25. Reconstruction of the Renal Pelvis and Ureter
KeywordsUreteropelvic junction obstructionPyeloplastyUreteroureterostomyTransureterureterostomyUreteroocalicostomyUreteroneocystotomyPsoas hitchBoari flapUreteral strictureIleal ureter
Overview of the Management of Renal Pelvis and Ureteral Strictures in Adult Patients
Ureteral strictures can be classified into extrinsic or intrinsic, benign or malignant, iatrogenic or non-iatrogenic. The potential etiology of ureteric stricture includes congenital, infection (Tuberculosis or Schistosomiasis), iatrogenic (ureteroscopy, gynecological or other pelvic surgery), radiation, malignancy, lymphadenopathy, urolithiasis, penetrating trauma, or retroperitoneal fibrosis. Iatrogenic injury at time of pelvic surgery could be due to crush injury, burn, or complete transection.
Conservative option for management of strictures can be placement of double J ureteral stent, either plastic or metallic. However this requires routine stent exchanges every 6–12 months with or without anesthesia. Unfortunately, there are high occlusion rates for ureteral stents in the subset of patients with extrinsic ureteral compression due to malignancy . The etiology is thought to be due to the idea that urine flows around the stent preferentially, and not through the stent. Therefore, with external compression around the stent from the extrinsic compression, urine is forced through the stent and can get more easily obstructed by debris. For these patients, some physicians advocate to leave larger bore stents or stiffer stents or even placing two parallel stents simultaneously . For the patients who do not want to manage their stricture with routine stent exchange or a permanent nephrostomy tube, reconstructive surgery is an option.
Ureteral reconstruction options
Ureteral stricture location
Length of ureteral defect (cm)
Above the sacroiliac joint to the ureteropelvic junction
Overlying the sacroiliac joint
+/− Boari flap
Sacroiliac joint to the ureterovesical junction
+/− Psoas hitch
+/− Boari flap
When conceptualizing reconstructive surgery of the renal pelvis and ureter, the goal is to preserve renal function by the restoration of non−obstructed drainage of the affected kidney in a dependent fashion. Classic urologic surgical standards are presumed with reconstructive techniques such that an anastomosis not under tension and dissection should be done in a fashion to preserve blood supply to the ureter and adjacent tissues.
The functional anatomy of the ureter is important to keep in mind when dissecting the ureter and planning reconstruction. The ureter is between 25 and 30 cm in length from the renal pelvis to the bladder. As the ureter crosses over the pelvic brim, it is divided anatomically into the abdominal and pelvic segments, each approximately 12–15 cm in length. Above the pelvic brim, the blood supply of the ureter is derived from medial vessels such as gonadal arteries and aorta, whereas more distally, the blood supply originates laterally. Thus, above the pelvic brim, dissection and mobilization of the ureter should be approached laterally and distal to the pelvic brim, medially. Maintaining blood supply is vital to the anastomotic success and to diminish the risk of future stricture.
When deciding which reconstructive option to pursue, consideration of the length of the stricture, the degree of peripelvic and ureteral fibrosis, degree of redundancy of renal pelvis, and the ability to mobilize the ureter and recipient target are all important factors. Usually a ureteral double J stent is placed through the repair anastomosis. The advantage of placing a stent across the anastomosis is to curtail the associated edema, allowing the healing of tissues to occur while minimizing anastomotic leak and to maintaining patency. The anastomosis is completed using fine, 4-0 or 5-0, non-reactive, monofilament, absorbable suture in an interrupted or running fashion. The sutures are placed in a watertight manner over an internal double J ureteral stent. A closed suction drain is usually placed near the anastomosis for a limited time and removed when appropriate. An indwelling Foley is also left in place when indicated.
Renal Pelvis Reconstruction
Open procedures for the treatment of UPJ obstruction include the Anderson-Hynes dismembered pyeloplasty  which is the gold standard of pyeloplasties: the strictured portion of ureter is excised and the healthy, patent ureter is spatulated and anastomosed to a dependent position of the renal pelvis. However if the renal pelvis is small or the ureteral length is inadequate, then dismembered pyeloplasty is not ideal and a non-dissmembered pyeloplasty should be considered. Non-dissmembered pyeloplasty options include the Culp de Weerd spiral flap procedure  and the Foley Y-V technique , which are ideal for long segment UPJ strictures. The latter is also ideal for high insertion ureters. Other options for long UPJ strictures include the vertical (Scardino –Prince) flap pyeloplasty . Because of its relative simplicity, the preferred method for open pyeloplasty is the Anderson-Hynes dismembered pyeloplasty with or without reduction of the redundant pelvis . This method provides lasting improvement in function (79%) and drainage in most patients (96%) . Most series reports success rates of open dismembered pyeloplasty ranging from 72 to 100%, with an average of 90% success rate .
