Renal Trauma Treatment & Management

Updated: Jan 01, 2019
  • Author: Dennis G Lusaya, MD; Chief Editor: Bradley Fields Schwartz, DO, FACS  more...
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Treatment

Approach Considerations

Santucci describes the contemporary approach to renal trauma as follows [32] :

  1. Operate immediately if the patient has life-threatening bleeding 
  2. Observe initially, but step in with metered responses as necessary
  3. Use ureteral stents for symptomatic or growing urinoma
  4. Use angioembolization for nonemergent bleeding or for urgent bleeding if those techniques are available at your center
  5. Do open surgery when needed
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Nonoperative Treatment

In the setting of blunt renal trauma and selected instances of penetrating renal trauma, a nonoperative approach may be selected. Patient selection is the preliminary step in adopting a nonoperative management strategy to renal trauma. One series, with predominantly blunt mechanisms of injury, documented that 85% of patients were treated successfully without surgery. Ultimately, the exclusion of concurrent injury may be the key point in treating patients nonoperatively.

The anatomic structure of the kidney lends itself to nonoperative management in the setting of blunt trauma. The kidney has an end artery blood supply with a segmental pattern of division that supplies the renal parenchyma. When subjected to blunt force that causes a laceration, the laceration tends to occur through the parenchyma. The resulting hematoma may displace renal tissue, but the segmental vessels themselves often are not lacerated.

The closed retroperitoneal space around the kidney also promotes tamponade of bleeding renal injuries. Finally, the kidney is rich in tissue factor, the molecule that activates the extrinsic coagulation cascade, further promoting hemostasis after injury.

Interventional radiology has extended the ability to treat renal lacerations nonoperatively. Techniques have included the following:

  • Percutaneous drainage of perinephric fluid collections or urinomas
  • Endourologic stenting
  • Angiography with selective embolization

For example, Wang et al reported that emergency transcatheter arterial embolization produced complete hemostasis in 80 of 83 patients with acute renal hemorrhage. Renal artery computed tomography angiography (CTA) was used to localize the bleeding artery in 35 of their cases. Embolic agents used varied with arteriographic presentation and included gelatin sponge, polyvinyl alcohol particles, and coils. [33]

In children with grade IV renal injury who are receiving conservative treatment, Lee et al recommend performing a follow-up imaging study 4-5 days after the trauma when any of the following are present [34] :

  • Need for transfusion
  • Main laceration location in the antero-medial portion of the kidney
  • Intravascular contrast extravasation
  • Large perinephric hematoma (>2.2 cm)

In their study of 26 consecutive cases of grade IV renal trauma in children, more patients with those predictive factors required urologic intervention, typically 4-8 days after the trauma. [34]

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Operative Treatment

The goals of operative therapy for renal laceration incorporate the two basic principles of hemorrhage control and renal tissue preservation, which must be balanced for each individual patient. Attempts to find a universal plan for this approach have generated controversy in the medical literature. The mindset of the medical community has also been changing as established practice patterns have been examined, challenged, and reassessed.

An additional benefit of operative therapy is the ability to address concurrent injuries. One study documented that 80% of patients with renal laceration had other associated injuries. In that same study, 47% of the patients with renal laceration had an associated injury that required immediate laparotomy.

Indications for renal exploration

In order to select a renal injury for nonoperative management, the injury needs to be imaged and accurately staged. An incompletely staged renal injury requires surgical exploration. Not all penetrating renal injuries require surgical exploration. The use of the improved imaging technique of CT has largely been responsible for the decreased rate of renal explorations at the authors’ institution. Guidelines for the surgical exploration of the injured kidney vary.

The only absolute indication for surgical renal exploration is a patient with external trauma and persistent renal bleeding. Signs of continued renal bleeding are a pulsatile, expanding, or uncontained retroperitoneal hematoma. Another sign is avulsion of the main renal artery or vein as noted by CT or arteriography.

