Author
Information
Samant
PY*, Parulekar SV**
(*
Additional Professor, ** Professor and Head, Department of Obstetrics
and Gynacology, Seth G.S. Medical College and K.E.M Hospital, Mumbai,
India.)
Abstract
Scar
dehiscence is not a unique finding at cesarean section. But
dehiscence at more than one site at the same time in a case is
extremely rare. We report an incidental finding of scar dehiscence at
two sites at elective cesarean section at 38 weeks gestation in a
registered antenatal patient with two previous cesarean sections.
Introduction
With
rising trend and incidence of cesarean section combined with high
parity and propensity to have unplanned and home deliveries; the
risks to maternal and fetal life posed by scar dehiscence and rupture
are very high. Scar dehiscence is defined as disruption of the
uterine muscle with intact uterine serosa.
[1] It is also
called as Cesarean scar
defect (CSD), and involves myometrial discontinuity at the site of a
previous Cesarean section scar. Though
the commonest etiological factor for dehiscence is a cesarean scar;
other scars like those of myomectomy, metroplasty, accidental
perforation during curettage are known to cause rupture or
dehiscence. Myomectomy using cautery is also known to cause scar
dehiscence and can pose risk of rupture [2].
With rising incidence of multiple cesarean sections, occurrence of
multiple dehiscent windows is plausible.
Case
Report
Thirty-four
years old multigravida with previous two cesarean sections was
admitted for elective cesarean section with tubal ligation after
thirty-eight weeks. Her
preoperative investigations were normal. Obstetric ultrasonography
was unremarkable. She did not report any abdominal pain or backache
before surgery.
Patient
had a high transverse scar of previous surgeries, about two inches
above the pubic hairline. The abdomen was opened transversely along
the scar. On laparotomy, the lower segment was well formed.
Uterovesical fold of peritoneum was opened and bladder was dissected
down. Two subcentimeter foci of translucent myometrial windows one
below the other were identified in the lower segment, with only a
layer of visceral peritoneum each covering them. Bladder was densely
adherent to the myometrium just below the lower window. Incision was
taken to include the upper window. After
delivering the baby, the edges were examined. Lower edge of the
current incision as well as the myometrium between the two windows
was extremely thin. Considering
the risk of bladder injury, and the fact that the patient desired
tubal ligation, repair the lower defect was not attempted. Scarred
myometrium edges of the upper window were excised and incision was
closed in single non interlocking layer with no 1 polyglactin. Tubal
ligation was performed. The patient and her relatives were informed
about the findings and need for caution in case they ever considered
recanalization of fallopian tubes.
Figure1:
Two scar defects (arrows) are seen one below the other on the lower segment.
Discussion
Generally
dehiscence of Cesarean scar is detected at laparotomy and it is
almost always asymptomatic. Scars of myomectomy
[2], uterine
perforation, and classical Cesarean section are known to cause
symptomatic dehiscence. Pathologists
have noted signs of inflammation like congested endometrium in the
scar recess, lymphocytic infiltration, foreign body giant cell
reaction and capillary dilatation; 2-15 years after cesarean section
in hysterectomy specimens.
[3] These are
considered to be responsible for diverse complaints such as lower
abdominal pain, dyspareunia, and dysmenorrhea. In
nonpregnant state, uterine scar defects may be associated with
intermenstrual bleeding in women with a previous cesarean
delivery.[4]
Wang et al found that
width of the CSD was associated with post- menstrual spotting,
dysmenorrhea, and chronic pelvic pain and that multiple Cesarean
sections were seen to be associated with increased width and depth of
the CSD.[5]
Multiple Cesarean sections were also found to be associated with
dysmenorrhea, independent of CSD width, but not with postmenstrual
bleeding or chronic pelvic pain.[5] Scar
dehiscence is a known complication associated with previous Cesarean
section. Risk of uterine scar dehiscence or window is about 4% and
that of scar rupture is 0.4 to 0.6% after previous lower segment
Cesarean section. [6]
Though in most
cases scar dehiscence is an incidental finding in an asymptomatic
parturient; this term implies possibility of clinically significant
events and should be considered as such.[7]
Use
of electrocautery at myomectomy has been shown to be associated with
scar dehiscence and rupture of uterus.[2]
Risk of pregnancy-related
uterine rupture attributable to laparoscopic myomectomy is 1%.[8] A
single-layer closure is associated with increase in the risk of
rupture compared with a double-layer closure.[9]
Lower
segment approximation excluding endometrium and using synthetic non
locking sutures makes the scar more secure.[9,10]
During closure of the uterine incision, excision of the previous scar
prevents scar defect in the fibrosed suture line.
In
a prospective observational study of 642 women with VBAC Rosenberg et
al found that thickness of lower uterine segment at around 37 weeks
of pregnancy was inversely proportional to the likelihood of
detection of defects at physical examination at delivery.[11]
Magnetic resonance
imaging is considered superior to CT in evaluating complications at
the incisional site.[12]
Based on MR
imaging, investigators
have classified dehiscence into complete; where all the layers except
peritoneum are separated and partial; where either innermost or
outermost layers are separated but myometrium is intact.[13] In
a study of 467 cases of VBAC, in 414 cases, Kaplan et al examined the
scar transcervically and did not detect a single case of dehiscence.
[14] Only
indications for scar exploration are unexpected vaginal bleeding or
hypovolemia after VBAC as per ACOG practice Bulletin on VBAC.[7]
Excision of the
previous scar and appropriate anatomical repair in continuous
nonlocking suture with delayed absorbable synthetic material should
be employed to reduce chance of multiple scar defects. Since scar
defects are also associated with abnormal uterine bleeding and
chronic pelvic pain, multiple scar defects may potentiate the
problem.
References
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- Hasbargen Uwe et al. Uterine dehiscence in nullipara. Human reproduction, 2002;17:2180-2182 .
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- Van Horenbeeck A, Temmerman M, Dhont M. Cesarean scar defect: correlation between Cesarean section number, defect size, clinical symptoms and uterine position. Obstet Gynecol. 2003;102:1137-9.
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- Rivlin ME, Patel RB, Carroll CS, Morrison JC. Diagnostic imaging in uterine incisional necrosis/dehiscence complicating cesarean section. J Reprod Med 2005;50: 928–932.
- Maldjian C1, Milestone B, Schnall M, Smith R. MR appearance of uterine dehiscence in the post-cesarean section patient. J Comput Assist Tomogr. 1998;22(5): 738-41.
- Kaplan B, Royburt M, Peled Y, Hirsch M, Hod M, Ovadla Y, Neri A. Routine revision of uterine scar after prior cesarean section. Acta Obstetricia et Gynecologica Scandinavica 1994;73:473-475.
Citation
Samant
PY, Parulekar SV.
Multiple
Cesarean Section Scar Dehiscences.
JPGO 2014 Volume 1
Number 9 Available from: http://www.jpgo.org/2014/09/multiple-cesarean-section-scar.html