Kidney and Ureter Trauma

Kidney and Ureter Trauma

Sarfraz Ahmad1 and Omar M. Aboumarzouk2,3

1 Aberdeen Royal Infirmary Hospital, Aberdeen, Scotland, UK

2 Glasgow Urological Research Unit, Department of Urology, Queen Elizabeth University Hospital, Glasgow, UK

3 University of Glasgow, School of Medicine, Dentistry & Nursing, , Glasgow, UK


Renal injuries are mostly managed conservatively. Operative intervention with view of kidney salvage is possible. However, nephrectomy may be the only option to control life‐threatening haemorrhage. During the conservative period, it is extremely important to keep patients under close monitoring because this will allow early identification of patients who will require surgical intervention. Ureteral injuries are relatively rare and mostly iatrogenic. Management of the ureteral injuries depends level of injury, severity, and on time (early or late) of recognition of the injury. Careful assessment (cystoscopy with retrograde pyelogram) and appropriate imaging computed tomography urogram or intravenous pyelogram (IVP) are essential to select most suitable method of repair of ureteral injury.

Keywords kidney injury; trauma; ureter injury

11.1 Kidney Injuries

The kidney is the most commonly injured genitourinary organ. It is involved in about 1–5% of all trauma [1, 2]. The kidney is protected by the perinephric fat surrounding it, the abdominal muscles, vertebra, and ribs; therefore, isolated renal injuries are rare and will require a large degree of force and are usually seen in multisystem injuries. However, children have proportionately less fat padding and muscle bulk; therefore, lesser force can cause renal injury. The renal injury can cause considerable morbidity and mortality; however, advances in imaging and management strategies have resulted in a decreased need for surgery in majority of renal trauma cases [35].

11.1.1 Types of Injuries

  1. Blunt trauma: a common (~90%) cause of renal injury
  2. Penetrating injury: less common cause and could be;

    • High velocity, for example, rifle bullet (800–1000 m s−1)
    • Medium velocity, for example, handheld guns (200–300 m s−1)
    • Low velocity, for example, knife stab injury

  3. Blast injury

It is important to note the type of injury because the majority of blunt injuries (>95%) can be managed conservatively, but half of stab injuries and >75% of gunshot injuries will require surgical exploration [4].

Blunt injuries to the kidney usually result from sport injuries, falling from heights, or road traffic accidents (RTAs).

Usual mechanism is a direct blow to the loin or kidney, compressing the kidney between the 12th rib and the lumbar vertebrae (Figure 11.1). Furthermore, in RTAs, the likely mechanism is rapid acceleration followed by rapid deceleration, which can cause renal pedicle injury (renal artery or vein disruption or tears or thrombosis or renal pedicle avulsions). The renal pedicle is more commonly injured this way because it is attached firmly to the retroperitoneal structures. Extent of deceleration is an important factor and should be enquired in the history. Mild trauma resulting in haematuria can be the result of occult pre‐existing pathology (e.g. pelviureteric junction [PUJ] obstruction, renal tumour etc.) [6].

Image described by caption.

Figure 11.1 Closed renal injury: the kidney is compressed between the 12th rib and the lumbar transverse processes. The lower ribs and the tips of the transverse processes are frequently fractured.

Penetrating injuries anterior to the anterior axillary line will most likely cause damage to the renal hilum (vessels or renal pelvis), whereas posterior to this will be in the parenchyma and injuries are less serious. Low‐velocity weapons usually cause damage confined to the line of the wound track. Although high‐velocity trauma causes greater injury and tissue loss as large energy is transmitted outside the path of the projectile. This results in temporary cavitation, deformity, shearing, and contamination of the effected site or organ. Blast injuries can have components of blunt and penetrating and invariably cause significantly more damage than either alone (Figure 11.2).

Image described by caption.

Figure 11.2 Gunshot injury with multiple pellets in various organs including left kidney.

11.1.2 Classification of Kidney Injury

The extent of injury following blunt trauma can result in cortical laceration, collecting system injury, and in extreme cases, complete disruption of the renal pedicle. These will lead to blood loss with or without extravasation of urine (Figures 11.311.8) [7]. Degree of injury depends on force of impact. The American Association for the Surgery of Trauma (AAST) has developed a grading system for renal trauma (Table 11.1), which is commonly used both in clinical and research settings.

