Transient ureteric obstruction following pelvic floor reconstruction

Abstract

We describe the first reported case of transient distal ureteric obstruction attributed to post-surgical oedema in a patient with a solitary kidney. This occurred following combined pelvic floor repair and sacrospinous fixation for recurrent pelvic organ prolapse and manifested clinically as anuria, radiological hydroureter and acute kidney injury in the postoperative period. The transient nature of this obstruction, which was managed by a temporary percutaneous nephrostomy, indicates that it was caused by ureteric compression secondary to soft tissue oedema following surgery. We highlight the importance of this potential complication in females with a history of nephrectomy, unilateral renal tract anomalies or severely diminished renal reserve.

Background

Ureteric injury is a rare, but serious complication arising in pelvic surgery. Women undergoing pelvic floor reconstruction are informed of this risk prior to surgery. In this case, the presentation and potential consequences of a ureteric obstructive injury were more exaggerated due the presence of a solitary kidney. The progressive anuria would suggest this is an evolving postoperative complication and unlikely to present intraoperatively. The spontaneous resolution of the ureteric obstruction following non-surgical management highlights a reversible aetiology, which may occur more frequently than is reported, owing to a subclinical disease course in patients where a contralateral kidney can compensate. We highlight that management with nephrostomy can be trialled successfully in patients with detected ureteric obstruction following pelvic organ prolapse surgery and avoid additional surgery.

Case presentation

A 77-year-old, para 2 woman was referred to our urogynaecology service with recurrence of symptomatic pelvic organ prolapse. She had previously undergone a combined vaginal hysterectomy and anterior colporrhaphy 15 years prior with a repeat anterior colporrhaphy 12 years after her primary repair. Her medical history included non-insulin-dependent diabetes, hypertension, chronic kidney disease stage 2 and a history of a left nephrectomy for a clear cell carcinoma 40 years previously. Following 24 months of conservative management with pessaries, the patient elected to proceed with a surgical repair for a stage 4 anterior compartment, posterior compartment and vault prolapse (Pelvic Organ Prolapse-Quantification (POP-Q): Ba +9, Bp +3, C +8). Following extensive regional multidisciplinary team discussions and considering patient preferences, the patient underwent a non-mesh anterior and posterior colporrhaphy with right-sided sacrospinous fixation using the Miya hook device. Postoperative assessment revealed successful elevation (POP-Q: Ba −3, Bp −3, C −6).

First day postoperatively, the patient developed worsening unilateral back pain and fever accompanied by an acute kidney injury (AKI) (estimated Glomerular Filtration Rate (eGFR): 22) despite a normal urine output (preoperative serum urea and electrolytes had shown a serum creatinine of 57, eGFR: 86). Initial management consisted of intravenous fluids and antibiotics for a suspected postoperative urinary tract infection (UTI). On the second postoperative day, the patient became anuric, with worsening AKI (eGFR: 16) and a renal ultrasound revealed right-sided hydronephrosis. Subsequent CT of the kidney–ureter–bladder (CT-KUB) revealed moderate right hydronephrosis and hydroureter extending to the lower pelvis (figure 1). An urgent percutaneous nephrostomy was performed due to significant deterioration in renal function (eGFR: 9). By day 4, renal function had improved with good urine output from the patient’s nephrostomy. A subsequent nephrostogram demonstrated complete ureteric obstruction at the level of the pelvic brim. Due to significant improvement in renal function (eGFR: 76) and good nephrostomy output, the patient was discharged on day 6 postoperatively with urology follow-up in place.

Figure 1.

CT urogram: right hydronephrosis and hydroureter and absent left kidney.

The patient was followed up by the urology team where plans were being made for possible ureteric reimplantation in the coming weeks; however, 3 weeks following discharge, the patient reported spontaneous transurethral voiding of urine. An outpatient nephrostogram showed free passage of urine beyond the point of the previous obstruction and normal renal function. Subsequently, the nephrostomy was clamped and removed successfully without complication.

Differential diagnosis

The initial presentation of flank pain with fever led to a diagnosis of sepsis secondary to ascending UTI. This was felt likely given intraoperative catheterisation has an associated risk of introducing pathogens to the urinary bladder.

When routine antibiotics and fluid management failed to improve the worsening renal function, imaging was performed to assess for evidence of possible ureteric compromise with differential diagnoses, including ureteric transection through sharp trauma or avulsion, or obstruction secondary to, ligation of the ureter, ureteric kinking or compression from a haematoma or soft tissue oedema. As renal ultrasound and subsequent CT-KUB revealed evidence of a hydroureter and hydronephrosis with an obstructive point at the level of the pelvic brim, a diagnosis of ureteric obstruction was made as non-obstructive ureteric injuries such as ureteric transection would have produced evidence of uroperitoneum or evolving uroma. At this point, the mechanism of ureteric obstruction remained unclear; however, due to the nature of her surgery, and in the absence of any evidence of a haematoma on imaging, it was deemed likely due to a ligation or angulation injury secondary to suture placement or vault elevation at sacrospinous fixation. A final diagnosis of ureteric obstruction secondary to postoperative surgical oedema was reached at follow-up when the revelation of free passage of urine beyond the point of previous obstruction (figures 2 and 3) highlighted a reversible nature of the obstruction, which would not be seen if injury were due to angulation or ligation, as these types of injuries would require stenting or reimplantation to resolve.

