Clinical indications for radiographic evaluation of blunt renal trauma

The evaluation of patients with blunt renal trauma has become controversial. We tested the hypothesis that renal contusion can be diagnosed clinically and that these patients do not require radiographic evaluation. To evaluate the association of microhematuria without shock and with renal contusion, we reviewed the medical records of 831 patients with hematuria following blunt renal trauma. Microscopic hematuria without shock was noted in 160 of 241 patients without and 334 of 590 with associated injuries. Of the former 160 patients 159 had renal contusion and 1 had a renal laceration, while of the latter 334 patients 329 had renal contusion, 3 had renal laceration, 1 had renal rupture and 1 had a pedicle injury. Most patients with microscopic hematuria and no shock after blunt renal trauma had a renal contusion, especially those with no associated injury. All of the patients with renal contusions experienced no complications from nonoperative management. However, avoiding a radiographic evaluation in patients with blunt renal trauma plus microhematuria and no shock would miss a few cases of severe renal injury.     

Renal trauma: re-evaluation of the indications for radiographic assessment

We studied prospectively 359 consecutive patients with blunt (306) or penetrating (53) renal trauma to refine the indications for radiographic evaluation. Various factors, including the degree of hematuria, presence of shock and associated injuries easily assessable at the time of initial evaluation, were correlated with the severity of renal injury to determine whether any combination of parameters will separate patients with renal contusions from those with significant renal injuries (minor and major lacerations, and vascular injuries). We identified 3 groups: group 1-85 patients with gross hematuria or microscopic hematuria and shock after blunt trauma (including all 23 with significant renal injuries), group 2-221 patients with microscopic hematuria but no shock after blunt trauma (all with renal contusions) and group 3-53 patients with penetrating trauma. No combination of parameters was able to predict a severe injury in group 3. Our data support radiographic evaluation in groups 1 and 3. However, because all patients in group 2 had renal contusions and experienced no complications from nonoperative management we believe that excretory urography, which is time-consuming and costly, can be avoided in patients with microscopic hematuria but no shock after blunt renal trauma.     

Efficacy of Radiographic Imaging in Pediatric Blunt Renal Trauma

Purpose

We sought to determine whether radiographic imaging can effectively detect significant renal injuries in children with blunt trauma who do not have significant hematuria.

Materials and Methods

We reviewed the records of 180 children who presented to our hospital for suspected renal trauma between 1977 and 1995. Results of excretory urography or abdominal computerized tomography were correlated with urinalysis findings and clinical outcome.

Results

Of 147 patients with microscopic hematuria after blunt trauma 77 underwent imaging. Only 1 patient had a significant renal injury (grade 2 or greater) and 76 had normal findings or renal contusions only, including 11 with microscopic hematuria and shock. Of the 74 patients who did not undergo imaging a clinical diagnosis of renal contusion was made and followup was available for 57 (77 percent). All patients healed without adverse sequelae. Of 33 patients with gross hematuria significant renal injuries were found in 9, including 3 who required immediate surgical repair of a major renal laceration or vascular injury. Combining our results with those of other reported series revealed significant renal injuries in only 11 of 548 children (2 percent) with less than 50 red blood cells per high power field on presenting urinalysis after blunt abdominal trauma. These patients were likely to have multiple associated injuries.

Conclusions

Significant renal injuries are unlikely in pediatric patients with blunt renal trauma but no gross or substantial microscopic hematuria. Shock does not appear to be a clinically useful indicator.     