Diagram depicting the grades I, II, III, IV, and V classification of renal injury.

Figure 11.3 Classification of renal injury depending on degree of injury.

Image described by caption.

Figure 11.4 (a) Grade 1 injury (renal contusion with no laceration). (b) Grade 2 injury (laceration <1 cm into the cortex) with small clot in renal pelvis. (c) Grade 3 injury (laceration >1 cm into the cortex).

Image described by caption.

Figure 11.5 Types of grade 4 injuries. (a) Laceration into the collecting system, (b) laceration into collecting system with segmental renal artery injury, (c) laceration of upper pole with associated segmental artery injury, and (d) laceration into collecting system with extravasation of urine and segmental renal artery injury.

Image described by caption.

Figure 11.6 Grade 4 injuries. (a) Segmental renal artery with small cortical laceration, (b) segmental renal artery injury, and (c1) and (c2) multiple thrombi in renal artery causing varying degree of avascularisation.

Image described by caption.

Figure 11.7 Grade 5 injury of a shattered kidney. (a) Coronal view, (b1) and (b2) axial view, and (c) sagittal view.

Image described by caption.

Figure 11.8 Grade 5 injury (renal pedicle injury), no blood supply to upper and middle lobes with lower pole supplied by an accessory renal artery from the aorta, therefore, maintaining its blood supply.

Table 11.1 CT‐based grading system of renal injury by AAST.

Grade of Renal Injury Description of injury
I Contusion or bruising, elevation of renal capsule (subcapsular haematoma). No parenchymal laceration.
II Cortical laceration <1 cm deep, not fully through cortex to collecting system. Haematoma confined to Gerota fascia.
No extravasation of urine.
III Cortical laceration >1 cm deep.
No extravasation of urine.
IV Parenchymal laceration through corticomedullary junction into collecting system
Vascular–segmental artery or vein injury or partial laceration or thrombosis
V Parenchymal laceration–shattered kidney
Vascular–renal pedicle injury or avulsion
Avulsion of PUJ

AAST, American Association for the Surgery of Trauma; CT, computed tomography; PUJ, pelviureteric junction.

In most minor injuries, the renal parenchyma is split, there is usually microscopic haematuria, minimal loss of blood, and patient remains haemodynamically stable. These are referred as renal contusions, and their prognosis is so good and further investigation is usually not required [8]. However, in very severe injuries, usually resulting from rapid deceleration injuries, the renal artery and vein are torn across, resulting in immediate and immense loss of blood. One needs to bear in mind that, nearly 25% of the cardiac output goes through both kidneys in a minute (12.5% for each); therefore, bleeding can be significant if not contained.

11.1.3 Diagnosis and Investigations History and Initial Assessment

Potential severity of renal damage is assessed from history, past medical history (single kidney, pre‐existing renal pathology), and examination, with emphasis on the nature of injury, pain, and haematuria. Haematuria is a hallmark of renal trauma, but it does not always correlate with the degree of injury. Indeed, in more serious injuries, such as renal pedicle injuries, arterial thrombosis or disruption of the ureteropelvic junction can occur without any haematuria [9, 10]. In young adults and children with renal trauma, hypotension is a late sign or may not occur despite life‐threatening blood loss, so vigilance is vital in management of the injured child.

Hemodynamic stability should be noted and used to guide future management. Blood pressure (BP), pulse, haemoglobin (Hgb), and haematocrit (Hct) are useful parameters.

Patients with shock (systolic blood pressure <90 mm Hg) will need immediate resuscitation and close monitoring. In penetrating injuries, bullet entry and exit wounds should be identified and the trajectory of the bullet considered. Similarly stab injuries can appear small but may penetrate deep into the abdominal cavity.

