Laparoscopic Ureteroureterostomy

Ureter is the conduit carrying urine from renal pelvis to bladder. Since it has long course; many extrinsic pathologies, intrinsic mural anomalies and luminal defects may affect continuity of the ureter. Ureteric reconstruction aims to achieve integrity of the urinary tract in pathological conditions while preserving renal function. However, ureteric reconstruction is one of the challenging procedures in urology since the length and location of the problematic ureter or underlying pathology does not allow performing one kind of surgery in all situations.


Introduction
Ureter is the conduit carrying urine from renal pelvis to bladder.Since it has long course; many extrinsic pathologies, intrinsic mural anomalies and luminal defects may affect continuity of the ureter.Ureteric reconstruction aims to achieve integrity of the urinary tract in pathological conditions while preserving renal function.However, ureteric reconstruction is one of the challenging procedures in urology since the length and location of the problematic ureter or underlying pathology does not allow performing one kind of surgery in all situations.
The level of ureteral disease is indicative to make a decision on appropriate reconstructive procedure.The repair of 2/3 proximal ureter located above the pelvic brim is generally more demanding.Ureteroureteral anastomosis (ureteroureterostomy) is a suitable procedure for short pathologies located in the mid-and proximal ureter; meanwhile transureteroureterostomy, ureteral substitution and renal autotransplantation techniques are useful for large affected ureteral disease.(Png & Chapple, 2000) On the other hand, ureteroneocyctostomy, Boari's flap or psoas hitch procedures are well-accepted treatment alternatives for the 1/3 distal part of ureter below the pelvic brim.All techniques may be performed with open, laparoscopic and robot-assisted laparoscopic approaches.
In the last 20 years, urological community witnessed a revolution that; traditional open surgery has been largely replaced by endoscopic and laparoscopic techniques.This radical leap has gained widespread acceptance due to well-documented advantages of minimally invasive surgery.Since the introduction of laparoscopy in the field of urology, the number of centers performing this approach has been increasing steadily.It is acknowledged that laparoscopy provides surgical outcomes with efficacy equal to that of open surgery.(Guillonneau et al., 2001) For this reason, more clinics are adapting the trend of laparoscopy.Due to the clear advantages of laparoscopic surgery, the indications of this approach have expanded dramatically over the years.(Dunn et al., 2000) Similarly, the renowned benefits of minimal invasive surgery such as less pain, quicker convalescence and improved cosmesis are also well perceived by the patients.Moreover, decreased intraoperative blood loss, lesser need of transfusions and shortened hospital stay makes this approach as a "sine qua non" of the current and future urologic surgery.
Even though, laparoscopic ureteroureterostomy (LUU) has been performed in major tertiary centers, where the surgeons facile with laparoscopic techniques and perfect surgery; the wide application of laparoscopy in many centers throughout the world encourages experienced surgical teams to perform challenging procedures such as LUU.Accordingly, this chapter will focus on LUU performed for relatively small pathologies that affect proximal 2/3 part of ureter.

