Incision
Sites of both abdominal and uterine incisions need careful consideration
when performing any CS for suspected PASD.
A longitudinal skin incision
which can initially be placed sub umbilically has advantages. It aids
access both for adhesiolysis especially if the uterus is adherent to the
anterior abdominal wall and for peripartum hysterectomy if required. It
can also protect against inadvertent bladder injury if the bladder is
drawn up. Extension offers access to the upper uterus should a classical
or fundal uterine incision be chosen for placental avoidance, which
itself allows placental retention
should there be no signs of separation and uterine preservation is
requested. However, a longitudinal skin incision may be less
cosmetically acceptable and associated with more postoperative morbidity
than a transverse wound.
A classical uterine incision on the upper segment may obscure the degree
of placental separation leading to delay in controlling blood loss and
difficulty in gaining access to the retracted muscle to repair the
defect obligating a second transverse incision to be made for
visualization, potentially increasing the risk of uterine rupture in any
subsequent pregnancy. A transverse incision in the lower segment or
isthmocele almost inevitably disturbs the placenta which can initially
cause heavy bleeding and rules out placental retention. However, the use
of a single uterine transverse incision through the previous scar has
the advantage of allowing the placenta to be delivered in a systematic
way under direct vision from its attachment on the posterior uterine
wall first followed by removal from the neovascularized anterior wall
while tracing the boundary of the sheared posterior myometrial defect
prior to repair. This moderates the initial high blood loss from the
neovascularised isthmocele associated with the more orthodox anterior
placental separation and helps in the management of the often
unrecognized bleeding from the posterior myometrial defect and the
bleeding from the anterior inferior muscle close to the level of the
internal os prior to repair.
We advocate entry through a pre-existing skin incision, usually
transverse and suprapubic followed by a transverse incision through the
upper third of the isthmocele above the level of the uterovesical fold
through which the fetus and placenta are delivered. This avoids
unnecessary dissection of the bladder and risk of renal tract injury as
well as disruption of troublesome bridging vessels which run over the
isthmocele and in the bladder serosa but does have the drawback of the
patient being subject to a higher peripartum blood loss.