A 60-year-old woman complains of air and stool coming from
her vagina. Digital rectal examination reveals an area of induration
on the rectovaginal septum, although contrast barium
enema does not demonstrate any abnormality. Which of the
following statements regarding her probable condition is true?
A. Eighty-five percent of fistulas caused by obstetric trauma
heal spontaneously.
B. Low rectovaginal fistulas may be treated effectively by
fistulotomy.
C. Rectovaginal fistulas associated with Crohn’s disease
usually necessitate proctectomy.
D. Radiation-induced fistulas generally necessitate a colostomy.
E. High rectovaginal fistulas respond well to fibrin glue.
COMMENTS: Rectovaginal fistulas are classified according to
location and cause, which influence the type of corrective surgery
required. High fistulas require an abdominal approach, whereas
low or midline fistulas can be repaired through a transanal, transperineal,
or transvaginal approach. The causes of these fistulas
include obstetric injuries, irradiation for pelvic cancers, recurrent
cancer, inflammatory bowel disease, violent trauma, or infection
(e.g., tuberculosis or lymphogranuloma venereum). Five percent of
all vaginal deliveries are accompanied by third- or fourth-degree
perineal lacerations. Approximately 10% of the repairs become
disrupted and result in incontinence and, potentially, a rectovaginal
fistula. Approximately 50% of these obstetric fistulas heal spontaneously
(not 85%); therefore, if the patient’s symptoms are not
disabling, a 3- to 6-month waiting period is recommended. This
waiting period also allows the tissue inflammation and edema to
subside before surgical intervention. Repair of a fistula secondary
to an obstetric injury can be performed transvaginally or transrectally.
With the former, the tract is excised and the rectovaginal
septum is inverted with serial purse-string sutures. With the latter,
a flap consisting of mucosa, submucosa, and muscularis is advanced
to cover the rectal side of the fistula. A diverting colostomy is not
required unless multiple previous surgical attempts have failed. An
anovaginal fistula may be treated by fistulotomy, but rectovaginal
fistulas (even distal ones) should not be treated by this method.
Partial or total incontinence may result if the fistula tract is divided.High rectovaginal fistulas are best treated through a transabdominal
approach so that coexisting pathologic conditions such
as diverticulitis, cancer, or inflammatory bowel disease can be
addressed. The rectovaginal septum is mobilized, the fistula is
divided, the vagina is closed, and normal tissue (such as omentum
or a muscle flap) is used to buttress the repair. Because the colon
is not usually normal (inflammation or radiation injury), bowel
resection is generally necessary.
Fistulas secondary to Crohn’s disease do not necessitate proctectomy
if the symptoms are minimal, the rectum is relatively
healthy, and continence is normal. In such cases, an advancement
flap can lead to healing. Refractory rectal Crohn’s disease (especially
the stricturing form) or incontinence usually necessitates
proctectomy. Radiation-induced fistulas may necessitate a colostomy
as sole therapy (e.g., poor-risk patient with recurrent, unresectable
cancer) or to divert stool from an anastomosis after
resection of diseased bowel.
A N S W E R : D
her vagina. Digital rectal examination reveals an area of induration
on the rectovaginal septum, although contrast barium
enema does not demonstrate any abnormality. Which of the
following statements regarding her probable condition is true?
A. Eighty-five percent of fistulas caused by obstetric trauma
heal spontaneously.
B. Low rectovaginal fistulas may be treated effectively by
fistulotomy.
C. Rectovaginal fistulas associated with Crohn’s disease
usually necessitate proctectomy.
D. Radiation-induced fistulas generally necessitate a colostomy.
E. High rectovaginal fistulas respond well to fibrin glue.
COMMENTS: Rectovaginal fistulas are classified according to
location and cause, which influence the type of corrective surgery
required. High fistulas require an abdominal approach, whereas
low or midline fistulas can be repaired through a transanal, transperineal,
or transvaginal approach. The causes of these fistulas
include obstetric injuries, irradiation for pelvic cancers, recurrent
cancer, inflammatory bowel disease, violent trauma, or infection
(e.g., tuberculosis or lymphogranuloma venereum). Five percent of
all vaginal deliveries are accompanied by third- or fourth-degree
perineal lacerations. Approximately 10% of the repairs become
disrupted and result in incontinence and, potentially, a rectovaginal
fistula. Approximately 50% of these obstetric fistulas heal spontaneously
(not 85%); therefore, if the patient’s symptoms are not
disabling, a 3- to 6-month waiting period is recommended. This
waiting period also allows the tissue inflammation and edema to
subside before surgical intervention. Repair of a fistula secondary
to an obstetric injury can be performed transvaginally or transrectally.
With the former, the tract is excised and the rectovaginal
septum is inverted with serial purse-string sutures. With the latter,
a flap consisting of mucosa, submucosa, and muscularis is advanced
to cover the rectal side of the fistula. A diverting colostomy is not
required unless multiple previous surgical attempts have failed. An
anovaginal fistula may be treated by fistulotomy, but rectovaginal
fistulas (even distal ones) should not be treated by this method.
Partial or total incontinence may result if the fistula tract is divided.High rectovaginal fistulas are best treated through a transabdominal
approach so that coexisting pathologic conditions such
as diverticulitis, cancer, or inflammatory bowel disease can be
addressed. The rectovaginal septum is mobilized, the fistula is
divided, the vagina is closed, and normal tissue (such as omentum
or a muscle flap) is used to buttress the repair. Because the colon
is not usually normal (inflammation or radiation injury), bowel
resection is generally necessary.
Fistulas secondary to Crohn’s disease do not necessitate proctectomy
if the symptoms are minimal, the rectum is relatively
healthy, and continence is normal. In such cases, an advancement
flap can lead to healing. Refractory rectal Crohn’s disease (especially
the stricturing form) or incontinence usually necessitates
proctectomy. Radiation-induced fistulas may necessitate a colostomy
as sole therapy (e.g., poor-risk patient with recurrent, unresectable
cancer) or to divert stool from an anastomosis after
resection of diseased bowel.
A N S W E R : D
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