Radiologic Evaluation of Pediatric Blunt Renal Trauma in Patients with Microscopic Hematuria

As a result of the rapid increase in medical costs, the efficacy of diagnostic imaging is under examination, and efforts have been made to identify patients who may safely be spared radiographic imaging. We reviewed the records of children who presented to our institution with suspected blunt renal injuries to determine if radiographic evaluation is necessary in children with microscopic hematuria and blunt renal trauma. We retrospectively reviewed the medical records of 1200 children (ages less than 18 years) who sustained blunt abdominal trauma and who presented to our level I pediatric trauma center between 1995 and 1997. Urinalysis was performed in 299 patients (25%). Urinalysis results were correlated with findings on abdominal computed tomography (CT). All patients had more than three red blood cells per high power field (RBC/ hpf) or gross hematuria. Renal injuries were graded according to the injury scale defined by the American Association for the Surgery of Trauma. Sixty-five patients had microscopic hematuria. Thirty-five (54%) were evaluated with an abdominal CT scan. Three patients sustained significant renal injuries (grade II-V), and 32 patients had normal findings or renal contusions. Therefore only 3 of 65 patients (4.6%) sustained a significant renal injury. All three patients had other associated major organ injuries. Of the three patients with gross hematuria evaluated with abdominal CT, one (33%) sustained a significant renal injury and had no associated injuries. The degree of hematuria did not correlate with the grade of renal injury. Pediatric patients with blunt trauma, microscopic hematuria, and no associated injuries do not require radiologic evaluation, as significant renal injuries are unlikely. However, children who present with associated injuries and microscopic hematuria after blunt trauma may have significant renal injuries and should undergo radiologic evaluation.     

An analysis of 30 patients with renal trauma: diagnostic value of radiographic examinations

To evaluate the diagnostic value of radiographic examinations in renal trauma, 30 patients treated between April, 1985 and March, 1988 were examined. The 25 male and 5 female patients ranged in age from 10 to 74 years, with 17 (57%) less than 30 years of age. Causes of injuries were traffic accidents in 19 patients (63%), falls in 5 (17%), sports in 2 (7%), and others in 4 (13%). Twenty-nine patients (97%) had hematuria and 3 (10%) had shock due to renal injury. The presence of shock indicated severe renal injury, but the degree of hematuria did not correlate to severity of injury. Of the 30 patients, 18 (60%) had renal contusions, 7 (23%) had minor lacerations, 4 (13%) had major lacerations and one had vascular injury. One patient had penetrating trauma and the other 29 had blunt trauma. Two patients (7%) had pre-existing renal anomalies. Associated injuries were present in 16 patients (53%). The presence of associated injuries had no relation to the severity of the renal injury. Computerized tomography (CT) with contrast medium was more sensitive to abnormal findings, especially subcapsular and perirenal hematoma, than excretory pyelography. Findings of renal angiography provided additional anatomical information for deciding immediate surgical treatment and for selecting operative methods for salvage of the kidney.(ABSTRACT TRUNCATED AT 250 WORDS)     

Evaluation and treatment of blunt renal trauma

We examined retrospectively the records of 126 patients with blunt renal trauma to determine the criteria for radiological investigations and the imaging study of choice. Of the 3,993 patients admitted to our regional trauma unit during the last 13 years 126 (3.1%) had blunt renal trauma. Mean patient age was 32 years (range 13 to 87 years) and the male-to-female ratio was 3:1. Mean followup was 7 months (median 4 months). Of the patients 72% had a minor renal injury, 17% had a moderate injury and 11% had a major renal injury. Treatment was conservative in 114 patients, while 9 underwent a genitourinary operation. Results were excellent in 87% of the patients and good in 8%, while 5% failed treatment. All patients who had microscopic hematuria without shock had minor injuries. Excretory urograms (IVPs) were normal in 74% and 39% of the patients when performed for minor and moderate renal injuries, respectively. Computerized tomography (CT) was abnormal in all cases when performed, and was more sensitive and specific than an IVP. Therefore, the majority of patients with blunt renal trauma can be treated conservatively with an excellent result. Furthermore, radiological investigations are not needed in those with microscopic hematuria and no shock. When radiological investigations are indicated a CT scan is the imaging study of choice.     