Laparoscopic anatomy of ureter
The ureter when measured from the ureteropelvic junction (UPJ) to the bladder is about 28 to 34 cm long.Anatomically, the ureter is divided in three segments.The proximal ureter extends from the UPJ to the area where the ureter crosses sacroiliac joint, the middle ureter courses over the bony pelvis and the distal ureter extends from the iliac vessels to the bladder.(Pereira et al., 2010) Each ureter passes over the medial part of the psoas major in the line with the ends of the transverse processes of the lumbar vertebrae.Then they cross the genitofemoral nerve and pass under the gonadal vessels into the pelvis near the bifurcation of the common iliac vessels (CIVs).After crossing the CIVs, the ureters follow the course of internal iliac artery and run along the anterior border of the greater sciatic notch.Thereupon, they turn medially at the ischial spine and lie along the levator ani just before entering the bladder.(Hinman, 1993) The vas deferens crosses in front of the ureters while the ureters; pass in front of the end of the seminal vesicle in the male.Whereas, in the female, they lie behind the ovary and at the ischial spine are in close proximity with the suspensory ligament of the ovary.The ovarian vessels make an oblique crossing over the ureters as a potential vulnerable site for injury in gynecological operations.After entering the parametrium of the broad ligaments, they run through the uterosacral, cardinal and vesicouterine ligaments.Then, they cross the lateral and posterior parts of the uterine arteries.The left ureter crossing the uterine artery runs anteromedially about 1 cm above the lateral vaginal fornix and from 1 to 4 cm lateral to the cervix passes through the anterior aspect of the vagina before entering the bladder.Thus, ureter is mostly injured as it crosses inferior to the uterine artery.(Elliot & McAninch, 2006) The blood supply of the ureter is so remarkable with multiple arteries anastomosing along its length.Thus, the division of any of the ureteral arteries does not usually produce ischemia.(Anderson et.al, 2007) The proximal ureteral arteries most often are supplied by the renal arteries (30%).The aorta provides 15% and the gonadal arteries 8% of its blood supply.Distally, the superior (12%) and inferior (12%) vesical arteries and internal iliac arteries (9%) provide the arterial supply to the lower portion of the ureter.(Hinman, 1993) The uretero-subperitoneal arteries lie outside the ureteral sheath.At the ureteral wall the arteries divide into "ureteral" arteries supplying the periureteral arterial plexus and the "subperitoneal" arteries supplying the periureteral tissue.(Landman & Pattaras, 2005) It is important to know that; the blood supply of the ureter in the abdomen is medial, while in the pelvis the blood supply is lateral.The ureteral arteries divide on the entering the loose ureteral sheath into long ascending and descending branches.Whereas; the subperitoneal arteries supply the periureteral tissue and provide a distribution to the peritoneum.Venules are distributed as a delicate network throughout the ureteral adventitia.The proximal ureter is drained via small veins into the renal or gonadal veins whereas; the distal end drain into those of broad ligament (in females), pelvic plexus and adjacent veins.

Patient selection and diagnostic work-up
Iatrogenic or traumatic injuries of the proximal 2/3 of the ureter, proximal ureteral stricture (e.g.due to stone, radiation, inflammation), retrocaval ureter (RCU) presenting 57 with reduced ipsilateral kidney function or symptomatic, ureteral endometriosis, proximal ureteral obstruction (e.g: crossing vessels, neoplasia, aberrant ureteral position, valves), ureteral ectopia and some duplication anomalies of the urinary tract (e.g.functioning upper pole hydronephrosis without ureterocele) are the main indications of LUU.In most cases, a kind of imaging modality such as intravenous urography (IVP) or computerized tomography (CT) urography is needed to demonstrate the site of ureteric problem or intrinsic or extrinsic pathology leading to hydronephrosis.If these imaging modalities are inconclusive, a cystoscopy and retrograde or antegrade pyelography are useful for identifying pathological processes.For some cases having problems such as diminished vascular supply or concomitant infection that may impair wound healing leading to urinary extravasation after surgery, placement of nephrostomy tube is advocated.In those cases, the nephrostomy tube should be kept in place until ensuring the patency of the anastomosis.
Before surgery, the patient should undergo routine preoperative laboratory investigations, including total blood count, kidney function tests, and coagulation tests [such as, prothrombin time, partial thromboplastin time, and international normalized ratio (INR)].Meanwhile, preoperative preparation of the patient should also include early withdrawal of drugs, such as acetylsalicylic acid or anticoagulants that affect platelet function.It is worth mentioning that, chronic renal failure or receiving hemodialysis treatment is not contraindications for laparoscopic ureteric reconstruction.(Sanli et al., 2010)

