Management of complete ureteral replacement. Experiences and review of the literature

Treatment of long ureteric strictures with a free peritoneal graft: long-term results

ZIEL DER STUDIE

Beschreibung einer neuen Technik zur Rekonstruktion von komplexen Ureterstrikturen unter Verwendung eines freien Peritoneallappens.

MATERIAL UND METHODEN

Zwischen 2006 und 2021 behandelten wir 11 Patienten mit langen komplexen Harnleiterstrikturen, die in 9 Fällen den mittleren- und in 2 Fällen den proximalen Harnleiter betrafen. Die Länge der Strikturen variierte von 3 bis 12 cm (Mittelwert 7 cm). In drei Fällen handelte es sich um eine retroperitoneale Fibrose nach einem gefäßchirurgischen Eingriff, in zwei Fällen um einen Morbus Ormond, in vier Fällen um eine ausgedehnte Resektion großer Harnleitertumoren, in drei Fällen um wiederholte endoskopische Eingriffe bei Harnsteinen und in einem Fall um eine viermal fehlgeschlagene Pyeloplastik. Der Harnleiter wurde längs gespalten, ein freier Peritoneallappen aus dem nahe gelegenen gesunden Bauchfell entnommen und nach Positionierung eines Harnleiterkatheters als Onlay-Patch mit einer fortlaufenden Naht an der verbleibenden Harnleiterplatte fixiert. Der Ureter wurde zuletzt mit Omentum gedeckt.

ERGEBNISSE

Die Nachbeobachtungszeit reichte von 12 bis 122 (Mittelwert 61,6) Monate. Sieben Patienten waren nach 12, 18, 60, 78, 98, 99 und 122 Monaten (Mittelwert 69,5 Monate) rezidivfrei, ohne Erweiterung des oberen Harntrakts und mit normaler Nierenfunktion. Bei vier Patienten kam es zu einem Rezidiv: Bei einem Patienten wurde das Rezidiv nach 60 Monaten ohne Symptome und mit leichter Hydronephrose festgestellt, ohne dass eine Operation erforderlich war. Bei einem Patienten mit Morbus Ormond trat das Rezidiv 6 Monate nach dem Eingriff symptomlos im distalen Teil des 10 cm langen Omlays auf. Es wurde eine Resektion des stenotischen Segments mit Psoas-Hitch durchgeführt. Bei den beiden anderen Patienten trat 3 und 6 Monate nach dem Eingriff eine Obstruktion unterhalb des rekonstruierten Segments mit Hydronephrose auf, ohne dass die Nierenfunktion beeinträchtigt war. Bei diesen Patienten wurde keine weitere Operation durchgeführt. Die Limitation dieser Studie besteht in der kleinen Studiengröße, die auf die strenge Indikationsstellung zurückzuführen ist.

SCHLUSSFOLGERUNGEN

Die beschriebene Technik ermöglicht den Erhalt der verbleibenden Gefäßversorgung des Harnleiters und stellt eine praktikable und nützliche Alternative zu Nephrektomie, Ileum-Ureter, Uretero-Uretero-Stomie und Autotransplantation in hochselektierten Fällen dar.

[Ureteral stricture as a late complication of radiotherapy : Possible treatment options]

Ureteral strictures are uncommon complications of radiotherapy which are often recognized late. Their consequences range from harmless dilatation of the ureter to loss of renal function and potential life-threatening urosepsis.Therapy of radiogenic ureteral stricture is a challenging task for every urologist. Several surgical strategies including minimally invasive procedures, reconstruction and partial or complete replacement of the ureter are available.This article provides an overview of the various options in the treatment of radiogenic stricture of the ureter, focusing on the use of ileum and colon segments for ureteral substitution.

