Injuries to the kidney
In civilian life injuries to the kidney result
most often from either blows or falls on the loin or crushing injury to the
abdomen, typically in a road traffic accident. Haematuria after trivial injury
to the kidney should suggest the possibility of a pre-existing abnormality, e.g.
calculus, hydronephrosis or tuberculosis.
The
degree of injury varies considerably from a small subcapsular haematoma to a
complete tear involving the whole thickness of the kidney (Fig.
64.14). The
kidney may be partially or wholly avulsed from its vascular pedicle; one pole
may be completely detached.
Closed
renal injury is almost always extraperitoneal. The exception is seen
occasionally in young children who have very little extraperitoneal fat. The
peritoneum, which is closely applied to the kidney, can tear with the renal
capsule allowing blood and urine to leak into the peritoneum.
Clinical
features
Superficial soft tissue bruising may testify
to the severity of the blow but is often absent. There is likely to be local
pain and tenderness.
Haematuria
Haematuria is the cardinal sign of a damaged kidney, but it may not appear until some hours after the injury. Profuse bleeding may be accompanied by clot colic.
Severe
delayed haematuria
Sudden profuse haematuria can occur between the third day and the third
week after the accident in a patient who appears to be progressing favourably.
It is due to a clot becoming dislodged.
Meteorism
Abdominal distension 24—48 hours after renal injury is probably due to
retroperitoneal haematoma implicating splanchnic nerves.
Management
and treatment
Conservative treatment of closed renal trauma is usually successful
but appropriate measures must be instituted without delay. The possibility of
injury to other organs must be considered at an early stage.
1. Blood should be cross matched and available for transfusion if
there is evidence of hypovolaemic shock or continuing haemorrhage. Intravenous
access should be established.
2. The patient must be confined to bed while there is macroscopic
haematuria and physical activity must be curtailed for at least 1 week after the
urine clears.
3. Morphine should be given as an analgesic and sedative.
4. Hourly pulse and blood pressure charts must be kept.
5. Antibiotics
should be given to prevent infection of the haematoma.
6.
Each sample of urine passed should be checked for haematuria and the
result charted.
7. An intravenous urogram (IVU) should be obtained
urgently (a) to assess
the damage to the kidney and (b) to show that the other kidney is normal.
Surgical
exploration
Surgical exploration is necessary in less that
10 per cent of closed injuries and is indicated if either there are signs of
progressive blood loss or there is an expanding mass in the loin. The aim is to
stop bleeding while conserving as much renal tissue as possible; and a renal
arteriogram performed preoperatively can be helpful in framing a strategy for
doing this. There is also a chance that a skilled radiologist will be able to
stop the haemorrhage by embolisation if a bleeding vessel can be identified.
The
approach to the kidney should be transperitoneal to exclude the possibility of
damage to other abdominal organs. The danger is that release of the tamponading
effect of the perirenal haematoma will result in massive uncontrollable
haemorrhage and this eventuality must be prepared for. When the kidney is
irretrievably ruptured or avulsed from its pedicle, nephrectomy is the only
course. Small tears can be sutured over a haemostatic sponge or a piece of
detached muscle. Large single rents in the kidney are best dealt with by passing
a tube nephrostomy through the defect and suturing the renal tissue around it.
If the laceration is confined to one pole of the kidney, partial nephrectomy may
be practicable.
When
a solitary existing kidney is sufficiently damaged to need exploration, it must
be repaired. Failing this, the wound is packed firmly with gauze to stop the
bleeding in the hope that some renal function may be retained when the ruptured
kidney heals.
Multiple
injuries
The mortality of cases of ruptured kidney with
damage to the liver spleen or hollow intra-abdominal organs is high.
Complications
1.
Heavy haematuria may lead to clot obstruction of the bladder outflow and
bladder washout through a catheter or a cystoscope may be necessary.
2.
Para renal pseudohydronephrosis may occur in the course of a few weeks as
a result of a combination of complete cortical tear and ureteric obstruction
caused by scarring.
3.
Hypertension resulting from renal fibrosis may occur 3 months or more
after injury. It is often refractory to medical treatment and nephrectomy may
be necessary.
4.
Aneurysm of the renal artery (Fig. 64.15) is a rare but striking
complication of severe renal trauma. There is pain in the loin and a nontender
swelling may be felt if the aneurysm is large. Congestion of the parenchyma
leads to intermittent haematuria. Aortography is diagnostic. Rupture of a
renal artery aneurysm is liable to be fatal and excision or nephrectomy is
urgently indicated.