A urine dipstick is a rapid and reliable test to screen for nonvisible haematuria; however, false‐negative findings do occur in approximately 3–10% of cases [11]. If there is nonvisible haematuria with normal systolic BP (>90 mmHg), the likelihood of renal trauma is <0.5%, whereas in the presence of visible haematuria, the risk increases to nearly 10%. Blood Tests

  • Serial Hgb level and Hct are important markers of blood loss and guide management strategies. A low Hct, especially in the presence of shock, implies the need for rapid resuscitation.
  • In a renal function test, an initially elevated creatinine level usually suggests pre‐existing renal pathology. Imaging

Computed tomography (CT) with intravenous contrast is the gold standard for the diagnosis of renal injuries in patients who are stable. CT can define the location and extent of renal injury; additionally, it allows identification of associated intra‐abdominal injuries. A renal pedicle injury is suggested by a lack of contrast enhancement of the kidney or a central parahilar hematoma, whereas a large medial hematoma displacing the renal vasculature suggests a venous injury. Delay images taken at a 10–15 minutes (after intravenous contrast) are important for visualisation of the renal collecting system and diagnosis of renal pelvis and ureteral injuries. In renal pelvis injuries, the contrast extravasation is usually seen medial to the renal hilum.

CT scans can be avoided in patients with blunt, nondeceleration trauma; microscopic haematuria; and no shock because incidence of renal injury is low [8].

Imaging is mandatory in;

  • Children with nonvisible haematuria and any degree of renal trauma.
  • Nonvisible haematuria with a BP <90 mm Hg.
  • Visible haematuria.
  • Rapid acceleration or deceleration injuries (to rule out renal pedicle injury or ureteric avulsion) [12].
  • Penetrating trauma because imaging should be performed regardless of haematuria status [13].

A CT scan provides good information, showing the full extent of the laceration of the renal parenchyma with a collection of blood outside the kidney confined within Gerota fascia.

Ultrasound may be useful in determining which patients need further imaging with CT and may eliminate unnecessary scans. Additionally, ultrasound can be used for serial evaluation of stable injuries or after urinoma or retroperitoneal hematoma [14].

Intravenous pyelography (IVP) is no longer the preferred modality in patients with renal trauma. However, if CT is not available, IVP can establish the presence or absence of the kidneys, define the parenchyma, and outline the collecting system. Non‐visualisation or non‐function of a kidney usually indicates severe trauma to the kidney, such as pedicle injury or shattered kidney. The IVP may show distortion of the renal outline on one side, with extravasation of contrast medium, or it may show no secretion at all.

In patients who are not stable and have to immediately go to the operating theatre, a one‐shot intra‐operative IVP on the table can be performed. A single plain film is taken 10 minutes after the injection of 2 ml kg−1 contrast medium. This can provide useful information on a suspected injury and can determine the functional status of the contralateral kidney [15].

Magnetic resonance imaging (MRI) and angiography are lesser used modalities in the initial evaluation of patient with renal trauma. However, MRI is used in patients with an iodine allergy, if CT is not available, or in rare cases, when CT findings are equivocal [16].

The most common indication for angiography is non‐visualisation of the kidney. In such cases, renal angiogram may show damage to the renal artery or its segmental branches. It is also the test of choice for the evaluation of renal vascular injuries and selective embolisation can be performed in same setting (Figure 11.9a–d). CT angiogram is a preferred modality in present era.

Image described by caption.

Figure 11.9 Grade 4 injury with multiple segmental artery bleeds being embolised. (a) Computed tomography of grade 4 injury; (b) angiography showing bleeding points; (c) embolization; and (d) post embolization showing bleeding stopped.

11.1.4 Management

Patients who are haemodynamically stable can be treated conservatively, whereas patients who are unstable need surgical or radiological intervention. Nonsurgical Management

Conservative management is the treatment of choice for the majority of patients with renal injuries. The conservative management has a low failure rate (1%) and may save kidneys that might otherwise be lost during attempted repair [3]. There is increasing trend for more severe injuries to be treated conservatively. Even patients with urinary extravasation and solitary injuries can be managed expectantly, with a resolution rate of >90% [17]. However, during the conservative management, close monitoring is vital to recognise need for added intervention or surgery.

The conservative nonoperative management is favourable in [8, 18]:

  • Patients who are haemodynamically stable or who remained stable after initial resuscitation.
  • Absence of grade V vascular or ureteral injuries.
  • Exploratory laparotomy for other abdominal injuries (in patients with renal injuries who do not require renal surgery) should not necessarily include retroperitoneal or renal exploration.

