Indication has led ureteroscopy to be a worldwide technique, with the expected appearance of multiple types of complications. Severe complications are possible including ureteral perforation or avulsion. Ureteral avulsion has been described as an upper urinary tract injury related to the action of blunt trauma, especially from traffic accidents, being the mechanism of injury, the result of an acute deceleration/acceleration movement. With the advent of endourology, that term is also applied to the extensive degloving injury resulting from a mechanism of stretching of the ureter that eventually breaks at the most weakened site, or ureteral avulsion is referred to as a discontinuation of the full thickness of the ureter. The paper presents a case report and literature review of the two-point or “scabbard” avulsion. The loss of long segment of the upper ureter, when end-to-end anastomosis is not technically feasible, presents a challenge to the urological surgeon. In the era of small calibre ureteroscopes these complications, due to growing incidence of renal stones will become more and more actual. Our message to other urologists is to know such a complication, to know the ways of treatment, and to analyse ureteroscopic signs, when to stop or pay attention.
Ureteroscopy is a diagnostic and treatment modality, used for different ureteral and renal pathologies. Ureteroscopy was first carried out in 1929 by Young and Mckay using a cystoscope in grossly dilated ureter [
Since its clinical introduction in 1982 by Perez-Castro Ellendt and Martinez-Pineiro, ureteroscopy has experienced an impressive development due to the technical improvements of new and smaller urological armamentarium [
Today it is increasingly used in the management of the common ureteral stones, and such frequent indication has led ureteroscopy to be a worldwide technique, with the expected appearance of multiple types of complications, some of which are severe, including ureteral perforation or avulsion, bleeding, and urinary tract infection [
The term ureteral avulsion has been described as an upper urinary tract injury related to the action of blunt trauma, especially from traffic accidents, being the mechanism of injury, the result of an acute deceleration/acceleration movement [
Ureteroscopy has gradually become a major technique for the diagnosis and treatment of lesions of both the ureter and the intrarenal collecting systems [
Scheme of complete ureter avulsion.
Two-point or “scabbard” avulsion.
At the same day lumbotomy was performed and proximal part of ureter just below pyeloureteric junction was tied. Ureter was sent for histological evaluation. Pathologist has found chronic ureteritis and fibrotic tissue (like scar) in the distal part of ureter, without elastic fibre. After operation patient remembered that he had a trauma of right iliac side after which was a period of haematuria. That can explain histological findings. After four months a laparotomy was performed, and ileum interposition was performed, with anastomosis end-to-end with renal pelvis and urinary bladder. 30 cm of ileum was used. Postoperatively no complications occurred. On the 16th postoperative day patient was discharged. During hospitalization, nephrostogram was performed, that revealed no obstruction or contrast leakage (Figure
Nephrostogram.
At home he was prescribed to use nitrofurantoin microcrystals 100 mg once a day before sleep. During follow-up of more than 6 months, routine diagnostic investigations revealed no hydronephrosis, and intravenous urography showed identical function of both kidneys. During voiding cystoureterogram, I° degree of vesicoileal reflux was found (contrast went up the ileum but did not reach the kidney) (Figure
Voiding cystoureterogram.
Complete avulsion of the ureter is a catastrophic complication and is fortunately exceptionally rare [
Complications of ureteroscopy have been categorized into minor and major events: minor complications include asymptomatic ureteral perforations, ileus, and fever, whereas major complications, which are more often associated with stone extractions, include tears, perforations during basketing, and, rarely, avulsions, intussusception, and sepsis. Necrosis of ureteral segments after ureteroscopy for stone removal has also been reported [
While reviewing literature we did not find specific classification of ureteral avulsion, we considered idea to propose and describe types of avulsion and to classify them into one-point and two-point ureteral avulsion (Table
Classification of ureteral avulsion.