Grade IV Renal Injuries: Evaluation, Treatment, and Outcome

Of our last 2483 renal trauma patients, 113 had grade IV injuries. In most the mechanism was a penetrating injury (60%: 30% gunshot, 30% stab wounds). Associated injuries were common (80%) and hospital stays prolonged, averaging 16 days. Most of the patients (70%) required transfusion, some massively (average volume 4.4 liters, range 0-30 liters). Surprisingly, not all patients with grade IV renal injuries had gross hematuria: 25% had microhematuria, and 4% had neither microscopic nor gross hematuria. Computed tomography (CT) diagnosed the injury correctly in 100% of the patients in whom it was performed; when CT was not available, "one-shot" intraoperative intravenous pyelography (IVP) demonstrated grossly abnormal findings in 90%. Renal exploration was performed in 78%, resulting in 69% renorrhaphy and 9% nephrectomy rates in our 113 patients. Almost all those with penetrating trauma required exploration (97%), whereas only 50% of those with blunt trauma did so. The overall complication rate and kidney-specific complication rate did not differ significantly between patients who were observed and those who underwent surgery. Complications rates were similar in grade IV renal laceration patients and grade III patients. Delayed complications after hospital discharge were not seen, although follow-up was rare in this inner-city trauma population. Among the 21% of patients in whom postoperative nucleotide renal function scans were available, function was generally good (average 36%). Only patients who underwent concomitant vascular repair had poor function (below 20%).     

A prospective analysis of 1,930 patients with hematuria to evaluate current diagnostic practice

PURPOSE: The commonly accepted diagnostic algorithm for hematuria includes excretory urography (IVP) and cystoscopy. Some have suggested that ultrasound of the upper urinary tract is adequate and that cystoscopy is not necessary in younger patients with microscopic hematuria. We ascertain whether a less intensive algorithm could be adopted while retaining diagnostic efficacy. MATERIALS AND METHODS: A total of 1,930 patients were enrolled prospectively in the study at a hematuria clinic between October 1994 and March 1997. Evaluation consisted of basic demographics, history and examination, routine blood tests, urinalysis and cytology. All patients underwent plain abdominal radiography, renal ultrasound, IVP and flexible cystoscopy. RESULTS: A total of 1,194 males and 736 females with a mean age of 58 years (range 17 to 96) were included in the study. Overall, 61% of patients had no basis found for hematuria, 12% had bladder cancer, 13% had urinary tract infection and 2% had stones. Kidney and upper tract tumors were noted in 14 patients (0.7%), including 4 who presented with microscopic hematuria. If only ultrasound or IVP had been performed 4 of these cases would have been missed. Of 982 patients presenting with microscopic hematuria 51 had cancer. Bladder cancer was found in 7 patients younger than 40 years. CONCLUSIONS: Our findings suggest that cystoscopy cannot be safely avoided even in younger patients with microscopic hematuria. Only a combination of ultrasound and IVP detected all upper tract tumors.     

Radiographic assessment of blunt renal trauma

Recent reports in the urologic literature suggest that radiographic evaluation of normotensive blunt trauma patients with microscopic hematuria is no longer necessary. Several facilities, however, including the Los Angeles County-University of Southern California Medical Center continue to routinely perform intravenous pyelography in this setting. To further evaluate whether this practice is indicated, we retrospectively reviewed the records of 337 patients seen at our facility between May, 1986 and December, 1989 following blunt trauma with resultant microscopic hematuria but no shock. All patients were radiographically assessed with an intravenous pyelogram. Of the 337 studies, 30 (9%) had an abnormal result, including 28 renal contusions, 1 ureteropelvic junction (UPJ) disruption, and 1 non-functioning kidney (which on further evaluation revealed a congenitally absent kidney). A total of 1 significant urologic injury was identified. Thus, only one injury (0.3%) would have been missed if a policy of observation was followed in this group of patients. Our data support other reports in the urologic literature that radiographic staging is not necessary in managing blunt trauma patients with microscopic hematuria but no shock.     

Blunt traumatic hematuria in children. Is a simplified algorithm justified?