Some patients with penetrating renal trauma can be managed conservatively as well. The site of penetration is helpful to determine management decisions. For example, nearly 90% of patients with stab wounds posterior to the anterior axillary line can be managed conservatively [19]. Operative intervention should be performed if the injury involves the hilum, or if there is continued bleeding, ureteral injuries or pelvic lacerations are present [20]. Low‐velocity gunshot and stab wounds in patients who are stable have good outcomes when managed with a nonoperative approach, but tissue damage resulting from high‐velocity gunshot injuries may necessitate exploration and even nephrectomy [21].

Grade V vascular injuries are regarded as an absolute indication for exploration, but parenchymal grade V injuries in patients who are stable at presentation may be safely treated conservatively [22, 23]. However, intervention is predicted by the need for continued fluid and blood resuscitation, perirenal haematoma size >3.5 cm, and the presence of intravascular contrast extravasation [24].

Initial conservative approach is appropriate in patients who are stable with urinary extravasation or devitalised renal fragments [25]. But in cases of persistent extravasation or urinoma, management is usually successful with ureteral stenting or nephrostomy tube placement. Persistence of extravasation might necessities exploration.

The need of follow‐up CT in patients managed conservatively is controversial; however, relative indications include fever, increased pain, or persistent bleeding or dropping haemoglobin. Most injuries will heal with conservative approach, but there can be an increased rate of complications [26, 27].

11.1.5 Surgical Exploration: Options

Operative exploration to control haemorrhage and salvage or remove a kidney is required in a minority of patients with renal trauma [28].

Absolute indications for renal exploration are:

  • Life‐threatening renal haemorrhage with hemodynamic instability, irrespective of the mode of injury [28]
  • An expanding or pulsatile perirenal hematoma identified intra‐operatively [28, 29]. (This signifies a grade V vascular injury.)

    Relative indications include:

  • Persistent bleeding and suspected renal pelvis or ureteral injury.
  • Penetrating renal trauma (isolated grades I–III stab and low‐velocity wounds (e.g. low‐velocity gunshot wounds in patients who are otherwise stable can be managed expectantly [19]).
  • Inconclusive imaging and a pre‐existing abnormality or an incidentally diagnosed tumour may require surgery even after minor renal injury [30].

The management of renal injury may also be influenced by the decision to explore or observe associated abdominal injuries [31]. For isolated renal trauma, surgery should be performed using a transperitoneal approach with early vascular control prior to opening the Gerota fascia [32, 33]. The renal vasculature is accessed through the posterior parietal peritoneum, incising over the aorta and medial to the inferior mesenteric vein (Figure 11.10).

Diagram depicting the exploration of renal injury, with the colon being reflected and the renal pedicle being secured without opening the Gerota fascia.

Figure 11.10 Exploration for renal injury. The colon is reflected. The renal pedicle is secured as soon as possible without opening Gerota fascia. IVC, inferior vena cava.

Renorrhaphy is the preferred technique for renal reconstruction. General principles of renorrhaphy include:

  • Early control of renal artery.
  • Evacuation of haematoma.
  • Examination of the lacerations, including repairing of the injured vessels and conserving as much of the parenchyma as possible.

If a polar injury occurs or if nonviable tissue is present, a partial nephrectomy may be necessary. Watertight closure of the collecting system is recommended. If it is not feasible, a simple closure of the parenchyma over the collecting system can be successful as well. An omental pedicle flap or perirenal fat bolster can be used in the case of renal capsule injury. The use of haemostatic agents and sealants in reconstruction are helpful for effective haemostasis [34]. In all cases, a retroperitoneal drain is usually required.

Nephrectomy is necessary if the kidney is not salvageable. The overall rate of patients who undergo a nephrectomy during exploration is around 13%, usually in patients with penetrating injuries and higher rates of transfusion requirements, haemodynamic instability, and higher injury severity scores [35].

The nephrectomy is generally required in patients who have a penetrating injury, an increased need for transfusion, hemodynamic compromise, high‐grade injury, and associated intra‐abdominal injuries [36, 37]. Mortality rate is higher in patients requiring nephrectomy, but cause of deaths are usually the associated injuries rather than the renal trauma alone [38]. Grade V vascular injuries are generally treated with nephrectomy because repair is usually not successful [39]. However, repair should be attempted in patients with a solitary kidney or bilateral renal injuries [40], but it is not used in the presence of a functioning contralateral kidney [4]. Similarly, in gunshot injuries caused by a high‐velocity bullet, reconstruction can be difficult, and nephrectomy is often required [41].

