Ureteroneocystostomy (UNC) is the implantation of the ureter onto the bladder. The indications for this are:

The ureter has a segmental blood supply. The proximal ureter is supplied by the renal artery, the mid-ureter is supplied by the common iliac and gonadal arteries, and the distal ureter is supplied by the common and internal iliac arteries. Therefore during renal transplantation, only the proximal ureter will remain viable. The ureter must therefore be cut to an appropriate length. Bleeding of the ureter is encouraging for adequate blood supply. Care must also be taken not to strip the ureter of its periureteric tissues, as these contain small feeding vessels.

There are several methods to perform a UNC, but there are three generic principles of a ureteric anastomosis:

The most common technique for ureteric anastomoses are the Lich-Gregoir [1] and modified Politano-Leadbetter.

The Lich-Gregoir extravesical ureteroneocystostomy , or modifications thereof, are most commonly used in renal transplantation. The Lich-Gregoir is also commonly used in the treatment of VUR because of its anti-reflux strategy.

The ureter is spatulated for a length of 2 cm. The bladder is identified by filled it with saline mixed with betadine or methylene blue via a urinary catheter. It is wise to confirm the bladder with a 30 G needle and syringe. The site of the cystostomy is based on the lie of the kidney and the length of the ureter. The anastomosis must not be under tension, and you should bear in mind that the bladder wall will fall further into the pelvis when the bladder is empty. The detrusor muscle is then incised along a 3 cm length using diathermy, and secured with Babcock forceps. Care should be taken to avoid entering into the bladder mucosa at this stage. Once the detrusor has been swept laterally, the mucosa is then sharply incised to form a cystostomy. Most centres would advocate insertion of a JJ ureteric stent in order to avoid major urological complications. The ureter is pulled down to engage the cystostomy. A continuous 4–0 or 5–0 polydioxanone (PDS) suture is used to anastomose the ureter to the bladder. The ‘heel’ and the ‘toe’ of the ureter are sutured individually to the upper and lower ends of the bladder mucosa. Starting from the ‘heel’, apply continuous sutures between ureter and bladder mucosa. This thread is then tied to the ‘toe’ suture. The anastomosis is then completed with continuous sutures from ‘toe’ to ‘heel’. The detrusor muscle is closed over the ureter with interrupted PDS sutures to reduce the reflux of urine retrogradely. You may wish to test the anastomosis by refilling the bladder. Ureteric stents are typically removed cystoscopically 6 weeks post-operatively.

The bladder is first mobilised and the ureter is identified and transected. The proximal ureter is spatulated for a length of 2 cm. The site of the cystostomy should be appropriate for the length of the ureter, bearing in mind that the bladder wall will fall further into the pelvis when the bladder is empty. The anastomosis must not be under tension. The bladder opened on its anterior surface, and the ureter tunnelled into the bladder superior and medial to the native ureteral orifice and towards the bladder neck. As a rough guide, the tunnel length should be three times the diameter of the ureter. Care should be taken to avoid placing the ureter to laterally as this often causes kinking of the ureter. Universal prophylactic ureteric stenting is recommended.

As described above, the ureter must not be under tension following ureteric reimplantation. Occasionally, the ureter may not be long enough to reach the bladder. This occurs either when the distal ureter has been excised in a native kidney, or the donor ureter is too short during a renal transplant. There are two techniques which can be used to abridge the distance between distal ureter and bladder: psoas hitch and boari flap . Psoas hitch may be sufficient in abridging the gap, but may be used in combination with a boari flap.

The bladder is identified by filled it with saline mixed with betadine or methylene blue via a urinary catheter. The bladder is mobilised by developing the retropubic space (also known as Retzius’ space ) and freeing the peritoneal attachments of the bladder with diathermy. The bladder is mobilised in order to reach superior to the iliac vessels. The contralateral superior vesicle artery can be ligated if extra length is required. The ipsilateral bladder dome is anchored to the psoas muscle with interrupted 4–0 PDS sutures. These sutures should avoid the genitofemoral nerve that runs along the anterior surface of the psoas muscle.