Relative indications include nonviable tissue. Substantial devitalized renal parenchyma (>25%) is a relative indication for exploration. [35] Husmann and Morris [36] noted that injuries with significant nonviable renal tissue (25-50%) associated with parenchymal laceration that are managed nonoperatively have a high complication rate (82%).

Husmann et al further compared the results of the nonoperative and surgical management of major renal lacerations and devitalized renal fragments after blunt trauma. Their findings demonstrated that when such renal injuries are associated with an intraperitoneal organ injury, the postinjury complication rate is much higher unless the kidney is surgically explored and repaired. By surgically repairing such injuries, they reduced the overall morbidity from 85% to 23%. Concomitant pancreatic and bowel injuries were particularly associated with higher rates of infected urinomas and abscesses.

Furthermore, since nearly all blunt trauma patients with intraperitoneal organ injuries undergo celiotomy by the general surgeon, this offers the opportunity to explore and repair the kidney with such major parenchymal injuries.

A systematic review by Chiron et al identified three risk factors that are not included in the grade 4 renal injury classification, but are associated with hemodynamic instability and need for surgery, as follows [35] :

  • Perirenal hematoma >3.5 cm
  • Intravascular contrast extravasation
  • Medial renal laceration

Additional relative indications include the following:

  • A major devitalized segment
  • Injury associated with urinary extravasation
  • Extensive renal injury
  • A large retroperitoneal hematoma, even without intraperitoneal injury

Urinary extravasation

Urinary extravasation in itself does not demand surgical exploration. Extravasation confirms the diagnosis of a major renal injury. Persistent extravasation or signs of sepsis usually require intervention. In general, urinary extravasation resolves spontaneously in the majority of patients with blunt trauma. In select patients, expectant management does not reduce the renal salvage rate and does not prolong hospitalization.

Nonoperative therapy may also require delayed intervention. However, the usual complications of urinoma and persistent urinary leak can be successfully managed by either percutaneous or endoscopic techniques, thus avoiding celiotomy and renal exploration. Matthews et al [37] reported that in patients with major renal injury and urinary extravasation who are managed conservatively, urinary extravasation spontaneously resolved in 87%. Extravasation persisted in 13% and was successfully managed endoscopically (eg, double-J stent). Overall hospitalization lasted 8 days and was not prolonged by the need for delayed intervention.

Ureteropelvic junction (UPJ) injuries rarely heal spontaneously and thus are often best managed by surgical repair at the time of injury. Conservative management of such injuries is fraught with persistent urine leakage, urinoma formation, ileus, and infection.

Incomplete staging

Only complete definition of the renal injury by appropriate imaging studies permits the selection of nonoperative management. Incomplete staging demands either further imaging or renal exploration and reconstruction. In the unstable patient who requires emergent celiotomy, the kidney can only be imaged by one-shot IVU on the operating room table. The nephrogram of the injured kidney is often poorly opacified due to the injury and is worsened by any hemodynamic instability. In so doing, the full extent of the injury is indeterminate. In such circumstances, the kidney should be explored after obtaining proximal vascular control.

The unexpected finding of a retroperitoneal hematoma upon celiotomy should be evaluated by on-table, one-shot IVU. If IVU results are abnormal or indeterminate or if the kidney is persistently bleeding, then the kidney should be explored.

Arterial thrombosis

Major deceleration injuries can result in stretching on the renal artery and tearing of the vessel intima, resulting in thrombosis of the main renal artery or its segmental branches and thus causing infarction of the renal parenchyma. Prompt diagnosis and the time until operation of a unilateral complete arterial thrombosis is vital to salvaging the kidney. The chance of renal salvage is remote after 12 hours of ischemia.

If the contralateral kidney is healthy, there is some controversy as to whether to attempt revascularization or to observe. If renal ischemia exceeds 12 hours, the kidney should be allowed to slowly atrophy. Nephrectomy should be performed only if delayed celiotomy is being performed for an associated injury or if persistent hypertension develops postoperatively. Bilateral complete renal artery thrombosis or a solitary kidney demands more immediate exploration and revascularization.