Preoperative auxiliary instrumentation
Laparoscopic ureteroureterostomy can be performed with transperitoneal (TP) or retroperitoneal (RP) approaches.Whether TP or RP approach is being used, it may be time saving to insert preoperatively a double-J (DJ) stent in low dorsal lithotomy position.In case of strictures or obstruction in the ureteral segment where the DJ stent cannot be inserted, it is advised to leave a ureteral stent as much as closed to the obstruction with its tether secured to the glans penis in males or the ipsilateral groin in females.This method will probably ease finding of pathological ureteral segment especially in cases of severe fibrosis.In addition, it is generally advocated to receive a clear liquid diet for 24 hours and a rectal suppository a night before the procedure.

Laparocopic ureteroureterostomy -Surgical technique
The principles of laparoscopic ureteric reconstruction are not different from those established for open surgery.These are ensuring good vascular supply in both ureteric ends with care to preserve the adventitia, complete excision of pathological lesions or nonviable tissue to a bleeding edge, good drainage with stenting and a wide spatulated and adequate ureteric end for tension-free anastomosis of mucosa to mucosa.(Elliot & McAninch, 2006;Png & Chapple, 2000)

Transperitoneal (TP) approach
After insertion of a Foley urethral catheter the patient is secured in a modified flank position over the kidney break at a 45-60˚ angle.A Veress needle is used to create a pneumoperitoneum and a 10-mm camera port is inserted at the level of umbilicus just lateral to the rectus abdominis muscle.On the occasion that the patient is slim; umbilicus may be used for this purpose.In right sided LUU, a 5-mm and a 10-mm port is inserted at the 1/3 caudal and 1/3 cranial points along a virtual line between xiphoid process and anterior superior iliac spine), respectively.Whereas, in case of left sided LUU, 5 and 10-mm port are inserted vice versa.
After proper port placement, the line of Toldt is incised and the colon is deflected medially to provide exposure of the RP (retroperitoneal) structures including inferior vena cava, ureter, gonadal vein, duodenum and renal pelvis in right side; ureter and gonadal vein in the left side.Subsequently, the ureter is found with proper RP dissection and problematic segment is visualized.This problematic ureter is then resected, making sure to reach healthy, well vascularized ureteral ends.If the situation is an injury due to thermal injury, wide debridement may be required because microvascular damage can extend for 2 cm beyond the evidence of visible injury.(Amato et al., 1970)

Retroperitoneal approach
For RP approach, the patient is placed in full lateral decubitus position with overextension in order to increase the distance between the ports.For port position, an incision is made below the 12 th rib in the posterior axillary line for 10-mm camera port and after division of muscular layer and lumbodorsal fascia RP space is entered and dilated with a balloon dissector.A 5-mm trocar is inserted below the costal margin in the anterior axillary line and another 10-mm trocar is inserted 2 cm above the superior border of iliac crest in the midaxillary line in right sided cases.Ten and 5-mm trocars are inserted vice versa in left sided cases.