Boari flap reconstruction in a male infant with solitary kidney and associated megaureter

A 1-year-old male infant presented with fever and abdominal lump for 3 months with increased leucocyte count (15 300/mm³) and serum creatinine (0.83 mg%). Abdominal ultrasound and renal scan demonstrated solitary left kidney with dilated tortuous left ureter. Voiding cystourethrogram was unequivocal. Left percutaneous nephrostomy was placed after poor response to perurethral catheterisation. His serum creatinine dropped to 0.58 mg/dL. Subsequent percutaneous nephrostogram and CT nephrostogram showed dilated left pelvicalyceal system, dilated, tortuous left ureter. A diagnosis of obstructed megaureter was made and ureteric plication and reimplantation planned. Intraoperatively, there were primitive ureteral valves until proximal one-third of the ureter. The distance between the upper ureter and bladder was ∼6 cm. This defect was bridged by Boari flap. The postoperative period was uneventful and now after 6 months of follow-up, he is doing fine.

Urethral reconstruction with tissue-engineered human amniotic scaffold in rabbit urethral injury models

BACKGROUND

Mitigating urethral injury remains a great challenge for urologists due to lack of ideal biomaterials for urethroplasty. The application of amniotic membranes (AM) over other synthetic materials make it a better potential source for urethral reconstruction. We separated the basement layer of AM to obtain denuded human amniotic scaffold (dHAS) and then inoculated primary rabbit urethral epithelial cells on the surface of dHAS to define whether this strategy minimize potential rejection and maximize the biocompatibility of human AM.

MATERIAL/METHODS

After the successful acquisition of dHAS from AM, cell-seeded dHAS were prepared and characterized. Both cell-seeded dHAS and acellular dHAS were subcutaneously implanted. Immune responses were compared by histological evaluation and CD4 cell and CD8 cell infiltrations. Then they were applied as urethroplastic materials in the rabbit models of urethral injury to fully explore the feasibility and efficacy of tissue-engineered dHAS xenografts in urethral substitution application.

RESULTS

Mild inflammatory infiltration was observed in cell-seeded dHAS grafts, as revealed by fewer accumulations of CD4 cells and CD8 cells (or neutrophils or other immune cells). Urethral defects of rabbits in the urethroplastic group with dHAS implantation (n=6) were completely resolved in one month, while there were one infection and one fistula in the control group with acellular dHAS patches (n=6). Histopathological analysis revealed mild immune response in cell-seeded dHAS group (P<0.05).

CONCLUSIONS

Tissue-engineered dHAS minimize potential rejection and maximize the biocompatibility of AM, which makes it a potential ideal xenograft for urethral reconstruction.

Use of ileum as ureteral replacement in urological reconstruction

PURPOSE

We reviewed indications and outcomes in patients undergoing ileal ureter replacement for ureteral reconstruction.

MATERIALS AND METHODS

Between December 1989 and September 2007, 105 patients underwent ileal ureter replacement, of whom 14 were excluded from study due to incomplete data. The remaining 91 patients (99 renal units) comprised the study cohort.

RESULTS

Mean patient age was 46.8 years and mean followup was 36.0 months. Indications for an ileal ureter were stricture following genitourinary surgery in 29 cases (31.9%), radiation induced stricture in 17 (18.7%), nonurological surgery iatrogenic injury in 16 (17.6%) and retroperitoneal fibrosis in 11 (12.1%). Only 4 patients (4.4%) had primary ureteral cancer. Long-term complications included anastomotic stricture in 3 patients (3.3%) and fistula in 6 (6.6%). Serum creatinine decreased or remained stable in 68 patients (74.7%) and hyperchloremic metabolic acidosis developed in 3. No patient complained of excessive urinary mucous production.

CONCLUSIONS

In 68.1% of patients indications for an ileal ureter included radiation induced stricture or iatrogenic injury. The ileal ureter is a reasonable option for long-term ureteral reconstruction with preserved renal function in carefully selected patients.

