Extravesical reimplantation of an extravesical-ectopic ureter from the upper pole of a duplicated kidney

Introduction

Extravesicular ureteral ectopia (EUE) occurs with a frequency of 0.05 – 0.025% (10 cases per 19,046 children). In girls, EUE occurs 5 times more often than in boys. EUE in boys is more often detected in the absence of duplex upper urinary tract (UUT), while in girls it is overwhelmingly associated with a complete duplex UUT [1]. Thus, EUE is accompanied by a complete duplex collecting system in 80% of cases [2]. In girls, the ureteral stoma can be ectopic into the urethra (35%), into the vaginal opening (34%), into the vagina (25%), into the fallopian tubes, and uterus (6%) [3].

The main clinical manifestation of EUE is constant urinary incontinence against the background of normal urination [4]. Diagnostic difficulties are associated with the low functional activity of the upper half of the kidney, as urine is drained by the ureter with an ectopic ureteral stoma, which makes it difficult to visualize the ectopic ureteral orifice both during X-ray contrast studies and during genitals examination. On the other hand, the late diagnosis of these conditions is associated with the absence of complaints from the parents of patients before potty training and refusal of nappies.

The frequent association of EUE with the duplex collecting system increases the likelihood of detecting urinary tract infection (UTI) in patients, both associated and unrelated to vesicoureteral reflux (VUR). The first step of surgical treatment in the VUR-cases is currently endoscopic treatment by using various bulking agents. The tissue reaction to the bolus of the bulking agent varies in a wide range: from short-term perifocal edema to significant structural changes, including the formation of calcifications inside the bolus of the bulking agent substance. The identification and interpretation of the described structural changes form a few tactical issues for which there is no broad professional consensus.

There is also no single surgical strategy for the treatment of these patients. Heminephrectomy (HNE), nephrectomy (NE), uretero-ureteral-anastomosis (UUA), single-block ureteral reimplantation, or selective reimplantation of the upper ureteral half are widely used.

From these points of view, the authors of this article find it interesting to present their clinical case.

Clinical case presentation

In September 2018, a three-year-old girl was admitted to our clinic with constant urinary incontinence against the background of normal urination, periodic leukocyturia. Therefore, two-three pads per day were used. Her physical and mental development was normal. On medical examination, it was found out that the genitals were formed correctly, the skin around was with moderate hyperemia due to constant urine leakage, the source of the urine leakage was not found.

From the anamnesis, it was known that in August 2016 the patient was examined in one of the clinics of another city. According to the data (standard and under the electro-optical converter) of voiding cystourethrography, no VUR was detected. Intravenous urography revealed ureterohydronephrosis (stage 3 according to SFU) of the upper half of the doubled left kidney. Conservative treatment was recommended.

In the spring of 2017, she was hospitalized at her place of residence due to the activity of UTI. Two months later, the UTI relapsed. Repeated voiding cystourethrography revealed stage 2 of coincident VUR in the lower half of the left kidney and stage 2 of coincident VUR in the right one. According to static nephroscintigraphy, there were no signs of a decrease in the volume of the functioning parenchyma. Endoscopic treatment of VUR was performed from both sides by using a hyaluronic acid dextranomer (Vurdex^Ò) as an implant. Subsequently, the patient was under dynamic supervision at the place of residence with periodic courses of antibacterial therapy against the background of UTI activation.

In May 2018, a control voiding cystourethrography at the clinic where endoscopic treatment was previously performed revealed a persistent coincident VUR in the lower half of the duplex collecting system of the left kidney (Fig. 1). Due to the low degree of reflux, repeated endoscopic treatment was considered inappropriate.

In October 2018, the girl was hospitalized in our clinic to clarify the diagnosis and determine further treatment tactics. According to the CT of the retroperitoneal organs, it was found out that the patient suffered from the ureterohydronephrosis of the upper half of the duplex upper urinary tract on the left side. The kidney on the right side was without features. In the angle projection, there is a rounded formation (12 – 8 mm) of an inhomogeneous structure with multiple hyperdensive inclusions on the left side (Fig. 2).

The indigocarmine test was performed for differential diagnosis of the urinary incontinence cause. The content into separated the pad was transparent, without any dye admixture, which allowed us to conclude that the girl suffered from EUE. During the day, the girl lost more than 60 ml of urine. Therefore, surgical treatment was offered to her parents.

In July 2019, repeated endoscopic treatment by using a hyaluronic acid dextranomer –CRM VurdexÒ (Bioscience GmbH, Germany) as an implant was performed. In the postoperative period, stable clinical and laboratory remission of UTI was achieved. The phenomena of urinary incontinence persisted.