Ureteroureterostomy technique
Spatulated ureteroureterostomy (UU) is the gold standard technique in patients with good vascular supply in both ureteric ends and adequeate ureteric length for tension-free anastomosis.If the lengths of proximal or distal ureter do not allow tension free anastomosis, kidney may be mobilized for gaining some extra length.Generally the following basic approach is applied: After adequate exposure, both upper and lower ureter is transected sharply and spatulated laterally and medially as needed.Spatulation helps the meticulous watertight suturing while preventing the rotation of the ureter.One of the essential roles of the spatulation process is the preservation of the longitudinal ascending and descending branches of the ureteral arteries as well as allows wider luminal diameter.It is accepted that the placement of stay sutures can improve one's ability to properly direct the incisions while minimizing trauma to the tissues.(Lucas & Sundaram, 2011) However, it should be noted that placing stay sutures may need extra trochars for making them functional.Instead of this 12 o'clock and 6 o'clock sutures may be used for this purpose (Figure 1 and 2).Thereupon, a tension-free watertight UU is fashioned (over a DJ stent) using posterior and anterior wall closures of interrupted or running stitches with absorbable suture materials such as 4-0 or 5-0 polyglactin/polydioxanone sutures.The authors of the present chapter prefer to use interrupted sutures which are not too close together (2-3 mm apart) to prevent ischemia of the suture line.
Before completion of the reconstruction, if not inserted before, a DJ stent is placed to secure the anastomosis (Figure 3 and 4).However, one should be ensured that proximal end of the stent is in the renal pelvis; while distal end in the bladder.The proximal end of the stent may be visualized in the proximal uterer or renal pelvis but sometimes it may be difficult to observe the distal end if it is in the bladder.For confirming this issue, the bladder may be filled with methylene blue via the urethral catheter and observe reflux of blue urine through the stent.At the last occasion, cystoscopy may be performed to see the stent within the bladder.For securing the anastomosis and facilitate wound healing, repaired ureteral segment may be wrapped with an omental flep in transperitoneal approach.Subsequently, if placed stay sutures are released and haemostasis is checked with lowering the pressure of pneumo-or pneumoretroperitoneum to 4 mmHg.Eventually, a drain is positioned over the renal fossa and left overnight with a Foley urethral catheter.For injuries at or below the pelvic brim, ureteroneocystostomy should be the treatment of choice which is beyond the scope of this chapter.

Transuretero-ureterostomy technique
Before Hendren popularized transuretero-ureterostomy (TUU) for use in undiversion, the technique has been restricted to patients who had suffered trauma or disease to the distal ureter, the excision of which left a defect that was too long to be bridged by mobilizing the bladder upwards by any means.(Hendren, 1973;Hodges et al., 1963) Other indications of TUU are cystectomy and substitution cystoplasty, Mitrofanoff-type urinary diversion and failed urinary diversion.(Kaiho et al., 2011;Noble et al., 1997) In 1999, Dechet et al. demonstrated the feasibility of laparoscopic TUU in a porcine model.(Dechet et al., 1999) Piaggio and Gonzalez first reported successful laparoscopic TUU in 3 children with ureteral obstruction, refluxing megaureter and ureteral injury after bladder diverticulectomy.(Piaggio & Gonzalez, 2007) The basic principles in open TUU are valid for the laparoscopic surgery, as well.These are mobilizing the ureter to be transposed across the posterior abdominal wall above the point of origin of the inferior mesenteric artery (to avoid kinking), to mobilize the recipient ureter to reduce the tension and to use an appropriate caliber stent across anastomosis.(Noble et al., 1997) For anastomosis, a small elliptic portion is excided from the medial wall of the recipient ureter and after spatulation of the donor ureter, an end to side anastomosis is performed.(Pesce et al, 2001) Although transureteroureterostomy has been proved to be safe and effective procedure, its place should certainly be restricted to ureteric defects above the pelvic brim, where a ureteroneocystostomy is not possible.(Png & Chapple, 2000) Transuretero-ureterostomy is a challenging approach used in selective cases; laparoscopic TUU is even more arduous because of the difficulty of passing donor ureter under mesocolon to the recipient ureter and currently should be reserved for very experienced referral centers.It is worth mentioning that inadequate surgical technique leading to urine leakage and subsequent stricture may compromise the drainage of the patent system.This is also valid for donor ureters with compromised vasculature due to radiation treatment or periureteral infection.Meanwhile TUU is discouraged if the renal unit on the side of injured ureter has minimal function.