Although open pyeloplasty does have high success rates, it does have its inherent post-operative complications . In contrast, improved patient tolerance is one of the principal benefits of minimally invasive approaches. Endoscopic methods to treat UPJ obstruction include antegrade endopyelotomy, retrograde endopyelotomy (Acucise™) and balloon dilation. All three of these endoscopic methods have been shown to be tolerated significantly better that open pyleoplasty as assessed by post-operative pain, length of hospital stay, and recovery time. Specifically, Acusize was found to be the best tolerated . The success rate for antegrade and Acusize pyelotomy appear to have similar success rates at approximately 78% . Additionally, endoscopic approach is commonly recommended for patients who have failed open operative repair .
For simple UPJ or proximal ureteral strictures, these can be managed surgically with pyeloplasty or UU. However for the more complex UPJ or recurrent strictures, the technique can be challenging. Salvage reconstructive options include TUU, ureterocalicostomy, renal autotransplantation, or an ileal ureter replacement, described in detail below. When the renal pelvis is relatively inaccessible, fibrotic, or has an intrarenal pelvis, an alternative option for reconstruction is the ureteroocalicostomy . There are reports of ileocalicostomy as ureteral substitution as well . These later two options may be useful for recurrent failed repairs with insufficient ureteral length such that the healthy portion of ureter is anastomosed to lower calyx parenchyma. Also, if all reconstructive options are not feasible, simple nephrectomy may be the only option for a patient who’s goal is to live free of stent or percutaneous nephrostomy tube. These options should be fully discussed with the patient and included in the surgical consent.
First described in 2001 , robotic-assisted laparoscopic pyeloplasty is a minimally invasive option for the correction of UPJ obstruction. Both laparoscopic or robotic pyleoplasty have been shown to have decreased length of stay, less post-operative opioid requirements, and similar success rates of 88–100% as compared to open pyeloplasty . Robotic pyeloplasty results in long-term improvement in subjective symptoms and resolution of obstruction for patients with success rates reported at 96% .
Repair of ureteral injuries can pose significant challenges depending on the location and length of the ureteral stricture as well as quality and health of the surrounding tissues. The location of ureteral stricture are divided, per se, into the proximal ureter (above the sacroiliac joint to the ureteropelvic junction), mid ureter (overlying the sacroiliac joint), and distal ureter (sacroiliac joint to the ureterovesical junction) (Table 25.1). Briefly, options for repair include primary anastomosis of ureter to ureter or ureter to bladder with or without psoas hitch and/or Boari flap. These approaches can also be done laparoscopically or robotically, with the robotic option providing for increased dexterity of intracorporeal suturing and improved visualization when compared to laparoscopic approaches. Most ureteral injuries that are short in length can be repaired with debridement and ureteroureterostomy in the proximal and mid-ureter or ureteroneocystostomy in the distal ureter .
Options for proximal and mid ureteral reconstructive repair of simple and short (2–3 cm) ureteral strictures are ureteroureterostomy (UU) or trans-ureterureterostostomy (TUU) (Table 25.1). Ureterouretosomy is done such that the proximal ureter and distal ureter is mobilized, the defect is excised and the remaining healthy tissues are widely spatulated and re-anastomosed together in a non-tension, end-to-end fashion. Prior to completion of the anastomosis, a double J stent should be placed. If possible, omentum or retroperitoneal fat is mobilized to surround the repair, and a drain is placed in the retroperitoneum near the anastomosis. A Foley catheter is left indwelling.
The complication rate after repair of traumatic ureteral injuries is 25%, with the most common complication being prolonged urinary leakage at the anastomotic site, which can lead to urinoma, abscess, or peritonitis. Placement of a closed suction drain in the retroperitoneum at the time of initial repair can minimize the risk of these complications . Other less common complications include recurrent stricture leading to hydronephrosis, abscess, fistula formation, and infection.