Figure 2.

Nephrostogram image 1: free passage of contrast, past previous point of obstruction.

Figure 3.

Nephrostogram image 2: free passage of contrast, past previous point of obstruction, into the urinary bladder.

Treatment

Initial management with percutaneous nephrostomy was deemed the most suitable immediate treatment option in this case. The planned definitive management was to be a laparoscopic repair or ureteric reimplantation. However, spontaneous resolution of the obstruction prior to definitive management confirmed the obstruction was likely due to a transient factor and no further intervention was required.

Outcome and follow-up

At 6-month follow-up, a repeat CT urogram revealed normal appearances of kidney parenchyma, with no evidence of a renal tract anomaly and renal function had returned to baseline levels. Postoperative clinical review demonstrated good elevation of vaginal walls and vault with high patient satisfaction and recorded outcome.

Discussion

Ureteric injury is a potential complication following any pelvic surgery, with a quoted incidence reported as ranging from 0.3% to 11% during pelvic reconstruction surgery.¹ Up to 75% of all iatrogenic ureteric injuries are associated with gynaecological procedures.² The risk of injury varies with procedure, experience of the surgeon and multiple patient characteristics, including adhesions from previous surgery.³ However, in over 40% of injuries, there are no identifiable risk factors and the injury arises due to intrinsic risk associated with operating on two systems in very close proximity within the pelvis.⁴ In patients with known risk factors, preventative strategies include preoperative MRI with or without intravenous urogram, this can inform preoperative planning. However, it is noted that laparoscopic surgery offers no benefit in routine cases,⁵ but may be more useful for complex cases. Other techniques such as ureterolysis and ureteric stenting are not so applicable in vaginal surgery, but can inform laparoscopic or open procedures. When ureteric injury is detected at the time of surgery, the outcomes for immediate treatment are more favourable with less associated morbidity and fewer surgical procedures when compared with a delayed diagnosis.⁶ Unfortunately, only 1 in 10 ureteric injuries are detected intraoperatively.⁷ Routine intraoperative cystoscopy has been described; however, as in this case, the anuria presented 24 hours after surgery, so it is likely that this would have provided false reassurance. Most complications occur due to an inadvertent laceration, ligature or transection of the distal ureter in the proximity of the cervix, typically at hysterectomy.² More rarely, injury has been attributed to ureteric obstruction by other means such as surgical oedema, kinking of the distal ureter and excessive folding of the bladder trigone following pelvic organ prolapse surgery.^8–10

Ureteric injury results in varying degrees of ureteric obstruction, and has a diverse range of presentations. These can include fever, flank pain and abdominal distension, and can produce renal cortical damage.¹⁰ Within 24 hours of an obstructive ureteric injury, the subsequent decline in renal function causes a transient measurable increase in serum creatinine, which then normalises as the contralateral kidney compensates, irreversible impairment of renal function can occur within 4 weeks if the injury is not repaired.¹¹

In the case described, the unique circumstances of a solitary kidney meant that ureteric compromise presented with a more significant biochemical disturbance, and a more severe clinical picture due to the absence of contralateral renal compensation. Management options for acute ureteric obstruction include JJ stent insertion or percutaneous nephrostomy. Percutaneous nephrostomy was deemed the most suitable in this case because it does not require a general anaesthetic or compromise the area of the obstruction, whereas the insertion of JJ stents may exacerbate damage at the site of obstruction. They may also increase the risk of urosepsis, produce delayed ureteric stricture and postobstructive renal atrophy. Planned definitive management for this patient was a laparoscopic repair or ureteric reimplantation once renal function had improved to a safe level for routine general anaesthetic. The spontaneous resolution of the obstruction prior to definitive management suggests that the obstruction was due to a transient factor, notably postsurgical oedema rather than a direct ureteric injury.

The transient nature of this ureteric obstruction calls into question the real incidence of postsurgical oedema following pelvic reconstructive surgery. We hypothesise that partial obstruction may pass an asymptomatic or subclinical course in patients with capacity for contralateral renal compensation. Indeed, this complication is only likely to be of clinical significance in patients such as this with a solitary kidney. However, patients with known chronic renal impairment may also suffer significant long-term morbidity in association with this complication. In this patient population, we suggest extensive preoperative planning. Alternative techniques should be clearly discussed and documented, such as sacrospinous fixation of the contralateral side to the functioning renal tract or a laparoscopic sacrocolpopexy. We would also recommend heightened postoperative monitoring, including fluid balance, renal function tests and close follow-up. This case highlights the need for detailed, individualised patient counselling and comprehensive multidisciplinary team involvement for such complex patients.

Patient’s perspective.

I am very pleased with the result of the operation and am very pleased I went ahead with it. I wish to thank the team who cared for me for their reassurance and support.

Learning points.

• Patients with chronic renal failure, renal tract anomalies and previous pelvic surgery should be considered complex when undergoing vaginal surgery.

• Individualised management plans should be developed preoperatively for complex patients and may include detailed imaging with multidisciplinary team involvement to inform intraoperative practices.

• In patients presenting with delayed onset oligo-anuria post pelvic floor repair, consideration should be made of the possible diagnosis of postsurgical oedema as a possible underlying cause.

• A non-surgical approach to ureteric obstruction with percutaneous nephrostomy and a period of observation can be adopted in such cases, to avoid complications arising from additional procedures in cases of transient ureteric obstructions.