Early experience in reconstruction of long ureteral strictures with allogenic amniotic membrane

OBJECTIVE

To present our experience with the application of human amniotic membrane for the reconstruction of extensive ureteral wall defects.

METHODS

Between 2003 and 2006, 11 patients underwent reconstructive surgery of the ureter. A human amniotic membrane allograft was used to supplement ureteral wall defects. Indications for the procedure included ureteral strictures of a 5.5 cm average (range, 3-8 cm) localized in different parts of the ureter: upper (5), middle (5) and lower (3). The etiology of ureteral loss was: postinflammatory after a complicated stone disease (5), iatrogenic (4) and idiopathic (2). Diagnosis of ureteral stricture was based on antegrade pyelography and excretory urography. Two patients had synchronous treatment for upper and middle ureteral stenosis. Treatment efficacy was assessed by excretory urography and ultrasound.

RESULTS

The mean hospitalization time was 11.9 days, mean operation time 128 min and with an average follow up of 25.2 months. Complications included: stricture recurrence (1) and symptomatic urinary tract infections (2). Excretory urography showed lack of obstruction and normal width of ureters. In one patient, residual hydronephrosis was present on ultrasound.

CONCLUSIONS

The described method seems to be a promising tool in the reconstruction of extensive ureteral strictures.

Ureteral reconstruction for retroperitoneal tumors in children

PURPOSE

Removal of solid tumors of the pelvis and abdominal cavity may require resection of an involved ureteral segment. Ureteral stricture can also be a result of intense therapy. We present our experience with urinary reconstruction in this situation.

METHODS

A retrospective review of pediatric oncology patients with solid abdominal/pelvic tumors who underwent a ureteral reconstructive procedure was done. Institutional review board wavier was obtained for the review. Patient data were collected on diagnosis, procedures performed, renal function, and follow-up.

RESULTS

Thirteen patients were identified: 8 male and 5 female. The mean age at surgery was 10.1 years. The most common reason for surgery was en bloc tumor resection (n = 8) followed by ureteral strictures (n = 3). The Boari flap, Leadbetter-Politano reimplantation, and psoas hitch were the most common procedures preformed. Follow-up studies included measurements of serum urea nitrogen/creatinine levels as well as renal scans to assess functional status; 2 patients had elevated serum urea nitrogen/creatinine levels at follow-up. The mean follow-up time was 18 months; 4 patients died-none was secondary to renal complications. There were no local tumor recurrences.

CONCLUSIONS

Abdominal and pelvic tumors frequently involve the ureter, and their removal should not necessitate acceptance of poor surgical margins. Complete surgical resection of tumor including involved ureteral segments can prolong survival in patients with extensive abdominopelvic cancers. In another group of patients, ureteral strictures arise secondary to therapy and reconstruction may preserve renal function.

Comparison between ureteral replacements using a transverse tubularized colonic tube or ileal ureter: experimental study in dogs

INTRODUCTION

We report the comparison between ureteral replacements using a transverse tubularized colonic tube or ileal ureter in dogs.

MATERIALS AND METHODS

Ten canines were studied. Four underwent ureteral substitution with an ileal ureter; 5 with a single transverse tubularized colonic tube and 1 with a double colonic transverse tubularized tube. The animals were observed for a predetermined interval of 30 days. At 30 days, the animals underwent an intravenous pyelogram, cystogram, urine analysis, and serum electrolyte sampling, and the kidney, ureteral conduit, and bladder were examined grossly and histologically.

RESULTS

The pyelograms of both the ileal ureter and the transverse tubularized colonic tube showed prompt bilateral renal excretion. Grade 1 hydronephrosis was seen in 3 of 4 animals that received the ileal ureter and with 1 of 5 animals that received the colonic tube. Histological exam of the kidneys showed small focal areas of pyelonephritis in both groups without significant injury to the collecting tubules or glomeruli.

