Ligasure being used to control the neovascularity found between the anterior uterine wall and posterior bladder
Anterior aspect of the uterus with the bladder successfully reflected forwards
Defining the utero-vesical fold
In cases of severe invasive PAS placental tissue may invade the bladder anteriorly, obliterating the plane of the utero-vesical (UV) fold. Extensive neo-vascularisation will also usually be present and, in combination with scarring from previous caesarean sections, this makes defining this plane extremely challenging.
Choice of hysterectomy
The SAC technique does not advocate performing a subtotal hysterectomy as the largest case series comparing the two strategies demonstrated sub-total hysterectomy to be associated with increased maternal mortality (Wright JD et al. Obstet Gynecol 2010:115(6);1187-1193)
Instead a careful and systematic approach to bladder reflection should be performed to facilitate en-bloc total hysterectomy.
The bladder should be routinely filled with 300-400mls of warmed normal saline via a giving set to demarcate the bladder border and guide safe dissection. A surgical assistant will also use the ‘swab on stick’ within the vagina to help the surgeon gauge the bladder reflection required to facilitate colpotomy (see vaginal preparation).
The extensive neovascularity often found between the anterior uterine wall and posterior aspect of the bladder is particularly difficult to manage. These vessels have rapidly developed during the pregnancy and as a consequence have not fully developed a muscular wall which makes them incredibly friable. Attempts at ligation often result in the suture 'cheese-wiring' through the vessels. These vessels may also disintegrate before haemostasis is fully achieved if standard diathermy techniques are attempted.
The SAC method of choice to divide this neovascular network is the Ligasure device (Medtronic, UK) as it holds the delicate vessel in the jaws and ensures complete coagulation before the vessel is divided. This enables haemostatic control as we gently reflect the bladder from the front of the uterus.
The extent of bladder reflection performed should also take into account any varicosities or placental invasion noted on earlier speculum examination and antenatal imaging findings. If present, these will need to be incorporated into the specimen as a vaginal cuff to achieve haemostatic control.
On occasion, it may be necessary to perform an intentional cystotomy in order to adequately remove all placental remnants and gain complete haemostasis. If cystotomy occurs either deliberately or accidentally, we advocate intra-operative attendance by a urolog colleague to guide bladder closure, any need for ureteric stenting and advice on post-operative management.
Our experience is that if the posterior wall of the bladder is invaded with placental tissue the catheter needs to remain in situ for 4-6 weeks to allow the bladder to heal. This is considerably longer than usual with an uncomplicated cystomtomy. A cystogram should be performed before removal.