In January 2020, the child was hospitalized for further medical examination and surgical treatment. Another voiding cystourethrography did not detect any VUR on both sides. In January 2020, voiding cystourethrography did not detect any VUR on both sides as well. Computer uroflowmetry demonstrated the indicators of the uroflowmetric line within the normal range. Hardware cystometry — parameters of intravesical pressure were within normal limits. Repeated test with indigocarmine showed that urine in a pad was without any dye admixture. Bladder ultrasound represented the formation of the bladder wall in the bottom area on the left. According to the CT of the retroperitoneal space organs, there was an ureterohydronephrosis of the kidney upper half on the left side, a formation of the bladder wall in the bottom area on the left side with multiple different-caliber hyperdensive inclusions. The kidney on the right side was without features (Fig. 3).

After preoperative preparation, the patient underwent surgery – ureterocystoanastomosis (UCA) with the ureter of the kidney upper half on the left side, intravesical removal of a neoplasm of the bladder.

Surgery technique. Transverse suprapubic skin incision with a length of 5 cm. The tissues were dissected in layers to aponeurosis, which was dissected vertically along the midline. The fibers of the m. abdominis rectus were separated, the lower third of the ureters on the left side was isolated outside the bladder. The moderately expanded ureter of the upper half was isolated as far as possible in the distal direction. Cystotomy. A through-hole was formed in the bladder wall above the projection of the ureteral stoma of the lower half. A submucosal tunnel (4 cm length) in the transverse direction was formed. The ureter of the upper half was passed through the submucosal tunnel, the ureteral stoma was formed. A mucosal defect was sutured at the point of the ureter entry of the upper half into the bladder.

The volumetric formation was located medial to the stoma of the left ureter. After the mucosa dissection over the volumetric formation, it was found out that it had a dense capsule within the bladder wall, the surrounding tissues were not visually altered. Bluntly and acutely, the formation was excised, then it was followed by suturing of the bladder wall with Vicryl 4/0 continuously. Then the wound of the mucous membrane was sutured by PDS 6/0. The bladder was drained with a urethral catheter, the ureter of the upper half was intubated with a catheter 6 Fr (drainage of the paravesical space).

The drainage was removed from the paravesical space on day 3, the catheter 6 Fr was removed on day 6 after surgery. The urethral catheter was removed on day 7 after surgery.

During the histological examination, the formation of the bladder was represented by a cavity formation with a fibrous capsule filled with uric acid and calcium salts with chronic inflammation.

In the postoperative period, a month later, the child demonstrated no symptoms of daytime urinary incontinence. There was not any dysuria during the day. According to the kidneys' ultrasound, the pelvicalyceal system (PCS) on the right side was not expanded. The upper half of the A-P dimension (APD) was up to 6 mm; the lower half of the PCS was not expanded.

Discussion

An ectopic ureter is a ureter that does not enter the bladder trigonal region. It can open anywhere from the bladder neck to the perineum (into the vagina, uterus, and even the rectum) [6]. The incidence of this pathology is 1 case per 1900 newborns. The anomaly is more often detected in girls (in 85% of cases). More than 80% of girls with ureteral ectopia have duplex ureters, whereas ectopia in boys is not associated with the duplex UUT in most cases [7].

EUE is manifested by constant urinary incontinence against the background of normal urination after potty training. Constant urinary incontinence, recurrent UTI, and VUR can often mask ectopia of the ureteral mouth [8].

Ultrasound and voiding cystourethrography remain the initial diagnostic methods for detecting EUE and the duplex PCS. Currently, CT urography is increasingly used to detect a doubling of the urinary tract and ectopia of the ureteral orifice [6, 8].

Surgical treatment is aimed at making the patient dry. At the same time, the surgery should not hurt the normal half of the kidney. There are many surgical options available for the treatment of ureter ectopia. These include HNE; reimplantation of the ureter/ureters (with a single block or only an ectopic ureter); UUA (upper or lower) [9]. Surgery in each case should be individual and the choice should be made depending on the anatomy of the ureter and the functional state of the upper half of the kidney [10].

The upper HNE is considered by many specialists to be the most radical surgery, providing almost absolute success, in terms of getting rid of urinary incontinence. This surgery is preferred when it is obvious that the upper half of the kidney is not functioning and there is pronounced ureterohydronephrosis. Nevertheless, HNE is a complex and traumatic intervention that does not exclude iatrogenic disruption of blood supply to the remaining part of the kidney with subsequent impairment of its function. In addition, the formation of a cystic formation in the upper pole projection of the kidney's left part associated with incomplete removal of the parenchyma of the upper half is not excluded. According to various authors, these formations occur after HNE in 21 – 60% of cases, but for the most part, they do not have any clinical manifestations and do not require repeated surgical intervention [11, 12, 13, 14].

Beganović et al. demonstrated good results in a study of 54 patients who underwent HNE [15]. Urine retention was achieved in 94% of patients. However, postoperative urination dysfunction was observed in 11 (20%) patients, and secondary interventions were required in 17 (31%) patients.

The advantages of HNE are that it avoids manipulation on the distal part of the ureters and subsequently eliminates possible negative systemic reactions associated with structural changes in the parenchyma of the upper half of the kidney [16].

