Bladder Trauma

19
Bladder Trauma


Abdullah Zreik1, Ahmed Mahrous2, and Omar M. Aboumarzouk1, 3


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


2 Bristol Urological Institute, Southmead Hospital, Bristol, UK


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



Abstract


The bladder is the most commonly injured organ in the urinary tract. Bladder injuries are usually associated with other injuries, and the patient should be assessed thoroughly. The main cause of traumatic bladder injuries is pelvic fracture, whereas iatrogenic injuries are caused by surgical procedures. Early diagnosis can lead to successful treatment; however, an undiagnosed bladder injury can lead to significant morbidity. A cystography can accurately diagnose the injury. Extraperitoneal injuries are more common and could be managed conservatively. Intraperitoneal injuries often require surgical repair.


Keywords: bladder injury; trauma; intraperitoneal; extraperitoneal; cystography


19.1 Bladder Injuries


The bladder is located deep in the pelvis; hence an empty bladder is protected from external trauma. Bladder injuries are usually associated with other injuries and patients should be carefully assed.


19.1.1 Classification of Bladder Injuries


Bladder injuries could be classified based on the type of injury:



  1. Noniatrogenic or traumatic injury (blunt or penetrating trauma)
  2. Iatrogenic (secondary to open, minimally invasive, or endoscopic procedures)

Alternatively, bladder injuries could be classified into intraperitoneal injury, extraperitoneal injury, or a mix of both.


19.1.1.1 Traumatic Bladder Injury


Pelvic fractures secondary to road traffic incidences involving motor vehicles are the most common cause of traumatic bladder injury followed by falls, industrial injuries, and direct blows to the suprapubic lower abdomen (Figure 19.1) [13]. Although, 4–10% of patients with pelvic fractures have associated bladder injuries, 60–95% of patients with bladder injuries have associated pelvic fractures [111]. Up to 45% of patients with bladder injuries are associated with at least one other intra‐abdominal injury, and about 10–30% have associated urethral injuries [2, 6, 1113].

Line drawing displaying a car with its front wheels on top of the body of a man (supine position).

Figure 19.1 The common cause of ruptured bladder is a combination of drunkenness, a full bladder and closed blunt injury.


Pelvic fracture associated bladder injuries are invariably always extraperitoneal [3]. The injury happens as a result of shearing the bladder, usually at the base, when the pelvic ring is disrupted (>1 cm) or as a result of a direct penetration of a sharp bony edge (Figure 19.2).

Image described by caption.

Figure 19.2 (a) The bladder may be pierced by a fragment of bone. (b) The bladder is opened. The ureters are protected by catheters when repairing the lacerated bladder.


Although a sudden blow to a distended bladder will likely be intraperitoneally because the weakest point of the bladder is the dome, and a sudden rupture here will shear the overlying peritoneal surface [2, 11].


19.1.1.2 Iatrogenic


The bladder is the most common organ subjected to iatrogenic injuries, with obstetric and gynaecological procedures being the most common culprit [2]. This includes caesarean section, hysterectomy, and surgical procedures for management of urinary incontinence or prolapse.


Internal iatrogenic bladder injuries on the other hand are most commonly caused by urological procedures, such as transurethral resection of bladder tumours (TURBTs) with a reported incidence rate of 4–60% depending on the surgeon’s experience [14, 15]. Risk factors include elderly, previous resection, previous intravesical instillation, and size and site of the tumour [16, 17]. Resecting a tumour on the lateral wall using monopolar diathermy without muscle relaxation carries the risk of stimulating the obturator nerve (obturator kick). More often than not, internal bladder injuries are usually extraperitoneal; however, resecting at the anterior area or at the dome can lead to intraperitoneal injury due to the anatomical layout of the peritoneum and its contents over the bladder at these areas.


Foreign bodies such as meshes, stents, catheters, clips, or sutures used in pelvic surgery could cause an injury by erosion. Spontaneous bladder rupture can occur in neuropathic bladders who have had an augmentation enterocystoplasty, and rarely in patients with continent reservoirs when performing intermittent self‐catheterisation [10].


19.1.2 Diagnosis and Investigations


19.1.2.1 Clinical Assessment


Rupture of the bladder without fracture of the pelvis is classically seen in the elderly drunk who has been injured (Figure 19.1). The patient seldom remembers the cause and the diagnosis may be difficult because leakage of uninfected hypotonic urine into the peritoneal cavity at first excites little reaction [18, 19]. There is no tenderness on palpation; bowel sounds persist. Only a very astute doctor will suspect a vesical injury, when there is any doubt the patient should be admitted for observation.