Post-operative care and follow-up
In case of doubt, a plain abdominal film may be obtained to confirm the stent position.Since ureteral reconstruction generally leads to clean-contaminated wound, prophylaxis with 2 nd generation cephalosporins is suggested.(Grabe et al, 2011) However, in case of positive urine culture before surgery, suitable antibiotics according to urine culture should be continued at least 7-10 days.The DJ stent should be removed in 2-6 weeks postoperatively.Retrograde pyelography (RGP) is not necessary while removing DJ catheter.We do not advocate DJ stents with an externalized tether since they may be a source of urinary tract infection (UTI).An IVP obtained 3 months after the operation can demonstrate the patency of anastomosis and is an excellent follow-up modality to discover any problems in continuity of urinary tract.The IVP can also demonstrate strictures and irregularities of reconstructed ureter.In case of any patency suspicion a 3-dimention reconstruction of a CT or magnetic resonance (MR) urography can facile the diagnosis.Six, 12 month and thereafter yearly follow up with IVP and yearly renal ultrasonography is recommended for 3 years.

Associated complications
Urinary tract infection, bleeding, haematoma formation, prolonged urine leakage from the drain and concomitant ileus (in TP approach) are the early complications that can be encountered with LUU.Meanwhile urinoma formation, retroperitoneal abscess and peritonitis may occur.The rate of early complications was found to be 3.8% (n= 4) in 109 renal units with the evaluation of the current literature (Table 1-4) Urinary tract infection can be managed with administration of antibiotics; the bleeding may require re-exploration, whereas haematoma can be followed with serial haematocrit counts and ultrasonography.Prolonged leakage from the drain and ileus due to urinary leakage may require replacement of DJ stent under fluoroscopic control or nephrostomy tube placement.
Ureteral stricture, fistulae formation, undrained urinoma formation and periureteral abscess are the late complications that may require re-exploration and anastomosis revision.The rate of late complications was found to be 2.8% (n= 3, Table 1-4) in 109 renal units mentioned in the literature.

