You are in: eMedicine Specialties > Urology > Surgery UreterocalicostomyArticle Last Updated: May 25, 2006AUTHOR AND EDITOR INFORMATIONSection 1 of 12
  Author: Martha K Terris, MD, FACS, Professor, Department of Surgery, Medical College of Georgia Martha K Terris is a member of the following medical societies: American Cancer Society, American College of Surgeons, American Institute of Ultrasound in Medicine, American Society of Clinical Oncology, American Urological Association, New York Academy of Sciences, and Society of University Urologists Coauthor(s): Kashif Siddiqi, MD, MS, Staff Physician, Section of Urology, Department of Surgery, Medical College of Georgia Editors: Peter Langenstroer, MD, Assistant Professor, Department of Surgery, Division of Urology, Medical College of Wisconsin; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine; J Stuart Wolf, Jr, MD, FACS, David A Bloom Professor of Urology, Director, Division of Minimally Invasive Urology, Department of Urology, University of Michigan Medical Center; Stephen W Leslie, MD, FACS, Founder and Medical Director of the Lorain Kidney Stone Research Center, Clinical Assistant Professor, Department of Urology, Medical College of Ohio Author and Editor Disclosure Synonyms and related keywords: UCO, ureter, calycoureterostomy, calicoureterostomy, calycoplasty, ureteroneopyelostomy, Anderson-Hynes kidney/calix plasty, ureteropyeloanastomosis, ureterocalycostomy INTRODUCTIONSection 2 of 12
  Ureterocalicostomy (UCO) is anastomosis of nondilated healthy ureter proximal to the lower calyceal system, which is exposed by amputation of the most dependent portion of the lower pole of the kidney, to bypass severe peripelvic fibrosis with a ureteropelvic junction (UPJ) obstruction or a long proximal ureteral stricture (see Image 1) if the renal pelvis is scarred or intrarenal in location. History of the ProcedureOriginally described by Neuwirt in 1947, UCO was slow to gain popularity. The small number of cases was due, in part, to the limited number of appropriate cases and the high restricture rate. Modern UCO was described by Hawthorne et al in 1976. Prior to these authors' innovations, UCO was performed with minimal resection of lower-pole tissue and was prone to anastomotic stricture and obstruction. Hawthorne et al introduced the importance of generous resection of the lower pole, extending cephalad to the intended calyx to be anastomosed to the ureter, in order to free the ureterocaliceal anastomosis from the surrounding cortical tissue. As prenatal ultrasound has increased the incidence of UPJ obstruction diagnosis and subsequent procedures for UPJ obstruction, complications of pyeloplasty have increased the need for this procedure. ProblemPeripelvic fibrosis, a scarred, contracted renal pelvis, or an intrarenal pelvis in combination with a proximal ureteral stricture may prevent UPJ reconstruction by standard pyeloplasty or endopyelotomy. Two surgical options remain in this situation: ureteropyelostomy and UCO. Ureteropyelostomy (anastomosing the healthy ureter to the renal pelvis) is preferred, but if ureteral length is insufficient to perform a tension-free anastomosis (even when combined with a psoas hitch and/or nephropexy), a UCO is an option. The kidney is doomed without surgical correction of the obstruction. With the advent of endoscopic surgical procedures, UCO is also used to manage failed endourological procedures or complications caused by them. FrequencyThe most common indication for this procedure is proximal ureteral stricture in combination with pelvic fibrosis or intrarenal pelvis occurring after multiple failed pyeloplasty attempts. Fortunately, this is extremely rare. Less than 0.5% of cases undergoing pyeloplasty subsequently require salvage with UCO. Even more scarce are cases requiring UCO for a horseshoe kidney, ischemic fibrosis of the renal pelvis/ureter in renal transplants, traumatic avulsion of the proximal ureter and/or renal pelvis, or extensive fibrosis following surgery for upper urinary tract stone disease. EtiologyPeripelvic fibrosis with long proximal ureteral strictures usually is the result of a failed pyeloplasty or other surgical procedures, stone disease, inflammatory processes, or trauma. Occasionally, similar severe obstruction can be observed in transplanted kidneys in which the transplanted ureter became devascularized during harvest. Horseshoe kidneys also have been salvaged with UCO. PathophysiologyHistologic findings of benign proximal ureteral strictures are nonspecific. Scar formation with collagen deposition and inflammatory infiltrate may be prominent. The obstruction can result in impairment of renal function, pain, infection, and/or stones. ClinicalClinical symptoms of obstruction include urosepsis, failure to thrive, flank pain or mass, and hematuria. As first described by Dietl, the episodes of flank pain, nausea, and vomiting may present during periods of rapid diuresis with large volumes of liquid intake (so-called Dietl crisis). This may manifest only after drinking liquids that promote brisk diuresis, such as beer or coffee. Most patients requiring UCO have a history of pyeloplasty, other urinary tract surgery (including ureteroscopy and endopyelotomy), stones, cancer, or trauma. INDICATIONSSection 3 of 12