11.1.6 Role of Angiogram and Embolisation

Arteriography with selective embolisation’s role is increasing in renal injuries (Figure 11.9); however, the results can be poor in patients with grade V injuries [42]. However, initial or repeated embolisation for the higher‐grade injuries can prevent a nephrectomy in more than 75% of patients. Segmental arterial injury can be managed non‐operatively with good results [43].

Radiological embolisation is indicated in patients with active bleeding from renal injury but without any other indication for immediate surgical exploration. Patients who are obviously showing evidence of internal bleeding (e.g. dropping Hgb), but are in a stable state, should have a renal angiogram with embolisation of bleeding vessels [44] (Figure 11.11).

Diagram displaying an angiographic catheter inserted into the kidney with bleeding arterial branch. A line marks the plug of gelfoam.

Figure 11.11 Angiography may reveal a bleeding arterial branch which can be plugged with gel foam or a coils.

11.1.7 Renal Injury in the Patient with Polytrauma

Most patients with penetrating renal trauma have associated adjacent organ injuries, and hence, a multidisciplinary team approach is required for effective management. In the absence of an expanding haematoma with haemodynamic instability, associated multi‐organ injuries do not increase the risk of nephrectomy [35]. In patients with polytrauma and associated renal injuries, it is vital to determine the most significant injury. Each injury should be managed on its merit irrespective of conservative or surgical approach. Iatrogenic Renal Injuries

Iatrogenic renal trauma is rare but can lead to significant morbidity, especially as the more common injuries are vascular. However, significant injury requiring intervention is rare. Patients with minor injuries should be treated conservatively. Severe or persistent injuries require intervention with embolisation. In patients who are stable, a second embolisation should be considered in case of failure [45]. Renal exploration might be required if bleeding continues or patient becomes unstable.

Haemorrhage is the most concerning complications after percutaneous nephrolithotomies (PCNLs), biopsies, or partial nephrectomy. Post‐PCNL bleeds can be conservatively managed with clamping of the nephrostomy; however, embolisation might be required for persistent bleeds. Arteriovenous (A‐V) fistula and pseudo‐aneurysms can occur after partial nephrectomy or more commonly percutaneous renal biopsies. The majority are small and heal spontaneously, but they can persist to cause retroperitoneal bleeding or heavy haematuria. Angiography detects the fistula and can proceed to embolisation for treatment. Persistence will require either a partial or complete nephrectomy. Complications of Renal Trauma

In all patients who are conservatively managed, a repeat CT scan should be done at least 48–86 hours after the trauma for re‐evaluation of the trauma stage and to ensure no missed complications.

Early complications (within 30 days of the injury):

  1. There is a small but real danger of delayed haemorrhage (i.e. secondary haemorrhage) in patients who have a major renal laceration. Delayed bleeding can occur within several weeks of the injury and is usually managed with selective angiographic embolisation [46]. Delayed onset of marked haematuria after penetrating trauma most often indicates the presence of an A‐V fistula. Percutaneous embolisation is often successful in these instances, but surgery may be required to repair large fistulas. Nephrectomy might be required if bleeding persists.
  2. Urinary extravasation usually resolves over time unless obstruction or infection is present (Figure 11.12). Persistent large volume extravasation usually responds well to stent placement or nephrostomy drainage [27]. Renal repair might be required if persistent urine leakage despite conservative measures.
  3. Although pseudocysts and urinomas are uncommon, it is most important to recognise them (Figure 11.12). A collection of extravasated urine becomes walled‐off by fibrous tissue but remains in communication with the renal pelvis [47]. The wall of the cavity becomes eventually more or less lined with urothelium, and in turn, this leads to calcification and heterotopic bone formation. In time, the urinoma takes on the appearance of an eggshell. The contents of the urinoma often become infected, but even if they do not, the absorption of urine from the granulation tissue lining the cavity leads to hyperchloraemic acidosis. Merely draining the cavity is seldom sufficient, and it is usually necessary to dissect out the lining of the cavity and repair the defect in the renal pelvis, which a difficult and time consuming operation.
  4. Perinephric abscess formation can be managed with percutaneous drainage or open drainage. However, open drainage can pose an increased risk of renal loss [28].
  5. The haematoma around the lacerated kidney may compress the ureter and lead to hydronephrosis, but it is rarely possible to be sure that a hydronephrosis was not present before the injury.