Outcomes analysis
In 1949 Anderson and Hynes published the first case of UU for retrocaval ureter.(Anderson & Hynes, 1949) Currently, open ureteric reconstruction is the standard of care.LUU has been successfully used for surgical correction of reterocaval ureters (RCU) since 1994.(Baba et al., 1994) Retrocaval ureter is a rare congenital abnormality (incidence of 1 in 1000) that results in external ureteral compression by the inferior vena cava (IVC) and becomes symptomatic in the 3 rd or 4 th decade of life.Its etiology is presumed to be abnormal embryologic development of the IVC, which results from the major portion of the infrarenal IVC being formed from the subcardinal vein that lies ventral to the ureter.(Considine, 1966) For the first time, Baba et al performed a TP approach in a case of RCU with mean operative time (OT) of 570 min.and an interrupted anastomosis in 150 min.(Baba et al., 1994) A decade was needed to shorten the OT to 82 min.reported by Li et al. (Li et al., 2010) Ten cases in the literature were performed through the TP approach with a mean OT of 235 min., whereas 22 cases with a RP approach having mean OT of 138 min do exist (Table 1).Even though the OT in RP approach is shorter, retroperitoneoscopy has its own disadvantage of limited working space for laparoscopic manipulation.On the contrary, the advantage of RP approach is the rapid and direct access to renal pelvis and ureter without violating the peritoneal cavity.(Li et al., 2010) Even if a decent number of authors claim that the RP-LUU is less time-consuming (Ameda et al., 2001;Gupta et al, 2001;Li et al., 2010;Mugiya et al., 1999;Salomon et al., 1999;Tobias-Machado et al., 2005;Xu et al., 2009); some prefer the TP access and affirm that it is easier than the RP approach.(Ameda et al., 2001;Autorino et al., 2010;Baba et al., 1994;Polascik & Chen, 1998;Ramalingam & Selvarajan, 2003;Sanli et al., 2010;Singh et al., 2010) Given the small number of cases reported in the literature, and bias from case selection; the OT favors the RP approach, nonetheless the surgeon should prefer the method that is most familiar with.
There is a general impression that performing an anastomosis with interrupted sutures is safer while performing UU.Most of the authors reporting LUU for RCU used interrupted suturing technique.(Ameda et al., 2001;Baba et al., 1994;Elliot & McAninch, 2006;Mugiya et al., 1999;Polascik & Chen, 1998;Ramalingam & Selvarajan, 2003;Salomon et al., 1999;Sanli et al., 2010;Xu et al., 2009) However, none of the authors using running sutures have reported any complication regarding urine anastomotic stricture.(Autorino et al., 2010;Li et al., 2010;Mugiya et al., 1999;Tobias-Machado et al., 2005) Li et al., has used posterior ureteroureteral anastomosis with running suture which every 2 sutures were coupled with a lock-stitch suture and anterior interrupted suture anastomosis.This technique reduced their OT to a mean of 82 min without compromising the anastomosis.Meanwhile, some authors advocate performing pyelopyelostomy instead of UU; because it is less likely to produce stricture formation due to the larger caliber structures as well as better blood supply in the level of renal pelvis.(Bhandarkar et al., 2003;Dogan et al., 2010;Simforoosh et al., 2005) We believe that this technique is a rational option especially for patients with Type I retrocaval ureter which is characterized by S or fish-hook deformity of the ureter and is usually associated with moderate to severe hydronephrosis (Type II RCU is sickle-cell shaped and is associated with mild hydronephrosis).In addition, pyelopyelostomy with the preservation of retrocaval segment was suggested by Simforoosh et al. (Simforoosh et al., 2005) The authors' rationale for leaving the retrocaval segment was the dysplastic and narrow nature of this segment which may not be suitable for UU.Meanwhile, leaving this segment may also prevent some complications such as venous bleeding during dissection of vena cava.
In order to decrease the OT different approaches have been utilized.Tobias-Machado et al performed the anastomosis extracorporeally.(Tobias-Machado, 2005) The ureteral ends were exteriorized though the incision of the 12-mm port after enlarging the skin incision to 20-mm.Despite decreasing the OT, we believe that exteriorizing the ureteral ends require additional dissection of the ureters which may impair the ureteral blood supply.Meanwhile, a half open (extracorporeal) technique does not address and fit the rationale laparoscopy.Nevertheless, it may be rational to suggest the use of this technique to novice laparoscopists with limited dexterity for intracorporeal suturing.