When pyeloplasty attempts for UPJ obstruction have failed and result in significant peripelvic fibrosis or a relatively long gap between the renal pelvis and the nonobstructed proximal ureter, the kidney can be salvaged with anastomosis of the proximal ureter directly to the lower calyceal system. This technique (ie, UCO) also may be used as the primary reconstructive procedure when a UPJ obstruction or proximal ureteral stricture is associated with a relatively small intrarenal pelvis. In this situation, repeat open or percutaneous pyeloplasty and balloon dilation have high restricture rates. If an extended length of ureter is not involved in the fibrotic/stenotic process, retrograde endopyelotomy with an Accusize catheter or ureteropyelostomy should be attempted before resorting to other types of repair, including UCO, ileal interposition, and autotransplantation. UCO also is a useful option when the UPJ is associated with a horseshoe or malrotated kidney in which a standard pyeloplasty does not result in dependent drainage of the collecting system. Alternatives include autotransplantation with a Boari flap pyelovesicostomy, ileourethral replacement, long-term nephrostomy tube/ureteral stent, renal capsule flap, and nephrectomy. The decision to perform a nephrectomy must be based on the level of function in the obstructed kidney and the function of the contralateral kidney. If the patient's renal function is less than 25% for the affected kidney, then surgical correction has a high risk for failure and nephrectomy ultimately may be required. If the patient's renal function is less than 10%, then recovery is unlikely and initial nephrectomy may be most appropriate. RELEVANT ANATOMYSection 4 of 12
The ureteral length is 20-30 cm, depending on the individual's height. The lumen size is 4-10 mm in circumference, depending on its location. The narrowest areas are the UPJ, the overpass by the ureter where it crosses over the bifurcation of the iliac arteries, and the ureterovesical junction (UVJ). In both men and women, the ureter courses posterior to the gonadal vessels and anterior to the iliopsoas muscles, crosses the common iliac artery and vein, and enters inferiorly into the pelvis. In men, the vas deferens loops anterior to the ureter prior to the ureter entering the bladder. In women, the ureter courses posterior to the uterine arteries (hence the "water under the bridge" analogy) and is in close proximity to the uterine cervix prior to reaching the intramural bladder. The ureteral blood supply comes from multiple sources. Superiorly, the renal artery may branch and supply the ureter, along with the gonadal artery. As the ureter courses through the retroperitoneum, the aorta contributes numerous small branches. In the pelvis, the iliac, vesical, uterine, and hemorrhoidal arteries also contribute to the blood supply of the ureter. CONTRAINDICATIONSSection 5 of 12
The major contraindication to any ureteral stricture surgery is an active and untreated urinary tract infection. A relative contraindication is uncorrected bleeding diathesis. If the patient has a terminal malignancy, is extremely elderly, or has a high surgical risk and tolerates internal stenting well, then long-term stenting may be most appropriate. If the patient's renal function is less than 10%, then recovery is unlikely and initial nephrectomy may be most appropriate. Ureteral obstruction from retroperitoneal malignancy, lymphadenopathy, or retroperitoneal fibrosis is a relative contraindication to UCO. Strictures from urinary tuberculosis that have not been treated medically and have been stable for less than 3-6 months also are a contraindication because postinflammatory scarring may continue to develop. The presence of malignancy, primarily transitional cell carcinoma, is a contraindication to UCO. However, peripelvic and focal proximal ureteral fibrosis resulting from endoscopic resection of transitional cell carcinoma or curative chemotherapy and/or radiation for retroperitoneal malignancy may be amenable to UCO, but such cases are rare. WORKUPSection 6 of 12