Penetrating trauma

The only absolute indication for exploration is persistent renal bleeding. Nearly all penetrating renal injuries should be managed surgically. The exception is stable patients with no missile penetration of the peritoneum in whom the injury is well staged by computed tomography.

Wessels et al have shown that gunshot wound victims who have no intra-abdominal organ injury and a demonstrated grade 1-2 renal injury, when managed conservatively, are relatively complication free. In sharp contrast, one of four expectantly managed grade 3-4 injuries were complicated by delayed renal bleeding. [38]

A study by Bjurlin et al found that selective nonoperative management of penetrating renal injuries resulted in a lower mortality rate, a decreased incidence of blood transfusion, and a shortened mean ICU and hospital stay compared with nephrectomy; however, results were similar to renorrhaphy. Rates of complication were low with selective nonoperative management and were comparable to operative management. [39]

Stab wounds posterior to the posterior axillary line are less likely to have an associated visceral injury. When the diagnostic peritoneal lavage or CT scan is negative for intraperitoneal organ injury and the renal injury not severe, observation of the renal injury may be appropriate. Most abdominal penetrating injuries undergo celiotomy by the general surgeons. The presence of an unexpected retroperitoneal hematoma upon exploratory laparotomy when the renal injury has not been fully staged radiographically usually warrants renal exploration.

Some controversy remains with the use of postoperative drains in the setting of renal trauma. The general trend has been away from the routine use of drains in this setting, although some centers still advocate their use. Suction drains should be avoided after renal repair.

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Preoperative Details

Patients with renal injuries should be managed with initial attention to the basic ABCDEs outlined in Advanced Trauma Life Support protocols. Because many patients have multisystem trauma with concurrent injuries, a systematic approach to the initial assessment and resuscitation allows for identification of other injuries. The decision-making process becomes more involved as additional injuries are found. For additional details, see Critical Care Considerations in Trauma or Initial Evaluation of the Trauma Patient.

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Intraoperative Details

Techniques for renal exploration and repair

Primary vascular control is achieved prior to all renal explorations by routinely obtaining proximal vascular control. For vascular control, the ipsilateral renal artery and vein are isolated individually with vessel loops.

The kidney is then exposed by incising the Gerota fascia lateral to the colon. When brisk bleeding is encountered, the renal artery is temporarily occluded with Rummel tourniquets. Warm ischemic time should not greatly exceed 30 minutes, in order to avoid permanent renal ischemic damage. If bleeding persists, the renal vein is occluded by Rummel tourniquet placement, in order to eliminate back bleeding. Temporary occlusion of the renal artery is needed in patients with renal vascular injuries, those in shock, and those with large or expanding retroperitoneal hematomas.

Rostas et al have proposed that exploration of the Gerota fascia may be used selectively rather than routinely for patients with renal gunshot wounds. Their retrospective 10-year review of 63 patients with renal gunshot wounds who underwent exploratory laparotomy concluded that most such patients do not require exploration of the Gerota fascia. Compared with patients (n=28) who underwent exploration of the Gerota fascia, those who did not (n=35) experienced significantly lower mortality (14% versus 29%), had very low complication rates, and were unlikely to need surgical intervention due to renal-associated complications. [40]

Renal reconstruction

In the absence of persistent hemodynamic instability or coagulopathy, renal reconstruction is safe and effective. The method of kidney reconstruction is dictated by the degree and location of the injury, and not by the associated intra-abdominal injuries. In the face of concomitant major pancreatic or colonic injuries with frank fecal contamination, renal reconstruction is successful, with only a slightly increased complication rate. The reconstructive principles for renal injures are as follows:

  • Adequate and broad exposure of the kidney and injured area

  • Temporary vascular occlusion for brisk renal bleeding not well controlled by manual compression of the parenchyma

  • Sharp excision of all nonviable parenchyma

  • Meticulous hemostasis (particularly, arterial)