    Late complications:

  1. Late onset hypertension: Hypertension after renal trauma occurs in <5% of patients [48] and is caused by external compression from a perirenal hematoma on the renal artery (Page kidney) or chronically as a result of compressive scar formation. Other causes include renal artery or branch thrombosis, stenosis (Goldblatt kidney), or an A‐V fistula. The reduced blood supply causes renal ischaemia, leading to excess renin excretion in an effort to increase the blood pressure to increase renal blood supply. The hypertension might develop over months to years after the initial trauma. Management is by pharmacological antihypertensive agents or by excision of the ischemic parenchyma, vascular reconstruction, or even nephrectomy [49].
  2. Renal insufficiency: due to the devascularised segment(s).
Image described by caption.

Figure 11.12 (a) Urinary extravasation after renal trauma (b) urinoma developed from persistent extravasation.

11.2 Ureteral Injuries

Trauma to the ureters is relatively rare, and the most common cause is iatrogenic. Overall, ureteral trauma accounts for 1–2.5% of genitourinary tract trauma [50, 51].

11.2.1 Causes of Ureteric Injuries

  1. Iatrogenic injuries to the ureter. The ureter can be injured during pelvic surgery (e.g. diathermy damage, caught in ligature, crushed in a clamp, divided by accident, or damage to the blood supply causing devascularisation and leading to ischæmic damage). Risk factors for iatrogenic ureteric trauma include advanced malignancy, prior abdominal or pelvic surgery or irradiation, inflammatory processes (e.g. diverticulitis, endometriosis, anatomical abnormalities, and major intra‐operative haemorrhage [52]). A list of common procedures with associated risks of ureteric injury is listed in Table 11.2 [45].
  2. Blunt trauma. About one‐third of cases of trauma to the ureters are caused by blunt trauma, mostly RTAs or fall from heights [53].
  3. Penetrating injuries (gunshot or stabbing). Penetrating ureteral trauma is the most prevalent after iatrogenic and is mainly caused by gunshot wounds [50, 51].
  4. Deceleration injuries (e.g. PUJ shearing). the renal pelvis tears away from the ureter.

Table 11.2 Ureteral injury with various procedures.

Procedure Percentage of ureteric injury
Vaginal hysterectomy
Abdominal hysterectomy
Laparoscopic hysterectomy
Urogynaecological (anti‐incontinence/prolapse)

Colorectal 0.3–10.0
Mucosal abrasion
Ureteral perforation
Intussusception or avulsion


11.2.2 Classification of Ureteral Injuries

Severity of ureteral injury are based on degree of ureteral injury (Table 11.3; Figure 11.13) [54].

Table 11.3 Classification of ureteral injury.

Grade of ureteral injury Description of injury
I Contusion or haematoma
II <50% transection
III >50% transection
IV Complete transection with <2‐cm devascularisation
V Avulsion with >2‐cm devascularisation
Image described by caption.

Figure 11.13 Ureteric injuries with contrast extravasation, (a) Grade 2 (obtained from, (b) grade 3, and (c) grade 4.

11.2.3 Clinical Features

The iatrogenic injury is usually not be recognised at time of surgery [44, 55]. More often, a delayed diagnosis is made when leakage of urine from the wound drain or vagina is noted.

Nonspecific features include abdominal or flank pain, infection/sepsis, haematuria, ileus, vomiting, and signs of urinary obstruction (hydronephrosis and reduced renal function).

11.2.4 Investigations

Investigations should not be delayed in patients with suspected ureteric injuries, and one should have a low threshold for its consideration. If suspicion of injury was intra‐operative, then direct inspection, injection of methylene blue into the ureter with observation of leakage, on‐table IVU, or retrograde studies can be done. However, postoperative or trauma‐related suspicion: a renal ultrasound can show variable degrees of hydronephrosis or a urinoma. Whereas a contrast CT scan with delated images would show extravasation of contrast from the ureteral injury site or an obstruction at the site of injury (Figure 11.14). However, diagnostic retrogrades are the gold standard, especially if other images were not conclusive.

Image described by caption.

Figure 11.14 Distal ureteral injury with urine extravasation.