Ureteral strictures (US) due to ureteral trauma, inflammation, stones or radiation are the leading indications for UU.Although, trauma to the ureter is relatively rare and accounts for only %1 of all urinary tract trauma, 75% of ureteric trauma is iatrogenic and of these 73%, 14% and %14 are in gynecological, urological and general surgical in origin, respectively.(Dobrowolski et al., 2002;Lynch et al., 2005) There is a trend of increase in incidence of iatrogenic urological trauma from 1990's due to development of new techniques such as ureteroscopy and laparoscopy.Ureteroscopy results in ureteral perforation in 2-6% of cases which is a significant risk factor for ureteral stricture.(Elliot & McAninch, 2006) LUU should be considered in patients with unsuccessful attempts by using standard minimal invasive therapies such as balloon dilatation and endoureterotomy with laser or electrocautery.While repairing the stricture, the length of the stricture has always been a subject of debate achieving tension-free anastomosis.Ou et al. published 3 cases of LUU performed on patients with US having operated for laparoscopic hysterectomy.(Ou et al., 2005) They have trimmed the necrotic tissue on ureteral ends, performed tension free LUU over DJ catheter and wrapped the repair with omentum.The authors suggested using LUU; when the injury is not close to the bladder and involves less than 1.5 cm of the ureter.They probably mentioned the use of this technique in strictures less than 1.5cm based on their clinical experience; but we believe that depending on the tortuosity of the ureter, more lengthy strictures may be repaired with LUU.Since for open surgery, it is known that defects up to 3 cm can be repaired at once without tension.(Mayor & Zingg, 1976) Meanwhile, if the defect is larger, this tension may be reduced by mobilizing and straightening its pelvic part.Cholkeri-Singh et al. have published 2 cases of laparoscopic ureteral repair after ureteral injury during laparoscopic procedures.(Cholkeri-Singh et al., 2007; Table 2) Similarly, Carvalho et al have reported successful repair of ureteral injury after hernia repair by LUU.(Carvalho et al., 2008) Furthermore, Simmons et al published 5 cases of LUU after stricture.(Simmons et al., 2007) All these authors acknowledge that favorable laparoscopic approach is possible if performed with the assistance of experienced surgeons.
Despite very limited evidence in the literature, laparoscopic segmental ureterectomy was suggested as alternative to open segmental ureterectomy for low grade transitional cell carcinoma (TCC) of the proximal and mid ureter.(Simforoosh et al., 2005) However, while performing this operation, one should leave a 1 cm safety margin proximally and distally and frozen section analysis for the both ureteral ends is highly recommended.Meanwhile, it is worth mentioning that TCC is very prone to port site metastasis and every attempt should be made to prevent this undesirable and life-threatening complication.
Urologic endometriosis is another disease that may require UU.Despite of the fact that urinary tract involvement is uncommon (1-5%), it may cause obstruction of the ureter leading to hydronephrosis.(Jimenez et al., 2000) In this circumstance, surgical resection of the involved ureteral segment is a viable option because it removes the disease and surrounding fibrosis.The first case of LUU in the literature is reported by Nezhat et al. (Nezhat et al, 1992) In a recent study, Antonelli et al., reported the outcomes of 11 patients with ureteral endometriosis treated with surgical excision.(Antonelli et al., 2006) Among these patients, endometriosis was found to be deeply infiltrating the muscle layer in 4 (intrinsic endometriosis), whereas only adventitia or periureteral tissues were affected in 7 (extrinsic endometriosis) patients.The authors reported no complications regarding UU technique in 2 patients and mentioned that laparoscopic ureterolysis is a more suitable approach for minimal, extrinsic and non-obstructive ureteral involvement; whereas LUU is favorable for intrinsic disease.Meanwhile, Mereu et al reported 17 cases of ureteral endometriosis managed with LUU.(Mereu et al., 2010) Of this cohort, 2 patients had complications with strictures postoperatively.Thus, the authors advocate the complete ureteral excision of the tissue involved since the left endometriosis tissue may lead to recurrences.Similar convincing outcomes were also reported by Nezhat et al (Table 2; Nezhat et al., 1998) Laparoscopic ureteroureterostomy may have place in some pediatric urological diseases mentioned in Table 3.Briefly, the OT and hospital stay ranges between 100 and 263 min.and 2 and 5.5 days, respectively.After a mean follow-up of 7.7 months, 3 complications were encountered for the operation of 23 renal units.These were febrile UTIs in 2 patients and urine leakage that was spontaneously resolved within 24 hours in 1 patient.(Bhandarkar et a.,2005;González & Piaggio, 2007;Nagraj et al., 2006;Piaggio & González, 2007;Steyaert et al., 2009;Storm et al., 2010)