Lab Studies
Imaging Studies
Histologic FindingsHistologic findings of a proximal ureteral stricture and fibrotic renal pelvis are nonspecific. Scar formation with collagen deposition and inflammatory infiltrate may be prominent. In cases of radiation-induced fibrosis, a lack of cellularity and vascular hypertrophy with acellular matrix may be present. Malignant obstruction displays characteristics of the specific carcinoma pathology, most commonly transitional cell carcinoma but occasionally other retroperitoneal tumors such as lymphoma or sarcoma. StagingUreteral strictures may be staged based on location and severity. Location is divided into proximal (UPJ to sacrum), mid (over sacrum), and distal (inlet of pelvis to UVJ). Severity commonly refers to the patient's degree of obstruction (ie, mild, moderate, severe). Candidates for UCO predominately are those with proximal severe obstruction. TREATMENTSection 7 of 12
Medical therapyNo medical therapy is available for ureteral stenosis or UPJ obstruction. Surgical therapyAlternatives to UCO include autotransplantation with a Boari flap pyelovesicostomy, ureteroileal interposition, long-term nephrostomy tube or ureteral stent, renal capsule flap, and nephrectomy. The decision to perform a nephrectomy must be based on the level of function in the obstructed kidney and on the function of the contralateral kidney. If the obstructed kidney is contributing 25% or more of the total renal function, nephrectomy should be avoided if possible. Preoperative detailsPreoperative drainage of an obstructed kidney is recommended if concomitant infection, renal insufficiency, or severe pain is present. A ureteral stent is preferable because it serves the dual function of facilitating dissection of the ureter during surgery. However, if the obstruction is of such severity that passage of a stent is not possible, percutaneous nephrostomy placement may be necessary. If the degree of renal function is low enough that nephrectomy is considered, measurements of differential renal function using 24-hour urine collection or nuclear renal scan should be repeated several weeks after temporary drainage is established to determine whether any recovery of function has taken place that would render the kidney salvageable. This also allows documentation of actual baseline kidney function. Intraoperative detailsPreliminary cystoscopic or antegrade placement of a ureteral catheter can aid in dissection of the ureter and renal pelvis. The ureter is isolated in the retroperitoneum and dissected proximally as far as possible, taking care to preserve a large amount of periureteral tissue. The ureter then is divided just distal to the area of fibrosis. The proximal ureteral stump is ligated, even if complete obstruction is present radiologically, to prevent potential leakage into the retroperitoneum. The kidney then is mobilized to allow access to the lower pole. If the length of ureter is inadequate to reach the lower pole, the kidney can be more thoroughly mobilized to allow it to be displaced downward. The parenchyma over the lower-pole calyx then is resected. The amount of parenchyma to be removed varies with the extent of cortical thinning. Simple incision of the parenchyma, instead of resection, results in postoperative stricture of the ureterocaliceal anastomosis. If substantial parenchymal tissue is present over the lower calyx, the technique may require more careful control of the parenchymal blood supply and maintenance of hemostasis as discussed in Partial Nephrectomy. In a horseshoe kidney, this resection may include removal of the entire isthmus joining the 2 moieties. The proximal ureter then is spatulated laterally, and the ureterocaliceal anastomosis is performed over an internal stent. An initial interrupted suture of small-diameter (eg, 4-0 or 5-0) absorbable suture material is placed from the apex of the ureteral spatulation to the lateral wall of the calyx. A second interrupted suture is placed from the medial unspatulated wall of the ureter to the medial wall of the calyx, 180° from the initial suture. Approximately 6-10 additional sutures are placed in an interrupted fashion, joining the posterior and anterior aspect of the ureter and calyx. No sutures are tied until all sutures are placed in order to facilitate visualization and careful placement of subsequent sutures. Once sutures are placed circumferentially, they are secured. If possible, close the renal capsule over the cut surface of the