  • Watertight closure of the collecting system

  • Parenchymal defect closure by approximation of the capsular/parenchymal edges over a Gel-foam bolster or coverage with omentum, perinephric fat, peritoneum, or polyglycolic acid mesh

  • Interposition of an omental pedicle flap between any vascular, colonic, or pancreatic injury and the injured kidney

  • Ureteral stent placement for a renal pelvis or ureteral injury

  • Retroperitoneal drain placement: The authors prefer to use a Penrose drain. Unless drainage is excessive, the Penrose drain is removed after 48 hours. Additionally, the urinary tract injury and the pancreatic injury are always drained separately.

Indications for nephrectomy

When proximal vascular control is initially achieved, before all renal explorations, nephrectomy is required in less than 12% of cases. [41] When primary vascular control is not achieved and massive bleeding is encountered, in the rush to control bleeding, a kidney that could have been salvaged may be unnecessarily sacrificed. Overall, nephrectomy is required when the patient is persistently hemodynamically unstable and, thus, is a life-saving maneuver. Other indications for nephrectomy are as follows:

  • Grade 5 injuries that are deemed irreparable (eg, major vascular pedicle injury, particularly on the right side)

  • Shattered kidney

  • Multiple concurrent injuries

  • Uncontrolled hemorrhage

Indications for partial nephrectomy are as follows:

  • Avulsed fragments

  • Polar penetrating mechanism of injury

  • Collecting system repair

Adjuncts include absorbable mesh wrap, topical thrombostatic agents, and omentum.

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Postoperative Details

As with all trauma patients, the postoperative course should be monitored to ensure successful hemostasis. Serial hematocrit measurements should be considered. In patients in whom a damaged but perfused kidney is left in situ, renovascular hypertension remains a theoretical possibility and the patient should be monitored clinically for this entity.

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Follow-up

For patient education resources, see the Kidneys and Urinary System Center, as well as Intravenous Pyelogram and Blood in the Urine.

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Complications

Complications that can follow renal trauma are dependent on the grade of the initial renal injury and the method of management. [42] In most cases, resulting complications are usually of minimal long-term morbidity, can be successfully managed by endourologic and percutaneous techniques, and do not significantly prolong the mean days of hospitalization. [43, 44]

Early complications

Early complications, those that occur within 1 month of injury, are urinoma, delayed bleeding, urinary fistula, abscess, and hypertension. Prolonged urinary extravasation is the most common complication after renal trauma. [6, 43]

Urinomas occur in less than 1% of renal trauma cases. Small, uninfected, and stable collections do not require intervention. Larger collections are usually successfully managed by the endoscopic or percutaneous placement of a ureteral/nephrostomy tube.

Delayed renal bleeding most commonly occurs within 2 weeks of injury. When bleeding is heavy or symptomatic, transfusions, angiography, and superselective embolization [20] may be required.

Urinary fistulas can occur in association with an undrained collection or from large segments of devitalized renal parenchyma.

Abscesses of the retroperitoneum are associated with ileus, high fever, and sepsis. Most collections can be easily drained percutaneously. The extent of the abscess and the presence of loculations are well delineated by CT imaging.

Hypertension in the early postoperative period is usually renin mediated and transient, and it does not require any treatment.

Late complications

Late complications after renal trauma are hydronephrosis, arteriovenous fistula, pyelonephritis, calculus formation, and delayed hypertension.

Scarring in the region of the renal pelvis and ureter after renal trauma can result in urinary obstruction and, subsequently, lead to stone formation and chronic infections.

Arteriovenous fistula more commonly occurs after a renal stab wound and can present with delayed bleeding. [20] Angiography can help determine the size and location of the fistula. In most cases, vessel embolization can be used to successfully close the fistula.

Long-term hypertension from renal trauma is a rare complication that is overdiagnosed. The experience at San Francisco General Hospital is that sustained hypertension occurs in only 0.2% of cases. [2] The etiology for hypertension after renal injury is renal ischemia stimulating the renin-angiotensin axis. Long-term follow-up of renal trauma patients is important in order to not miss these late complications, which are often of insidious onset and silent progression.