The ipsilateral ureter is identified and mobilised proximally (safeguarding the blood supply within the ureteric adventitia). Once spatulated, the ureter can then be anastomosed to the superolateral aspect of the bladder using 4–0 or 5–0 PDS. The anastomosis can be tunnelled in the submucosal space (like the Lich-Gregoire ureteroneocystostomy) in order to avoid vesico-ureteric reflux.

A Boari flap is formation of a conduit using the bladder walls. Almost always used in combination with a psoas hitch (see above).

A ‘U’ shaped incision is made through the anterior and superior aspects of the bladder wall in order to form a flap. The base of this flap should be wide so not to devitalise the blood supply of the tissue. The superior aspect of the flap will be used as the point to carry out the psoas hitch. As with psoas hitch alone, the bladder wall is anchored to the psoas muscle using interrupted 4–0 PDS—however, do not tied these immediately—leave these untied on Dunhill haemostats . A submucosal tunnel of 4–5 cm is developed using McIndoe scissors through which the ureter will be pulled through. From within the bladder, incise through the bladder mucosa into the tunnel that you have created, and cut out an oval that would accommodate the anastomosis. Pull the ureter through the tunnel. Using 4–0 or 5–0 PDS, anastomose the ureteric and bladder mucosa together using a continuous suture. A ureteric stent can be inserted at this point. You may now tie the anchoring sutures on the psoas muscle. The bladder is finally closed in two layers (mucosa followed by detrusor) using continuous 4–0 or 5–0 PDS sutures. Some surgeons will also insert a cystostomy catheter which is passed through the anterior bladder wall and through the skin, to be removed post-operatively.

Major ureteric complications (MUCs) occurs in approximately 7% following ureteroneocystostomy [2], and these typically include urinary leak and/or ureteric stenosis with hydronephrosis. However, Cochraine reviews have shown that universal prophylactic ureteric stenting reduces the incidence of MUCs [3]. Therefore most centres have adopted the use of JJ stenting following ureteroneocystostomy to avoid MUCs. However, it has not been universally agreed when these stents should be removed. Our centre carries out cystoscopic removal of JJ stents 4–6 weeks post-operatively.

MUCs can reveal themselves following removal of the ureteric stent. For this reason, some centres advocate post-stent removal graft ultrasonography (PSRGU) [4].

Rarely, the mid ureter is diseased or injured requiring a transuretero-ureterostomy . Transuretero-ureterostomy is the mobilisation of the proximal end of the ureter. The ipsilateral ureter is then passed under the small howel mesentery, between the inferior mesenteric artery and the aorta, to the contralateral ureter. The ipsilateral ureter is spatulated and a ureterostomy is made on the medial aspect of the contralateral ureter. An end-to-side uretero-ureteral anastomosis is performed using continuous 5–0 PDS sutures. Where possible, a uretero-ureterostomy and transuretero-ureterostomy should be avoided if possible in place of ureteroneocystostomy, because the latter has fewer complications.

The renal hilum may be approached in two ways: trans-abdominal approach and retroperitoneal approach . Both approaches may be utilised in open surgery, laparoscopic surgery and robotic surgery.

The indications for using these approaches are:

The indication of the operation changes the strategy. In a donor nephrectomy, the renal artery and vein should be preserved until the last manoeuvre. This is because the warm ischaemic time should be as short as possible (time from ligation of blood supply to the organ, to perfusion with cold fluid). In nephrectomy of a diseased kidney, the blood supply is ligated at the earliest convenience in order to avoid bleeding from the organ during the dissection.

The kidneys lie in the retroperitoneum covered by Gerota’s fascia . This fascia also covers the adrenal gland, which sits cephalad to the kidney. The kidney gains its blood supply from the renal arteries. The renal arteries are paired branches arising from the abdominal aorta. The renal arteries carry up to a third of the cardiac output. The right renal artery is relatively longer than the left, as it passes across the midline, behind the inferior vena cava, into the right renal hilum. Fourty-two percent on patient have more than one renal artery supplying each kidney. There can be up to four renal arteries, of varying size, supplying each kidney. These additional arteries can be detected on contrast-enhanced cross-sectional imaging, however small vessels may not be see. This is of importance when ligating the blood supply of the kidney during nephrectomy. In transplantation, these branches need to be anastomosed in the kidney recipient.