Nephrology for Family Physicians - O.I. Bakaliuk 2003

Emergency Uro-Nephrology
Kidney Injuries

Kidney damage can be caused by a sudden body jolt, a direct blow to the lumbar region, or the hypochondriac area. Notably, severe impact force is not strictly required for renal injury; most often, kidney trauma results from a hydraulic effect accompanying a jolt or blow. The latter is attributed to the fact that a well-fixed kidney contains a high volume of fluid and thus cannot spring back upon impact. In some instances (such as a fall from a height), the kidney is injured on the side opposite to the impact. Renal trauma can also occur almost spontaneously, i.e., under METABOLISM/18.html">The Influence of minor factors, such as Polycystic Kidney Disease, Hydronephrosis, or a tumor.

Kidney injuries are classified as closed and open.

Closed injuries rank first among traumas to the abdominal Organs, retroperitoneal space, and Urinary System.

Several forms of closed renal injuries are distinguished (A.V. Lyulko et al., 1996): renal contusion without capsule integrity disruption; renal parenchyma ruptures not extending into the renal pelvis and calyces; renal parenchyma ruptures penetrating into the pelvis and calyces; kidney rupture with injury or avulsion of the Ureter; and injury to the renal vascular pedicle.

A schematic representation of closed renal injuries is shown in Figure 109.

The Diagnosis of closed renal injuries is based on the analysis of anamnestic data and the presence of four symptoms of varying severity: pain, lumbar Swelling, gross Hematuria (GH), and impaired renal function.

Naturally, the Clinical presentation of a closed renal injury depends on the depth of parenchymal damage and the direction of hematoma expansion. If the hematoma expands toward the capsule, the leading symptoms will be pain and lumbar swelling; if it extends toward the pelvicalyceal system, gross hematuria (GH) predominates.

Lumbar pain on the injured side is observed in 80–95% of patients with isolated injuries and in 10–20% of those with Combined Trauma. Pain of varying character (bursting, acute Renal Colic-like) persists from 2–4 days to several weeks, gradually subsiding.

An important symptom of closed renal injury is The Development of a lumbar swelling due to the accumulation of Blood (with or without urine) in the perirenal or retroperitoneal adipose tissue. Changes in the contour of the lumbar region become apparent within a few hours after trauma, or within 3–6 days in cases of minor injuries.

Gross hematuria (GH) is a crucial symptom of closed renal injury; however, it may be absent in cases of vascular pedicle avulsion, pelvic or ureteral rupture, Hemorrhage into the paranephric tissue, or complete occlusion of the ureteral lumen by blood clots. Its intensity and duration vary—ranging from microhematuria to profuse, life-threatening bleeding lasting 1–30 days.

It should be noted that a patient's satisfactory condition following trauma can be quite unstable and deteriorate to severe within a matter of minutes. This is because kidney injuries can be complicated by a so-called biphasic subcapsular rupture. When the kidney is injured while the capsule remains intact, bleeding stops rather quickly because the subcapsular hematoma essentially tamponades the rupture site (first phase). Subsequently, an careless movement by the patient or a sudden change in body position (e.g., sitting up) can lead to a rupture of the renal fibrous capsule, dislodgement of the blood clot from the rupture site, and the onset of profuse hemorrhage (second phase of the subcapsular rupture). The possibility of such a scenario compels the physician to exercise utmost vigilance regarding patients who exhibit even the slightest signs of closed renal trauma.

Class="center">

Fig. 109. Schematic representation of closed renal injuries: a — hemorrhage beneath the renal capsule; b — subcapsular hematoma; c — incomplete rupture of the parenchyma and capsule with perirenal hematoma; d — incomplete rupture of the parenchyma and renal pelvis — macrohematuria; e — rupture of the pelvis and ureter, urine extravasation into the perirenal Tissues; f — complete rupture of the parenchyma and pelvis — blood and urine extravasation into the perirenal tissues, macrohematuria; g — rupture of the vascular pedicle, massive perirenal hematoma.

All patients, even with suspected closed renal injuries, must be immediately hospitalized in a specialized urological department for dynamic monitoring.

Outpatient Treatment in this situation is unacceptable!

In the long-term period following a closed renal injury, arterial Hypertension (AH), renal failure (RF), hydronephrotic transformation of the kidney, and post-traumatic Nephroptosis may develop. Arterial hypertension (AH) is the most frequent complication; its Pathogenesis is attributed not only to the compression of the renal parenchyma by fibrous tissue at the site of the former hematoma (akin to a "cellophane kidney"), but also to The formation of a hematoma in the renal hilum area, encompassing the adipose tissue of the renal sinus. Its subsequent Organization leads to the compression of lymphatic and venous vessels, accompanied by the development of venous hypertension, subsequent Hypoxia of renal structures, and stimulation of the renin-angiotensin-aldosterone system (RAAS), or impaired urine outflow due to the development of retroperitoneal fibrosis (Wunderlich syndrome).

Hydronephrosis occurs As a result of the displacement and compression of the Ureters, followed by impaired urine passage caused by Connective Tissue developing at the site of the former hematoma. Urodynamic disturbances provide the Background for the development of urolithiasis (the micellar core can be formed, for example, by a necrotic piece of renal tissue or a blood clot).