Nonetheless, gross haematuria is present in >80% of patients; if this is coupled with a pelvic fracture, then at least 30% of patients will have a bladder rupture and immediate imaging is warranted [2, 3, 8, 9, 20]. Therefore, other signs of injury need to be sought for, such as suprapubic or abdominal tenderness, inability to void, suprapubic bruising, clots in the urine, or signs of peritonitis if intraperitoneal rupture.


Extraperitoneal ruptures causes extravasation of urine which can track down to the scrotum causing it to enlarge or down the thighs or even anterior abdominal wall between the transversalis fascia and the peritoneum [2, 11].


Intraoperative bladder injuries are usually noticed when excessive clear fluid appears in the surgical field, when the laceration or the urinary catheter is seen, or when blood is noted in the urinary catheter bag, while air inflation of the urine bag is seen during laparoscopic or robotic procedures. If there is a high suspicion of a bladder injury, despite absence of overt signs, then the instillation of methylene blue into the bladder might illicit the injury site.


If an injury is missed at the original operation (e.g. hysterectomy), urine can leak from the vagina a few days later, forming a vesicovaginal fistula. However, the patient can slowly develop ileus and peritonitis if the injury was intraperitoneal. If injured extraperitoneally, urine collection with pain and or sepsis can develop.


Endoscopic iatrogenic bladder injuries are diagnosed when seeing extra vesicle fat, a dark gap between the detrusor muscles or bowels [14]. One can also notice that the bladder fails to distend despite adequate irrigation with low return of irrigation fluid and abdominal distention.


If an intraperitoneal injury is not recognised, the patient gradually develops a chemical peritonitis, the abdomen becomes swollen and tender, and bowel sounds disappear. Eventually, there may be fat necrosis and sloughing of omentum and bowel. When in any doubt, it is safer to perform a laparotomy and close the rent in the bladder and drain it because these injuries carry a high mortality (nearly 15%) if left untreated [1].


Patients with an intravesical forging body may present with recurrent infections, dysuria, pelvic pain, frequency, and urgency and can lead to bladder stone formation.


19.1.2.2 Blood Tests


Renal function test: Elevated creatinine and urea levels could be found in patients with intraperitoneal ruptures as a result of the reabsorption of urea, nitrogen, and creatinine.


The fluid leaking from the vagina may be shown to be urine by measuring its creatinine concentration; no other body fluid can have a creatinine concentration greater than that of the plasma postoperatively [21].


19.1.2.3 Imaging


19.1.2.3.1 Cystography

Cystograms are the gold standard for diagnosing bladder injuries and are highly accurate when performed appropriately (>95% accuracy) (Figure 19.3). The absolute indication is visible haematuria associated with pelvic fracture or penetrating injuries. The relative indication for cystogram after blunt trauma is visible haematuria without pelvic fracture or microscopic haematuria with pelvic fracture.

Image described by caption.

Figure 19.3 Computed tomography (CT) cystogram of a patient with multitrauma showing bladder rupture and extravasation of the contrast anteriorly.


Computed tomography (CT) cystogram is comparable to plain X‐ray cystogram; however, it can diagnose other injuries and is therefore considered more efficient (Figure 19.3) [1, 2].


Whether a CT cystogram or a plane film cystogram is obtained, a stress cystogram should be performed. During a stress cystogram, the bladder is filled with 350–400 ml of diluted contrast and three images obtained: a precontrast plain film, a film when bladder is full, and a postcontrast image for detection of posterior extravasation.


Extraperitoneal bladder injury in a plain cystogram gives a flame‐shaped collection of contrast medium in the pelvis. In intraperitoneal injuries, the contrast medium will freely flow to the abdominal cavity and outline the loops of bowel or other abdominal organs.


Clamping the catheter in an attempt to antegrade fill the bladder and obtaining delayed images is considered to be inadequate [22].


19.1.2.3.2 Ultrasonography Scan

Ultrasound may demonstrate fluid in the abdomen or the presence of extra peritoneal collection; however, ultrasounds are not sufficient to diagnose bladder injury [2].


19.1.2.3.3 Cystoscopy

Cystoscopy can diagnose intraoperative bladder injury by direct visualisation of the defect or failure to distend the bladder during TURBT. Ureterograms are done on both sides to rule out concomitant ureteric injury. Cystoscopy should ideally be performed after suburethral sling insertion to ensure the trocar has not gone through the bladder wall (Figure 19.4).

Image described by caption and surrounding text.

Figure 19.4 It is a wise precaution to perform bilateral ureterograms even when a hole can be seen in the bladder.