PURPOSE: We determined whether radiographic evaluation is indicated in all children with traumatic hematuria. MATERIALS AND METHODS: We retrospectively reviewed the records of 110 children from 1992 to 1999 diagnosed with blunt trauma and hematuria. It is routine practice at our emergency department to perform radiographic evaluation in all children with hematuria regardless of the degree. Each chart was evaluated for the mechanism of injury, degree of hematuria, hypotension, imaging studies, renal injury, renal anomalies, associated injuries and outcome. RESULTS: A total of 110 patients 1 to 18 years old (mean age 9) were identified. The most common mechanism of injury was motor vehicle accident in 37 children (34%), followed by a fall in 32 (29%). Grades I to V renal injury was present in 5, 6, 6, 6 and 1 cases, respectively (22%), while 1 (0.9%) involved ureteropelvic junction avulsion. No child had renal pedicle injury. In 9 patients renal anomalies were detected incidentally. Of the 110 patients 101 underwent radiographic evaluation, including computerized tomography in 97 (88%). The 24 patients (22%) with significant renal injury and all with incidentally diagnosed renal anomalies had 50 or greater red blood cells per high power field on urinalysis, while 1 with ureteropelvic junction avulsion presented without hematuria. Hypotension was present in only 3 patients (2.7%), who also had associated injuries, including 2 who presented with renal injury. All 3 with associated injuries. Associated injuries were identified in 11 of 25 patients (44%). The 9 patients (8%) who did not undergo radiographic imaging had negative results on repeat urinalysis with an excellent outcome. CONCLUSIONS: We recommend that radiological evaluation consisting of abdominal and pelvic computerized tomography should be performed only in patients with 50 or greater red blood cells on urinalysis, hypotension at presentation to the emergency room or based on the severity of mechanism of injury, for example high speed motor vehicle accident deceleration injuries. The patient who presented with ureteropelvic junction avulsion without hematuria would have undergone imaging considering the mechanism of injury and number of associated injuries.     

Operative indications in penetrating renal trauma

In a review of 53 patients with penetrating renal injuries treated between 1978 and 1983 at San Francisco General Hospital, we correlated several factors with the extent of renal damage to determine whether major and minor injuries could be differentiated preoperatively, thereby avoiding unnecessary surgical exploration. Of 56 injured kidneys (three patients had bilateral injuries), 35 sustained major injuries, 17 minor, and four vascular pedicle injuries. The presence of shock, the degree of hematuria, the location of the entry site, and the type of injury did not permit reliable discrimination among these categories. Intravenous urography was most often nondiagnostic, and only the presence of extravasation or nonfunction was specific for major injury. Computed tomography provided accurate preoperative assessment in 11 cases, however, allowing nonoperative management in eight renal injuries.     

Radiographic assessment of renal trauma: a 10-year prospective study of patient selection

To develop criteria to determine which patients require radiographic assessment after blunt renal trauma, we studied prospectively 1,146 consecutive patients with either blunt (1,007) or penetrating (139) renal trauma between 1977 and 1987. Based on our preliminary results from 1977 to 1983, in which none of the 221 patients with blunt trauma and microscopic hematuria without shock had significant renal injuries, we designed a prospective study to determine if such patients could be managed safely without radiographic staging. During the last 10 years significant renal injuries were found in 44 patients (4.4 per cent) with blunt trauma and gross hematuria or microscopic hematuria associated with shock, and in 88 patients (63 per cent) with penetrating trauma. No significant injuries occurred in the 812 patients with blunt trauma and microscopic hematuria without shock, 404 of whom had complete radiographic assessment and 408 of whom did not. There were no delayed operations or significant sequelae related to the renal injury in these patients. We conclude that complete radiographic staging is mandatory in patients with penetrating trauma to the flank or abdomen and in patients with blunt trauma associated with either gross hematuria or microscopic hematuria and shock. However, patients with blunt trauma, microscopic hematuria and no shock who do not have associated major intra-abdominal injuries can be managed safely without excretory urography.     