In 2005, Gundeti et al. reported the condition of the function of the kidney lower half in 60 patients who underwent open upper HNE. In many patients (92%) in the postoperative period, there was no impairment of the function of the lower half. However, 8% of patients showed a decrease in the function of the lower half by 10% or more [17].

Complications of HNE may include bleeding, loss of function of the lower half of the kidney due to vascular spasms, or damage to them. In their study, Jayram et al. showed that this risk varies from 5 to 9% in the child population. From our point of view, the loss of function of the lower half of the kidney in the long-term period (in adults) may occur even more often [18].

Joyeux et al. reported a 9-year retrospective multicenter study of 25 children who underwent upper HNE. They showed that there was no complete loss of function of the lower half of the kidney. However, 17% had a slight decrease in function [19].

An important argument of the supporters of HNE is to eliminate the possibility of complications associated with changes in the upper pole of the kidney. Levy et al. note that arterial hypertension in patients with dysplasia of the kidney tissue (or without it) was associated with the presence of renal scars after recurrent UTI in a healthy half [20].

More than two decades ago D.A. Husmann reported that these complications are rare, and the preserved dysplastic half does not require removal on this basis [21].

Thus, the upper HNE makes it possible to radically solve the problem of urinary incontinence but does not exclude a violation of the blood supply to the lower pole with a possible loss of its function. This argument combined with the high traumatic nature of the technique does not allow, from our point of view, to consider the described technology as surgery of choice.

On the other side, UUA is a variant of surgical treatment which is actively discussed on the legality of involving a conditionally healthy ureter of the lower half of the kidney in the surgical impact zone. The technique is attractive from the point of view of its low traumatism, the absence of severe complications with fatal consequences for the renal parenchyma of the ipsilateral kidney. This technique eliminates the impact on the bladder.

The use of laparoscopic and robotic methods for UUA has aroused new interest in the use of this technique in the treatment of ectopia of the ureteral stoma.

Chacko et al., McLeod et al., and Michaud et al. have shown that with a highly dilated ureter, UUA is a safe and successful treatment method regardless of the function of the upper pole [22][23][24].

The performance of NE, HNE, and the formation of ipsilateral UUA does not exclude the possibility of preserving the distal ureter. The remaining ureteral stump can cause the formation of ureteral stump syndrome in the form of recurrent UTI, hematuria, pain syndrome, and even stump empyema [25].

Reimplantation of the ureters/ureter of the upper half is used when the function of the ectopic half of the kidney is preserved. The use of this technique involves the transplantation of both ureters with a single-block or only an ectopic ureter. The results of using this technique in the treatment of urinary incontinence against the background of EUE were demonstrated by Gran et al. on the experience of treating 16 patients [26]. According to these authors, none of the patients required additional interventions during the follow-up period (62.3 months). Similar results were obtained by M.H. Wang [27].

It is believed that dilated ureters have a good blood supply and tolerate dissection well. With careful dissection, the expanded section of the upper doubled ureter, with its ectopia, is easily separated from the ureter of the lower half for the duration necessary for its reimplantation. A similar technique was described by Castagnetti et al., who performed selective reimplantation of the ureter of the upper half in 16 patients [28].

Over the past four decades, transurethral administration of bulk agents that have various stability indicators has been actively used in the treatment of VUR. One of the agents widely used in the Russian Federation is the hyaluronic acid dextranomer (Dx/HA) — CRM VurdexÒ.

The histopathological effect of Dx/HA injections on the distal ureter was first studied by A. Stenberg et al. in animal models [29]. Subsequently, the first clinical study was conducted by the same authors, where they showed that Dx/HA injection is associated with granulomatous inflammation, as evidenced by multinucleated giant cells. Initially, the inflammatory reaction is an active cellular process, which is subsequently replaced by fibrosis. Calcification, pseudocapsulation, and infiltration by fibroblasts and inflammatory cells are also observed at the implantation site [30].

Bozkurt et al. report a confusing radiographically detected calcified bolus Dx/HA in a patient complaining of lower back pain. Initially, the patient was mistakenly diagnosed with a stone of the distal ureter [31].

In the case of the authors’ patient, the volumetric formation of the bladder wall before surgery was regarded because of the migration of the implant and histopathological changes in the surrounding tissues, which was subsequently confirmed by the results of histological examination. This influenced the choice of surgical tactics since the planned removal of the formation did not exclude the need for extravesicular manipulations, which made it convenient to form a UCA with the ureter of the upper half after its extravesical discharge.

Conclusion

Calcification of the implant after endoscopic treatment of reflux using Dx/HA is a rarely recorded variant of changes. The presence of a volumetric formation in the area of surgical interest determined the choice of surgical technique in favor of the formation of UCA with the ureter of the upper half of the doubled kidney. This variant of surgical technology is rarely used in the treatment of urinary incontinence due to EUE. The case presented by the authors and the result of surgical treatment emphasizes the need for further studies to assess the effectiveness and safety of UCA with the ureter of the upper half of the doubled kidney in the treatment of urinary incontinence due to EUE.