Laparoscopic transposition of crossing vessels („vascular hitch “) in ureteropelvic junction obstruction – a case report

Summary

Aim of the study: Crossing vessels of the lower renal pole are found in 10–15 % of children with ureteropelvic junction (UPJ) obstruction, and in more than half of older children and adolescents (2). The obstruction, caused by external pressure of the vessels on the UPJ or proximal ureter, is often intermittent and manifests by recurrent and even colic pain. In an acute condition, we can detect a high grade hydronephrosis that may disappear after resolution of the acute episode. The aim of this video is to show intraoperative evaluation and policy in hydronephrosis accompanied by crossing vessels and performance of laparoscopic repair without opening of the urinary tract according to Hellström (1).

Methods: Doppler ultrasound examination is of paramount importance in detection of crossing vessels of the lower renal pole. On intravenous urography, a globular shape of the pelvis with a flat bottom and calyceal dilatation has been described in crossing vessels (3). Surgery is considered in confirmed UPJ obstruction based on symptoms and findings on dynamic renal scintigraphy or on intravenous urography with furosemide. Functional magnetic resonance urography is a good alternative, moreover, detecting the crossing vessels (4) CT urography is inappropriate in children because of a high radiation burden.

If the vascular hitch is being considered, it should be born in mind, that an „extrinsic obstruction “, caused by external pressure of vessels or adhesions, may be accompanied by an „intrisic“ obstruction, a real UPJ or proximal ureter stenosis with pathohistological changes in the ureteric wall. In this case a dismembered repair should be performed (3).

Hellström described elevation and adventitial fixation of the vessels to the renal pelvis outside the region of UPJ in 1949 (1). Chapman proposed to stabilise the vessels in the new position by wrapping them in the pelvic wall. This method has gained popularity in selected patients especially after introduction of laparoscopy as an easier alternative to technically demanding laparoscopic suturing in dismembered pyeloplasty (5–7). The Chapman modification has been used in our case as well. Surgery has three phases. First, releasing of crossing vessels from the pelvis and ureter is performed and the vessels are freely pulled cranially outside the UPJ region. The second phase should prove free passage of urine after liquid infusion and furosemide administration. It is necessary to wait 10 minutes to achieve full diuretic effect. If UPJ obstruction persists at visual control, then a dismembered repair is to be used (8). During the third phase, the vessels are wrapped within the anterior pelvic wall at the elevated position according to Chapman.

Results and discussion: An 8-year-old boy was investigated because of intermittent abdominal pain. Grade II hydronephrosis of the right kidney with crossing vessels to the lower pole was detected on ultrasound and Doppler imaging. Diuretic scintigraphy with 99mTc-MAG3 has shown symmetrical differential renal function (48 %) and delayed drainage of the radionuclide pointing to a partial obstruction of the right kidney.

The right kidney was laparoscopically exposed in conventional transperitoneal way with three 5mm trocars inserted at umbilicus, above umbilicus in the midline and pararectal to umbilicus. The crossing vessels were released from the enlarged pelvis, UPJ and proximal ureter to enable free movement up and down behind the vessels („shoeshine manoeuvre “). After i.v. liquid infusion, the vessels were elevated from the UPJ region and 10 mg furosemide i.v. was administered. A good passage of urine from the pelvis to the ureter across the UPJ was confirmed. The vessels were wrapped into the pelvic wall well above the UPJ using two absorbable polyglactin 4/0 sutures. Length of surgery 115 min. Stenting was not necessary, therefore, no worry of stent syndrome and of necessity for additional anaesthesia to remove it. Postoperative course was uneventful, pain settled and dilatation of the pelvicalyceal system decreased at 3- and 12- months follow-up. Doppler imaging showed adequate cranial deflection of the crossing vessels and good perfusion of the kidney.

The laparoscopic vascular hitch was first published by Meng and Stoller in 2003 (6). Several articles have been published proving safety of the procedure. Its success rate (97,5 % ± 1,6 %) is comparable with dismembered pyeloplasty (9). The pros are: unstented repair, shorter length of surgery and hospital stay (9, 10).

Conclusions: Laparoscopic transposition of crossing vessels is a good alternative of dismembered pyeloplasty in selected patients with intermittent hydronephrosis once concomitant „intrinsic“ cause of UPJ obstruction has been excluded. It is a stent free procedure with a shorter operative time and shorter hospitalization.

Keywords:

hydronephrosis – ureteropelvic junction obstruction – UPJO – vascular hitch – transposition of renal crossing vessels