One-point ureteral avulsion | Two-point ureteral avulsion (discontinuity of ureter) |
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Ureteral avulsion, when ureter rupture is in the distal part of ureter | Avulsion of ureter from proximal to middle part of ureter (upper third) |
Ureteral avulsion, when ureter rupture is in the middle part of ureter | Avulsion of middle part of ureter (middle third) |
Ureteral avulsion, when ureter rupture is in the proximal part of ureter | Avulsion of distal part of ureter (lower third) |
Avulsed only endothelium (there is no discontinuation of whole ureter walls) | Avulsion of proximal and middle part of ureter (upper and middle third) |
Avulsion of middle and distal part of ureter (middle and lower third) | |
Avulsion of whole ureter (scabbard avulsion) |
Lithotripsy method during ureteroscopy may have effect on complication rate. Georgescu with colleagues in large study demonstrated that while using electrohydraulic fragmentation they had 3.9% complication rate. In cases when pneumatic or laser lithotripsy was used they had 3% and 2.8% complication rate. But the difference among those methods was not statistically significant (
The mechanism of complete avulsion of ureter in patients can occur during advancement of ureteroscope through a very tight ureteric stricture up to the level where the stone is tightly impacted. The tight grip of fibrous stricture on the body of scope can cause the first avulsion at distal third of ureter during its advancement. The second avulsion then occurs during withdrawal of ureteroscope, at the site where stone is impacted and this area was further weakened by the microtrauma created by the shockwave lithotripsy or stone impaction. Discrepancy between ureteroscope size and calibre of the patient’s ureter is another factor of possible avulsion [
In recent publication of Ulvik and Wentzel-Larsen it was explained that the forces needed to advance and retract the ureteroscope were considerably larger in the upper ureter than in the lower. It is conceivable that the resistance between the ureteral wall and the ureteroscope will increase as the area of contact between them becomes larger during the advancement of the instrument. Interestingly, the forces needed for retraction of the ureteroscope were significantly smaller than the forces needed for insertion at all levels of the ureter, except at the level of the iliac vessels. The insertion of the ureteroscope dilates the ureter and may thereby facilitate the subsequent retraction [
Conversely, in the cases with the ureteroscope already up the ureter, there is no limit to the amount of force that may be applied. The degree of force applied is limited only by the sense and experience of the operator [
This complication is more common in the proximal ureter where the muscular and mucous layers are less present. However, when a ureter becomes less resistant and elastic, due to previous traumas or endourological procedures, it may be subject to avulsions in any of its segments [
The loss of long segment of the upper ureter, when end-to-end anastomosis is not technically feasible, presents a challenge to the urological surgeon. Autotransplantation is often the preferred treatment [
Since Hardy in 1963 described the use of renal autotransplantation in ureteral injury, this method became one of the treatment modalities in irreversible ureteral injuries [
In modern era, when we are trying to find answers to all possible questions we have guidelines that can help us in resolving even that kind of complications. EAU guidelines indicate reconstruction options by site of injury (Table
Reconstruction options by site of injury [
Site of injury | Reconstruction options |
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Upper ureter | Ureteroureterostomy |
|
|
Mid ureter | Ureteroureterostomy |
|
|
Lower ureter | Ureteral reimplantation |
|
|
Complete | Ileal interposition graft |
Ileal interposition is a very rare operation. During literature review it was possible to find only articles which were written between 1960 and 1990. However we have found several newer articles that described their analysis of patients for whom ileal interposition was performed. Some of these patients had follow-up as long as 6.04 years and mean age was 48.1 years [
Prophylaxis of ureteral avulsion concurs especially with the endoscopic skill of the urologist and the adherence to some basic rules, such as using a small ureteroscope or avoiding Dormia basket retrieval of the stone in cases of large calculus or partial view of the area where the calculus is impacted [
Other practical suggestions are (1) that prior to insertion of ureteroscope to the ureter insert a guidewire, because then you will not have full contact between scope and ureter lumen; (2) if the urologist finds it difficult to advance the ureteroscope despite full visualization of the lumen and senses that the scope feels tight in the ureter, the scope should be withdrawn immediately and either replaced with a smaller calibre scope and reinserted after ureteral dilation or ureteroscopy should be repeated on a later occasion after placement of a ureteral stent to allow ureteral dilation; (3) if you see ureteral stricture, dilatation prior to the insertion of scope or incision of stricture should be performed; (4) if you plan to perform proximal ureteroscopy lubricant should be applied along the entire length of the shaft; and (5) if you feel that scope is impacted or you need more power for extraction of scope, a second semirigid ureteroscope should be passed into the bladder beside the first and the situation is evaluated [
Two-point or “scabbard” ureter avulsion is extremely rare ureteroscopy complication, which terrifies urologists performing ureteroscopic procedures. Today we use semirigid and flexible small calibre ureteroscopes. These complications, due to growing incidence of renal stones and cases or ureteroscopes, will become more and more actual. Our message to other urologists is to know such a complication, to know the ways of treatment, and to analyse ureteroscopic signs, when to stop or pay attention. The best way of resolving that kind of complication would be ileal interposition or laparoscopic nephrectomy with or without autotransplantation.
The authors declare that there is no conflict of interests regarding the publication of this paper.