Source: Case courtesy of Dr. Chris O’Donnell,, rID: 36562.

Fluid (leaked urine) from drain or vagina can be tested for creatinine to confirm diagnosis, if the level is >300 umol l−1 than serum creatinine, then it is urine.

11.2.5 Management of Ureteral Injuries

Patient should be managed as a whole; therefore, if the ureter is obstructed and patient is unwell (i.e. infection or sepsis), a percutaneous nephrostomy should be placed to decompress the drainage system and allow the infection to settle, followed by a delayed repair. Otherwise, early repair is the best option with more favourable outcomes. Retrograde Study and JJ Stent Insertion

In all ureteral injuries, it is necessary to confirm the diagnosis by retrograde urography. Bilateral retrogrades should be done despite injury to one side because bilateral ureteric injury is not uncommon. Careful assessment should be made for a vesicovaginal fistula because these may well co‐exist with the ureteral injury [56].

At the time of performing the retrograde urogram, an attempt may be made to pass a guidewire up the ureter from below, or if there is a percutaneous nephrostomy in position, from above (Figure 11.15). If the guidewire can be wriggled past the site of the obstruction, a JJ stent may be passed over it and left in situ for four to six weeks by which time the injured ureter may be found to heal completely without any stricture [57].

Diagram displaying a guidewire (left) and a double‐J stent (right) inserted into the ureter up to the kidney.

Figure 11.15 If a guidewire can be made to pass the site of the injury a double‐J stent may be passed over it.

Partial ureteric injuries can be repaired immediately with a stent or urine diversion by a nephrostomy tube. Stenting is helpful because it provides canalization and may decrease the risk of ureteric stricture [52]. Other Operative Repair Options

Management of a ureteric trauma depends on many factors, including the location of the injury, timing of detection of the injury, and the nature and severity of the injury (e.g. previous radiotherapy can cause poor healing). The principles of ureteral repair should to be adhered to (Table 11.4).

Table 11.4 Principles of ureteral repair.

  • Debridement of necrotic tissue
  • Spatulation of ureteral ends
  • Mucosa‐to‐mucosa anastomosis
  • Tension‐free anastomosis
  • Absorbable sutures
  • Ureteral stenting
  • External drain
  • Isolation of injury with peritoneum or omentum

Depending on location of injury various types of reconstruction are available:

Upper Ureter:

  • Uretero‐ureterostomy if the injured section is short (<3 cm)
  • Transuretero‐ureterostomy (TUU) for longer injuries ( > 3 cm)
  • Uretero‐calycostomy if the either the TUU or the uretero‐ureterostomy fails

Mid Ureter:

  • Uretero‐ureterostomy
  • TUU
  • Ureteric reimplantation (ureteroneocystostomy) with or without Boari flap

Lower Ureter:

  • Ureteral reimplantation
  • Ureteral reimplantation with or without psoas hitch

Complete Ureteric loss:

  • Ileal interposition
  • Autotransplantation
  • Nephrectomy

Depending on the timing of the injury:

Early recognition

If a ureteral injury is suspected intra‐operatively or in the first 14 days postoperatively, a retrograde pyelogram study followed by attempting a JJ stent insertion is a reasonable choice. However, if the ureter is accidently ligated with suture or transected, an open repair is required. Repair options are based on location.

Later recognition

Injuries that are diagnosed late are usually treated first by a nephrostomy tube with or without a stent [52]. Retrograde stenting is often unsuccessful in this setting. These patients can present with peritonitis and anuria, urinoma, sepsis, wound or vaginal leakage, and flank pain.

A careful management is required for this group of patients. This includes resuscitation, treatment of sepsis, and a percutaneous nephrostomy inserted to divert urine and relieve the obstruction. A CT urogram should be done to determine the location and severity of the ureteral injury. After the acute phase, a cystoscopy, examination under anaesthesia, and retrograde pyelogram study are required before definitive management.

If small fistula is detected, a JJ stent insertion is usually enough to allow spontaneous recovery. The endourological treatment of small ureteral fistulae and strictures is safe and effective in selected cases [58], but an open surgical repair is often necessary. For uretero‐ and vesicovaginal fistulas repair with interposition of intact layer of healthy tissue is important. Ureteral repair, otherwise, is similar to other management options.