DISCUSSION

The transverse tubularized colonic tube is an effective form of ureteral replacement in the animal model. The advantages of using the colon include its proximity to the ureters, the minimal mobilization needed, position outside the radiation portals, and the short colonic segment necessary.

Ureteral replacement using the Yang-Monti principle: Long-term follow-up

OBJECTIVES

To present the long-term results for 2 patients with ureteral replacement using reconfigured transversely tubularized bowel segments according to the Yang-Monti principle.

METHODS

Between May 1999 and November 2001, 2 patients underwent ureteral replacement at our institution using a reconfigured ileal segment in one and colon in the other. The first patient was a 33-year-old man who had lost 6 cm of the proximal left ureter after two attempts to repair a ureteral stricture. A reconfigured small bowel tube was interposed between the proximal and distal ureteral stumps after excision of the left ureteral stricture. The second patient was a 66-year-old woman with a poorly functioning right kidney and total bilateral ureteral strictures resulting from radiotherapy for metastatic cervical cancer. She underwent complete left ureteral substitution with a double Monti sigmoid tube in association with a Boari flap.

RESULTS

With a follow-up of 5.75 and 3.25 years, both patients were clinically doing well with a stable split renal function on mercaptotriglycylglycine renal scan and no evidence of obstruction. The man had required exploratory laparotomy 4 weeks postoperatively to correct a small bowel obstruction secondary to a bowel kink.

CONCLUSIONS

The transverse tubularized bowel tube is an effective technique for partial and complete ureteral replacement with sustained, good, long-term results. Reconfigured tubes of small or large bowel seem to promote an equally efficient urine transport mechanism that persists unaltered for long periods.

Canine ureteral replacement with long acellular matrix tube: is it clinically applicable?

PURPOSE

We evaluated the effectiveness of acellular matrix used as a tube for replacement of a relatively long segment of the canine ureter.

MATERIALS AND METHODS

Acellular matrix was obtained by excision of the whole ureter of donor dogs that were sacrificed and not included in the study group. Retrieved ureters were treated to have complete cell lysis, while maintaining the fiber framework. The study included 10 mongrel dogs in which a 3 cm segment was excised from 1 ureter and replaced by a tube of acellular matrix of the same length and width. The new tube was sutured proximal and distal by watertight interrupted sutures around a 5Fr Double-J stent (Medical Engineering Corp., New York, New York) that remained for 6 weeks. Excretory urography was done 1 and 2 weeks after stent removal and the dogs were then sacrificed. Before sacrifice the ureter was exposed and carefully examined, and the whole specimen was excised for histopathological examination.

RESULTS

All dogs survived surgery except 1, which died 1 week postoperatively of a malpositioned stent and urinary ascites. There was no clinically apparent postoperative complications during the presence or after the removal of the ureteral stents. One week after stent removal excretory urography showed ipsilateral mild to moderate hydroureteronephrosis in 3 dogs and no dye excretion in 6 with a normal contralateral kidney. One week later no dye excretion was detected in all except 1 dog, which showed more radiological deterioration. At the time of sacrifice there was moderate to marked hydroureteronephrosis above the level of the new tube in all dogs. Although the graft was intact in all subjects, marked shrinkage was observed. On ureteral calibration there was significant narrowing of the lumen up to complete occlusion. At 8 weeks histopathological examination showed extensive fibrosis.

CONCLUSIONS

An acellular matrix tube is not able to replace a 3 cm segment of the canine ureter.

Hydronephrosis after aorto bifemoral graft surgery: a marker for late graft complications

Ureteral obstructions are serious late complications after aortoiliac reconstructive vascular surgery, which lead to loss of kidney function if they remain untreated. One case report serves to describe the incidence, aetiology, clinical presentation and treatment options of an obstructive uropathy following graft surgery. Hydronephrosis due to a ureteral obstruction is considered as a "marker" of graft complication. Therefore, ultrasound examination and close follow-up beyond 1 year are recommended in all patients who undergo aortoiliac surgery.