of bone anchors in perineal hernia repair: a practical note.
| journal = Langenbecks Arch Surg
| volume  = 390
| issue   = 3
| pages   = 255–8
| year    = 2005
| pmid    = 15580523
| doi     = 10.1007/s00423-004-0523-6 
| s2cid = 10049165
}}&lt;/ref&gt; a [[gluteus maximus]] muscle flap,&lt;ref name=&quot;pmid9207665&quot;/&gt;&lt;ref name=&quot;pmid16705361&quot;&gt;{{cite journal
|vauthors=Brizendine JB, LeFaivre JF, Yost MJ, Fann SA | title   = Reconstruction of parasacral hernia with acellular human dermis graft.
| journal = Hernia
| volume  = 10
| issue   = 4
| pages   = 360–3
| year    = 2006
| pmid    = 16705361
| doi     = 10.1007/s10029-006-0092-4 
| s2cid = 33604955
}}&lt;/ref&gt; an acellular human dermis graft,&lt;ref name=&quot;pmid16705361&quot;/&gt; and an acellular pig collagen graft.&lt;ref name=&quot;pmid18439796&quot;&gt;{{cite journal
|vauthors=Abhinav K, Shaaban M, Raymond T, Oke T, Gullan R, Montgomery AC | title   = Primary reconstruction of pelvic floor defects following sacrectomy using Permacoltrade mark graft
| journal = Eur J Surg Oncol
| volume  = 35
| issue   = 4
| pages   = 439–43
| date    = April 2008
| pmid    = 18439796
| doi     = 10.1016/j.ejso.2008.03.007
}}&lt;/ref&gt;

==In dogs and cats==
[[File:Perineal-hernia-dog.jpg|thumb|Advanced perineal hernia on the left side in a dog. The overlying skin is already blueish.]]
In dogs, perineal hernia usually is found on the right side.&lt;ref&gt;{{cite journal |vauthors=Head L, Francis D |title=Mineralized paraprostatic cyst as a potential contributing factor in the development of perineal hernias in a dog |journal=J Am Vet Med Assoc |volume=221 |issue=4 |pages=533–5, 500 |year=2002 |pmid=12184704 |doi=10.2460/javma.2002.221.533|doi-access=free }}&lt;/ref&gt;  Most cases are in older intact (not [[neutering|neutered]]) male dogs (93 percent in one study).&lt;ref&gt;{{cite web | last = Seim | first = Howard B., III | title = Perineal Hernia Repair | work = Proceedings of the 29th World Congress of the World Small Animal Veterinary Association |year=2004 | url = http://www.vin.com/proceedings/Proceedings.plx?CID=WSAVA2004&amp;PID=8772&amp;O=Generic | access-date = 2007-03-25 }}&lt;/ref&gt;  Breeds that may be at risk include [[Welsh Corgi]]s, [[Boxer (dog)|Boxer]]s, [[Australian Kelpie]]s, [[Boston Terrier]]s, [[Collie]]s, [[Dachshund]]s, [[Old English Sheepdog]]s, and [[Pekingese]].&lt;ref&gt;{{cite web | title = Perineal Hernia | work = The Merck Veterinary Manual |year=2006 | url = http://www.merckvetmanual.com/mvm/index.jsp?cfile=htm/bc/20605.htm | access-date = 2007-03-25 }}&lt;/ref&gt;  Perineal hernias are rare in female dogs and uncommon in [[cat]]s.

Dogs with [[benign prostatic hyperplasia]] have been found to have increased [[relaxin]] levels and suspected subsequent weakening of the pelvic diaphragm.&lt;ref&gt;{{cite journal |vauthors=Niebauer G, Shibly S, Seltenhammer M, Pirker A, Brandt S |title=Relaxin of prostatic origin might be linked to perineal hernia formation in dogs |journal=Annals of the New York Academy of Sciences |volume=1041 |pages=415–22 |year=2005 |issue=1 |pmid=15956739 |doi=10.1196/annals.1282.062|bibcode=2005NYASA1041..415N |s2cid=5754439 }}&lt;/ref&gt;  In cats, perineal hernias are seen most commonly following perineal [[urethrostomy]] surgery or secondary to [[megacolon]].&lt;ref name=DVM&gt;{{cite journal | last = Hoskins | first = Johnny D. | title = Anorectal Disease | journal = DVM | pages = 8S–10S | publisher = Advanstar Communications |date=September 2006 }}&lt;/ref&gt;  Medical treatment consists of treatment of the underlying disease, [[enema]]s, and stool softeners.  Because only about 20 percent of cases treated medically are free of symptoms, surgery is often necessary.&lt;ref name=DVM/&gt;  Recurrence is common with or without surgery.

Several surgeries have been described for perineal hernias in dogs.  The current standard involves transposition of the [[Obturator internus muscle|internal obturator muscle]].  This technique has a lower recurrence and complication rate than traditional hernia repair.  A new technique uses [[pig|porcine]] [[small intestine|small intestinal]] [[submucosa]] as a [[biomaterial]] to help repair the defect.  This is can also be done in combination with internal obturator muscle transposition, especially when that muscle is weak.&lt;ref name=Ettinger&gt;{{cite book|author1=Ettinger, Stephen J. |author2=Feldman, Edward C. |title=Textbook of Veterinary Internal Medicine|edition=6th|publisher=W.B. Saunders Company|year=2005|isbn=1-4160-0110-7}}&lt;/ref&gt;

==References==
{{Reflist}}

[[Category:Dog diseases]]
[[Category:Hernias]]