11.2.6 Operative Repair Options for Ureteral Injury

There are four alternative methods of repairing an injured ureter:

  • Boari‐Ockerblad flap
  • Psoas hitch
  • Transureteroureteric anastomosis
  • Ileal loop interposition Boari–Ockerblad Flap

This is the preferred and most reliable method of repairing an injured ureter [56, 59]. The original incision is reopened, unless the hysterectomy has been performed by the vaginal route, in which case a vertical midline incision gives marginally easier access than a Pfannenstiel incision especially in patients with high body mass index (BMI).

The injured ureter is followed down to the site of injury where it is seldom possible to see exactly how it has been injured; sometimes a distinct suture can be found but usually the site of injury is concealed in scar tissue and oedema (Figure 11.16). The ureter is divided at the site of blockage. It always retracts cranially for several centimetres, leaving a gap larger than first anticipated (Figure 11.17). The bladder is now filled, and a widely based flap is marked out with stay sutures before the wall of the bladder is incised (Figure 11.18). Careful haemostasis is obtained by suture ligature rather than diathermy. The opposite ureter is marked and protected by passing a catheter into it.

Image described by caption and surrounding text.

Figure 11.16 The ureter is followed down to the site of the injury.

Image described by caption and surrounding text.

Figure 11.17 The ureter is divided above the site of the injury: it always retracts. The bladder is filled and the ⋂ − shaped Boari flap marked out with stay sutures.

Image described by caption and surrounding text.

Figure 11.18 The ⋂ − shaped Boari flap is raised and a submucosal tunnel formed with scissors.

A long submucosal tunnel is made in the Boari flap, and the ureter is drawn down this into the bladder. The end of the ureter is spatulated, everted, and sewn to the Boari–Ockerblad flap with interrupted fine absorbable sutures (Figure 11.19). The flap is intubated using a JJ stent. The flap is closed in the line of the opening in the bladder using two layers of fine absorbable suture. It is sometimes helpful to attach the flap to adjacent fibrous tissue to make sure it lies correctly and that there is no tension at all on the anastomosis (Figure 11.20).

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Figure 11.19 The ureter is drawn through the submucosal tunnel, spatulated, and sutured to the mucosa of the bladder over a suitable splinting catheter.

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Figure 11.20 The Boari flap is closed.

The bladder is drained with a suitable urethral catheter and the wound closed with absorbable sutures with a drain to the retropubic space.

The JJ stent is usually removed after six weeks followed by CT urogram or IVP three months’ after surgery. Psoas Hitch

This is an alternative method for ureteral repair [60]. Having found the injured ureter and divided it at the site of injury, the bladder is mobilised by dividing the superior vesical vessels on the opposite side. The bladder is then incised at right angles to the line of the ureter (Figure 11.21), drawn up, and attached with two or three stout sutures of absorbable material to the tendon of psoas minor (when present) or to some adjacent strong fibrous tissue in those patients without this tendon. The implantation of the ureter is performed using an antireflux tunnel (Figure 11.22).

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Figure 11.21 Psoas hitch. The bladder is mobilised and incised at right angles to the·line of the ureter.

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Figure 11.22 The bladder is sutured to the tendon of psoas minor, when present, and the ureter is implanted through a long antireflux tunnel. Transureteroureteric Anastomosis

The injured ureter is led behind the mesosigmoid to the good side, and there it is spatulated and anastomosed end‐to‐side onto the good ureter using very fine absorbable sutures (Figure 11.23).

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Figure 11.23 The principle of uretero‐ureterostomy.

Of these three methods, the Boari–Ockerblad technique is the most reliable and versatile [61, 62]. It can even be brought right up to the kidney in some cases [63]. There is a temptation with the psoas hitch to allow a little tension on the anastomosis, and with transureteroureteric anastomosis, there is a risk that the good ureter will be damaged [60]. Ileal Loop Interposition

For very high injuries of the ureter where it is not possible to effect an end‐to‐end anastomosis, it is usually safer to make an ileal conduit in the usual way, and anastomose one end to the ureter and the other to the bladder (Figure 11.24).

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Figure 11.24 A long gap in the ureter may be bridged with an ileal conduit.

Aug 6, 2020 | Posted by in UROLOGY | Comments Off on Kidney and Ureter Trauma

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