Renal malposition in patients with omphalocele

We describe a boy with a history of omphalocele who presented with gross hematuria. Subsequent evaluation revealed a cephalad right kidney malposition and the hematuria was of lower tract origin. To investigate the frequency of this radiographic finding the medical records of 15 patients with omphalocele who presented between 1979 and 1985 were reviewed. Studies of the urinary tract were performed after omphalocele closure. Of 7 cases (46 per cent) with abnormal cephalad renal displacement the kidney was on the right side only in 3 and it was bilateral in 4. The omphalocele contents consisted of gastrointestinal tract only in 9 patients, and liver and gastrointestinal tract in 6. All 6 patients with omphaloceles that included the liver had cephalad renal displacement. One patient with small bowel alone in the omphalocele had right kidney displacement. Clinicians should be aware of this variation to avoid confusion and further unnecessary evaluation.     

Indications for radiographic assessment in suspected renal trauma

We recommend that the criteria for radiographic assessment of suspected renal trauma be: (1) penetrating trauma to the flank or abdomen, regardless of the degree of hematuria; (2) blunt trauma and gross hematuria; or (3) blunt trauma associated with microhematuria and blood pressure below 90 mm Hg before or after emergency room admission. In hemodynamically stable patients in whom renal injury alone is suspected, we recommend intravenous urography, which will adequately stage 60 to 85 per cent of renal injuries. Computed tomography should be performed if the urography results are equivocal or as the primary study when multiple injuries are suspected. Arteriography can be reserved for patients with suspected renovascular injuries in whom CT scans are inconclusive.     

Investigation and management of blunt renal injuries in children: a review of 11 years' experience

Over an 11-year period, 333 patients aged 6 months to 13 years were investigated for suspected blunt renal trauma. Ninety-one renal injuries were demonstrated. All patients who had preexisting pathology sustained major (ie, grade III or IV) injuries and all those who required surgery presented with 4+ or macroscopic hematuria with or without loin signs. Intravenous pyelography (IVP) showed no injury in 140 (89%) of 157 patients who had 0 to 3+ microscopic hematuria, and did not influence management in the remaining 17 patients. Seventy-eight (84%) patients were treated nonoperatively, with one death and few complications. Thirteen (14%) patients underwent early laparotomy, with a nephrectomy rate of 92%. No patient with a renal pedicle injury was considered suitable for vascular reconstruction. We conclude that (1) contrast studies are of little value in pediatric patients with asymptomatic microscopic hematuria after blunt trauma; (2) IVP remains the most cost-effective means of investigating renal injuries; and (3) laparotomy is only indicated for ongoing hemorrhage from the severely injured kidney and in a few selected patients with renal pedicle injuries.     

Microscopic hematuria as a screening marker for urinary tract malignancies

BACKGROUND: Although a mass screening urinalysis is a widely accepted procedure, it has not yet been shown if microhematuria is an appropriate and useful screening marker for urologic malignancies. METHODS: (1) The incidence of hematuria was studied in 113 patients with renal cell carcinoma (RCC), 185 with bladder carcinoma and 51 with renal pelvic or ureteral carcinoma. The association of the T stage with the intensity of hematuria in each malignancy was also examined. (2) In 823 asymptomatic adults with microhematuria, the prevalence of these malignancies was studied retrospectively to find the positive predictive value (PPV). RESULTS: (1) The incidence of hematuria was 35% for RCC, including gross and microhematuria. Advanced RCC (T3 and T4) were diagnosed more frequently in the gross hematuria group than in the microhematuria and no hematuria groups. In contrast, the incidence of hematuria was 94% for urothelial carcinomas either in the upper urinary tract or in the bladder. There was no significant difference in the T stage nor grade between the gross hematuria group and the microhematuria group. (2) Regarding asymptomatic microhematuria, the PPV was 1.7% (14 cases) for bladder carcinoma, 0.4% (3 cases) for ureteral/renal pelvic carcinoma and 0.2% (2 cases) for RCC. In men aged 50 years or older, PPV was 6.2% for urothelial carcinomas. In 14 cases of bladder carcinoma, 3 cases showed muscle invasion. CONCLUSIONS: Microhematuria is an appropriate screening marker for urothelial carcinomas, particularly in elderly men, but not for RCC. However, it is unlikely that a mass screening urinalysis using a single voided urine sample would contribute to earlier detection of bladder carcinoma.     