parenchyma, taking care to not compress the ureterocaliceal anastomosis. The anastomosis should be surrounded by viable perinephric fat or omentum. Consider the placement of a nephrostomy tube and an external drain. Recently, laparoscopic UCO have been performed with promising results. Both a transperitoneal and a retroperitoneal approach have been described. In the transperitoneal approach, the patient is placed in the 45-60° flank position, and 3-4 ports are placed in the abdomen. The colon is mobilized to gain access to the renal hilum. A 2-cm circular rim of the tip of the lower pole renal parenchyma is excised. The UPJ is then transected, and the ureter is spatulated laterally. End-to-end ureterocaliceal anastomosis is performed in a mucosa-to-mucosa fashion using running 3-0 polyglactin suture. Postoperative detailsExternal drains are advanced and removed 24-48 hours after any urinary drainage has ceased. If a nephrostomy tube has been placed, a nephrostogram is obtained at least 7-10 days postoperatively. If the study findings show no obstruction or extravasation, the tube is clamped for 12-24 hours and then removed if no flank pain, fever, or leakage exists. Follow-upInternal stents are removed in an outpatient setting in 4-6 weeks. Perform follow-up evaluations of the functional results with an intravenous urogram or nuclear renogram approximately 2 weeks after stents or nephrostomy tubes have been removed. If the patient becomes symptomatic, performing studies earlier may be indicated. Postoperative study findings should show improvement when compared to preoperative study findings. For excellent patient education resources, visit eMedicine's Kidneys and Urinary System Center. Also, see eMedicine's patient education article Intravenous Pyelogram. COMPLICATIONSSection 8 of 12
Prolonged leakage usually resolves spontaneously. If a ureteral stent is not placed intraoperatively, is removed prematurely, becomes obstructed, or migrates distally with resulting anastomotic drainage persisting for 7-10 days postoperatively or recurring after the external drain has been removed, perform retrograde studies and replace the internal stent. Urinoma formation secondary to extravasation can occur even with adequate placement of drains, stents, and nephrostomy tubes. This is managed best with direct percutaneous drainage of the fluid collection using guidance with an ultrasound or CT scan. Recurrent stenosis is rare after this procedure. If it occurs, options include autotransplantation with a Boari flap pyelovesicostomy, ureteroileal interposition, long-term nephrostomy tube/ureteral stent, and nephrectomy. OUTCOME AND PROGNOSISSection 9 of 12
Success rates of 70-90% have been reported following UCO. Patients in whom this procedure fails often eventually loose the kidney. Although the studies involving laparoscopic UCO have been scarce, success rates are similar to those of open. Gill et al reported on 2 patients undergoing transperitoneal laparoscopic UCO with documented improvement in renal drainage, although one patient did ultimately undergo nephrectomy because of persistent flank pain. Terai et al reported one case of a patient undergoing retroperitoneal laparoscopic UCO, with no recurrence at 2-year follow-up. These results are encouraging, and the minimally invasive technique is feasible option in these patients. FUTURE AND CONTROVERSIESSection 10 of 12
An element of controversy exists in all salvage procedures for previous surgical failures. Because these severe cases are uncommon and exhibit an array of anatomic findings, direct comparison of the techniques available for salvage are unavailable. In the absence of such data, urologists usually perform the salvage procedure with which they have the highest comfort level. A future application of the UCO technique may be used to treat infundibular stenosis. Gupta et al reported a case of UCO with anastomosis of the middle calyx to the ureter to provide drainage to the middle calyx without lower polar nephrectomy. The future of urinary tract reconstruction may involve extraurinary tissue used as grafts or vascular pedicle flaps to replace damaged portions of ureter. Naude recently reported the successful use of buccal mucosal grafts with omental wrap in 4 patients with segmental ureteric loss. Innovative tissue engineering technology may produce ureteral tissue that closely mimics native ureter for ureteral replacement. Similar technology is being used by Atala to engineer bladder, cavernosal, urethral, and ureteral tissue. MULTIMEDIASection 11 of 12
REFERENCESSection 12 of 12
Article Last Updated: May 25, 2006 | |||||||