Novel techniques
Tissue engineering has been applied experimentally for the reconstitution of several urologic tissues and organs, including ureter.(Atala, 2004) In one of these studies, Osman et al. have reported the replacement of 3cm segment ureteral defect by acellular tube matrix from canine decellularized ureters.However, ureteral replacement with this naïve bioscaffold was unsuccessful due to fibrosis.(Osman et al., 2004) Smith et al reported a small intestinal submucosa (SIS) allograft to bridge a 2 cm ureteral defect and noted that SIS graft was replaced with ureteral growth in 9 weeks.(Smith et al., 2002) Meanwhile Matsunuma et al. used decellularized matrix with cultured uroepithelial cells for tissue engineered ureter and showed that angiogenesis of this bioscaffold may be increased by seeded bone marrow derived mononuclear cells.(Matsunuma et al., 2006) Recently, a model of "omental bioreactor" for differentiation of engineered neoureter was recently introduced by Baumert et al. (Baumert et al., 2007) In this model bladder biopsies were taken and smooth muscle and urothelial cells were cultured.Then the cultured cells were seeded to small intestinal submucosa (SIS) matrix.Afterwards the cultured cells were wrapped by the omentum around a silicone drain to obtain neoureters.Thus, the authors obtained mature well differentiated multilayered urothelium.Consequently, although animal studies express promising results, the actual ureteral replacement with viable grafts has to wait the studies to mature further (Baumert et al., 2008) Fibrin sealants are being used more and more in urology.It has been used for laparoscopic pyeloplasty, partial nephrectomy, ureteral injuries, closure of ureterotomies in stone surgery and occlusion of the distal ureter while performing distal ureterectomy with "pluck" technique for the treatment of upper urinary tract TCC.(Eden et al., 1997;Kouba et al., 2004;Mueller et al., 2005;Schultz & Christiansen, 1985) Moreover, a large volume urine leakage after renal cyst decortication was stopped with endoscopic retrograde fibrin glue injection and ureteral stent placement.(Chen et al., 2011) Meanwhile, there is some evidence in the literature that fibrin sealants promote wound healing and reinforce ureteral anastomosis.(Kumar et al., 2001) In animal model, it was shown that LUU made by fibrin glue without stay sutures produced better radiographic findings, flow characteristics and histology.(Wolf et al., 1997) Consequently, fibrin sealants may be used for further water-tightness of the anastomosis.In addition, the use of tissue sealants may reduce the number of sutures placed for anastomosis which may theoretically decrease suture line ischemia.(Detweiler et al., 1999) Robotic technology has been increasingly used in urological procedures.It tends to replace conventional laparoscopic techniques in complex urologic surgeries and especially in reconstructive procedures.Some series of robotic UU has been published recently.(Hemal et al., 2008;Lee et al., 2010) Apart from the ergonomic advantages for the surgeon and technical benefits such as meticulous sharp dissection and precise spatulation of the ureter with the aid of wristed instruments and magnified 3D vision; this technology did not yet contribute significantly over laparoscopy.(Hemal et al., 2008) However, it is worth mentioning that intracorporeal suturing is much easier with robot which is probably the most important factor on OT.The cost and the lack of haptic feedback are the major disadvantages of robotic technology.Recently, Lee et al. reported 3 successful re-anastomosis of the ureter robotically (Lee et al., 2010).The mean operation time was 136.6 minutes and none of the patients developed recurrent stricture after a 24 months of follow-up.Meanwhile, Smith et al. reported successful robotic UU in 2 children with the length of hospital stay roughly 30 hours.(Smith et al., 2009) The authors reported resolution of hydronephrosis at 1 month follow-up imaging.To our knowledge, 10 renal units were operated with the robot for different indications.The OT is ranging from 136.6 min to 485 min and no complication were encountered after mean followup ranging 1 to 24 months (Table 4).
Laparoendoscopic single-site (LESS) surgery for UU is promising and the feasibility of the technique has been reported by Autorino et al. in a patient diagnosed with RCU.(Autorino et al., 2010)

Conclusions
Ureteroureterostomy has always been a challenging procedure in the history of urology.Surgical approaches for UU have steadily evolved over the last 50 years paralleling the introduction of new technologies.
In the past decade, laparoscopy has been increasingly utilized for a variety of complex urological procedures.The recent technological advancements in laparoscopy had significant impacts on urologic surgery.The technical refinement and development of laparoscopic devices have enabled laparoscopic surgeons perform challenging urinary tract reconstructions.Due to the small number of cases, LUU cannot be stated that it is superior to open surgery.But the benefit of magnification with improved visualization and minimal

Fig. 1 .
Fig. 1. "12 o'clock suture" is used as stay suture that helps direct visualization and minimizing trauma to surrounding tissues