TUU was first described by Higgins in 1935 . The idea of the TUU is to bring the injured ureter from one side of the body, across the midline under the mesentery of the intestine to the healthy ureter on the opposite side, such that a contra-lateral UU anastomosis is reconstructed following the same surgical principals as the UU. If TUU is chosen, decision should be made intra-operatively whether or not the ureter will cross above or below the inferior mesenteric artery between the levels of L4 to S2. The anastomosis is made into a Y formation in an end-to-side or end-to-end fashion with a widely spatulated donor ureter. Double J ureteral stent or pediatric feeding tube (which will provide more length) should be placed such that it course through the donor ureter across the anastomosis and through the distal portion of the recipient ureter to the bladder. When considering a TUU, preference should always be given to direct reimplantation into the bladder if possible . Contraindications for a TUU include any disease which might involve both kidneys or ureters (TB, papillomatosis, recurrent stone formation) or retroperitoneal fibrosis. The accepting ureter and kidney must be normal due to the fact that after the TUU is performed, any disease process that affects one ureter or kidney puts the contralateral ureter and kidney now at risk. Also, if the ureter is chronically dilated and atonic, TUU should not be considered as it can lead to persistent, poor drainage .
Distal ureteral strictures can be managed by ureteral re-implantation into the bladder, or ureteroneocystotomy (UNC). This option should always be selected if the distal ureter can reach the bladder easily (up to 3–5 cm length) as it has a high success rate of approximately 85% . For correction of ureteral defects that are longer than 5 cm, options for modification include psoas hitch and/or a Boari flap.
Ureteral reimplantation with a psoas hitch was first described by Zimmerman in 1960  and is a way to tack the posterior bladder wall to the psoas muscle to allow the bladder to be repositioned closer to ureter, tension free. Briefly, the steps for the psoas hitch should include : bladder mobilization with development of the space of Retzius, freeing of the peritoneal attachments, and division of contralateral obliterated umbilical artery to provide enough mobility for the bladder to reach the ureter of injury for a tension-free anastomosis. If the contralateral superior aspect of the bladder is mobilized well, it should allow for the bladder to reach the ipsilateral psoas muscle tendon. The addition of a downward nephropexy can further increase the gap length to be spanned. A vertical, oblique, or horizontal-closed-vertically cystotomy on the low anterior surface of the bladder is made, manually displacing the bladder toward the ipsilateral ureter. The incision should not include the bladder dome, so the surgeon can insert fingers into the bladder and facilitate fixation to the ipsilateral psoas tendon, avoiding the genitofemoral or femoral nerves. Non-absorbable or delayed absorbable suture (PDS) is used to place with several interrupted sutures. Preplacing psoas hitch sutures prior to ureteral anastomosis, allows the surgeon to verify that the anchoring sutures are not inadvertently placed too deep through the bladder mucosa. It is also preferred to do this prior to anastomosis so the reimplanted ureter can lay in place in an unkinked, dependent fashion. The ureter is then implanted in a non-refluxing submucosal tunnel or a refluxing-type direct anastamosis. Indwelling stents are left in place for 1–3 weeks post operatively. Cystotomy is closed in two layers with absorbable suture. In review, successful UNC should be made in a fashion to be a tension free anastomosis with debridement and spatulation of the ureter and include a post-operative closed suction drainage system. The success rate of ureteral reimplantation with a psoas hitch exceeds 85% in both adults and children .
Modifications of this technique with the addition of the submucosal tunnel to prevent reflux has also been described . Although the advantage of a non-refluxing ureteral anastomosis is a significant concern for the pediatric population over concerns for pyelonephritis and renal insufficiency secondary to chronic reflux and infection, these risks in the adult population are less clear . Antireflux procedures offer no advantage over refluxing ureteric reimplantation in adults . However, the advantages of a refluxing-type ureteral anastomosis include: technically simpler, offer a shorter operating time, decrease the risk of distal ureteral stricture, and provides an additional 2–3 cm of ureteral length that would have been devoted to a submucosal tunnel .
Ureteral defects proximal to the pelvic brim usually require more than a simple psoas hitch alone. Therefore sometimes an additional modification with the Boari flap in addition to the psoas hitch provides for extra length up to more 5 cm to bridge the ureter to bladder. First described in 1947 , the Boari flap is a surgical maneuver in which the bladder is tubularized into a flap to extend from the bladder to the ureter . In fact, the Boari flap can be selected for injuries to the ureter with defects up to 14 cm in length .