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Perineal Hernia 775

Advanced or Confirmatory Testing • Colopexy may be necessary for severe
• Ultrasound exam sacculation
VetBooks.ir ○ Identify bladder herniation Nutrition/Diet Diseases and Disorders
○ Prostatic evaluation
○ If history of castration status of male dog
• Postoperatively
is unknown, search for testicle(s)
○ Easily digestible fiber diets produce soft
• Gonadotropin-releasing hormone (GnRH) ○ Prevention of tenesmus
stimulation testing if castration status but formed stool.
unknown ○ Stool softeners (e.g., lactulose, psyllium) if
pain or tenesmus is noted during defecation
TREATMENT
Possible Complications
Treatment Overview • Complications associated with perineal hernia
Perineal hernias require surgical repair for suc- ○ Urinary obstruction
cessful resolution. Goals of surgical intervention ○ Urinary incontinence secondary to pelvic
are to replace the herniated contents into the or pudendal nerve entrapment and
abdomen and reconstruct the pelvic diaphragm. dysfunction
Complicated hernias may require an additional ○ Constipation
abdominal approach to surgically fix herniated ○ Compromised intestinal segments
organs in place. Concurrent castration decreases • Complications associated with herniorrhaphy
risk of recurrence. Medical management consist- ○ Up to 27% recurrence rate when an
ing of stool softeners and a high-fiber diet may internal obturator flap is used
be instituted if other medical conditions make ○ Tenesmus postoperatively led to higher
the patient a poor surgical candidate. rate of recurrence and contralateral side
herniation.
Acute General Treatment ○ A 2.7 times greater risk of recurrence when
• Emergency treatment to relieve urinary left sexually intact (male dogs)
PERINEAL HERNIA Large, right-sided perineal obstruction caused by a retroflexed bladder ○ Incisional dehiscence and infection
hernia with omental herniation. Note the deviation ○ Passage of a red rubber catheter can ○ Fecal incontinence (<15%)
of the rectum to the left. (Courtesy Dr. Bryden Stanley.) alleviate the obstruction. ○ Sciatic nerve entrapment (<5%)
○ Percutaneous cystocentesis
• Tenesmus causes excessive strain on pelvic ○ Indwelling urinary catheter Recommended Monitoring
diaphragm. • Constipation/impaction relief Routine rectal exam to evaluate integrity of
• Neurogenic atrophy of pelvic diaphragm ○ Manual evacuation under sedation pelvic diaphragm repair
muscles ○ Stool softeners/dietary management
• Trauma in cats and female dogs • Surgical repair (herniorrhaphy) PROGNOSIS & OUTCOME
○ Ensure organ viability, and replace herni-
DIAGNOSIS ated contents into abdomen. • Good to excellent outcome with successful
○ Use tension-free closure with reconstruc- herniorrhaphy and no other concurrent
Diagnostic Overview tion of the pelvic diaphragm. The internal diseases
Perineal hernia is suspected in cases of unilateral obturator flap technique is the surgical • Fair to poor prognosis if the patient cannot
or bilateral perineal swelling. It may be identi- procedure of choice (<25% recurrence rate) undergo surgical correction, there is recur-
fied during workup of tenesmus. Rectal exam ○ Uncomplicated hernias can be repaired rence after appropriate surgical correction,
is necessary for confirmation. Bilateral pelvic using a perineal approach. and/or cannot resolve cause of tenesmus/
diaphragmatic muscle weakness is often identi- ○ Complicated hernias may require addi- dysuria
fied, even when perineal swelling is unilateral. tional abdominal approach for cystopexy ± • Highest complication rate seen with con-
vas deferens–pexy for bladder entrapment tinued tenesmus after surgery and if not
Differential Diagnosis or colopexy for severe rectal sacculation concurrently castrated
• Perianal adenoma (consider staged procedures).
• Anal sac adenocarcinoma • Prevent recurrence PEARLS & CONSIDERATIONS
• Anal sac abscess ○ Castration: to remove androgen effect on
• Colorectal mass pelvic diaphragm muscles Comments
○ Treatment of underlying cause of tenes- • Perineal hernia may be a hormonally related
Initial Database mus (e.g., castration for prostatomegaly, disease in the male dog.
• CBC, serum biochemistry profile, urinalysis enrofloxacin 10 mg/kg PO q 24h for • Herniorrhaphy plus castration is the
○ Presurgical screening prostatitis) treatment of choice; consider referral to a
○ Bladder entrapment (renal and/or post- • Bilateral herniorrhaphy often is necessary, soft-tissue surgeon.
renal azotemia) but more affected side should be performed • Diagnosis and elimination of underlying
○ Elevated white blood cell count, first. causes of tenesmus are important for a
toxic changes (entrapped/incarcerated successful outcome.
bowel or tissue) Chronic Treatment • Revision perineal herniorrhaphy is chal-
• External perineal and rectal exam • Prevention of tenesmus in the postoperative lenging and should not be undertaken by
○ Unilateral versus bilateral period inexperienced surgeons.
○ Rule out rectal/colonic neoplasia and ○ Dietary management
prostatic disease. ○ Stool softeners Prevention
• Survey abdominal and pelvic radiographs. • Identification of causes of prostatomegaly • Prevention of tenesmus plays a role in slowing
○ Position of bladder/prostate • Cystopexy ± vas deferens–pexy may be the development or progression of perineal
○ Evaluation of contents of hernia necessary for bladder herniation. hernia.

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