Describtion
Boari Flap
For ureteric defects longer than 6–8 cm, which cannot be bridged by the psoas hitch technique, the Boari flap offers an option for a tension-free ureteric anastomosis. The ureter is exposed through an extraperitoneal approach in the same technique described for the psoas hitch technique. In a case of redo surgery, a transperitoneal approach may be preferable depending on the amount of scarring and fibrosis. After radiation therapy of the pelvis or after multiple previous operations, the ureter is easier identified at its crossing with the common iliac artery or higher, in a healthy area. The bladder is filled through the Foley catheter and maximum mobilisation of the bladder is performed, including division of the median umbilical ligament (urachus) and both medial umbilical ligaments (umbilical arteries). The classical rectangular Boari flap of about 3–4 cm in width is marked by stay sutures with its base at the posterior lateral bladder wall above the original ureteric orifice and its tip at the contralateral anterior bladder wall. In the Übelhör modification, the bladder is incised on the affected side slightly oblique and this incision is anteriorly and distally extended to the contralateral site. This results in a wide rhombic flap with a broad basis, which can be rotated to the psoas muscle.
For fixation of the bladder flap to the psoas
muscle, two to three 3/0 poly-p-dioxanone
monofilament absorbable sutures (e.g.
Monoplus® or PDS®) are placed preferentially
through the tendon of the psoas muscle. The
sutures must encompass the entire detrusor
muscle thickness without mucosa.The sutures
must not be tied at this stage of the operation
After creation of the submucosal tunnel an
Overholt clamp is inserted retrogradely into the
tunnel and the ureter is pulled on its stay suture
into the tunnel. Thereafter the fixation sutures to
the psoas muscle are tied. After bladder fixation,
the ureter should enter the Boari flap in a
straight course without kinking at the entrance.
The ureter is re-implanted into the bladder flap
using the same technique as for the psoas
hitch
Before closing the bladder, the ureteric stent is
passed through the anterior bladder wall and a
cystostomy catheter (e.g. 10 F pigtail) is placed
into the bladder, both of which are anchored to
the detrusor on the outside with fast-absorbing
suture. The bladder is closed in two layers. Firstly
the mucosa is closed with a 4/0 or 5/0
glyconate monofilament absorbable running
suture (e.g. Monosyn® or Monocryl®). The
detrusor is closed with another running 3/0 or
4/0 poly-p-dioxanone monofilament absorbable
suture (e.g. Monoplus®). A paravesical gravity
drain is placed in the vicinity of the anastomosis
Raimund Stein, Peter Rubenwolf, Christopher Ziesel, Mohamed M. Kamal* and
Joachim W. Thüroff*
Division of Paediatric Urology and *Department of Urology, University Medical Center, Johannes Gutenberg
University, Mainz, Germany
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