Clinical analysis of 35 patients with renal injury]

Because of the increase of abdominal trauma owing to traffic accident, the number of renal injury is increasing. Between May 1, 1986 and December 31, 1989, thirty-five cases with renal injury were treated in our hospital. The cases were classified as contusion, minor laceration, major laceration and vascular injury by the clinical findings and the radiographic evaluation. Contusion had 22 patients, who were treated conservatively except one with preexisting hydronephrosis. Four patients of minor laceration were all treated conservatively. In four cases of major laceration nephrectomy was performed, the other five cases were healed conservatively. There were two death cases caused by other organ injuries. The extent of associated injuries influenced the prognosis, rather than the degree of renal damage. Thirty-three cases except two survived with no complication. In cases of major injury same were managed conservatively, other required surgical treatment. Sometimes it is difficult to determine which treatment should be done. Indication for surgical treatment is discussed.     

Radiographic staging of renal injuries

Radiographic staging of renal injuries is the orderly process of establishing an immediate diagnosis so as to expedite effective treatment. Adult patients with gross hematuria or microhematuria associated with shock should undergo urgent imaging. Computerized tomography (CT scan) is the study of choice for evaluation of stable adult and pediatric patients with suspected renal trauma. Those in need of immediate surgical intervention are best evaluated by one-shot intravenous pyelogram (IVP) to determine the extent of the injured kidney and to document the normal function of the contralateral unit. Successful management of renal trauma is guided to a major degree by appropriate renal imaging.     

Type of blunt renal injury rather than associated extravasation should determine treatment

The significance of extravasation of dye during excretion urography in blunt renal injuries has been controversial, with some believing that extravasation, even if copious, is largely innocuous and characterized by spontaneous resolution, and others believing extravasation is an indication for surgical correction of the underlying blunt renal injury. Thirty-two patients with extravasation diagnosed on excretion urography after blunt external trauma were evaluated. Immediate surgical management of the renal injury was performed in 18 patients who had a contusion in 1, laceration in 13, rupture in 3, and pedicle injury in 1, and averaged 2.0 associated injuries per patient. Conservative management of the renal injury was performed in 14 patients who averaged 1.1 associated injuries per patient. Ten of the 14 patients had a large renal laceration splitting the kidney or disrupting a pole with extravasation and none settled to normal. The data showed that extravasation with a small laceration resolved spontaneously while extravasation with a major disruption of the kidney did not settle to normal.     

Diagnostic and treatment problems in renal injuries

The case records of 112 patients with 116 renal injuries seen at Detroit Receiving Hospital (July 1980 to June 1985) were reviewed. Eighty-three (74%) of the injuries were caused by gunshot wounds, 18 (16%) by stab wounds, and 11 (10%) by blunt trauma. Of 102 patients who had a urinalysis (U/A) in the Emergency Department (ED), 12 had a normal U/A. Five of these 12 patients had severe renal pedicle injuries. Of 75 excretory urograms (IVPs) performed preoperatively, 21 (28%) were normal including seven in patients with major renal injuries requiring surgical treatment. The incidence of shock was 38 per cent in patients with injuries not requiring renal explorations, 69 per cent in patients with renal parenchymal injuries requiring surgery, and 93 per cent in patients with pedicle injuries requiring repair or nephrectomy. Although it is generally believed that traumatic perirenal hematomas should not be explored, there was an increased incidence of complications with this approach in this series. Of 65 stable renal injuries treated conservatively (without exploration of the renal parenchyma), there were nine (14%) complications including three reoperation for missed injuries and three perinephric abscesses. In 46 injuries that were explored (38 for bleeding and eight without bleeding), there were only two complications (5%), including a perinephric abscess.