In noniatrogenic injuries, it is too difficult to see the tear during cystoscopy because of bleeding and is seldom worthwhile to do.


19.1.3 Management


All injuries recognised during surgery should be primarily closed. However, if the injury is missed or occurred during a TURBT procedure, management will depend on whether the perforation was intraperitoneal or extraperitoneal. For all intraperitoneal injuries, the standard is surgical exploration and repair of the injury. If the injury was extraperitoneal, then the vast majority can be treated conservatively with adequate drainage and antibiotics, with <1% requiring further intervention [1].


19.1.3.1 Conservative Management


Conservative management is the standard treatment for extraperitoneal bladder injury. The principles include adequate bladder drainage using a wide‐bore catheter, clinical observations, and antibiotics prophylaxis given to prevent the infection of the extravesicle haematoma [4, 7]. Conservative management may also be considered in intraperitoneal injuries that were not recognised at time of TURBT if the patient is stable and in the absence of peritonitis and ileus [6].


The catheter is left on free drainage for 7–14 days, at which point cystography should be carried out to confirm complete healing.


19.1.3.2 Surgical Management


Intraperitoneal injury and all penetrating trauma should be managed by exploration and surgical repair.


For extraperitoneal injury, surgical repair is indicated where there is bladder neck injury, if the patient is having exploratory laparotomy for other injuries (associated rectal or vaginal injuries or if the patient is undergoing internal fixation of pelvic fracture), if the bladder is entrapped between two bone fragments, or a bone spike has penetrated the bladder wall [2].


19.1.3.2.1 Surgical Approach

Exploration is carried out through a lower midline abdominal incision. Any pelvic haematoma should not be disrupted. The anterior bladder wall is opened between stay sutures, and the whole of the bladder wall should be carefully inspected. The ureteric orifices should be identified and inspected for efflux (Figure 19.5). Injuries are often larger than they appear on imaging.

Image described by caption.

Figure 19.5 (a) Extraperitoneal bladder perforation, and (b–d) intraperitoneal bladder perforation with contrast outlining bowel.


The bladder wall is then closed in two layers. The bowels should be examined to rule out any concomitant injuries. Injuries sustained during laparoscopy could be repaired laparoscopically if the surgeon is experienced in this technique. A large drain is left in situ. Either a suprapubic or urethral catheter is left on free drainage [9, 23]. The catheter could be removed 7–14 days after the repair; cystography should be done before removing the catheter to ensure bladder integrity.


If vaginal or rectal injuries are present, they should be repaired separately, and viable tissue should be interposed between the two repaired organs to reduce the risk of fistula formation.


19.1.4 Variant Injuries


19.1.4.1 Silent Rupture of the Bladder


After bladder tumours on the dome have been coagulated with diathermy, especially in patients who are elderly, the coagulated part of the thin wall of the bladder may give way and allow urine to escape into the peritoneum. The early physical signs are minimal: the urine gives rise too little irritation and it is only after two or three days that the patient develops abdominal pain and distension. With prompt catheterization, the condition is easily remedied and laparotomy can be avoided.


19.1.4.2 Catheter Trauma


A catheter may be forced through the wall of the bladder, usually one that is already severely contracted. The diagnosis is as difficult to make as in the other groups of ‘silent’ perforation but should always be suspected.


19.1.4.3 Cather Balloon Rupture


A diabolically dangerous method for bursting a Foley catheter balloon used to be to inject ether down the side channel. Before it burst, the balloon could rupture the bladder. Unless great care was taken in every case to wash the bladder out, bits of rubber from the balloon could be left behind on which stones can subsequently form.


19.1.4.4 Gunshot Wounds


It is necessary to distinguish between gunshot injuries caused by high‐ and low‐velocity missiles [24]. In both types of injury, if there is any suspicion of trauma to the rectum, a diverting colostomy will avoid the risk of the havoc caused by gas gangrene with its consequent massive loss of tissue [5, 24, 25].


High‐velocity bullets produce an enormous spherical blast injury with devitalization of all lining tissue within its radius. In the few who survive, all devitalized tissue must be excised. Primary repair must not be attempted [25]. Free drainage is provided. Delayed primary or secondary suture can be carried out 5–10 days later.


Low‐velocity missiles, bullets, and shrapnel fragments call for more conservative debridement, but primary closure should not be performed; delayed primary or secondary suture is safer [25]. In bladder injuries, the main requirement is to provide free drainage.

Aug 6, 2020 | Posted by in UROLOGY | Comments Off on Bladder Trauma

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