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Outcome and Prognosis

In many cases of renal trauma, the outcome and prognosis depend on the associated injuries. In situations in which nonoperative management is used, concern exists about leaving perfused but nonviable renal tissue in situ, which may lead to hypertension. However, the occurrence of hypertension in this setting seems to be rare. One study documents no evidence of hypertension after 5 years of follow-up in children who had sustained renal trauma. Other series report only isolated instances of hypertension. Therefore, the risk of hypertension alone does not seem to warrant surgical exploration in cases with nonperfused renal segments.

A single-center review of renal injuries in 171 children found that grades II and III renal injuries carry a low risk of complication, so repeat imaging and close follow-up are likely not necessary. However, close follow-up is warranted for patients with grades IV and V injuries, as those carry a meaningful risk of adverse outcome (eg, need for nephrectomy or stenting, or development of hypertension). [45]

 

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Future and Controversies

Preoperative IVP for penetrating trauma

Proponents of the one-shot IVP point out that it can be performed as the patient is being prepared for surgery and that it allows a quick assessment of the functionality of the contralateral kidney.

Opponents believe that preservation of renal tissue is always a goal as long as the approach is safe for the patient. Knowledge of the functional status of the contralateral kidney does not change whether or not trying to salvage the kidney is safe. The timing of the injection may yield suboptimal views, and often, more time is needed to obtain images than is anticipated.

The consensus on this technique remains incomplete. Intraoperative IVP can potentially allow leaving a perinephric hematoma unexplored if the study shows findings of a completely normal system. Some practitioners make extra efforts to succeed with operative salvage of a damaged kidney if the contralateral kidney is known to be absent.

Operative technique (central vascular control)

Proponents believe that data demonstrate enhanced renal salvage when vascular control is obtained outside the Gerota fascia. This technique allows controlled assessment of the nature of the renal laceration, and it may impart less trauma on the vessels compared to more urgent control measures.

Opponents believe that not all renal injuries have sufficient bleeding to warrant central control of vessels. The technique requires some operative time and exposes the renal vessels to potential operative trauma. Anatomic variants, such as multiple arteries or veins, may not be recognized and may elicit a false sense of security.

Hypertension

Although concern exists that leaving perfused but nonviable renal tissue in situ potentially leads to hypertension, the occurrence of hypertension in this setting seems to be rare. One study documents no evidence of hypertension after 5 years of follow-up in children who had sustained renal trauma. Other series report only isolated instances of hypertension. Therefore, the risk of hypertension alone does not seem to warrant surgical exploration in cases with nonperfused renal segments.

Nonperfused kidney

Controversy exists regarding whether to revascularize a nonperfused kidney. The incidence rate of renal salvage in the setting of a nonperfused kidney due to trauma has been reported to be approximately 0%. Isolated case reports of success do exist. Most centers advocate an expectant management approach.

The need for ultimate nephrectomy also remains somewhat controversial. Possible or documented renovascular injury continues to be a controversial arena of renal injury management. Only aggressive intervention provides the opportunity for renal salvage. However, the clinician must be aware that the salvage rate is low, and, ultimately, the life of the patient must take priority over the life of the kidney. Continued investigation and evolution of surgical techniques may help resolve this controversy.

Conclusion

The approach to the diagnosis and management of renal trauma continues to evolve. In the setting of significant hemodynamic instability, operative exploration remains the diagnostic and therapeutic modality of choice. In patients with blunt trauma and in certain cases of penetrating trauma, a progressive trend is towards nonoperative management of renal trauma.

Continued change in the approach to renal trauma is almost a certainty. Interventional radiology and endourologic manipulation have increased the ability to successfully treat patients without surgery and to address common complications of renal trauma. Numerous diagnostic options exist in the setting of a stable patient. With awareness of these modalities, the clinician can provide each patient with optimal treatment.

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